ABAP 指针。

SAP ABAP--通过Field-symbols修改内表( same as c and c++ point)

 

1.      什么是ABAP指针：
在ABAP里面，field symbol就相当于c语言的指针。如果你定义并且分配了相应的结构或者变量给它，其实它就指

向这个结构或者变量的地址，如果修改了field symbol的值，则相应结构或者变量的值也随之更改。

2.      如何定义指针：
基本形式：FIELD-SYMBOLS <fs>.
附加信息：
  1. ... TYPE :定义一个数据类型，然后定义指针
  2. ... TYPE REF TO ：指针指向类或者接口
  3. ... TYPE REF TO ：指针指向数据结构
  4. ... TYPE LINE OF ：指针内表的行项目
  5. ... LIKE ：指针为数据库表类型
  6. ... LIKE LINE OF ：指针类型为数据库表的行项目

3.      如何分配指针：
（1）. ASSIGN f TO .：分配一个指针，包括以下几种类型
1. ... CASTING ... ：主要对unicode系统地操作
  1a. ... CASTING
  1b. ... CASTING TYPE type
  1c. ... CASTING ... DECIMALS dec
  1d. ... CASTING LIKE f1
2. ... TYPE type ：直接指定类型
3. ... DECIMALS dec ：指定小数点位数
4. ... RANGE range：指定范围
（2）. 分配结构中的某个字段给指针
ASSIGN COMPONENT idx  OF STRUCTURE struc TO .
ASSIGN COMPONENT name OF STRUCTURE struc TO .
（3）. 分配类的方法给指针
ASSIGN dref->* TO .
（4）. 从f开始，是f的n倍长之后的内容分配给指针
ASSIGN f INCREMENT n TO .
（5）. 分配局部变量给指针
ASSIGN LOCAL COPY
    3a. ASSIGN LOCAL COPY OF f TO .
    3b. ASSIGN LOCAL COPY OF INITIAL f TO .
    3c. ASSIGN LOCAL COPY OF INITIAL LINE OF itab TO .
    4c. ASSIGN LOCAL COPY OF MAIN TABLE FIELD (f) TO .
（6）. ASSIGN dynamicJ：动态分配指针
    4a. ASSIGN (f) TO .
    4b. ASSIGN oref->(f) TO .
    4c. ASSIGN (f1)=>(f2) TO .
    4d. ASSIGN TABLE FIELD (f) TO .
    4e. ASSIGN LOCAL COPY OF MAIN TABLE FIELD (f) TO .
    4f. ASSIGN LOCAL COPY OF ... (f) TO .

4.      如何取消分配：
    UNASSIGN .

不清楚内表内表到底是itab还是itab2,但是又要访问内表里的第2个字段。所以在loop的时候不能用to到一个结构体，而要用assigning一个指向ANY的指针,然后进行后面的操作。

IF n = 1.
  ASSIGN itab[] TO <tab_fs>. " <tab_fs>是指向standard table的
ELSE.
  ASSIGN itab2[] TO <tab_fs>.
ENDIF.
LOOP AT <tab_fs> ASSIGNING <wa_fs>.
  ASSIGN COMPONENT 2 OF STRUCTURE <wa_fs> TO <field_fs>. ”filed_fs是ANY的
  WRITE: / <field_fs>.
ENDLOOP.

具体实现：

1.结构的动态查询

DEFINE SELECT_DATA_TO_WA.
  SELECT &1
    FROM &2
    INTO CORRESPONDING FIELDS OF &3
   WHERE (&4).
    EXIT.
  ENDSELECT.
END-OF-DEFINITION.

2.变量的动态查询

DEFINE SELECT_DATA_TO_VARIANT.
  SELECT &1
    FROM &2
    INTO &3
   WHERE (&4).
    EXIT.
  ENDSELECT.
END-OF-DEFINITION.

3.内表的动态查询

DEFINE SELECT_DATA_TO_VARIANT.
  SELECT &1
    FROM &2
    INTO CORRESPONDING FIELDS OF TABLE &3
   WHERE (&4).
    EXIT.
  ENDSELECT.
END-OF-DEFINITION.

具体程序实现：

DATA: L_FIELD(100) TYPE C,
      L_TABLE(10)  TYPE C,
      L_COND(100)  TYPE C.

DATA: I_COND TYPE TALBE OF L_COND.

FIELD-SYMBOLS TYPE ANY.

START-OF-SELECTION.

  CONCATENATE 'CARRID' 'CONNID' 'CITYFROM'
         INTO L_S
  SEPARATE BY SPACE.

  CONCATENATE 'CONNID = ' '0123'
         INTO L_COND.

APPEND COND TO I_COND.

L_TABLE = 'SPFLI'.

IF IS ASSIGNED.

  UNASSIGN .
  ASSIGN SPFLI TO .

ELSE.

  ASSIGN SPFLI TO .

ENDIF.

SELECT_DATA_TO_WA (L_S) (L_TABLE) I_COND.

=================================================================================

FIELD-SYMBOLS CASTING

REPORT z_barry_fs_casting.

TYPES: BEGIN OF t_date,
          year(4)  TYPE n,
          month(2) TYPE n,
          day(2)   TYPE n,
       END OF t_date.

FIELD-SYMBOLS <fs> TYPE t_date.

ASSIGN sy-datum TO <fs> CASTING.

WRITE: / sy-datum,
       / <fs>-year , / <fs>-month, / <fs>-day.

=================================================================================

光标操作

DATA: w_fname(20) TYPE c,
      w_val(10) TYPE c.

PARAMETERS: p1(10) TYPE c,
            p2(10) TYPE c,
            p3(10) TYPE c.

AT SELECTION-SCREEN.
  CHECK sy-ucomm IS INITIAL.
  GET CURSOR FIELD w_fname VALUE w_val.
  CHECK w_val IS INITIAL.   "如果没有输入
  CLEAR w_fname.

AT SELECTION-SCREEN OUTPUT.
  CASE w_fname.
    WHEN 'P1'.
      CLEAR w_fname.
      SET CURSOR FIELD 'P2'.
    WHEN 'P2'.
      CLEAR w_fname.
      SET CURSOR FIELD 'P3'.
  ENDCASE.

  ======================================================================

ABAP--Field Symbol 的Example(来自SAP的样例)

Full type specification

REPORT demo_field_symbols_type .
DATA: BEGIN OF line,
         col1(1) TYPE c,
         col2(1) TYPE c VALUE 'X',
       END OF line.
FIELD-SYMBOLS <fs> LIKE line.
ASSIGN line TO <fs>.
MOVE <fs>-col2 TO <fs>-col1.
WRITE: <fs>-col1, <fs>-col2.

---

Forcing structures

REPORT demo_field_symbols_structure .
DATA: wa(10) TYPE c VALUE '0123456789'.
DATA: BEGIN OF line1,
         col1(3) TYPE c,
         col2(2) TYPE c,
         col3(5) TYPE c,
      END OF line1.
DATA: BEGIN OF line2,
         col1(2) TYPE c,
         col2 TYPE sy-datum,
      END OF line2.
* obsolete -------------------------------------------------------------
FIELD-SYMBOLS: <f1> STRUCTURE line1 DEFAULT wa,
               <f2> STRUCTURE line2 DEFAULT wa.
* correct --------------------------------------------------------------
FIELD-SYMBOLS <f3> LIKE line1.
ASSIGN wa TO <f3> CASTING.
FIELD-SYMBOLS <f4> LIKE line2.
ASSIGN wa TO <f4> CASTING.
* ----------------------------------------------------------------------
WRITE: / <f1>-col1, <f1>-col2, <f1>-col3,
       / <f2>-col1, <f2>-col2.
SKIP.
WRITE: / <f3>-col1, <f3>-col2, <f3>-col3,
       / <f4>-col1, <f4>-col2. 

---

Static assign

REPORT demo_field_symbols_stat_assign .
FIELD-SYMBOLS: <f1> TYPE ANY, <f2> TYPE i.
DATA: text(20)  TYPE c VALUE 'Hello, how are you?',
      num       TYPE i VALUE 5,
      BEGIN OF line1,
        col1 TYPE f VALUE '1.1e+10',
        col2 TYPE i VALUE '1234',
      END OF line1,
      line2 LIKE line1.
ASSIGN text TO <f1>.
ASSIGN num TO  <f2>.
DESCRIBE FIELD <f1> LENGTH <f2>.
WRITE: / <f1>, 'has length', num.
ASSIGN line1 TO <f1>.
ASSIGN line2-col2 TO <f2>.
MOVE <f1> TO line2.
ASSIGN 'LINE2-COL2 =' TO <f1>.
WRITE: / <f1>, <f2>.

---

Assign with offset

REPORT demo_field_symbols_stat_as_off .
FIELD-SYMBOLS <fs> TYPE ANY.
DATA: BEGIN OF line,
        string1(10) VALUE '0123456789',
        string2(10) VALUE 'abcdefghij',
      END OF line.
WRITE / line-string1+5.
ASSIGN line-string1+5 TO <fs>.
WRITE / <fs>.
ASSIGN line-string1+5(*) TO <fs>.
WRITE / <fs>.

REPORT demo_field_symbols_stat_as_of2 .
FIELD-SYMBOLS <fs> TYPE ANY.
DATA: BEGIN OF line,
        a TYPE c VALUE '1', b TYPE c VALUE '2',
        c TYPE c VALUE '3', d TYPE c VALUE '4',
        e TYPE c VALUE '5', f TYPE c VALUE '6',
        g TYPE c VALUE '7', h TYPE c VALUE '8',
      END OF line,
      off TYPE i,
      len TYPE i VALUE 2.
DO 2 TIMES.
  off = sy-index * 3.
  ASSIGN line-a+off(len) TO <fs>.
  <fs> = 'XX'.
ENDDO.
DO 8 TIMES.
  off = sy-index - 1.
  ASSIGN line-a+off(1) TO <fs>.
  WRITE <fs>.
ENDDO.

---

Dynamic assign

REPORT demo_field_symbols_dynami_as_2 .
TABLES sbook.
DATA: name1(20) TYPE c VALUE 'SBOOK-FLDATE',
      name2(20) TYPE c VALUE 'NAME1'.
FIELD-SYMBOLS <fs> TYPE ANY.
ASSIGN TABLE FIELD (name1) TO <fs>.
WRITE: / 'SY-SUBRC:', sy-subrc.
ASSIGN TABLE FIELD (name2) TO <fs>.
WRITE: / 'SY-SUBRC:', sy-subrc.

---

Assigning field symbols

REPORT demo_field_symbols_dynami_as_3 .
DATA: BEGIN OF s,
        a TYPE c VALUE '1', b TYPE c VALUE '2', c TYPE c VALUE '3',
        d TYPE c VALUE '4', e TYPE c VALUE '5', f TYPE c VALUE '6',
        g TYPE c VALUE '7', h TYPE c VALUE '8',
      END OF s.
DATA off TYPE i.
FIELD-SYMBOLS <fs> TYPE ANY.
ASSIGN s-a TO <fs>.
DO 4 TIMES.
  off = sy-index - 1.
  ASSIGN <fs>+off(1) TO <fs>.
  WRITE <fs>.
ENDDO. 

---

Assigning a structure by component

REPORT demo_field_symbols_assign_comp .
DATA: BEGIN OF line,
        col1 TYPE i VALUE '11',
        col2 TYPE i VALUE '22',
        col3 TYPE i VALUE '33',
      END OF line.
DATA comp(5) TYPE c VALUE 'COL3'.
FIELD-SYMBOLS: <f1> TYPE ANY, <f2> TYPE ANY, <f3> TYPE ANY.
ASSIGN line TO <f1>.
ASSIGN comp TO <f2>.
DO 3 TIMES.
  ASSIGN COMPONENT sy-index OF STRUCTURE <f1> TO <f3>.
  WRITE <f3>.
ENDDO.
ASSIGN COMPONENT <f2> OF STRUCTURE <f1> TO <f3>.
WRITE / <f3>. 

---

Casting with field symbol type

REPORT demo_field_symbols_casting.
TYPES: BEGIN OF t_date,
          year(4)  TYPE n,
          month(2) TYPE n,
          day(2)   TYPE n,
       END OF t_date.
FIELD-SYMBOLS <fs> TYPE t_date.
ASSIGN sy-datum TO <fs> CASTING.
WRITE / sy-datum.
SKIP.
WRITE: / <fs>-year , / <fs>-month, / <fs>-day. 

---

Casting with explicit type

REPORT demo_field_symbols_casting_typ.
TYPES: BEGIN OF t_date,
          year(4)  TYPE n,
          month(2) TYPE n,
          day(2)   TYPE n,
       END OF t_date.
FIELD-SYMBOLS: <fs> TYPE ANY,
               <f>  TYPE n.
ASSIGN sy-datum TO <fs> CASTING TYPE t_date.
WRITE / sy-datum.
SKIP.
DO.
  ASSIGN COMPONENT sy-index OF STRUCTURE <fs> TO <f>.
  IF sy-subrc <> 0.
    EXIT.
  ENDIF.
  WRITE / <f>.
ENDDO. 

---

Casting with predefined data types

REPORT demo_field_symbols_assign_type .
DATA txt(8) TYPE c VALUE '19980606'.
DATA mytype(1) VALUE 'X'.
FIELD-SYMBOLS <fs> TYPE ANY.
ASSIGN txt TO <fs>.
WRITE / <fs>.
SKIP.
* obsolete -------------------------------------------------------------
ASSIGN txt TO <fs> TYPE 'D'.
WRITE / <fs>.
ASSIGN txt TO <fs> TYPE mytype.
WRITE / <fs>.
SKIP.
* correct --------------------------------------------------------------
ASSIGN txt TO <fs> CASTING TYPE d.
WRITE / <fs>.
ASSIGN txt TO <fs> CASTING TYPE (mytype).
WRITE / <fs>. 

---

Casting decimla places

REPORT demo_field_symbols_assign_deci .
DATA: pack1 TYPE p DECIMALS 2 VALUE '400',
      pack2 TYPE p DECIMALS 2,
      pack3 TYPE p DECIMALS 2.
FIELD-SYMBOLS: <f1> TYPE ANY ,
               <f2> TYPE ANY.
WRITE: / 'PACK1', pack1.
SKIP.
* obsolete -------------------------------------------------------------
ASSIGN pack1 TO <f1> DECIMALS 1.
WRITE: / '<F1> ', <f1>.
pack2 = <f1>.
WRITE: / 'PACK2', pack2.
ASSIGN pack2 TO <f2> DECIMALS 4.
WRITE: / '<F2> ', <f2>.
pack3 = <f1> + <f2>.
WRITE: / 'PACK3', pack3.
<f2> = '1234.56789'.
WRITE: / '<F2> ', <f2>.
WRITE: / 'PACK2', pack2.
SKIP.
* correct --------------------------------------------------------------
ASSIGN pack1 TO <f1> CASTING TYPE p DECIMALS 1.
WRITE: / '<F1> ', <f1>.
pack2 = <f1>.
WRITE: / 'PACK2', pack2.
ASSIGN pack2 TO <f2> CASTING TYPE p DECIMALS 4.
WRITE: / '<F2> ', <f2>.
pack3 = <f1> + <f2>.
WRITE: / 'PACK3', pack3.
<f2> = '1234.56789'.
WRITE: / '<F2> ', <f2>.
WRITE: / 'PACK2', pack2.

---

Data areas for field symbols

REPORT demo_field_symbols_assign_err .
DATA: text1(10) TYPE c, text2(10) TYPE c, text3(5) TYPE c.
FIELD-SYMBOLS <fs> TYPE ANY.
DO 100 TIMES.                          "Runtime-Error!
  ASSIGN text1+sy-index(1) TO <fs>.
ENDDO. 

---

Data references

REPORT demo_data_reference.
TYPES: BEGIN OF t_struct,
         col1 TYPE i,
         col2 TYPE i,
       END OF t_struct.
DATA: dref1 TYPE REF TO data,
      dref2 TYPE REF TO data.
FIELD-SYMBOLS: <fs1> TYPE t_struct,
               <fs2> TYPE i.
CREATE DATA dref1 TYPE t_struct.
ASSIGN dref1->* TO <fs1>.
<fs1>-col1 = 1.
<fs1>-col2 = 2.
dref2 = dref1.
ASSIGN dref2->* TO <fs2> CASTING.
WRITE / <fs2>.
GET REFERENCE OF <fs1>-col2 INTO dref2.
ASSIGN dref2->* TO <fs2>.
WRITE / <fs2>. 

===========================================================================

ABAP--通过Field-symbols修改内表

report demo_field_symbols_assign_comp .

DATA: BEGIN OF gs_itab,
      drph(10) ,
      cmsl01(17),
      cmsl02(17),
      sl01(17),
      sl02(17),
      END OF gs_itab.
DATA: gt_ita1 LIKE gs_itab OCCURS 0 WITH HEADER LINE.

data gv_zd(15).

FIELD-SYMBOLS <sl> TYPE c.
FIELD-SYMBOLS <cmsl> TYPE c.
FIELD-SYMBOLS <fs> LIKE LINE OF gt_ita1.

DO 15 TIMES.
  gt_ita1-drph =  SY-INDEX .
  gt_ita1-cmsl01 = 2.
  append gt_ita1.
enddo.

write 'Before Modify:'.
write:/ 'cmsl01','cmsl02','sl01','sl02'.
loop at gt_ita1.
  write:/ '|',gt_ita1-cmsl01,'|',gt_ita1-cmsl02,'|',gt_ita1-sl01,'|' ,gt_ita1-sl02,'|'.
endloop.
loop at gt_ita1 aSSIGNING <fs>.
  ASSIGN COMPONENT 'CMSL01' OF STRUCTURE <fs> TO <cmsl>.
  ASSIGN COMPONENT 'SL01' OF STRUCTURE <fs> TO <sl>.
  move <cmsl>  to  <sl>.
  ASSIGN COMPONENT 'SL02' OF STRUCTURE <fs> TO <sl>.
  move <cmsl>  to  <sl>.
  <fs>-CMSL02 = 'A' .
endloop.

write / 'After Modify:'.
loop at gt_ita1.
  write:/ '|',gt_ita1-cmsl01,'|',gt_ita1-cmsl02,'|',gt_ita1-sl01,'|' ,gt_ita1-sl02,'|'.
endloop. 

注意：ASSIGN TABLE FIELD (f) TO <fs>. 只能用TABLES定义的变量
An important, but frequently misunderstood aspect of ABAP, is the "Field Symbol". But you'll find they aren't mysterious. In fact, they may remind you of some features in popular general-purpose programming languages.
Field symbols allow you to:
** Assign an alias to a data object(for example, a shortened name for data objects structured through several hierarchies
        For Example: <fs>-f instead of rec1-rec2-rec3-f)
** Set the offset and length for a string variably at runtime
** Set a pointer to a data object that you determine at runtime (dynamic ASSIGN)
** Adopt or change the type of a field dynamically at runtime
** Access components of a structure (from Release 4.5A) Point to lines of an internal table (process internal tables without a separate work area)

Field symbols in ABAP are similar to pointers in other programming languages. However, pointers (as used in PASCAL or C) differ from ABAP field symbols in their reference syntax.

The statement ASSIGN f to <fs> assigns the field f to field symbol <fs>. The field symbol <fs> then "points" to the contents of field f at runtime. This means that all changes to the
contents of f are visible in <fs> and vice versa. You declare the field symbol <fs> using the statement FIELD-SYMBOLS: <fs>.

Reference syntax
Programming languages such as PASCAL and C use a dereferencing symbol to indicate the difference between a reference and the object to which it refers; so PASCAL would use p^ for a pointer instead of p, C would use *p instead of p. ABAP does not have any such dereferencing symbol.
** In PASCAL or C, if you assign a pointer p1 to a pointer p2, you force p1 to point to the object to which p2 refers (reference semantics).
** In ABAP, if you assign a field symbol <fs1> to a field  symbol <fs2>, <fs1> takes the value of the data object to which <fs2> refers (value semantics).
** Field symbols in ABAP are always dereferenced, that is, they always access the referenced data object. If you want to change the reference yourself in ABAP, you can use the ASSIGN statement
to assign field symbol <fs1> to field symbol <fs2>.

SAP WD IE 8 Hang system,CPU HIGH 100%问题解决。

Sap Web Dynpro for ABAP ,IE 8访问，CPU消耗到100%，并且一直处于挂死状态。

经过google得到方法如下：

设置IE 显示固定在100%,而不让IE 8自己调整。

如图，则问题解决.

如何建立sap icm web admin访问地址

进入 D:\usr\sap\SA1\SYS\exe\uc\NTAMD64
icmon -a 新建如下用户.

1.      As user <sid>adm go to the directory where the executables are kept and call up icmon ‑a pf=<instance profile> .

The following appears:

Maintain authentication file

============================

File name (icmauth.txt):   .

       2.      If you are happy with the default file name, press the enter key, otherwise enter a different file name or path.

       3.      In the next menu choose a (add user to set).

       4.      Enter the user name, then the password twice, the group name, the subject of the X.509 certificate (wildcards allowed, and it can be left empty).

User Name: icmadm

Enter Password: *****

Re-enter Password: *****

Group name: admin

Subject Value of Client Cert: CN=template,*

new entry locally created

The user created is in group admin, the user is therefore an administration user without administration authorization. In particular this user can create further users in the Web admin interface.

If you select another group name other than admin, create a monitoring user that can monitor, but not administrate, the ICM/Web Dispatcher.

If you want a user to be able to log on only with the X.509 client certificate, you can enter an x as the password (with queries), which makes the following entry (in the example) in file:

icmadm:x:admin:CN=muster,*

       5.      Choose s (save changes of set to file), to copy your changes from the local buffer to the authorization file.

       6.      Choose q, to quit the program.

然后然后icmauth.txt复制到 :D:\usr\sap\SA1\SYS\global\security\data

可以 可以在 SAPGUI用 T-CODE :SMICM  然后从点击 display-All (shift+F5)显示 trace 文件

然后 从web http://localhost:8000/sap/admin 输入用户名，再进入管理UI 了

然后

然后

SE80删除一个class出现错误:You cannot perform this action in modification/enhancement mode

进入SE37 ，运行FUNCTION OO_INTERFACE_DELETE或 OO_CLASS_DELETE
来删除CLASS.

COMMIT 和FORCE的值设置为'X'

如图

或者关闭 modification assistant,双击打开class后，选择菜单:
edit menu and select modifications and select "switch off modification assistant".

如下图

(fixed)如何清空/删除 SAP MMC SYSLOG?

如何清空/删除 SAP MMC SYSLOG?

清空文件：usr\sap\<SID>\DVEBMGS00\log\SLOG00.LOG
使用Ultraedit 打开文件删除里面的所有内容保存空文件即可

如何清空/删除 SAP MMC SYSLOG?

如何清空/删除 SAP MMC SYSLOG?

清空文件：usr\sap\<SID>\DVEBMGS00\log\SLOG00.LOG

ABAP 动态定义select help

主要利用了，AT SELECTION-SCREEN ON  VALUE-REQUEST
编写自己的 trigger POV 事件.更加灵活

*&---------------------------------------------------------------------*
*& Report  Z_SEARCH_HELP
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT  Z_SEARCH_HELP NO STANDARD PAGE HEADING.

TABLES: pa0001.
parameters: ppernr type pa0001-pernr .

DATA: i_return TYPE ddshretval OCCURS 0 WITH HEADER LINE,
      c TYPE c VALUE 'S'.

* Search Help for Ppernr-low
AT SELECTION-SCREEN ON  VALUE-REQUEST   for ppernr.
 message 'request value?' type 'I'.
  TYPES: BEGIN OF t_pernr,
    pernr LIKE pa0001-pernr,
    ename LIKE pa0001-ename,
  END OF t_pernr.

  DATA: it_pa0001 TYPE STANDARD TABLE OF t_pernr WITH HEADER LINE.

  SELECT pernr ename from pa0001
    INTO CORRESPONDING FIELDS OF TABLE it_pa0001
    where pa0001~endda = '99991231' .
*    WHERE zsdo~kunnr IN sokunnr.

  DELETE it_pa0001 WHERE pernr = '00000000'.
  SORT it_pa0001 BY pernr.

  CALL FUNCTION 'F4IF_INT_TABLE_VALUE_REQUEST'
    EXPORTING
      retfield    = 'PERNR'
      dynpprog    = sy-repid
      dynpnr      = sy-dynnr
      dynprofield = 'PERNR'
      value_org   = c
    TABLES
      value_tab   = it_pa0001
      return_tab  = i_return.

如何在用户登录时sap时自动执行一特定程序

sap提供了两种方法t.
1)SE37然后如图操作
使用函数 'NAVIGATION_SET_START_TCODE' ,用该函数可以设置用户和一个TCODE，该TCODE当用户登录sap系统后就可以自动执行。sap对应的程 序：ADMIN_SET_START_TRANSACTION_FO

2)使用用户出口(user Exit)
该用户出口的模块名称是：SUSR0001，你可以在该单元里增加你的代码进行相应的控制。.
SAP用户登录增强示例
* Transaction CMOD -> Utiliteis -> SAP Enhancements
* Exit Name SUSR0001
* Double click EXIT_SAPLSUSF_001
* Double click ZXUSRU01
* Insert -> include zsesschk.
** zsesschk limits the number of login sessions per user
* in a certain client
* It runs from user exit SUSR0001 after the SAP Login
* n-1 is the number of concurrent sessions allowed
TABLES: UINFO.
DATA: N TYPE I VALUE 2.              "Upper limit of login sessions
DATA: OPCODE TYPE X VALUE 2, I TYPE I, A(60).
DATA: BEGIN OF BDC_TAB1 OCCURS 5.
        INCLUDE STRUCTURE BDCDATA.
DATA: END OF BDC_TAB1.
DATA: BEGIN OF USR_TABL OCCURS 10.
        INCLUDE STRUCTURE UINFO.
DATA: END OF USR_TABL.
* Exclude Limit login by Users
IF  SY-UNAME <> 'XXX'
AND SY-UNAME <> 'XXX'.
CALL 'ThUsrInfo' ID 'OPCODE' FIELD OPCODE
  ID 'TAB' FIELD USR_TABL-*SYS*.
LOOP AT USR_TABL.
  IF SY-UNAME = USR_TABL-BNAME AND SY-MANDT = USR_TABL-MANDT.
    I = I + 1.
  ENDIF.
ENDLOOP.
IF I >= N.
A = 'You have already '.
A+17(2) = I - 1.
A+19(25) = 'login sessions in client '.
A+44(4) = SY-MANDT.
  CALL FUNCTION 'POPUP_TO_INFORM'
       EXPORTING
            TITEL = 'UNSUCCESSFUL LOGIN'
            TXT1  = A
            TXT2  = 'You are not allowed to log in'.
  MOVE: 'SAPMSSY0' TO BDC_TAB1-PROGRAM,
          '120' TO BDC_TAB1-DYNPRO,
          'X' TO BDC_TAB1-DYNBEGIN.
  APPEND BDC_TAB1.CLEAR BDC_TAB1.
  MOVE: 'BDC_OKCODE' TO BDC_TAB1-FNAM,
         '/nex' TO BDC_TAB1-FVAL.
  APPEND BDC_TAB1.CLEAR BDC_TAB1.
  CALL TRANSACTION 'SM04' USING BDC_TAB1 MODE 'N'.
ENDIF.
ENDIF.

Emacs Lisp 如何配置. macrs 文件 c-x -c-f

(add-to-list 'load-path "D:/slime-2010-06-13")
(setq inferior-lisp-program "d:\\sbcl\\1.0.37\\sbcl.exe")
(require 'slime)
(slime-setup)

(add-to-list 'load-path "D:\\color-theme-6.6.0")
(require 'color-theme)
(eval-after-load "color-theme"
  '(progn
     (color-theme-initialize)
     (color-theme-hober)))

Lisp 提示在read之后才出来

(defun ask-number ()
(format t "Please enter a number. ")
(let ((val (read)))
(if (numberp val)
val
(ask-number))))

(defvar val)
(setf val (ask-number))
(defparameter *s* (open "f:\\temp\\mytest.txt" :direction :output :if-does-not-exist :create :if-exists :append))
(format *s* "your input:~A~%" val)
(close *s*)

原因:
format 需要输出一个新行后，才会刷新，所以，加入~%

(format t "Please enter a number. ~%")

ABAP处理所有异常

语法，

TRY.

  ...                       " TRY block (application coding)

CATCH cx_... cx_... ...

    ...                     " CATCH block (exception handler)

CATCH cx_... cx_... ...

    ...                     " CATCH block (exception handler)

  ...

  CLEANUP.

    ...                     " CLEANUP block (cleanup context)

ENDTRY.

如果想处理所有异常，使用

catch cx_root.

1. A TRY block, in which exceptions can occur.
   This exception block consists of all the statements between the TRY and the CATCH statement.
2. One or more CATCH blocks for catching exceptions.
   These exception blocks are initiated with CATCH and ended with a further CATCH, CLEANUP, or ENDTRY.
3. A CLEANUP block for cleanup work after the exceptions have been caught.
   This statement block is initiated by CLEANUP and ended with ENDTRY. A TRY-ENDTRY structure must not contain more than one CLEANUP block in precisely this position.

LISP CDR 和 CAR意思

（在第一台实作 Lisp 语言的机器上， CAR 与 CDR 指令分别表示"Contents of Address Register" 及"Contents of Decrement Register"。
而 cons 就是透过这两个缓存器而实作的。） Cons 很容易使用：

如何在Java Mail中是用Log4j来记录Java Mail Debug 信息？的

Java Mail 的debug信息非常丰富，包含了同服务器完整的协议过程，
但是这个debug是直接输出到System.out的，需要用 >>来截获。

不过Java Mail 提供了setDebugOut(PrintStream）的接口，
就用这个可以实现 Java Mail和 log4j的联合使用

首先编写一个PrintStream的类做一个Bridge 同  Log4j


package com.email;

import java.io.IOException;
import java.io.OutputStream;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.log4j.*;
/**
 *
 * @author U253MIS038
 */
public class LoggingOutputStream extends OutputStream
{

    protected boolean hasBeenClosed = false;

    protected byte[] buf;

    protected int count;

    private int bufLength;

    public static final int DEFAULT_BUFFER_LENGTH = 2048;

    protected Logger logger;

    protected Level level;

    private LoggingOutputStream()
    {

    }



    public LoggingOutputStream(Logger log, Level level)
            throws IllegalArgumentException {
        if (log == null) {
            throw new IllegalArgumentException("cat == null");
        }
        if (level == null) {
            throw new IllegalArgumentException("priority == null");
        }

        this.level = level;
        logger = log;
        bufLength = DEFAULT_BUFFER_LENGTH;
        buf = new byte[DEFAULT_BUFFER_LENGTH];
        count = 0;
    }



    public void close()
    {
        flush();
        hasBeenClosed = true;
    }



    public void write(final int b) throws IOException
    {
        if (hasBeenClosed) {
            throw new IOException("The stream has been closed.");
        }

        if (count == bufLength)
        {
            final int newBufLength = bufLength + DEFAULT_BUFFER_LENGTH;
            final byte[] newBuf = new byte[newBufLength];

            System.arraycopy(buf, 0, newBuf, 0, bufLength);

            buf = newBuf;
            bufLength = newBufLength;
        }

        buf[count] = (byte) b;
        count++;
    }



    public void flush()
    {
        if (count == 0)
        {
            return;
        }


        if (count == 1 && ((char) buf[0]) == '\n')
        {
            reset();
            return;
        }
        final byte[] theBytes = new byte[buf.length];
        System.arraycopy(buf, 0, theBytes, 0, count);
        logger.log(level, new String(theBytes));
        reset();
    }


    private void reset()
    {
             count = 0;
    }

}

2,然后再调用Java Mail中使用如下方法实现了定向

            static Logger log  = Logger.getLogger( email.class );
            Properties props = System.getProperties();
               
            config = new PropertiesConfiguration(PROP_FILE);
            String mailip = config.getString("EMAIL_SERVER_IP");       
            props.put("mail.smtp.host", mailip);

            Session session = Session.getInstance(props, null);
            session.setDebugOut(new PrintStream(new  LoggingOutputStream(Logger.getRootLogger(),Level.DEBUG), true));
                        session.setDebug(enableDebug);

java 如何确定一个对象是否数组?

Java array reflection: isArray vs. instanceof

那个方法好呢？

if(obj.getClass().isArray()) {}
 

and

if(obj instanceof Object[]) {}
 

In general, use the instanceof operator to test whether an object is an array. At the JVM level, the instanceof operator translates to a specific "instanceof" byte code, which is highly optimized in most JVM implementations. The reflective approach (getClass().isArray()) is compiled to two separate "invokevirtual" instructions. The more generic optimizations applied by the JVM to these may not be as fast as the hand-tuned optimizations inherent in the "instanceof" instruction. There are two special cases: null references and references to primitive arrays. A null reference will cause instanceof to result false, while the isArray throws a NullPointerException. Applied to a primitive array, the instanceof results false, but the isArray returns true.

If obj is of type int[] say, then that will 
have an array Class but not be an instance of Object[].
 So what do you want to do with obj. If you are going to 
 cast it, go with instanceof. If you are going to use 

reflection, then use .getClass().isArray().

总结:
isArray的方位更加广泛。
instance Object[]不能确别int[]等数组。

所以，那个更好，要看自己的具体情况了
 

Lisp命名规则2

另外一个重要的习惯是全局变量的名字以*号开始和结束(*THREADS*);常量名字用+号开始和结尾(+PI+),
低级函数用%开始和技术(%SUM%).语言标准名字的定义只允许用字母(A-Z)和*,+,-,/,1,2,<,=,> &

self-evaluating：
自执行

最重要的两个自执行常量:T和NIL代表 true和false.
另一类最重要的自执行符号是关键词符号.其名字以:开始

最基本的程序组件:
函数,变量,及宏
function,variable,macro

Lisp的命名

在LISP程序中,名字比如FORMAT和hello-world及*db*用来代表一个对象称之为符号(symbols).读者对指定
的名字是否用在变量，函数或其它东西一无所知。.它只是按照字符序列读出并被代表一个对象的名字。
几乎所有的字符都可用在名字中.空白字符不行,因为在list中元素也是用空白字符来分割的.
数字也可以用在名字中的一部分而不是解释成一个数字.相似的,名字可以包含一个句号(.),但无法阅读
只包含一个句号的名字。10个字符用于其他目的而不能在名字中出现:

1. 1.开始和结束括号() open and close parentheses
2. 2.双引号和单引号 "' double and single quotes
3. 3.反引号(`)backtick
4. 4.逗号 comma,
5. 5.冒号: colon
6. 6.分号;semicolon
7. 7.反斜线 \ backslash
8. 8.竖线| vertical bar

Re: Lisp注释语句.

Lisp 注释规则二:

缩进规则：
    函数调用形式参数对齐
    宏和特殊形式针对最后一个左括号缩进两格
    ;;;; 文件级别注释
    ;;; 段落级别注释
    ;;  函数内部代码注释
    ;   函数内部代码单行注释，放在代码后面

2010/5/7 William Wang <javacave@gmail.com>

在阅读 Practical Common Lisp书的时候，突然想到LISP的注释符号应该是如何写呢？
google了下。
http://www.cc.gatech.edu/computing/classes/cs2360/ghall/style/com_mechanics.html

单句注释;分号表示 ;;;header
块注释 #|
 Notes:zh
  #
另外一种非常规的注释，是在代码中用“ ”来表示，比如下列代码

	(defun mumble_fcn ( arg1 arg2  ) 
	  "This function takes two arbitrary arguments and returns some
             arbitrarily random result. NOTE: both arguments should be non-nil."
	   (do-random-thing (do-random-thing arg1 ) arg2 ))

SAP NetWeaver Composition Environment 7.2 Trial Version 安装 步骤 Create secure store 出现错误

SAP NetWeaver Composition Environment 7.2 Trial Version
首先下载了jdk 1.6.0_07之上的版本，我下载的是 1.6.0_20版本，并且下载了jce 6的文件，很小只有8K.
安装到步骤时候出现错误:

安装 ：18/29的时候,Create secure store
 
根据提示打开错误日志：
C:\Program Files\sapinst_instdir\NW72_DEV_ADA\SERVER\SecureStoreCreate.log
发现如下提示:

FATAL: Main class "com.sap.security.core.server.secstorefs.SecStoreFS" cannot be started:
  FATAL: java.lang.ExceptionInInitializerError
    at javax.crypto.Cipher.getInstance(DashoA13*..)
    at javax.crypto.Cipher.getInstance(DashoA13*..)
    at iaik.security.provider.IAIK.a(Unknown Source)
    at iaik.security.provider.IAIK.addAsJDK14Provider(Unknown Source)
    at iaik.security.provider.IAIK.addAsJDK14Provider(Unknown Source)
    at com.sap.security.core.server.secstorefs.Crypt.<clinit>(Crypt.java:85)
    at com.sap.security.core.server.secstorefs.SecStoreFS.setSID(SecStoreFS.java:177)
    at com.sap.security.core.server.secstorefs.SecStoreFS.handleCreate(SecStoreFS.java:838)
    at com.sap.security.core.server.secstorefs.SecStoreFS.main(SecStoreFS.java:1308)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.sap.engine.offline.OfflineToolStart.main(OfflineToolStart.java:161)
Caused by: java.lang.SecurityException: Cannot set up certs for trusted CAs
    at javax.crypto.SunJCE_b.<clinit>(DashoA13*..)
    ... 14 more
Caused by: java.lang.SecurityException: Cannot locate policy or framework files!
    at javax.crypto.SunJCE_b.i(DashoA13*..)
    at javax.crypto.SunJCE_b.g(DashoA13*..)
    at javax.crypto.SunJCE_b$1.run(DashoA13*..)
    at java.security.AccessController.doPrivileged(Native Method)
    ... 15 more

  FATAL: com.sap.engine.offline.OfflineToolStart will abort now with exitcode 2

Solution:
copy
C:\Program Files\Java\jre6\lib\security 下所有文件到sap临时安装JVM目录下，
如果有提示是否需要覆盖，不要覆盖SAP原来的文件。
to
C:\Program Files\sapinst_instdir\NW72_DEV_ADA\SERVER\sapjvm\sapjvm_6\jre\lib\security

Lisp注释语句.

在阅读 Practical Common Lisp书的时候，突然想到LISP的注释符号应该是如何写呢？
google了下。
http://www.cc.gatech.edu/computing/classes/cs2360/ghall/style/com_mechanics.html

单句注释;分号表示 ;;;header
块注释 #|
 Notes:zh
  #
另外一种非常规的注释，是在代码中用“ ”来表示，比如下列代码

	(defun mumble_fcn ( arg1 arg2  ) 
	  "This function takes two arbitrary arguments and returns some
            arbitrarily random result. NOTE: both arguments should be non-nil."
	   (do-random-thing (do-random-thing arg1 ) arg2 ))

数据库Auto time stamp字段

MYSQL 5.x支持:通过字段申明：
ts2 TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP);

MSSQL:支持:
版本戳 timestamp 字段类型。

SAP相关 第一帖

2010.4.20日。

今天装好了Net Weaver 7.1 SR1
和 笔记本上ECC 6.0 EH4 FOR MSSQL 2005 WINDOW 7

准备全力投入SAP 了

jsp code too large for try statement

必杀技：
在JAVA_OPTS里加入以下变量：

1.java -Dcom.sun.tools.javac.main.largebranch=true

java lib\tools.jar 包内

注意，如果装有多个版本的JDK，需要通过设置JAVA_HOME来指明使用的JDK的路径
只是在path中加入是不够的。

Linux文件名包含特殊字符无法使用通配符:Argument list too long

Linux文件名包含特殊字符比如-，括弧()等等，grep "xxx" filename

会出现:Argument list too long错误

简单解决办法，同find 一起使用

find . -exec grep -l "搜索字符" "{}" \;

列出包含 “搜索字符”的文件名

IE getElementById display

Could not get the display property. Invalid argument

使用obj.style.display='none'
出现错误:
Could not get the display property. Invalid argument

function hider() {
var label, control;

if(document.getElementById && (label = document.getElementById('hidden1'))
&& (control = document.getElementById('hidden2'))
&& label.style && control.style)
{
label.style.display = control.style.display
= ('none' == label.style.display) ? '' : 'none';
}

clear window update store directory

clear window update store directory

%systemdrive%\windows\SoftwareDistribution

clear

wxwidgets convet wxString to C Style char

wxString 提供的 c_str,fn_str,char_str等都source code encoding相关

如果想转换成功，必须注意编译的encoding选择。

比如如果打开了unicode的编译选择，wxWidgets想从一个wxString得到一个 c Style的char *
最安全的方法为:
wxString asc=wxString("this is 汉字");
char *=asc.mb_str(wxConvUTF8);

curl 如何在mingw下使用

首先从http://curl.haxx.se/下载最新的源代码包。
比如 curl-7.19.7.tar.gz
1.然后将其展开到一个目录下，将来将要引用这里面的内容，include和lib
2.进入lib目录下：运行 mingw32-make -f Makefile.m32 编译生成所有的库.libcur.a及libcurl.dll等
3.进入/curl/docs/examples/ 编译个测试程序:
gcc -DCURL_STATICLIB -I ../../include -L ../../lib simple.c -o simple -lcurl -lws2_32 -lwinmm

运行simple.exe,能够正常运行。
CodeBlocks 里如何使用libcurl 实现static link(静态连接，避免运行使用libcurl.dll)

在codeblocks里可以在项目属性build options link setting 里加入 libcur.a的包，以及定义编译使用静态链接的属性
CURL_STATICLIB或者在使用的代码里加入:

#define CURL_STATICLIB

codeblock配置如图:


注意：如果编译的时候出现符号错误:
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_set_optionA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_initA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_set_optionA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_simple_bind_sA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_search_sA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_first_entry'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_get_dnA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_first_attributeA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_get_values_lenA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_value_free_len'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_memfreeA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_next_attributeA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_memfreeA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_next_entry'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_err2stringA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_unbind_s'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_msgfree'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_err2stringA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_set_optionA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_simple_bind_sA'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ber_free'
curl-7.19.7\lib\libcurl.a(ldap.o) undefined reference to `_imp__ldap_err2stringA'

这是需要连接mingw32的 ldap32 .这个需要在项目的build option link lib 里加入:
D:\MinGW\lib\libwldap32.a,顺序要注意.

libwldap32.a必须在libcurl.a的后面

Windows rundll32 utility

Any program using the Windows file association mechanism can be started with the rundll32 utility.

用一个编辑器,打开一个默认后缀的文件:

RUNDLL32.EXE SHELL32.DLL,OpenAs_RunDLL c:\temp\a.txt

ere a list of what is available

rundll32 shell32,Control_RunDLL                     Run The Control Panel
rundll32 shell32,Control_RunDLL X                   Start applet X of Control Panel
                                                   ("X" = any CPL filename)
rundll32.exe shell32.dll,Control_RunDLL intl.cpl,,4 Regional setting, Date tab

rundll32 shell32,OpenAs_RunDLL \dir\filename.txt    Open The 'Open With...' Window
rundll32 shell32,ShellAboutA Info-Box               Open 'About Window Window'
rundll32 shell32,Control_RunDLL desk.cpl            Open Display Properties
rundll32 user,cascadechildwindows                   Cascade All Windows
rundll32 user,tilechildwindows                      Minimize All Child-Windows
rundll32 user,repaintscreen                         Refresh Desktop
rundll32 keyboard,disable                           Lock The Keyboard
rundll32 mouse,disable                              Disable Mouse
rundll32 user,swapmousebutton                       Swap Mouse Buttons
rundll32 user,setcursorpos                          Set Cursor Position To (0,0)
rundll32 user,wnetconnectdialog                     Show 'Map Network Drive' Window
rundll32 user,wnetdisconnectdialog                  Show 'Disconnect Network Disk' Window
rundll32 user,disableoemlayer                       Display The BSOD (blue screen of death)Window
rundll32 diskcopy,DiskCopyRunDll                    Show Copy Disk Window
rundll32 rnaui.dll,RnaWizard                        Run 'Internet Connection Wizard'
rundll32 shell32,SHFormatDrive                      Run 'Format Disk (A)' Window
rundll32 shell32,SHExitWindowsEx -1                 Cold Restart Of Windows Explorer
rundll32 shell32,SHExitWindowsEx 1                  Shut Down Computer
rundll32 shell32,SHExitWindowsEx 0                  Logoff Current User
rundll32 shell32,SHExitWindowsEx 2                  Windows9x Quick Reboot
rundll32 krnl386.exe,exitkernel                     Force Windows 9x To Exit (no confirmation)
rundll32 rnaui.dll,RnaDial "MyConnect"              Run 'Net Connection' Dialog
rundll32 msprint2.dll,RUNDLL_PrintTestPage          Choose & Print Test Page Of Current Printer
rundll32 user,setcaretblinktime                     Set New Cursor Rate Speed
rundll32 user, setdoubleclicktime                   Set New DblClick Speed (Rate)
rundll32 sysdm.cpl,InstallDevice_Rundll             Hardware installation wizard
rundll32 user,MessageBeep                           Default beep sound
rundll32 user32.dll,MessageBeep                     Default beep sound (XP)
rundll32 shell32.dll,Control_RunDLL appwiz.cpl      Add/remove programs
rundll32 shell32.dll,Control_RunDLL timedate.cpl,,0 Date/time settings
rundll32 shell32.dll,Control_RunDLL odbccp32.cpl    ODBC settings

rundll32.exe url.dll,FileProtocolHandler http:\\www.rgagnon.com
rundll32.exe url.dll,FileProtocolHandler c:\mypdf.pdf
                                                   Open the associated application
rundll32 amovie.ocx,RunDll /play /close c:\mymovie.mpg                                   
                                                   Play multimedia (movie or sound)

Rundll32.exe powrprof.dll,SetSuspendState Sleep     Put the computer in Sleep mode 

                                                  
Privacy (IE) 
rundll32.exe InetCpl.cpl,ClearMyTracksByProcess 8   Internet temporary files
rundll32.exe InetCpl.cpl,ClearMyTracksByProcess 2   Cookies
rundll32.exe InetCpl.cpl,ClearMyTracksByProcess 1   History
rundll32.exe InetCpl.cpl,ClearMyTracksByProcess 16  Forms Data
rundll32.exe InetCpl.cpl,ClearMyTracksByProcess 32  Passwords
rundll32.exe InetCpl.cpl,ClearMyTracksByProcess 255 Delete everything

mysql get table index SQL command

1.show index from tablename
2.select * from information_schema.statistics where table_name='tableName' ;

Mysql 性能分析

EXPLAIN SELECT * FROM table IGNORE INDEX (indexname) WHERE

网络地址类型一览

URL: http://publib.boulder.ibm.com/infocenter/zvm/v5r4/topic/com.ibm.zvm.v54.kijl0/hcsk7b3014.htm

The type of a IPv6 address is identified by the high-order bits of the address, as follows:

Table 2. Types of IPv6 Addresses

Address type	Binary prefix	IPv6 notation
Unspecified	00 . . . 0 (128 bits)	::/128
Loopback	00 . . . 1 (128 bits)	::1/128
Multicast	11111111	FF00::/8
Link-local unicast	1111111010	FE80::/10
Site-local unicast	1111111011	FEC0::/10
Global unicast	(everything else)

Three categories of IP addresses are supported in IPv6:

Unicast

An identifier for a single interface. A packet sent to a unicast address is delivered to the interface identified by that address. It can be link-local scope, site-local scope, or global scope.

Multicast

An identifier for a group of interfaces (typically belonging to different nodes). A packet sent to a multicast address is delivered to all interfaces identified by that address.

Anycast

An identifier for a group of interfaces (typically belonging to different nodes). A packet sent to an anycast address is delivered to the closest member of a group, according to the routing protocols' measure of distance.

Anycast addresses are taken from the unicast address spaces (of any scope) and are not syntactically distinguishable from unicast addresses. Anycast is described as a cross between unicast and multicast. Like multicast, multiple nodes may be listening on an anycast address. Like unicast, a packet sent to an anycast address will be delivered to one (and only one) of those nodes. The exact node to which it is delivered is based on the IP routing tables in the network.

There are no broadcast addresses in IPv6. Multicast addresses have superseded this function.

Unicast IPv6 Addresses

IPv6 unicast addresses can be aggregated with prefixes of arbitrary bit-length similar to IPv4 addresses under Classless Interdomain Routing (CIDR).

A unicast address has the following format:

Figure 8. Unicast Address Format

n bits	128-n bits
network prefix	interface ID

There are several types of unicast addresses in IPv6: global unicast, site-local unicast, and link-local unicast. There are also some special-purpose subtypes of global unicast, such as IPv6 addresses with embedded IPv4 addresses. Additional address types or subtypes can be defined in the future.

Global Unicast Addresses

The general format for IPv6 global unicast addresses is:

Figure 9. Global Unicast Address Format

n bits	m bits	128-n-m bits
global routing prefix	subnet ID	interface ID

The global routing prefix is a (typically hierarchically-structured) value assigned to a site (a cluster of subnets/links). The subnet ID is an identifier of a link within the site. The interface ID is used to identify an interface on a link; interface IDs are required to be unique within a subnet prefix.

All global unicast addresses other than those that start with B'000' have a 64-bit interface ID field (that is, n + m = 64). Global unicast addresses that start with B'000' have no such constraint on the size or structure of the interface ID field.

Examples of global unicast addresses that start with B'000' are IPv6 address with embedded IPv4 addresses. These include IPv4-mapped IPv6 addresses and IPv4-compatible IPv6 addresses.

Local Use Address

There are two types of local-use unicast addresses defined: link-local and site-local. The link-local address is for use on a single link and the site-local address is for use in a single site.

Link-local Addresses

Link-local addresses have the following format:

Figure 10. Link-local address format

10 bits	54 bits	64 bits
1111111010	0	interface ID

A link-local address is required on each physical interface. Link-local addresses are designed to be used for addressing on a single link for purposes such as automatic address configuration, neighbor discovery, or in the absence of routers. It also may be used to communicate with other nodes on the same link. A link-local address is automatically assigned.

Routers will not forward any packets with link-local source or destination addresses to other links.

Site-local Addresses

Site-local addresses have the following format:

Figure 12. Site-local address format

10 bits	38 bits	16 bits	64 bits
1111111011	0	subnet ID	interface ID

Site-local addresses are designed to be used for addressing inside of a site without the need for a global prefix. A site-local address cannot be reached from another site. A site-local address is not automatically assigned to a node. It must be assigned using automatic or manual configuration.

Routers will not forward any packets with site-local source or destination addresses outside of the site.

Loopback Address

The unicast address 0:0:0:0:0:0:0:1 is called the loopback address. It cannot be assigned to any physical interface. It may be thought of as a link-local unicast address assigned to a virtual interface (typically called the loopback interface) that allows local applications to send messages to each other.

The loopback address cannot be used as the source address in IPv6 packets that are sent outside of a node. An IPv6 packet with a destination address of loopback cannot be sent outside of a node and be forwarded by an IPv6 router. A packet received on an interface with destination address of loopback will be dropped.

Unspecified Address

The address 0:0:0:0:0:0:0:0 is called the unspecified address. It will not be assigned to any node. It indicates the absence of an address. One example of its use is in the Source Address field of any IPv6 packets sent by an initializing host before it has learned its own address.

The unspecified address cannot be used as the destination address of IPv6 packets or in IPv6 routing headers. An IPv6 packet with a source address of unspecified cannot be forwarded by an IPv6 router.

IPv4-mapped IPv6 Addresses

These addresses hold an embedded global IPv4 address. They are used to represent the addresses of IPv4 nodes as IPv6 addresses to applications that are enabled for IPv6 and are using AF_INET6 sockets. This allows IPv6 enabled applications always to deal with IP addresses in IPv6 format regardless of whether the TCP/IP communications are occurring over IPv4 or IPv6 networks. The dual-mode TCP/IP stack performs the transformation of the IPv4-mapped addresses to and from native IPv4 format. IPv4-mapped addresses have the following format:

Figure 14. IPv4-mapped IPv6 address

80 bits	16	32 bits
0000...0000	FFFF	IPv4 address

Examples:

• In IPv6-IPv4 decimal form:

  ::FFFF:129.144.52.38

• In IPv6-compressed form

  ::FFFF:8190:3426

IPv4-compatible IPv6 Addresses

These addresses hold an embedded global IPv4 address. They are used dynamically to tunnel IPv6 packets over IPv4 networks. IPv6 nodes that use this technique are assigned special IPv6 unicast addresses which hold an IPv4 address in the low-order 32-bits. IPv4-compatible IPv6 addresses have the following format:

Figure 15. IPv4-compatible IPv6 address

80 bits	16	32 bits
0000...0000	0000	IPv4 address

Examples:

• In IPv6-IPv4 decimal form

  ::129.144.52.38

• In IPv6-compressed form

  ::8190:3426

Multicast IPv6 Addresses

An IPv6 multicast address is an identifier for a group of interfaces (typically on different nodes). It is identified with a prefix of 11111111 or FF in hexadecimal notation. It provides a way of sending packets to multiple destinations. An interface may belong to any number of multicast groups.

Multicast address format

Binary 11111111 at the start of the address identifies the address as being a multicast address. Multicast addresses have the following format:

Figure 16. Multicast address format

8	4	4	112 bits
11111111	flags	scope	group ID

Figure 17. Flags in multicast address

 ---------------
| 0 | 0 | 0 | T |

---------------

• The 3 high-order flags are reserved, and must be initialized to 0.
• T = 0 indicates a permanently-assigned (well-known) multicast address, assigned by the Internet Assigned Number Authority (IANA).
• T = 1 indicates a non-permanently assigned (transient) multicast address.

Scope is a 4-bit multicast scope value used to limit the scope of the multicast group. Group ID identifies the multicast group, either permanent or transient, within the given scope.

Multicast scope

The scope field indicates the scope of the IPv6 internetwork for which the multicast traffic is intended. The size of this field is 4 bits. In addition to information provided by multicast routing protocols, routers use multicast scope to determine whether multicast traffic can be forwarded. For multicast addresses there are 14 possible scopes (some are still unassigned), ranging from interface-local to global (including both link-local and site-local).

The following table lists the defined values for the scope field:

Table 3. Multicast scope field values

Value	Scope
0	Reserved
1	Interface-local scope (same node)
2	Link-local scope (same link)
3	Subnet-local scope
4	Admin-local scope
5	Site-local scope (same site)
8	Organization-local scope
E	Global scope
F	Reserved
All other scope field values are currently undefined.

For example, traffic with the multicast address of FF02::2 has a link-local scope. An IPv6 router never forwards this type of traffic beyond the local link.

Interface-local

The interface-local scope spans a single interface only. A multicast address of interface-local scope is useful only for loopback delivery of multicasts within a node, for example, as a form of interprocess communication within a computer. Unlike the unicast loopback address, interface-local multicast addresses may be joined on any interface.

Link-local

Link-local addresses are used by nodes when communicating with neighboring nodes on the same link. The scope of the link-local address is the local link.

Subnet-local

Subnet-local scope is given a different and larger value than link-local to enable possible support for subnets that span multiple links.

Admin-local

Admin-local scope is the smallest scope that must be administratively configured, that is, not automatically derived from physical connectivity or other, non-multicast-related configuration.

Site-local

The scope of a site-local address is the site or organization internetwork. Addresses must remain within their scope. A router must not forward packets outside of its scope.

Organization-local

This scope is intended to span multiple sites belonging to a single organization.

Global

Global scope is used for uniquely identifying interfaces anywhere in the Internet.

Multicast groups

Group ID identifies the multicast group, either permanent or transient, within the given scope. The size of this field is 112 bits. Permanently assigned groups can use the group ID with any scope value and still refer to the same group. Transient assigned groups can use the group ID in different scopes to refer to different groups. Multicast addresses from FF01:: through FF0F:: are reserved, well-known addresses. Use of these group IDs for any other scope values, with the T flag equal to 0, is not allowed.

All-nodes multicast groups

These groups identify all IPv6 nodes within a given scope. Defined groups include:

• Interface-local all-nodes group (FF01::1)
• Link-local all-nodes group (FF02::1)

All-routers multicast groups

These groups identify all IPv6 routers within a given scope. Defined groups include:

• Interface-local all-routers group (FF01::2)
• Link-local all-routers group (FF02::2)
• Site-local all-routers group (FF05::2)

Solicited-node multicast group

For each unicast address which is assigned to an interface, the associated solicited-node multicast group is joined on that interface. The solicited-node multicast address facilitates the efficient querying of network nodes during address resolution.

Anycast IPv6 Addresses

An IPv6 anycast address is an identifier for a set of interfaces (typically belonging to different nodes). A packet sent to an anycast address is delivered to one of the interfaces identified by that address (the nearest interface), according to the routing protocols' measure of distance. It uses the same formats as a unicast address, so one cannot differentiate between a unicast and an anycast address simply by examining the address. Instead, anycast addresses are defined administratively.

For more information about IPv6 addressing, see RFC 3513, Internet Protocol Version 6 (IPv6) Addressing Architecture.

Java中如何得到网卡的IP地址而不是127.0.0.1

tip:最后发现,如果是web程序可以通过,javax.servlet.http .HttpServletRequest里的:getServerName()可以用来得到外部IP，很奇怪。getLocalAddr().getHostAddress()的结果不同.


String ipaddress="";
java.util.Enumeration interfaces = java.net.NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements())
{
java.net.NetworkInterface card = (java.net.NetworkInterface) interfaces.nextElement();
java.util.Enumeration addresses = card.getInetAddresses();
if (addresses == null)
continue;

while (addresses.hasMoreElements())
{
java.net.InetAddress address = (java.net.InetAddress) addresses.nextElement();
if(!address.isLoopbackAddress())//skip 127.0.0.1 address
{
if(address.isSiteLocalAddress())//yes,it,not NIC link address
{
ipaddress=address.getHostAddress();
break;
}
}
}
}

wxButton 如何捕获Enter回车事件

动态事件connect 需要使用wxEVT_COMMAND_BUTTON_CLICKED事件，而不是wxEVT_KEY_DOWN

wxButton *toclip = new wxButton(books,ID_BUTTON_TO_CLIP, wxT("复制剪贴板"), wxPoint(x,y));
toclip ->Connect(wxEVT_COMMAND_BUTTON_CLICKED ,wxCommandEventHandler(GlobalEvtHandler::OnPagingHandler));

get jboss tomcat http server config port and SSL etc

通过MBean jmx的方式来发现系统配置是个比较好的program思路
发现Mbean的几个方法如下:
那个可以工作要看不同的jboss 版本。第一个一般是可以的

1.MBeanServer server = (MBeanServer) MBeanServerFactory.findMBeanServer(null).get(0);
2.MBeanServer server = org.jboss.mx.util.MBeanServerLocator.locateJBoss();

InitialContext ctx = new InitialContext(table); // From table
         
MBeanServerConnection server = (MBeanServerConnection) ctx.lookup("jmx/invoker/HttpAdaptor");
         
System.out.println("Version = "
           + (String)server.getAttribute(new ObjectName("jboss.system:type=Server"), new String("Version")));


JBOSS 允许SSL及配置的数字签名文件
早server.xml或tomcat config.xml文件中加入两个属性
keystoreFile="${user.home}/.keystore" keystorePass="changeit"

然后到.keystore指定的目录下运行如下命令:

%JAVA_HOME%\bin\keytool -genkey -alias tomcat -keyalg RSA

跟随提示，密码同keystorePass属性指定的保持一致就可以了

all is ok.

wxWidgets 连续打开两个Dialog造成exception的原因

使用wxwidgets打开wxDialog出现一个奇怪的问题.

代码如下:
原因:
Destroy();造成了异常。
只需要最后一次打开Dialog的时候，调用Destroy()就可以了。
不知道为什么，很奇怪。

最后发现:这样解决了一场问题，但是，引用程序不会退出了，挂死了!!!!

经过再次的研究，在每次点ok按钮 退出Dialog的时候，要调用:EndModal(wxID_OK);
奇怪之极。要加入
dlg.EndModal(wxID_OK);
dlg2.EndModal(wxID_OK);

void test()
{
wxDialog dlg;
dlg.Create(NULL, wxNewId(), _T("Step 1"),
wxDefaultPosition, wxSize(500,300));
wxPanel* bgpanel=new wxPanel(&dlg, wxID_ANY, wxDefaultPosition, wxSize(dlg.GetSize().GetWidth(),dlg.GetSize().GetHeight()), wxTAB_TRAVERSAL|wxWANTS_CHARS, _T("Step 1"));
wxButton* ok = new wxButton(bgpanel,wxID_OK,_("ok"),wxPoint(bgpanel->GetSize().GetWidth()/2-50,bgpanel->GetSize().GetHeight()-60));

dlg.ShowModal();
dlg.Destroy();

wxDialog dlg2;
dlg2.Create(NULL, wxNewId(), _T("Step 2"),
wxDefaultPosition, wxSize(500,300));
wxPanel* bgpane2=new wxPanel(&dlg2, wxID_ANY, wxDefaultPosition, wxSize(dlg2.GetSize().GetWidth(),dlg2.GetSize().GetHeight()), wxTAB_TRAVERSAL|wxWANTS_CHARS, _T("step 1"));
wxButton* ok2 = new wxButton(bgpane2,wxID_OK,_("ok"),wxPoint(bgpane2->GetSize().GetWidth()/2-50,bgpane2->GetSize().GetHeight()-60));

dlg2.ShowModal();
dlg2.Destroy();
}