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 ))