<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[pacozhong的专栏]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/pacozhong</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; pacozhong]]></copyright><item><title><![CDATA[C/C++语言中各种数据类型长度的总结[转]]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83674763</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83674763</guid><author>pacozhong</author><pubDate>Mon, 26 Jul 2010 09:48:25 +0800</pubDate><description><![CDATA[下面是我关于C语言中各种数据类型长度的总结：(参考The C Programming Language)

1. c语言中的整数类型有char, short, int, long等几种, 下面是C语言对每种数据类型长度的规定:
(a). short和long类型的长度不相同
(b). int类型通常同具体机器的物理字长相同
(c). short通常是16bits, int通常是16bit...]]></description><category></category></item><item><title><![CDATA[ Java 内存管理原理、内存泄漏实例及解决方案研究【转】]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83673894</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83673894</guid><author>pacozhong</author><pubDate>Fri, 23 Jul 2010 14:13:14 +0800</pubDate><description><![CDATA[为了判断Java中是否有内存泄露，我们首先必须了解Java是如何管理内存的。Java的内存管理就是对象的分配 和释放问题。在Java中，程序员需要通过关键字new为每个对象申请内存空间 (基本类型除外)，所有的对象都在堆 (Heap)中分配空间。另外，对象的释放是由GC决定和执行的。在Java中，内存的分配是由程序完成的，而内存的释放是有GC完成的，这种收支两条线 的方法确实简化了程序员的工作。但...]]></description><category></category></item><item><title><![CDATA[String StringBuffer StringBuilder [转]]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83672822</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83672822</guid><author>pacozhong</author><pubDate>Wed, 21 Jul 2010 15:38:06 +0800</pubDate><description><![CDATA[String 字符串常量
StringBuffer 字符串变量（线程安全）
StringBuilder 字符串变量（非线程安全）
简要的说， String 类型和 StringBuffer 类型的主要性能区别其实在于 String 是不可变的对象, 因此在每次对 String 类型进行改变的时候其实都等同于生成了一个新的 String 对象，然后将指针指向新的 String 对象，所以经常改...]]></description><category></category></item><item><title><![CDATA[java 容器相关]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83611227</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83611227</guid><author>pacozhong</author><pubDate>Sat, 08 May 2010 15:47:47 +0800</pubDate><description><![CDATA[      The HashMap class is roughly equivalent to Hashtable, except that it is unsynchronized and permits nulls.

      ]]></description><category></category></item><item><title><![CDATA[容器Iterator的fail-fast]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83609993</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83609993</guid><author>pacozhong</author><pubDate>Wed, 05 May 2010 22:33:40 +0800</pubDate><description><![CDATA[   A structural modification is any operation that adds or deletes one or more elements, or explicitly resizes the backing array; merely setting the value of an element is not a structural modificatio...]]></description><category></category></item><item><title><![CDATA[(3)chapter 5: The Java Virtual Machine II]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83604682</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83604682</guid><author>pacozhong</author><pubDate>Fri, 23 Apr 2010 21:13:56 +0800</pubDate><description><![CDATA[The Class Loader Subsystem

     primordial class loader and class loader object

The primordial class loader is a class loader implemented in JVM, and class loader object is the objects of classe...]]></description><category></category></item><item><title><![CDATA[(2)chapter 5: The Java Virtual Machine I]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83604238</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83604238</guid><author>pacozhong</author><pubDate>Thu, 22 Apr 2010 22:05:48 +0800</pubDate><description><![CDATA[  When talking JVM, it may refer any of these:
1. the abstract specification
2. a concrete implementation
3. a runtime instance

The life-cycle of instance of JVM
    Only one mission in the lif...]]></description><category></category></item><item><title><![CDATA[(1)chaper 1: Introduction ]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83604188</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83604188</guid><author>pacozhong</author><pubDate>Thu, 22 Apr 2010 20:37:28 +0800</pubDate><description><![CDATA[Three advantages:
    platform independence
    security
    network-mobility
   These three facets of java's architecture work together to make java suitable for the emerging networked computing ...]]></description><category></category></item><item><title><![CDATA[java Thread 状态转换图]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83602299</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83602299</guid><author>pacozhong</author><pubDate>Mon, 19 Apr 2010 19:38:15 +0800</pubDate><description><![CDATA[
[img]http://dl.iteye.com/upload/attachment/236790/d2283fc2-0eb0-345a-9338-050a86dbbdb0.jpg[/img]
]]></description><category></category></item><item><title><![CDATA[ClassLoader]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83598859</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83598859</guid><author>pacozhong</author><pubDate>Mon, 12 Apr 2010 16:50:31 +0800</pubDate><description><![CDATA[   今天研究了一下classloader,分享了一篇文章http://www.iteye.com/topic/83978
  
    一直想找一本介绍JVM的书来看，这回算是找到了《inside JVM》。

  顺便也写了一个测试程序：
[code=&quot;java&quot;]

public class A {

	static{
		System.out.println(&quot;stat...]]></description><category></category></item><item><title><![CDATA[hadoop org.apache.hadoop.io.serializer包]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83597394</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83597394</guid><author>pacozhong</author><pubDate>Thu, 08 Apr 2010 21:11:51 +0800</pubDate><description><![CDATA[   hadoop的org.apache.hadoop.io.serializer包提供了一种可插拔的持久化框架(Pluggable Serialization Framework)。之所以说是可插拔的，是因为可以把现存的持久化方式嵌入到hadoop的程序中。这个包中有以下的一些类：

1、Serializer和Deserializer：这是两个接口，定义序列化和反序列化的接口。
2、Ser...]]></description><category></category></item><item><title><![CDATA[各种Serialization机制]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83597368</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83597368</guid><author>pacozhong</author><pubDate>Thu, 08 Apr 2010 19:56:19 +0800</pubDate><description><![CDATA[    这些天看到的关于持久化的内容比较多，这里做一些总结：

1、java api的持久化，主要靠两个类：ObjectOutputStream和ObjectInputStream
2、Hibernate
3、与云计算有关的：
       1、hadoop的Writable接口实现的持久化
       2、hadoop的org.apache.hadoop.io.serializer...]]></description><category></category></item><item><title><![CDATA[Log4j的类图]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83596158</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83596158</guid><author>pacozhong</author><pubDate>Tue, 06 Apr 2010 15:25:33 +0800</pubDate><description><![CDATA[
[img]http://dl.iteye.com/upload/attachment/229978/83adf6ae-14c4-3679-9b70-d79a60cf9be4.png[/img]
]]></description><category></category></item><item><title><![CDATA[［转］C中的const]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83596149</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83596149</guid><author>pacozhong</author><pubDate>Tue, 06 Apr 2010 15:18:38 +0800</pubDate><description><![CDATA[C中的CONST
　　C中CONST的使用：
　　const是一个C语言的关键字，它限定一个变量不允许被改变。使用const在一定程度上可以提高程序的安全性和可靠性，另外，在观看别人代码的时候，清晰理解const所起的作用，对理解对方的程序也有一些帮助。
　　虽然这听起来很简单，但实际上，const的使用也是c语言中一个比较微妙的地方，微妙在何处呢？请看下面几个问题。
　　问题：const...]]></description><category></category></item><item><title><![CDATA[hadoop的序列化机制]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83596143</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83596143</guid><author>pacozhong</author><pubDate>Tue, 06 Apr 2010 15:15:12 +0800</pubDate><description><![CDATA[[size=large]hadoop不用java的serialization机制[/size]
doug cutting 是这样解释的：
[quote]
Why didn’t I use Serialization when we first started Hadoop? Because it looked
big and hairy and I thought we needed so...]]></description><category></category></item><item><title><![CDATA[xml的"特殊字符"]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83596116</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83596116</guid><author>pacozhong</author><pubDate>Tue, 06 Apr 2010 14:26:10 +0800</pubDate><description><![CDATA[    遇到这一方面的问题是因为我试图把一个对象序列化之后存贮到xml文件中，然后从xml文件中读取字符串，并反序列化对象（hadoop mapreduce程序中通过JobConf向tasktracker传送对象）。有关序列化：[url]http://zzy1943.iteye.com/blog/634418[/url]
     当我把序列化之后的数据直接存在xml中后，在解析xml时遇到解析...]]></description><category></category></item><item><title><![CDATA[java的Serialization 机制]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83596029</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83596029</guid><author>pacozhong</author><pubDate>Tue, 06 Apr 2010 11:23:02 +0800</pubDate><description><![CDATA[[size=large]基本使用方法[/size]       
        Serialization是指把类或者基本的数据类型持久化(persistence)到数据流(Stream)中，包括文件、字节流、网络数据流。
         JAVA中实现serialization主要靠两个类：ObjectOuputStream和ObjectInputStream。他们是JAVA IO系统里...]]></description><category></category></item><item><title><![CDATA[DTD or Schema]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83595987</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83595987</guid><author>pacozhong</author><pubDate>Tue, 06 Apr 2010 10:12:44 +0800</pubDate><description><![CDATA[XML   schemas   provide   the   following   advantages   over   XML   DTDs:  
 1   XML   schemas   support   rich   data   typing,   which   enables   you   to   constrain   element  
  contents   t...]]></description><category></category></item><item><title><![CDATA[［转］Log4j 多logger设置]]></title><link>https://blog.youkuaiyun.com/pacozhong/article/details/83595984</link><guid>https://blog.youkuaiyun.com/pacozhong/article/details/83595984</guid><author>pacozhong</author><pubDate>Tue, 06 Apr 2010 10:03:50 +0800</pubDate><description><![CDATA[    log4j的强大功能无可置疑，但实际应用中免不了遇到某个功能需要输出独立的日志文件的情况，怎样才能把所需的内容从原有日志中分离，形成单独的日志文件呢？其实只要在现有的log4j基础上稍加配置即可轻松实现这一功能。

　　先看一个常见的log4j.properties文件，它是在控制台和myweb.log文件中记录日志：

log4j.rootLogger=DEBUG, stdout...]]></description><category></category></item></channel></rss>