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public class ActionContext implements Serializable The ActionContext is the context in which anActionis executed. Each context is basically a container of objects an actionneeds for executionlike the session, parameters, locale, etc. The ActionContext is thread local which means that values stored i Read More

1.Unable to find 'struts.multipart.saveDir' property setting. Defaulting to javax.servlet.context.tempdirjavax.servlet.context.tempdir默认就是$CATALINA_BASE/work文件夹下。2.Struts Upload上传文件对应Action类里面的xxx、xxxContentType和xxxFileName三个属性。对应Action类里面的caption属性。 Read More

1.struts.xml 1 2 3 4 5 6 7 8 9 10 tip 11 12 13 14 15 2.User.java1 package com.model;2 3 public class User {4 5 private String username; 6 private String password; 7 ... Read More

1.如下，变量i,j,k 的作用域是相同的。 1 function test(obj){ 2 var i= 0; 3 if(typeof obj == "object"){ 4 var j = 0; 5 for(var k = 0; k< 1; k++){ 6 document.write(k); 7 } 8 document.write(k); 9 }10 document.write(j);11 12 }2.将变量放置在函数开关是好的编程习惯1 var scope = "... Read More

一、ThreadLocalMap是ThreadLocal的内部类、Thread持有ThreadLocalMap的引用 Entry类继承了WeakReference<ThreadLocal<?>>，即每个Entry对象都有一个ThreadLocal的弱引用（作为key），这是为了防止内存泄露。 key Read More

what happens in more sophisticated environments where you do not necessarily know ahead of time which bean class you are going to be using, or which property you want to retrieve or modify? The APIs in the BeanUtils package are intended to simplify getting and setting bean properties dynamically,... Read More

An entry in aWeakHashMapwill automatically be removed when its key is no longer in ordinary use. More precisely,the presence of a mappingfor a given key will not prevent the key from being discarded by the garbage collector,that is, made finalizable, finalized, and then reclaimed.When a key has bee. Read More

javaScript中的单引号与双引号没有什么区别。但因为xhtml规范要求所有xhtml属性要用双引号括起来。所以在javaScript中使用单引号。1 var html = 'go go go !'这样做比用双引号更清晰var html = "go go go !" Read More

1 var myConstructor = function(message){ 2 //实例变量 3 this.message = message; 4 5 //私有变量，外部不可见。用var声明的变量具有块作用域 6 var separator = '-'; 7 var owner = this; 8 9 //私有方法：只能在构造器内调用10 function alertMessage(){11 alert(owner.message);12 //alert(this.message);则下面... Read More

这些天在看《How Tomcat Works》这本书。里面讲到了JMX的内容。对我来说是个新知识点。 JMX--Java Management Extensions，即Java管理扩展,是一个为应用程序、设备、系统等植入管理功能的框架。JMX可以跨越一系列异构操作系统平台、系统体系结构和网络传输协议，灵活的开发无缝集成的系统、网络和服务管理应用。可以非常容易的管理应用程序。许多基于服务器的应用程序（Tomcat, JBoss)都使用了JMX技术来管理各自的资源。1.Architectural Overview■ Instrumentation level（设备层）---定义了编写可由J... Read More