Java Web应用中使用ANT在线编译不用重起tomcat的方法

在WEB应用中可通过ANT的API调用ant的工程配置文件来在线编译java文件,在工程配置文件中(如build.xml)将编译的class文件或者变更的xml文件直接复制到WEB-INF\classes中的对应目录,不用重新启动tomcat.

由于在平台应用中经常由用户定义表结构,并由表结构生成java实体类和hibernate映射文件,通过热编译部署的方式可不用停止WEB应用,下面是在Java中调用ant的代码,注意这种方式不是调用ant的批处理的,也不提倡这样做,下面的方式可使用户通过点击WEB页面上的按钮来调用ANT编译:

package org.apache.easframework.common;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintStream;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.DefaultLogger;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.ProjectHelper;

public class CompileJava {

public static synchronized boolean compile(String buildFilePath, String logFilePath) {
File buildFile = new File(buildFilePath);
Project project = new Project();

DefaultLogger consoleLogger = new DefaultLogger();
try {
FileOutputStream fs = new FileOutputStream(logFilePath);
PrintStream ps = new PrintStream(fs);
consoleLogger.setErrorPrintStream(ps);
consoleLogger.setOutputPrintStream(ps);
} catch (FileNotFoundException e1) {

e1.printStackTrace();
}

consoleLogger.setMessageOutputLevel(Project.MSG_INFO);
project.addBuildListener(consoleLogger);

try {
project.fireBuildStarted();
project.init();
ProjectHelper helper = ProjectHelper.getProjectHelper();
helper.parse(project, buildFile);
System.out.println("默认target:");
System.out.println(project.getDefaultTarget()); //默认的target是help
project.executeTarget("all"); //调用的task是all
project.fireBuildFinished(null);
return true;

} catch (BuildException e) {
project.fireBuildFinished(e);
return false;
}

}

public static String startCompile(String buildFile,String logFile)
{
if(CompileJava.compile(buildFile, logFile))
{
return "编译成功!";
}
else
{
return "编译失败!";
}
}

/**
* @param args
*/
public static void main(String[] args) {
System.out.println("开始编译...");

boolean b = CompileJava.compile("D:/easdev/build/userbuild.xml",
"D:/easdev/build/userbuild.log");
if(b)
{
System.out.println("编译成功!");
}
else
{
System.out.println("编译失败!");
}
System.out.println("结束编译...");

}

}

下面是Java页面通过dwr调用此类的代码:

<%@ page contentType="text/html; charset=GBK"%>

<%@ page import="org.apache.easframework.common.*" %>
<%@ taglib prefix="ww" uri="webwork" %>
<%@ include file="/common/head.jsp"%>
<script type='text/javascript' src='<%=request.getContextPath()%>/js/util.js?Math.random();'></script>
<script type='text/javascript' src='<%=request.getContextPath()%>/js/engine.js?Math.random();'></script>
<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/interface/CompileJava.js?Math.random();'></script>
<meta http-equiv="epires" content=0>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<script language="JavaScript">
<!--
function compileJava()
{
CompileJava.startCompile("D:/easdev/build/userbuild.xml","D:/easdev/build/userbuild.log",callback);

// document.listForm.elements['pageLoaderInfo.custSort'].value = sortValue;
// document.listForm.operate.value="selectPageList";
// document.listForm.submit();
}
function callback(data)
{
alert(data);
}
-->
</script>

<table><tr><td><input type="button" name="compile" value="编译" class="mybutton" onClick="compileJava()"></td></tr></table>
<%@include file="/common/tail.jsp"%>

上面在编译成功时弹出编译成功的JS提示,否则提示编译失败

另外需要说明的是,要实现在线ANT编译,需要把ant工具相关的一些jar包复制到tomcat的shared\lib或者WEB-INF\lib中.