Java Web应用中使用ANT在线编译不用重起tomcat的方法

来源：作者：来自网络出处：巧巧读书 2008-05-14 进入讨论组

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">

</script>

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