假设目录结构是maven标准结构
复制代码 代码如下:
-src
-target
-test.jar(你需要更新的jar包)

复制代码 代码如下:
package com.foo.common.base.utils.development;

import static org.junit.Assert.*;

import java.io.File;
import java.io.IOException;
import java.util.Date;
import java.util.Properties;

import org.apache.commons.io.FileUtils;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.io.ClassPathResource;

public class JarUpdater {
public static final Logger logger = LoggerFactory
.getLogger(JarUpdater.class);

@Test
/**
* 更新com目录下的所有文件到jar的对应目录结构中去
*
* 一次成功的代码更新，我们断言jar的大小是不一样的
*/
public void updateClass() throws IOException, InterruptedException {

ClassPathResource myPath = new ClassPathResource(
"jarUpdaterConfig.properties");
Properties p = new Properties();
p.load(myPath.getInputStream());

ClassUpdater classUpdater = new ClassUpdater().applySettings(p);

classUpdater.compileAndCopyClass();

String workingDirectory = p.getProperty("workingDirectory");
String jar4UpdateName = p.getProperty("jar4UpdateName");
// class compile path
String updateSourcePath = workingDirectory + "target";
// class root folder
String updateSourceDir = "com";

Date startDate = new Date();

File myJar = new File(workingDirectory + jar4UpdateName);
if (!myJar.isFile()) {
logger.error("file with following path {} does not exist.",
jar4UpdateName);
return;
}
long oldLength = myJar.length();
logger.info("Now ready to update jar file with name:{},size:{}",
myJar.getName(), myJar.length());
String myCommand = "jar uf " + workingDirectory + jar4UpdateName
+ " -C " + updateSourcePath + " " + updateSourceDir;
logger.info("Update command【{}】", myCommand);

Runtime.getRuntime().exec(myCommand);

while (!FileUtils.isFileNewer(myJar, startDate)) {
logger.info("sleep for two seconds,checking changes...");
Thread.sleep(2000);
}
assertNotEquals(
"jar may not be updated successfully,check the code please",
oldLength, myJar.length());
logger.info("Now finish update jar file with size:{}", myJar.length());
}
}