Update your jar package with code

Assume that the directory structure is the maven standard structure

Copy the code code as follows:

-src

-target

-test.jar (the jar package you need to update)

Copy the code code as follows:

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

/**

* Update all files in the com directory to the corresponding directory structure of the jar

*

* A successful code update, we assert that the size of the jar is different

*/

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());

}

}