从jar中拷贝资源文件 或者文件夹到指定目录

package com.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FilenameFilter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import org.apache.commons.io.FileUtils;
import org.apache.log4j.Logger;
import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipFile;

import com.github.junrar.Archive;
import com.github.junrar.rarfile.FileHeader;

import dk.dren.hunspell.Hunspell;
import sun.net.www.protocol.file.FileURLConnection;

public class FileUtil {
private static final Logger log = Logger.getLogger(FileUtil.class);
public static void loadRecourseFromJarByFolder(String folderPath,String targetFolderPath ,Class clazz) throws IOException {
URL url = clazz.getResource(folderPath);
URLConnection urlConnection = url.openConnection();
if (urlConnection instanceof FileURLConnection) {
copyFileResources(url, folderPath,targetFolderPath,clazz);
} else if (urlConnection instanceof JarURLConnection) {
copyJarResources((JarURLConnection) urlConnection,folderPath,targetFolderPath,clazz);
}
}

/**
* 当前运行环境资源文件是在文件里面的
*
* @param url
* @param folderPath
* @param clazz
* @throws IOException
*/
private static void copyFileResources(URL url, String folderPath,String targetFolderPath, Class clazz) throws IOException {
File root = new File(url.getPath());
if (root.isDirectory()) {
File[] files = root.listFiles();
for (File file : files) {
if (file.isDirectory()) {
loadRecourseFromJarByFolder(folderPath + "/" + file.getName(),targetFolderPath,clazz);
} else {
loadRecourseFromJar(folderPath + "/" + file.getName(),folderPath,clazz);
}
}
}
}

/**
* 当前运行环境资源文件是在jar里面的
*
* @param jarURLConnection
* @throws IOException
*/
private static void copyJarResources(JarURLConnection jarURLConnection,String folderPath,String targetFolderPath,Class clazz) throws IOException {
JarFile jarFile = jarURLConnection.getJarFile();
Enumeration<JarEntry> entrys = jarFile.entries();
while (entrys.hasMoreElements()) {
JarEntry entry = entrys.nextElement();
if (entry.getName().startsWith(jarURLConnection.getEntryName()) && !entry.getName().endsWith("/")) {
loadRecourseFromJar("/" + entry.getName(),targetFolderPath,clazz);
}
}
jarFile.close();
}

public static void loadRecourseFromJar(String path,String recourseFolder,Class clazz) throws IOException {
if (!path.startsWith("/")) {
throw new IllegalArgumentException("The path has to be absolute (start with '/').");
}

if (path.endsWith("/")) {
throw new IllegalArgumentException("The path has to be absolute (cat not end with '/').");
}

int index = path.lastIndexOf('/');

String filename = path.substring(index + 1);
String folderPath = recourseFolder + path.substring(0, index + 1);

// If the folder does not exist yet, it will be created. If the folder
// exists already, it will be ignored
File dir = new File(folderPath);
if (!dir.exists()) {
dir.mkdirs();
}

// If the file does not exist yet, it will be created. If the file
// exists already, it will be ignored
filename = folderPath + filename;
File file = new File(filename);

if (!file.exists() && !file.createNewFile()) {
log.error("create file :{} failed .fileName:"+ filename);
return;
}

// Prepare buffer for data copying
byte[] buffer = new byte[1024];
int readBytes;

// Open and check input stream
URL url = clazz.getResource(path);
URLConnection urlConnection = url.openConnection();
InputStream is = urlConnection.getInputStream();

if (is == null) {
throw new FileNotFoundException("File " + path + " was not found inside JAR.");
}
OutputStream os = new FileOutputStream(file);
try {
while ((readBytes = is.read(buffer)) != -1) {
os.write(buffer, 0, readBytes);
}
} finally {
os.close();
is.close();
}

}
public static void main(String[] args) throws IOException {
loadRecourseFromJarByFolder("/hunspell-win-x86-64.dll", "D:\test" ,Hunspell.class);
loadRecourseFromJarByFolder("/META-INF/maven", "D:\test" ,Hunspell.class);
}
}
直接运行即可获取jar包hunspell中的文件及文件夹

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版权声明：本文为CSDN博主「月慕向阳」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/weixin_41796956/article/details/82856675