Java读取Jar中资源文件

import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import org.apache.commons.io.IOUtils;

public class ResourceLoadFromJarUtil {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {

/* 资源文件路径,不能以'/'字符字符开头 */
String resourcePath = "struts-plugin.xml";

/* 获取ClassPath下的所有jar路径 */
String[] cps = System.getProperty("java.class.path").split(";");

/* 读取本地Jar文件 */
for (String cp : cps) {
if (!cp.endsWith(".jar")) {
continue;
}
InputStream in = loadResourceFromJarFile(cp, resourcePath);
if (in != null) {
System.err.println(IOUtils.toString(in));
in.close();
}
}

/* 读取本地Jar文件 */
for (String cp : cps) {
if (!cp.endsWith(".jar")) {
continue;
}
InputStream in = loadResourceFromJarURL(cp, resourcePath);
if (in != null) {
System.err.println(IOUtils.toString(in));
in.close();
}
}

/* 读取网络Jar文件 */
InputStream in = loadResourceFromJarURL(
"http://localhost:8080/SpringStruts2Integration/struts2-spring-plugin-2.3.4.1.jar", resourcePath);
if (in != null) {
System.err.println(IOUtils.toString(in));
in.close();
}
}

/**
* 读取Jar文件中的资源
*
* @param jarPath
*            本地jar文件路径
* @param resPath
*            资源文件所在jar中的路径(不能以'/'字符开头)
* @return 如果资源加载失败,返回null
*/
public static InputStream loadResourceFromJarFile(String jarPath, String resPath) {
if (!jarPath.endsWith(".jar")) {
return null;
}
try {
JarFile jarFile = new JarFile(jarPath);
JarEntry jarEntry = jarFile.getJarEntry(resPath);
if (jarEntry == null) {
return null;
}
return jarFile.getInputStream(jarEntry);
} catch (IOException e) {
e.printStackTrace();
return null;
}
}

/**
* 读取Jar文件中的资源
*
* @param jarUrl
*            本地jar文件或网络上(ttp://host:port/subpath/jarfile.jar)jar文件路径
* @param resPath
*            资源文件所在jar中的路径(不能以'/'字符开头)
* @return 如果资源加载失败,返回null
*/
public static InputStream loadResourceFromJarURL(String jarUrl, String resPath) {
if (!jarUrl.endsWith(".jar")) {
return null;
}
URL url = null;
if (jarUrl.startsWith("http://")) {
try {
url = new URL("jar:" + jarUrl + "!/");
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
}
} else {
try {
url = new URL("jar:file:/" + jarUrl + "!/");
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
}
}
try {
JarURLConnection jarURLConnection;
jarURLConnection = (JarURLConnection) url.openConnection();
JarFile jarFile = jarURLConnection.getJarFile();
JarEntry jarEntry = jarFile.getJarEntry(resPath);
if (jarEntry == null) {
return null;
}
return jarFile.getInputStream(jarEntry);
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}