get Jars From Path - Java Reflection

Java examples for Reflection:Jar

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Description

get Jars From Path

Demo Code


//package com.java2s;
import javax.swing.*;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLDecoder;
import java.util.*;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

public class Main {
    public static List<URL> getJarsFromPath(Class clazz, String path)
            throws URISyntaxException, IOException {
        URL dirURL = clazz.getClassLoader().getResource(path);
        if (dirURL != null && dirURL.getProtocol().equals("file")) {
            /* A file path: easy enough */
            File[] jars = new File(dirURL.toURI())
                    .listFiles(new FileFilter() {
                        @Override
                        public boolean accept(File pathname) {
                            return pathname.getName().toLowerCase()
                                    .endsWith(".jar");
                        }/*from  w w  w . j  a v  a 2 s  . co  m*/
                    });
            List<URL> jarFiles = new ArrayList<>();
            for (File f : jars) {
                jarFiles.add(f.toURI().toURL());
            }
            return jarFiles;
        }

        if (dirURL == null) {
            /*
             * In case of a jar file, we can't actually find a directory.
             * Have to assume the same jar as clazz.
             */
            String me = clazz.getName().replace(".", "/") + ".class";
            dirURL = clazz.getClassLoader().getResource(me);
        }
        if (dirURL.getProtocol().equals("jar")) {
            /* A JAR path */
            String jarPath = dirURL.getPath().substring(5,
                    dirURL.getPath().indexOf("!")); //strip out only the JAR file
            JarFile jar = new JarFile(URLDecoder.decode(jarPath, "UTF-8"));
            Enumeration<JarEntry> entries = jar.entries(); //gives ALL entries in jar
            List<URL> result = new ArrayList<>(); //avoid duplicates in case it is a subdirectory
            while (entries.hasMoreElements()) {
                JarEntry jarEntry = entries.nextElement();
                String name = jarEntry.getName();
                if (name.startsWith(path)
                        && name.toLowerCase().endsWith(".jar")) { //filter according to the path\
                    String jarFile = name.replaceAll("\\.", "/");
                    jarFile = jarFile.substring(0, jarFile.length()
                            - "/jar".length())
                            + ".jar";
                    jarFile = new File(jarFile).getName();
                    URL url = new URL(dirURL + "/" + jarFile);
                    JOptionPane.showConfirmDialog(null, url);
                    result.add(url);
                }
            }
            return result;
        }

        throw new UnsupportedOperationException(
                "Cannot list files for URL " + dirURL);
    }
}

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