Extracts the file archive to the target dir target Dir and deletes the files extracted upon jvm exit if the flag deleteOnExit is true. - Java File Path IO

Java examples for File Path IO:File delete

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Description

Extracts the file archive to the target dir target Dir and deletes the files extracted upon jvm exit if the flag deleteOnExit is true.

Demo Code

//Licensed under the Apache License, Version 2.0 (the "License");
//package com.java2s;
import java.io.File;

import java.io.IOException;
import java.net.URL;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;

public class Main {
    public static void main(String[] argv) throws Exception {
        File archive = new File("Main.java");
        File targetDir = new File("Main.java");
        System.out.println(extract(archive, targetDir));
    }/*from   ww w.j  a  va2s  .  c o  m*/

    /**
     * The suffixes of the files to support.
     */
    public static final String[] SUPPORTED_FILES = new String[] { ".zip",
            ".jar", ".war" };

    public static boolean extract(File archive, File targetDir)
            throws IOException {
        return extract(archive.toURI().toURL(), targetDir, true);
    }

    public static boolean extract(File archive, File targetDir,
            boolean deleteOnExit) throws IOException {
        return extract(archive.toURI().toURL(), targetDir, deleteOnExit);
    }

    public static boolean extract(URL archive, File targetDir)
            throws IOException {
        return extract(archive, targetDir, true);
    }

    /**
     * Extracts the file {@code archive} to the target dir {@code targetDir} and deletes the 
     * files extracted upon jvm exit if the flag {@code deleteOnExit} is true.
     */
    public static boolean extract(URL archive, File targetDir,
            boolean deleteOnExit) throws IOException {
        String archiveStr = archive.toString();
        String jarEntry = null;
        int idx = archiveStr.indexOf("!/");
        if (idx != -1) {
            if (!archiveStr.startsWith("jar:")
                    && archiveStr.length() == idx + 2)
                return false;
            archive = new URL(archiveStr.substring(4, idx));
            jarEntry = archiveStr.substring(idx + 2);
        } else if (!isSupported(archiveStr))
            return false;

        JarInputStream jis = new JarInputStream(archive.openConnection()
                .getInputStream());
        if (!targetDir.exists())
            targetDir.mkdirs();
        JarEntry entry = null;
        while ((entry = jis.getNextJarEntry()) != null) {
            String entryName = entry.getName();
            File entryFile = new File(targetDir, entryName);
            if (!entry.isDirectory()) {
                if (jarEntry == null || entryName.startsWith(jarEntry)) {
                    if (!entryFile.exists()
                            || entryFile.lastModified() != entry.getTime())
                        extractEntry(entryFile, jis, entry, deleteOnExit);
                }
            }
        }
        try {
            jis.close();
        } catch (Exception e) {
        }
        return true;
    }

    /**
     * Returns true if the given {@code resource} is either a zip, jar or war file.
     */
    public static boolean isSupported(String resource) {
        int idx = resource.lastIndexOf('.');
        if (resource.length() == idx + 4) {
            for (int i = 0; i < SUPPORTED_FILES.length; i++) {
                if (resource.endsWith(SUPPORTED_FILES[i]))
                    return true;
            }
        }
        return false;
    }

    private static void extractEntry(File entryFile, JarInputStream jis,
            JarEntry entry, boolean deleteOnExit) throws IOException {
        File parent = new File(entryFile.getParent());
        if (!parent.exists())
            parent.mkdirs();
        //ResourceUtil.copy(jis, new FileOutputStream(entryFile));     
        entryFile.setLastModified(entry.getTime());
        if (deleteOnExit) {
            parent.deleteOnExit();
            entryFile.deleteOnExit();
        }
    }
}

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