jarfile.java

JAVA基本类源代码,大家可以学习学习!

/*
 * @(#)JarFile.java	1.50 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.util.jar;

import java.io.*;
import java.util.*;
import java.util.zip.*;
import java.security.cert.Certificate;
import java.security.AccessController;
import sun.security.action.GetPropertyAction;
import sun.security.util.ManifestEntryVerifier;
import sun.misc.SharedSecrets;

/**
 * The <code>JarFile</code> class is used to read the contents of a JAR file
 * from any file that can be opened with <code>java.io.RandomAccessFile</code>.
 * It extends the class <code>java.util.zip.ZipFile</code> with support
 * for reading an optional <code>Manifest</code> entry. The
 * <code>Manifest</code> can be used to specify meta-information about the
 * JAR file and its entries.
 *
 * @author  David Connelly
 * @version 1.50, 01/23/03
 * @see	    Manifest
 * @see     java.util.zip.ZipFile
 * @see     java.util.jar.JarEntry
 * @since   1.2
 */
public
class JarFile extends ZipFile {
    private Manifest man;
    private JarEntry manEntry;
    private boolean manLoaded;
    private JarVerifier jv;
    private boolean jvInitialized;
    private boolean verify;
    private boolean computedHasClassPathAttribute;
    private boolean hasClassPathAttribute;

    // Set up JavaUtilJarAccess in SharedSecrets
    static {
        SharedSecrets.setJavaUtilJarAccess(new JavaUtilJarAccessImpl());
    }

    /**
     * The JAR manifest file name.
     */
    public static final String MANIFEST_NAME = "META-INF/MANIFEST.MF";

    /**
     * Creates a new <code>JarFile</code> to read from the specified
     * file <code>name</code>. The <code>JarFile</code> will be verified if
     * it is signed.
     * @param name the name of the JAR file to be opened for reading
     * @exception IOException if an I/O error has occurred
     * @exception SecurityException if access to the file is denied
     *            by the SecurityManager
     */
    public JarFile(String name) throws IOException {
	this(new File(name), true, ZipFile.OPEN_READ);
    }

    /**
     * Creates a new <code>JarFile</code> to read from the specified
     * file <code>name</code>.
     * @param name the name of the JAR file to be opened for reading
     * @param verify whether or not to verify the JarFile if
     * it is signed.
     * @exception IOException if an I/O error has occurred
     * @exception SecurityException if access to the file is denied
     *            by the SecurityManager 
     */
    public JarFile(String name, boolean verify) throws IOException {
        this(new File(name), verify, ZipFile.OPEN_READ);
    }

    /**
     * Creates a new <code>JarFile</code> to read from the specified
     * <code>File</code> object. The <code>JarFile</code> will be verified if
     * it is signed.
     * @param file the JAR file to be opened for reading
     * @exception IOException if an I/O error has occurred
     * @exception SecurityException if access to the file is denied
     *            by the SecurityManager
     */
    public JarFile(File file) throws IOException {
	this(file, true, ZipFile.OPEN_READ);
    }


    /**
     * Creates a new <code>JarFile</code> to read from the specified
     * <code>File</code> object.
     * @param file the JAR file to be opened for reading
     * @param verify whether or not to verify the JarFile if
     * it is signed.
     * @exception IOException if an I/O error has occurred
     * @exception SecurityException if access to the file is denied
     *            by the SecurityManager.
     */
    public JarFile(File file, boolean verify) throws IOException {
	this(file, verify, ZipFile.OPEN_READ);
    }


    /**
     * Creates a new <code>JarFile</code> to read from the specified
     * <code>File</code> object in the specified mode.  The mode argument
     * must be either <tt>OPEN_READ</tt> or <tt>OPEN_READ | OPEN_DELETE</tt>.
     *
     * @param file the JAR file to be opened for reading
     * @param verify whether or not to verify the JarFile if
     * it is signed.
     * @param mode the mode in which the file is to be opened
     * @exception IOException if an I/O error has occurred
     * @exception IllegalArgumentException
     *            If the <tt>mode</tt> argument is invalid
     * @exception SecurityException if access to the file is denied
     *            by the SecurityManager
     */
    public JarFile(File file, boolean verify, int mode) throws IOException {
	super(file, mode);
	this.verify = verify;
    }

    /**
     * Returns the JAR file manifest, or <code>null</code> if none.
     *
     * @return the JAR file manifest, or <code>null</code> if none
     */
    public Manifest getManifest() throws IOException {
	if (!manLoaded) {
	    // First look up manifest entry using standard name
	    manEntry = getJarEntry(MANIFEST_NAME);
	    if (manEntry == null) {
		// If not found, then iterate through all the "META-INF/"
		// entries to find a match.
		String[] names = getMetaInfEntryNames();
		if (names != null) {
		    for (int i = 0; i < names.length; i++) {
			if (MANIFEST_NAME.equals(
                            names[i].toUpperCase(Locale.ENGLISH))) {
			    manEntry = getJarEntry(names[i]);
			    break;
			}
		    }
		}
	    }
	    // If found then load the manifest
	    if (manEntry != null) {
		if (verify) {
		    byte[] b = getBytes(manEntry);
 		    man = new Manifest(new ByteArrayInputStream(b));
		    jv = new JarVerifier(man, b);
		} else {
		    man = new Manifest(super.getInputStream(manEntry));
		}
	    }
	    manLoaded = true;
	}
	return man;
    }

    private native String[] getMetaInfEntryNames();

    /**
     * Returns the <code>JarEntry</code> for the given entry name or
     * <code>null</code> if not found.
     *
     * @param name the JAR file entry name
     * @return the <code>JarEntry</code> for the given entry name or
     *         <code>null</code> if not found.
     * @see java.util.jar.JarEntry
     */
    public JarEntry getJarEntry(String name) {
	return (JarEntry)getEntry(name);
    }

    /**
     * Returns the <code>ZipEntry</code> for the given entry name or
     * <code>null</code> if not found.
     *
     * @param name the JAR file entry name
     * @return the <code>ZipEntry</code> for the given entry name or
     *         <code>null</code> if not found
     * @see java.util.zip.ZipEntry
     */
    public ZipEntry getEntry(String name) {
	ZipEntry ze = super.getEntry(name);
	if (ze != null) {
	    return new JarFileEntry(ze);
	}
	return null;
    }

    /**
     * Returns an enumeration of the ZIP file entries.
     */
    public Enumeration entries() {
	final Enumeration enum = super.entries();
	return new Enumeration() {
	    public boolean hasMoreElements() {
		return enum.hasMoreElements();
	    }
	    public Object nextElement() {
		ZipEntry ze = (ZipEntry)enum.nextElement();
		return new JarFileEntry(ze);
	    }
	};
    }

    private class JarFileEntry extends JarEntry {
	JarFileEntry(ZipEntry ze) {
	    super(ze);
	}
	public Attributes getAttributes() throws IOException {
	    Manifest man = JarFile.this.getManifest();
	    if (man != null) {
		return man.getAttributes(getName());
	    } else {
		return null;
	    }
	}
	public java.security.cert.Certificate[] getCertificates() {
            try {
                maybeInstantiateVerifier();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
	    if (certs == null && jv != null) {
		Certificate[] cs = jv.getCerts(getName());
		if (cs != null) {
		    certs = (Certificate[])cs.clone();