manifest.java

Use the links below to download a source distribution of Ant from one of our mirrors. It is good pra

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package org.apache.tools.ant.taskdefs;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.util.FileUtils;

/**
 * Holds the data of a jar manifest.
 *
 * Manifests are processed according to the
 * {@link <a href="http://java.sun.com/j2se/1.5.0/docs/guide/jar/jar.html">Jar
 * file specification.</a>}.
 * Specifically, a manifest element consists of
 * a set of attributes and sections. These sections in turn may contain
 * attributes. Note in particular that this may result in manifest lines
 * greater than 72 bytes being wrapped and continued on the next
 * line. If an application can not handle the continuation mechanism, it
 * is a defect in the application, not this task.
 *
 *
 * @since Ant 1.4
 */
public class Manifest {
    /** The standard manifest version header */
    public static final String ATTRIBUTE_MANIFEST_VERSION
        = "Manifest-Version";

    /** The standard Signature Version header */
    public static final String ATTRIBUTE_SIGNATURE_VERSION
        = "Signature-Version";

    /** The Name Attribute is the first in a named section */
    public static final String ATTRIBUTE_NAME = "Name";

    /** The From Header is disallowed in a Manifest */
    public static final String ATTRIBUTE_FROM = "From";

    /** The Class-Path Header is special - it can be duplicated */
    public static final String ATTRIBUTE_CLASSPATH = "Class-Path";

    /** Default Manifest version if one is not specified */
    public static final  String DEFAULT_MANIFEST_VERSION = "1.0";

    /** The max length of a line in a Manifest */
    public static final int MAX_LINE_LENGTH = 72;

    /**
     * Max length of a line section which is continued. Need to allow
     * for the CRLF.
     */
    public static final int MAX_SECTION_LENGTH = MAX_LINE_LENGTH - 2;

    /** The End-Of-Line marker in manifests */
    public static final String EOL = "\r\n";
    /** Error for attributes */
    public static final String ERROR_FROM_FORBIDDEN = "Manifest attributes should not start "
                        + "with \"" + ATTRIBUTE_FROM + "\" in \"";

    /** Encoding to be used for JAR files. */
    public static final String JAR_ENCODING = "UTF-8";

    /**
     * An attribute for the manifest.
     * Those attributes that are not nested into a section will be added to the "Main" section.
     */
    public static class Attribute {

        /**
         * Maximum length of the name to have the value starting on the same
         * line as the name. This to stay under 72 bytes total line length
         * (including CRLF).
         */
        private static final int MAX_NAME_VALUE_LENGTH = 68;

        /**
         * Maximum length of the name according to the jar specification.
         * In this case the first line will have 74 bytes total line length
         * (including CRLF). This conflicts with the 72 bytes total line length
         * max, but is the only possible conclusion from the manifest specification, if
         * names with 70 bytes length are allowed, have to be on the first line, and
         * have to be followed by ": ".
         */
        private static final int MAX_NAME_LENGTH = 70;

        /** The attribute's name */
        private String name = null;

        /** The attribute's value */
        private Vector values = new Vector();

        /**
         * For multivalued attributes, this is the index of the attribute
         * currently being defined.
         */
        private int currentIndex = 0;

        /**
         * Construct an empty attribute */
        public Attribute() {
        }

        /**
         * Construct an attribute by parsing a line from the Manifest
         *
         * @param line the line containing the attribute name and value
         *
         * @throws ManifestException if the line is not valid
         */
        public Attribute(String line) throws ManifestException {
            parse(line);
        }

        /**
         * Construct a manifest by specifying its name and value
         *
         * @param name the attribute's name
         * @param value the Attribute's value
         */
        public Attribute(String name, String value) {
            this.name = name;
            setValue(value);
        }

        /**
         * @see java.lang.Object#hashCode
         * @return a hashcode based on the key and values.
         */
        public int hashCode() {
            int hashCode = 0;

            if (name != null) {
                hashCode += getKey().hashCode();
            }

            hashCode += values.hashCode();
            return hashCode;
        }

        /**
         * @param rhs the object to check for equality.
         * @see java.lang.Object#equals
         * @return true if the key and values are the same.
         */
        public boolean equals(Object rhs) {
            if (rhs == null || rhs.getClass() != getClass()) {
                return false;
            }

            if (rhs == this) {
                return true;
            }

            Attribute rhsAttribute = (Attribute) rhs;
            String lhsKey = getKey();
            String rhsKey = rhsAttribute.getKey();
            if ((lhsKey == null && rhsKey != null)
                 || (lhsKey != null && !lhsKey.equals(rhsKey))) {
                return false;
            }

            return values.equals(rhsAttribute.values);
        }

        /**
         * Parse a line into name and value pairs
         *
         * @param line the line to be parsed
         *
         * @throws ManifestException if the line does not contain a colon
         * separating the name and value
         */
        public void parse(String line) throws ManifestException {
            int index = line.indexOf(": ");
            if (index == -1) {
                throw new ManifestException("Manifest line \"" + line
                    + "\" is not valid as it does not "
                    + "contain a name and a value separated by ': ' ");
            }
            name = line.substring(0, index);
            setValue(line.substring(index + 2));
        }

        /**
         * Set the Attribute's name; required
         *
         * @param name the attribute's name
         */
        public void setName(String name) {
            this.name = name;
        }

        /**
         * Get the Attribute's name
         *
         * @return the attribute's name.
         */
        public String getName() {
            return name;
        }

        /**
         * Get the attribute's Key - its name in lower case.
         *
         * @return the attribute's key.
         */
        public String getKey() {
            if (name == null) {
                return null;
            }
            return name.toLowerCase();
        }

        /**
         * Set the Attribute's value; required
         *
         * @param value the attribute's value
         */
        public void setValue(String value) {
            if (currentIndex >= values.size()) {
                values.addElement(value);
                currentIndex = values.size() - 1;
            } else {
                values.setElementAt(value, currentIndex);
            }
        }

        /**
         * Get the Attribute's value.
         *
         * @return the attribute's value.
         */
        public String getValue() {
            if (values.size() == 0) {
                return null;
            }

            String fullValue = "";
            for (Enumeration e = getValues(); e.hasMoreElements();) {
                String value = (String) e.nextElement();
                fullValue += value + " ";
            }
            return fullValue.trim();
        }

        /**
         * Add a new value to this attribute - making it multivalued.
         *
         * @param value the attribute's additional value
         */
        public void addValue(String value) {
            currentIndex++;
            setValue(value);
        }

        /**
         * Get all the attribute's values.
         *
         * @return an enumeration of the attributes values
         */
        public Enumeration getValues() {
            return values.elements();
        }

        /**
         * Add a continuation line from the Manifest file.
         *
         * When lines are too long in a manifest, they are continued on the
         * next line by starting with a space. This method adds the continuation
         * data to the attribute value by skipping the first character.
         *
         * @param line the continuation line.
         */
        public void addContinuation(String line) {
            String currentValue = (String) values.elementAt(currentIndex);
            setValue(currentValue + line.substring(1));
        }

        /**
         * Write the attribute out to a print writer.
         *
         * @param writer the Writer to which the attribute is written
         *
         * @throws IOException if the attribute value cannot be written
         */
        public void write(PrintWriter writer) throws IOException {
            for (Enumeration e = getValues(); e.hasMoreElements();) {
                writeValue(writer, (String) e.nextElement());
            }
        }

        /**
         * Write a single attribute value out
         *
         * @param writer the Writer to which the attribute is written
         * @param value the attribute value
         *
         * @throws IOException if the attribute value cannot be written
         */
        private void writeValue(PrintWriter writer, String value)
             throws IOException {
            String line = null;
            int nameLength = name.getBytes(JAR_ENCODING).length;
            if (nameLength > MAX_NAME_VALUE_LENGTH) {
                if (nameLength > MAX_NAME_LENGTH) {
                    throw new IOException("Unable to write manifest line "
                            + name + ": " + value);
                }
                writer.print(name + ": " + EOL);
                line = " " + value;
            } else {
                line = name + ": " + value;
            }
            while (line.getBytes(JAR_ENCODING).length > MAX_SECTION_LENGTH) {
                // try to find a MAX_LINE_LENGTH byte section
                int breakIndex = MAX_SECTION_LENGTH;
                if (breakIndex >= line.length()) {
                    breakIndex = line.length() - 1;
                }
                String section = line.substring(0, breakIndex);
                while (section.getBytes(JAR_ENCODING).length > MAX_SECTION_LENGTH
                     && breakIndex > 0) {
                    breakIndex--;
                    section = line.substring(0, breakIndex);
                }
                if (breakIndex == 0) {
                    throw new IOException("Unable to write manifest line "
                        + name + ": " + value);
                }
                writer.print(section + EOL);
                line = " " + line.substring(breakIndex);
            }