com.redhat.rcm.maven.plugin.buildmetadata.util.ManifestHelper.java Source code

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Here is the source code for com.redhat.rcm.maven.plugin.buildmetadata.util.ManifestHelper.java

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/*
 * Copyright 2006-2014 smartics, Kronseder & Reiner GmbH
 *
 * Licensed 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 com.redhat.rcm.maven.plugin.buildmetadata.util;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Map;
import java.util.Properties;
import java.util.jar.Attributes;
import java.util.jar.Manifest;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.CharUtils;
import org.apache.commons.lang.ObjectUtils;
import org.codehaus.plexus.util.StringUtils;

/**
 * Helper to write the Manifest to.
 */
public class ManifestHelper {
    // ********************************* Fields *********************************

    // --- constants ------------------------------------------------------------

    // --- members --------------------------------------------------------------

    /**
     * The maximum length of a key in a Manifest file.
     */
    private static final int MANIFEST_KEY_MAX_LENGTH = 70;

    /**
     * The location to write the manifest to.
     */
    private final File manifestFile;

    /**
     * The section to add the keys in the manifest.
     */
    private final String manifestSection;

    // ****************************** Initializer *******************************

    // ****************************** Constructors ******************************

    /**
     * Default constructor.
     *
     * @param manifestFile the location to write the manifest to.
     * @param manifestSection the section to add the keys in the manifest.
     */
    public ManifestHelper(final File manifestFile, final String manifestSection) {
        this.manifestFile = manifestFile;
        this.manifestSection = manifestSection;
    }

    // ****************************** Inner Classes *****************************

    // ********************************* Methods ********************************

    // --- init -----------------------------------------------------------------

    // --- get&set --------------------------------------------------------------

    // --- business -------------------------------------------------------------

    /**
     * Creates a Manifest file based on the given properties.
     *
     * @param buildMetaDataProperties the properties to add to the Manifest file
     *          to be written.
     * @throws IOException on any problem writing the file.
     */
    public void createManifest(final Properties buildMetaDataProperties) throws IOException {
        final Manifest manifest = createManifestInstance(buildMetaDataProperties);

        OutputStream out = null;
        try {
            out = new BufferedOutputStream(new FileOutputStream(manifestFile));
            manifest.write(out);
        } finally {
            IOUtils.closeQuietly(out);
        }
    }

    private Manifest createManifestInstance(final Properties buildMetaDataProperties) {
        final Manifest manifest = new Manifest();
        final Attributes attributes = fetchAttributes(manifest);
        manifest.getMainAttributes().put(Attributes.Name.MANIFEST_VERSION, "1.0");
        for (final Map.Entry<Object, Object> entry : buildMetaDataProperties.entrySet()) {
            final String key = ObjectUtils.toString(entry.getKey(), null);
            if (key.length() > MANIFEST_KEY_MAX_LENGTH) {
                continue;
            }

            final String normalizedKey = normalize(key);
            final String value = ObjectUtils.toString(entry.getValue(), null);

            attributes.putValue(normalizedKey, value);
        }

        return manifest;
    }

    private Attributes fetchAttributes(final Manifest manifest) {
        if (StringUtils.isBlank(manifestSection) || "Main".equals(manifestSection)) {
            return manifest.getMainAttributes();
        }

        Attributes attributes = manifest.getAttributes(manifestSection);
        if (attributes == null) {
            attributes = new Attributes();
            manifest.getEntries().put(manifestSection, attributes);
        }
        return attributes;
    }

    private static String normalize(final String key) {
        final int length = key.length();
        final StringBuilder buffer = new StringBuilder(length);
        for (int i = 0; i < length; i++) {
            final char ch = key.charAt(i);
            if (CharUtils.isAsciiAlphanumeric(ch) || ch == '-' || ch == '_') {
                buffer.append(ch);
            } else {
                buffer.append('_');
            }
        }

        return buffer.toString();
    }

    // --- object basics --------------------------------------------------------

}