src/java/org/apache/pluto/driver/util/Properties.java

/*
 * Copyright 2003,2004 The Apache Software Foundation.
 * 
 * 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 org.apache.pluto.driver.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Iterator;

/**
 * * This class loads name/value pairs from a properties * file. The properties
 * file is specified as input stream * and follows the usual convention for Java
 * properties files.
 */

public class Properties extends NameValuePairs {

    /**
     * * Loads name/value pairs from the given input stream.
     */

    public void load(InputStream aInputStream) throws IOException {
        if (aInputStream == null) {
            return;
        }

        BufferedReader reader = new BufferedReader(
            new InputStreamReader(aInputStream, "UTF-8"));

        String line;

        while ((line = reader.readLine()) != null) {
            if (line.startsWith("#") ||
                line.startsWith("//")) {
                continue;
            }

            int index = line.indexOf('=');

            if (index > 0) {
                String name = line.substring(0, index).trim();

                if (name.length() == 0) {
                    name = null;
                }

                String value = null;

                if (index + 1 < line.length()) {
                    value = line.substring(index + 1).trim();

                    if (value.length() == 0) {
                        value = null;
                    }
                }

                if (name != null && value != null) {
                    add(name, value);
                }
            }
        }
    }


    /**
     * * Returns a subset of the NameValuePairs where the names are starting
     * with the specified prefix. * As keys of the result set all start with the
     * same prefix, this prfix is cut off.</br> * E.g:</br> * Given following
     * set: {[A1,x], [A2,y], [A3,z], [B1,x], [B2,y]]}</br> * getSubSet("A")
     * returns {[1,x], [2,y], [3,z]}</p> * * Please note: the implementation of
     * this method is <b>slow</b>, to be used only for initialisation tasks or
     * alike! * * @param   aNamePrefix *          the prefix that all returned
     * pair names have in common.
     */

    public Properties getSubSet(String aNamePrefix) {
        Properties subset = new Properties();
        int prefixLength = aNamePrefix.length();
        String name;

        for (Iterator iter = this.names(); iter.hasNext();) {
            name = (String) iter.next();

            if (name.startsWith(aNamePrefix)) {
                subset.add(name.substring(prefixLength), getStrings(name));
            }
        }
        return (subset);
    }
}