src/main/java/org/apache/xmlbeans/impl/repackage/EditBuildScript.java

/*   Copyright 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.xmlbeans.impl.repackage;

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;

public class EditBuildScript {
    //
    // usgae: edit buildfile token new-value
    //

    public static void main(String[] args) throws Exception {
        if (args.length != 3) {
            throw new IllegalArgumentException("Wrong number of arguments");
        }

        args[0] = args[0].replace('/', File.separatorChar);

        File buildFile = new File(args[0]);

        StringBuffer sb = readFile(buildFile);

        String tokenStr = "<property name=\"" + args[1] + "\" value=\"";

        int i = sb.indexOf(tokenStr);

        if (i < 0) {
            throw new IllegalArgumentException("Can't find token: " + tokenStr);
        }

        int j = i + tokenStr.length();

        while (sb.charAt(j) != '"') {
            j++;
        }

        sb.replace(i + tokenStr.length(), j, args[2]);

        writeFile(buildFile, sb);
    }

    static StringBuffer readFile(File f) throws IOException {
        try (Reader r = Files.newBufferedReader(f.toPath(), StandardCharsets.ISO_8859_1);
             StringWriter w = new StringWriter()) {
            copy(r, w);
            return w.getBuffer();
        }
    }

    static void writeFile(File f, StringBuffer chars) throws IOException {
        try (Writer w = Files.newBufferedWriter(f.toPath(), StandardCharsets.ISO_8859_1);
             Reader r = new StringReader(chars.toString())) {
            copy(r, w);
        }
    }

    static void copy(Reader r, Writer w) throws IOException {
        char[] buffer = new char[1024 * 16];

        for (; ; ) {
            int n = r.read(buffer, 0, buffer.length);

            if (n < 0) {
                break;
            }

            w.write(buffer, 0, n);
        }
    }
}