Ant example source code file (JikesOutputParser.java)

This example Ant source code file (JikesOutputParser.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

bufferedreader, bufferedreader, executestreamhandler, inputstreamreader, io, ioexception, ioexception, jikesoutputparser, jikesoutputparser, string, string, task

The JikesOutputParser.java source code

/*
 *  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.OutputStream;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Task;

/**
 * Parses output from jikes and
 * passes errors and warnings
 * into the right logging channels of Project.
 *
 * <p>As of Ant 1.2, this class is considered to be dead code
 * by the Ant developers and is unmaintained.  Don't use
 * it.</strong>

 *
 * @deprecated since 1.2.
 *             Use Jikes' exit value to detect compilation failure.
 */
public class JikesOutputParser implements ExecuteStreamHandler {
    // CheckStyle:VisibilityModifier OFF - bc
    protected Task task;
    protected boolean errorFlag = false; // no errors so far
    protected int errors;
    protected int warnings;
    protected boolean error = false;
    protected boolean emacsMode;

    protected BufferedReader br;
    // CheckStyle:VisibilityModifier ON

    /**
     * Ignore.
     * @param os ignored
     */
    public void setProcessInputStream(OutputStream os) {
    }

    /**
     * Ignore.
     * @param is ignored
     */
    public void setProcessErrorStream(InputStream is) {
    }

    /**
     * Set the inputstream
     * @param is the input stream
     * @throws IOException on error
     */
    public void setProcessOutputStream(InputStream is) throws IOException {
        br = new BufferedReader(new InputStreamReader(is));
    }

    /**
     * Invokes parseOutput.
     * @throws IOException on error
     */
    public void start() throws IOException {
        parseOutput(br);
    }

    /**
     * Ignore.
     */
    public void stop() {
    }

    /**
     * Construct a new Parser object
     * @param task      task in which context we are called
     * @param emacsMode if true output in emacs mode
     */
    protected JikesOutputParser(Task task, boolean emacsMode) {
        super();

        System.err.println("As of Ant 1.2 released in October 2000, the "
            + "JikesOutputParser class");
        System.err.println("is considered to be dead code by the Ant "
            + "developers and is unmaintained.");
        System.err.println("Don\'t use it!");

        this.task = task;
        this.emacsMode = emacsMode;
    }

    /**
     * Parse the output of a jikes compiler
     * @param reader - Reader used to read jikes's output
     * @throws IOException on error
     */
    protected void parseOutput(BufferedReader reader) throws IOException {
       if (emacsMode) {
           parseEmacsOutput(reader);
       } else {
           parseStandardOutput(reader);
       }
    }

    private void parseStandardOutput(BufferedReader reader) throws IOException {
        String line;
        String lower;
        // We assume, that every output, jikes does, stands for an error/warning
        // XXX
        // Is this correct?

        // TODO:
        // A warning line, that shows code, which contains a variable
        // error will cause some trouble. The parser should definitely
        // be much better.

        while ((line = reader.readLine()) != null) {
            lower = line.toLowerCase();
            if (line.trim().equals("")) {
                continue;
            }
            if (lower.indexOf("error") != -1) {
                setError(true);
            } else if (lower.indexOf("warning") != -1) {
                setError(false);
                   } else {
                // If we don't know the type of the line
                // and we are in emacs mode, it will be
                // an error, because in this mode, jikes won't
                // always print "error", but sometimes other
                // keywords like "Syntax". We should look for
                // all those keywords.
                if (emacsMode) {
                    setError(true);
                }
            }
            log(line);
        }
    }

    private void parseEmacsOutput(BufferedReader reader) throws IOException {
       // This may change, if we add advanced parsing capabilities.
       parseStandardOutput(reader);
    }

    private void setError(boolean err) {
        error = err;
        if (error) {
            errorFlag = true;
        }
    }

    private void log(String line) {
       if (!emacsMode) {
           task.log("", (error ? Project.MSG_ERR : Project.MSG_WARN));
       }
       task.log(line, (error ? Project.MSG_ERR : Project.MSG_WARN));
    }

    /**
     * Indicate if there were errors during the compile
     * @return if errors occurred
     */
    protected boolean getErrorFlag() {
        return errorFlag;
    }
}