Ant example source code file (Javac12.java)

This example Ant source code file (Javac12.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

a, boolean, boolean, buildexception, buildexception, class, class, classic_compiler_classname, commandline, constructor, error, io, object, object, reflection, string

The Javac12.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.compilers;

import java.io.OutputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.util.JavaEnvUtils;
import org.apache.tools.ant.util.FileUtils;
import org.apache.tools.ant.taskdefs.LogOutputStream;
import org.apache.tools.ant.types.Commandline;

/**
 * The implementation of the javac compiler for JDK 1.2
 * This is primarily a cut-and-paste from the original javac task before it
 * was refactored.
 *
 * @since Ant 1.3
 */
public class Javac12 extends DefaultCompilerAdapter {
    protected static final String CLASSIC_COMPILER_CLASSNAME = "sun.tools.javac.Main";

    /**
     * Run the compilation.
     * @return true if the compiler ran with a zero exit result (ok)
     * @exception BuildException if the compilation has problems.
     */
    public boolean execute() throws BuildException {
        attributes.log("Using classic compiler", Project.MSG_VERBOSE);
        Commandline cmd = setupJavacCommand(true);

        OutputStream logstr = new LogOutputStream(attributes, Project.MSG_WARN);
        try {
            // Create an instance of the compiler, redirecting output to
            // the project log
            Class c = Class.forName(CLASSIC_COMPILER_CLASSNAME);
            Constructor cons =
                c.getConstructor(new Class[] {OutputStream.class,
                                              String.class});
            Object compiler
                = cons.newInstance(new Object[] {logstr, "javac"});

            // Call the compile() method
            Method compile = c.getMethod("compile",
                                         new Class [] {String[].class});
            Boolean ok =
                (Boolean) compile.invoke(compiler,
                                        new Object[] {cmd.getArguments()});
            return ok.booleanValue();
        } catch (ClassNotFoundException ex) {
            throw new BuildException("Cannot use classic compiler , as it is "
                                        + "not available. \n"
                                        + " A common solution is "
                                        + "to set the environment variable"
                                        + " JAVA_HOME to your jdk directory.\n"
                                        + "It is currently set to \""
                                        + JavaEnvUtils.getJavaHome()
                                        + "\"",
                                        location);
        } catch (Exception ex) {
            if (ex instanceof BuildException) {
                throw (BuildException) ex;
            } else {
                throw new BuildException("Error starting classic compiler: ",
                                         ex, location);
            }
        } finally {
            FileUtils.close(logstr);
        }
    }
}