com.github.sviperll.meta.FilerCodeWriter Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of metachicory Show documentation
Metaprogramming tools. Useful for annotation processors implementation. Part of chicory.
There is a newer version: 0.36
/*
 * Copyright (c) 2014, Victor Nazarov 
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation and/or
 *     other materials provided with the distribution.
 *
 *  3. Neither the name of the copyright holder nor the names of its contributors
 *     may be used to endorse or promote products derived from this software
 *     without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 *  THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 *  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *  EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.github.sviperll.meta;

import com.github.sviperll.Throwables;
import com.helger.jcodemodel.AbstractCodeWriter;
import com.helger.jcodemodel.JPackage;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.processing.Filer;
import javax.annotation.processing.Messager;
import javax.tools.Diagnostic;
import javax.tools.JavaFileObject;

/**
 * Writes java classes through {@code Filer}.
 * 
 * {@code AbstractCodeWriter} to be used with {@code JCodeModel}.
 * 
 * This writer uses {@code Filer} to write actual java source files.
 * {@code Filer} object is provided by Java-compiler and is available to annotation processors.
 *
 * @see com.helger.jcodemodel.JCodeModel
 * @see javax.annotation.processing.AbstractProcessor
 * @see com.helger.jcodemodel.AbstractCodeWriter
 * @see javax.annotation.processing.Filer
 *
 * @author Victor Nazarov <[email protected]>
 */
public class FilerCodeWriter extends AbstractCodeWriter {
    private static final String JAVA_SOURCE_SUFFIX = ".java";
    private final Filer filer;
    private final List closeables = new ArrayList();
    private final Messager messager;

    /**
     * Creates new instance.
     *
     * @param filer {@code Filer} used to create java sources
     * @param messager is only used for error reporting
     */
    public FilerCodeWriter(Filer filer, Messager messager) {
        super(Charset.defaultCharset(), System.lineSeparator());
        this.filer = filer;
        this.messager = messager;
    }

    @Override
    public OutputStream openBinary(JPackage pkg, String fileName) throws IOException {
        String className = fileName.substring(0, fileName.length() - JAVA_SOURCE_SUFFIX.length());
        if (!fileName.endsWith(JAVA_SOURCE_SUFFIX))
            throw new IllegalStateException("Unexpected file name passed to code writer: " + fileName);
        JavaFileObject fileObject = filer.createSourceFile(pkg.name() + "." + className);
        OutputStream stream = fileObject.openOutputStream();
        closeables.add(stream);
        return stream;
    }

    @Override
    public void close() throws IOException {
        Exception exception = null;
        for (OutputStream stream: closeables) {
            try {
                stream.close();
            } catch (IOException ex) {
                if (exception != null)
                    messager.printMessage(Diagnostic.Kind.WARNING, Throwables.render(exception));
                exception = ex;
            } catch (RuntimeException ex) {
                if (exception != null)
                    messager.printMessage(Diagnostic.Kind.WARNING, Throwables.render(exception));
                exception = ex;
            }
        }
        closeables.clear();
        if (exception != null) {
            if (exception instanceof IOException) {
                throw (IOException)exception;
            } else if (exception instanceof RuntimeException) {
                throw (RuntimeException)exception;
            } else
                throw new IllegalStateException("Unexpected exception", exception);
        }
    }
}