org.eclipse.persistence.tools.dbws.InMemoryCompiler Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation
EclipseLink build based upon Git transaction 346465e
There is a newer version: 5.0.0-B07
/*******************************************************************************
 * Copyright (c) 2011, 2012 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Mike Norman - July 13 2010
 *       fix for https://bugs.eclipse.org/bugs/show_bug.cgi?id=318207
 ******************************************************************************/
package org.eclipse.persistence.tools.dbws;

//javase imports
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.StringWriter;
import java.net.URI;
import java.util.Arrays;

//java eXtension imports
import javax.tools.DiagnosticCollector;
import javax.tools.FileObject;
import javax.tools.ForwardingJavaFileManager;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileManager;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
import javax.tools.JavaCompiler.CompilationTask;
import javax.tools.JavaFileObject.Kind;

/**
* 
* PRIVATE: InMemoryCompiler wraps a {@link javax.tools.JavaCompiler}.
* Only supports compiling a single file in-memory.
*
* @author mnorman
*
*/
public class InMemoryCompiler {

    static final Iterable OPTIONS = Arrays.asList("-g:source,lines,vars");

    protected String targetFileName;
    protected JavaCompiler compiler;
    protected DiagnosticCollector diagnosticsCollector;
    protected JavaFileManager fileManager;

    public InMemoryCompiler(String targetFileName) {
        super();
        this.targetFileName = targetFileName;
        compiler = ToolProvider.getSystemJavaCompiler();
        diagnosticsCollector = new DiagnosticCollector();
    }

    public JavaCompiler getCompiler() {
        return compiler;
    }

    public DiagnosticCollector getDiagnosticsCollector() {
        return diagnosticsCollector;
    }

    public byte[] compile(CharSequence source) {
        JavaFileObject targetSource =
            new JavaSourceFromString(targetFileName, source.toString());
        ByteArrayJavaFileObject targetClass =
            new ByteArrayJavaFileObject(targetFileName);
        Iterable compilationUnits = Arrays.asList(targetSource);
        ByteArrayFileManager bafm = new ByteArrayFileManager(
            compiler.getStandardFileManager(null, null, null), targetClass);
        StringWriter sw = new StringWriter();
        CompilationTask task = compiler.getTask(sw, bafm, diagnosticsCollector, OPTIONS, null,
            compilationUnits);
        task.call();
        return targetClass.toByteArray();
    }

    // wrapper class - not really a 'FileObject', uses in-memory string 'source'
    class JavaSourceFromString extends SimpleJavaFileObject {
        CharSequence source;
        JavaSourceFromString(String name, CharSequence source) {
            // URI trick from SimpleJavaFileObject constructor - it only recognizes
            // ('file:/' or 'jar:/'); anything else forces the 'getCharContent' callback for Kind.SOURCE
            super(URI.create("string:///" + name.replace('.','/') + Kind.SOURCE.extension),
                Kind.SOURCE);
            this.source = source;
        }
        @Override
        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
            return source;
        }
    }

    // wrapper class - not really a 'FileObject', uses in-memory ByteArrayOutputStream 'bos'
    class ByteArrayJavaFileObject extends SimpleJavaFileObject {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        public ByteArrayJavaFileObject(String name) {
            // URI trick from SimpleJavaFileObject constructor - it only recognizes
            // ('file:' or 'jar:'); anything else forces the 'openOutputStream' callback for Kind.CLASS
            super(URI.create("string:///" + name.replace('.', '/') + Kind.CLASS.extension),
                Kind.CLASS);
        }
        public byte[] toByteArray() {
            return bos.toByteArray();
        }
        @Override
        public OutputStream openOutputStream() throws IOException {
            return bos;
        }
    }
    // wrapper class - compiler will use this 'FileManager' to manage compiler output
    class ByteArrayFileManager extends ForwardingJavaFileManager {
        ByteArrayJavaFileObject bajfo;
        ByteArrayFileManager(StandardJavaFileManager sjfm, ByteArrayJavaFileObject bajfo) {
            super(sjfm);
            this.bajfo = bajfo;
        }
        @Override
        public JavaFileObject getJavaFileForOutput(Location location, String name, Kind kind,
            FileObject sibling) throws IOException {
            return bajfo;
        }
    }
}