com.google.gwt.dev.util.log.PrintWriterTreeLogger.java Source code

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Here is the source code for com.google.gwt.dev.util.log.PrintWriterTreeLogger.java

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/*
 * Copyright 2006 Google Inc.
 * 
 * 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 com.google.gwt.dev.util.log;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URL;

/**
 * Tree logger that logs to a print writer.
 */
public final class PrintWriterTreeLogger extends AbstractTreeLogger {

    private final String indent;

    private final PrintWriter out;

    private final Object mutex = new Object();

    public PrintWriterTreeLogger() {
        this(new PrintWriter(System.out, true));
    }

    public PrintWriterTreeLogger(PrintWriter out) {
        this(out, "");
    }

    public PrintWriterTreeLogger(File logFile) throws IOException {
        boolean existing = logFile.exists();
        this.out = new PrintWriter(new FileWriter(logFile, true), true);
        this.indent = "";
        if (existing) {
            out.println(); // blank line to mark relaunch
        }
    }

    protected PrintWriterTreeLogger(PrintWriter out, String indent) {
        this.out = out;
        this.indent = indent;
    }

    @Override
    protected AbstractTreeLogger doBranch() {
        return new PrintWriterTreeLogger(out, indent + "   ");
    }

    @Override
    protected void doCommitBranch(AbstractTreeLogger childBeingCommitted, Type type, String msg, Throwable caught,
            HelpInfo helpInfo) {
        doLog(childBeingCommitted.getBranchedIndex(), type, msg, caught, helpInfo);
    }

    @Override
    protected void doLog(int indexOfLogEntryWithinParentLogger, Type type, String msg, Throwable caught,
            HelpInfo helpInfo) {
        synchronized (mutex) { // ensure thread interleaving...
            out.print(indent);
            if (type.needsAttention()) {
                out.print("[");
                out.print(type.getLabel());
                out.print("] ");
            }

            out.println(msg);
            if (helpInfo != null) {
                URL url = helpInfo.getURL();
                if (url != null) {
                    out.print(indent);
                    out.println("For additional info see: " + url.toString());
                }
            }
            if (caught != null) {
                caught.printStackTrace(out);
            }
        }
    }
}