net.sf.jasperreports.phantomjs.ProcessOutputReader.java Source code

Introduction

Here is the source code for net.sf.jasperreports.phantomjs.ProcessOutputReader.java

Source

/*
 * JasperReports - Free Java Reporting Library.
 * Copyright (C) 2001 - 2019 TIBCO Software Inc. All rights reserved.
 * http://www.jaspersoft.com
 *
 * Unless you have purchased a commercial license agreement from Jaspersoft,
 * the following license terms apply:
 *
 * This program is part of JasperReports.
 *
 * JasperReports is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * JasperReports is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with JasperReports. If not, see <http://www.gnu.org/licenses/>.
 */
package net.sf.jasperreports.phantomjs;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import net.sf.jasperreports.engine.JRRuntimeException;

/**
 * @author Lucian Chirita (lucianc@users.sourceforge.net)
 */
public class ProcessOutputReader {
    private static final Log log = LogFactory.getLog(ProcessOutputReader.class);

    private PhantomJSProcess process;
    private String processId;
    private CountDownLatch startLatch;
    private volatile boolean confirmed;

    public ProcessOutputReader(PhantomJSProcess process) {
        this.process = process;
        this.processId = process.getId();
        this.startLatch = new CountDownLatch(1);
    }

    public void start() {
        //FIXME is two threads per process too much?  consider stream polling.
        OutputReader outputReader = new OutputReader();
        Thread outputThread = new Thread(outputReader, "JR PhantomJS output " + processId);
        outputThread.setDaemon(true);
        outputThread.start();

        ErrorReader errorReader = new ErrorReader();
        Thread errorThread = new Thread(errorReader, "JR PhantomJS error " + processId);
        errorThread.setDaemon(true);
        errorThread.start();
    }

    public boolean waitConfirmation(int processStartTimeout) {
        try {
            boolean done = startLatch.await(processStartTimeout, TimeUnit.MILLISECONDS);
            if (log.isDebugEnabled()) {
                log.debug(processId + " done " + done + ", confirmed " + confirmed);
            }
            return confirmed;
        } catch (InterruptedException e) {
            throw new JRRuntimeException(e);
        }
    }

    protected void signalEnd() {
        process.signalEnd();

        if (!confirmed) {
            startLatch.countDown();
        }
    }

    private class OutputReader implements Runnable {
        @Override
        public void run() {
            InputStream processInput = process.getProcess().getInputStream();
            try (BufferedReader reader = new BufferedReader(
                    new InputStreamReader(processInput, StandardCharsets.UTF_8))) {
                String line;
                while ((line = reader.readLine()) != null) {
                    if (log.isDebugEnabled()) {
                        log.debug(processId + ": " + line);
                    }

                    if (line.trim().equals(PhantomJSProcess.PHANTOMJS_CONFIRMATION_MESSAGE)) {
                        confirmed = true;
                        startLatch.countDown();
                    }
                }

                if (log.isDebugEnabled()) {
                    log.debug(processId + " stream ended");
                }
            } catch (IOException e) {
                log.error(processId + " error reading phantomjs output", e);
            } finally {
                signalEnd();
            }
        }
    }

    private class ErrorReader implements Runnable {
        @Override
        public void run() {
            InputStream processInput = process.getProcess().getErrorStream();
            try (BufferedReader reader = new BufferedReader(
                    new InputStreamReader(processInput, StandardCharsets.UTF_8))) {
                String line;
                while ((line = reader.readLine()) != null) {
                    log.error("PhantomJS " + processId + " error: " + line);
                }

                if (log.isDebugEnabled()) {
                    log.debug(processId + " error stream ended");
                }
            } catch (IOException e) {
                log.error(processId + " error reading phantomjs output", e);
            } finally {
                signalEnd();
            }
        }
    }

}