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ActiveMQ example source code file (CreateCommand.java)

This example ActiveMQ source code file (CreateCommand.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 - ActiveMQ tags/keywords

activemq_base, activemq_home, base_sub_dirs, creating, dom, file, file, filechannel, io, ioexception, ioexception, nio, param, parser, prg, prg, string, string, xml, xpath

The ActiveMQ CreateCommand.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.activemq.console.command;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;

public class CreateCommand extends AbstractCommand {

    protected final String[] helpFile = new String[] {
        "Task Usage: Main create path/to/brokerA [create-options]",
        "Description:  Creates a runnable broker instance in the specified path.",
        "",
        "List Options:",
        "    --amqconf <file path>   Path to ActiveMQ conf file that will be used in the broker instance. Default is: conf/activemq.xml",
        "    --version               Display the version information.",
        "    -h,-?,--help            Display the create broker help information.",
        ""
    };

    protected final String DEFAULT_TARGET_ACTIVEMQ_CONF = "conf/activemq.xml"; // default activemq conf to create in the new broker instance
    protected final String DEFAULT_BROKERNAME_XPATH = "/beans/broker/@brokerName"; // default broker name xpath to change the broker name

    protected final String[] BASE_SUB_DIRS = { "bin", "conf" }; // default sub directories that will be created
    protected final String BROKER_NAME_REGEX = "[$][{]brokerName[}]"; // use to replace broker name property holders

    protected String amqConf = "conf/activemq.xml"; // default conf if no conf is specified via --amqconf

    // default files to copy from activemq home to the new broker instance
    protected String[][] fileCopyMap = {
        { "conf/log4j.properties", "conf/log4j.properties" },
        { "conf/broker.ks", "conf/broker.ks" },
        { "conf/broker.ts", "conf/broker.ts" },
        { "conf/camel.xml", "conf/camel.xml" },
        { "conf/jetty.xml", "conf/jetty.xml" },
        { "conf/jetty-realm.properties", "conf/jetty-realm.properties" },
        { "conf/credentials.properties", "conf/credentials.properties" }
    };

    // default files to create 
    protected String[][] fileWriteMap = {
        { "winActivemq", "bin/${brokerName}.bat" },
        { "unixActivemq", "bin/${brokerName}" }
    };


    protected String brokerName;
    protected File amqHome;
    protected File targetAmqBase;

    protected void runTask(List<String> tokens) throws Exception {
        context.print("Running create broker task...");
        amqHome = new File(System.getProperty("activemq.home"));
        for (String token : tokens) {

            targetAmqBase = new File(token);
            brokerName = targetAmqBase.getName();
            

            if (targetAmqBase.exists()) {
                BufferedReader console = new BufferedReader(new InputStreamReader(System.in));
                String resp;
                while (true) {
                    context.print("Target directory (" + targetAmqBase.getCanonicalPath() + ") already exists. Overwrite (y/n): ");
                    resp = console.readLine();
                    if (resp.equalsIgnoreCase("y") || resp.equalsIgnoreCase("yes")) {
                        break;
                    } else if (resp.equalsIgnoreCase("n") || resp.equalsIgnoreCase("no")) {
                        return;
                    }
                }
            }

            context.print("Creating directory: " + targetAmqBase.getCanonicalPath());
            targetAmqBase.mkdirs();
            createSubDirs(targetAmqBase, BASE_SUB_DIRS);
            writeFileMapping(targetAmqBase, fileWriteMap);
            copyActivemqConf(amqHome, targetAmqBase, amqConf);
            copyFileMapping(amqHome, targetAmqBase, fileCopyMap);
        }
    }

    /**
     * Handle the --amqconf options.
     *
     * @param token  - option token to handle
     * @param tokens - succeeding command arguments
     * @throws Exception
     */
    protected void handleOption(String token, List<String> tokens) throws Exception {
        if (token.startsWith("--amqconf")) {
            // If no amqconf specified, or next token is a new option
            if (tokens.isEmpty() || tokens.get(0).startsWith("-")) {
                context.printException(new IllegalArgumentException("Attributes to amqconf not specified"));
                return;
            }

            amqConf = tokens.remove(0);
        } else {
            // Let super class handle unknown option
            super.handleOption(token, tokens);
        }
    }

    protected void createSubDirs(File target, String[] subDirs) throws IOException {
        File subDirFile;
        for (String subDir : BASE_SUB_DIRS) {
            subDirFile = new File(target, subDir);
            context.print("Creating directory: " + subDirFile.getCanonicalPath());
            subDirFile.mkdirs();
        }
    }

    protected void writeFileMapping(File targetBase, String[][] fileWriteMapping) throws IOException {
        for (String[] fileWrite : fileWriteMapping) {
            File dest = new File(targetBase, resolveParam(BROKER_NAME_REGEX, brokerName, fileWrite[1]));
            context.print("Creating new file: " + dest.getCanonicalPath());
            writeFile(fileWrite[0], dest);
        }
    }

    protected void copyFileMapping(File srcBase, File targetBase, String[][] fileMapping) throws IOException {
        for (String[] fileMap : fileMapping) {
            File src = new File(srcBase, fileMap[0]);
            File dest = new File(targetBase, resolveParam(BROKER_NAME_REGEX, brokerName, fileMap[1]));
            context.print("Copying from: " + src.getCanonicalPath() + "\n          to: " + dest.getCanonicalPath());
            copyFile(src, dest);
        }
    }

    protected void copyActivemqConf(File srcBase, File targetBase, String activemqConf) throws IOException, ParserConfigurationException, SAXException, TransformerException, XPathExpressionException {
        File src = new File(srcBase, activemqConf);

        if (!src.exists()) {
            throw new FileNotFoundException("File: " + src.getCanonicalPath() + " not found.");
        }

        File dest = new File(targetBase, DEFAULT_TARGET_ACTIVEMQ_CONF);
        context.print("Copying from: " + src.getCanonicalPath() + "\n          to: " + dest.getCanonicalPath());

        DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Element docElem = builder.parse(src).getDocumentElement();

        XPath xpath = XPathFactory.newInstance().newXPath();
        Attr brokerNameAttr = (Attr) xpath.evaluate(DEFAULT_BROKERNAME_XPATH, docElem, XPathConstants.NODE);
        brokerNameAttr.setValue(brokerName);

        writeToFile(new DOMSource(docElem), dest);
    }

    protected void printHelp() {
        context.printHelp(helpFile);
    }

    // write the default files to create (i.e. script files)
    private void writeFile(String typeName, File dest) throws IOException {
        String data;
        if (typeName.equals("winActivemq")) {
            data = winActivemqData;
            data = resolveParam("[$][{]activemq.home[}]", amqHome.getCanonicalPath().replaceAll("[\\\\]", "/"), data);
            data = resolveParam("[$][{]activemq.base[}]", targetAmqBase.getCanonicalPath().replaceAll("[\\\\]", "/"), data);
        } else if (typeName.equals("unixActivemq")) {
            data = unixActivemqData;
            data = resolveParam("[$][{]activemq.home[}]", amqHome.getCanonicalPath().replaceAll("[\\\\]", "/"), data);
            data = resolveParam("[$][{]activemq.base[}]", targetAmqBase.getCanonicalPath().replaceAll("[\\\\]", "/"), data);
        } else {
            throw new IllegalStateException("Unknown file type: " + typeName);
        }

        ByteBuffer buf = ByteBuffer.allocate(data.length());
        buf.put(data.getBytes());
        buf.flip();

        FileChannel destinationChannel = new FileOutputStream(dest).getChannel();
        destinationChannel.write(buf);
        destinationChannel.close();

        // Set file permissions available for Java 6.0 only
//        dest.setExecutable(true);
//        dest.setReadable(true);
//        dest.setWritable(true);
    }

    // utlity method to write an xml source to file
    private void writeToFile(Source src, File file) throws TransformerException {
        TransformerFactory tFactory = TransformerFactory.newInstance();
        Transformer fileTransformer = tFactory.newTransformer();

        Result res = new StreamResult(file);
        fileTransformer.transform(src, res);
    }

    // utility method to copy one file to another
    private void copyFile(File from, File dest) throws IOException {
        if (!from.exists()) {
            return;
        }
        FileChannel sourceChannel = new FileInputStream(from).getChannel();
        FileChannel destinationChannel = new FileOutputStream(dest).getChannel();
        sourceChannel.transferTo(0, sourceChannel.size(), destinationChannel);
        sourceChannel.close();
        destinationChannel.close();
    }

    // replace a property place holder (paramName) with the paramValue
    private String resolveParam(String paramName, String paramValue, String target) {
        return target.replaceAll(paramName, paramValue);
    }

    // Embedded windows script data
    private static final String winActivemqData =
        "@echo off\n"
            + "set ACTIVEMQ_HOME=\"${activemq.home}\"\n"
            + "set ACTIVEMQ_BASE=\"${activemq.base}\"\n"
            + "\n"
            + "set PARAM=%1\n"
            + ":getParam\n"
            + "shift\n"
            + "if \"%1\"==\"\" goto end\n"
            + "set PARAM=%PARAM% %1\n"
            + "goto getParam\n"
            + ":end\n"
            + "\n"
            + "%ACTIVEMQ_HOME%/bin/activemq %PARAM%";


    // Embedded unix script data
    private static final String unixActivemqData = "## Figure out the ACTIVEMQ_BASE from the directory this script was run from\n"
        + "PRG=\"$0\"\n"
        + "progname=`basename \"$0\"`\n"
        + "saveddir=`pwd`\n"
        + "# need this for relative symlinks\n"
        + "dirname_prg=`dirname \"$PRG\"`\n"
        + "cd \"$dirname_prg\"\n"
        + "while [ -h \"$PRG\" ] ; do\n"
        + "  ls=`ls -ld \"$PRG\"`\n"
        + "  link=`expr \"$ls\" : '.*-> \\(.*\\)$'`\n"
        + "  if expr \"$link\" : '.*/.*' > /dev/null; then\n"
        + "    PRG=\"$link\"\n"
        + "  else\n"
        + "    PRG=`dirname \"$PRG\"`\"/$link\"\n"
        + "  fi\n"
        + "done\n"
        + "ACTIVEMQ_BASE=`dirname \"$PRG\"`/..\n"
        + "cd \"$saveddir\"\n"
        + "\n"
        + "ACTIVEMQ_BASE=`cd \"$ACTIVEMQ_BASE\" && pwd`\n\n"
        + "export ACTIVEMQ_HOME=${activemq.home}\n"
        + "export ACTIVEMQ_BASE=$ACTIVEMQ_BASE\n\n"
        + "${ACTIVEMQ_HOME}/bin/activemq \"$*\"";

}

Other ActiveMQ examples (source code examples)

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