org.apache.ambari.client.NodeGet.java Source code

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Here is the source code for org.apache.ambari.client.NodeGet.java

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/*
 * 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.ambari.client;

import java.net.URI;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.UriBuilder;

import org.apache.ambari.common.rest.entities.Node;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;

import com.sun.jersey.api.client.Client;
import com.sun.jersey.api.client.ClientResponse;
import com.sun.jersey.api.client.WebResource;
import com.sun.jersey.api.client.config.ClientConfig;
import com.sun.jersey.api.client.config.DefaultClientConfig;

public class NodeGet extends Command {

    String[] args = null;
    Options options = null;

    CommandLine line;

    public NodeGet() {
    }

    public NodeGet(String[] args) throws Exception {
        /*
         * Build options for node get
         */
        this.args = args;
        addOptions();
    }

    public void printUsage() {
        HelpFormatter formatter = new HelpFormatter();
        formatter.printHelp("ambari node get", this.options);
    }

    public void addOptions() {

        Option help = new Option("help", "Help");

        OptionBuilder.withArgName("node_name");
        OptionBuilder.isRequired();
        OptionBuilder.hasArg();
        OptionBuilder.withDescription("Name of the node");
        Option name = OptionBuilder.create("name");

        this.options = new Options();
        options.addOption(name);
        options.addOption(help);
    }

    public void parseCommandLine() {

        // create the parser
        CommandLineParser parser = new GnuParser();
        try {
            // parse the command line arguments
            line = parser.parse(this.options, this.args);

            if (line.hasOption("help")) {
                printUsage();
                System.exit(0);
            }
        } catch (ParseException exp) {
            // oops, something went wrong
            System.err.println("Command parsing failed. Reason: <" + exp.getMessage() + ">\n");
            printUsage();
            System.exit(-1);
        }
    }

    private static URI getBaseURI() {
        return UriBuilder.fromUri("http://localhost:4080/rest/").build();
    }

    public void run() throws Exception {
        /* 
         * Parse the command line to get the command line arguments
         */
        parseCommandLine();

        ClientConfig config = new DefaultClientConfig();
        Client client = Client.create(config);
        WebResource service = client.resource(getBaseURI());
        String nodeName = line.getOptionValue("name");

        /*
         * Get node
         */
        ClientResponse response;
        response = service.path("nodes/" + nodeName).accept(MediaType.APPLICATION_JSON)
                .type(MediaType.APPLICATION_JSON).get(ClientResponse.class);
        if (response.getStatus() != 200) {
            System.err.println("Node get command failed. Reason [Code: <" + response.getStatus() + ">, Message: <"
                    + response.getHeaders().getFirst("ErrorMessage") + ">]");
            System.exit(-1);
        }

        /* 
         * Retrieve the node Information from the response
         */
        Node node = response.getEntity(Node.class);
        System.out.println("Node Information:\n");
        printNodeInformation(node);
    }
}