第五章 MyEclipse配置hadoop开发环境

1.首先要下载相应的hadoop版本的插件，我这里就给2个例子：

hadoop-1.2.1插件：http://download.csdn.net/download/hanyongan300/6238153

hadoop2.2.0插件：http://blog.csdn.net/twlkyao/article/details/17334693

上一章我也讲了怎么制作相应版本的插件，这些插件可以在网上搜到

2.把插件拷贝到myeclipse根目录下/dropins目录下。

3、 启动myeclipse，打开Perspective：

【Window】->【Open Perspective】->【Other...】->【Map/Reduce】->【OK】

3、 打开一个View：

【Window】->【Show View】->【Other...】->【MapReduce Tools】->【Map/Reduce Locations】->【OK】

4、 添加Hadoop location：

location name: 我填写的是：hadoop，这个可以任意填写

Map/Reduce Master 这个框里：

这两个参数就是mapred-site.xml里面mapred.job.tracker里面的ip和port

Host：就是jobtracker 所在的集群机器，这里写192.168.0.155，我这个myeclipse是在windows下的，所以去连接liunx下的hadoop要写地址
Hort：就是jobtracker 的port，这里写的是9001

DFS Master 这个框里

这两个参数就是core-site.xml里面fs.default.name里面的ip和port
Host：就是namenode所在的集群机器，这里写192.168.0.155
Port：就是namenode的port，这里写9000

（Use M/R master host，这个复选框如果选上，就默认和Map/Reduce Master这个框里的host一样，如果不选择，就可以自己定义输入，这里jobtracker 和namenode在一个机器上，所以是一样的，就勾选上）

user name：这个是连接hadoop的用户名，我创建的用户就是hadoop。

然后继续填写advanced parameters

在这里只需要填写  hadoop.tmp.dir这一栏，跟在core-site.xml里面配置写的一样

然后关闭myeclipse重启，就可以看到连接成功了。。。

连接DFS，是为了帮助你查看hdfs目录的，在这里，你可以直接操作hdfs.点击右键：

create new directory:创建文件

Refresh:刷新

upload files to DFS:上传文本

upload directory to DFS:上传文件夹

如果要是创建hadoop项目，先配置下：Window------preferences----Hadoop Map/Reduce,指定本地的hadoop

然后在本地配置远程hadoop的IP，打开C:\Windows\System32\drivers\etc\hosts文件，添加hadoop所安装的服务器IP和主机名

下面就可以在myeclipse创建mapreduce项目了，file----new Prokect-----

下面就正常写代码：下面是操作hase的代码

package hbase;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.Get;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
import org.apache.hadoop.hbase.util.Bytes;

/**
 * 对hbase进行增删改查
 * @author Administrator
 *
 */
public class HbaseTest {
    private static Configuration conf=null;
    static{
        conf=HBaseConfiguration.create();
        conf.set("hbase.zookeeper.property.clientPort", "2181");
        conf.set("hbase.zookeeper.quorum", "192.168.0.26");
        //configuration.set("hbase.master", "192.168.1.25:6000");
        File workaround = new File(".");
        System.getProperties().put("hadoop.home.dir",
                workaround.getAbsolutePath());
        new File("./bin").mkdirs();
        try {
            new File("./bin/winutils.exe").createNewFile();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    /**
     * 创建一张表
     * @param tablename
     * @param cfg
     * @throws IOException
     */

    public static void createTable(String tablename,String[] cfg)
            throws IOException{
        HBaseAdmin admin=new HBaseAdmin(conf);
        if(admin.tableExists(tablename)){
            System.out.println("表已经存在！");
        }else{
            HTableDescriptor tableDesc=new HTableDescriptor(tablename);
            for(int i=0;i<cfg.length;i++){
                tableDesc.addFamily(new HColumnDescriptor(cfg[i]));
                }
            admin.createTable(tableDesc);
            System.out.println("表创建成功！");
        }
    }
    /**
     * 删除表
     * @param tablename
     * @throws IOException

     */
    public static void deleteTable(String tablename)
            throws IOException{
        HBaseAdmin admin=new HBaseAdmin(conf);
        admin.disableTable(tablename);
        admin.deleteTable(tablename);
        System.out.println("表删除成功");
    }
    /**
     * 插入一行记录
     * @param tablename
     * @param rowkey
     * @param family
     * @param qualifier
     * @param value
     */
    public static void writeRow(String tablename,String rowkey,String family,String qualifier,String value) {
        try {
            HTable table=new HTable(conf,tablename);
            Put put =new Put(Bytes.toBytes(rowkey));
            put.add(Bytes.toBytes(family),Bytes.toBytes(qualifier),Bytes.toBytes(value));
                table.put(put);
            System.out.println("插入数据成功");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
    /**
     * 查找开始与结束之间的数据
     * @param tableName
     */
     public static void getAll(String tableName) {
         try{
             HTable table = new HTable(conf, tableName);
             Scan scan = new Scan(Bytes.toBytes("a"), Bytes.toBytes("z"));
//             scan.addColumn(Bytes.toBytes("a"), Bytes.toBytes("z"));
//             SingleColumnValueFilter filter = new SingleColumnValueFilter(Bytes.toBytes("a"),
//                     Bytes.toBytes("z"),
//                     CompareOp.NOT_EQUAL, Bytes.toBytes("0"));
//             filter.setFilterIfMissing(true);
//             scan.setFilter(filter);  

             ResultScanner ss = table.getScanner(scan);
             for(Result r:ss){
                 for(KeyValue kv : r.raw()){
                     System.out.print("rowid为："+new String(kv.getRow()) + " ");
                     System.out.print("列族为："+new String(kv.getFamily()) + " ");
                     System.out.print("列限定符为："+new String(kv.getQualifier()) + " ");
                     System.out.print("时间戳"+kv.getTimestamp() + " ");
                     System.out.println("值为"+new String(kv.getValue()));
                 }
             }
         } catch (IOException e){
             e.printStackTrace();    

         }
     }
    /**
     * 查找一行记录
     * @param tablename
     * @param rowKey
     * @throws IOException
     */
    @SuppressWarnings("deprecation")
    public static void getOne(String tablename,String rowKey) throws IOException{
        HTable table = new HTable(conf, tablename);
        Get get = new Get(rowKey.getBytes());
        Result rs = table.get(get);
        for(KeyValue kv : rs.raw()){
            System.out.print(new String(kv.getRow()) + " " );
            System.out.print(new String(kv.getFamily()) + ":" );
            System.out.print(new String(kv.getQualifier()) + " " );
            System.out.print(kv.getTimestamp() + " " );
            System.out.println(new String(kv.getValue()));
        }    

    }
    /**
     * 显示所有数据
     */
     public static void getAllRecord (String tableName) {
         try{
             HTable table = new HTable(conf, tableName);
             Scan s = new Scan();
             ResultScanner ss = table.getScanner(s);
             for(Result r:ss){
                 for(KeyValue kv : r.raw()){
                     System.out.print("rowid为："+new String(kv.getRow()) + " ");
                     System.out.print("列族为："+new String(kv.getFamily()) + " ");
                     System.out.print("列限定符为："+new String(kv.getQualifier()) + " ");
                     System.out.print("时间戳"+kv.getTimestamp() + " ");
                     System.out.println("值为"+new String(kv.getValue()));
                 }
             }
         } catch (IOException e){
             e.printStackTrace();    

         }
     }
     /**
      * 删除一行记录
      */
      public static void delRecord (String tableName, String rowKey) throws IOException{
          HTable table = new HTable(conf, tableName);
          List list = new ArrayList();
          Delete del = new Delete(rowKey.getBytes());
          list.add(del);
          table.delete(list);
          System.out.println("del recored " + rowKey + " ok.");
      }    

    public static void main(String[] agrs){
        String tablename="score";
        String[] familys={"grade","course"};
                    try {
                        HbaseTest.createTable(tablename, familys);
                        //HbaseTest.delvalue(tablename, "zkb","course" , "click", "90");
//                        HbaseTest.delRecord(tablename, "zkb");

                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }

//            HbaseTest.writeRow(tablename, "zkb", "grade", "title", "5");
//            HbaseTest.writeRow(tablename, "zkb", "course", "click", "90");
//            HbaseTest.writeRow(tablename, "zkb", "course", "url", "97");
//            HbaseTest.writeRow(tablename, "zkb", "course", "author", "87");
//
//            HbaseTest.writeRow(tablename, "baoniu", "grade", "reply", "4");
//            HbaseTest.writeRow(tablename, "baoniu", "course", "siteName", "89");
//            HbaseTest.writeRow(tablename, "1", "grade", "title", "5");
//            HbaseTest.writeRow(tablename, "1", "course", "click", "90");
//            HbaseTest.writeRow(tablename, "2", "course", "url", "97");
//            HbaseTest.writeRow(tablename, "2", "course", "author", "87");
//
//            HbaseTest.writeRow(tablename, "3", "grade", "reply", "4");
//            HbaseTest.writeRow(tablename, "3", "course", "siteName", "89");
//            HbaseTest.getOne(tablename, "zkb");
//            HbaseTest.getAllRecord(tablename);   

//        HbaseTest.getAllRecord(tablename);
        HbaseTest.getAll(tablename);

    }

}