HADOOP-输出数据实体类承载

新建一个bean包：

　　1.实现Writerable

　　2.有一个空的构造方法

代码实现：

 import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;

 import org.apache.hadoop.io.Writable;
 //实现 hadoop中 的 Writable 接口
 public class Phone implements Writable{
     private int up;
     private int down;
     public Phone(int up, int down) {
         this.up = up;
         this.down = down;
     }
     public Phone() { //保留空构造器
     }

     @Override//自定义 格式 tostring
     public String toString() {
         return up + "\t" + down + "\t"+(up+down);
     }
     public int getUp() {
         return up;
     }
     public void setUp(int up) {
         this.up = up;
     }
     public int getDown() {
         return down;
     }
     public void setDown(int down) {
         this.down = down;
     }
     @Override  //重写 两个方法， 按顺序 写和读。
     public void readFields(DataInput input) throws IOException {
         this.up=input.readInt();
         this.down= input.readInt();
     }
     @Override
     public void write(DataOutput output) throws IOException {
         output.writeInt(up);
         output.writeInt(down);
     }
 }