HDFS序列化

import java.io.DataInput;
import java.io.DataInputStream;
import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
public class TestWritableComparable {
	
	public static void main(String[] agrs) throws Exception{
		
		Student s = new Student("li",20,"man");
		FileOutputStream fout = new FileOutputStream(
				new File("/usr/local/test.txt"));
		
		DataOutputStream out = new DataOutputStream(fout);
		
		s.write(out);
		
		fout.close();
		
		out.close();
		
		Student s1 = new Student();
		
		FileInputStream  fin = new FileInputStream(
				new File("/usr/local/test.txt"));
		
		DataInputStream in = new DataInputStream(fin);
		
		s1.readFields(in);
		
		System.out.println(s1.toString());
		
	}
}
class Student implements WritableComparable<Student>{
	
	private Text name = new Text();
	private IntWritable age = new IntWritable();
	private Text sex = new Text();
	
	@Override
	public String toString() {
		return "Student [name=" + name + ", age=" + age + ", sex=" + sex + "]";
	}
	public Student() {
		super();
	}
	public Student(String name, int age, String sex) {
		super();
		this.name = new Text(name);
		this.age = new IntWritable(age);
		this.sex = new Text(sex);
	}
	public Text getName() {
		return name;
	}
	public void setName(Text name) {
		this.name = name;
	}
	public IntWritable getAge() {
		return age;
	}
	public void setAge(IntWritable age) {
		this.age = age;
	}
	public Text getSex() {
		return sex;
	}
	public void setSex(Text sex) {
		this.sex = sex;
	}
	@Override
	public void readFields(DataInput in) throws IOException {
		name.readFields(in);
		age.readFields(in);
		sex.readFields(in);
	}
	@Override
	public void write(DataOutput out) throws IOException {
		name.write(out);
		age.write(out);
		sex.write(out);
	}
	@Override
	public int compareTo(Student o) {
		int result = 0;
		if((result = name.compareTo(o.getName())) != 0){
			return result;
		}
		if((result = age.compareTo(o.getAge())) != 0){
			return result;
		}
		if((result = sex.compareTo(o.getSex())) != 0){
			return result;
		}
		return result;
	}
}