Redis学习笔记二

学习Redis添加Object时，由于Redis只能存取字符串String，对于其它数据类型形容：Int，long，double,Date等不提供支持，因而需要设计到对象的序列化和反序列化.java序列化的过程就是将对象转变为byte，字节码的过程. Java的反序列过程就是就是将字节码恢复成对象的过程。

一正一逆，也迎合了电脑存储数据的特点。

关于Java的序列化和反序列化的Demo：

 package hbut.base;

 import org.junit.Test;

 import java.io.*;

 /**
  * @Author XiJun.Gong
  * @DATE 2016/6/12.
  * aim:   hbut.base
  * function: 对象的序列化和反序列
  */
 public class serializableDemo {

     private User user = null;
     private ByteArrayOutputStream byteArrayOutputStream = null;
     private ObjectOutputStream outputStream = null;
     private ObjectInputStream inputStream = null;
     private ByteArrayInputStream byteArrayInputStream = null;
     private byte[] result;

     @Test
     public void test() {
         user = new User();
         user.setUsername("huifeidmeng");
         user.setAge();

         try {
             byteArrayOutputStream = new ByteArrayOutputStream();
             outputStream = new ObjectOutputStream(byteArrayOutputStream);
             outputStream.writeObject(user);
             result = byteArrayOutputStream.toByteArray();
         } catch (IOException e1) {
             e1.printStackTrace();
         } finally {
             try {
                 if (outputStream != null) outputStream.close();
                 if (byteArrayOutputStream != null) byteArrayOutputStream.close();
             } catch (IOException e2) {
                 e2.printStackTrace();
             }
         }
         /*tmp sout*/
         System.out.println(result);
         User tmpUser = new User();
         try {
             byteArrayInputStream = new ByteArrayInputStream(result);
             inputStream = new ObjectInputStream(byteArrayInputStream);
             tmpUser = (User) inputStream.readObject();
         } catch (IOException e) {
             e.printStackTrace();
         } catch (ClassNotFoundException e3) {
             e3.printStackTrace();
         } finally {
             try {
                 if (byteArrayInputStream != null) byteArrayInputStream.close();
                 if (inputStream != null) inputStream.close();
             } catch (IOException e4) {
                 e4.printStackTrace();
             }

         }
         System.out.println(tmpUser.getUsername() + ":   " + tmpUser.getAge());
     }

 }

 class User implements Serializable {
     private static final long serialVersionUID = -1941046831377985500L;
     String username;
     Integer age;

     public User() {
     }

     public String getUsername() {
         return username;
     }

     public void setUsername(String username) {
         this.username = username;
     }

     public Integer getAge() {
         return age;
     }

     public void setAge(Integer age) {
         this.age = age;
     }
 }

在编写demo的过程中，发现一个问题，当使用内部类作为对象的的时候，序列化总是抛出异常，但是一旦将User类迁出的时候，又恢复正常。

关于序列化和反序列工具类Dmeo:

 package com.hbut.util;

 import java.io.*;

 /**
  * @Author XiJun.Gong
  * @DATE 2016/6/13.
  * aim:   com.hbut.util
  */
 public class SerializableTool {

     private ByteArrayOutputStream byteArrayOutputStream = null;
     private ObjectOutputStream outputStream = null;
     private ObjectInputStream inputStream = null;
     private ByteArrayInputStream byteArrayInputStream = null;

     public byte[] serializable(Object object) {
         byte[] result = null;
         try {
             byteArrayOutputStream = new ByteArrayOutputStream();
             outputStream = new ObjectOutputStream(byteArrayOutputStream);
             outputStream.writeObject(object);
             result = byteArrayOutputStream.toByteArray();
         } catch (IOException e1) {
             e1.printStackTrace();
         } finally {
             try {
                 if (outputStream != null) outputStream.close();
                 if (byteArrayOutputStream != null) byteArrayOutputStream.close();
             } catch (IOException e2) {
                 e2.printStackTrace();
             }
         }
         return result;
     }

     public Object unSerializable(byte[] bytes) {
         Object object = null;
         try {
             byteArrayInputStream = new ByteArrayInputStream(bytes);
             inputStream = new ObjectInputStream(byteArrayInputStream);
             object = inputStream.readObject();
         } catch (IOException e) {
             e.printStackTrace();
         } catch (ClassNotFoundException e3) {
             e3.printStackTrace();
         } finally {
             try {
                 if (byteArrayInputStream != null) byteArrayInputStream.close();
                 if (inputStream != null) inputStream.close();
             } catch (IOException e4) {
                 e4.printStackTrace();
             }
         }
         return object;
     }
 }

Redis存取对象和读取对象Demo

 class UserModel implements Serializable {

     private String username;
     private String password;
     private Integer age;

     @Override
     public String toString() {
         return "UserModel{" +
                 "username='" + username + '\'' +
                 ", password='" + password + '\'' +
                 ", age=" + age +
                 '}';
     }

     public UserModel() {

     }

     public Integer getAge() {
         return age;
     }

     public void setAge(Integer age) {
         this.age = age;
     }

     public String getUsername() {

         return username;
     }

     public void setUsername(String username) {
         this.username = username;
     }

     public String getPassword() {
         return password;
     }

     public void setPassword(String password) {
         this.password = password;
     }
 }

该是这部分的继续：

启动Redis服务器，后运行如下代码：

 package com.hbut.util;

 import com.google.common.collect.Maps;
 import org.junit.Before;
 import org.junit.Test;
 import redis.clients.jedis.Jedis;
 import redis.clients.jedis.JedisPool;
 import redis.clients.jedis.JedisPoolConfig;

 import java.io.Serializable;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;

 /**
  * Created by XiJun.Gong on 14-2-28.
  */
 public class TestRedis {

     JedisPool pool;
     Jedis jedis;

     /**
      * connection
      */
     @Before
     public void init() {
         pool = new JedisPool(new JedisPoolConfig(), "localhost");
         jedis = pool.getResource();
         //jedis.auth("*******"); //密码验证
     }

     /**
      * for object*
      */
     @Test
     public void testObject() {

         SerializableTool serializableTool = new SerializableTool();
         UserModel userModel = new UserModel();
         userModel.setAge(123);
         userModel.setUsername("huifeidmeng");
         userModel.setPassword("******");
         byte[] bytes = serializableTool.serializable(userModel);
         jedis.set("useModel".getBytes(), bytes);
         byte[] result = jedis.get("useModel".getBytes());
         Object object = serializableTool.unSerializable(result);
         UserModel tmpUser = (UserModel) object;
         System.out.println(tmpUser.toString());
     }

 }

运行结果：

UserModel{username='huifeidmeng', password='******', age=123}