欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页

redis应用于缓存

程序员文章站 2022-03-22 21:22:23
...
import redis.clients.jedis.Jedis;
public class RedisJava {
private static String host = "192.168.1.101";

public static void main(String[] args) {
//isServerRunning();

// set(); //1.保存放键/值对

// setSigleList(); //2.保存List

// getRedisServerAllKeys(); //3.获取所有的key

// setSingleMap(); //4.保存Map

//setObject(); //5.保存序列化的对象

setObjectWithTimeout(); //6.保存序列化的对象并设置超时时间

//setJson(); //
}

private static void isServerRunning(){
  //连接本地的 Redis 服务
      Jedis jedis = new Jedis(host);
      System.out.println("Connection to server sucessfully");
      //查看服务是否运行
      System.out.println("Server is running: "+jedis.ping());
}

static void set(){
//连接本地的 Redis 服务
      Jedis jedis = new Jedis(host);
      System.out.println("Connection to server sucessfully");
      //设置 redis 字符串数据
      jedis.set("w3ckey", "Redis tutorial");
     // 获取存储的数据并输出
     System.out.println("Stored string in redis:: "+ jedis.get("w3ckey"));
}

static void setSigleList(){
//连接本地的 Redis 服务
      Jedis jedis = new Jedis(host);
      System.out.println("Connection to server sucessfully");
      //存储数据到列表中
      jedis.lpush("tutorial-list", "Redis");
      jedis.lpush("tutorial-list", "Mongodb");
      jedis.lpush("tutorial-list", "Mysql");
     
      jedis.lpush("tutorial-list", "Mysql2");
      jedis.lpush("tutorial-list", "Mysql3");
      jedis.lpush("tutorial-list", "Mysql4");
      jedis.lpush("tutorial-list", "Mysql5");
     // 获取存储的数据并输出
     List<String> list = jedis.lrange("tutorial-list", 0 ,2);
     for(int i=0; i<list.size(); i++) {
       System.out.println("Stored string in redis:: "+list.get(i));
     }
    
     System.out.println();
     list = jedis.lrange("tutorial-list", 1, 2);
     for(int i=0; i<list.size(); i++) {
       System.out.println("Stored string in redis:: "+list.get(i));
     }
    
     String val = jedis.lpop("tutorial-list"); //移除list.get(0)并返回值
     System.out.println("list.get(0): "+val);
    
     for(int i=0; i<list.size(); i++) {
       System.out.println("Stored string in redis:: "+list.get(i));
}
}

static void getRedisServerAllKeys(){
//连接本地的 Redis 服务
      Jedis jedis = new Jedis(host);
      System.out.println("Connection to server sucessfully");
     
     // 获取数据并输出
     Set<String> list = jedis.keys("*");
     String key = null;
     for(Iterator it = list.iterator(); it.hasNext();) {
       key = (String)it.next();
       System.out.println("List of stored keys:: "+key);
     }
}

static void setSingleMap(){
Jedis jedis = new Jedis(host);
Map<String, String> map = new HashMap<String, String>();
map.put("name", "fujianchao");
map.put("password", "123");
map.put("age", "12");
// 存入一个map
jedis.hmset("user", map);
// map key的个数
System.out.println("map的key的个数" + jedis.hlen("user"));
// map key
System.out.println("map的key" + jedis.hkeys("user"));
// map value
System.out.println("map的value" + jedis.hvals("user"));
// (String key, String... fields)返回值是一个list
List<String> list = jedis.hmget("user", "age", "name");
System.out.println("redis中key的各个 fields值:"
+ jedis.hmget("user", "age", "name") + list.size());
// 删除map中的某一个键 的值 password
// 当然 (key, fields) 也可以是多个fields
jedis.hdel("user", "age");
System.out.println("删除后map的key" + jedis.hkeys("user"));

jedis.hset("user", "num", "100");
System.out.println("新增后map的key" + jedis.hkeys("user"));
}

static void setObject(){
Jedis jedis = new Jedis(host);

User user = new User();
user.setName("张三");
user.setId(1000);

jedis.set("user1".getBytes(), SerializationUtil.serialize(user));

byte[] val = jedis.get("user1".getBytes());
User u1 = (User)SerializationUtil.deserialize(val);
System.out.println(u1.getName());
}

//redis缓存
static void setObjectWithTimeout(){
Jedis jedis = new Jedis(host);

User user = new User();
user.setName("张三");
user.setId(1000);

jedis.set("user1".getBytes(), SerializationUtil.serialize(user));
int timeout=2;
jedis.expire("user1".getBytes(), timeout); //2秒过期

byte[] val = jedis.get("user1".getBytes());
User u1 = (User)SerializationUtil.deserialize(val);
System.out.println(u1.getName());

try {
Thread.currentThread().sleep(3000); //阻塞3秒
} catch (InterruptedException e) {
e.printStackTrace();
}
val = jedis.get("user1".getBytes());
// u1 = (User)SerializationUtil.deserialize(val);
System.out.println(val); //超时值为空
}

}

public class SerializationUtil {
    /**
     * 序列化
     *
     * @param object
     * @return
     */
    public static byte[] serialize(Object object) {
        ObjectOutputStream oos = null;
        ByteArrayOutputStream baos = null;
        try {
            baos = new ByteArrayOutputStream();
            oos = new ObjectOutputStream(baos);
            oos.writeObject(object);
            byte[] bytes = baos.toByteArray();
            return bytes;
        } catch (Exception e) {
        }
        return null;
    }

    /**
     * 反序列化
     *
     * @param bytes
     * @return
     */
    public static Object deserialize(byte[] bytes) {
        ByteArrayInputStream bais = null;
        try {
            bais = new ByteArrayInputStream(bytes);
            ObjectInputStream ois = new ObjectInputStream(bais);
            return ois.readObject();
        } catch (Exception e) {

        }
        return null;
    }

}
相关标签: redis