JavaWeb [Redis] Jedis reads and writes redis and connection pool

JavaWeb [Redis] Jedis reads and writes redis and connection pool

Jedis introduction

• (1) What is Jedis?
  Tools for operating Redis: Jedis
  "" Redis: the name of the database
  " "Jedis: the name of the tool.
  Jedis is also hosted on github, address: https://github.com/xetorthio/jedis .
• (2) How to build Jedis? To
  use Jedis to operate redis, you need to import the jar package as follows
  

Jedis operation

• (1) How to use Jedis?
  Operation steps:
  "1: Create a Jedis object
  " "2: Execute Redis instructions

       //1:创建Jedis对象
        Jedis jedis = new Jedis("localhost", 6379);
        //2:调用方法执行Redis指令(每一条指令，都有一个方法)
        jedis.set("name", "wzx");
        jedis.sadd("mylist","aaa","bbb","ccc");

        String addr = jedis.get("addr");
        System.out.println("addr:"+addr);
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Jdbc connection pool principle

• (1) When do you contact the connection pool?
  Jdbc connection pool
• (2) Connection pool principle
  Frequent creation and destruction of links consumes performance.
  Create a collection and initialize multiple Connections . Call
  getConnection() when needed
  . Call close() and put it back when you are done using it.
• (3) The significance of the connection pool
  Reuse connections and improve performance

Basic implementation of Jedis connection poolOne

• (1) The principle of Jedis connection pool is
  basically similar
  
• (2) Code implementation step
  1: Create the configuration object of the connection pool
  2: Create the connection pool
  3: Get a connection from the connection pool
  4: Execute Redis execute Map<String,String> set get
  5: Release the connection

       //1:创建连接池的配置对象
        JedisPoolConfig config = new JedisPoolConfig();
         //1.1 设置最大连接数
        config.setMaxTotal(30);
        //1.2 设置空闲连接数
        config.setMaxIdle(10);

        //2:创建连接池
        JedisPool pool = new JedisPool(config, "localhost", 6379);

        //3:从连接池中获取一个连接
        Jedis jedis = pool.getResource();

        //4:执行Redis执行
        jedis.set("email", "[email protected]");

        //5:释放连接
        jedis.close();
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Basic implementation of Jedis connection poolOne

• (1) Hard-coded The
  configuration parameters are written in java code and compiled into a class. You must modify the java code in the future to change the configuration. In the
  project, use the configuration file to configure the parameters
• (2) Change to tools plus configuration files

src\com.wzx.pack01_redis\Demo3JedisPool.java

public class Demo3JedisPool {
    
    
    @Test
    public void test01() {
    
    
        Jedis jedis = JedisUtils.getJedis();//调用静态方法
        jedis.set("xxx", "yyyyy");
        jedis.close();
    }
}
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src\jedis.properties

• The properites file configures the parameters, and then the program reads these configuration parameters for the object to use. This is the way that JAVAEE often uses

maxTotal=30
maxIdle=10
url=localhost
port=6379
1234

src \ com.wzx.pack01_redis \ JedisUtils.java

To read the .properties file, you can first use the class loader to load it into a stream, and then use the Properties class to read it.
You can also use ResourceBundleread.propties

public class JedisUtils {
    
    
    private static JedisPool pool = null;
    //1:创建一个连接池
    static{
    
    
        //1.1 解析properties文件
        ResourceBundle bundle = ResourceBundle.getBundle("jedis");
        //获取参数
        String maxTotal = bundle.getString("maxTotal");
        String maxIdle = bundle.getString("maxIdle");
        String url = bundle.getString("url");
        String port = bundle.getString("port");

        //1.2创建连接池
        //1:创建连接池的配置对象
        JedisPoolConfig config = new JedisPoolConfig();
        //1.1 设置最大连接数
        config.setMaxTotal(Integer.parseInt(maxTotal));
        //1.2 设置空闲连接数
        config.setMaxIdle(Integer.parseInt(maxIdle));

        //2:创建连接池
         pool = new JedisPool(config, url, Integer.parseInt(port));
    }

    //2:对外提供一个获取连接的方法
    public static Jedis getJedis(){
    
    
        return  pool.getResource();
    }

    //3:提供释放资源的方法
    public static void close(Jedis jedis){
    
    
        if(jedis != null) {
    
    
            jedis.close();
        }
    }
}