java redis使用之利用jedis实现redis消息队列

应用场景

对于数据库查询的IO连接数高、连接频繁的情况，可以考虑使用缓存实现。

从网上了解到redis可以对所有的内容进行二进制的存储，而java是可以对所有对象进行序列化的，序列化的方法会在下面的代码中提供实现。

序列化

这里我编写了一个java序列化的工具，主要是对对象转换成byte[]，和根据byte[]数组反序列化成java对象；

主要是用到了ByteArrayOutputStream和ByteArrayInputStream；

需要注意的是每个自定义的需要序列化的对象都要实现Serializable接口；

其代码如下：

package com.bean.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
public class ObjectUtil {
    /**对象转byte[]
     * @param obj
     * @return
     * @throws IOException
     */
    public static byte[] objectToBytes(Object obj) throws Exception{
        ByteArrayOutputStream bo = new ByteArrayOutputStream();
        ObjectOutputStream oo = new ObjectOutputStream(bo);
        oo.writeObject(obj);
        byte[] bytes = bo.toByteArray();
        bo.close();
        oo.close();
        return bytes;
    }
    /**byte[]转对象
     * @param bytes
     * @return
     * @throws Exception
     */
    public static Object bytesToObject(byte[] bytes) throws Exception{
        ByteArrayInputStream in = new ByteArrayInputStream(bytes);
        ObjectInputStream sIn = new ObjectInputStream(in);
        return sIn.readObject();
    }
}

定义一个消息类，主要用于接收消息内容和消息下表的设置。

package com.bean;

import java.io.Serializable;

/**定义消息类接收消息内容和设置消息的下标
 * @author lenovo
 *
 */
public class Message implements Serializable{
    private static final long serialVersionUID = 7792729L;
    private int id;
    private String content;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
}

用redis做队列，我们采用的是redis中list的push和pop操作；

结合队列的特点：

只允许在一端插入新元素只能在队列的尾部FIFO：先进先出原则

redis中lpush（rpop）或rpush(lpop)可以满足要求，而redis中list 里要push或pop的对象仅需要转换成byte[]即可

java采用Jedis进行redis的存储和redis的连接池设置。

package com.redis.util;

import java.util.List;
import java.util.Map;
import java.util.Set;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

public class JedisUtil {

    private static String JEDIS_IP;
    private static int JEDIS_PORT;
    private static String JEDIS_PASSWORD;
    //private static String JEDIS_SLAVE;

    private static JedisPool jedisPool;

    static {
        Configuration conf = Configuration.getInstance();
        JEDIS_IP = conf.getString("jedis.ip", "127.0.0.1");
        JEDIS_PORT = conf.getInt("jedis.port", 6379);
        JEDIS_PASSWORD = conf.getString("jedis.password", null);
        JedisPoolConfig config = new JedisPoolConfig();
        config.setMaxActive(5000);
        config.setMaxIdle(256);//20
        config.setMaxWait(5000L);
        config.setTestOnBorrow(true);
        config.setTestOnReturn(true);
        config.setTestWhileIdle(true);
        config.setMinEvictableIdleTimeMillis(60000l);
        config.setTimeBetweenEvictionRunsMillis(3000l);
        config.setNumTestsPerEvictionRun(-1);
        jedisPool = new JedisPool(config, JEDIS_IP, JEDIS_PORT, 60000);
    }

    /**
     * 获取数据
     * @param key
     * @return
     */
    public static String get(String key) {

        String value = null;
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            value = jedis.get(key);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }

        return value;
    }

    public static void close(Jedis jedis) {
        try {
            jedisPool.returnResource(jedis);

        } catch (Exception e) {
            if (jedis.isConnected()) {
                jedis.quit();
                jedis.disconnect();
            }
        }
    }

    /**
     * 获取数据
     * 
     * @param key
     * @return
     */
    public static byte[] get(byte[] key) {

        byte[] value = null;
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            value = jedis.get(key);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }

        return value;
    }

    public static void set(byte[] key, byte[] value) {

        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            jedis.set(key, value);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }
    }

    public static void set(byte[] key, byte[] value, int time) {

        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            jedis.set(key, value);
            jedis.expire(key, time);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }
    }

    public static void hset(byte[] key, byte[] field, byte[] value) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            jedis.hset(key, field, value);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }
    }

    public static void hset(String key, String field, String value) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            jedis.hset(key, field, value);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }
    }

    /**
     * 获取数据
     * 
     * @param key
     * @return
     */
    public static String hget(String key, String field) {

        String value = null;
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            value = jedis.hget(key, field);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }

        return value;
    }

    /**
     * 获取数据
     * 
     * @param key
     * @return
     */
    public static byte[] hget(byte[] key, byte[] field) {

        byte[] value = null;
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            value = jedis.hget(key, field);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }

        return value;
    }

    public static void hdel(byte[] key, byte[] field) {

        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            jedis.hdel(key, field);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }
    }

    /**
     * 存储REDIS队列 顺序存储
     * @param byte[] key reids键名
     * @param byte[] value 键值
     */
    public static void lpush(byte[] key, byte[] value) {

        Jedis jedis = null;
        try {

            jedis = jedisPool.getResource();
            jedis.lpush(key, value);

        } catch (Exception e) {

            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {

            //返还到连接池
            close(jedis);

        }
    }

    /**
     * 存储REDIS队列 反向存储
     * @param byte[] key reids键名
     * @param byte[] value 键值
     */
    public static void rpush(byte[] key, byte[] value) {

        Jedis jedis = null;
        try {

            jedis = jedisPool.getResource();
            jedis.rpush(key, value);

        } catch (Exception e) {

            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {

            //返还到连接池
            close(jedis);

        }
    }

    /**
     * 将列表 source 中的最后一个元素(尾元素)弹出，并返回给客户端
     * @param byte[] key reids键名
     * @param byte[] value 键值
     */
    public static void rpoplpush(byte[] key, byte[] destination) {

        Jedis jedis = null;
        try {

            jedis = jedisPool.getResource();
            jedis.rpoplpush(key, destination);

        } catch (Exception e) {

            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {

            //返还到连接池
            close(jedis);

        }
    }

    /**
     * 获取队列数据
     * @param byte[] key 键名
     * @return
     */
    public static List lpopList(byte[] key) {

        List list = null;
        Jedis jedis = null;
        try {

            jedis = jedisPool.getResource();
            list = jedis.lrange(key, 0, -1);

        } catch (Exception e) {

            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {

            //返还到连接池
            close(jedis);

        }
        return list;
    }

    /**
     * 获取队列数据
     * @param byte[] key 键名
     * @return
     */
    public static byte[] rpop(byte[] key) {

        byte[] bytes = null;
        Jedis jedis = null;
        try {

            jedis = jedisPool.getResource();
            bytes = jedis.rpop(key);

        } catch (Exception e) {

            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {

            //返还到连接池
            close(jedis);

        }
        return bytes;
    }

    public static void hmset(Object key, Map hash) {
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            jedis.hmset(key.toString(), hash);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {
            //返还到连接池
            close(jedis);

        }
    }

    public static void hmset(Object key, Map hash, int time) {
        Jedis jedis = null;
        try {

            jedis = jedisPool.getResource();
            jedis.hmset(key.toString(), hash);
            jedis.expire(key.toString(), time);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {
            //返还到连接池
            close(jedis);

        }
    }

    public static List hmget(Object key, String... fields) {
        List result = null;
        Jedis jedis = null;
        try {

            jedis = jedisPool.getResource();
            result = jedis.hmget(key.toString(), fields);

        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {
            //返还到连接池
            close(jedis);

        }
        return result;
    }

    public static Set hkeys(String key) {
        Set result = null;
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            result = jedis.hkeys(key);

        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {
            //返还到连接池
            close(jedis);

        }
        return result;
    }

    public static List lrange(byte[] key, int from, int to) {
        List result = null;
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            result = jedis.lrange(key, from, to);

        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {
            //返还到连接池
            close(jedis);

        }
        return result;
    }

    public static Map hgetAll(byte[] key) {
        Map result = null;
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            result = jedis.hgetAll(key);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();

        } finally {
            //返还到连接池
            close(jedis);
        }
        return result;
    }

    public static void del(byte[] key) {

        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            jedis.del(key);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }
    }

    public static long llen(byte[] key) {

        long len = 0;
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            jedis.llen(key);
        } catch (Exception e) {
            //释放redis对象
            jedisPool.returnBrokenResource(jedis);
            e.printStackTrace();
        } finally {
            //返还到连接池
            close(jedis);
        }
        return len;
    }

}

Configuration主要用于读取redis配置信息

package com.redis.util;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class Configuration extends Properties {

    private static final long serialVersionUID = 50440463580273222L;

    private static Configuration instance = null;

    public static synchronized Configuration getInstance() {
        if (instance == null) {
            instance = new Configuration();
        }
        return instance;
    }

    public String getProperty(String key, String defaultValue) {
        String val = getProperty(key);
        return (val == null || val.isEmpty()) ? defaultValue : val;
    }

    public String getString(String name, String defaultValue) {
        return this.getProperty(name, defaultValue);
    }

    public int getInt(String name, int defaultValue) {
        String val = this.getProperty(name);
        return (val == null || val.isEmpty()) ? defaultValue : Integer.parseInt(val);
    }

    public long getLong(String name, long defaultValue) {
        String val = this.getProperty(name);
        return (val == null || val.isEmpty()) ? defaultValue : Integer.parseInt(val);
    }

    public float getFloat(String name, float defaultValue) {
        String val = this.getProperty(name);
        return (val == null || val.isEmpty()) ? defaultValue : Float.parseFloat(val);
    }

    public double getDouble(String name, double defaultValue) {
        String val = this.getProperty(name);
        return (val == null || val.isEmpty()) ? defaultValue : Double.parseDouble(val);
    }

    public byte getByte(String name, byte defaultValue) {
        String val = this.getProperty(name);
        return (val == null || val.isEmpty()) ? defaultValue : Byte.parseByte(val);
    }

    public Configuration() {
        InputStream in = ClassLoader.getSystemClassLoader().getResourceAsStream("config.xml");
        try {
            this.loadFromXML(in);
            in.close();
        } catch (IOException e) {
        }
    }
}

测试redis队列

package com.quene.test;

import com.bean.Message;
import com.bean.util.ObjectUtil;
import com.redis.util.JedisUtil;

public class TestRedisQuene {
    public static byte[] redisKey = "key".getBytes();
    static{
        init();
    }
    public static void main(String[] args) {
        pop();
    }

    private static void pop() {
        byte[] bytes = JedisUtil.rpop(redisKey);
        Message msg = (Message) ObjectUtil.bytesToObject(bytes);
        if(msg != null){
            System.out.println(msg.getId()+"   "+msg.getContent());
        }
    }

    private static void init() {
        Message msg1 = new Message(1, "内容1");
        JedisUtil.lpush(redisKey, ObjectUtil.objectToBytes(msg1));
        Message msg2 = new Message(2, "内容2");
        JedisUtil.lpush(redisKey, ObjectUtil.objectToBytes(msg2));
        Message msg3 = new Message(3, "内容3");
        JedisUtil.lpush(redisKey, ObjectUtil.objectToBytes(msg3));
    }

}

测试结果如下：

1   内容1
2   内容2
3   内容3