java redis使用之利用jedis实现redis消息队列

应用场景

最近在公司做项目，需要对聊天内容进行存储，考虑到数据库查询的IO连接数高、连接频繁的因素，决定利用缓存做。

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;    }}

利用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<byte[]> lpopList(byte[] key) {        List<byte[]> 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<String, String> 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<String, String> 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<String> hmget(Object key, String... fields) {        List<String> 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<String> hkeys(String key) {        Set<String> 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<byte[]> lrange(byte[] key, int from, int to) {        List<byte[]> 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<byte[], byte[]> hgetAll(byte[] key) {        Map<byte[], byte[]> 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

转自http://www.itnose.net/detail/6284422.html

还有几篇好的文章：
http://www.cnblogs.com/kinglf/p/5972300.html
http://www.jianshu.com/p/9c04890615ba
http://blog.csdn.net/noaman_wgs/article/details/73194700
http://blog.csdn.net/jiuhanfengganlin/article/details/50789994