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 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12 内容23 内容3