(转)java redis使用之利用jedis实现redis消息队列
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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
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