應用場景

最近在公司做項目，需要對聊天內容進行存儲，考慮到數據庫查詢的IO連接數高、連接頻繁的因素，決定利用緩存做。

從網上了解到redis可以對所有的內容進行二進制的存儲，而java是可以對所有對象進行序列化的，序列化的方法會在下面的代碼中提供實現。

序列化

這里我編寫了一個java序列化的工具，主要是對對象轉換成byte[]，和根據byte[]數組反序列化成java對象；

主要是用到了ByteArrayOutputStream和ByteArrayInputStream；

需要注意的是每個自定義的需要序列化的對象都要實現Serializable接口；

其代碼如下：

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 {/**對象轉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[]轉對象* @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();} }

定義一個消息類，主要用于接收消息內容和消息下表的設置。

package com.bean;import java.io.Serializable;/**定義消息類接收消息內容和設置消息的下標* @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做隊列，我們采用的是redis中list的push和pop操作；

結合隊列的特點：

• 只允許在一端插入
• 新元素只能在隊列的尾部
• FIFO：先進先出原則

  redis中lpush（rpop）或rpush(lpop)可以滿足要求，而redis中list 里要push或pop的對象僅需要轉換成byte[]即可

  java采用Jedis進行redis的存儲和redis的連接池設置

  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);//20config.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);}/*** 獲取數據* @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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}return value;}public static void close(Jedis jedis) {try {jedisPool.returnResource(jedis);} catch (Exception e) {if (jedis.isConnected()) {jedis.quit();jedis.disconnect();}}}/*** 獲取數據* * @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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}}/*** 獲取數據* * @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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}return value;}/*** 獲取數據* * @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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}}/*** 存儲REDIS隊列 順序存儲* @param byte[] key reids鍵名* @param byte[] value 鍵值*/public static void lpush(byte[] key, byte[] value) {Jedis jedis = null;try {jedis = jedisPool.getResource();jedis.lpush(key, value);} catch (Exception e) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}}/*** 存儲REDIS隊列 反向存儲* @param byte[] key reids鍵名* @param byte[] value 鍵值*/public static void rpush(byte[] key, byte[] value) {Jedis jedis = null;try {jedis = jedisPool.getResource();jedis.rpush(key, value);} catch (Exception e) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}}/*** 將列表 source 中的最后一個元素(尾元素)彈出，并返回給客戶端* @param byte[] key reids鍵名* @param byte[] value 鍵值*/public static void rpoplpush(byte[] key, byte[] destination) {Jedis jedis = null;try {jedis = jedisPool.getResource();jedis.rpoplpush(key, destination);} catch (Exception e) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}}/*** 獲取隊列數據* @param byte[] key 鍵名* @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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}return list;}/*** 獲取隊列數據* @param byte[] key 鍵名* @return*/public static byte[] rpop(byte[] key) {byte[] bytes = null;Jedis jedis = null;try {jedis = jedisPool.getResource();bytes = jedis.rpop(key);} catch (Exception e) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池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) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}return result;}public static void del(byte[] key) {Jedis jedis = null;try {jedis = jedisPool.getResource();jedis.del(key);} catch (Exception e) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}}public static long llen(byte[] key) {long len = 0;Jedis jedis = null;try {jedis = jedisPool.getResource();jedis.llen(key);} catch (Exception e) {//釋放redis對象jedisPool.returnBrokenResource(jedis);e.printStackTrace();} finally {//返還到連接池close(jedis);}return len;}}

  Configuration主要用于讀取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) {}} }

  
  測試redis隊列

  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, "內容1");JedisUtil.lpush(redisKey, ObjectUtil.objectToBytes(msg1));Message msg2 = new Message(2, "內容2");JedisUtil.lpush(redisKey, ObjectUtil.objectToBytes(msg2));Message msg3 = new Message(3, "內容3");JedisUtil.lpush(redisKey, ObjectUtil.objectToBytes(msg3));}} 測試結果如下： 1?? 內容1 2?? 內容2

  3?? 內容3

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

轉載于:https://www.cnblogs.com/yewg/p/5586216.html

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