本篇内容主要讲解“redis存储对象方法的比较”,感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷,实用性强。下面就让小编来带大家学习“redis存储对象方法的比较”吧!
redis 存储对象的方法对比
问题背景:
原来项目里面全部是直接redis存储对象的json数据,需要频繁的序列化和反序列化,后来考虑更换项目中的redis存储对象为hash对象存储的,但是获取后不能方便的set get操作,很是蛋疼,怎么才能解决这个问题呢?
1.1 直接存储对象的json
存放redis的时候,直接先用fastJson 或者 jackJson或者Gson把对象序列化为json数据,然后用直接存放,key表示用户id或许和openid,value则是对象的json数据
public String get(String key) {Object value = redisTemplate.boundValueOps(key).get();return (String) value;}public void set(String key, String json) {if (json == null) {return;}redisTemplate.boundValueOps(key).set(json);}
优点:虽然需要序列化和反序列化,但是可以直接操作对象的方法,方便快捷
缺点:需要序列化和反序列化,并且修改单个字段,需要获取整个json,修改后,序列化保存,浪费空间,浪费时间,效率低
1.2 采用redis hash key field value 存储
key代表主键,比如用户id,或者openId,value是一个map,对应各个字段的属性和值
存放单个字段
public void hset(String key, String field, String obj) {redisTemplate.boundHashOps(key).put(field,obj);}
存放整个:
public void hSetMap(String key,Map<Object,Object> map){redisTemplate.boundHashOps(key).putAll(map);}
优点:存储方方便,节省内存空间,并且可以直接对单个字段修改,而不用获取整个对象,效率高
缺点:获取value后,是个map,不能方便的直接调用(set get)处理,需要手动map.get(filed)或者map.put(field,value)
1.3 如何解决redis hash存储对象的操作方便性问题
其实关于map和pojo的转换问题,网上给出了利用反射做的转换方法,但是加上了转换和反转,这和序列化和反序列化的问题一样了,效率问题,也不敢指直接用,纠结,思考再三,还是先维持代码不动了,以后考虑好了再说,或者广发网友有啥好解决方法,请多多指教哈!
Redis存储对象的三种方式
一、 将对象序列化后保存到Redis
序列化工具类实现
public class SerializeUtil { public static byte[] serizlize(Object object){ ObjectOutputStream oos = null; ByteArrayOutputStream baos = null; try { baos = new ByteArrayOutputStream(); oos = new ObjectOutputStream(baos); oos.writeObject(object); byte[] bytes = baos.toByteArray(); return bytes; } catch (Exception e) { e.printStackTrace(); }finally { try { if(baos != null){ baos.close(); } if (oos != null) { oos.close(); } } catch (Exception e2) { e2.printStackTrace(); } } return null; } public static Object deserialize(byte[] bytes){ ByteArrayInputStream bais = null; ObjectInputStream ois = null; try{ bais = new ByteArrayInputStream(bytes); ois = new ObjectInputStream(bais); return ois.readObject(); }catch(Exception e){ e.printStackTrace(); }finally { try { } catch (Exception e2) { e2.printStackTrace(); } } return null; }}
获取jedis实例
public class RedisConnection { private static String HOST = "127.0.0.1"; private static int PORT = 6379; private static int MAX_ACTIVE = 1024; private static int MAX_IDLE = 200; private static int MAX_WAIT = 10000; private static JedisPool jedisPool = null; private static void initPool(){ try { JedisPoolConfig config = new JedisPoolConfig(); config.setMaxTotal(MAX_ACTIVE);//最大连接数 config.setMaxIdle(MAX_IDLE);//最大空闲连接数 config.setMaxWaitMillis(MAX_WAIT);//获取可用连接的最大等待时间 jedisPool = new JedisPool(config, HOST, PORT); } catch (Exception e) { e.printStackTrace(); } } public synchronized static Jedis getJedis() { try { if(jedisPool == null){ initPool(); } Jedis jedis = jedisPool.getResource(); jedis.auth("redis");//密码 return jedis; } catch (Exception e) { e.printStackTrace(); return null; } }}
redis操作类
public class RedisOps { public static void set(String key,String value){ Jedis jedis = RedisConnection.getJedis(); jedis.set(key, value); jedis.close(); } public static String get(String key){ Jedis jedis = RedisConnection.getJedis(); String value = jedis.get(key); jedis.close(); return value; } public static void setObject(String key,Object object){ Jedis jedis = RedisConnection.getJedis(); jedis.set(key.getBytes(), SerializeUtil.serizlize(object)); jedis.close(); } public static Object getObject(String key){ Jedis jedis = RedisConnection.getJedis(); byte[] bytes = jedis.get(key.getBytes()); jedis.close(); return SerializeUtil.deserialize(bytes); }}
User对象
public class User implements Serializable{ private static final long serialVersionUID = -3210884885630038713L; private int id; private String name; public User(){ } public User(int id,String name){ this.id = id; this.name = name; } //setter和getter方法}
测试
public class RedisTest { @Test public void testString(){ RedisOps.set("user:1", "sisu"); String user = RedisOps.get("user:1"); Assert.assertEquals("sisu", user); } @Test public void testObject(){ RedisOps.setObject("user:2",new User(2,"lumia")); User user = (User)RedisOps.getObject("user:2"); Assert.assertEquals("lumia", user.getName()); } }
二、将对象用FastJSON转为JSON字符串后存储
redis操作类
public class RedisOps { public static void setJsonString(String key,Object object){ Jedis jedis = RedisConnection.getJedis(); jedis.set(key, JSON.toJSONString(object)); jedis.close(); } public static Object getJsonObject(String key,Class clazz){ Jedis jedis = RedisConnection.getJedis(); String value = jedis.get(key); jedis.close(); return JSON.parseObject(value,clazz); }}
测试
@Test public void testObject2(){ RedisOps.setJsonString("user:3", new User(3,"xiaoming")); User user = (User)RedisOps.getJsonObject("user:3",User.class); Assert.assertEquals("xiaoming", user.getName()); }
三、将对象用Hash数据类型存储
redis操作类
public class RedisOps { public static void hSet(String key,String value){ Jedis jedis = RedisConnection.getJedis(); jedis.hSet(key, value); jedis.close(); } public static String hGet(String key){ Jedis jedis = RedisConnection.getJedis(); String value = jedis.hGet(key); jedis.close(); return value; }}
测试
@Test public void testObject3(){ //存 RedisOps.hSet("user:3","id","3"); RedisOps.hSet("user:3","name","xiaoming"); //取 String id = RedisOps..hGet("user:3","id"); String name = RedisOps.hGet("user:3","name"); Assert.assertEquals("3", id); Assert.assertEquals("xiaoming", name); }
到此,相信大家对“redis存储对象方法的比较”有了更深的了解,不妨来实际操作一番吧!这里是编程网网站,更多相关内容可以进入相关频道进行查询,关注我们,继续学习!