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,MapObject,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 {
/*
* 序列化
* */
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;
}
/*
* 反序列化
* */
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;
/*
* 初始化redis连接池
* */
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();
}
}
/*
* 获取jedis实例
* */
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);
}
以上为个人经验,希望能给大家一个参考,也希望大家多多支持脚本之家。
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