Redis在SSM框架中最为缓存

爱被打了一巴掌 2022-05-29 06:58 198阅读 0赞

添加缓存在view层和service层均可，建议在service层使用。

在工作中，一般开放连接单机版，在上线时才真正连接集群，为此我们也呈现两种方式。但，无论哪种方式，都一样，只不过xml配置不一样；

创建一个interface：

public interface IRedis {
    	String set(String key,String value);
    	String get(String key);
    	Boolean exists(String key);
    	Long expire(String key,int seconds);
    	Long ttl(String key);
    	Long incr(String key);
    	String hget(String key,String field);
    	Long hset(String key, String field, String value);
    	Long hdel(String key,String... field);
    	Boolean hexistes(String key,String field);
    	List<String> hvals(String key);
    	Long del(String key);
    
    }

一、连接单机版：

1、创建class，集成上面的接口：

`package com.aynu.redis.imp; import java.util.List; import com.aynu.redis.IRedis; import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; public class Redis implements IRedis {`

`//jedis连接池文件 private JedisPool jedispool; public JedisPool getJedispool() { return jedispool; } public void setJedispool(JedisPool jedispool) { this.jedispool = jedispool; } @Override public String set(String key, String value) { // TODO Auto-generated method stub`

`//从连接池中获得一个连接 Jedis jedis=jedispool.getResource();`

`//直接操作redis String result = jedis.set(key, value);`

`//关闭该连接 jedis.close(); return result; } @Override public String get(String key) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); String result = jedis.get(key); jedis.close(); return result; } @Override public Boolean exists(String key) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); Boolean result = jedis.exists(key); jedis.close(); return result; } @Override public Long expire(String key, int seconds) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); Long result = jedis.expire(key, seconds); jedis.close(); return result; } @Override public Long ttl(String key) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); Long result = jedis.ttl(key); return result; } @Override public Long incr(String key) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); Long result = jedis.incr(key); jedis.close(); return result; } @Override public String hget(String key, String field) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); String result = jedis.hget(key, field); jedis.close(); return result; } @Override public Long hdel(String key, String... field) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); Long result = jedis.hdel(key, field); jedis.close(); return result; } @Override public Boolean hexistes(String key, String field) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); Boolean result = jedis.hexists(key, field); jedis.close(); return result; } @Override public List<String> hvals(String key) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); List<String> result = jedis.hvals(key); jedis.close(); return result; } @Override public Long del(String key) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); Long result = jedis.del(key); jedis.close(); return result; } @Override public Long hset(String key, String field, String value) { // TODO Auto-generated method stub Jedis jedis=jedispool.getResource(); Long result = jedis.hset(key, field, value); jedis.close(); return result; } }`

`2、创建一个spring-redis.xml文件，进行配置：`

3、在service层使用：

策略：查询时，先从redis中查，如果有，直接返回，没有从数据库中查，将查到的结果放到redis中

在查询缓存时，和添加缓存时为了防止没有查到报异常而影响整个系统的运行，我们采用try,catch方式进行捕获；

（1），注入上面的接口：

@Autowired
    	private IRedis redis;
    	
    	
    	public IRedis getRedis() {
    		return redis;
    	}
    
    	public void setRedis(IRedis redis) {
    		this.redis = redis;
    	}

（2）、去缓存中查找：

`try { //去缓存中查，得到的是个json类型数据`

`String json = redis.hget("customer", "pageStartIndex");`

`//判断是否为空，不为空将json转为list if(! json.isEmpty()) { List<Customer> list=new ArrayList<Customer>(); list=JSONObject.parseArray(json, Customer.class); } return list; }catch (Exception e) { // TODO: handle exception }`

`（3），如果缓存中没有，从数据库中查，将结果放入：`

redis.hset("customer", "pageStartIndex", customerdata);
    		redis.hset("customer", "pageStartIndex", customerdata);
    		redis.hset("customer", "pageStartIndex", customerdata);

二、连接集群：

1、创建class，继承接口：

package com.aynu.redis.imp;
    
    import java.util.List;
    
    import com.aynu.redis.IRedis;
    
    import redis.clients.jedis.HostAndPort;
    import redis.clients.jedis.JedisCluster;
    
    public class Cluster implements IRedis {
    
       private JedisCluster jedisCluster;
    	
    
    	public JedisCluster getJedisCluster() {
    		return jedisCluster;
    	}
    
    	public void setJedisCluster(JedisCluster jedisCluster) {
    		this.jedisCluster = jedisCluster;
    	}
    
    	@Override
    	public String set(String key, String value) {
    		// TODO Auto-generated method stub
    		return jedisCluster.set(key, value);
    	}
    
    	@Override
    	public String get(String key) {
    		// TODO Auto-generated method stub
    		return jedisCluster.get(key);
    	}
    
    	@Override
    	public Boolean exists(String key) {
    		// TODO Auto-generated method stub
    		return jedisCluster.exists(key);
    	}
    
    	@Override
    	public Long expire(String key, int seconds) {
    		// TODO Auto-generated method stub
    		return jedisCluster.expire(key, seconds);
    	}
    
    	@Override
    	public Long ttl(String key) {
    		// TODO Auto-generated method stub
    		return jedisCluster.ttl(key);
    	}
    
    	@Override
    	public Long incr(String key) {
    		// TODO Auto-generated method stub
    		return jedisCluster.incr(key);
    	}
    
    	@Override
    	public String hget(String key, String field) {
    		// TODO Auto-generated method stub
    		return jedisCluster.hget(key, field);
    	}
    
    	@Override
    	public Long hset(String key, String field, String value) {
    		// TODO Auto-generated method stub
    		return jedisCluster.hset(key, field, value);
    	}
    
    	@Override
    	public Long hdel(String key, String... field) {
    		// TODO Auto-generated method stub
    		return jedisCluster.hdel(key, field);
    	}
    
    	@Override
    	public Boolean hexistes(String key, String field) {
    		// TODO Auto-generated method stub
    		return jedisCluster.hexists(key, field);
    	}
    
    	@Override
    	public List<String> hvals(String key) {
    		// TODO Auto-generated method stub
    		return jedisCluster.hvals(key);
    	}
    
    	@Override
    	public Long del(String key) {
    		// TODO Auto-generated method stub
    		return jedisCluster.del(key);
    	}
    
    }

2、在spring-redis.xml文件中进行配置：

3、使用同单机版

注意：单机版和集群版的切换，只在xml的配置进行即可。