详解SSH框架和Redis的整合

一个已有的Struts+Spring+Hibernate项目，以前使用MySQL数据库，现在想把Redis也整合进去。

1. 相关Jar文件

下载并导入以下3个Jar文件：

commons-pool2-2.4.2.jar、jedis-2.3.1.jar、spring-data-redis-1.3.4.RELEASE.jar。

2. Redis配置文件

在src文件夹下面新建一个redis.properties文件，设置连接Redis的一些属性。

redis.host=127.0.0.1 
redis.port=6379 
redis.default.db=1 
redis.timeout=100000 
redis.maxActive=300 
redis.maxIdle=100 
redis.maxWait=1000 
redis.testOnBorrow=true

再新建一个redis.xml文件。

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xmlns:p="http://www.springframework.org/schema/p" 
 xmlns:context="http://www.springframework.org/schema/context" 
 xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd 
 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> 
 
 <context:property-placeholder location="classpath:redis.properties"/> 
 
 <bean id="propertyConfigurerRedis" 
  class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> 
  <property name="order" value="1" /> 
  <property name="ignoreUnresolvablePlaceholders" value="true" /> 
  <property name="systemPropertiesMode" value="1" /> 
  <property name="searchSystemEnvironment" value="true" /> 
  <property name="locations"> 
  <list> 
   <value>classpath:redis.properties</value> 
  </list> 
  </property> 
 </bean>
 
 <bean id="jedisPoolConfig" 
  class="redis.clients.jedis.JedisPoolConfig"> 
  <property name="maxIdle" value="${redis.maxIdle}" /> 
  <property name="testOnBorrow" value="${redis.testOnBorrow}" /> 
 </bean>
  
 <bean id="jedisConnectionFactory" 
  class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"> 
  <property name="usePool" value="true"></property> 
  <property name="hostName" value="${redis.host}" /> 
  <property name="port" value="${redis.port}" /> 
  <property name="timeout" value="${redis.timeout}" /> 
  <property name="database" value="${redis.default.db}"></property> 
  <constructor-arg index="0" ref="jedisPoolConfig" /> 
 </bean>
 
 <bean id="redisTemplate" 
  class="org.springframework.data.redis.core.StringRedisTemplate" 
  p:connectionFactory-ref="jedisConnectionFactory" 
 > 
 </bean>
  
 <bean id="redisBase" abstract="true"> 
  <property name="template" ref="redisTemplate"/> 
 </bean> 
 
 <context:component-scan base-package="com.school.redisclient" />
 
</beans>

3. Redis类

新建一个com.school.redisclient包，结构如下：

接口IRedisService：

public interface IRedisService<K, V> {  
 public void set(K key, V value, long expiredTime); 
 public V get(K key);
 public Object getHash(K key, String name);
 public void del(K key);   
}

抽象类AbstractRedisService，主要是对RedisTemplate进行操作：

public abstract class AbstractRedisService<K, V> implements IRedisService<K, V> { 
  @Autowired 
  private RedisTemplate<K, V> redisTemplate; 
  
  public RedisTemplate<K, V> getRedisTemplate() { 
   return redisTemplate; 
  }   
  public void setRedisTemplate(RedisTemplate<K, V> redisTemplate) { 
   this.redisTemplate = redisTemplate; 
  }   
  @Override 
  public void set(final K key, final V value, final long expiredTime) { 
   BoundValueOperations<K, V> valueOper = redisTemplate.boundValueOps(key); 
   if (expiredTime <= 0) { 
    valueOper.set(value); 
   } else { 
    valueOper.set(value, expiredTime, TimeUnit.MILLISECONDS); 
   } 
  } 
  @Override 
  public V get(final K key) { 
   BoundValueOperations<K, V> valueOper = redisTemplate.boundValueOps(key); 
   return valueOper.get(); 
  } 
  @Override 
  public Object getHash(K key, String name){
   Object res = redisTemplate.boundHashOps(key).get(name);
   return res;
  }  
  @Override 
  public void del(K key) { 
   if (redisTemplate.hasKey(key)) { 
    redisTemplate.delete(key); 
   } 
  } 
  
 }

实现类RedisService：

@Service("redisService") 
public class RedisService extends AbstractRedisService<String, String> { 
 
}

工具类RedisTool：

public class RedisTool { 
 private static ApplicationContext factory;
 private static RedisService redisService;
 
 public static ApplicationContext getFactory(){
  if (factory == null){
   factory = new ClassPathXmlApplicationContext("classpath:redis.xml");
  }
  return factory;
 } 
 public static RedisService getRedisService(){
  if (redisService == null){
   redisService = (RedisService) getFactory().getBean("redisService");
  }  
  return redisService;
 }

}

4. 查询功能的实现

新建一个Action：RClasQueryAction，返回Redis里面所有的课程数据。

@SuppressWarnings("serial")
public class RClasQueryAction extends ActionSupport {
  RedisService rs = RedisTool.getRedisService();
 List<Clas> claslist = new ArrayList<Clas>();
 Clas c;
 public String execute(){
  if (rs != null){
   System.out.println("RedisService : " + rs);
   getAllClas();
  }
  ServletActionContext.getRequest().setAttribute("claslist", claslist);
  return SUCCESS;
 }
 private void getAllClas(){
  claslist = new ArrayList<Clas>();  
  int num = Integer.parseInt(rs.get("clas:count"));
  for (int i=0; i<num; i++){
   String cid = "clas:" + (i+1);
   c = new Clas();
   int id = Integer.parseInt(String.valueOf(rs.getHash(cid, "ID")));
   c.setId(id);
   System.out.println("ID:" + id);
   String name = (String) rs.getHash(cid, "NAME");
   c.setName(name);
   System.out.println("NAME:" + name);
   String comment = (String) rs.getHash(cid, "COMMENT");
   c.setComment(comment);
   System.out.println("COMMENT:" + comment);
   claslist.add(c);
  }
 }

}

Struts的设置和jsp文件就不详细讲了。

5. Redis数据库

Redis数据库里面的内容（使用的是Redis Desktop Manager）：

最后是运行结果：

当然，这只是实现了从Redis查询数据，还没有实现将Redis作为MySQL的缓存。

5. 添加功能的实现

新建一个Action：RClasAction，实现向Redis添加课程数据，并同步到MySQL。

package com.school.action;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import com.opensymphony.xwork2.ActionSupport;
import com.school.entity.Clas;
import com.school.redisclient.RedisService;
import com.school.redisclient.RedisTool;
import com.school.service.ClasService;
@SuppressWarnings("serial")
public class RClasAction extends ActionSupport { 
 @Autowired
 private ClasService clasService; 
 RedisService rs = RedisTool.getRedisService();
 List<Clas> claslist = new ArrayList<Clas>(); 
 private Clas clas;
 public Clas getClas() {
  return clas;
 } 
 public void setClas(Clas Clas) {
  this.clas = Clas;
 } 
 public String execute(){
  saveClas(clas);
  return SUCCESS;
 } 
 @SuppressWarnings({ "rawtypes", "unchecked" })
 private void saveClas(Clas c){
  List<String> ids = rs.getList("clas:id");
  // clas:id
  int num = ids.size();
  int id = Integer.parseInt(ids.get(num-1)) + 1;
  rs.rightPushList("clas:id", String.valueOf(id));
  // clas:count
  int count = Integer.parseInt(rs.get("clas:count"));
  rs.set("clas:count", String.valueOf(count+1), -1);
  // 增加
  HashMap hashmap = new HashMap();
  hashmap.put("ID", String.valueOf(id));
  hashmap.put("NAME", clas.getName());
  hashmap.put("COMMENT", clas.getComment());
  rs.addHash("clas:" + id, hashmap);
  // 同步到MySQL
  clasService.saveClas(clas);
 }
}

clas:id是一个List类型的Key-Value，记录了所有的课程ID，取出最后一个ID，再+1，作为增加的课程的ID，同时clas:count的值也要+1。使用addHash()方法向Redis添加了一个Hash类型的Key-Value(也就是一门课程)：

  @SuppressWarnings({ "unchecked", "rawtypes" })
  public synchronized void addHash(K key, HashMap map){
   redisTemplate.opsForHash().putAll(key, map);
  }

同时将该门课程增加到MySQL。

6. 删除功能的实现

新建一个Action：RClasDeleteAction，实现删除Redis的课程数据，并同步到MySQL。

package com.school.action;
import org.springframework.beans.factory.annotation.Autowired;
import com.opensymphony.xwork2.ActionSupport;
import com.school.redisclient.RedisService;
import com.school.redisclient.RedisTool;
import com.school.service.ClasService;
@SuppressWarnings("serial")
public class RClasDeleteAction extends ActionSupport { 
 @Autowired
 private ClasService clasService; 
 RedisService rs = RedisTool.getRedisService() 
 private int id;
 public int getId(){
  return id;
 }
 public void setId(int id){
  this.id=id;
 } 
 public String execute(){ 
  deleteClas(id);
  // 同步到MySQL
  clasService.deleteClas(id);
  return SUCCESS;
 }
 private void deleteClas(int id){
  // 删除
  rs.del("clas:" + id);
  // clas:count
  int count = Integer.parseInt(rs.get("clas:count"));
  rs.set("clas:count", String.valueOf(count-1), -1);
  // clas:id
  rs.delListItem("clas:id", String.valueOf(id));
 }
}

直接删除clas:id，再将clas:count的值-1，这两步比较简单，复杂的是从clas:id中删除该课程的ID，使用了delListItem()方法来实现：

  @Override
  public synchronized void delListItem(K key, V value){
   redisTemplate.opsForList().remove(key, 1, value);
  }

redisTemplate.opsForList().remove()方法类似于LREM命令。最后在MySQL中也删除相同的课程。

7. 修改功能的实现

新建一个Action：RClasUpdateAction，实现删除Redis的课程数据，并同步到MySQL。

package com.school.action;

import java.util.HashMap;

import org.springframework.beans.factory.annotation.Autowired;

import com.opensymphony.xwork2.ActionSupport;
import com.school.entity.Clas;
import com.school.redisclient.RedisService;
import com.school.redisclient.RedisTool;
import com.school.service.ClasService;

@SuppressWarnings("serial")
public class RClasUpdateAction extends ActionSupport{ 
 @Autowired
 private ClasService clasService; 
 RedisService rs = RedisTool.getRedisService(); 
 private Clas clas;
 public Clas getClas() {
  return clas;
 }
 public void setClas(Clas clas) {
  this.clas = clas;
 }
  @SuppressWarnings({ "unchecked", "rawtypes" })
 public String execute(){
  HashMap hashmap = new HashMap();
  hashmap.put("ID", String.valueOf(clas.getId()));
  hashmap.put("NAME", clas.getName());
  hashmap.put("COMMENT", clas.getComment());
  rs.putHash("clas:" + clas.getId(), hashmap);
  // 同步到MySQL
  clasService.updateClas(clas);
  return SUCCESS;
 }

}

使用了putHash()方法来更新：

  @SuppressWarnings({ "rawtypes", "unchecked" })
  @Override
  public synchronized void putHash(K key, HashMap map){
   redisTemplate.boundHashOps(key).putAll(map);
  }

同时在MySQL做相同的更新操作。

频道导航

详解SSH框架和Redis的整合

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