数据库 发布日期:2024/12/29 浏览次数:1
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。
<"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。
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。