Spring Cache 使用

喜欢ヅ旅行 2022-08-10 09:14 176阅读 0赞

## 1.Maven配置项目所需要的JAR包 ##

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    	<modelVersion>4.0.0</modelVersion>
    
    	<groupId>com.zhaochao</groupId>
    	<artifactId>Demo</artifactId>
    	<version>0.0.1-SNAPSHOT</version>
    	<packaging>jar</packaging>
    
    	<name>Demo</name>
    	<url>http://maven.apache.org</url>
    
    	<properties>
    		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    		<org.springframework.version>4.1.6.RELEASE</org.springframework.version>
    		<project.version>1.0.0-SNAPSHOT</project.version>
    		<junit.version>4.12</junit.version>
    
    	</properties>
    
    	<dependencies>
    		
    		<dependency>
    			<groupId>junit</groupId>
    			<artifactId>junit</artifactId>
    			<version>${junit.version}</version>
    			<scope>test</scope>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-core</artifactId>
    			<version>${org.springframework.version}</version>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-beans</artifactId>
    			<version>${org.springframework.version}</version>
    		</dependency>
    
    		
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-aop</artifactId>
    			<version>${org.springframework.version}</version>
    		</dependency>
    
    		
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-context</artifactId>
    			<version>${org.springframework.version}</version>
    		</dependency>
    
    
    		
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-test</artifactId>
    			<version>${org.springframework.version}</version>
    			<scope>test</scope>
    		</dependency>
    
    
    
    
    
    	</dependencies>
    </project>

## 2.Spring配置 ##

<?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:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc"
    	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xmlns:cache="http://www.springframework.org/schema/cache"
    	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
    		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
    		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
    		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
    		http://www.springframework.org/schema/cache
            http://www.springframework.org/schema/cache/spring-cache.xsd"
    	default-autowire="byType">
    
    	<context:annotation-config />
    	<context:component-scan base-package="com.zhaochao.service" />
    	<cache:annotation-driven cache-manager="cacheManager" />
    	
    	<bean id="cacheManager" class="org.springframework.cache.support.SimpleCacheManager">
    		<property name="caches">
    			<set>
    				<bean class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean">
    					<property name="name" value="userCache" />
    				</bean>
    			</set>
    		</property>
    	</bean>
    
    
    </beans>

## 3.定义用户类 ##

package com.zhaochao.service;
    
    public class User {
    	private Integer id;
    	private String  name;
    	public Integer getId() {
    		return id;
    	}
    	public void setId(Integer id) {
    		this.id = id;
    	}
    	public String getName() {
    		return name;
    	}
    	@Override
    	public String toString() {
    		return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public Integer getAge() {
    		return age;
    	}
    	public void setAge(Integer age) {
    		this.age = age;
    	}
    	private Integer age;
    }

## 4.用户服务类 ##

package com.zhaochao.service;
    import org.springframework.cache.annotation.CacheEvict;
    import org.springframework.cache.annotation.CachePut;
    import org.springframework.cache.annotation.Cacheable;
    import org.springframework.stereotype.Service;
    
    @Service("userService")
    public class UserService {
    
    	// 查询缓存
    	@Cacheable(value = "userCache", key = "#userId")
    	public User getUserById(Integer userId) {
    		System.err.println("===queryUserById from db======");
    		User u=new User();
    		u.setId(userId);
    		u.setName("赵云");
    		u.setAge(20);
    		return u;
    	}
    	// 删除缓存
    	@CacheEvict(value = "userCache", condition ="#userId <=2 ")
    	public String deleteUserById(int userId) {
    	
    		System.err.println("===deleteUserById===="+userId+"===");
    		return String.valueOf(userId);
    	}
    	// 更新缓存
    	@CachePut(value = "userCache", key = "#userId")
    	public User updateUserById(Integer userId) {
    		System.err.println("updateUserById ======== in DB =========");
    		User u=new User();
    		u.setId(userId);
    		u.setName("马超");
    		u.setAge(20);
    		return u;
    	}
    
    }

## 5.测试类 ##

package com.zhaochao.service.test;
    
    import org.junit.Test;
    
    
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.test.context.ContextConfiguration;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    
    import com.zhaochao.service.UserService;
    
    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration("classpath:spring-common.xml")
    public class UserServiceTest {
    	@Autowired
    	private UserService userService;
    
    	@Test
    	public void testCache(){
    		//首次查询
    		System.err.println(userService.getUserById(1));
    		System.err.println(userService.getUserById(2));
    		System.err.println(userService.getUserById(3));
    		System.err.println(userService.getUserById(4));
    		System.err.println();
    		//缓存查询
    		System.err.println(userService.getUserById(1));
    		System.err.println(userService.getUserById(2));
    		System.err.println();
    		//更新缓存
    		System.err.println(userService.updateUserById(1));
    		System.err.println(userService.getUserById(1));
    		System.err.println();
    		//删除缓存中userId<2
    		System.err.println(userService.deleteUserById(1));
    		System.err.println(userService.deleteUserById(4));
    		System.err.println(userService.getUserById(1));
    		System.err.println(userService.getUserById(4));
    		
    		
    	}
    }

## 6.结果 ##

![Center][]

## 7.自定义缓存将spring 配置改成 ##

<?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:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc"
    	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xmlns:cache="http://www.springframework.org/schema/cache"
    	xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
    		http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
    		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
    		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
    		http://www.springframework.org/schema/cache
            http://www.springframework.org/schema/cache/spring-cache.xsd"
    	default-autowire="byType">
    
    	<context:annotation-config />
    	<context:component-scan base-package="com.zhaochao.service" />
    	<cache:annotation-driven cache-manager="cacheManager" />
    
      
    	<bean id="cacheManager" class="com.zhaochao.service.MyCacheManager">
    		<property name="caches">
    			<set>
    				<bean class="com.zhaochao.service.MyCache" p:name="userCache" />
    			</set>
    		</property>
    	</bean>
    
    </beans>

## 8.MyCache ##

package com.zhaochao.service;
    
    import java.util.HashMap;
    import java.util.Map;
    import org.springframework.cache.Cache;
    import org.springframework.cache.support.SimpleValueWrapper;
    
    public class MyCache implements Cache {
    	private String name;
    
    	public void setName(String name) {
    		this.name = name;
    	}
    	private Map<Integer, User> store = new HashMap<Integer, User>();
    	public MyCache() {
    
    	}
    	public MyCache(String name) {
    		this.name = name;
    	}
    	public String getName() {
    		return this.name;
    	}
    
    	public Object getNativeCache() {
    		return null;
    	}
    	public ValueWrapper get(Object key) {
    		ValueWrapper result = null;
    		User thevalue = store.get(key);
    		if (thevalue != null) {
    			result = new SimpleValueWrapper(thevalue);
    		}
    		return result;
    	}
    	public <User> User get(Object key, Class<User> type) {
    		return (User) store.get(key);
    	}
    	public void put(Object key, Object value) {
    		store.put((Integer) key, (User) value);
    	}
    	public ValueWrapper putIfAbsent(Object key, Object value) {
    		return null;
    	}
    
    	public void evict(Object key) {
    		store.remove((String) key);
    	}
    	public void clear() {
    		store.clear();
    	}
    
    }

## 9.MyCacheManager ##

package com.zhaochao.service;
    
    import java.util.Collection;
    
    import org.springframework.cache.support.AbstractCacheManager;
    
    public class MyCacheManager extends AbstractCacheManager {
    	private Collection<? extends MyCache> caches;
    
    	public void setCaches(Collection<? extends MyCache> caches) {
    		this.caches = caches;
    	}
    	@Override
    	protected Collection<? extends MyCache> loadCaches() {
    		return this.caches;
    	}
    
    }

[Center]: /images/20220731/71fa251d25e440b98354eb423cf7c958.png