SSM整合Redis，用快取減少對資料庫的訪問次數？
阿新 • • 發佈：2018-11-25
資料：
一、首先匯入依賴：
<spring-version>4.3.13.RELEASE</spring-version> <mybatis-version>3.4.5</mybatis-version> <servlet-version>4.0.0</servlet-version> <mysql-version>5.1.46</mysql-version> <dbcp-version>1.4</dbcp-version> <log4j-version>1.2.12</log4j-version> <slf4j-version>1.5.6</slf4j-version> <jackson-version>2.9.2</jackson-version> <jedis-version>2.9.0</jedis-version>
<dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <!-- spring核心包 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-oxm</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring-version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring-version}</version> </dependency> <!-- mybatis核心包 --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>${mybatis-version}</version> </dependency> <!-- mybatis/spring包 --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.3.1</version> </dependency> <!--加入servlet依賴--> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>${servlet-version}</version> </dependency> <!-- 匯入Mysql資料庫連結jar包 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql-version}</version> </dependency> <!-- 匯入dbcp的jar包，用來在applicationContext.xml中配置資料庫 --> <dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>${dbcp-version}</version> </dependency> <!-- 日誌檔案管理包 --> <!-- log start --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>${log4j-version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>${slf4j-version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>${slf4j-version}</version> <scope>test</scope> </dependency> <!-- log end --> <!--加入jackson包--> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>${jackson-version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>${jackson-version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> <version>${jackson-version}</version> </dependency> <!--匯入jedis的依賴--> <dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> <version>${jedis-version}</version> </dependency>
在build標籤里加上（不加則會造成找不到myBatis的核心檔案）：
<resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.xml</include> </includes> </resource> </resources>
二、編寫java程式碼（java資料夾下）：
1、pojo包的實體類 User.java：
/**
* 測試類的實體類
*/
public class User implements Serializable {
/**
* 編號
*/
private String user_id;
/**
* 使用者名稱
*/
private String user_name;
/**
* 密碼
*/
private String user_pwd;
/**
* 型別
*/
private int user_type;
public User() {
}
public User(String user_id, String user_name, String user_pwd, int user_type) {
this.user_id = user_id;
this.user_name = user_name;
this.user_pwd = user_pwd;
this.user_type = user_type;
}
public String getUser_id() {
return user_id;
}
public void setUser_id(String user_id) {
this.user_id = user_id;
}
public String getUser_name() {
return user_name;
}
public void setUser_name(String user_name) {
this.user_name = user_name;
}
public String getUser_pwd() {
return user_pwd;
}
public void setUser_pwd(String user_pwd) {
this.user_pwd = user_pwd;
}
public int getUser_type() {
return user_type;
}
public void setUser_type(int user_type) {
this.user_type = user_type;
}
@Override
public String toString() {
return "User{" +
"user_id='" + user_id + '\'' +
", user_name='" + user_name + '\'' +
", user_pwd='" + user_pwd + '\'' +
", user_type=" + user_type +
'}';
}
}
2、mapper包的介面 IUsersMapper.java：
/**
* 測試類mapper包的介面
*/
@Repository
public interface IUsersMapper {
/**
* 查詢測試類的所有資料的方法
*
* @return
*/
public List<User> findUsersAll();
/**
* 新增資料
*
* @param user
* @return
*/
public int addUsers(User user);
/**
* 編輯資料
*
* @param user
* @return
*/
public int editUsers(User user);
/**
* 刪除資料
*
* @param user
* @return
*/
public int removeUser(User user);
}3、mapper包的MyBatis核心配置檔案 IUsersMapper.xml：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.zking.mapper.IUsersMapper">
<!--查詢測試類的所有資料的sql語句-->
<select id="findUsersAll" resultType="User">
SELECT * FROM USER
</select>
<!--新增資料的sql語句-->
<insert id="addUsers" parameterType="User">
<!-- <selectKey resultType="java.lang.String" keyProperty="user_id" order="BEFORE">
SELECT UUID();
</selectKey>-->
INSERT INTO USER VALUES(UUID(),#{user_name},#{user_pwd},#{user_type})
</insert>
<!--編輯資料的sql語句-->
<update id="editUsers" parameterType="User">
UPDATE USER
<set>
<if test="user_name!=null">
user_name=#{user_name},
</if>
<if test="user_pwd!=null">
user_pwd=#{user_pwd},
</if>
<if test="user_type!=null">
user_type=#{user_type},
</if>
</set>
where user_id=#{user_id}
</update>
<!--刪除資料的sql語句-->
<delete id="removeUser" parameterType="User">
delete from User WHERE user_id=#{user_id}
</delete>
</mapper>4、service包的介面 IUsersService：
/**
* 測試類service包的介面
*/
public interface IUsersService {
/**
* 查詢測試類的所有資料的方法
*
* @return
*/
public List<User> findUsersAll();
/**
* 新增資料
*
* @param user
* @return
*/
public int addUsers(User user);
/**
* 編輯資料
*
* @param user
* @return
*/
public int editUsers(User user);
/**
* 刪除資料
*
* @param user
* @return
*/
public int removeUser(User user);
}5、service.impl包的實現類 UsersServiceImpl.java：
/**
* 測試類service包的實現類
*/
@Service("IUsersService")
public class UsersServiceImpl implements IUsersService {
@Resource(name = "IUsersMapper")
private IUsersMapper ium;
@Override
public List<User> findUsersAll() {
return ium.findUsersAll();
}
@Override
public int addUsers(User user) {
return ium.addUsers(user);
}
@Override
public int editUsers(User user) {
return ium.editUsers(user);
}
@Override
public int removeUser(User user) {
return ium.removeUser(user);
}
}
6、redis包的類 RedisCache.java：
public class RedisCache {
//redis的緩衝池
private JedisPool jedisPool;
public JedisPool getJedisPool() {
return jedisPool;
}
public void setJedisPool(JedisPool jedisPool) {
this.jedisPool = jedisPool;
}
/**
* 設定redis快取資訊
*
* @param key
* @param value
*/
public <T> void setRedisDate(String key, T value) throws Exception {
ObjectMapper objectMapper = new ObjectMapper();
if (value != null) {
String outStr = objectMapper.writeValueAsString(value);
jedisPool.getResource().set(key, outStr);
}
}
/**
* 獲取redis的String的快取資訊
*
* @param key
* @return
*/
public String getRedisDate(String key) {
return jedisPool.getResource().get(key);
}
/**
* 獲取redis的list集合的快取資訊
*
* @param <T>
* @return
* @throws Exception
*/
public <T> List<T> getRedisDateList(String key) throws Exception {
String readStr = jedisPool.getResource().get(key);
ObjectMapper objectMapper = new ObjectMapper();
return objectMapper.readValue(readStr, new TypeReference<List<T>>() {
});
}
/**
* 獲取redis的單個物件的快取資訊
*
* @param key
* @param valueType
* @param <T>
* @return
* @throws Exception
*/
public <T> T getRedisDateObject(String key, Class<T> valueType) throws Exception {
String readStr = jedisPool.getResource().get(key);
ObjectMapper objectMapper = new ObjectMapper();
return objectMapper.readValue(readStr, valueType);
}
}7、controller包的資料互動類 UsersController.java：
@Controller//定義為是一個控制器類
@RequestMapping("user")//提供初步的請求對映資訊，相對於 WEB 應用的根目錄
public class UsersController {
//建立一個公用的key值
private final String key = "com.zking.service.IUsersService";
@Resource(name = "IUsersService")
private IUsersService ius;
@Autowired
private RedisCache redisCache;
@ResponseBody//返回的物件為JSON資料
@RequestMapping(value = "findUserAll")//提供進一步的細分對映資訊。相對於類定義處的 URL
public String findUserAll() throws Exception {
//判斷是不是要讀取快取資訊
//如果沒有快取資訊，那麼久先載入到快取中，然後根據當前資料庫的返回進行資料的返回
//如果有快取則直接讀取快取資訊裡面的資料
String outStr = redisCache.getRedisDate(key);
if (outStr == null) {
redisCache.setRedisDate(key, ius.findUsersAll());
}
System.out.println("快取值" + redisCache.getRedisDate(key));
return outStr;
}
//更新資料，讀取redis的快取，並將快取轉換為list的集合，然後重新寫入到redis中，
//key值不改變的情況下，value會覆蓋。
@RequestMapping("addUser")
@ResponseBody
public Map addUser(User user) throws Exception {
Map<String, String> map = new HashMap<>();
System.out.println("新增物件：" + user);
if (ius.addUsers(user) > 0) {
//首先獲取快取中的集合，將當前這個物件加入到快取集合中，將集合重新寫入到快取中
List<User> userList = redisCache.getRedisDateList(key);
userList.add(user);
redisCache.setRedisDate(key, userList);
map.put("message", "Y");
} else {
map.put("message", "N");
}
return map;
}
/**
* 編輯資料
*
* @param user
* @return
* @throws Exception
*/
@RequestMapping("editUser")
@ResponseBody
public Map editUser(User user) throws Exception {
Map<String, String> map = new HashMap<>();
System.out.println("編輯物件：" + user);
if (ius.editUsers(user) > 0) {
//首先獲取快取中的集合，將當前這個物件加入到快取集合中，將集合重新寫入到快取中
List<User> userList = redisCache.getRedisDateList(key);
for (User u : userList) {
if (u.getUser_id().equals(user.getUser_id())) {
u.setUser_name(user.getUser_name());
u.setUser_pwd(user.getUser_pwd());
u.setUser_type(user.getUser_type());
}
}
redisCache.setRedisDate(key, userList);
map.put("message", "Y");
} else {
map.put("message", "N");
}
return map;
}
/**
* 刪除資料
*
* @param user
* @return
* @throws Exception
*/
@RequestMapping("removeUser")
@ResponseBody
public Map removeUser(User user) throws Exception {
Map<String, String> map = new HashMap<>();
System.out.println("刪除物件：" + user);
if (ius.removeUser(user) > 0) {
//首先獲取快取中的集合，將當前這個物件加入到快取集合中，將集合重新寫入到快取中
List<User> userList = redisCache.getRedisDateList(key);
for (User u : userList) {
if (u.getUser_id().equals(user.getUser_id())) {
userList.remove(user);
map.put("message", "Y");
break;
}
}
redisCache.setRedisDate(key, userList);
} else {
map.put("message", "N");
}
return map;
}
}三、配置資訊（resources資料夾下）：
1、spring-mvc.xml檔案：
<?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"
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.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!--1) 排除掃描@Component、@Repository、@Service 註解-->
<context:component-scan base-package="com.zking.controller"></context:component-scan>
<!--2) 此標籤預設註冊DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter -->
<!--兩個bean，這兩個bean是spring MVC為@Controllers分發請求所必須的。並提供了資料繫結支援，-->
<[email protected]支援，@DateTimeFormat支援，@Valid支援，讀寫XML的支援（JAXB），讀寫JSON的支援（Jackson）-->
<mvc:annotation-driven></mvc:annotation-driven>
<!--但是，從spring3.1開始DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter的使用已經過時-->
<!--spring3.1開始我們應該用RequestMappingHandlerMapping 來替換DefaultAnnotationHandlerMapping，-->
<!--spring3.1開始我們應該用用RequestMappingHandlerAdapter 來替換AnnotationMethodHandlerAdapter-->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<property name="messageConverters">
<list>
<ref bean="mappingJackson2HttpMessageConverter"/>
</list>
</property>
</bean>
<bean id="mappingJackson2HttpMessageConverter"
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<!--處理中文亂碼以及避免IE執行AJAX時，返回JSON出現下載檔案-->
<property name="supportedMediaTypes">
<list>
<value>text/html;charset=UTF-8</value>
<value>text/json;charset=UTF-8</value>
<value>application/json;charset=UTF-8</value>
</list>
</property>
</bean>
<!--3) ViewResolver -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--4) 單獨處理圖片、樣式、js等資源 -->
<!--<mvc:resources location="/css/" mapping="/css/**"/>-->
<!--<mvc:resources location="/images/" mapping="/images/**"/>-->
<!--<mvc:resources location="/js/" mapping="/js/**"/>-->
<!-- <mvc:resources location="/jquery-easyui/" mapping="/jquery-easyui/**"/>-->
<!-- ********************* 國際化配置開始***************** -->
<!--修改springmvc-servlet.xml-->
<!--1) 配置國際化資原始檔 -->
<!--<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">-->
<!--<property name="basenames">-->
<!--<list>-->
<!--<value>i18n</value>-->
<!--</list>-->
<!--</property>-->
<!--</bean>-->
<!--<!–2) 指定語言區域解析器，由它來確定使用哪個語言 –>-->
<!--<bean id="localeResolver" class="org.springframework.web.servlet.i18n.SessionLocaleResolver">-->
<!--</bean>-->
<!--<!–3) 配置國際化操作攔截器–>-->
<!--<mvc:interceptors>-->
<!--<bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"/>-->
<!--</mvc:interceptors>-->
<!-- ********************* 檔案上傳配置開始***************** -->
<!--<bean id="multipartResolver"-->
<!--class="org.springframework.web.multipart.commons.CommonsMultipartResolver">-->
<!--<!– 必須和使用者JSP 的pageEncoding屬性一致，以便正確解析表單的內容 –>-->
<!--<property name="defaultEncoding" value="UTF-8"></property>-->
<!--<!– 檔案最大大小(位元組) 1024*1024*100=50M–>-->
<!--<property name="maxUploadSize" value="52428800"></property>-->
<!--<!–resolveLazily屬性啟用是為了推遲檔案解析，以便捕獲檔案大小異常–>-->
<!--<property name="resolveLazily" value="true"/>-->
<!--</bean>-->
</beans>2、spring-mybatis.xml檔案：
<?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:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<!--配置註解掃描-->
<context:component-scan base-package="com.zking"/>
<!--配置dbcp的資料庫連線池-->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<!--連線物件-->
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<!--連線地址-->
<property name="url" value="jdbc:mysql://localhost:3306/chencao"/>
<!--使用者名稱-->
<property name="username" value="root"/>
<property name="password" value="sasa"/>
<!-- 初始化連線大小 -->
<property name="initialSize" value="20"></property>
<!-- 連線池最大數量 -->
<property name="maxActive" value="100"></property>
<!-- 連線池最大空閒 -->
<property name="maxIdle" value="20"></property>
<!-- 連線池最小空閒 -->
<property name="minIdle" value="1"></property>
<!-- 獲取連線最大等待時間 -->
<property name="maxWait" value="6000"></property>
</bean>
<!--建立sessionFactory工廠-->
<bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="typeAliasesPackage" value="com.zking.pojo"></property>
<property name="mapperLocations" value="classpath*:com/zking/mapper/*.xml"></property>
</bean>
<!--自動掃描 將Mapper介面生成代理注入到Spring-->
<bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.zking.mapper"></property>
<property name="sqlSessionFactoryBeanName" value="sessionFactory"></property>
</bean>
<!--建立驅動-->
<bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"></property>
</bean>
<!--驅動管理-->
<tx:annotation-driven transaction-manager="dataSourceTransactionManager"/>
<!--配置redis的緩衝池-->
<bean id="jedisPool" class="redis.clients.jedis.JedisPool">
<!--ip連線地址-->
<constructor-arg name="host" value="192.168.42.150"></constructor-arg>
<!--埠號-->
<constructor-arg name="port" value="6379"></constructor-arg>
</bean>
<!--建立redis快取類物件-->
<bean id="redisCache" class="com.zking.redis.RedisCache">
<property name="jedisPool" ref="jedisPool"></property>
</bean>
</beans>3、在web.xml檔案裡配置：
<!--載入spring配置檔案-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mybatis.xml</param-value>
</context-param>
<!-- 在Spring框架中是如何解決從頁面傳來的字串的編碼問題的呢？
下面我們來看看Spring框架給我們提供過濾器CharacterEncodingFilter
這個過濾器就是針對於每次瀏覽器請求進行過濾的，然後再其之上添加了父類沒有的功能即處理字元編碼。
其中encoding用來設定編碼格式，forceEncoding用來設定是否理會 request.getCharacterEncoding()方法，設定為true則強制覆蓋之前的編碼格式。-->
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.action</url-pattern>
</servlet-mapping>四、頁面呼叫（這裡只是去測試用，實際頁面操作根據情況更改）：
<body>
<a href="/user/findUserAll.action">獲取Json</a>
<a href="/user/addUser.action?user_name=張三&user_pwd=111&user_type=1">新增資料</a>
<a href="/user/editUser.action?user_id=4c830c1e-ecd4-11e8-9fb6-80fa5b5015f0&user_name=李四&user_pwd=222&user_type=1">編輯資料</a>
<a href="/user/removeUser.action?user_id=4c830c1e-ecd4-11e8-9fb6-80fa5b5015f0">刪除資料</a>
</body>