Java從入門到實戰之（32）Maven+SSM
阿新 • • 發佈：2020-11-16
1、專案說明：
框架：Spring + Spring MVC + Mybatis +AspectJ
開發環境：jdk1.7，Tomcat7
使用框架AspectJ實現自動切換多資料來源，原理是AOP技術，類似於過濾器、監聽器、攔截器底層也都是與AOP技術相似，都是將某個你想要做處理的“塊”，當成切面或切點。Maven如何建立，我並沒有作說明，因為網上的例子實在是太多了，如果有需要我也會新增上的。
本文大部分大部分是程式碼的例項，一些說明我都寫在程式碼中的註釋中了，唯有AspectJ框架需要道友們自己上網查了，這塊的知識點還挺豐富的。最後，程式碼如有不足之處請多指教！
程式碼展示
1.pom.xml檔案
<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/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.test.multipleSource</groupId> <artifactId>multipleSource-ssm</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>multipleSource-ssm Maven Webapp</name> <url>http://maven.apache.org</url> <properties> <!-- spring版本號 --><spring.version>4.0.2.RELEASE</spring.version> <!-- mybatis版本號 --> <mybatis.version>3.2.6</mybatis.version> <!-- log4j日誌檔案管理包版本 --> <slf4j.version>1.7.7</slf4j.version> <log4j.version>1.2.17</log4j.version> </properties> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <!-- 表示開發的時候引入，釋出的時候不會載入此包 --> <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>1.2.2</version> </dependency> <!-- 匯入java ee jar 包 --> <dependency> <groupId>javax</groupId> <artifactId>javaee-api</artifactId> <version>7.0</version> </dependency> <!-- 匯入Mysql資料庫連結jar包 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.30</version> </dependency> <!-- JSTL標籤類 --> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</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.codehaus.jackson</groupId> <artifactId>jackson-mapper-asl</artifactId> <version>1.9.13</version> </dependency> <!-- 上傳元件包 --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.1</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.4</version> </dependency> <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.9</version> </dependency> <dependency> <groupId>net.sf.json-lib</groupId> <artifactId>json-lib</artifactId> <version>2.4</version> <type>jar</type> <classifier>jdk15</classifier> </dependency> <dependency> <groupId>commons-beanutils</groupId> <artifactId>commons-beanutils</artifactId> <version>1.8.0</version> </dependency> <dependency> <groupId>commons-collections</groupId> <artifactId>commons-collections</artifactId> <version>3.2.1</version> <scope>compile</scope> </dependency> <dependency> <groupId>commons-lang</groupId> <artifactId>commons-lang</artifactId> <version>2.5</version> <scope>compile</scope> </dependency> </dependencies> <build> <finalName>multipleSource-ssm</finalName> <plugins> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat6-maven-plugin</artifactId> <version>2.1</version> <configuration> <url>http://localhost:9080</url> <server>tomcat6</server> <port>8080</port> <charset>UTF-8</charset> </configuration> </plugin> </plugins> </build> </project>
2.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:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <!-- 設定AOP代理開啟 --> <!-- AOP的代理開啟放在必須在所有載入的 最前面 (意思是說這個檔案必須是第一個唄Spring容器載入的)--> <aop:aspectj-autoproxy proxy-target-class="true" /> <!-- 自動掃描該包，使SpringMVC認為包下用了@controller註解的類是控制器 --> <!-- 此掃描路徑很重要，必須囊括你所自定義AOP的所在位置 --> <context:component-scan base-package="com.multiple" /> <!--避免IE執行AJAX時，返回JSON出現下載檔案 --> <bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"> <property name="supportedMediaTypes"> <list> <value>text/html;charset=UTF-8</value> </list> </property> </bean> <!-- 啟動SpringMVC的註解功能，完成請求和註解POJO的對映 --> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"> <property name="messageConverters"> <list> <ref bean="mappingJacksonHttpMessageConverter" /> <!-- JSON轉換器 --> </list> </property> </bean> <!-- 定義跳轉的檔案的前後綴 ，檢視模式配置 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 這裡的配置我的理解是自動給後面action的方法return的字串加上字首和字尾，變成一個 可用的url地址 --> <property name="prefix" value="/" /> <property name="suffix" value=".jsp" /> </bean> <!-- 為Controller內的@ResponseBody的 json方法實現中文亂碼的解決 --> <mvc:annotation-driven> <mvc:message-converters> <bean class="org.springframework.http.converter.StringHttpMessageConverter"> <property name="supportedMediaTypes"> <list> <value>application/json;charset=UTF-8</value> </list> </property> </bean> </mvc:message-converters> </mvc:annotation-driven> </beans>
3.spring-mybatis.xml
<?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" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd"> <!-- 自動掃描 --> <!-- <context:component-scan base-package="com.multiple" /> --> <!-- 引入配置檔案 --> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location" value="classpath:jdbc.properties" /> </bean> <bean id="dataSourceMaster" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${driver}" /> <property name="url" value="${masterUrl}" /> <property name="username" value="${username}" /> <property name="password" value="${password}" /> </bean> <bean id="dataSourceSecondary" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="${driver}" /> <property name="url" value="${secondaryUrl}" /> <property name="username" value="${username}" /> <property name="password" value="${password}" /> </bean> <bean id="dynamicDataSource" class="com.multiple.utils.DynamicDataSource"> <property name="targetDataSources"> <map key-type="java.lang.String"> <entry value-ref="dataSourceMaster" key="dataSourceMaster"></entry> <entry value-ref="dataSourceSecondary" key="dataSourceSecondary"></entry> </map> </property> <property name="defaultTargetDataSource" ref="dataSourceMaster"> </property> </bean> <!-- spring和MyBatis完美整合，不需要mybatis的配置對映檔案 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dynamicDataSource" /> <!-- 自動掃描mapping.xml檔案 --> <property name="mapperLocations"> <list> <value>classpath:com/multiple/master/mapper/*.xml</value> <value>classpath:com/multiple/secondary/mapper/*.xml</value> </list> </property> </bean> <!-- DAO介面所在包名，Spring會自動查詢其下的類 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com/multiple/master/dao,com/multiple/secondary/dao" /> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property> </bean> <!-- (事務管理)transaction manager, use JtaTransactionManager for global tx --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dynamicDataSource" /> </bean> </beans>
5.jdbc.properties
driver=com.mysql.jdbc.Driver
masterUrl=jdbc:mysql://127.0.0.1:3306/master
secondaryUrl=jdbc:mysql://127.0.0.1:3306/secondary
username=root
password=root
initialSize=0
maxActive=20
maxIdle=20
minIdle=1
maxWait=60000
log4j.properties
log4j.rootLogger=INFO,Console,File
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.Target=System.out
log4j.appender.Console.layout = org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=[%c] - %m%n
log4j.appender.File = org.apache.log4j.RollingFileAppender
log4j.appender.File.File = logs/ssm.log
log4j.appender.File.MaxFileSize = 10MB
log4j.appender.File.Threshold = ALL
log4j.appender.File.layout = org.apache.log4j.PatternLayout
log4j.appender.File.layout.ConversionPattern =[%p] [%d{yyyy-MM-dd HH\:mm\:ss}][%c]%m%n
6.web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> <display-name>Archetype Created Web Application</display-name> <!-- Spring和mybatis的配置檔案 --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring-mybatis.xml</param-value> </context-param> <!-- 編碼過濾器 --> <filter> <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <async-supported>true</async-supported> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!-- Spring監聽器 --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- 防止Spring記憶體溢位監聽器 --> <listener> <listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class> </listener> <!-- Spring MVC servlet --> <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> <load-on-startup>1</load-on-startup> <async-supported>true</async-supported> </servlet> <servlet-mapping> <servlet-name>SpringMVC</servlet-name> <!-- 此處可以可以配置成*.do，對應struts的字尾習慣 --> <url-pattern>/</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>/index.jsp</welcome-file> </welcome-file-list> </web-app>
工程的目錄結構圖
在目錄結構上我分com.multiple.master、com.multiple.secondary，這是為了對應AOP的攔截路徑
6.DynamicDataSource.java
package com.multiple.utils; import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource; /** * @author Wh * 一個動態資料來源 */ public class DynamicDataSource extends AbstractRoutingDataSource { public static final String DATA_SOURCE_MASTER = "dataSourceMaster"; //主資料來源名稱。與XML檔案中名稱對應 public static final String DATA_SOURCE_SECONDARY = "dataSourceSecondary"; //從資料來源名稱。與XML檔案中名稱對應 private static final ThreadLocal<String> contextHolder = new ThreadLocal<String>(); /** * 引數為要切換的資料來源名稱，就是上面的final變數 * @param customerType */ public static void setCustomerType(String customerType) { contextHolder.set(customerType); } /** * 通過執行緒的方式獲取資料來源，目的是為了在併發的情況下依然能夠正常切換 * @return */ public static String getCustomerType() { return contextHolder.get(); } /** * 用於關閉當前切換的資料來源 */ public static void clearCustomerType() { contextHolder.remove(); } /** * @author Wh * 這個用於切換動態資料來源必須要實現的一個方法 */ @Override protected Object determineCurrentLookupKey() { return getCustomerType(); } }
7.ServiceAspect.java
package com.multiple.utils; import org.aspectj.lang.JoinPoint; import org.aspectj.lang.annotation.After; import org.aspectj.lang.annotation.AfterThrowing; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; import org.springframework.core.annotation.Order; import org.springframework.stereotype.Component; /** * @author Wh * 通過AOP實現對資料來源的自動切換，AOP是Spring的核心。通過AspectJ框架實現對AOP的操作 */ @Component @Aspect // 設定當前載入的順序 @Order(-1) public class ServiceAspect { /** * 設定切點：路徑為Secondary層的service層，*.*(..)代表其service報下的所有類和方法 */ @Pointcut("execution(* com.multiple.secondary.service.*.*(..))") public void aspect() { } /** * @param joinPoint * 進入切點方法之前（切點是專業術語，在本文中就是你要切換資料來源的的方法） * 切換資料來源，當一個工程中兩個資料來源時可以對不常用的資料來源寫死，因為工程中必定有一個主資料來源，當超過兩個以上的資料來源時可以通過傳參的形式到該方法中 */ @Before("aspect()") public void before(JoinPoint joinPoint) { DynamicDataSource .setCustomerType(DynamicDataSource.DATA_SOURCE_SECONDARY); } /** * @param joinPoint * 當退出切點方法之後，關閉所切換額資料來源 */ @After("aspect()") public void after(JoinPoint joinPoint) { DynamicDataSource.clearCustomerType(); } /** * @param joinPoint * @param ex * 針對當前攔截的切點方法中出現異常時所做的處理 */ @AfterThrowing(pointcut = "aspect()", throwing = "ex") public void afterThrow(JoinPoint joinPoint, Exception ex) { DynamicDataSource.clearCustomerType(); } }
2.Master資料來源
1.Goods.java
package com.multiple.master.entity; import java.util.Date; /** * @author Wh * 商品表 */ public class Goods { private String uuid; // uuid private String goodsName; // 商品名稱 private float prices; // 商品價格 private Date generateDate; // 生成日期 private int number; // 商品數量 public String getUuid() { return uuid; } public void setUuid(String uuid) { this.uuid = uuid; } public String getGoodsName() { return goodsName; } public void setGoodsName(String goodsName) { this.goodsName = goodsName; } public float getPrices() { return prices; } public void setPrices(float prices) { this.prices = prices; } public Date getGenerateDate() { return generateDate; } public void setGenerateDate(Date generateDate) { this.generateDate = generateDate; } public int getNumber() { return number; } public void setNumber(int number) { this.number = number; } }
2.GoodsMapper.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.multiple.master.dao.GoodsMapper">
<select id="queryGoodsList" resultType="com.multiple.master.entity.Goods">
select
uuid as uuid,
goods_name as goodsName,
prices as prices,
generate_date as generateDate,
number as number
from merchandise;
</select>
</mapper>
3.GoodsMapper.java
package com.multiple.master.dao; import java.util.List; import com.multiple.master.entity.Goods; public interface GoodsMapper { List<Goods> queryGoodsList(); }
IGoodsService.java
package com.multiple.master.service; import java.util.List; import com.multiple.master.entity.Goods; public interface IGoodsService { List<Goods> queryGoodsList(); }
4.GoodsServiceImpl.java
package com.multiple.master.service.impl; import java.util.List; import javax.annotation.Resource; import org.springframework.stereotype.Service; import com.multiple.master.dao.GoodsMapper; import com.multiple.master.entity.Goods; import com.multiple.master.service.IGoodsService; /** * @author Wh * Master資料庫下商品表的業務層 */ @Service("goodsService") public class GoodsServiceImpl implements IGoodsService { @Resource private GoodsMapper goodsMapper; @Override public List<Goods> queryGoodsList() { return goodsMapper.queryGoodsList(); } }
3.Secondary層
1.Orders.java
package com.multiple.secondary.entity; /** * @author Wh * 訂單表 */ public class Orders { private String uuid; // 訂單uuid private String goods_uuids; // 商品UUID組 private float orderPrice; // 訂單價格 public String getUuid() { return uuid; } public void setUuid(String uuid) { this.uuid = uuid; } public String getGoods_uuids() { return goods_uuids; } public void setGoods_uuids(String goods_uuids) { this.goods_uuids = goods_uuids; } public float getOrderPrice() { return orderPrice; } public void setOrderPrice(float orderPrice) { this.orderPrice = orderPrice; } }
2.OrdersMapper.java
package com.multiple.secondary.dao; import java.util.List; import com.multiple.secondary.entity.Orders; public interface OrdersMapper { List<Orders> queryOrdersList(); }
3.OrdersMapper.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.multiple.secondary.dao.OrdersMapper">
<select id="queryOrdersList" resultType="com.multiple.secondary.entity.Orders">
select
uuid as uuid,
goods_uuids as goodsUuids,
order_price as orderPrice
from orders;
</select>
</mapper>
4.IOrdersService.java
package com.multiple.secondary.service; import java.util.List; import com.multiple.secondary.entity.Orders; public interface IOrdersService { List<Orders> queryOrdersList(); }
5.OrdersServiceImpl.java
package com.multiple.secondary.service.impl; import java.util.List; import javax.annotation.Resource; import org.springframework.stereotype.Service; import com.multiple.secondary.dao.OrdersMapper; import com.multiple.secondary.entity.Orders; import com.multiple.secondary.service.IOrdersService; /** * @author Wh * Secondary資料庫下的訂單表的業務層 */ @Service("ordersService") public class OrdersServiceImpl implements IOrdersService { @Resource private OrdersMapper ordersMapper; @Override public List<Orders> queryOrdersList() { return ordersMapper.queryOrdersList(); } }
6.TestController.java
package com.multiple.controller; import java.io.UnsupportedEncodingException; import java.util.List; import javax.annotation.Resource; import net.sf.json.JSONArray; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import com.multiple.master.entity.Goods; import com.multiple.master.service.IGoodsService; import com.multiple.secondary.entity.Orders; import com.multiple.secondary.service.IOrdersService; /** * @author Wh * 一個測試的Controller類 */ @Controller @RequestMapping("/testController") public class TestController { @Resource @Qualifier("goodsService") private IGoodsService goodsService; @Resource @Qualifier("ordersService") private IOrdersService ordersService; /** * * 實現對Master資料庫的資訊查詢 * * @return * @throws UnsupportedEncodingException */ @RequestMapping(value = "/queryGoods", produces = "application/json;charset=GBK") @ResponseBody private String queryGoodsList() throws UnsupportedEncodingException { List<Goods> goodsList = goodsService.queryGoodsList(); JSONArray jsonObject = JSONArray.fromObject(goodsList); String jsonStr = jsonObject.toString(); return jsonStr; } /** * 實現對Secondary資料庫的資訊查詢 * * @return * @throws UnsupportedEncodingException */ @RequestMapping(value = "/queryOrders", produces = "application/json;charset=GBK") @ResponseBody private String queryOrdersList() throws UnsupportedEncodingException { List<Orders> goodsList = ordersService.queryOrdersList(); JSONArray jsonObject = JSONArray.fromObject(goodsList); String jsonStr = jsonObject.toString(); return jsonStr; } }