Spring 實戰總結：MyBatis、事務、JUnit4、日誌、定時任務、Jetty、RESTful 全棧整合指南

專案背景

模仿博客園核心功能：用戶註冊/登入、隨筆發布/閱讀、評論互動、定時任務排名。三表設計：user、essay、comment。技術棧：IntelliJ IDEA + Maven + Spring 4.2.4 + MyBatis 3.3 + MySQL + Jetty 9.3 + Jersey 1.19。

核心模組實現精華

1. MyBatis 整合 (spring-mybatis.xml)

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="driverClass" value="${db.mysql.driverClass}" />
    <property name="jdbcUrl" value="${db.mysql.jdbcUrl}" />
    <!-- c3p0 核心池參數 -->
    <property name="minPoolSize" value="10" />
    <property name="maxPoolSize" value="100" />
</bean>

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="configLocation" value="classpath:mybatis.xml" />
    <property name="mapperLocations" value="classpath*:com/example/*Mapper.xml" />
</bean>

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.example.dao" />
    <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
</bean>

2. 宣告式事務管理

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" />

Service 類標註 @Transactional，發表評論同時更新 comment、essay.comment_count、user.score 三表，保證原子性。

3. JUnit4 整合測試

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/spring.xml"})
public class TestUserService extends AbstractTransactionalJUnit4SpringContextTests {
    @Resource UserService userService;
    
    @Test
    @Rollback(false) // 驗證入庫
    public void testAddUser() {
        userService.addUser(new User("test", "123456"));
    }
}

4. SLF4J + Log4j 日誌規範

# log4j.properties 關鍵配置
log4j.rootCategory = INFO, R, stdout
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout.ConversionPattern = [%p]-[%t]-[%l]-[%d{yyyyMMdd HH:mm:ss}]%n%m%n
log4j.appender.R = org.apache.log4j.DailyRollingFileAppender
log4j.appender.R.File = /logs/output.log
log4j.appender.R.DatePattern = '.'yyyy-MM-dd

代碼中使用佔位符避免字串拼接開銷：log.info("用戶 {} 登入耗時 {} ms", username, cost);

5. 定時任務雙模式

<!-- spring-task: 簡單輕量 -->
<task:annotation-driven executor="executor" scheduler="scheduler"/>
@Component
public class SpringTask {
    @Scheduled(cron = "0/20 * * * * ?")
    public void rankingJob() { userDao.rankingByScore(); }
}

<!-- Quartz: 功能強大、支援叢集 -->
<bean id="quartzTask" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
    <property name="targetObject" ref="quartzTaskBean"/>
    <property name="targetMethod" value="rankingByScore"/>
</bean>
<bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean">
    <property name="cronExpression" value="0/10 * * * * ?"/>
</bean>

6. Jetty 嵌入式啟動

public class JettyLauncher {
    public static void main(String[] args) throws Exception {
        Server server = new Server(8080);
        WebAppContext ctx = new WebAppContext();
        ctx.setContextPath("/");
        ctx.setWar("src/main/webapp");
        server.setHandler(ctx);
        server.start();
        server.join();
    }
}

7. Jersey RESTful 接口

@Path("/user")
@Component
public class UserResource {
    @Resource UserService userService;
    
    @GET @Path("/{username}") @Produces(MediaType.APPLICATION_JSON)
    public User get(@PathParam("username") String username) {
        return userService.getByUsername(username);
    }
}

專案結構與代碼地址

src/
├── main/
│   ├── java/com/example/
│   │   ├── entity/ dao/ service/ task/ jetty/ action/
│   │   └── util/SpringContextUtils.java
│   ├── resources/
│   │   ├── spring.xml, spring-mybatis.xml, spring-task.xml, spring-jetty.xml
│   │   ├── mybatis.xml, db.properties, log4j.properties
│   │   └── com/example/*Mapper.xml
│   └── webapp/WEB-INF/web.jsp
└── test/...TestUserService.java

完整代碼：GitHub Repository