JAVA配置&注解方式搭建简单的SpringMVC前后台交互系统

前面两篇文章介绍了 基于XML方式搭建SpringMVC前后台交互系统的方法，博文链接如下：
　　http://www.cnblogs.com/hunterCecil/p/8252060.html
　　http://www.cnblogs.com/hunterCecil/p/6924935.html

本文重点介绍一下基于java配置+注解方式搭建系统的过程步骤。

一、摘要
　　1、所需软件列表：
　　　　1) tomcat : apache-tomcat-7.0.54　 服务端容器
　　　　2) Intellij： Intellij IDEA 2016.3.1 　  开发工具　　
　　　　3) Syslog: SQLyog Community 　 　数据库工具
　　2. 步骤简述：
　　　1） 新建一个 Java 项目， 按下图依次选择：
　　　　　
　　　2） 项目目录如下：
　　　　
各目录存储文件如下：

（1）java.com ： 目录下用于存放后台代码：

　　　　config: 配置启动类
　　　　controller: 应用层实现类
　　　　dao: 数据访问层的bean
　　　　entity: 对象实体类
　　　　service: 业务层bean, 具体的数据库操作实现类
（2）resource:
　　　　jdbc.properties: 数据库配置
　　　　log4j.properties: 日志配置相关属性
　　　　users.sql: 建表语句

（3）webapp: 客户端展示相关文件

二、 相关配置文件
　　1. web.xml配置（用于配置Spring 相关配置项：上下文、日志、字符集、监听器等通过配置文件加载，这里只配置welcome-file-list及session-config）

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
	version="3.0" metadata-complete="false">

	<!-- session超时 -->
	<session-config>
		<session-timeout>60</session-timeout>
	</session-config>
	<!-- 欢迎页面 -->;
	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
	
</web-app>

　　2. jdbc. properties

jdbc.driver = com.mysql.jdbc.Driver
db.url = jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8
db.username = root
db.password = *****

　　3. log4j.properties

#日志输出级别
log4j.rootLogger=INFO,stdout,other

#设置stdout的日志输出控制台
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
#输出日志到控制台的方式，默认为System.out
log4j.appender.stdout.Target = System.out
#设置使用灵活布局
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
#灵活定义输出格式
log4j.appender.stdout.layout.ConversionPattern=[%p][%d{yyyy-MM-dd HH:mm:ss}] %l %m %n

#设置other的日志输出控制台
log4j.appender.other=org.apache.log4j.RollingFileAppender
#设置other的输出日志
log4j.appender.other.File=/WEB-INF/logs/log.log
#设置other的日志最大限制
log4j.appender.other.MaxFileSize=1024KB
#最多只保存20个备份文件
log4j.appender.other.MaxBackupIndex=1000
#输出INFO级别以上的日志
og4j.appender.other.Threshold=INFO
#设置使用灵活布局
log4j.appender.other.layout=org.apache.log4j.PatternLayout
#灵活定义输出格式
log4j.appender.other.layout.ConversionPattern=[%p][%d{yyyy-MM-dd HH:mm:ss}] %l %t %m %n

　　4. uses.sql

-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
  `id` tinyint (20),
	`name` varchar (90),
	`age` tinyint (100),
  PRIMARY KEY (`id`),
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;


-- ----------------------------
-- Records of user
-- ----------------------------
insert into `user` (`id`, `name`, `age`) values('2','zhangsan','32');
insert into `user` (`id`, `name`, `age`) values('3','lisi','33');
insert into `user` (`id`, `name`, `age`) values('1','wangwu','12');　

　5. config目录下文件：
　　DatabaseConfig　

@Configuration
@EnableTransactionManagement
public class DatabaseConfig {
    private static final Logger logger = Logger.getLogger(DatabaseConfig.class.getName());

    @Value("${jdbc.driver}")
    private String jdbcDriver;

    @Value("${db.url}")
    private String dbUrl;

    @Value("${db.username}")
    private String username;

    @Value("${db.password}")
    private String password;

    @Bean(destroyMethod = "close")
    public DataSource dataSource() {
        logger.info("mysql url:"+dbUrl);
        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName(jdbcDriver);
        dataSource.setUrl(dbUrl);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    }

    @Bean
    public DataSourceTransactionManager txManager() {
        return new DataSourceTransactionManager(dataSource());
    }

    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(dataSource());
        return sessionFactory.getObject();
    }
}

　PropertiesConfig

@Configuration
@PropertySource(value={"classpath:jdbc.properties"})
public class PropertiesConfig {
    @Bean
    public static PropertySourcesPlaceholderConfigurer propertyConfigInDev() {
        return new PropertySourcesPlaceholderConfigurer();
    }
}

　RootConfig

@Configuration
@ComponentScan(basePackages = {"com"})
public class RootConfig {
}

　WebConfig

@Configuration
@EnableWebMvc
@EnableAspectJAutoProxy
@EnableTransactionManagement
@ComponentScan("com.controller")
@MapperScan("com.dao")
public class WebConfig extends WebMvcConfigurerAdapter {
    @Bean
    public ViewResolver viewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        resolver.setExposeContextBeansAsAttributes(true);
        return resolver;
    }

    @Bean
    public StringHttpMessageConverter stringHttpMessageConverter(){
        return new StringHttpMessageConverter();
    }

    @Bean
    public MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter(){
        return new MappingJackson2HttpMessageConverter();
    }

    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        converters.add(stringHttpMessageConverter());
        converters.add(mappingJackson2HttpMessageConverter());
        super.configureMessageConverters(converters);
    }

    /**
     * 启用spring mvc 的注解
     */
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }
}

　　WebAppInitializer

/**
 * 配置SpringMVC需要添加DispatchServlet ，
 * DispatcherServlet主要负责前端调用URL的分发，
 * 它在Web容器初始化的时候被注册。
 * 这里配置中继承了DispatchServlet 的一个抽象类AbstractAnnotationConfigDispatcherServletInitializer ，
 * 此抽象类的父类在实例化的时候会注册一个DispatchServlet到容器中
 * 这里配置了容器初始化时需要加载的配置类 RootConfig,PropertiesConfig  和 WebConfig
 */
public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    /** 应用上下文、配置文件读取，数据库配置*/
    @Override
    protected Class<?>[] getRootConfigClasses() {
        System.out.println("======1.应用上下文、配置文件读取，数据库配置 load ================");
        return new Class<?>[]{RootConfig.class, PropertiesConfig.class, DatabaseConfig.class};
    }

    /* web上下文  */
    @Override
    protected Class<?>[] getServletConfigClasses() {
        System.out.println("======2.web上下文 load ================");
        return new Class<?>[]{WebConfig.class};
    }

    /*  DispatcherServlet的映射路径 */
    @Override
    protected String[] getServletMappings() {
        System.out.println("======3.DispatcherServlet的映射路径 load ================");
        return new String[]{"/"};
    }

    /* 注册过滤器，映射路径与DispatcherServlet一致，路径不一致的过滤器需要注册到另外的WebApplicationInitializer中*/
    @Override
    protected Filter[] getServletFilters() {
        CharacterEncodingFilter characterEncodingFilter = new CharacterEncodingFilter();
        characterEncodingFilter.setEncoding("UTF-8");
        characterEncodingFilter.setForceEncoding(true);
        return new Filter[]{characterEncodingFilter};
    }
}

　　6.  controller-TestController

@Controller
public class TestController {

    @Autowired
    @Qualifier("userService")
    private UserService userService;

    @RequestMapping(value = "/test", method = RequestMethod.GET)
    public String test() {
        return "test";
    }

    @RequestMapping(value = "/getuser/{username}", method = RequestMethod.GET)
    @ResponseBody
    public User getUser(@PathVariable String username) {
        return  userService.loadUserByUsername(username);
    }
}

　　7. dao-UserDao

@Controller
public class TestController {

    @Autowired
    @Qualifier("userService")
    private UserService userService;

    @RequestMapping(value = "/test", method = RequestMethod.GET)
    public String test() {
        return "test";
    }

    @RequestMapping(value = "/getuser/{username}", method = RequestMethod.GET)
    @ResponseBody
    public User getUser(@PathVariable String username) {
        return  userService.loadUserByUsername(username);
    }
}

　　8. entity-User

public class User {
    private Integer id;
    private String name;
    private Integer age;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

　　9. log-logAspect

@Component
@Aspect
public class LogAspect {
    private static final Logger logger = Logger.getLogger(LogAspect.class.getName());

    @Pointcut("execution(* com.controller.*.*(..))")
    public void performance() {
    }

    @Before("performance()")
    public void optionBefore(JoinPoint joinPoint){
        System.out.println("@Before开始执行"+joinPoint.getSignature().getDeclaringTypeName() +
                "." + joinPoint.getSignature().getName());
    }

    @After("performance()")
    public void optionAfter(JoinPoint joinPoint){
        System.out.println("@After结束执行"+joinPoint.getSignature().getDeclaringTypeName() +
                "." + joinPoint.getSignature().getName());
    }
    @Around("performance()")
    public Object optionAround(ProceedingJoinPoint pjp) throws Throwable {
        Object retVal = null;
        System.out.println("@Around start..");
        try {
            retVal = pjp.proceed();
        } catch (Throwable ex) {
            System.out.println("error in @Around");
            throw ex;
        }
        System.out.println("@Around end");
        return retVal;
    }

    @AfterReturning(pointcut = "performance()", returning = "returnValue")
    public void optionAfterReturn(JoinPoint joinPoint, Object returnValue) {
        System.out.println("@AfterReturning：目标方法为：" +
                joinPoint.getSignature().getDeclaringTypeName() +
                "." + joinPoint.getSignature().getName());
        System.out.println("@AfterReturning：参数为：" +
                Arrays.toString(joinPoint.getArgs()));
        System.out.println("@AfterReturning：返回值为：" + returnValue);
        System.out.println("@AfterReturning：被织入的目标对象为：" + joinPoint.getTarget());

    }

    @AfterThrowing(pointcut = "performance()", throwing = "e")
    public void optionError(JoinPoint joinPoint, Throwable e) {
        logger.log(Level.WARNING,"异常方法:{" + joinPoint.getTarget().getClass().getName() +
                "." + joinPoint.getSignature().getName() + "}" +
                "异常类型:{" + e.getClass().getName() + "}" +
                "异常信息:{" + e.getMessage() + "}" +
                "参数:{" + Arrays.toString(joinPoint.getArgs()) + "}", e);
    }
}

　　10. service-UserService

public interface UserService {

    User loadUserByUsername(String username);

    void saveUser(User user);
}

　　 11. service-impl-UserServiceImpl

@Service("userService")
public class UserServiceImpl implements UserService {

    @Autowired
    private UserDao userDao;

    @Transactional(readOnly = true)
    public User loadUserByUsername(String username) {
        return userDao.loadUserByUsername(username);
    }

    @Transactional
    public void saveUser(User user) {
        userDao.saveUser(user);
    }
}

　　12. maven 对应的pom文件如下：

<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</groupId>
    <artifactId>springJavaConfig</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>springJavaConfig Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.6</java.version>
    </properties>
    <dependencies>
        <dependency>
            <!--Unit Test -->
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
            <scope>test</scope>
        </dependency>
        <!-- Servlet -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <!-- SpringMVC -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.3.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>4.3.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
　　　　<!--Mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.2.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.1.1</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.8.5</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.8.5</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>springJavaConfig</finalName>
    </build>
</project>

　三. 启动过程打印日志：

Connected to server
[2018-01-17 10:47:20,950] Artifact springJavaConfig:war exploded: Artifact is being deployed, please wait...
一月 17, 2018 10:47:23 上午 org.apache.catalina.startup.TldConfig execute
信息: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
======1.应用上下文、配置文件读取，数据库配置 load ================
======2.web上下文 load ================
======3.DispatcherServlet的映射路径 load ================
一月 17, 2018 10:47:24 上午 org.springframework.web.context.ContextLoader initWebApplicationContext
信息: Root WebApplicationContext: initialization started
一月 17, 2018 10:47:24 上午 org.springframework.web.context.support.AnnotationConfigWebApplicationContext prepareRefresh
信息: Refreshing Root WebApplicationContext: startup date [Wed Jan 17 10:47:24 CST 2018]; root of context hierarchy
一月 17, 2018 10:47:24 上午 org.springframework.web.context.support.AnnotationConfigWebApplicationContext loadBeanDefinitions
信息: Registering annotated classes: [class com.config.RootConfig,class com.config.PropertiesConfig,class com.config.DatabaseConfig]
一月 17, 2018 10:47:25 上午 com.config.DatabaseConfig dataSource
信息: mysql url:jdbc:mysql://10.42.120.201:3306/test?useUnicode=true&characterEncoding=UTF-8
一月 17, 2018 10:47:25 上午 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping register
信息: Mapped "{[/test],methods=[GET]}" onto public java.lang.String com.controller.TestController.test()
一月 17, 2018 10:47:25 上午 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping register
信息: Mapped "{[/getuser/{username}],methods=[GET]}" onto public com.entity.User com.controller.TestController.getUser(java.lang.String)
一月 17, 2018 10:47:25 上午 org.springframework.web.servlet.handler.SimpleUrlHandlerMapping registerHandler
信息: Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.DefaultServletHttpRequestHandler]
一月 17, 2018 10:47:26 上午 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter initControllerAdviceCache
信息: Looking for @ControllerAdvice: Root WebApplicationContext: startup date [Wed Jan 17 10:47:24 CST 2018]; root of context hierarchy
一月 17, 2018 10:47:26 上午 org.springframework.web.context.ContextLoader initWebApplicationContext
信息: Root WebApplicationContext: initialization completed in 2370 ms
一月 17, 2018 10:47:26 上午 org.springframework.web.servlet.DispatcherServlet initServletBean
信息: FrameworkServlet 'dispatcher': initialization started
一月 17, 2018 10:47:26 上午 org.springframework.web.context.support.AnnotationConfigWebApplicationContext prepareRefresh
信息: Refreshing WebApplicationContext for namespace 'dispatcher-servlet': startup date [Wed Jan 17 10:47:26 CST 2018]; parent: Root WebApplicationContext
一月 17, 2018 10:47:26 上午 org.springframework.web.context.support.AnnotationConfigWebApplicationContext loadBeanDefinitions
信息: Registering annotated classes: [class com.config.WebConfig]
一月 17, 2018 10:47:26 上午 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping register
信息: Mapped "{[/test],methods=[GET]}" onto public java.lang.String com.controller.TestController.test()
一月 17, 2018 10:47:26 上午 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping register
信息: Mapped "{[/getuser/{username}],methods=[GET]}" onto public com.entity.User com.controller.TestController.getUser(java.lang.String)
一月 17, 2018 10:47:26 上午 org.springframework.web.servlet.handler.SimpleUrlHandlerMapping registerHandler
信息: Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.DefaultServletHttpRequestHandler]
一月 17, 2018 10:47:26 上午 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter initControllerAdviceCache
信息: Looking for @ControllerAdvice: WebApplicationContext for namespace 'dispatcher-servlet': startup date [Wed Jan 17 10:47:26 CST 2018]; parent: Root WebApplicationContext
一月 17, 2018 10:47:26 上午 org.springframework.web.servlet.DispatcherServlet initServletBean
信息: FrameworkServlet 'dispatcher': initialization completed in 356 ms
[2018-01-17 10:47:26,774] Artifact springJavaConfig:war exploded: Artifact is deployed successfully
[2018-01-17 10:47:26,775] Artifact springJavaConfig:war exploded: Deploy took 5,825 milliseconds　

可以看到，WebAppInitializer类中我们的配置类已经按顺序加载过了。

四、 测试

url 输入 http://localhost:8080/getuser/zhangsan，可以查看切面部分打印日志如下：

@Around start..
@Before开始执行com.controller.TestController.getUser
@Around end
@After结束执行com.controller.TestController.getUser
@AfterReturning：目标方法为：com.controller.TestController.getUser
@AfterReturning：参数为：[zhangsan]
@AfterReturning：返回值为：com.entity.User@182bab1a
@AfterReturning：被织入的目标对象为：com.controller.TestController@24b0c989