spring boot java配置搭建ssm 小案例（IDEA）

1、创建Maven工程，在pom.xml文件上添加<packaging>war</packaging> 并且添加 spring-webmvc 的依赖

<?xml version="1.0" encoding="UTF-8"?>
<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>org.javaboy</groupId>
    <artifactId>javassm</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>


    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
</project>

2、创建两个配置类，SpringConfig.java 和 SpringMVCConfig.java，两个类分别都加上 @Configuration 注解（标明此类为配置类）和 @ComponentScan注解（指定扫描包的位置）

SpringConfig.java 对应 Spring 容器的配置

@Configuration
@ComponentScan(basePackages = "org.javaboy",useDefaultFilters = true,excludeFilters = {@ComponentScan.Filter(type =
        FilterType.ANNOTATION,classes = Controller.class)})
public class SpringConfig {
}

 SpringMVCConfig.java 对应 springMVC 容器的配置

@Configuration
@ComponentScan(basePackages = "org.javaboy",useDefaultFilters = false,includeFilters = {@ComponentScan.Filter(type =
        FilterType.ANNOTATION,classes = Controller.class),@ComponentScan.Filter(type = FilterType.ANNOTATION,classes
        = Configuration.class)} )
public class SpringMVCConfig {

为什么 SpringMVCConfig.java 上的 @ComponentScan 注解包含有 @ComponentScan.Filter(type = FilterType.ANNOTATION,classes= Configuration.class)

因为创建好这两个配置类后，需要再创建一个类来加载它们，那就创建一个 WebInit.java 并实现 WebApplicationInitializer 接口，此处所做的事情就是 web.xml 所做的一样

public class WebInit implements WebApplicationInitializer {
    @Override
    public void onStartup(javax.servlet.ServletContext servletContext) throws ServletException {

        AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
        context.setServletContext(servletContext);
        context.register(SpringMVCConfig.class);
        ServletRegistration.Dynamic springmvc = servletContext.addServlet("springmvc", new DispatcherServlet(context));
        springmvc.addMapping("/");
        springmvc.setLoadOnStartup(1);
    }
}

此类只加载了一个 SpringMVCConfig.java , 而 SpringConfig.java 没有被加载，但是，在 SpringMVCConfig.java 上的 @ComponentScan 注解包含有 @ComponentScan.Filter(type = FilterType.ANNOTATION,classes= Configuration.class)

所以 SpringConfig.java 的加载可以通过先加载 SpringMVCConfig.java ，再加载包含有 @Configuration 注解的类。

3、创建controller

@RestController
public class HelloController {
    @Autowired
    HelloService helloService;
    @GetMapping(value = "/hello",produces = "text/html;charset=utf-8")
    public String hello(){
        return helloService.hello();
    }
}

4、创建service

@Service
public class HelloService {

    public String hello(){
        return "你好！世界！";
    }
}

5、配置Tomcat，跟 spring boot xml配置搭建ssm 操作一样；最后，启动tomcat，访问http://localhost:8080/hello

此文章是通过个人搬砖汇总所得，用于个人复习。如有错误，麻烦指出，谢谢！