回顾传统SpringMVC搭建

1.pom依赖

<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.2.2.RELEASE</version>
</dependency>

<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.2.2.RELEASE</version>
</dependency>

2.添加spring支持

?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_2_5.xsd"
	id="WebApp_ID" version="2.5">

	<display-name>Archetype Created Web Application</display-name>

	<!-- needed for ContextLoaderListener -->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:bean.xml</param-value>
	</context-param>

	<!-- Bootstraps the root web application context before servlet initialization -->
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
</web-app>

3.添加springmvc支持

<!-- The front controller of this Spring Web application, responsible for 
		handling all application requests -->
<servlet>
    <servlet-name>springDispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:mvc.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<!-- Map all requests to the DispatcherServlet for handling -->
<servlet-mapping>
    <servlet-name>springDispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

4.编码问题

<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>
</filter>

<filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

5.mvc.xml配置

<context:component-scan base-package="demo.controller" use-default-filters="false">
		<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
		<context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
</context:component-scan>

<mvc:default-servlet-handler/>
<!-- 	当配置了mvc:annotation-driven/后，Spring就知道了我们启用注解驱动。然后Spring通过context:component-scan/标签的配置，会自动为我们将扫描到的@Component，@Controller，@Service，@Repository等注解标记的组件注册到工厂中，来处理我们的请求。 -->
<mvc:annotation-driven></mvc:annotation-driven>

6.控制器

@RequestMapping("/hello")
@RestController
public class HelloController {

	@GetMapping
	public String hello() {
		
		return "hello";
	}
}

7.测试

8.返回对象

public class User {

	private int id;

	private String name;
	

	public User(int id, String name) {
		super();
		this.id = id;
		this.name = name;
	}

	public int getId() {
		return id;
	}

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

	public String getName() {
		return name;
	}

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

}

@RequestMapping("/hello")
@RestController
public class HelloController {

	@GetMapping
	public String hello() {
		
		return "hello";
	}
	
	@GetMapping("/user")
	public User getUser() {
		return new User(30,"luopeng");
	}
}

9.测试

10.解决

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.10.1</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.10.1</version>
</dependency>

11.测试