SpringMVC
1.
1.新建一個Maven-webapp項目
2.導入依賴pom.xml
<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>org.example</groupId><artifactId>SpringMVC</artifactId><packaging>pom</packaging><modules><module>SpringMVC01-hellomvc</module></modules><version>1.0-SNAPSHOT</version><name>SpringMVC Maven Webapp</name><url>http://maven.apache.org</url><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>3.8.1</version><scope>test</scope></dependency> ?<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.33</version></dependency> ?<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis --><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.19</version></dependency> ?<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc --><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>6.2.9</version></dependency> ?<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc --><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>6.2.9</version></dependency> ?<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver --><dependency><groupId>org.aspectj</groupId><artifactId>aspectjweaver</artifactId><version>1.9.24</version></dependency> ?<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring --><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>3.0.5</version></dependency> ?<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.38</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.13.2</version><scope>test</scope></dependency> ?<dependency><groupId>jakarta.servlet</groupId><artifactId>jakarta.servlet-api</artifactId><version>6.0.0</version></dependency> ? ?</dependencies><build><resources><resource><directory>src/main/resources</directory><includes><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>true</filtering></resource><resource><directory>src/main/java</directory><includes><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>true</filtering></resource></resources></build> </project> ?
3.檢查項目結構/工件/WEB-INF/lib里有沒有導入依賴包
4.給webapp/WEB-INF/web.xml里替換了
<?xml version="1.0" encoding="UTF-8"?> <web-appxmlns="https://jakarta.ee/xml/ns/jakartaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_0.xsd"version="6.0"><display-name>Welcome to Tomcat</display-name><description>Welcome to Tomcat</description> </web-app>
5.在webapp/WEB-INF/jsp里寫個test.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head><title>Title</title> </head> <body> <h2>Hello World!111111111111111</h2> </body> </html> ?
6.在web.xml里配置DIspatchServlet
注意點: / 和 /*不一樣
-
/:只匹配所有的請求,不會去匹配jsp頁面
-
/*:匹配所有的請求,包括jsp頁面
<?xml version="1.0" encoding="UTF-8"?> <web-appxmlns="https://jakarta.ee/xml/ns/jakartaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_0.xsd"version="6.0"><display-name>Welcome to Tomcat</display-name><description>Welcome to Tomcat</description> ? <!-- 配置DispatchServlet,這是SpringMVC的核心,請求分發器,前端控制器--><servlet><servlet-name>springmvc</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- ? DispatchServlet要綁定Spring-mvc的配置文件--><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:springmvc-servlet.xml</param-value></init-param> <!-- ? 啟動級別:1--><load-on-startup>1</load-on-startup></servlet> ?<servlet-mapping><servlet-name>springmvc</servlet-name><url-pattern>/</url-pattern></servlet-mapping> </web-app>
7.SpringMVC的核心三要素:
-
處理器映射器
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處理器適配器
-
視圖解析器
在springmvc-servlet.xml中配置核心三要素
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beanshttps://www.springframework.org/schema/beans/spring-beans.xsd"> ? <!-- ? 處理器映射器--><bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/> <!-- ? 處理器適配器--><bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/> <!-- ? 視圖解析器--><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"> <!-- ? ? ? 前綴 ? prefix后綴 ? suffix --><property name="prefix" value="WEB-INF/jsp/"/><property name="suffix" value=".jsp"/></bean> ? </beans>
8.寫業務代碼HelloController
package com.lyj.controller; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; public class HelloController implements Controller {@Overridepublic ModelAndView handleRequest(jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response) throws Exception {ModelAndView mv = new ModelAndView();//業務代碼String result = "Hello World!";mv.addObject("msg", result);//視圖跳轉mv.setViewName("test");return mv;} } ?
9.回到springmvc-servlet.xml
BeanNameUrlHandlerMapping處理器有個特性,它會根據bean的名字來找,所有需要寫個bean
BeanNameUrlHandlerMapping根據輸入(http://localhost:8080/hello)的url(/hello)去匹配bean的id尋找controller
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beanshttps://www.springframework.org/schema/beans/spring-beans.xsd"> ?<!-- ? 處理器映射器--><bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/><!-- ? 處理器適配器--><bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/><!-- ? 視圖解析器--><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"><!-- ? ? ? 前綴 ? prefix后綴 ? suffix--><property name="prefix" value="WEB-INF/jsp/"/><property name="suffix" value=".jsp"/></bean> <!-- ? BeanNameUrlHandlerMapping bean--><bean id="/hello" class="com.lyj.controller.HelloController"/> ? </beans>
2.使用注解開發SpringMVC
1.導包
2.web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-appxmlns="https://jakarta.ee/xml/ns/jakartaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_0.xsd"version="6.0"><display-name>Welcome to Tomcat</display-name><description>Welcome to Tomcat</description> ?<!-- 配置DispatchServlet,這是SpringMVC的核心,請求分發器,前端控制器--><servlet><servlet-name>springmvc</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><!-- ? DispatchServlet要綁定Spring-mvc的配置文件--><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:springmvc-servlet.xml</param-value></init-param><!-- ? 啟動級別:1--><load-on-startup>1</load-on-startup></servlet> ? ?<servlet-mapping><servlet-name>springmvc</servlet-name><url-pattern>/</url-pattern></servlet-mapping> </web-app>
3.配置springmvc-servlet.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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/beanshttps://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttps://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvchttps://www.springframework.org/schema/mvc/spring-mvc.xsd"> ? ? <!-- ? 自動掃描包,讓指定報下的注解生效,由IOC容器統一管理--><context:component-scan base-package="com.lyj.controller"/> ? <!-- ? 過濾:讓SpringMVC不處理靜態資源--><mvc:default-servlet-handler/> <!-- ? 支持mvc注解驅動--> <!-- ? 在spring中一般采用@RequestMapping注解來完成映射關系--> <!-- ? 要使注解生效--> <!-- ? 必須想上下文中注冊DefaultAnnotationHandlerMapping--> <!-- ? 和一個AnnotationMethodHandlerAdapter實例--> <!-- ? 這兩個實例分別在類級別和方法級別處理--> <!-- ? 而annotation-driver配置幫助我們自動完成上述兩個實例的注入--> ? ?<!-- ? 視圖解析器--><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"><!-- ? ? ? 前綴 ? prefix后綴 ? suffix--><property name="prefix" value="WEB-INF/jsp/"/><property name="suffix" value=".jsp"/></bean> ? ? </beans> ? ?
4.HelloController
package com.lyj.controller; ? import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; ? @Controller public class HelloController {@RequestMapping("/hello")public String hello(Model model){//封裝數據model.addAttribute("msg","hello,controller"); ?return "hello";//會被視圖解析器處理} ? } ?
3.RestFul
3.1
1.配置web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-appxmlns="https://jakarta.ee/xml/ns/jakartaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_0.xsd"version="6.0"><display-name>Welcome to Tomcat</display-name><description>Welcome to Tomcat</description> ?<!-- 配置DispatchServlet,這是SpringMVC的核心,請求分發器,前端控制器--><servlet><servlet-name>springmvc</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><!-- ? DispatchServlet要綁定Spring-mvc的配置文件--><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:springmvc-servlet.xml</param-value></init-param><!-- ? 啟動級別:1--><load-on-startup>1</load-on-startup></servlet> ? ?<servlet-mapping><servlet-name>springmvc</servlet-name><url-pattern>/</url-pattern></servlet-mapping> </web-app>
2.配置springmvc-servlet.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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/beanshttps://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttps://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvchttps://www.springframework.org/schema/mvc/spring-mvc.xsd"> ? ? <!-- ? 自動掃描包,讓指定報下的注解生效,由IOC容器統一管理--><context:component-scan base-package="com.lyj.controller"/> ? <!-- ? 過濾:讓SpringMVC不處理靜態資源--><mvc:default-servlet-handler/> ?<mvc:annotation-driven/> <!-- ? 支持mvc注解驅動--> <!-- ? 在spring中一般采用@RequestMapping注解來完成映射關系--> <!-- ? 要使注解生效--> <!-- ? 必須想上下文中注冊DefaultAnnotationHandlerMapping--> <!-- ? 和一個AnnotationMethodHandlerAdapter實例--> <!-- ? 這兩個實例分別在類級別和方法級別處理--> <!-- ? 而annotation-driver配置幫助我們自動完成上述兩個實例的注入--> ? ?<!-- ? 視圖解析器--><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"><!-- ? ? ? 前綴 ? prefix后綴 ? suffix--><property name="prefix" value="/WEB-INF/jsp/"/><property name="suffix" value=".jsp"/></bean> ? ? </beans> ? ?
3.實現Controller接口,ControllerTest1
package com.lyj.controller; ? import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.Controller; ? public class ControllerTest1 implements Controller {@Overridepublic ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {ModelAndView mv = new ModelAndView();mv.addObject("msg","ControllerTest1");mv.setViewName("test");return mv;} } ?
4.寫一下webapp/WEb-INF/jsp/test.jsp
? <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head><title>Title</title> </head> <body> ${msg} ? </body> </html> ?
5.在springmvc-servlet .xml中注冊請求的bean:name對應的請求路徑,class對應處理請求的類
<bean name="/t3" class="com.lyj.controller.ControllerTest1"/>
<?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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/beanshttps://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttps://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvchttps://www.springframework.org/schema/mvc/spring-mvc.xsd"> ? ? <!-- ? 自動掃描包,讓指定報下的注解生效,由IOC容器統一管理--><context:component-scan base-package="com.lyj.controller"/> ? <!-- ? 過濾:讓SpringMVC不處理靜態資源--><mvc:default-servlet-handler/> ?<mvc:annotation-driven/> <!-- ? 支持mvc注解驅動--> <!-- ? 在spring中一般采用@RequestMapping注解來完成映射關系--> <!-- ? 要使注解生效--> <!-- ? 必須想上下文中注冊DefaultAnnotationHandlerMapping--> <!-- ? 和一個AnnotationMethodHandlerAdapter實例--> <!-- ? 這兩個實例分別在類級別和方法級別處理--> <!-- ? 而annotation-driver配置幫助我們自動完成上述兩個實例的注入--> ? ?<!-- ? 視圖解析器--><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"><!-- ? ? ? 前綴 ? prefix后綴 ? suffix--><property name="prefix" value="/WEB-INF/jsp/"/><property name="suffix" value=".jsp"/></bean> ?<bean name="/t3" class="com.lyj.controller.ControllerTest1"/> ? </beans> ? ?
6.測試ControllerTest2
package com.lyj.controller; ? import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; ? @Controller public class ControllerTest2 { ?@RequestMapping("/t2")public String test1(Model model){model.addAttribute("msg","ControllerTest2");return "test";}@RequestMapping("/t3")public String test2(Model model){model.addAttribute("msg","ControllerTest3");return "test";} } ?
3.2
1.新建一個類RestFulController
有兩種訪問路徑
-
訪問路徑1:http://localhost:8080/add?a=1&b=2
-
訪問路徑2:http://localhost:8080/add/a/b
2.訪問路徑1,RestFulController
package com.lyj.controller; ? import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; ? @Controller public class RestFulController { ?// 訪問路徑:http://localhost:8080/add?a=1&b=2@RequestMapping("/add")public String test(@RequestParam("a") int a, ?// 顯式指定參數名為"a"@RequestParam("b") int b, ?// 顯式指定參數名為"b"Model model ){int res = a + b;model.addAttribute("msg", "結果是" + res);return "test";} ? ? } ?
3.訪問路徑2:在SpringMVC中可以使用@PathVariable注解,讓方法參數的值對用綁定到一個URL模板變量上
package com.lyj.controller; ? import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; ? @Controller public class RestFulController { ? ? ?@RequestMapping("/add/{a}/{b}")public String test(@PathVariable("a") int a, ?// 顯式指定參數名為"a"@PathVariable("b") int b, ?// 顯式指定參數名為"b"Model model ){int res = a + b;model.addAttribute("msg", "結果是" + res);return "test";} } ?
想要指定的方式請求:
1:
2:
@getMapping @PostMapping @PutMapping @DeleteMapping @PatchMapping
4.轉發和重定向
4.1
在沒有配置視圖解析器的情況要要實現轉發和重定向
4.2
在有配置視圖解析器的情況要要實現轉發和重定向
5.接收請求參數及數據回顯
1.實體類 pojo/User
package com.lyj.pojo; ? import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; ? @Data @AllArgsConstructor @NoArgsConstructor public class User {private int id;private String name;private int age; } ?
2.UserController
t1是@ResquestParam
t2是使用User對象,如果使用對象,前端傳遞的參數名必須和對象名一致
package com.lyj.controller; ? import com.lyj.pojo.User; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; ? @Controller @RequestMapping("/user") public class UserController { ?@GetMapping("/t1")public String test1(//請求方式http://localhost:8080/t3/user/t1?name=1111@RequestParam("name") String name, ?// 顯式綁定請求參數 "name"Model model) {System.out.println("接收到前端的參數為:" + name);model.addAttribute("msg", name); // 傳遞到前端視圖return "test"; // 跳轉至 test.jsp 或其他視圖} ?@GetMapping("/t2")public String test2(User user, Model model){//http://localhost:8080/t3/user/t2?id=888&name=1111&age=321System.out.println(user);return "test";} }//請求方式http://localhost:8080/t3/user/t1?name=1111 ?
6.JSON講解
1.jackson 依賴包
<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind --> <dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.19.2</version> </dependency>
2.web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-appxmlns="https://jakarta.ee/xml/ns/jakartaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_0.xsd"version="6.0"><display-name>Welcome to Tomcat</display-name><description>Welcome to Tomcat</description> ?<!--1.注冊servlet--><servlet><servlet-name>SpringMVC</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><!--通過初始化參數指定SpringMVC配置文件的位置,進行關聯--><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:springmvc-servlet.xml</param-value></init-param><!-- 啟動順序,數字越小,啟動越早 --><load-on-startup>1</load-on-startup></servlet> ?<!--所有請求都會被springmvc攔截--><servlet-mapping><servlet-name>SpringMVC</servlet-name><url-pattern>/</url-pattern></servlet-mapping> ?<filter><filter-name>encoding</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>encoding</filter-name><url-pattern>/</url-pattern></filter-mapping> </web-app>
3.springmvc-servlet.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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/beanshttps://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttps://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvchttps://www.springframework.org/schema/mvc/spring-mvc.xsd"> ? ?<!-- ? 自動掃描包,讓指定報下的注解生效,由IOC容器統一管理--><context:component-scan base-package="com.lyj.controller"/> ?<!-- ? 過濾:讓SpringMVC不處理靜態資源--><mvc:default-servlet-handler/> ?<mvc:annotation-driven/><!-- ? 支持mvc注解驅動--><!-- ? 在spring中一般采用@RequestMapping注解來完成映射關系--><!-- ? 要使注解生效--><!-- ? 必須想上下文中注冊DefaultAnnotationHandlerMapping--><!-- ? 和一個AnnotationMethodHandlerAdapter實例--><!-- ? 這兩個實例分別在類級別和方法級別處理--><!-- ? 而annotation-driver配置幫助我們自動完成上述兩個實例的注入--> ? ?<!-- ? 視圖解析器--><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"><!-- ? ? ? 前綴 ? prefix后綴 ? suffix--><property name="prefix" value="/WEB-INF/jsp/"/><property name="suffix" value=".jsp"/></bean> ?? </beans> ? ?
4.webapp/WEB-INF/jsp
5.pojo/User
package com.lyj.pojo; ? import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; ? @Data @AllArgsConstructor @NoArgsConstructor public class User { ?private String name;private int age;private String sex; } ?
6.UserControllre
package com.lyj.controller; ? import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.lyj.pojo.User; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; ? @Controller public class UserController {@RequestMapping(value = "/j1",produces ="application/json;charset=utf-8" )@ResponseBodypublic String json1() throws JsonProcessingException {ObjectMapper mapper = new ObjectMapper(); ?User user = new User("名字",20,"男"); ?String str = mapper.writeValueAsString(user);return str;} } ?
@Controller和@RestController
@Controller 走視圖解析器
@RestController 直接返回字符串
@ResponseBody 是配合@Controller使用的
亂碼問題
注意:亂碼問題解決:
@RequestMapping(value = "/j1",produces ="application/json;charset=utf-8" )
上述方法需要頻繁添加,所以在springmvc-servlet.xml 里添加 mvc:annotation-driven/配置
<?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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/beanshttps://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttps://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvchttps://www.springframework.org/schema/mvc/spring-mvc.xsd"> ? ?<!-- ? 自動掃描包,讓指定報下的注解生效,由IOC容器統一管理--><context:component-scan base-package="com.lyj.controller"/> ? <!-- ? 解決JSON亂碼問題配置--><mvc:annotation-driven><mvc:message-converters register-defaults="true"><bean class="org.springframework.http.converter.StringHttpMessageConverter"><constructor-arg value="UTF-8"/></bean><bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"><property name="objectMapper"><bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean"><property name="failOnEmptyBeans" value="false"/></bean></property></bean></mvc:message-converters></mvc:annotation-driven> ? ?<!-- ? 過濾:讓SpringMVC不處理靜態資源--><mvc:default-servlet-handler/> ? <!-- ? <mvc:annotation-driven/>--><!-- ? 支持mvc注解驅動--><!-- ? 在spring中一般采用@RequestMapping注解來完成映射關系--><!-- ? 要使注解生效--><!-- ? 必須想上下文中注冊DefaultAnnotationHandlerMapping--><!-- ? 和一個AnnotationMethodHandlerAdapter實例--><!-- ? 這兩個實例分別在類級別和方法級別處理--><!-- ? 而annotation-driver配置幫助我們自動完成上述兩個實例的注入--> ? ?<!-- ? 視圖解析器--><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"><!-- ? ? ? 前綴 ? prefix后綴 ? suffix--><property name="prefix" value="/WEB-INF/jsp/"/><property name="suffix" value=".jsp"/></bean> ? ? ? </beans> ? ?
7.fastjson
<!-- https://mvnrepository.com/artifact/com.alibaba.fastjson2/fastjson2 --> <dependency><groupId>com.alibaba.fastjson2</groupId><artifactId>fastjson2</artifactId><version>2.0.57</version> </dependency>