1.SpringMvc的常用注解
1. @Controller:用于声明一个控制器类。
2. @RequestMapping:用于映射请求 URL 到控制器类或处理方法上。
3. @RequestParam:用于获取请求参数的值。
4. @PathVariable:用于获取 URL 中的参数值。
5. @ResponseBody:用于将返回值转化为 JSON 格式或其他格式的数据。
6. @ModelAttribute:用于将请求参数绑定到模型对象上。
7. @Valid:用于验证请求参数。
8. @InitBinder:用于定义数据类型转换和格式化规则。
9. @SessionAttributes:用于将模型对象存储到会话中。
10. @ExceptionHandler:用于处理控制器方法中抛出的异常。
11. @RequestMapping(value=“”, method=RequestMethod.GET) 用于处理 GET 请求。
12. @RequestMapping(value=“”, method=RequestMethod.POST) 用于处理 POST 请求。
13. @RequestMapping(value=“”, method=RequestMethod.PUT) 用于处理 PUT 请求。
14. @RequestMapping(value=“”, method=RequestMethod.DELETE) 用于处理 DELETE 请求。
2.参数传递
基础类型(String)
@RequestMapping("/hello1") public String toHello1(Integer bid,String bname){ log.info(">>>> 基础类型+String传参:{},{}",bid,bname); return "index"; }
创建一个paramController类:
package com.zking.web; import lombok.extern.slf4j.Slf4j; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; /** * @author bin人 * @site www.zking.com * @company xy集团 * @create 2023-09-05-14:44 */ @Slf4j @Controller @RequestMapping("/param") public class ParamController { @RequestMapping("/hello1") public String index(String bname,Integer bid){ // System.out.println("放下屠刀"); log.info("简单类型参数:bname:{},bid:{}",bname,bid); return "index"; } }
创建一个index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <h1>立地成佛</h1> </body> </html>
测试结果
复杂方式
测试结果
@RequestParam
(用了这个required=false必须要传参数,要不然进入不了方法)
测试结果
必须要传bname要不然会报错,也接受不到值
传了值之后就可以正常访问了
@PathVariable
@RequestMapping("/hello4/{bid}") public String hello4(@PathVariable("bid") Integer bid){ log.info("@PathVariable:bid:{}",bid); // fail..error warning info debug return "index"; }
测试结果
@RequestBody
@RequestMapping("/hello5/{bid}") public String hello5(Map map){ log.info("@RequestBody:map:{}",map); // fail..error warning info debug return "index"; } @RequestMapping("/hello6/{bid}") public String hello6(@RequestBody Map map){ log.info("@RequestBody:map:{}",map); // fail..error warning info debug return "index"; }
想要用这个注解就必须导入架包依赖
pom.xml依赖导入
<?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>com.zking</groupId> <artifactId>yxssm</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>yxssm Maven Webapp</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <maven.compiler.plugin.version>3.7.0</maven.compiler.plugin.version> <!--添加jar包依赖--> <!--1.spring 5.0.2.RELEASE相关--> <spring.version>5.0.2.RELEASE</spring.version> <!--2.mybatis相关--> <mybatis.version>3.4.5</mybatis.version> <!--mysql--> <mysql.version>5.1.44</mysql.version> <!--pagehelper分页jar依赖--> <pagehelper.version>5.1.2</pagehelper.version> <!--mybatis与spring集成jar依赖--> <mybatis.spring.version>1.3.1</mybatis.spring.version> <!--3.dbcp2连接池相关 druid--> <commons.dbcp2.version>2.1.1</commons.dbcp2.version> <commons.pool2.version>2.4.3</commons.pool2.version> <!--4.log日志相关--> <log4j2.version>2.9.1</log4j2.version> <log4j2.disruptor.version>3.2.0</log4j2.disruptor.version> <slf4j.version>1.7.13</slf4j.version> <!--5.其他--> <junit.version>4.12</junit.version> <servlet.version>4.0.0</servlet.version> <lombok.version>1.18.2</lombok.version> <!-- jstl+standard --> <jstl.version>1.2</jstl.version> <standard.version>1.1.2</standard.version> <!-- spring --> <spring.version>5.0.2.RELEASE</spring.version> <jackson.version>2.9.3</jackson.version> </properties> <dependencies> <!--1.spring相关--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <!--2.mybatis相关--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>${mybatis.version}</version> </dependency> <!--mysql--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <!--pagehelper分页插件jar包依赖--> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>${pagehelper.version}</version> </dependency> <!--mybatis与spring集成jar包依赖--> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>${mybatis.spring.version}</version> </dependency> <!--3.dbcp2连接池相关--> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-dbcp2</artifactId> <version>${commons.dbcp2.version}</version> <exclusions> <exclusion> <artifactId>commons-pool2</artifactId> <groupId>org.apache.commons</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-pool2</artifactId> <version>${commons.pool2.version}</version> </dependency> <!--4.log日志相关依赖--> <!-- log4j2日志相关依赖 --> <!-- log配置:Log4j2 + Slf4j --> <!-- slf4j核心包--> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>${slf4j.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>jcl-over-slf4j</artifactId> <version>${slf4j.version}</version> <scope>runtime</scope> </dependency> <!--核心log4j2jar包--> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>${log4j2.version}</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>${log4j2.version}</version> </dependency> <!--用于与slf4j保持桥接--> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-slf4j-impl</artifactId> <version>${log4j2.version}</version> <exclusions> <exclusion> <artifactId>slf4j-api</artifactId> <groupId>org.slf4j</groupId> </exclusion> </exclusions> </dependency> <!--web工程需要包含log4j-web,非web工程不需要--> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-web</artifactId> <version>${log4j2.version}</version> <scope>runtime</scope> </dependency> <!--需要使用log4j2的AsyncLogger需要包含disruptor--> <dependency> <groupId>com.lmax</groupId> <artifactId>disruptor</artifactId> <version>${log4j2.disruptor.version}</version> </dependency> <!--5.其他--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>${junit.version}</version> <!--<scope>test</scope>--> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>${servlet.version}</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>${lombok.version}</version> <scope>provided</scope> </dependency> <!-- spring mvc相关依赖 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>${jstl.version}</version> </dependency> <dependency> <groupId>taglibs</groupId> <artifactId>standard</artifactId> <version>${standard.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>${jackson.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>${jackson.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> <version>${jackson.version}</version> </dependency> </dependencies> <build> <finalName>yxssm</finalName> <resources> <!--解决mybatis-generator-maven-plugin运行时没有将XxxMapper.xml文件放入target文件夹的问题--> <resource> <directory>src/main/java</directory> <includes> <include>**/*.xml</include> </includes> </resource> <!--解决mybatis-generator-maven-plugin运行时没有将jdbc.properites文件放入target文件夹的问题--> <resource> <directory>src/main/resources</directory> <includes> <include>jdbc.properties</include> <include>*.xml</include> </includes> </resource> </resources> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>${maven.compiler.plugin.version}</version> <configuration> <source>${maven.compiler.source}</source> <target>${maven.compiler.target}</target> <encoding>${project.build.sourceEncoding}</encoding> </configuration> </plugin> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.2</version> <dependencies> <!--使用Mybatis-generator插件不能使用太高版本的mysql驱动 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> </dependencies> <configuration> <overwrite>true</overwrite> </configuration> </plugin> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.1.0</version> </plugin> <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.1</version> </plugin> <plugin> <artifactId>maven-war-plugin</artifactId> <version>3.2.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> </plugins> </build> </project>
在导入依赖后我们还需要postman或者apipost/eolink等工具发送请求数据。 因为浏览器发送不了JSON数据请求。所以我们需要安装Eolink等第三方工具进行测试。
安装好后,按照以下步骤把参数填写好,query参数是往域名链接添加属性,如下:
输出结果
请看录像
通过方法五跟方法六的对比,可得出@RequestBody适用于专门接受Json
@RequestHeader
@RequestMapping("/hello7") public String hello7(@RequestHeader("jwt") String jwt){ // System.out.println("刘三金去拿奶茶喽。。。"); log.info("@RequestHeader参数:jwt:{}",jwt); // fail..error warning info debug return "index"; } @RequestMapping("/hello8") public String hello8(Book book, @RequestBody Map map, @RequestHeader("jwt") String jwt){ // System.out.println("刘三金去拿奶茶喽。。。"); log.info("Book:Book:{}",book.toString()); log.info("@RequestBody参数:Map:{}",map); log.info("@RequestHeader参数:jwt:{}",jwt); // fail..error warning info debug return "index"; }
测试结果
3.返回值
void
先写工具类:
package com.zking.utils; import java.io.PrintWriter; import javax.servlet.http.HttpServletResponse; import com.fasterxml.jackson.databind.ObjectMapper; public class ResponseUtil { public static void write(HttpServletResponse response,Object o)throws Exception{ response.setContentType("text/html;charset=utf-8"); PrintWriter out=response.getWriter(); out.println(o.toString()); out.flush(); out.close(); } public static void writeJson(HttpServletResponse response,Object o)throws Exception{ ObjectMapper om = new ObjectMapper(); // om.writeValueAsString(o)代表了json串 write(response, om.writeValueAsString(o)); } }
package com.zking.web; import com.zking.utils.ResponseUtil; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import javax.servlet.http.HttpServletResponse; import java.util.HashMap; import java.util.Map; /** * @author bing人 * @site * @company xy集团 * @create 2023-09-06 22:12 */ @Controller @RequestMapping("/rs") public class ReturnController { @RequestMapping("/hello1") public void hello1(HttpServletResponse response){ Map<String,Object> map=new HashMap<>(); map.put("code",200); map.put("msg","成功添加。"); try { ResponseUtil.writeJson(response,map); } catch (Exception e) { e.printStackTrace(); } } }
测试结果
Map
@ResponseBody//响应json数据 @RequestMapping("/hello2") public Map hello2(HttpServletResponse response) { Map<String, Object> map = new HashMap<>(); map.put("code", 200); map.put("msg", "成功添加。"); return map; }
测试结果
String
@RequestMapping("/hello3") public String hello3() { return "index"; }
测试结果
String+model
//String+model @RequestMapping("/hello4") public String hello4(Model model, HttpServletRequest request) { model.addAttribute("currentName","浏阳鞭炮"); request.setAttribute("location","来自于刘老板的"); return "index"; }
测试结果
ModelAndView
4.页面跳转
转发
// 场景一:转发到后台的某一个方法(当前类) @RequestMapping("/hello6") public String hello6(){ System.out.println("hello6"); return "forward:hello2"; } // 场景二:转发到后台的某一个方法(其他类) @RequestMapping("/hello7") public String hello7(){ System.out.println("hello7"); return "forward:/param/hello1"; }
测试结果
重定向
// 场景三:重定向到后台的某一个方法(当前类) @RequestMapping("/hello8") public String hello8(){ System.out.println("hello8"); return "forward:hello2"; } // 场景四:重定向后台的某一个方法(其他类) @RequestMapping("/hello9") public String hello9(){ System.out.println("hello9"); return "forward:/param/hello1"; }
测试结果