spring boot——请求与参数校验——spring-mvc——通过实体类对象获取（推荐）

本是古典何须时尚 2023-09-29 00:20 63阅读 0赞

### 通过实体类对象获取(推荐) ###

我们可以在 Controller 控制器方法的形参中设置一个实体类形参，如果请求参数的参数名与实体类中的属性名一致，那么 Spring MVC 会自动将请求参数封装到该实体类对象中。此时我们就可以通过该实体类对象获取所需的请求参数了。

> 注：我们推荐大家使用实体类对象来获取请求参数，这也是最常用的请求参数的方式之一，它能够有效地解决“控制器方法形参不适用于请求参数过多的请求”问题。

package org.example.entity;
    
    public class Student
    {
        private String firstName;
        private String lastName;
    
        public void setFirstName(String firstName)
        {
            this.firstName = firstName;
        }
    
        public String getFirstName()
        {
            return firstName;
        }
    
        public void setLastName(String lastName)
        {
            this.lastName = lastName;
        }
    
        public String getLastName()
        {
            return lastName;
        }
    
    }

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package org.example.controller.requestparam;
    
    import org.example.entity.Student;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.ResponseBody;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.servlet.http.HttpServletRequest;
    
    
    @RestController
    public class ForParamController
    {
    
        // http://localhost:8080/getRequestParam?name=C语言中文网&url=c.biancheng.net
    
        /**
         * 通过 HttpServletRequest 获取请求参数
         * @param request
         * @return
         */
        @RequestMapping("/getRequestParam")
        public String requestParam(HttpServletRequest request) {
    
            String name = request.getParameter("name");
            String url = request.getParameter("url");
    
            System.out.println("name:" + name);
            System.out.println("url:" + url);
    
    
            return "cheng_gong";
        }
    
    
        // http://localhost:8080/getRequestParam?firstName=C语言中文网&lastName=c.biancheng.net
        /**
         * 通过 HttpServletRequest 获取请求参数
         * @param request
         * @return
         */
        @RequestMapping(value = "/getRequestParam2")
        public String test2(HttpServletRequest request) {
            String a = request.getParameter("firstName");
            String b = request.getParameter("lastName");
            return a + b;
        }
    
    
    
    
        //http://localhost:8080/getRequestParam3?name=tom&language=java
    
        @RequestMapping("/getRequestParam3")
        public String test3(String name, String language) {
            System.out.println("a：" + name);
            System.out.println("b：" + language);
            return "success";
        }
    
    
    
        //  http://localhost:8080/getRequestParam4?name=tom&language=2
    
        @RequestMapping("/getRequestParam4")
        public String test4(String name, Integer language) {
            System.out.println("a：" + name);
            System.out.println("b：" + language);
            return "success";
        }
    
    
    
    
    
    
        //  http://localhost:8080/testRequestParam5?name=Java&pass=yyds
    
        @RequestMapping("/testRequestParam5")
        public String testRequestParam(@RequestParam("name") String username, @RequestParam("pass") String password) {
            System.out.println(username + "," + password);
            return "success";
        }
    
    
    
    
    
    
    
        //    http://localhost:8080/requestParam6?username=Java
    
        //    http://localhost:8080/requestParam6?username=
    
        @RequestMapping("/requestParam6")
        public String requestParam22(@RequestParam(value = "username",defaultValue = "abc21") String name)
        {
    
            return name;
        }
    
    
    
        
        
        // http://localhost:8080/requestParam7?firstName=Java&lastName=python
    
        @RequestMapping(value = "/requestParam7")
        public String test5(Student student)
        {
            String a = student.getFirstName();
            String b = student.getLastName();
            return a+b;
        }
    
    
    
    }

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[404ec02b066b5abf32c52dec20f7f2f1.png]: https://img-blog.csdnimg.cn/img_convert/404ec02b066b5abf32c52dec20f7f2f1.png
[16598217dd1a361cd2668261874dbe00.png]: https://img-blog.csdnimg.cn/img_convert/16598217dd1a361cd2668261874dbe00.png
[3dfc0777aad0fc944a04b74ddcb2216f.png]: https://img-blog.csdnimg.cn/img_convert/3dfc0777aad0fc944a04b74ddcb2216f.png