简单参数

• 原始方式

  在原始的web程序中，获取请求参数，需要通过HttpServletRequest对象手动获取。

      @RequestMapping("/simpleParam")
      public String simpleParam(HttpServletRequest request) {
          String name = request.getParameter("name");
          String age = request.getParameter("age");
          System.out.println("Name: " + name + " Age: " + age);
          return "Name: " + name + " Age: " + age;
      }
  

  

• SpringBoot方式

  • 请求参数名与方法形参变量名相同
  • 会自动进行类型转换

      @RequestMapping("/simpleParam")
      public String simpleParam(String name, Integer age) {
          System.out.println("Name: " + name + " Age: " + age);
          return "Name: " + name + " Age: " + age;
      }
  

  

  如果方法形参名称与请求参数名称不匹配，可以使用@RequestParam完成映射。

      @RequestMapping("/simpleParam")
      public String simpleParam(@RequestParam(name="Name") String name, Integer age) {
          System.out.println("Name: " + name + " Age: " + age);
          return "Name: " + name + " Age: " + age;
      }
  

  注意：@RequestParam中的required属性默认为true，代表该请求参数必须传递，如果不传递将报错。如果该参数是可以选的，可以将required属性设置为false。

      @RequestMapping("/simpleParam")
      public String simpleParam(@RequestParam(name="Name", required = false) String name, Integer age) {
          System.out.println("Name: " + name + " Age: " + age);
          return "Name: " + name + " Age: " + age;
      }
  

实体参数

• 简单实体参数：请求参数名与形参对象属性名相同，定义POJO接收即可。

  在pojo目录下新建User.java文件，并设置：

  package com.example.pojo;
  
  public class User {
      private String name;
      private Integer age;
  
      public User() {
      }
  
      public User(String name, Integer age) {
          this.name = name;
          this.age = age;
      }
  
      public String getName() {
          return name;
      }
  
      public void setName(String name) {
          this.name = name;
      }
  
      public Integer getAge() {
          return age;
      }
  
      public void setAge(Integer age) {
          this.age = age;
      }
  }
  
  

  在controller层内添加：

      @RequestMapping("/simplePojo")
      public String simplePojo(User user) {
          System.out.println("Name: " + user.getName() + " Age: " + user.getAge());
          return "simplePoj:  Name: " + user.getName() + " Age: " + user.getAge();
      }
  

  

• 复杂实体参数

  

  新建Address.java文件

  package com.example.pojo;
  
  public class Address {
      private String province;
      private String city;
  
      public String getProvince() {
          return province;
      }
  
      public void setProvince(String province) {
          this.province = province;
      }
  
      public String getCity() {
          return city;
      }
  
      public void setCity(String city) {
          this.city = city;
      }
      public String toString() {
          return "Address{" +
                  "province='" + province + '\'' +
                  ", city='" + city + '\'' +
                  '}';
      }
  }
  
  

  修改User.java：

  package com.example.pojo;
  
  public class User {
      private String name;
      private Integer age;
  
      private Address address;
  
      public Address getAddress() {
          return address;
      }
  
      public void setAddress(Address address) {
          this.address = address;
      }
  
      public User() {
      }
  
      public User(String name, Integer age) {
          this.name = name;
          this.age = age;
      }
  
      public String getName() {
          return name;
      }
  
      public void setName(String name) {
          this.name = name;
      }
  
      public Integer getAge() {
          return age;
      }
  
      public void setAge(Integer age) {
          this.age = age;
      }
      public String toString() {
          return "User{" +
                  "name='" + name + '\'' +
                  ", age=" + age +
                  ", address=" + address +
                  '}';
      }
  }
  
  

  在controller层添加新GET：

      @RequestMapping("/complexPojo")
      public String complexPojo(User user) {
          System.out.println(user);
          return "complexPojo: " + user;
      }