SpringMVC学习笔记二：请求与响应
请求映射路径
- 多人开发，每人设置不同的请求路径，冲突问题如何解决？
设置模块名作为请求路径前缀
@Controller
//设置整体请求路径前缀
@RequestMapping("/hello")
public class HelloController {
//请求方式为-->localhost/hello/save
@RequestMapping("/save")
@ResponseBody
public String save(){
return "{'module':'springmvc'}";
}
//请求方式为-->localhost/hello/save
@RequestMapping("/delete")
@ResponseBody
public String delete(){
return "{'module':'springmvc delete'}";
}
}
请求方式
get请求
@Controller
public class HelloController {
//请求方式为-->localhost/hello/save?name=输入值&age=输入值2
@RequestMapping("/save")
@ResponseBody
public String save(String name,int age){
return "name = "+ name+"\n"+"age = "+ age;
}
}
测试结果
post请求
java程序不变，post使用请求体发送表单
post请求中文乱码的情况（在Servlet容器内设置过滤器）
public class ServletContainersInitConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
@Override
protected Class<?>[] getRootConfigClasses() {
return new Class[]{SpringConfig.class};
}
@Override
protected Class<?>[] getServletConfigClasses() {
return new Class[]{{SpringMVCConfig.class}};
}
@Override
protected String[] getServletMappings() {
return new String[]{"/"};
}
@Override
protected Filter[] getServletFilters() {
CharacterEncodingFilter filter = new CharacterEncodingFilter("UTF-8");
return new Filter[]{filter};
}
}
请求参数（一般类型）
1. 绑定请求参数和形参的映射关系
@Controller
public class HelloController {
//请求方式为-->localhost/hello/save?name=输入值&age=输入值2
@RequestMapping("/save")
@ResponseBody
//将请求参数name映射到形参username上
//请求方式为-->localhost/hello/save?name=输入值&age=输入值2
public String save(@RequestParam("name")String username,int age){
return "name = "+ name+"\n"+"age = "+ age;
}
}
2. 实体类传参
@Controller
public class HelloController {
//请求方式为-->localhost/hello/save?name=输入值&age=输入值2
@RequestMapping("/user")
@ResponseBody
//实体类：根据构造函数的形参名自动填充
public String save(User user){
System.out.println(user);
return user.toString();;
}
}
public class User {
private String username;
private int age ;
private Address address;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
@Override
public String toString() {
return "User{" +
"username='" + username + '\'' +
", age=" + age +
", address=" + address +
'}';
}
}
public class Address {
private String location;
public String getLocation() {
return location;
}
public void setLocation(String location) {
this.location = location;
}
@Override
public String toString() {
return "Address{" +
"location='" + location + '\'' +
'}';
}
}
结果
3. 数组传参
@Controller
public class HelloController {
@RequestMapping("/array")
@ResponseBody
public String user(String[] hobby){
System.out.println(Arrays.toString(hobby));
return Arrays.toString(hobby);
}
}
4. 集合传参
@Controller
public class HelloController {
@RequestMapping("/list")
@ResponseBody
public String user(@RequestParam List<String> list){
System.out.println(list.toString());
return list.toString();
}
}
json数据传输
- pom文件中导入依赖包
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.0</version>
</dependency>
- 在配置类加上注解
@Configuration
@ComponentScan({"controller"})
//自动转换json数据功能的开启
@EnableWebMvc
public class SpringMVCConfig{
}
- 在控制器类里面对应的方法中添加注解
@RequestMapping("/json/list")
@ResponseBody
//添加请求体注解：因为json数据是以请求体的形式进行发送
public String jsuser(@RequestBody List<String> list){
System.out.println(list.toString());
return list.toString();
}
@RequestMapping("/json/users")
@ResponseBody
public String jsuserlist(@RequestBody List<User> list){
System.out.println(list.toString());
return list.toString();
}
@RequestBody与@RequestParam区别
区别：
- @RequestBody：用于接收url地址传参，表单传参
- @RequestParam：用于接收json数据
应用 - 后期开发中，发送json格式数据为主，@RequestParam使用较广
- 发送非json数据格式，使用@RequestBody
日期类型参数传参
//日期类型传参
@RequestMapping("/date")
@ResponseBody
public String date(@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss") Date date){
System.out.println(date);
return date.toString();
}
实现原理
通过类型转换器Converter接口将一种类型转换为另一种类型
public interface Converter<S,T> {
@Nullable
T convert(S var1);
}
响应
在控制器类中定义以下功能函数
jsp页面
@RequestMapping("/page")
public String toPage(){
System.out.println("打开page页面");
return "page.jsp";
}
文本
@RequestMapping("/text")
@ResponseBody
public String toText(){
System.out.println("打开text");
return "text";
}
json对象
@RequestMapping("/useroutput")
@ResponseBody
public User toUser(){
User user = new User("LK", 12, null);
System.out.println("打开User");
return user;
}
响应@ResponseBody
HttpMessageConvertver:专门的web转换接口
