Spring Web MVC基础理论概念

package com.example.demo;
import org.springframework.web.bind.annotation.*;
@RestController
public class DemoController {
    @RequestMapping("/hello")//可以理解为资源路径
    public String hello() {
        return "Hello World";
    }
}

package com.example.demo;
import org.springframework.web.bind.annotation.*;
@RequestMapping("/demo")
public class DemoController {
    @RequestMapping("/hello")//可以理解为资源路径
    public String hello() {
        return "Hello World";
    }
}

package com.example.demo;
import org.springframework.web.bind.annotation.*;
@RestController
@RequestMapping("/demo")
public class DemoController {
    @RequestMapping("/hello")//可以理解为资源路径
    public String hello() {
        return "Hello World";
    }
}

@RequestMapping(value = "/hello1",method = RequestMethod.GET)
public String hello1() {
    return "Hello World 1";
}

public @interface RequestMapping {
    String name() default "";
    @AliasFor("path")
    String[] value() default {};
    @AliasFor("value")
    String[] path() default {};
    RequestMethod[] method() default {};//method返回的是一个RequestMethod类型的数组
    String[] params() default {};
    String[] headers() default {};
    String[] consumes() default {};
    String[] produces() default {};
}

public enum RequestMethod {
    GET,
    HEAD,
    POST,
    PUT,
    PATCH,
    DELETE,
    OPTIONS,
    TRACE;
}

@RequestMapping(value = "/hello1",method = {RequestMethod.GET, RequestMethod.POST})
public String hello1() {
    return "Hello World 1";
}

@GetMapping("/hello3")
public String hello3() {
    return "Hello World 3";
}

@PostMapping("/hello4")
public String hello4() {
    return "Hello World 4";
}

@RequestMapping("/name1")
public String name1(String name) {
    System.out.println("接收到了" + name);
    return "接收到了" + name;
}

@RequestMapping("/age1")
public String age1(int age) {
    System.out.println("接收到了" + age);
    return "接收到了" + age;
}
@RequestMapping("/age2")
public String age2(Integer age) {
    return "接收到了" + age;
}

@RequestMapping("/person1")
public String person1(String name,Integer age) {
    return "接收到了name" + name + "接收到了age" + age;
}

@RequestMapping("/person3")
public String person3(Person person) {
    return person.getName()+person.getAge()+person.getSex();
}
package com.example.demo;
public class Person {
    public String name;
    public int age;
    public String sex;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
}

@RequestMapping("/person2")
public String person2(@RequestParam("Name") String name,Integer age) {
    return "接收到name" + name + "接收到age" + age;
}

public @interface RequestParam {
    @AliasFor("name")
    String value() default "";
    @AliasFor("value")
    String name() default "";
    boolean required() default true;
    String defaultValue() default "\n\t\t\n\t\t\n\ue000\ue001\ue002\n\t\t\t\t\n";
}

@RequestMapping("/person2")
public String person2(@RequestParam(value = "Name",required = false) String name,Integer age) {
    return "接收到name" + name + "接收到age" + age;
}

@RequestMapping("/param1")
public String param1(String[] arrayParam) {
    return Arrays.toString(arrayParam);
}

@RequestMapping("/param2")
public String param2(@RequestParam("ArrayParam") List<String> arrayParam) {
    return Arrays.toString(arrayParam.toArray());
}

{
	 "squadName": "Super hero squad",
	 "homeTown": "Metro City",
	 "formed": 2016,
	 "secretBase": "Super tower",
	 "active": true,
	 //数据保存在键值对中
	 //键和值之间使用:分割,键值对之间使用,分割
	 "members": [{
	 "name": "Molecule Man",
	 "age": 29,
	 "secretIdentity": "Dan Jukes",
	 "powers": ["Radiation resistance", "Turning tiny", "Radiation 
	blast"]//数组中可以包含多个元素
	 }, {//这个元素也可以是对象
	 "name": "Madame Uppercut",
	 "age": 39,
	 "secretIdentity": "Jane Wilson",
	 "powers": ["Million tonne punch", "Damage resistance", "Superhuman 
	reflexes"]
	 }, {
	 "name": "Eternal Flame",
	 "age": 1000000,
	 "secretIdentity": "Unknown",
	 "powers": ["Immortality", "Heat Immunity", "Inferno", 
	"Teleportation", "Interdimensional travel"]
	 }]
}

{"squadName":"Super hero squad","homeTown":"Metro 
City","formed":2016,"secretBase":"Super tower","active":true,"members":
[{"name":"Molecule Man","age":29,"secretIdentity":"Dan Jukes","powers":
["Radiation resistance","Turning tiny","Radiation blast"]},{"name":"Madame 
Uppercut","age":39,"secretIdentity":"Jane Wilson","powers":["Million tonne 
punch","Damage resistance","Superhuman reflexes"]},{"name":"Eternal 
Flame","age":1000000,"secretIdentity":"Unknown","powers":["Immortality","Heat 
Immunity","Inferno","Teleportation","Interdimensional travel"]}]}

package com.example.demo;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
public class json {
    private static ObjectMapper objectMapper = new ObjectMapper();
    public static void main(String[] args) throws JsonProcessingException {
        Person person = new Person();
        person.setName("zhangsan");
        person.setAge(18);
        person.setSex("男");
        String json = objectMapper.writeValueAsString(person);
        System.out.println(json);
        Person person2 = objectMapper.readValue(json, Person.class);//传入一个json字符串和一个类的类对象
        System.out.println(person2.toString());
    }
}
package com.example.demo;
public class Person {
    public String name;
    public int age;
    public String sex;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", sex='" + sex + '\'' +
                '}';
    }
}

@RequestMapping("/param3")
public String param3(@RequestBody Person person) {
    return person.toString();
}

{
    "name":"zhangsan",
    "age":18,
    "sex":"male"
}

@RequestMapping("/param4/{name}/{age}")
public String param4(@PathVariable String name,@PathVariable Integer age){
    return name+age;
}

@RequestMapping("/param4/{Name}/{Age}")
public String param4(@PathVariable("Name") String name,@PathVariable("Age") Integer age){
    return name+age;
}

@RequestMapping("/param5")
public String param5(@RequestPart("file") MultipartFile file) throws IOException {
    file.transferTo(new File("D:/personal/" + file.getOriginalFilename()));
    //上传文件,前面写的是存储文件的路径,后面加上原文件的名字
    return "已经获取到" + file.getOriginalFilename();
}

@RequestMapping("/param6")
public String param6(HttpServletRequest request, HttpServletResponse response) throws IOException  {
    Cookie[] cookies = request.getCookies();
    for (Cookie cookie : cookies) {
        System.out.print(cookie.getName()+":"+cookie.getValue());
    }
    return "已经获取到Cookie";
}

@RequestMapping("/param7")
public String param7(HttpServletRequest request) {
    Cookie[] cookies = request.getCookies();
    for (Cookie cookie : cookies) {
        if ("bite".equals(cookie.getName())) {
            return cookie.getValue();
        }
    }
    return "为获取到指定的Cookie";
}

    @RequestMapping("/param8")
    public String param8(@CookieValue("bite") String bite) {
        System.out.println("获取到了" + bite);
        return bite;
    }

@RequestMapping("/param9")
public String param9(HttpServletRequest request){
    //获取Session对象,如果不存在Session对象,getSession之后不加或参数为true会自动创建
    HttpSession session = request.getSession();
    if (session != null) {//确保Session成功创建
        session.setAttribute("bite", "888");
    }
    return "Session存储成功";
}

@RequestMapping("/param10")
public String param10(HttpServletRequest request){
    HttpSession session = request.getSession(false);
    if (session != null){
        String s = (String) session.getAttribute("bite");
        System.out.println("获取到了Session");
        return s;
    }
    return "未获取到Session";
}

@RequestMapping("/param11")
public String param11(@SessionAttribute(value = "bite",required = false)
                      String bite){
    return bite;
}

@RequestMapping("/param12")
public String param12(HttpSession session){
    String string = (String) session.getAttribute("bite");
    System.out.println("成功获取到了Session");
    return string;
}

@RequestMapping("/param13")
public String param13(HttpServletRequest request){
    return request.getHeader("User-Agent");
}

@RequestMapping("/param14")
public String param14(@RequestHeader("sec-ch-ua-platform") String string){
    return string;
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h1>我是index文件</h1>
</body>
</html>

@RequestMapping("/demo2")
@RestController
public class DemoController2 {
    @RequestMapping("/param1")
    public Object param1(){
        return "/index.html";
    }
}

@RequestMapping("/demo2")
@Controller
public class DemoController2 {
    @RequestMapping("/param1")
    public Object param1(){
        return "/index.html";
    }
}

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Controller
@ResponseBody
public @interface RestController {
    @AliasFor(
        annotation = Controller.class
    )
    String value() default "";
}

@RequestMapping("/demo2")
@Controller
public class DemoController2 {
    @RequestMapping("/param1")
    public Object param1(){
        return "/index.html";
    }
    @RequestMapping("param2")
    @ResponseBody
    public Object param2(){
        return "String";
    }
}

    @RequestMapping("/param3")
    @ResponseBody
    public String param3(){
        return "<h1>我是html~</h1>";
    }

@RequestMapping("/param4")
@ResponseBody
public HashMap<String,Integer> param4(){
    HashMap<String, Integer> map = new HashMap<>();
    map.put("aa",1);
    map.put("bb",2);
    map.put("cc",3);
    return map;
}

@RequestMapping("/param5")
@ResponseBody
public Person param5(){
    Person person = new Person();
    person.setName("zhangsan");
    person.setAge(19);
    person.setSex("male");
    return person;
}

@RequestMapping("/param6")
@ResponseBody
public String param6(HttpServletResponse response){
    response.setStatus(400);
    return "设置状态码为400";
}

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Mapping
@Reflective({ControllerMappingReflectiveProcessor.class})
public @interface RequestMapping {
    String name() default "";
    @AliasFor("path")
    String[] value() default {};
    @AliasFor("value")
    String[] path() default {};
    RequestMethod[] method() default {};
    String[] params() default {};
    String[] headers() default {};
    String[] consumes() default {};
    String[] produces() default {};
}

//返回的响应是json格式
@RequestMapping(value = "/param7",produces = "application/json")
@ResponseBody
public String param7(){
    return "{\"success\":true}";
}

@RequestMapping("/param8")
@ResponseBody
public String param8(HttpServletResponse response){
    response.setHeader("MyHeader","value");
    return "设置Header成功";
}