Spring MVC数据绑定入门总结

1.基本类型

基本类型参数不可为空
正例：http://localhost:8080/demo/he?id=2
反例：http://localhost:8080/demo/he?id=（报400错误）
注意：String不是基本类型，具体参考>Java数据类型

@RestController //定义控制器返回字符串
public class HelloController {

    @RequestMapping(value = "/hello", method = RequestMethod.GET)
    public String printHello(int id) {
        return "Response:"+id;
    }

    //添加@RequestParam(required=false)参数可为空
    @RequestMapping(value = "/hello", method = RequestMethod.GET)
    public String printHello(@RequestParam(required=false)int id) {
        return "Response:"+id;
    }

}

2.包装类和数组的处理

@RestController
public class HelloController {

    // http://localhost:8080/demo/hello?id=1
    @RequestMapping(value = "/hello", method = RequestMethod.GET)
    public String printHello(Integer id) {
        return "Response:"+id;
    }

    // http://localhost:8080/demo/hi?name=Tom&name=Jim
    @RequestMapping(value = "/hi", method = RequestMethod.GET)
    public String printHello(String[] name) {
        return "Response:"+anme;
    }

}

3.简单对象&多层级对象&同属性对象

    //简单对象
    //http://127.0.0.1:8080/Spring/hi?age=10&name=Tom
    @RequestMapping(value="/hi", method = RequestMethod.GET)
    @ResponseBody
    public String object(Student student){
        return student.toString();
    }

    //多层级对象
    //http://127.0.0.1:8080/Spring/hi2?age=10&name=Tom&student.age=18
    @RequestMapping(value="/hi2", method = RequestMethod.GET)
    @ResponseBody
    public String object2(Admin admin){
        return admin.toString();
    }

    //同属性的多对象
    //http://127.0.0.1:8080/Spring/hi3?name=Tom&student.age=18
    @RequestMapping(value="/hi3", method = RequestMethod.GET)
    @ResponseBody
    public String object3(Student student, Admin admin){
        return student.toString()+admin.toString();
    }

    //同属性的多对象赋值 需指定对象的前缀
    @InitBinder("student")
    public void initStudent(WebDataBinder binder){
        binder.setFieldDefaultPrefix("student.");
    }

    //同属性的多对象赋值 需指定对象的前缀
    @InitBinder("admin")
    public void initStudent2(WebDataBinder binder){
        binder.setFieldDefaultPrefix("admin.");
    }

4.List&Set&Map

public class ListFrom {
    private List<Student> users ;

    getter setter...

    @Override
    public String toString() {
        return "ListFrom [users=" + users + "]";
    }

}

public class MapFrom {
    private Map<String, Student> users ;

    getter setter...

    @Override
    public String toString() {
        return "MapFrom [users=" + users + "]";
    }   

}

@RestController
public class DataController {

    //List对象
    //http://127.0.0.1:8080/Spring/list?users[0].age=10&users[1].name=Tom
    @RequestMapping(value="/list", method = RequestMethod.GET, produces={"text/html;charset=UTF-8"})    //支持中文
    public String object2(ListFrom s){
        return s.toString();
    }

    //Map对象
    //http://127.0.0.1:8080/Spring/map?users["X"].age=10&users["Y"].name=Tom
    @RequestMapping(value="/map", method = RequestMethod.GET)
    public String object3(MapFrom s){
        return s.toString();
    }
}

5.Json或Xml 数据参数

@RequestBody 注解

    //发送json数据到该url即可实现数据绑定
    @RequestMapping(value="/json", method = RequestMethod.POST)
    public String object3(@RequestBody Student s){
        return s.toString();
    }

对于xml数据，需要在实体类中添加注释

@XmlRootElement(name = "admin")
public class Admin {
    private String name;
    private Integer age;

    @XmlElement(name = "name")
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @XmlElement(name = "age")
    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

然后

    //发送xml数据到该url即可实现数据绑定
    @RequestMapping(value="/xml", method = RequestMethod.POST)
    public String object3(@RequestBody Admin s){
        return s.toString();
    }

6. PropertyEditor、Formatter、Converter

局部配置

    //PropertyEditor
    //http://127.0.0.1:8080/Spring_iMooc/date1?date1=2018-01-01
    @RequestMapping(value="/date1", method = RequestMethod.GET)
    public String date1(Date date1){
        return date1.toString();
    }
    @InitBinder("date1")
    public void initDate1(WebDataBinder binder){
        binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd"), true));
    }

全局配置
1）自定义Formatter

2）注入

3）使用

也可以使用自定义Converter
1）自定义

2）配置

3）使用

7.RESTful扩展

简单来说，就是把参数移到URL上，比如下面。

   https://docs.spring.io/spring-boot/docs/1.5.10.RELEASE/reference/pdf/spring-boot-reference.pdf　 http://jbk.39.net/xebm/

使用方法

@RequestMapping("/subject/{name}")public String demo(@PathVariable("name") String name){　　return name;}

路径URL也支持通配符匹配

通配符	描述
?	匹配任何单字符
*	匹配0或者任意数量的字符
**	匹配0或者更多的目录