0. servlet-context-path
Servlet的默认初始前缀
server.servlet.context-path=/SpringMVCLearning
1. @RequestMapping 请求映射
@RequestMapping 源码：
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Mapping
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 {};
}
用来映射请求
@RestController
@RequestMapping("/annotationTest")
public class AnnotationTestController {
@RequestMapping(value = "/requestMapping1", method = RequestMethod.GET)
public String requestMappingTest1() {
return "RequestMapping1";
}
}
访问 http://127.0.0.1:8080/SpringMVCLearning/annotationTest/requestMapping1 得到结果：
RequestMapping1
1.1 Ant风格映射
? 匹配一个字符
* 匹配文件名中的任意字符
** 匹配多重路径
示例：
@RequestMapping(value = "/antMapping1/**", method = RequestMethod.GET)
public String antMappingTest(HttpServletRequest request) {
String requestURI = request.getRequestURI();
return requestURI;
}
访问 http://127.0.0.1:8080/SpringMVCLearning/annotationTest/antMapping1/hahaha 得到结果：
/SpringMVCLearning/annotationTest/antMapping1/hahaha
2. @RequestParam 获取请求参数
@RequestParam 源码：
@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
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";
}
2.1 获得具体的请求参数
示例：
@RequestMapping(value = "/requestParam")
public String requestParam(@RequestParam(value = "username", required = true) String username) {
return username;
}
访问 http://127.0.0.1:8080/SpringMVCLearning/annotationTest/requestParam?username=tom 得到结果：
tom
2.2 获取全部的请求参数 Map<String, String>
由源码注释可知，如果方法参数是一个 Map<String, String> 就可以获得全部的请求参数名和值。
示例：(示例中直接返回Map，供SpringBoot自动解析成为JSON，打印在浏览器上)
@RequestMapping(value = "/requestParamMap")
public Map<String, String> requestParamMap(@RequestParam Map<String, String> requestParam) {
return requestParam;
}
访问路径 ： http://127.0.0.1:8080/SpringMVCLearning/annotationTest/requestParamMap?username=tom&age=100&address=Shenzhen 得到结果:
3. @PathVariable 路径变量
@PathVariable 源码：
@Target({ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface PathVariable {
@AliasFor("name")
String value() default "";
@AliasFor("value")
String name() default "";
boolean required() default true;
}
3.1 获得具体的路径变量
示例：
@RequestMapping(value = "/pathVariable/{id}")
public String pathVariable(@PathVariable(value = "id") Integer id) {
return "Input Id is " + id;
}
访问 http://127.0.0.1:8080/SpringMVCLearning/annotationTest/pathVariable/1 ，得到结果：
Input Id is 1
3.2 获得全部的路径变量 Map<String, String>
由源码注释可知，如果方法参数是Map<String, String> , 则这个Map将会被填充为 全部的路径变量名和值。
@RequestMapping(value = "/pathVariableMap")
public String pathVariableMap(@PathVariable Map<String, String> map) {
map.get("xxx");
return "success";
}
4. @RequestHeader 获取请求头属性
@RequestHeader 源码：
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestHeader {
@AliasFor("name")
String value() default "";
@AliasFor("value")
String name() default "";
boolean required() default true;
String defaultValue() default ValueConstants.DEFAULT_NONE;
}
4.1 获取具体的请求头属性
示例：
@RequestMapping(value = "/requestHeader")
public Map<String, Object> requestHeader(@RequestHeader(value = "Connection") String connection,
@RequestHeader(value = "Host") String host) {
Map<String, Object> map = new HashMap<>();
map.put("Connection", connection);
map.put("Host", host);
return map;
}
访问路径 http://127.0.0.1:8080/SpringMVCLearning/annotationTest/requestHeader ，得到结果：
4.2 获取全部的请求头属性
根据源码注释可知，如果方法参数为 Map<String, String> 或者 HttpHeaders 将会被填充全部的请求头名称和值。
@RequestMapping(value = "/requestHeaderMap")
public Map<String, String> requestHeaderMap(@RequestHeader Map<String, String> map) {
return map;
}
访问 http://127.0.0.1:8080/SpringMVCLearning/annotationTest/requestHeaderMap，得到结果：
HttpHeaders 是 MultiValueMap 的实现类
5. @CookieValue 获得Cookie中的属性
@Cookie 源码：
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface CookieValue {
@AliasFor("name")
String value() default "";
@AliasFor("value")
String name() default "";
boolean required() default true;
String defaultValue() default ValueConstants.DEFAULT_NONE;
}
5.1 获得具体的Cookie属性
@RequestMapping(value = "/cookieValue")
public String cookieValue(@CookieValue("name") String name,
@CookieValue("name") HttpCookie cookie) {
System.out.println(cookie.getName() + cookie.getValue());
return name;
}
6. @RequestBody 获得请求体
@RequestBody 源码：
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestBody {
boolean required() default true;
}
6.1 获得请求体内容
@RequestMapping(value = "/requestBody")
public String requestBody(@RequestBody String requestBody) {
return requestBody;
}
7. @RequestAttribute 获取请求域中的值
@RequestAttribute 源码 ：
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestAttribute {
@AliasFor("name")
String value() default "";
@AliasFor("value")
String name() default "";
boolean required() default true;
}
7.1 获得具体的请求域中的值
取出之前通过 ServletRequest.setAttribute(String name, Object o) 设置的 Attribute 。
示例：
@RequestMapping(value = "/forward")
public String forward(HttpServletRequest request) {
// 设置Attribute
request.setAttribute("username", "tom");
return "forward:/annotationTest/requestAttribute";
}
@ResponseBody
@RequestMapping(value = "/requestAttribute")
public String requestAttribute(@RequestAttribute("username") String username) {
return username;
}
访问路径 http://127.0.0.1:8080/SpringMVCLearning/annotationTest/forward ，得到结果：
tom