SpringMVC (three): springMVC common comment

1、RequestMapping

1.1 Role

• Action indicates the first stage based on the access directory;
• Action represents the second level of access to the directory on the method.

Note: The path can not write / presentation applications start at the root

1.2 Properties

• url given request path: path
• value: value attribute and path attribute is the same
• method: given request of the method
• params: Specifies restriction request condition parameter
• Request header request sent must be included: headers

1.3, RequestMapping use

    /**
     * RequestMapping注解
     * @return
     */
    @RequestMapping(value = "/testRequestMapping",params = {"username=heihei"},headers = {"Accept"})
    public String testRequestMapping() {
        System.out.println("测试RequestMapping注解...");
        return "success";
    }

2、RequestParam

2.1 Role

• Parameter specifies the name of the transfer request to the controller of the assigned parameter, parameter names commonly used in the solution and the request parameter name inconsistencies.

2.2 Properties

• value: Request parameter name
• equired: Request parameter whether this parameter must be provided, the default value is true, it must be provided

2.3, RequestParam use annotations

    /**
     * RequestParam注解：
     * @param username
     * @return
     */
    @RequestMapping("/testRequestParam")
    public String testRequestParam(@RequestParam(name="name") String username){
        System.out.println(username);
        return "success";
    }

3、RequestBody

3.1 Role

• A request for acquiring the content thereof (Note: get methods can not);
• Converting the character string into json JavaBean object.

3.2 Properties

• equired: Is it necessary to have the request body, the default value is true

3.3, RequestBody use annotations

    /**
     * RequestBody注解：获取到请求体的内容
     * @param body
     * @return
     */
    @RequestMapping("/testRequestBody")
    public String testRequestBody(@RequestBody String body){
        System.out.println(body);//username=zhangsan&password=123
        return "success";
    }

4, PathVariable

4.1 Role

• Binding has the url placeholder.

4.2 Properties

• value: Specifies the name url placeholder

4.3, PathVariable use annotations

    /**
     * PathVariable注解：
     * @return
     */
    @RequestMapping(value="/testPathVariable/{sid}")
    public String testPathVariable(@PathVariable(name="sid") String id){
        System.out.println(id);
        return "success";
    }

5、RequestHeader

5.1 Role

• Gets the value specified in the request header

5.2 Properties

• value: request header name

5.3, RequestHeader use annotations

    /**
     * RequestHeader注解：获取请求头的值
     * @param header
     * @param request
     * @param response
     * @return
     * @throws IOException
     */
    @RequestMapping(value="/testRequestHeader")
    public String testRequestHeader(@RequestHeader(value="Accept") String header, HttpServletRequest request, HttpServletResponse response) throws IOException {
        System.out.println(header);
        return "success";
        // response.sendRedirect(request.getContextPath()+"/anno/testCookieValue");
        //return "redirect:/param.jsp";
    }

6, Cookie Value

6.1 Role

• Gets the value for the cookie name

6.2 Properties

• value: cookie name

6.3, CookieValue use annotations

    /**
     * CookieValue注解：获取Cookie的值
     * @param cookieValue
     * @return
     */
    @RequestMapping(value="/testCookieValue")
    public String testCookieValue(@CookieValue(value="JSESSIONID") String cookieValue){
        System.out.println(cookieValue);
        return "success";
    }

7, ModelAttribute

7.1 Role

• Acting on the method that is the current front-line approach uses the method in the controller;
• Acting on the parameters, gets the specified data to the parameter assignment.

7.2, ModelAttribute use

    /**
     * ModelAttribute注解：作用在方法时，表示当前方法会在控制器方法执行前执行。
     * @param username
     * @param map
     */
    @ModelAttribute
    public void showUser(String username, Map<String,UserInfo> map){
        UserInfo userInfo = new UserInfo();
        userInfo.setUsername(username);
        userInfo.setPassword("123");
        userInfo.setDate(new Date());
        map.put("userInfo",userInfo);
    }

8、SessionAttribute

8.1 Role

• Parameters for performing the control method of sharing among multiple

8.2 Properties

• value: Specifies the name of the property into

8.3, SessionAttribute use annotations

package com.wedu.springmvc.web;

import com.wedu.springmvc.domain.UserInfo;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.bind.support.SessionStatus;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Date;
import java.util.Map;

/**
 * springmvc常用注解的使用
 */
@Controller
@RequestMapping("/annotation")
@SessionAttributes(value = {"msg"})
public class AnnoController {

    /**
     * SessionAttributes注解：用于多次执行控制器方法间的参数共享
     * 向session中存储数据
     * @return
     */
    @RequestMapping(value="/testSessionAttributes")
    public String testSessionAttributes(Model model){
        // 底层会存储到request域对象中
        model.addAttribute("msg","测试OK");
        return "success";
    }

    /**
     * 从session中获取值
     * @param modelMap
     * @return
     */
    @RequestMapping(value="/getSessionAttributes")
    public String getSessionAttributes(ModelMap modelMap){
        String msg = (String) modelMap.get("msg");
        System.out.println(msg);
        return "success";
    }

    /**
     * 将session中的值清除
     * @param status
     * @return
     */
    @RequestMapping(value="/delSessionAttributes")
    public String delSessionAttributes(SessionStatus status){
        System.out.println("将session中的值清除...");
        status.setComplete();
        return "success";
    }

}