GET And POST request

List of articles

Common situation

GET

1. form label method=get
2. a label
3. link Tags introduced css
4. Script Tags introduced js file
5. img The tag introduces the picture
6. iframe introduce html page
7. Enter the address in the browser address bar and press enter

POST

1. form label method=pos

difference

The code problem

Tips

1. tomcat The default character encoding used in ：iso-8859-1, No Chinese support
2. Common coding methods that support Chinese

Problem analysis

Reference article ：
  Tomcat Of URIEncoding、useBodyEncodingForURI and CharacterEncodingFilter
   from StringHttpMessageConverter Analysis of the garbled code process between the client and server
  URL The problem of Chinese character coding and the solution of garbled code
  URIEncoding and UseBodyEncodingForURI The explanation of
  Post,Get Reason and solution of request garbled code

1. When we enter parameters in the form, we jump , The address bar will show http://localhost:8080/test?userName= Zhang San &userPwd=1&rePwd=1&bd= cell-phone number , If you copy the address and paste , The content is http://localhost:8080/day0321/login/doLogin.jsp?userName=%E5%BC%A0%E4%B8%89&userPwd=1&rePwd=1&bd=%E6%89%8B%E6%9C%BA%E5%8F%B7, This is the encoded address , What kind of coding method is called URL code
   （chrome The browser always starts with UTF-8 Convert China into a byte array ）
2. When a browser sends a request , The server is requested content-type To parse the request data , When the browser request does not specify content-type when ,Tomcat The server defaults to ISO-8859-1
3. Because the two coding methods are different , So there is garbled code
    

resolvent

1. Set the encoding of requests and responses （ Apply to post）

// The call is valid until the request parameter is obtained. 
request.setCharacterEncoding("utf-8");// Set the encoding of the request 
response.setCharacterEncoding("utf-8");// commonly page It has been set up utf-8 了 , This sentence can be omitted 
<%@ page language="java" contentType="text/html; charset=utf-8"%>

2. get The request is garbled
     ① Cure the symptoms ：new String( s.getBytes("iso-8859-1"), "utf-8" );
     ② Permanent cure ： To configure tomcat\conf\server.xml file
       URIEncoding="UTF-8"： Unified settings are used for decoding URL Character encoding of （ Including address and parameters ）, The default value is ISO-8859-1
       useBodyEncodingForURI="true"： Whether to use request.setCharacterEncoding The set code has no effect on the request parameters （ Do not include address ） decode , Default false, It is mainly used for Tomcat4.1.x in .
   

    

Why? post And get The solutions of the two submission methods are different

POST
  ① The coding is determined by the page , namely ContentType(“text/html; charset=utf-8”)
  ② When the form is submitted , The browser will start with ContentType Encode the parameters in the encoding format , Then submit it to the server .
  ③ It is also used on the server side ContentType To decode

GET
  ① GET The submission method will attach parameters to the address , Therefore, the coding of parameters is by URL It depends on the code
  ② page Medium ContentType And request.setCharacterEncoding The method is not correct HTTP Decode the content of the header
  ③ therefore GET Method still uses the default ISO-8859-1 decode
  ④ If you want to decode correctly, you must set URIEncoding perhaps Set the request.setCharacterEncoding To set up useBodyEncodingForURI