Dark Horse day03 Character stream garbled solution method and principle analysis

1. Garbled Characters of character stream

Response.getwriter (). Write ("China"); This line of code will first write China to the buffer and then encode it using a foreigner's favorite iso-8859-1.

The browser then decodes using the local encoding table. Therefore, garbled characters are generated.

Package Com.itheima;import Java.io.ioexception;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;public class Demo7servlet extends HttpServlet {public void doget ( HttpServletRequest request, HttpServletResponse response) throws Servletexception, IOException {response.getwriter (). Write ("China");} public void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { Doget (request, Response);}}

Operation Result:

Then the solution: is to tell the server to use GBK encoding: response.setcharacterencoding ("GBK");

Package Com.itheima;import Java.io.ioexception;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;public class Demo7servlet extends HttpServlet {public void doget ( HttpServletRequest request, HttpServletResponse response) throws Servletexception, IOException {// Tell the server to encode response.setcharacterencoding ("GBK") using GBK, Response.getwriter (). Write ("China"); public void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { Doget (request, Response);}}

Operation Result:

2. If you tell the server to use Utf-8 for encoding, but the browser will use the default encoding GBK, so in order to prevent garbled, so you need to tell the browser to use Utf-8 to decode

Package Com.itheima;import Java.io.ioexception;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;public class Demo7servlet extends HttpServlet {public void doget ( HttpServletRequest request, HttpServletResponse response) throws Servletexception, IOException {// Inform the server to encode response.setcharacterencoding ("Utf-8") using GBK,//Tell the browser to decode Response.setheader using Utf-8 ("Content-type", "text /html;charset=utf-8 "); Response.getwriter (). Write (" China "); public void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { Doget (request, Response);}}

Operation Result:

3.sun Company uses Response.setcontenttype ("Text/html;charset=utf-8") for ease of use, tells the browser to decode using Utf-8, but the underlying can know in advance what encoding the server uses to encode.

So this is the equivalent of telling the server to use ut8-8 encoding and also telling the browser to decode it using Utf-8. This sentence replaces the effect of these two words:

Tell the server to encode using GBK
Response.setcharacterencoding ("Utf-8");
Tell the browser to decode using Utf-8
Response.setheader ("Content-type", "text/html;charset=utf-8");
Response.getwriter (). Write ("China");

Package Com.itheima;import Java.io.ioexception;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;public class Demo7servlet extends HttpServlet {public void doget ( HttpServletRequest request, HttpServletResponse response) throws Servletexception, IOException {//that tells the server to use ut8-8 encoding, It also tells the browser to decode using Utf-8. Response.setcontenttype ("Text/html;charset=utf-8"); Response.getwriter (). Write ("China"); public void DoPost (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { Doget (request, Response);}}

Operation Result:

Dark Horse day03 Character stream garbled solution method and principle analysis