When we javaWeb project, and use doget dopost will always be a variety of reasons Chinese garbage problem, the landlord after a lot of information, why there will be such a problem, how to solve this problem and make a summary.
1. First throw doPost method request.getParameter ( "xxx"); garbled solution
In the beginning of the method body plus:
//设置request对象的解码方式
request.setCharacterEncoding("utf-8");Encoding format string thus obtained is utf-8, the console Chinese distortion can be solved; (At this time the output page PrintWriter distortion still present)
2.doGet and doPost use PrintWriter out = response.getWriter (); Solution distortion output
In PrintWriter out = response.getWriter (); preceded by:
//设置response返回输出的编码方式
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();With respect to these two added:
response.setHeader("Content-type", "text/html;charset=UTF-8");
response.setCharacterEncoding("UTF-8");
PrintWriter out = response.getWriter();3. highlights: doGet method request.getParameter ( "xxx"); garbled solution
Why do we like to use doPost ? Because it is safe, it unlimited capacity, which is followed by body requset request over the data,
Means
request.setCharacterEncoding ( "utf-8"); it works! Encodes a code value problem solving, not Yoshiya?
The doGet method? Unsafe (URL will be shipped back parameter), small capacity (up to 1,2KB), the data do not follow requset request body , but on the end of the URL!
Means
request.setCharacterEncoding ( "utf-8"); no use for the doGet, we need additional transcoding, Gee, Haofan ~
Among the re-: tomcat different versions, different default encoding to resolve the url
Before tomcat8.0 version
Before tomcat8.0 version, the default encoding is ISO-8859-1
Solution 1: Manual string transcoding
So we can see many people doget Chinese garbled solve is this:
String username=new String(request.getParameter("username").getBytes("ISO-8859-1"), "UTF-8");Because the default encoding is ISO-8859-1, with getBytes ( "ISO-8859-1") to get the original code byte array, and then converted to a String utf-8 encoded by the new.
But the drawback is that each parameter must be transcoded, you can change your brain to tremble ~
Solution 2: Modify the default encoded as UTF-8
Since the default encoding is ISO-8859-1, then modify the default encoding like
Find tomcat directory \\ conf \ server.xml
添加 URIEncoding="UTF-8"
After the addition, analytic encoding is UTF-8, doGet values do not need to take a page from transcoded
However, this method is not recommended, because of the different circumstances of each machine, run on your machine, to others it is not run.
Solution 3: Filters transcoding
Online there are examples:
He wrote more full, dopost and can be configured both doget
Servlet filter to solve the Chinese garbled
After tomcat8.0 version
After tomcat8.0 version, a default encoding. 8-UTF , equivalent added URIEncoding = "UTF-8" (i.e. above the solution 2) before 8.0
At this point doget very easy to use, saving even more than dopost line request.setCharacterEncoding ( "utf-8");
Gratifying ~
dopost still the same, adding that things have to add!
4. Specific examples of
Examples tomcat 7 (no servlet.xml modify default encoding is ISO-8859-1, doget need to manually transcoding )
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet(
urlPatterns = "/RequestParamsServlet"
)
public class RequestParamsServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//设置request对象的解码方式
request.setCharacterEncoding("utf-8");
//设置response返回输出的编码方式
response.setContentType("text/html;charset=utf-8");
String name = request.getParameter("username");
String password = request.getParameter("password");
System.out.println("用户名:" + name);
System.out.println("密 码:" + password);
PrintWriter out = response.getWriter();
out.println("用户名:" + name);
out.println("密 码:" + password);
// 获取参数名为“hobby”的值
String[] hobbys = request.getParameterValues("hobby");
System.out.print("爱好:");
out.println("爱好:");
for (int i = 0; i < hobbys.length; i++) {
System.out.print(hobbys[i] + ",");
out.println(hobbys[i] + ",");
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//设置response返回输出的编码方式
response.setContentType("text/html;charset=utf-8");
String name=new String(request.getParameter("username").getBytes("ISO-8859-1"), "UTF-8");
String password=new String(request.getParameter("password").getBytes("ISO-8859-1"), "UTF-8");
System.out.println("用户名:" + name);
System.out.println("密 码:" + password);
PrintWriter out = response.getWriter();
out.println("用户名:" + name);
out.println("密 码:" + password);
// 获取参数名为“hobby”的值
String[] hobbys = request.getParameterValues("hobby");
System.out.print("爱好:");
out.println("爱好:");
for (int i = 0; i < hobbys.length; i++) {
hobbys[i]=new String(hobbys[i].getBytes("ISO-8859-1"),"UTF-8");
System.out.print(hobbys[i] + ",");
out.println(hobbys[i] + ",");
}
}
}
Examples tomcat 9 (no servlet.xml modify default encoding is UTF-8, doget without transcoding )
package org.hc.maven.testnew;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet(
urlPatterns = "/RequestParamsServlet"
)
public class RequestParamsServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//设置request对象的解码方式
request.setCharacterEncoding("utf-8");
//设置response返回输出的编码方式
response.setContentType("text/html;charset=utf-8");
String name = request.getParameter("username");
String password = request.getParameter("password");
System.out.println("用户名:" + name);
System.out.println("密 码:" + password);
PrintWriter out = response.getWriter();
out.println("用户名:" + name);
out.println("密 码:" + password);
// 获取参数名为“hobby”的值
String[] hobbys = request.getParameterValues("hobby");
System.out.print("爱好:");
out.println("爱好:");
for (int i = 0; i < hobbys.length; i++) {
System.out.print(hobbys[i] + ",");
out.println(hobbys[i] + ",");
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//设置response返回输出的编码方式
response.setContentType("text/html;charset=utf-8");
String name = request.getParameter("username");
String password = request.getParameter("password");
System.out.println("用户名:" + name);
System.out.println("密 码:" + password);
PrintWriter out = response.getWriter();
out.println("用户名:" + name);
out.println("密 码:" + password);
// 获取参数名为“hobby”的值
String[] hobbys = request.getParameterValues("hobby");
System.out.print("爱好:");
out.println("爱好:");
for (int i = 0; i < hobbys.length; i++) {
System.out.print(hobbys[i] + ",");
out.println(hobbys[i] + ",");
}
}
}
Pro-test oh absolutely right, there is an error to see the students pay attention to servlet.xml tomcat is not added redundant configuration, or idea of the character encoding configuration editor is wrong.
I believe seriously read here, on the issue of Chinese garbled already know
If you help, support what the point of praise ~
