java 出現亂碼如何解決
阿新 • • 發佈：2019-02-14
(一)post
[1]通過request.setCharacterEncodeing("UTF-8");
[2]通過String name = new String(request.getParameter("name").getBytes("ios8859-1"),"utf-8")
[3]在web.xml配置一個過濾器filter
[4]如果是spring ,在web.xml配置一個過濾器：org.springframework.web.filter.CharacterEncodingFilter
src 處理輸出程式碼
[1]通過request.setCharacterEncodeing("UTF-8");
[2]通過String name = new String(request.getParameter("name").getBytes("ios8859-1"),"utf-8")
[3]在web.xml配置一個過濾器filter
[4]如果是spring ,在web.xml配置一個過濾器：org.springframework.web.filter.CharacterEncodingFilter
[5Struts2]待看
(二)get
[1]在tomcat中servlet.xml中增加URIEncoding="UTF-8"
[2]用上面的通過String name = new String(request.getParameter("name").getBytes("ios8859-1"),"utf-8")
程式碼實現（註釋部分為實現的）
login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>測試</title> </head> <body> <form action="login" method="get"> <table align="center"> <tr> <td>使用者名稱： <input type="text" name="username"></input></td> </tr> <tr> <td>密碼： <input type="password" name="password"></input> </td> </tr> <tr> <td align="center"><input type="submit" value="登陸"></input></td> </tr> </table> </form> </body> </html>
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <servlet> <servlet-name>Login</servlet-name> <servlet-class>com.ay.login.LoginServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>Login</servlet-name> <url-pattern>/login</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>login.jsp</welcome-file> </welcome-file-list> <!-- <filter> <filter-name>encoding</filter-name> <filter-class>com.ay.login.SetCharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> --> <!-- 使用spring作為過濾器， --> <!--<filter> --> <!-- 過濾器使用spring類CharacterEncodingFilter --> <!-- <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> --> <!-- 過濾器過濾後的編碼為utf-8 --> <!-- <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> --> <!-- 過濾所有的路徑：/*代表所有的路徑 --> <!--<filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> --> </web-app>
filter
package com.ay.login;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class SetCharacterEncodingFilter implements Filter {
/**
* The default character encoding to set for requests that pass through
* this filter.
*/
protected String encoding = null;
/**
* The filter configuration object we are associated with. If this value
* is null, this filter instance is not currently configured.
*/
protected FilterConfig filterConfig = null;
/**
* Should a character encoding specified by the client be ignored?
*/
protected boolean ignore = true;
public void destroy() {
this.encoding = null;
this.filterConfig = null;
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
// Conditionally select and set the character encoding to be used
System.out.println("encoding1->"+encoding);
if (ignore || (request.getCharacterEncoding() == null)) {
String encoding = selectEncoding(request);
if (encoding != null)
request.setCharacterEncoding(encoding);
}
chain.doFilter(request, response);
}
/**
* Place this filter into service.
* @param filterConfig The filter configuration object
*/
public void init(FilterConfig filterConfig) throws ServletException {
System.out.println("encoding2"+encoding);
this.filterConfig = filterConfig;
this.encoding = filterConfig.getInitParameter("encoding");
String value = filterConfig.getInitParameter("ignore");
if (value == null)
this.ignore = true;
else if (value.equalsIgnoreCase("true"))
this.ignore = true;
else if (value.equalsIgnoreCase("yes"))
this.ignore = true;
else
this.ignore = false;
}
protected String selectEncoding(ServletRequest request) {
return (this.encoding);
}
}src 處理輸出程式碼
package com.ay.login;
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 LoginServlet extends HttpServlet{
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//一、post
//// //1.設定編碼格式
//// request.setCharacterEncoding("UTF-8");
// System.out.println("登陸");
// String name=request.getParameter("username");
// String password=request.getParameter("password");
// //2.通過getBtyes("ios8859-1")轉化成“UTF-8”
//// String uname = new String(name.getBytes("iso8859-1"),"UTF-8");
//// System.out.println("uname:"+uname);
// //3.增加一個過濾器Filter(自己寫的)
// System.out.println("使用者名稱："+name);
// System.out.println("密碼："+password);
// //4.如果用Struts,以後會專門寫一下關於Struts2如何解決亂碼
// //5.若使用了spring也簡單，配置一個spring中提供的攔截器：
//二、get
//1.通過getBtyes("ios8859-1")轉化成“UTF-8”
String name=request.getParameter("username");
String password=request.getParameter("password");
// String uname = new String(name.getBytes("iso8859-1"),"UTF-8");
// System.out.println("uname："+uname);
System.out.println("使用者名稱："+name);
System.out.println("密碼："+password);
//2.設定tomcat伺服器的server.xml這個檔案，找到下面的這個段程式碼，新增上URIEncoding="UTF-8"，在下面這個配置中
//<connector URIEncoding="UTF-8" redirectPort="8443" protocol="HTTP/1.1" port="8080" connectionTimeout
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
}