Ⅰ javaweb，給HTML文件加上過濾器以後，HTML顯示亂碼。
那是你的瀏覽器不識別Content-Type，採用了默認的GBK/GB2312編碼顯示，這個可以在打開頁面「右鍵-編碼」看到；meta最好給一個結束符，即：<meta http-equiv="content-type" content="text/html; charset=utf-8" />
Ⅱ Java獲取字元的Unicode編碼以及如何過濾特
java中可以使用char類提供的charAt()方法來獲得字元的unicode的編碼值，示例如下：
public static String getUnicode(String source){ String returnUniCode=null; String uniCodeTemp=null; for(int i=0;i<source.length();i++){ uniCodeTemp = "\\u"+Integer.toHexString((int)source.charAt(i));//使用char類的charAt()的方法 returnUniCode=returnUniCode==null?uniCodeTemp:returnUniCode+uniCodeTemp; } System.out.print(source +" 's unicode = "+returnUniCode); return returnUniCode;//返回一個字元的unicode的編碼值}
Ⅲ 在java中，使用過濾器編碼過濾亂碼時，過濾器的編碼怎麼寫
public void doFilter(ServletRequest srequest, ServletResponse sresponse,
FilterChain chain) throws IOException, ServletException {
if (null != encoding) {
HttpServletRequest request = (HttpServletRequest)srequest;
HttpServletResponse response = (HttpServletResponse)sresponse;
// 對請求進行編碼設置
request.setCharacterEncoding(encoding); //把請求用指定的方法編碼
response.setContentType("text/html");
response.setCharacterEncoding(encoding); //把返回響應指定 編碼方式
System.out.println("------------過濾編碼-------------" + encoding);
}
// 把處理許可權交給下一個過濾器
chain.doFilter(srequest, sresponse);
}//這是核心方法
正好項目中有用到
Ⅳ java filter 過濾器中文亂碼 怎麼解決啊
1、首先編寫一個Java類的filter代碼。操作步驟：
(1)在myeclipse中新建一個java類，
(2)單擊「Add」按鈕，在彈出來的對話框中「選擇介面」文本框中輸入Filter，
並選擇匹配好的類型javax.servlet
(3)單擊「OK」按鈕返回"New Java Class"對話，然後單擊「Finish」按鈕，就可以看到創建的過濾器框架:
過濾器類：Encoding.java,代碼如下:
package com;
import java.io.IOException;
import javax.servlet.*;
public class Encoding implements Filter {
protected String encoding=null;
protected FilterConfig config;
public void destroy() {
// TODO Auto-generated method stub
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
if(request.getCharacterEncoding()==null){
//得倒指定的編碼
String encode=getEncoding();
if(encode!=null){
//設置request的編碼
request.setCharacterEncoding(encode);
response.setCharacterEncoding(encode);
}
}
chain.doFilter(request, response);
}
public void init(FilterConfig filterConfig) throws ServletException {
this.config=filterConfig; //得到web.xml中的配置編碼
this.encoding=filterConfig.getInitParameter("Encoding");
}
protected String getEncoding(){
return encoding;
}
}
2、在web.xml文件寫入以下代碼：
<?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">
<display-name></display-name>
<filter> <!-- 控制編碼 -->
<filter-name>EncodingFilter</filter-name>
<filter-class>com.Encoding</filter-class>
<init-param> <!-- 初始化參數 -->
<param-name>Encoding</param-name>
<param-value>GB2312</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>EncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
Ⅳ java如何創建過濾器
弄過濾器，要實現filter介面，下面我寫一個小例子
主要是用過濾器處理中文編碼，至於你要用來做什麼，你再自己寫。。。比如許可權控制，登錄驗證，之類
//下面這是一個類。。。。
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;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class EncodingFilter implements Filter {
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
request.setCharacterEncoding("GBK");//處理編碼
response.setCharacterEncoding("GBK");//處理編碼
chain.doFilter(request, response);//讓過濾器執行下一個請求
}
public void destroy() {}
public void init(FilterConfig arg0) throws ServletException {}
}
//下面這個是在web.xml下的配置
<filter>
<filter-name>encoding</filter-name>
<filter-class>
剛剛創建的那個實現filter介面的類的位置
例如：com.temp.filter.EncodingFilter
</filter-class>
</filter>
<filter-mapping>
<filter-name>encoding</filter-name>
<url-pattern>*.jsp這個是以jsp為後綴的文件都攔截下來</url-pattern>
</filter-mapping>
可以寫多個的<filter-mapping>來配置你所要攔截的東西
恩，有點嘮叨，希望可以幫助到你
Ⅵ jsp\java 如何編寫過濾器過濾特殊字元
package com.jing.common;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class IllegalCharacterFilter implements Filter {
private String[] characterParams = null;
private boolean OK=true;
public void init(FilterConfig config) throws ServletException {
// if(config.getInitParameter("characterParams").length()<1)
// OK=false;
// else
// this.characterParams = config.getInitParameter("characterParams").split(",");
System.out.println("初始化");
}
@SuppressWarnings("unchecked")
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain arg2) throws IOException, ServletException {
HttpServletRequest servletrequest = (HttpServletRequest) request;
HttpServletResponse servletresponse = (HttpServletResponse) response;
String param = "";
String paramValue = "";
//設置請求編碼格式
servletresponse.setContentType("text/html");
servletresponse.setCharacterEncoding("UTF-8");
servletrequest.setCharacterEncoding("UTF-8");
java.util.Enumeration params = request.getParameterNames();
//循環讀取參數
while (params.hasMoreElements()){
param = (String) params.nextElement(); //獲取請求中的參數
String[] values = servletrequest.getParameterValues(param);//獲得每個參數對應的值
for (int i = 0; i < values.length; i++) {
paramValue = values[i];
//轉換目標字元變成對象字元，可以多個。後期擴展特殊字元庫用於管理
paramValue = paramValue.replaceAll("'","");
paramValue = paramValue.replaceAll("@","");
paramValue = paramValue.replaceAll("胡錦濤","***");
//這里還可以增加，如領導人 自動轉義成****,可以從資料庫中讀取非法關鍵字。
values[i] = paramValue;
}
//把轉義後的參數重新放回request中
request.setAttribute(param, paramValue);
}
//繼續向下 執行請求，如果有其他過濾器則執行過濾器
arg2.doFilter(request, response);
}
public void destroy() {
// TODO Auto-generated method stub
}
}
Ⅶ java編程中，過濾器如何調用
<filter>
<description>編碼抄格式控制</description>
<filter-name>CharacterFilter</filter-name>
<filter-class>com.bjsxt.util.filters.CharacterFilter</filter-class>
<init-param>
<description>編碼格式</description>
<param-name>charset</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
在XML裡面配置