JSP MySQL Tomcat Apache乱码解决一例
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<script type="text/javascript">google_ad_client = "pub-8800625213955058";/* 336x280, 创建于 07-11-21 */google_ad_slot = "0989131976";google_ad_width = 336;google_ad_height = 280;//</script><script type="text/javascript"src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 本文以最常见的JSP MySQL Tomcat Apache乱码解决为例,望能为你的环境配置起到抛砖引玉之效! 乱码问题已历来已久,在开源环境下,乱码问题更是令程序员措手不及。本人在Unix(Freebsd)下的一次乱码经历可谓经典,故撰以此文以滋效尤! 我将本次所遇乱码归为三类: 1.页面字符乱码 2.记录显示乱码 3.request传递乱码 以下将对上述三类乱码进行解析:一.页面字符乱码: 1.大小写不一致:org.apache.jasper.JasperException: /top.jsp(1,1) Page directive: illegal to have multiple occurrences of contentType with different values (old: text/html;charset=gb2312, new: text/html;charset=GB2312) 2.间隔不一致:org.apache.jasper.JasperException: /top.jsp(1,1) Page directive: illegal to have multiple occurrences of contentType with different values (old: text/html; charset=GB2312, new: text/html;charset=GB2312)*解决方案:首先,在Apache中增加AddDefaultCharset GB2312或AddDefaultCharset GBK其次,统一使用页面编码定义,如:<%@page contentType="text/html;charset=GB2312"%>*注:GB2312为GBK之子集。二.记录显示乱码: 1.MySQL默人语言为latin1_swedish_ci,即拉丁语,所以取出的中文全是乱码。*解决方案: 1.将charset设为8859_1即:<%@page contentType="text/html;charset=8859_1"%> 这个方法只能暂时缓解字符显示问题,并权益之计。因为8859_1为字节型字库,并非字型字库,故在非全角状态下,将出现半字乱码,表现为“?”。 2.在数据库连接语句中加上?useUnicode=true;characterEncoding=GBK,如:jdbc:mysql://localhost/dbname?useUnicode=true;characterEncoding=GBK*注:一般教科书上都会加上localhost:3306,因为默认端口为3306,故可舍去!同时,请使用连接池的朋友注意,在注册xml文件时,是不可以单独出现“;”的,所以必须使用“&”,即:jdbc:mysql://localhost/dbname?useUnicode=true&characterEncoding=GBK。 否则提示出错:Parse Fatal Error at line 213 column 91: The reference to entity "characterEncoding" must end with the ';' delimiter.org.xml.sax.SAXParseException: The reference to entity "characterEncoding" mustend with the ';' delimiter.at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source) 也曾有人提意:在MySQL的my.ini文件中加入default-character-set=gbk,本人不赞同此法,因为这样破坏了原有的环境,除非这是MySQL的第一个站点。三.request传递乱码: 1.也许,此时你已经可以正常使用系统了,那么恭喜~乱码问题已经离开你了!但是,大伙通常都没那么走运,乱码问题依旧存在。也许,这时你向数据库添加了一条记录以测试系统,可是此时显示出的还是乱码。那么可以肯定是Request参数传递出错!那么先写个测试语句:<%= request.getParameter(“Para”) %>,OK,果然是乱。那么,现在有两种解决方法。*解决方案: 1.加上这条语句:request.setCharacterEncoding("gbk");在一/两页上可行,但此法也非权益之计。 2.注册SetCharacterEncodingFilter类: 首先,编写SetCharacterEncodingFilter.java文件,代码如下:package cn.com.jsp;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.UnavailableException;public class SetCharacterEncodingFilter implements Filter { protected String encoding = null; protected FilterConfig filterConfig = null; 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 if (ignore || (request.getCharacterEncoding() == null)) { String encoding = selectEncoding(request); if (encoding != null) { request.setCharacterEncoding(encoding); } } // Pass control on to the next filter chain.doFilter(request, response); } public void init(FilterConfig filterConfig) throws ServletException { 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); }} 此文件为request过滤类,在全局编译前需进行注册。 注册文件为:<%wwwroot%>/WEB-INF/web.xml。 在此文件中加入如下代码即可: wwwroot MySQL Test App setCharacterEncodingFilter setCharacterEncodingFilter setCharacterEncodingFilter cn.com.jsp.SetCharacterEncodingFilter encoding GBK </init-param> </filter> setCharacterEncodingFilter /*</url-pattern> </filter-mapping>……</web-app> OK,现在可以编译你的SetCharacterEncodingFilter.java文件啦! 至此,乱码将与你格格不入!