現在將常見的亂碼問題分爲JSP頁面顯示中文亂碼、表單提交亂碼兩類。
1)JSP頁面中顯示中文亂碼
在JSP文件中使用page命令指定響應結果的MIME類型,如<%@ page language="java" contentType="text/html;charset=gb2312" %>
2)表單提交亂碼
表單提交時(post和Get方法),使用request.getParameter方法得到亂碼,這是因爲tomcat處理提交的參數時默認的是iso-8859-1,表單提交get和post處理亂碼問題不同,下面分別說明。
(1)POST處理
對post提交的表單通過編寫一個過濾器的方法來解決,過濾器在用戶提交的數據被處理之前被調用,可以在這裏改變參數的編碼方式,過濾器的代碼如下:
package example.util;
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 {
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 {
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);
}
}
文中紅色的代碼即爲處理亂碼的代碼。
web.xml文件加入過濾器
<filter>
<filter-name>Encoding</filter-name>
<filter-class>
example.util.SetCharacterEncodingFilter
</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>gbk</param-value>
<!--gbk或者gb2312或者utf-8-->
</init-param>
<init-param>
<param-name>ignore</param-name>
<param-value>true</param-value>
</init-param>
</filter><filter-mapping>
<filter-name>Encoding</filter-name>
<servlet-name>/*</servlet-name>
</filter-mapping>
(2) Get方法的處理
tomcat對post和get的處理方法不一樣,所以過濾器不能解決get的亂碼問題,它需要在其他地方設置。
打開<tomcat_home>/conf目錄下server.xml文件,找到對8080端口進行服務的Connector組件的設置部分,給這個組件添加一個屬性:URIEncoding="GBK"。修改後的Connector設置爲:
<Connector port="8080" maxHttpHeaderSize="8192"
maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
enableLookups="false" redirectPort="8443" acceptCount="100"
connectionTimeout="20000" disableUploadTimeout="true" URIEncoding="GBK" />
* 注意修改後重新啓動tomcat才能起作用。