以前遇到JSP 处理MySQL数据库时的中文问题时，采取的是很笨的一种方法，直接用字符串编码转换函数进行转换，这次从网上搜了一下，找到了一个使用Filter的可行方法。在Tomcat 5.5＋ MySQL4.0.16下通过。
filter类源码是从网上找的，如下
/**
*
*/
package com.lzy;
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;
/**
* @author lzy
*
*/
public class SetCharacterEncodingFilter implements Filter {
protected String encoding = null;
protected FilterConfig filterConfig = null;
protected boolean ignore = true;
/* (non-Javadoc)
* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
*/
public void init(FilterConfig filterConfig) throws ServletException {
// TODO Auto-generated method stub
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;
}
/* (non-Javadoc)
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
// TODO Auto-generated method stub
if (ignore || (request.getCharacterEncoding() == null)) {
String encoding = selectEncoding(request);
if (encoding != null)
request.setCharacterEncoding(encoding);
}
chain.doFilter(request, response);
}
/* (non-Javadoc)
* @see javax.servlet.Filter#destroy()
*/
public void destroy() {
// TODO Auto-generated method stub
this.encoding = null;
this.filterConfig = null;
}
protected String selectEncoding(ServletRequest request) {
return (this.encoding);
}
}
在web.xml 文件中作如下设置：（我使用的是Struts框架）
<filter>
<filter-name>Encoding</filter-name>
<filter-class>com.lzy.SetCharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>GBK</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>Encoding</filter-name>
<servlet-name>action</servlet-name>
</filter-mapping>
<filter-mapping>
<filter-name>Encoding</filter-name>
<url-pattern>*.jsp</url-pattern>
</filter-mapping>
最后，连接数据库时，使用下面的url：
jdbc:mysql://localhost:3306/数据库名?useUnicode=true&characterEncoding=GBK