看了网友Roy的评论，研究了一下用filter来解决Struts中文乱码的问题！

package tutorial.struts.filter;

import javax.servlet.Filter;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;
import javax.servlet.FilterChain;
import java.io.IOException;

public class SetCharacterEncodingFilter implements Filter {

protected FilterConfig filterConfig;
protected String encodingName;
protected boolean enable;

public SetCharacterEncodingFilter() {
this.encodingName = "UTF-8";
this.enable = false;
}

public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
loadConfigParams();
}

private void loadConfigParams() {
//encoding
this.encodingName = this.filterConfig.getInitParameter("encoding");
//filter enable flag
String strIgnoreFlag = this.filterConfig.getInitParameter("enable");
if (strIgnoreFlag.equalsIgnoreCase("true")) {
this.enable = true;
} else {
this.enable = false;
}
}

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
if(this.enable) {
request.setCharacterEncoding(this.encodingName);
}
chain.doFilter(request, response);
}

public void destroy() {
}

}

Set Character Encoding
tutorial.struts.filter.SetCharacterEncodingFilter

encoding
UTF-8


enable
true



Set Character Encoding
Action Servlet


Set Character Encoding
Faces Servlet