JAVA工具类集锦3--编码过滤器

3、编码过滤器

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;

/**
* 字符编码filter
*/
public class EncodingFilter extends HttpServlet implements Filter{
private FilterConfig filterConfig;
private String encoding = null;
protected boolean ignore = true;

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;
}
}

//Process the request/response pair
public void doFilter(ServletRequest request,ServletResponse response,
FilterChain filterChain){
try{
if (ignore || (request.getCharacterEncoding() == null)) {
String encoding = selectEncoding(request);
if (encoding != null)
request.setCharacterEncoding(encoding);
}
filterChain.doFilter(request,response);
} catch(Exception sx){
sx.getMessage();
}

}

private String selectEncoding(ServletRequest request) {
return (this.encoding);
}

//Clean up resources
public void destroy(){
encoding = null;
filterConfig = null;
}
}