package cn.hsm.web.filter;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
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.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
public class EncodingFilter implements Filter {
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
request.setCharacterEncoding(“utf-8”);
// 在传递request之前对request.getParameter方法进行增强
/**
* 装饰者模式(包装)
*
* 1.增强类与被增强的类要实现统一接口 2.在增强类中传入被增强的类 3.需要增强的方法重写 不需要增强的方法调用被增强对象
*/
// 被增强对象
HttpServletRequest req = (HttpServletRequest) request;
// 增强对象
EnhanceRequest enhanceRequest = new EnhanceRequest(req);
chain.doFilter(enhanceRequest, response);
}
public void destroy() {
}
public void init(FilterConfig fConfig) throws ServletException {
// TODO Auto-generated method stub
}
}
class EnhanceRequest extends HttpServletRequestWrapper {
private HttpServletRequest request;
public EnhanceRequest(HttpServletRequest request) {
super(request);
this.request = request;
}
@Override
public String getParameter(String name) {
String string = request.getParameter(name);
try {
string = new String(string.getBytes("iso8859-1"), "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return string;
}
}