ipfilter.java

jsp 应用开发技术光盘 是《jsp应用开发技术》这本书的源代码

package ch17;

import java.io.IOException;
import javax.servlet.*;

/**
 * 根据IP地址进行访问控制
 */
public class IPFilter implements Filter {

	protected FilterConfig config;
	protected String rejectedIP;

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

		// 读取初始参数
		rejectedIP = config.getInitParameter("RejectedIP");
		if (rejectedIP == null) {
			rejectedIP = "";
		}
	}

	public void doFilter(
		ServletRequest request,
		ServletResponse response,
		FilterChain chain)
		throws IOException, ServletException {
		RequestDispatcher dispatcher =
			request.getRequestDispatcher("rejectedError.jsp");

		String remoteIP = request.getRemoteAddr();

		if (remoteIP.equals(rejectedIP)) {
			// 重定向到rejectedError.jsp页面
			dispatcher.forward(request, response);
			return;
		} else {
			chain.doFilter(request, response);
		}
	}

	public void destroy() {

	}

}