forward的细节(1)

最新推荐文章于 2024-02-29 18:58:22 发布

原创最新推荐文章于 2024-02-29 18:58:22 发布 · 656 阅读

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本文详细解释了在Java Web开发中，使用Servlet进行页面跳转时出现的“Cannot forward after response has been committed”异常的原因及解决方案。提醒开发者在使用forward之前避免往response中写入数据。

package request;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//forward的细节
public class RequestDemo6 extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String data="aaaaa";
        PrintWriter writer = response.getWriter();
        writer.write(data);
        writer.close();
        //以下会导致：java.lang.IllegalStateException: Cannot forward after response has been committed
        request.getRequestDispatcher("/message.jsp").forward(request, response); 
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}