Question

我对java servlet和使用netbeans有点新，问题是，我没有得到预期的输出.. 这是我拥有的ColorServlet.java文件 - ＆gt;

import javax.servlet.*;
import java.io.*;
public class ColorServlet extends GenericServlet
{

    @Override
    public void service(ServletRequest request,ServletResponse response) throws IOException,ServletException
    {
        PrintWriter out=response.getWriter();
        response.setContentType("text/html");
        String s=request.getParameter("s1");
        out.println("<Body bgcolor="+s+"></body>");
        out.close();
    }
}

这是我拥有的myhtml.html文件 - ＆gt;

<html>
    <head><title>This is a Color project</title></head>
    <body>
        <form action="ColorServlet">
            Select your favorite Color
            <select name="s1">
                <option value="Red">Red</option>
                <option>Green</option>
                <option>Yellow</option>
            </select>
            <br>
            <input type="submit" value ="OK"/>
        </form>
    </body>
</html>

当我运行这个项目时，就像这样 - ＆gt; http://localhost:8080/ColorProject/ColorServlet 我只能在浏览器上看到一个完整的黑屏..可能是什么问题？

Answer 1

您需要HttpServlet来获取请求并构建响应。像这样改变你的servlet

import javax.servlet.*;
import java.io.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;

@WebServlet(name = "ColorServlet", urlPatterns = {"/ColorServlet"})
public class ColorServlet extends HttpServlet
{

    @Override
    public void service(ServletRequest request,ServletResponse response) throws IOException,ServletException
    {
        PrintWriter out=response.getWriter();
        response.setContentType("text/html");
        String s=request.getParameter("s1");
        out.println("<Body bgcolor="+s+"></body>");
        out.close();
    }
}

netbeans中的项目已成功部署但未按预期运行

1 个答案: