Question

我试图在servlet中创建一个注册页面...使用eclipse的tomcat 7，它返回空白页面，我已经尝试了可用的步骤但是没有去...请帮助....

这是JSP页面

<form method="post" action="mbregistrationservlet">
First Name: <input type=text name=firstfame><br>
Last Name: <input type=text name=lastname></br>
Gender: <input type="radio" name="gender" Value="Male" checked>Male
<input type="radio" name="Gender" Value="Female">Female</br>
E-mail: <input type="email" name="email"><br>
Password:<input type="password" name="password"><br>
Security Question<select name="securityquestion">
                <option value="Name of your first pet">Name of your first pet</option>
                <option value="Name of your first byke">Name of your first byke</option>
                <option value="Name of your first car">Name of your first car</option>
                <option value="Name of your first school">Name of your first school</option>
                <option value="Name of your first GF/BF">Name of your first GF/BF</option>
            </select><br>
Answer: <input type="text" name="answer"><br>
Telephone:<input type="text" name="telephone"><br>
Address:<input type="text" name="address"><br>
City:<input type="text" name="city"><br>
State:<input type="text" name="state"><br>
Country:<input type="text" name="country"><br>
 <input type="submit" value="suuubmit" name="Submit"> 
</form>

Servlet页面

public class mbregistrationservlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public static boolean register(String firstname, String lastname, String gender,String email, String password, String securityquestion, String answer, String telephone, String address, String city, String state, String country) throws IOException
{
HttpServletResponse response = null;
    //response.setContentType("text/html"); 
    PrintWriter out = response.getWriter();

    boolean x =false;
    try{
        /*dbconn obj=new dbconn();*/
        DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
        Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","******","*******");
        PreparedStatement ps = con.prepareStatement("insert into mbregistration  values(?,?,?,?,?,?,?,?,?,?,?,?)");
        ps.setString(1,firstname);
        ps.setString(2,lastname);
        ps.setString(3,gender);
        ps.setString(4, email);
        ps.setString(5, password);
        ps.setString(6, securityquestion);
        ps.setString(7, answer);
        ps.setString(8, telephone);
        ps.setString(9, address);
        ps.setString(10,city);
        ps.setString(11,state);
        ps.setString(12,country);
       int i = ps.executeUpdate();
        if (i>0){
            x=true;
        }
        out.print("registered succcessfully");
        //out.close();

    }
    catch(Exception e) 
    {
        out.print("error");
        //out.close();
    }
    return x;
}

XML页面

<display-name>MobileWorld</display-name>
   <welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
 </welcome-file-list>
  <servlet>
<description></description>
<display-name>mbloginservlet</display-name>
<servlet-name>mbloginservlet</servlet-name>
<servlet-class>mbworld.mbloginservlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>mbloginservlet</servlet-name>
<url-pattern>/mbloginservlet</url-pattern>
</servlet-mapping>
<servlet>
<description></description>
<display-name>Validate</display-name>
<servlet-name>Validate</servlet-name>
<servlet-class>mbworld.Validate</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Validate</servlet-name>
<url-pattern>/Validate</url-pattern>
</servlet-mapping>
<servlet>
<description></description>
<display-name>success</display-name>
<servlet-name>success</servlet-name>
<servlet-class>mbworld.success</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>success</servlet-name>
<url-pattern>/success</url-pattern>
</servlet-mapping>
<servlet>
<description></description>
<display-name>mbregistrationservlet</display-name>
<servlet-name>mbregistrationservlet</servlet-name>
<servlet-class>mbworld.mbregistrationservlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>mbregistrationservlet</servlet-name>
<url-pattern>/mbregistrationservlet</url-pattern>
</servlet-mapping>

如果我做错了，请告诉我.......

Answer 1

将方法名称更改为doPost而不是register（不带static关键字），并使用getParameter api使用http servlet请求访问表单字段。所以它看起来像：

 public class mbregistrationservlet extends HttpServlet {
      public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
     String firstName = request.getParameter("firstfame");

     //and so on
 }

Answer 2

我没有在servlet中看到一个doPost（）方法，当你提交表单时，它实际上将由服务方法调用。

doPost（）方法的结构

public void doPost(HttpServletRequest request, HttpServletResponse response)
                        throws ServletException, IOException 
{
// Servlet code
}

<强>更正

您不会像您期望的那样通过参数获取输入字段register method
```
public static boolean register(...)
```
更多，这是非法的。
在，为了获取输入字段参数user Enumeration params = request.getParameterNames()，它将返回所有参数的枚举，并通过request.getParameterValue(params.nextElement())，您可以访问与{{指定的输入字段对应的值1}}。 EXAMPLE

Answer 3

首先，您必须使用doPost方法编写代码，第二件事是，如果您在rd.forward(request,response)之后未使用RequestDispatcher rd=request.getRequestDispatcher("Name of page you want to redirect");，则在单击“提交”按钮后它将成为空白页。 / p>

所以应该是这样的：

RequestDispatcher rd=request.getRequestDispatcher("Welcome");
rd.forward(request,response);

servlet返回空白页面

3 个答案: