看下面程序，这个firstName和 lastName是咋回事
日期：2014-05-20 浏览次数：20750 次
看下面程序，这个firstName和 lastName是怎么回事？
Source Code for Request Parameter Example
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestParamExample extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>Request Parameters Example</title>");
out.println("</head>");
out.println("<body>");
out.println("<h3>Request Parameters Example</h3>");
out.println("Parameters in this request:<br>");
if (firstName != null || lastName != null) {
out.println("First Name:");
out.println(" = " + HTMLFilter.filter(firstName) + "<br>");
out.println("Last Name:");
out.println(" = " + HTMLFilter.filter(lastName));
} else {
out.println("No Parameters, Please enter some");
}
out.println("<P>");
out.print("<form action=\"");
out.print("RequestParamExample\" ");
out.println("method=POST>");
out.println("First Name:");
out.println("<input type=text size=20 name=firstname>");
out.println("<br>");
out.println("Last Name:");
out.println("<input type=text size=20 name=lastname>");
out.println("<br>");
out.println("<input type=submit>");
out.println("</form>");
out.println("</body>");
out.println("</html>");
}
public void doPost(HttpServletRequest request, HttpServletResponse res)
throws IOException, ServletException
{
doGet(request, response);
}
}
------解决方案--------------------
lz你的程序不对哦。firstName和lastName，首先没有定义，其次都没有值，要从HttpServletRequest request中拿值的。
Source Code for Request Parameter Example
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RequestParamExample extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>Request Parameters Example</title>");
out.println("</head>");
out.println("<body>");
out.println("<h3>Request Parameters Example</h3>");
out.println("Parameters in this request:<br>");
if (firstName != null || lastName != null) {
out.println("First Name:");
out.println(" = " + HTMLFilter.filter(firstName) + "<br>");
out.println("Last Name:");
out.println(" = " + HTMLFilter.filter(lastName));
} else {
out.println("No Parameters, Please enter some");
}
out.println("<P>");
out.print("<form action=\"");
out.print("RequestParamExample\" ");
out.println("method=POST>");
out.println("First Name:");
out.println("<input type=text size=20 name=firstname>");
out.println("<br>");
out.println("Last Name:");
out.println("<input type=text size=20 name=lastname>");
out.println("<br>");
out.println("<input type=submit>");
out.println("</form>");
out.println("</body>");
out.println("</html>");
}
public void doPost(HttpServletRequest request, HttpServletResponse res)
throws IOException, ServletException
{
doGet(request, response);
}
}
------解决方案--------------------
lz你的程序不对哦。firstName和lastName，首先没有定义，其次都没有值，要从HttpServletRequest request中拿值的。
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