package a;
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TServlet extends HttpServlet
{
public void doPost(HttpServletRequest request, HttpServletResponse res) throws ServletException, IOException
{
try {
...
...
PrintWriter out = request.getWriter();
out.print("用户名不能为空");
...
}提示out有错....
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class TServlet extends HttpServlet
{
public void doPost(HttpServletRequest request, HttpServletResponse res) throws ServletException, IOException
{
try {
...
...
PrintWriter out = request.getWriter();
out.print("用户名不能为空");
...
}提示out有错....
cannot resolve symbol
symbol:method getWriter();
location:interface javax.servlet.http.HttpServletRequest
定义PrintWriter对象时,需要使用response对象的getWriter()方法,而不是request的。
修改之后的代码如下:
package a;
import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;public class TServlet extends HttpServlet
{
public void doPost(HttpServletRequest request, HttpServletResponse res)
throws ServletException, IOException
{
try{
PrintWriter out = res.getWriter();
out.print("用户名不能为空");
}catch(Exception e){
e.printStackTrace();
}
}
}
希望我没有理解错误,也希望能够给你帮助!!!呵呵。