java包返回值到servlet

Question

我有一个名为 apt1.java 的用户定义包，我将它导入一个名为 aptservlet1.java 的 servlet。它运行正确，但仅返回与正确参数无关的错误值。如果我通过简单的 java 程序（在命令提示符中有输出）使用这个包，那么它会给出正确的答案。

请回答这个问题.. 接下来是我的程序..

aptservlet1.java：

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

public class aptservlet1 extends HttpServlet {
    public void doGet(HttpServletRequest req, HttpServletResponse res)
            throws IOException, ServletException {
        boolean correct;
        res.setContentType("text/html");
        PrintWriter out = res.getWriter();
        String user, pass;
        user = req.getParameter("user");
        pass = req.getParameter("pass");
        apt1 o1 = new apt1();
        correct = o1.confirmadmin(user, pass);
        out.println("value of correct=" + correct);
        ServletContext sc = this.getServletContext();
        if (correct) {
            out.println("correct");

        }
        if (correct) {
            out.println("incorret");
        }
    }
}

apt1.java：

public class apt1 {
String url = "jdbc:mysql://localhost/" + "aptitude";

public apt1() {
    try {
        Class.forName("con.mysql.jdbc.Driver");
    } catch (ClassNotFoundException ce) {
    }
}

public boolean confirmadmin(String user, String pass) {
    boolean c = false;
    try {
        String url = "jdbc:mysql://localhost/" + "aptitude";
        Connection con = DriverManager.getConnection(url, "root", "");
        Statement s = con.createStatement();
        ResultSet rs = s
                .executeQuery("select a_pass from admin_database where          a_user='"
                        + user + "'");
        rs.next();
        String s1 = rs.getString(1);
        int k = s1.compareTo(pass);
        if (k == 0) {
            c = true;
        } else {
            c = false;
        }
    } catch (SQLException se) {
    }
    return c;
}
}

Answer 1

我认为你这里有一个错字：

if(correct){
    out.println("correct");

}
if(correct) {
    out.println("incorret");}
}

当正确为真时，这将打印出正确和错误。

试试：

if(correct){
    out.println("correct");

}
if(!correct) {
    out.println("incorret");}
}