JDBC:MySql 连接在 Ajax 请求中不工作 -Java

Question

我在 Main 方法和其他方法中具有完全相同的功能 JDBC 连接工作正常。如果我调用另一个函数，它会抛出错误 java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/wine:

我在库 [Netbeans] 中包含 MySql 驱动程序；

processRequest方法：

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    response.setContentType("text/html;charset=UTF-8");
    String process = (String) request.getParameter("process");
    String name = (String) request.getParameter("process");
    String phone=(String) request.getParameter("phone");
    String email = (String) request.getParameter("email");
    String pwd = (String) request.getParameter("pwd");
    PrintWriter out = response.getWriter();
    out.println("Hello");
   signup(out,process,name,email,phone,pwd);

}

报名方式：

private static int signup(PrintWriter out,String process,String name,String email,String phone,String pwd){
    Connection con = null;
    PreparedStatement stmt = null;
    ResultSet rs = null;
    try {
        con = DriverManager.getConnection("jdbc:mysql://localhost:3306/wine", "root", "");


        out.println("Process Not Found");
        if (process == "signup") {

            String query = "INSERT INTO user(name,phone,email,password,role) VALUES(?,?,?,?,1)";
            stmt = con.prepareStatement(query);
            stmt.setString(1, name);
            stmt.setString(2, phone);
            stmt.setString(3, email);
            stmt.setString(4, pwd);

            stmt.execute();

        } else {
            out.println("Process Not Found");
        }
    } catch (SQLException e) {
        // do something appropriate with the exception, *at least*:

        out.println(e);
        e.printStackTrace();
        return 0;
    }
    return 1;
}

主要方法：

public static void main(String[] args) {

    Connection con = null;
    PreparedStatement stmt = null;
    ResultSet rs = null;
    String process = "signup";
    String name = "Test";
    String phone="45885";
    String email = "Test@gmail.com";
    String pwd = "dkjsdh";

    try {
        con = DriverManager.getConnection("jdbc:mysql://localhost:3306/wine", "root", "");



        if (process == "signup") {

            String query = "INSERT INTO user(name,phone,email,password,role,status) VALUES(?,?,?,?,1,1)";
            stmt = con.prepareStatement(query);
            stmt.setString(1, name);
            stmt.setString(2, phone);
            stmt.setString(3, email);
            stmt.setString(4, pwd);

            stmt.execute();

        } else {
            System.out.println("Process Not Found");
        }
    } catch (SQLException e) {
        // do something appropriate with the exception, *at least*:

        System.out.println(e);
        e.printStackTrace();
    }
}

Answer 1

有两种方案可以尝试：

Class.forName("com.mysql.jdbc.Driver").newInstance() //older bug

和

Class.forName("com.mysql.jdbc.Driver");

在评论中我粘贴了旧的错误解决方案，而我打算粘贴第二个。

不管怎样，我很高兴它对你有用

JDBC:MySql 连接在 Ajax 请求中不工作 -Java

JDBC:MySql connection is not working in Ajax request -Java

java

mysql

servlets

jdbc

sqlexception