Java Servlet 在没有 getParameter() 的情况下插入数据库； [复制]

Question

我正在尝试编写将数据插入数据库（mysql）的 servlet。问题是我需要将它写在从 servlet 调用的其他类中，并在没有 getParameter() 的情况下插入数据； UPD：这是一个完整的代码，我想压缩成 2 个类，1 个用于 servlet，1 个用于包含参数的类

1. UserController.java

    protected void doPost(UserDao request, HttpServletResponse 
       response) throws ServletException, IOException {
   
   
   
       UserDao.addUser();
   
   }
   

2. UserDAO.java

    public class UserDao {
   
     private static Connection connection;
   
     public UserDao() {
     connection = (Connection) DBconnect.getConnection();
        }
   
    public static void addUser(String fname, String lname, String dob,      String email, String uid) {
        try {
    PreparedStatement preparedStatement = ((java.sql.Connection)      connection).prepareStatement("insert into users(firstname,lastname,dob,email) values (?, ?, ?, ? );");
     preparedStatement.setString(1, fname);
    preparedStatement.setString(2, lname);
    preparedStatement.setString(3, dob);
    preparedStatement.setString(4, email);
    preparedStatement.executeUpdate();
   
    } catch (SQLException e) {
    e.printStackTrace();
    }
     }
   
   
   }
   

Answer 1

从您的代码中，我可以看到请求中的所有参数现在都设置在用户对象中。

-> 编写一个接受用户对象的 DAO 层类。然后编写查询以使用用户对象插入数据。

Answer 2

我不确定你到底在问什么，所以我做了两种不同的方法...... 希望这会给你一个足够好的例子来做你想做的任何事情。

----有用户对象----

servlet：

protected void doPost(HttpServletRequest request, HttpServletResponse 
response) throws ServletException, IOException {

String fname = request.getParameter("firstName");
String lname = request.getParameter("lastName");
String dob = request.getParameter("dob");
String email = request.getParameter("email");
String uid = request.getParameter("userid");

dao.newUser(fname,lname,dob,email,uid);

}

userDao

 public class UserDao {

 private Connection connection;

 public UserDao() {
 connection = DbConnect.getConnection();
    }

public void newUser(String fname, String lname, String dob, String email, String uid){

    User user = new User();
    user.setFirstName(fname);
    user.setLastName(lname);
    user.setDob(dob);
    user.setEmail(email);

    addUser(user);}

}

    public void addUser(User user) {
        try {
    PreparedStatement preparedStatement = connection
            .prepareStatement("insert into     
  users(firstname,lastname,dob,email) values (?, ?, ?, ? )");

    preparedStatement.setString(1, user.getFirstName());
    preparedStatement.setString(2, user.getLastName());
    preparedStatement.setString(3, user.getDob());
    preparedStatement.setString(4, user.getEmail());
    preparedStatement.executeUpdate();

} catch (SQLException e) {
    e.printStackTrace();
}
     }


}

----没有用户对象----

servlet：

protected void doPost(HttpServletRequest request, HttpServletResponse 
response) throws ServletException, IOException {

String fname = request.getParameter("firstName");
String lname = request.getParameter("lastName");
String dob = request.getParameter("dob");
String email = request.getParameter("email");
String uid = request.getParameter("userid");

dao.addUser(fname,lname,dob,email,uid);

}

userDao

public class UserDao {

 private Connection connection;

 public UserDao() {
 connection = DbConnect.getConnection();
    }

public void addUser(String fname, String lname, String dob, String email, String uid) {
    try {
PreparedStatement preparedStatement = connection
        .prepareStatement("insert into users(firstname,lastname,dob,email) values (?, ?, ?, ? );");

preparedStatement.setString(1, fname);
preparedStatement.setString(2, lname);
preparedStatement.setString(3, dob);
preparedStatement.setString(4, email);
preparedStatement.executeUpdate();

} catch (SQLException e) {
e.printStackTrace();
}
 }


}