Java login interface

Written in front of the words:

1. Reference material: Java implements login and registration interface【Click here for details】
2. Reference materials: Java Swing Graphical Interface Development【Click here for details】
3. In this chapter: The Java Swing Login Screen
4. IDE：IntelliJ IDEA 2021.2.1
5. JDK：Java8

---

Table of contents

1. Project display 

2. Project structure 

 3. Relevant knowledge understanding

 3.1 Create a window 

 3.2 Set font color

 3.2 Set font size

3.3 Set the position of the text in the label 

 4. Actual login interface 

---

1. Project display 

Project display: 

2. Project structure 

Project structure:

 3. Relevant knowledge understanding

 3.1 Create a window 

MyFrame.java  role: create a window 

import javax.swing.*;

public class MyFrame {

    public static void main(String[] args) {

        //1.创建一个主要框架
        JFrame jFrame = new JFrame("测试");

        //2.设置窗口大小
        jFrame.setSize(500,500);

        //3.启动窗口关闭功能
        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        //4.设置窗口是否禁止放大功能
        /*
            true  -> 窗口可以进行缩放
            false -> 窗口不可以进行放大
         */
        jFrame.setResizable(false);

        //5.设置窗口初始位置为屏幕中央
        jFrame.setLocationRelativeTo(null);

        //6.设置窗口可见
        jFrame.setVisible(true);
    }
}

Effect screenshot: 

 3.2 Set font color

setForeground(new Color(0xFF0000));

 Parameter Description:

1. 0xff0000 means red, fill in the hexadecimal representation of the color here [online color picker]
2. Color can also be a parameter or you can fill in a variety of

The basic usage of the above Color class: new Color(255,255,255,255);//Set color and transparency

 for example:

import javax.swing.*;
import java.awt.*;

public class MyFrame {

    public static void main(String[] args) {

        JFrame jFrame = new JFrame("测试");
        jFrame.setSize(500,500);
        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        jFrame.setResizable(false);
        jFrame.setLocationRelativeTo(null);

        /*
            创建一个标签
         */
        //1.创建一个标签,并给标签指定参数"测试文本"
        JLabel jLabel = new JLabel("测试文本");
        //2.设置标签的字体颜色,如：红色
        jLabel.setForeground(new Color(0xff0000));
        //3.将标签添加进框架中
        jFrame.add(jLabel);

        jFrame.setVisible(true);
    }
}

Screenshot of the result:

 3.2 Set font size

setFont(new Font("黑体", Font.PLAIN,20));

Parameter Description:

1. "黑体" indicates the font name
2. Font.PLAIN means normal font (in addition, there are bold BOLD and italic ITALIC )
3. 20 means font size

Font style (normal, bold, italic) 

for example: 

import javax.swing.*;
import java.awt.*;

public class Frame01 {

    public static void main(String[] args) {

        JFrame jFrame = new JFrame("测试");
        jFrame.setSize(500,500);
        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        jFrame.setResizable(false);
        jFrame.setLocationRelativeTo(null);

        /*
            创建一个标签
         */
        //1.创建一个标签,并给标签指定参数"测试文本"
        JLabel jLabel = new JLabel("测试文本");
        //2.设置标签的字体颜色,如：红色
        jLabel.setForeground(new Color(0xff0000));
        //3.设置标签的字体大小
        jLabel.setFont(new Font("黑体", Font.PLAIN,50));
        //4.将标签添加进框架中
        jFrame.add(jLabel);

        jFrame.setVisible(true);
    }
}

 Effect screenshot:

3.3 Set the position of the text in the label 

setBounds(140,60,300,300);

 Parameter Description:

1. 140 represents the coordinates on the horizontal axis
2. 60    represents the coordinates on the vertical axis
3. 300 means width
4. 300 means height

Screen coordinates (important!)

 for example:

import javax.swing.*;
import java.awt.*;

public class Frame01 {

    public static void main(String[] args) {

        JFrame jFrame = new JFrame("测试");
        jFrame.setSize(500,500);
        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        jFrame.setResizable(false);
        jFrame.setLocationRelativeTo(null);

        //不使用布局管理器,采取绝对定位
        jFrame.setLayout(null);

        /*
            创建一个标签
         */
        //1.创建一个标签,并给标签指定参数"测试文本"
        JLabel jLabel = new JLabel("测试文本");
        //2.设置标签的字体颜色,如：红色
        jLabel.setForeground(new Color(0xff0000));
        //3.设置标签的字体大小
        jLabel.setFont(new Font("黑体", Font.PLAIN,50));
        //4.设置文本在标签的位置
        jLabel.setBounds(140,60,300,300);
        //5.将标签添加进框架中
        jFrame.add(jLabel);

        jFrame.setVisible(true);
    }
}

Effect screenshot: (displayed in the center)

 4. Actual login interface 

Login.java login interface

package login;

import student_manage.StudentManage;

import javax.swing.*;
import java.awt.*;

public class Login{

    public static void main(String[] args) {

        //创建一个主要框架,将其命名为”登录"
        JFrame jFrame = new JFrame("登录");

        //设置窗口大小
        jFrame.setSize(900,507);

        //先将布局管理器置为null
        jFrame.setLayout(null);

        //添加标签【学生管理系统】
        JLabel textStudentManage = new JLabel("学生管理系统");//创建一个标签,并命名为“学生管理系统“
        textStudentManage.setForeground(new Color(0x0010FF));//设置字体颜色
        textStudentManage.setFont(new Font("黑体", Font.PLAIN,50));//设置字体大小
        textStudentManage.setBounds(280,50,800,100);//设置标签的绝对位置
        jFrame.add(textStudentManage);//向框架中添加组件【标签(学生管理系统)】

        //添加标签【用户名】
        JLabel textUser = new JLabel("用户名:");
        textUser.setForeground(new Color(0xFF0000));
        textUser.setFont(new Font("黑体", Font.PLAIN,30));
        textUser.setBounds(200,140,200,100);
        jFrame.add(textUser);

        //添加输入框【用户名输入框】
        JTextField user = new JTextField(20);
        user.setFont(new Font("黑体", Font.PLAIN,18));
        user.setSelectedTextColor(new Color(0xFF0000));
        user.setBounds(330,170,280,40);
        jFrame.add(user);

        //添加标签【密码】
        JLabel textPassword = new JLabel("密码  :");
        textPassword.setForeground(new Color(0xFF0000));
        textPassword.setFont(new Font("黑体", Font.PLAIN,30));
        textPassword.setBounds(200,200,200,100);
        jFrame.add(textPassword);

        //添加密码输入框【密码】
        JPasswordField password = new JPasswordField(20);
        password.setBounds(330,230,280,40);
        jFrame.add(password);

        //添加按钮【登录】
        JButton jButton = new JButton("登录");
        jButton.setForeground(new Color(0x023BF6));
        jButton.setBackground(new Color(0x38FF00));
        jButton.setFont(new Font("黑体", Font.PLAIN,20));
        jButton.setBorderPainted(false);
        jButton.setBounds(300,330,100,50);
        jFrame.add(jButton);

        //添加按钮【注册】
        JButton register = new JButton("注册");
        register.setForeground(new Color(0x0029FF));
        register.setBackground(new Color(0xECA871));
        register.setFont(new Font("黑体", Font.PLAIN,20));
        register.setBorderPainted(false);
        register.setBounds(500,330,100,50);
        jFrame.add(register);

        //对按钮事件进行处理
        jButton.addActionListener((e -> {

            /*
                账号：admin
                密码：123456
             */

            //设定条件
            String pwd = new String(password.getPassword());
            if(user.getText().equals("admin")){
                if(pwd.equals("123456")){
                    //密码账号正确,进入学生管理系统
                    //进入学生管理系统
                    jFrame.setVisible(false);//将登录界面设定为不可见
                    new StudentManage().StudentMainInterface();
                }else{
                    //密码不正确
                    JOptionPane.showMessageDialog(jFrame,"密码错误","提示",JOptionPane.INFORMATION_MESSAGE);
                    //将密码框置空
                    password.setText("");
                }
            }else{
                //用户名错误
                JOptionPane.showMessageDialog(jFrame,"用户名错误","提示",JOptionPane.INFORMATION_MESSAGE);
                //将用户名和密码置空
                user.setText("");
                password.setText("");
            }
        }));

        //设置相对位置：屏幕中间
        jFrame.setLocationRelativeTo(null);

        //确保使用窗口关闭按钮，能够正常退出，结束进程！
        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        //禁止对窗口大小进行缩放处理
        jFrame.setResizable(false);

        //设置可见
        jFrame.setVisible(true);
    }

}

 StudentManage.java student management system empty frame

package student_manage;

/*
    登录之后进入的页面【学生管理系统】
 */

import javax.swing.*;

public class StudentManage {


    public void StudentMainInterface(){

        //创建一个窗口,并设置窗口名称为”登录”
        JFrame jFrame = new JFrame("学生管理系统");

        //设置窗口大小
        jFrame.setSize(1400,900);

        //设置相对位置：屏幕中间
        jFrame.setLocationRelativeTo(null);

        //确保使用窗口关闭按钮，能够正常退出，结束进程！
        jFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        //禁止对窗口大小进行缩放处理
        jFrame.setResizable(false);

        //设置可见
        jFrame.setVisible(true);

    }

}

Demo part:

 

 If the password is wrong, a prompt will be displayed.

 After successfully logging in with the user name and password, enter the "Student Management System".