21xrx.com
2024-12-23 03:01:10 Monday
登录
文章检索 我的文章 写文章
Java技术栈全图:Java开发者必看!
2023-06-15 16:35:12 深夜i     --     --
Java技术栈 Web开发 桌面开发 数据库操作 安全开发

Java作为一种常用的编程语言,具有广泛的应用范围。本文将为您呈现Java技术栈全图,包括Java Web开发、Java桌面开发、Java数据库开发、Java安全开发等技术栈,并介绍了相关的代码案例,是Java开发者必看的一份资料。

Java Web开发:

在Java Web开发方面,我们需要掌握的知识点有:Servlet、JSP、Spring、Struts2、Hibernate等。他们分别是服务器端的开发框架,用于处理Web页面的请求响应。下面是一个简单的代码案例,展示了如何使用Servlet来完成对请求的处理。


@WebServlet("/HelloServlet")

public class HelloServlet extends HttpServlet {

  private static final long serialVersionUID = 1L;

  public HelloServlet() {

    super();

  }

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

    PrintWriter out = response.getWriter();

    out.println("Hello World");

    out.close();

  }

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

    doGet(request, response);

  }

}

Java桌面开发:

在Java桌面开发方面,我们需要掌握的知识点有:Swing、JavaFX等。他们是用于开发图形界面应用程序的框架,可以制作各种类型的应用程序。以下是一个使用Swing框架实现的简单登陆界面:


public class Login extends JFrame{

  private JPanel contentPane;

  private JTextField textField;

  private JPasswordField passwordField;

  private JButton btnLogin;

  public static void main(String[] args) {

    EventQueue.invokeLater(new Runnable() {

      public void run() {

        try {

          Login frame = new Login();

          frame.setVisible(true);

        } catch (Exception e) {

          e.printStackTrace();

        }

      }

    });

  }

  public Login() {

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    setBounds(100, 100, 450, 300);

    contentPane = new JPanel();

    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

    setContentPane(contentPane);

    contentPane.setLayout(null);

    JLabel lblNewLabel = new JLabel("Login Form");

    lblNewLabel.setFont(new Font("Tahoma", Font.PLAIN, 22));

    lblNewLabel.setBounds(133, 25, 178, 27);

    contentPane.add(lblNewLabel);

    JLabel lblUsername = new JLabel("Username");

    lblUsername.setFont(new Font("Tahoma", Font.PLAIN, 18));

    lblUsername.setBounds(55, 79, 85, 27);

    contentPane.add(lblUsername);

    JLabel lblPassword = new JLabel("Password");

    lblPassword.setFont(new Font("Tahoma", Font.PLAIN, 18));

    lblPassword.setBounds(55, 138, 85, 27);

    contentPane.add(lblPassword);

    textField = new JTextField();

    textField.setBounds(150, 79, 217, 27);

    contentPane.add(textField);

    textField.setColumns(10);

    passwordField = new JPasswordField();

    passwordField.setBounds(150, 140, 217, 27);

    contentPane.add(passwordField);

    btnLogin = new JButton("Login");

    btnLogin.addActionListener(new ActionListener() {

      public void actionPerformed(ActionEvent arg0)

        //TODO 登陆验证

      

    });

    btnLogin.setBounds(170, 202, 89, 23);

    contentPane.add(btnLogin);

  }

}

Java数据库开发:

Java数据库开发需要掌握的知识点包括JDBC、Mybatis等。他们用于与数据库进行连接和操作。以下是一个使用JDBC实现的简单的查询操作:


try{

  Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "root");

  String sql="select * from info";

  Statement stmt=conn.createStatement();

  ResultSet rs=stmt.executeQuery(sql);

  while(rs.next()){

    System.out.println(rs.getInt("id")+" "+rs.getString("name")+" "+rs.getInt("age"));

  }

  rs.close();

  stmt.close();

  conn.close();

}catch(SQLException se){

  se.printStackTrace();

}

Java安全开发:

在Java安全开发方面,我们需要掌握的知识点包括加密、认证、授权等。Java提供了相关的类库,如Java Cryptography Extension(Java密码扩展库)来支持数据的加密、解密,Spring Security用于开发安全认证授权。以下是使用Java密码扩展库实现DES加解密相关代码:


public static byte[] encryptDES(byte[] originData, byte[] key) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {

  SecretKeySpec secretKeySpec = new SecretKeySpec(key, "DES");

  Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");

  cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);

  byte[] encryptedData = cipher.doFinal(originData);

  return encryptedData;

}

public static byte[] decryptDES(byte[] encryptedData, byte[] key) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {

  SecretKeySpec secretKeySpec = new SecretKeySpec(key, "DES");

  Cipher cipher = Cipher.getInstance("DES/ECB/PKCS5Padding");

  cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);

  byte[] decryptedData = cipher.doFinal(encryptedData);

  return decryptedData;

}

文章

  
  

评论区

{{item['qq_nickname']}}
()
回复
回复