JAVA - SQL 테이블 연결 예제

package pack.db2;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import javax.swing.JButton;

import javax.swing.JDialog;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JScrollPane;

import javax.swing.JTable;

import javax.swing.JTextField;

import javax.swing.table.DefaultTableModel;

public class DbTest13CRD extends JFrame implements ActionListener {

    private JButton btnInsert, btnDelte, btnExit;

    private String[][] datas = new String[0][5];

    private String[] title = { "코드", "상품명", "수량", "단가", "금액" };

    private DefaultTableModel model = new DefaultTableModel(datas, title);

    private JTable table = new JTable(model);

    private JLabel lblCount = new JLabel("개수: + 0");

    private Connection conn;

    private PreparedStatement pstmt;

    private ResultSet rs;

    public DbTest13CRD() {

        initLayout();

        accDb();

        setTitle("상품처리");

        setResizable(false); // 사이즈 조절 못하게

        setBounds(200, 200, 300, 250);

        setVisible(true);

        addWindowListener(new WindowAdapter() {

            @Override

            public void windowClosing(WindowEvent arg0) {

                int re = JOptionPane.showConfirmDialog(DbTest13CRD.this, "정말 종료할까요?", "종료",

                        JOptionPane.OK_CANCEL_OPTION);

                if (re == JOptionPane.OK_OPTION) {

                    System.exit(0);

                } else {

                    setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);

                }

            }

        });

    }

    private void initLayout() {

        btnInsert = new JButton("추가");

        btnDelte = new JButton("삭제");

        btnExit = new JButton("종료");

        btnInsert.addActionListener(this);

        btnDelte.addActionListener(this);

        btnExit.addActionListener(this);

        JPanel panel = new JPanel();

        panel.add(btnInsert);

        panel.add(btnDelte);

        panel.add(btnExit);

        add("North", panel);

        // 테이블의 열폭 조절

        table.getColumnModel().getColumn(0).setPreferredWidth(30);

        table.getColumnModel().getColumn(1).setPreferredWidth(100);

        JScrollPane scrollPane = new JScrollPane(table);

        add("Center", scrollPane);

        add("South", lblCount);

    }

    private void accDb() {

        try {

            Class.forName("oracle.jdbc.driver.OracleDriver");

        }catch (Exception e) {

            System.out.println("accDb : " + e);

            return;

        }

        

        displayData();

    }

    private void displayData() {

        model.setNumRows(0);

        try {

            conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl", "scott", "tiger");

            String sql = "select * from sangdata order by code desc";

            pstmt = conn.prepareStatement(sql);

            rs = pstmt.executeQuery();

            int count = 0;

            while (rs.next()) {

                String[] imsi = { rs.getString("code"), rs.getString("sang"), rs.getString("su"), rs.getString("dan"),

                        Integer.toString(rs.getInt("su") * rs.getInt("dan")) };

                model.addRow(imsi);

                count++;

            }

            lblCount.setText("개수 :" + count);

        } catch (Exception e) {

            System.out.println("에러 발생 : " + e);

        } finally {

            try {

                if (rs != null)

                    rs.close();

                if (pstmt != null)

                    pstmt.close();

                if (conn != null)

                    conn.close();

            } catch (Exception e2) {

            }

        }

    }

    @Override

    public void actionPerformed(ActionEvent arg0) {

        if(arg0.getSource() == btnInsert) { // 상품추가

            InsertForm insertForm = new InsertForm(this);

            displayData(); // 추가 후 자료 refresh

            

    }else if(arg0.getSource() == btnDelte) { // 상품삭제

        String delNo = JOptionPane.showInputDialog(this,"삭제할 코드 입력");

        System.out.println(delNo);

        int re = JOptionPane.showConfirmDialog(this, delNo + "삭제하시겠습니까?", "삭제", JOptionPane.OK_CANCEL_OPTION);

        if(re == JOptionPane.CANCEL_OPTION) return;// 삭제 취소

        

        try {

            conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl", "scott", "tiger");

            String sql = "delete from sangdata where code=?";

            pstmt = conn.prepareStatement(sql);

            pstmt.setString(1, delNo);

            if(pstmt.executeUpdate() == 0) {

                JOptionPane.showConfirmDialog(this, delNo + "번은 등록된 자료가 아닙니다"    );

            }

            displayData(); // 삭제 후 자료 보기

            

        } catch (Exception e) {

            System.out.println("삭제 오류 :" + e);

        }    finally {

            try {

                if (rs != null)

                    rs.close();

                if (conn != null)

                    conn.close();

            } catch (Exception e2) {

                // TODO: handle exception

            }

        }        

        

    }else if(arg0.getSource() == btnExit) { // 종료

        int re = JOptionPane.showConfirmDialog(DbTest13CRD.this, "정말 종료할까요?", "종료",

                JOptionPane.OK_CANCEL_OPTION);

        if (re == JOptionPane.OK_OPTION) {

            System.exit(0);

        } else {

            setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);

        }

    }

    }

    // 상품 추가를 위한 내부 클래스 생성

    class InsertForm extends JDialog implements ActionListener{

        JTextField txtSang = new JTextField();

        JTextField txtSu = new JTextField();

        JTextField txtDan = new JTextField();

        JButton btnOk = new JButton("등록");

        JButton btnCancel = new JButton("취소");

        

        public InsertForm(JFrame frame) {

            super(frame, "상품추가");

            setModal(true);

        

            // 추가 화면 디자인

            JPanel pn1 = new JPanel(new GridLayout(4,2));

            pn1.add(new JLabel("품명"));

            pn1.add(txtSang); // 여기까지가 1행

            pn1.add(new JLabel("수량"));

            pn1.add(txtSu);

            pn1.add(new JLabel("단가"));

            pn1.add(txtDan);

            pn1.add(btnOk);

            btnOk.addActionListener(this);

            btnCancel.addActionListener(this);

            

            add("North", new JLabel("--자료 입력 --"));

            add("Center", pn1);

            

            setBounds(210,210,150,150);

            setVisible(true);

            

            addWindowListener(new WindowAdapter() {

                @Override

                public void WindowClosing(WindowEvent arg0) {

                    dispose();

                }

            });

            

        }

        @Override

        public void actionPerformed(ActionEvent arg0) {

            if(arg0.getSource() == btnOk) { // 신상품 추가

            // 입력자료 검사

            if(txtSang.getText().equals("")) {

                JOptionPane.showMessageDialog(this, "상품명 입력!");

                txtSang.requestFocus();

                return;

            }

            if(txtSu.getText().equals("")) {

                JOptionPane.showMessageDialog(this, "수량 입력!");

                txtSang.requestFocus();

                return;

            }

            if(txtDan.getText().equals("")) {

                JOptionPane.showMessageDialog(this, "단가 입력!");

                txtSang.requestFocus();

                return;

            }    

            

            //수량과 단가는 숫자만 허용. try~ , ascii code, 정규 표현식...

            int su = 0;

            try {

                su = Integer.parseInt(txtSu.getText());

            } catch (Exception e) {

                JOptionPane.showMessageDialog(this, "수량은 숫자만 가능");

                txtSu.requestFocus();

                return;

            }

            

            int dan = 0;

            try {

                su = Integer.parseInt(txtSu.getText());

            } catch (Exception e) {

                JOptionPane.showMessageDialog(this, "수량은 숫자만 가능");

                txtSu.requestFocus();

                return;

            }

                // 등록이 가능한 상태----

            try {

                conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl", "scott", "tiger");

                

                // 새상품 코드 구하기

                int new_code = 0;

                String sql = "select max(code) from sangdata";

                pstmt = conn.prepareStatement(sql);

                rs = pstmt.executeQuery();

                if(rs.next()) {

                    new_code = rs.getInt(1);

                }

                //System.out.println(new_code +1);

                sql ="insert into sangdata values(?,?,?,?)";

                pstmt = conn.prepareStatement(sql);

                pstmt.setInt(1, new_code + 1);

                pstmt.setString(2, txtSang.getText().trim()); // " 홍 길동 "

                pstmt.setInt(3, su);

                pstmt.setInt(4, dan);

                if(pstmt.executeUpdate() > 0) {

                    JOptionPane.showMessageDialog(this, "등록성공");

                }else {

                    JOptionPane.showConfirmDialog(this, "헐, 실패");

                }                

                

                

                // 입력자료 초기화

                txtSang.setText(null);

                txtSu.setText("");

                txtDan.setText("");

                txtSang.setText("");

                txtSang.requestFocus();

                                

            } catch (Exception e) {

                System.out.println("신상품 등록 실패 : " + e);

                }finally {

                    try {

                        if (rs != null)

                            rs.close();

                        if (conn != null)

                            conn.close();

                    } catch (Exception e2) {

                        // TODO: handle exception

                    }

                }

            

            

            

            }else if(arg0.getSource() == btnCancel)    { //작업 취소

                dispose();

                        

        }

        }

    }

    

    public static void main(String[] args) {

        new DbTest13CRD();

    }

}

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