首先我們創建好項目，由於我使用的是mysql數據庫，就要導入連接mysql的jar包：mysql-connector-java-5.1.3-rc-bin.jar。
接下來，我們就要對項目分好層
這次我們主要講ui層的編寫，其它層的代碼就不一 一展示了，有需要的可以在此處下載 https://pan.baidu.com/s/1uYPkjUOI_NLL6ktkAdq5EQ
主界面的步驟都在以下的代碼中，在代碼中對每一步操作都已注釋了
import java.awt.BorderLayout; import java.awt.event.FocusAdapter; import java.awt.event.FocusEvent; import java.awt.event.FocusListener; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import java.util.Set; import java.util.TreeSet; import java.util.Vector; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.JTextField; import javax.swing.ListSelectionModel; import javax.swing.event.TableModelEvent; import javax.swing.event.TableModelListener; import javax.swing.table.DefaultTableModel; import javax.swing.table.TableColumn; import pojo.Student; import pojo.StudentConstant; import service.StudentService; import service.impl.StudentServiceImpl; import util.DataConversion; public class JTableTest extends JFrame{ private JPanel jp1=new JPanel(); private JPanel jp2=new JPanel(); private JPanel jp3=new JPanel(); private JTable jt =null; private JButton select =new JButton("查詢"); private JButton delete =new JButton("刪除"); private JButton update =new JButton("確認修改"); private JButton add =new JButton("增加"); private JButton recover =new JButton("恢復"); private JTextField jtf=new JTextField(20); private JScrollPane jsp=null; private DefaultTableModel dtm=null; private StudentService ss=new StudentServiceImpl(); private List<Student> list=null; private Vector<Vector<String>> vec1; private Vector<String> vec2=null; private String st=null; //===========保存修改后的列名===================== private Set<Integer> li=null; public JTableTest() { this.setTitle("學生表"); this.setSize(500, 600); this.setLocationRelativeTo(null); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setResizable(false); //============設置一個保存表頭的Vector========== vec2=new Vector<String>(); vec2.add("學號"); vec2.add("編號"); vec2.add("姓名"); vec2.add("分數");
list=ss.selectStudentAll();
// vec1=DataConversion.zhuanHuan(list);
//============為表模型設置數據和表頭============= dtm=new DefaultTableModel(vec1,vec2); jt=new JTable(){
//===============設置數據是否可編輯================ public boolean isCellEditable(int row, int column) {
//==============姓名、分數可編輯================== if(column==StudentConstant.SNAME||column==StudentConstant.SCORE) return true; else return false; } }; jt.setModel(dtm);
//===========設置表的點擊方式為只可單選=============== jt.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
//================設置列不可移動============= jt.getTableHeader().setReorderingAllowed(false);
//===============設置所以列不可調整大小=================== jt.getTableHeader().setResizingAllowed(false); //===============隱藏學號這一列因為學號不可被客戶查看，但我們對數據的增刪改查需要用到主鍵，所以隱藏=================== TableColumn tc=jt.getColumnModel().getColumn(0); tc.setMaxWidth(0); tc.setMinWidth(0); tc.setPreferredWidth(0); tc.setResizable(false); li=new TreeSet<Integer>(); //===========查詢========================== select.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { String sname=jtf.getText(); list=new ArrayList<Student>(); list=ss.selectStudentBySname(sname); flush(); } }); //===============增加===================== add.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) {
//=============new一個新的增加窗口============= AddJFrame ad=new AddJFrame();
//=============當主窗體獲得焦點時刷新一下Jtable============ add.addFocusListener(new FocusAdapter() { public void focusGained(FocusEvent e) { list=ss.selectStudentAll(); flush(); } }); } }); //================刪除===================== delete.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { int i=jt.getSelectedRow(); //=======判斷是否選中不選中不彈窗口============== if(i!=-1) { String s=(String) dtm.getValueAt(i, StudentConstant.SID);
//=================彈確認刪除窗口================================== int t=JOptionPane.showConfirmDialog(JTableTest.this, "是否刪除該數據"); switch (t) { case JOptionPane.YES_OPTION: ss.deleteStudent(Integer.parseInt(s)); list=ss.selectStudentAll(); flush(); } } } }); //=================修改數據==================== //==================獲取修改前的數據=============== jt.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { int i=jt.getSelectedRow(); int j=jt.getSelectedColumn(); st = (String) jt.getValueAt(i, j); } });
dtm.addTableModelListener(new TableModelListener() { public void tableChanged(TableModelEvent e) { int i=jt.getSelectedRow(); int j=jt.getSelectedColumn(); String s= (String) jt.getValueAt(i, j);
//=================判斷修改后數據有沒有發生改變=============== if(e.getType()==TableModelEvent.UPDATE) { if(st!=null&!st.equals(s)) {
//================改變后就加入set集合里，注意此處使用set集合重復修改的也只會提交一次可以提高性能===================== li.add(i); } } } }); //================確認修改============ update.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { int t=JOptionPane.showConfirmDialog(JTableTest.this, "你確認修改嗎，修改后不可恢復"); switch (t) {
//========================確認修改，在數據庫中修改============================ case JOptionPane.YES_OPTION: for (Integer i : li) { Student s=new Student(); String ssid=(String) jt.getValueAt(i, StudentConstant.SID); int sid=Integer.parseInt(ssid); String sname=(String) jt.getValueAt(i, StudentConstant.SNAME); int score=Integer.parseInt((String) jt.getValueAt(i, StudentConstant.SCORE)); s.setSid(sid); s.setSname(sname); s.setScore(score); ss.upadteStudent(s); } list=ss.selectStudentAll(); flush(); } } }); //===================恢復==================== recover.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { int t=JOptionPane.showConfirmDialog(JTableTest.this, "你確認恢復嗎，只可以恢復到上一次確認修改后的位置"); switch (t) { case JOptionPane.YES_OPTION:
//==============確認修改之前只是在表上修改了數據沒有對數據庫進行操作，點擊恢復只需要重新查詢數據庫刷新界面======================== list=ss.selectStudentAll(); flush(); } } }); jsp=new JScrollPane(jt); jp1.add(jtf); jp1.add(select); jp2.add(jsp); jp3.add(add); jp3.add(delete); jp3.add(recover); jp3.add(update); this.getContentPane().add(jp1, BorderLayout.NORTH); this.getContentPane().add(jp2); this.getContentPane().add(jp3, BorderLayout.SOUTH); this.setVisible(true); } private void flush() {
//==============改變模型的數據==================== vec1=DataConversion.zhuanHuan(list); dtm=new DefaultTableModel(vec1,vec2); jt.setModel(dtm);
//======每次刷新的時候隱藏第一列================= TableColumn tc=jt.getColumnModel().getColumn(0); tc.setMaxWidth(0); tc.setMinWidth(0); tc.setPreferredWidth(0); tc.setResizable(false); } public static void main(String[] args) throws SQLException { new JTableTest(); } }
以下為增加功能的彈窗
package ui; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; import pojo.Student; import service.StudentService; import service.impl.StudentServiceImpl; public class AddJFrame extends JFrame{ private JLabel sname=new JLabel("姓名"); private JTextField jtf1=new JTextField(); private JLabel score=new JLabel("分數"); private JTextField jtf2=new JTextField(); private JButton jb=new JButton("保存"); private StudentService ss=new StudentServiceImpl(); public AddJFrame() { this.setTitle("新增"); this.setSize(400, 300); this.setLocationRelativeTo(null); this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); this.setResizable(false); this.setLayout(null); sname.setBounds(120, 100, 55, 20); this.add(sname); jtf1.setBounds(180, 100, 90, 20); this.add(jtf1); score.setBounds(120, 145, 55, 20); this.add(score); jtf2.setBounds(180, 145, 90, 20); this.add(jtf2); jb.setBounds(160, 195, 90, 20); jb.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { Student s=new Student(); //==========非空判斷=========== String name=jtf1.getText(); String scc=jtf2.getText(); if(name.length()!=0&&scc.length()!=-1) { int sc =Integer.parseInt(scc); s.setSname(name); s.setScore(sc); ss.addStudent(s); AddJFrame.this.dispose(); } } }); this.add(jb); this.setVisible(true); } }
總結：在對學生表的刪除功能中，我在一開始寫的時候並沒有判斷有沒有選中，這一點要注意，因為不判斷的話，在String s=(String) dtm.getValueAt(i, StudentConstant.SID)；這一行代碼中就會報數組越界異常，因為沒有選中的時候i為-1.
還有就是在增加窗口的非空判斷，如果沒有判斷輸入空時就會報數字轉換異常，由於在寫的時候比較疏忽也就沒有對成績進行進行判斷，希望大家諒解。
看完后記得留條評論啊！