系统实现的功能是增删改查
通过这次练习，我对java布局和数据库的操作更加熟练了。对MVC模式有了一定的理解，所有的信息处理和提交数据库的逻辑都在Student类里面，界面的显示逻辑在ShowStuInfoFrame
里面。
对数据库做增删改查的4个5个函数入下声明：
添加学生信息：
public boolean addStuInfo(int sNum, String sName, String sClass, String sProfessional)
删除学生信息：
public boolean deleteStuInfo(int sNum)
修改学生信息：
public boolean modifyStuInfo(Student stu, int sNum, String sName, String sClass, String sProfessional)查询学生信息：public List<Student> queryAllStuInfo()修改学生信息所用到的子函数：查询单个学生信息public Student queryStuInfo(int sNum)连接数据库的函数：public Connection connectToMySql()ShowStuInfoFrame类的代码如下：package com.baidu.studentmanage; import java.awt.*; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.util.List; import javax.swing.*; import java.sql.*; /** * * @author Z7M-SL7D2 * @since 2018年1月22日21:24:27 * 用来显示学生管理系统主界面 */ public class ShowStuInfoFrame extends JFrame { Student stu = new Student(); JTextArea stuInfoListJTA = null; //对输出进行处理 public String setStringLen(int len) { String string = ""; for(int i = 0; i < 35-len; ++i) { string += " "; } return string; } /** * 显示所有学生信息 */ public void showAllStuInfo(){ stuInfoListJTA.setText(""); List<Student> list = stu.queryAllStuInfo(); for(Student student:list) { String sNum = new Integer(student.getStuNum()).toString(); String sName = student.getStuName(); String sClass = student.getStuClass(); String sProfessional = student.getStuProfessional(); stuInfoListJTA.setText(stuInfoListJTA.getText() + sNum + setStringLen(sNum.getBytes().length) + sName + setStringLen(sName.getBytes().length) + sClass + setStringLen(sClass.getBytes().length) + sProfessional + setStringLen(sProfessional.getBytes().length) + "\n"); } } /** * 构造函数 */ public ShowStuInfoFrame() { this.setSize(600, 600); this.setLocationRelativeTo(null); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setLayout(null); //界面标题部分 JLabel titleJL = new JLabel("学生管理系统"); Font font = new Font("微软雅黑", 1, 15); titleJL.setFont(font); titleJL.setLayout(null); titleJL.setBounds(250, 10, 100, 20); //按钮部分 JPanel buttonJP = new JPanel(); buttonJP.setLayout(null); // buttonJP.setBackground(Color.blue); buttonJP.setBounds(0, 50, 600, 40); JButton jbAdd = new JButton("添加学生信息"); jbAdd.setBounds(25, 10, 120, 30); jbAdd.setBackground(Color.gray); JButton jbDelete = new JButton("删除学生信息"); jbDelete.setBounds(170, 10, 120, 30); jbDelete.setBackground(Color.gray); JButton jbModify = new JButton("修改学生信息"); jbModify.setBounds(315, 10, 120, 30); jbModify.setBackground(Color.gray); JButton jbQuery = new JButton("查询学生信息"); jbQuery.setBounds(455, 10, 120, 30); jbQuery.setBackground(Color.gray); // buttonJP.setLayout(new FlowLayout()); buttonJP.add(jbAdd); buttonJP.add(jbDelete); buttonJP.add(jbModify); buttonJP.add(jbQuery); JPanel listHeadJP = new JPanel(); listHeadJP.setBackground(Color.lightGray); listHeadJP.setLayout(null); listHeadJP.setBounds(0, 120, 580, 30); JLabel numHeadJL = new JLabel(" 学 号"); numHeadJL.setBackground(Color.gray); numHeadJL.setBounds(20, 0, 150, 25); JLabel nameHeadJL = new JLabel("姓 名"); nameHeadJL.setBounds(170, 0, 150, 25); JLabel classHeadJL = new JLabel("班 级"); classHeadJL.setBounds(320, 0, 150, 25); JLabel professionalHeadJL = new JLabel("专 业"); professionalHeadJL.setBounds(470, 0, 150, 25); listHeadJP.add(numHeadJL); listHeadJP.add(nameHeadJL); listHeadJP.add(classHeadJL); listHeadJP.add(professionalHeadJL); Font stuInfoListFont = new Font("微软雅黑", 0, 13); stuInfoListJTA = new JTextArea(20,20); stuInfoListJTA.setBounds(10, 152, 560, 400); stuInfoListJTA.setBorder (BorderFactory.createEmptyBorder (1,1,1,5)); stuInfoListJTA.setColumns (20); stuInfoListJTA.setRows (20);//相当于设置文本区组件的初始大小,并不是说一行只能写0 stuInfoListJTA.setFont(stuInfoListFont); this.add(titleJL); this.add(buttonJP); this.add(listHeadJP); this.add(stuInfoListJTA); showAllStuInfo(); this.setVisible(true); //添加学生信息 jbAdd.addMouseListener(new MouseAdapter(){ //匿名内部类使用方法的临时变量需要提前，负责会让你改为final，改为final是为了延长变量的声明周期 JTextField nameJTF = null; JTextField numJTF = null; JTextField classJTF = null; JTextField professionalJTF = null; @Override public void mouseClicked(MouseEvent e) { final JFrame addJF = new JFrame(); addJF.setSize(300, 400); addJF.setBackground(Color.gray); addJF.setLocationRelativeTo(null); addJF.setVisible(true); addJF.setLayout(new FlowLayout()); JLabel numJL = new JLabel("学号："); numJTF = new JTextField(20); JLabel nameJL = new JLabel("姓名："); nameJTF = new JTextField(20); JLabel classJL = new JLabel("班级："); classJTF = new JTextField(20); JLabel professionalJL = new JLabel("专业："); professionalJTF = new JTextField(20); //addJF.dispose();//销毁子窗口 addJF.add(numJL); addJF.add(numJTF); addJF.add(nameJL); addJF.add(nameJTF); addJF.add(classJL); addJF.add(classJTF); addJF.add(professionalJL); addJF.add(professionalJTF); JButton addJB = new JButton("添加"); addJF.add(addJB); addJB.addMouseListener(new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { Integer snumAddI = new Integer(numJTF.getText().toString()); int snumAdd = snumAddI; String snameAdd = nameJTF.getText(); String sclassAdd = classJTF.getText(); String sprofessionalAdd = professionalJTF.getText(); //输入的信息为空的处理 if(snumAdd <0 | snameAdd == null | sclassAdd == "" | sprofessionalAdd == "") { JFrame tipJF = new JFrame("提示"); tipJF.setVisible(true); tipJF.setSize(200,100); tipJF.setLocationRelativeTo(null); JLabel tipJL = new JLabel("请填入了所有的信息之后再点击提交"); tipJF.add(tipJL); }else { stu = new Student(); stu.addStuInfo(snumAdd, snameAdd, snameAdd, sprofessionalAdd); addJF.dispose(); JFrame addSuccessfulJF = new JFrame("提示"); addSuccessfulJF.setLocationRelativeTo(null); addSuccessfulJF.setSize(260, 100); addSuccessfulJF.setVisible(true); addSuccessfulJF.setLayout(new FlowLayout()); JLabel SuccessfulJL = new JLabel("添加学生信息成功！"); addSuccessfulJF.add(SuccessfulJL); } } }); } }); //删除学生信息 jbDelete.addMouseListener(new MouseAdapter() { JTextField numJTF = null; @Override public void mouseClicked(MouseEvent e) { final JFrame deleteJF = new JFrame("删除学生信息"); deleteJF.setLayout(new FlowLayout()); deleteJF.setSize(300, 80); deleteJF.setVisible(true); deleteJF.setLocationRelativeTo(null); JLabel numJL = new JLabel("学号:"); numJTF = new JTextField(15); JButton numJB = new JButton("提交"); deleteJF.add(numJL); deleteJF.add(numJTF); deleteJF.add(numJB); numJB.addMouseListener(new MouseAdapter(){ @Override public void mouseClicked(MouseEvent e) { Integer sNumI = new Integer(numJTF.getText().toString()); stu.deleteStuInfo(sNumI); deleteJF.dispose(); JFrame deleteSuccessfulJF = new JFrame("提示"); deleteSuccessfulJF.setLocationRelativeTo(null); deleteSuccessfulJF.setSize(260, 100); deleteSuccessfulJF.setVisible(true); deleteSuccessfulJF.setLayout(new FlowLayout()); JLabel SuccessfulJL = new JLabel("删除学生信息成功！"); deleteSuccessfulJF.add(SuccessfulJL); } }); } }); //修改学生信息 jbModify.addMouseListener(new MouseAdapter(){ JTextField num1JTF = null; @Override public void mouseClicked(MouseEvent e) { final JFrame modifyJF = new JFrame("修改学生信息"); modifyJF.setSize(300, 80); modifyJF.setLocationRelativeTo(null); modifyJF.setLayout(new FlowLayout()); modifyJF.setVisible(true); JLabel numJL = new JLabel("学号："); num1JTF = new JTextField(15); JButton numJB = new JButton("提交"); modifyJF.add(numJL); modifyJF.add(num1JTF); modifyJF.add(numJB); numJB.addMouseListener(new MouseAdapter() { JTextField numJTF = null; JTextField nameJTF = null; JTextField classJTF = null; JTextField professionalJTF = null; String tempNum = null; String tempName = null; String tempClass = null; String tempProfessional = null; Connection conn = null; @Override public void mouseClicked(MouseEvent e) { ////////////////////////////////////////////////////////////// //////////////显示学号对应的学生信息/////////////////////////////// ///////////////////////////////////////////////////////////// final JFrame modifyJF1 = new JFrame(); modifyJF1.setSize(300, 400); modifyJF1.setBackground(Color.gray); modifyJF1.setLocationRelativeTo(null); modifyJF1.setVisible(true); modifyJF1.setLayout(new FlowLayout()); JLabel numJL = new JLabel("学号："); numJTF = new JTextField(20); JLabel nameJL = new JLabel("姓名："); nameJTF = new JTextField(20); JLabel classJL = new JLabel("班级："); classJTF = new JTextField(20); JLabel professionalJL = new JLabel("专业："); professionalJTF = new JTextField(20); modifyJF1.add(numJL); modifyJF1.add(numJTF); modifyJF1.add(nameJL); modifyJF1.add(nameJTF); modifyJF1.add(classJL); modifyJF1.add(classJTF); modifyJF1.add(professionalJL); modifyJF1.add(professionalJTF); //查询学生信息 Integer sNum = new Integer(num1JTF.getText().toString()); final Student stuRet = stu.queryStuInfo(sNum); numJTF.setText(new Integer(stuRet.getStuNum()).toString()); nameJTF.setText(stuRet.getStuName()); classJTF.setText(stuRet.getStuClass()); professionalJTF.setText(stuRet.getStuProfessional()); ////////////////////////////////////////////////////////////// //////////////提交修改后的学生信息/////////////////////////////// ///////////////////////////////////////////////////////////// JButton submitJB = new JButton("提交修改"); modifyJF1.add(submitJB); submitJB.addMouseListener(new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { String sName = nameJTF.getText(); String sClass = classJTF.getText(); String sProfessional = professionalJTF.getText(); stu.modifyStuInfo(stuRet, stuRet.getStuNum(), sName, sClass, sProfessional); modifyJF1.dispose(); JFrame updateSucessfulJF = new JFrame("提示"); updateSucessfulJF.setLocationRelativeTo(null); updateSucessfulJF.setSize(260, 100); updateSucessfulJF.setVisible(true); updateSucessfulJF.setLayout(new FlowLayout()); JLabel SuccessfulJL = new JLabel("修改学生信息成功！"); updateSucessfulJF.add(SuccessfulJL); } }); modifyJF.dispose(); } }); } }); //查询学生信息 jbQuery.addMouseListener(new MouseAdapter() { @Override public void mouseClicked(MouseEvent e) { //显示所有的学生信息 showAllStuInfo(); } }); } public static void main(String[] args) { new ShowStuInfoFrame(); } }
Student类的代码如下：package com.baidu.studentmanage; import java.sql.*; import java.util.ArrayList; import java.util.List; public class Student { private int stuNum;//学号 private String stuName;//姓名 private String stuClass;//班级 private String stuProfessional;//专业 public Student() { } public Student(int stuNum, String stuName, String stuClass, String stuProfessional) { super(); this.stuNum = stuNum; this.stuName = stuName; this.stuClass = stuClass; this.stuProfessional = stuProfessional; } public int getStuNum() { return stuNum; } public void setStuNum(int stuNum) { this.stuNum = stuNum; } public String getStuName() { return stuName; } public void setStuName(String stuName) { this.stuName = stuName; } public String getStuClass() { return stuClass; } public void setStuClass(String stuClass) { this.stuClass = stuClass; } public String getStuProfessional() { return stuProfessional; } public void setStuProfessional(String stuProfessional) { this.stuProfessional = stuProfessional; } public Connection connectToMySql() { try { String driver = "com.mysql.jdbc.Driver"; String url = "jdbc:mysql://localhost/student?useUnicode=true&characterEncoding=UTF-8&user=" + "root&password=123456"; Class.forName(driver).newInstance(); Connection connection = DriverManager.getConnection(url); return connection; } catch (Exception e) { e.printStackTrace(); System.out.println("数据库连接出错"); } return null; } public boolean addStuInfo(int sNum, String sName, String sClass, String sProfessional) { String sqlInsert = "insert into student values(" + sNum + ",'" + sName + "','" + sClass + "','" + sProfessional + "')"; System.out.println(sNum + sName + sClass + sProfessional); Connection conn = connectToMySql(); PreparedStatement ps = null; try { ps = conn.prepareStatement(sqlInsert); ps.executeUpdate(); return true; } catch (Exception e1) { e1.printStackTrace(); System.out.println("添加学生信息失败！"); return false; } finally { try { ps.close(); conn.close(); } catch (SQLException e1) { e1.printStackTrace(); } } } public boolean deleteStuInfo(int sNum) { Connection conn = connectToMySql(); String deleteSQL = "delete from student where stuNum=" + sNum; PreparedStatement ps = null; try { ps = conn.prepareStatement(deleteSQL); ps.executeUpdate(); return true; } catch (Exception e3) { e3.printStackTrace(); System.out.println("数据库语句检查或执行出错"); return false; } finally { try { ps.close(); conn.close(); } catch (SQLException e1) { e1.printStackTrace(); } } } public Student queryStuInfo(int sNum) { Student stu = new Student(); String querySql = "select * from student where stuNum="+sNum; Connection conn = connectToMySql(); try { Statement statement = conn.createStatement(); ResultSet rs = statement.executeQuery(querySql); while(rs.next()) { stu.stuNum = new Integer(rs.getString("stuNum")); stu.stuName = rs.getString("stuName"); stu.stuClass = rs.getString("stuClass"); stu.stuProfessional = rs.getString("stuProfessional"); } return stu; } catch (SQLException e1) { e1.printStackTrace(); return null; } } //修改学生信息 public boolean modifyStuInfo(Student stu, int sNum, String sName, String sClass, String sProfessional) { Connection conn = connectToMySql(); //信息有改动才提交 if(false == sName.equals(stu.stuName)) { String updateSql = "update student set stuName='"+sName+"' where stuNum=" + stu.stuNum; try { PreparedStatement ps = conn.prepareStatement(updateSql); ps.executeUpdate(); ps.close(); } catch (SQLException e1) { e1.printStackTrace(); return false; } } if(false == sClass.equals(stu.stuClass)) { String updateSql = "update student set stuClass='"+sClass+"' where stuNum=" + stu.stuNum; try { PreparedStatement ps = conn.prepareStatement(updateSql); ps.executeUpdate(); ps.close(); } catch (SQLException e1) { e1.printStackTrace(); return false; } } if(false == sProfessional.equals(stu.stuProfessional)) { String updateSql = "update student set stuProfessional='"+sProfessional+"' where stuNum=" + stu.stuNum; try { PreparedStatement ps = conn.prepareStatement(updateSql); ps.executeUpdate(); ps.close(); } catch (SQLException e1) { e1.printStackTrace(); return false; } } return true; } public List<Student> queryAllStuInfo() { List<Student> stuList = new ArrayList<Student>(); Student stu = null; ResultSet queryRS = null; Statement queryStatement = null; Connection queryConn = null; try{ queryConn = connectToMySql(); queryStatement = queryConn.createStatement(); String sqlQuery = "select * from student"; queryRS = queryStatement.executeQuery(sqlQuery); while(queryRS.next()) { stu = new Student(); stu.stuNum = new Integer(queryRS.getString("stuNum")); stu.stuName = queryRS.getString("stuName"); stu.stuClass = queryRS.getString("stuClass"); stu.stuProfessional = queryRS.getString("stuProfessional"); stuList.add(stu); } return stuList; }catch(Exception e2) { e2.printStackTrace(); return null; }finally{ try { queryRS.close(); queryStatement.close(); queryConn.close(); } catch (SQLException e1) { e1.printStackTrace(); } } } }