哈工大 java实验5 数据库程序设计
这次试验涉及数据库的一些操作，大概用到如下几个命令。
新建一个数据库
create database phplampDB;
创建一个表 TYPE=MyISAM是指该表使用MyISAM存储引擎，不写也行，主键要设成username 创建student的表类似。
CREATE TABLE `admin` ( `username` varchar(20) NOT NULL, `passwd` varchar(20) NOT NULL, PRIMARY KEY (`username`) ) TYPE=MyISAM;
查询表中的记录
select * from table;
插入一条记录 into 不写也行
insert into admin values(“tom”,”123”);
查看mySQL所使用的端口 写程序的时候要用到，不过一般都是默认的。
show variables like 'port';
最后提醒一下MySQL里的数据都可以用用双引号引起来，字段名什么的可以用键盘上1左边tab上边的那个键引起来，很容易弄混。
try{
Class.forName(driver);
conn=DriverManager.getConnection(url,user,pass);
if (!conn.isClosed()){
System.out.println("Success");
statement = conn.createStatement();
rs = statement.executeQuery("select * from admin");
}
}catch(Exception e){
System.out.println("exception");
}变量如下：
private static String driver = "com.mysql.jdbc.Driver";
private static String url = "jdbc:mysql://127.0.0.1:3306/hit";
private static String user="root";
private static String pass="nihaoa";
private static Connection conn;
private static ResultSet rs;
private static Statement statement;
Class.forName()静态方法是为了动态加载类，一般在加载完成后还需要调用newInstance()来实例化对象，其实它和new差不多，不过newInstance()只支持无参数初始化。
Class.forName("")返回一个类
Class.forName("").newInstance()返回一个object
刚才提到，Class.forName("");的作用是要求JVM查找并加载指定的类，如果在类中有静态初始化器的话，JVM必然会
执行该类的静态代码 段。而在JDBC规范中明确要求这个Driver类必须向DriverManager注册自己，即任何一个JDBC
Driver的 Driver类的代码都必须类似如下：
public class MyJDBCDriver implements Driver {
static {
DriverManager.registerDriver(new MyJDBCDriver());
}
}
既然在静态初始化器的中已经进行了注册，所以我们在使用JDBC时只需要Class.forName(XXX.XXX);就可以了。
布局都很熟了就不多说了
工具栏我是这样写的
private void installTollBar(){
toolBar = new JToolBar();
button1.addActionListener(this);
button2.addActionListener(this);
toolBar.add(button1);
toolBar.add(button2);
add(toolBar,BorderLayout.NORTH);
}
table是这样 这里要注意一点最好把table加在一个其他的pane(JScrollPane最好)，不然有可能出现显示不出字段名的情况。
private void installTable(){
table = new JTable(data,name);
table.setBounds(0, 0, 450, 450);
pane=new JScrollPane(table);
add(pane);
}参数如下
private JTable table;
private Object[][] data = {};
private String[] name = {"number","name","sex","age","brith","collage"};
JScrollPane pane = null;
从数据库里读出记录 用好rs.next()就可以了 ， 需要注意rs.getObject()是从一开始的。
public void databaseInit(){
try{
rs = statement.executeQuery("select * from student");
System.out.println("Success Init");
int i=0;
rs.last();
data = new Object[rs.getRow()][6];
System.out.println(rs.getRow());
rs.beforeFirst();
while (rs.next()){
for(int j=0;j<6;j++){
data[i][j]=rs.getObject(j+1);
//System.out.print(rs.getObject(j+1)+" ");
}
System.out.println();
i++;
}
installTable();
}catch(Exception ex){
System.out.println("Exception In databaseInit()");
}
}
判断年份是否合法
用DateFormat简单判断一下，格式有错的话抛出异常，不过MySQL的Date类型也会帮你检查数据是否正确，大月小月也会检查很强大
Y=text4.getText();
M=text5.getText();
D=text6.getText();
T=Y+"-"+M+"-"+D;
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
dateFormat.setLenient(true);
try{
dateFormat.parse(T);
}catch(Exception ex){
INData();
System.out.println("Date");
}
其他就没有什么了，纯体力活。完整代码如下。
import java.awt.BorderLayout;
import java.awt.Choice;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.text.SimpleDateFormat;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.JToolBar;
public class MyDateBase {
public static void main(String[] args) {
try{
Class.forName(driver);
conn=DriverManager.getConnection(url,user,pass);
if (!conn.isClosed()){
System.out.println("Success");
statement = conn.createStatement();
rs = statement.executeQuery("select * from admin");
}
}catch(Exception e){
System.out.println("exception");
}
MyLogin = new Login();
}
private static class MyCons extends GridBagConstraints {
public MyCons(int a, int b, int c, int d) {
super.weightx = 1;
super.weighty = 1;
super.gridx = a;
super.gridy = b;
super.gridwidth = c;
super.gridheight = d;
}
}
private static class Login extends JFrame implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
String userName;
String passWd;
if (e.getSource().equals(button1)) {
userName=text1.getText();
passWd=text2.getText();
boolean b=false;
try{
while(rs.next()){
System.out.println(rs.getString(1)+" "+rs.getString(2));
//System.out.println(rs.getString(1)==userName+" "+rs.getString(2));
if((rs.getString(1).equals(userName))&&(rs.getString(2).equals(passWd))){
b=true;
}
}
}catch(Exception ex){
}
if(b)
MyMain = new Main();
this.dispose();
}
if (e.getSource().equals(button2)){
this.dispose();
}
}
public Login() {
super("Login");
setSize(200, 200);
this.setVisible(true);
init();
}
private void init() {
button1.addActionListener(this);
button2.addActionListener(this);
setLayout(new GridBagLayout());
add(label1, new MyCons(0, 0, 1, 1));
add(text1, new MyCons(1, 0, 3, 1));
add(label2, new MyCons(0, 1, 1, 1));
add(text2, new MyCons(1, 1, 3, 1));
add(button1, new MyCons(1, 2, 1, 1));
add(button2, new MyCons(3, 2, 1, 1));
}
private JLabel label1 = new JLabel("UserID:");
private JLabel label2 = new JLabel("PassWord:");
private TextField text1 = new TextField(15);
private TextField text2 = new TextField(15);
private JButton button1 = new JButton("Login");
private JButton button2 = new JButton("Exit");
}
private static class Main extends JFrame implements ActionListener{
@Override
public void actionPerformed(ActionEvent e) {
if (e.getSource().equals(Item_Insert)||e.getSource().equals(button1)) {
MyInsert = new Insert();
}
else if (e.getSource().equals(Item_Exit)||e.getSource().equals(button2)){
this.dispose();
}
}
public Main() {
super("Main");
setSize(400, 400);
setVisible(true);
init();
}
private void init() {
databaseInit();
installMenu();
installTollBar();
}
public void databaseInit(){
try{
rs = statement.executeQuery("select * from student");
System.out.println("Success Init");
int i=0;
rs.last();
data = new Object[rs.getRow()][6];
System.out.println(rs.getRow());
rs.beforeFirst();
while (rs.next()){
for(int j=0;j<6;j++){
data[i][j]=rs.getObject(j+1);
//System.out.print(rs.getObject(j+1)+" ");
}
System.out.println();
i++;
}
installTable();
}catch(Exception ex){
System.out.println("Exception In databaseInit()");
}
}
private void installTable(){
table = new JTable(data,name);
table.setBounds(0, 0, 450, 450);
pane=new JScrollPane(table);
add(pane);
}
private void installTollBar(){
toolBar = new JToolBar();
button1.addActionListener(this);
button2.addActionListener(this);
toolBar.add(button1);
toolBar.add(button2);
add(toolBar,BorderLayout.NORTH);
}
private void installMenu() {
Mb = new JMenuBar();
sysMenu = new JMenu("System");
Item_Insert = new JMenuItem("Insert");
Item_Exit = new JMenuItem("Exit");
Item_Exit.addActionListener(this);
Item_Insert.addActionListener(this);
sysMenu.add(Item_Insert);
sysMenu.add(Item_Exit);
Mb.add(sysMenu);
setJMenuBar(Mb);
}
private JMenuItem Item_Insert;
private JMenuItem Item_Exit;
private JMenuBar Mb;
private JMenu sysMenu;
private JPanel insertS;
private JToolBar toolBar;
private JButton button1 = new JButton("Ins");
private JButton button2 = new JButton("Ext");
private JTable table;
private Object[][] data = {};
private String[] name = {"number","name","sex","age","brith","collage"};
JScrollPane pane = null;
}
private static class Insert extends JFrame implements ItemListener,ActionListener{
@Override
public void itemStateChanged(ItemEvent e) {
// TODO Auto-generated method stub
}
@Override
public void actionPerformed(ActionEvent e){
String Y,M,D,T="";
CheckDate=true;
if (e.getSource().equals(button1)){
String sql = "insert student values(";
if (text1.getText().length()==10&&text2.getText().length()!=0){
int age=Integer.parseInt(text3.getText());
if(0<age&&age<100){
Y=text4.getText();
M=text5.getText();
D=text6.getText();
T=Y+"-"+M+"-"+D;
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
dateFormat.setLenient(true);
try{
dateFormat.parse(T);
}catch(Exception ex){
INData();
System.out.println("Date");
}
sql+="\""+text1.getText()+"\",";
sql+="\""+text2.getText()+"\",";
if (box1.isSelected())
sql+="\""+"Male"+"\",";
else
sql+="\""+"Female"+"\",";
sql+=age+",";
sql+="\""+T+"\",";
sql+="\""+choice.getSelectedItem()+"\");";
if (CheckDate)
try{
System.out.println(sql);
statement.execute(sql);
MyMain.dispose();
MyMain=new Main();
this.dispose();
}catch(Exception ex){
System.out.println("Exception in Insert");
}
}
}
else{
INData();
}
}
else if (e.getSource().equals(button2)){
this.dispose();
}
}
public Insert() {
super("Insert");
setSize(300, 300);
setVisible(true);
init();
}
private void INData(){
System.out.println("Data Exception!");
CheckDate=false;
//this.dispose();
}
private void init(){
setLayout(new GridBagLayout());
add(label1,new MyCons(0,0,1,1));
add(text1,new MyCons(1,0,3,1));
//---------------------------------------
add(label2,new MyCons(0,1,1,1));
add(text2,new MyCons(1,1,3,1));
//---------------------------------------
add(label3,new MyCons(0,2,1,1));
sexGroup.add(box1);
sexGroup.add(box2);
add(box1,new MyCons(1,2,1,1));
add(box2,new MyCons(2,2,1,1));
//---------------------------------------
add(label4,new MyCons(0,3,1,1));
add(text3,new MyCons(1,3,3,1));
//---------------------------------------
add(label5,new MyCons(0,4,1,1));
add(text4,new MyCons(1,4,2,1));
add(label7,new MyCons(3,4,1,1));
add(text5,new MyCons(5,4,1,1));
add(label8,new MyCons(6,4,1,1));
add(text6,new MyCons(7,4,1,1));
add(label9,new MyCons(8,4,1,1));
//---------------------------------------
choice.add("software1");
choice.add("software2");
choice.addItemListener(this);
add(label6,new MyCons(0,5,1,1));
add(choice,new MyCons(1,5,3,1));
//---------------------------------------
button1.addActionListener(this);
button2.addActionListener(this);
add(button1,new MyCons(0,6,1,1));
add(button2,new MyCons(1,6,1,1));
}
private JLabel label1 = new JLabel("Number:");
private JLabel label2 = new JLabel("Name:");
private JLabel label3 = new JLabel("Sex:");
private JLabel label4 = new JLabel("Age:");
private JLabel label5 = new JLabel("Brith:");
private JLabel label6 = new JLabel("College");
private JLabel label7 = new JLabel("Y");
private JLabel label8 = new JLabel("M");
private JLabel label9 = new JLabel("D");
private JTextField text1 = new JTextField(10);
private JTextField text2 = new JTextField(10);
private JTextField text3 = new JTextField(10);
private JTextField text4 = new JTextField(5);
private JTextField text5 = new JTextField(3);
private JTextField text6 = new JTextField(3);
private ButtonGroup sexGroup = new ButtonGroup();
private JRadioButton box1 = new JRadioButton("male",true);
private JRadioButton box2 = new JRadioButton("female",false);
private Choice choice = new Choice();
private JButton button1 = new JButton("Submit");
private JButton button2 = new JButton("Exit");
private boolean CheckDate;
}
private class MyException extends Exception{
}
private static Login MyLogin;
private static Main MyMain;
private static Insert MyInsert;
private static String driver = "com.mysql.jdbc.Driver";
private static String url = "jdbc:mysql://127.0.0.1:3306/hit";
private static String user="root";
private static String pass="nihaoa";
private static Connection conn;
private static ResultSet rs;
private static Statement statement;
}