package 学生管理系统;

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class MainClass extends JFrame {

public MainClass() {
super("学生管理系统---管理员登陆");
this.init();
}

public void init() {
Container cp = this.getContentPane();
cp.setLayout(null);


JLabel jlabel1 = new JLabel("管理员帐号:");
JLabel jlabel2 = new JLabel("管理员密码:");
JButton jbutton = new JButton("登陆");
final JTextField text = new JTextField(10);
final JPasswordField password = new JPasswordField();
jbutton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String[] str =
new DatabaseUtilities().getDataTypes("Admin_info");
if(str[0].equals(text.getText()))
if(str[1].equals(password.getText()))
JOptionPane.showMessageDialog(f,"你以管理员"
+str[0]+"的身份登陆");　　//这里有错误，该怎么办。。。意思是不认识F
else
JOptionPane.showMessageDialog(f,"你输入的密码有误");
else
JOptionPane.showMessageDialog(f,"你输入的用户名不存在");
}
});

cp.add(jlabel1);
cp.add(jlabel2);
cp.add(text);
cp.add(password);
cp.add(jbutton);

jlabel1.setBounds(150, 150, 100, 20);
jlabel2.setBounds(150, 200, 100, 20);
text.setBounds(260, 150, 150, 20);
password.setBounds(260, 200, 150, 20);
jbutton.setBounds(220, 270, 90, 40);

this.setSize(new Dimension(600, 400));
this.setLocation(200, 200);
this.show();

this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
}

/*class ButtonListener implements ActionListener {
public void actionPerformed(ActionEvent event) {
String SQLCommand = "SELECT * FROM Admin_info";
execute(SQLCommand);
}
}*/

public static void main(String[] args) {
final MainClass f = new MainClass();
}

}

如果我想让他访问外面的那个在MAIN中声明的F　该怎么办？
把F声明为FINAL？好像不管用。。。

晕。。。楼上的　　我E文不好。。。
建的包太多了。。。这样中文名我自已好认识。。。。
自已做练习的东西。。。。。

this不可以啊，因为我是在BUTTON这个ACTION方法中声明写的这段代码。。
THIS不是对当初引用对像的引用么。。。那如果我用 THIS的话就得到BUTTON这个对像啦。。。。

这个我知道啊　　呵呵　　　还是谢谢楼上的好心提醒。。
至于你那个问题。。。因为用的那个类是我自已建的啊
下面那个SHOWMESSAGE的错误　是因为你的参数不对。。。我上面已经说过了　　THIS表示对当前引用此方法的对像的引用　　所以是一个BUTTON而不是一个容器。。。

呵呵　　传入NULL也可以啦　　　我只想忽然想到这个问题　　所以就问下了　　　多了解点东西不是坏事嘛

不能明白版主的意思　　如果版主有空就烦请写个eg　　没空就算了　　也许以后我再遇到的时候领悟到了

版主费心了　　

那个是我自已写的类，专门用来处理数据库操作的。。。。
呵呵！！！不是系统JDK里的。。。。

我也是跟着书上来写的，呵呵！！！
[CODE]

import java.awt.event.*;
import java.sql.*;
import java.util.Vector;
import sun.jdbc.odbc.JdbcOdbcDriver;

public class DatabaseUtilities {

static String jdbcDriver = "sun.jdbc.odbc.JdbcOdbcDriver";
static String dbName = "JDBC";
static String urlRoot = "jdbc:odbc:";
private ActionListener exceptionListener = null;

public DatabaseUtilities() {
registerDriver();
}

public void setDatabaseName(String dbName) {
this.dbName = dbName;
}

public void registerDriver() {
try {
Class.forName(jdbcDriver);
DriverManager.registerDriver(new JdbcOdbcDriver());

} catch(ClassNotFoundException e) {
reportException(e.getMessage());

} catch(SQLException e) {
reportException(e.getMessage());
}
}

public String login(String tableName, String dbuser, String dbpassword)
{
String message = null;
Vector user = new Vector();
Vector password = new Vector();
String url = urlRoot + dbName;
String SQLCommand = "SELECT * FROM " + tableName + ";";

try {
Connection con = DriverManager.getConnection(url);
Statement stms = con.createStatement();
ResultSet rs = stms.executeQuery(SQLCommand);
while(rs.next()) {
user.add(rs.getString("name").trim());
password.add(rs.getString("password").trim());
}
} catch(SQLException sqlExc) {
reportException(sqlExc.getMessage());
}

if (!user.contains(dbuser) && !password.contains(dbpassword))
{
message = "你输入的用户名不存在";
}
else
{
if (!password.contains(dbpassword))
{
message = "你输入的密码有误";
}else
{
message = "你以管理员"+dbuser+"的身份登陆";
}
}
return message;
}

public void execute(String SQLCommand) {
String url = urlRoot + dbName;
try {
Connection con = DriverManager.getConnection(url);
Statement stmt = con.createStatement();
stmt.execute(SQLCommand);
con.close();

} catch(SQLException e) {
reportException(e.getMessage());
}
}

public void excute(String[] SQLCommand) {
String url = urlRoot + dbName;
try {
Connection con = DriverManager.getConnection(url);
Statement stmt = con.createStatement();
for(int i = 0; i < SQLCommand.length; i++) {
stmt.execute(SQLCommand[i]);
}
con.close();

} catch(SQLException e) {
reportException(e.getMessage());
}
}

public String[] getColumnNames(String tableName) {
Vector dataSet = new Vector();
String[] columnNames = null;
String url = urlRoot + dbName;
String SQLCommand = "SELECT * FROM " + tableName + ";";

try {
Connection con = DriverManager.getConnection(url);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(SQLCommand);
ResultSetMetaData md = rs.getMetaData();

columnNames = new String[md.getColumnCount()];
for(int i = 0; i < columnNames.length; i++) {
columnNames[i] = md.getColumnLabel(i+1);
}
con.close();

} catch(SQLException e) {
reportException(e.getMessage());
}
return columnNames;
}

public String[] getColumnNamesUsingQuery(String SQLCommand) {

Vector dataSet = new Vector();
String[] columnNames = null;
String url = urlRoot + dbName;

try {
Connection con = DriverManager.getConnection(url);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(SQLCommand);
ResultSetMetaData md = rs.getMetaData();

columnNames = new String[md.getColumnCount()];
for(int i = 0; i < columnNames.length; i++) {
columnNames[i] = md.getColumnLabel(i+1);
}
con.close();

} catch(SQLException e) {
reportException(e.getMessage());
}
return columnNames;
}

public String[] getDataTypes(String tableName) {
Vector dataSet = new Vector();
String[] dataTypes = null;
String url = urlRoot + dbName;
String SQLCommand = "SELECT * FROM " + tableName + ";";

try {
Connection con = DriverManager.getConnection(url);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(SQLCommand);
ResultSetMetaData md = rs.getMetaData();

dataTypes = new String[md.getColumnCount()];
for(int i = 0; i < dataTypes.length; i++) {
dataTypes[i] = md.getColumnTypeName(i+1);
}
con.close();

} catch(SQLException e) {
reportException(e.getMessage());
}
return dataTypes;
}

public Vector executeQuery(String SQLQuery) {

Vector dataSet = new Vector();
String url = urlRoot + dbName;

try {
Connection con = DriverManager.getConnection(url);
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(SQLQuery);
ResultSetMetaData md = rs.getMetaData();

int nColumns = md.getColumnCount();
while(rs.next()) {
Vector rowData = new Vector();
for(int i = 1; i <= nColumns; i++) {
rowData.addElement(rs.getObject(i));
}
dataSet.addElement(rowData);
}
con.close();

} catch(SQLException e) {
reportException(e.getMessage());
}
return dataSet;
}
public void setExceptionListener(ActionListener exceptionListener) {
this.exceptionListener = exceptionListener;
}

private void reportException(String exception) {
if(exceptionListener != null) {
ActionEvent evt = new ActionEvent(this, 0, exception);
exceptionListener.actionPerformed(evt);
}
else {
System.err.println(exception);
}
}
}
[/CODE]

其它的一些方法，我写的程序用没用到。。。我只是把我的代码，插入到原来书上例题中去了。。。
个人认为这些方法应该可以包括操作数据库所有的操作了　

[此贴子已经被作者于2007-1-14 13:01:48编辑过]