连接数据库的代码用java怎么做?

连接数据库的代码用java怎么做?,第1张

import java.sql.*

import javax.swing.*

import java.awt.*

import java.awt.event.*

import java.util.*

public class inensshow extends JFrame {

private Connection connection

private Statement statement

private ResultSet resultSet

private ResultSetMetaData rsMetaData

//GUI变量定义

private JTable table

private JTextArea inputQuery

private JButton submitQuery

public inensshow()

{

//Form的标题

super( "输入SQL语句,按查询按钮查看结果。" )

String url = "jdbc:mysql://localhost:3306/web"

String username = "inens"

String password = "inens"

//加载驱动程序连接数据库

try {

Class.forName( "org.gjt.mm.mysql.Driver" )

connection = DriverManager.getConnection(

url, username, password )

}

//捕获加载驱动程序异常

catch ( ClassNotFoundException cnfex ) {

System.err.println(

"装载 JDBC/ODBC 驱动程序失败。" )

cnfex.printStackTrace()

System.exit( 1 )// terminate program

}

//捕获连接数据库异常

catch ( SQLException sqlex ) {

System.err.println( "无法连接数据库" )

sqlex.printStackTrace()

System.exit( 1 )// terminate program

}

//如果数据库连接成功,则建立GUI

//SQL语句

String test="SELECT * FROM data"

inputQuery = new JTextArea( test, 4, 30 )

submitQuery = new JButton( "查询" )

//Button事件

submitQuery.addActionListener(

new ActionListener() {

public void actionPerformed( ActionEvent e )

{

getTable()

}

}

)

JPanel topPanel = new JPanel()

topPanel.setLayout( new BorderLayout() )

//将"输入查询"编辑框布置到 "CENTER"

topPanel.add( new JScrollPane( inputQuery), BorderLayout.CENTER )

//将"提交查询"按钮布置到 "SOUTH"

topPanel.add( submitQuery, BorderLayout.SOUTH )

table = new JTable()

Container c = getContentPane()

c.setLayout( new BorderLayout() )

//将"topPanel"编辑框布置到 "NORTH"

c.add( topPanel, BorderLayout.NORTH )

//将"table"编辑框布置到 "CENTER"

c.add( table, BorderLayout.CENTER )

getTable()

setSize( 500, 300 )

//显示Form

show()

}

private void getTable()

{

try {

//执行SQL语句

String query = inputQuery.getText()

statement = connection.createStatement()

resultSet = statement.executeQuery( query )

//在表格中显示查询结果

displayResultSet( resultSet )

}

catch ( SQLException sqlex ) {

sqlex.printStackTrace()

}

}

private void displayResultSet( ResultSet rs )

throws SQLException

{

//定位到达第一条记录

boolean moreRecords = rs.next()

//如果没有记录,则提示一条消息

if ( ! moreRecords ) {

JOptionPane.showMessageDialog( this,

"结果集中无记录" )

setTitle( "无记录显示" )

return

}

Vector columnHeads = new Vector()

Vector rows = new Vector()

try {

//获取字段的名称

ResultSetMetaData rsmd = rs.getMetaData()

for ( int i = 1i <= rsmd.getColumnCount()++i )

columnHeads.addElement( rsmd.getColumnName( i ) )

//获取记录集

do {

rows.addElement( getNextRow( rs, rsmd ) )

} while ( rs.next() )

//在表格中显示查询结果

table = new JTable( rows, columnHeads )

JScrollPane scroller = new JScrollPane( table )

Container c = getContentPane()

c.remove(1)

c.add( scroller, BorderLayout.CENTER )

//刷新Table

c.validate()

}

catch ( SQLException sqlex ) {

sqlex.printStackTrace()

}

}

private Vector getNextRow( ResultSet rs,

ResultSetMetaData rsmd )

throws SQLException

{

Vector currentRow = new Vector()

for ( int i = 1i <= rsmd.getColumnCount()++i )

currentRow.addElement( rs.getString( i ) )

//返回一条记录

return currentRow

}

public void shutDown()

{

try {

//断开数据库连接

connection.close()

}

catch ( SQLException sqlex ) {

System.err.println( "Unable to disconnect" )

sqlex.printStackTrace()

}

}

public static void main( String args[] )

{

final inensshow app =

new inensshow()

app.addWindowListener(

new WindowAdapter() {

public void windowClosing( WindowEvent e )

{

app.shutDown()

System.exit( 0 )

}

}

)

}

}

------------------------------------------------------------

这次在WIN98中就不好使了。因为Mysql的驱动程序没有也没能加入到CLASSPATH 当中,但是JSP却可以使用(JSP的98驱动加载详见Jsp与Mysql连接查错文章),所以这次我是在XPServer中测试的。

用JDBC技术连数据库 或者用io流保存在文件中你可以在SWING中写个方法 方法中定义一个连接把上次运行次数读出来 再+1存进去然后在每次程序启动的时候调用这个方法不就可以了先配个数据源再个数据库连接类吧先导入java.sql包import java.sql.*public class DB{Connection conStatement stt


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原文地址: http://outofmemory.cn/sjk/10054485.html

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