JAVA数据库连接有关问题
日期：2014-05-20 浏览次数：20825 次
JAVA数据库连接问题
检查密码是否正确的Checkpasswd类
连接数据库的父类SQLException
检查密码是否正确的Checkpasswd类
package com.qdgxy.sql;
import java.sql.SQLException;
public class Checkpasswd extends SQL_connection{
private static int i =0;
//select count(*) from consumer where consumer_password='12345678' and exists(
//select * from consumer where consumer_no=00001 )
//final String querystatement="select "+s1+" from "+s2;
public static void query(String s1,String s2)
{
SQL_connection.query(s1,s2);
System.out.println("query");
/* final String querystatement="select "+s1+" from "+s2;
try {
rs=stmt.executeQuery(querystatement);
} catch (SQLException e) {
e.getMessage();
}*/
}
public static void exe()
{
System.out.println("exe");
try{
i = rs.getInt(1);
System.out.println("exe");
System.out.println(i);
}catch(SQLException e) {
e.getMessage();
}
}
public static int isexist()
{
System.out.println("isexist");
if(i !=0)
return 0;//存在此账户
else
return 1;//不存在此账户
}
}
连接数据库的父类SQLException
package com.qdgxy.sql;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class SQL_connection {
/**
* @param args
* @throws ClassNotFoundException
* @throws SQLException
*/
/**
* @param args
*/
// TODO Auto-generated method stub
final static String Drivername="com.microsoft.sqlserver.jdbc.SQLServerDriver";
final static String Connection="jdbc:sqlserver://localhost:1433;DatabaseName=LaboratoryDatabase";
final static String Username="sa";
final static String Passwd="123";
protected static Connection conn=null;
protected static Statement stmt=null;
protected static ResultSet rs=null;
public static void classforname()
{
try {
Class.forName(Drivername);
}catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.getMessage();
}
}
public static void connection()
{
try{
conn=DriverManager.getConnection(Connection,Username,Passwd);
System.out.println("conn");
System.out.println(conn);
}catch(SQLException e){
e.getMessage();
}
}
public static void statement()
{
try {
stmt=conn.createStatement();
System.out.println("stmt");
System.out.println(stmt);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.getMessage();
}
}
public static void query(String s1,String s2)
//s1代表列名，s2代表表名
{
final String querystatement="select "+s1+" from "+s2;
try {
rs=stmt.executeQuery(querystatement);
System.out.println("rs");
System.out.println(rs);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.getMessage();
}
}
public static void exe()
{
/* try{
while(rs.next())
{
String s1=rs.getString(1);
System.out.println(s1);
}
}catch(SQLException e) {
e.getMessage();
} */
}
public static void close()
{
System.out.println("close");
try {
rs.close();
stmt.close();
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
btnNewButton.addMouseListener(new MouseAdapter() {
@Override
public void mouseDown(MouseEvent e) {
String name=text.getText();
String passwd=text_1.getText();
final String s1="count(*)";
final String s2="consumer where consumer_password='"+passwd+"' and exists(select * from consumer where consumer_no='"+name+"');";
Checkpasswd.classforname();
Checkpasswd.connection();
Checkpasswd.statement();
Checkpasswd.query(s1,s2);
Checkpasswd.exe();
Checkpasswd.close();
if(Checkpasswd.isexist() ==0)
{
System.out.println("new mainmenu");
shell.dispose();
new Mainmenu();
}
else{
create_worrymessagebox();
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