السلام عليكــم ورحمـة الله وبركاتــه
عملت برنامج phone book مع داتا بيس من نوع mysql كل ماشي وزرابط ماعدا الكلاس هاد فيه مشكله ممكن حد يقولي وين المشكله
بطلع
NullPointerException
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.DriverManager;
import java.sql.ResultSetMetaData;
import java.util.Vector;
public class DataBastOperation
{
private String username = "";
private String password = "";
Connection connection = null;
Statement statement = null;
ResultSet resultset = null;
private String DriverMange = "com.mysql.jdbc.Driver";
private String URl = "jdbc:mysql://localhost/Alaa";
public DataBastOperation()
{
try
{
Class.forName(DriverMange);
connection = DriverManager.getConnection(DriverMange,username,password);
statement = connection.createStatement();
}
catch(ClassNotFoundException e)
{
}
catch(SQLException e)
{
}
}
public Vector<Vector<Object>> QueryStatement(String sql)
{
Vector<Vector<Object>> rows = new Vector<Vector<Object>>();
try
{
resultset = statement.executeQuery(sql);
while(resultset.next())
{
Vector<Object> res = new Vector<Object>();
res.add(resultset.getInt(1));
res.add(resultset.getString(2));
res.add(resultset.getInt(3));
res.add(resultset.getInt(4));
res.add(resultset.getString(5));
res.add(resultset.getString(6));
rows.add(res);
}
}
catch(SQLException e)
{
}
return rows;
}
public Vector<String> getHeading()
{
Vector<String> head = new Vector<String>();
try
{
ResultSetMetaData res = resultset.getMetaData();
int count = res.getColumnCount();
for(int i = 0; i<count;i++)
{
head.add(res.getColumnName(i));
}
}
catch(SQLException e)
{
}
return head;
}
}
import java.sql.Connection;
