hi, Everyone ,i'm learning jdbc, i got an nullpointerexception when execute this program.

ConnectionProvider.java import java.util.*; import java.io.*; import java.sql.*; class ConnectionProvider { static Properties prop; static { prop=new Properties(); try { prop.load(new FileInputStream("db.Properties")); }catch(Exception e) { System.out.println(e); } } public static Connection getConnection() { Connection con=null; try { Class.forName(prop.getProperty("driver class")); con=DriverManager.getConnection(prop.getProperty("url"),prop.getProperty("user"),prop.getProperty("password")); }catch(Exception e) { System.out.println(e); } return con; }

}

Selecttest1.java

import java.sql.*; class SelectTest1
{ public static void main(String arr[]) { try { Connection con=ConnectionProvider.getConnection(); System.out.println("name of Connection class is:"+con.getClass().getName()); Statement stmt=con.createStatement(); System.out.println("name of statement class is:"+stmt.getClass().getName()); ResultSet rset=stmt.executeQuery("select * from emp"); System.out.println("Name of resultset Class is:"+rset.getClass().getName()); System.out.println("following record are selected"); while(rset.next()) { System.out.println(rset.getInt(1)+"\t"+rset.getString(2)+"\t"+rset.getString(3)+"\t"+rset.getInt(4)); } }catch(Exception e) { System.out.println(e); } } }

And db.properties Class

driver class=oracle.jdbc.driver.OracleDriver url=jdbc:oracle:thin:@localhost:1521:xe user=system pasword=oracle

September 26, 2011 at 6:02 PM

It seems that problem lies in reading a properties file.

Go through the following link:

http://www.roseindia.net/tutorial/java/core/propertiesFile.html