example2.java

本书中的源代码是以JBuilder工程形式组织的

package jdbcexample;
import java.sql.*;
import javax.naming.*;
import javax.sql.*;
import java.util.Properties;
import javax.rmi.PortableRemoteObject;

public class Example2 {
  public static void main(String[] args) {
    DataSource ds = null;
   Context ctx = null;
   Connection myConn = null;
   try {
     ctx = getInitialContext();
     ds = (javax.sql.DataSource)
         ctx.lookup("myDataSource");
   }
   catch (Exception E) {
     System.out.println("Init Error: " + E);
   }
   Statement myStatement=null;
   ResultSet myResultSet=null;
   try {
     myConn = ds.getConnection();
     myStatement = myConn.createStatement();
     myResultSet = myStatement.executeQuery(
         "SELECT * from employee" );

    for(int j=1;j<=myResultSet.getMetaData().getColumnCount();j++)
    {
       System.out.print(myResultSet.getMetaData().getColumnName(j)+"\t");
    }
    System.out.println();
    while(myResultSet.next())
    {
       for(int j=1;j<=myResultSet.getMetaData().getColumnCount();j++)
      {
        System.out.print(myResultSet.getObject(j)+"\t");
       }
       System.out.println();
     }
     myResultSet.close();
   }
   catch (SQLException e) {
     System.out.println("Error code = " + e.getErrorCode());
     System.out.println("Error message = " + e.getMessage());
   }
   finally {
     try {
       if (myStatement != null) {
         myStatement.close();
       }
       if (myConn != null) {
         myConn.close();
       }
     }
     catch (SQLException e) {
       System.out.println("Error code = " + e.getErrorCode());
       System.out.println("Error message = " + e.getMessage());
     }
   }



    }
    private static Context getInitialContext() throws Exception {
           String url = "t3://localhost:7001";
           String user = "system";
           String password = "security";
           Properties properties = null;
           try {
             properties = new Properties();
             properties.put(Context.INITIAL_CONTEXT_FACTORY,
                 "weblogic.jndi.WLInitialContextFactory");
             properties.put(Context.PROVIDER_URL, url);
             if (user != null) {
               properties.put(Context.SECURITY_PRINCIPAL, user);
               properties.put(Context.SECURITY_CREDENTIALS, password == null ? "" : password);
             }
             return new InitialContext(properties);
           }
           catch(Exception e) {
             throw e;
           }
         }

}