import java.sql.*; 
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

public class DerbyFloat {
    
    /* Derby */
    static final String userName = "APP";
    static final String password = "APP";
    static final String connectionURL =
//            "jdbc:derby://localhost:1527/testdb;retrieveMessagesFromServerOnGetMessage=true;create=true;";
            "jdbc:derby://localhost:1527/sun-appserv-samples;retrieveMessagesFromServerOnGetMessage=true;";
    static final String driverName = "org.apache.derby.jdbc.ClientDriver";
    Connection conn;
    
    public DerbyFloat() {}
    
    void init() throws SQLException {
        conn = getConnection(driverName, connectionURL, userName, password);
//        printDataBaseMetaData(conn);
    }
    
    private static Connection getConnection(String driverName, String connectionURL,
           String userName, String password) throws SQLException {
       Connection conn = null;

       try {
           Class.forName (driverName);
       }
       catch (ClassNotFoundException e) {
           System.out.println("Could not load the driver class. Error is " + e);
       }

       try {
           conn = DriverManager.getConnection(connectionURL, userName, password);
           conn.setAutoCommit(false);
       } catch (SQLException e) {
           System.out.println("Error while getting connection");
           SQLException currentException = e;
           do {
               System.out.println("Exception is" + currentException);
               System.out.println(
                       "getMessage()" + currentException.getMessage());
               System.out.println(
                       "getErrorCode()" + currentException.getErrorCode());
               System.out.println(
                       "getSQLState()" + currentException.getSQLState());
               currentException = currentException.getNextException();
           } while (currentException != null);
           throw e;
       }

       return conn;
    }
   
    static void printDataBaseMetaData(Connection con) throws SQLException {
        DatabaseMetaData metaData = con.getMetaData();
        Method[] declaredMethods = DatabaseMetaData.class.getDeclaredMethods();
        for(int i = 0 ; i < declaredMethods.length; i++) {
            Method currentMethod = declaredMethods[i];
            if(currentMethod.getParameterTypes().length == 0) {
                //Trace only methods that require no iput
                System.out.print(currentMethod.getName() + "():");
                try {
                    System.out.println(currentMethod.invoke(metaData,(Object[]) null) );
                } catch (Throwable e) {
                    System.out.println("Exception for " + Modifier.toString(currentMethod.getModifiers() ) + currentMethod.getName() + e);
                }

            }
        }
        System.out.print("supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE): " + metaData.supportsTransactionIsolationLevel(Connection.TRANSACTION_SERIALIZABLE));
    }
     
   public void insertRows() throws java.sql.SQLException {
       PreparedStatement ps;
        try {
            ps = conn.prepareStatement("DROP TABLE DERBYFLOAT");
            ps.executeUpdate();           
        } catch (SQLException e) {
            System.out.println("Table does not exist");
        }       
       
        ps = conn.prepareStatement("CREATE TABLE DERBYFLOAT (ID INT PRIMARY KEY, FLOATDATA FLOAT)");
//        ps = conn.prepareStatement("CREATE TABLE DERBYFLOAT (ID INT PRIMARY KEY, FLOATDATA FLOAT(24))");       
        ps.executeUpdate();        
       
        ps = conn.prepareStatement("DELETE FROM DERBYFLOAT");
        ps.executeUpdate();        
        ps = conn.prepareStatement(
            "INSERT INTO DERBYFLOAT(ID, FLOATDATA) VALUES(1, 1)");
        ps.executeUpdate();    
        ps = conn.prepareStatement(
            "INSERT INTO DERBYFLOAT(ID, FLOATDATA) VALUES(2, 124567890123456)");
        ps.executeUpdate();          
        ps = conn.prepareStatement(
            "INSERT INTO DERBYFLOAT(ID, FLOATDATA) VALUES(3, 3.4028235E37)");
        ps.executeUpdate(); 
        ps = conn.prepareStatement(
            "INSERT INTO DERBYFLOAT(ID, FLOATDATA) VALUES(4, 3.4028235E38)");
        ps.executeUpdate();          
        
    }
   
    public void testFloat() throws java.sql.SQLException {        
        PreparedStatement ps = conn.prepareStatement(
               "SELECT ID, FLOATDATA FROM DERBYFLOAT");
        ResultSet rs = ps.executeQuery();
        ResultSetMetaData rsmd = rs.getMetaData();
        while(rs.next()) {
//            for(int i=1;i<= rsmd.getColumnCount();i++) {
/*
               Object o = rs.getObject(i);

               String columnTypeName = rsmd.getColumnTypeName(i);
               System.out.println("column " + (i) + " type: " + columnTypeName +
                     " (" + rsmd.getColumnType(i) + ") " + "\t\tJava Type: " +  o.getClass());
*/               
                System.out.println("\n Value of field 1 uing getInt() : " + rs.getInt(1));  
                try {
                    System.out.println("\n Value of field 2 using getFloat() : " + rs.getFloat(2));    
                } catch (SQLException e) {
                    System.out.println("\n Value of field 2 using getFloat() resulted in a SQLException");
                    e.printStackTrace();
                    System.out.println("\n Value of field 2 using getObject() : " + rs.getObject(2));
                }
                    
//            }
       }
        
    }
    
    public static final void main (String args [])
    {
        DerbyFloat dbFloat = new DerbyFloat();
        try {
            dbFloat.init();
            dbFloat.insertRows();
            dbFloat.testFloat();
        } catch (SQLException ex) {
            System.out.println("SQLException : "+ ex);
            ex.printStackTrace();            
        }
    }
    
}