example6.java

BEA WebLogic Server 8.1大全 = BEA webLogic server 8.1 unleashed (美) Mark Artiges等著 袁毅 ... [等] 译 eng

/* 
 * WebLogic Server Unleashed
 * 
 */

package com.wlsunleashed.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * This class demonstrates an SQL Update using an updateable 
 * ResultSet
 * 
 * @version 1.0
 */
public class Example6 {
	
	/** The host to connect to */
	private static final String HOST = "localhost"; 
	
	/** The port number **/
	private static final int PORT = 9092;
	
	/** The database name **/
	private static final String DBNAME = "demo";

    /** User id in the database */
    private static final String USERID = "PBSYSADMIN";
    
    /** Password for the user */
    private static final String PASSWORD = "PBSYSADMIN";
    	
    /**
     * The main method - the point of entry into this class
     * 
     * @param args : all run-time args are passed in this String array
     */
    public static void main(String[] args) {
        Example6 obj = new Example6();
        obj.incrementStock();
    }

    private String getDBConnectionURL() {
        return
            "jdbc:pointbase:server://" + HOST + ":" + PORT + "/" 
            + DBNAME;
    	
    }
    /**
     * Returns a connection to a pointbase database, whose server is running at
     * the given host and port, and the database being called dbName. The
     * credentials supplied while connecting is also accepted as paramter
     * 
     * @return            an object of type java.sql.Connection
     */
    private Connection getConnection( ) {
        Connection conn = null;

        try {
            Class.forName("com.pointbase.jdbc.jdbcUniversalDriver");

            String url = getDBConnectionURL();
            System.out.println("Using url string " + url);
            conn = DriverManager.getConnection(url, USERID, PASSWORD);
            System.out.println("Obtained Connection");
        } catch (Throwable t) {
            t.printStackTrace();
            conn = null;
        }

        return conn;
    }

    /**
     * increments the stock of the items in the ITEM table based on the
     * stockArray passed as a parameter. The stock array is assumed to have as
     * many entries as there are items in the table
     * 
     * @param stockArray : a list of increments to the stock.
     */
    private void incrementStock( ) {
        System.out.println("Trying to obtain a connection ... ");

        Connection conn = getConnection();

        if (conn == null) {
            return;
        }

        System.out.println("Connection obtained !");

        String anSQLStmt =
			" SELECT ITEM_ID,  " + 
			" STOCK_QTY FROM XYZCONF.ITEM";
			
        try {
            Statement stmt = conn.createStatement(
                 ResultSet.TYPE_SCROLL_SENSITIVE,
                 ResultSet.CONCUR_UPDATABLE);

            ResultSet rs = stmt.executeQuery(anSQLStmt);
            rs.beforeFirst();
            
            System.out.println("Before Updating Stock for first item");
            while (rs.next()) {
            	System.out.println("Item Code = " + 
            	    rs.getInt(1) + " stock = " + 
            	    rs.getDouble(2));
            }

			if (rs.first()) {
	            rs.updateDouble(2, rs.getDouble(2) + 10.0);
    	        rs.updateRow();
			}

			rs.close();
			rs = stmt.executeQuery(anSQLStmt);
            
            //rs.beforeFirst();
            System.out.println("AFTER Updating Stock for first item");
            while (rs.next()) {
            	System.out.println("Item Code = " + 
            	    rs.getInt(1) + " stock = " + 
            	    rs.getDouble(2));
            }

			rs.close();
            stmt.close();
            conn.close();
        } catch (SQLException t) {
            t.printStackTrace();
        }
    }
}