example2.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.SQLException;
import java.sql.Statement;

/**
 * This class demonstrates the use of the Connection object to insert
 * and delete rows from a database table.
 * 
 * @version 1.0
 */
public class Example2 {
    /**
     * 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) {
        Example2 obj = new Example2();
        obj.insertRows();
    }

    /**
     * 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
     * 
     * @param host     : The host where the server is running
     * @param port     : The port where the server is listening to
     * @param dbName   : the database name
     * @param userid   : The user id to use while connecting
     * @param password : The password of the specified user
     * 
     * @return          An object of type java.sql.Connection
     */
    private Connection getConnection(
        String host,
        int port,
        String dbName,
        String userid,
        String password) {
        Connection conn = null;

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

            String url =
                "jdbc:pointbase:server://" + host + ":" + port + "/" + dbName;
            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;
    }

    /**
     * This method delete all items from the ITEM table
     * 
     * @param aConnection : The connection to be used
     */
    private void deleteAllItems(Connection aConnection) {
        String anSQLStmt = " DELETE FROM XYZCONF.ITEM ";
        executeUpdate(aConnection, anSQLStmt);
    }

    /**
     * This is a generic executeUpdate method which executes the SQL statement
     * passed in as a parameter. The connection is also passed in as a
     * parameter.
     * 
     * @param aConnection : The connection to be used
     * @param anSQLStmt   : The statement to be executed
     * 
     * @return              The number of rows affected. If update 
     *                       fails, the method returns a -1
     */
    private int executeUpdate(Connection aConnection, String anSQLStmt) {
        int numRowsAffected = -1;

        try {
            System.out.println("Executing statement : " + anSQLStmt);

            Statement stmt = aConnection.createStatement();
            numRowsAffected = stmt.executeUpdate(anSQLStmt);
            System.out.println("Number of rows affected: " + numRowsAffected);
            stmt.close();
        } catch (SQLException sqle) {
            sqle.printStackTrace();
        }

        return numRowsAffected;
    }

    /**
     * This method inserts one item into the ITEM table. the values of the row
     * are obtained as parameters to this method
     * 
     * @param aConnection : The connection to use
     * @param id          : The id of the item
     * @param desc        : The description of the item
     * @param stock       : the stock of the item
     * @param unitPrice   : unit price of the item
     */
    private void insertOneItem(
        Connection aConnection,
        int id,
        String desc,
        double stock,
        double unitPrice) {
        String anSQLStmt =
            " INSERT INTO XYZCONF.ITEM VALUES ( "
                + id
                + ",'"
                + desc
                + "',"
                + stock
                + ","
                + unitPrice
                + " )";

        if (executeUpdate(aConnection, anSQLStmt) != 1) {
            System.out.println("Insert failed");
        } else {
            System.out.println("Insert succeeded");
        };
    }

    /**
     * inserts five rows into the ITEM table
     */
    private void insertRows() {
        System.out.println("Trying to obtain a connection ... ");

        Connection conn =
            getConnection(
                "localhost",
                9092,
                "demo",
                "PBSYSADMIN",
                "PBSYSADMIN");

        if (conn == null) {
            return;
        }

        System.out.println("Connection obtained !");
        System.out.println("Emptying item table first ");
        deleteAllItems(conn);
        insertOneItem(conn, 1, "Candy", 50.0, 2.0);
        insertOneItem(conn, 2, "Crunchies", 24.0, 1.4);
        insertOneItem(conn, 3, "Snickers", 40.0, 2.3);
        insertOneItem(conn, 4, "Polo", 55.0, 2.0);
        insertOneItem(conn, 5, "Wafers", 40.0, 2.55);

        try {
            conn.close();
        } catch (Throwable t) {
            t.printStackTrace();
        }
    }
}