Sử dụng HashMap trong java


import  java.util.HashMap; Khởi dựng HashMap (HashMap Contructor) HashMap hashMapName = new HashMap(); HashMap hashMapName = new HashMap(5); //The 5 sets the initial element capcaity. HashMap hashMapName = new HashMap(5, .9); //The 5 sets the initial element capcaity. //The .9 is the load factor. //  The default load factor is .75. HashMap hashMapName = new HashMap(mapIn);…

Tạo java JSP với Bean


Tạo 1 trang JSP : <HTML> <HEAD> <TITLE>LotteryGuesser.JSP</TITLE> </HEAD> <BODY> <jsp:useBean id=”guessingBean” scope=”session”/> <jsp:setProperty name=”guessingBean” property=”highNumberString” param=”highNumberString” /> <jsp:setProperty name=”guessingBean” property=”numberOfNumbersString” param=”numberOfNumbersString” /> <jsp:setProperty name=”guessingBean” property=”usingBonusBall” param=”usingBonusBall” /> <h4> Using a Highest Number of: <jsp:getProperty name=”guessingBean” property=”highNumber” /> </b> </h4> <h4> Using Number of Numbers: <jsp:getProperty name=”guessingBean” property=”numberOfNumbers” /> </h4> <h4> Using a Bonus Ball?…

Sử dụng JDBC kết nối và lấy dữ liệu từ cơ sở dữ liệu oracle


import java.sql.*; class Get_CatsFavoriteFood { public static void main(String[] args) { try { Class.forName(“oracle.jdbc.driver.OracleDriver”); //loads the driver class //an alternative is to use: //  DriverManager.registerDriver( //    new oracle.jdbc.driver.OracleDriver()); //  which creates a new instance of the //    Oracle driver and registers it Connection connection = DriverManager.getConnection( “jdbc:oracle:thin:@orcl:1521:catinfo”, “percy”, “sardine”); //connects to the Oracle catinfo database…

Sử dụng PreparedStatement trong java


a PreparedStatement example PreparedStatement preparedStatement = connection.prepareStatement( “Select favoritefood from favoritefoods where catname = ?”); preparedStatement.setString(1, “Cappuccino”); ResultSet resultSet = preparedStatement.executeQuery(); //now run the SQL  Sử dụng PreparedStatement thực thi truy vấn SQL preparedStatementName.execute(); //will execute any SQL preparedStatementName.executeQuery(); //will execute a query preparedStatementName.executeUpdate(); //will execute an insert, update, or delete //Parent public ResultSet get_Result_catParent(int…