Eclipse新建Dynamic Web Project，新建index.html，執行看見沒有提示404錯誤的頁面即Tomcat伺服器部署成功。這是搭建Java Web環境時需要完成的工作。詳細內容請看點選開啟連結

涉及的檔案與專案結構：

一、Servlet類

接收客戶端發來的請求，（Post方法），呼叫Service類中的方法來實現功能。

程式碼：LoginServlet.java

public class LoginServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	static int LOGIN_FAILED = 0;
    static int LOGIN_SUCCEEDED = 1;
       
    public LoginServlet() {
        super();
    }

	protected void doGet(HttpServletRequest request, HttpServletResponse response) 
			throws ServletException, IOException {
		doPost(request, response);  
		response.getWriter().append("Served at: ").append(request.getContextPath());
	}
	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) 
			throws ServletException, IOException {
		// 返回字串  
        String responseMsg="FAILED";  
        // 輸出流  
        PrintWriter out = response.getWriter();  
        // 設定編碼形式  
        request.setCharacterEncoding("utf-8");    
        // 獲取傳入資料  
        String id = request.getParameter("id");  
        String password = request.getParameter("password");
        System.out.println("id:" + id + " --try to login");
  
        // 訪問資料庫  
        int value = Service.login(id, password);
        if(value == LOGIN_SUCCEEDED) {  
            responseMsg = "SUCCEEDED";  
        }
        System.out.println("login servlet responseMsg:" + responseMsg);  
        out.print(responseMsg);
	}

}
 

用到的兩個Servlet都要在web.xml中如下注冊一下：

<servlet>
    <servlet-name>servlet.LoginServlet</servlet-name>
    <servlet-class>    
            servlet.LoginServlet
    </servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>servlet.LoginServlet</servlet-name>
    <url-pattern>/LoginServlet</url-pattern>
  </servlet-mapping>
 

二、Service類

處理Servlet傳來的資料並執行相應sql語句。

程式碼：MyService.java

public class MyService {
	static PreparedStatement preparedStatement = null;  
    static ResultSet resultSet = null;  
    static int updateRowCnt = 0;
    static int LOGIN_FAILED = 0;
    static int LOGIN_SUCCEEDED = 1;
    static int REGISTER_FAILED = 2;
    static int REGISTER_SUCCEEDED = 3;
      
    public static int login(String id, String password) {  
        int result = LOGIN_FAILED;  
        resultSet = null;
        // 執行 SQL 查詢語句  
        String sql = "select * from user_list where id='" + id +"'";  
        try {     
            Connection con = DBManager.getConnection();  
            preparedStatement = con.prepareStatement(sql);  
            try{  
                resultSet = preparedStatement.executeQuery();  
                // 查詢結果  
                if(resultSet.next()){    
                	if(resultSet.getString("password").equals(password)){
                		result = LOGIN_SUCCEEDED;
                		System.out.println("id:" + id 
                    		+ " username:" + resultSet.getString("username")
                    		+ " --login");
                	}
                }  
                preparedStatement.close();  
                con.close();  
            }catch(Exception e){  
                e.printStackTrace();  
            }  
        }catch(Exception e){  
            e.printStackTrace();  
        }  
        System.out.println("login service result:" + result);
        return result;  
    }  
    
    public static int register(String id, String username, String password) {  
        int result = REGISTER_FAILED;  
        updateRowCnt = 0;
        // 執行 SQL 插入語句  
        String sql = "insert into user_list(`id`, `username`,`password`) values ('"
        		+ id + "', '" + username + "', '" + password + "')";
        try {     
            Connection con = DBManager.getConnection();  
            preparedStatement = con.prepareStatement(sql);  
            try{  
                updateRowCnt = preparedStatement.executeUpdate();  
                // 插入結果  
                if(updateRowCnt != 0){    
                		result = REGISTER_SUCCEEDED;
                		System.out.println("id:" + id 
                    		+ " username:" + resultSet.getString("username")
                    		+ " --register");
                }  
                preparedStatement.close();  
                con.close();  
            }catch(Exception e){  
                e.printStackTrace();  
            }  
        }catch(Exception e){  
            e.printStackTrace();  
        }  
        System.out.println("register service result:" + result);
        return result;  
    }
    
}
 

被Service類呼叫來連線資料庫，包括說明連線的資料庫的地址、使用者名稱和密碼。

public class DBManager {
	// 載入的驅動  
    private static final String DRIVER_CLASS = "com.mysql.jdbc.Driver";  
    // 資料庫URL  
    private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/db_test?useUnicode=true&characterEncoding=utf8";  
    // 資料庫連線使用者名稱  
    private static final String DATABASE_USERNAME = "admin";  
    // 資料庫連線密碼  
    private static final String DATEBASE_PASSWORD = "123456";  
    public static Connection getConnection() throws SQLException {  
        try {  
            Class.forName(DRIVER_CLASS);  
        } catch (ClassNotFoundException e) {  
            e.printStackTrace();  
        }  
        Connection con = DriverManager.getConnection(DATABASE_URL,DATABASE_USERNAME, DATEBASE_PASSWORD);  
        return con;  
    }  
}

最後，連線資料庫和執行sql語句成功的前提是：已經MySQl中建立相應資料庫和表格

在左下角SCHEMAS欄中可以看到建立資料庫的情況，右鍵表格名->Select Rows可以查看錶格內容

至此，伺服器端的工作也完成了。

程式碼下載：

客戶端 http://download.csdn.net/detail/qq_24833289/9620063