Java笔记

1.

SWT第三方图形用户界面。

JDBC、OCBC完成主机/服务器应用程序与数据库建立连接。

步骤：

1)

import java.sql.*;

2)加载驱动

class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

3)

连接数据库地址

String url = "jdbc:odbc:Test";

String url = "jdbc:odbc:Driver = {Microsoft Access Driver(*.mdb)};DBQ = Exam3.mdb";

4)

创建与数据库连接

Connection conn = null;

try{

    conn = DriverManager.getConnection(url);

    Statement s = conn.createStatement();

    int n = s.executeUpdate();

    int n = s.executeQuery();

/*

while(rs.next()){

System.out.print(rs.getString(2)+" ");

      .......

}

rs.close();

*/

s.close();

}catch(Exception ex){

System.out.println("连接失败："+ ex);

}finally{

//关闭连接，释放资源。

if(conn != null){

                   conn.close();

                        }

}

 

2.

匿名内部类在方法内声明。

 

3.

用接口和内部类实现多重继承

interface A{}

interface B{}

class D implements A,B{}

public class Multi{

static void makeA(A a){

                System.out.println("A");

                                      }

static void makeB(B b){

                 System.out.println("B");

                                     }

public static void main(String args[]){

                                        D d = new D();

                                        makeA(d);

                                        makeB(d);           //相当于makeB(d.makeB());

                                                            }

}

 

class D extends A{

              B makeB(){

                  return new B(){

                                                }

                                    }

}

 

4.

Scanner n = new Scanner(System.in);

int a = n.nextInt();