JDBC 와 데이터베이스 연결 탱크 에 대해 얼마나 알 고 있 습 니까?

DriverManager.registerDriver(new com.mysql.jdbc.Driver());

//   
DriverManager.getConnection("jdbc:mysql://localhost/test?user=root&password=root");
//   ：   +       ，   ：   ，   ：  。
//   
conn = DriverManager.getConnection("jdbc:mysql://localhost/test", "root", "root");

//  statement，       ，        
st = conn.createStatement();

//    ，     
String sql = "select * from stu";
rs = st.executeQuery(sql);

//         
while (rs.next()) {
	int id = rs.getInt("id");
	String name = rs.getString("name");
	int age = rs.getInt("age");
	System.out.println("id=" + id + "==name==" + name + "==age==" + age);
}

if (rs != null) {
	try {
		rs.close();
	} catch (SQLException sqlEx) { } // ignore 
	rs = null;
}
...

DriverManager.registerDriver(new com.mysql.jdbc.Driver());
// Driver            ，       ，              。         。
//       --->     ，   。 java.sql.DriverManager.registerDriver(new Driver());
//           。
Class.forName("com.mysql.jdbc.Driver");	

INSERT INTO t_stu (name, age) VALUES ('wangqiang', 28);
INSERT INTO t_stu VALUES (NULL, 'wangqiang2', 28);

// 1.       
conn = JDBCUtil.getConn();
// 2.       ，  statement
st = conn.createStatement();
// 3.     
String sql = "insert into t_stu values(null , 'aobama' , 59)";
//     ，    0      ，    
int result = st.executeUpdate(sql);
if (result > 0) {
	System.out.println("    ");
} else {
	System.out.println("    ");
}

DELETE FROM t_stu WHERE id = 6;

// 1.       
conn = JDBCUtil.getConn();
// 2.       ，  statement
st = conn.createStatement();

// 3.     
String sql = "delete from t_stu where name='aobama'";
//      ，    0      ，    
int result = st.executeUpdate(sql);
if (result > 0) {
	System.out.println("    ");
} else {
	System.out.println("    ");
}

SELECT * FROM t_stu;

// 1.       
conn = JDBCUtil.getConn();
// 2.       ，  statement
st = conn.createStatement();
// 3.   sql  ，  ResultSet
String sql = "select * from t_stu";
rs = st.executeQuery(sql);

// 4.      
while (rs.next()) {
	String name = rs.getString("name");
	int age = rs.getInt("age");
	System.out.println(name + "   " + age);
}

UPDATE t_stu SET age = 38 WHERE id = 1;

// 1.       
conn = JDBCUtil.getConn();
// 2.       ，  statement
st = conn.createStatement();
// 3.     
String sql = "update t_stu set age = 26 where name ='qyq'";
//      ，    0      ，    
int result = st.executeUpdate(sql);

if (result > 0) {
	System.out.println("    ");
} else {
	System.out.println("    ");
}

/**
*           
*/
public interface UserDao {
	/**
	*     
	*/
	void findAll();
}

public class UserDaoImpl implements UserDao{
	@Override
	public void findAll() {
		Connection conn = null;
		Statement st = null;
		ResultSet rs = null;
		try {
			//1.       
			conn = JDBCUtil.getConn();
			//2.   statement  
			st = conn.createStatement();
			String sql = "select * from t_user";
			rs = st.executeQuery(sql);
			while(rs.next()){
				String userName = rs.getString("username");
				String password = rs.getString("password");
				
				System.out.println(userName+"="+password);
			}
			
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			JDBCUtil.release(conn, st, rs);
		}
	}
}

@Test
public void testFindAll(){
	UserDao dao = new UserDaoImpl();
	dao.findAll();
}

String sql = "select * from t_user where username='"+ username  +"' and password='"+ password +"'";

UserDao dao = new UserDaoImpl();
dao.login("admin", "100234khsdf88' or '1=1"); //         
// SELECT * FROM t_user WHERE username='admin' AND PASSWORD='100234khsdf88' or '1=1' 
//      sql  ，                ，          。          。 
rs = st.executeQuery(sql);

String sql = "insert into t_user values(null , ? , ?)";
ps = conn.prepareStatement(sql);
//              ，1        ， 1  。
ps.setString(1, userName);
ps.setString(2, password);

/*
* 	1.     10   。
* 	2.       getConnection    
* 	3.     ，  addBack    。
* 	4.   。
*/
public class MyDataSource implements DataSource {
	
	List <Connection> list = new ArrayList<Connection>();
	
	public  MyDataSource() {
		for (int i = 0; i < 10; i++) {
			Connection conn = JDBCUtil.getConn();
			list.add(conn);
		}
	}
	
	//                 
	@Override
	public Connection getConnection() throws SQLException {
		//       ，   ，        。
		if(list.size() == 0 ){
			for (int i = 0; i < 5; i++) {
				Connection conn = JDBCUtil.getConn();
				list.add(conn);
			}
		}
		
		//remove(0) --->      。           。           
		Connection conn = list.remove(0);
		return conn;
	}
	/**
	*     ，    。
	* @param conn
	*/
	public void addBack(Connection conn){
		list.add(conn);
	}
	......
}

UserDao dao = new UserDaoImpl();
dao.insert();
DataSource dataSource = new MyDataSource();
//           addBack  。

public void testDBCP01() {
	Connection conn = null;
	PreparedStatement ps = null;
	try {
		// 1.        
		BasicDataSource dataSource = new BasicDataSource();
		//            ，          ，   ，  。。
		// jdbc:mysql://localhost/bank    ：    ://  /   
		dataSource.setDriverClassName("com.mysql.jdbc.Driver");
		dataSource.setUrl("jdbc:mysql://localhost/bank");
		dataSource.setUsername("root");
		dataSource.setPassword("root");
		
		// 2.       
		conn = dataSource.getConnection();
		String sql = "insert into account values(null , ? , ?)";
		ps = conn.prepareStatement(sql);
		ps.setString(1, "admin");
		ps.setInt(2, 1000);
		ps.executeUpdate();
	} catch (SQLException e) {
		e.printStackTrace();
	} finally {
		JDBCUtil.release(conn, ps);
	}
}

Connection conn = null;
PreparedStatement ps = null;
try {
	// 1.   datasource
	ComboPooledDataSource dataSource = new ComboPooledDataSource();
	// 2.          
	dataSource.setDriverClass("com.mysql.jdbc.Driver");
	dataSource.setJdbcUrl("jdbc:mysql://localhost/bank");
	dataSource.setUser("root");
	dataSource.setPassword("root");
	
	// 2.       
	conn = dataSource.getConnection();
	String sql = "insert into account values(null , ? , ?)";
	ps = conn.prepareStatement(sql);
	ps.setString(1, "admi234n");
	ps.setInt(2, 103200);
	ps.executeUpdate();
} catch (Exception e) {
	e.printStackTrace();
} finally {
	JDBCUtil.release(conn, ps);
}

//      xml    default-config   。 
ComboPooledDataSource dataSource = new ComboPooledDataSource();
// 1.          
dataSource.setDriverClass("com.mysql.jdbc.Driver");
dataSource.setJdbcUrl("jdbc:mysql://localhost/bank");
dataSource.setUser("root");
dataSource.setPassword("root");

// 2.       
conn = dataSource.getConnection();
String sql = "insert into account values(null , ? , ?)";
ps = conn.prepareStatement(sql);
ps.setString(1, "admi234n");
ps.setInt(2, 103200);

//dbutils         CRUD    ，              。         
QueryRunner queryRunner = new QueryRunner(new ComboPooledDataSource());

//  
queryRunner.update("insert into account values (null , ? , ? )", "aa" ,1000);

//  
queryRunner.update("delete from account where id = ?", 5);

//  
queryRunner.update("update account set money = ? where id = ?", 10000000 , 6);

QueryRunner queryRunner = new QueryRunner(new ComboPooledDataSource());

Account  account =  queryRunner.query("select * from account where id = ?", new ResultSetHandler<Account>(){
	@Override
	public Account handle(ResultSet rs) throws SQLException {
		Account account  =  new Account();
		while(rs.next()){
			String name = rs.getString("name");
			int money = rs.getInt("money");
			
			account.setName(name);
			account.setMoney(money);
		}
		return account;
	}	
}, 6);
System.out.println(account.toString());

QueryRunner queryRunner = new QueryRunner(new ComboPooledDataSource());
//      
Account account = queryRunner.query("select * from account where id = ?", new BeanHandler<Account>(Account.class), 8);

QueryRunner queryRunner = new QueryRunner(new ComboPooledDataSource());

List<Account> list = queryRunner.query("select * from account ",new BeanListHandler<Account>(Account.class));

//             
BeanHandler,        //                 
BeanListHandler,    //               List
// -------------------------------------------------
ArrayHandler,       //                
ArrayListHandler,   //                 ，          。 
MapHandler,         //              map
MapListHandler,     //                 ，        map。