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875天前//单态设计模式的JDBC |
package com.util; |
import java.sql.Connection; |
import java.sql.DriverManager; |
import java.sql.ResultSet; |
import java.sql.SQLException; |
import java.sql.Statement; |
/** |
* JDBC |
* @author Administrator |
* |
*/ |
public class DbUtil { |
private static DbUtil db=new DbUtil(); |
private final String URL="jdbc:mysql://localhost:3306/Librarymanagement"; |
private final String NAME="root"; |
private final String PASSWORD="123456"; |
|
/** |
* 注册驱动 |
*/ |
private DbUtil(){ |
try { |
Class.forName("com.mysql.jdbc.Driver"); |
} catch (ClassNotFoundException e) { |
// TODO Auto-generated catch block |
System.out.println("注册驱动失败"); |
} |
} |
/** |
* 得到db链接数据库 |
* @return |
*/ |
public static DbUtil getDb() { |
return db; |
} |
|
/** |
* 链接数据库 |
* @return |
*/ |
public Connection getConn(){ |
Connection con=null; |
try { |
con=DriverManager.getConnection(URL,NAME,PASSWORD); |
System.out.println("ok-ok-lianjie"); |
} catch (SQLException e) { |
// TODO Auto-generated catch block |
e.printStackTrace(); |
}//链接数据库 |
|
return con; |
} |
|
/** |
* 关闭数据库 |
* @param obj |
*/ |
public void closeDb(Object obj){ |
try { |
if(obj instanceof ResultSet){ |
ResultSet th=(ResultSet)obj; |
|
th.close(); |
}else if(obj instanceof Statement){ |
Statement st=(Statement)obj; |
|
st.close(); |
}else if(obj instanceof Connection){ |
Connection con=(Connection)obj; |
|
con.close(); |
} |
} catch (SQLException e) { |
// TODO Auto-generated catch block |
System.out.println("关闭失败"); |
} |
|
} |
|
} |
