数据库连接池proxool的两种使用方式

数据库连接池可以通过两种方式来应用，针对web应用和非web应用而来。

非web应用的数据库连接池配置

第一种方式：工厂类

非web应用可以使用工厂模式将数据库连接创建封装在一个工具类中，工具类中又使用单例模式来创建加载驱动，代码如下：

工厂类：ConnectPoolFactory.java

 1 import java.io.InputStream;
 2 import java.sql.Connection;
 3 import java.sql.DriverManager;
 4 import java.util.Properties;
 5
 6 import org.logicalcobwebs.proxool.configuration.PropertyConfigurator;
 7
 8 public class ConnectPoolFactory {
 9
10     private static ConnectPoolFactory connectPoolFactory=null;
11
12     private ConnectPoolFactory() {//构造方法
13         init();
14     }
15
16     public void init(){//把properties文件加载到链接对象
17         InputStream is = ConnectPoolFactory.class.getResourceAsStream("/proxool.properties");
18         Properties properties = new Properties();
19         try {
20             properties.load(is);
21             PropertyConfigurator.configure(properties);
22         } catch (Exception e) {
23             e.printStackTrace();
24         }
25     }
26
27     public static  ConnectPoolFactory getInstance(){//单例模式
28         if(null == connectPoolFactory){
29             connectPoolFactory = new ConnectPoolFactory();
30         }
31
32         return connectPoolFactory;
33     }
34
35
36     public Connection getConnect(){
37         Connection conn=null;
38         try {
39             Class.forName("org.logicalcobwebs.proxool.ProxoolDriver");// 加载数据库连接池配备的驱动
40             conn = DriverManager.getConnection("proxool.test");//proxool为配置文件名，test为连接池别名
41         } catch (Exception e) {
42             e.printStackTrace();
43         }
44         return conn;
45     }
46
47 }

配置文件：proxool.properties

 1  jdbc-1.proxool.alias=test
 2  #jdbc-1.proxool.driver-class=oracle.jdbc.OracleDriver
 3  #jdbc-1.proxool.driver-url=jdbc:oracle:thin:@127.0.0.1:1521:orcl
 4  jdbc-1.proxool.driver-class=com.mysql.jdbc.Driver
 5  jdbc-1.proxool.driver-url=jdbc:mysql://localhost:3306/db_course
 6  jdbc-1.user=root
 7  jdbc-1.password=root
 8
 9  jdbc-1.proxool.maximum-connection-count=8
10  jdbc-1.proxool.minimum-connection-count=5
11  jdbc-1.proxool.prototype-count=4
12  jdbc-1.proxool.verbose=true
13  jdbc-1.proxool.statistics=10s,1m,1d
14  jdbc-1.proxool.statistics-log-level=error

然后通过工厂类创建工厂对象，通过工厂对象获取连接池实例，通过实例创建连接

测试类：ProxoolTest.java

1 public class ProxoolTest {
2     public static void main(String[] args) {
3         ConnectPoolFactory factory = ConnectPoolFactory.getInstance();
4         Connection connect = factory.getConnect();
5         System.out.println("ProxoolTest.main(conncet): " + connect);
6     }
7 }

第二种方式：工具类中加载

工具类：DBUtil.java

 1 public class DBUtil {
 2     static {
 3         InputStream is = DBUtil.class
 4                 .getResourceAsStream("/proxool.properties");
 5         Properties properties = new Properties();
 6         try {
 7             properties.load(is);
 8             PropertyConfigurator.configure(properties);
 9         } catch (Exception e) {
10             e.printStackTrace();
11         }
12     }
13
14     /**
15      * 获取数据库连接
16      *
17      * @return
18      */
19     public static Connection getConn() {
20         Connection conn = null;
21         try {
22             Class.forName("org.logicalcobwebs.proxool.ProxoolDriver");
23             conn = DriverManager.getConnection("proxool.test");
24         } catch (SQLException e) {
25             e.printStackTrace();
26         } catch (ClassNotFoundException e) {
27             e.printStackTrace();
28         }
29         return conn;
30     }
31
32     /**
33      * 获取sql语句发送器
34      *
35      * @param conn
36      * @return
37      */
38     public static Statement getStmt(Connection conn) {
39         Statement stmt = null;
40         try {
41             stmt = conn.createStatement();
42         } catch (SQLException e) {
43             e.printStackTrace();
44         }
45         return stmt;
46     }
47
48     /**
49      * 获取预处理发送器
50      *
51      * @param conn
52      * @param sql
53      * @return
54      */
55     public static PreparedStatement getPstmt(Connection conn, String sql) {
56         PreparedStatement pstmt = null;
57         try {
58             pstmt = conn.prepareStatement(sql);
59         } catch (SQLException e) {
60             e.printStackTrace();
61         }
62         return pstmt;
63     }
64
65     /**
66      * 动态绑定参数
67      *
68      * @param pstmt
69      * @param params
70      */
71     public static void bindParam(PreparedStatement pstmt, Object... params) {
72         for (int i = 0; i < params.length; i++) {
73             try {
74                 pstmt.setObject(i + 1, params[i]);
75             } catch (SQLException e) {
76                 e.printStackTrace();
77             }
78         }
79     }
80
81     /**
82      * 关闭资源
83      * @param autoCloseables 实现了AutoCloseable接口的实现类对象
84      */
85     public static void closeAll(AutoCloseable...autoCloseables) {
86         for (AutoCloseable autoCloseable : autoCloseables) {
87             if(autoCloseable!=null){
88                 try {
89                     autoCloseable.close();
90                 } catch (Exception e) {
91                     e.printStackTrace();
92                 }
93             }
94         }
95     }
96 }

在web应用中使用数据库连接池

proxool.properties配置文件是不可少的，但是DBUtil.java中的静态代码块就不再需要了。

不过要在web.xml中添加如下代码：

 1 <!-- 配置连接池信息 -->
 2   <servlet>
 3     <servlet-name>servletConfigurator</servlet-name>
 4     <servlet-class>org.logicalcobwebs.proxool.configuration.ServletConfigurator</servlet-class>
 5     <init-param>
 6         <param-name>propertyFile</param-name>
 7         <param-value>WEB-INF/classes/proxool.properties</param-value>
 8     </init-param>
 9     <load-on-startup>1</load-on-startup><!-- 应用启动时加载配置信息 -->
10   </servlet>
11
12   <!-- 监控连接池 -->
13   <servlet>
14     <servlet-name>adminServlet</servlet-name>
15     <servlet-class>org.logicalcobwebs.proxool.admin.servlet.AdminServlet</servlet-class>
16   </servlet>
17   <servlet-mapping>
18     <servlet-name>adminServlet</servlet-name>
19     <url-pattern>/admin</url-pattern>
20   </servlet-mapping>

其中<url-pattern>/admin</url-pattern>用来配置访问监控连接池页面