DBCP(DataBase connection pool),数据库连接池。是 apache 上的一个 java 连接池项目,也是 tomcat 使用的连接池组件。
单独使用dbcp需要3个包:common-dbcp.jar,common-pool.jar,common-collections.jar
由于建立数据库连接是一个非常耗时耗资源的行为,所以通过连接池预先同数据库建立一些连接,放在内存中,应用程序需要建立数据库连接时直接到连接池中申请一个就行,用
完后再放回去。
获取数据库连接的类:DbcpConnection.java
- import java.io.FileInputStream;
- import java.io.FileNotFoundException;
- import java.io.IOException;
- import java.sql.Connection;
- import java.sql.SQLException;
- import java.util.Properties;
- import javax.sql.DataSource;
- import org.apache.commons.dbcp.BasicDataSource;
- public class DbcpConnection {
- private static DataSource dataSource;
- private static Connection connection;
- public static void initDataSource(){
- FileInputStream is = null;
- Properties properties = new Properties();
- String driverClassName = null;
- String url = null;
- String username = null;
- String password = null;
- int initialSize = 0;
- int minIdle = 0;
- int maxIdle = 0;
- int maxWait = 0;
- int maxActive = 0;
- try {
- String path = System.getProperty("user.dir")+"\\src\\com\\xiami\\db\\connection\\";
- is = new FileInputStream(path+"dbcp.properties");
- properties.load(is);
- driverClassName = properties.getProperty("dbcp.driverClassName");
- url = properties.getProperty("dbcp.url");
- username = properties.getProperty("dbcp.username");
- password = properties.getProperty("dbcp.password");
- initialSize = Integer.parseInt((properties.getProperty("dbcp.initialSize").trim()));
- minIdle = Integer.parseInt((properties.getProperty("dbcp.minIdle")).trim());
- maxIdle = Integer.parseInt((properties.getProperty("dbcp.maxIdle")).trim());
- maxWait = Integer.parseInt((properties.getProperty("dbcp.maxWait")).trim());
- maxActive = Integer.parseInt((properties.getProperty("dbcp.maxActive")).trim());
- } catch (FileNotFoundException e) {
- e.printStackTrace();
- } catch (IOException ioe){
- ioe.printStackTrace();
- }finally{
- try {
- is.close();
- } catch (IOException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- }
- BasicDataSource bds = new BasicDataSource();
- bds.setUrl(url);
- bds.setDriverClassName(driverClassName);
- bds.setUsername(username);
- bds.setPassword(password);
- bds.setInitialSize(initialSize);
- bds.setMaxActive(maxActive);
- bds.setMinIdle(minIdle);
- bds.setMaxIdle(maxIdle);
- bds.setMaxWait(maxWait);
- dataSource = bds;
- }
- public static Connection getConnection() throws SQLException {
- if (dataSource == null) {
- initDataSource();
- }
- Connection conn = null;
- if (dataSource != null) {
- conn = dataSource.getConnection();
- }
- return conn;
- }
- }
连接数据库信息的配置文件:dbcp.properties
- dbcp.driverClassName=com.ibm.db2.jcc.DB2Driver
- dbcp.url=jdbc\:db2\://192.168.3.11\:50000/DBNAME
- dbcp.username=db2admin
- dbcp.password=password
- dbcp.initialSize=30
- dbcp.minIdle=10
- dbcp.maxIdle=10
- dbcp.maxWait=1000
- dbcp.maxActive=30
在Service层使用的时候:ZhiDianJieDu.java (业务逻辑处理的类)
- import java.sql.Connection;
- import java.sql.PreparedStatement;
- import java.sql.ResultSet;
- import java.sql.SQLException;