需要的jar包：1.commons-dbcp.jar

????????????????? ?2.commons-collections.jar

?????????????????? 3.commons-pool.jar

import java.io.FileInputStream;
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 con;
	public DbcpConnection(){
		
	}

	public static Connection getConnection() {
		if (dataSource == null) {
			
			initDataSource();
		}
		try {
			con = dataSource.getConnection();
			print();
			
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return con;

	}

@SuppressWarnings("deprecation")
public static  void initDataSource() {
		FileInputStream is=null;
		
		Properties p = 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 {
			is= new FileInputStream("dbcp.properties");
			p.load(is);
			driverClassName = p.getProperty("dbcp.driverClassName");
			url = p.getProperty("dbcp.url");
			username = p.getProperty("dbcp.username");
			password = p.getProperty("dbcp.password");

			initialSize = Integer.parseInt(p.getProperty("dbcp.initialSize"));
			minIdle = Integer.parseInt(p.getProperty("dbcp.minIdle"));
			maxIdle = Integer.parseInt(p.getProperty("dbcp.maxIdle"));
			maxWait = Integer.parseInt(p.getProperty("dbcp.maxWait"));
			maxActive = Integer.parseInt(p.getProperty("dbcp.maxActive"));
		} catch (NumberFormatException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			try {
				is.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

		BasicDataSource ds = new BasicDataSource();
		ds.setUrl(url);
        ds.setDriverClassName(driverClassName);
		ds.setUsername(username);
		ds.setPassword(password);
		
		ds.setInitialSize(initialSize); // 初始的连接数；
		ds.setMaxActive(maxActive);
		ds.setMinIdle(minIdle);
		ds.setMaxIdle(maxIdle);
		ds.setMaxWait(maxWait);
		//ds.setRemoveAbandoned(true);
		//ds.setRemoveAbandonedTimeout(2000);
		
	
		 

		dataSource = ds;
		
	}
/* 用于测试连接状态的方法*/
public static void print(){
	BasicDataSource ds=(BasicDataSource)dataSource;
	
	System.out.println(ds.getInitialSize());
	System.out.println(ds.getNumActive());
	System.out.println(ds.getNumIdle());
	System.out.println(ds.getDefaultAutoCommit());
	
	
}

}

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2.数据库的连接属性的配置文件：dbcp.properties

dbcp.driverClassName=com.microsoft.sqlserver.jdbc.SQLServerDriver
dbcp.url=jdbc:sqlserver://localhost:1433;DatabaseName=Library;userName=sa;password=123456
dbcp.username=sa
dbcp.password=123456
dbcp.initialSize=10
dbcp.minIdle=5
dbcp.maxIdle=15
dbcp.maxWait=3000
dbcp.maxActive=20

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