JavaJDBC【六、连接池】

背景

1、连接是一种重要资源

2、频繁连接数据库会增加数据库压力

常用连接池

dbcp

1、导入jar包（官网下载）
commons-dbcp.jar
commons-pool.jar
commons-logging.jar
2、配置
dbcp.properties
![](http://images2015.cnblogs.com/blog/692906/201704/692906-20170406081212363-330328016.png)
3、用配置创建DataSource
Properties p = new Properties();
p.load(Object.class.getResourceAsStream("fileName");
DataSource ds = BasicDataSourceFactory.createDataSource(p);
4、用DataSource获取连接
Connection con = ds.getConnection();

Demo:

public class DBCPUtil {
private static DataSource DS;
private static final String config = "/dbcp.properties";

public DBCPUtil() {
	initDBCP();
}

private static void initDBCP() {
	Properties ppts = new Properties();
	try {
		ppts.load(Object.class.getResourceAsStream(config));
		DS = BasicDataSourceFactory.createDataSource(ppts);
	} catch (IOException e) {
		e.printStackTrace();
	} catch (Exception e) {
		e.printStackTrace();
	}
}

public Connection GetConnection() {
	Connection con = null;
	try {
		if (DS != null) {
			con = DS.getConnection();
		}
	} catch (SQLException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	return con;
}
}

c3p0

1、导入jar包（官网下载）
c3p0.jar
mchange-commons.jar
2、配置
c3p0.properties![](http://images2015.cnblogs.com/blog/692906/201704/692906-20170407082502113-1572894078.png)
3、创建DataSource
ComboPooledDataSource DS = new ComboPooledDataSource();
4、用DataSource获取连接
Connection con = DS.getConnection();

Demo:

public class C3P0Util {
private static ComboPooledDataSource DS = new ComboPooledDataSource();

public static Connection GetConnection() throws SQLException {
	Connection con = DS.getConnection();
	return con;
}
}

差异