java基础之JDBC八：Druid连接池的使用

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基本使用代码:

/**
* Druid连接池及简单工具类的使用
*/
public class Test{
public static void main(String[] args) {
Connection conn = null;
Statement stat = null;
ResultSet rs = null;
try {
//使用简单工具类从Druid数据库连接池内取出Connection对象
conn = DruidSimpleUtils.getConnection();
stat = conn.createStatement();
String sql = "SELECT * FROM users";
rs = stat.executeQuery(sql);
while (rs.next()) {
int id = rs.getInt("uid");
String name = rs.getString("uname");
String psw = rs.getString("psw");
System.out.println(id + "--" + name + "--" + psw);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DruidSimpleUtils.release(conn, stat, rs);
}
}
}

简单工具类:

/**
* Druid简单工具类
*/
public class DruidSimpleUtils {
//构造私有 public DruidSimpleUtils() {
} //定义一个变量用来记录数据库连接池对象
private static DataSource ds; //由于Druid不会像C3P0那样自动读取配置文件所以我们使用静态代码块读取配置文件并给数据库连接池赋值
static {
Properties pp = new Properties();
try {
//加载properties配置文件这里地址写到src的上一级即可
pp.load(new FileReader("jdbcTest\\src\\config.properties"));
//数据库连接池配置使用DruidDataSourceFactory工厂来创建Druid连接池
ds = DruidDataSourceFactory.createDataSource(pp);
} catch (Exception e) {
e.printStackTrace();
}
} //后面基本跟C3P0简单工具类基本一致 /**
* 获取数据库连接Connection
* @return
*/
public static Connection getConnection() {
try {
return ds.getConnection();
} catch (SQLException e) {
e.printStackTrace();
}
return null;
} // 释放资源
public static void release(Connection conn, Statement stat, ResultSet rs) {
try {
if (rs != null) {
rs.close();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
if (stat != null) {
stat.close();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
} public static void release(Connection conn, Statement stat) {
try {
if (stat != null) {
stat.close();
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}