public class JBDC_V1 { private static String driver; private static String url; private static String username; private static String password; /** * 静态代码块加载配置文件信息 */ static { try{ ResourceBundle bundle = ResourceBundle.getBundle("db"); driver = bundle.getString("driver"); url = bundle.getString("url"); username = bundle.getString("username"); password = bundle.getString("password"); }catch (Exception e){ e.printStackTrace(); } } public static Connection getConnection() { Connection conn = null; try { Class.forName(driver); conn = DriverManager.getConnection(url, username, password); } catch (Exception e) { e.printStackTrace(); } return conn; } public static void release(Connection conn, PreparedStatement pstmt, ResultSet rs) { if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if (pstmt != null) { try { pstmt.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } }
public class JBDC_V2 { private static String driver; private static String url; private static String username; private static String password; /** * 静态代码块加载配置文件信息 */ static { try { // 1.通过当前类获取类加载器 ClassLoader classLoader = JBDC_V2.class.getClassLoader(); // 2.通过类加载器的方法获得一个输入流 InputStream is = classLoader.getResourceAsStream("db.properties"); // 3.创建一个properties对象 Properties props = new Properties(); // 4.加载输入流 props.load(is); // 5.获取相关参数的值 driver = props.getProperty("driver"); url = props.getProperty("url"); username = props.getProperty("username"); password = props.getProperty("password"); } catch (IOException e) { e.printStackTrace(); } } /** * 获取连接方法 * * @return */ public static Connection getConnection() { Connection conn = null; try { Class.forName(driver); conn = DriverManager.getConnection(url, username, password); } catch (Exception e) { e.printStackTrace(); } return conn; } public static void release(Connection conn, PreparedStatement pstmt, ResultSet rs) { if (rs != null) { try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if (pstmt != null) { try { pstmt.close(); } catch (SQLException e) { e.printStackTrace(); } } if (conn != null) { try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } }
配置文件（放置src目录）
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/db1?useUnicode=true&characterEncoding=utf8
username=root
password=
检测类
public class JBDC_Test {
@Test
public void test2() {
Connection conn = null;
PreparedStatement pstmt = null;
try {
// 1.获取连接
conn = JBDC_V2.getConnection();
// 2.编写sql语句
String sql = "insert t1 (id,name) value (?,?)";
// 3.获取执行sql语句对象
pstmt = conn.prepareStatement(sql);
// 4.设置参数
pstmt.setInt(1, 5);
pstmt.setString(2, "xjj");
// 5.执行删除操作
int row = pstmt.executeUpdate();
if (row > 0) {
System.out.println("删除成功!");
} else {
System.out.println("删除失败!");
}
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
// 6.释放资源
JBDC_V2.release(conn, pstmt, null);
}
}
public class JBDC_V2 {
private static String driver;
private static String url;
private static String username;
private static String password;
/**
* 静态代码块加载配置文件信息
*/
static {
try {
// 1.通过当前类获取类加载器
ClassLoader classLoader = JBDC_V2.class.getClassLoader();
// 2.通过类加载器的方法获得一个输入流
InputStream is = classLoader.getResourceAsStream("db.properties");
// 3.创建一个properties对象
Properties props = new Properties();
// 4.加载输入流
props.load(is);
// 5.获取相关参数的值
driver = props.getProperty("driver");
url = props.getProperty("url");
username = props.getProperty("username");
password = props.getProperty("password");
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 获取连接方法
*
* @return
*/
public static Connection getConnection() {
Connection conn = null;
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, username, password);
} catch (Exception e) {
e.printStackTrace();
}
return conn;
}
public static void release(Connection conn, PreparedStatement pstmt, ResultSet rs) {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (pstmt != null) {
try {
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
Java—JBDC（通过properties配置文件链接数据库）
原文：https://www.cnblogs.com/zhuzhiwei-2019/p/11300565.html