init: 遗留订单系统初始版本

src/main/java/com/legacy/order/util/DbUtil.java

@@ -0,0 +1,50 @@
+package com.legacy.order.util;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+
+public class DbUtil {
+
+    private static final String URL = "jdbc:h2:mem:legacydb;DB_CLOSE_DELAY=-1";
+    private static final String USER = "sa";
+    private static final String PASSWORD = "password123";
+
+    private static DbUtil instance;
+    private static Connection conn;
+
+    private DbUtil() {
+        System.out.println("DbUtil初始化了");
+    }
+
+    public static DbUtil getInstance() {
+        if (instance == null) {
+            instance = new DbUtil();
+        }
+        return instance;
+    }
+
+    public Connection getConnection() {
+        try {
+            Class.forName("org.h2.Driver");
+            conn = DriverManager.getConnection(URL, USER, PASSWORD);
+            System.out.println("创建了新数据库连接");
+            return conn;
+        } catch (Exception e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    public void closeConnection() {
+        try {
+            if (conn != null && !conn.isClosed()) {
+                conn.close();
+            }
+        } catch (Exception e) {
+        }
+    }
+
+    public static Connection getConn() {
+        return DbUtil.getInstance().getConnection();
+    }
+}