fix connection pool bug

hutool-db/src/main/java/org/dromara/hutool/db/ds/pooled/PooledConnection.java

@@ -99,6 +99,16 @@ public class PooledConnection extends ConnectionWrapper {
 		return this.isClosed;
 	}
 
+	/**
+	 * 打开连接
+	 *
+	 * @return this
+	 */
+	PooledConnection open() {
+		this.isClosed = false;
+		return this;
+	}
+
 	/**
 	 * 销毁连接，即彻底关闭并丢弃连接
 	 */

hutool-db/src/main/java/org/dromara/hutool/db/ds/pooled/PooledDataSource.java

@@ -86,7 +86,7 @@ public class PooledDataSource extends AbstractDataSource {
 
 	@Override
 	public PooledConnection getConnection() throws SQLException {
-		return connPool.borrowObject();
+		return connPool.borrowObject().open();
 	}
 
 	@Override