pref: 优化默认图片生成，减少空间占用

pom.xml

@@ -10,7 +10,7 @@
     </parent>
     <groupId>com.example</groupId>
     <artifactId>DotMatrix</artifactId>
-    <version>0.2.3</version>
+    <version>0.2.4</version>
     <name>DotMatrix</name>
     <description>DotMatrix</description>
 

src/main/java/com/yeechart/dotMatrix/signage/SignageDrawUtil.java

@@ -235,6 +235,9 @@ public class SignageDrawUtil {
 
 //        String path = SignageFileUtil.fileName + dId + "/";//路径;
         String sessionId = System.currentTimeMillis() + "";
+        if(dId.equals("default")) {
+            sessionId = "1749865200000";
+        }
         String path = SignageFileUtil.fileName + dId + "/" + sessionId + "/";//路径;