add install app

main_app/src/main/java/com/ihaoin/hooloo/device/update/UpdateService.java

@@ -106,9 +106,16 @@ public class UpdateService extends Thread {
     private void startDownload(UpdateDataVo dataVo) {
         String filename = "hooloo-device_" + dataVo.getVersion() + "_" + dataVo.getVersionCode() + "_" + System.currentTimeMillis() + ".apk";
         String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/hooloo";
-        if (!new File(path).exists()) {
-            new File(path).mkdirs();
+        File pathFile = new File(path);
+        if (!pathFile.exists()) {
+            pathFile.mkdirs();
         }
+        if (pathFile.listFiles() != null) {
+            for (File subfile : pathFile.listFiles()) {
+                subfile.delete();
+            }
+        }
+
         String file = path + "/" + filename;
         Utils.i(AppConfig.TAG_UPDATE, String.format("开始下载文件 url: %s, file: %s", dataVo.getUrl(), file));
         if (AppConfig.DEBUG) {