[incubator-skywalking] branch 5.x updated: FileUtils Transaction problem (#1996)

[pengys]

This is an automated email from the ASF dual-hosted git repository.

pengys pushed a commit to branch 5.x
in repository https://gitbox.apache.org/repos/asf/incubator-skywalking.git


The following commit(s) were added to refs/heads/5.x by this push:
     new 69a765d  FileUtils Transaction  problem (#1996)
69a765d is described below

commit 69a765d32bf1fdf4fb207272d8f79fb2316382f4
Author: caoyixiong <32847163+ian...@users.noreply.github.com>
AuthorDate: Wed Dec 5 21:03:57 2018 +0800

    FileUtils Transaction  problem (#1996)
    
    * close inputStream safety
    
    * FIX NPE in AlarmService
    
    * fix 5.x too many open files bug
    
    * checkstyle bug
    
    * checkstyle bug
    
    * checkstyle bug
    
    * fix offset bug
    
    * change param name
---
 .../org/apache/skywalking/apm/collector/core/util/FileUtils.java  | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git 
a/apm-collector/apm-collector-core/src/main/java/org/apache/skywalking/apm/collector/core/util/FileUtils.java
 
b/apm-collector/apm-collector-core/src/main/java/org/apache/skywalking/apm/collector/core/util/FileUtils.java
index 8803670..97c1e99 100644
--- 
a/apm-collector/apm-collector-core/src/main/java/org/apache/skywalking/apm/collector/core/util/FileUtils.java
+++ 
b/apm-collector/apm-collector-core/src/main/java/org/apache/skywalking/apm/collector/core/util/FileUtils.java
@@ -43,8 +43,9 @@ public enum FileUtils {
                 long position = length - 1;
                 randomAccessFile.seek(position);
                 while (position >= 0) {
-                    if (randomAccessFile.read() == '\n') {
-                        return randomAccessFile.readLine();
+                    String lineString = "";
+                    if (randomAccessFile.read() == '\n' && 
StringUtils.isNotEmpty(lineString = randomAccessFile.readLine())) {
+                        return lineString;
                     }
                     randomAccessFile.seek(position);
                     if (position == 0) {
@@ -73,8 +74,7 @@ public enum FileUtils {
             randomAccessFile = new RandomAccessFile(file, "rwd");
             long length = randomAccessFile.length();
             randomAccessFile.seek(length);
-            randomAccessFile.writeBytes(System.lineSeparator());
-            randomAccessFile.writeBytes(value);
+            randomAccessFile.writeBytes(System.lineSeparator() + value);
         } catch (IOException e) {
             logger.error(e.getMessage(), e);
         } finally {