diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/buffer/OffsetManager.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/buffer/OffsetManager.java
index e895b52c096170c109aa38568823c3232ed0bb8f..c2e64b34d35d7eb66e7a94ecbb15ec5842b523e7 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/buffer/OffsetManager.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/buffer/OffsetManager.java
@@ -142,11 +142,7 @@ public enum OffsetManager {
 
     class PrefixFileNameFilter implements FilenameFilter {
         @Override public boolean accept(File dir, String name) {
-            if (name.startsWith(OFFSET_FILE_PREFIX)) {
-                return true;
-            } else {
-                return false;
-            }
+            return name.startsWith(OFFSET_FILE_PREFIX);
         }
     }
 }
diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/buffer/SegmentBufferReader.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/buffer/SegmentBufferReader.java
index 775c6c9d6371f646907100bcbb7e1d56df6cf817..3fd3f7db62612f2c4bc396da7f6863c21b4d4d17 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/buffer/SegmentBufferReader.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/buffer/SegmentBufferReader.java
@@ -141,11 +141,7 @@ public enum SegmentBufferReader {
 
     class PrefixFileNameFilter implements FilenameFilter {
         @Override public boolean accept(File dir, String name) {
-            if (name.startsWith(SegmentBufferManager.DATA_FILE_PREFIX)) {
-                return true;
-            } else {
-                return false;
-            }
+            return name.startsWith(SegmentBufferManager.DATA_FILE_PREFIX);
         }
     }
 }
diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/standardization/ReferenceIdExchanger.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/standardization/ReferenceIdExchanger.java
index 683ba5ff3aa9c89ad0fdc6cbc38d969e9e91f139..10b43955cd9e45d52c4e5e1ffc896553f6213f54 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/standardization/ReferenceIdExchanger.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/standardization/ReferenceIdExchanger.java
@@ -33,13 +33,13 @@ public class ReferenceIdExchanger implements IdExchanger<ReferenceDecorator> {
 
     private final Logger logger = LoggerFactory.getLogger(ReferenceIdExchanger.class);
 
-    private static ReferenceIdExchanger exchanger;
+    private static ReferenceIdExchanger EXCHANGER;
 
     public static ReferenceIdExchanger getInstance() {
-        if (exchanger == null) {
-            exchanger = new ReferenceIdExchanger();
+        if (EXCHANGER == null) {
+            EXCHANGER = new ReferenceIdExchanger();
         }
-        return exchanger;
+        return EXCHANGER;
     }
 
     @Override public boolean exchange(ReferenceDecorator standardBuilder, int applicationId) {
diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/standardization/SpanIdExchanger.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/standardization/SpanIdExchanger.java
index 2ab1c056f948951b3f59c2a16316198d723367c6..b06a1c54039457712ce9a30be3b47cb244fdcff9 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/standardization/SpanIdExchanger.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/worker/segment/standardization/SpanIdExchanger.java
@@ -28,13 +28,13 @@ import org.skywalking.apm.collector.core.util.StringUtils;
  */
 public class SpanIdExchanger implements IdExchanger<SpanDecorator> {
 
-    private static SpanIdExchanger exchanger;
+    private static SpanIdExchanger EXCHANGER;
 
     public static SpanIdExchanger getInstance() {
-        if (exchanger == null) {
-            exchanger = new SpanIdExchanger();
+        if (EXCHANGER == null) {
+            EXCHANGER = new SpanIdExchanger();
         }
-        return exchanger;
+        return EXCHANGER;
     }
 
     @Override public boolean exchange(SpanDecorator standardBuilder, int applicationId) {