diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/LogJsonReader.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/LogJsonReader.java
index f8d6526b2..78b8a79ee 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/LogJsonReader.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/LogJsonReader.java
@@ -11,17 +11,17 @@ public class LogJsonReader implements StreamJsonReader<LogMessage> {
 
     private KeyWithStringValueJsonReader keyWithStringValueJsonReader = new KeyWithStringValueJsonReader();
 
-    private static final String TI = "ti";
-    private static final String LD = "ld";
+    private static final String TIME = "ti";
+    private static final String LOG_DATA = "ld";
 
     @Override public LogMessage read(JsonReader reader) throws IOException {
         LogMessage.Builder builder = LogMessage.newBuilder();
 
         while (reader.hasNext()) {
             switch (reader.nextName()) {
-                case TI:
+                case TIME:
                     builder.setTime(reader.nextLong());
-                case LD:
+                case LOG_DATA:
                     reader.beginArray();
                     while (reader.hasNext()) {
                         builder.addData(keyWithStringValueJsonReader.read(reader));
diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/ReferenceJsonReader.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/ReferenceJsonReader.java
index bd979d6be..113edd199 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/ReferenceJsonReader.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/ReferenceJsonReader.java
@@ -11,17 +11,17 @@ public class ReferenceJsonReader implements StreamJsonReader<TraceSegmentReferen
 
     private UniqueIdJsonReader uniqueIdJsonReader = new UniqueIdJsonReader();
 
-    private static final String TS = "ts";
-    private static final String AI = "ai";
-    private static final String SI = "si";
-    private static final String VI = "vi";
-    private static final String VN = "vn";
-    private static final String NI = "ni";
-    private static final String NN = "nn";
-    private static final String EA = "ea";
-    private static final String EI = "ei";
-    private static final String EN = "en";
-    private static final String RV = "rv";
+    private static final String PARENT_TRACE_SEGMENT_ID = "ts";
+    private static final String PARENT_APPLICATION_ID = "ai";
+    private static final String PARENT_SPAN_ID = "si";
+    private static final String PARENT_SERVICE_ID = "vi";
+    private static final String PARENT_SERVICE_NAME = "vn";
+    private static final String NETWORK_ADDRESS_ID = "ni";
+    private static final String NETWORK_ADDRESS = "nn";
+    private static final String ENTRY_APPLICATION_INSTANCE_ID = "ea";
+    private static final String ENTRY_SERVICE_ID = "ei";
+    private static final String ENTRY_SERVICE_NAME = "en";
+    private static final String REF_TYPE_VALUE = "rv";
 
     @Override public TraceSegmentReference read(JsonReader reader) throws IOException {
         TraceSegmentReference.Builder builder = TraceSegmentReference.newBuilder();
@@ -29,37 +29,37 @@ public class ReferenceJsonReader implements StreamJsonReader<TraceSegmentReferen
         reader.beginObject();
         while (reader.hasNext()) {
             switch (reader.nextName()) {
-                case TS:
+                case PARENT_TRACE_SEGMENT_ID:
                     builder.setParentTraceSegmentId(uniqueIdJsonReader.read(reader));
                     break;
-                case AI:
+                case PARENT_APPLICATION_ID:
                     builder.setParentApplicationInstanceId(reader.nextInt());
                     break;
-                case SI:
+                case PARENT_SPAN_ID:
                     builder.setParentSpanId(reader.nextInt());
                     break;
-                case VI:
+                case PARENT_SERVICE_ID:
                     builder.setParentServiceId(reader.nextInt());
                     break;
-                case VN:
+                case PARENT_SERVICE_NAME:
                     builder.setParentServiceName(reader.nextString());
                     break;
-                case NI:
+                case NETWORK_ADDRESS_ID:
                     builder.setNetworkAddressId(reader.nextInt());
                     break;
-                case NN:
+                case NETWORK_ADDRESS:
                     builder.setNetworkAddress(reader.nextString());
                     break;
-                case EA:
+                case ENTRY_APPLICATION_INSTANCE_ID:
                     builder.setEntryApplicationInstanceId(reader.nextInt());
                     break;
-                case EI:
+                case ENTRY_SERVICE_ID:
                     builder.setEntryServiceId(reader.nextInt());
                     break;
-                case EN:
+                case ENTRY_SERVICE_NAME:
                     builder.setEntryServiceName(reader.nextString());
                     break;
-                case RV:
+                case REF_TYPE_VALUE:
                     builder.setRefTypeValue(reader.nextInt());
                     break;
                 default:
diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/SegmentJsonReader.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/SegmentJsonReader.java
index c88a18f4b..a2daa965c 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/SegmentJsonReader.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/SegmentJsonReader.java
@@ -17,11 +17,11 @@ public class SegmentJsonReader implements StreamJsonReader<TraceSegmentObject> {
     private ReferenceJsonReader referenceJsonReader = new ReferenceJsonReader();
     private SpanJsonReader spanJsonReader = new SpanJsonReader();
 
-    private static final String TS = "ts";
-    private static final String AI = "ai";
-    private static final String II = "ii";
-    private static final String RS = "rs";
-    private static final String SS = "ss";
+    private static final String TRACE_SEGMENT_ID = "ts";
+    private static final String APPLICATION_ID = "ai";
+    private static final String APPLICATION_INSTANCE_ID = "ii";
+    private static final String TRACE_SEGMENT_REFERENCE = "rs";
+    private static final String SPANS = "ss";
 
     @Override public TraceSegmentObject read(JsonReader reader) throws IOException {
         TraceSegmentObject.Builder builder = TraceSegmentObject.newBuilder();
@@ -29,7 +29,7 @@ public class SegmentJsonReader implements StreamJsonReader<TraceSegmentObject> {
         reader.beginObject();
         while (reader.hasNext()) {
             switch (reader.nextName()) {
-                case TS:
+                case TRACE_SEGMENT_ID:
                     builder.setTraceSegmentId(uniqueIdJsonReader.read(reader));
                     if (logger.isDebugEnabled()) {
                         StringBuilder segmentId = new StringBuilder();
@@ -37,20 +37,20 @@ public class SegmentJsonReader implements StreamJsonReader<TraceSegmentObject> {
                         logger.debug("segment id: {}", segmentId);
                     }
                     break;
-                case AI:
+                case APPLICATION_ID:
                     builder.setApplicationId(reader.nextInt());
                     break;
-                case II:
+                case APPLICATION_INSTANCE_ID:
                     builder.setApplicationInstanceId(reader.nextInt());
                     break;
-                case RS:
+                case TRACE_SEGMENT_REFERENCE:
                     reader.beginArray();
                     while (reader.hasNext()) {
                         builder.addRefs(referenceJsonReader.read(reader));
                     }
                     reader.endArray();
                     break;
-                case SS:
+                case SPANS:
                     reader.beginArray();
                     while (reader.hasNext()) {
                         builder.addSpans(spanJsonReader.read(reader));
diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/SpanJsonReader.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/SpanJsonReader.java
index 074929525..8de743512 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/SpanJsonReader.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/SpanJsonReader.java
@@ -12,21 +12,21 @@ public class SpanJsonReader implements StreamJsonReader<SpanObject> {
     private KeyWithStringValueJsonReader keyWithStringValueJsonReader = new KeyWithStringValueJsonReader();
     private LogJsonReader logJsonReader = new LogJsonReader();
 
-    private static final String SI = "si";
-    private static final String TV = "tv";
-    private static final String LV = "lv";
-    private static final String PS = "ps";
-    private static final String ST = "st";
-    private static final String ET = "et";
-    private static final String CI = "ci";
-    private static final String CN = "cn";
-    private static final String OI = "oi";
-    private static final String ON = "on";
-    private static final String PI = "pi";
-    private static final String PN = "pn";
-    private static final String IE = "ie";
-    private static final String TO = "to";
-    private static final String LO = "lo";
+    private static final String SPAN_ID = "si";
+    private static final String SPAN_TYPE_VALUE = "tv";
+    private static final String SPAN_LAYER_VALUE = "lv";
+    private static final String PARENT_SPAN_ID = "ps";
+    private static final String START_TIME = "st";
+    private static final String END_TIME = "et";
+    private static final String COMPONENT_ID = "ci";
+    private static final String COMPONENT_NAME = "cn";
+    private static final String OPERATION_NAME_ID = "oi";
+    private static final String OPERATION_NAME = "on";
+    private static final String PEER_ID = "pi";
+    private static final String PEER = "pn";
+    private static final String IS_ERROR = "ie";
+    private static final String TAGS = "to";
+    private static final String LOGS = "lo";
 
     @Override public SpanObject read(JsonReader reader) throws IOException {
         SpanObject.Builder builder = SpanObject.newBuilder();
@@ -34,53 +34,53 @@ public class SpanJsonReader implements StreamJsonReader<SpanObject> {
         reader.beginObject();
         while (reader.hasNext()) {
             switch (reader.nextName()) {
-                case SI:
+                case SPAN_ID:
                     builder.setSpanId(reader.nextInt());
                     break;
-                case TV:
+                case SPAN_TYPE_VALUE:
                     builder.setSpanTypeValue(reader.nextInt());
                     break;
-                case LV:
+                case SPAN_LAYER_VALUE:
                     builder.setSpanLayerValue(reader.nextInt());
                     break;
-                case PS:
+                case PARENT_SPAN_ID:
                     builder.setParentSpanId(reader.nextInt());
                     break;
-                case ST:
+                case START_TIME:
                     builder.setStartTime(reader.nextLong());
                     break;
-                case ET:
+                case END_TIME:
                     builder.setEndTime(reader.nextLong());
                     break;
-                case CI:
+                case COMPONENT_ID:
                     builder.setComponentId(reader.nextInt());
                     break;
-                case CN:
+                case COMPONENT_NAME:
                     builder.setComponent(reader.nextString());
                     break;
-                case OI:
+                case OPERATION_NAME_ID:
                     builder.setOperationNameId(reader.nextInt());
                     break;
-                case ON:
+                case OPERATION_NAME:
                     builder.setOperationName(reader.nextString());
                     break;
-                case PI:
+                case PEER_ID:
                     builder.setPeerId(reader.nextInt());
                     break;
-                case PN:
+                case PEER:
                     builder.setPeer(reader.nextString());
                     break;
-                case IE:
+                case IS_ERROR:
                     builder.setIsError(reader.nextBoolean());
                     break;
-                case TO:
+                case TAGS:
                     reader.beginArray();
                     while (reader.hasNext()) {
                         builder.addTags(keyWithStringValueJsonReader.read(reader));
                     }
                     reader.endArray();
                     break;
-                case LO:
+                case LOGS:
                     reader.beginArray();
                     while (reader.hasNext()) {
                         builder.addLogs(logJsonReader.read(reader));
diff --git a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/TraceSegmentJsonReader.java b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/TraceSegmentJsonReader.java
index 26045e3c9..d00883b53 100644
--- a/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/TraceSegmentJsonReader.java
+++ b/apm-collector/apm-collector-agentstream/src/main/java/org/skywalking/apm/collector/agentstream/jetty/handler/reader/TraceSegmentJsonReader.java
@@ -15,8 +15,8 @@ public class TraceSegmentJsonReader implements StreamJsonReader<TraceSegment> {
     private UniqueIdJsonReader uniqueIdJsonReader = new UniqueIdJsonReader();
     private SegmentJsonReader segmentJsonReader = new SegmentJsonReader();
 
-    private static final String GT = "gt";
-    private static final String SG = "sg";
+    private static final String GLOBAL_TRACE_IDS = "gt";
+    private static final String SEGMENT = "sg";
 
     @Override public TraceSegment read(JsonReader reader) throws IOException {
         TraceSegment traceSegment = new TraceSegment();
@@ -24,7 +24,7 @@ public class TraceSegmentJsonReader implements StreamJsonReader<TraceSegment> {
         reader.beginObject();
         while (reader.hasNext()) {
             switch (reader.nextName()) {
-                case GT:
+                case GLOBAL_TRACE_IDS:
                     reader.beginArray();
                     while (reader.hasNext()) {
                         traceSegment.addGlobalTraceId(uniqueIdJsonReader.read(reader));
@@ -39,7 +39,7 @@ public class TraceSegmentJsonReader implements StreamJsonReader<TraceSegment> {
                         });
                     }
                     break;
-                case SG:
+                case SEGMENT:
                     traceSegment.setTraceSegmentObject(segmentJsonReader.read(reader));
                     break;
                 default: