diff --git a/.travis.yml b/.travis.yml
index 031635c67..8bffa1ac8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,5 +9,5 @@ before_install:
 
 install:
   - jdk_switcher use oraclejdk8
-  - mvn clean install --quiet jacoco:report coveralls:report
+  - mvn clean install -Papache-release --quiet jacoco:report coveralls:report
 
diff --git a/apm-commons/apm-datacarrier/src/main/java/org/apache/skywalking/apm/commons/datacarrier/DataCarrier.java b/apm-commons/apm-datacarrier/src/main/java/org/apache/skywalking/apm/commons/datacarrier/DataCarrier.java
index 081b25a6f..d53fda539 100644
--- a/apm-commons/apm-datacarrier/src/main/java/org/apache/skywalking/apm/commons/datacarrier/DataCarrier.java
+++ b/apm-commons/apm-datacarrier/src/main/java/org/apache/skywalking/apm/commons/datacarrier/DataCarrier.java
@@ -41,11 +41,10 @@ public class DataCarrier<T> {
     }
 
     /**
-     * set a new IDataPartitioner. It will cover the current one or default one.(Default is {@link
-     * SimpleRollingPartitioner)}
+     * set a new IDataPartitioner. It will cover the current one or default one.(Default is {@link SimpleRollingPartitioner}
      *
-     * @param dataPartitioner
-     * @return
+     * @param dataPartitioner to partition data into different channel by some rules.
+     * @return DataCarrier instance for chain
      */
     public DataCarrier setPartitioner(IDataPartitioner<T> dataPartitioner) {
         this.channels.setPartitioner(dataPartitioner);
@@ -53,7 +52,7 @@ public class DataCarrier<T> {
     }
 
     /**
-     * override the strategy at runtime. Notice, {@link Channels<T>} will override several channels one by one.
+     * override the strategy at runtime. Notice, {@link Channels} will override several channels one by one.
      *
      * @param strategy
      */
@@ -84,7 +83,7 @@ public class DataCarrier<T> {
     }
 
     /**
-     * set consumers to this Carrier. consumer begin to run when {@link DataCarrier<T>#produce(T)} begin to work.
+     * set consumers to this Carrier. consumer begin to run when {@link DataCarrier#produce} begin to work.
      *
      * @param consumerClass class of consumer
      * @param num number of consumer threads
@@ -99,7 +98,7 @@ public class DataCarrier<T> {
     }
 
     /**
-     * set consumers to this Carrier. consumer begin to run when {@link DataCarrier<T>#produce(T)} begin to work with 20
+     * set consumers to this Carrier. consumer begin to run when {@link DataCarrier#produce} begin to work with 20
      * millis consume cycle.
      *
      * @param consumerClass class of consumer
@@ -110,7 +109,7 @@ public class DataCarrier<T> {
     }
 
     /**
-     * set consumers to this Carrier. consumer begin to run when {@link DataCarrier<T>#produce(T)} begin to work.
+     * set consumers to this Carrier. consumer begin to run when {@link DataCarrier#produce} begin to work.
      *
      * @param consumer single instance of consumer, all consumer threads will all use this instance.
      * @param num number of consumer threads
@@ -126,7 +125,7 @@ public class DataCarrier<T> {
     }
 
     /**
-     * set consumers to this Carrier. consumer begin to run when {@link DataCarrier<T>#produce(T)} begin to work with 20
+     * set consumers to this Carrier. consumer begin to run when {@link DataCarrier#produce} begin to work with 20
      * millis consume cycle.
      *
      * @param consumer single instance of consumer, all consumer threads will all use this instance.
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java
index abfbf348e..86fbebb49 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/Config.java
@@ -117,7 +117,7 @@ public class Config {
         /**
          * Log files directory. Default is blank string, means, use "system.out" to output logs.
          *
-         * @see {@link WriterFactory#getLogWriter()}
+         * Ref to {@link WriterFactory#getLogWriter()}
          */
         public static String DIR = "";
 
@@ -129,8 +129,6 @@ public class Config {
 
         /**
          * The log level. Default is debug.
-         *
-         * @see {@link LogLevel}
          */
         public static LogLevel LEVEL = LogLevel.DEBUG;
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
index 2e674177f..f96f84cbd 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
@@ -16,7 +16,6 @@
  *
  */
 
-
 package org.apache.skywalking.apm.agent.core.conf;
 
 import java.io.File;
@@ -37,7 +36,6 @@ import org.apache.skywalking.apm.util.StringUtil;
  * The <code>SnifferConfigInitializer</code> initializes all configs in several way.
  *
  * @author wusheng
- * @see {@link #initialize()}, to learn more about how to initialzie.
  */
 public class SnifferConfigInitializer {
     private static final ILog logger = LogManager.getLogger(SnifferConfigInitializer.class);
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/AbstractTracerContext.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/AbstractTracerContext.java
index df1278512..e3ffdace7 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/AbstractTracerContext.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/AbstractTracerContext.java
@@ -20,9 +20,6 @@
 package org.apache.skywalking.apm.agent.core.context;
 
 import org.apache.skywalking.apm.agent.core.context.trace.AbstractSpan;
-import org.apache.skywalking.apm.agent.core.context.trace.EntrySpan;
-import org.apache.skywalking.apm.agent.core.context.trace.ExitSpan;
-import org.apache.skywalking.apm.agent.core.context.trace.LocalSpan;
 
 /**
  * The <code>AbstractTracerContext</code> represents the tracer context manager.
@@ -35,7 +32,6 @@ public interface AbstractTracerContext {
      * How to initialize the carrier, depends on the implementation.
      *
      * @param carrier to carry the context for crossing process.
-     * @see {@link TracingContext} and {@link IgnoredTracerContext}
      */
     void inject(ContextCarrier carrier);
 
@@ -44,7 +40,6 @@ public interface AbstractTracerContext {
      * How to build, depends on the implementation.
      *
      * @param carrier carried the context from a cross-process segment.
-     * @see {@link TracingContext} and {@link IgnoredTracerContext}
      */
     void extract(ContextCarrier carrier);
 
@@ -54,7 +49,6 @@ public interface AbstractTracerContext {
      * How to build, depends on the implementation.
      *
      * @return the {@link ContextSnapshot} , which includes the reference context.
-     * @see {@link TracingContext} and {@link IgnoredTracerContext}
      */
     ContextSnapshot capture();
 
@@ -63,7 +57,6 @@ public interface AbstractTracerContext {
      * How to build, depends on the implementation.
      *
      * @param snapshot from {@link #capture()} in the parent thread.
-     * @see {@link TracingContext} and {@link IgnoredTracerContext}
      */
     void continued(ContextSnapshot snapshot);
 
@@ -72,7 +65,6 @@ public interface AbstractTracerContext {
      * How to build, depends on the implementation.
      *
      * @return the string represents the id.
-     * @see {@link TracingContext} and {@link IgnoredTracerContext}
      */
     String getReadableGlobalTraceId();
 
@@ -81,7 +73,6 @@ public interface AbstractTracerContext {
      *
      * @param operationName most likely a service name
      * @return the span represents an entry point of this segment.
-     * @see {@link EntrySpan} if the implementation is {@link TracingContext}
      */
     AbstractSpan createEntrySpan(String operationName);
 
@@ -90,7 +81,6 @@ public interface AbstractTracerContext {
      *
      * @param operationName most likely a local method signature, or business name.
      * @return the span represents a local logic block.
-     * @see {@link LocalSpan} if the implementation is {@link TracingContext}
      */
     AbstractSpan createLocalSpan(String operationName);
 
@@ -100,7 +90,6 @@ public interface AbstractTracerContext {
      * @param operationName most likely a service name of remote
      * @param remotePeer the network id(ip:port, hostname:port or ip1:port1,ip2,port, etc.)
      * @return the span represent an exit point of this segment.
-     * @see {@link ExitSpan} if the implementation is {@link TracingContext}
      */
     AbstractSpan createExitSpan(String operationName, String remotePeer);
 
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ContextManager.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ContextManager.java
index 3ead3c3c8..16b6a1dd2 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ContextManager.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ContextManager.java
@@ -16,7 +16,6 @@
  *
  */
 
-
 package org.apache.skywalking.apm.agent.core.context;
 
 import org.apache.skywalking.apm.agent.core.boot.BootService;
@@ -34,8 +33,8 @@ import org.apache.skywalking.apm.util.StringUtil;
 /**
  * {@link ContextManager} controls the whole context of {@link TraceSegment}. Any {@link TraceSegment} relates to
  * single-thread, so this context use {@link ThreadLocal} to maintain the context, and make sure, since a {@link
- * TraceSegment} starts, all ChildOf spans are in the same context. <p> What is 'ChildOf'? {@see
- * https://github.com/opentracing/specification/blob/master/specification.md#references-between-spans}
+ * TraceSegment} starts, all ChildOf spans are in the same context. <p> What is 'ChildOf'?
+ * https://github.com/opentracing/specification/blob/master/specification.md#references-between-spans
  *
  * <p> Also, {@link ContextManager} delegates to all {@link AbstractTracerContext}'s major methods.
  *
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
index f848502b7..16c9b3218 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
@@ -94,8 +94,8 @@ public class TracingContext implements AbstractTracerContext {
      * Inject the context into the given carrier, only when the active span is an exit one.
      *
      * @param carrier to carry the context for crossing process.
-     * @throws IllegalStateException, if the active span isn't an exit one.
-     * @see {@link AbstractTracerContext#inject(ContextCarrier)}
+     * @throws IllegalStateException  if the active span isn't an exit one.
+     * Ref to {@link AbstractTracerContext#inject(ContextCarrier)}
      */
     @Override
     public void inject(ContextCarrier carrier) {
@@ -155,7 +155,7 @@ public class TracingContext implements AbstractTracerContext {
      * Extract the carrier to build the reference for the pre segment.
      *
      * @param carrier carried the context from a cross-process segment.
-     * @see {@link AbstractTracerContext#extract(ContextCarrier)}
+     * Ref to {@link AbstractTracerContext#extract(ContextCarrier)}
      */
     @Override
     public void extract(ContextCarrier carrier) {
@@ -172,7 +172,7 @@ public class TracingContext implements AbstractTracerContext {
      * Capture the snapshot of current context.
      *
      * @return the snapshot of context for cross-thread propagation
-     * @see {@link AbstractTracerContext#capture()}
+     * Ref to {@link AbstractTracerContext#capture()}
      */
     @Override
     public ContextSnapshot capture() {
@@ -214,7 +214,7 @@ public class TracingContext implements AbstractTracerContext {
      * Continue the context from the given snapshot of parent thread.
      *
      * @param snapshot from {@link #capture()} in the parent thread.
-     * @see {@link AbstractTracerContext#continued(ContextSnapshot)}
+     * Ref to {@link AbstractTracerContext#continued(ContextSnapshot)}
      */
     @Override
     public void continued(ContextSnapshot snapshot) {
@@ -237,7 +237,7 @@ public class TracingContext implements AbstractTracerContext {
      *
      * @param operationName most likely a service name
      * @return span instance.
-     * @see {@link EntrySpan}
+     * Ref to {@link EntrySpan}
      */
     @Override
     public AbstractSpan createEntrySpan(final String operationName) {
@@ -285,7 +285,7 @@ public class TracingContext implements AbstractTracerContext {
      *
      * @param operationName most likely a local method signature, or business name.
      * @return the span represents a local logic block.
-     * @see {@link LocalSpan}
+     * Ref to {@link LocalSpan}
      */
     @Override
     public AbstractSpan createLocalSpan(final String operationName) {
@@ -318,7 +318,7 @@ public class TracingContext implements AbstractTracerContext {
      * @param operationName most likely a service name of remote
      * @param remotePeer the network id(ip:port, hostname:port or ip1:port1,ip2,port, etc.)
      * @return the span represent an exit point of this segment.
-     * @see {@link ExitSpan}
+     * @see  ExitSpan
      */
     @Override
     public AbstractSpan createExitSpan(final String operationName, final String remotePeer) {
@@ -443,7 +443,7 @@ public class TracingContext implements AbstractTracerContext {
 
     /**
      * The <code>ListenerManager</code> represents an event notify for every registered listener, which are notified
-     * when the <cdoe>TracingContext</cdoe> finished, and {@link #segment} is ready for further process.
+     * when the <code>TracingContext</code> finished, and {@link #segment} is ready for further process.
      */
     public static class ListenerManager {
         private static List<TracingContextListener> LISTENERS = new LinkedList<TracingContextListener>();
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ids/GlobalIdGenerator.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ids/GlobalIdGenerator.java
index e5188dfb8..b6060f785 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ids/GlobalIdGenerator.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ids/GlobalIdGenerator.java
@@ -16,7 +16,6 @@
  *
  */
 
-
 package org.apache.skywalking.apm.agent.core.context.ids;
 
 import java.util.Random;
@@ -42,8 +41,8 @@ public final class GlobalIdGenerator {
      *
      * The second one represents thread id. (most likely just an integer value, would be helpful in protobuf)
      *
-     * The third one also has two parts,<br/>
-     * 1) a timestamp, measured in milliseconds<br/>
+     * The third one also has two parts,
+     * 1) a timestamp, measured in milliseconds
      * 2) a seq, in current thread, between 0(included) and 9999(included)
      *
      * Notice, a long costs 8 bytes, three longs cost 24 bytes. And at the same time, a char costs 2 bytes. So
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java
index 2028215ae..4b80e0d30 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java
@@ -59,7 +59,7 @@ public abstract class AbstractTracingSpan implements AbstractSpan {
     protected String componentName;
 
     /**
-     * Log is a concept from OpenTracing spec. <p> {@see https://github.com/opentracing/specification/blob/master/specification.md#log-structured-data}
+     * Log is a concept from OpenTracing spec. https://github.com/opentracing/specification/blob/master/specification.md#log-structured-data
      */
     protected List<LogDataEntity> logs;
 
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/EntrySpan.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/EntrySpan.java
index b8b3b00fc..a96308747 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/EntrySpan.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/EntrySpan.java
@@ -29,7 +29,7 @@ import org.apache.skywalking.apm.network.trace.component.Component;
  *
  * But with the last <code>EntrySpan</code>'s tags and logs, which have more details about a service provider.
  *
- * Such as: Tomcat Embed -> Dubbox The <code>EntrySpan</code> represents the Dubbox span.
+ * Such as: Tomcat Embed - Dubbox The <code>EntrySpan</code> represents the Dubbox span.
  *
  * @author wusheng
  */
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/ExitSpan.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/ExitSpan.java
index 4280bad23..2a2776d01 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/ExitSpan.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/ExitSpan.java
@@ -31,7 +31,7 @@ import org.apache.skywalking.apm.network.trace.component.Component;
  *
  * The <code>ExitSpan</code> only presents the first one.
  *
- * Such as: Dubbox -> Apache Httpcomponent -> ....(Remote)
+ * Such as: Dubbox - Apache Httpcomponent - ...(Remote)
  * The <code>ExitSpan</code> represents the Dubbox span, and ignore the httpcomponent span's info.
  *
  * @author wusheng
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/TraceSegment.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/TraceSegment.java
index bf33b6829..d60728e7e 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/TraceSegment.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/TraceSegment.java
@@ -22,16 +22,16 @@ package org.apache.skywalking.apm.agent.core.context.trace;
 import java.util.LinkedList;
 import java.util.List;
 import org.apache.skywalking.apm.agent.core.conf.RemoteDownstreamConfig;
-import org.apache.skywalking.apm.agent.core.context.ids.DistributedTraceIds;
-import org.apache.skywalking.apm.agent.core.context.ids.ID;
 import org.apache.skywalking.apm.agent.core.context.ids.DistributedTraceId;
+import org.apache.skywalking.apm.agent.core.context.ids.DistributedTraceIds;
 import org.apache.skywalking.apm.agent.core.context.ids.GlobalIdGenerator;
+import org.apache.skywalking.apm.agent.core.context.ids.ID;
 import org.apache.skywalking.apm.agent.core.context.ids.NewDistributedTraceId;
 import org.apache.skywalking.apm.network.proto.TraceSegmentObject;
 import org.apache.skywalking.apm.network.proto.UpstreamSegment;
 
 /**
- * {@link TraceSegment} is a segment or fragment of the distributed trace. {@see https://github.com/opentracing/specification/blob/master/specification.md#the-opentracing-data-model}
+ * {@link TraceSegment} is a segment or fragment of the distributed trace. See https://github.com/opentracing/specification/blob/master/specification.md#the-opentracing-data-model
  * A {@link TraceSegment} means the segment, which exists in current {@link Thread}. And the distributed trace is formed
  * by multi {@link TraceSegment}s, because the distributed trace crosses multi-processes, multi-threads. <p>
  *
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java
index abad6f141..ed975e500 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java
@@ -42,7 +42,7 @@ public abstract class AbstractClassEnhancePluginDefine {
      * @param builder byte-buddy's builder to manipulate target class's bytecode.
      * @param classLoader load the given transformClass
      * @return the new builder, or <code>null</code> if not be enhanced.
-     * @throws PluginException, when set builder failure.
+     * @throws PluginException when set builder failure.
      */
     public DynamicType.Builder<?> define(String transformClassName,
         DynamicType.Builder<?> builder, ClassLoader classLoader, EnhanceContext context) throws PluginException {
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bytebuddy/ArgumentTypeNameMatch.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bytebuddy/ArgumentTypeNameMatch.java
index 367468a96..de73e6b5a 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bytebuddy/ArgumentTypeNameMatch.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bytebuddy/ArgumentTypeNameMatch.java
@@ -71,7 +71,7 @@ public class ArgumentTypeNameMatch implements ElementMatcher<MethodDescription>
 
     /**
      * The static method to create {@link ArgumentTypeNameMatch}
-     * This is a delegate method to follow byte-buddy {@link ElementMatcher<MethodDescription>}'s code style.
+     * This is a delegate method to follow byte-buddy {@link ElementMatcher}'s code style.
      *
      * @param index the index of arguments list.
      * @param argumentTypeName target argument type
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassInstanceMethodsEnhancePluginDefine.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassInstanceMethodsEnhancePluginDefine.java
index fa979894f..3837a9c03 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassInstanceMethodsEnhancePluginDefine.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassInstanceMethodsEnhancePluginDefine.java
@@ -24,7 +24,7 @@ import org.apache.skywalking.apm.agent.core.plugin.interceptor.StaticMethodsInte
 /**
  * Plugins, which only need enhance class static methods. Actually, inherit from {@link
  * ClassInstanceMethodsEnhancePluginDefine} has no differences with inherit from {@link ClassEnhancePluginDefine}. Just
- * override {@link ClassEnhancePluginDefine#getStaticMethodsInterceptPoints}, and return {@link null}, which means
+ * override {@link ClassEnhancePluginDefine#getStaticMethodsInterceptPoints}, and return NULL, which means
  * nothing to enhance.
  *
  * @author wusheng
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassStaticMethodsEnhancePluginDefine.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassStaticMethodsEnhancePluginDefine.java
index 987fd8512..abc69dcad 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassStaticMethodsEnhancePluginDefine.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassStaticMethodsEnhancePluginDefine.java
@@ -26,7 +26,7 @@ import org.apache.skywalking.apm.agent.core.plugin.interceptor.ConstructorInterc
  * Plugins, which only need enhance class static methods. Actually, inherit from {@link
  * ClassStaticMethodsEnhancePluginDefine} has no differences with inherit from {@link ClassEnhancePluginDefine}. Just
  * override {@link ClassEnhancePluginDefine#getConstructorsInterceptPoints} and {@link
- * ClassEnhancePluginDefine#getInstanceMethodsInterceptPoints}, and return {@link null}, which means nothing to
+ * ClassEnhancePluginDefine#getInstanceMethodsInterceptPoints}, and return NULL, which means nothing to
  * enhance.
  *
  * @author wusheng
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstanceMethodsAroundInterceptor.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstanceMethodsAroundInterceptor.java
index 1d67e78b4..4d7fa5d33 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstanceMethodsAroundInterceptor.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstanceMethodsAroundInterceptor.java
@@ -31,7 +31,6 @@ public interface InstanceMethodsAroundInterceptor {
     /**
      * called before target method invocation.
      *
-     * @param method
      * @param result change this result, if you want to truncate the method.
      * @throws Throwable
      */
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/MethodInterceptResult.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/MethodInterceptResult.java
index 052ac8675..925e2a332 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/MethodInterceptResult.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/MethodInterceptResult.java
@@ -16,13 +16,14 @@
  *
  */
 
-
 package org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance;
 
+import java.lang.reflect.Method;
+
 /**
- * This is a method return value manipulator. When a interceptor's method, such as {@link
- * InstanceMethodsAroundInterceptor#beforeMethod(org.apache.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext,
- * InstanceMethodInvokeContext, MethodInterceptResult)}, has this as a method argument, the interceptor can manipulate
+ * This is a method return value manipulator. When a interceptor's method, such as
+ * {@link InstanceMethodsAroundInterceptor#beforeMethod(EnhancedInstance, Method, Object[], Class[], MethodInterceptResult)} (org.apache.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext,
+ * has this as a method argument, the interceptor can manipulate
  * the method's return value. <p> The new value set to this object, by {@link MethodInterceptResult#defineReturnValue(Object)},
  * will override the origin return value.
  *
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/sampling/SamplingService.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/sampling/SamplingService.java
index c902e90fd..666a00409 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/sampling/SamplingService.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/sampling/SamplingService.java
@@ -37,7 +37,7 @@ import org.apache.skywalking.apm.util.RunnableWithExceptionProtection;
  * have been traced, but, considering CPU cost of serialization/deserialization, and network bandwidth, the agent do NOT
  * send all of them to collector, if SAMPLING is on.
  * <p>
- * By default, SAMPLING is on, and {@see {@link Config.Agent#SAMPLE_N_PER_3_SECS }}
+ * By default, SAMPLING is on, and  {@link Config.Agent#SAMPLE_N_PER_3_SECS }
  *
  * @author wusheng
  */
diff --git a/pom.xml b/pom.xml
index 83985a493..7911cfcf7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -25,6 +25,12 @@
     <artifactId>apm</artifactId>
     <version>5.0.0-alpha</version>
 
+    <parent>
+        <groupId>org.apache</groupId>
+        <artifactId>apache</artifactId>
+        <version>19</version>
+    </parent>
+
     <developers>
         <developer>
             <name>Wu Sheng</name>