Some code style and refactor (#4355)

* extract duplicated method

* change while loop to if since once rs.next() return false, it will never return true for the following calls

* simplify if() return true; return false pattern

* fix compilation
Signed-off-by: Nliqiang.clq <liqiang.clq@alibaba-inc.com>

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/match/ClassAnnotationMatch.java

@@ -65,10 +65,7 @@ public class ClassAnnotationMatch implements IndirectMatch {
         for (AnnotationDescription annotation : declaredAnnotations) {
             annotationList.remove(annotation.getAnnotationType().getActualName());
         }
-        if (annotationList.isEmpty()) {
-            return true;
-        }
-        return false;
+        return annotationList.isEmpty();
     }
 
     private ElementMatcher.Junction buildEachAnnotation(String annotationName) {

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/match/HierarchyMatch.java

@@ -75,11 +75,8 @@ public class HierarchyMatch implements IndirectMatch {
             matchHierarchyClass(typeDescription.getSuperClass(), parentTypes);
         }
 
-        if (parentTypes.size() == 0) {
-            return true;
-        }
+        return parentTypes.size() == 0;
 
-        return false;
     }
 
     private void matchHierarchyClass(TypeDescription.Generic clazz, List<String> parentTypes) {

apm-sniffer/apm-sdk-plugin/servicecomb-plugin/servicecomb-java-chassis-0.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/servicecomb/TransportClientHandlerInterceptor.java

@@ -91,10 +91,7 @@ public class TransportClientHandlerInterceptor implements InstanceMethodsAroundI
      * registered then return false.
      */
     private Boolean checkRegisterStatus(Invocation invocation) {
-        if (null == invocation.getOperationMeta() || null == invocation.getEndpoint()) {
-            return false;
-        }
-        return true;
+        return null != invocation.getOperationMeta() && null != invocation.getEndpoint();
     }
 
 }

apm-sniffer/apm-sdk-plugin/servicecomb-plugin/servicecomb-java-chassis-1.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/servicecomb/v1/TransportClientHandlerInterceptor.java

@@ -91,10 +91,7 @@ public class TransportClientHandlerInterceptor implements InstanceMethodsAroundI
      * registered then return false.
      */
     private Boolean checkRegisterStatus(Invocation invocation) {
-        if (null == invocation.getOperationMeta() || null == invocation.getEndpoint()) {
-            return false;
-        }
-        return true;
+        return null != invocation.getOperationMeta() && null != invocation.getEndpoint();
     }
 
 }

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/manual/endpointrelation/EndpointRelationServerSideMetrics.java

@@ -182,10 +182,7 @@ public class EndpointRelationServerSideMetrics extends Metrics {
         if (componentId != metrics.componentId)
             return false;
 
-        if (getTimeBucket() != metrics.getTimeBucket())
-            return false;
-
-        return true;
+        return getTimeBucket() == metrics.getTimeBucket();
     }
 
     public static class Builder implements StorageBuilder<EndpointRelationServerSideMetrics> {

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/manual/relation/service/ServiceRelationClientSideMetrics.java

@@ -181,10 +181,7 @@ public class ServiceRelationClientSideMetrics extends Metrics {
         if (componentId != metrics.componentId)
             return false;
 
-        if (getTimeBucket() != metrics.getTimeBucket())
-            return false;
-
-        return true;
+        return getTimeBucket() == metrics.getTimeBucket();
     }
 
     public static class Builder implements StorageBuilder<ServiceRelationClientSideMetrics> {

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/manual/relation/service/ServiceRelationServerSideMetrics.java

@@ -181,10 +181,7 @@ public class ServiceRelationServerSideMetrics extends Metrics {
         if (componentId != metrics.componentId)
             return false;
 
-        if (getTimeBucket() != metrics.getTimeBucket())
-            return false;
-
-        return true;
+        return getTimeBucket() == metrics.getTimeBucket();
     }
 
     public static class Builder implements StorageBuilder<ServiceRelationServerSideMetrics> {

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/register/EndpointInventory.java

@@ -89,10 +89,7 @@ public class EndpointInventory extends RegisterSource {
             return false;
         if (!name.equals(source.getName()))
             return false;
-        if (detectPoint != source.getDetectPoint())
-            return false;
-
-        return true;
+        return detectPoint == source.getDetectPoint();
     }
 
     @Override

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/register/NetworkAddressInventory.java

@@ -87,10 +87,7 @@ public class NetworkAddressInventory extends RegisterSource {
             return false;
 
         NetworkAddressInventory source = (NetworkAddressInventory) obj;
-        if (!name.equals(source.getName()))
-            return false;
-
-        return true;
+        return name.equals(source.getName());
     }
 
     public NetworkAddressInventory getClone() {

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/register/ServiceInstanceInventory.java

@@ -163,10 +163,7 @@ public class ServiceInstanceInventory extends RegisterSource {
             return false;
         if (isAddress != source.getIsAddress())
             return false;
-        if (addressId != source.getAddressId())
-            return false;
-
-        return true;
+        return addressId == source.getAddressId();
     }
 
     public ServiceInstanceInventory getClone() {

oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/register/ServiceInventory.java

@@ -168,10 +168,7 @@ public class ServiceInventory extends RegisterSource {
             return false;
         if (isAddress != source.getIsAddress())
             return false;
-        if (addressId != source.getAddressId())
-            return false;
-
-        return true;
+        return addressId == source.getAddressId();
     }
 
     @Override

oap-server/server-receiver-plugin/skywalking-trace-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/trace/provider/parser/listener/segment/TraceSegmentSampler.java

@@ -46,9 +46,7 @@ public class TraceSegmentSampler {
         if (idPartsList.size() == 3) {
             Long lastLong = idPartsList.get(2);
             long sampleValue = lastLong % 10000;
-            if (sampleValue < sampleRate) {
-                return true;
-            }
+            return sampleValue < sampleRate;
         }
         return false;
     }

oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/h2/dao/H2MetadataQueryDAO.java

@@ -71,9 +71,13 @@ public class H2MetadataQueryDAO implements IMetadataQueryDAO {
         sql.append(" and ").append(ServiceInventory.IS_ADDRESS).append("=" + BooleanUtils.FALSE);
         sql.append(" and ").append(ServiceInventory.NODE_TYPE).append("=" + NodeType.Normal.value());
 
+        return getNum(sql, condition);
+    }
+
+    private Integer getNum(StringBuilder sql, List<Object> condition) throws IOException {
         try (Connection connection = h2Client.getConnection()) {
             try (ResultSet resultSet = h2Client.executeQuery(connection, sql.toString(), condition.toArray(new Object[0]))) {
-                while (resultSet.next()) {
+                if (resultSet.next()) {
                     return resultSet.getInt("num");
                 }
             }
@@ -90,17 +94,7 @@ public class H2MetadataQueryDAO implements IMetadataQueryDAO {
         sql.append("select count(*) num from ").append(EndpointInventory.INDEX_NAME).append(" where ");
         sql.append(EndpointInventory.DETECT_POINT).append("=").append(DetectPoint.SERVER.ordinal());
 
-        try (Connection connection = h2Client.getConnection()) {
-            try (ResultSet resultSet = h2Client.executeQuery(connection, sql.toString(), condition.toArray(new Object[0]))) {
-
-                while (resultSet.next()) {
-                    return resultSet.getInt("num");
-                }
-            }
-        } catch (SQLException e) {
-            throw new IOException(e);
-        }
-        return 0;
+        return getNum(sql, condition);
     }
 
     @Override
@@ -111,16 +105,7 @@ public class H2MetadataQueryDAO implements IMetadataQueryDAO {
         sql.append(ServiceInventory.NODE_TYPE).append("=?");
         condition.add(nodeTypeValue);
 
-        try (Connection connection = h2Client.getConnection()) {
-            try (ResultSet resultSet = h2Client.executeQuery(connection, sql.toString(), condition.toArray(new Object[0]))) {
-                while (resultSet.next()) {
-                    return resultSet.getInt("num");
-                }
-            }
-        } catch (SQLException e) {
-            throw new IOException(e);
-        }
-        return 0;
+        return getNum(sql, condition);
     }
 
     @Override