Apply p3c pmd plugin/rules and fix/ignore all violations of priority 1

.travis.yml

@@ -12,6 +12,10 @@ matrix:
   allow_failures:
   - env: BUILD_JDK=ORACLE_JDK_11
 
+# https://docs.travis-ci.com/user/languages/java/#maven-dependency-management
+install:
+  - mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V -DminimumPriority=1
+
 after_success:
   - bash <(curl -s https://codecov.io/bash)
 

pom.xml

@@ -186,6 +186,46 @@
 
     <build>
         <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-pmd-plugin</artifactId>
+                <version>3.8</version>
+                <configuration>
+                    <sourceEncoding>${project.build.sourceEncoding}</sourceEncoding>
+                    <targetJdk>1.8</targetJdk>
+                    <excludes>
+                        <exclude>**/*_jmhTest.java</exclude>
+                    </excludes>
+                    <printFailingErrors>true</printFailingErrors>
+                    <rulesets>
+                        <ruleset>rulesets/java/ali-comment.xml</ruleset>
+                        <ruleset>rulesets/java/ali-concurrent.xml</ruleset>
+                        <ruleset>rulesets/java/ali-constant.xml</ruleset>
+                        <ruleset>rulesets/java/ali-exception.xml</ruleset>
+                        <ruleset>rulesets/java/ali-flowcontrol.xml</ruleset>
+                        <ruleset>rulesets/java/ali-naming.xml</ruleset>
+                        <ruleset>rulesets/java/ali-oop.xml</ruleset>
+                        <ruleset>rulesets/java/ali-orm.xml</ruleset>
+                        <ruleset>rulesets/java/ali-other.xml</ruleset>
+                        <ruleset>rulesets/java/ali-set.xml</ruleset>
+                    </rulesets>
+                </configuration>
+                <executions>
+                    <execution>
+                        <phase>verify</phase>
+                        <goals>
+                            <goal>check</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <dependencies>
+                    <dependency>
+                        <groupId>com.alibaba.p3c</groupId>
+                        <artifactId>p3c-pmd</artifactId>
+                        <version>1.3.6</version>
+                    </dependency>
+                </dependencies>
+            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>

sentinel-cluster/sentinel-cluster-client-default/src/main/java/com/alibaba/csp/sentinel/cluster/client/NettyTransportClient.java

@@ -60,6 +60,7 @@
  */
 public class NettyTransportClient implements ClusterTransportClient {
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private static final ScheduledExecutorService SCHEDULER = Executors.newScheduledThreadPool(1,
         new NamedThreadFactory("sentinel-cluster-transport-client-scheduler"));
 

sentinel-cluster/sentinel-cluster-server-default/src/main/java/com/alibaba/csp/sentinel/cluster/server/connection/ConnectionPool.java

@@ -38,6 +38,7 @@
  */
 public class ConnectionPool {
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private static final ScheduledExecutorService TIMER = Executors.newScheduledThreadPool(2);
 
     /**

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/degrade/DegradeRule.java

@@ -57,6 +57,7 @@ public class DegradeRule extends AbstractRule {
 
     private static final int RT_MAX_EXCEED_N = 5;
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private static ScheduledExecutorService pool = Executors.newScheduledThreadPool(
         Runtime.getRuntime().availableProcessors(), new NamedThreadFactory("sentinel-degrade-reset-task", true));
 

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/block/flow/FlowRuleManager.java

@@ -51,6 +51,7 @@ public class FlowRuleManager {
     private static final FlowPropertyListener LISTENER = new FlowPropertyListener();
     private static SentinelProperty<List<FlowRule>> currentProperty = new DynamicSentinelProperty<List<FlowRule>>();
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private static final ScheduledExecutorService SCHEDULER = Executors.newScheduledThreadPool(1,
         new NamedThreadFactory("sentinel-metrics-record-task", true));
 

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/system/SystemRuleManager.java

@@ -88,6 +88,7 @@ public class SystemRuleManager {
     private final static SystemPropertyListener listener = new SystemPropertyListener();
     private static SentinelProperty<List<SystemRule>> currentProperty = new DynamicSentinelProperty<List<SystemRule>>();
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private final static ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1,
         new NamedThreadFactory("sentinel-system-status-record-task", true));
 

sentinel-dashboard/src/main/java/com/alibaba/csp/sentinel/dashboard/metric/MetricFetcher.java

@@ -84,6 +84,8 @@ public class MetricFetcher {
     private AppManagement appManagement;
 
     private CloseableHttpAsyncClient httpclient;
+
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private ScheduledExecutorService fetchScheduleService = Executors.newScheduledThreadPool(1,
         new NamedThreadFactory("sentinel-dashboard-metrics-fetch-task"));
     private ExecutorService fetchService;

sentinel-demo/sentinel-demo-dubbo/src/main/java/com/alibaba/csp/sentinel/demo/dubbo/demo2/FooConsumerBootstrap.java

@@ -48,6 +48,7 @@ public class FooConsumerBootstrap {
     private static final String RES_KEY = "com.alibaba.csp.sentinel.demo.dubbo.FooService:sayHello(java.lang.String)";
     private static final String INTERFACE_RES_KEY = "com.alibaba.csp.sentinel.demo.dubbo.FooService";
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private static final ExecutorService pool = Executors.newFixedThreadPool(10,
         new NamedThreadFactory("dubbo-consumer-pool"));
 

sentinel-demo/sentinel-demo-rocketmq/src/main/java/com/alibaba/csp/sentinel/demo/rocketmq/PullConsumerDemo.java

@@ -44,6 +44,7 @@ public class PullConsumerDemo {
 
     private static final Map<MessageQueue, Long> OFFSET_TABLE = new HashMap<MessageQueue, Long>();
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private static final ExecutorService pool = Executors.newFixedThreadPool(32);
 
     private static final AtomicLong SUCCESS_COUNT = new AtomicLong(0);

sentinel-demo/sentinel-demo-spring-webflux/src/main/java/com/alibaba/csp/sentinel/demo/spring/webflux/service/FooService.java

@@ -31,6 +31,7 @@
 @Service
 public class FooService {
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private final ExecutorService pool = Executors.newFixedThreadPool(8);
     private final Scheduler scheduler = Schedulers.fromExecutor(pool);
 

sentinel-extension/sentinel-datasource-extension/src/main/java/com/alibaba/csp/sentinel/datasource/AutoRefreshDataSource.java

@@ -48,6 +48,7 @@ public AutoRefreshDataSource(Converter<S, T> configParser, final long recommendR
         startTimerService();
     }
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private void startTimerService() {
         service = Executors.newScheduledThreadPool(1,
             new NamedThreadFactory("sentinel-datasource-auto-refresh-task", true));

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/transport/init/HeartbeatSenderInitFunc.java

@@ -35,6 +35,7 @@
  */
 public class HeartbeatSenderInitFunc implements InitFunc {
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private static ScheduledExecutorService pool = Executors.newScheduledThreadPool(2,
         new NamedThreadFactory("sentinel-heartbeat-send-task", true));
 

sentinel-transport/sentinel-transport-netty-http/src/main/java/com/alibaba/csp/sentinel/transport/command/NettyHttpCommandCenter.java

@@ -35,6 +35,7 @@ public class NettyHttpCommandCenter implements CommandCenter {
 
     private final HttpServer server = new HttpServer();
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private final ExecutorService pool = Executors.newSingleThreadExecutor(
         new NamedThreadFactory("sentinel-netty-command-center-executor"));
 

sentinel-transport/sentinel-transport-simple-http/src/main/java/com/alibaba/csp/sentinel/transport/command/SimpleHttpCommandCenter.java

@@ -55,6 +55,7 @@ public class SimpleHttpCommandCenter implements CommandCenter {
     @SuppressWarnings("rawtypes")
     private static final Map<String, CommandHandler> handlerMap = new ConcurrentHashMap<String, CommandHandler>();
 
+    @SuppressWarnings("PMD.ThreadPoolCreationRule")
     private ExecutorService executor = Executors.newSingleThreadExecutor(
         new NamedThreadFactory("sentinel-command-center-executor"));
     private ExecutorService bizExecutor;