fail build on warnings and fix existing issues (#157)

Author: meiliang86

build.gradle

@@ -57,7 +57,7 @@ compileJava {
     dependsOn 'googleJavaFormat'
     options.encoding = 'UTF-8'
     options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation" << "-XepExcludedPaths:" +
-            ".*/generated-sources/.*"
+            ".*/generated-sources/.*" << "-Werror"
 }
 
 license {
@@ -68,7 +68,7 @@ license {
 compileTestJava {
     options.encoding = 'UTF-8'
     options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation" << "-XepExcludedPaths:" +
-            ".*/generated-sources/.*"
+            ".*/generated-sources/.*" << "-Werror"
 }
 
 if (JavaVersion.current().isJava8Compatible()) {

src/main/java/com/uber/cadence/converter/JsonDataConverter.java

@@ -17,6 +17,7 @@
 
 package com.uber.cadence.converter;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonArray;
@@ -33,8 +34,6 @@
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.nio.charset.StandardCharsets;
-import java.util.HashSet;
-import java.util.Set;
 import java.util.function.Function;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -66,15 +65,10 @@ public final class JsonDataConverter implements DataConverter {
    * Stop emitting stack trace after this line. Makes serialized stack traces more readable and
    * compact as it omits most of framework level code.
    */
-  private static final Set<String> CUTOFF_METHOD_NAMES =
-      new HashSet<String>() {
-        {
-          add(
-              "com.uber.cadence.internal.worker.POJOActivityImplementationFactory$POJOActivityImplementation.execute");
-          add(
-              "com.uber.cadence.internal.sync.POJODecisionTaskHandler$POJOWorkflowImplementation.execute");
-        }
-      };
+  private static final ImmutableSet<String> CUTOFF_METHOD_NAMES =
+      ImmutableSet.of(
+          "com.uber.cadence.internal.worker.POJOActivityImplementationFactory$POJOActivityImplementation.execute",
+          "com.uber.cadence.internal.sync.POJODecisionTaskHandler$POJOWorkflowImplementation.execute");
 
   private static final DataConverter INSTANCE = new JsonDataConverter();
   private static final byte[] EMPTY_BLOB = new byte[0];

src/main/java/com/uber/cadence/internal/worker/ActivityWorker.java

@@ -148,7 +148,7 @@ public void resumePolling() {
     }
   }
 
-  private class MeasurableActivityTask {
+  private static class MeasurableActivityTask {
     PollForActivityTaskResponse task;
     Stopwatch sw;
 

src/main/java/com/uber/cadence/serviceclient/WorkflowServiceTChannel.java

@@ -322,7 +322,7 @@ public WorkflowServiceTChannel(String host, int port, ClientOptions options) {
       ArrayList<InetSocketAddress> peers = new ArrayList<>();
       peers.add(new InetSocketAddress(address, port));
       this.subChannel = tChannel.makeSubChannel(options.getServiceName()).setPeers(peers);
-      log.info("Initialized TChannel: " + this.subChannel.toString());
+      log.info("Initialized TChannel for service " + this.subChannel.getServiceName());
     } catch (UnknownHostException e) {
       tChannel.shutdown();
       throw new RuntimeException("Unable to get name of host " + host, e);

src/test/java/com/uber/cadence/internal/sync/Tracer.java

@@ -70,4 +70,9 @@ public void setExpected(String... expected) {
   public void assertExpected() {
     Assert.assertEquals(expected, trace);
   }
+
+  @Override
+  public String toString() {
+    return "expected " + String.join(",", expected) + " trace " + String.join(",", trace);
+  }
 }