Fixed some findbugs issues.

Author: millems

build-tools/src/main/resources/software/amazon/awssdk/spotbugs-suppressions.xml

@@ -167,6 +167,7 @@
             <Class name="software.amazon.awssdk.protocols.json.internal.dom.JsonDomParser"/>
             <Class name="software.amazon.awssdk.testutils.service.AwsIntegrationTestBase"/>
             <Class name="software.amazon.awssdk.protocol.asserts.marshalling.XmlAsserts" />
+            <Class name="software.amazon.awssdk.testutils.FileUtils"/>
         </Or>
         <Bug pattern="RCN_REDUNDANT_NULLCHECK_WOULD_HAVE_BEEN_A_NPE"/>
     </Match>
@@ -224,4 +225,9 @@
         <Method name="create"/>
         <Bug pattern="ISC_INSTANTIATE_STATIC_CLASS"/>
     </Match>
+
+    <!-- This is very buggy https://github.com/spotbugs/spotbugs/issues/1539 -->
+    <Match>
+        <Bug pattern="DMI_RANDOM_USED_ONLY_ONCE" />
+    </Match>
 </FindBugsFilter>

core/metrics-spi/src/main/java/software/amazon/awssdk/metrics/internal/DefaultMetricCollection.java

@@ -41,7 +41,7 @@ public DefaultMetricCollection(String name, Map<SdkMetric<?>,
         List<MetricRecord<?>>> metrics, List<MetricCollection> children) {
         this.name = name;
         this.metrics = new HashMap<>(metrics);
-        this.children = children != null ? Collections.unmodifiableList(new ArrayList<>(children)) : Collections.emptyList();
+        this.children = children != null ? new ArrayList<>(children) : Collections.emptyList();
         this.creationTime = Instant.now();
     }
 
@@ -65,7 +65,7 @@ public <T> List<T> metricValues(SdkMetric<T> metric) {
 
     @Override
     public List<MetricCollection> children() {
-        return children;
+        return Collections.unmodifiableList(children);
     }
 
     @Override

core/profiles/src/main/java/software/amazon/awssdk/profiles/Profile.java

@@ -108,7 +108,7 @@ private Boolean parseBooleanProperty(String propertyKey, String property) {
      * Retrieve an unmodifiable view of all of the properties currently in this profile.
      */
     public Map<String, String> properties() {
-        return properties;
+        return Collections.unmodifiableMap(properties);
     }
 
     @Override

core/profiles/src/main/java/software/amazon/awssdk/profiles/ProfileFile.java

@@ -59,7 +59,7 @@ public final class ProfileFile {
     private ProfileFile(Map<String, Map<String, String>> rawProfiles) {
         Validate.paramNotNull(rawProfiles, "rawProfiles");
 
-        this.profiles = Collections.unmodifiableMap(convertToProfilesMap(rawProfiles));
+        this.profiles = convertToProfilesMap(rawProfiles);
     }
 
     /**
@@ -107,7 +107,7 @@ public Optional<Profile> profile(String profileName) {
      * @return An unmodifiable collection of the profiles in this file, keyed by profile name.
      */
     public Map<String, Profile> profiles() {
-        return profiles;
+        return Collections.unmodifiableMap(profiles);
     }
 
     @Override

core/sdk-core/src/test/java/software/amazon/awssdk/core/http/InterruptFlagAlwaysClearsTest.java

@@ -62,7 +62,7 @@ public class InterruptFlagAlwaysClearsTest {
     @Mock
     private HttpResponseHandler<SdkResponse> responseHandler;
 
-    @Mock
+    @Mock(lenient = true)
     private HttpResponseHandler<SdkServiceException> errorResponseHandler;
 
     @BeforeClass

http-clients/netty-nio-client/src/test/java/software/amazon/awssdk/http/nio/netty/internal/FutureCancelHandlerTest.java

@@ -16,7 +16,7 @@
 package software.amazon.awssdk.http.nio.netty.internal;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.mockito.Matchers.any;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;

pom.xml

@@ -106,7 +106,7 @@
         <unitils.version>3.4.6</unitils.version>
         <xmlunit.version>1.3</xmlunit.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <spotbugs.version>4.5.3.0</spotbugs.version>
+        <spotbugs.version>4.2.3</spotbugs.version>
         <netty-reactive-streams-http.version>2.0.5</netty-reactive-streams-http.version>
         <javapoet.verion>1.13.0</javapoet.verion>
         <org.eclipse.jdt.version>3.10.0</org.eclipse.jdt.version>
@@ -228,8 +228,7 @@
                     <artifactId>maven-surefire-plugin</artifactId>
                     <version>${maven.surefire.version}</version>
                     <configuration>
-                        <!-- Blockhound doesn't support Java 13+ without flags: https://github.com/reactor/BlockHound/issues/33 -->
-                        <argLine>${argLine} -XX:+AllowRedefinitionToAddDeleteMethods</argLine>
+                        <argLine>${argLine}</argLine>
                         <excludes>
                             <exclude>**/*StabilityTest.java</exclude>
                             <exclude>**/*StabilityTests.java</exclude>
@@ -657,6 +656,17 @@
             </properties>
         </profile>
 
+        <profile>
+            <id>jdk-13-plus</id>
+            <activation>
+                <jdk>[13,)</jdk>
+            </activation>
+            <properties>
+                <!-- Blockhound doesn't support Java 13+ without flags: https://github.com/reactor/BlockHound/issues/33 -->
+                <argLine>-XX:+AllowRedefinitionToAddDeleteMethods</argLine>
+            </properties>
+        </profile>
+
         <profile>
             <id>quick</id>
             <properties>

test/test-utils/pom.xml

@@ -112,4 +112,16 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>com.github.spotbugs</groupId>
+                <artifactId>spotbugs-maven-plugin</artifactId>
+                <configuration>
+                    <skip>true</skip>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 </project>

utils/src/main/java/software/amazon/awssdk/utils/ReflectionMethodInvoker.java

@@ -117,7 +117,7 @@ private Method getTargetMethod() throws NoSuchMethodException {
         try {
             targetMethod = clazz.getMethod(methodName, parameterTypes);
             return targetMethod;
-        } catch (NullPointerException e) {
+        } catch (RuntimeException e) {
             throw new RuntimeException(createInvocationErrorMessage(), e);
         }
     }

utils/src/main/java/software/amazon/awssdk/utils/async/FlatteningSubscriber.java

@@ -107,7 +107,7 @@ public void onNext(Iterable<U> nextItems) {
                 Validate.notNull(nextItems, "Collections flattened by the flattening subscriber must not contain null.");
                 allItems.add(item);
             });
-        } catch (NullPointerException e) {
+        } catch (RuntimeException e) {
             upstreamSubscription.cancel();
             onError(e);
             throw e;