Merge PR #400: [WIP] Update micrometer-meter-provider module to follow style guide

Author: trask

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/MicrometerMeter.java

@@ -5,6 +5,8 @@
 
 package io.opentelemetry.contrib.metrics.micrometer;
 
+import static java.util.Objects.requireNonNull;
+
 import io.opentelemetry.api.metrics.DoubleGaugeBuilder;
 import io.opentelemetry.api.metrics.DoubleHistogramBuilder;
 import io.opentelemetry.api.metrics.LongCounterBuilder;
@@ -15,7 +17,6 @@
 import io.opentelemetry.contrib.metrics.micrometer.internal.instruments.MicrometerLongCounter;
 import io.opentelemetry.contrib.metrics.micrometer.internal.instruments.MicrometerLongUpDownCounter;
 import io.opentelemetry.contrib.metrics.micrometer.internal.state.MeterSharedState;
-import java.util.Objects;
 
 final class MicrometerMeter implements Meter {
   final MeterSharedState meterSharedState;
@@ -26,25 +27,25 @@ final class MicrometerMeter implements Meter {
 
   @Override
   public LongCounterBuilder counterBuilder(String name) {
-    Objects.requireNonNull(name, "name");
+    requireNonNull(name, "name");
     return MicrometerLongCounter.builder(meterSharedState, name);
   }
 
   @Override
   public LongUpDownCounterBuilder upDownCounterBuilder(String name) {
-    Objects.requireNonNull(name, "name");
+    requireNonNull(name, "name");
     return MicrometerLongUpDownCounter.builder(meterSharedState, name);
   }
 
   @Override
   public DoubleHistogramBuilder histogramBuilder(String name) {
-    Objects.requireNonNull(name, "name");
+    requireNonNull(name, "name");
     return MicrometerDoubleHistogram.builder(meterSharedState, name);
   }
 
   @Override
   public DoubleGaugeBuilder gaugeBuilder(String name) {
-    Objects.requireNonNull(name, "name");
+    requireNonNull(name, "name");
     return MicrometerDoubleGauge.builder(meterSharedState, name);
   }
 }

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/MicrometerMeterProvider.java

@@ -5,12 +5,13 @@
 
 package io.opentelemetry.contrib.metrics.micrometer;
 
+import static java.util.Objects.requireNonNull;
+
 import io.micrometer.core.instrument.MeterRegistry;
 import io.opentelemetry.api.metrics.MeterBuilder;
 import io.opentelemetry.api.metrics.MeterProvider;
 import io.opentelemetry.contrib.metrics.micrometer.internal.MemoizingSupplier;
 import io.opentelemetry.contrib.metrics.micrometer.internal.state.MeterProviderSharedState;
-import java.util.Objects;
 import java.util.function.Supplier;
 
 /**
@@ -44,13 +45,13 @@ public void close() {
   /** {@inheritDoc} */
   @Override
   public MeterBuilder meterBuilder(String instrumentationScopeName) {
-    Objects.requireNonNull(instrumentationScopeName, "instrumentationScopeName");
+    requireNonNull(instrumentationScopeName, "instrumentationScopeName");
     return new MicrometerMeterBuilder(meterProviderSharedState, instrumentationScopeName);
   }
 
   /** Returns a new builder instance for this provider with the specified {@link MeterRegistry}. */
   public static MicrometerMeterProviderBuilder builder(MeterRegistry meterRegistry) {
-    Objects.requireNonNull(meterRegistry, "meterRegistry");
+    requireNonNull(meterRegistry, "meterRegistry");
     return new MicrometerMeterProviderBuilder(() -> meterRegistry);
   }
 
@@ -62,7 +63,7 @@ public static MicrometerMeterProviderBuilder builder(MeterRegistry meterRegistry
    */
   public static MicrometerMeterProviderBuilder builder(
       Supplier<MeterRegistry> meterRegistrySupplier) {
-    Objects.requireNonNull(meterRegistrySupplier, "meterRegistrySupplier");
+    requireNonNull(meterRegistrySupplier, "meterRegistrySupplier");
     return new MicrometerMeterProviderBuilder(new MemoizingSupplier<>(meterRegistrySupplier));
   }
 }

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/MicrometerMeterProviderBuilder.java

@@ -12,7 +12,7 @@
 import javax.annotation.Nullable;
 
 /** Builder utility class for creating instances of {@link MicrometerMeterProvider}. */
-public class MicrometerMeterProviderBuilder {
+public final class MicrometerMeterProviderBuilder {
   private final Supplier<MeterRegistry> meterRegistrySupplier;
   @Nullable private CallbackRegistrar callbackRegistrar;
 

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/ScheduledCallbackRegistrar.java

@@ -5,8 +5,9 @@
 
 package io.opentelemetry.contrib.metrics.micrometer;
 
+import static java.util.Objects.requireNonNull;
+
 import java.util.List;
-import java.util.Objects;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
@@ -39,7 +40,7 @@ public final class ScheduledCallbackRegistrar implements CallbackRegistrar {
 
   public static ScheduledCallbackRegistrarBuilder builder(
       ScheduledExecutorService scheduledExecutorService) {
-    Objects.requireNonNull(scheduledExecutorService, "scheduledExecutorService");
+    requireNonNull(scheduledExecutorService, "scheduledExecutorService");
     return new ScheduledCallbackRegistrarBuilder(scheduledExecutorService);
   }
 

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/ScheduledCallbackRegistrarBuilder.java

@@ -5,9 +5,10 @@
 
 package io.opentelemetry.contrib.metrics.micrometer;
 
+import static java.util.Objects.requireNonNull;
+
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.time.Duration;
-import java.util.Objects;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
@@ -27,7 +28,7 @@ public final class ScheduledCallbackRegistrarBuilder {
   /** Sets the period between successive executions of each registered callback */
   @CanIgnoreReturnValue
   public ScheduledCallbackRegistrarBuilder setPeriod(long period, TimeUnit unit) {
-    Objects.requireNonNull(unit, "unit");
+    requireNonNull(unit, "unit");
     this.period = period;
     this.timeUnit = unit;
     return this;
@@ -36,7 +37,7 @@ public ScheduledCallbackRegistrarBuilder setPeriod(long period, TimeUnit unit) {
   /** Sets the period between successive executions of each registered callback */
   @CanIgnoreReturnValue
   public ScheduledCallbackRegistrarBuilder setPeriod(Duration period) {
-    Objects.requireNonNull(period, "period");
+    requireNonNull(period, "period");
     this.period = period.toMillis();
     this.timeUnit = TimeUnit.MILLISECONDS;
     return this;

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/internal/Constants.java

@@ -13,7 +13,7 @@
  * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
  * at any time.
  */
-public final class Constants {
+public class Constants {
   public static final String OTEL_INSTRUMENTATION_NAME = "otel.instrumentation.name";
   public static final String OTEL_INSTRUMENTATION_VERSION = "otel.instrumentation.version";
   public static final Tag UNKNOWN_INSTRUMENTATION_VERSION_TAG =

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/internal/MemoizingSupplier.java

@@ -16,7 +16,7 @@
  * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
  * at any time.
  */
-public final class MemoizingSupplier<T> implements Supplier<T> {
+public class MemoizingSupplier<T> implements Supplier<T> {
   private final Supplier<T> delegate;
   private volatile boolean initialized;
   @Nullable private volatile T cachedResult;

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/internal/PollingMeterCallbackRegistrar.java

@@ -23,7 +23,7 @@
  * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
  * at any time.
  */
-public final class PollingMeterCallbackRegistrar implements CallbackRegistrar {
+public class PollingMeterCallbackRegistrar implements CallbackRegistrar {
   static final String OTEL_POLLING_METER_NAME = "otel_polling_meter";
 
   private final Supplier<MeterRegistry> meterRegistrySupplier;

micrometer-meter-provider/src/main/java/io/opentelemetry/contrib/metrics/micrometer/internal/state/InstrumentState.java

@@ -18,7 +18,7 @@
  * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
  * at any time.
  */
-public final class InstrumentState {
+public class InstrumentState {
   private final MeterSharedState meterSharedState;
   private final String name;
   @Nullable private final String description;