Improve consistency with unified code format/imports (#3156)

Configures the spring-javaformat plugin to enforce and apply code formatting as part of the build. Applies the formatting to existing code. Also adds to editorconfig configuration for import order and updates all imports. There is no generic support for Java import order configuration in editorconfig, so an IntelliJ specific configuration is used.

Author: shakuzen

.editorconfig

@@ -7,3 +7,6 @@ insert_final_newline = true
 indent_style = space
 indent_size = 4
 continuation_indent_size = 8
+ij_java_imports_layout = *,|,javax.**,java.**,|,$*
+ij_java_class_count_to_use_import_on_demand = 5
+ij_java_names_count_to_use_import_on_demand = 3

.springjavaformatconfig

@@ -0,0 +1,2 @@
+java-baseline=8
+indentation-style=spaces

CONTRIBUTING.md

@@ -42,6 +42,13 @@ The wrapper can be used with a command, for example, `./gradlew check` to build
 
 This repository should be imported as a Gradle project into your IDE of choice.
 
+## Code formatting
+
+The [spring-javaformat plugin](https://github.com/spring-io/spring-javaformat) is configured to check and apply consistent formatting in the codebase through the build.
+The `checkFormat` task checks the formatting as part of the `check` task.
+Apply formatting with the `format` task.
+You should rely on the formatting the `format` task applies instead of your IDE's configured formatting.
+
 ## Testing changes locally
 
 Specific modules or a test class can be run from your IDE for convenience.

benchmarks/benchmarks-core/src/jmh/java/io/micrometer/benchmark/compare/CompareCountersWithOtherLibraries.java

@@ -37,9 +37,12 @@
 @OutputTimeUnit(TimeUnit.NANOSECONDS)
 @Threads(16)
 public class CompareCountersWithOtherLibraries {
+
     @State(Scope.Benchmark)
     public static class DropwizardState {
+
         com.codahale.metrics.MetricRegistry registry;
+
         com.codahale.metrics.Counter counter;
 
         @Setup(Level.Trial)
@@ -52,12 +55,16 @@ public void setup() {
         public void tearDown(Blackhole hole) {
             hole.consume(counter.getCount());
         }
+
     }
 
     @State(Scope.Benchmark)
     public static class MicrometerState {
+
         io.micrometer.core.instrument.MeterRegistry registry;
+
         io.micrometer.core.instrument.Counter counter;
+
         io.micrometer.core.instrument.Counter counterWithTags;
 
         @Setup(Level.Trial)
@@ -75,13 +82,16 @@ public void tearDown(Blackhole hole) {
                 }
             }
         }
+
     }
 
     @State(Scope.Benchmark)
     public static class Dropwizard5State {
 
         io.dropwizard.metrics5.MetricRegistry registry;
+
         io.dropwizard.metrics5.Counter counter;
+
         io.dropwizard.metrics5.Counter counterWithTags;
 
         @Setup(Level.Trial)
@@ -100,39 +110,44 @@ public void tearDown(Blackhole hole) {
                 hole.consume(c.getCount());
             }
         }
+
     }
 
     @State(Scope.Benchmark)
     public static class PrometheusState {
+
         io.prometheus.client.Counter counter;
+
         io.prometheus.client.Counter counterWithTags;
 
         @Setup(Level.Trial)
         public void setup() {
             counter = io.prometheus.client.Counter.build().name("counter").help("A counter").create();
-            counterWithTags = io.prometheus.client.Counter.build().name("counter").help("Counter with two tags declared").labelNames("key1", "key2").register();
+            counterWithTags = io.prometheus.client.Counter.build().name("counter")
+                    .help("Counter with two tags declared").labelNames("key1", "key2").register();
         }
+
     }
 
-//    @Benchmark
+    // @Benchmark
     public void dropwizard5Counter(Dropwizard5State state) {
         state.counter.inc();
     }
 
-//    @Benchmark
+    // @Benchmark
     public void dropwizard5CounterFixedTags(Dropwizard5State state) {
         state.counterWithTags.inc();
     }
 
-//    @Benchmark
+    // @Benchmark
     public void dropwizard5CounterTags(Dropwizard5State state) {
         Map<String, String> tags = new HashMap<>();
         tags.put("key1", "value1");
         tags.put("key2", "value2");
         state.registry.counter(new io.dropwizard.metrics5.MetricName("tagged", tags)).inc();
     }
 
-//    @Benchmark
+    // @Benchmark
     public void micrometerCounter(MicrometerState state) {
         state.counter.increment();
     }
@@ -142,12 +157,12 @@ public void micrometerCounterTags(MicrometerState state) {
         state.registry.counter("dynamicTags", "key1", "value1", "key2", "value2").increment();
     }
 
-//    @Benchmark
+    // @Benchmark
     public void micrometerCounterFixedTags(MicrometerState state) {
         state.counterWithTags.increment();
     }
 
-//    @Benchmark
+    // @Benchmark
     public void prometheusCounter(PrometheusState state) {
         state.counter.inc();
     }
@@ -158,10 +173,9 @@ public void prometheusCounterWithTags(PrometheusState state) {
     }
 
     public static void main(String[] args) throws RunnerException {
-        Options opt = new OptionsBuilder()
-                .include(CompareCountersWithOtherLibraries.class.getSimpleName())
-                .addProfiler(GCProfiler.class)
-                .build();
+        Options opt = new OptionsBuilder().include(CompareCountersWithOtherLibraries.class.getSimpleName())
+                .addProfiler(GCProfiler.class).build();
         new Runner(opt).run();
     }
+
 }

benchmarks/benchmarks-core/src/jmh/java/io/micrometer/benchmark/compare/CompareHistogramsWithOtherLibraries.java

@@ -22,7 +22,7 @@
 //CHECKSTYLE:OFF
 import com.google.common.collect.Iterators;
 import com.google.common.primitives.Doubles;
-////CHECKSTYLE:ON
+//CHECKSTYLE:ON
 import io.micrometer.core.instrument.Clock;
 import io.micrometer.core.instrument.DistributionSummary;
 import io.micrometer.core.instrument.distribution.DistributionStatisticConfig;
@@ -63,30 +63,30 @@ public static class Data {
         @Setup(Level.Iteration)
         public void setup() {
             final Random r = new Random(1234567891L);
-            dataIterator = Iterators.cycle(
-                    Stream.generate(() -> Math.round(Math.exp(2.0 + r.nextGaussian()))).limit(1048576)
-                            .collect(Collectors.toList()));
+            dataIterator = Iterators.cycle(Stream.generate(() -> Math.round(Math.exp(2.0 + r.nextGaussian())))
+                    .limit(1048576).collect(Collectors.toList()));
         }
+
     }
 
     @State(Scope.Benchmark)
     public static class DropwizardState {
 
         MetricRegistry registry;
+
         Histogram histogram;
+
         Histogram histogramSlidingTimeWindow;
+
         Histogram histogramUniform;
 
         @Setup(Level.Iteration)
         public void setup() {
             registry = new MetricRegistry();
             histogram = registry.histogram("histogram");
-            histogramSlidingTimeWindow =
-                    registry.register("slidingTimeWindowHistogram",
-                            new Histogram(new SlidingTimeWindowReservoir(10, TimeUnit.SECONDS)));
-            histogramUniform =
-                    registry.register("uniformHistogram",
-                            new Histogram(new UniformReservoir()));
+            histogramSlidingTimeWindow = registry.register("slidingTimeWindowHistogram",
+                    new Histogram(new SlidingTimeWindowReservoir(10, TimeUnit.SECONDS)));
+            histogramUniform = registry.register("uniformHistogram", new Histogram(new UniformReservoir()));
         }
 
         @TearDown(Level.Iteration)
@@ -95,33 +95,34 @@ public void tearDown(Blackhole hole) {
             hole.consume(histogramSlidingTimeWindow.getSnapshot().getMedian());
             hole.consume(histogramUniform.getSnapshot().getMedian());
         }
+
     }
 
     @State(Scope.Benchmark)
     public static class MicrometerState {
 
         io.micrometer.core.instrument.MeterRegistry registry;
+
         io.micrometer.core.instrument.DistributionSummary summary;
 
         @Setup(Level.Iteration)
         public void setup() {
-            registry = new PrometheusMeterRegistry(PrometheusConfig.DEFAULT, new CollectorRegistry(),
-                    Clock.SYSTEM);
-            summary = DistributionSummary.builder("summary")
-                    .publishPercentileHistogram()
-                    .register(registry);
+            registry = new PrometheusMeterRegistry(PrometheusConfig.DEFAULT, new CollectorRegistry(), Clock.SYSTEM);
+            summary = DistributionSummary.builder("summary").publishPercentileHistogram().register(registry);
         }
 
         @TearDown(Level.Iteration)
         public void tearDown(Blackhole hole) {
             hole.consume(summary.takeSnapshot().count());
         }
+
     }
 
     @State(Scope.Benchmark)
     public static class MicrometerPlainSummaryState {
 
         io.micrometer.core.instrument.MeterRegistry registry;
+
         io.micrometer.core.instrument.DistributionSummary summary;
 
         @Setup(Level.Iteration)
@@ -134,6 +135,7 @@ public void setup() {
         public void tearDown(Blackhole hole) {
             hole.consume(summary.takeSnapshot().count());
         }
+
     }
 
     @State(Scope.Benchmark)
@@ -143,55 +145,54 @@ public static class PrometheusState {
 
         @Setup(Level.Trial)
         public void setup() {
-            double[] micrometerBuckets =
-                    Doubles.toArray(PercentileHistogramBuckets.buckets(
-                            DistributionStatisticConfig.builder().minimumExpectedValue(0.0).maximumExpectedValue(Double.POSITIVE_INFINITY)
-                                    .percentilesHistogram(true).build()));
-            histogram = io.prometheus.client.Histogram.build("histogram", "A histogram")
-                    .buckets(micrometerBuckets).create();
+            double[] micrometerBuckets = Doubles.toArray(
+                    PercentileHistogramBuckets.buckets(DistributionStatisticConfig.builder().minimumExpectedValue(0.0)
+                            .maximumExpectedValue(Double.POSITIVE_INFINITY).percentilesHistogram(true).build()));
+            histogram = io.prometheus.client.Histogram.build("histogram", "A histogram").buckets(micrometerBuckets)
+                    .create();
         }
 
         @TearDown(Level.Iteration)
         public void tearDown(Blackhole hole) {
             hole.consume(histogram.collect());
         }
+
     }
 
     @Benchmark
     public void micrometerPlainHistogram(MicrometerPlainSummaryState state, Data data) {
         state.summary.record(1);
     }
 
-    //    @Benchmark
+    // @Benchmark
     public void micrometerHistogram(MicrometerState state, Data data) {
         state.summary.record(data.dataIterator.next());
     }
 
-    //    @Benchmark
+    // @Benchmark
     public void dropwizardHistogram(DropwizardState state, Data data) {
         state.histogram.update(data.dataIterator.next());
     }
 
     // This benchmark is likely broken, results vary wildly between runs.
-//    @Benchmark
+    // @Benchmark
     public void dropwizardHistogramSlidingTimeWindow(DropwizardState state, Data data) {
         state.histogramSlidingTimeWindow.update(data.dataIterator.next());
     }
 
-    //    @Benchmark
+    // @Benchmark
     public void dropwizardHistogramUniform(DropwizardState state, Data data) {
         state.histogramUniform.update(data.dataIterator.next());
     }
 
-    //    @Benchmark
+    // @Benchmark
     public void prometheusHistogram(PrometheusState state, Data data) {
         state.histogram.observe(data.dataIterator.next());
     }
 
     public static void main(String[] args) throws RunnerException {
-        Options opt = new OptionsBuilder()
-                .include(CompareHistogramsWithOtherLibraries.class.getSimpleName())
-                .build();
+        Options opt = new OptionsBuilder().include(CompareHistogramsWithOtherLibraries.class.getSimpleName()).build();
         new Runner(opt).run();
     }
+
 }

benchmarks/benchmarks-core/src/jmh/java/io/micrometer/benchmark/core/CounterBenchmark.java

@@ -30,22 +30,27 @@
 @State(Scope.Benchmark)
 @OutputTimeUnit(TimeUnit.MICROSECONDS)
 public class CounterBenchmark {
+
     public static void main(String[] args) throws RunnerException {
+        // @formatter:off
         Options opt = new OptionsBuilder()
                 .include(CounterBenchmark.class.getSimpleName())
                 .warmupIterations(5)
                 .measurementIterations(10)
                 .mode(Mode.SampleTime)
                 .forks(1)
                 .build();
+        // @formatter:on
 
         new Runner(opt).run();
     }
 
     private int x = 923;
+
     private int y = 123;
 
     private MeterRegistry registry;
+
     private Counter counter;
 
     @Setup
@@ -70,4 +75,5 @@ public int countSumWithRegistryLookup() {
     public int sum() {
         return x + y;
     }
+
 }

benchmarks/benchmarks-core/src/jmh/java/io/micrometer/benchmark/core/MeterRegistrationBenchmark.java

@@ -28,7 +28,9 @@
 @State(Scope.Benchmark)
 @OutputTimeUnit(TimeUnit.MICROSECONDS)
 public class MeterRegistrationBenchmark {
+
     public static void main(String[] args) throws RunnerException {
+        // @formatter:off
         Options opt = new OptionsBuilder()
                 .include(MeterRegistrationBenchmark.class.getSimpleName())
                 .warmupIterations(2)
@@ -37,11 +39,13 @@ public static void main(String[] args) throws RunnerException {
                 .timeUnit(TimeUnit.SECONDS)
                 .forks(1)
                 .build();
+        // @formatter:on
 
         new Runner(opt).run();
     }
 
     private int x = 923;
+
     private int y = 123;
 
     @Benchmark
@@ -57,4 +61,5 @@ public int insert10_000() {
     public int sum() {
         return x + y;
     }
+
 }

benchmarks/benchmarks-core/src/jmh/java/io/micrometer/benchmark/core/TagsBenchmark.java

@@ -30,6 +30,7 @@
 @BenchmarkMode(Mode.AverageTime)
 @OutputTimeUnit(TimeUnit.NANOSECONDS)
 public class TagsBenchmark {
+
     @Threads(16)
     @Benchmark
     public void of() {
@@ -43,9 +44,8 @@ public void dotAnd() {
     }
 
     public static void main(String[] args) throws RunnerException {
-        Options opt = new OptionsBuilder()
-                .include(TagsBenchmark.class.getSimpleName())
-                .build();
+        Options opt = new OptionsBuilder().include(TagsBenchmark.class.getSimpleName()).build();
         new Runner(opt).run();
     }
+
 }