Add gradle plugin for google java format. Enforce all files to be formatted. (#771)

* Add gradle plugin for google java format. Enforce all files to be formatted.

* Fix javadoc comments.

* update to google-java-formatter 1.5

* Fix comments and run formatter only for java8.

* Formatter works only on java8.

22 files changed, 125 insertions, 166 deletions

diff --git a/api/src/main/java/io/opencensus/common/Duration.java b/api/src/main/java/io/opencensus/common/Duration.java
index 77ba3db7..b4b59a57 100644
--- a/api/src/main/java/io/opencensus/common/Duration.java
+++ b/api/src/main/java/io/opencensus/common/Duration.java
@@ -92,8 +92,8 @@ public abstract class Duration implements Comparable<Duration> {
    * Compares this {@code Duration} to the specified {@code Duration}.
    *
    * @param otherDuration the other {@code Duration} to compare to, not {@code null}.
-   * @return the comparator value: zero if equal, negative if this duration is smaller
-   *     than otherDuration, positive if larger.
+   * @return the comparator value: zero if equal, negative if this duration is smaller than
+   *     otherDuration, positive if larger.
    * @throws NullPointerException if otherDuration is {@code null}.
    */
   @Override
diff --git a/api/src/main/java/io/opencensus/common/ExperimentalApi.java b/api/src/main/java/io/opencensus/common/ExperimentalApi.java
index 266da4e9..9906cbff 100644
--- a/api/src/main/java/io/opencensus/common/ExperimentalApi.java
+++ b/api/src/main/java/io/opencensus/common/ExperimentalApi.java
@@ -27,26 +27,26 @@ import java.lang.annotation.Target;
  * backward-compatibility.
  *
  * <p>Usage guidelines:
+ *
  * <ol>
- * <li>This annotation is used only on public API. Internal interfaces should not use it.</li>
- * <li>After OpenCensus has gained API stability, this annotation can only be added to new API.
- * Adding it to an existing API is considered API-breaking.</li>
- * <li>Removing this annotation from an API gives it stable status.</li>
+ *   <li>This annotation is used only on public API. Internal interfaces should not use it.
+ *   <li>After OpenCensus has gained API stability, this annotation can only be added to new API.
+ *       Adding it to an existing API is considered API-breaking.
+ *   <li>Removing this annotation from an API gives it stable status.
  * </ol>
  */
 @Internal
 @Retention(RetentionPolicy.SOURCE)
 @Target({
-    ElementType.ANNOTATION_TYPE,
-    ElementType.CONSTRUCTOR,
-    ElementType.FIELD,
-    ElementType.METHOD,
-    ElementType.PACKAGE,
-    ElementType.TYPE})
+  ElementType.ANNOTATION_TYPE,
+  ElementType.CONSTRUCTOR,
+  ElementType.FIELD,
+  ElementType.METHOD,
+  ElementType.PACKAGE,
+  ElementType.TYPE
+})
 @Documented
 public @interface ExperimentalApi {
-  /**
-   * Context information such as links to discussion thread, tracking issue etc.
-   */
+  /** Context information such as links to discussion thread, tracking issue etc. */
   String value() default "";
-}
\ No newline at end of file
+}
diff --git a/api/src/main/java/io/opencensus/common/OpenCensusLibraryInformation.java b/api/src/main/java/io/opencensus/common/OpenCensusLibraryInformation.java
index 1b1c75e4..aa5d69d5 100644
--- a/api/src/main/java/io/opencensus/common/OpenCensusLibraryInformation.java
+++ b/api/src/main/java/io/opencensus/common/OpenCensusLibraryInformation.java
@@ -16,14 +16,10 @@
 
 package io.opencensus.common;
 
-/**
- * Class holder for all common constants (such as the version) for the OpenCensus Java library.
- */
+/** Class holder for all common constants (such as the version) for the OpenCensus Java library. */
 @ExperimentalApi
 public final class OpenCensusLibraryInformation {
 
-  /**
-   * The current version of the OpenCensus Java library.
-   */
-  public static final String VERSION = "0.9.0-SNAPSHOT";  // CURRENT_OPENCENSUS_VERSION
+  /** The current version of the OpenCensus Java library. */
+  public static final String VERSION = "0.9.0-SNAPSHOT"; // CURRENT_OPENCENSUS_VERSION
 }
diff --git a/api/src/main/java/io/opencensus/common/Timestamp.java b/api/src/main/java/io/opencensus/common/Timestamp.java
index 0fa7c800..b62a1102 100644
--- a/api/src/main/java/io/opencensus/common/Timestamp.java
+++ b/api/src/main/java/io/opencensus/common/Timestamp.java
@@ -138,8 +138,8 @@ public abstract class Timestamp implements Comparable<Timestamp> {
    * Compares this {@code Timestamp} to the specified {@code Timestamp}.
    *
    * @param otherTimestamp the other {@code Timestamp} to compare to, not {@code null}.
-   * @return the comparator value: zero if equal, negative if this timestamp happens
-   *     before otherTimestamp, positive if after.
+   * @return the comparator value: zero if equal, negative if this timestamp happens before
+   *     otherTimestamp, positive if after.
    * @throws NullPointerException if otherTimestamp is {@code null}.
    */
   @Override
diff --git a/api/src/main/java/io/opencensus/internal/NoopScope.java b/api/src/main/java/io/opencensus/internal/NoopScope.java
index 1edac98e..f4a8da07 100644
--- a/api/src/main/java/io/opencensus/internal/NoopScope.java
+++ b/api/src/main/java/io/opencensus/internal/NoopScope.java
@@ -18,9 +18,7 @@ package io.opencensus.internal;
 
 import io.opencensus.common.Scope;
 
-/**
- * A {@link Scope} that does nothing when it is created or closed.
- */
+/** A {@link Scope} that does nothing when it is created or closed. */
 public final class NoopScope implements Scope {
   private static final Scope INSTANCE = new NoopScope();
 
diff --git a/api/src/main/java/io/opencensus/stats/Aggregation.java b/api/src/main/java/io/opencensus/stats/Aggregation.java
index f12517c8..90341af4 100644
--- a/api/src/main/java/io/opencensus/stats/Aggregation.java
+++ b/api/src/main/java/io/opencensus/stats/Aggregation.java
@@ -23,10 +23,11 @@ import io.opencensus.common.Function;
 import javax.annotation.concurrent.Immutable;
 
 /**
- * {@link Aggregation} is the process of combining a certain set of {@code MeasureValue}s
- * for a given {@code Measure} into an {@link AggregationData}.
+ * {@link Aggregation} is the process of combining a certain set of {@code MeasureValue}s for a
+ * given {@code Measure} into an {@link AggregationData}.
  *
  * <p>{@link Aggregation} currently supports 4 types of basic aggregation:
+ *
  * <ul>
  *   <li>Sum
  *   <li>Count
@@ -40,12 +41,9 @@ import javax.annotation.concurrent.Immutable;
 @Immutable
 public abstract class Aggregation {
 
-  private Aggregation() {
-  }
+  private Aggregation() {}
 
-  /**
-   * Applies the given match function to the underlying data type.
-   */
+  /** Applies the given match function to the underlying data type. */
   public abstract <T> T match(
       Function<? super Sum, T> p0,
       Function<? super Count, T> p1,
@@ -58,8 +56,7 @@ public abstract class Aggregation {
   @AutoValue
   public abstract static class Sum extends Aggregation {
 
-    Sum() {
-    }
+    Sum() {}
 
     private static final Sum INSTANCE = new AutoValue_Aggregation_Sum();
 
@@ -88,8 +85,7 @@ public abstract class Aggregation {
   @AutoValue
   public abstract static class Count extends Aggregation {
 
-    Count() {
-    }
+    Count() {}
 
     private static final Count INSTANCE = new AutoValue_Aggregation_Count();
 
@@ -118,8 +114,7 @@ public abstract class Aggregation {
   @AutoValue
   public abstract static class Mean extends Aggregation {
 
-    Mean() {
-    }
+    Mean() {}
 
     private static final Mean INSTANCE = new AutoValue_Aggregation_Mean();
 
@@ -144,15 +139,14 @@ public abstract class Aggregation {
   }
 
   /**
-   * Calculate distribution stats on aggregated {@code MeasureValue}s. Distribution includes
-   * mean, count, histogram, min, max and sum of squared deviations.
+   * Calculate distribution stats on aggregated {@code MeasureValue}s. Distribution includes mean,
+   * count, histogram, min, max and sum of squared deviations.
    */
   @Immutable
   @AutoValue
   public abstract static class Distribution extends Aggregation {
 
-    Distribution() {
-    }
+    Distribution() {}
 
     /**
      * Construct a {@code Distribution}.
diff --git a/api/src/main/java/io/opencensus/stats/AggregationData.java b/api/src/main/java/io/opencensus/stats/AggregationData.java
index b91d0d19..d5cacfc5 100644
--- a/api/src/main/java/io/opencensus/stats/AggregationData.java
+++ b/api/src/main/java/io/opencensus/stats/AggregationData.java
@@ -27,10 +27,11 @@ import java.util.List;
 import javax.annotation.concurrent.Immutable;
 
 /**
- * {@link AggregationData} is the result of applying a given {@link Aggregation} to a set of
- * {@code MeasureValue}s.
+ * {@link AggregationData} is the result of applying a given {@link Aggregation} to a set of {@code
+ * MeasureValue}s.
  *
  * <p>{@link AggregationData} currently supports 5 types of basic aggregation values:
+ *
  * <ul>
  *   <li>SumDataDouble
  *   <li>SumDataLong
@@ -39,18 +40,15 @@ import javax.annotation.concurrent.Immutable;
  *   <li>DistributionData
  * </ul>
  *
- * <p>{@link ViewData} will contain one {@link AggregationData}, corresponding to its
- * {@link Aggregation} definition in {@link View}.
+ * <p>{@link ViewData} will contain one {@link AggregationData}, corresponding to its {@link
+ * Aggregation} definition in {@link View}.
  */
 @Immutable
 public abstract class AggregationData {
 
-  private AggregationData() {
-  }
+  private AggregationData() {}
 
-  /**
-   * Applies the given match function to the underlying data type.
-   */
+  /** Applies the given match function to the underlying data type. */
   public abstract <T> T match(
       Function<? super SumDataDouble, T> p0,
       Function<? super SumDataLong, T> p1,
@@ -64,8 +62,7 @@ public abstract class AggregationData {
   @AutoValue
   public abstract static class SumDataDouble extends AggregationData {
 
-    SumDataDouble() {
-    }
+    SumDataDouble() {}
 
     /**
      * Creates a {@code SumDataDouble}.
@@ -101,8 +98,7 @@ public abstract class AggregationData {
   @AutoValue
   public abstract static class SumDataLong extends AggregationData {
 
-    SumDataLong() {
-    }
+    SumDataLong() {}
 
     /**
      * Creates a {@code SumDataLong}.
@@ -138,8 +134,7 @@ public abstract class AggregationData {
   @AutoValue
   public abstract static class CountData extends AggregationData {
 
-    CountData() {
-    }
+    CountData() {}
 
     /**
      * Creates a {@code CountData}.
@@ -175,8 +170,7 @@ public abstract class AggregationData {
   @AutoValue
   public abstract static class MeanData extends AggregationData {
 
-    MeanData() {
-    }
+    MeanData() {}
 
     /**
      * Creates a {@code MeanData}.
@@ -223,8 +217,7 @@ public abstract class AggregationData {
   @AutoValue
   public abstract static class DistributionData extends AggregationData {
 
-    DistributionData() {
-    }
+    DistributionData() {}
 
     /**
      * Creates a {@code DistributionData}.
@@ -238,7 +231,11 @@ public abstract class AggregationData {
      * @return a {@code DistributionData}.
      */
     public static DistributionData create(
-        double mean, long count, double min, double max, double sumOfSquaredDeviations,
+        double mean,
+        long count,
+        double min,
+        double max,
+        double sumOfSquaredDeviations,
         List<Long> bucketCounts) {
       if (min != Double.POSITIVE_INFINITY || max != Double.NEGATIVE_INFINITY) {
         checkArgument(min <= max, "max should be greater or equal to min.");
diff --git a/api/src/main/java/io/opencensus/stats/BucketBoundaries.java b/api/src/main/java/io/opencensus/stats/BucketBoundaries.java
index b9a808f4..8af83a4e 100644
--- a/api/src/main/java/io/opencensus/stats/BucketBoundaries.java
+++ b/api/src/main/java/io/opencensus/stats/BucketBoundaries.java
@@ -38,7 +38,7 @@ public abstract class BucketBoundaries {
    */
   public static final BucketBoundaries create(List<Double> bucketBoundaries) {
     checkNotNull(bucketBoundaries, "bucketBoundaries list should not be null.");
-    List<Double> bucketBoundariesCopy = new ArrayList<Double>(bucketBoundaries);  // Deep copy.
+    List<Double> bucketBoundariesCopy = new ArrayList<Double>(bucketBoundaries); // Deep copy.
     // Check if sorted.
     if (bucketBoundariesCopy.size() > 1) {
       double lower = bucketBoundariesCopy.get(0);
@@ -52,6 +52,8 @@ public abstract class BucketBoundaries {
   }
 
   /**
+   * Returns a list of histogram bucket boundaries.
+   *
    * @return a list of histogram bucket boundaries.
    */
   public abstract List<Double> getBoundaries();
diff --git a/api/src/main/java/io/opencensus/stats/Measure.java b/api/src/main/java/io/opencensus/stats/Measure.java
index 062a35bf..52fadfa0 100644
--- a/api/src/main/java/io/opencensus/stats/Measure.java
+++ b/api/src/main/java/io/opencensus/stats/Measure.java
@@ -30,9 +30,7 @@ public abstract class Measure {
 
   @VisibleForTesting static final int NAME_MAX_LENGTH = 255;
 
-  /**
-   * Applies the given match function to the underlying data type.
-   */
+  /** Applies the given match function to the underlying data type. */
   public abstract <T> T match(
       Function<? super MeasureDouble, T> p0,
       Function<? super MeasureLong, T> p1,
@@ -46,35 +44,35 @@ public abstract class Measure {
    */
   public abstract String getName();
 
-  /**
-   * Detailed description of the measure, used in documentation.
-   */
+  /** Detailed description of the measure, used in documentation. */
   public abstract String getDescription();
 
   /**
    * The units in which {@link Measure} values are measured.
    *
    * <p>The suggested grammar for a unit is as follows:
-   * Expression = Component { "." Component } { "/" Component } ;
-   * Component = [ PREFIX ] UNIT [ Annotation ] | Annotation | "1" ;
-   * Annotation = "{" NAME "}" ;
-   * For example, string “MBy{transmitted}/ms” stands for megabytes per milliseconds, and the
+   *
+   * <ul>
+   *   <li>Expression = Component { "." Component } {"/" Component };
+   *   <li>Component = [ PREFIX ] UNIT [ Annotation ] | Annotation | "1";
+   *   <li>Annotation = "{" NAME "}" ;
+   * </ul>
+   *
+   * <p>For example, string “MBy{transmitted}/ms” stands for megabytes per milliseconds, and the
    * annotation transmitted inside {} is just a comment of the unit.
    */
   // TODO(songya): determine whether we want to check the grammar on string unit.
   public abstract String getUnit();
 
   // Prevents this class from being subclassed anywhere else.
-  private Measure() {
-  }
+  private Measure() {}
 
   /** {@link Measure} with {@code Double} typed values. */
   @Immutable
   @AutoValue
   public abstract static class MeasureDouble extends Measure {
 
-    MeasureDouble() {
-    }
+    MeasureDouble() {}
 
     /**
      * Constructs a new {@link MeasureDouble}.
@@ -85,9 +83,11 @@ public abstract class Measure {
      * @return a {@code MeasureDouble}.
      */
     public static MeasureDouble create(String name, String description, String unit) {
-      checkArgument(StringUtil.isPrintableString(name) && name.length() <= NAME_MAX_LENGTH,
+      checkArgument(
+          StringUtil.isPrintableString(name) && name.length() <= NAME_MAX_LENGTH,
           "Name should be a ASCII string with a length no greater than "
-              + NAME_MAX_LENGTH + " characters.");
+              + NAME_MAX_LENGTH
+              + " characters.");
       return new AutoValue_Measure_MeasureDouble(name, description, unit);
     }
 
@@ -114,8 +114,7 @@ public abstract class Measure {
   @AutoValue
   public abstract static class MeasureLong extends Measure {
 
-    MeasureLong() {
-    }
+    MeasureLong() {}
 
     /**
      * Constructs a new {@link MeasureLong}.
@@ -126,9 +125,11 @@ public abstract class Measure {
      * @return a {@code MeasureLong}.
      */
     public static MeasureLong create(String name, String description, String unit) {
-      checkArgument(StringUtil.isPrintableString(name) && name.length() <= NAME_MAX_LENGTH,
+      checkArgument(
+          StringUtil.isPrintableString(name) && name.length() <= NAME_MAX_LENGTH,
           "Name should be a ASCII string with a length no greater than "
-              + NAME_MAX_LENGTH + " characters.");
+              + NAME_MAX_LENGTH
+              + " characters.");
       return new AutoValue_Measure_MeasureLong(name, description, unit);
     }
 
diff --git a/api/src/main/java/io/opencensus/stats/Measurement.java b/api/src/main/java/io/opencensus/stats/Measurement.java
index 10fc5888..1bb746d8 100644
--- a/api/src/main/java/io/opencensus/stats/Measurement.java
+++ b/api/src/main/java/io/opencensus/stats/Measurement.java
@@ -26,22 +26,17 @@ import javax.annotation.concurrent.Immutable;
 @Immutable
 public abstract class Measurement {
 
-  /**
-   * Applies the given match function to the underlying data type.
-   */
+  /** Applies the given match function to the underlying data type. */
   public abstract <T> T match(
       Function<? super MeasurementDouble, T> p0,
       Function<? super MeasurementLong, T> p1,
       Function<? super Measurement, T> defaultFunction);
 
-  /**
-   * Extracts the measured {@link Measure}.
-   */
+  /** Extracts the measured {@link Measure}. */
   public abstract Measure getMeasure();
 
   // Prevents this class from being subclassed anywhere else.
-  private Measurement() {
-  }
+  private Measurement() {}
 
   /** {@code Double} typed {@link Measurement}. */
   @Immutable
@@ -49,9 +44,7 @@ public abstract class Measurement {
   public abstract static class MeasurementDouble extends Measurement {
     MeasurementDouble() {}
 
-    /**
-     * Constructs a new {@link MeasurementDouble}.
-     */
+    /** Constructs a new {@link MeasurementDouble}. */
     public static MeasurementDouble create(MeasureDouble measure, double value) {
       return new AutoValue_Measurement_MeasurementDouble(measure, value);
     }
@@ -76,9 +69,7 @@ public abstract class Measurement {
   public abstract static class MeasurementLong extends Measurement {
     MeasurementLong() {}
 
-    /**
-     * Constructs a new {@link MeasurementLong}.
-     */
+    /** Constructs a new {@link MeasurementLong}. */
     public static MeasurementLong create(MeasureLong measure, long value) {
       return new AutoValue_Measurement_MeasurementLong(measure, value);
     }
diff --git a/api/src/main/java/io/opencensus/stats/View.java b/api/src/main/java/io/opencensus/stats/View.java
index 26b1177f..c4b152e0 100644
--- a/api/src/main/java/io/opencensus/stats/View.java
+++ b/api/src/main/java/io/opencensus/stats/View.java
@@ -31,8 +31,8 @@ import java.util.List;
 import javax.annotation.concurrent.Immutable;
 
 /**
- * A View specifies an aggregation and a set of tag keys. The aggregation will be broken
- * down by the unique set of matching tag values for each measure.
+ * A View specifies an aggregation and a set of tag keys. The aggregation will be broken down by the
+ * unique set of matching tag values for each measure.
  */
 @Immutable
 @AutoValue
@@ -40,27 +40,18 @@ public abstract class View {
 
   @VisibleForTesting static final int NAME_MAX_LENGTH = 256;
 
-  View() {
-  }
+  View() {}
 
-  /**
-   * Name of view. Must be unique.
-   */
+  /** Name of view. Must be unique. */
   public abstract Name getName();
 
-  /**
-   * More detailed description, for documentation purposes.
-   */
+  /** More detailed description, for documentation purposes. */
   public abstract String getDescription();
 
-  /**
-   * Measure type of this view.
-   */
+  /** Measure type of this view. */
   public abstract Measure getMeasure();
 
-  /**
-   * The {@link Aggregation} associated with this {@link View}.
-   */
+  /** The {@link Aggregation} associated with this {@link View}. */
   public abstract Aggregation getAggregation();
 
   /**
@@ -97,8 +88,7 @@ public abstract class View {
       Aggregation aggregation,
       List<TagKey> columns,
       AggregationWindow window) {
-    checkArgument(new HashSet<TagKey>(columns).size() == columns.size(),
-        "Columns have duplicate.");
+    checkArgument(new HashSet<TagKey>(columns).size() == columns.size(), "Columns have duplicate.");
 
     return new AutoValue_View(
         name,
@@ -109,9 +99,7 @@ public abstract class View {
         window);
   }
 
-  /**
-   * The name of a {@code View}.
-   */
+  /** The name of a {@code View}. */
   // This type should be used as the key when associating data with Views.
   @Immutable
   @AutoValue
@@ -127,8 +115,8 @@ public abstract class View {
     public abstract String asString();
 
     /**
-     * Creates a {@code View.Name} from a {@code String}. Should be a ASCII string with a length
-     * no greater than 256 characters.
+     * Creates a {@code View.Name} from a {@code String}. Should be a ASCII string with a length no
+     * greater than 256 characters.
      *
      * <p>Suggested format for name: {@code <web_host>/<path>}.
      *
@@ -136,7 +124,8 @@ public abstract class View {
      * @return a {@code View.Name} with the given name {@code String}.
      */
     public static Name create(String name) {
-      checkArgument(StringUtil.isPrintableString(name) && name.length() <= NAME_MAX_LENGTH,
+      checkArgument(
+          StringUtil.isPrintableString(name) && name.length() <= NAME_MAX_LENGTH,
           "Name should be a ASCII string with a length no greater than 256 characters.");
       return new AutoValue_View_Name(name);
     }
@@ -148,9 +137,7 @@ public abstract class View {
 
     private AggregationWindow() {}
 
-    /**
-     * Applies the given match function to the underlying data type.
-     */
+    /** Applies the given match function to the underlying data type. */
     public abstract <T> T match(
         Function<? super Cumulative, T> p0,
         Function<? super Interval, T> p1,
@@ -182,7 +169,7 @@ public abstract class View {
           Function<? super Cumulative, T> p0,
           Function<? super Interval, T> p1,
           Function<? super AggregationWindow, T> defaultFunction) {
-        return  p0.apply(this);
+        return p0.apply(this);
       }
     }
 
@@ -202,7 +189,6 @@ public abstract class View {
        */
       public abstract Duration getDuration();
 
-
       /**
        * Constructs an interval {@code AggregationWindow} that has a finite explicit {@code
        * Duration}.
@@ -222,7 +208,7 @@ public abstract class View {
           Function<? super Cumulative, T> p0,
           Function<? super Interval, T> p1,
           Function<? super AggregationWindow, T> defaultFunction) {
-        return  p1.apply(this);
+        return p1.apply(this);
       }
     }
   }
diff --git a/api/src/main/java/io/opencensus/stats/ViewData.java b/api/src/main/java/io/opencensus/stats/ViewData.java
index 007022e7..458b1f1a 100644
--- a/api/src/main/java/io/opencensus/stats/ViewData.java
+++ b/api/src/main/java/io/opencensus/stats/ViewData.java
@@ -41,8 +41,8 @@ public abstract class ViewData {
   public abstract View getView();
 
   /**
-   * The {@link AggregationData} grouped by combination of tag values, associated with this
-   * {@link ViewData}.
+   * The {@link AggregationData} grouped by combination of tag values, associated with this {@link
+   * ViewData}.
    */
   public abstract Map<List<TagValue>, AggregationData> getAggregationMap();
 
@@ -91,11 +91,9 @@ public abstract class ViewData {
             Functions.<Void>throwIllegalArgumentException());
 
     Map<List<TagValue>, AggregationData> deepCopy = Maps.newHashMap();
-    for (Entry<? extends List<TagValue>, ? extends AggregationData> entry : map
-        .entrySet()) {
+    for (Entry<? extends List<TagValue>, ? extends AggregationData> entry : map.entrySet()) {
       deepCopy.put(
-          Collections.unmodifiableList(new ArrayList<TagValue>(entry.getKey())),
-          entry.getValue());
+          Collections.unmodifiableList(new ArrayList<TagValue>(entry.getKey())), entry.getValue());
     }
 
     return new AutoValue_ViewData(view, Collections.unmodifiableMap(deepCopy), windowData);
diff --git a/api/src/main/java/io/opencensus/stats/ViewManager.java b/api/src/main/java/io/opencensus/stats/ViewManager.java
index 908221c6..f98e8058 100644
--- a/api/src/main/java/io/opencensus/stats/ViewManager.java
+++ b/api/src/main/java/io/opencensus/stats/ViewManager.java
@@ -19,13 +19,13 @@ package io.opencensus.stats;
 import javax.annotation.Nullable;
 
 /**
- * Provides facilities to register {@link View}s for collecting stats and retrieving
- * stats data as a {@link ViewData}.
+ * Provides facilities to register {@link View}s for collecting stats and retrieving stats data as a
+ * {@link ViewData}.
  */
 public abstract class ViewManager {
   /**
-   * Pull model for stats. Registers a {@link View} that will collect data to be accessed
-   * via {@link #getView(View.Name)}.
+   * Pull model for stats. Registers a {@link View} that will collect data to be accessed via {@link
+   * #getView(View.Name)}.
    *
    * @param view the {@code View} to be registered.
    */
diff --git a/api/src/main/java/io/opencensus/tags/InternalUtils.java b/api/src/main/java/io/opencensus/tags/InternalUtils.java
index c55ca7d4..734fcf98 100644
--- a/api/src/main/java/io/opencensus/tags/InternalUtils.java
+++ b/api/src/main/java/io/opencensus/tags/InternalUtils.java
@@ -18,9 +18,7 @@ package io.opencensus.tags;
 
 import java.util.Iterator;
 
-/**
- * Internal tagging utilities.
- */
+/** Internal tagging utilities. */
 @io.opencensus.common.Internal
 public final class InternalUtils {
   private InternalUtils() {}
diff --git a/api/src/main/java/io/opencensus/tags/package-info.java b/api/src/main/java/io/opencensus/tags/package-info.java
index e18c68d1..eb19ee77 100644
--- a/api/src/main/java/io/opencensus/tags/package-info.java
+++ b/api/src/main/java/io/opencensus/tags/package-info.java
@@ -22,8 +22,8 @@
  * io.opencensus.stats} package labels all stats with the current tags.
  *
  * <p>{@link io.opencensus.tags.Tag Tags} are key-value pairs. The {@link io.opencensus.tags.TagKey
- * keys} and {@link io.opencensus.tags.TagValue values} are wrapped {@code String}s. They are
- * stored as a map in a {@link io.opencensus.tags.TagContext}.
+ * keys} and {@link io.opencensus.tags.TagValue values} are wrapped {@code String}s. They are stored
+ * as a map in a {@link io.opencensus.tags.TagContext}.
  *
  * <p>Note that tags are independent of the tracing data that is propagated in the {@code
  * io.grpc.Context}, such as trace ID.
diff --git a/api/src/main/java/io/opencensus/trace/CurrentSpanUtils.java b/api/src/main/java/io/opencensus/trace/CurrentSpanUtils.java
index ab8282de..dbbe3a33 100644
--- a/api/src/main/java/io/opencensus/trace/CurrentSpanUtils.java
+++ b/api/src/main/java/io/opencensus/trace/CurrentSpanUtils.java
@@ -20,9 +20,7 @@ import io.grpc.Context;
 import io.opencensus.common.Scope;
 import io.opencensus.trace.unsafe.ContextUtils;
 
-/**
- * Util methods/functionality to interact with the {@link Span} in the {@link io.grpc.Context}.
- */
+/** Util methods/functionality to interact with the {@link Span} in the {@link io.grpc.Context}. */
 final class CurrentSpanUtils {
   // No instance of this class.
   private CurrentSpanUtils() {}
diff --git a/api/src/main/java/io/opencensus/trace/Sampler.java b/api/src/main/java/io/opencensus/trace/Sampler.java
index 429ffe92..e30b5fdd 100644
--- a/api/src/main/java/io/opencensus/trace/Sampler.java
+++ b/api/src/main/java/io/opencensus/trace/Sampler.java
@@ -44,8 +44,8 @@ public abstract class Sampler {
       List<Span> parentLinks);
 
   /**
-   * Returns the description of this {@code Sampler}. This may be displayed on debug pages or in
-   * the logs.
+   * Returns the description of this {@code Sampler}. This may be displayed on debug pages or in the
+   * logs.
    *
    * <p>Example: "ProbabilitySampler{0.000100}"
    *
diff --git a/api/src/main/java/io/opencensus/trace/Span.java b/api/src/main/java/io/opencensus/trace/Span.java
index b58a1fde..3ede6686 100644
--- a/api/src/main/java/io/opencensus/trace/Span.java
+++ b/api/src/main/java/io/opencensus/trace/Span.java
@@ -77,8 +77,8 @@ public abstract class Span {
   }
 
   /**
-   * Sets an attribute to the {@code Span}. If the {@code Span} previously contained a mapping
-   * for the key, the old value is replaced by the specified value.
+   * Sets an attribute to the {@code Span}. If the {@code Span} previously contained a mapping for
+   * the key, the old value is replaced by the specified value.
    *
    * @param key the key for this attribute.
    * @param value the value for this attribute.
@@ -103,7 +103,6 @@ public abstract class Span {
     addAttributes(attributes);
   }
 
-
   /**
    * @deprecated Use {@link #putAttributes(Map)}
    * @param attributes the attributes that will be added and associated with the {@code Span}.
diff --git a/api/src/main/java/io/opencensus/trace/TraceComponent.java b/api/src/main/java/io/opencensus/trace/TraceComponent.java
index 4472ba26..e1806490 100644
--- a/api/src/main/java/io/opencensus/trace/TraceComponent.java
+++ b/api/src/main/java/io/opencensus/trace/TraceComponent.java
@@ -23,8 +23,8 @@ import io.opencensus.trace.export.ExportComponent;
 import io.opencensus.trace.propagation.PropagationComponent;
 
 /**
- * Class that holds the implementation instances for {@link Tracer}, {@link
- * PropagationComponent}, {@link Clock}, {@link ExportComponent} and {@link TraceConfig}.
+ * Class that holds the implementation instances for {@link Tracer}, {@link PropagationComponent},
+ * {@link Clock}, {@link ExportComponent} and {@link TraceConfig}.
  *
  * <p>Unless otherwise noted all methods (on component) results are cacheable.
  */
@@ -40,8 +40,8 @@ public abstract class TraceComponent {
   public abstract Tracer getTracer();
 
   /**
-   * Returns the {@link PropagationComponent} with the provided implementation. If no
-   * implementation is provided then no-op implementation will be used.
+   * Returns the {@link PropagationComponent} with the provided implementation. If no implementation
+   * is provided then no-op implementation will be used.
    *
    * @return the {@code PropagationComponent} implementation.
    */
diff --git a/api/src/main/java/io/opencensus/trace/TraceOptions.java b/api/src/main/java/io/opencensus/trace/TraceOptions.java
index 35181e28..fc594853 100644
--- a/api/src/main/java/io/opencensus/trace/TraceOptions.java
+++ b/api/src/main/java/io/opencensus/trace/TraceOptions.java
@@ -200,7 +200,8 @@ public final class TraceOptions {
       if (isSampled) {
         options = (byte) (options | IS_SAMPLED);
       } else {
-        options = (byte) (options & ~IS_SAMPLED);;
+        options = (byte) (options & ~IS_SAMPLED);
+        ;
       }
       return this;
     }
diff --git a/api/src/main/java/io/opencensus/trace/export/ExportComponent.java b/api/src/main/java/io/opencensus/trace/export/ExportComponent.java
index abf5c531..9b7e1664 100644
--- a/api/src/main/java/io/opencensus/trace/export/ExportComponent.java
+++ b/api/src/main/java/io/opencensus/trace/export/ExportComponent.java
@@ -20,8 +20,8 @@ import io.opencensus.trace.TraceOptions;
 import javax.annotation.Nullable;
 
 /**
- * Class that holds the implementation instances for {@link SpanExporter}, {@link
- * RunningSpanStore} and {@link SampledSpanStore}.
+ * Class that holds the implementation instances for {@link SpanExporter}, {@link RunningSpanStore}
+ * and {@link SampledSpanStore}.
  *
  * <p>Unless otherwise noted all methods (on component) results are cacheable.
  */
@@ -48,8 +48,8 @@ public abstract class ExportComponent {
   public abstract SpanExporter getSpanExporter();
 
   /**
-   * Returns the {@link RunningSpanStore} that can be used to get useful debugging information
-   * about all the current active spans.
+   * Returns the {@link RunningSpanStore} that can be used to get useful debugging information about
+   * all the current active spans.
    *
    * @return the {@code RunningSpanStore} or {@code null} if not supported.
    */
diff --git a/api/src/main/java/io/opencensus/trace/propagation/PropagationComponent.java b/api/src/main/java/io/opencensus/trace/propagation/PropagationComponent.java
index e8abda76..7dfa8202 100644
--- a/api/src/main/java/io/opencensus/trace/propagation/PropagationComponent.java
+++ b/api/src/main/java/io/opencensus/trace/propagation/PropagationComponent.java
@@ -17,16 +17,16 @@
 package io.opencensus.trace.propagation;
 
 /**
- * Container class for all the supported propagation formats. Currently supports only Binary
- * format see {@link BinaryFormat} but more formats will be added.
+ * Container class for all the supported propagation formats. Currently supports only Binary format
+ * see {@link BinaryFormat} but more formats will be added.
  */
 public abstract class PropagationComponent {
   private static final PropagationComponent NOOP_PROPAGATION_COMPONENT =
       new NoopPropagationComponent();
 
   /**
-   * Returns the {@link BinaryFormat} with the provided implementations. If no implementation
-   * is provided then no-op implementation will be used.
+   * Returns the {@link BinaryFormat} with the provided implementations. If no implementation is
+   * provided then no-op implementation will be used.
    *
    * @return the {@code BinaryFormat} implementation.
    */