Remove usages of Guava Precondtions from opencensus-api (issue #1081).

This commit replaces the most commonly used precondtion checks with methods in
a new utility class, io.opencensus.internal.Utils.

3 files changed, 14 insertions, 17 deletions

diff --git a/api/src/main/java/io/opencensus/tags/NoopTags.java b/api/src/main/java/io/opencensus/tags/NoopTags.java
index 973a1b40..fb52b164 100644
--- a/api/src/main/java/io/opencensus/tags/NoopTags.java
+++ b/api/src/main/java/io/opencensus/tags/NoopTags.java
@@ -16,11 +16,9 @@
 
 package io.opencensus.tags;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.base.Preconditions;
 import io.opencensus.common.Scope;
 import io.opencensus.internal.NoopScope;
+import io.opencensus.internal.Utils;
 import io.opencensus.tags.propagation.TagContextBinarySerializer;
 import io.opencensus.tags.propagation.TagPropagationComponent;
 import java.util.Collections;
@@ -105,8 +103,8 @@ final class NoopTags {
     @Override
     @Deprecated
     public void setState(TaggingState state) {
-      Preconditions.checkNotNull(state, "state");
-      Preconditions.checkState(!isRead, "State was already read, cannot set state.");
+      Utils.checkNotNull(state, "state");
+      Utils.checkState(!isRead, "State was already read, cannot set state.");
     }
   }
 
@@ -131,7 +129,7 @@ final class NoopTags {
 
     @Override
     public TagContextBuilder toBuilder(TagContext tags) {
-      checkNotNull(tags, "tags");
+      Utils.checkNotNull(tags, "tags");
       return getNoopTagContextBuilder();
     }
 
@@ -142,7 +140,7 @@ final class NoopTags {
 
     @Override
     public Scope withTagContext(TagContext tags) {
-      checkNotNull(tags, "tags");
+      Utils.checkNotNull(tags, "tags");
       return NoopScope.getInstance();
     }
   }
@@ -153,14 +151,14 @@ final class NoopTags {
 
     @Override
     public TagContextBuilder put(TagKey key, TagValue value) {
-      checkNotNull(key, "key");
-      checkNotNull(value, "value");
+      Utils.checkNotNull(key, "key");
+      Utils.checkNotNull(value, "value");
       return this;
     }
 
     @Override
     public TagContextBuilder remove(TagKey key) {
-      checkNotNull(key, "key");
+      Utils.checkNotNull(key, "key");
       return this;
     }
 
@@ -203,13 +201,13 @@ final class NoopTags {
 
     @Override
     public byte[] toByteArray(TagContext tags) {
-      checkNotNull(tags, "tags");
+      Utils.checkNotNull(tags, "tags");
       return EMPTY_BYTE_ARRAY;
     }
 
     @Override
     public TagContext fromByteArray(byte[] bytes) {
-      checkNotNull(bytes, "bytes");
+      Utils.checkNotNull(bytes, "bytes");
       return getNoopTagContext();
     }
   }
diff --git a/api/src/main/java/io/opencensus/tags/TagKey.java b/api/src/main/java/io/opencensus/tags/TagKey.java
index ba0b91ed..615c2d46 100644
--- a/api/src/main/java/io/opencensus/tags/TagKey.java
+++ b/api/src/main/java/io/opencensus/tags/TagKey.java
@@ -16,10 +16,9 @@
 
 package io.opencensus.tags;
 
-import static com.google.common.base.Preconditions.checkArgument;
-
 import com.google.auto.value.AutoValue;
 import io.opencensus.internal.StringUtils;
+import io.opencensus.internal.Utils;
 import javax.annotation.concurrent.Immutable;
 
 /**
@@ -61,7 +60,7 @@ public abstract class TagKey {
    * @since 0.8
    */
   public static TagKey create(String name) {
-    checkArgument(isValid(name));
+    Utils.checkArgument(isValid(name), "Invalid TagKey name: " + name);
     return new AutoValue_TagKey(name);
   }
 
diff --git a/api/src/main/java/io/opencensus/tags/TagValue.java b/api/src/main/java/io/opencensus/tags/TagValue.java
index 95e13002..5c1019ff 100644
--- a/api/src/main/java/io/opencensus/tags/TagValue.java
+++ b/api/src/main/java/io/opencensus/tags/TagValue.java
@@ -17,8 +17,8 @@
 package io.opencensus.tags;
 
 import com.google.auto.value.AutoValue;
-import com.google.common.base.Preconditions;
 import io.opencensus.internal.StringUtils;
+import io.opencensus.internal.Utils;
 import javax.annotation.concurrent.Immutable;
 
 /**
@@ -55,7 +55,7 @@ public abstract class TagValue {
    * @since 0.8
    */
   public static TagValue create(String value) {
-    Preconditions.checkArgument(isValid(value));
+    Utils.checkArgument(isValid(value), "Invalid TagValue: " + value);
     return new AutoValue_TagValue(value);
   }