diff --git a/api/src/main/java/io/grpc/Attributes.java b/api/src/main/java/io/grpc/Attributes.java
index 9063e6e7c8..cadafece3e 100644
--- a/api/src/main/java/io/grpc/Attributes.java
+++ b/api/src/main/java/io/grpc/Attributes.java
@@ -252,7 +252,7 @@ public final class Attributes {
       return this;
     }
 
-    public <T> Builder setAll(Attributes other) {
+    public Builder setAll(Attributes other) {
       data(other.data.size()).putAll(other.data);
       return this;
     }
diff --git a/api/src/main/java/io/grpc/InternalMethodDescriptor.java b/api/src/main/java/io/grpc/InternalMethodDescriptor.java
index 9ffc188087..23bb039e0f 100644
--- a/api/src/main/java/io/grpc/InternalMethodDescriptor.java
+++ b/api/src/main/java/io/grpc/InternalMethodDescriptor.java
@@ -30,11 +30,11 @@ public final class InternalMethodDescriptor {
     this.transport = checkNotNull(transport, "transport");
   }
 
-  public Object geRawMethodName(MethodDescriptor<?, ?> md) {
-    return md.getRawMethodName(transport.ordinal());
+  public Object geRawMethodName(MethodDescriptor<?, ?> descriptor) {
+    return descriptor.getRawMethodName(transport.ordinal());
   }
 
-  public void setRawMethodName(MethodDescriptor<?, ?> md, Object o) {
-    md.setRawMethodName(transport.ordinal(), o);
+  public void setRawMethodName(MethodDescriptor<?, ?> descriptor, Object o) {
+    descriptor.setRawMethodName(transport.ordinal(), o);
   }
 }
diff --git a/api/src/main/java/io/grpc/NameResolverRegistry.java b/api/src/main/java/io/grpc/NameResolverRegistry.java
index fe97f828d0..2e914e2fbc 100644
--- a/api/src/main/java/io/grpc/NameResolverRegistry.java
+++ b/api/src/main/java/io/grpc/NameResolverRegistry.java
@@ -86,8 +86,8 @@ public final class NameResolverRegistry {
     // sort() must be stable, as we prefer first-registered providers
     Collections.sort(providers, Collections.reverseOrder(new Comparator<NameResolverProvider>() {
       @Override
-      public int compare(NameResolverProvider p1, NameResolverProvider p2) {
-        return p1.priority() - p2.priority();
+      public int compare(NameResolverProvider o1, NameResolverProvider o2) {
+        return o1.priority() - o2.priority();
       }
     }));
     effectiveProviders = Collections.unmodifiableList(providers);
diff --git a/protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java b/protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java
index 326e4ee895..ddba5b8d5b 100644
--- a/protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java
+++ b/protobuf-lite/src/main/java/io/grpc/protobuf/lite/ProtoLiteUtils.java
@@ -97,8 +97,8 @@ public final class ProtoLiteUtils {
   /** Copies the data from input stream to output stream. */
   static long copy(InputStream from, OutputStream to) throws IOException {
     // Copied from guava com.google.common.io.ByteStreams because its API is unstable (beta)
-    checkNotNull(from);
-    checkNotNull(to);
+    checkNotNull(from, "inputStream cannot be null!");
+    checkNotNull(to, "outputStream cannot be null!");
     byte[] buf = new byte[BUF_SIZE];
     long total = 0;
     while (true) {
@@ -162,7 +162,7 @@ public final class ProtoLiteUtils {
             @SuppressWarnings("unchecked")
             T message = (T) ((ProtoInputStream) stream).message();
             return message;
-          } catch (IllegalStateException ex) {
+          } catch (IllegalStateException ignored) {
             // Stream must have been read from, which is a strange state. Since the point of this
             // optimization is to be transparent, instead of throwing an error we'll continue,
             // even though it seems likely there's a bug.