java: add proper lint task to CI

bindings/java/Makefile

@@ -8,6 +8,9 @@ SOURCE_DIR = $(realpath $(CURDIR)/../..)
 OUT_DIR = $(CURDIR)/c/build
 BUILD_DIR = $(OUT_DIR)/_cmake_build
 
+lint: gradlew
+	./gradlew --no-daemon clean spotlessCheck
+
 build: gradlew $(OUT_DIR)/lib/libevmc-java.so
 	mkdir -p ./java/build
 	./gradlew --no-daemon clean spotlessApply build

bindings/java/build.gradle

@@ -18,15 +18,15 @@ allprojects {
     apply plugin: 'com.diffplug.gradle.spotless'
     spotless {
         java {
-        // This path needs to be relative to each project
-        target fileTree('.') {
-            include '**/*.java'
-            exclude '**/.gradle/**'
-        }
-        importOrder 'org.ethereum', 'java', ''
-        trimTrailingWhitespace()
-        endWithNewline()
-        googleJavaFormat('1.7')
+            // This path needs to be relative to each project
+            target fileTree('.') {
+                include '**/*.java'
+                exclude '**/.gradle/**'
+            }
+            importOrder 'org.ethereum', 'java', ''
+            trimTrailingWhitespace()
+            endWithNewline()
+            googleJavaFormat('1.7')
         }
     }
 }

bindings/java/java/src/main/java/org/ethereum/evmc/EvmcLoaderException.java

@@ -4,7 +4,7 @@
 package org.ethereum.evmc;
 
 public class EvmcLoaderException extends Exception {
-   public EvmcLoaderException(String message) {
-      super(message);
-   }
+  public EvmcLoaderException(String message) {
+    super(message);
+  }
 }

bindings/java/java/src/main/java/org/ethereum/evmc/EvmcVm.java

@@ -3,8 +3,6 @@
 // Licensed under the Apache License, Version 2.0.
 package org.ethereum.evmc;
 
-import org.ethereum.evmc.EvmcLoaderException;
-
 import java.nio.ByteBuffer;
 import java.util.Objects;
 
@@ -21,7 +19,7 @@ public final class EvmcVm implements AutoCloseable {
    * This method loads the specified evm shared library and loads/initializes the jni bindings.
    *
    * @param filename /path/filename of the evm shared object
-   * @throws EvmcLoaderException
+   * @throws org.ethereum.evmc.EvmcLoaderException
    */
   public static EvmcVm create(String filename) throws EvmcLoaderException {
     if (!EvmcVm.isEvmcLibraryLoaded) {
@@ -49,7 +47,7 @@ private EvmcVm(String filename) throws EvmcLoaderException {
    *
    * @param Path to the dynamic object representing the EVM implementation.
    * @return Internal object pointer.
-   * @throws EvmcLoaderException
+   * @throws org.ethereum.evmc.EvmcLoaderException
    */
   private static native ByteBuffer load_and_create(String filename) throws EvmcLoaderException;
 
@@ -152,9 +150,7 @@ public int set_option(String name, String value) {
   /** get size of result struct */
   private static native int get_result_size();
 
-  /**
-   * This method cleans up resources.
-   */
+  /** This method cleans up resources. */
   @Override
   public void close() {
     destroy(nativeVm);

bindings/java/java/src/main/java/org/ethereum/evmc/Host.java

@@ -3,23 +3,19 @@
 // Licensed under the Apache License, Version 2.0.
 package org.ethereum.evmc;
 
-import static java.util.Objects.requireNonNull;
-
 import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
 
 /**
  * The Host interface.
  *
  * <p>The set of all callback functions expected by VM instances.
  */
 final class Host {
-  static private ByteBuffer ensureDirectBuffer(ByteBuffer input) {
+  private static ByteBuffer ensureDirectBuffer(ByteBuffer input) {
     // Reallocate if needed.
-    if (!input.isDirect())
+    if (!input.isDirect()) {
       return ByteBuffer.allocateDirect(input.remaining()).put(input);
+    }
     return input;
   }
 

circle.yml

@@ -301,14 +301,15 @@ jobs:
       - checkout
       - build
       - test
+      - run:
+          name: "Java Lint (spotlessCheck)"
+          command: cd bindings/java && make lint
       - run:
           name: "Java Build"
-          command: |
-            cd bindings/java && make clean build
+          command: cd bindings/java && make clean build
       - run:
           name: "Java Test"
-          command: |
-            cd bindings/java && make test
+          command: cd bindings/java && make test
 
   bindings-rust:
     docker: