add style check for java and scala code

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/Booster.java

@@ -99,10 +99,10 @@ public interface Booster {
    * Predict with data
    * @param data dmatrix storing the input
    * @param treeLimit Limit number of trees in the prediction; defaults to 0 (use all trees).
-   * @param predLeaf When this option is on, the output will be a matrix of (nsample, ntrees), nsample = data.numRow
-  with each record indicating the predicted leaf index of each sample in each tree.
-  Note that the leaf index of a tree is unique per tree, so you may find leaf 1
-  in both tree 1 and tree 0.
+   * @param predLeaf When this option is on, the output will be a matrix of (nsample, ntrees),
+   *                 nsample = data.numRow with each record indicating the predicted leaf index of
+   *                 each sample in each tree. Note that the leaf index of a tree is unique per
+   *                 tree, so you may find leaf 1 in both tree 1 and tree 0.
    * @return predict result
    * @throws XGBoostError native error
    */
@@ -131,7 +131,8 @@ public interface Booster {
    * @param withStats  bool
    *                   Controls whether the split statistics are output.
    */
-  void dumpModel(String modelPath, String featureMap, boolean withStats) throws IOException, XGBoostError;
+  void dumpModel(String modelPath, String featureMap, boolean withStats)
+          throws IOException, XGBoostError;
 
   /**
    * get importance of each feature

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/DMatrix.java

@@ -1,10 +1,10 @@
 /*
- Copyright (c) 2014 by Contributors 
+ Copyright (c) 2014 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
-    
+
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software
@@ -32,7 +32,7 @@ public class DMatrix {
   //load native library
   static {
     try {
-      NativeLibLoader.InitXgboost();
+      NativeLibLoader.initXgBoost();
     } catch (IOException ex) {
       logger.error("load native library failed.");
       logger.error(ex);
@@ -84,8 +84,6 @@ public class DMatrix {
 
   /**
    * used for DMatrix slice
-   *
-   * @param handle
    */
   protected DMatrix(long handle) {
     this.handle = handle;
@@ -216,8 +214,6 @@ public class DMatrix {
 
   /**
    * save DMatrix to filePath
-   *
-   * @param filePath file path
    */
   public void saveBinary(String filePath) {
     XgboostJNI.XGDMatrixSaveBinary(handle, filePath, 1);
@@ -225,8 +221,6 @@ public class DMatrix {
 
   /**
    * Get the handle
-   *
-   * @return native handler id
    */
   public long getHandle() {
     return handle;
@@ -234,9 +228,6 @@ public class DMatrix {
 
   /**
    * flatten a mat to array
-   *
-   * @param mat
-   * @return
    */
   private static float[] flatten(float[][] mat) {
     int size = 0;

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/IEvaluation.java

@@ -1,10 +1,10 @@
 /*
- Copyright (c) 2014 by Contributors 
+ Copyright (c) 2014 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
-    
+
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/IObjective.java

@@ -1,10 +1,10 @@
 /*
- Copyright (c) 2014 by Contributors 
+ Copyright (c) 2014 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
-    
+
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/JNIErrorHandle.java

@@ -1,10 +1,10 @@
 /*
- Copyright (c) 2014 by Contributors 
+ Copyright (c) 2014 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
-    
+
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software
@@ -30,7 +30,7 @@ class JNIErrorHandle {
   //load native library
   static {
     try {
-      NativeLibLoader.InitXgboost();
+      NativeLibLoader.initXgBoost();
     } catch (IOException ex) {
       logger.error("load native library failed.");
       logger.error(ex);

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/JavaBoosterImpl.java

@@ -1,10 +1,10 @@
 /*
- Copyright (c) 2014 by Contributors 
+ Copyright (c) 2014 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
-    
+
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software
@@ -38,7 +38,7 @@ class JavaBoosterImpl implements Booster {
   //load native library
   static {
     try {
-      NativeLibLoader.InitXgboost();
+      NativeLibLoader.initXgBoost();
     } catch (IOException ex) {
       logger.error("load native library failed.");
       logger.error(ex);
@@ -80,7 +80,7 @@ class JavaBoosterImpl implements Booster {
   private void init(DMatrix[] dMatrixs) throws XGBoostError {
     long[] handles = null;
     if (dMatrixs != null) {
-      handles = dMatrixs2handles(dMatrixs);
+      handles = dmatrixsToHandles(dMatrixs);
     }
     long[] out = new long[1];
     JNIErrorHandle.checkCall(XgboostJNI.XGBoosterCreate(handles, out));
@@ -151,7 +151,8 @@ class JavaBoosterImpl implements Booster {
       throw new AssertionError(String.format("grad/hess length mismatch %s / %s", grad.length,
               hess.length));
     }
-    JNIErrorHandle.checkCall(XgboostJNI.XGBoosterBoostOneIter(handle, dtrain.getHandle(), grad, hess));
+    JNIErrorHandle.checkCall(XgboostJNI.XGBoosterBoostOneIter(handle, dtrain.getHandle(), grad,
+            hess));
   }
 
   /**
@@ -164,9 +165,10 @@ class JavaBoosterImpl implements Booster {
    * @throws XGBoostError native error
    */
   public String evalSet(DMatrix[] evalMatrixs, String[] evalNames, int iter) throws XGBoostError {
-    long[] handles = dMatrixs2handles(evalMatrixs);
+    long[] handles = dmatrixsToHandles(evalMatrixs);
     String[] evalInfo = new String[1];
-    JNIErrorHandle.checkCall(XgboostJNI.XGBoosterEvalOneIter(handle, iter, handles, evalNames, evalInfo));
+    JNIErrorHandle.checkCall(XgboostJNI.XGBoosterEvalOneIter(handle, iter, handles, evalNames,
+            evalInfo));
     return evalInfo[0];
   }
 
@@ -322,7 +324,8 @@ class JavaBoosterImpl implements Booster {
       statsFlag = 1;
     }
     String[][] modelInfos = new String[1][];
-    JNIErrorHandle.checkCall(XgboostJNI.XGBoosterDumpModel(handle, featureMap, statsFlag, modelInfos));
+    JNIErrorHandle.checkCall(XgboostJNI.XGBoosterDumpModel(handle, featureMap, statsFlag,
+            modelInfos));
     return modelInfos[0];
   }
 
@@ -444,7 +447,7 @@ class JavaBoosterImpl implements Booster {
    * @param dmatrixs
    * @return handle array for input dmatrixs
    */
-  private static long[] dMatrixs2handles(DMatrix[] dmatrixs) {
+  private static long[] dmatrixsToHandles(DMatrix[] dmatrixs) {
     long[] handles = new long[dmatrixs.length];
     for (int i = 0; i < dmatrixs.length; i++) {
       handles[i] = dmatrixs[i].getHandle();

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/NativeLibLoader.java

@@ -1,10 +1,10 @@
 /*
- Copyright (c) 2014 by Contributors 
+ Copyright (c) 2014 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
-    
+
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software
@@ -34,7 +34,7 @@ class NativeLibLoader {
   private static final String nativeResourcePath = "/lib/";
   private static final String[] libNames = new String[]{"xgboost4j"};
 
-  public static synchronized void InitXgboost() throws IOException {
+  public static synchronized void initXgBoost() throws IOException {
     if (!initialized) {
       for (String libName : libNames) {
         smartLoad(libName);
@@ -50,14 +50,17 @@ class NativeLibLoader {
    * The temporary file is deleted after exiting.
    * Method uses String as filename because the pathname is "abstract", not system-dependent.
    * <p/>
-   * The restrictions of {@link File#createTempFile(java.lang.String, java.lang.String)} apply to {@code path}.
+   * The restrictions of {@link File#createTempFile(java.lang.String, java.lang.String)} apply to
+   * {@code path}.
    *
-   * @param path The filename inside JAR as absolute path (beginning with '/'), e.g. /package/File.ext
+   * @param path The filename inside JAR as absolute path (beginning with '/'),
+   *             e.g. /package/File.ext
    * @throws IOException              If temporary file creation or read/write operation fails
    * @throws IllegalArgumentException If source file (param path) does not exist
-   * @throws IllegalArgumentException If the path is not absolute or if the filename is shorter than three characters
+   * @throws IllegalArgumentException If the path is not absolute or if the filename is shorter than
+   * three characters
    */
-  private static void loadLibraryFromJar(String path) throws IOException {
+  private static void loadLibraryFromJar(String path) throws IOException, IllegalArgumentException{
 
     if (!path.startsWith("/")) {
       throw new IllegalArgumentException("The path has to be absolute (start with '/').");
@@ -126,7 +129,6 @@ class NativeLibLoader {
     addNativeDir(nativePath);
     try {
       System.loadLibrary(libName);
-      System.out.println("======load " + libName + " successfully");
     } catch (UnsatisfiedLinkError e) {
       try {
         String libraryFromJar = nativeResourcePath + System.mapLibraryName(libName);

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/XGBoost.java

@@ -1,10 +1,10 @@
 /*
- Copyright (c) 2014 by Contributors 
+ Copyright (c) 2014 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
-    
+
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software

jvm-packages/xgboost4j/src/main/java/org/dmlc/xgboost4j/XGBoostError.java

@@ -1,10 +1,10 @@
 /*
- Copyright (c) 2014 by Contributors 
+ Copyright (c) 2014 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
-    
+
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software

jvm-packages/xgboost4j/src/main/scala/org/dmlc/xgboost4j/scala/Booster.scala

@@ -1,3 +1,19 @@
+/*
+ Copyright (c) 2014 by Contributors
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
 package org.dmlc.xgboost4j.scala
 
 import java.io.IOException
@@ -111,10 +127,10 @@ trait Booster {
    *
    * @param data      dmatrix storing the input
    * @param treeLimit Limit number of trees in the prediction; defaults to 0 (use all trees).
-   * @param predLeaf  When this option is on, the output will be a matrix of (nsample, ntrees), nsample = data.numRow
-  with each record indicating the predicted leaf index of each sample in each tree.
-  Note that the leaf index of a tree is unique per tree, so you may find leaf 1
-  in both tree 1 and tree 0.
+   * @param predLeaf  When this option is on, the output will be a matrix of (nsample, ntrees),
+   *                  nsample = data.numRow with each record indicating the predicted leaf index of
+   *                  each sample in each tree. Note that the leaf index of a tree is unique per
+   *                  tree, so you may find leaf 1 in both tree 1 and tree 0.
    * @return predict result
    * @throws XGBoostError native error
    */

jvm-packages/xgboost4j/src/main/scala/org/dmlc/xgboost4j/scala/DMatrix.scala

@@ -1,3 +1,19 @@
+/*
+ Copyright (c) 2014 by Contributors
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
 package org.dmlc.xgboost4j.scala
 
 import org.dmlc.xgboost4j.{DMatrix => JDMatrix, XGBoostError}

jvm-packages/xgboost4j/src/main/scala/org/dmlc/xgboost4j/scala/EvalTrait.scala

@@ -0,0 +1,38 @@
+/*
+ Copyright (c) 2014 by Contributors
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+package org.dmlc.xgboost4j.scala
+
+import org.dmlc.xgboost4j.IEvaluation
+
+trait EvalTrait extends IEvaluation {
+
+  /**
+   * get evaluate metric
+   *
+   * @return evalMetric
+   */
+  def getMetric: String
+
+  /**
+   * evaluate with predicts and data
+   *
+   * @param predicts predictions as array
+   * @param dmat     data matrix to evaluate
+   * @return result of the metric
+   */
+  def eval(predicts: Array[Array[Float]], dmat: DMatrix): Float
+}

jvm-packages/xgboost4j/src/main/scala/org/dmlc/xgboost4j/scala/ObjectiveTrait.scala

@@ -0,0 +1,30 @@
+/*
+ Copyright (c) 2014 by Contributors
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+package org.dmlc.xgboost4j.scala
+
+import org.dmlc.xgboost4j.IObjective
+
+trait ObjectiveTrait extends IObjective {
+  /**
+   * user define objective function, return gradient and second order gradient
+   *
+   * @param predicts untransformed margin predicts
+   * @param dtrain   training data
+   * @return List with two float array, correspond to first order grad and second order grad
+   */
+  def getGradient(predicts: Array[Array[Float]], dtrain: DMatrix): java.util.List[Array[Float]]
+}

jvm-packages/xgboost4j/src/main/scala/org/dmlc/xgboost4j/scala/ScalaBoosterImpl.scala

@@ -1,3 +1,19 @@
+/*
+ Copyright (c) 2014 by Contributors
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
 package org.dmlc.xgboost4j.scala
 
 import scala.collection.JavaConverters._
@@ -35,7 +51,8 @@ private[scala] class ScalaBoosterImpl private[xgboost4j](booster: JBooster) exte
     booster.evalSet(evalMatrixs.map(_.jDMatrix), evalNames, iter)
   }
 
-  override def evalSet(evalMatrixs: Array[DMatrix], evalNames: Array[String], eval: IEvaluation): String = {
+  override def evalSet(evalMatrixs: Array[DMatrix], evalNames: Array[String], eval: IEvaluation):
+      String = {
     booster.evalSet(evalMatrixs.map(_.jDMatrix), evalNames, eval)
   }
 
@@ -51,7 +68,8 @@ private[scala] class ScalaBoosterImpl private[xgboost4j](booster: JBooster) exte
     booster.predict(data.jDMatrix, outPutMargin)
   }
 
-  override def predict(data: DMatrix, outPutMargin: Boolean, treeLimit: Int): Array[Array[Float]] = {
+  override def predict(data: DMatrix, outPutMargin: Boolean, treeLimit: Int):
+      Array[Array[Float]] = {
     booster.predict(data.jDMatrix, outPutMargin, treeLimit)
   }
 

jvm-packages/xgboost4j/src/main/scala/org/dmlc/xgboost4j/scala/XGBoost.scala

@@ -1,30 +1,47 @@
+/*
+ Copyright (c) 2014 by Contributors
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
 package org.dmlc.xgboost4j.scala
 
 import _root_.scala.collection.JavaConverters._
-
-import org.dmlc.xgboost4j
-import org.dmlc.xgboost4j.{XGBoost => JXGBoost, IEvaluation, IObjective}
+import org.dmlc.xgboost4j.{IEvaluation, IObjective, XGBoost => JXGBoost}
 
 object XGBoost {
 
-  def train(params: Map[String, AnyRef], dtrain: xgboost4j.DMatrix, round: Int,
-            watches: Map[String, xgboost4j.DMatrix], obj: IObjective, eval: IEvaluation): Booster = {
-    val xgboostInJava = JXGBoost.train(params.asJava, dtrain, round, watches.asJava, obj, eval)
+  def train(params: Map[String, AnyRef], dtrain: DMatrix, round: Int,
+            watches: Map[String, DMatrix], obj: IObjective, eval: IEvaluation): Booster = {
+    val jWatches = watches.map{case (name, matrix) => (name, matrix.jDMatrix)}
+    val xgboostInJava = JXGBoost.train(params.asJava, dtrain.jDMatrix, round, jWatches.asJava,
+      obj, eval)
     new ScalaBoosterImpl(xgboostInJava)
   }
 
-  def crossValiation(params: Map[String, AnyRef],
-                     data: DMatrix,
-                     round: Int,
-                     nfold: Int,
-                     metrics: Array[String],
-                     obj: IObjective,
-                     eval: IEvaluation): Array[String] = {
-    JXGBoost.crossValiation(params.asJava, data.jDMatrix, round, nfold, metrics, obj,
-      eval)
+  def crossValiation(
+      params: Map[String, AnyRef],
+      data: DMatrix,
+      round: Int,
+      nfold: Int,
+      metrics: Array[String],
+      obj: EvalTrait,
+      eval: ObjectiveTrait): Array[String] = {
+    JXGBoost.crossValiation(params.asJava, data.jDMatrix, round, nfold, metrics,
+      obj.asInstanceOf[IObjective], eval.asInstanceOf[IEvaluation])
   }
 
-  def initBoostModel(params: Map[String, AnyRef],  dMatrixs: Array[DMatrix]): Booster = {
+  def initBoostModel(params: Map[String, AnyRef], dMatrixs: Array[DMatrix]): Booster = {
     val xgboostInJava = JXGBoost.initBoostingModel(params.asJava, dMatrixs.map(_.jDMatrix))
     new ScalaBoosterImpl(xgboostInJava)
   }