数组工具类。

src/main/java/xyz/zhouxy/plusone/commons/util/MoreArrays.java

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+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 xyz.zhouxy.plusone.commons.util;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import javax.annotation.Nullable;
+
+import com.google.common.annotations.Beta;
+
+@Beta
+public class MoreArrays {
+
+    public static float[] concatFloatArray(Collection<float[]> arrays) {
+        int length = 0;
+        for (float[] arr : arrays) {
+            length += arr.length;
+        }
+        float[] result = new float[length];
+        int i = 0;
+        for (float[] arr : arrays) {
+            for (float item : arr) {
+                result[i++] = item;
+            }
+        }
+        return result;
+    }
+
+    public static double[] concatDoubleArray(Collection<double[]> arrays) {
+        int length = 0;
+        for (double[] arr : arrays) {
+            length += arr.length;
+        }
+        double[] result = new double[length];
+        int i = 0;
+        for (double[] arr : arrays) {
+            for (double item : arr) {
+                result[i++] = item;
+            }
+        }
+        return result;
+    }
+
+    public static byte[] concatByteArray(Collection<byte[]> arrays) {
+        int length = 0;
+        for (byte[] arr : arrays) {
+            length += arr.length;
+        }
+        byte[] result = new byte[length];
+        int i = 0;
+        for (byte[] arr : arrays) {
+            for (byte item : arr) {
+                result[i++] = item;
+            }
+        }
+        return result;
+    }
+
+    public static long[] concatLongArray(Collection<long[]> arrays) {
+        int length = 0;
+        for (long[] arr : arrays) {
+            length += arr.length;
+        }
+        long[] result = new long[length];
+        int i = 0;
+        for (long[] arr : arrays) {
+            for (long item : arr) {
+                result[i++] = item;
+            }
+        }
+        return result;
+    }
+
+    public static int[] concatIntArray(Collection<int[]> arrays) {
+        int length = 0;
+        for (int[] arr : arrays) {
+            length += arr.length;
+        }
+        int[] result = new int[length];
+        int i = 0;
+        for (int[] arr : arrays) {
+            for (int item : arr) {
+                result[i++] = item;
+            }
+        }
+        return result;
+    }
+
+    public static <T> List<T> concatToList(@Nullable Collection<T[]> arrays) {
+        if (arrays == null || arrays.isEmpty()) {
+            return Collections.emptyList();
+        }
+        int length = 0;
+        for (T[] arr : arrays) {
+            length += arr.length;
+        }
+        final List<T> result = new ArrayList<>(length);
+        for (T[] arr : arrays) {
+            Collections.addAll(result, arr);
+        }
+        return result;
+    }
+
+    private MoreArrays() {
+        throw new IllegalStateException("Utility class");
+    }
+}