您可以尝试连接多个数组的方法：

public static <T> T[] concatMultipleArrays(T[]... arrays)
{
   int length = 0;
   for (T[] array : arrays)
   {
      length += array.length;
   }
   T[] result = (T[]) Array.newInstance(arrays.getClass().getComponentType(), length) ;

   length = 0;
   for (int i = 0; i < arrays.length; i++)
   {
      System.arraycopy(arrays[i], 0, result, length, arrays[i].length);
      length += arrays[i].length;
   }

   return result;
}

应该会成功的。这是假设String[]第一个，String[]第二个

List<String> myList = new ArrayList<String>(Arrays.asList(first));
myList.addAll(new ArrayList<String>(Arrays.asList(second)));
String[] both = myList.toArray(new String[myList.size()]);

看看这个优雅的解决方案（如果您需要除char以外的其他类型，请更改它）：

private static void concatArrays(char[] destination, char[]... sources) {
    int currPos = 0;
    for (char[] source : sources) {
        int length = source.length;
        System.arraycopy(source, 0, destination, currPos, length);
        currPos += length;
    }
}

您可以连接每个数组计数。

我发现我必须处理数组可以为空的情况。。。

private double[] concat  (double[]a,double[]b){
    if (a == null) return b;
    if (b == null) return a;
    double[] r = new double[a.length+b.length];
    System.arraycopy(a, 0, r, 0, a.length);
    System.arraycopy(b, 0, r, a.length, b.length);
    return r;

}
private double[] copyRest (double[]a, int start){
    if (a == null) return null;
    if (start > a.length)return null;
    double[]r = new double[a.length-start];
    System.arraycopy(a,start,r,0,a.length-start); 
    return r;
}

非Java 8解决方案：

public static int[] combineArrays(int[] a, int[] b) {
        int[] c = new int[a.length + b.length];

        for (int i = 0; i < a.length; i++) {
            c[i] = a[i];
        }

        for (int j = 0, k = a.length; j < b.length; j++, k++) {
            c[k] = b[j];
        }

        return c;
    }

算法爱好者的另一个答案是：

public static String[] mergeArrays(String[] array1, String[] array2) {
    int totalSize = array1.length + array2.length; // Get total size
    String[] merged = new String[totalSize]; // Create new array
    // Loop over the total size
    for (int i = 0; i < totalSize; i++) {
        if (i < array1.length) // If the current position is less than the length of the first array, take value from first array
            merged[i] = array1[i]; // Position in first array is the current position

        else // If current position is equal or greater than the first array, take value from second array.
            merged[i] = array2[i - array1.length]; // Position in second array is current position minus length of first array.
    }

    return merged;

用法：

String[] array1str = new String[]{"a", "b", "c", "d"}; 
String[] array2str = new String[]{"e", "f", "g", "h", "i"};
String[] listTotalstr = mergeArrays(array1str, array2str);
System.out.println(Arrays.toString(listTotalstr));

结果：

[a, b, c, d, e, f, g, h, i]