使用流的Java8的另一种方式

  public String[] concatString(String[] a, String[] b){ 
    Stream<String> streamA = Arrays.stream(a);
    Stream<String> streamB = Arrays.stream(b);
    return Stream.concat(streamA, streamB).toArray(String[]::new); 
  }

使用高性能System.arraycopy而不需要@SuppressWarnings注释的通用静态版本：

public static <T> T[] arrayConcat(T[] a, T[] b) {
    T[] both = Arrays.copyOf(a, a.length + b.length);
    System.arraycopy(b, 0, both, a.length, b.length);
    return both;
}

Object[] mixArray(String[] a, String[] b)
String[] s1 = a;
String[] s2 = b;
Object[] result;
List<String> input = new ArrayList<String>();
for (int i = 0; i < s1.length; i++)
{
    input.add(s1[i]);
}
for (int i = 0; i < s2.length; i++)
{
    input.add(s2[i]);
}
result = input.toArray();
return result;

怎么样：

public String[] combineArray (String[] ... strings) {
    List<String> tmpList = new ArrayList<String>();
    for (int i = 0; i < strings.length; i++)
        tmpList.addAll(Arrays.asList(strings[i]));
    return tmpList.toArray(new String[tmpList.size()]);
}

只是想添加，您也可以使用System.arraycopy：

import static java.lang.System.out;
import static java.lang.System.arraycopy;
import java.lang.reflect.Array;
class Playground {
    @SuppressWarnings("unchecked")
    public static <T>T[] combineArrays(T[] a1, T[] a2) {
        T[] result = (T[]) Array.newInstance(a1.getClass().getComponentType(), a1.length+a2.length);
        arraycopy(a1,0,result,0,a1.length);
        arraycopy(a2,0,result,a1.length,a2.length);
        return result;
    }
    public static void main(String[ ] args) {
        String monthsString = "JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC";
        String[] months = monthsString.split("(?<=\\G.{3})");
        String daysString = "SUNMONTUEWEDTHUFRISAT";
        String[] days = daysString.split("(?<=\\G.{3})");
        for (String m : months) {
            out.println(m);
        }
        out.println("===");
         for (String d : days) {
            out.println(d);
        }
        out.println("===");
        String[] results = combineArrays(months, days);
        for (String r : results) {
            out.println(r);
        }
        out.println("===");
    }
}

每个答案都是复制数据并创建新阵列。这并不是绝对必要的，如果您的阵列相当大，这绝对不是您想要做的。Java创建者已经知道数组拷贝是浪费的，这就是为什么他们提供System.arrayCopy（）来在我们必须时在Java之外进行这些拷贝的原因。

与其四处复制数据，不如考虑将其保留在原地，并从中提取数据所在的位置。仅仅因为程序员想组织数据位置而复制数据位置并不总是明智的。

// I have arrayA and arrayB; would like to treat them as concatenated
// but leave my damn bytes where they are!
Object accessElement ( int index ) {
     if ( index < 0 ) throw new ArrayIndexOutOfBoundsException(...);
     // is reading from the head part?
     if ( index < arrayA.length )
          return arrayA[ index ];
     // is reading from the tail part?
     if ( index < ( arrayA.length + arrayB.length ) )
          return arrayB[ index - arrayA.length ];
     throw new ArrayIndexOutOfBoundsException(...); // index too large
}