Question

我正在尝试＆＃34; chunk＆＃34;上升图像的字节。这将允许我以字节数组上传大图像。我将当前存储的图像存储为一个大字节[]。我想将字节数组拆分为byte []＆＃39; s，每个都精确到5 MB。

Answer 1

您可以使用copyOfRange：

T[] copyOfRange (T[] original, 
            int from, 
            int to);

在你的情况下，像这样：

Byte[] copyOfRange (original, 
            0, 
            5000000);

确保计算偏移量：

class test {

  // this is just for dummy data
  public static byte[] getTestBytes() {
    byte[] largeByteArray = new byte[50_000_000];
    for(int i = 0; i < 50_000_000; i ++) {
      largeByteArray[i] = 0;
    }
    return largeByteArray;
  }


  // this method splits your byte array into small portions 
  // and returns a list with those portions
  public static List<byte[]> byteToPortions(byte[] largeByteArray) {
    // create a list to keep the portions
    List<byte[]> byteArrayPortions = new ArrayList<>();

    // 5mb is about 5.000.000 bytes
    int sizePerPortion = 5_000_000;
    int offset = 0;

    // split the array
    while(offset < largeByteArray.length) {
      // into 5 mb portions
      byte[] portion = Arrays.copyOfRange(largeByteArray, offset, offset + sizePerPortion);

      // update the offset to increment the copied area
      offset += sizePerPortion;

      // add the byte array portions to the list
      byteArrayPortions.add(portion);
    }

    // return portions
    return byteArrayPortions;
  }

  // create your byte array, and split it to portions
  public static void main(String[] args) {
    byte[] largeByteArray = getTestBytes();

    List<byte[]> portions = byteToPortions(largeByteArray);

    // work with your portions
  }
}

很酷：价值to 不必须是数组中的索引，它会为您检查而不会出错并复制对目标数组有效的子集。

Answer 2

divideArray(common.fullyReadFileToBytes(wallpaperDirectory), 5 * 1024 * 1024)

通过

调用它

$("input[type='file']").val("");

将byte []拆分为多个byte []数组

2 个答案: