java - 新字符串(字节)在 GWT 客户端中导致 "Maximum call stack size exceeded"

Question

以下内容适用于短字符串

result = new String(bytes);

我有一个大约 140000 字节的 byte[]，当我尝试使用上面的代码从中创建一个 String 时，浏览器会抛出异常 超过最大调用堆栈大小。我正在使用 GWT 2.6.0。

我相信创建大型数组时可能会抛出此异常，但我找不到在 GWT 中从 byte[] 创建字符串的替代方法。我可以使用任何建议或解决方法来使其正常工作吗？

下面是 JavaScript 异常和调用堆栈。

Uncaught RangeError: Maximum call stack size exceeded
valueOf_86  @   String.java:630
utf8ToString    @   String.java:210
_String_0   @   String.java:322
_String_1   @   String.java:237
handleHttpResponse_7    @   BaseRequest.java:38
onResponseReceived  @   GwtNet.java:56
$fireOnResponseReceived @   Request.java:315
onReadyStateChange_1    @   RequestBuilder.java:42
(anonymous function)    @   XMLHttpRequest.java:402
apply_24    @   Impl.java:58
entry0  @   Impl.java:385
(anonymous function)    @   Impl.java:91

Answer 1

我无法找到一个简单的方法来解决这个问题，所以我最终编写了一个方法来将 UTF-8 字节数组切成 block 并逐 block 解码。如果有人知道更好的方法，请发布新答案。

/**
 * Decoding very long strings in GWT causes exceptions, so anything that could be decoding a large string in
 * GWT must use this method instead
 * @param bytes The array of UTF-8 bytes
 * @return String representation of the array
 * @throws UnsupportedEncodingException
 */
public static String getUTF8String(byte[] bytes) throws UnsupportedEncodingException {
    StringBuilder stringBuilder = new StringBuilder();
    int charLength;
    int lastDecodeOffset = 0;
    int charCount = 0;

    int offset = 0;
    while (offset < bytes.length) {
        if ((bytes[offset] & 0b10000000) == 0b00000000) charLength = 1;
        else if ((bytes[offset] & 0b11100000) == 0b11000000) charLength = 2;
        else if ((bytes[offset] & 0b11110000) == 0b11100000) charLength = 3;
        else if ((bytes[offset] & 0b11111000) == 0b11110000) charLength = 4;
        else if ((bytes[offset] & 0b11111100) == 0b11111000) charLength = 5;
        else if ((bytes[offset] & 0b11111110) == 0b11111100) charLength = 6;
        else throw new UnsupportedEncodingException("Invalid UTF-8 data");

        if (offset + charLength > bytes.length) {
            throw new UnsupportedEncodingException("Invalid UTF-8 data");
        }

        offset += charLength;
        charCount++;

        if (charCount > 2048 || offset >= bytes.length) {
            stringBuilder.append(new String(bytes, lastDecodeOffset, offset - lastDecodeOffset, "UTF-8"));
            lastDecodeOffset = offset;
            charCount = 0;
        }
    }

    return stringBuilder.toString();
}