Question

我已尝试 200 MB 的图像文件并将其转换为字节数组但由于OOM而崩溃，因此如何读取大文件并转换为byte []

引起：java.lang.OutOfMemoryError：无法分配210288697字节分配4108138个空闲字节和186MB直到OOM

byte[] fullyReadFileToBytes(File file) throws IOException {

        int size = (int) file.length();
        byte bytes[] = new byte[size];
        byte tmpBuff[] = new byte[size];
        FileInputStream fis = new FileInputStream(file);
        try {

            int read = fis.read(bytes, 0, size);
            if (read < size) {
                int remain = size - read;
                while (remain > 0) {
                    read = fis.read(tmpBuff, 0, remain);
                    System.arraycopy(tmpBuff, 0, bytes, size - remain, read);
                    remain -= read;
                }
            }
        } catch (IOException e) {
            throw e;
        } finally {
            fis.close();
        }

        return bytes;
    }

注意：我已经尝试过100MB并且它工作正常但是如果大小超过150MB则会造成崩溃。

Answer 1

使用Http post multipart transfer，即

$(document).ready(function () {
    // append plus symbol to every list item that has children
    $('#mobile-nav .parent').append('<span class="open-menu fa fa-angle-down"></span>');

    // fix non-scrolling overflow issue on mobile devices
    $('#mobile-nav > ul').wrap('<div class="overflow"></div>');
    $(window).on('load resize', function () {
        var vph = $(window).height(); // 57px - height of #mobile-nav
        $('.overflow').css('max-height', vph);
    });

    // global variables
    var menu = $('.overflow > ul');
    var bg = $('html, body');

    // toggle background scrolling
    function bgScrolling() {
        // if menu has toggled class... *
        if (menu.hasClass('open')) {
            // * disable background scrolling
            bg.css({
                'overflow-y': 'hidden',
                'height': 'auto'
            });
        // if menu does not have toggled class... *
        } else {
            // * enable background scrolling
            bg.css({
                'overflow-y': 'visible',
                'height': '100%'
            });
        }
    }

    // menu button click events
    $('.menu-button').on('click', function (e) {
        e.preventDefault();
        // activate toggles
        menu.slideToggle(250);
        menu.toggleClass('open');
        bgScrolling();
    });

    // list item click events
    $('.open-menu').on('click', function (e) {
        e.preventDefault();
        $(this).prev('ul').slideToggle(250);
        $(this).toggleClass('rotate');
    });
});

使用volley多次传输请求。它将跟踪故障 https://gist.github.com/anggadarkprince/a7c536da091f4b26bb4abf2f92926594

Answer 2

以下代码有助于压缩位图图像并转换为字符串字节。

 public String BitMapToString(Bitmap bitmap) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 50, baos);
        byte[] b = baos.toByteArray();
        String temp = null;
        try {
            System.gc();
            temp = Base64.encodeToString(b, Base64.DEFAULT);
        } catch (Exception e) {
            e.printStackTrace();
        } catch (OutOfMemoryError e) {
            baos = new ByteArrayOutputStream();
            bitmap.compress(Bitmap.CompressFormat.JPEG, 50, baos);
            b = baos.toByteArray();
            temp = Base64.encodeToString(b, Base64.DEFAULT);
        }
        return temp;
    }

如何读取大文件到字节数组？

2 个答案: