文件流数据不完整

文件流保存成文件后，提示文件不完整，或打不开。

Stream A 写入到 Stream B 后，未及时 Close A

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// 构建zip文件
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
// 利用 try() ，zipOutputStream 运行到范围外时自动 close
try (ZipOutputStream zipOutputStream = new ZipOutputStream(outputStream)) {
    zipOutputStream.putNextEntry(new ZipEntry(taskUuid + "-" + uuid + ".jpg"));
    ImageIO.write(bufferedImage, "jpeg", zipOutputStream);
    zipOutputStream.closeEntry();
    zipOutputStream.putNextEntry(new ZipEntry(taskUuid + "-" + uuid + "-dataInfo.json"));
    zipOutputStream.write(pixelsLandJsonStr.getBytes(Charsets.UTF_8));
    zipOutputStream.closeEntry();
    zipOutputStream.flush();
    // 此处的 outputStream 不完整
}
// 此处的 outputStream 才是完整的

write 时把空的 byte 也写入了 stream

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// 错误示范
try (OutputStream outputStream = response.getOutputStream()) {
    // 读取filename
    try (BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(filePath))) {
        byte[] buffer = new byte[1024];
        int length = -1;
        while ((length = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer);
        }
    }
}

// 正确（向 outputStream 写入数据的时候，必须指定相应的 length ）
try (OutputStream outputStream = response.getOutputStream()) {
    // 读取filename
    try (BufferedInputStream inputStream = new BufferedInputStream(new FileInputStream(filePath))) {
        byte[] buffer = new byte[1024];
        int length = -1;
        while ((length = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, length);
        }
    }
}