如何写一个潜在的巨大InputStream到文件？

Question

我有一个API调用,返回一个字节数组.我当前将结果流式传输到字节数组,然后确保校验和匹配,然后将ByteArrayOutputStream写入File.代码是这样的,它运行得很好.

    String path = "file.txt";
    ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
    int bufferSize = 1024;
    byte[] buffer = new byte[bufferSize];
    int len = 0;
    while ((len = inputStream.read(buffer)) != -1) {
        byteBuffer.write(buffer, 0, len);
    }
    FileOutputStream stream = new FileOutputStream(path); 
    stream.write(byteBuffer.toByteArray());

我担心输入流的结果可能大于android中的堆大小,如果整个字节数组在内存中,我可能会得到OutOfMemory异常.将inputStream写入文件块的最优雅方法是什么,这样字节数组永远不会大于堆大小？

Answer 1

不写信给ByteArrayOutputStream.直接写到FileOutputStream.

String path = "file.txt";
FileOutputStream output = new FileOutputStream(path); 
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int len = 0;
while ((len = inputStream.read(buffer)) != -1) {
    output.write(buffer, 0, len);
}

Answer 2

我接受了建议,跳过ByteArrayOutputStream并写入FileOutputStream,这似乎解决了我的顾虑.通过一个快速调整,FileOutputStream由BufferedOutputStream修饰

String path = "file.txt";
OutputStream stream = new BufferedOutputStream(new FileOutputStream(path)); 
int bufferSize = 1024;
byte[] buffer = new byte[bufferSize];
int len = 0;
while ((len = is.read(buffer)) != -1) {
    stream.write(buffer, 0, len);
}
if(stream!=null)
    stream.close();