尝试将inputstream复制到outputstream时出现Java IOException

Question

我试图将输入流图像写入OutputStream以在浏览器中显示图像,这是代码:

try
{
    InputStream input = Filer.readImage("images/test.jpg");
    byte[] buffer = new byte[1024];
    int bytesRead;
    while ((bytesRead = input.read(buffer)) != -1)
    {
        responseBody.write(buffer, 0, bytesRead);
    }
}
catch(IOException e)
{
    System.out.println(e);
}

readImage:

public static InputStream readImage(String file) throws IOException {
    try (InputStream input = new FileInputStream(file)) {

        return input;
    }
}

但写作时我收到错误:

java.io.IOException: Stream Closed

有任何想法吗？

Answer 1

退出块时,try-with-resources会关闭流

try (InputStream input = new FileInputStream(file)) {

即.当你的方法返回时.

只需删除它,并在其他方法体的末尾处理关闭流.

正如评论中所述,这里是官方教程的链接try-with-resources.