如何在Java中的finally块中处理抛出异常

Question

在Java中，不建议finally在try-chatch块的section中抛出异常，因为它会隐藏任何throwable在tryor catch块中抛出的未处理的传播。blocker根据默认的声纳配置文件，此做法违反了液位。

声纳错误：从此finally块中删除此throw语句。

请考虑以下代码段。

例如：在finally块内关闭输入流，并在关闭流时处理可能的异常。

    public void upload(File file) {
        ChannelSftp c = (ChannelSftp) channel;
        BufferedInputStream bis = new BufferedInputStream(file.toInputStream());
        try {
            String uploadLocation = Files.simplifyPath(this.fileLocation + "/" + file.getName());
            c.put(bis, uploadLocation);
        } catch (SftpException e) {
            throw new IllegalTargetException("Error occurred while uploading " + e.getMessage());
        } finally {
            try {
                bis.close();
            } catch (IOException e) {
                throw new UnsupportedOperationException("Exception occurred while closing Input stream " + e.getMessage());
            }
        }
    }

如果您能展示处理这些情况的常规方法，将不胜感激。

Answer 1

处理此问题的最佳方法是使用try-with-resource. 但是如果有人想手动关闭连接并显示tryorcatch块的异常而不隐藏，下面的代码片段是解决方案。

public void upload(File file) throws IOException {
    ChannelSftp c = (ChannelSftp) channel;
    BufferedInputStream bis = new BufferedInputStream(file.toInputStream());
    SftpException sftpException = null;
    try {
        String uploadLocation = Files.simplifyPath(this.fileLocation + "/" + file.getName());
        c.put(bis, uploadLocation);
    } catch (SftpException e) {
        sftpException = e;
        throw new IllegalTargetException("Error occurred while uploading " + e.getMessage());
    } finally {
        if (sftpException != null) {
            try {
                bis.close();
            } catch (Throwable t) {
                sftpException.addSuppressed(t);
            }
        } else {
            bis.close();
        }
    }
}