请问布尔值方法是怎么理解

尔值方法怎么理解呢？看代码，每次在最后return XX；的时候总是有点理解不了，特别是看API的时候......请问用下面这段代码讲解一下，怎么理解这种有布尔值的方法？
这段代码有两个return.

private boolean downURlToStream(String url, OutputStream outputStream) {

                BufferedInputStream in = null;
                BufferedOutputStream out = null;
                HttpURLConnection http = null;

                try {
                        URL url1 = new URL(url);
                        http = (HttpURLConnection) url1.openConnection();
                        http.setReadTimeout(3000);
                        http.setRequestMethod("GET");
                        in = new BufferedInputStream(http.getInputStream(), 8 * 1024);
                        out = new BufferedOutputStream(outputStream, 8 * 1024);

                        int b;
                        while ((b = in.read()) != -1) {

                                out.write(b);
                        }

                        return true;
                } catch (MalformedURLException e) {
                        e.printStackTrace();
                } catch (IOException e) {
                        e.printStackTrace();
                } finally {
                        if (http != null) {
                                http.disconnect();
                        }
                        try {
                                if (in != null) {
                                        in.close();
                                }

                                if (out != null) {
                                        out.close();
                                }
                        } catch (IOException e) {
                                e.printStackTrace();
                        }
                }
                return false;
        }