Android獲取網絡數據進行GZIP解壓

說明：現在很多網站都會在回傳數據的時候進行GZIP壓縮，我們可以在請求頭中申明支持GZIP壓縮。可以減輕網絡傳輸壓力，Xutils中已經實現。

下面是一個DEMO，便於理解。

private void initGzip() {
        findViewById(R.id.btn1).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                new Thread(new Runnable() {

                    @Override
                    public void run() {

                        try {
                            boolean isGzip = false;

                            // 初始化httpClient對象
                            DefaultHttpClient httpClient = new DefaultHttpClient();

                            // 初始化httpGe對象
                            HttpGet get = new HttpGet("http://mobileif.maizuo.com/city");
                            // 1.發送請求頭:`Accept-Encoding:gzip`
                            get.addHeader("Accept-Encoding", "gzip");

                            // HttpGet get = new HttpGet("http://httpbin.org/gzip");

                            // 發起請求
                            HttpResponse response = httpClient.execute(get);
                            if (response.getStatusLine().getStatusCode() == 200) {
                                // 2. 取的響應頭`Content-Encoding`,判斷是否包含Content-Encoding:gzip
                                Header[] headers = response.getHeaders("Content-Encoding");
                                for (Header header : headers) {
                                    String value = header.getValue();
                                    if (value.equals("gzip")) {
                                        isGzip = true;
                                    }
                                }

                                // 3.相應的解壓
                                String result;
                                HttpEntity entity = response.getEntity();
                                if (isGzip) {// gzip解壓
                                    InputStream in = entity.getContent();

                                    GZIPInputStream gzipIn = new GZIPInputStream(in);

                                    // inputStream-->string
                                    result = convertStreamToString(gzipIn);
                                } else {// 標准解壓

                                    // 打印響應結果
                                    result = EntityUtils.toString(entity);
                                }
                                System.out.println("result:" + result);
                            }

                        } catch (ClientProtocolException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }

                    }
                }).start();
            }
        });

    }

    public static String convertStreamToString(InputStream is) throws IOException {
        try {
            if (is != null) {
                StringBuilder sb = new StringBuilder();
                String line;
                try {
                    BufferedReader reader = new BufferedReader(new InputStreamReader(is, "utf-8"));
                    // BufferedReader reader = new BufferedReader(new InputStreamReader(is));
                    while ((line = reader.readLine()) != null) {
                        // sb.append(line);
                        sb.append(line).append("\n");
                    }
                } finally {
                    is.close();
                }
                return sb.toString();
            } else {
                return "";
            }
        } catch (Exception e) {
            e.printStackTrace();
            return "";
        }

    }