Android网络编程专栏--get和post请求，上传下载文件，提交Cookie

</pre>一.get和post请求方法的封装<p></p><p><span style="white-space:pre"></span>首先是post方法：</p><p></p><pre code_snippet_id="601727" snippet_file_name="blog_20150210_2_1231912" name="code" class="java">/**     * 进行ｐｏｓｔ请求     *     * @param client HttpClient实例     * @param url    　链接地址     * @param list   需要提交的数据的Ｌｉｓｔ     * @return 请求后返回的信息     */    public static String doPost(DefaultHttpClient client, String url,                                List<NameValuePair> list) {        try {            UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, HTTP.UTF_8); // 设置编码            HttpPost post = new HttpPost(url.trim()); // 进行ｐｏｓｔ请求            post.setEntity(entity); // 加入请求头            Log.d(TESTHTTPCLIENT, "请求头内容：" + post.getAllHeaders().toString() + "::"                    + post.getHeaders("email").toString() + "::" + post.getEntity().getContent().toString());            HttpResponse response = client.execute(post); // 执行ｐｏｓｔ请求            int codeReturn = response.getStatusLine().getStatusCode(); //　获取返回码            if (codeReturn == HttpStatus.SC_OK) {                Log.d(TESTHTTPCLIENT, "请求成功");                HttpEntity httpEntity = response.getEntity();                return httpEntity == null ? null : EntityUtils.toString(httpEntity);            } else {                Log.d(TESTHTTPCLIENT, "请求失败");                return null;            }        } catch (UnsupportedEncodingException e) {            return null;        } catch (ClientProtocolException e) {            e.printStackTrace();            return null;        } catch (IOException e) {            e.printStackTrace();            return null;        }    }

然后是get方法:

/**     * 执行GET请求     *     * @param client     HttpClient实例     * @param url        请求的链接     * @param map        需要提交的参数，放在ｍａｐ中     * @return 获取ｘｍｌ信息     */    public static String doGet(DefaultHttpClient client, String url, Map<String, String> map) {        StringBuilder sb = null;        if (map != null) {            // url重新构造            sb = new StringBuilder(url);            sb.append('?');            // ?page=1&tags="计算机"(全部则为all)            for (Map.Entry<String, String> entry : map.entrySet()) {                try {                    sb.append(entry.getKey()).append('=').append(URLEncoder.encode(entry.getValue(), "UTF-8"))                            .append('&');                } catch (UnsupportedEncodingException e) {                    e.printStackTrace();                }            }            sb.deleteCharAt(sb.length() - 1);            Log.d("TestApp", "构造的ＵＲＬ为：" + sb.toString());        } else {            sb = new StringBuilder(url);        }        // 开始请求操作        try {            HttpGet httpGet = new HttpGet(sb.toString());            HttpResponse response = client.execute(httpGet);            int codeReturn = response.getStatusLine().getStatusCode(); //　获取返回码            if (codeReturn == HttpStatus.SC_OK) {                Log.d(TESTHTTPCLIENT, "请求成功");                HttpEntity httpEntity = response.getEntity();                return httpEntity == null ? null : EntityUtils.toString(httpEntity);            } else {                Log.d(TESTHTTPCLIENT, "请求失败");                return null;            }        } catch (IOException e) {            e.printStackTrace();            return null;        }    }

二．上传下载文件

        首先是上传文件的代码：

 MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);                    for (int index = 0; index < list.size(); index++) {                        if (list.get(index).getName().equalsIgnoreCase("img") ||                                list.get(index).getName().equalsIgnoreCase("headImg") ||                                list.get(index).getName().equalsIgnoreCase("doc")) {                            // 将NameValuePair中的地址取出，通过地址获取文件并上传                            entity.addPart(list.get(index).getName(),                                    new FileBody(new File(list.get(index).getValue())));                            Log.d("TestApp", "已经提交文件！");                        } else {                            // 普通文字                            entity.addPart(list.get(index).getName(),                                    new StringBody(list.get(index).getValue()));                        }                    }

解释一下，首先我们需要引用两个包，我的build.gradle中是这么写的

    compile files('libs/apache-mime4j-0.6.jar')    compile files('libs/httpmime-4.0.1.jar')

下载链接一会儿附上．这个代码片段，其实际意义是从传入的List<NameValuePair>中通过key筛选出文件路径的value,获取路径后直接获取文件，加入到请求头中即可！

然后说一下下载文件的问题，这里仅仅展示如何直接获取下载的文件并获取，多线程下载以及断点下载将在后边进行展示.

public static boolean doGetFileDownload(DefaultHttpClient client, String url) {        try {            HttpGet httpGet = new HttpGet(url);            HttpResponse response = client.execute(httpGet);            int codeReturn = response.getStatusLine().getStatusCode(); //　获取返回码            if (codeReturn == HttpStatus.SC_OK) {                Log.d(TESTHTTPCLIENT, "请求成功");                String filePath = Environment.getExternalStorageDirectory()                        .getAbsolutePath() + "/1.doc"; // 文件路径                Log.d(TESTHTTPCLIENT, "文件保存路径：" + filePath);                File file = new File(filePath);                FileOutputStream outputStream = new FileOutputStream(file);                InputStream inputStream = response.getEntity()                        .getContent();                byte b[] = new byte[1024];                int j = 0;                while ((j = inputStream.read(b)) != -1) {                    outputStream.write(b, 0, j);                }                outputStream.flush();                outputStream.close();                return true;            } else {                Log.d(TESTHTTPCLIENT, "请求失败");                return false;            }        } catch (IOException e) {            e.printStackTrace();            return false;        }    }

三．提交Cookie

首先需要创建CookieStore这个变量，

private static CookieStore cookieStore = null;

作为一个缓存，然后我们先获取一次缓存，存到变量中，

cookieStore = client.getCookieStore();

最后我们加到请求中并提交：

 　　　　　　　　　　　// 取出Cookie并添加到请求头                    if (cookieStore != null) {                        client.setCookieStore(cookieStore);                        Log.d("TestApp", "提交Ｃｏｏｋie完毕！" + cookieStore.toString());                    } else {                        Log.d("TestApp", "提交Ｃｏｏｋｉｅ时，未获取到ｃｏｏｋｉｅ");                    }

到这里，这篇文章正是完成!