判断网络是否可用

 1. **1.判断网络是否可用：**


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    private boolean isNet(Context context) {
    ConnectivityManager con = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkinfo = con.getActiveNetworkInfo();
    if (networkinfo == null || !networkinfo.isAvailable()) {
    // 当前网络不可用
    return false;
    }
    return true;
    }


 1. **post requets**


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    public String connect(String url, Map<String, Object> values, Context context) {
    if (!isNet(context)) {
    return "";
    }
    HttpClient httpClient = getHttpClient();
    String result = "";
    HttpPost httpPost = new HttpPost(url);
    HttpResponse httpResponse = null;
    List<NameValuePair> parameters = new ArrayList<NameValuePair>();
    if (values != null && !values.isEmpty()) {
    // if (!CompareUtils.isEmpty(values)) {
    Set<Entry<String, Object>> set = values.entrySet();
    for (Entry<String, Object> entry : set) {
    parameters.add(new BasicNameValuePair(entry.getKey(), String.valueOf(entry.getValue())));
    }
    }
    try {
    Log.i("tag", "jsonParam" + parameters.toString());
    httpPost.setEntity(new UrlEncodedFormEntity(parameters, HTTP.UTF_8));
    httpResponse = httpClient.execute(httpPost);
    int code = httpResponse.getStatusLine().getStatusCode();
    if (code == HttpStatus.SC_OK) {
    result = EntityUtils.toString(httpResponse.getEntity());
    Log.i("tag", "jsonResult" + result.toString());
    } else {
    Log.i("json_error", url + "____网络：" + httpResponse.getStatusLine().getStatusCode());
    }
    } catch (ConnectTimeoutException e) {
    e.printStackTrace();
    return "";
    } catch (SocketTimeoutException e) {
    e.printStackTrace();
    return "";
    } catch (Exception e) {
    e.printStackTrace();
    return "";
    } finally {
    httpClient.getConnectionManager().shutdown();
    }
    return result;
    }