Question

我正在尝试将此JSON字符串划分为每个联系人项目的单个字符串，例如emailAddress＆amp;电话号码。我正在使用System.out.print来查看信息是否存储在字符串中。 system.out中没有显示任何内容，所有发生的事情都是您在logcat中看到的内容。

JSON字符串：

{"items":[{"description":"payment confirmed","emailAddress":"abc@aqw.com","id":"Fri Aug 30 17:20:35 EDT 2013","nameFirst":"Bill","nameLast":"Sanders","phone":"5555555555","state":"KS","streetAddress":"123 Rick Dr","zipCode":"44444","kind":"contactinfoendpoint#resourcesItem"},{"description":"payment confirmed","emailAddress":"qwe@msn.com","id":"Fri Aug 30 17:21:37 EDT 2013","nameFirst":"Frank","nameLast":"Lloyd","phone":"5554567896","state":"KY","streetAddress":"999 Rock St","zipCode":"44555","kind":"contactinfoendpoint#resourcesItem"}],"kind":"contactinfoendpoint#resources","etag":"\"NiDXI3T89oRrAPGJAhgGQje1Z0w/z0W4p01mjHc5cNgcOt3Kb_1xo8E\""}

这是logcat。

09-03 14:51:18.755: W/System.err(27991): org.json.JSONException: No value for emailAddress
09-03 14:51:18.755: W/System.err(27991):    at org.json.JSONObject.get(JSONObject.java:354)
09-03 14:51:18.755: W/System.err(27991):    at org.json.JSONObject.getString(JSONObject.java:510)
09-03 14:51:18.755: W/System.err(27991):    at com.indeeditis.FinderActivity$EndpointsTask.doInBackground(FinderActivity.java:112)
09-03 14:51:18.765: W/System.err(27991):    at com.indeeditis.FinderActivity$EndpointsTask.doInBackground(FinderActivity.java:1)
09-03 14:51:18.765: W/System.err(27991):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
09-03 14:51:18.765: W/System.err(27991):    at java.util.concurrent.FutureTask.run(FutureTask.java:234)
09-03 14:51:18.765: W/System.err(27991):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
09-03 14:51:18.765: W/System.err(27991):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
09-03 14:51:18.765: W/System.err(27991):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
09-03 14:51:18.765: W/System.err(27991):    at java.lang.Thread.run(Thread.java:856)

我的节目：

public class FinderActivity extends ListActivity   {


private static final String TAG_ID = "id";
private static final String TAG_FIRSTNAME = "nameFirst";
private static final String TAG_LASTNAME = "nameLast";
private static final String TAG_EMAIL = "emailAddress";
private static final String TAG_ADDRESS = "streetAddress";
private static final String TAG_STATE = "state";

private static final String TAG_PHONE = "phone";
JSONArray contacts = null;



@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);


    new EndpointsTask().execute(getApplicationContext());

}

public class EndpointsTask extends AsyncTask<Context, Integer, Long> {

    public Long doInBackground(Context... contexts) {

      Contactinfoendpoint.Builder endpointBuilder = new Contactinfoendpoint.Builder(
          AndroidHttp.newCompatibleTransport(),
          new JacksonFactory(),
          new HttpRequestInitializer() {
          public void initialize(HttpRequest httpRequest) { }
          });
  Contactinfoendpoint endpoint = CloudEndpointUtils.updateBuilder(
  endpointBuilder).build();

  try {

    String apples = endpoint.listContactInfo().execute().toString();

    JSONObject jObject = new JSONObject(apples);

    JSONArray jsonArr = jObject.getJSONArray("items");

     for(int i =0 ; i<jsonArr.length() ;i++ ){
         JSONObject jsonObj1 = jsonArr.getJSONObject(i);


                    // Storing each json item in variable
                    String id = jsonObj1.getString(TAG_ID);
                    String nameFirst1 = jsonObj1.getString(TAG_FIRSTNAME);
                    String nameLast1 = jsonObj1.getString(TAG_LASTNAME);
                    String emailAddress1 = jsonObj1.getString(TAG_EMAIL);
                    String streetAddress1 = jsonObj1.getString(TAG_ADDRESS);
                    String phone1 = jsonObj1.getString(TAG_PHONE);

                    //test to see if made it to string

                    System.out.print(nameFirst1);
                    System.out.print(nameLast1);


     }

    } catch (IOException e) {
    e.printStackTrace();
  } catch (JSONException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
      return (long) 0;
    }


    }

}

您在logcat中的标记。在循环之前验证字符串的内容。

09-03 15:13:57.690: D/YOUR_TAG(30179): [{"streetAddress":"123 Rick Dr","id":"Fri Aug 30 17:20:35 EDT 2013","phone":"5555555555","nameLast":"Sanders","nameFirst":"Bill","description":"payment confirmed","zipCode":"44444","state":"KS","emailAddress":"abc@aqw.com","kind":"contactinfoendpoint#resourcesItem"},{"streetAddress":"999 Rock St","id":"Fri Aug 30 17:21:37 EDT 2013","phone":"5554567896","nameLast":"Lloyd","nameFirst":"Frank","description":"payment confirmed","zipCode":"44555","state":"KY","emailAddress":"qwe@msn.com","kind":"contactinfoendpoint#resourcesItem"},{"id":"Sat Aug 31 12:46:33 EDT 2013","nameLast":"j","nameFirst":"j","kind":"contactinfoendpoint#resourcesItem","description":"payment confirmed"},{"id":"Sat Aug 31 14:33:03 EDT 2013","emailAddress":"c","nameLast":"b","nameFirst":"a","kind":"contactinfoendpoint#resourcesItem","description":"payment confirmed"}]

好的，我已从我的数据存储中删除了以后的条目。我现在没有收到任何错误，但我没有得到任何我想要的系统输出。

Answer 1

看起来您正在假设数组中每个对象的数据。其中一个对象没有每一个数据，这是一个错误。我猜你的错误就在以下一行中：

String id = jsonObj1.getString(TAG_ID);
String nameFirst1 = jsonObj1.getString(TAG_FIRSTNAME);
String nameLast1 = jsonObj1.getString(TAG_LASTNAME);
String emailAddress1 = jsonObj1.getString(TAG_EMAIL);
String streetAddress1 = jsonObj1.getString(TAG_ADDRESS);
String phone1 = jsonObj1.getString(TAG_PHONE);

由于您没有看到任何打印内容，因此设置断点并在首次进入for循环时验证每个数据是否实际存在。另外，我建议做一些防御性编码并使用has（）来验证jsonObject实际上是否有数据，然后再尝试抓取它，这样你以后就不会得到这些堆栈跟踪。像

这样的东西

String id = "";
if (jsonObj1.has(TAG_ID)) {
   id = jsonObj1.getString(TAG_ID);
} else {
   ///Handle bad data
}

Answer 2

您可以使用droidQuery来简化解析：

Object[] array = $.makeArray(jsonArr);
for (Object obj : array)
{
    Map<String, ?> map = $.map((JSONObject) obj);
    for (Map.Entry<String, ?> entry : map)
    {
        Log.d("DEBUG", String.format(Locale.US, "Object contains Key %s and value %s", entry.getKey(), entry.getValue().toString());
    }
}

Answer 3

如您所见，您没有为第三个对象定义任何emailAddress。如果您不确定JSON中是否包含每个属性，则必须先检查密钥。

if (jsonObject.has(TAG)) {
    jsonObject.getString(TAG_ID);
}

有些时候我使用utils来简化代码，例如：

public static String getString(JSONObject object, String tag, String defString) {
    if (object.has(tag))
        return object.getString(tag);
    else
        return defString;
}

所以我的代码看起来像这样：

String nameFirst1 = Utils.getString(jsonObj1, TAG_ID, ""); // your firstName default.
String nameLast1 = Utils.getString(jsonObj1, TAG_ID, null); // maybe null??

您的JSON已格式化，请使用此link查看格式化（这对我有很大帮助）

[
   {
      "streetAddress":"123 Rick Dr",
      "id":"Fri Aug 30 17:20:35 EDT 2013",
      "phone":"5555555555",
      "nameLast":"Sanders",
      "nameFirst":"Bill",
      "description":"payment confirmed",
      "zipCode":"44444",
      "state":"KS",
      "emailAddress":"abc@aqw.com",
      "kind":"contactinfoendpoint#resourcesItem"
   },
   {
      "streetAddress":"999 Rock St",
      "id":"Fri Aug 30 17:21:37 EDT 2013",
      "phone":"5554567896",
      "nameLast":"Lloyd",
      "nameFirst":"Frank",
      "description":"payment confirmed",
      "zipCode":"44555",
      "state":"KY",
      "emailAddress":"qwe@msn.com",
      "kind":"contactinfoendpoint#resourcesItem"
   },
   {
      "id":"Sat Aug 31 12:46:33 EDT 2013",
      "nameLast":"j",
      "nameFirst":"j",
      "kind":"contactinfoendpoint#resourcesItem",
      "description":"payment confirmed"
   },
   {
      "id":"Sat Aug 31 14:33:03 EDT 2013",
      "emailAddress":"c",
      "nameLast":"b",
      "nameFirst":"a",
      "kind":"contactinfoendpoint#resourcesItem",
      "description":"payment confirmed"
   }
]

Answer 4

我知道答案已被接受，您也可以考虑使用GSON库。

IT完全符合您的要求，并且有很多文档和示例，并且库甚至都有很好的文档记录：

https://code.google.com/p/google-gson/

http://www.javacreed.com/simple-gson-example/

希望这有助于您未来的项目。

将JSON字符串分隔为android中的变量

4 个答案: