我尝试将这个JSON字符串划分为每个联系人项目的单独字符串，例如emailAddress和电话号码。我使用System.out.print来查看信息是否按其应该的方式存储在字符串中。在system.out中没有显示任何内容，所发生的一切就是您在下面的logcat中看到的。
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)我的程序：
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;
}
}}
在logcat.before循环中验证字符串内容的标记。
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"}]好了，我已经从我的数据存储中删除了后面的条目。我现在没有收到任何错误，但是我没有得到任何我正在寻找的系统输出。
4条答案
按热度按时间waxmsbnn1#
正如你所看到的，你没有为第三个对象定义任何emailAddress。如果你不确定你将拥有JSON中的每个属性，你将不得不在之前检查键。
有时候我使用utils来简化代码，例如：
所以我的代码看起来像这样：
你的JSON格式，使用这个link来查看它的格式（它帮了我很多）
qni6mghb2#
看起来你在假设数组中的每个对象都有什么数据。其中一个对象没有所有的数据，这会抛出一个错误。我猜你的错误在下面的一行中：
因为你没有看到任何输出，设置一个断点，并在你第一次进入for循环时验证每一段数据是否真的在那里。另外，我建议在你尝试抓取数据之前，做一些防御性的编码并使用has（）来验证jsonObject是否真的有数据，这样你就不会在将来得到这些堆栈跟踪。类似这样的
yx2lnoni3#
我知道一个答案已经被接受了，你也可以考虑使用GSON库。
IT完全可以做到你想要的，有很多文档和示例，库甚至有很好的文档记录：
https://code.google.com/p/google-gson/
http://www.javacreed.com/simple-gson-example/
希望这对你未来的项目有所帮助。
n9vozmp44#
你可以使用我的droidQuery库）来简化解析：