我查看了无数项目和教程，但无法弄清楚为什么我的应用程序一运行就崩溃。如果我注释掉 try catch "JSONObject dataObject = json.getJSONObject("data");" 中的第一行，它似乎运行良好 我试图解析的 JSON 格式如下：
{"recordcount":3,
"columnlist":"department,emailaddress,firstname,has_photos,job_full_title,job_title,kid,lastname,location,middlename,no_show_photo,phone,school",
"data":
{"department":["Public Safety","Information Technology","Information Technology"],
"emailaddress":["todd.mongeon@wne.edu","amutti@wne.edu","fatemeh.shams@wne.edu"],
"firstname":["Todd","Tony","Toffee"],
"has_photos":["Y","Y","N"],
"job_full_title":["Officer","Director, Administrative Information Systems","Sr.Technical Programmer/Analyst and Integ Specialist"],
"job_title":["Officer","Director, Administrative Information Systems","Sr.Technical Programmer/Analyst and Integ Specialist"],
"kid":[286899,2497,297411],
"lastname":["Mongeon","Mutti","Shams"],
"location":["PS","12 V","12 V"],
"middlename":["A.","M.",""],
"no_show_photo":["","",""],
"phone":["413-782-1207","413-782-1212","413-796-2398"],
"school":["Public Safety Group","Information Technology Group","Information Technology Group"]}}
我的程序看起来像这样（请原谅格式/不需要的东西......它需要从我试图让它工作的很多东西中清理出来......）
public class Directory_finalActivity extends ListActivity {
public static String url = "http://www1.wne.edu/webservices/directorydemo.cfc?wsdl&method=getEmployees&limit=25&firstname=to&outputtype=JSON";
// JSON array names
private static final String TAG_FIRST = "firstname";
private static final String TAG_LAST = "lastname";
private static final String TAG_SCHOOL = "school";
private static final String TAG_DEPARTMENT = "department";
private static final String TAG_EMAIL = "emailaddress";
private static final String TAG_PHONE = "phone";
private static final String TAG_JOB = "job_title";
private static final String TAG_LOCATION = "location";
//create JSON array
JSONArray firstNames = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
String[] firstNames = null;
try {
// Getting the data object
JSONObject dataObject = json.getJSONObject("data"); //This is the line that seems to be causing the error.
int numResults = json.getInt("recordcount");
/**
JSONArray firstNameArray = dataObject.getJSONArray("firstname");
JSONArray lastNameArray = dataObject.getJSONArray("lastname");
JSONArray schoolArray = dataObject.getJSONArray("school");
JSONArray departmentArray = dataObject.getJSONArray("department");
JSONArray eMailArray = dataObject.getJSONArray("emailaddress");
JSONArray phoneNumberArray = dataObject.getJSONArray("phone");
JSONArray jobTitleArray = dataObject.getJSONArray("job_title");
JSONArray locationArray = dataObject.getJSONArray("location");
//Loop through index of array(s)
for(int i = 0; i <= numResults; i++)
{
//Store value of JSONArray at index "i" into string variables.
String firstName = firstNameArray.getString(i);
String eMail = eMailArray.getString(i);
String phone = phoneNumberArray.getString(i);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_FIRST, firstName);
map.put(TAG_EMAIL, eMail);
map.put(TAG_PHONE, phone);
//add the hashmap to array list.
contactList.add(map);
}*/
}
catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
//ListAdapter adapter = new SimpleAdapter(this, contactList,
// R.layout.list_item,
// new String[] { TAG_FIRST, TAG_EMAIL, TAG_PHONE }, new int[] {
// R.id.name, R.id.email, R.id.mobile });
//setListAdapter(adapter);
}
}
我的 JSONParser 类 public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
我可能在这里做了一些非常愚蠢的事情，我是新手，所以请让我休息一下，哈哈。我很感激你们可能为我提供的任何信息。
出于好奇，最终目标是搜索数据库（名字、姓氏、学校和部门）并将结果放入列表视图中，单击时会弹出一个窗口，显示其他相关信息以及其他一些功能。
似乎我看到他们从 url 收到的 JSON 输出的每个示例的格式都大不相同，所以即使有大量可用的示例，我也无法完成此操作（抱歉重新发布）。再次感谢您的任何帮助。
编辑 1：LOGCAT：
04-17 00:45:35.828: W/System.err(305): java.net.UnknownHostException: api.androidhive.info
04-17 00:45:35.828: W/System.err(305): at java.net.InetAddress.lookupHostByName(InetAddress.java:513)
04-17 00:45:35.838: W/System.err(305): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:278)
04-17 00:45:35.838: W/System.err(305): at java.net.InetAddress.getAllByName(InetAddress.java:242)
04-17 00:45:35.838: W/System.err(305): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:136)
04-17 00:45:35.838: W/System.err(305): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
04-17 00:45:35.838: W/System.err(305): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
04-17 00:45:35.838: W/System.err(305): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:348)
04-17 00:45:35.838: W/System.err(305): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
04-17 00:45:35.838: W/System.err(305): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
04-17 00:45:35.838: W/System.err(305): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
04-17 00:45:35.838: W/System.err(305): at directory.plus.JSONParser.getJSONFromUrl(JSONParser.java:39)
04-17 00:45:35.838: W/System.err(305): at directory.plus.Directory_finalActivity.onCreate(Directory_finalActivity.java:53)
04-17 00:45:35.849: W/System.err(305): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-17 00:45:35.849: W/System.err(305): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
04-17 00:45:35.849: W/System.err(305): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
04-17 00:45:35.849: W/System.err(305): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
04-17 00:45:35.849: W/System.err(305): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
04-17 00:45:35.849: W/System.err(305): at android.os.Handler.dispatchMessage(Handler.java:99)
04-17 00:45:35.849: W/System.err(305): at android.os.Looper.loop(Looper.java:123)
04-17 00:45:35.849: W/System.err(305): at android.app.ActivityThread.main(ActivityThread.java:4627)
04-17 00:45:35.849: W/System.err(305): at java.lang.reflect.Method.invokeNative(Native Method)
04-17 00:45:35.849: W/System.err(305): at java.lang.reflect.Method.invoke(Method.java:521)
04-17 00:45:35.858: W/System.err(305): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-17 00:45:35.858: W/System.err(305): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-17 00:45:35.858: W/System.err(305): at dalvik.system.NativeStart.main(Native Method)
04-17 00:45:35.858: E/Buffer Error(305): Error converting result java.lang.NullPointerException
04-17 00:45:35.868: E/JSON Parser(305): Error parsing data org.json.JSONException: End of input at character 0 of
04-17 00:45:35.868: D/AndroidRuntime(305): Shutting down VM
04-17 00:45:35.868: W/dalvikvm(305): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
04-17 00:45:35.888: E/AndroidRuntime(305): FATAL EXCEPTION: main
04-17 00:45:35.888: E/AndroidRuntime(305): java.lang.RuntimeException: Unable to start activity ComponentInfo{directory.plus/directory.plus.Directory_finalActivity}: java.lang.NullPointerException
04-17 00:45:35.888: E/AndroidRuntime(305): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
04-17 00:45:35.888: E/AndroidRuntime(305): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
04-17 00:45:35.888: E/AndroidRuntime(305): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
04-17 00:45:35.888: E/AndroidRuntime(305): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
04-17 00:45:35.888: E/AndroidRuntime(305): at android.os.Handler.dispatchMessage(Handler.java:99)
04-17 00:45:35.888: E/AndroidRuntime(305): at android.os.Looper.loop(Looper.java:123)
04-17 00:45:35.888: E/AndroidRuntime(305): at android.app.ActivityThread.main(ActivityThread.java:4627)
04-17 00:45:35.888: E/AndroidRuntime(305): at java.lang.reflect.Method.invokeNative(Native Method)
04-17 00:45:35.888: E/AndroidRuntime(305): at java.lang.reflect.Method.invoke(Method.java:521)
04-17 00:45:35.888: E/AndroidRuntime(305): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-17 00:45:35.888: E/AndroidRuntime(305): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-17 00:45:35.888: E/AndroidRuntime(305): at dalvik.system.NativeStart.main(Native Method)
04-17 00:45:35.888: E/AndroidRuntime(305): Caused by: java.lang.NullPointerException
04-17 00:45:35.888: E/AndroidRuntime(305): at directory.plus.Directory_finalActivity.onCreate(Directory_finalActivity.java:59)
04-17 00:45:35.888: E/AndroidRuntime(305): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-17 00:45:35.888: E/AndroidRuntime(305): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
编辑 2：新的 LOGCAT 输出：
04-17 01:26:12.899: E/JSON Parser(548): Error parsing data in JSONParser org.json.JSONException: Value <wddxPacket of type java.lang.String cannot be converted to JSONObject
04-17 01:26:12.899: D/AndroidRuntime(548): Shutting down VM
04-17 01:26:12.899: W/dalvikvm(548): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
04-17 01:26:12.919: E/AndroidRuntime(548): FATAL EXCEPTION: main
04-17 01:26:12.919: E/AndroidRuntime(548): java.lang.RuntimeException: Unable to start activity ComponentInfo{directory.plus/directory.plus.Directory_finalActivity}: java.lang.NullPointerException
04-17 01:26:12.919: E/AndroidRuntime(548): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
04-17 01:26:12.919: E/AndroidRuntime(548): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
04-17 01:26:12.919: E/AndroidRuntime(548): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
04-17 01:26:12.919: E/AndroidRuntime(548): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
04-17 01:26:12.919: E/AndroidRuntime(548): at android.os.Handler.dispatchMessage(Handler.java:99)
04-17 01:26:12.919: E/AndroidRuntime(548): at android.os.Looper.loop(Looper.java:123)
04-17 01:26:12.919: E/AndroidRuntime(548): at android.app.ActivityThread.main(ActivityThread.java:4627)
04-17 01:26:12.919: E/AndroidRuntime(548): at java.lang.reflect.Method.invokeNative(Native Method)
04-17 01:26:12.919: E/AndroidRuntime(548): at java.lang.reflect.Method.invoke(Method.java:521)
04-17 01:26:12.919: E/AndroidRuntime(548): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-17 01:26:12.919: E/AndroidRuntime(548): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-17 01:26:12.919: E/AndroidRuntime(548): at dalvik.system.NativeStart.main(Native Method)
04-17 01:26:12.919: E/AndroidRuntime(548): Caused by: java.lang.NullPointerException
04-17 01:26:12.919: E/AndroidRuntime(548): at directory.plus.Directory_finalActivity.onCreate(Directory_finalActivity.java:59)
04-17 01:26:12.919: E/AndroidRuntime(548): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-17 01:26:12.919: E/AndroidRuntime(548): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
04-17 01:26:12.919: E/AndroidRuntime(548): ... 11 more
04-17 01:26:33.279: I/Process(548): Sending signal. PID: 548 SIG: 9
编辑最后：问题已解决：需要获取从 html 返回的结果的子字符串并将其传递给 json 对象