Question

我正在为JSONObject请求服务器，它包含一些id的列表。这适用于Android 4.2，但不适用于Android 2.3（已在设备和模拟器上进行过测试。）

JSONObject如下。

{"IdList":[{"id":"004502"},{"id":"S007901"},{"id":"041501"},{"id":"S139001"}]}

这适用于4.2，但在2.3中显示NullPointerException。

我的LogCat如下：

org.json.JSONException: Value Nullpointer of type java.lang.String cannot be converted to JSONObject
06-06 11:23:46.881: W/System.err(1820):     at org.json.JSON.typeMismatch(JSON.java:107)
06-06 11:23:46.893: W/System.err(1820):     at org.json.JSONObject.<init>(JSONObject.java:158)
06-06 11:23:46.893: W/System.err(1820):     at org.json.JSONObject.<init>(JSONObject.java:171)
06-06 11:23:46.893: W/System.err(1820):     at my.Site.serverInterface.executeHttpRequest(serverInterface.java:128)
06-06 11:23:46.893: W/System.err(1820):     at my.Site.serverInterface.getAtmId(serverInterface.java:54)
06-06 11:23:46.901: W/System.err(1820):     at my.Site.TrackLocation$AtmGetter.doInBackground(TrackLocation.java:379)
06-06 11:23:46.901: W/System.err(1820):     at android.os.AsyncTask$2.call(AsyncTask.java:185)
06-06 11:23:46.901: W/System.err(1820):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
06-06 11:23:46.901: W/System.err(1820):     at java.util.concurrent.FutureTask.run(FutureTask.java:138)
06-06 11:23:46.901: W/System.err(1820):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
06-06 11:23:46.901: W/System.err(1820):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
06-06 11:23:46.901: W/System.err(1820):     at java.lang.Thread.run(Thread.java:1019)
06-06 11:23:46.901: I/System.out(1820): null
06-06 11:23:46.912: I/System.out(1820)://e
06-06 11:23:46.912: W/System.err(1820): java.lang.NullPointerException
06-06 11:23:46.912: W/System.err(1820):     at my.Site.TrackLocation$AtmGetter.doInBackground(TrackLocation.java:384)
06-06 11:23:46.912: W/System.err(1820):     at android.os.AsyncTask$2.call(AsyncTask.java:185)
06-06 11:23:46.912: W/System.err(1820):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
06-06 11:23:46.912: W/System.err(1820):     at java.util.concurrent.FutureTask.run(FutureTask.java:138)
06-06 11:23:46.912: W/System.err(1820):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
06-06 11:23:46.912: W/System.err(1820):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
06-06 11:23:46.912: W/System.err(1820):     at java.lang.Thread.run(Thread.java:1019)
06-06 11:23:46.921: W/dalvikvm(1820): threadid=10: thread exiting with uncaught exception (group=0xb60c84f0)
06-06 11:23:46.931: E/AndroidRuntime(1820): FATAL EXCEPTION: AsyncTask #3
06-06 11:23:46.931: E/AndroidRuntime(1820): java.lang.RuntimeException: An error occured while executing doInBackground()
06-06 11:23:46.931: E/AndroidRuntime(1820):     at android.os.AsyncTask$3.done(AsyncTask.java:200)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at java.util.concurrent.FutureTask.run(FutureTask.java:138)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at java.lang.Thread.run(Thread.java:1019)
06-06 11:23:46.931: E/AndroidRuntime(1820): Caused by: java.lang.NullPointerException
06-06 11:23:46.931: E/AndroidRuntime(1820):     at my.Site.TrackLocation$AtmGetter.doInBackground(TrackLocation.java:427)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at android.os.AsyncTask$2.call(AsyncTask.java:185)
06-06 11:23:46.931: E/AndroidRuntime(1820):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
06-06 11:23:46.931: E/AndroidRuntime(1820):     ... 4 more

Answer 1

只需将json库文件导入项目即可 http://www.json.org/java/index.html https://code.google.com/p/android-json-rpc/downloads/list

Answer 2

下载org.json jar并导入它。它也适用于2.3。

请参阅..

JSON Parsing works on Android 4.0 but not on Android < 4.0

Answer 3

您是否尝试将responseType设置为json。如果问题仍然存在，这些帖子中有一些建议

JSON Parsing works on Android 4.0 but not on Android < 4.0

Issue initializing a JSONObject

JSON parsing problem

JSONObject不适用于Android 2.3但适用于Android 4.2，为什么？

3 个答案: