java - Android App在启动时崩溃，没有进行任何更改。

Question

This question already has answers here:

What is a NullPointerException, and how do I fix it?

(12个答案)


3年前关闭。




[已解决]-> NullPointerException不是由Java引起的，而是由外部源(WCF Web服务)实现错误而引起的。

我在Android Studio中有一个Android App项目，几天前我的工作情况就很好。我今天开始工作，实际上什么也没改变，而现在启动它时，它在启动时就崩溃了。我真的不明白stacktrace试图告诉我什么。

                                             [ 08-21 16:59:35.445  8492: 
8492 D/         ]
                                             HostConnection::get() New Host 
Connection established 0xa279c3c0, tid 8492


                                             [ 08-21 16:59:35.499  8492: 
8520 D/         ]
                                             HostConnection::get() New Host 
Connection established 0xa279c740, tid 8520
08-21 16:59:35.559 8492-8492/com.example.pmatthews.appointmentcreator 
E/AndroidRuntime: FATAL EXCEPTION: main

Process: com.example.pmatthews.appointmentcreator, PID: 8492

java.lang.NullPointerException: Attempt to invoke virtual method 
'java.lang.String[] java.lang.String.split(java.lang.String)' on a null 
object reference

at 



com.example.pmatthews.appointmentcreator.
appointments$GetConNum.onPostExecute(ap
pointments.java:142)

at 

  com.example.pmatthews.appointmentcreator.
appointments$GetConNum.onPostExecute(appointments.java:71)

at android.os.AsyncTask.finish(AsyncTask.java:667)

at android.os.AsyncTask.-wrap1(AsyncTask.java)

at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:684)

at android.os.Handler.dispatchMessage(Handler.java:102)

at android.os.Looper.loop(Looper.java:154)

at android.app.ActivityThread.main(ActivityThread.java:6119)

at java.lang.reflect.Method.invoke(Native Method)

at 



com.android.internal.os.
ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
08-21 16:59:36.728 2155-2243/com.google.android.googlequicksearchbox:search 
E/AudioRecord: Could not get audio input for session 897, record source 
1999, sample rate 16000, format 0x1, channel mask 0x10, flags 0
08-21 16:59:36.731 2155-2243/com.google.android.googlequicksearchbox:search 
E/AudioRecord-JNI: Error creating AudioRecord instance: initialization check 
failed with status -22.
08-21 16:59:36.731 2155-2243/com.google.android.googlequicksearchbox:search 
E/android.media.AudioRecord: Error code -20 when initializing native 
AudioRecord object.
08-21 16:59:36.731 2155-2243/com.google.android.googlequicksearchbox:search 
E/ActivityThread: Failed to find provider info for 
com.google.android.apps.gsa.testing.ui.audio.recorded

启动 Activity -约会.java:

class GetConNum extends AsyncTask<String, Void, String> {
    StringBuilder sb = new StringBuilder();

    String status = null;
    Activity context;
    ListView listView = (ListView) findViewById(R.id.list);
    TextView txtV = (TextView) findViewById(R.id.txtConNum);
    TextView txtV1 = (TextView) findViewById(R.id.txtConNum1);
    TextView txtV2 = (TextView) findViewById(R.id.txtConNum2);
    TextView txtV3 = (TextView) findViewById(R.id.txtConNum3);
    TextView txtV4 = (TextView) findViewById(R.id.txtConNum4);
    TextView txtV5 = (TextView) findViewById(R.id.txtConNum5);
    TextView txtV6 = (TextView) findViewById(R.id.txtConNum6);
    TextView txtV7 = (TextView) findViewById(R.id.txtConNum7);
    TextView txtV8 = (TextView) findViewById(R.id.txtConNum8);
    TextView txtV9 = (TextView) findViewById(R.id.txtConNum9);
    TextView txtV10 = (TextView) findViewById(R.id.txtConNum10);
    TextView txtV11 = (TextView) findViewById(R.id.txtConNum11);
    TextView txtV12 = (TextView) findViewById(R.id.txtConNum12);
    TextView txtV13 = (TextView) findViewById(R.id.txtConNum13);
    TextView txtV14 = (TextView) findViewById(R.id.txtConNum14);
    TextView txtV15 = (TextView) findViewById(R.id.txtConNum15);
    TextView txtV16 = (TextView) findViewById(R.id.txtConNum16);
    TextView txtV17 = (TextView) findViewById(R.id.txtConNum17);
    TextView txtV18 = (TextView) findViewById(R.id.txtConNum18);
    TextView txtV19 = (TextView) findViewById(R.id.txtConNum19);

    public GetConNum(Activity context, ListView listView){
        this.context = context;
        this.listView = listView;
    }

    public void onPreExecute(){

    }
    public String doInBackground(String... connUrl){
        HttpURLConnection conn = null;
        BufferedReader reader;

        try{
            final URL url = new URL(connUrl[0]);
            conn = (HttpURLConnection) url.openConnection();
            conn.addRequestProperty("Content-Type", "application/json; 
charset=utf-8");
            conn.setRequestMethod("GET");
            int result = conn.getResponseCode();
            if(result == 200){



                InputStream in = new 
BufferedInputStream(conn.getInputStream());
                reader = new BufferedReader(new InputStreamReader(in));

                String line = null;

                while ((line = reader.readLine()) != null){
                    status = line;
                    res = res + result;

                }

            }

        }catch(Exception ex){

        }
        return status;

    }
    protected void onPostExecute(String result){
        super.onPostExecute(result);

        String[] resultArray = result.split(",");

        if (resultArray.length == 0){

        }else if (resultArray.length == 1) {
            txtV.setText(resultArray[0].replaceAll("
[[{}]]","").replaceAll("\\[", "").replaceAll("\\]", 
"").replaceAll("\"","").replaceAll(":", " : 
").replaceAll("/","").replaceAll("00 
: 00 AM", ""));
        }else if (resultArray.length == 2){

最佳答案

检查您的AsyncTask。
您正在尝试拆分空String。

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String[] java.lang.String.split(java.lang.String)' on a null object reference

关于java - Android App在启动时崩溃，没有进行任何更改。 ，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/45805558/

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Answer 1

检查您的AsyncTask。
您正在尝试拆分空String。

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String[] java.lang.String.split(java.lang.String)' on a null object reference