我有問題,這樣的代碼:的Android ArrayList的奇怪的空指針異常
for(int i2=0;i2<ftdata.size();i2++){
System.out.println("FTDATASIZE: " +ftdata.get(i2)); // here pass and shows null
String test=ftdata.get(i2); // here gets Null Pointer Exception ????
if(test.equals("null")){
}
}
的System.out顯示logcat的「FTDATASIZE:空」,但我得到的錯誤與該行「字符串測試= ftdata.get(I2 );」我沒有明白嗎?爲什麼我得到空指針異常?
04-07 05:42:36.309: I/System.out(12983): STDATASIZE: 1
04-07 05:42:36.309: I/System.out(12983): FTDATASIZE: 1
04-07 05:42:36.309: I/System.out(12983): FTDATASIZE: null
04-07 05:42:36.309: W/dalvikvm(12983): threadid=10: thread exiting with uncaught exception (group=0x40166560)
04-07 05:42:36.309: E/AndroidRuntime(12983): FATAL EXCEPTION: Thread-11
04-07 05:42:36.309: E/AndroidRuntime(12983): java.lang.NullPointerException
04-07 05:42:36.309: E/AndroidRuntime(12983): at soft.ProDb.distanceRunsMonthly(ProDb.java:22718)
04-07 05:42:36.309: E/AndroidRuntime(12983): at soft.ProDb.runsMonthly(ProDb.java:22593)
04-07 05:42:36.309: E/AndroidRuntime(12983): at soft.SHtmlM.exportALLHtml(StringaHtmlM.java:111)
04-07 05:42:36.309: E/AndroidRuntime(12983): at soft.ProDb$1.run(ProDb.java:12714)
04-07 05:42:36.309: E/AndroidRuntime(12983): at java.lang.Thread.run(Thread.java:1019)
OK 固定
這對我的作品
if(ftdata.size()==1&& ftdata.get(0)==null){
ftdata=stdata;
}
只是想測試是否ftdata.get(0)爲空或不是
請從logcat發佈堆棧跟蹤... – Karakuri 2013-04-07 02:55:58
ftdata.get(i2)爲空並且無法將空值傳遞給字符串? – 2013-04-07 02:56:39
@Karakuri它完成了 – 2013-04-07 02:58:26