问题
I am creating an .xls-file using following code. i have got reference from http://www.vogella.de/articles/JavaExcel/article.html and http://www.andykhan.com/jexcelapi/tutorial.html Please suggest solution or alternate way to do this.
below is the code
String filename = "SpreadsheetTest.xls";
File root = Environment.getExternalStorageDirectory();
WorkbookSettings wbSettings = new WorkbookSettings();
wbSettings.setLocale(new Locale("en", "EN"));
WritableWorkbook workbook = Workbook.createWorkbook(new File(root, filename), wbSettings);
WritableSheet sheet = workbook.createSheet("First Sheet", 0);
Label label = new Label(0, 2, "A label record");
sheet.addCell(label);
Number number = new Number(3, 4, 3.1459);
sheet.addCell(number);
workbook.write();
workbook.close();
The above code is giving NullPointerException:
08-19 14:34:46.354: ERROR/AndroidRuntime(3298): Uncaught handler: thread main exiting due to uncaught exception
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.spreadsheet/com.spreadsheet.MainScreen}: java.lang.NullPointerException
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.os.Handler.dispatchMessage(Handler.java:99)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.os.Looper.loop(Looper.java:123)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.app.ActivityThread.main(ActivityThread.java:4363)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at java.lang.reflect.Method.invokeNative(Native Method)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at java.lang.reflect.Method.invoke(Method.java:521)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at dalvik.system.NativeStart.main(Native Method)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): Caused by: java.lang.NullPointerException
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at jxl.biff.StringHelper.getUnicodeBytes(StringHelper.java:141)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at jxl.biff.FontRecord.getData(FontRecord.java:289)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at jxl.biff.WritableRecordData.getBytes(WritableRecordData.java:71)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at jxl.write.biff.File.write(File.java:147)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at jxl.biff.Fonts.write(Fonts.java:110)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at jxl.write.biff.WritableWorkbookImpl.write(WritableWorkbookImpl.java:821)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at com.spreadsheet.MainScreen.onCreate(MainScreen.java:59)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
08-19 14:34:46.362: ERROR/AndroidRuntime(3298): ... 11 more
Please guide me to solve this issue. Please suggest me any alternate way to generate xls file if any.
回答1:
Add user permission to write the external storage.
回答2:
Have you seen this blog post:
It is using Apache POI to read/write Excel from Android.
回答3:
I had the same error. For me it was caused as I had not specified any memory for sd card in the simulator.
File got created, once I edited the simulator using the device manager.
来源：https://stackoverflow.com/questions/7119462/problem-in-creating-spreadsheetxls-file