在我的应用程序中,我通过向OutputStream写入逗号分隔的数组来创建文件。然后我想通过电子邮件分享这个文件,以便用户获取数据。这是我用来创建文件的代码:
public String getLogFile(String logName) {
String path = FileSystemStorage.getInstance().getAppHomePath() + "exp " + logName + ".csv";
Set<Long> keys;
OutputStream os = null;
try {
os = FileSystemStorage.getInstance().openOutputStream(path);
Hashtable<Long, Integer> log = (Hashtable<Long, Integer>) dataStorage
.readObject(logName);
keys = log.keySet();
for (Long key : keys) {
String outString = (key + "," + log.get(key) + "\n");
System.out.println(outString);
byte[] buffer = outString.getBytes();
os.write(buffer);
}
} catch (IOException e) {
AnalyticsService.sendCrashReport(e, "Error writing log", false);
e.printStackTrace();
} finally {
try {
os.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
return path;
}
然后,我创建了一个按钮,当按下时会传递要分享的文件路径。我尝试使用 MIME 类型,如“text/plain”和“text/comma-separated-values”,但这会导致错误。以下是按下按钮时执行的代码。
public void exportLog(String logName) {
String path = dataBuffer.getLogFile(logName);
EmailShare email = new EmailShare();
// email.share("Here is your log.", path, "text/plain");
email.share("Here is your log.", path, "text/comma-separated-values");
}
在模拟器中按下时,选择虚拟电子邮件联系人发送后,我得到了以下堆栈:
java.lang.NullPointerException
at com.codename1.impl.javase.JavaSEPort.scale(JavaSEPort.java:3483)
at com.codename1.ui.Image.scale(Image.java:963)
at com.codename1.ui.Image.scaledImpl(Image.java:933)
at com.codename1.ui.Image.scaled(Image.java:898)
at com.codename1.impl.javase.JavaSEPort$60.save(JavaSEPort.java:6693)
at com.codename1.share.ShareForm.<init>(ShareForm.java:75)
at com.codename1.share.EmailShare$1$2$1.actionPerformed(EmailShare.java:102)
at com.codename1.ui.util.EventDispatcher.fireActionSync(EventDispatcher.java:455)
at com.codename1.ui.util.EventDispatcher.fireActionEvent(EventDispatcher.java:358)
at com.codename1.ui.List.fireActionEvent(List.java:1532)
at com.codename1.ui.List.pointerReleasedImpl(List.java:2011)
at com.codename1.ui.List.pointerReleased(List.java:2021)
at com.codename1.ui.Form.pointerReleased(Form.java:2560)
at com.codename1.ui.Component.pointerReleased(Component.java:3108)
at com.codename1.ui.Display.handleEvent(Display.java:2017)
at com.codename1.ui.Display.edtLoopImpl(Display.java:1065)
at com.codename1.ui.Display.mainEDTLoop(Display.java:994)
at com.codename1.ui.RunnableWrapper.run(RunnableWrapper.java:120)
at com.codename1.impl.CodenameOneThread.run(CodenameOneThread.java:176)