小编VIC*_*TSC的帖子

我有一个方法如下,这个方法包含两个arraylist("eventList"和"emailList").

List<EmailUID> emailid=SharedEvent.getEmailUid(filter, uri, exchWD, EmailShare);

public static List<EmailUID> getEmailUid(Filter filter, String uri, NexWebDav exchWD,
            List<String> emailShare)
List eventsToday = null;
List<EmailUID> arrayList = new ArrayList<EmailUID>();
List<EmailUID> emailList = new ArrayList<EmailUID>();
List<EmailUID> eventList = new ArrayList<EmailUID>();

        for (String email : emailShare) {
            String uris = uri + email + "/events/";
            InputStream stream = null;
            try {
                stream = exchWD.get(uris);
                BufferedReader br = new BufferedReader(new InputStreamReader(stream));
                CalendarBuilder builder = new CalendarBuilder();
                net.fortuna.ical4j.model.Calendar calendar = builder.build(br);

                //eventsToday.add(email);

                eventsToday = (List<?>) filter.filter(calendar.getComponents(Component.VEVENT));
                arrayList=getEmailUID(eventsToday,email); …

我想使用java获取缓冲的图像格式或图像类型,

 InputStream stream = request.getResponseStream();   
 BufferedImage image=  ImageIO.read(stream);
 LOGGER.info(image);

我怎么能避免NullPointerExceptions？我尝试过使用try-catch块但是没有用.

我的程序应该从Google日历中获取数据.我得到了很多元素,但这里只是一个元素作为例子......

for (Iterator<?> i = eventsToday.iterator(); i.hasNext();) {
    Component component = (Component) i.next();
    String Attachement=null;
    if(component.getProperty(Property.ATTACH).toString().trim()!=null){
        Attachement=component.getProperty(Property.ATTACH).toString();
    }
}

有人可以帮我这个.