ParseQuery-正确处理IndexOutOfBoundsException-Parse.com? [英] ParseQuery - Properly handling IndexOutOfBoundsException - Parse.com?

问题描述

一个人如何正确处理throwIndexOutOfBoundsException?基本上，我正在查询用户.如果用户存在，则显示其个人资料.但是，如果找不到任何条目，它将使我的应用程序崩溃并引发异常.我应该在"else"语句中添加些什么，以使应用程序不会崩溃?

How does one properly handle throwIndexOutOfBoundsException? Basically, I'm querying for a user. If the user exists, it shows their profile. However, if no entry is found it crashes my app and throws the exception. What should I put in my "else" statement so that the app doesn't crash?

                    @Override
                    public void done(List<ParseUser> parseUsers, ParseException e) {
                            if (e == null) {
                                    // The query was successful.
                                    ParseUser user = parseUsers.get(0);
                                    String userId = user.getObjectId();
                                    showProfileActivity(userId);

                            } else {
                                // The query was unsuccessful.

                            }
                        }
                    });

这是logcat:

10-14 21:27:06.888  28595-28595/com.app.social E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.elgami.customizer, PID: 28595
    java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
            at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
            at java.util.ArrayList.get(ArrayList.java:308)
            at com.elgami.feed.SearchActivity$1$1.done(SearchActivity.java:74)
            at com.elgami.feed.SearchActivity$1$1.done(SearchActivity.java:67)
            at com.parse.Parse$6$1.run(Parse.java:944)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:148)
            at android.app.ActivityThread.main(ActivityThread.java:5417)
            at java.lang.reflect.Method.invoke(Native Method)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

推荐答案

您可以检查列表是否为空:

you can check if the list is empty :

 @Override
      public void done(List<ParseUser> parseUsers, ParseException e) {
                                if (!parseUsers.isEmpty()) {
                                        // The query was successful.
                                        ParseUser user = parseUsers.get(0);
                                        String userId = user.getObjectId();
                                        showProfileActivity(userId);

                                } else {
                                    // The query was unsuccessful.

                                }
                            }
                        });

或者，如果您想捕获异常，请使用try -catch像这样:

or if you want to catch the Exception use try -catch like this :

 @Override
  public void done(List<ParseUser> parseUsers, ParseException e) {
          if (e==null) {
            // The query was successful.
          try{
               ParseUser user = parseUsers.get(0);
               String userId = user.getObjectId();
             }
       catch(ArrayIndexOutOfBoundsException e)
           {
       // Print message for user does not exist . 
            }
             showProfileActivity(userId);
            } 
              else {
                   // The query was unsuccessful.
                     }
                       }
                            });

这篇关于ParseQuery-正确处理IndexOutOfBoundsException-Parse.com?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！