堆栈跟踪 E/UncaughtException：java.lang.IndexOutOfBoundsException：索引 1 无效

Question

我正在开发一个带有 firebase 排行榜的 android 应用程序，它运行良好，但是当我点击 leaderboard 时崩溃，这是堆栈跟踪日志，我收到 2 个错误：

E/UncaughtException: java.lang.IndexOutOfBoundsException: 索引 1 无效，大小为 1

E/AndroidRuntime：致命异常：main

12-02 01:05:53.969 3508-3508/com.example.myapp E/UncaughtException: java.lang.IndexOutOfBoundsException: Invalid index 1, size is 1
                                                                            at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
                                                                            at java.util.ArrayList.get(ArrayList.java:308)
                                                                            at com.example.myapp.activity.LeaderboardActivity.onChildAdded(LeaderboardActivity.java:167)
                                                                            at com.google.android.gms.internal.zzaer.zza(Unknown Source)
                                                                            at com.google.android.gms.internal.zzagp.zzSu(Unknown Source)
                                                                            at com.google.android.gms.internal.zzags.run(Unknown Source)
                                                                            at android.os.Handler.handleCallback(Handler.java:739)
                                                                            at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                            at android.os.Looper.loop(Looper.java:135)
                                                                            at android.app.ActivityThread.main(ActivityThread.java:5254)
                                                                            at java.lang.reflect.Method.invoke(Native Method)
                                                                            at java.lang.reflect.Method.invoke(Method.java:372)
                                                                            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                                                                            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
12-02 01:05:54.215 3508-3508/com.example.myapp E/AndroidRuntime: FATAL EXCEPTION: main
                                                                     Process: com.example.myapp, PID: 3508
                                                                     java.lang.IndexOutOfBoundsException: Invalid index 1, size is 1
                                                                         at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
                                                                         at java.util.ArrayList.get(ArrayList.java:308)
                                                                         at com.examle.myapp.activity.LeaderboardActivity.onChildAdded(LeaderboardActivity.java:167)
                                                                         at com.google.android.gms.internal.zzaer.zza(Unknown Source)
                                                                         at com.google.android.gms.internal.zzagp.zzSu(Unknown Source)
                                                                         at com.google.android.gms.internal.zzags.run(Unknown Source)
                                                                         at android.os.Handler.handleCallback(Handler.java:739)
                                                                         at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                         at android.os.Looper.loop(Looper.java:135)
                                                                         at android.app.ActivityThread.main(ActivityThread.java:5254)
                                                                         at java.lang.reflect.Method.invoke(Native Method)
                                                                         at java.lang.reflect.Method.invoke(Method.java:372)
                                                                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                                                                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

两条蓝线表示 leaderboardactivity.java

中此行的错误

if (leaderboards.get(1).getName().equalsIgnoreCase(displayName)) {

这是来自 leaderboardactivity.java

的代码片段

private void getLeaderboard() {

        databaseLeaderboard.orderByChild("score").limitToLast((int) totalValue).addChildEventListener(new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) {
                Leaderboard leaderboard = dataSnapshot.getValue(Leaderboard.class);
                leaderboards.add(leaderboard);

                if (leaderboards.size() >= (int) totalValue) {
                    Collections.reverse(leaderboards);
                    leaderboardAdapterNew.notifyDataSetChanged();
                }

                if (leaderboards.size() == totalValue) {


                    if (leaderboards.get(0).getName().equalsIgnoreCase(displayName)) {
                        txtUname1.setText("Me");
                    } else {
                        txtUname1.setText(leaderboards.get(0).getName());
                    }
                    if (leaderboards.get(1).getName().equalsIgnoreCase(displayName)) {
                        txtUname2.setText("Me");
                    } else {
                        txtUname2.setText(leaderboards.get(1).getName());
                    }
                    if (leaderboards.get(2).getName().equalsIgnoreCase(displayName)) {
                        txtUname3.setText("Me");
                    } else {
                        txtUname3.setText(leaderboards.get(2).getName());
                    }

有人能告诉我我的错在哪里吗？

Answer 1

是的，您正在尝试访问不存在的索引：

改变这个：

if (leaderboards.size() == totalValue) {

为此：

if (leaderboards.size() == totalValue && totalValue > 2) {

堆栈跟踪 E/UncaughtException：java.lang.IndexOutOfBoundsException：索引 1 无效

stacktrace E/UncaughtException: java.lang.IndexOutOfBoundsException: Invalid index 1

java

android

indexoutofboundsexception

leaderboard