Question

请帮助，我试图找出服务器上是否有一个文件夹以下方法

我初始化并连接

mGoogleApiClient = new GoogleApiClient.Builder(AMain.this)
.addApi(Fitness.CONFIG_API)
.addApi(Drive.API)
.addScope(Drive.SCOPE_FILE)
.addConnectionCallbacks(AMain.this)
.addOnConnectionFailedListener(AMain.this)
.build();

mGoogleApiClient.connect();

建立连接

@Override
public void onConnected(Bundle connectionHint) {
    DriveFolder appFolder = Drive.DriveApi.getAppFolder(mGoogleApiClient);
    DriveFolder myFldr = search(appFolder, "AMain");
}

继续尝试查找文件夹

private static DriveFolder search(DriveFolder appFolder, String folder) {
    Query query = new Query.Builder().addFilter(Filters.eq(SearchableField.TITLE, folder)).build();
    MetadataBuffer metadataBuffer = appFolder.queryChildren(mGoogleApiClient, query).await().getMetadataBuffer();
    if(metadataBuffer != null&&metadataBuffer.getCount()>0) {
        Log.v("ME","Found "+metadataBuffer.getCount()+" existing folders");
        Metadata metadata = metadataBuffer.get(0);
        if (metadata != null && metadata.isFolder()) {
            Log.v("ME","Returning existing folder");
            return Drive.DriveApi.getFolder(mGoogleApiClient, metadata.getDriveId());
        }else{
            Log.v("ME","Returning created folder even though we found meta data");
            return appFolder.createFolder(mGoogleApiClient, new MetadataChangeSet.Builder().setTitle(folder).build()).await().getDriveFolder();
        }
    }else{
        Log.v("ME","Returning created folder");
        return appFolder.createFolder(mGoogleApiClient, new MetadataChangeSet.Builder().setTitle(folder).build()).await().getDriveFolder();
    }
}

但在第二行收到错误

05-08 17:06:19.261  16538-16538/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: ru.moore.aisuchettehniki, PID: 16538
    java.lang.NullPointerException: Attempt to invoke interface method 'com.google.android.gms.common.api.PendingResult com.google.android.gms.drive.DriveFolder.queryChildren(com.google.android.gms.common.api.GoogleApiClient, com.google.android.gms.drive.query.Query)' on a null object reference
            at ru.moore.aisuchettehniki.AMain.search(AMain.java:147)
            at ru.moore.aisuchettehniki.AMain.onConnected(AMain.java:142)
            at com.google.android.gms.common.internal.zzl.zzj(Unknown Source)
            at com.google.android.gms.common.api.zzd.zzie(Unknown Source)
            at com.google.android.gms.common.api.zzd.zzc(Unknown Source)
            at com.google.android.gms.common.api.zzd$6.onConnected(Unknown Source)
            at com.google.android.gms.common.internal.zzl.zzj(Unknown Source)
            at com.google.android.gms.common.internal.zzl.zzfe(Unknown Source)
            at com.google.android.gms.common.internal.zzk$zzf.zzje(Unknown Source)
            at com.google.android.gms.common.internal.zzk$zza.zzc(Unknown Source)
            at com.google.android.gms.common.internal.zzk$zza.zzi(Unknown Source)
            at com.google.android.gms.common.internal.zzk$zzc.zzjg(Unknown Source)
            at com.google.android.gms.common.internal.zzk$zzb.handleMessage(Unknown Source)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:211)
            at android.app.ActivityThread.main(ActivityThread.java:5321)
            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:1016)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)

Answer 1

您需要提供另一个范围来访问＆＃34; app文件夹＆＃34;。

添加：

        .addScope(Drive.SCOPE_APPFOLDER)

到GoogleApiClient.Builder

获取DriveFolder谷歌硬盘

1 个答案: