Question

我的应用程序运行如下：

从网址
提取下载的文件，获取csv文件和文件夹音频
将csv文件保存到领域
删除zip文件，fle extract，csv文件，只留下文件夹音频
显示来自领域的数据。

这里的问题是，当我从服务器更新数据时，我想通过比较url中的最后一个修改文件和设备中的文件来更新领域中的数据但我删除了zip文件，解压缩文件，csv文件，离开只有带mp3文件的文件夹音频。当我得到最后一个修改过的mp3文件时，它只是获取我上次在服务器上更新的日期，而不是我在设备上提取它的日期。它应该始终小于还是等于服务器上的更新文件。

代码示例

功能提取文件zip

// Get LastModified file from server, it's true
HttpURLConnection connection = ....
long dt=connection.getLastModified();
if (dt == 0)
    Log.d("carot", "download: No date information.");
else
    Log.d("carot", "download: "+ new Date(dt)+ "::"+ dt );

从url检查lastModified

// Get LastModified file mp3 from device

File file = new File(holder.getContext().getFilesDir() + "/Data/Audio/", test.getQuestions().get(0).getAudio() + ".mp3");
long dt = file.lastModified();
if (dt == 0)
    Log.d("carot", "click: No date information.");
else
    Log.d("carot", "click: " + new Date(dt) + "::" + dt);

代码检查设备中的lastModified文件

//Realm Object Test with fields lastUpdated, created ..Always null because I did not process them before

public class Test extends RealmObject{
@PrimaryKey
    @Required
    private String id;
    private String name;
    private int duration;
    private int number_of_questions;
    private int display_order;
    private int progress;
    private String path;
    private boolean is_deleted;
    private String lastUpdated;
    private String created;
    private RealmList<Question> questions;
}

\\Question RealmObject 
public class Question extends RealmObject{
@PrimaryKey
    @Required
    private String id;
    @Index
    private String audio;
    @Index
    private String photo;
    private String text;
    @Index
    private String transcript;
    private String typeName;
    private int display_order;
}

领域对象

PRINT N'Dropping [dbo].[AspNetUserClaims].[IX_UserId]...';
GO
DROP INDEX [IX_UserId] ON [dbo].[AspNetUserClaims];
GO

PRINT N'Dropping [dbo].[AspNetUserLogins].[IX_UserId]...';
GO
DROP INDEX [IX_UserId] ON [dbo].[AspNetUserLogins];
GO


PRINT N'Dropping [dbo].[AspNetUserRoles].[IX_RoleId]...';
GO
DROP INDEX [IX_RoleId] ON [dbo].[AspNetUserRoles];
GO


PRINT N'Dropping [dbo].[AspNetUserRoles].[IX_UserId]...';
GO
DROP INDEX [IX_UserId] ON [dbo].[AspNetUserRoles];
GO


PRINT N'Dropping [dbo].[FK_dbo.AspNetUserRoles_dbo.AspNetRoles_RoleId]...';
GO
ALTER TABLE [dbo].[AspNetUserRoles] DROP CONSTRAINT [FK_dbo.AspNetUserRoles_dbo.AspNetRoles_RoleId];
GO


PRINT N'Dropping [dbo].[FK_dbo.AspNetUserClaims_dbo.AspNetUsers_UserId]...';
GO
ALTER TABLE [dbo].[AspNetUserClaims] DROP CONSTRAINT [FK_dbo.AspNetUserClaims_dbo.AspNetUsers_UserId];
GO


PRINT N'Dropping [dbo].[FK_dbo.AspNetUserLogins_dbo.AspNetUsers_UserId]...';
GO
ALTER TABLE [dbo].[AspNetUserLogins] DROP CONSTRAINT [FK_dbo.AspNetUserLogins_dbo.AspNetUsers_UserId];
GO


PRINT N'Dropping [dbo].[FK_dbo.AspNetUserRoles_dbo.AspNetUsers_UserId]...';
GO
ALTER TABLE [dbo].[AspNetUserRoles] DROP CONSTRAINT [FK_dbo.AspNetUserRoles_dbo.AspNetUsers_UserId];
GO


PRINT N'Starting rebuilding table [dbo].[AspNetRoles]...';
GO
BEGIN TRANSACTION;

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;

SET XACT_ABORT ON;

CREATE TABLE [dbo].[tmp_ms_xx_AspNetRoles] (
    [Id]               NVARCHAR (128) NOT NULL,
    [ConcurrencyStamp] NVARCHAR (MAX) NULL,
    [Name]             NVARCHAR (256) NULL,
    [NormalizedName]   NVARCHAR (256) NULL,
    CONSTRAINT [tmp_ms_xx_constraint_PK_AspNetRoles1] PRIMARY KEY CLUSTERED ([Id] ASC)
);

IF EXISTS (SELECT TOP 1 1 
           FROM   [dbo].[AspNetRoles])
    BEGIN
        INSERT INTO [dbo].[tmp_ms_xx_AspNetRoles] ([Id], [Name], [NormalizedName])
        SELECT   [Id],
                 [Name],
                 UPPER([Name])
        FROM     [dbo].[AspNetRoles]
        ORDER BY [Id] ASC;
    END

DROP TABLE [dbo].[AspNetRoles];

EXECUTE sp_rename N'[dbo].[tmp_ms_xx_AspNetRoles]', N'AspNetRoles';

EXECUTE sp_rename N'[dbo].[tmp_ms_xx_constraint_PK_AspNetRoles1]', N'PK_AspNetRoles', N'OBJECT';

COMMIT TRANSACTION;

SET TRANSACTION ISOLATION LEVEL READ COMMITTED;


GO
PRINT N'Creating [dbo].[AspNetRoles].[RoleNameIndex]...';


GO
CREATE NONCLUSTERED INDEX [RoleNameIndex]
    ON [dbo].[AspNetRoles]([NormalizedName] ASC);


GO
PRINT N'Starting rebuilding table [dbo].[AspNetUserClaims]...';


GO
BEGIN TRANSACTION;

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;

SET XACT_ABORT ON;

CREATE TABLE [dbo].[tmp_ms_xx_AspNetUserClaims] (
    [Id]         INT            IDENTITY (1, 1) NOT NULL,
    [ClaimType]  NVARCHAR (MAX) NULL,
    [ClaimValue] NVARCHAR (MAX) NULL,
    [UserId]     NVARCHAR (128) NOT NULL,
    CONSTRAINT [tmp_ms_xx_constraint_PK_AspNetUserClaims1] PRIMARY KEY CLUSTERED ([Id] ASC)
);

IF EXISTS (SELECT TOP 1 1 
           FROM   [dbo].[AspNetUserClaims])
    BEGIN
        SET IDENTITY_INSERT [dbo].[tmp_ms_xx_AspNetUserClaims] ON;
        INSERT INTO [dbo].[tmp_ms_xx_AspNetUserClaims] ([Id], [UserId], [ClaimType], [ClaimValue])
        SELECT   [Id],
                 [UserId],
                 [ClaimType],
                 [ClaimValue]
        FROM     [dbo].[AspNetUserClaims]
        ORDER BY [Id] ASC;
        SET IDENTITY_INSERT [dbo].[tmp_ms_xx_AspNetUserClaims] OFF;
    END

DROP TABLE [dbo].[AspNetUserClaims];

EXECUTE sp_rename N'[dbo].[tmp_ms_xx_AspNetUserClaims]', N'AspNetUserClaims';

EXECUTE sp_rename N'[dbo].[tmp_ms_xx_constraint_PK_AspNetUserClaims1]', N'PK_AspNetUserClaims', N'OBJECT';

COMMIT TRANSACTION;

SET TRANSACTION ISOLATION LEVEL READ COMMITTED;


GO
PRINT N'Creating [dbo].[AspNetUserClaims].[IX_AspNetUserClaims_UserId]...';


GO
CREATE NONCLUSTERED INDEX [IX_AspNetUserClaims_UserId]
    ON [dbo].[AspNetUserClaims]([UserId] ASC);


GO
PRINT N'Starting rebuilding table [dbo].[AspNetUserLogins]...';


GO
BEGIN TRANSACTION;

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;

SET XACT_ABORT ON;

CREATE TABLE [dbo].[tmp_ms_xx_AspNetUserLogins] (
    [LoginProvider]       NVARCHAR (128) NOT NULL,
    [ProviderKey]         NVARCHAR (450) NOT NULL,
    [ProviderDisplayName] NVARCHAR (MAX) NULL,
    [UserId]              NVARCHAR (128) NOT NULL,
    CONSTRAINT [tmp_ms_xx_constraint_PK_AspNetUserLogins1] PRIMARY KEY CLUSTERED ([LoginProvider] ASC, [ProviderKey] ASC)
);

IF EXISTS (SELECT TOP 1 1 
           FROM   [dbo].[AspNetUserLogins])
    BEGIN
        INSERT INTO [dbo].[tmp_ms_xx_AspNetUserLogins] ([LoginProvider], [ProviderKey], [ProviderDisplayName], [UserId])
        SELECT   [LoginProvider],
                 [ProviderKey],
                 [LoginProvider] AS [ProviderDisplayName],
                 [UserId]
        FROM     [dbo].[AspNetUserLogins]
        ORDER BY [LoginProvider] ASC, [ProviderKey] ASC;
    END

DROP TABLE [dbo].[AspNetUserLogins];

EXECUTE sp_rename N'[dbo].[tmp_ms_xx_AspNetUserLogins]', N'AspNetUserLogins';

EXECUTE sp_rename N'[dbo].[tmp_ms_xx_constraint_PK_AspNetUserLogins1]', N'PK_AspNetUserLogins', N'OBJECT';

COMMIT TRANSACTION;

SET TRANSACTION ISOLATION LEVEL READ COMMITTED;


GO
PRINT N'Creating [dbo].[AspNetUserLogins].[IX_AspNetUserLogins_UserId]...';


GO
CREATE NONCLUSTERED INDEX [IX_AspNetUserLogins_UserId]
    ON [dbo].[AspNetUserLogins]([UserId] ASC);


GO
PRINT N'Starting rebuilding table [dbo].[AspNetUserRoles]...';


GO
BEGIN TRANSACTION;

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;

SET XACT_ABORT ON;

CREATE TABLE [dbo].[tmp_ms_xx_AspNetUserRoles] (
    [UserId] NVARCHAR (128) NOT NULL,
    [RoleId] NVARCHAR (128) NOT NULL,
    CONSTRAINT [tmp_ms_xx_constraint_PK_AspNetUserRoles1] PRIMARY KEY CLUSTERED ([UserId] ASC, [RoleId] ASC)
);

IF EXISTS (SELECT TOP 1 1 
           FROM   [dbo].[AspNetUserRoles])
    BEGIN
        INSERT INTO [dbo].[tmp_ms_xx_AspNetUserRoles] ([UserId], [RoleId])
        SELECT   [UserId],
                 [RoleId]
        FROM     [dbo].[AspNetUserRoles]
        ORDER BY [UserId] ASC, [RoleId] ASC;
    END

DROP TABLE [dbo].[AspNetUserRoles];

EXECUTE sp_rename N'[dbo].[tmp_ms_xx_AspNetUserRoles]', N'AspNetUserRoles';

EXECUTE sp_rename N'[dbo].[tmp_ms_xx_constraint_PK_AspNetUserRoles1]', N'PK_AspNetUserRoles', N'OBJECT';

COMMIT TRANSACTION;

SET TRANSACTION ISOLATION LEVEL READ COMMITTED;


GO
PRINT N'Creating [dbo].[AspNetUserRoles].[IX_AspNetUserRoles_RoleId]...';


GO
CREATE NONCLUSTERED INDEX [IX_AspNetUserRoles_RoleId]
    ON [dbo].[AspNetUserRoles]([RoleId] ASC);


GO
PRINT N'Creating [dbo].[AspNetUserRoles].[IX_AspNetUserRoles_UserId]...';


GO
CREATE NONCLUSTERED INDEX [IX_AspNetUserRoles_UserId]
    ON [dbo].[AspNetUserRoles]([UserId] ASC);


GO

-- CHANGE THE REST OF THE SCRIPT! We should NOT drop AspNetUsers
PRINT N'Starting rebuilding table [dbo].[AspNetUsers]...';


GO
BEGIN TRANSACTION;

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;

SET XACT_ABORT ON;

ALTER TABLE [dbo].[AspNetUsers]
ADD [ConcurrencyStamp] NVARCHAR(MAX) NULL
GO

ALTER TABLE [dbo].[AspNetUsers]
ADD [LockoutEnd] DATETIMEOFFSET(7) NULL
GO

ALTER TABLE [dbo].[AspNetUsers]
ADD [NormalizedEmail] NVARCHAR(256) NULL
GO

ALTER TABLE [dbo].[AspNetUsers]
ADD [NormalizedUserName] NVARCHAR(256) NULL
GO

DROP INDEX [UserNameIndex] ON [dbo].[AspNetUsers];
GO

UPDATE [dbo].[AspNetUsers]
SET [NormalizedEmail] = UPPER([Email]), [NormalizedUserName] = UPPER([UserName])
GO

COMMIT TRANSACTION;

SET TRANSACTION ISOLATION LEVEL READ COMMITTED;
GO

PRINT N'Creating [dbo].[AspNetUsers].[EmailIndex]...';
GO
CREATE NONCLUSTERED INDEX [EmailIndex]
    ON [dbo].[AspNetUsers]([NormalizedEmail] ASC);
GO


PRINT N'Creating [dbo].[AspNetUsers].[UserNameIndex]...';
GO
CREATE UNIQUE NONCLUSTERED INDEX [UserNameIndex]
    ON [dbo].[AspNetUsers]([NormalizedUserName] ASC);
GO


PRINT N'Creating [dbo].[AspNetRoleClaims]...';
GO
CREATE TABLE [dbo].[AspNetRoleClaims] (
    [Id]         INT            IDENTITY (1, 1) NOT NULL,
    [ClaimType]  NVARCHAR (MAX) NULL,
    [ClaimValue] NVARCHAR (MAX) NULL,
    [RoleId]     NVARCHAR (128) NOT NULL,
    CONSTRAINT [PK_AspNetRoleClaims] PRIMARY KEY CLUSTERED ([Id] ASC)
);
GO


PRINT N'Creating [dbo].[AspNetRoleClaims].[IX_AspNetRoleClaims_RoleId]...';
GO
CREATE NONCLUSTERED INDEX [IX_AspNetRoleClaims_RoleId]
    ON [dbo].[AspNetRoleClaims]([RoleId] ASC);
GO


PRINT N'Creating [dbo].[AspNetUserTokens]...';
GO
CREATE TABLE [dbo].[AspNetUserTokens] (
    [UserId]        NVARCHAR (128) NOT NULL,
    [LoginProvider] NVARCHAR (128) NOT NULL,
    [Name]          NVARCHAR (450) NOT NULL,
    [Value]         NVARCHAR (MAX) NULL,
    CONSTRAINT [PK_AspNetUserTokens] PRIMARY KEY CLUSTERED ([UserId] ASC, [LoginProvider] ASC, [Name] ASC)
);
GO


PRINT N'Creating [dbo].[FK_AspNetUserClaims_AspNetUsers_UserId]...';
GO
ALTER TABLE [dbo].[AspNetUserClaims] WITH NOCHECK
    ADD CONSTRAINT [FK_AspNetUserClaims_AspNetUsers_UserId] FOREIGN KEY ([UserId]) REFERENCES [dbo].[AspNetUsers] ([Id]) ON DELETE CASCADE;
GO

PRINT N'Creating [dbo].[FK_AspNetUserLogins_AspNetUsers_UserId]...';
GO


ALTER TABLE [dbo].[AspNetUserLogins] WITH NOCHECK
    ADD CONSTRAINT [FK_AspNetUserLogins_AspNetUsers_UserId] FOREIGN KEY ([UserId]) REFERENCES [dbo].[AspNetUsers] ([Id]) ON DELETE CASCADE;
GO


PRINT N'Creating [dbo].[FK_AspNetUserRoles_AspNetRoles_RoleId]...';
GO
ALTER TABLE [dbo].[AspNetUserRoles] WITH NOCHECK
    ADD CONSTRAINT [FK_AspNetUserRoles_AspNetRoles_RoleId] FOREIGN KEY ([RoleId]) REFERENCES [dbo].[AspNetRoles] ([Id]) ON DELETE CASCADE;
GO


PRINT N'Creating [dbo].[FK_AspNetUserRoles_AspNetUsers_UserId]...';
GO
ALTER TABLE [dbo].[AspNetUserRoles] WITH NOCHECK
    ADD CONSTRAINT [FK_AspNetUserRoles_AspNetUsers_UserId] FOREIGN KEY ([UserId]) REFERENCES [dbo].[AspNetUsers] ([Id]) ON DELETE CASCADE;
GO


PRINT N'Creating [dbo].[FK_AspNetRoleClaims_AspNetRoles_RoleId]...';
GO
ALTER TABLE [dbo].[AspNetRoleClaims] WITH NOCHECK
    ADD CONSTRAINT [FK_AspNetRoleClaims_AspNetRoles_RoleId] FOREIGN KEY ([RoleId]) REFERENCES [dbo].[AspNetRoles] ([Id]) ON DELETE CASCADE;
GO


PRINT N'Checking existing data against newly created constraints';
GO
ALTER TABLE [dbo].[AspNetUserClaims] WITH CHECK CHECK CONSTRAINT [FK_AspNetUserClaims_AspNetUsers_UserId];

ALTER TABLE [dbo].[AspNetUserLogins] WITH CHECK CHECK CONSTRAINT [FK_AspNetUserLogins_AspNetUsers_UserId];

ALTER TABLE [dbo].[AspNetUserRoles] WITH CHECK CHECK CONSTRAINT [FK_AspNetUserRoles_AspNetRoles_RoleId];

ALTER TABLE [dbo].[AspNetUserRoles] WITH CHECK CHECK CONSTRAINT [FK_AspNetUserRoles_AspNetUsers_UserId];

ALTER TABLE [dbo].[AspNetRoleClaims] WITH CHECK CHECK CONSTRAINT [FK_AspNetRoleClaims_AspNetRoles_RoleId];


GO
PRINT N'Update complete.';

（Realm version（s）：1.2.0）

Answer 1

1。）添加一个将lastModified日期设置为new Date()的无参数构造函数。

2。）将您的架构版本增加到现在的+1，并定义一个迁移，将lastModified的值设置为new Date()，其中lastModified为目前为null。

如何使用android获取RealmObject中的最后一个Modified RealmObject或字段

代码示例

1 个答案: