data-persistence

问题 I am developing an application using Struts 2 and Hibernate. On a JSP page I have one form in which all CRUD operations I am performing. I want my Form data to be persisted, which is temporarily entered in the form fields. One approach which I tried is to bind all the data into an Object and store that object in a session or cache but I know there is some limitation of storing data like this. My form is having the functionality to add n number of rows which means I have to store large amount

问题 I am developing an application using Struts 2 and Hibernate. On a JSP page I have one form in which all CRUD operations I am performing. I want my Form data to be persisted, which is temporarily entered in the form fields. One approach which I tried is to bind all the data into an Object and store that object in a session or cache but I know there is some limitation of storing data like this. My form is having the functionality to add n number of rows which means I have to store large amount

问题 I'm trying to write a program to store large amount of data (100s of PB) on tapes. I'm using tar to group files together, but for technical reasons I've decided to write multiple tars in one tape. In order to easily find what data are on a tape, I've decided to create a small index and write it at the beginning of the tape. So I'm doing something like this: # create an empty index file head -c 1M < /dev/urandom > index.txt # rewind tape mt -f /dev/nst0 rewind # write index to the beginning of

问题 This is third time I've posted this issues and am yet to get a working response. So I have a fitness app, the user selected one workout before it been displayed as table view, when a cell is selected I want it to show that cell(containing an exercise) as completed by marking it with a checkmark. this works fine but I am struggling with how to save that check mark when the app is terminated and re launched. Below I have given an example of one of the workout models and the table view

问题 So I was trying to serialize some DefaultStyledDocument objects using XMLEncoder. They encode just fine, however when I look at the data, it doesn't encode any actually data, it just gives the class file. I've looked on the internet and saw that many people had trouble with this, but there were no helpful solutions. The best answer I saw was "DefaultStyledDocument isn't a proper bean, so it won't work." So, is there anyway I can serialize DefaultStyledDocuments, without having to deal with

问题 I create a class as following and want to save array: [costCategory] to disk, class costCategory : NSObject, NSCoding { var name : String var defaultValue : Int var thisMonthsEstimate : Int var sumOfThisMonthsActuals : Int var riskFactor : Float var monthlyAverage : Float var icon: UIImage! init (name:String, defaultValue:Int, thisMonthsEstimate:Int, sumOfThisMonthsActuals:Int, riskFactor:Float, monthlyAverage:Float, icon: UIImage) { self.name = name self.defaultValue = defaultValue self

问题 I have a problem with my connection between my app and firebase database. After adding: Database.database().isPersistenceEnabled = true To my AppDelegate, some of the data is out of sync. To get my data i use: self.ref?.child("Stores").observe(.childAdded, with: { (snapshot) in if let dictionary = snapshot.value as? [String: AnyObject] { let store = Store() store.Latitude = dictionary["Latitude"]?.doubleValue store.Longitude = dictionary["Longitude"]?.doubleValue store.Store = dictionary[

问题 For a simulation program I'm working in Delphi 2010. The simulation isn't a problem but I need to use large collection of data which gives a problem. The data is available in excel sheets, so there is no need to edit this data in Delphi, but collecting this data from the excel sheets takes around 10min. This isn't a problem as long as you don't need to collect the data every time the program runs. So I made a program which collects all the data makes it visible, not problems here,and then

问题 I've been struggling with this for days. I'll appreciate any help. I have a Location NSManagedObject and an Image NSManagedObject , they have one-to-many relationship, i.e., one location has many images. I have 2 screens, in the first one the user adds locations on the view context and they get added and retrieved without problems. Now, in the second screen, I want to retrieve images based on the location selected in the first screen, then display the images in a Collection View. The images

问题 The MSI installation would call my (native/C++) custom action functions. Since the DLL is freshly loaded, and the MSIEXEC.EXE process is launched separately for each function (the callable actions, as specified in MSI/WiX script), I cannot use any global data in C/C++ program. How (or Where) can I store some information about the installation going on? I cannot use named objects (like shared-memory) as the "process" that launches the DLL to call the "action" function would exit, and OS will