i have a sample code to copy a file from one location to another. am using that as a backup for an SQLite database file which copies the file from My Documents folder to the desktop.. the sample code is below:
try{
DateTimeFormatter date = DateTimeFormatter.ofPattern("yyyy/MM/dd HHmmss");
String sys =System.getProperty("user.home");
String fileurl = sys+"\\Desktop\\school database backup";
File dest = new File(fileurl+date.format(java.time.LocalDateTime.now()));dest.mkdir();
String sys1 =System.getProperty("user.home");
File source = new File(sys1+"\\Documents\\hyper-DB\\intellect");
FileUtils.copyDirectory(source, dest);
JOptionPane.showMessageDialog(null,"Backup Successful");
}
catch(IOException e){
e.getMessage();
} finally{
try{
rs.close();
pst.close();
}
catch(Exception e){
}
}
this code works perfectly on my my pc which I used to create the project. but when I install it on another user's pc. it doesn't work. and am sure its unable to locate the database in My Documents folder though its there. please what do I do to make it work on another pc. thank you
As with every programming problem there are multiple ways to solve the problem. I will try to explain a couple of ways I would solve your problem. If you are heck bent on using the copy function from FileUtils. Have the entire project in a dedicated folder, with all the files in, you can even have sub-folders, this will keep thing consistent and you won't have to worry about file permissions, like the ones found on school computers. Another way to achieve the same out come is to read the main database and copy the data to the backup database one element at a time. This can also let you have the main database in the same directory as the backup database. It wouldn't hurt to have it all in a single folder too.
Related
My Dataflow pipeline needs to read a resource file GeoLite2-City.mmdb. I added it to my project and ran the pipeline. I confirmed that the project package zip file exists in the staging bucket on GCS.
However, when I try to read the resource file GeoLite-City.mmdb, I get a FileNotFoundException. How can I fix this? This is my code:
String path = myClass.class.getResource("/GeoLite2-City.mmdb").getPath();
File database = new File(path);
try
{
DatabaseReader reader = new DatabaseReader.Builder(database).build(); //<-this line get a FileNotFoundException
}
catch (IOException e)
{
LOG.info(e.toString());
}
My project package zip file is "classes-WOdCPQCHjW-hRNtrfrnZMw.zip"
(it contains class files and GeoLite2-City.mmdb)
The path value is "file:/dataflow/packages/staging/classes-WOdCPQCHjW-hRNtrfrnZMw.zip!/GeoLite2-City.mmdb", however it cannot be opened.
and This is the options.
--runner=BlockingDataflowPipelineRunner
--project=peak-myproject
--stagingLocation=gs://mybucket/staging
--input=gs://mybucket_log/log.68599ca3.gz
The Goal is transform the log file on GCS, and insert the transformed data to BigQuery.
When i ran locally, it was success importing to Bigquery.
i think there is a difference local PC and GCE to get the resource path.
I think the issue might be that DatabaseReader does not support paths to resources located inside a .zip or .jar file.
If that's the case, then your program worked with DirectPipelineRunner not because it's direct, but because the resource was simply located on the local filesystem rather than within the .zip file (as your comment says, the path was C:/Users/Jennie/workspace/DataflowJavaSDK-master/eclipse/starter/target/classes/GeoLite2-City.mmdb, while in the other case it was file:/dataflow/packages/staging/classes-WOdCPQCHjW-hRNtrfrnZMw.zip!/GeoLite2-City.mmdb)
I searched the web for what DatabaseReader class you might be talking about, and seems like it is https://github.com/maxmind/GeoIP2-java/blob/master/src/main/java/com/maxmind/geoip2/DatabaseReader.java .
In that case, there's a good chance that your code will work with the following minor change:
try
{
InputStream stream = myClass.class.getResourceAsStream("/GeoLite2-City.mmdb");
DatabaseReader reader = new DatabaseReader.Builder(stream).build();
}
catch (IOException e)
{
...
}
I'm developing a program with NetBeans 8.0 and JavaFX Scene Builder 2.0 that need store some variables in a file, where admin users can modify it when needed, (like change server IP address, or a number value from a no editable textfield) and if they close and load again the program, the changes made in variables are kept. Like any settings section of a program.
I just try do it with the Properties file, but i have problems to store it in the same folder as .jar file. When the program execute the line new FileOutputStream("configuration.properties"); the file is created at root of the disk. As the folder of the file can be stored anywhere, i not know how indicate the right path.
Creating the properties file in the package of the main project and using getClass().getResourceAsStream("configuration.properties"); i can read it but then i can not write in for change values of variables.
Is there a better method to create a configuration file? Or properties file is the best option for this case?
My other question is whether it is possible to prevent access to the contents of the file or encrypt the content?
PD: I've been testing this part of the code in Linux operating system currently, but the program will be used in Windows 7 when ready.
If you use Maven, you can store your property files in your resources folder, say resources/properties/. When you need to load them, do this:
private Properties createProps(String name)
{
Properties prop = new Properties();
InputStream in = null;
try
{
in = getClass().getResourceAsStream(name);
prop.load(in);
}
catch (IOException ex)
{
System.err.println("failed to load \"" + name + "\": " + ex);
}
finally
{
try
{
if (in != null)
{
in.close();
}
}
catch (IOException ex)
{
System.err.println("failed to close InputStream for \"" + name + "\":\n" + FXUtils.extractStackTrace(ex));
}
}
return prop;
}
Where name is the full path to your properties file within your resources folder. For example, if you store props.properties in resources/properties/, then you would pass in properties/props.properties.
I am not 100% sure if you can carry over this exact procedure to a non-Maven project. You'd need to instruct whatever compiler tool you are using to also include your property files.
As far as your final question goes, in regards to encrypting your properties, I would consider posting that as a separate question (after having done thorough research to try to discover an existing solution that works for you).
At last i found how obtain the absolute path from folder where is .jar file to create properties file in, and read/write it. Here is the code:
File file = new File(System.getProperty("java.class.path"));
File filePath = file.getAbsoluteFile().getParentFile();
String strPath = filePath.toString();
File testFile = new File(strPath+"/configuration.properties");
Tested in Ubuntu 13.04 And Windows 7 and it works.
For encrypt the properties values i found this thread that answer how do it.
I am trying to output numeric values one at a time from an Android application I'm writing, but I'm having a lot of trouble figuring out what's going on. Tried looking for answers, but only confused further. This strikes me as something that should be relatively straightforward, so I feel pretty dumb for being so confused by it.
String directory = Environment.getExternalStorageDirectory().getAbsolutePath();
When I log the directory I get a path "/storage/emulated/0" Where is that? Is that different from what I would get if I wasn't debugging?
Then I have:
String fileName = directory + "/Android/data/com.sample.app/files/test.txt"
File myFile = new File(fileName);
FileOutputStream fos;
try {
fos = new FileOutputStream(myFile);
String text = "Test text\n";
fos.write(text.getBytes());
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e){
e.printStackTrace();
}
I tried using the Windows Explorer to figure out where stuff is saving and/or is supposed to be saved but I don't see it. This is code based on the information in this link: http://developer.android.com/guide/topics/data/data-storage.html, but I really don't understand where the "/storage/emulated/0" comes from and how I either access that location or get rid of it.
EDIT: Right now I just want to save all the numbers so I can check what is coming out. The numbers are recorded from the audio input.
EDIT: Using the ASTRO File app on my phone revealed the files
Didn't need the "/Android/data/com.sample.app/files/" part, don't know how to use that.
Path wrong?
/storage/emulated/0 is a path at your filesystem which represents the external storage. At earlier versions of Android we often had /mnt/sdcard/ or something similiar, but many devices today don't have a sdcard but emulate an external storage anyway.
To view the files at your Android filesystem I'd recommend to use an App like Astro File Manager. Just take a look if your file has been written.
One possible mistake could be, that you you are missing a File.separator between your directory and the local path.
String fileName = directory + File.seperator + "Android/data/com.sample.app/file/test.txt"
Directory created?
You should also make sure, that the directory exists by calling myDir.mkDirs();, where myDir is the complete path without the filename.
To create the directory you can use the following code
directory = directory + "/Android/data/com.sample.app/file/test.txt"
new File(directory).mkDirs();
Uses-Permission in Manifest?
Last error source could be, that you might miss the external storage permission, you need a
You also need to make sure, that you require the permission for writing to the external storage. Take a look for <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> in your Android Manifest file.
I want to save a Unique ID (which is a String) which gets created when I launch my Java application. Now I want to save this somewhere (I think in some file on the disk) so that when I relaunch my application I should be able to read it and use that ID.
I want to know what is the good way to saving such ID. I am thinking of creating a Properties file and save it then retrieve it from it when I relaunch application. Is there a better or standard way for this?
EDIT :
Additionally what should be the folder location for storing on the disk. Should it be relative to my execution path or some Logged-in user specific path?
1. If its the same Java application that writes or reads this String, then use Serialization, it will be in non-readable form when saved.
2. If reading and writing is from different program, then use Text file.
3. Using Property file will be also a good approach.
If your app/program needs to store more data at some point sqlite3 might be the best option for you. It is easy to implement and use.
Download sqlite3
EDIT: How many IDs will be stored in the app? If there are just a few, a textfile or property file is enough.
EDIT2: Navigate to your Documents folder on your machine and you will see folders of programs/games. Thats where you should place the file/db. However you can also store it in the installation path on your hard drive. Also make sure your user launches the app trough a shortcut, not the actual execution file
Use the FileWriter and File classes from Java.
It should be something like that:
File f = new File(your path here);
if (f.exists()){
BufferedReader br = new BufferedReader(new FileReader(your path here));
String a = br.readLine();
br.close();
}else{
FileWriter fw = new FileWriter(your path here);
fw.write(your ID String);
fw.flush();
fw.close();
I hope this is want u meant.
Best regards
edit: just noticed too late that your edited your post....
Given a string location and string file name, is it possible to execute a java command to delete said file? If so, what package or class should I look at using for this?
Using the file's string location and name, get a file handle for it:
File doomedFile = new File (location, name);
doomedFile.delete();
Note that you should encapsulate this with appropriate code to catch potential problem cases, such as if Java does not have the permission to delete that file on your current system. Or, if the file isn't found or another, similar, edge case.
The API you want to look at in this case is java.io.File.
You can use this code:
File fileToDelete= new File(yourPath, fileName);
if(fileToDelete.delete()){
System.out.println("File deleted");
} else {
System.out.println("Operation failed");
}