maybe a simple question but for me as starter with Neo4j a hurdle. I installed the neo4jphp with composer in the same directory as my application. Vendor-Subfolder has been created and the everyman/neo4j folder below is available. For a first test I used this code snippet from the examples:
spl_autoload_register(function ($className) {
$libPath = 'vendor\\';
$classFile = $className.'.php';
$classPath = $libPath.$classFile;
if (file_exists($classPath)) {
require($classPath);
}
});
require('vendor/autoload.php');
use everyman\Neo4j\Client,
everyman\Neo4j\Transport;
$client = new Client(new Transport('localhost', 7474));
print_r($client->getServerInfo());
I always stumple upon the error
Fatal error: Cannot instantiate abstract class Everyman\Neo4j\Transport
Googling brought me to a comment from Josh Adell stating
You can't instantiate Everyman\Neo4j\Transport, since it is an abstract class. You must instantiate Everyman\Neo4j\Transport\Curl or Everyman\Neo4j\Transport\Stream depending on your needs
So I thought I just need to alter the use-statements to
use everyman\Neo4j\Client,
everyman\Neo4j\Transport\Curl;
but this doesnt work, debugging shows, that the autoloader only get "Transport.php" instead of "everyman\Neo4j\Transport\Curl.php". For "Client.php" its still working ("vendor\everyman\Neo4j\Client.php") so I am guessing that the use-statement is wrong or the code is not able to handle an additional subfolder-structure.
Using
require('phar://neo4jphp.phar');
works fine but I read that this is deprecated and should be replaced by composer / autoload.
Anyone has a hint what to change or had the same problem?
Thanks for your time,
Balael
Curl is the default transport. You only need to instantiate your own Transport object if you want to use Stream instead of Curl. If you really want to instantiate your own Curl Transport, the easiest change to your existing code is to modify the use statement to be:
use everyman\Neo4j\Client,
everyman\Neo4j\Transport\Curl as Transport;
Also, you don't need to register your own autoload function if you are using the Composer package. vendor/autoload.php does that for you.
Thanks Josh, I was trying but it seems I still stuck somewhere. I am fine with using the default CURL - so I shrinked the code down to
require('vendor/autoload.php');
use everyman\Neo4j\Client;
$client = new Everyman\Neo4j\Client('localhost', 7474);
print_r($client->getServerInfo());`
The folder structure is main (here are the files and the composer.json with the content
{
"require": {
"everyman/Neo4j": "dev-master"
}
}
and in the subfolder "vendor" we have the "autoload.php" and the subfolder everyman with the related content. When I run the file I come out with
Fatal error: Class 'Everyman\Neo4j\Client' not found
which does not happen when I have the autoloadfunction. I guess I made a mistake somewehere - can you give me a hint?
Thanks a lot, B
Hmmm... I was just trying around and it seems the Transport CLASS is not needed in the use-statement and the class instantiation. This seems to work:
require('vendor/autoload.php');
use everyman\Neo4j\Client;
$client = new Client();
print_r($client->getServerInfo());
also valid for having a dedicated server/port:
$client = new Everyman\Neo4j\Client('localhost', 7474);
If you have more input I would be happy to learn more - thanks, all input & thoughts are very appreciated.
Balael
How can I change the current working directory from within a Java program? Everything I've been able to find about the issue claims that you simply can't do it, but I can't believe that that's really the case.
I have a piece of code that opens a file using a hard-coded relative file path from the directory it's normally started in, and I just want to be able to use that code from within a different Java program without having to start it from within a particular directory. It seems like you should just be able to call System.setProperty( "user.dir", "/path/to/dir" ), but as far as I can figure out, calling that line just silently fails and does nothing.
I would understand if Java didn't allow you to do this, if it weren't for the fact that it allows you to get the current working directory, and even allows you to open files using relative file paths....
There is no reliable way to do this in pure Java. Setting the user.dir property via System.setProperty() or java -Duser.dir=... does seem to affect subsequent creations of Files, but not e.g. FileOutputStreams.
The File(String parent, String child) constructor can help if you build up your directory path separately from your file path, allowing easier swapping.
An alternative is to set up a script to run Java from a different directory, or use JNI native code as suggested below.
The relevant OpenJDK bug was closed in 2008 as "will not fix".
If you run your legacy program with ProcessBuilder, you will be able to specify its working directory.
There is a way to do this using the system property "user.dir". The key part to understand is that getAbsoluteFile() must be called (as shown below) or else relative paths will be resolved against the default "user.dir" value.
import java.io.*;
public class FileUtils
{
public static boolean setCurrentDirectory(String directory_name)
{
boolean result = false; // Boolean indicating whether directory was set
File directory; // Desired current working directory
directory = new File(directory_name).getAbsoluteFile();
if (directory.exists() || directory.mkdirs())
{
result = (System.setProperty("user.dir", directory.getAbsolutePath()) != null);
}
return result;
}
public static PrintWriter openOutputFile(String file_name)
{
PrintWriter output = null; // File to open for writing
try
{
output = new PrintWriter(new File(file_name).getAbsoluteFile());
}
catch (Exception exception) {}
return output;
}
public static void main(String[] args) throws Exception
{
FileUtils.openOutputFile("DefaultDirectoryFile.txt");
FileUtils.setCurrentDirectory("NewCurrentDirectory");
FileUtils.openOutputFile("CurrentDirectoryFile.txt");
}
}
It is possible to change the PWD, using JNA/JNI to make calls to libc. The JRuby guys have a handy java library for making POSIX calls called jnr-posix. Here's the maven info
As mentioned you can't change the CWD of the JVM but if you were to launch another process using Runtime.exec() you can use the overloaded method that lets you specify the working directory. This is not really for running your Java program in another directory but for many cases when one needs to launch another program like a Perl script for example, you can specify the working directory of that script while leaving the working dir of the JVM unchanged.
See Runtime.exec javadocs
Specifically,
public Process exec(String[] cmdarray,String[] envp, File dir) throws IOException
where dir is the working directory to run the subprocess in
If I understand correctly, a Java program starts with a copy of the current environment variables. Any changes via System.setProperty(String, String) are modifying the copy, not the original environment variables. Not that this provides a thorough reason as to why Sun chose this behavior, but perhaps it sheds a little light...
The working directory is a operating system feature (set when the process starts).
Why don't you just pass your own System property (-Dsomeprop=/my/path) and use that in your code as the parent of your File:
File f = new File ( System.getProperty("someprop"), myFilename)
The smarter/easier thing to do here is to just change your code so that instead of opening the file assuming that it exists in the current working directory (I assume you are doing something like new File("blah.txt"), just build the path to the file yourself.
Let the user pass in the base directory, read it from a config file, fall back to user.dir if the other properties can't be found, etc. But it's a whole lot easier to improve the logic in your program than it is to change how environment variables work.
I have tried to invoke
String oldDir = System.setProperty("user.dir", currdir.getAbsolutePath());
It seems to work. But
File myFile = new File("localpath.ext");
InputStream openit = new FileInputStream(myFile);
throws a FileNotFoundException though
myFile.getAbsolutePath()
shows the correct path.
I have read this. I think the problem is:
Java knows the current directory with the new setting.
But the file handling is done by the operation system. It does not know the new set current directory, unfortunately.
The solution may be:
File myFile = new File(System.getPropety("user.dir"), "localpath.ext");
It creates a file Object as absolute one with the current directory which is known by the JVM. But that code should be existing in a used class, it needs changing of reused codes.
~~~~JcHartmut
You can use
new File("relative/path").getAbsoluteFile()
after
System.setProperty("user.dir", "/some/directory")
System.setProperty("user.dir", "C:/OtherProject");
File file = new File("data/data.csv").getAbsoluteFile();
System.out.println(file.getPath());
Will print
C:\OtherProject\data\data.csv
You can change the process's actual working directory using JNI or JNA.
With JNI, you can use native functions to set the directory. The POSIX method is chdir(). On Windows, you can use SetCurrentDirectory().
With JNA, you can wrap the native functions in Java binders.
For Windows:
private static interface MyKernel32 extends Library {
public MyKernel32 INSTANCE = (MyKernel32) Native.loadLibrary("Kernel32", MyKernel32.class);
/** BOOL SetCurrentDirectory( LPCTSTR lpPathName ); */
int SetCurrentDirectoryW(char[] pathName);
}
For POSIX systems:
private interface MyCLibrary extends Library {
MyCLibrary INSTANCE = (MyCLibrary) Native.loadLibrary("c", MyCLibrary.class);
/** int chdir(const char *path); */
int chdir( String path );
}
The other possible answer to this question may depend on the reason you are opening the file. Is this a property file or a file that has some configuration related to your application?
If this is the case you may consider trying to load the file through the classpath loader, this way you can load any file Java has access to.
If you run your commands in a shell you can write something like "java -cp" and add any directories you want separated by ":" if java doesnt find something in one directory it will go try and find them in the other directories, that is what I do.
Use FileSystemView
private FileSystemView fileSystemView;
fileSystemView = FileSystemView.getFileSystemView();
currentDirectory = new File(".");
//listing currentDirectory
File[] filesAndDirs = fileSystemView.getFiles(currentDirectory, false);
fileList = new ArrayList<File>();
dirList = new ArrayList<File>();
for (File file : filesAndDirs) {
if (file.isDirectory())
dirList.add(file);
else
fileList.add(file);
}
Collections.sort(dirList);
if (!fileSystemView.isFileSystemRoot(currentDirectory))
dirList.add(0, new File(".."));
Collections.sort(fileList);
//change
currentDirectory = fileSystemView.getParentDirectory(currentDirectory);
I am using SharpSvn in my C# project. I am having a folder with some text files in it and another folders with subfolders in it. I am adding the folder under version control and commit it. So far, so good. This is my code:
using (SvnClient client = new SvnClient())
{
SvnCommitArgs ca = new SvnCommitArgs();
SvnStatusArgs sa = new SvnStatusArgs();
sa.Depth = SvnDepth.Empty;
Collection<SvnStatusEventArgs> statuses;
client.GetStatus(pathsConfigurator.FranchisePath, sa, out statuses);
if (statuses.Count == 1)
{
if (!statuses[0].Versioned)
{
client.Add(pathsConfigurator.FranchisePath);
ca.LogMessage = "Added";
client.Commit(pathsConfigurator.FranchisePath, ca);
}
else if (statuses[0].Modified)
{
ca.LogMessage = "Modified";
client.Commit(pathsConfigurator.FranchisePath, ca);
}
}
}
I make some changes to one of the text files and then run the code againg. The modification is not committed. This condition is false:
if (statuses.Count == 1)
and all the logic in the if block does not execute.
I have not written this logic and cannot quite get this lines of code:
client.GetStatus(pathsConfigurator.FranchisePath, sa, out statuses);
if (statuses.Count == 1) {}
I went on the oficial site of the API but couldn`t find documentation about this.
Can someone that is more familiar with this API tell what these two lines do ?
What changes need to be done to this code so if some of the contents of the pathsConfigurator.FranchisePath folder are changed, the whole folder with the changes to be commited. Any suggestions with working example will be greatly appreciated.
Committing one directory with everything inside is pretty easy: Just call commit on that directory.
The default Depth of commit is SvnDepth.Infinity so that would work directly. You can set additional options by providing a SvnCommitArgs object to SvnClient.Commit()
I'm using a TransactionalEditingDomain to manage changes on my model. However, I have some problems in creating an empty model. I think that the problem is when I add the model to the model Resource (modelResource.getContents().add(model);), because it should be put within a transaction. Accordingly, I was trying to use the AddCommand to perform such operation, but I am not able to find a EStructuralFeature for the Resource's contents.
In other words, I would like to write something like:
Command cmd = AddCommand.create(editingDomain, modelResource, FEAT_CONTENTS, model);
commandStack.execute(cmd);
The problem is that I cannot find the FEAT_CONTENTS... does anybody have a suggestion?
I have found the "official" solution with using AddCommand on the Eclipse Forum of EMF:
Command cmd = new AddCommand(editingDomain, modelResource.getContents(), model);
commandStack.execute(cmd);
Since removing a root object is also non-trivial, the same approach can be used with RemoveCommand:
Command cmd = new RemoveCommand(editingDomain, modelResource.getContents(), model);
Finally, for completeness, you should also know that DeleteCommand (that also removes all references to the removed object) does not work on root objects at all.
I found a solution, but sincerely I do not like it:
commandStack.execute(new RecordingCommand(editingDomain) {
protected void doExecute() {
modelResource.getContents().add(model);
}
});
I'm doing some work at the command line using using the TFS object model, and I want to reproduce the workspace-detection bahavior seen in tf.exe and tfpt.exe without introducing artifacts because of my own particular implementation. Currently, my scripts require more information than what tf.exe needs--a significant amount of my parameters are there simply to instantiate the connection.
Specifically, I have to require users to explicitly pass in the server Uri (tfsUriString) and the collection name (tfsCollectionName), but this seems needless and annoying since tf.exe is able to do it.
Uri tfsUri = new Uri(tfsUriString);
TfsConfigurationServer configurationServer = TfsConfigurationServerFactory.GetConfigurationServer(tfsUri);
ReadOnlyCollection<CatalogNode> collectionNodes = configurationServer.CatalogNode.QueryChildren( new[] { CatalogResourceTypes.ProjectCollection }, false, CatalogQueryOptions.None);
CatalogNode collectionNode = collectionNodes.Where(node => node.Resource.DisplayName == tfsCollectionName).SingleOrDefault();
Guid collectionId = new Guid(collectionNode.Resource.Properties["InstanceId"]);
TfsTeamProjectCollection teamProjectCollection = configurationServer.GetTeamProjectCollection(collectionId);
var vcServer = teamProjectCollection.GetService<VersionControlServer>();
What classes and methods can be used to perform this detection in the same way that tf.exe does?
Team Foundation Server clients use a workspace cache that contains all the user's workspaces for each Team Project Collection that they've used from the current machine. tf.exe uses this cache to determine the TfsTeamProjectCollection and Workspace to use for the paths given on the command line.
You can get the cached WorkspaceInfo for a particular local path by using:
Workstation.Current.GetLocalWorkspaceInfo(localPath)
Or you can get the entire workspace cache by calling:
Workstation.Current.GetAllLocalWorkspaceInfo()
The WorkspaceInfo.ServerUri property will contain the server URI you can use to create a TfsTeamProjectCollection with.