Is there any method which performs similar tasks to the GetDriveType() method of Microsoft Visual C++. I've already gone through the FileSystemView class of Java Swing. But the method available there are limited and does not fulfill my requirement.
So please tell me someone if Java defines any such method for Windows platform or Platform Independent.
You can use File.listRoots() method. It will list all the drives in your system.
And to get detail information about that drive you can use the following code.
List roots = Arrays.asList(File.listRoots());
for(File f:roots)
{
String s = FileSystemView.getFileSystemview().getSystemTypeDescription(f);
}
This code shows the actual information of drives and other PnP devices. Use this link to know more. And according to your question you must be want to know the hardware details of connected drives to PC. Use JNI if you want to do all code in java.
Are you using JDK7?
If so, there is FileStore which returns the type as a String.
However, looking at the source code itself (FileStore.java) there is a warning that the return value might be implementation specific.
Related
I am creating a linux vm using a custom image from an shared image gallery using java sdk.
virtualMachine = azure.virtualMachines()
.define(linuxVMName)
.withRegion(location)
.withExistingResourceGroup(resourceGroup)
.withExistingPrimaryNetworkInterface(networkInterface)
.withLinuxCustomImage(customImageUrl)
.withRootUsername(username)
.withRootPassword(password)
.withCustomData(custDatastring)
.withComputerName(linuxVMName)
.withExistingStorageAccount(storageAccount)
.withSize(vmSize())
.create();
this also supports creating linux instances from generic public images also like
.withLatestLinuxImage(publisher, offer, sku)
What I want to know is
whether it is possible to use conditional statements in this pattern like whether Azure has implemented that part.
Another scenario is instead of root password, i can also use root SSH, so many conditions here
I had no luck with the documentation part also.
Yes I can write an whole if else and copy paste the code also, I just want to know is there a better way to implement this.
Thanks in advance
I am trying to get the hang of jsonnet files. So far all I have is hard-coded values but what if I wanted to get the hostname for a Java application. For example in Java I would just do:
String hostName = System.getenv("HOSTNAME");
But obviously I can't just have a key-value pair like the following JSON in a jsonnet file.
{name: "hostname", value:System.getenv("HOSTNAME")}
I need a bit of help in understanding how I can do this.
I have looked up std.extvar(x) but the examples I look at just arent clear to me for whatever reason. Is this method relevant? Otherwise, I'm not really sure.
Jsonnet requires all parameters to be passed explicitly. To use a hostname in your Jsonnet code, you need to pass it to the interpreter. For example you can run it as follows:
❯ jsonnet --ext-str "HOSTNAME=$HOST" foo.jsonnet
foo.jsonnet:
std.extVar('HOSTNAME')
You can also use top-level-arguments mechanism to a similar effect (top-level-arguments are passed as function arguments to the evaluated script.
Please see: https://jsonnet.org/learning/tutorial.html#parameterize-entire-config for more in-depth explanation of these features.
FYI not being able to just grab any environment variable or access the system directly is very much by design. The result of Jsonnet evaluation depends only on the code and explicitly passed parameters. This has a lot of benefits, such as the following:
You can easily evaluate on another machine, even on a completely different platform and get exactly the same result.
You are never locked in to configuration on any particular machine – you can always pass any parameters on any machine (very useful for development and debugging).
Avoiding surprises – the evaluation won't break one day, because some random aspect of local configuration changed and some deep part of the code happens to depend on it – all parameters are accounted for.
I have a Java application that I want to automate for testing. Unfortunately, the app window only registers as a SunAWTFrame, which means none of the controls are exposed to typical window analysis and automation tools.
My search has lead me to C# and utilising Java Access Bridge DLLS in a C# program to automate it.
Has anyone had any experience of this?
Oracle provides JavaAccessBridge (JAB) with some DLLS to help with this as I understand it after reading a few articles around the internet. There are some code examples but I'm really not groking it right now. By breaking it down, I think this is what needs to be achieved:
Import / load / parse the JAB dlls
Map functions in the JAB dll to methods / calls within my program
Have the Java application to automate run (with JAB enabled) and get handle of it to my program
Utilise the JAB functions to control the Java application
I don't know C# as well as I know Java, but that's not going to stop me.
If anyone can provide help, guidance, pointers or anything to get me started, that'd be truly awesome.
As of 2019 we have a great tool AccessBridgeExplorer created and open-sourced by google. It's a really good staring point that contains a WindowsAccessBridgeInterop project which encapsulates almost every JAB API into a class oriented, .NET friendly assembly.
One notable thing, AccessBridge.Initialize() must be called in WPF/WinForm UI thread or in your own messaging pump thread, otherwise some methods like AccessBridge.EnumJvms() will always return false/empty.
Building on Stackia's great tip to use Google's AccessBridgeExplorer, Here are some tips to get you going:
Download Access Bridge Explorer
Use the WindowsAccessBridgeInterop.dll in your own (WinForms not Console) project (Add> Project Reference> Select the DLL)
Create a new access bridge object
AccessBridge Java = new AccessBridge();
Initialize the Access Bridge object
Java.Initialize();
Call Application.DoEvents() - A hack to wait for Java.Initialize to complete (My simple understanding is Java Access Bridge Uses a hidden window or similar)
Application.DoEvents(); //this waits for Java Bridge to initilize ;)
Get the handle of the Java Window
(plenty of examples online of how to get a Window Handle in C#)
Get Access to the Java Object that represents the window:
Java.Functions.GetAccessibleContextFromHWND(Handle, out int vmid, out JavaObjectHandle javaObjectHandle);
Get AccessibleWindow Object for Window (so you can find its children)
AccessibleWindow win = Java.CreateAccessibleWindow(handle);
Come up with your own way to cycle through the children, and the childrens children until you find the object you are after:
//Similar to:
foreach(var child in win.GetChildren())
JavaObjectHandle? javaObject = Java.Functions.GetAccessibleChildFromContext(node.JvmId, parentJavaObject, child.GetIndexInParent());
//to get the label or title of the object:
child.GetTitle();
To Interact with an object (eg click a button), do similar to the following:
(please note where it says JavaObject - it means the child java object (eg. to click a button you need to get the JavaObject for that button using GetAccessibleChildFromContext as i mentioned above)
//Get Possible Actions
JavaAutomation.Java.Functions.GetAccessibleActions(VMID, JavaObject, out AccessibleActions accessibleActions);
foreach( var action in accessibleActions.actionInfo)
{
Log.Info($"DoAction: {action.name}");
}
AccessibleActionsToDo accessibleActionsToDo = new AccessibleActionsToDo();
accessibleActionsToDo.actions = accessibleActions.actionInfo;
accessibleActionsToDo.actionsCount = accessibleActions.actionsCount;
//Do Actions
JavaAutomation.Java.Functions.DoAccessibleActions(VMID, JavaObject, ref accessibleActionsToDo, out int failure);
My system has USB DAC capable to play formats 24/96 and 24/192, however when I try to play them using Java I am getting line unavailable exception. Accordingly Java sound documentation, Java doesn't bring any limitations for sample and bits rates, and the limitations are coming for underline sound system. So I traced down where the exception coming from and it looks like native function
private static native void nGetFormats(int mixerIndex, int deviceID,
boolean isSource, Vector formats);
doesn't fill formats with corresponding line info above 16/48.
I looked in sources here.
However to prove that the function really doesn't return format I need or it just returns slight different, I have to see actual formats list. But I can't figure out how reach it. Method of DirectDL is private:
private AudioFormat[] getHardwareFormats() {
return hardwareFormats;
}
So my question has two parts:
How can I still get list of supported formats Java gets from hardware? In this case I could just write own DirectAudioDevice.
Is there any other alternative to standard Java sound to manage higher sample rates from Java? For example, Tritonus, but it seems really old and not supported.
I did my testing on Window, so plan to repeat it on Linux using different than Oracle JRE. However I need to find portable solution anyway.
I found some solution so I can listen to 24/96Khz and 24/192Khz recording using Java in FLAC, APE, and Wavpack formats.
After some debugging in Java sound I found that for some reason Java runtime limits bits depth to 16bits, however accepts high sample rates as 96Khz and 192KHz. So I borrowed down sampling solution from MediaChest. I also got JustFLAC which provides 24/192 support for FLAC files. Supporting 24/192 directly through hardware seems not possible without updating Java runtime native libraries that I plan to do soon.
Edit: the latest update is: I looked in native Java runtime and found the following:
static INT32 bitsArray[] = { 8, 16};
....
#define BITS_COUNT sizeof(bitsArray)/sizeof(INT32)
....
for (rateIndex = 0; rateIndex < SAMPLERATE_COUNT; rateIndex++) {
for (channelIndex = 0; channelIndex < CHANNELS_COUNT; channelIndex++) {
for (bitIndex = 0; bitIndex < BITS_COUNT; bitIndex++) {
DAUDIO_AddAudioFormat(creator, bitsArray[bitIndex],
So as you can see 8, and 16 bits are hardcoded and used in supported formats matrix generation. A fix seems to be easy just by adding two more constants, however it leads in creation own copy of Java runtime and it isn't acceptable. So it looks like I need to initiate some community process to make my recommendations accepted by and then included in next Java runtime updates.
Edit: One more update. Linux sound native implementation seems better. It has only limitation 24bits sample size. So if underline sound system (ALSA) allows the sample depth, then Java can play 24 bits/ 192,000 format. I tested it on Raspberry Pi using latest Raspbian and JDK 8 EA. Unfortunately even latest Arch and Pidora do not have the ALSA improvement.
For reading and writing the value in the private field, you can use reflection. The Java Tutorial and a question in StackOverflow.
About your second question, I've found a library called jd3lib that seems recent.
I'm writing android app, which drawing 4 graphs in 1 plot. Graph data is stored in object GraphViewData(x,y). I also have List which contains 4 GraphVieData objects.
I want to give user ability to switch off/on some graphs.
I tried to write myList.set(index, null) to hide graph and then myList.set(index, myObject) to show it again, but every time the List size is changing. So I'm getting IndexOutOfBound exception.
Please, tell me why the List size is changing? Here is List.set() description:
Replaces the element at the specified location in this List with the
specified object. This operation does not change the size of the List.
Code:
public void removeSerie(int id){
graphSeries.set(id, null);
Log.d("CurrentListSize: ", graphSeries.size() + "");
}
public void addSerie(GraphViewData series, int id){
graphSeries.set(id, series);
}
There is a discrepancy between the javadocs for List.set(int, T) between Java and Android. This is worrying, but you should resolve it as following:
The Oracle version of the javadoc is definitive for Java. A List implementation is permitted to change the list size on set.
The Android version of the javadoc should be viewed as incorrect as a source for Java. You could argue that it is correct for Android, but that doesn't really help if you are dealing with code that wasn't specifically written for Android. (For example, code that was written for Java and then compiled for Android.)
The standard List classes in Java and Android won't do this. (Check the source code to be sure, but I'd be extremely surprised if any of them did without the javadocs saying so.)
A custom / 3rd-party List class could do this, and still follow the Java List contract (though arguably not the Android contract).
There are no guarantees that a custom / 3rd-party List class will follow either contract. This renders the whole argument moot ... unless you can persuade the relevant author / supplier to change the relevant list class. (And good luck with that, because it will probably break other peoples' code!!)
So what should you do? I recommend:
If you want to be able to do this with set, make sure that you are using a list class that supports it. Check the code of the list class if necessary.
Otherwise, change your algorithm.