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Access public assets with Java in Play Framework

Is it possible to access Assets inside the Java code in Play Framework? How?
We access assets from the scala HTML templates this way:
<img src="#routes.Assets.versioned("images/myimage.png")" width="800" />
But I could not find any documentation nor code example to do it from inside the Java code. I just found a controllers.Assets class but it is unclear how to use it. If this is the class that has to be used, should it maybe be injected?

I finally found a way to access the public folder even from a production mode application.
In order to be accessible/copied in the distributed version, public folder need to be mapped that way in build.sbt:
import NativePackagerHelper._
mappings in Universal ++= directory("public")
The files are then accessible in the public folder in the distributed app in production form the Java code:
private static final String PUBLIC_IMAGE_DIRECTORY_RELATIVE_PATH = "public/images/";
static File getImageAsset(String relativePath) throws ResourceNotFoundException {
final String path = PUBLIC_IMAGE_DIRECTORY_RELATIVE_PATH + relativePath;
final File file = new File(path);
if (!file.exists()) {
throw new ResourceNotFoundException(String.format("Asset %s not found", path));
}
return file;
}
This post put me on the right way to find the solution: https://groups.google.com/forum/#!topic/play-framework/sVDoEtAzP-U

The assets normally are in the "public" folder, and I don't know how you want to use your image so I have used ImageIO .
File file = new File("./public/images/nice.png");
boolean exists = file.exists();
String absolutePath = file.getAbsolutePath();
try {
ImageInputStream input = ImageIO.read(file); //Use it
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("EX = "+exists+" - "+absolutePath);

Java Properties Class

using java 8, tomcat 8
Hi, i am loading a file using properties, but i have a check before loading which returns the same properties object if its already been loaded (not null). which is a normal case scenario but i want to know if there is any way that if any change occur in target file, and some trigger should be called and refreshes all the properties objects. here is my code.
public static String loadConnectionFile(String keyname) {
String message = "";
getMessageFromConnectionFile();
if (propertiesForConnection.containsKey(keyname))
message = propertiesForConnection.getProperty(keyname);
return message;
}
public static synchronized void getMessageFromConnectionFile() {
if (propertiesForConnection == null) {
FileInputStream fileInput = null;
try {
File file = new File(Constants.GET_CONNECTION_FILE_PATH);
fileInput = new FileInputStream(file);
Reader reader = new InputStreamReader(fileInput, "UTF-8");
propertiesForConnection = new Properties();
propertiesForConnection.load(reader);
} catch (Exception e) {
Utilities.printErrorLog(Utilities.convertStackTraceToString(e), logger);
} finally {
try {
fileInput.close();
} catch (Exception e) {
Utilities.printErrorLog(Utilities.convertStackTraceToString(e), logger);
}
}
}
}
the loadConnectionFile method executes first and calls getMessageFromConnectionFile which has check implemented for "null", now if we remove that check it will definitely load updated file every time but it will slower the performance. i want an alternate way.
hope i explained my question.
thanks in advance.

Java has a file watcher service. It is an API. You can "listen" for changes in files and directories. So you can listen for changes to your properties file, or the directory in which your properties file is located. The Java Tutorials on Oracle's OTN Web site has a section on the watcher service.
Good Luck,
Avi.

AccessDeniedException: C:\Windows\System32\drivers\etc\hosts

I'm trying to make a java program which blocks the facebook page in web browsers. I'm trying to overwrite somehow the hosts file, but the file is disabled to overwriting. I tried to copy him to my desktop, then append a line which blocks the page, and then copy to the etc folder and click to copy (or overwrite) the file. But i can't do it in java, all what i did was create another file in the same folder and append lines to it. But then i can't copy the new file to old, i dont know how to do it, here's my code, i'm waiting for a solutions :)
public class Sandbox {
private final static File zdroj = new File("C:\\Windows\\System32\\drivers\\etc\\hosts");
private final static File ciel = new File("C:\\Windows\\System32\\drivers\\etc\\hostsTemp");
public static void main(String[] args) {
try {
Files.copy(zdroj.toPath(), ciel.toPath());
PrintWriter writer = new PrintWriter(new BufferedWriter(new FileWriter(ciel, true)));
writer.append("\n\n127.0.0.1 facebook.com www.facebook.com http://www.facebook.com/ http://facebook.com");
writer.close();
Files.delete(zdroj.toPath());
Files.copy(ciel.toPath(), zdroj.toPath());
} catch (IOException ex) {
Logger.getLogger(Sandbox.class.getName()).log(Level.SEVERE, null, ex);
}
}
}

You will need to run your application with elevated permissions. Try starting it with some administrator user.

JavaScript to Java Applet using DeployJava.js to run commandline

I am pretty new to Java. I want to create a Java Applet that will allow my JavaScript to pass a commandline to the Java Applet. This will only ever be run on my development machine - no need to remind me what a security issue that is. The use-case is that I have an introspector for my ExtJS app that allows me to display the classes. I want to be able to click a class, pass the relevant pathname to the Applet and have that file open in Eclipse for editing.
I am using Win7x64, jre 1.7
So, to get Eclipse to open the file from the commandline the command is:
D:\Eclipse\eclipse.exe --launcher.openFile C:\mytestfile.js
This works.
I have written the Applet, self signed it and tested the say() method using the code shown below. That works. However when I run the executecmd() method, I don't get any output. If I comment out the whole try/catch block so that I am simply returning the cmd string passed in, the method works. Therefore, I suspect that I have the try catch incorrectly setup and since my Java skills and knowledge of the exceptions are primitive I am lost.
Can anyone help me please? At least to get some output returned, if not how to actually run the command line passed in?
And, I am passing the whole command line because when I have this working I would like to share it (since the Ext introspector is really useful). Other developers will be using different editors so this way they can use it by passing their specific commandline.
Thanks!
Murray
My HTML test page:
<html>
<head>
<meta charset="UTF-8">
<title>Test Run</title>
<script src="http://www.java.com/js/deployJava.js"></script>
<script>
var attributes = { id:'testapp', code:'systemcmd.Runcmd', archive:'runcmd.jar', width:300, height:50} ;
var parameters = {} ;
deployJava.runApplet(attributes, parameters, '1.6');
</script>
</head>
<body>
<p>Hello</p>
<script type="text/javascript">
//alert(testapp.say("Hello test")); // This works
var command = "D:\Eclipse\eclipse.exe --launcher.openFile C:\mytestfile.js";
alert(testapp.executecmd(command)); // Nothing returned at all.
</script>
</body>
</html>
My class:
package systemcmd;
import java.applet.Applet;
import java.io.IOException;
import java.security.AccessController;
//import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
public class Runcmd extends Applet {
private static final long serialVersionUID = -4370650602318597069L;
/**
* #param args
*/
public static void main(String[] args) {
}
public String say(String arg)
{
String msg[] = {null};
msg[0] = "In Say. You said: " + arg;
String output ="";
for(String str: msg)
output=output+str;
return output;
}
public String executecmd(final String cmd) throws IOException
{
final String msg[] = {null};
String output ="";
msg[0] = "In executecmd, cmd="+cmd;
try {
try {
AccessController.doPrivileged(
new PrivilegedExceptionAction() {
public Object run() throws IOException { //RuntimeException,
msg[1] = " Pre exec()";
Runtime.getRuntime().exec(cmd);
msg[2] = " Post exec()";
return null;
}
}
);
} catch (PrivilegedActionException e) {
msg[3] = " Caught PrivilegedActionException:"+ e.toString();
throw (IOException) e.getException();
}
}
catch (Exception e) {
msg[4] = " Command:" + cmd + ". Exception:" + e.toString();
}
msg[5] = " End of executecmd.";
for(String str: msg)
output=output+str;
return output;
}
}

Set Eclipse as the default consumer for .java files and use Desktop.open(File) which..
Launches the associated application to open the file.

Ok, #Andrew. Some progress, thank you!
I set the default program for *.js files to Eclipse and if I double click a file it opens in Eclipse. All good.
I then had success running the following using RunAs Java Application - the test file opened in Eclipse. Getting closer!
public class Runcmd extends Applet {
File file;
private static Desktop desktop;
private static final long serialVersionUID = -4370650602318597069L;
/**
* #param args
* #throws IOException
*/
public static void main(String[] args) throws IOException {
System.out.println("hello");
if (Desktop.isDesktopSupported()) {
desktop = Desktop.getDesktop();
}
File file = new File("C:\\sites\\test.js");
// This works if I execute it from the Eclipse RunsAs Java Application.
// ie the file is opened in Eclipse for editing.
// And, if I specify a non-existant file, it correctly throws and prints the error
try {
desktop.open(file);
} catch (Exception ioe) {
ioe.printStackTrace();
System.out.println("Error: " + ioe.toString());
}
}}
However, when I added the following method and ran it via the DeployJava.js (as per my original post above), I get the following output returned with the error appearing whether or not the jar is self signed.
Started: , Desktop is supported , Error:
java.security.AccessControlException: access denied
("java.awt.AWTPermission" "showWindowWithoutWarningBanner")
public static String openfile(String arg) {
String output = "Started: ";
File file = new File("C:\\sites\\test.js");
if (Desktop.isDesktopSupported()) {
desktop = Desktop.getDesktop();
output = output + ", Desktop is supported ";
}
try {
desktop.open(file);
} catch (Exception ioe) {
output = output + ", Error: " + ioe.toString();
}
return output + arg;
}
So, what do I need to add to get around the apparent security issue? I have read the docs and the tutorials and I am going around in circles! There seems to be a lot of conflicting advice. :-(
Thanks again,
Murray

want to copy a file from a server to a client

i want to copy a file from a server to a client in java.this is my code up to now
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.URL;
public class Copy {
private ListDirectory dir = new ListDirectory();
public Copy() {
}
public String getCopyPath(String file) throws Exception {
String path = dir.getCurrentPath();
path += "\\" + file;
return path;
}
public void copyFile(String file) {
try {
File inputFile = new File(dir.getCurrentPath());
URL copyurl;
InputStream outputFile;
copyurl = new URL(getCopyPath(file));
outputFile = copyurl.openStream();
FileOutputStream out = new FileOutputStream(inputFile);
int c;
while ((c = outputFile.read()) != -1)
out.write(c);
outputFile.close();
out.close();
} catch (Exception e) {
System.out.println("Failed to Copy File from server");
e.printStackTrace();
}
}
public static void main(String args[]) {
String a = "put martin";
String b = a.substring(0, 3);
String c = a.substring(4);
System.out.println(a);
System.out.println(b);
System.out.println(c);
}
}
Problem is , the server is not uploadded online , but it is on my local drive, and the URL thing doesnt work. is there any other way? is this way correct? thanks

If you're expecting to access your file from the local file system (whether that be via network drive or a local disk), you'll need to treat this as if it is a straight file copy.
If you're expecting to access your file as if it is available for download from an HTTP server, you will need to treat it as an HTTP download (which is what it looks like you're trying to do with the URL).
If you want to test the HTTP download functionality using a file on your local system, just set up a simple HTTP server on your dev machine with a directory on your local system, and give your HTTP-downloading code a URL pointing to that local server (on http://localhost, or using your IP address).
Unfortunately, HTTP is a very different animal from a file system, and I don't think there's any way to use the same code to handle both scenarios. If you want your program to ultimately support both protocols, you should build methods/classes to handle both situations, and then have your program detect and use the appropriate protocol for a given path. You'll need to do the same for any other protocol you wish to support (FTP, SFTP, etc).