How can i implement theming support in Play Framework 2?
I want to create directory structure like:
views/default <- default template directory
views/site1 <- template for site 1
views/site2 <- template for site 2
If template doesn`t exist (ie. views/site1/home) it should render template from default directory.
I have tried cls = Class.forName("views.html.home); But I get class not found exception.
SOLUTION:
Maybe someone will find this useful:
protected static String renderTemplate(final String template, final String action,final ViewData templateParams) {
Class<?> cls = null;
String ret = "Template not found";
try {
cls = Class.forName(template);
} catch (ClassNotFoundException e) {
ret = e.toString();
}
if (cls == null) {
try {
cls = Class.forName("views.html.default."+action);
} catch (ClassNotFoundException e) {
ret = e.toString();
}
}
if (cls != null) {
Method htmlRender;
try {
htmlRender = cls.getMethod("render", ViewData.class);
ret = htmlRender.invoke("",templateParams).toString();
} catch (NoSuchMethodException e) {
ret = "Method not found"+e.toString();
} catch (IllegalAccessException e) {
ret = "illegal access exception";
} catch (InvocationTargetException e) {
ret = "InvocationTargetException";
}
}
return ret;
}
ViewData vd=new ViewData();
renderTemplate("views.html.custom."+viewname, actionname, vd)
You have to implement it yourself, as a reference, check the Play Authenticate usage sample, it allows to send ie. validation emails basing on Play's template and depending on the client's language, so for an instance, if your main language is Polish it will render the verify_email_pl.scala.html otherwise if your browser uses language not supported by PA, it will silently fallback to: verify_email_en.scala.html.
Check the usage and declaration of the method.
For your case it will be good solution, of course just criteria of the choice will be different.
This process is called "Branding". What you have to do is following.
Create a table in db by name "BRANDING" and add theme names in it against each instance of website.
Now you will make folders hierarchy as you mentioned and in jsp pages where load css files you will do that like this <link rel="stylesheet" type="text/css" href="/views/${themeName}.css">
where themeName would be a server side variable that you will program in your controller to be fetched from db or first time you will fetch it and then cache it.
Related
I've come across many posts about these two topics: Auto-Updating and URLClassloaders. I'll start with the auto updating goal. I found this post here that talks about a 2 jar system. One jar that launches the main app jar: From Stephen C:
The launcher could be a Java application that creates a classloader for the new JAR, loads an entrypoint class and calls some method on it. If you do it this way, you have to watch for classloader storage leaks, but that's not difficult. (You just need to make sure that no objects with classes loaded from the JAR are reachable after you relaunch.)
This is the approach I'm taking, but I'm open to other ideas if they prove easier and/or more reliable. The Coordinator has posted some pretty cool launcher code to which I plan on incorporating some of this reload type code in my launcher, but first I need to get it to work.
My issue is that my main app jar has many other dependencies, and I cannot get some of those classes to load despite the fact that all the jars have been added to the URL's array. This brings up the second topic URLClassloader.
Side Note for future readers: When passing a URL to the URLClassloader that is a directory, a helpful note that would have saved me (an embarrassingly large) amount of time is that the contents of the directory must be .class files! I was originally pointing to my dependent jar directory, no good.
Context for the code below, my launcher jar resides in the same directory as my app jar, which is why I'm using user.dir. I will probably change this, but for now the code works and gets far enough into my app's code to request a connection to a sqlite database before failing.
Launcher:
public class Launcher {
public static void main(String[] args) {
try {
String userdir = System.getProperty("user.dir");
File parentDir = new File(userdir);
ArrayList<URL> urls = getJarURLs(parentDir);
URL[] jarURLs = new URL[urls.size()];
int index = 0;
for (URL u : urls) {
System.out.println(u.toString());
jarURLs[index] = u;
index ++;
}
URLClassLoader urlCL = new URLClassLoader(jarURLs);
Class<?> c = urlCL.loadClass("main.AppStart");
Object [] args2 = new Object[] {new String[] {}};
c.getMethod("main", String[].class).invoke(null, args2);
urlCL.close();
} catch (Exception e1) {
e1.printStackTrace();
}
}
public static ArrayList<URL> getJarURLs(File parentDir) throws MalformedURLException {
ArrayList<URL> list = new ArrayList<>();
for (File f : parentDir.listFiles()) {
if (f.isDirectory()) {
list.addAll(getJarURLs(f));
} else {
String name = f.getName();
if (name.endsWith(".jar")) {
list.add(f.toURI().toURL());
}
}
}
return list;
}
}
Here's an example of the URL output added to the array:
file:/C:/my/path/to/dependent/jars/sqlite-jdbc-3.32.3.2.jar
file:/C:/my/path/to/main/app.jar
file: ... [10 more]
The URLClassloader seems to work well enough to load my main method in app.jar. The main executes a some startup type stuff, before attempting to load a login screen. When the request is made to get the user info database, my message screen loads and displays (<-this is important for later)
the stacktrace containing:
java.sql.SQLException: No suitable driver found for jdbc:sqlite:C:\...\users.db
I understand that this is because that jar is not on the class path, but it's loaded via the class loader, so why can't it find the classes from the jar? From this post JamesB suggested adding Class.forName("org.sqlite.JDBC"); before the connection request. I rebuilt the app jar with this line of code and it worked!
The weird thing that happened next, is that my message screen class can no longer be found even though earlier it loaded and displayed correctly. The message screen is a class inside my main app.jar and not in a dependent jar, which is why I'm baffled. Am I going to have to add Class.forName before every instance of any of my classes? That seems rude..
So what could I be doing wrong with the class loader? Why does it load some classes and not others despite that fact that all the jars have been added to the URL array?
Some other relative info: My app works perfectly as intended when launched from windows command line when the classpath is specified: java -cp "main-app.jar;my/dependent/jar/directory/*" main.AppStart. It's only when I try launching the app via this classloader that I have these issues.
By the way, is this java command universal? Will it work on all operating systems with java installed? If so, could I not just scrap this launcher, and use a process builder to execute the above command? Bonus points for someone who can tell me how to execute the command from a jre packaged with my app, as that's what I plan on doing so the user does not have to download Java.
EDIT
I figured out one of the answers to one of the questions below. Turns out, I didn't need to do any of the code below. My main method loads a login screen but after it's loaded it returns back to the AppLauncher code, thus closing the URLClassLoader! Of course, at that point any requested class will not be found as the loader has been closed! What an oof! Hopefully I will save someone a headache in the future...
Original
Well, after more time, effort, research, and effective use of Eclipse's debugging tool, I was able to figure out what I needed to do to resolve my issues.
So the first issue was my JDBC driver was never registered when passing the jars to the URLClassloader. This is the part I sorta don't understand, so advisement would be welcomed, but there is a static block in the JDBC class that registers the driver so it can be used by DriverManager see code below. Loading the class is what executes that static block, hence why calling Class.forName works.
static {
try {
DriverManager.registerDriver(new JDBC());
} catch (SQLException e) {
e.printStackTrace();
}
}
What I don't understand, is how class loading works if jars are specified via the class path. The URLClassLoader doesn't load any of those classes until they are called, and I never directly work with the JDBC class, thus no suitable driver exception, but are all the classes specified via the classpath loaded initially? Seems that way for static blocks to execute.
Anyhow, to resolve my other issue with some of my app's classes not being found I had to implement my own classloader. I get what I did and how it works well, but still don't understand why I had to do it. All of my jars were loaded to the original URLClassloader so if I could find them and the files within, why couldn't it do it?
Basically, I had to override the findClass and findResource methods to return jarEntry information that I had to store. I hope this code helps someone!
public class SBURLClassLoader extends URLClassLoader {
private HashMap<String, Storage> map;
public SBURLClassLoader(URL[] urls) {
super(urls);
map = new HashMap<>();
try {
storeClasses(urls);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
private void storeClasses(URL[] urls) throws ClassNotFoundException {
for (URL u : urls) {
try {
JarFile jarFile = new JarFile(new File(u.getFile()));
Enumeration<JarEntry> e = jarFile.entries();
while (e.hasMoreElements()) {
JarEntry jar = e.nextElement();
String entryName = jar.getName();
if (jar.isDirectory()) continue;
if (!entryName.endsWith(".class")) {
//still need to store these non-class files as resources
//let code continue to store entry un-altered
} else {
entryName = entryName.replace(".class", "");
entryName = entryName.replace("/", ".");
}
map.put(entryName, new Storage(jarFile, jar));
System.out.println(entryName);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
#Override
protected Class<?> findClass(String name) throws ClassNotFoundException {
Class<?> c = null;
try {
c = super.findClass(name);
} catch (ClassNotFoundException e) {
Storage s = map.get(name);
try {
InputStream in = s.jf.getInputStream(s.je);
int len = in.available();
c = defineClass(name, in.readAllBytes(), 0, len);
resolveClass(c);
} catch (IOException e1) {
e1.printStackTrace();
}
if (c == null) throw e;
}
return c;
}
#Override
public URL findResource(String name) {
URL url = super.findResource(name);
if (url == null) {
Storage s = map.get(name);
if (s != null) {
try {
url = new URL("jar:"+s.base.toString() + "!/" + name);
} catch (Exception e) {
e.printStackTrace();
}
}
}
return url;
}
private class Storage {
public JarFile jf;
public JarEntry je;
public URL base;
public Storage(JarFile jf, JarEntry je) {
this.jf = jf;
this.je = je;
try {
base = Path.of(jf.getName()).toUri().toURL();
} catch (MalformedURLException e) {
e.printStackTrace();
}
}
}
}
We have a legacy system that has a admim module that allows users to upload jar files. After the upload, the jar file is validated and if not compliant to internal rules, it is deleted.
The problem is that windows is throwing an exception telling that the file "is already being used by another process." (when I call Files.delete(tmpJar);). I'm not able to identify why the file is open. Seems to me that I have closed everything.
First, we are using primefaces (4.0) to upload the file. Primefaces relies on commons-fileupload (1.3.1). It call the following method:
public void handleFileUpload(FileUploadEvent event) {
Path tmpJar = null;
try {
tmpJar = Files.createFile(Paths.get(event.getFile().getFileName()));
Files.write(tmpJar, event.getFile().getContents());
} catch (IOException e) {
LOGGER.error(e.getMessage(), e);
}
if (tmpJar != null) {
try {
this.validateJar(tmpJar.toString());
Files.delete(tmpJar);
} catch (IOException e) {
LOGGER.error(e.getMessage(), e);
}
}
}
Before NIO Files.write, I was using "standard" java IO classes. The problem isn't related to the above code, because if I comment the call to validateJar, Files.delete(tmpJar) is executed without problems and the file is removed. So, the problem is related with the code below, but I can't find where...
Job is an internal class, basically a simple POJO. "jobAnnotation" is a custom annotation to identify Jobs. I have shortened the code, but the essencial parts are preserved.
private List<Job> validateJar(final String jarPath) throws IOException {
List<Job> jobs = new ArrayList<Job>();
try (JarFile jarFile = new JarFile(jarPath)) {
URL[] jars = { new URL("file:" + jarPath) };
ClassLoader jobClassLoader = URLClassLoader.newInstance(jars, this.getClass().getClassLoader());
Enumeration<JarEntry> jarEntries = jarFile.entries();
while (jarEntries.hasMoreElements()) {
JarEntry jarEntry = jarEntries.nextElement();
String className = jarEntry.getName();
Class<?> classToLoad;
try {
classToLoad = Class.forName(className, true, jobClassLoader);
} catch (Exception e1) {
LOGGER.error(e1.getMessage(), e1);
continue;
}
if (classToLoad.isAnnotationPresent(jobAnnotation)) {
String vlr = null;
try {
Class<?> jobClass = (Class<?>) Class.forName(classToLoad.getCanonicalName(), true, jobClassLoader);
Annotation annotation = jobClass.getAnnotation(jobAnnotation);
Method method = annotation.getClass().getMethod("getValue");
vlr = ((String) method.invoke(annotation, new Object[0]));
} catch (Exception e1) {
LOGGER.error(e1.getMessage(), e1);
}
Job job = new Job();
job.setEnabled(true);
job.setJarfile(jarPath);
job.setClassName(classToLoad.getName());
Parameter parameter = new Parameter();
parameter.setRequired(true);
parameter.setName("name");
parameter.setValue(vlr);
job.addParameter(parameter);
jobs.add(job);
}
}
} catch (IOException e) {
throw e;
}
return jobs;
}
Before using try-with-resources, I was using regular try-catch-finally to close the JarFile, thats the only thing that has a explicit close method. Probably is the classloading that is holding the file open, but I don't know how to close it.
I did some searches, and I found that I can't unload classes (Unloading classes in java?).
So, the problem is, how do I release it? Or how can I remove the file?
BTW, I'm using java 1.7.0_71, jboss 7.1.1, windows 7 (64).
The URLClassLoader class already has a close() method. The close() method will close any Jar file that are opened with the URLClassLoader. This should prevent the "file already in use" exception.
File is already being used by another process. says that it could be not your fault, maybe just another application is used that file. You can check this question to find a process which is used your file.
Some Virus scanner software take a long time in checking JARs. Try to disable the Virusscanner. Other candidates can be the Windows indexer process, or the explorer.exe itself. When you don't find any reason for the file lock, try a delay between the validation and the deletion. Maybe you need a loop with multiple tries.
I'm trying to get windows username from liferay portlet in java code using javascript and active-x.
When I run the code only with javascript and acitive-x on plain HTML it works.
But when I put it in java, it doesn't work.
Here is my code:
String script = "function getUser() {return ((new ActiveXObject('WScript.NetWork')).UserName); }";
try {
engine.eval(script);
} catch (ScriptException e) {
e.printStackTrace();
}
Invocable inv = (Invocable) engine;
try {
log.info("try invoke script");
String teste = (String) inv.invokeFunction("getUser");
log.info("meu teste " +teste);
} catch (ScriptException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
}
When I change the content on function for somthing else like returning string it prints the result.
Java-s JavaScript doesn't have Active X capabilities, but you don't have to use JavaScript to get the running machines users username.
Get login username in java
If you want to know client-s OS-s username then one approach would be to use client side JavaScript to find it out and submit this information to server side via AJAX.
We work on a Java (Java EE) application, and we generate XML files in order to send them to a remote .NET application with MSMQ reading on their side.
The XML file is generated by JDom, like so :
// add elements...
Document doc = new Document(root);
String XmlData = new XMLOutputter(Format.getPrettyFormat().setOmitEncoding(true)).outputString(doc);
try {
SendFile( XmlData, "title" , "path");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (MessageQueueException e) {
e.printStackTrace();
}
Then we use this function, using the MsmqJava library to send the file :
private void SendFile(String data, String title, String outputPath) throws UnsupportedEncodingException, MessageQueueException{
String qname="name_of_the_queue";
String fullname= "server_path" + qname;
String body = data;
String label = title;
String correlationId= "L:none";
try {
Queue queue= new Queue(fullname);
Message msg= new Message(body, label, correlationId);
queue.send(msg);
} catch (MessageQueueException ex1) {
System.out.println("Put failure: " + ex1.toString());
}
}
They correctly receive the file, but they told us that the bodyType was set to "VT_EMPTY" while they wanted "VT_BSTR", and we haven't find a clue about how to fix this. If you know another lib who does the job, or a workaround to this one, we can change with no problem.
Thanks !
Looking at the documentation for the library you use, it is not possible using that library.
Jmsmqqueue also doesn't provide the functionality you need.
It seems sun also had an adapter: https://wikis.oracle.com/display/JavaCAPS/Sun+Adapter+for+MSMQ
I want to be able to launch native and J2ME applications through my application using the content handler API (JSR 211) on a Nokia 6212.
At the moment, I am unable to do so, as it always states that there is "No Content Handler Found" and throws a javax.microedition.content.ContentHandlerException.
At the moment, I am trying to get the phone to launch its browser and go to a certain website, just to test that I can use the framework. I have tried many different Invocation objects:
//throw exceptions
new Invocation("http://www.somesite.com/index.html",
"application/internet-shortcut");
new Invocation("http://www.google.co.uk","text/html");
// a long shot, I know
new Invocation("http://www.somesite.com/text.txt","text/plain");
// massive long shot
new Invocation("http://www.google.co.uk","application/browser");
//appears to download the link and content (and definitely does in the Nokia
// emulator) and then throws an exception
new Invocation("http://www.google.co.uk");
new Invocation("http://www.somesite.com/index.html");
Below is the code that I have been using, please bear in mind the parameters often changed to generate the different Invocation objects.
/*
* Invokes an application using the Content Handler API
*/
public void doInvoke(String url, String mime, String payload){
Registry register = Registry.getRegistry(this.getClass().getName());
Invocation invoke = new Invocation(url, mime, null, false,
ContentHandler.ACTION_OPEN);
boolean mustQuit = false;
try {
mustQuit = register.invoke(invoke);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (ContentHandlerException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
if(mustQuit){
this.quit();
}
}
Try this:
Registry register = Registry.getRegistry(this.getClass().getName());
You must call Registry.getRegistry for the MIDlet inheritor. Just use your MIDlet for getting the class name.