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Maven project - load file from outside of resources folder (project root)

I am creating a contacts application using Maven in Netbeans. For the operation of the program I want users to add and store images (contact avatars) in a folder /avatars and access them on a listener event. I can access images from within the ProjectRoot/src/main/resources/images directory, but cannot access ProjectRoot/avatars. Note: I do not want to store avatars in the resources directory because these will be user-added during the programs operation.
I have tried using getClass().getResource(avatarPath); as suggested in similar questions, but it has not worked. I have also tried adding the "avatars" directory to the POM as its own resource directory, but that has not worked either.
How can I access files/folders in the root directory of my project when using Maven?
listviewContacts.getSelectionModel().selectedItemProperty().addListener(new ChangeListener<Contact>() {
#Override
public void changed(ObservableValue<? extends Contact> observable, Contact oldValue, Contact newValue) {
String avatar = newValue.getAvatar();
String avatarPath = null;
if (avatar.isEmpty()) {
avatarPath = "/images/" + DEFAULT_AVATAR; // loads from ProjectRoot/src/main/resources/images
} else {
avatarPath = "/avatars/" + avatar; // won't load from ProjectRoot/avatars
}
try {
imageviewContact.setImage(new Image(avatarPath));
} catch (IllegalArgumentException ex) {
System.err.println("Could not locate " + avatarPath);
}
}
});

You are mixing 2 different things.
You can either have a classpath resource packed in jarfile along with your classes, or in a directory that is explicitly added java to java classpath(using java -cp commandline argument). That can be accessed via getClass().getResource.
Or you can load a file from arbitrary location, using java.io.File. Then your "projectRoot" is some folder in a filesystem, that you can either hardcode, configure by -DprojectRoot=C:/fun/with/files, or use some of relative paths.
Maven has nothing to do with it, as avatars "will be will be user-added during the programs operation".
Your users will not launch your IDE, right ?

The problem was in understanding where the different constructors of javafx.scene.image.Image begin their path.
When using the URL constructor for Image, the URL path will start in Maven's defined resources folder (/src/main/resources or whatever additional resource directories were added to the pom.xml file):
// the supplied string invokes the URL constructor
Image image = new Image("path/to/file");
When using the InputStream constructor for Image (via FileInputStream), the path will start at the root directory of the project/application:
// the FileInputStream invokes the InputStream constructor
Image image = new Image(new FileInputStream("path/to/file"));

Java JNI GDAL native library error with ClassLoader when redeploying as web application

I'm using GDAL native library (C++ and it is installed in /usr/lib/java/gdal). I found a trick short time ago, to allow Tomcat can load the web application and this library (cannot use System.load() or System.loadLibrary() as all will return error)
Caused by: java.lang.UnsatisfiedLinkError: org.gdal.osr.osrJNI.new_SpatialReference__SWIG_1()J
Then I need to use a trick to add the library path to JVM when application starts:
final Field usrPathsField = ClassLoader.class.getDeclaredField("usr_paths");
usrPathsField.setAccessible(true);
// get array of paths
final String[] paths = (String[]) usrPathsField.get(null);
// check if the path to add is already present
for (String path : paths) {
if (path.equals(pathToAdd)) {
return;
}
}
//add the new path
final String[] newPaths = Arrays.copyOf(paths, paths.length + 1);
newPaths[newPaths.length - 1] = pathToAdd;
usrPathsField.set(null, newPaths);
This works well when the Tomcat starts with application, however, if I redeploy the application, it will return error:
Caused by: java.lang.UnsatisfiedLinkError: Native Library /usr/lib/java/gdal/libgdaljni.so already loaded in another classloader
I could not find any solution in StackOverflow, so I ask here if anyone can give some information. I also cannot change or add library path to environment variable or Tomcat folder, all should be done in Java code only.

So to avoid to add library to Tomcat/lib folder, I copy all the GDAL native folder to a temp directory with time stamp (e.g: /tmp/gdal_native/date.time), then I use the code above normally, except when it checks for the previous path, it will override with the new one.
String tmpTargetNativeFolderPath = "/tmp/gdal_native" + "/" + current date time
int i = 0;
// check if the path to add is already present
for (String path : paths) {
String pathFolder = StringUtils.substringBeforeLast(path, "/");
if (pathFolder.equals("/tmp/gdal_native")) {
// Override the old path with the new one
paths[i] = tmpTargetNativeFolderPath;
usrPathsField.set(null, paths);
return;
}
i++;
}
Then Classloader will load the library from another folder when the web application is redeployed without the error and the usrPathsField only contains one folder path to /tmp/gdal_native/timestamp.

cmu sphinx4 java - Runtime exception caused by FileNotFoundException

I have recently made a Java project with Sphinx4. I found this code online, and I slimmed it down to this to test if Sphinx4 was working:
public class App
{
private static final String ACOUSTIC_MODEL =
"resource:/edu/cmu/sphinx/models/en-us/en-us";
private static final String DICTIONARY_PATH =
"resource:/edu/cmu/sphinx/models/en-us/cmudict-en-us.dict";
public static void main(String[] args) throws Exception {
Configuration configuration = new Configuration();
configuration.setAcousticModelPath(ACOUSTIC_MODEL);
configuration.setDictionaryPath(DICTIONARY_PATH);
configuration.setGrammarName("dialog");
LiveSpeechRecognizer jsgfRecognizer =
new LiveSpeechRecognizer(configuration);
jsgfRecognizer.startRecognition(true);
while (true) {
String utterance = jsgfRecognizer.getResult().getHypothesis();
if (utterance.startsWith("hello")) {
System.out.println("Hello back!");
}
else if (utterance.startsWith("exit")) {
break;
}
}
jsgfRecognizer.stopRecognition();
}
}
However, it gave me this error:
Exception in thread "main" java.lang.RuntimeException: Allocation of search manager resources failed
at edu.cmu.sphinx.decoder.search.WordPruningBreadthFirstSearchManager.allocate(WordPruningBreadthFirstSearchManager.java:247)
at edu.cmu.sphinx.decoder.AbstractDecoder.allocate(AbstractDecoder.java:103)
at edu.cmu.sphinx.recognizer.Recognizer.allocate(Recognizer.java:164)
at edu.cmu.sphinx.api.LiveSpeechRecognizer.startRecognition(LiveSpeechRecognizer.java:47)
at com.weebly.controllingyourcomputer.bartimaeus.App.main(App.java:27)
Caused by: java.io.FileNotFoundException:
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at java.io.FileInputStream.<init>(FileInputStream.java:93)
at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:90)
at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:188)
at java.net.URL.openStream(URL.java:1038)
at edu.cmu.sphinx.linguist.language.ngram.SimpleNGramModel.open(SimpleNGramModel.java:403)
at edu.cmu.sphinx.linguist.language.ngram.SimpleNGramModel.load(SimpleNGramModel.java:277)
at edu.cmu.sphinx.linguist.language.ngram.SimpleNGramModel.allocate(SimpleNGramModel.java:114)
at edu.cmu.sphinx.linguist.lextree.LexTreeLinguist.allocate(LexTreeLinguist.java:334)
at edu.cmu.sphinx.decoder.search.WordPruningBreadthFirstSearchManager.allocate(WordPruningBreadthFirstSearchManager.java:243)
... 4 more
I thought it might be something about it not being able to find the paths for ACOUSTIC_MODEL or DICTIONARY_PATH, so I changed the resource: strings to things like %HOME%\\Downloads\\sphinx4-5prealpha-src\\sphinx4-5prealpha-src\\sphinx4-data\\src\\main\\resources\\edu\\cmu\\sphinx\\models\\en-us or paths with forward slashes or with C:\Users\Username\... but none of the paths worked. I know the paths exist because I copy and pasted them from the properties window of the actual resources.
So my question is: is it some of the code that I deleted from the original source code that is causing this error, is it something wrong with the paths, or is it entirely different?
EDIT
By the way, I am using Maven to build my project. I added the dependencies specified on the Sphinx4 website to my pom.xml, but it didn't work (it didn't recognize imports such as edu.com.sphinx.xxx) so I downloaded the JARs from the website they said to download them from and added them to my projects "Libraries" in my Java Build Path in Eclipse.

is it some of the code that I deleted from the original source code that
is causing this error
Yes, you deleted too much.
To recognize with grammar you need to make three calls:
configuration.setGrammarPath(GRAMMAR_PATH);
configuration.setGrammarName(GRAMMAR_NAME);
configuration.setUseGrammar(true);

ClassLoader always returns null when called from within a jar

I ran into library loading problems after creating a jar from my code via maven. I use intelliJ idea on Ubuntu. I broke the problem down to this situation:
Calling the following code from within idea it prints the path correctly.
package com.myproject;
public class Starter {
public static void main(String[] args) {
File classpathRoot = new File(Starter.class.getResource("/").getPath());
System.out.println(classpathRoot.getPath());
}
}
Output is:
/home/ted/java/myproject/target/classes
When I called mvn install and try to run it from command line using the following command I'm getting a NullPointerException since class.getResource() returns null:
cd /home/ted/java/myproject/target/
java -cp myproject-0.1-SNAPSHOT.jar com.myproject.Starter
same for calling:
cd /home/ted/java/myproject/target/
java -Djava.library.path=. -cp myproject-0.1-SNAPSHOT.jar com.myproject.Starter
It doesn't matter if I use class.getClassLoader().getRessource("") instead. Same problem when accessing single files inside of the target directory instead via class.getClassLoader().getRessource("file.txt").
I want to use this way to load native files in the same directory (not from inside the jar). What's wrong with my approach?

The classpath loading mechanism in the JVM is highly extensible, so it's often hard to guarantee a single method that would work in all cases. e.g. What works in your IDE may not work when running in a container because your IDE and your container probably have highly specialized class loaders with different requirements.
You could take a two tiered approach. If the method above fails, you could get the classpath from the system properties, and scan it for the jar file you're interested in and then extract the directory from that entry.
e.g.
public static void main(String[] args) {
File f = findJarLocation("jaxb-impl.jar");
System.out.println(f);
}
public static File findJarLocation(String entryName) {
String pathSep = System.getProperty("path.separator");
String[] pathEntries = System.getProperty("java.class.path").split(pathSep);
for(String entry : pathEntries) {
File f = new File(entry);
if(f.getName().equals(entryName)) {
return f.getParentFile();
}
}
return null;
}

Java Trouble compiling maxmind geoip LookupService class

I wonder if some one can please help as I am struggling to compile maxmind.geoip.LookupService.java
I have downloaded geoip-api-1.2.10.jar for inclusion in WEB-INF\lib and I have referenced it in my classes path, but it just won't compile.
I have compiled the following successfully so I'm a bit at a loss:
com.maxmind.geoip.Country
com.maxmind.geoip.DatabaseInfo
com.maxmind.geoip.Location
com.maxmind.geoip.Region
com.maxmind.geoip.timeZone
Can't seem to find a full set of compiled java classes for com.maxmind.geoip, any help would be much appreciated :-)

I resolved this by downloading the latest java files from http://dev.maxmind.com/geoip/legacy/downloadable/ unpacked the folder and then opened a command prompt and typed the following:
cd source/com/maxmind/geoip/
javac *.java
I'm using jdk1.6.0_34 and all classes compiled with no errors.
I copied the com.maxmind.geoip folder to \WEB-INF\classes and downloaded geoip-api-1.2.10.jar and placed that in the WEB-INF\lib folder.
Finally I download GeoIP.dat from http://dev.maxmind.com/geoip/legacy/geolite/ and placed it in a new folder called GeoIP under webapps so that all my applications can use it.
The following code is to obtain the country code from a users IP Address:
import com.maxmind.geoip.*;
import java.io.IOException;
class CountryLookupTest {
public static void main(String[] args) {
try {
String sep = System.getProperty("file.separator");
String dir = "C:/Program Files/Apache Software Foundation/Tomcat 7.0/GeoIP";
String dbfile = dir + sep + "GeoIP.dat";
LookupService cl = new LookupService(dbfile,LookupService.GEOIP_MEMORY_CACHE);
System.out.println(cl.getCountry("151.38.39.114").getCode());
System.out.println(cl.getCountry("151.38.39.114").getName());
System.out.println(cl.getCountry("12.25.205.51").getName());
System.out.println(cl.getCountry("64.81.104.131").getName());
System.out.println(cl.getCountry("200.21.225.82").getName());
cl.close();
}
catch (IOException e) {
System.out.println("IO Exception");
}
}
}
Hope this proves useful to others.

According to the MaxMind dev site, the API is available on the Maven Central Repository. You shouldn't need to compile anything unless you downloaded the source package.

You have to download a Jar file called geoIP-api from this link to maven repository,In case you haven't downloaded the other Jar files from go this geoIP2 also don't forget to download the .DAT file from geoIP.dat. Then add the files to your project class path from project properties and then libraries finally add Jar in netbeans.
Now use this code:
public String IpGeoLocation(String IP) {
try {
String dbfile = "C:\\Users\\User Name \\Documents\\NetBeansProjects\\IP Tools\\resources/GeoIP.dat";
String location = "";
LookupService cl = new LookupService(dbfile, LookupService.GEOIP_MEMORY_CACHE);
location = cl.getCountry(IP).getName() + " " + cl.getCountry(IP).getCode();
cl.close();
return location;
} catch (Exception e) {
return "Error";
}
}
I was able to find the country and country code only !!