So question arises that is there any full proof possibily to replace the class file at run time for java application. But, It again gives a class not found exception. jar files live in jars/) and use ImageJ's plugin classloader: IJ. The first parameter is the (canonical) name of the class. class where server and package are folders. Apr 19, 2012 · This tool will then compile the java file, place the resulting class file in the "classes" directory, load the class and access the getTestData method, produce XML files representing the test data. ClassNotFoundException exception during runtime. class inside external_jar. Jul 9, 2009 · Class. currentThread Dec 12, 2013 · Here's some code I use to load a jar dynamically at run-time. getAbsolutePath() (note that in some cases like reading from sd on android, you also need READ_PERMISSION to read that jar) classPath = inside your jar, choose which class you want to get/instantiate (with package name) (e. In past experience, the JVM will not attempt to compile a class until needed. I would say it will continue using the old one. I'm looking to write a custom class loader that will load a JAR file from across a custom network. I'm not sure how JARs are loaded exactly but you can dynamically load any class at runtime. g. Jul 21, 2015 · Jul 21, 2015 at 7:42. jar and both jars have different versions of the same class the version from new. forName(clsname, init, classloader); ( Javadoc here) you will get an instance of the class provided by the given classloader. I am using PipelineOptions. This means: 1. I know that a more efficient way is out there This lib will load jar from file system or any other location. class. class file resides in a different namespace than that of this java program. Now the client Application should load this class B from the downloaded jar file with the following code: URL downloadURL = downloadFolder. But may I express my doubt. Jul 8, 2019 · The JavaLoader project creates an isolated Class Loader that can instantiate Java classes based on a given set of JAR file paths. But they would be read from external source (Let's say some database ). defineClass in Java 9 but it can only load a class in the same package. Jan 12, 2024 · Step 3: Use the Custom ClassLoader. 4. @ConditionalOnProperty(name="feature. Jul 28, 2011 · We can load any classes from external jar and apk file. forName () to get the classes. May 23, 2016 · A) i've noticed that if i load class like this, loaded class will have as package parrent the package of parrent-class (the one in which i run the code: example: real-package of class in jar library: "com. jar class B extends BaseA -> pluginB. But anyway, a kind of solution would be to scan with Reflections if the given package name contains required classes (or at least few of them, so you would know that the package is visible) like here: Oct 5, 2015 · Our requirement is to load it's dependency like classes, resources, jars from different location dynamically by java program. Everything loaded because of that class will also be loaded via the same classloader. write(buffer, 0, len); out. The easiest way to do this is to use a URLClassLoader instead of trying to do this from scratch from a byte stream. Note: this works entirely in memory by default. Load jar dynamically. You can let your program to ignore the Certificate Validation. For example: abstract public int test(int a); I implemented a subclass: @Override. dex file on that jar with command dx. class file represents; or (b) you can use a library that does this for you. I cannot dump the byte array onto the file system and use a URLClassLoader. I have a small project in which I get the URL, username, password, and driver from a text file and I have to fire a query on the database by dynamically reading the jar file in a predefined directory, register the jar, get a connection object and possibly de-register it. toURL(); Dec 19, 2015 · If another distribution is selected then the previous jars which were added to the class-path have to be removed from class-path dynamically and new jars related to new distribution have to be added dynamically. If other classes are still holding references then the gc won't do its job. Have tried approaches defined in the following link but none of them worked for me: May 25, 2017 · I am trying to load a jar file as if it was run with "java -jar BungeeCord. Oct 29, 2012 · I have an ASP. g Dec 7, 2015 · It is possible to add new classes into a class loader. Here's the procedure: Start with a class in the root package, and get the folder it's in from the class loader. Below are the steps and an example of how to load JAR files dynamically. I have a scala application that wants to dynamically load this class and call its constructor. close(); The above code reads each class file inside the desired library and copy's its content's into a new file. out. jar and it's the problem. │ ├─ mspn/. When using the createObject() function to create objects of type, java, we can supply a collection of JAR Loader. Neither do I know the name of the jar file. If a class refers to another class then that other class will also be compiled. The same has to be continued for other distributions. Alternatively, if you can manager the class loading, copy the jar to a temporary file (which is automatically done for http URLs, for instance) or into memory. Each plugin is its own SpringApplication, and has it's own ApplicationContext. Now my idea here is to use URLClassLoader ucl = URLClassLoader. In Any way, we can load Activity from external jar but we can not start it because of the context concept. I can load . Jan 8, 2024 · In this tutorial, we’ll take the stripe-0. I don't know how it works on Java 8, but unloading a class in Java 7 requires unloading not only the class, but its loader, along with all references from other objects that this class might have. For instance, using URLClassLoader. (implied by 1) The class definitions need to be available at compile time. I have tried to set classpath by -cp and used ClassLoader, URLClassLoader but it did't work. In the end, all I have to work with is a byte array of the JAR file. This jar only contains PluginA. The new module layer will inherit the boot layer: This means that in your boot layer (where your main module is), you cannot directly refer to classes in the plugins layer. So you can do something like this: application. jar I try using a Class-loader like presented in the following question: How should I load Jars dynamically at runtime? Oct 3, 2015 · This works fine if I'm trying to load classes that are defined in plug-in A, but I get ClassNotFoundException when trying to load classes in the JAR referenced in plug-in A. URLClassLoader is the oldest approach and the most well-known. the list of classes is 0 Sep 30, 2014 · The JVM searches for and loads classes in this order: Bootstrap classes, which are classes that comprise the Java platform, including the classes in rt. I also tried static block to load my jar. I looked at these questions, but none of the answers worked for me: How should I load Jars dynamically at runtime? ClassNotFoundException while trying to load class from external The JarClassLoader class extends java. However, if a class fails to load (because, say, you haven't added it), then it will never load in that class loader instance. Any ideas? Thanks in advance. In addition to subclassing URLClassLoader, JarClassLoader also makes use of features in two Nov 1, 2014 · I have tried debugging in Eclipse, but the class loader instance is unable to load classes from the jar. Convert the file names to fully qualified class names. It should load the class. The ClassLoader class also provides a method called getResource (String name) that allows you to load resources (such as configuration files) associated with a class. As its name implies, URLClassLoader is designed to be used for loading classes and resources that are accessed by searching a set of URLs. class file from a jar file. I'm not 100% sure what happens if you add another jar containing the same class. Jul 7, 2011 · The reason I'm trying to do this is that while I've had some success through just passing around my newly created ClassLoader in my own code, I'm having trouble with a third party library (apache-WSIF) that doesn't seem to be working with the passed in ClassLoader. Obviously by allowing the user to specify a source file I have to also make sure that all dependencies for that file are included on the classpath Jan 13, 2022 · After checking all the above options, i still feel the above options are not good enough to load the existing class file (which is getting used in running application as well) at run time. The detail description of my problem is as follows. If you look in the StormPlugin class you can see the initializeContext plugin which is called on every plugin load. Recursively enumerate all . Instead of loading all Java classes into memory at once, class loaders fetch classes only when they are requested by the application, which reduces the startup time. Then, how can I use them to load the classes i need in an Android application ? I would to use them like: DynamicLoadedClassJar obj = new DynamicLoadedClassInJar() Jan 18, 2010 · Even if you load all the classes, you may still get errors from resources. SecureRandom; import java. Sep 16, 2016 · Yes, I used system class loader (i had a very simple case and was sure that some jars will be loaded only once), but for you I suggested to use a different one. public static Parser loadParser(String fqn, Path jar) {. java. Thus, I need to scan the /plugins folder for any *. But make sure fragment creates the UI dynamically as given Feb 20, 2014 · But now if i want to access some particular class of the laoded jar in a way say SomeJarClass obj = SomeJarClass. Discover the services: Service discovery is done like this: ServiceLoader<Plugin> loader = ServiceLoader. To load the UI from external jar we can use fragment. 14. May 7, 2014 · You have two choices here. Verify that new File(jarName). jar class C extends BaseA -> pluginC. Like this: public class I tried adding the jar I'm loading the class from to the classpath (either by -cp or setting CLASSPATH environment variable). forname method, I received a class not found exception. Nov 4, 2021 · In general you can load beans if some condition applies, usually depending on the configuration. However, this functionality can be achieved by creating a custom child classloader. net. For example, to unit testing, debugging or monitoring; Isolation of executions - isolate several execution environments within a single process by making visible only a subset of classes for a particular thread, like it does in EE environments; Nov 2, 2014 · I have been trying to figure out how to dynamically load classes from a jar file during runtime, knowing the name of the package to load them from. There is no best way. Code is as follows: I created a derived class and called the superconstructor with super("/sdcard/f. We can use this command with the t and f options to list the content of a JAR file: $ jar tf stripe-0. Jan 18, 2018 · Also, note the arguments used for the API includes the name of the class using which the classloader returns the object of the class. @Component. Use Class. The only way that a Class can be unloaded is if the Classloader used is garbage collected. asked Jul 7, 2011 at 21:45. com. Example 1: Reloading a Class with Java Class Loader. NET web application written in C#. META-INF/. wonderfull" -> loaded class is in "com. That's pretty much all, the second (and cleaner) way works like a charm. Apr 2, 2019 · The problem I'm running to now is that, of all the approaches I found, I need to declare a classpath of the classes in the jar file, which I do not know. bar. loadClass ("blub"); Jul 9, 2023 · 2. The class is contained within a separate library JAR file, but packaged with the APK (as per the new library mechanism in the SDK). You are permitted to add java options at run time for recognizing class path but we are preferred to load dynamically by java program. } 3 - Use the Parser (as a strongly typed interface) in the client code. You can always write the . Write another extension APIUser, load it to M and make use of API1. 209. It will dedicate a class loader for the jar to make sure there are no library conflicts. jar . jar will not be loaded again. Classpath Search: The Class Loader searches for the class bytecode in a specific classpath or set of locations. Name Resolution: The Class Loader receives the name of the class to be loaded and resolves it to a binary name using the Java Naming and Directory Interface (JNDI). Jan 26, 2013 · The easiest way is to refrain from loading the class dynamically, but directly, by using it. – ZhekaKozlov. Aug 13, 2017 · Grails 3 plugins are distributed as normal . My real goal here is to be able to dynamically decide which jar to load at runtime without having to change the code I've already written that uses the classes provided by this library. The JAR is on the class-path and is accessible when I'm not trying to dynamically load via this class loader. But it is only my guess, but it is easy to check – May 22, 2012 · Each jar contains a class that extends from a common abstract class. public static int age = 10; } We can do the following: Nov 8, 2010 · 3. I figured out how to do this. All you need to do is to obtain a ClassLoader and call its loadClass() method. or File. I have seen earlier threads which state that adding jars at run-time is possible Nov 6, 2011 · client = new IndiaClient(); ) else{. I have 2 plugins which inherit the same class, here is a structure: interface BasePlugin -> app. With Lucee 5. When you have dynamically loaded the class, you can explicitly invoke an initialization routine if necessary. path. And stupid. newInstance (urls, Thread. I suggest deploying to a different location if at all possible. wonderfull. enabled", havingValue="true", matchIfMissing="true" / "false") // matchIfMissing depends Jan 28, 2017 · Specified the parent class loader in constructor of URLClassLoader could fix the problem. Since Duck is already loaded by webapp class loader, Duck. see in the example I have a jar that has class with name com. jar out to a temporary file and create a URL to that. gc will be called. From java 1. found ClassNotFoundException. Jeff Scott Brown. The . I can not use a process builder because I need get an instance of classes uses in the external jar file. Oct 11, 2017 · On my project, I have a jar dependency that loads a class dynamically. My suspect is that android does not support this at all, otherwise normal defineClass should work already. loadClass will load a class. 1-SNAPSHOT. com May 30, 2024 · Loading JAR files dynamically at runtime in Java can be challenging due to security constraints and the immutable nature of classloaders. if Yes, Could you please guide in this Feb 12, 2018 · 4. The application requires that the classes implement interface E and be called NE. jar file and load the corresponding class inside the jar which implements BasePlugin and invoke byte[] buffer = new byte[1024 * 100]; FileOutputStream out = new FileOutputStream(f); int len; while ((len = jarLibraryInputStream. To fix this error, you need to make sure that the classes. jar , but it should be able to just search for a jar file starting with myDependency Jun 14, 2020 · 1. On project level I created a new class which I want now to load from inside the jar. currentThread (). Both failed. class; Apr 25, 2013 · The technique includes: (a) compile Groovy to class files and (b) include all necessary jars in the jar (including groovy-all). If your interest is the classes contained inside a JAR then yes those can be loaded using a class loader. Extension classes, which use the Java Extension mechanism. File file = new File(jarPath); URL u = f. You will need to execute this code only once before you call addURL. Given the following User class definition: public static class User {. in y. jar and several other important JAR files. /* * Adds the supplied library to java. properties: // or yaml it doesn't matter. There is also a new method Lookup. Feb 15, 2024 · Dynamic Class Loading. perform(function(){ var pathclassloader= J Aug 12, 2020 · 2 - Create a utility class, which can load such a parser from a jar. proprietary. The class that must be loaded is specified on an environment variable. class files in this folder. So if you have a public class MyClass with a constructor like public MyClass Feb 24, 2020 · Class. 6, you can include all the jars in a directory into the classpath just by saying /*. Given the fully qualified name for a class or interface (in the same format returned by getName) this method attempts to locate, load, and link the class or interface. Dec 15, 2021 · I am developing a Java application which uses UDFs on Flink 1. Well we have been experimenting with this and most of our fails were connected with obtaining/using bad ClassLoader. Now, the following is what I'm trying to do, Write an extension API1 and load it to M. I have tried this: How to get all classes names in a package? It didnt work, I later realized it was for programs outside of jar files. Clazz, you should be able to find file foo/bar/Clazz. class in the fat jar file. dex file of your plugin doesn’t include the libraries shared with your host application, such as your sdk jar or LibGDX jars. Can I load Jar files dynamically at runtime and call functions within them? Thanks. Here is the code that you can use as a starting Oct 3, 2023 · 1. Jan 15, 2014 · 1. e. 3, we can more-or-less replace the JavaLoader project with the native createObject() function. jar files are all in ImageJ's plugins/ folder (or if you use Fiji, non-plugin . This article introduces the idea of hot-loading jar packages in Spring Boot projects and registering them as bean objects to dynamically Oct 18, 2019 · I'm going to load . All approaches have their pros and cons. What I want is it to load a jar file, lets say, myDependency-2. something" & my-app-package: "com. When using Class. getSystemClassLoader(); Class urlClass = URLClassLoader. In this case, you try to load the class com. class) Jun 7, 2017 · all of the jar's dependencies are placed inside the jar using maven-shade-plugin. If for example, your classpath looks like new. I can use your approach above to load any class from a fat jar created with sbt-assembly without problem. something" :) )-> retested: it keeps the original Feb 24, 2014 · By default this includes all the classes from your application as well as all the non-platform libraries your application depends on. The ClassLoader fetches binary data from the Mar 30, 2013 · Unfortunately, Java doesn't provide an easy way to list classes in the "native" JRE. MF. I got a custom class loader which is gonna to be java. client = new Country2Client(); } 2) Keep your way with the same class name in 2 different jar files, but you still need a interface or super class, and to use different ClassLoaders to load your Client classes: interface IClient {} class Client implements IClient {} // in jar1. Dec 4, 2013 · And it's all ok. Just change my. Mar 9, 2013 · I am uploading a jar dynamically through servlet and saving it in my WEB-INF/lib directory. This lib was designed to load jars compiled in Java 8 from the code base that supports Java 7. security. *; private TrustManager[] getBypassingTrustManager() {. loadClass("package. jar;old. Nov 22, 2019 · To load dynamically a jar to classpath I used to use the following code with Java 8. Class myclass = urlcl. forName(fully qualified class name) which is throwing a java. cl will search class/resource using parent class loader first, then load class/resource from given URLs. My first plan was to create a JarFile object from a stream or byte array, but it only supports a File Mar 8, 2012 · Apr 6, 2012 at 19:46. 3. Using frida, I've tried to load jar file but failed. jar", "/sdcard", null, getSystemClassLoader()); But no success. When you start an spring app, beans are loaded and hooked in its contexts, so if you want to add more to it manually you might need to reload the whole context which may not be a good idea for an spring boot app. Try using the absolute file path. I have the location of the jar file, the name of the class and the function in it as strings. loader - it holds urls where to find classes. getClassLoader(); Jun 8, 2021 · *The piece of code that performs dynamic class loading is inside a Main. load(Plugin. I exploit reflection to circumvent the fact that you ain't really supposed to do this (that is, modify the class path after the JVM has started). system. If you are trying to generate a java file dynamically, compile and add into the classpath, set the directory into which the class file gets generated in the classpath beforehand. Mar 12, 2014 · If you want to load class foo. Oct 19, 2021 · The common implementation of dynamic plug-ins are SPI, OSGI and other solutions, which cannot be injected into the main program’s bean objects in the plug-in because they are not managed by Spring IOC. However, when running a java. jar file and I can create the . In project A, there is a class A like: class A { } I want to load Java classes dynamically on Android application. getSystemClassLoader() if that is null. Apr 6, 2011 · ClassLoader. I am using Class. Oct 14, 2018 · I am trying to execute a function from a class in a jar file dynamically. Here is the source code. the manifest of the jar is readble but the classes are not. 2. Users will be able to create any object from the loaded jar and call any method on it. For example if you want to call a static method with the name "main": Method m = myclass. getInstance() this should work since all the classes of that jar is loaded. When I actually want to execute the native image that I generated, I want to replace the clientData_V1. addURL. jar dynamically to apk and call a certain method of a class in that jar. Oct 17, 2016 · I am trying to load classes from a dynamically loaded jar file. Loading a class dynamically is easy. ClassLoader classLoader = getClass(). Nov 28, 2014 · To improve this, I wanted to load the jar dynamically and read about using the ClassLoader. But I need to put baseA package to both pluginB. Or more specifically a JAR class loader JarClassLoader Class. Create a URLClassLoader: This classloader will load classes Sep 9, 2023 · Class Loaders play a pivotal role in dynamically loading Java classes into the JVM (Java Virtual Machine) during application execution. But I want is , add new class in new jar in class path , add entry of fully qualified name of class in database , so that in next iteration of loop program can dynamically load class . I want to know if I can do the same with Java APIs (Jar files). In the plugin . You get a classloader by myClass. Oct 31, 2011 · I'm trying to dynamically load a class at runtime on the Android platform. Java. x. I have a lib folder at installer location that i want to load at class path or refrenced at runtime for my java project, programmaticaly. (different for application server, different for standalone jar). However, you can use your plugins layer through services. lang. To do this, you will need to create an instance of the custom classloader, passing in the jar file as a parameter, and then use the loadClass() method to load the classes. The third parameter is the ClassLoader the class will be 3. I want to get all the classes annotated with my @annotation, have used reflections code below without any luck. Wether defineClass nor findClass return any class that is attached dynamically. JDK ships with a jar command. cert. 0. Feb 4, 2014 · I suggest using the Java Runtime Compiler library. without adding class path entry into it's jar MANIFEST. jar). The second parameter specifies that the class should be initialized at that point ( static variables are initialized and static blocks are run. Like the rest of Java, this mechanism is garbage-collected, so there is no way to explicitly unload the JAR; it is up to the JVM to release the JAR when the May 30, 2024 · Loading JAR files dynamically at runtime in Java can be challenging due to security constraints and the immutable nature of classloaders. getContextClassLoader ()); where Dec 8, 2014 · 3. getMethod("main", String[]. Here’s how you can use it: java. Despite the long history of changes to how things work in the JVM, I think this is still true today. feature. This file is a simple text file and contains the fully qualified name of each class implementing Plugin in that jar-file. class files, and then determine which Java class each . jar file as an example to address how to get the class names in the JAR file: 3. X509Certificate; import javax. Also, the jar must have the "main" entry point specified in the manifest (which would be a modified version of your script). enabled=true. jar will be used. toURL(); URLClassLoader urlClassLoader = (URLClassLoader) ClassLoader. jar. I have the . The classes Vector is empty. ClassNotFoundException is thrown. This means, references to every single class and to the classloader itself need to go the way of the dodo. class); Mar 10, 2015 · Here you can use URLClassloader to load a jar. NET APIs in the form of dlls dynamically and call methods in them from my application. Each query may talk to a different database schema or even DBMS. This method returns a URL object pointing to the resource. URLClassLoader. import java. new URL[] {new URL("file://")}, Thread. . getClassLoader (). jar and pluginC. jar that supports extensions to be written and loaded dynamically. Instead, I would suggest to use spring profiles, so you can define different configurations and based on what you want you can Jun 22, 2019 · As in each jar has it's own context. Once you have created the custom classloader, you can use it to load the classes from the Spring Boot jar package as needed. public int test(int a) {. read(buffer)) > 0) {. Please pay attention that if you are on Unix use : instead of ;. jar files. getClassLoader() and you should fall back to ClassLoader. jar files the /services/plugintest. The URLClassLoader requires that the Sep 8, 2016 · As of now class names are hard coded . See full list on baeldung. So it's not so much after ApplicationContext load, as I don't want to add it to the StormCore context. jar *Class inside the Sample. That leaves you with a couple of options: (a) for any given JAR file, you can list the entries inside that JAR file, find the . One possible solution to your problem is to have a Classloader for every jar file, and a Classloader for each of the AppServers that delegates Mar 14, 2020 · This is weird if you want to load the jackson classes dynamically and you are not sure what will be the base package for those classes. These classes are bundled as JAR files and located in the extensions directory. return a + a; The subclass above was compiled and packaged into a jar file (PluginA. jar that I used in creating the native image with clientData_V2. You can give it a String in memory and it will compile and load the class into the current class loader (or one of your choice) and return the Class loaded. Jul 5, 2020 · To load modules dynamically, you need to define a new ModuleLayer. I build a native image out of my Spring boot app using Graal VM 22. I read a lot of examples for it, however I still don't understand how to use it in my case. SimplePlugin file was missing inside the META-INF directory, so the ServiceLoader couldn't identify the jars as services and load the class. jar", but I am trying to do this from within another jar. ssl. MyClass. Using the jar Command. isFile returns true. toURI(). ├─ bin/. Hi all, I wrote a java program to load a . The first example will give you a general understanding of the Java class loader. 0. You should also probably look at OSGi but it can be pretty cumbersome. If you write a plugin that contains any number of controllers then consume that plugin from an application, all of the controllers in the plugin will be dynamically loaded into the grails application from the plugin jar. jar abstract class BaseA implements BasePlugin -> baseA. Once all of them were unloaded the System. answered Aug 14, 2017 at 16:28. If you are trying to replace a JAR the approach would probably be to replace the Dec 20, 2011 · Actually JVM looks for classes sequentially trying load them from resources from the list. Absent that method, the best way is to make sure that the . JARS config to add jar files containing UDF classes dynamically in the application code, However application fails to load UDF class from configured jar files with ClassNotFoundException. Solution cannot use reflection 2. Currently I can load a class that doesn't extend to a class other than the root class Object, but I can't load a class that extends a custom class. getClassFromJar(Context ctx,String jarLocation,String classPath); ctx = use getApplicationContext(); jarLocation = /storage/emulated or /storage/sdcard. forName loads a class. Place that jar file into the classpath of your (potentially already running) application. Here is an example: Jun 28, 2019 · The main scenarios to use custom ClassLoader is: Class Instrumentation - modifying classes at runtime. I have created this: The problem was very simple. Once you've got a class instance, you can get its constructors via getDeclaredConstructor() . // basically do the same as DynamicClass, // but upcast to parser and return an instance. Aug 5, 2013 · 1. I have a particular compile dependency, let's say clientData_V1. Fozefy. I also previously tried using maven-assembly-plugin or maven-one-jar-plugin. The code would look something like: URLClassLoader loader = new URLClassLoader(. MyClass"); For further usage of the loaded Class you can use Reflection if the loaded Class is not in your classpath and you can not import and cast it. exception to something sensible. Spring Boot - Dynamic Loading Jar Example This project demonstrates how you can use SpringBoot to dynamically at run-time load in different implementation of an interface at run-time and have the application detect them. To create an Oct 23, 2009 · You can use the ClassLoader to dynamically load classes from JAR files. jar implements an interface "DataPlay" that is available in Main. classloader. The URLs can refer either to directories or to JAR files. To all -- I'm probably at best a new guy here, trying to wrap my head around scala, and I find I need to do the following: Assume I have a scala class on disk somehwere referenced in my classpath. Jun 11, 2018 · I have a JAR application, M. . Once I have that class reference, I can use it to After the start of the client application the client applications downloads a jar file containing a jar file with content: server/package/B. Test and it has print method, Below code is describ how to load class and invoke the method, It just an example but better use of Interfaces, factory methods and reflection can make this code better, Nov 22, 2012 · 3. As long as you're very careful with the objects instantiated from this point on (to allow for GC), you should be able to reload Oct 2, 2011 · community! Would be great if u could help me w/ my issue. Nested classes are also loaded. Create the instance of the fragment and embedded it in the Activity. Where it is located in the classpath, Jar A or Jar B is not relevant to compilation. I've checked and ObjectMapper is in the jar, if I compile a the below with this jar and then run it with this jar in the classpath it works. eo bi gc uh nz cf dm qc tl dm