Mohit Gaur Mohit Gaur - 10 months ago 139
Android Question

Getting compilation error when using Refrofit simple xml converter

I am a beginner in android and xmpp, i am developing a chat application using xmpp as protocol and openfire as server.I am using xmpp rest api to create a group.To create a group i need to send GET request to server with xml data body..I am using retrofit2 in android client.Whenever i am building my application it is giving me this error



rror:warning: Ignoring InnerClasses attribute for an anonymous inner class
Error:($1) that doesn't come with an
Error:associated EnclosingMethod attribute. This class was probably produced by a
Error:compiler that did not target the modern .class file format. The recommended
Error:solution is to recompile the class from source, using an up-to-date compiler
Error:and without specifying any "-target" type options. The consequence of ignoring
Error:this warning is that reflective operations on this class will incorrectly
Error:indicate that it is *not* an inner class.
Error:trouble processing "javax/xml/XMLConstants.class":
Error:Ill-advised or mistaken usage of a core class (java.* or javax.*)
Error:when not building a core library.
Error:This is often due to inadvertently including a core library file
Error:in your application's project, when using an IDE (such as
Error:Eclipse). If you are sure you're not intentionally defining a
Error:core class, then this is the most likely explanation of what's
Error:going on.
Error:However, you might actually be trying to define a class in a core
Error:namespace, the source of which you may have taken, for example,
Error:from a non-Android virtual machine project. This will most
Error:assuredly not work. At a minimum, it jeopardizes the
Error:compatibility of your app with future versions of the platform.
Error:It is also often of questionable legality.
Error:If you really intend to build a core library -- which is only
Error:appropriate as part of creating a full virtual machine
Error:distribution, as opposed to compiling an application -- then use
Error:the "--core-library" option to suppress this error message.
Error:If you go ahead and use "--core-library" but are in fact
Error:building an application, then be forewarned that your application
Error:will still fail to build or run, at some point. Please be
Error:prepared for angry customers who find, for example, that your
Error:application ceases to function once they upgrade their operating
Error:system. You will be to blame for this problem.
Error:If you are legitimately using some code that happens to be in a
Error:core package, then the easiest safe alternative you have is to
Error:repackage that code. That is, move the classes in question into
Error:your own package namespace. This means that they will never be in
Error:conflict with core system classes. JarJar is a tool that may help
Error:you in this endeavor. If you find that you cannot do this, then
Error:that is an indication that the path you are on will ultimately
Error:lead to pain, suffering, grief, and lamentation.
Error:1 error; aborting
:app:transformClassesWithDexForDebug FAILED
Error:Execution failed for task ':app:transformClassesWithDexForDebug'.
> java.lang.RuntimeException: java.util.concurrent.ExecutionException: org.gradle.process.internal.ExecException: Process 'command 'C:\Program Files\Java\jdk1.8.0_05\bin\java.exe'' finished with non-zero exit value 1

This is my retrofit code below

Call<Void> createGroup(@Header("Accept") String content_type,
@Header("Authorization") String authorization,
@Body Group group);


public static int doCreateGroup(String content_type, String authorization, Group group) {
Retrofit retrofit = new Retrofit.Builder().baseUrl(StaticVariables.base_url)
.client(new OkHttpClient())
Alfa alfa = retrofit.create(Alfa.class);
Call<Void> call = alfa.createGroup(content_type, authorization, group);
try {
Response<Void> response = call.execute();
Log.e("Group Upi", String.valueOf(response.code()));
return response.code();
} catch (IOException e) {
return 0;


Below is my model of group

@Root(name = "group")
public class Group {
@Element(name = "name")
public String name;

@Element(name = "description")
public String description;

public Group(String name,String description){


Below is the actual xml which i have to send

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<description>Some description</description>

Below is my dependencies

compile ''
compile ''
compile ''
compile ''
compile 'org.igniterealtime.smack:smack-android:4.1.4'
compile 'org.igniterealtime.smack:smack-tcp:4.1.4'
compile 'org.igniterealtime.smack:smack-im:4.1.4'
compile 'org.igniterealtime.smack:smack-extensions:4.1.4'
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:converter-gson:2.1.0'
compile 'com.squareup.okhttp3:logging-interceptor:3.2.0'
compile ''
compile 'com.squareup.retrofit2:converter-simplexml:2.1.0'
compile('') {
transitive = true;

Please tell me where i am wrong

Answer Source

The error is because of some classes in simple xml converter.So we just need to remove some classes,The solution is,just add below lines in gradle compile dependency

compile ('com.squareup.retrofit2:converter-simplexml:2.1.0') {
        exclude group: 'xpp3', module: 'xpp3'
        exclude group: 'stax', module: 'stax-api'
        exclude group: 'stax', module: 'stax'