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Why do I get a Reflection exception NoSuchMethodException if the tests runs fine

I'm using Reflection to Mock a private method (I don't want to discuss if that makes sense or not).
Anyone know why? I'll let my testClass source code here it may help. I've tryed much of the Internet helps and ways to solve this but none have worked for me.
public class testProtexManagerProcessRequiredFile {
#Mock
ProtexManager PxManager;
#Before
public void inicializa() {
MockitoAnnotations.initMocks(this);
}
#Test
public void processRequiredFileTest() throws ClassNotFoundException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException, InstantiationException {
Method method;
try {
method = ProtexManager.class.getDeclaredMethod("processRequiredFile", File.class);
method.setAccessible(true);
File FileExample = new File();
String NameExample = "Nome";
File outputs = new File();
outputs = (File) Mockito.when(method.invoke(PxManager, FileExample,NameExample)).thenReturn(FileExample);
assertNotNull(outputs);
assertEquals(outputs, method.invoke(PxManager, FileExample,NameExample));
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("Teste Concluido.");
}
}
That's the method code:
private File processRequiredFile(File file, String name) {
if (!file.exists()) {
this.message = name + " file not found at location: " + file;
this.msgResponse.addMsgList(MsgCode.FAILURE, MsgLevel.ERROR, this.message, StringUtils.EMPTY);
}
return file;
}
And thank you all for helping me in my doubts.

To answer your question,
Because you caught the NoSuchMethodException. To get a test failure you have to somehow get some exception or error during the test execution
To follow up on the comments, here's how one can test this method:
// let's assume there are getter for this.message / this.msgResponse
// and this method is in the class foo.bar.Foobar
protected File processRequiredFile(File file, String name) {
if (!file.exists()) {
this.message = name + " file not found at location: " + file;
this.msgResponse.addMsgList(MsgCode.FAILURE, MsgLevel.ERROR, this.message, StringUtils.EMPTY);
}
return file;
}
In a test class foo.bar.FoobarTest:
#Mock
private File file;
private Foobar foobar = new Foobar();
#Test
public void testWithNonExistingFile() {
Mockito.when(this.file.exists()).thenReturn(false); // this is to illustrate, you could also use some non existent file: new File("/does-not-exists.foo")
File result = this.foobar.processRequiredFile(this.file, "some name");
assertThat(result).isEqualTo(this.file);
assertThat(foobar.getMsgResponse()).isNotEmpty(); // TODO: better assertion
assertThat(foobar.getMessage()).isEqualTo( "some name file not found at location: " + this.file);
}
#Test
public void testWithExistingFile() {
Mockito.when(this.file.exists()).thenReturn(true);
File result = this.foobar.processRequiredFile(this.file, "some name");
assertThat(result).isEqualTo(this.file);
assertThat(foobar.getMsgResponse()).isEmpty();
assertThat(foobar.getMessage()).isNull();
}
The class under test (i.e. Foobar) is really tested, this uses a real instance of it and call its method. A mock is used to replace something we don't have (here it's a file to illustrate but it's usually something more complicated)

What is your actual question? Why the testcase succeeds? That's already answered in the comments. You catch the exception and essentially ignore it. If you want to see the stacktrace on STDERR and let the testcase fail, you have to initiate the failing procedure yourself, e.g by calling
throw (AssertionFailedError) new AssertionFailedError("method not found").initCause(e);
This construct looks strange but JUnit 3 (I assume you're using that given your code) doesn't come with an AssertionFailedError with a constructor allowing to pass a cause. This way you see the stacktrace in your IDE as well and will be visible in JUnit-reports created during build processes.
Or is your question why the particular method is not found? One reason can be that someClass.getDeclaredMethod only returns a result if the method is declared in that particular class. If that class has a super class inheriting this method, you have to use the superclass when calling getDeclaredMethod to get the method.
If you don't know what class actually contains a method you have to iterate over all superclasses until reaching the "end":
Class<?> clazz = ProtexManager.class;
while (clazz != null) {
try {
return clazz.getDeclaredMethod("processRequiredFile", File.class);
catch(NoSuchMethodException e) {
clazz = clazz.getSuperClass();
}
}
That code block swallows the NoSuchMethodException but I don't want to do things more complicated than necessary to illustrate the idea.
Another reason why the method is not found might be that the class in question has a method processRequiredFile(java.io.File) and not processRequiredFile(com.blackducksoftware.sdk.codecenter.deeplicense.data.File). Also you later call the method by method.invoke using three parameters (PxManager, File, String) so either your call of getDeclaredMethod is missing parameter classes or your call of invoke will later fail due to the differences between declaration of the method and passed parameters.

JAVA : How to get the name of variable with annotation in Java?

I am trying to get the name of variable in android using java.
The variable has a annotation, and I want to get the variable's name with the annotation's name. is this possible?
just like this,
#getnameofthisfield
private String name;
use getnameofthisfield and get name

You can do it like this:
Class<YourClass> clazz = // somehow get a reference to the class that contains the field
Field[] fields = clazz.getDeclaredFields();
List<String> fieldNames = new LinkedList<>();
for (Field field : fields) {
if (field.isAnnotationPresent(#getnameofthisfield.class)) {
fieldNames.add(field.getName);
}
}
In the end fieldNames will contain the names of all fields, annotated with #getnameofthisfield.

This comes up when you have a Data holder class that is a model for Firebase fields (for example) and the spelling of the member names must exactly equal the Strings in the Firebase tree. While I have not eliminated the duplicate typing/spelling of the Strings/fields, this will at least detect these programming errors at run-time.
public class User {
private String email;
private String name;
// avoid out-of-sync String names of fields in other files
public static String getFieldName(String fieldRequest) {
try {
return User.class.getDeclaredField(fieldRequest).getName();
} catch (NoSuchFieldException e1) {
e1.printStackTrace();
throw new RuntimeException("Unrecognized field in "
+ User.class.getSimpleName() + ", (" + fieldRequest + ")"); }
}
Here is an example usage:
// demonstration of how the getFieldName() protects against mistakes...
String userNameField = User.getFieldName("name"); // this works
String userEmailField = User.getFieldName("userEmail"); // this throws an error

Get annotation value
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
public class Util{
#SuppressWarnings("unchecked")
public static<T> T getAnnotationValue(Class<?> clazz,Class<? extends Annotation> annotationClass,String element) throws Exception {
Annotation annotation = clazz.getAnnotation(annotationClass);
Method method = annotationClass.getMethod(element,(Class[])null);
if (annotation == null)
return((T)method.getDefaultValue());
return((T)method.invoke(annotation,(Object[])null));
}
}

In my understanding that isnt possible, the java compiler doesn't save variable names. What is it that your trying to do with such name?

Dynamically loading method from external class

I am trying to load methods Customer.cypher and Customer.cypherCBC method from my class Configuration. Customer class is rendering from different environments so few environmets are having cypherCBC() and cypher() method and few are having only cypher() method.
Now i want to check if cypherCBC if not there in Customer class then load cypher() method. My function is so far;
try {
Class<?> customerClass = Class.forName("com.myapp.impl.service.Customer");
Object obj = customerClass.newInstance();
//here getting "NoSuchMethodException" exception
Method methodCBC = customerClass.getDeclaredMethod("cypherCBC", String.class); //line - 7
if(methodCBC.getName().equals("cypherCBC")){
methodCBC.invoke(obj, new String(dbshPass));
System.out.println("CYPHER_CBC: "
+ methodCBC.invoke(obj, new String(dbshPass)));
}else{
Method method = customerClass.getDeclaredMethod("cypher", String.class);
method.invoke(obj, new String(dbshPass));
System.out.println("CYPHER: " + method.invoke(obj, new String(dbshPass)));
}
}catch (Exception e){
e.printStackTrace();
}
Getting an error at line 7.
NoSuchMethodException:
com.myapp.impl.service.Customer.cypherCBC(java.lang.String)
that means for particular environment class Customer doesn't having cypherCBC() method, but ideally it should come in else part and execute cypher() method.
Class<?> client = null;
Object obj = null;
try{
client = Class.forName("com.myapp.impl.service.Client");
obj = client.newInstance();
}catch (InstantiationException ex) {
System.err.println("Not able to create Instance of Class");
} catch (IllegalAccessException ex) {
System.err.println("Not able to access Class");
} catch (ClassNotFoundException ex) {
System.err.println("Not able to find Class");
}
try {
Method methodCBC = client.getDeclaredMethod("cypherCBC", String.class);
System.out.println("CYPHER_CBC: " + methodCBC.invoke(obj, new String(dbshPass)));
}catch (NoSuchMethodException ex) {
System.err.println("Not able to find Method on class");
ex.printStackTrace();
} catch (Exception e){
e.printStackTrace();
}

That is exactly what is to be expected: getDeclaredMethod() throws that exception when no method exists that meets your specification. And you are wondering that it throws an exception if the required method is missing? Hint: better read the javadoc next time. Don't assume that something does something, but verify your assumptions!
Besides: read your code again. What is it doing? You are asking "give me the method named 'foo'". And then, your next step is to ask that method "is your name 'foo'". So even without reading javadoc, it should become clear that your logic is flawed.
As solution, you can implement a non-throwing lookup yourself, like
private Method lookupCypher(Class<?> client, String methodName) {
for (Method declaredMethod : client.getDeclardMethods()) {
if (declaredMethod.getName().equals(methodName)) {
Class<?>[] parameterTypes = declaredMethod.getParameterTypes();
if (parameterTypes.length == 1 && parameterTypes[0].equals(String.class)) {
// so declaredMethod has the given name, and takes one string as argument!
return declaredMethod;
}
}
// our search didn't reveal any matching method!
return null;
}
Using that helper method, you can rewrite your code to:
Method toInvoke = lookupCypher(client, "cypherCBC");
if (toInvoke == null) {
toInvoke = lookupCypher(client, "cypher");
}
toInvoke(obj, new String ...
Or, with the idea from hunter in mind; a much more "OO like" version:
interface CustomerCypherWrapper {
void cypher(String phrase);
}
class NewCustomerWrapper() implements CustomerCypherWrapper {
#Override
void cypher(String phrase) {
new Customer.cypherCBC(phrase);
}
}
class oldCustomerWrapper() implements CustomerCypherWrapper {
#Override
void cypher(String phrase) {
new Customer.cypher(phrase);
}
}
And your client code boils down to:
CustomerCypherWrapper wrapper =
(lookupCypher(..., "cypherCBC") == null)
? new NewCustomerWrapper()
: new OldCustomerWrapper();
wrapper.cypher();
[ I hope you notice that my version A) is easier to read and B) doesn't contain any duplicated code any more. ]
And yes, an alternative implementation of the lookup method could just go like
private Method lookupCyper(Client<?>, String methodName) {
try {
return client.getDeclaredMethod(methodName, String.class);
} catch ....
and return null;
}
... return your public cypherCBC method
But that is an "uncommon practice" in Java. In Java, we ask for permission; instead of forgiveness. Unlike other languages

if you compile the application with a Customer class which has both method,you can use reflection once to check whether the cypherCBC method available or not at runtime, then you can keep that status, you can call the method without using reflection
if(newVersion)
{
customer.cypherCBC(arg);
}
else
{
customer.cypher(arg);
}
But to write a better application,you should use two version baselines.
even though this is a small code fragment you should setup a another module to hide this Customer class and its interactions,that module should have two versions. but your main module has only single version.Now when you you deliver the application , product should be packaged with right version baseline based on compatibility for the target environment.

Although reflection works (as explained in the other answers). if you have control over the Customer class, you can try a non-reflection approach.
interface CBCCypherable {
public String cypherCBC(String pass);
}
You can now have two versions of Customer class, one that implements CBCCypherable and one that doesn't. And when you call it, it looks like this:
Customer c = new Customer();
if (c instanceof CBCCypherable) {
((CBCCypherable)c).cypherCBC(pass);
} else {
c.cypher(pass);
}
What you get with this solution is much simpler code, and as a bonus the compiler will check that you use the correct method name and parameter types. Unlike with reflection, where that's all your job, and you have to run the code to find out if something's wrong.
P.s.: I don't know if this is just sample code or you are really encrypting/hashing passwords here, but it's generally considered a bad idea to roll your own security code.

Java Beans, BeanUtils, and the Boolean wrapper class

I'm using BeanUtils to manipulate Java objects created via JAXB, and I've run into an interesting issue. Sometimes, JAXB will create a Java object like this:
public class Bean {
protected Boolean happy;
public Boolean isHappy() {
return happy;
}
public void setHappy(Boolean happy) {
this.happy = happy;
}
}
The following code works just fine:
Bean bean = new Bean();
BeanUtils.setProperty(bean, "happy", true);
However, attempting to get the happy property like so:
Bean bean = new Bean();
BeanUtils.getProperty(bean, "happy");
Results in this exception:
Exception in thread "main" java.lang.NoSuchMethodException: Property 'happy' has no getter method in class 'class Bean'
Changing everything to a primitive boolean allows both the set and get call to work. I don't have this option, however, since these are generated classes. I assume this happens because the Java Bean libraries only consider an is<name> method to represent a property if the return type is a primitive boolean, and not the wrapper type Boolean. Does anyone have a suggestion as to how to access properties like these through BeanUtils? Is there some kind of workaround I can use?

Finally I've found legal confirmation:
8.3.2 Boolean properties
In addition, for boolean properties, we allow a getter method to match the pattern:
public boolean is<PropertyName>();
From JavaBeans specification. Are you sure you haven't came across JAXB-131 bug?

Workaround to handle Boolean isFooBar() case with BeanUtils
Create new BeanIntrospector
private static class BooleanIntrospector implements BeanIntrospector{
#Override
public void introspect(IntrospectionContext icontext) throws IntrospectionException {
for (Method m : icontext.getTargetClass().getMethods()) {
if (m.getName().startsWith("is") && Boolean.class.equals(m.getReturnType())) {
String propertyName = getPropertyName(m);
PropertyDescriptor pd = icontext.getPropertyDescriptor(propertyName);
if (pd == null)
icontext.addPropertyDescriptor(new PropertyDescriptor(propertyName, m, getWriteMethod(icontext.getTargetClass(), propertyName)));
else if (pd.getReadMethod() == null)
pd.setReadMethod(m);
}
}
}
private String getPropertyName(Method m){
return WordUtils.uncapitalize(m.getName().substring(2, m.getName().length()));
}
private Method getWriteMethod(Class<?> clazz, String propertyName){
try {
return clazz.getMethod("get" + WordUtils.capitalize(propertyName));
} catch (NoSuchMethodException e) {
return null;
}
}
}
Register BooleanIntrospector:
BeanUtilsBean.getInstance().getPropertyUtils().addBeanIntrospector(new BooleanIntrospector());

you can just create second getter with SET - sufix as workaround :)

Is there something like PostConstruct for JAXB-annnotated classes?

Is there such a functionality in JAXB to perform operations on a class after it is unmarshalled i.e. after it is constructed by JAXB? If not, how could I achieve this?

You can use JAXB Unmarshal Event Callbacks which are defined in your JAXB class e.g:
// This method is called after all the properties (except IDREF) are unmarshalled for this object,
// but before this object is set to the parent object.
void afterUnmarshal( Unmarshaller u, Object parent )
{
System.out.println( "After unmarshal: " + this.state );
}

Though the the demanded functionality seems not to be present in JAXB, I managed to
achieve something which goes into the right direction:
I'm using JSR-305's #PostConstruct annotation
(it's just a nacked annotation, no functionality is provided by the JSR)
I add an unmasrshaller-listener to the unmarshaller, which gets invoked by JAXB every time an object was unmarshalled.
I inspect this object using Java reflection and search for the #PostConstruct annotation on a method
I execute the method
Tested. Works.
Here is the code. Sorry, I'm using some external reflection API to get all methods, but I think the idea is understandable:
Implementation
JAXBContext context = // create the context with desired classes
Unmarshaller unmarshaller = context.createUnmarshaller();
unmarshaller.setListener(new Unmarshaller.Listener() {
#Override
public void afterUnmarshal(Object object, Object arg1) {
System.out.println("unmarshalling finished on: " + object);
Class<?> type = object.getClass();
Method postConstructMethod = null;
for (Method m : ReflectionUtils.getAllMethods(type)) {
if (m.getAnnotation(PostConstruct.class) != null) {
if (postConstructMethod != null) {
throw new IllegalStateException(
"#PostConstruct used multiple times");
}
postConstructMethod = m;
}
}
if (postConstructMethod != null) {
System.out.println("invoking post construct: "
+ postConstructMethod.getName() + "()");
if (!Modifier.isFinal(postConstructMethod.getModifiers())) {
throw new IllegalArgumentException("post construct method ["
+ postConstructMethod.getName() + "] must be final");
}
try {
postConstructMethod.setAccessible(true); // thanks to skaffman
postConstructMethod.invoke(object);
} catch (IllegalAccessException ex) {
throw new RuntimeException(ex);
} catch (InvocationTargetException ex) {
throw new RuntimeException(ex);
}
}
}
});
EDIT
Added a check for #PostConstruct-annotated method, to ensure it is final.
Do you think it's a useful restriction?
Usage
Here is how the concept might be used.
#XmlAccessorType(XmlAccessType.NONE)
public abstract class AbstractKeywordWithProps
extends KeywordCommand {
#XmlAnyElement
protected final List<Element> allElements = new LinkedList<Element>();
public AbstractKeywordWithProps() {
}
#PostConstruct
public final void postConstruct() {
// now, that "allElements" were successfully initialized,
// do something very important with them ;)
}
}
// further classes can be derived from this one. postConstruct still works!
Filed a feature request
https://jaxb.dev.java.net/issues/show_bug.cgi?id=698

It's not a 100% solution, but you can always register a XmlAdapter using #XmlJavaTypeAdapter annotation
for this type.
The downside would be that you have to serialize the class yourself (?). I am not aware of any simple way of accessing and calling the default serialization mechanism. But with custom [XmlAdapter] you can control how is the type serialized and what happens before/after it.