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@strongant

strongant/get-class-method-param-field.java

Created August 28, 2024 02:08
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classgraph get class info
Raw
get-class-method-param-field.java
try (ScanResult scanResult = new ClassGraph().enableAllInfo().acceptPackages("com.xyz")
.scan()) {
ClassInfo form = scanResult.getClassInfo("com.xyz.Form");
if (form != null) {
MethodInfoList formMethods = form.getMethodInfo();
for (MethodInfo mi : formMethods) {
String methodName = mi.getName();
MethodParameterInfo[] mpi = mi.getParameterInfo();
for (int i = 0; i < mpi.length; i++) {
String parameterName = mpi[i].getName();
TypeSignature parameterType =
mpi[i].getTypeSignatureOrTypeDescriptor();
// ...
}
}
FieldInfoList formFields = form.getFieldInfo();
for (FieldInfo fi : formFields) {
String fieldName = fi.getName();
TypeSignature fieldType = fi.getTypeSignatureOrTypeDescriptor();
// ...
}
AnnotationInfoList formAnnotations = form.getAnnotationInfo();
for (AnnotationInfo ai : formAnnotations) {
String annotationName = ai.getName();
List<AnnotationParameterValue> annotationParamVals =
ai.getParameterValues();
// ...
}
}
}
@strongant
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strongant commented Aug 28, 2024 

public class TestReadingTypeArgs {
    static class A<X> {
    }

    static abstract class B {
        abstract A<Integer> a();
    }

    public static void main(String[] args) {
        try (ScanResult scanResult = new ClassGraph()
                .acceptPackages(TestReadingTypeArgs.class.getPackage().getName())
                .enableAllInfo().scan()) {
            ClassInfo bClass = scanResult.getClassInfo(B.class.getName());
            MethodInfo aMethodInfo = bClass.getMethodInfo("a").get(0);
            MethodTypeSignature aType = aMethodInfo.getTypeSignatureOrTypeDescriptor();
            TypeSignature aResultType = aType.getResultType();
            ClassRefTypeSignature aResultTypeConcrete = (ClassRefTypeSignature) aResultType;
            String aTypeBaseClassName = aResultTypeConcrete.getBaseClassName();
            List<TypeArgument> aTypeArgs = aResultTypeConcrete.getTypeArguments();
            TypeArgument aTypeArg0 = aTypeArgs.get(0);
            String aTypeArg0BaseClassName =
                    ((ClassRefTypeSignature) aTypeArg0.getTypeSignature()).getBaseClassName();
            System.out.println("Method a() returns type " + aTypeBaseClassName
                    + " with argument " + aTypeArg0BaseClassName);
        }
    }
}

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