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Improved version of the DBus-Java library provided by freedesktop.org (https://dbus.freedesktop.org/doc/dbus-java/).
package org.freedesktop.dbus;
import org.freedesktop.dbus.annotations.Position;
import org.freedesktop.dbus.types.DBusStructType;
import org.freedesktop.dbus.types.Variant;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.*;
/**
* Helper util to create {@link Struct} subclasses when receiving it from DBus.
*
* @author David M.
* @since v3.2.1 - 2019-10-25
*/
public final class StructHelper {
private StructHelper() {
}
/**
* Creates a {@link ArrayList} of struct of the given type using the list of object arrays.
*
* @param _obj list of object arrays to process
* @param _structType struct class to create
*
* @param struct type
*
* @return List of given struct type
*
* @throws NoSuchMethodException when no constructor can be found for the arguments of the struct
* @throws SecurityException when constructor cannot be accesses
* @throws InstantiationException when reflection fails
* @throws IllegalAccessException if this Constructor object is enforcing Java language access control and the underlying constructor is inaccessible.
* @throws IllegalArgumentException when data types are incompatible or incompatible argument length
* @throws InvocationTargetException if the underlying constructor throws an exception
*
* @since 4.3.1 - 2023-08-16
*/
public static List convertToStructList(List _obj, Class _structType) throws NoSuchMethodException, SecurityException, InstantiationException,
IllegalAccessException, IllegalArgumentException, InvocationTargetException {
List result = new ArrayList<>();
convertToStructCollection(_obj, _structType, result);
return result;
}
/**
* Creates a {@link LinkedHashSet} of struct of the given type using the list of object arrays.
*
* @param _obj list of object arrays to process
* @param _structType struct class to create
*
* @param struct type
*
* @return List of given struct type
*
* @throws NoSuchMethodException when no constructor can be found for the arguments of the struct
* @throws SecurityException when constructor cannot be accesses
* @throws InstantiationException when reflection fails
* @throws IllegalAccessException if this Constructor object is enforcing Java language access control and the underlying constructor is inaccessible.
* @throws IllegalArgumentException when data types are incompatible or incompatible argument length
* @throws InvocationTargetException if the underlying constructor throws an exception
*
* @since 4.3.1 - 2023-08-16
*/
public static Set convertToStructSet(Set _obj, Class _structType) throws NoSuchMethodException, SecurityException, InstantiationException,
IllegalAccessException, IllegalArgumentException, InvocationTargetException {
Set result = new LinkedHashSet<>();
convertToStructCollection(_obj, _structType, result);
return result;
}
/**
* Creates a collection of struct of the given type using the list of object arrays.
*
* @param _input list of object arrays to process
* @param _structType struct class to create
* @param _result collection to store results
*
* @param struct type
*
* @return List of given struct type
*
* @throws NoSuchMethodException when no constructor can be found for the arguments of the struct
* @throws SecurityException when constructor cannot be accesses
* @throws InstantiationException when reflection fails
* @throws IllegalAccessException if this Constructor object is enforcing Java language access control and the underlying constructor is inaccessible.
* @throws IllegalArgumentException when data types are incompatible or incompatible argument length
* @throws InvocationTargetException if the underlying constructor throws an exception
*
* @since 4.3.1 - 2023-08-16
*/
public static void convertToStructCollection(Collection _input, Class _structType, Collection _result)
throws NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
Objects.requireNonNull(_structType, "Struct class required");
Objects.requireNonNull(_result, "Collection for result storage required");
Objects.requireNonNull(_input, "Input data required");
Class[] constructorArgClasses = Arrays.stream(_structType.getDeclaredFields())
.filter(f -> f.isAnnotationPresent(Position.class))
.sorted((f1, f2) -> Integer.compare(f1.getAnnotation(Position.class).value(), f2.getAnnotation(Position.class).value()))
.map(f -> f.getType())
.toArray(Class[]::new);
for (Object[] object : _input) {
if (constructorArgClasses.length != object.length) {
throw new IllegalArgumentException("Struct length does not match argument length");
}
T x = StructHelper.createStruct(constructorArgClasses, (Object) object, _structType);
_result.add(x);
}
}
/**
* Creates a instance of the given {@link Struct} subclass if the given variant is some sort of Struct.
* @param _variant variant to convert
* @param _structClass {@link Struct} subclass to create
*
* @param type of struct
*
* @return instance of _structClass or null if _variant is not Struct compatible or any input parameter is null
*
* @throws NoSuchMethodException when no constructor can be found for the arguments of the struct
* @throws SecurityException when constructor cannot be accesses
* @throws InstantiationException when reflection fails
* @throws IllegalAccessException if this Constructor object is enforcing Java language access control and the underlying constructor is inaccessible.
* @throws IllegalArgumentException when data types are incompatible
* @throws InvocationTargetException if the underlying constructor throws an exception
*/
public static T createStructFromVariant(Variant _variant, Class _structClass)
throws NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
if (_variant == null || _structClass == null) {
return null;
}
if (_variant.getType() instanceof DBusStructType && _variant.getValue() instanceof Object[]) {
Class[] argTypes = Arrays.stream((Object[]) _variant.getValue()).map(a -> a.getClass()).toArray(size -> new Class[size]);
return createStruct(argTypes, _variant.getValue(), _structClass);
}
return null;
}
/**
* Will create a new {@link Struct} subclass instance if possible.
* May replace Wrapper-classes with primitive classes in _constructorArgs if constructor does not match.
*
* @param _constructorArgs argument-classes expected by constructor
* @param _values values passed to the constructor
* @param _classToConstruct {@link Struct} subclass to instantiate
*
* @param type of struct
*
* @return instance of _classToConstruct or null if any input argument is null
*
* @throws NoSuchMethodException when no constructor can be found for the arguments of the struct
* @throws SecurityException when constructor cannot be accesses
* @throws InstantiationException when reflection fails
* @throws IllegalAccessException if this Constructor object is enforcing Java language access control and the underlying constructor is inaccessible.
* @throws IllegalArgumentException when data types are incompatible
* @throws InvocationTargetException if the underlying constructor throws an exception
*/
public static T createStruct(Class[] _constructorArgs, Object _values, Class _classToConstruct)
throws NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
if (_constructorArgs == null || _classToConstruct == null || _values == null) {
return null;
}
try {
Constructor declaredConstructor = _classToConstruct.getDeclaredConstructor(_constructorArgs);
declaredConstructor.setAccessible(true);
if (_values instanceof Object[]) {
return declaredConstructor.newInstance((Object[]) _values);
} else {
return declaredConstructor.newInstance(_values);
}
} catch (NoSuchMethodException | SecurityException _ex) {
for (int i = 0; i < _constructorArgs.length; i++) {
Class class1 = _constructorArgs[i];
if (ArrayFrob.getWrapperToPrimitiveTypes().containsKey(class1)) {
_constructorArgs[i] = ArrayFrob.getWrapperToPrimitiveTypes().get(class1);
return createStruct(_constructorArgs, _values, _classToConstruct);
}
}
}
throw new NoSuchMethodException("Cannot find suitable constructor for arguments " + Arrays.toString(_constructorArgs) + " in class " + _classToConstruct + ".");
}
}