Complex version of AttributeEncryptionListener (support nested objects with attributes + decrypting in memory objects back)

gistfile1.java

@Component
public class AttributeEncryptionListener extends AbstractMongoEventListener {

    /**
     *  This method called first before object persistence. It encrypts all the attributes of password type
     */
    @Override
    public void onBeforeConvert(Object source) {
        super.onBeforeConvert(source);
        passwordsPersistenceCare(source, true);
    }

    /**
     * Once the data encrypted and saved to the disk we would like to use the passwords in our code => so they mast be
     * in plane text while we have them in memory
     */
    @Override
    public void onAfterSave(Object source, DBObject dbo) {
        super.onAfterSave(source, dbo);
        passwordsPersistenceCare(source, false);
    }

    private void passwordsPersistenceCare(Object source, boolean shouldEncrypt) {
        Field[] declaredFields = source.getClass().getDeclaredFields();
        if (declaredFields.length == 0) {
            declaredFields = source.getClass().getSuperclass().getDeclaredFields();
        }
        for (Field field : declaredFields) {
            if (Collection.class.isAssignableFrom(field.getType())) {
                if (((ParameterizedType) field.getGenericType()).getActualTypeArguments()[0].toString().endsWith(Attribute.class.getName())) {
                    try {
                        field.setAccessible(true);
                        Collection<Attribute> attrs = (Collection<Attribute>) field.get(source);
                        for (Attribute attr : attrs) {
                            if (!AttributeUtils.isEmpty(attr) && AttributeType.PASSWORD.equals(attr.getAttributeType())) {
                                if (shouldEncrypt) {
                                    // in case the same object referenced more than once by different objects it will come here and try to encrypt it again
                                    // encrypted string always ends with  "==\r\n", Same logic works for decryption
                                    if(attr.getValue().toString().endsWith("==\r\n")) {
                                        continue;
                                    }
                                    attr.setValue(EncryptionUtils.AESEncrypt(attr.getValue().toString()));
                                } else {
                                    if(!attr.getValue().toString().endsWith("==\r\n")) {
                                        continue;
                                    }
                                    attr.setValue(EncryptionUtils.AESDecrypt(attr.getValue().toString()));
                                }
                            }
                        }
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    }
                }
            } else if (Context.class.isAssignableFrom(field.getType()) || BaseModel.class.isAssignableFrom(field.getType())) {
                try {
                    field.setAccessible(true);
                    if (field.get(source) != null) {
                        passwordsPersistenceCare(field.get(source), shouldEncrypt);
                    }
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                }
            } else if (Map.class.isAssignableFrom(field.getType())) {
                try {
                    field.setAccessible(true);
                    if (field.get(source) != null) {
                        Map tmpMap = (Map) field.get(source);
                        for (Object key : tmpMap.keySet()) {
                            if(tmpMap.get(key) != null && BaseModel.class.isAssignableFrom(tmpMap.get(key).getClass())){
                                passwordsPersistenceCare(tmpMap.get(key), shouldEncrypt);
                            }
                        }
                    }
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                }

            }
        }
    }

    @Override
    public void onAfterConvert(DBObject dbo, Object source) {
        super.onAfterConvert(dbo, source);
        passwordsPersistenceCare(source, false);
    }
}