How to merge two complex objects in java

Question

I have two java objects and I want to merge them into single object. Problem is the two objects does not contain plain primitive type properties(fields) they contain complex

Answer 1

try this

public  T objectMerge(T local, T remote, boolean toappend) throws Exception {
    Class clazz = local.getClass();
    Object merged = clazz.newInstance();
    for (Field field : clazz.getDeclaredFields()) {
        field.setAccessible(true);
        Object localValue = field.get(local);
        Object remoteValue = field.get(remote);
        if (localValue != null) {
            String key = "";
            if (localValue.getClass().getSimpleName().toLowerCase().contains("map")) {
                key = "map";
            } else if (localValue.getClass().getSimpleName().toLowerCase().contains("set")) {
                key = "set";
            } else if (localValue.getClass().getSimpleName().toLowerCase().contains("list")) {
                key = "list";
            } else {
                key = localValue.getClass().getSimpleName();
            }
            switch (key) {
                case "Default":
                case "Detail":
                case "String":
                case "Date":
                case "Integer":
                case "Float":
                case "Long":
                case "Double":
                case "Object":
                    field.set(merged, (remoteValue != null) ? remoteValue : localValue);
                    break;
                case "map":
                    if (toappend) {
                        ((Map) localValue).putAll((Map) remoteValue);
                    } else {
                        localValue = (remoteValue != null) ? remoteValue : localValue;
                    }
                    field.set(merged, localValue);
                    break;
                case "list":
                    if (toappend) {
                        ((List) localValue).addAll((List) remoteValue);
                    } else {
                        localValue = (remoteValue != null) ? remoteValue : localValue;
                    }
                    field.set(merged, localValue);
                    break;
                case "set":
                    if (toappend) {
                        ((Set) localValue).addAll((Set) remoteValue);
                    } else {
                        localValue = (remoteValue != null) ? remoteValue : localValue;
                    }
                    field.set(merged, localValue);
                    break;
                default:
                    field.set(merged, this.objectMerge(localValue, remoteValue, toappend));
                    break;
            }
        }
    }
    return (T) merged;
}