JSON to Java Converter

import json
from dataclasses import dataclass, field
from typing import List, Optional

# Manual POJO equivalent: Python dataclass
@dataclass
class Address:
    street: str = ""
    city: str = ""
    zip: str = ""

@dataclass
class User:
    id: int = 0
    name: str = ""
    email: str = ""
    is_active: bool = True
    score: float = 0.0
    address: Optional[Address] = None
    tags: List[str] = field(default_factory=list)

# Deserialize JSON to Python object
json_str = '''{"id": 1, "name": "Alice", "email": "alice@example.com",
               "is_active": true, "score": 9.5,
               "address": {"street": "123 Main St", "city": "Springfield"},
               "tags": ["admin"]}'''
data = json.loads(json_str)
user = User(**{k: v for k, v in data.items() if k != "address"})
if "address" in data:
    user.address = Address(**data["address"])
print(user.name, user.address.city)