import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.ConcurrentHashMap;
import java.util.Map;

/**
 * 基于文件路径的XML转JavaBean工具类
 * 支持缓存机制和完整的异常处理
 */
public class FilePathJaxbUtil {

    private static final Map<Class<?>, JAXBContext> CONTEXT_CACHE = new ConcurrentHashMap<>();

    /**
     * 从XML文件路径直接转换为JavaBean对象
     */
    public static <T> T xmlFileToObject(String filePath, Class<T> clazz) {
        try {
            // 读取XML文件内容
            String xmlContent = readXmlFile(filePath);

            // 使用JAXB进行反序列化
            JAXBContext context = getJAXBContext(clazz);
            Unmarshaller unmarshaller = context.createUnmarshaller();

            return clazz.cast(unmarshaller.unmarshal(new StringReader(xmlContent)));

        } catch (JAXBException e) {
            throw new RuntimeException("XML文件转换JavaBean失败，文件路径：" + filePath, e);
        }
    }
    /**
     * 读取XML文件内容
     */
    private static String readXmlFile(String filePath) {
        StringBuilder content = new StringBuilder();
        try (
//                BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(filePath), StandardCharsets.UTF_8))) {
                BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(filePath), "GB2312"))) {

            String line;
            while ((line = reader.readLine()) != null) {
                content.append(line).append("\n");
            }
            return content.toString();

        } catch (IOException e) {
            throw new RuntimeException("读取XML文件失败，文件路径：" + filePath, e);
        }
    }

    /**
     * 将JavaBean对象保存为XML文件
     */
    public static void objectToXmlFile(Object object, String filePath) {
        try {
            JAXBContext context = getJAXBContext(object.getClass());
            Marshaller marshaller = context.createMarshaller();
            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
            marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");

            try (FileWriter writer = new FileWriter(filePath)) {
                marshaller.marshal(object, writer);
            }

        } catch (JAXBException | IOException e) {
            throw new RuntimeException("JavaBean保存为XML文件失败，文件路径：" + filePath, e);
        }
    }

    /**
     * 获取或创建JAXBContext实例（带缓存）
     */
    private static JAXBContext getJAXBContext(Class<?> clazz) throws JAXBException {
        return CONTEXT_CACHE.computeIfAbsent(clazz, key -> {
            try {
                return JAXBContext.newInstance(key);
            } catch (JAXBException e) {
                throw new RuntimeException("创建JAXBContext失败，类：" + clazz.getName(), e);
            }
        });
    }

    /**
     * 清空缓存（用于热部署等场景）
     */
    public static void clearCache() {
        CONTEXT_CACHE.clear();
    }
}