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 * The MIT License (MIT)                                                         *
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package org.aoju.bus.mapper.reflect;

import org.aoju.bus.core.exception.InternalException;
import org.aoju.bus.core.lang.function.XFunction;
import org.apache.ibatis.cache.Cache;
import org.apache.ibatis.cache.decorators.SoftCache;
import org.apache.ibatis.cache.impl.PerpetualCache;
import org.apache.ibatis.mapping.MappedStatement;

import java.beans.Introspector;
import java.lang.invoke.SerializedLambda;
import java.lang.reflect.Method;
import java.util.regex.Pattern;

/**
 * 反射支持
 *
 * @author Kimi Liu
 * @since Java 17+
 */
public class Reflector {

    public static final Cache CLASS_CACHE = new SoftCache(new PerpetualCache("MAPPER_CLASS_CACHE"));

    private static final Pattern GET_PATTERN = Pattern.compile("^get[A-Z].*");
    private static final Pattern IS_PATTERN = Pattern.compile("^is[A-Z].*");

    private Reflector() {

    }

    public static String fnToFieldName(XFunction fn) {
        try {
            Method method = fn.getClass().getDeclaredMethod("writeReplace");
            method.setAccessible(Boolean.TRUE);
            SerializedLambda serializedLambda = (SerializedLambda) method.invoke(fn);
            String getter = serializedLambda.getImplMethodName();
            if (GET_PATTERN.matcher(getter).matches()) {
                getter = getter.substring(3);
            } else if (IS_PATTERN.matcher(getter).matches()) {
                getter = getter.substring(2);
            }
            return Introspector.decapitalize(getter);
        } catch (ReflectiveOperationException e) {
            throw new InternalException(e);
        }
    }

    /**
     * 根据msId获取接口类
     *
     * @param msId 方法
     * @return the class
     */
    public static Class getMapperClass(String msId) {
        if (msId.indexOf(".") == -1) {
            throw new InternalException("当前MappedStatement的id=" + msId + ",不符合MappedStatement的规则!");
        }
        String mapperClassStr = msId.substring(0, msId.lastIndexOf("."));
        // 由于一个接口中的每个方法都会进行下面的操作，因此缓存
        Class mapperClass = (Class) CLASS_CACHE.getObject(mapperClassStr);
        if (mapperClass != null) {
            return mapperClass;
        }
        ClassLoader[] classLoader = getClassLoaders();

        for (ClassLoader cl : classLoader) {
            if (null != cl) {
                try {
                    mapperClass = Class.forName(mapperClassStr, true, cl);
                    if (mapperClass != null) {
                        break;
                    }
                } catch (ClassNotFoundException e) {
                    // we'll ignore this until all class loaders fail to locate the class
                }
            }
        }
        if (mapperClass == null) {
            throw new InternalException("class loaders failed to locate the class " + mapperClassStr);
        }
        CLASS_CACHE.putObject(mapperClassStr, mapperClass);
        return mapperClass;
    }

    private static ClassLoader[] getClassLoaders() {
        return new ClassLoader[]{Thread.currentThread().getContextClassLoader(), Reflector.class.getClassLoader()};
    }

    /**
     * 获取执行的方法名
     *
     * @param ms MappedStatement
     * @return the string
     */
    public static String getMethodName(MappedStatement ms) {
        return getMethodName(ms.getId());
    }

    /**
     * 获取执行的方法名
     *
     * @param msId 方法
     * @return the string
     */
    public static String getMethodName(String msId) {
        return msId.substring(msId.lastIndexOf(".") + 1);
    }

}