ReflectUtil.java 7.68 KB
package com.infoloop.tianting.utils;

import cn.hutool.core.convert.Convert;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.Date;

/**
 * 反射工具类. 提供调用getter/setter方法, 访问私有变量, 调用私有方法, 获取泛型类型Class, 被AOP过的真实类等工具函数.
 */
@Slf4j
public class ReflectUtil {
    private static final String SETTER_PREFIX = "set";

    private static final String GETTER_PREFIX = "get";

    /**
     * 调用Setter方法, 仅匹配方法名。
     * 支持多级,如:对象名.对象名.方法
     */
    public static <E> void invokeSetter(Object obj, String propertyName, E value) {
        Object object = obj;
        String[] names = StringUtils.split(propertyName, ".");
        for (int i = 0; i < names.length; i++) {
            if (i < names.length - 1) {
                String getterMethodName = GETTER_PREFIX + StringUtils.capitalize(names[i]);
                object = invokeMethod(object, getterMethodName, new Class[]{}, new Object[]{});
            } else {
                String setterMethodName = SETTER_PREFIX + StringUtils.capitalize(names[i]);
                invokeMethodByName(object, setterMethodName, new Object[]{value});
            }
        }
    }

    /**
     * 直接调用对象方法, 无视private/protected修饰符.
     * 用于一次性调用的情况,否则应使用getAccessibleMethod()函数获得Method后反复调用.
     * 同时匹配方法名+参数类型,
     */
    @SuppressWarnings("unchecked")
    public static <E> E invokeMethod(final Object obj, final String methodName, final Class<?>[] parameterTypes,
                                     final Object[] args) {
        if (obj == null || methodName == null) {
            return null;
        }
        Method method = getAccessibleMethod(obj, methodName, parameterTypes);
        if (method == null) {
            log.debug("在 [" + obj.getClass() + "] 中,没有找到 [" + methodName + "] 方法 ");
            return null;
        }
        try {
            return (E) method.invoke(obj, args);
        } catch (Exception e) {
            String msg = "method: " + method + ", obj: " + obj + ", args: " + Arrays.toString(args);
            throw convertReflectionExceptionToUnchecked(msg, e);
        }
    }

    /**
     * 直接调用对象方法, 无视private/protected修饰符,
     * 用于一次性调用的情况,否则应使用getAccessibleMethodByName()函数获得Method后反复调用.
     * 只匹配函数名,如果有多个同名函数调用第一个。
     */
    public static void invokeMethodByName(final Object obj, final String methodName, final Object[] args) {
        Method method = getAccessibleMethodByName(obj, methodName, args.length);
        if (method == null) {
            log.debug("在 [" + obj.getClass() + "] 中,没有找到 [" + methodName + "] 方法 ");
            return;
        }
        try {
            // 类型转换(将参数数据类型转换为目标方法参数类型)
            Class<?>[] cs = method.getParameterTypes();
            for (int i = 0; i < cs.length; i++) {
                if (args[i] != null && !args[i].getClass().equals(cs[i])) {
                    if (cs[i] == String.class) {
                        args[i] = Convert.toStr(args[i]);
                        if (StringUtils.endsWith((String) args[i], ".0")) {
                            args[i] = StringUtils.substringBefore((String) args[i], ".0");
                        }
                    } else if (cs[i] == Integer.class) {
                        args[i] = Convert.toInt(args[i]);
                    } else if (cs[i] == Long.class) {
                        args[i] = Convert.toLong(args[i]);
                    } else if (cs[i] == Double.class) {
                        args[i] = Convert.toDouble(args[i]);
                    } else if (cs[i] == Float.class) {
                        args[i] = Convert.toFloat(args[i]);
                    } else if (cs[i] == Date.class) {
                        if (args[i] instanceof String) {
                            args[i] = DateUtil.parseDate(args[i]);
                        } else {
                            args[i] = org.apache.poi.ss.usermodel.DateUtil.getJavaDate((Double) args[i]);
                        }
                    } else if (cs[i] == boolean.class || cs[i] == Boolean.class) {
                        args[i] = Convert.toBool(args[i]);
                    }
                }
            }
            method.invoke(obj, args);
        } catch (Exception e) {
            String msg = "method: " + method + ", obj: " + obj + ", args: " + Arrays.toString(args);
            throw convertReflectionExceptionToUnchecked(msg, e);
        }
    }

    /**
     * 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问.
     * 如向上转型到Object仍无法找到, 返回null.
     * 匹配函数名+参数类型。
     * 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
     */
    public static Method getAccessibleMethod(final Object obj, final String methodName,
                                             final Class<?>... parameterTypes) {
        if (obj == null) {
            return null;
        }
        Validate.notBlank(methodName, "methodName can't be blank");
        for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
            try {
                Method method = searchType.getDeclaredMethod(methodName, parameterTypes);
                makeAccessible(method);
                return method;
            } catch (NoSuchMethodException e) {
            }
        }
        return null;
    }

    /**
     * 循环向上转型, 获取对象的DeclaredMethod,并强制设置为可访问.
     * 如向上转型到Object仍无法找到, 返回null.
     * 只匹配函数名。
     * 用于方法需要被多次调用的情况. 先使用本函数先取得Method,然后调用Method.invoke(Object obj, Object... args)
     */
    public static Method getAccessibleMethodByName(final Object obj, final String methodName, int argsNum) {
        if (obj == null) {
            return null;
        }
        Validate.notBlank(methodName, "methodName can't be blank");
        for (Class<?> searchType = obj.getClass(); searchType != Object.class; searchType = searchType.getSuperclass()) {
            Method[] methods = searchType.getDeclaredMethods();
            for (Method method : methods) {
                if (method.getName().equals(methodName) && method.getParameterTypes().length == argsNum) {
                    makeAccessible(method);
                    return method;
                }
            }
        }
        return null;
    }

    public static void makeAccessible(Method method) {
        if ((!Modifier.isPublic(method.getModifiers()) || !Modifier.isPublic(method.getDeclaringClass().getModifiers())) && !method.canAccess(method)) {
            method.setAccessible(true);
        }
    }

    public static RuntimeException convertReflectionExceptionToUnchecked(String msg, Exception e) {
        if (e instanceof IllegalAccessException || e instanceof IllegalArgumentException || e instanceof NoSuchMethodException) {
            return new IllegalArgumentException(msg, e);
        } else if (e instanceof InvocationTargetException) {
            return new RuntimeException(msg, ((InvocationTargetException) e).getTargetException());
        }
        return new RuntimeException(msg, e);
    }
}