Java_通过反射调用类中的方法

Posted 2020-07-11 GisClub

先上一个基本的封装：

 /**
     * 获取classType
     *
     * @param type
     * @param provinceCode
     * @param cityCode
     * @return
     * @throws Exception
     */
    public Class<?> getClassType(String type, String provinceCode, String cityCode, String suffix) throws Exception {
        Class<?> classType = Class.forName("com.lkb.sb." + type + "." + provinceCode + "." + cityCode + suffix);
        return classType;
    }

    /**
     * 获取base
     *
     * @param className
     * @return
     * @throws Exception
     */
    public Class<?> getClassType(String className) throws Exception {
        Class<?> classType = Class.forName(className);
        return classType;
    }

    /**
     * @param classType
     * @return
     * @throws Exception
     */
    public Object getClassInstance(Class<?> classType) throws Exception {
        return getClassInstance(classType, null, null);
    }

    /**
     * 获取对象client
     *
     * @param classType
     * @param classes
     * @param objects
     * @return
     * @throws Exception
     */
    public Object getClassInstance(Class<?> classType, Class[] classes, Object[] objects) throws Exception {
        Object client = classType.getConstructor(classes).newInstance(objects);
        return client;
    }

    /**
     * 执行不带参数的方法
     *
     * @param classType
     * @param instance
     * @param method
     * @return
     * @throws Exception
     */
    public Object implementMethod(Class<?> classType, Object instance, String method) throws Exception {
        return implementMethod(classType, instance, method, null, null);
    }

    /**
     * 执行方法
     *
     * @param classType
     * @param instance
     * @param method
     * @param paramTypes
     * @param params
     * @return
     * @throws Exception
     */
    public Object implementMethod(Class<?> classType, Object instance, String method, Class[] paramTypes, Object[] params) throws Exception {
        Method getStrMethod;
        Object result;
        if (paramTypes == null) {
            getStrMethod = classType.getMethod(method);
            result = getStrMethod.invoke(instance);
        } else {
            getStrMethod = classType.getMethod(method, paramTypes);
            result = getStrMethod.invoke(instance, params);
        }
        return result;
    }

 

 

进一步封装，通过实现接口的形式调用，这样就省略了每次反射方法时还要写上参数类型数组：

package com.lkb.autoCode.util;

import com.lkb.autoCode.constant.AutoCodeConstant;

import java.lang.reflect.Method;

/**
 * DefultClassLoader 默认的类加载器
 *
 * @author Lilin
 * @date 2016/5/24
 */
public class DefultClassLoader<T> {

    private Class<?> classType = null;
    private T reflectClass = null;

    /**
     * @param fullClassName 全包路径
     * @throws Exception
     */
    public DefultClassLoader(String fullClassName) throws Exception {
        classType = getClassType(fullClassName);
    }

    /**
     * @param type         模板类型
     * @param provinceCode 省Id
     * @param cityCode     市Id
     * @param className    类名称
     * @throws Exception
     */
    public DefultClassLoader(String type, String provinceCode, String cityCode, String className) throws Exception {
        classType = getClassType(type, provinceCode, cityCode, className);
    }


    /**
     * 获取classType
     *
     * @param type
     * @param provinceCode
     * @param cityCode
     * @return
     * @throws Exception
     */
    public Class<?> getClassType(String type, String provinceCode, String cityCode, String suffix) throws Exception {
        Class<?> classType = Class.forName(AutoCodeConstant.BASE_SB_PACKAGE + "." + type + "." + provinceCode + "." + cityCode + suffix);
        return classType;
    }

    /**
     * 获取base
     *
     * @param fullClassName
     * @return
     * @throws Exception
     */
    public Class<?> getClassType(String fullClassName) throws Exception {
        Class<?> classType = Class.forName(fullClassName);
        return classType;
    }

    /**
     * 获取对象client
     * @return
     * @throws Exception
     */
    public T getClassInstance() throws Exception {
        return getClassInstance(null, null);
    }

    /**
     * 获取对象client
     *
     * @param classes
     * @param objects
     * @return
     * @throws Exception
     */
    public T getClassInstance(Class[] classes, Object[] objects) throws Exception {
        T client = (T) classType.getConstructor(classes).newInstance(objects);
        return client;
    }

    /**
     * 执行不带参数的方法(忽略)
     *
     * @param classType
     * @param instance
     * @param method
     * @return
     * @throws Exception
     */
    public Object implementMethod(Class<?> classType, Object instance, String method) throws Exception {
        return implementMethod(classType, instance, method, null, null);
    }

    /**
     * 执行方法（忽略）
     *
     * @param classType
     * @param instance
     * @param method
     * @param paramTypes
     * @param params
     * @return
     * @throws Exception
     */
    public Object implementMethod(Class<?> classType, Object instance, String method, Class[] paramTypes, Object[] params) throws Exception {
        Method getStrMethod;
        Object result;
        if (paramTypes == null) {
            getStrMethod = classType.getMethod(method);
            result = getStrMethod.invoke(instance);
        } else {
            getStrMethod = classType.getMethod(method, paramTypes);
            result = getStrMethod.invoke(instance, params);
        }
        return result;
    }
}

 

 

路漫漫其修远兮！！！

 

缺点：构造器的创建还得传递参数类型数组