反射的基本知识

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读取配置文件

Properties properties = new Properties();FileReader reader = new FileReader("src/class.txt");properties.load(reader);reader.close();String methodName = properties.getProperty("methodName");String className = properties.getProperty("className");System.out.println(methodName);System.out.println(className);

下面是反射的基本步骤：

Class c = Class.forName(className);Constructor constructor = c.getConstructor();Method method = c.getMethod(methodName,null);Object o = constructor.newInstance();method.invoke(o);

接下来我们写一个工具类来设置对象。

public class ReflectTool {    public static void setProperties(Object obj,String propertyName,Object value) throws NoSuchFieldException, IllegalAccessException {        // 根据对象获取字节码文件对象        Class c = obj.getClass();        // 获取该对象的propertyName成员变量        Field field = c.getDeclaredField(propertyName);        // 取消访问检查        field.setAccessible(true);        // 给对象的成员变量赋值为指定的值        field.set(obj, value);    }}

测试：

class Dog{    private String name;    private Integer age;    public String getName() {        return name;    }    public Integer getAge() {        return age;    }}public class Main {    public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException {        Dog dog = new Dog();        ReflectTool.setProperties(dog,"name","哈巴狗");        ReflectTool.setProperties(dog,"age",12);        System.out.println(dog.getName());        System.out.println(dog.getAge());    }}

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