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添加反射例子到reflectiontutorial
1 parent 42d06f7 commit 3b7bc78

6 files changed

Lines changed: 158 additions & 17 deletions

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‎src/main/java/cn/byhieg/reflectiontutorial/AnnotationObject.java‎

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package cn.byhieg.reflectiontutorial;
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/**
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* Created by byhieg on 17/1/9.
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* Mail to byhieg@gmail.com
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*/
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@MyAnnotation(name="byhieg",value = "hello world")
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public class AnnotationObject {
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@MyAnnotation(name="field",value = "变量")
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public String field;
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@MyAnnotation(name="method",value = "方法")
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public void doSomeThing(){
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System.out.println("做一些事情");
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}
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public void doOtherThing(@MyAnnotation(name="param",value = "参数") String param){
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}
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}

‎src/main/java/cn/byhieg/reflectiontutorial/ExampleObject.java‎

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@@ -4,12 +4,12 @@
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* Created by shiqifeng on 2017/1/9.
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* Mail byhieg@gmail.com
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*/
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public class ExampleObject extends FatherObject{
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public class ExampleObject extends FatherObject {
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public int age = 30;
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public String name = "byhieg";
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private Integer score = 60;
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public void printName(){
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public void printName() {
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System.out.println(name);
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}
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@@ -37,21 +37,25 @@ public void setScore(Integer score) {
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this.score = score;
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}
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public ExampleObject(){
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public ExampleObject() {
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}
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public ExampleObject(String name){
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public ExampleObject(String name) {
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}
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public ExampleObject(int age,Integer score){
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public ExampleObject(int age, Integer score) {
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}
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@Override
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public void doSomething() {
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super.doSomething();
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}
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@Override
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public void run() {
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System.out.println("run......");
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}
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}

‎src/main/java/cn/byhieg/reflectiontutorial/FatherObject.java‎

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Original file line numberDiff line numberDiff line change
@@ -4,13 +4,10 @@
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* Created by shiqifeng on 2017/1/9.
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* Mail byhieg@gmail.com
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*/
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public class FatherObject implements Runnable{
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public abstract class FatherObject implements Runnable{
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public void run() {
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System.out.println("运行中......");
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}
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protected String father = "";
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public void doSomething(){
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System.out.println("做事情......");
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}

‎src/main/java/cn/byhieg/reflectiontutorial/MyAnnotation.java‎

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package cn.byhieg.reflectiontutorial;
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import java.lang.annotation.ElementType;
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import java.lang.annotation.Retention;
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import java.lang.annotation.RetentionPolicy;
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import java.lang.annotation.Target;
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/**
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* Created by byhieg on 17/1/9.
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* Mail to byhieg@gmail.com
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*/
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@Retention(RetentionPolicy.RUNTIME)
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public @interface MyAnnotation {
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public String name();
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public String value();
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}

‎src/test/java/cn/byhieg/reflectiontutorialtest/AnnotationObjectTest.java‎

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package cn.byhieg.reflectiontutorialtest;
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import cn.byhieg.reflectiontutorial.AnnotationObject;
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import cn.byhieg.reflectiontutorial.MyAnnotation;
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import junit.framework.TestCase;
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import java.lang.annotation.Annotation;
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import java.lang.reflect.Field;
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import java.lang.reflect.Method;
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/**
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* Created by byhieg on 17/1/9.
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* Mail to byhieg@gmail.com
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*/
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public class AnnotationObjectTest extends TestCase {
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public void testAnnotation() throws Exception{
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Class clz = AnnotationObject.class;
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Annotation[] annotationsInClass = clz.getAnnotations();
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for (Annotation annotation : annotationsInClass){
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if (annotation instanceof MyAnnotation){
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MyAnnotation myAnnotation = (MyAnnotation)annotation;
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System.out.println("name: " + myAnnotation.name());
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System.out.println("value:" + myAnnotation.value());
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}
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}
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Method method = clz.getMethod("doSomeThing");
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Annotation[] annotationsInMethod = method.getDeclaredAnnotations();
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for (Annotation annotation : annotationsInMethod){
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if (annotation instanceof MyAnnotation){
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MyAnnotation myAnnotation = (MyAnnotation)annotation;
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System.out.println("name: " + myAnnotation.name());
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System.out.println("value:" + myAnnotation.value());
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}
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}
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Field field = clz.getField("field");
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Annotation[] annotationsInField = field.getDeclaredAnnotations();
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for (Annotation annotation : annotationsInField){
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if (annotation instanceof MyAnnotation){
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MyAnnotation myAnnotation = (MyAnnotation)annotation;
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System.out.println("name: " + myAnnotation.name());
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System.out.println("value:" + myAnnotation.value());
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}
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}
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Method method1 = clz.getMethod("doOtherThing",String.class);
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Annotation[][] annotationInParam = method1.getParameterAnnotations();
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Class[] params = method1.getParameterTypes();
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int i = 0;
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for (Annotation[] annotations: annotationInParam){
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Class para = params[i++];
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for (Annotation annotation : annotations){
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if(annotation instanceof MyAnnotation){
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MyAnnotation myAnnotation = (MyAnnotation) annotation;
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System.out.println("param: " + para.getName());
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System.out.println("name : " + myAnnotation.name());
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System.out.println("value :" + myAnnotation.value());
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}
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}
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}
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}
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}

‎src/test/java/cn/byhieg/reflectiontutorialtest/ExampleObjectTest.java‎

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@@ -16,7 +16,7 @@
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public class ExampleObjectTest extends TestCase {
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public void testReflect()throws Exception{
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Class exampleObjectClass = ExampleObject.class;
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Class exampleObjectClass = Class.forName("cn.byhieg.reflectiontutorial.ExampleObject");
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//得到类的名字
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String fullClassName = exampleObjectClass.getName();
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String simpleClassName = exampleObjectClass.getSimpleName();
@@ -30,6 +30,20 @@ public void testReflect()throws Exception{
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System.out.println("method = "+ method.getName());
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}
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Method method = exampleObjectClass.getMethod("setAge",int.class);
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System.out.println(method.getName());
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for (Class clz : method.getParameterTypes()){
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System.out.println("方法的参数" + clz.getName());
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}
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System.out.println(method.getReturnType().getName());
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System.out.println(method.invoke(exampleObjectClass.newInstance(),1));
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//得到类的关键字
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int modifiers = exampleObjectClass.getMethods()[0].getModifiers();
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System.out.println(Modifier.isPublic(modifiers));
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//得到父类
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Class superClass = exampleObjectClass.getSuperclass();
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System.out.println(superClass.getSimpleName());
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System.out.println("父类是不是抽象类 " + Modifier.isAbstract(superClass.getModifiers()));
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Field field2 = superClass.getDeclaredField("father");
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System.out.println(field2.getName());
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//得到接口
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Class[] classes = superClass.getInterfaces();
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System.out.println("父类的接口" + classes[0]);
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//构造器
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Constructor[] constructors = exampleObjectClass.getConstructors();
54-
for (Constructor constructor : constructors){
55-
System.out.println(constructor.toString());
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for (int i = 0;i < constructors.length;i++){
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Class[] parameterTypes = constructors[i].getParameterTypes();
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System.out.println("构造器参数如下========================");
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for (Class clz : parameterTypes){
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System.out.println("参数类型 " + clz.toString());
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}
5676
}
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//得到构造器的参数类型
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Constructor constructor = exampleObjectClass.getConstructor(int.class,Integer.class);
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System.out.println(constructor.getParameterTypes()[0].toString());
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System.out.println(constructor.toString());
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Constructor constructor1 = exampleObjectClass.getConstructor(String.class);
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System.out.println(constructor1.newInstance("byhieg"));
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//得到变量
5987
Field[] fields = exampleObjectClass.getFields();
6088
for (Field field : fields){
61-
System.out.println(field.toString());
89+
System.out.println("变量为： " + field.getName());
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}
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Field field1 = exampleObjectClass.getField("age");
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System.out.println("变量为:" + field1.toString());
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ExampleObject object = ((ExampleObject) constructor1.newInstance("byhieg"));
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System.out.println("原先的age是 " + object.age);
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field1.set(object,10);
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System.out.println("更改之后的age是" + object.age);
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//得到注解
65-
Annotation[] annotations = exampleObjectClass.getMethod("doSomething").getAnnotations();
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Annotation[] annotations = exampleObjectClass.getAnnotations();
66101
for (Annotation annotation : annotations){
67102
System.out.println(annotation.toString());
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}

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