反射相关api东西：
Class<? extends Annotation> annType = annotation.annotationType();
if (annType.getName().startsWith("java.")) {
continue;
}
package mainTest;
import test1.Student;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class Main {
public static void main(String[] args) throws ClassNotFoundException, IllegalAccessException, InstantiationException, NoSuchMethodException, InvocationTargetException, NoSuchFieldException {
//获取类型
Class clazz = Class.forName("test1.Student");
//空构造
Student student1 = (Student) clazz.newInstance();//反射方式获取空参构造方法
System.out.println(student1);
Constructor con1 = clazz.getConstructor();
Student student2 = (Student) con1.newInstance();
System.out.println(student2);
//获取有参构造方法
Constructor con2 = clazz.getConstructor(String.class, int.class, String.class);
Student student3 = (Student) con2.newInstance("刘瑞祺", 10, "1001");
System.out.println(student3);
//反射获取私有成员变量并修改
Constructor con3 = clazz.getConstructor(String.class, int.class, String.class);
Student student4 = (Student) con3.newInstance("刘瑞祺", 10, "1001");
Object obj1 = con3.newInstance("刘瑞祺", 10, "1001");
Field name = clazz.getDeclaredField("id");
name.setAccessible(true);
name.set(student4,"1002");
name.set(obj1, "1002");
System.out.println(obj1);
//反射获取公有成员变量并修改
Constructor con4 = clazz.getConstructor(String.class);
Student student5 = (Student) con4.newInstance("12.4");
Field score = clazz.getField("score");
score.set(student5, "99");
System.out.println(student5);
Constructor con5 = clazz.getConstructor(String.class, int.class, String.class, String.class);
Student student6 = (Student) con5.newInstance("liuruiqi", 23, "1001", "23.5");
Field score = clazz.getField("score");
score.set(student6, "100");
System.out.println(student6);
//反射调用成员方法
Constructor con1 = clazz.getConstructor();
Student student7 = (Student) con1.newInstance();
Method m = clazz.getMethod("eat");
m.invoke(student7);
Method m2 = clazz.getMethod("eat", String.class);
m2.invoke(student7, "你");
//调用静态方法
Method m3 = clazz.getMethod("staticMethod");
m3.invoke(null);
//调用私有成员方法
Constructor con3 = clazz.getConstructor();
Object obj2 = con3.newInstance();
Method m4 = clazz.getDeclaredMethod("privateMethod");
m4.setAccessible(true);
m4.invoke(obj2);
//获取所有成员变量
Field[] fields = clazz.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
System.out.println(fields[i]);
}
//获取所有方法
Method[] methods = clazz.getDeclaredMethods();
for (int i = 0; i < methods.length; i++) {
System.out.println(methods[i]);
}
//判断有没有注解
boolean isExist = c.isAnnotationPresent(Decription.class);
if (isExist){
// 从类上获得自定义的注解
Decription d = (Decription) c.getAnnotation(Decription.class);
System.out.println(d.decription() + d.id());
}
// 得到该类及父类中的所有方法
Method[] ms = c.getMethods();
// 遍历所有方法
for (Method m:ms){
// 判断在方法上是否使用了自定的注解
boolean isExistMothed = m.isAnnotationPresent(Decription.class);
if (isExistMothed){
// 从方法上获得自定义的注解
Decription d = m.getAnnotation(Decription.class);
System.out.println(d.decription());
}
}
}
}
public static void main(String[] args) {
B b=new B();
out.println("通过Class.NewInstance()调用私有构造函数:");
b.newInstanceByClassNewInstance();
out.println("通过Constructor.newInstance()调用私有构造函数:");
b.newInstanceByConstructorNewInstance();
}
/*通过Class.NewInstance()创建新的类示例*/
private void newInstanceByClassNewInstance(){
try {/*当前包名为reflect，必须使用全路径*/
A a=(A)Class.forName("reflect.A").newInstance();
} catch (Exception e) {
out.println("通过Class.NewInstance()调用私有构造函数【失败】");
}
}
/*通过Constructor.newInstance()创建新的类示例*/
private void newInstanceByConstructorNewInstance(){
try {/*可以使用相对路径，同一个包中可以不用带包路径*/
Class c=Class.forName("A");
/*以下调用无参的、私有构造函数*/
Constructor c0=c.getDeclaredConstructor();
c0.setAccessible(true);
A a0=(A)c0.newInstance();
/*以下调用带参的、私有构造函数*/
Constructor c1=c.getDeclaredConstructor(new Class[]{int.class,int.class});
c1.setAccessible(true);
A a1=(A)c1.newInstance(new Object[]{5,6});
} catch (Exception e) {
e.printStackTrace();
}
}
Map<String, Object> parameters = converterItemProperties.getParameters();
PropertyDescriptor[] descriptors = ReflectUtils.getBeanSetters(type);
for (PropertyDescriptor descriptor : descriptors) {
String name = descriptor.getName();
Object value = parameters.get(name);
Method method = descriptor.getWriteMethod();
if (method != null) {
try {
method.invoke(converter, value);
} catch (IllegalAccessException e) {
throw new ForestRuntimeException("An error occurred during setting the property " + type.getName() + "." + name, e);
} catch (InvocationTargetException e) {
throw new ForestRuntimeException("An error occurred during setting the property " + type.getName() + "." + name, e);
}
}
}
D:\workspace-idea\home\github\coody-verification
总结：我有一个对象，那么我就能拿到这个对象的一切，最后再遍历的时候，我可以拿到它的注解，然后去到注解里面的值，进行判断！
流式克隆：
cn.hutool.core.util;
ObjectUtil.cloneByStream(ruleExecJSONObject);
遍历map以后都要用这种方式啊，其他的都过时了啊：
aMap.forEach( (k,v)->{System.out.println(k+" "+v);} );
注解没有set方法，如何动态的设置属性值
/**
* 设置注解字段值
*
* @throws SecurityException
* @throws NoSuchFieldException
*/
public static void setAnnotationValue(Annotation annotation, String propertyName, Object value)
throws IllegalArgumentException, IllegalAccessException, NoSuchFieldException, SecurityException {
InvocationHandler invocationHandler = Proxy.getInvocationHandler(annotation);
Field declaredField = invocationHandler.getClass().getDeclaredField("memberValues");
declaredField.setAccessible(true);
Map<String, Object> memberValues = (Map<String, Object>) declaredField.get(invocationHandler);
Object oldValue = memberValues.get(propertyName);
if (oldValue != null) {
value = PropertUtil.parseValue(value, oldValue.getClass());
}
memberValues.put(propertyName, value);
}
获取类的父类的泛型：
//获取
Type genType = clazz.getGenericSuperclass();
Type[] params = ((ParameterizedType) genType).getActualTypeArguments();
//手动创建
Type type1 = new ParameterizedTypeImpl(HashMap.class, new Type[]{String.class, new ParameterizedTypeImpl(List.class, new Type[]{CharSequence.class}, null)}, null);
Assert.assertEquals(type, type1);
利用requestMappingHandlerMapping 和过滤器，能够实现抓取当前请求的方法上的和类的所有东西！包括注解啊！这岂不是挺好的！
@Autowired
private RequestMappingHandlerMapping requestMappingHandlerMapping;
@Autowired
@Qualifier("executorService")
private ExecutorService executorService;
public void saveLog(HttpServletRequest request, HttpServletResponse response) throws Exception {
PatternsRequestCondition prevCondition = null;
HandlerMethod handlerMethod = null;
Map<RequestMappingInfo, HandlerMethod> handlerMethods = requestMappingHandlerMapping.getHandlerMethods();
for (Map.Entry<RequestMappingInfo, HandlerMethod> methodEntry : handlerMethods.entrySet()) {
RequestMappingInfo key = methodEntry.getKey();
HandlerMethod value = methodEntry.getValue();
PatternsRequestCondition patternsCondition = key.getPatternsCondition();
PatternsRequestCondition matchingCondition = patternsCondition.getMatchingCondition(request);
if (matchingCondition == null) {
continue;
}
if (prevCondition == null) {
prevCondition = matchingCondition;
handlerMethod = value;
continue;
}
//prevCondition优先级高
if (prevCondition.compareTo(matchingCondition, request) == 1) {
prevCondition = matchingCondition;
handlerMethod = value;
}
}
if (handlerMethod == null) {
return;
}
saveLog(request, response, handlerMethod);
}
private void saveLog(
HttpServletRequest request,
HttpServletResponse response,
HandlerMethod handlerMethod
) {
//请求参数
Map<String, String[]> parameterMap = request.getParameterMap();
String parameter = JSONObject.toJSONString(parameterMap);
//请求路径
String servletPath = request.getServletPath();
Method method = handlerMethod.getMethod();
//方法名称
String methodName = method.getName();
//类名称
Class<?> beanType = handlerMethod.getBeanType();
Auth classAuth = beanType.getDeclaredAnnotation(Auth.class);
if (classAuth == null) {
return;
}
String name = classAuth.name();
String currentUser = ssoUserService.currentUser();
executorService.execute(() -> {
//功能名称
String functionName = null;
Auth auth = method.getDeclaredAnnotation(Auth.class);
if (auth == null) {
return;
}
functionName = name + ":" + auth.name();
OperaLog operaLog = new OperaLog();
operaLog.setCreateDate(new Date());
operaLog.setModifyDate(operaLog.getCreateDate());
operaLog.setParameter(servletPath);
operaLog.setContent(parameter);
operaLog.setOperation(functionName);
//当前操作人
operaLog.setOperator(currentUser);
operaLog.setIp(getRealIp(request));
operaLogDao.save(operaLog);
});
}
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