Java开发 反射使用记录

前言

　　记录一些反射使用情况

 

使用反射判断一个类的是否继承指定接口类

接口类

public interface DemoService {

    void run();
}

实现类

public class DemoImport implements DemoService{
    @Override
    public void run() {
        Log.e("调试_临时_log", "this_run");
    }
}

判断代码

    private void hasInterfaces() {
        Class<?> d = DemoImport.class;
        Class<?>[] interfacesArray = d.getInterfaces();//获取这个类的所以接口类数组
        for (Class<?> item : interfacesArray) {
            if (item == DemoService.class) { //判断是否有继承的接口
                Log.e("调试_临时_log", "this_true");
            }
        }
    }

 

注解,反射实例,反射调用方法

/*
       扫描特定包下的所有带有WORKANNOTATION的注解类，实例化后注册，如果work需要特别的实例化，需要实现静态函数creat。
       必须在子线程调用，否则会阻塞主线程
     */
    public static void launch(Context c, String[] packageNameList) {
        if(null == packageNameList || packageNameList.length == 0){
            throw new IllegalArgumentException("WorkService launch packageNameList is empty !");
        }

        L.dd(TAG, "launch begin = " + System.currentTimeMillis());
        for(int i =0; i<packageNameList.length; i++) {
            List<String> allClassStr = ClassUtil.getClassName(c, packageNameList[i]);
            for (int j = 0; j < allClassStr.size(); j++) {
                String classStr = allClassStr.get(j);
                //L.dd(TAG, "launch begin classStr = " + classStr);
                Class<?> className = null;
                try {
                    className = Class.forName(classStr);
                } catch (ClassNotFoundException e) {
                    e.printStackTrace();
                }
                if (null == className) {
                    L.ww(TAG, "Class  = " + classStr + " no found !");
                    continue;
                }

                WORKANNOTATION classAnn = className.getAnnotation(WORKANNOTATION.class);
                if (classAnn == null) {
                    continue;
                }

                Method createMethod = null;
                try {
                    createMethod = className.getMethod("create");
                }catch (Exception e){
                    e.printStackTrace();
                }
                IWork work = null;
                //如果没有创建的函数，则实例化无参数的构造函数
                if(null == createMethod){
                    L.ee(TAG, "Class  = " + classStr + " has no create method !");
                    try {
                        work = (IWork)className.newInstance();
                    } catch (InstantiationException e) {
                        e.printStackTrace();
                        L.ee(TAG, "Class  = " + classStr + " newInstance throw InstantiationException !");
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                        L.ee(TAG, "Class  = " + classStr + " newInstance throw IllegalAccessException !");
                    };
                }else{
                    try {
                        work = (IWork) createMethod.invoke(null);
                    }catch (IllegalAccessException e){
                        e.printStackTrace();
                        L.ee(TAG, "Class  = " + classStr + " create throw IllegalAccessException !");
                    }catch (InvocationTargetException e){
                        e.printStackTrace();
                        L.ee(TAG, "Class  = " + classStr + " create throw InvocationTargetException !");
                    }
                }

                if(null == work){
                    L.ee(TAG, "Class  = " + classStr + " create fail !");
                    continue;
                }

                L.d("Work className = " + className.toString() + " register sucess ! ");
                WorkService.register(work);
            }
        }
        L.dd(TAG, "launch end = " + System.currentTimeMillis());

        Intent intent = new Intent(c, WorkService.class);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
           c.startForegroundService(intent);
        } else {
           c.startService(intent);
        }
    }

 反射Android系统AIDL服务

    fun demo1(){
        try {
            val getServiceMethod: Method = Class.forName("android.os.ServiceManager").getDeclaredMethod("getService", String::class.java)
            val windowManager = getServiceMethod.invoke(null, "window")
            val cStub = Class.forName("android.view.IWindowManager\$Stub")
            val asInterface: Method = cStub.getMethod("asInterface", IBinder::class.java)
            val iWindowManager = asInterface.invoke(null, windowManager)
            val updateRotation = iWindowManager.javaClass.getMethod("updateRotation", Boolean::class.java,Boolean::class.java)
            Log.e("zh", "onCreate: windowManager ${iWindowManager}" )
            //registerPointerEventListener
            val methods = iWindowManager.javaClass.methods
//            val interfaces = iWindowManager.javaClass.interfaces
            val superclass = iWindowManager.javaClass.methods

            superclass.forEach {
                Log.e("zh", "onCreate: interfaces = ${it.name}" )
            }

//            val setforcedDisplaySize = iWindowManager.javaClass.getMethod("setForcedDisplaySize", Int::class.javaPrimitiveType, Int::class.javaPrimitiveType, Int::class.javaPrimitiveType)
//            val clearForcedDisplaySize = iWindowManager.javaClass.getMethod("clearForcedDisplaySize", Int::class.javaPrimitiveType)
//            Log.e("zh", "onCreate:${setforcedDisplaySize} ")
//            Log.e("zh", "onCreate:${clearForcedDisplaySize} ")
        } catch (e: NoSuchMethodException) {
            e.printStackTrace()
            Log.e("zh", "无此方法例外" )

        } catch (e: ClassNotFoundException) {
            e.printStackTrace()
            Log.e("zh", "类未找到异常" )

        } catch (e: IllegalAccessException) {
            e.printStackTrace()
            Log.e("zh", "非法访问例外" )

        } catch (e: InvocationTargetException) {
            e.printStackTrace()
            Log.e("zh", "调用目标异常" )

        }
    }

 

 

 

End