参考文章：

1. 使用AspectJ在Android中实现Aop
2. 深入理解Android之AOP
3. 自动打印日志

主要知识点：

1. 主要是JPoint、pointcuts、advice以及他们之间的关系
2. 可以通过aj文件、或@AspectJ注解的Java文件实现
3. AspectJ和其他模块交互
4. 重载方法会多次调用，需要用within限制是基类还是子类。

案例代码，实现自动化埋点：改自gradle-android-aspectj-plugin：

activity_my.xml

<com.uphyca.gradle.android.aspectj.CLinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:id="@+id/root"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:paddingBottom="@dimen/activity_vertical_margin"android:paddingLeft="@dimen/activity_horizontal_margin"android:paddingRight="@dimen/activity_horizontal_margin"android:paddingTop="@dimen/activity_vertical_margin"android:orientation="vertical"android:clickable="true"tools:context=".MyActivity"><TextViewandroid:id="@+id/greeting"android:layout_width="wrap_content"android:layout_height="100dp"android:gravity="center"/><TextViewandroid:id="@+id/greeting1"android:layout_width="wrap_content"android:layout_height="100dp"android:layout_below="@id/greeting"android:text="click me"android:gravity="center"/><TextViewandroid:id="@+id/greeting2"android:layout_width="wrap_content"android:layout_height="100dp"android:layout_below="@id/greeting1"android:text="click me"android:gravity="center"/></com.uphyca.gradle.android.aspectj.CLinearLayout>

MyActivity.java

public class MyActivity extends AppCompatActivity implements View.OnClickListener{@InjectGreeter greeter;private View.OnClickListener clickListener = new View.OnClickListener() {@Overridepublic void onClick(View v) {Log.i("aaaaaaaaaaaa", "AppCompatActivity.clickListener");}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);((MyApplication) getApplication()).getComponent().inject(this);setContentView(R.layout.activity_my);TextView.class.cast(findViewById(R.id.greeting)).setText(greeter.greet());TextView.class.cast(findViewById(R.id.greeting)).setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doActivityKisClick(v);}});TextView.class.cast(findViewById(R.id.greeting1)).setOnClickListener(this);TextView.class.cast(findViewById(R.id.greeting2)).setOnClickListener(clickListener);init();}private void init(){Log.i("aaaaaaaaaaaa", "init");}private void doActivityKisClick(View v){Log.i("aaaaaaaaaaaa", "doActivityKisClick");}@Overridepublic void onClick(View v) {Log.i("aaaaaaaaaaaa", "MyActivity.onClick");}
}

MyAspect.aj

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;public aspect MyAspect {pointcut callGreet() : call(String com.uphyca.gradle.android.aspectj.Greeter+.greet());pointcut callInit() : call(private void com.uphyca.gradle.android.aspectj.MyActivity.init());/* 不管是匿名OnClickListener还是Activity implements方式，包括Activity、Fragment、自定义View中，都可以匹配*/pointcut callClick(android.view.View v) : execution(* android.view.View.OnClickListener.onClick(..)) && args(v);/* callClick也匹配了*/pointcut callDoClick(android.view.View v) : call(private void com.uphyca.gradle.android.aspectj.MyActivity.doActivityKisClick(android.view.View)) && target(com.uphyca.gradle.android.aspectj.MyActivity) && args(v);/* callClick也匹配了*/pointcut doCLayoutClick(android.view.View v) : call(private void com.uphyca.gradle.android.aspectj.CLinearLayout.doCKisClick(android.view.View)) && target(com.uphyca.gradle.android.aspectj.CLinearLayout) && args(v);/* 匹配所有KisClick结尾的事件, public/private/protect，以及static/final属于可选项。如果不设置它们，则默认都会选择，不需要用*代替 */pointcut doAllClick(android.view.View v) : call(* *.*KisClick(android.view.View)) && args(v);String around() : callGreet() {String result = proceed();return result.replace("world", "aspect");}before() : callInit() {android.util.Log.i("aaaaaaaaaaaa", "callInit");}before(android.view.View v) : callClick(v) {android.util.Log.i("aaaaaaaaaaaa", "callClick");}before(android.view.View v) : callDoClick(v) {android.util.Log.i("aaaaaaaaaaaa", "callDoClick");}before(android.view.View v) : doCLayoutClick(v) {android.util.Log.i("aaaaaaaaaaaa", "doCLayoutClick");}before(android.view.View v) : doAllClick(v) {org.aspectj.lang.Signature signature = thisJoinPoint.getSignature();String typeName = signature.getDeclaringTypeName();String methodName = signature.getName();android.util.Log.i("aaaaaaaaaaaa", "DeclaringTypeName: " + typeName + "." + methodName);}
}

CLinearlayout.java

public class CLinearLayout extends LinearLayout{public CLinearLayout(Context context) {this(context, null);}public CLinearLayout(Context context, AttributeSet attrs) {super(context, attrs);setOrientation(VERTICAL);setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doCKisClick(v);doCSecondKisClick(v);}});}private void doCKisClick(View v){Log.i("aaaaaaaaaaaa", "CLinearLayout.click");}private void doCSecondKisClick(View v){Log.i("aaaaaaaaaaaa", "CLinearLayout.doCSecondKisClick");}}