AndroidStudio中 AspectJ 基础使用 简介

AOP（Aspect Oriented Programming）切面编程在处理一些与业务逻辑无关，但在很多地方又不得不添加相关逻辑代码，可以很好的解决相关问题，比如在Android中有些地方需要打LOG日志，或者在某些地方需要检查系统权限等，可以很好的解决这类问题。

而AOP中主要使用的就是AspectJ，AspectJ有自己相关的一套语法，大致和JAVA类似。官方简介

那么在AndroidStudio 中要怎么使用AOP呢？

首先需要新建一个module,方便引入相关的AspectJ配置，便于在其中编写与业务逻辑无关紧要，并且在代码中经常出现的常用代码，
之后在module下的build.gradle中 导入AspectJ的dependences

compile ‘org.aspectj:aspectjrt:1.8.9’

并在build.gradle根下配置

repositories {    mavenCentral()}buildscript {    repositories {        mavenCentral()    }    dependencies {        classpath 'com.android.tools.build:gradle:2.1.3'        classpath 'org.aspectj:aspectjtools:1.8.9'        classpath 'org.aspectj:aspectjweaver:1.8.9'    }}android.libraryVariants.all { variant ->    LibraryPlugin plugin = project.plugins.getPlugin(LibraryPlugin)    JavaCompile javaCompile = variant.javaCompile    javaCompile.doLast {        String[] args = ["-showWeaveInfo",                         "-1.5",                         "-inpath", javaCompile.destinationDir.toString(),                         "-aspectpath", javaCompile.classpath.asPath,                         "-d", javaCompile.destinationDir.toString(),                         "-classpath", javaCompile.classpath.asPath,                         "-bootclasspath", plugin.project.android.bootClasspath.join(                File.pathSeparator)]        MessageHandler handler = new MessageHandler(true);        new Main().run(args, handler)        def log = project.logger        for (IMessage message : handler.getMessages(null, true)) {            switch (message.getKind()) {                case IMessage.ABORT:                case IMessage.ERROR:                case IMessage.FAIL:                    log.error message.message, message.thrown                    break;                case IMessage.WARNING:                case IMessage.INFO:                    log.info message.message, message.thrown                    break;                case IMessage.DEBUG:                    log.debug message.message, message.thrown                    break;            }        }    }}以上module的build.gradle 配置主要是搭建AspectJ运行环境

之后在app下的build.gradle添加module的依赖，并且添加如下配置

repositories {    mavenCentral()}buildscript {    repositories {        mavenCentral()    }    dependencies {        classpath 'org.aspectj:aspectjtools:1.8.9'    }}final def log = project.loggerfinal def variants = project.android.applicationVariantsvariants.all { variant ->    if (!variant.buildType.isDebuggable()) {        log.debug("Skipping non-debuggable build type '${variant.buildType.name}'.")        return;    }    JavaCompile javaCompile = variant.javaCompile    javaCompile.doLast {        String[] args = ["-showWeaveInfo",                         "-1.5",                         "-inpath", javaCompile.destinationDir.toString(),                         "-aspectpath", javaCompile.classpath.asPath,                         "-d", javaCompile.destinationDir.toString(),                         "-classpath", javaCompile.classpath.asPath,                         "-bootclasspath", project.android.bootClasspath.join(File.pathSeparator)]        log.debug "ajc args: " + Arrays.toString(args)        MessageHandler handler = new MessageHandler(true);        new Main().run(args, handler);        for (IMessage message : handler.getMessages(null, true)) {            switch (message.getKind()) {                case IMessage.ABORT:                case IMessage.ERROR:                case IMessage.FAIL:                    log.error message.message, message.thrown                    break;                case IMessage.WARNING:                    log.warn message.message, message.thrown                    break;                case IMessage.INFO:                    log.info message.message, message.thrown                    break;                case IMessage.DEBUG:                    log.debug message.message, message.thrown                    break;            }        }    }}

以上配置主要是将app和module关联起来。

然后在module中创建TestAspectJ类，
具体代码如下：

package com.clayx.org.aspectj;import android.annotation.TargetApi;import android.os.Build;import android.util.Log;import org.aspectj.lang.ProceedingJoinPoint;import org.aspectj.lang.annotation.Around;import org.aspectj.lang.annotation.Aspect;import org.aspectj.lang.annotation.Pointcut;/** * Created by Administrator on 2016/9/2. */@Aspectpublic class TestAspectJ {    private static final String METHOD_EXECUTION = "execution(* *..MainActivity+.onCreate(..))";    private static final String METHOD_CALL = "call(* *..MainActivity+.test(..)) && args(name)";    private String TAG = "Clayx";    @Pointcut(METHOD_EXECUTION)    public void methodExecution() {    }    @Pointcut(METHOD_CALL)    public void methodCall(String name) {    }    @Around("methodExecution()")    public void aroundMethodExecution(ProceedingJoinPoint joinPoint) throws Throwable {        joinPoint.proceed();        String result = "-----------------------------MethodExecution";        Log.e(TAG, result);    }    @Around("methodCall(String)")    public Object arouneMethodCall(ProceedingJoinPoint joinPoint){        String name = (String) joinPoint.getArgs()[0];        Log.e(TAG,name);        return name;    }}

运行APP，打印出Log如下：

对于注解的使用，可以更好的和AspectJ结合使用，

注解类如下:

package com.clayx.org.aspectj.anno;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;/** * Created by Administrator on 2016/9/2. */@Target(ElementType.METHOD)@Retention(RetentionPolicy.RUNTIME)public @interface TestAspectJ {}

注解相关的AspectJ的实现类

package com.clayx.org.aspectj.anno;import android.content.Context;import android.widget.Toast;import org.aspectj.lang.ProceedingJoinPoint;import org.aspectj.lang.annotation.Around;import org.aspectj.lang.annotation.Aspect;import org.aspectj.lang.annotation.Pointcut;/** * Created by Administrator on 2016/9/2. */@Aspectpublic class TestAspect {    @Pointcut("execution(@TestAspectJ private * *..*.*(..))")    public void testAspect() {    }    @Around("testAspect()")    public void testTestAspect(ProceedingJoinPoint joinPoint) {        Toast.makeText((Context) joinPoint.getTarget(), "OK", Toast.LENGTH_SHORT).show();    }}

注解运行如下：

代码下载地址