1、在buildsrc中新建AsmInjectPlugin插件
public class AsmInjectPlugin implements Plugin<Project>{
@Override
void apply(Project project) {
System.out.println("========================")
System.out.println("这是AsmInjectPlugin插件!")
System.out.println("========================")
}
}
2、在groovy下新建AsmInjectTrans继承Transform
public class AsmInjectTrans extends Transform{
@Override
void transform(TransformInvocation transformInvocation) throws TransformException, InterruptedException, IOException {
super.transform(transformInvocation)
// Transform的inputs有两种类型，一种是目录，一种是jar包，要分开遍历
transformInvocation.inputs.each { TransformInput input ->
//对类型为“文件夹”的input进行遍历
input.directoryInputs.each { DirectoryInput directoryInput ->
//文件夹里面包含的是我们手写的类以及R.class、BuildConfig.class以及R$XXX.class等
if (directoryInput.file.isDirectory()) {
// println "==== directoryInput.file = " + directoryInput.file
directoryInput.file.eachFileRecurse { File file ->
def name = file.name
// println "==== directoryInput file name ==== " + file.getAbsolutePath()
if (name.endsWith(".class")
&& !name.endsWith("R.class")
&& !name.endsWith("BuildConfig.class")
&& !name.contains("R\$")) {
println "==== directoryInput file name ==== " + file.getAbsolutePath()
}
}
}
// 获取output目录
def dest = transformInvocation.outputProvider.getContentLocation(directoryInput.name,
directoryInput.contentTypes, directoryInput.scopes,
Format.DIRECTORY)
// 将input的目录复制到output指定目录
FileUtils.copyDirectory(directoryInput.file, dest)
}
//对类型为jar文件的input进行遍历
input.jarInputs.each { JarInput jarInput ->
//jar文件一般是第三方依赖库jar文件
// 重命名输出文件（同目录copyFile会冲突）
def jarName = jarInput.name
def md5Name = DigestUtils.md5Hex(jarInput.file.getAbsolutePath())
if (jarName.endsWith(".jar")) {
jarName = jarName.substring(0, jarName.length() - 4)
}
//生成输出路径
def dest = transformInvocation.outputProvider.getContentLocation(jarName + md5Name,
jarInput.contentTypes, jarInput.scopes, Format.JAR)
//将输入内容复制到输出
FileUtils.copyFile(jarInput.file, dest)
}
}
}
//用于指明本Transform的名字，也是代表该Transform的task的名字
@Override
String getName() {
return "AsmInject"
}
//指明Transform的输入类型，可以作为输入过滤的手段
@Override
Set<QualifiedContent.ContentType> getInputTypes() {
return TransformManager.CONTENT_CLASS
}
//指明Transform的作用域
@Override
Set<? super QualifiedContent.Scope> getScopes() {
return TransformManager.SCOPE_FULL_PROJECT
}
//指明是否是增量构建
@Override
boolean isIncremental() {
return false
}
}
3、在AsmInjectPlugin的apply中添加如下代码
def android = project.extensions.getByType(AppExtension)
AsmInjectTrans asmInjectTrans = new AsmInjectTrans()
android.registerTransform(asmInjectTrans)
4、app下的gradle.build中添加
apply plugin: com.liujian.AsmInjectPlugin
Clean project，然后make project，从messages窗口中看到如下打印信息（app工程下，只有一个MainActivity）
屏幕快照 2018-04-12 下午10.28.57.png
5、在buidlsrc的gradle.build中添加asm依赖
compile 'org.ow2.asm:asm:5.1'
compile 'org.ow2.asm:asm-commons:5.1'
然后在AsmInjectTrans的transform 中编写注入代码:
void transform(TransformInvocation transformInvocation) throws TransformException, InterruptedException, IOException {
super.transform(transformInvocation)
// Transform的inputs有两种类型，一种是目录，一种是jar包，要分开遍历
transformInvocation.inputs.each { TransformInput input ->
//对类型为“文件夹”的input进行遍历
input.directoryInputs.each { DirectoryInput directoryInput ->
//文件夹里面包含的是我们手写的类以及R.class、BuildConfig.class以及R$XXX.class等
if (directoryInput.file.isDirectory()) {
// println "==== directoryInput.file = " + directoryInput.file
directoryInput.file.eachFileRecurse { File file ->
def name = file.name
// println "==== directoryInput file name ==== " + file.getAbsolutePath()
if (name.endsWith(".class")
&& !name.endsWith("R.class")
&& !name.endsWith("BuildConfig.class")
&& !name.contains("R\$")) {
println "==== directoryInput file name ==== " + file.getAbsolutePath()
ClassReader classReader = new ClassReader(file.bytes)
ClassWriter classWriter = new ClassWriter(classReader, ClassWriter.COMPUTE_MAXS)
AsmClassVisitor classVisitor = new AsmClassVisitor(Opcodes.ASM5, classWriter)
classReader.accept(classVisitor, ClassReader.EXPAND_FRAMES)
byte[] bytes = classWriter.toByteArray()
File destFile = new File(file.parentFile.absoluteFile, name)
//project.logger.error "==== 重新写入的位置->lastFilePath === " + destFile.getAbsolutePath()
FileOutputStream fileOutputStream = new FileOutputStream(destFile)
fileOutputStream.write(bytes)
fileOutputStream.close()
}
}
}
// 获取output目录
def dest = transformInvocation.outputProvider.getContentLocation(directoryInput.name,
directoryInput.contentTypes, directoryInput.scopes,
Format.DIRECTORY)
// 将input的目录复制到output指定目录
FileUtils.copyDirectory(directoryInput.file, dest)
}
//对类型为jar文件的input进行遍历
input.jarInputs.each { JarInput jarInput ->
//jar文件一般是第三方依赖库jar文件
// 重命名输出文件（同目录copyFile会冲突）
def jarName = jarInput.name
def md5Name = DigestUtils.md5Hex(jarInput.file.getAbsolutePath())
if (jarName.endsWith(".jar")) {
jarName = jarName.substring(0, jarName.length() - 4)
}
//生成输出路径
def dest = transformInvocation.outputProvider.getContentLocation(jarName + md5Name,
jarInput.contentTypes, jarInput.scopes, Format.JAR)
//将输入内容复制到输出
FileUtils.copyFile(jarInput.file, dest)
}
}
}
6、完成注入过程
新建AsmClassVisitor
public class AsmClassVisitor extends ClassVisitor {
public AsmClassVisitor(int api) {
super(api);
}
public AsmClassVisitor(int api, ClassVisitor classVisitor) {
super(api, classVisitor);
}
@Override
public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
super.visit(version, access, name, signature, superName, interfaces);
}
@Override
public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
return super.visitAnnotation(desc, visible);
}
@Override
public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
MyLog.log("=====---------- visitMethod ----------=====");
MethodVisitor mv = cv.visitMethod(access, name, desc, signature, exceptions);
AsmMethodVisitor mMethodVisitor = new AsmMethodVisitor(Opcodes.ASM5, mv, access, name, desc);
return mMethodVisitor;
}
@Override
public void visitEnd() {
super.visitEnd();
}
}
然后新建AsmMethodVisitor
public class AsmMethodVisitor extends AdviceAdapter{
private String methodName;
private String methodDes;
public AsmMethodVisitor(int api, MethodVisitor mv, int access, String name, String desc) {
super(api, mv, access, name, desc);
methodName = name;
methodDes = desc;
}
@Override
public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
return super.visitAnnotation(desc, visible);
}
@Override
protected void onMethodEnter() {
if("onClick".equals(methodName) && "(Landroid/view/View;)V".equals(methodDes)){
mv.visitVarInsn(ALOAD, 1);
mv.visitMethodInsn(Opcodes.INVOKESTATIC, "com/example/liujian/asmdemo/LogUtils", "system", "(Landroid/view/View;)V", false);
}
}
@Override
protected void onMethodExit(int opcode) {
super.onMethodExit(opcode);
}
}
7、调试。在app工程下，新建com.example.liujian.asmdemo包下LogUtils类
public class LogUtils {
public static void system(View v){
Log.d("MainActivity-asm--", "onclick---"+v.getId());
}
}
然后在MainActivity添加调试代码调试
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.btn_1).setOnClickListener(this);
findViewById(R.id.btn_2).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Log.d("MainActivity-btn_2-", "onclick---"+view.getId());
}
});
}
@Override
public void onClick(View view) {
Log.d("MainActivity-btn_1-", "onclick---"+view.getId());
}
}
clean project，然后run
屏幕快照 2018-04-12 下午11.13.02.png
完成注入!
此时在app/build/intermediates/classes/debug/com/example/liujian/asmdemo 下查看MainActivity.class文件
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//
package com.example.liujian.asmdemo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends AppCompatActivity implements OnClickListener {
public MainActivity() {
}
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(2131296283);
this.findViewById(2131165219).setOnClickListener(this);
this.findViewById(2131165220).setOnClickListener(new OnClickListener() {
public void onClick(View view) {
LogUtils.system(view);
Log.d("MainActivity-btn_2-", "onclick---" + view.getId());
}
});
}
public void onClick(View view) {
LogUtils.system(view);
Log.d("MainActivity-btn_1-", "onclick---" + view.getId());
}
}
其中 LogUtils.system(view);为我们plugin注入的代码
