buildscript {
    repositories {
        maven { url 'https://raw.githubusercontent.com/Ivonhoe/mvn-repo/master/' }
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.0'
        classpath 'ivonhoe.gradle.dexguard:dexguard-gradle:0.0.4-SNAPSHOT'
    }
}

apply plugin: 'ivonhoe.dexguard'
dexguard {
    guardConfig = "${rootDir}/map.txt"
}

// 动态生成Exist.class
public class Exist {
    public static boolean a() {
        return false;
    }

    public static void b(int test) {
    }
}

// 插入到特定的Java函数内
Exist.b(Exist.a());

ClassWriter cw = new ClassWriter(0);
FieldVisitor fv;
MethodVisitor mv;
AnnotationVisitor av0;

cw.visit(51, ACC_PUBLIC + ACC_SUPER, "ivonhoe/dexguard/java/Exist", null, "java/lang/Object", null);

cw.visitSource("Exist.java", null);

mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
mv.visitCode();
Label l0 = new Label();
mv.visitLabel(l0);
mv.visitLineNumber(7, l0);
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
mv.visitInsn(RETURN);
Label l1 = new Label();
mv.visitLabel(l1);
mv.visitLocalVariable("this", "Livonhoe/dexguard/java/Exist;", null, l0, l1, 0);
mv.visitMaxs(1, 1);
mv.visitEnd();
        

mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "a", "()Z", null, null);
mv.visitCode();
l0 = new Label();
mv.visitLabel(l0);
mv.visitLineNumber(10, l0);
mv.visitInsn(ICONST_0);
mv.visitInsn(IRETURN);
mv.visitMaxs(1, 0);
mv.visitEnd();

MV = CW.VISITmETHOD(acc_public + acc_static, "b", "(i)v", NULL, NULL);
MV.VISITcODE();
L0 = NEW lABEL();
MV.VISITlABEL(L0);
MV.VISITlINEnUMBER(14, L0);
MV.VISITiNSN(return);
L1 = NEW lABEL();
MV.VISITlABEL(L1);
MV.VISITlOCALvARIABLE("TEST", "i", NULL, L0, L1, 0);
MV.VISITmAXS(0, 1);
MV.VISITeND();

//refer hack class when object init
private static byte[] referHackWhenInit(InputStream inputStream, String methodName) {
    ClassReader cr = new ClassReader(inputStream);
    ClassWriter cw = new ClassWriter(cr, 0);

    ClassVisitor cv = new InjectCassVisitor(Opcodes.ASM4, cw, methodName);
    cr.accept(cv, 0);
    return cw.toByteArray();
}

static class InjectClassVisitor extends ClassVisitor {

        private String methodName;

        InjectClassVisitor(int i, ClassVisitor classVisitor, String method) {
            super(i, classVisitor)

            this.methodName = method;
        }

        @Override
        public MethodVisitor visitMethod(int access, String name, String desc,
                                         String signature, String[] exceptions) {

            MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
            mv = new MethodVisitor(Opcodes.ASM4, mv) {

                @Override
                void visitCode() {
                    // 在方法体开始调用时
                    if (name.equals(methodName)) {
                        mv.visitMethodInsn(INVOKESTATIC, "ivonhoe/dexguard/java/Exist", "a", "()Z", false);
                        mv.visitMethodInsn(INVOKESTATIC, "ivonhoe/dexguard/java/Exist", "b", "(I)V", false);
                    }
                    super.visitCode()
                }

                @Override
                public void visitMaxs(int maxStack, int maxLocal) {
                    if (name.equals(methodName)) {
                        super.visitMaxs(maxStack + 1, maxLocal);
                    } else {
                        super.visitMaxs(maxStack, maxLocal);
                    }
                }
            }
            return mv;
        }
    }