# java语言反编译 smali 汇编基础语法（5）之内部类以及内部类的访问

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• 内部类
• 匿名内部类
• 内部类访问外部类的私有变量
• 外部类访问内部类的私有变量

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内部类

内部类的smali特点，就是会在外部类的后面加一个$符号，然后是内部类名，如

MainActivity$Myinner

如下面的例子
java：

  class MyInner{
        int mInt =1;
        public void Test(){
            System.out.println(mInt);
        }

    }
    

.class Lscience/cole/myapplication/MainActivity$MyInner;
.super Ljava/lang/Object;
.source "MainActivity.java"


# annotations
.annotation system Ldalvik/annotation/EnclosingClass;
    value = Lscience/cole/myapplication/MainActivity;
.end annotation

.annotation system Ldalvik/annotation/InnerClass;
    accessFlags = 0x0
    name = "MyInner"
.end annotation


# instance fields
.field mInt:I

.field final synthetic this$0:Lscience/cole/myapplication/MainActivity;


# direct methods
#可以看到，在调用内部类的构造函数的时候，会传入外部类的指针
.method constructor <init>(Lscience/cole/myapplication/MainActivity;)V
    .locals 1
    #这吧外部类的对象的指针给了p1,让内部类知道是谁调用的
    .param p1, "this$0"    # Lscience/cole/myapplication/MainActivity;

    .prologue
    .line 19
    iput-object p1, p0, Lscience/cole/myapplication/MainActivity$MyInner;->this$0:Lscience/cole/myapplication/MainActivity;

    invoke-direct {p0}, Ljava/lang/Object;-><init>()V

    .line 20
    const/4 v0, 0x1

    iput v0, p0, Lscience/cole/myapplication/MainActivity$MyInner;->mInt:I

    return-void
.end method


# virtual methods
#下面就是自定义的函数，其实跟别的是函数是一样的
.method public Test()V
    .locals 2

    .prologue
    .line 22
    sget-object v0, Ljava/lang/System;->out:Ljava/io/PrintStream;

    #将p0寄存器中指向mInt的实例引用存入到v1寄存器中
    iget v1, p0, Lscience/cole/myapplication/MainActivity$MyInner;->mInt:I

    invoke-virtual {v0, v1}, Ljava/io/PrintStream;->println(I)V

    .line 23
    return-void
.end method

这里需要注意的就是，在调用内部类的构造的时候，会把外部类对象指针作为参数给构造函数，看到有这个特征的就是内部类无疑了

匿名内部类

匿名内部类的smali特点，就是会在外部类的后面加一个$符号，然后是一个编号，如

MainActivity$1

如下面的例子

        Button btn  =(Button)findViewById(R.id.btn_test);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                System.out.println("test 匿名内部类");
            }
        });

smali:

 #外部在调用匿名内部类的时候，MainActivity$1 就是匿名外部类的类名
    new-instance v1, Lscience/cole/myapplication/MainActivity$1;
     #匿名内部类在构造的时候，还是会传入外部类的指针
    invoke-direct {v1, p0}, Lscience/cole/myapplication/MainActivity$1;-><init>(Lscience/cole/myapplication/MainActivity;)V

    invoke-virtual {v0, v1}, Landroid/widget/Button;->setOnClickListener(Landroid/view/View$OnClickListener;)V

内部类访问外部类的私有变量

内部类访问外部类的共有成员时，与在外部类中是一样的
内部类访问外部类的私有成员时，在内部类会生成类似access$100这种方法来回去外部类的私有变量

java:

public class MainActivity extends AppCompatActivity {

    private  int nNumber =2;
    public int nNumber2= 3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 测试
        MyInner my =new MyInner();
        my.Test();

    }


    class MyInner{
        int mInt ;
        public void Test(){
            mInt = nNumber2;
            mInt = nNumber;
        }

    }

}

smali:

# virtual methods
.method public Test()V
    .locals 1

    .prologue
    .line 34
    iget-object v0, p0, Lscience/cole/myapplication/MainActivity$MyInner;->this$0:Lscience/cole/myapplication/MainActivity;

    iget v0, v0, Lscience/cole/myapplication/MainActivity;->nNumber2:I

    iput v0, p0, Lscience/cole/myapplication/MainActivity$MyInner;->mInt:I

    .line 35
    iget-object v0, p0, Lscience/cole/myapplication/MainActivity$MyInner;->this$0:Lscience/cole/myapplication/MainActivity;

    #关键的就是这个地方，内部类访问外部类的私有变量的时候，会产生一个access$xxxxx
    # getter for: Lscience/cole/myapplication/MainActivity;->nNumber:I
    invoke-static {v0}, Lscience/cole/myapplication/MainActivity;->access$000(Lscience/cole/myapplication/MainActivity;)I

    move-result v0

    iput v0, p0, Lscience/cole/myapplication/MainActivity$MyInner;->mInt:I

    .line 36
    return-void
.end method

外部类访问内部类的私有变量

当外部类访问内部类的私有变量的时候，会产生类似access$002这种的方法，来获取变量的值

java：

public class MainActivity extends AppCompatActivity {

    int number;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 测试
        MyInner my =new MyInner();
        number =my.mInt;

    }


    class MyInner{
        private int mInt=5 ;
    }

}

smali：

    .line 19
    .local v0, "my":Lscience/cole/myapplication/MainActivity$MyInner;
    # getter for: Lscience/cole/myapplication/MainActivity$MyInner;->mInt:I
    #外部类调用内部类的私有属性
    invoke-static {v0}, Lscience/cole/myapplication/MainActivity$MyInner;->access$000(Lscience/cole/myapplication/MainActivity$MyInner;)I

    move-result v1

    iput v1, p0, Lscience/cole/myapplication/MainActivity;->number:I

    iput v1, p0, Lscience/cole/myapplication/MainActivity;->number:I

The post # java语言反编译 smali 汇编基础语法（5）之内部类以及内部类的访问 appeared first on cole.

http://ift.tt/2DyyCGb Smali, smali January 24, 2018 at 03:22PM