当动态代理遇到ioc （四）真正的cglib

0 当动态代理遇到ioc （二）cglib 中的代理仍然不能切子函数，所以有本篇

1 此前已经解决cglib与asm冲突：当动态代理遇到ioc （三）cglib与asm jar包冲突

 

2 事务的try catch模型由exception扩叨叨throwable

 

3 抽象层

由于我们反射调用方法时，不再是method.invoke(origin object, args[])，所以抽象层要修改一下

protected Object invokeHasTransactional(SCEF_DB_TRANSACTIONAL scef_db_transactional, Method method, Object[] args, MethodProxy methodProxy, Object oCglib) throws Throwable {

protected Object invokeNoTransactional(Method method, Object[] args, MethodProxy methodProxy, Object oCglib) throws Throwable {

　　

Object returnValue = aopInvoke(method, args, methodProxy, oCglib);

　　

jdk

    protected Object aopInvoke(Method method, Object [] args, MethodProxy methodProxy, Object oCglib) throws Throwable {
        Object returnValue = method.invoke(target, args);
        return returnValue;
    }

　　

        if(scef_db_transactional != null) {
            res = invokeHasTransactional(scef_db_transactional, method, args, null, null);
        } else {
            res = invokeNoTransactional(method, args, null, null);
        }

　　

cglib

    @Override
    protected Object aopInvoke(Method method, Object[] args, MethodProxy methodProxy, Object oCglib) throws Throwable {
////////return method.invoke(target, args);
        return methodProxy.invokeSuper(oCglib, args);
    }

　　

        if (scef_db_transactional != null) {
            res = invokeHasTransactional(scef_db_transactional, null, objects, methodProxy, o);
        } else {
            res = invokeNoTransactional(null, objects, methodProxy, o);
        }

　　

 

4 ioc反哺

解决了3形成了子函数切面后，报错：

首次处理 class sun.myproxybean.MyServiceImpl的ioc
处理 class sun.myproxybean.MyServiceImpl的myMapper1
处理 class sun.myproxybean.MyServiceImpl的myMapper2
处理 class sun.myproxybean.MyServiceImpl的myDao
public void sun.myproxybean.MyServiceImpl.multi()
@sun.myproxy.MY_TRANSACTIONAL()
public final void sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.multi()
null
public abstract void sun.myproxybean.MyService.multi()
null
Exception in thread "main" java.lang.RuntimeException: java.lang.NullPointerException
	at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:112)
	at sun.myproxy.OdsTransactionCglibFactory.intercept(OdsTransactionCglibFactory.java:65)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.multi(<generated>)
	at sun.mybatis.Main.main(Main.java:58)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.NullPointerException
	at sun.myproxybean.MyServiceImpl.multi(MyServiceImpl.java:29)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.CGLIB$multi$0(<generated>)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d$$FastClassByCGLIB$$8fca1f76.invoke(<generated>)
	at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
	at sun.myproxy.OdsTransactionCglibFactory.aopInvoke(OdsTransactionCglibFactory.java:73)
	at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:100)
	... 8 more

 

显示ioc null了，故我们回顾一下IOC()中，反哺是反到原始对象

为了切子函数，不再使用method.invoke(origin object, args[])原对象，而是使用代理对象（子类对象）methodProxy.invokeSuper(oCglib, args);，因此反哺应在代理对象（子类对象）上的private成员变量上进行，注意子类没有继承父类的private field，是在子类对象上用反射操作内存对象中父类那一部分的内存

 

protected Object getTarget() {
    return this.target;
}

@SuppressWarnings("squid:S3011")
protected void IOC() throws IllegalAccessException {
    if (!alreadyIOC) {
        Class clProxy = target.getClass();
        Field[] fields = clProxy.getDeclaredFields();
        for (Field field : fields) {

            field.setAccessible(true);
            if (!field.isAnnotationPresent(getBeanInjectAnnotationGuice()))
                continue;
            String name = field.getName();
            Class fieldType = field.getType();
            Object obj = getBeanFromFactoryGuice(fieldType);
            if (obj != null)
                field.set(getTarget(), obj);
        }
        alreadyIOC = true;
    }
}

public class OdsTransactionCglibFactory extends OdsTransactionProxyFactory implements MethodInterceptor {

    public OdsTransactionCglibFactory(Object target) {
        super(target);
    }

    private Object targetCglib;

    @Override
    protected Object getTarget() {
        return targetCglib;
    }

@Override
public Object getProxyInstance() {
    Enhancer en = new Enhancer();
    en.setSuperclass(target.getClass());
    en.setCallback(this);
    Object oCglib = en.create();
    this.targetCglib = oCglib;
    return oCglib;
}

 

5 发现一个bug

    @Inject
    private MyDao myDao;   // https://www.cnblogs.com/silyvin/p/14237270.html 第5点
//    private MyDaoImpl myDao;  // 导致myDao不是注入代理类对象，而是new MyDaoImpl，guice会自己newInstance一个

 

6 对于接口MyService中没有，仅在MyServiceImpl中有的子函数，处理“迎合某些人习惯将注解加到接口上”的时候去取接口的getMethod时报错

首次处理 class sun.myproxybean.MyServiceImpl的ioc
处理 class sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d的myMapper1
处理 class sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d的myMapper2
处理 class sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d的myDao
public void sun.myproxybean.MyServiceImpl.multi()
@sun.myproxy.MY_TRANSACTIONAL()
public final void sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.multi()
null
public abstract void sun.myproxybean.MyService.multi()
null
Exception in thread "main" java.lang.RuntimeException: java.lang.NoSuchMethodException: sun.myproxybean.MyService.subFunction()
	at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:117)
	at sun.myproxy.OdsTransactionCglibFactory.intercept(OdsTransactionCglibFactory.java:74)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.multi(<generated>)
	at sun.mybatis.Main.main(Main.java:58)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.NoSuchMethodException: sun.myproxybean.MyService.subFunction()
	at java.lang.Class.getMethod(Class.java:1786)
	at sun.myproxy.OdsTransactionCglibFactory.intercept(OdsTransactionCglibFactory.java:42)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.subFunction(<generated>)
	at sun.myproxybean.MyServiceImpl.multi(MyServiceImpl.java:30)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.CGLIB$multi$0(<generated>)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d$$FastClassByCGLIB$$8fca1f76.invoke(<generated>)
	at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
	at sun.myproxy.OdsTransactionCglibFactory.aopInvoke(OdsTransactionCglibFactory.java:83)
	at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:105)
	... 8 more

 

jdk动态代理的子函数没有办法切，被切到的一定是接口中有的方法，所以天然无此问题；而cglib会切到大概率没有事务注解的子函数，所以就暴露了这个问题

@Override
public Object intercept(Object o, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {

    IOC();

    // ewirweod
    MY_TRANSACTIONAL scef_db_transactional = method.getAnnotation(MY_TRANSACTIONAL.class);

    // 迎合有些人习惯将注解加到接口上
    Class[] interfaces = target.getClass().getInterfaces();
    if(scef_db_transactional == null) {
        for(Class inter : interfaces) {
            try {
                Method classMethod = inter.getMethod(method.getName(), method.getParameterTypes());
                scef_db_transactional = classMethod.getAnnotation(MY_TRANSACTIONAL.class);
            } catch (NoSuchMethodException e1) {
                ; 
            } catch (Throwable e) {
                e.printStackTrace();
            }
            break;
        }
    }

 

6.5 又引出了一个知识：

        // MyServiceImpl&&CGLIB.method  uewoqruwiiii
        {
            Method classMethod = o.getClass().getMethod(method.getName(), method.getParameterTypes());
            System.out.println(classMethod);
            MY_TRANSACTIONAL my_transactional = classMethod.getAnnotation(MY_TRANSACTIONAL.class);
            System.out.println(my_transactional);
        }

 

这个地方居然也报错了

public class MyServiceImpl implements MyService {

    。。。。。

    /**
     * public o.getClass().getMethod 可以找到
     * protected 不行
     */
    public void subFunction() {
        System.out.println(this);
    }

 原因为：

getDeclaredMethod*()获取的是类自身声明的所有方法，包含public、protected和private方法。getMethod*()获取的是类的所有共有方法，这就包括自身的所有public方法，和从基类继承的、从接口实现的所有public方法。

anyway，所有getMethod方法都加上try catch throwable吧，以免影响主体进程

 

7 最终的日志

首次处理 class sun.myproxybean.MyServiceImpl的ioc
处理 class sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d的myMapper1
处理 class sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d的myMapper2
处理 class sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d的myDao
public void sun.myproxybean.MyServiceImpl.multi()
@sun.myproxy.MY_TRANSACTIONAL()
public final void sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.multi()
null
public abstract void sun.myproxybean.MyService.multi()
null
protected void sun.myproxybean.MyServiceImpl.subFunction()
null
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
首次处理 class sun.myproxybean.MyDaoImpl的ioc
处理 class sun.myproxybean.MyDaoImpl$$EnhancerByCGLIB$$4b5f7f6c的myMapper2
public void sun.myproxybean.MyDaoImpl.multi()
@sun.myproxy.MY_TRANSACTIONAL()
public final void sun.myproxybean.MyDaoImpl$$EnhancerByCGLIB$$4b5f7f6c.multi()
null
public abstract void sun.myproxybean.MyDao.multi()
null
Exception in thread "main" java.lang.RuntimeException: java.lang.RuntimeException: java.lang.ArithmeticException: / by zero
	at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:117)
	at sun.myproxy.OdsTransactionCglibFactory.intercept(OdsTransactionCglibFactory.java:74)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.multi(<generated>)
	at sun.mybatis.Main.main(Main.java:58)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.RuntimeException: java.lang.ArithmeticException: / by zero
	at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:117)
	at sun.myproxy.OdsTransactionCglibFactory.intercept(OdsTransactionCglibFactory.java:74)
	at sun.myproxybean.MyDaoImpl$$EnhancerByCGLIB$$4b5f7f6c.multi(<generated>)
	at sun.myproxybean.MyServiceImpl.multi(MyServiceImpl.java:33)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d.CGLIB$multi$1(<generated>)
	at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$5b3ba48d$$FastClassByCGLIB$$8fca1f76.invoke(<generated>)
	at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
	at sun.myproxy.OdsTransactionCglibFactory.aopInvoke(OdsTransactionCglibFactory.java:83)
	at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:105)
	... 8 more
Caused by: java.lang.ArithmeticException: / by zero
	at sun.myproxybean.MyDaoImpl.multi(MyDaoImpl.java:18)
	at sun.myproxybean.MyDaoImpl$$EnhancerByCGLIB$$4b5f7f6c.CGLIB$multi$0(<generated>)
	at sun.myproxybean.MyDaoImpl$$EnhancerByCGLIB$$4b5f7f6c$$FastClassByCGLIB$$e94f8239.invoke(<generated>)
	at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
	at sun.myproxy.OdsTransactionCglibFactory.aopInvoke(OdsTransactionCglibFactory.java:83)
	at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:105)
	... 16 more

 

 

 

 

 8

2021.4.3 发现一个大bug，延迟rollback

/Users/joyce/work/MyTest/MyModbus/src/main/java/sun/myproxy/OdsTransactionProxyFactory.java

protected Object invokeHasTransactional(MY_TRANSACTIONAL scef_db_transactional, Method method, Object[] args, MethodProxy methodProxy, Object oCglib) throws Throwable {

    try {
        startTransaction();
    //    Object returnValue = method.invoke(target, args);
        Object returnValue = aopInvoke(method, args, methodProxy, oCglib);
        commit();
        return returnValue;
    } catch (InvocationTargetException ie) {
        Throwable throwable = ie.getTargetException();

        rollback();

        // RuntimeException will popup the default error popup view of ecore
        throw throwable;

    } catch (Throwable e) {
        /**
         * 上面的InvocationTargetException是为了jdk动态代理
         * 调整为cglib时忘了在这里也rollback
         * 也就是说rollback被延迟到endTransaction
         * 最终依托DefaultSqlSession.BaseExecutor.close回滚
         * 在这期间，其它session若处于RU隔离级别则可见这些未回滚的数据
         * 顺便说一句，resetAutoCommit也在这条线上，reset后归连接给连接池
         */
        rollback();
        throw e;
    } finally {
        endTransaction();
    }
}

最初发现这个问题，是由于发现异常居然没有走InvocationTargetException，这才意识到这会用的是cglib，异常直接走Exception/Throwable，不会再像jdk那样抛InvocationTargetException

进而又发现exception/throwable里面居然没有rollback

 

我们做个实验印证这个延迟rollback的想法

在OdsTransactionProxyProvider中确认使用的是cglib代理，去掉我们此次加的rollback

java	another db client
	打开一个mysql 5.7默认会话，show variables like "tx_isolation"; 显示REPEATABLE-READ
	set session transaction isolation level read uncommitted; 再次执行查询，READ-UNCOMMITTED
在endTransaction处打断点，run
到断点（注意可能有多次，因为链路上service和dao的multi方法都有事务注解 而我们要查看的回滚数据是service层插入的，故在第2个endTransactional打断点观察） 此时入参method：public void sun.myproxybean.MyServiceImpl.multi()	查询数据，显示100 db，即没有回滚
放开断点，结束
	发现回滚

 

*

//设置read uncommitted级别：
set session transaction isolation level read uncommitted;

//设置read committed级别：
set session transaction isolation level read committed;

//设置repeatable read级别：
set session transaction isolation level repeatable read;

//设置serializable级别：
set session transaction isolation level serializable;

 

加上我们此次的rollback

 

java	another db client
	打开一个mysql 5.7默认会话，show variables like "tx_isolation"; 显示REPEATABLE-READ
	set session transaction isolation level read uncommitted; 再次执行查询，READ-UNCOMMITTED
在endTransaction处打断点，run
到断点（注意可能有多次，因为链路上service和dao的multi方法都有事务注解 而我们要查看的回滚数据是service层插入的，故在第2个endTransactional打断点观察） 此时入参method：public void sun.myproxybean.MyServiceImpl.multi()	查询数据，第1次有，第2次无，证明此次加入rollback有效
放开断点，结束

 

8.5

2020.4.23

这个问题不仅会导致事务delay回滚，也会导致norollbackfor 失效，因为它在InnovationTargetException（jdk）里面处理，调整为cglib就忘记了 ，以下代码不入仓库

 

 

 

 9

2021.4.28

关于第4点 ioc反哺，一直有莫名其妙的疑问，后来发现，是这个知识点的薄弱所致疑问：

子类虽然没继承父类private属性，但是子类对象空间里是有这些字段的，通过反射存取

简单的说，子类虽然没有，但子类对象有

而且反射要拿父类去getDeclaredFields，然后field.set(cglib子类对象, val)

这里又引出另一个知识点：cglib切面模型

 

　　　　cglibobj.mother

　　　　aopfront

　　　　　　origin.mother

　　　　　　this.sun

　　　　　　this->cglibobj

　　　　　　cglibobj.sun (protected, public)

　　　　　　aopfront

　　　　　　　　origin.sun

　　　　　　　　set/get this.field1

　　　　　　aopend

　　　　aopend

 

　　

cglib的代理对象，在cglib类方法中是不操作的，而且也无法操作（针对父类private属性），也不需要操作

 

 用一段代码建模：（不进仓库）

// 此类代表原始类，里面有有很多@Inject或@Autowired
public class TestTemp {

    //@Inject or @Autowired
    // 由于这个类的对象没有注入（注入的是cglib子类对象），故自动装配失败，需要我们手动反哺
    private String guiceService;

    protected String getGuiceService() {
        return guiceService;
    }

}

　　

// 此类代表cglib
public class SubTestTemp extends TestTemp {
    public static void main(String []f) throws IllegalAccessException {
        SubTestTemp subTestTemp = new SubTestTemp();
        Field [] fields = TestTemp.class.getDeclaredFields();
        for(Field field : fields) {
            field.setAccessible(true);
            field.set(subTestTemp, "反哺的ioc对象");
        }

        System.out.println(subTestTemp.getGuiceService());
    }
}

　　

"C:\Program Files\Java\jdk1.8.0_221\bin\java.exe" "。。。。。。。

反哺的ioc对象

Process finished with exit code 0

 

 

10

2021.4.30

事物中控支持按名称getBean。此部分代码不入git仓库：/Users/mac/work/MyTest/MyModbus/src/main/java/sun/myproxy/OdsTransactionProxyFactory.java

 

 

 

后来还是在本地写了一段测试代码：

如果不支持allowNamed时，报错：

首次处理 class sun.myproxybean.MyDaoImpl的ioc
处理 class sun.myproxybean.MyDaoImpl$$EnhancerByCGLIB$$aa3d8422的myMapper2
Exception in thread "main" com.google.inject.ConfigurationException: Guice configuration errors:

1) No implementation for sun.guicename.IGuiceName was bound.
Did you mean?
* sun.guicename.IGuiceName annotated with @com.google.inject.name.Named(value=guiceName1)
* sun.guicename.IGuiceName annotated with @com.google.inject.name.Named(value=guiceName2)
while locating sun.guicename.IGuiceName

1 error
at com.google.inject.internal.InjectorImpl.getProvider(InjectorImpl.java:1075)
at com.google.inject.internal.InjectorImpl.getProvider(InjectorImpl.java:1034)
at com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1086)
at sun.myproxy.OdsTransactionProxyFactory.getBeanFromFactoryGuice(OdsTransactionProxyFactory.java:35)
at sun.myproxy.OdsTransactionProxyFactory.getBeanFromFactoryGuice(OdsTransactionProxyFactory.java:44)
at sun.myproxy.OdsTransactionProxyFactory.IOC(OdsTransactionProxyFactory.java:73)
at sun.myproxy.OdsTransactionCglibFactory.intercept(OdsTransactionCglibFactory.java:32)
at sun.myproxybean.MyDaoImpl$$EnhancerByCGLIB$$aa3d8422.multi(<generated>)
at sun.myproxybean.MyServiceImpl.multi(MyServiceImpl.java:33)
at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$ba19a943.CGLIB$multi$0(<generated>)
at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$ba19a943$$FastClassByCGLIB$$97cd6499.invoke(<generated>)
at net.sf.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
at sun.myproxy.OdsTransactionCglibFactory.aopInvoke(OdsTransactionCglibFactory.java:97)
at sun.myproxy.OdsTransactionProxyFactory.invokeHasTransactional(OdsTransactionProxyFactory.java:123)
at sun.myproxy.OdsTransactionCglibFactory.intercept(OdsTransactionCglibFactory.java:88)
at sun.myproxybean.MyServiceImpl$$EnhancerByCGLIB$$ba19a943.multi(<generated>)
at sun.mybatis.Main.main(Main.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

 

 

11 2022.7.16 支持一层继承

 

此代码不进仓库，完整代码在transaction 继承备案

 

注入B/C，不注入A

A

　　@Inject M1

　　@Inject M2

　　func() {

　　　　M1/M2.xxx　　　　报错 null

　　}

B/C extends A

　　@Inject M3

　　function() {

　　　　xxx

　　　　super.func();

　　}

 

12 2022.7.16

cglib debug的bug

ioc这段代码放着debug 没进断点，但事情做了，日志尽然也打了

去掉这段代码，报null，证明ioc是有用的，虽然debug没进去

对于本地demo，Run时，不会打“异常”（重复set），debug时有；对于线上，run时也有“异常”，但ioc确实不能少