利用AOP实现SqlSugar自动事务

2020-01-24 00:26:34

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本文实例为大家分享了如何利用AOP实现SqlSugar自动事务，供大家参考，具体内容如下

先看一下效果,带接口层的三层架构:

BL层：

 public class StudentBL : IStudentService   {     private ILogger mLogger;     private readonly IStudentDA mStudentDa;     private readonly IValueService mValueService;     public StudentService(IStudentDA studentDa,IValueService valueService)     {       mLogger = LogManager.GetCurrentClassLogger();       mStudentDa = studentDa;       mValueService = valueService;     }     [TransactionCallHandler]     public IList<Student> GetStudentList(Hashtable paramsHash)     {       var list = mStudentDa.GetStudents(paramsHash);       var value = mValueService.FindAll();       return list;     }   }

假设GetStudentList方法里的mStudentDa.GetStudents和mValueService.FindAll不是查询操作，而是更新操作，当一个失败另一个需要回滚，就需要在同一个事务里，当一个出现异常就要回滚事务。

特性TransactionCallHandler就表明当前方法需要开启事务，并且当出现异常的时候回滚事务,方法执行完后提交事务。

DA层：

 public class StudentDA : IStudentDA   {     private SqlSugarClient db;     public StudentDA()     {       db = SugarManager.GetInstance().SqlSugarClient;     }     public IList<Student> GetStudents(Hashtable paramsHash)     {       return db.Queryable<Student>().AS("T_Student").With(SqlWith.NoLock).ToList();     }   }

对SqlSugar做一下包装

 public class SugarManager   {     private static ConcurrentDictionary<string,SqlClient> _cache =       new ConcurrentDictionary<string, SqlClient>();     private static ThreadLocal<string> _threadLocal;     private static readonly string _connStr = @"Data Source=localhost;port=3306;Initial Catalog=thy;user id=root;password=xxxxxx;Charset=utf8";     static SugarManager()     {       _threadLocal = new ThreadLocal<string>();     }     private static SqlSugarClient CreatInstance()     {       SqlSugarClient client = new SqlSugarClient(new ConnectionConfig()       {         ConnectionString = _connStr, //必填         DbType = DbType.MySql, //必填         IsAutoCloseConnection = true, //默认false         InitKeyType = InitKeyType.SystemTable       });       var key=Guid.NewGuid().ToString().Replace("-", "");       if (!_cache.ContainsKey(key))       {         _cache.TryAdd(key,new SqlClient(client));         _threadLocal.Value = key;         return client;       }       throw new Exception("创建SqlSugarClient失败");     }     public static SqlClient GetInstance()     {       var id= _threadLocal.Value;       if (string.IsNullOrEmpty(id)||!_cache.ContainsKey(id))         return new SqlClient(CreatInstance());       return _cache[id];     }     public static void Release()     {       try       {         var id = GetId();         if (!_cache.ContainsKey(id))           return;         Remove(id);       }       catch (Exception e)       {         throw e;       }     }     private static bool Remove(string id)     {       if (!_cache.ContainsKey(id)) return false;       SqlClient client;       int index = 0;       bool result = false;       while (!(result = _cache.TryRemove(id, out client)))       {         index++;         Thread.Sleep(20);         if (index > 3) break;       }       return result;     }     private static string GetId()     {       var id = _threadLocal.Value;       if (string.IsNullOrEmpty(id))       {         throw new Exception("内部错误: SqlSugarClient已丢失.");       }       return id;     }     public static void BeginTran()     {       var instance=GetInstance();       //开启事务       if (!instance.IsBeginTran)       {         instance.SqlSugarClient.Ado.BeginTran();         instance.IsBeginTran = true;       }     }     public static void CommitTran()     {       var id = GetId();       if (!_cache.ContainsKey(id))         throw new Exception("内部错误: SqlSugarClient已丢失.");       if (_cache[id].TranCount == 0)       {         _cache[id].SqlSugarClient.Ado.CommitTran();         _cache[id].IsBeginTran = false;       }     }     public static void RollbackTran()     {       var id = GetId();       if (!_cache.ContainsKey(id))         throw new Exception("内部错误: SqlSugarClient已丢失.");       _cache[id].SqlSugarClient.Ado.RollbackTran();       _cache[id].IsBeginTran = false;       _cache[id].TranCount = 0;     }     public static void TranCountAddOne()     {       var id = GetId();       if (!_cache.ContainsKey(id))         throw new Exception("内部错误: SqlSugarClient已丢失.");       _cache[id].TranCount++;     }     public static void TranCountMunisOne()     {       var id = GetId();       if (!_cache.ContainsKey(id))         throw new Exception("内部错误: SqlSugarClient已丢失.");       _cache[id].TranCount--;     }   }

_cache保存SqlSugar实例，_threadLocal确保同一线程下取出的是同一个SqlSugar实例。

不知道SqlSugar判断当前实例是否已经开启事务，所以又将SqlSugar包了一层。

 public class SqlClient   {     public SqlSugarClient SqlSugarClient;     public bool IsBeginTran = false;     public int TranCount = 0;     public SqlClient(SqlSugarClient sqlSugarClient)     {       this.SqlSugarClient = sqlSugarClient;     }   }

IsBeginTran标识当前SqlSugar实例是否已经开启事务，TranCount是一个避免事务嵌套的计数器。

一开始的例子

 [TransactionCallHandler]      public IList<Student> GetStudentList(Hashtable paramsHash)      {        var list = mStudentDa.GetStudents(paramsHash);        var value = mValueService.FindAll();        return list;      }

TransactionCallHandler表明该方法要开启事务，但是如果mValueService.FindAll也标识了TransactionCallHandler,又要开启一次事务？所以用TranCount做一个计数。

使用Castle.DynamicProxy

要实现标识了TransactionCallHandler的方法实现自动事务，使用Castle.DynamicProxy实现BL类的代理

Castle.DynamicProxy一般操作

 public class MyClass : IMyClass  {    public void MyMethod()    {      Console.WriteLine("My Mehod");    } } public class TestIntercept : IInterceptor   {     public void Intercept(IInvocation invocation)     {       Console.WriteLine("before");       invocation.Proceed();       Console.WriteLine("after");     }   }  var proxyGenerate = new ProxyGenerator();  TestIntercept t=new TestIntercept();  var pg = proxyGenerate.CreateClassProxy<MyClass>(t);  pg.MyMethod();  //输出是  //before  //My Mehod  //after

before就是要开启事务的地方，after就是提交事务的地方

最后实现

 public class TransactionInterceptor : IInterceptor   {     private readonly ILogger logger;     public TransactionInterceptor()     {       logger = LogManager.GetCurrentClassLogger();     }     public void Intercept(IInvocation invocation)     {       MethodInfo methodInfo = invocation.MethodInvocationTarget;       if (methodInfo == null)       {         methodInfo = invocation.Method;       }       TransactionCallHandlerAttribute transaction =         methodInfo.GetCustomAttributes<TransactionCallHandlerAttribute>(true).FirstOrDefault();       if (transaction != null)       {         SugarManager.BeginTran();         try         {           SugarManager.TranCountAddOne();           invocation.Proceed();           SugarManager.TranCountMunisOne();           SugarManager.CommitTran();         }         catch (Exception e)         {           SugarManager.RollbackTran();           logger.Error(e);           throw e;         }       }       else       {         invocation.Proceed();       }     }   }   [AttributeUsage(AttributeTargets.Method, Inherited = true)]   public class TransactionCallHandlerAttribute : Attribute   {     public TransactionCallHandlerAttribute()     {     }   }

Autofac与Castle.DynamicProxy结合使用

创建代理的时候一个BL类就要一次操作

 proxyGenerate.CreateClassProxy<MyClass>(t);

而且项目里BL类的实例化是交给IOC容器控制的，我用的是Autofac。当然Autofac和Castle.DynamicProxy是可以结合使用的

using System.Reflection;using Autofac;using Autofac.Extras.DynamicProxy;using Module = Autofac.Module;public class BusinessModule : Module  {    protected override void Load(ContainerBuilder builder)    {      var business = Assembly.Load("FTY.Business");      builder.RegisterAssemblyTypes(business)        .AsImplementedInterfaces().InterceptedBy(typeof(TransactionInterceptor)).EnableInterfaceInterceptors();      builder.RegisterType<TransactionInterceptor>();    }  }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持武林网。

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