小编Asi*_*med的帖子

我想声明将在项目中的各个类中使用的字符串常量.我正在考虑两种选择

选项1:

#header file 
class constants{
    static const string const1;
};

#cpp file

const string constants::const1="blah";

选项2:

#header file 
namespace constants{
    static const string const1="blah";
};

只是想知道什么是更好的实现.

已经看过了

在C++中存储类特定命名常量的位置

在C++中放置常量字符串的位置:静态类成员或匿名名称空间

更新:

选项3:

根据"potatoswatter"和"sellibitze"的建议,我目前有以下实施方案？

#header file
namespace constants{
    extern const string& const1(); //WORKS WITHOUT THE EXTERN  ***WHY***
};

#cpp file
namespace constants{
   const string& const1(){static string* str = new string ("blah"); return *str;}
}

我包含头文件,我需要使用常量.这种实施有什么主要缺点吗？

当我尝试在Visual Studio 2008中进行调试时,我收到以下错误.我已经清理了ASP.NET临时文件夹并重新启动了VS. 我还删除了所谓的破坏参考并将其添加回来.但似乎没有任何效果.有没有人遇到类似的情况,有没有解决方案？

无法加载文件或程序集"GCS.Common(asif mohammed的冲突副本2010-01-29)"或其依赖项之一.给定的程序集名称或代码库无效.(HRESULT异常:0x80131047)

[FileLoadException:无法加载文件或程序集'"GCS.Common(asif mohammed的冲突副本2010-01-29)"或其依赖项之一.给定的程序集名称或代码库无效.(来自HRESULT的异常:0x80131047)]
System.Reflection.AssemblyName.nInit(Assembly&assembly,Boolean forIntrospection,Boolean raiseResolveEvent)+0
System.Reflection.Assembly.InternalLoad(String assemblyString,Evidence assemblySecurity,StackCrawlMark&stackMark,Boolean forIntrospection)+114 System .Reflection.Assembly.Load(String assemblyString)+28
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName,Boolean starDirective)+46

[ConfigurationErrorsException:无法加载文件或程序集'"GCS.Common(asif mohammed的冲突副本2010-01-29)"'或其依赖项之一.给定的程序集名称或代码库无效.(来自HRESULT的异常:0x80131047)]
System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName,Boolean starDirective)+613 System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory()+203 System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo) ai)+105
System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig)+178
System.Web.Compilation.BuildProvidersCompiler..ctor(VirtualPath configPath,Boolean supportLocalization,String outputAssemblyName)+54
System.Web.Compilation.CodeDirectoryCompiler.GetCodeDirectoryAssembly (VirtualPath virtualDir,CodeDirectoryType dirType,String assemblyName,StringSet excludedSubdirectories,Boolean isDirectoryAllowed)+8809426
System.Web.Compilation.BuildManager.CompileCodeDirectory(VirtualPath virtualDir,CodeDirectoryType dirType,String assemblyName,StringSet excludedSubdirectories)+128
System.Web.Compilation.BuildManager. CompileCodeDirectories()+26 5 System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled()+ 320

[HttpException(0x80004005):无法加载文件或程序集"GCS.Common(asif mohammed的冲突副本2010-01-29)"或其依赖项之一.给定的程序集名称或代码库无效.(来自HRESULT的异常:0x80131047)]
System.Web.Compilation.BuildManager.ReportTopLevelCompilationException()+ 58 System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled()+512 System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager,IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory,HostingEnvironmentParameters hostingParameters)+729

[HttpException(0x80004005):无法加载文件或程序集"GCS.Common(asif mohammed的冲突副本2010-01-29)"或其依赖项之一.给定的程序集名称或代码库无效.(来自HRESULT的异常:0x80131047)]
System.Web.HttpRuntime.FirstRequestInit(HttpContext context)+8890735
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context)+85
System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr)+259

我正在使用hbmddl.autoset在hibernate配置文件中创建并使用它以网络模式连接到derby数据库(未嵌入,不知道是否相关).

这是我的 hibernate.cfg.xml

    <!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">org.apache.derby.jdbc.ClientDriver</property>
        <property name="connection.url">jdbc:derby://localhost:1527/HibernateDb;create=true</property>
        <property name="connection.username">admin</property>
        <property name="connection.password">admin</property>

        <!-- JDBC connection pool (use the built-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.DerbyDialect</property>

        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

        <!-- Drop and re-create the database schema on startup -->
        <property name="hbm2ddl.auto">create-drop</property>

        <!-- Names the annotated entity class …

我正在尝试使用本网络研讨会中概述的单独模式方法将多租户添加到Java应用程序

我想知道如何通过spring配置多个数据源,可能是使用属性文件,并根据租户id从spring上下文中获取数据源.

更重要的是,虽然我希望能够配置我的自定义连接提供程序实现,该实现支持Hibernate使用的多租户功能,而不是ConnectionProvider默认情况下使用的注入.

我怎样才能做到这一点.

当我尝试编译以下内容时出现编译错误.....请评论.

这是我的代码:ffs.h

#ifndef FFS_H
#define FFS_H
     #include <iostream>
        #include <string>
        #include "commands.h"

        class ffs{
        private:
            Filesystem *filesys;
            Superblock block;
            void processCommands(InputParser command);
            void performQuit();
            void performInit(InputParser command);

        public:
            void acceptCommands();
            ffs(){};
        };

        #endif 

ffs.cpp

#include "ffs.h"

void ffs::acceptCommands(){
    std::string input;
    while(true){
        std::cout<< "Enter command : ";
        getline(std::cin,input);
        InputParser parser(input);
        processCommands(parser);
    }
}

void ffs::performInit(InputParser command){
    command.getCommand().pop_front();
    int n = atoi(command.getCommand().front().c_str());
    std::cout<< n << " : number of blocks "<<std::endl;
    command.getCommand().pop_front();
    int m = atoi(command.getCommand().front().c_str());
    std::cout<<m << " : number of …