Question

我必须创建一个原子的[INFO] Error stacktraces are turned on. [INFO] Scanning for projects... [WARNING] [WARNING] Some problems were encountered while building the effective model for synchroProject:synchroProject:war:0.0.1-SNAPSHOT [WARNING] 'build.plugins.plugin.(groupId:artifactId)' must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-compiler-plugin @ line 27, column 15 [WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent! [INFO] Copying 1 resource [INFO] [INFO] --- maven-compiler-plugin:3.7.0:compile (default-compile) @ synchroProject --- [INFO] Changes detected - recompiling the module! [WARNING] File encoding has not been set, using platform encoding Cp1252, i.e. build is platform dependent! [INFO] Compiling 3 source files to C:\Users\anonyme\eclipse-workspace\synchroProject\target\classes [INFO] ------------------------------------------------------------- [ERROR] COMPILATION ERROR : [INFO] ------------------------------------------------------------- [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[15,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[16,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[21,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[22,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[21,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[22,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[29,6] cannot find symbol symbol: class NotNull location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[32,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[35,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[50,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[37,6] cannot find symbol symbol: class NotNull location: class com.sagemcom.tn.entities.PersonneGroupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[40,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.PersonneGroupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[49,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.PersonneGroupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[52,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.PersonneGroupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[37,6] cannot find symbol symbol: class NotNull location: class com.sagemcom.tn.entities.Groupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[40,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.Groupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[43,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.Groupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[46,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.Groupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[52,6] cannot find symbol symbol: class Size location: class com.sagemcom.tn.entities.Groupe [INFO] 22 errors [INFO] ------------------------------------------------------------- [INFO] ------------------------------------------------------------------------ [INFO] BUILD FAILURE [INFO] ------------------------------------------------------------------------ [INFO] Total time: 1.259 s [INFO] Finished at: 2017-11-26T23:23:30+01:00 [INFO] Final Memory: 14M/211M [INFO] ------------------------------------------------------------------------ [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:compile (default-compile) on project synchroProject: Compilation failure: Compilation failure: [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[15,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[16,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[21,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[22,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[21,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[22,36] package javax.validation.constraints does not exist [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[29,6] cannot find symbol [ERROR] symbol: class NotNull [ERROR] location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[32,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[35,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[38,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[41,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[44,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Personne.java:[50,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Personne [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[37,6] cannot find symbol [ERROR] symbol: class NotNull [ERROR] location: class com.sagemcom.tn.entities.PersonneGroupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[40,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.PersonneGroupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[49,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.PersonneGroupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/PersonneGroupe.java:[52,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.PersonneGroupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[37,6] cannot find symbol [ERROR] symbol: class NotNull [ERROR] location: class com.sagemcom.tn.entities.Groupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[40,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Groupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[43,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Groupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[46,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Groupe [ERROR] /C:/Users/anonyme/eclipse-workspace/synchroProject/src/com/sagemcom/tn/entities/Groupe.java:[52,6] cannot find symbol [ERROR] symbol: class Size [ERROR] location: class com.sagemcom.tn.entities.Groupe [ERROR] -> [Help 1] org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.7.0:compile (default-compile) on project synchroProject: Compilation failure at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80) at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106) at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288) at org.apache.maven.cli.MavenCli.main(MavenCli.java:199) 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 org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356) Caused by: org.apache.maven.plugin.compiler.CompilationFailureException: Compilation failure at org.apache.maven.plugin.compiler.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:1161) at org.apache.maven.plugin.compiler.CompilerMojo.execute(CompilerMojo.java:168) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207) ... 20 more [ERROR] [ERROR] Re-run Maven using the -X switch to enable full debug logging. [ERROR] [ERROR] For more information about the errors and possible solutions, please read the following articles: [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException。

NSOperationQueue

我有这个吸气剂：

@property (atomic, strong) NSOperationQueue *queue;

但是Xcode说我必须创建一个setter。

我的这个案子应该怎么做？我不知道。

Answer 1

两个观察结果：

如果你要定义自己的setter，它可能看起来像：
```
- (void)setQueue:(NSOperationQueue *)queue {
    _queue = queue; 
}
```
请记住，如果同时实施两种访问方法（setter和getter），则必须手动合成ivar，例如：
```
@synthesize queue = _queue;
```
在@implementation中，因为编译器无法再安全地假设您需要特定名称的ivar。
您应该重新审视这应该是atomic还是nonatomic。你的getter不是atomic（也不是我的示例设置器），所以你可能只想制作这个nonatomic。成为atomic＆＃34;意味着合成访问器确保始终通过getter方法完全检索值或通过setter方法完全设置，即使从不同的线程同时调用访问器也是如此。（来自Programming with Objective-C: Properties are atomic by default）。您通常不需要原子访问器方法，但如果您这样做，您将更改这些实现以进行相应的同步（例如，使用NSLock，@synchronized指令，串行队列，读写器模式等）。

请注意，如果您已将其设为nonatomic，那么您也无需为自定义getter编写自定义setter。如果您为atomic属性实现了自己的getter，则编译器无法合成相应的atomic setter，因为它无法知道如何将其setter与getter同步（因为有很多不同的可能）同步机制）。但是如果你创建你的属性nonatomic，那里不需要同步，编译器可以为你合成简单的，不同步的setter，并且指示你实现setter的警告也会消失。
< / LI>

Answer 2

首先，您声明了属性＆＃34; queue＆＃34;是一个读/写属性。这没有意义。你真的不希望每个人都分配到＃34;队列＆＃34;。

其次，您将该属性声明为＆＃34; atomic＆＃34;。你要么读到＆＃34; atomic＆＃34;是的，或者你只是相信我，这是非常罕见的，它是有用的。手写的getter或setter总是非原子的。所以你有一个非原子的getter，并且因为属性本身是一个原子读/写属性，你有一个自动生成的原子的setter。您不能将非原子吸气剂与原子设定器结合使用，反之亦然。

如何解决：将属性更改为非原子和只读。一个副作用是你丢失了_queue支持变量（如果实现了所有必需的访问器，你就不会得到支持变量），所以你必须自己声明_queue。

为NSOperationQueue创建一个Setter

2 个答案: