Java 自动关联定义为<;util:set>;春天
我试图在Spring上下文中定义Java 自动关联定义为<;util:set>;春天,java,spring,Java,Spring,我试图在Spring上下文中定义集,如下所示: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:util="http://www.springframework.org/
集,如下所示:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:util="http://www.springframework.org/schema/util"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">
<context:component-scan base-package="org.foo"/>
<!-- Artifact LocationResolvers -->
<bean id="fsLocationResolver" class="org.foo.storage.resolvers.FSLocationResolver" />
<bean id="memoryLocationResolver" class="org.foo.storage.resolvers.InMemoryLocationResolver" />
<!-- The Set<LocationResolver> -->
<util:set id="resolvers" value-type="org.foo.storage.resolvers.LocationResolver">
<ref bean="memoryLocationResolver"/>
<ref bean="fsLocationResolver"/>
</util:set>
<bean id="configurationManager"
class="org.foo.configuration.ConfigurationManager"
init-method="init">
</bean>
<bean id="artifactResolutionService" class="org.foo.resolvers.ArtifactResolutionService">
<property name="resolvers" ref="resolvers"/>
</bean>
</beans>
我的ConfigurationManager
课程:
package org.foo.configuration;
import org.foo.resource.ConfigurationResourceResolver;
import org.foo.storage.Storage;
import org.foo.storage.resolvers.ArtifactResolutionService;
import org.foo.storage.resolvers.LocationResolver;
import org.foo.xml.parsers.ConfigurationParser;
import java.io.IOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Component;
@Component
@Scope ("singleton")
public class ConfigurationManager
{
private static final Logger logger = LoggerFactory.getLogger(ConfigurationManager.class);
private String configurationPath;
private Configuration configuration;
@Autowired
private ConfigurationResourceResolver configurationResourceResolver;
@Autowired
private ArtifactResolutionService artifactResolutionService;
public ConfigurationManager()
{
}
public void init()
throws IOException
{
Resource resource = configurationResourceResolver.getConfigurationResource("etc/configuration.xml",
"repository.config.xml",
"etc/configuration.xml");
logger.info("Loading configuration from " + resource.toString() + "...");
ConfigurationParser parser = new ConfigurationParser();
configuration = parser.parse(resource.getInputStream());
configuration.setResource(resource);
dump();
}
public void dump()
{
System.out.println("Configuration version: " + configuration.getVersion());
System.out.println("Listening on port: " + configuration.getPort());
System.out.println("Loading storages...");
for (String storageKey : configuration.getStorages().keySet())
{
System.out.println(" -> Storage: " + storageKey);
Storage storage = configuration.getStorages().get(storageKey);
for (String repositoryKey : storage.getRepositories().keySet())
{
System.out.println(" -> Repository: " + repositoryKey);
}
}
//
// This throws a NullPointerException, as the resolvers are null.
//
System.out.println("Loading resolvers...");
for (LocationResolver resolver : artifactResolutionService.getResolvers())
{
System.out.println(" -> " + resolver.getClass());
}
}
public void storeConfiguration(Configuration configuration, String file)
throws IOException
{
ConfigurationParser parser = new ConfigurationParser();
parser.store(configuration, file);
}
public Configuration getConfiguration()
{
return configuration;
}
public void setConfiguration(Configuration configuration)
{
this.configuration = configuration;
}
public String getConfigurationPath()
{
return configurationPath;
}
public void setConfigurationPath(String configurationPath)
{
this.configurationPath = configurationPath;
}
public ArtifactResolutionService getArtifactResolutionService()
{
return artifactResolutionService;
}
public void setArtifactResolutionService(ArtifactResolutionService artifactResolutionService)
{
this.artifactResolutionService = artifactResolutionService;
}
}
然而,解析器
,最终变成了null
,我似乎无法理解这一点。有没有什么明显的,我做错了
非常感谢 应该注意两件事
首先你有这个
<context:component-scan base-package="org.foo"/>
这意味着您正在隐式地创建一个ArtifactResolutionService
bean。你也有
<bean id="artifactResolutionService" class="org.foo.resolvers.ArtifactResolutionService">
<property name="resolvers" ref="resolvers"/>
</bean>
将实际拾取所有LocationResolver
bean,而不是此处定义的Set
bean
<!-- The Set<LocationResolver> -->
<util:set id="resolvers" value-type="org.foo.storage.resolvers.LocationResolver">
<ref bean="memoryLocationResolver"/>
<ref bean="fsLocationResolver"/>
</util:set>
应该注意两件事
首先你有这个
<context:component-scan base-package="org.foo"/>
这意味着您正在隐式地创建一个ArtifactResolutionService
bean。你也有
<bean id="artifactResolutionService" class="org.foo.resolvers.ArtifactResolutionService">
<property name="resolvers" ref="resolvers"/>
</bean>
将实际拾取所有LocationResolver
bean,而不是此处定义的Set
bean
<!-- The Set<LocationResolver> -->
<util:set id="resolvers" value-type="org.foo.storage.resolvers.LocationResolver">
<ref bean="memoryLocationResolver"/>
<ref bean="fsLocationResolver"/>
</util:set>
您在哪里使用ArtifactResolutionService
?您有两个ArtifactResolutionService
实例。一个是通过组件扫描检测到的,另一个是用XML配置的。使用
@SotiriosDelimanolis已经暗示了一个提示:谢谢你的回答!我已经删除了组件扫描
并按照建议添加了@资源
,但是解析程序仍然是空的
。你在哪里调用配置管理器#init
方法?@SotiriosDelimanolis:我想知道问题是否与init方法
有关?具体什么时候调用?在字段值自动连线之前或之后?您在哪里使用ArtifactResolutionService
?您有两个ArtifactResolutionService
实例。一个是通过组件扫描检测到的,另一个是用XML配置的。使用
@SotiriosDelimanolis已经暗示了一个提示:谢谢你的回答!我已经删除了组件扫描
并按照建议添加了@资源
,但是解析程序仍然是空的
。你在哪里调用配置管理器#init
方法?@SotiriosDelimanolis:我想知道问题是否与init方法
有关?具体什么时候调用?在字段值自动连接之前或之后?@carlspring您可以发布NPE的堆栈跟踪吗?根据您的请求,我已将异常粘贴到此处:@carlspring您的LocationResolver
bean似乎有一个对ConfigurationManager
的反向引用。这可能会导致种族问题。哪个bean首先被初始化并被注入?这些循环依赖关系可能是一个问题。仔细看看。这也是我的赌注,不管它值多少钱。你们会建议我如何处理它?@carlspring你能发布NPE的堆栈跟踪吗?根据你的要求,我已经在这里粘贴了一个例外:。@carlspring你的LocationResolver
bean似乎有一个对ConfigurationManager
的反向引用。这可能会导致种族问题。哪个bean首先被初始化并被注入?这些循环依赖关系可能是一个问题。看看吧。这也是我的赌注,不管它值多少钱。你们会建议我怎么处理它?
@Resource(name = "resolvers")
private Set<LocationResolver> resolvers;