Question

需要以下问题的帮助。我接受了测试并且失败了，我真的想知道答案，以便我可以研究它....

假设金字塔结构中的对象列表（C＃）具有以下属性：

id
名称
值
parentId的

示例（C＃）：

2016-08-04 21:18:09.472 ERROR 26837 --- [  restartedMain] o.s.boot.SpringApplication               : Application startup failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vinhosRestController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.algaworks.projeto.service.VinhosService com.algaworks.projeto.RestFull.VinhosRestController.vinhoService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vinhoService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.util.List com.algaworks.projeto.service.VinhosServImp.vinhos; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.algaworks.projeto.models.Vinho] found for dependency [collection of com.algaworks.projeto.models.Vinho]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:760) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
    at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:360) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:306) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174) [spring-boot-1.3.6.RELEASE.jar:1.3.6.RELEASE]
    at com.algaworks.projeto.WineApplication.main(WineApplication.java:10) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_101]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_101]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_101]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.3.6.RELEASE.jar:1.3.6.RELEASE]
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.algaworks.projeto.service.VinhosService com.algaworks.projeto.RestFull.VinhosRestController.vinhoService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vinhoService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.util.List com.algaworks.projeto.service.VinhosServImp.vinhos; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.algaworks.projeto.models.Vinho] found for dependency [collection of com.algaworks.projeto.models.Vinho]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    ... 22 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'vinhoService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.util.List com.algaworks.projeto.service.VinhosServImp.vinhos; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.algaworks.projeto.models.Vinho] found for dependency [collection of com.algaworks.projeto.models.Vinho]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1192) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1116) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:545) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    ... 24 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.util.List com.algaworks.projeto.service.VinhosServImp.vinhos; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.algaworks.projeto.models.Vinho] found for dependency [collection of com.algaworks.projeto.models.Vinho]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    ... 35 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.algaworks.projeto.models.Vinho] found for dependency [collection of com.algaworks.projeto.models.Vinho]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1373) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1071) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:545) ~[spring-beans-4.2.7.RELEASE.jar:4.2.7.RELEASE]
    ... 37 common frames omitted

2016-08-04 21:18:09.475  INFO 26837 --- [  restartedMain] .b.l.ClasspathLoggingApplicationListener : Application failed to start with classpath: [file:/home/ismael/Java/Wine/target/classes/]

Process finished with exit code 0

编写一个递归函数，该函数接受一个ID作为唯一参数，并循环一个未确定大小和级别数的数组或列表。递归函数将计算

var b = new block();
b.id = 100;
b.name = "block 100"
b.value = 102.50;
b.parentid = 99;

我需要一个能给我一个总价值的功能＆＃34;来自＆＃34;价值＆＃34;父母及其所有子女及其子女的财产。有人可以帮忙吗？

  block block1 = new block(1, null, "block 1", 11.34M);
    block block11 = new block(11, 1, "block 11", 234.34M);
      block block111 = new block(111, 11, "block 111", 111);
    block block12 = new block(12, 1, "block 12", 564);
    block block13 = new block (13, 1, "block 13", 342.23M);
      block block131 = new block(131, 13, "block 131", 945);
      block block132 = new block(132, 13, "block 132", 10M);
      block block133 = new block(133, 13, "block 133", 88M);
        block block1331 = new block(1331, 133, "block 1331", 45);

  block block2 = new block(2, null, "block 2", 234);
  block block3 = new block(3, null, "block 3", 1249.34M);

  blocks = new List<block>();
  blocks.Add(block1);
  blocks.Add(block11);
  blocks.Add(block111);
  blocks.Add(block12);
  blocks.Add(block13);
  blocks.Add(block131);
  blocks.Add(block132);
  blocks.Add(block133);
  blocks.Add(block1331);
  blocks.Add(block2);
  blocks.Add(block3);

  decimal sum = SumAll(1);
  Console.WriteLine(sum);
  Console.ReadKey();
}

Answer 1

为了让你感动（并希望用你迄今为止尝试过的方式编辑你的问题），你需要这样的东西：

// defined at class level/scope outside method
private List<block> blocks;

...

private int SumAll(int id) {
      var initialBlock = blocks.FirstOrDefault(b => b.id == id);
      int value = initialBlock.Value;

      var childBlocks = blocks.Where(b => b.parentId = id).ToList();
      foreach (var childBlock in childBlocks) {
            // recursive call for children
            value += SumAll(childBlock.id);
      }

      return value;
}

Answer 2

这对我有用：

var lookup = blocks.ToLookup(x => x.parentid, x => x.id);
var map = blocks.ToDictionary(x => x.id);
Func<int, decimal> sumAll = null;
sumAll = n => map[n].value + lookup[n].Select(x => sumAll(x)).Sum();

只需致电sumAll(1)。

public decimal SumAll(List<block> blocks, int id)
{
    return SumAll(id, blocks.ToLookup(x => x.parentid, x => x.id), blocks.ToDictionary(x => x.id));
}

private decimal SumAll(int id, ILookup<int?, int> lookup, Dictionary<int, block> map)
{
    return map[id].value + lookup[id].Select(x => SumAll(x, lookup, map)).Sum();
}

只需致电SumAll(blocks, 1)。

使用递归来获取父值和子值以及其子项的所有值

2 个答案: