找不到类型的 java.util.Date bean

Question

Spring Boot 应用程序在运行时失败，并出现以下错误:

***************************
APPLICATION FAILED TO START
***************************
Description:

Parameter 0 of constructor in com.bla.Application.Domain.SomeJavaClass required a bean of type 'java.util.Date' that could not be found.

Action:

Consider defining a bean of type 'java.util.Date' in your configuration.

我正在使用:

1. Spring Boot(v1.5.8.RELEASE)
2. STS4 集成开发环境
3. Java 8
4. Linux Ubuntu 18

user@host:~$ java -version
openjdk版本“1.8.0_222” OpenJDK 运行时环境(版本 1.8.0_222-8u222-b10-1ubuntu1~18.04.1-b10)
OpenJDK 64 位服务器虚拟机(版本 25.222-b10，混合模式)

我完全重装了Java，错误还是一样...有问题的类:

有问题的类位于域模型中:

package com.vip.SmartScheduler.Domain;

import java.util.Date;
import java.util.List;

import org.springframework.stereotype.Component;

import com.vip.SmartScheduler.Enum.PeriodUnit;

@Component
public class PeriodContainer {

    private Date periodBeginTimestamp;
    private List<UserStats> agentsWithStatistics;
    private PeriodUnit periodUnit;

    public PeriodContainer(Date periodBeginTimestamp, List<UserStats> agents, PeriodUnit periodUnit){
        this.periodBeginTimestamp = periodBeginTimestamp;
        this.agentsWithStatistics = agents;
        this.periodUnit = periodUnit;
    }

    public Date getPeriodBeginTimestamp() {
        return periodBeginTimestamp;
    }

    public void setPeriodBeginTimestamp(Date periodBeginTimestamp) {
        this.periodBeginTimestamp = periodBeginTimestamp;
    }

    public List<UserStats> getAgentsWithStatistics() {
        return agentsWithStatistics;
    }

    public void setAgentsWithStatistics(List<UserStats> agents) {
        this.agentsWithStatistics = agents;
    }

    public PeriodUnit getPeriodUnit() {
        return periodUnit;
    }

    public void setPeriodUnit(PeriodUnit periodUnit) {
        this.periodUnit = periodUnit;
    }

}

Answer 1

问题是你的类有其构造函数的参数，但你没有为你的参数定义bean

您可以做几件事:

定义您的 Bean

@Configuration
public class MyBeans {

  @Bean
  public Date periodBeginTimestamp() {
    return new Date();
  }

  @Bean
  public List<UserStats> agents() {
    return new ArrayList<UserStats>();
  }

  @Bean
  public PeriodUnit periodUnit() {
    return new PeriodUnit();
  }

}

这将创建必要的 bean 来注入(inject)您的参数，但不确定这是否会给您提供用于填充值的控件。

零参数构造函数

另一种方法是创建一个零参数构造函数，然后有一个方法来设置您需要的内容:

@Component
public class PeriodContainer {

  private Date periodBeginTimestamp;
  private List<UserStats> agentsWithStatistics;
  private PeriodUnit periodUnit;

  public PeriodContainer(){}

  public void setValues(Date periodBeginTimestamp, List<UserStats> agents, PeriodUnit periodUnit){
    this.periodBeginTimestamp = periodBeginTimestamp;
    this.agentsWithStatistics = agents;
    this.periodUnit = periodUnit;
  }

  ...
}

那么你需要它吗:

@Service
public class MyClass {
  @Autowire
  private PeriodContainer container;

  @PostConstruct
  private void init() {
    Date periodBeginTimestamp = getTimeStamp();
    List<UserStats> agents = getUserStatsList();
    PeriodUnit periodUnit = getPeriodUnit();
    container.setValues(periodBeginTimestamp, agents, periodUnit); 
  }
}