Spring源码学习--BeanDefinitionHolder

上一篇博客​​Spring源码学习--Bean注入解析结果BeanDefinition​​我们已经介绍了BeanDefinition相关的知识，这边博客我们介绍一下BeanDefinitionHolder，简单来说其就是一个BeanDefinition的持有者，其定义了一下变量，并对以下变量提供get和set操作。

private final BeanDefinition beanDefinition;

private final String beanName;

private final String[] aliases;

BeanDefinitionHolder的源码中都是有关这几个变量的get和set操作。

public class BeanDefinitionHolder implements BeanMetadataElement {

  private final BeanDefinition beanDefinition;

  private final String beanName;

  private final String[] aliases;


  
  public BeanDefinitionHolder(BeanDefinition beanDefinition, String beanName) {
    this(beanDefinition, beanName, null);
  }

  
  public BeanDefinitionHolder(BeanDefinition beanDefinition, String beanName, String[] aliases) {
    Assert.notNull(beanDefinition, "BeanDefinition must not be null");
    Assert.notNull(beanName, "Bean name must not be null");
    this.beanDefinition = beanDefinition;
    this.beanName = beanName;
    this.aliases = aliases;
  }

  
  public BeanDefinitionHolder(BeanDefinitionHolder beanDefinitionHolder) {
    Assert.notNull(beanDefinitionHolder, "BeanDefinitionHolder must not be null");
    this.beanDefinition = beanDefinitionHolder.getBeanDefinition();
    this.beanName = beanDefinitionHolder.getBeanName();
    this.aliases = beanDefinitionHolder.getAliases();
  }


  
  public BeanDefinition getBeanDefinition() {
    return this.beanDefinition;
  }

  public String getBeanName() {
    return this.beanName;
  }

  
  public String[] getAliases() {
    return this.aliases;
  }

  
  @Override
  public Object getSource() {
    return this.beanDefinition.getSource();
  }

  
  public boolean matchesName(String candidateName) {
    return (candidateName != null && (candidateName.equals(this.beanName) ||
        candidateName.equals(BeanFactoryUtils.transformedBeanName(this.beanName)) ||
        ObjectUtils.containsElement(this.aliases, candidateName)));
  }


  
  public String getShortDescription() {
    StringBuilder sb = new StringBuilder();
    sb.append("Bean definition with name '").append(this.beanName).append("'");
    if (this.aliases != null) {
      sb.append(" and aliases [").append(StringUtils.arrayToCommaDelimitedString(this.aliases)).append("]");
    }
    return sb.toString();
  }

  
  public String getLongDescription() {
    StringBuilder sb = new StringBuilder(getShortDescription());
    sb.append(": ").append(this.beanDefinition);
    return sb.toString();
  }

  
  @Override
  public String toString() {
    return getLongDescription();
  }


  @Override
  public boolean equals(Object other) {
    if (this == other) {
      return true;
    }
    if (!(other instanceof BeanDefinitionHolder)) {
      return false;
    }
    BeanDefinitionHolder otherHolder = (BeanDefinitionHolder) other;
    return this.beanDefinition.equals(otherHolder.beanDefinition) &&
        this.beanName.equals(otherHolder.beanName) &&
        ObjectUtils.nullSafeEquals(this.aliases, otherHolder.aliases);
  }

  @Override
  public int hashCode() {
    int hashCode = this.beanDefinition.hashCode();
    hashCode = 29 * hashCode + this.beanName.hashCode();
    hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.aliases);
    return hashCode;
  }

}