mybatis-ResultMappingResolver类信息

ResultMappingResolver类介绍

一个ResultMap元素对应一个ResultMap对象
  resultMap元素中的idArg/result/association/collection元素对应一个ResultMapping对象,所有resultMap会有多个ResultMapping对象
  association/collection元素对应一个内映射的ResultMap
  不管是ResultMap对象还是内映射的ResultMap对象都被会加入到Configuration.resultMap属性

ration.resultMap属性

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一个ResultMap元素对应一个ResultMap对象

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  resultMap元素中的idArg/result/association/collection元素对应一个ResultMapping对象,所有resultMap会有多个ResultMapping对象

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  association/collection元素对应一个内映射的ResultMap

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  不管是ResultMap对象还是内映射的ResultMap对象都被会加入到Configuration.resultMap属性

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ResultMappingResolver类分析

public class ResultMapResolver {
  private final MapperBuilderAssistant assistant;
  private final String id;
  private final Class<?> type;
  private final String extend;
  private final Discriminator discriminator;
  private final List<ResultMapping> resultMappings;
  private final Boolean autoMapping;

  public ResultMap resolve() {
    return assistant.addResultMap(this.id, this.type, this.extend, this.discriminator, this.resultMappings, this.autoMapping);
  }

}

public class MapperBuilderAssistant extends BaseBuilder {
  ...
   public ResultMap addResultMap(String id,Class<?> type,String extend,Discriminator discriminator,List<ResultMapping> resultMappings,
      Boolean autoMapping) {
    id = applyCurrentNamespace(id, false);
    extend = applyCurrentNamespace(extend, true);
    if (extend != null) {
      if (!configuration.hasResultMap(extend)) {
        throw new IncompleteElementException("Could not find a parent resultmap with id '" + extend + "'");
      }
      ResultMap resultMap = configuration.getResultMap(extend);
      List<ResultMapping> extendedResultMappings = new ArrayList<ResultMapping>(resultMap.getResultMappings());
      extendedResultMappings.removeAll(resultMappings);
      // Remove parent constructor if this resultMap declares a constructor.
      boolean declaresConstructor = false;
      for (ResultMapping resultMapping : resultMappings) {
        if (resultMapping.getFlags().contains(ResultFlag.CONSTRUCTOR)) {
          declaresConstructor = true;
          break;
        }
      }
      if (declaresConstructor) {
        Iterator<ResultMapping> extendedResultMappingsIter = extendedResultMappings.iterator();
        while (extendedResultMappingsIter.hasNext()) {
          if (extendedResultMappingsIter.next().getFlags().contains(ResultFlag.CONSTRUCTOR)) {
            extendedResultMappingsIter.remove();
          }
        }
      }
      resultMappings.addAll(extendedResultMappings);
    }
    // 交由ResultMap.Builder来创建ResultMap对象
    ResultMap resultMap =
        new ResultMap.Builder(configuration, id, type, resultMappings, autoMapping).discriminator(discriminator).build();
    // 将ResultMap加载在Configuration中
    configuration.addResultMap(resultMap);
    return resultMap;
  }

}

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public class ResultMapResolver {

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  private final MapperBuilderAssistant assistant;

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  private final String id;

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  private final Class<?> type;

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  private final String extend;

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  private final Discriminator discriminator;

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  private final List<ResultMapping> resultMappings;

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  private final Boolean autoMapping;

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  public ResultMap resolve() {

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    return assistant.addResultMap(this.id, this.type, this.extend, this.discriminator, this.resultMappings, this.autoMapping);

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  }

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}

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public class MapperBuilderAssistant extends BaseBuilder {

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  ...

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   public ResultMap addResultMap(String id,Class<?> type,String extend,Discriminator discriminator,List<ResultMapping> resultMappings,

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      Boolean autoMapping) {

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    id = applyCurrentNamespace(id, false);

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    extend = applyCurrentNamespace(extend, true);

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    if (extend != null) {

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      if (!configuration.hasResultMap(extend)) {

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        throw new IncompleteElementException("Could not find a parent resultmap with id '" + extend + "'");

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      }

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      ResultMap resultMap = configuration.getResultMap(extend);

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      List<ResultMapping> extendedResultMappings = new ArrayList<ResultMapping>(resultMap.getResultMappings());

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      extendedResultMappings.removeAll(resultMappings);

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      // Remove parent constructor if this resultMap declares a constructor.

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      boolean declaresConstructor = false;

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      for (ResultMapping resultMapping : resultMappings) {

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        if (resultMapping.getFlags().contains(ResultFlag.CONSTRUCTOR)) {

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          declaresConstructor = true;

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          break;

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        }

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      }

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      if (declaresConstructor) {

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        Iterator<ResultMapping> extendedResultMappingsIter = extendedResultMappings.iterator();

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        while (extendedResultMappingsIter.hasNext()) {

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          if (extendedResultMappingsIter.next().getFlags().contains(ResultFlag.CONSTRUCTOR)) {

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            extendedResultMappingsIter.remove();

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          }

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        }

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      }

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      resultMappings.addAll(extendedResultMappings);

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    }

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    // 交由ResultMap.Builder来创建ResultMap对象  

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    ResultMap resultMap = 

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        new ResultMap.Builder(configuration, id, type, resultMappings, autoMapping).discriminator(discriminator).build();

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    // 将ResultMap加载在Configuration中  

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    configuration.addResultMap(resultMap);

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    return resultMap;

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  }

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}