org.apache.ibatis.executor.result.DefaultResultContext Java Examples

/**
 * Client code <b>must</b> call this method once the query returns so that the final results
 * can be passed to the inner RowHandler.  If a query is limited by size, then it is
 * possible that the unprocessed results represent an incomplete final object; in this case
 * it would be best to ignore the last results.  If the query is complete (i.e. all results
 * are returned) then this method should be called.
 * <p>
 * If you want X results and each result is made up of N rows (on average), then set the query
 * limit to: <br/>
 *   L = X * (N+1)<br/>
 * and don't call this method.
 */
public void processLastResults()
{
    // Shortcut if we have processed enough results
    if (maxResults > 0 && resultCount >= maxResults)
    {
        return;
    }
    // Handle any outstanding results
    Object resultObject = coalesceResults(configuration, rawResults, collectionProperty);
    if (resultObject != null)
    {
        DefaultResultContext resultContext = new DefaultResultContext();
        resultContext.nextResultObject(resultObject);
        
        resultHandler.handleResult(resultContext);
        resultCount++;
        rawResults.clear();                         // Stop it from being used again
    }
}
 

private void handleRowValuesForNestedResultMap(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping) throws SQLException {
  final DefaultResultContext resultContext = new DefaultResultContext();
  skipRows(rsw.getResultSet(), rowBounds);
  Object rowValue = null;
  while (shouldProcessMoreRows(resultContext, rowBounds) && rsw.getResultSet().next()) {
    final ResultMap discriminatedResultMap = resolveDiscriminatedResultMap(rsw.getResultSet(), resultMap, null);
    final CacheKey rowKey = createRowKey(discriminatedResultMap, rsw, null);
    Object partialObject = nestedResultObjects.get(rowKey);
    // issue #577 && #542
    if (mappedStatement.isResultOrdered()) {
      if (partialObject == null && rowValue != null) {
        nestedResultObjects.clear();
        storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
      }
      rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
    } else {
      rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
      if (partialObject == null) {
        storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
      }
    }
  }
  if (rowValue != null && mappedStatement.isResultOrdered() && shouldProcessMoreRows(resultContext, rowBounds)) {
    storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
  }
}
 

private void handleRowValuesForNestedResultMap(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping) throws SQLException {
  final DefaultResultContext resultContext = new DefaultResultContext();
  skipRows(rsw.getResultSet(), rowBounds);
  Object rowValue = null;
  while (shouldProcessMoreRows(resultContext, rowBounds) && rsw.getResultSet().next()) {
    final ResultMap discriminatedResultMap = resolveDiscriminatedResultMap(rsw.getResultSet(), resultMap, null);
    final CacheKey rowKey = createRowKey(discriminatedResultMap, rsw, null);
    Object partialObject = nestedResultObjects.get(rowKey);
    // issue #577 && #542
    if (mappedStatement.isResultOrdered()) {
      if (partialObject == null && rowValue != null) {
        nestedResultObjects.clear();
        storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
      }
      rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
    } else {
      rowValue = getRowValue(rsw, discriminatedResultMap, rowKey, rowKey, null, partialObject);
      if (partialObject == null) {
        storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
      }
    }
  }
  if (rowValue != null && mappedStatement.isResultOrdered() && shouldProcessMoreRows(resultContext, rowBounds)) {
    storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
  }
}
 

public void handleResult(ResultContext context)
{
    // Shortcut if we have processed enough results
    if (maxResults > 0 && resultCount >= maxResults)
    {
        return;
    }
    
    Object valueObject = context.getResultObject();
    MetaObject probe = configuration.newMetaObject(valueObject);
    
    // Check if the key has changed
    if (lastKeyValues == null)
    {
        lastKeyValues = getKeyValues(probe);
        resultCount = 0;
    }
    // Check if it has changed
    Object[] currentKeyValues = getKeyValues(probe);
    if (!Arrays.deepEquals(lastKeyValues, currentKeyValues))
    {
        // Key has changed, so handle the results
        Object resultObject = coalesceResults(configuration, rawResults, collectionProperty);
        if (resultObject != null)
        {
            DefaultResultContext resultContext = new DefaultResultContext();
            resultContext.nextResultObject(resultObject);
            
            resultHandler.handleResult(resultContext);
            resultCount++;
        }
        rawResults.clear();
        lastKeyValues = currentKeyValues;
    }
    // Add the new value to the results for next time
    rawResults.add(valueObject);
    // Done
}
 

@Override
public <K, V> Map<K, V> selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds) {
  //转而去调用selectList
  final List<?> list = selectList(statement, parameter, rowBounds);
  final DefaultMapResultHandler<K, V> mapResultHandler = new DefaultMapResultHandler<K, V>(mapKey,
      configuration.getObjectFactory(), configuration.getObjectWrapperFactory());
  final DefaultResultContext context = new DefaultResultContext();
  for (Object o : list) {
    //循环用DefaultMapResultHandler处理每条记录
    context.nextResultObject(o);
    mapResultHandler.handleResult(context);
  }
  //注意这个DefaultMapResultHandler里面存了所有已处理的记录(内部实现可能就是一个Map)，最后再返回一个Map
  return mapResultHandler.getMappedResults();
}
 

private void handleRowValuesForSimpleResultMap(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping)
    throws SQLException {
  DefaultResultContext resultContext = new DefaultResultContext();
  skipRows(rsw.getResultSet(), rowBounds);
  while (shouldProcessMoreRows(resultContext, rowBounds) && rsw.getResultSet().next()) {
    ResultMap discriminatedResultMap = resolveDiscriminatedResultMap(rsw.getResultSet(), resultMap, null);
    Object rowValue = getRowValue(rsw, discriminatedResultMap);
    storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
  }
}
 

private void storeObject(ResultHandler resultHandler, DefaultResultContext resultContext, Object rowValue, ResultMapping parentMapping, ResultSet rs) throws SQLException {
  if (parentMapping != null) {
    linkToParents(rs, parentMapping, rowValue);
  } else {
    callResultHandler(resultHandler, resultContext, rowValue);
  }
}
 

@Override
public <K, V> Map<K, V> selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds) {
  //转而去调用selectList
  final List<?> list = selectList(statement, parameter, rowBounds);
  final DefaultMapResultHandler<K, V> mapResultHandler = new DefaultMapResultHandler<K, V>(mapKey,
      configuration.getObjectFactory(), configuration.getObjectWrapperFactory());
  final DefaultResultContext context = new DefaultResultContext();
  for (Object o : list) {
    //循环用DefaultMapResultHandler处理每条记录
    context.nextResultObject(o);
    mapResultHandler.handleResult(context);
  }
  //注意这个DefaultMapResultHandler里面存了所有已处理的记录(内部实现可能就是一个Map)，最后再返回一个Map
  return mapResultHandler.getMappedResults();
}
 

private void handleRowValuesForSimpleResultMap(ResultSetWrapper rsw, ResultMap resultMap, ResultHandler resultHandler, RowBounds rowBounds, ResultMapping parentMapping)
    throws SQLException {
  DefaultResultContext resultContext = new DefaultResultContext();
  skipRows(rsw.getResultSet(), rowBounds);
  while (shouldProcessMoreRows(resultContext, rowBounds) && rsw.getResultSet().next()) {
    ResultMap discriminatedResultMap = resolveDiscriminatedResultMap(rsw.getResultSet(), resultMap, null);
    Object rowValue = getRowValue(rsw, discriminatedResultMap);
    storeObject(resultHandler, resultContext, rowValue, parentMapping, rsw.getResultSet());
  }
}
 

private void storeObject(ResultHandler resultHandler, DefaultResultContext resultContext, Object rowValue, ResultMapping parentMapping, ResultSet rs) throws SQLException {
  if (parentMapping != null) {
    linkToParents(rs, parentMapping, rowValue);
  } else {
    callResultHandler(resultHandler, resultContext, rowValue);
  }
}
 

@SuppressWarnings("unchecked")
@Override
public void selectChildAssocs(
        Long parentNodeId,
        QName assocTypeQName,
        QName assocQName,
        final int maxResults,
        ChildAssocRefQueryCallback resultsCallback)
{
    ChildAssocEntity assoc = new ChildAssocEntity();
    // Parent
    NodeEntity parentNode = new NodeEntity();
    parentNode.setId(parentNodeId);
    assoc.setParentNode(parentNode);

    // Type QName
    if (assocTypeQName != null)
    {
        if (!assoc.setTypeQNameAll(qnameDAO, assocTypeQName, false))
        {
            resultsCallback.done();
            return;                 // Shortcut
        }
    }
    // QName
    if (assocQName != null)
    {
        if (!assoc.setQNameAll(qnameDAO, assocQName, false))
        {
            resultsCallback.done();
            return;                 // Shortcut
        }
    }
    // Order
    assoc.setOrdered(resultsCallback.orderResults());

    ChildAssocResultHandler resultHandler = new ChildAssocResultHandler(resultsCallback);
    
    RowBounds rowBounds = new RowBounds(0, maxResults);
    List<?> entities = template.selectList(SELECT_CHILD_ASSOCS_OF_PARENT_LIMITED, assoc, rowBounds);
    @SuppressWarnings("rawtypes")
    final DefaultResultContext resultContext = new DefaultResultContext();
    for (Object entity : entities)
    {
          resultContext.nextResultObject(entity);
          resultHandler.handleResult(resultContext);
    }
    
    resultsCallback.done();
}
 

private void callResultHandler(ResultHandler resultHandler, DefaultResultContext resultContext, Object rowValue) {
  resultContext.nextResultObject(rowValue);
  resultHandler.handleResult(resultContext);
}
 

private void callResultHandler(ResultHandler resultHandler, DefaultResultContext resultContext, Object rowValue) {
  resultContext.nextResultObject(rowValue);
  resultHandler.handleResult(resultContext);
}