Solr
  1. Solr
  2. SOLR-4048

Add a "findRecursive" method to NamedList

    Details

    • Type: New Feature New Feature
    • Status: Closed
    • Priority: Minor Minor
    • Resolution: Fixed
    • Affects Version/s: 4.0
    • Fix Version/s: 4.4, Trunk
    • Component/s: None
    • Labels:
      None

      Description

      Most of the time when accessing data from a NamedList, what you'll be doing is using get() to retrieve another NamedList, and doing so over and over until you reach the final level, where you'll actually retrieve the value you want.

      I propose adding a method to NamedList which would do all that heavy lifting for you. I created the following method for my own code. It could be adapted fairly easily for inclusion into NamedList itself. The only reason I did not include it as a patch is because I figure you'll want to ensure it meets all your particular coding guidelines, and that the JavaDoc is much better than I have done here:

      	/**
      	 * Recursively parse a NamedList and return the value at the last level,
      	 * assuming that the object found at each level is also a NamedList. For
      	 * example, if "response" is the NamedList response from the Solr4 mbean
      	 * handler, the following code makes sense:
      	 * 
      	 * String coreName = (String) getRecursiveFromResponse(response, new
      	 * String[] { "solr-mbeans", "CORE", "core", "stats", "coreName" });
      	 * 
      	 * 
      	 * @param namedList the NamedList to parse
      	 * @param args A list of values to recursively request
      	 * @return the object at the last level.
      	 * @throws SolrServerException
      	 */
      	@SuppressWarnings("unchecked")
      	private final Object getRecursiveFromResponse(
      			NamedList<Object> namedList, String[] args)
      			throws SolrServerException
      	{
      
      		NamedList<Object> list = null;
      		Object value = null;
      		try
      		{
      			for (String key : args)
      			{
      				if (list == null)
      				{
      					list = namedList;
      				}
      				else
      				{
      					list = (NamedList<Object>) value;
      				}
      				value = list.get(key);
      			}
      			return value;
      		}
      		catch (Exception e)
      		{
      			throw new SolrServerException(
      					"Failed to recursively parse NamedList", e);
      		}
      	}
      
      1. SOLR-4048.patch
        5 kB
        Shawn Heisey
      2. SOLR-4048.patch
        4 kB
        Shawn Heisey
      3. SOLR-4048.patch
        4 kB
        Shawn Heisey
      4. SOLR-4048.patch
        3 kB
        Shawn Heisey
      5. SOLR-4048.patch
        3 kB
        Shawn Heisey
      6. SOLR-4048.patch
        3 kB
        Shawn Heisey
      7. SOLR-4048.patch
        3 kB
        Shawn Heisey
      8. SOLR-4048-cleanup.patch
        13 kB
        Shawn Heisey

        Activity

        No work has yet been logged on this issue.

          People

          • Assignee:
            Shawn Heisey
            Reporter:
            Shawn Heisey
          • Votes:
            0 Vote for this issue
            Watchers:
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            Dates

            • Created:
              Updated:
              Resolved:

              Development