Package org.apache.solr.common.util

Class NamedList<T>

java.lang.Object
org.apache.solr.common.util.NamedList<T>
All Implemented Interfaces:
Serializable, Cloneable, Iterable<Map.Entry<String,T>>, MapSerializable, MapWriter, NavigableObject, org.noggit.JSONWriter.Writable
Direct Known Subclasses:
CloudSolrClient.RouteResponse, SimpleOrderedMap
public class NamedList<T> extends Object implements Cloneable, Serializable, Iterable<Map.Entry<String,T>>, MapWriter
A simple container class for modeling an ordered list of name/value pairs.

Unlike Maps:

  • Names may be repeated
  • Order of elements is maintained
  • Elements may be accessed by numeric index
  • Names and Values can both be null

A NamedList provides fast access by element number, but not by name.

When a NamedList is serialized, order is considered more important than access by key, so ResponseWriters that output to a format such as JSON will normally choose a data structure that allows order to be easily preserved in various clients (i.e. not a straight map). If access by key is more important for serialization, see SimpleOrderedMap, or simply use a regular Map

See Also:

  • Field Details

  • Constructor Details

    • NamedList

      public NamedList()
      Creates an empty instance

    • NamedList

      public NamedList(int sz)

    • NamedList

      public NamedList(Map.Entry<String,? extends T>[] nameValuePairs)
      Creates a NamedList instance containing the "name,value" pairs contained in the Entry[].

      Modifying the contents of the Entry[] after calling this constructor may change the NamedList (in future versions of Solr), but this is not guaranteed and should not be relied upon. To modify the NamedList, refer to add(String, Object) or remove(String).

      Parameters:
      nameValuePairs - the name value pairs

    • NamedList

      public NamedList(Map<String,? extends T> nameValueMap)
      Creates a NamedList instance containing the "name,value" pairs contained in the Map.

      Modifying the contents of the Map after calling this constructor may change the NamedList (in future versions of Solr), but this is not guaranteed and should not be relied upon. To modify the NamedList, refer to add(String, Object) or remove(String).

      Parameters:
      nameValueMap - the name value pairs

  • Method Details

    • writeMap

      public void writeMap(MapWriter.EntryWriter ew) throws IOException
      Description copied from interface: MapWriter
      Writes this object's entries out to ew.
      Specified by:
      writeMap in interface MapWriter
      Throws:
      IOException

    • size

      public int size()
      The total number of name/value pairs

    • getName

      public String getName(int idx)
      The name of the pair at the specified List index
      Returns:
      null if no name exists

    • getVal

      public T getVal(int idx)
      The value of the pair at the specified List index
      Returns:
      may be null

    • add

      public void add(String name, T val)
      Adds a name/value pair to the end of the list.

    • setName

      public void setName(int idx, String name)
      Modifies the name of the pair at the specified index.

    • setVal

      public T setVal(int idx, T val)
      Modifies the value of the pair at the specified index.
      Returns:
      the value that used to be at index

    • remove

      public T remove(int idx)
      Removes the name/value pair at the specified index.
      Returns:
      the value at the index removed

    • indexOf

      public int indexOf(String name, int start)
      Scans the list sequentially beginning at the specified index and returns the index of the first pair with the specified name.
      Parameters:
      name - name to look for, may be null
      start - index to begin searching from
      Returns:
      The index of the first matching pair, -1 if no match

    • indexOf

      public int indexOf(String name)
      Scans the names of the list sequentially beginning at index 0 and returns the index of the first pair with the specified name.
      See Also:

    • get

      public T get(String name)
      Gets the value for the first instance of the specified name found.

      NOTE: this runs in linear time (it scans starting at the beginning of the list until it finds the first pair with the specified name).

      Returns:
      null if not found or if the value stored was null.
      See Also:

    • getOrDefault

      public T getOrDefault(String name, T def)
      Like get(String) but returns a default value if it would be null.

    • get

      @Deprecated public T get(String name, int start)
      Deprecated.
      Use indexOf(String, int) then getVal(int).
      Gets the value for the first instance of the specified name found starting at the specified index.

      NOTE: this runs in linear time (it scans starting at the specified position until it finds the first pair with the specified name).

      Returns:
      null if not found or if the value stored was null.
      See Also:

    • getAll

      public List<T> getAll(String name)
      Gets the values for the specified name
      Parameters:
      name - Name
      Returns:
      List of values

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • getImmutableCopy

      public NamedList<T> getImmutableCopy()

    • asShallowMap

      @Deprecated public Map<String,T> asShallowMap()
      Deprecated.
      Use SimpleOrderedMap instead.

    • asShallowMap

      @Deprecated public Map<String,T> asShallowMap(boolean allowDps)
      Deprecated.
      use SimpleOrderedMap instead of NamedList when a Map is required.

    • asMap

      public Map asMap(int maxDepth)

    • toSolrParams

      public SolrParams toSolrParams()
      Create SolrParams from NamedList. Values must be String[] or List (with toString()-appropriate entries), or otherwise have a toString()-appropriate value. Nulls are retained as such in arrays/lists but otherwise will NPE.

    • addAll

      public boolean addAll(Map<String,T> args)
      Iterates over the Map and sequentially adds its key/value pairs

    • addAll

      public boolean addAll(NamedList<? extends T> nl)
      Appends the elements of the given NamedList to this one.

    • clone

      public NamedList<T> clone()
      Makes a shallow copy of the named list.
      Overrides:
      clone in class Object

    • iterator

      public Iterator<Map.Entry<String,T>> iterator()
      Support the Iterable interface
      Specified by:
      iterator in interface Iterable<T>

    • remove

      public T remove(String name)
      NOTE: this runs in linear time (it scans starting at the beginning of the list until it finds the first pair with the specified name).

    • removeAll

      public List<T> removeAll(String name)
      Removes and returns all values for the specified name. Returns null if no matches found. This method will return all matching objects, regardless of data type. If you are parsing Solr config options, the removeConfigArgs(String) or removeBooleanArg(String) methods will probably work better.
      Parameters:
      name - Name
      Returns:
      List of values

    • removeBooleanArg

      public Boolean removeBooleanArg(String name)
      Used for getting a boolean argument from a NamedList object. If the name is not present, returns null. If there is more than one value with that name, or if the value found is not a Boolean or a String, throws an exception. If there is only one value present, and it is a Boolean or a String, the value is removed and returned as a Boolean. If an exception is thrown, the NamedList is not modified. See removeAll(String) and removeConfigArgs(String) for additional ways of gathering configuration information from a NamedList.
      Parameters:
      name - The key to look up in the NamedList.
      Returns:
      The boolean value found.
      Throws:
      SolrException - If multiple values are found for the name or the value found is not a Boolean or a String.

    • getBooleanArg

      public Boolean getBooleanArg(String name)
      Used for getting a boolean argument from a NamedList object. If the name is not present, returns null. If there is more than one value with that name, or if the value found is not a Boolean or a String, throws an exception. If there is only one value present, and it is a Boolean or a String, the value is returned as a Boolean. The NamedList is not modified. See remove(String), removeAll(String) and removeConfigArgs(String) for additional ways of gathering configuration information from a NamedList.
      Parameters:
      name - The key to look up in the NamedList.
      Returns:
      The boolean value found.
      Throws:
      SolrException - If multiple values are found for the name or the value found is not a Boolean or a String.

    • removeConfigArgs

      public Collection<String> removeConfigArgs(String name) throws SolrException
      Used for getting one or many arguments from NamedList objects that hold configuration parameters. Finds all entries in the NamedList that match the given name. If they are all strings or arrays of strings, remove them from the NamedList and return the individual elements as a Collection. Parameter order will be preserved if the returned collection is handled as an ArrayList. Throws SolrException if any of the values associated with the name are not strings or arrays of strings. If exception is thrown, the NamedList is not modified. Returns an empty collection if no matches found. If you need to remove and retrieve all matching items from the NamedList regardless of data type, use removeAll(String) instead. The removeBooleanArg(String) method can be used for retrieving a boolean argument.
      Parameters:
      name - The key to look up in the NamedList.
      Returns:
      A collection of the values found.
      Throws:
      SolrException - If values are found for the input key that are not strings or arrays of strings.

    • clear

      public void clear()

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • forEach

      public void forEach(BiConsumer<? super String,? super T> action)