Package org.apache.accumulo.core.client

Class IteratorSetting

java.lang.Object
org.apache.accumulo.core.client.IteratorSetting
All Implemented Interfaces:
org.apache.hadoop.io.Writable
public class IteratorSetting extends Object implements org.apache.hadoop.io.Writable
Configure an iterator for minc, majc, and/or scan. By default, IteratorSetting will be configured for scan. Every iterator has a priority, a name, a class, a set of scopes, and configuration parameters. A typical use case configured for scan: 
 IteratorSetting cfg = new IteratorSetting(priority, "myIter", MyIterator.class);
 MyIterator.addOption(cfg, 42);
 scanner.addScanIterator(cfg);

  • Constructor Details

    • IteratorSetting

      public IteratorSetting(int priority, String name, String iteratorClass)
      Constructs an iterator setting configured for the scan scope with no parameters. (Parameters can be added later.)
      Parameters:
      priority - the priority for the iterator (see setPriority(int))
      name - the distinguishing name for the iterator
      iteratorClass - the fully qualified class name for the iterator

    • IteratorSetting

      public IteratorSetting(int priority, String name, String iteratorClass, Map<String,String> properties)
      Constructs an iterator setting configured for the specified scopes with the specified parameters.
      Parameters:
      priority - the priority for the iterator (see setPriority(int))
      name - the distinguishing name for the iterator
      iteratorClass - the fully qualified class name for the iterator
      properties - any properties for the iterator

    • IteratorSetting

      public IteratorSetting(int priority, Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass)
      Constructs an iterator setting using the given class's SimpleName for the iterator name. The iterator setting will be configured for the scan scope with no parameters.
      Parameters:
      priority - the priority for the iterator (see setPriority(int))
      iteratorClass - the class for the iterator

    • IteratorSetting

      public IteratorSetting(int priority, Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass, Map<String,String> properties)
      Constructs an iterator setting using the given class's SimpleName for the iterator name and configured for the specified scopes with the specified parameters.
      Parameters:
      priority - the priority for the iterator (see setPriority(int))
      iteratorClass - the class for the iterator
      properties - any properties for the iterator

    • IteratorSetting

      public IteratorSetting(int priority, String name, Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass)
      Constructs an iterator setting configured for the scan scope with no parameters.
      Parameters:
      priority - the priority for the iterator (see setPriority(int))
      name - the distinguishing name for the iterator
      iteratorClass - the class for the iterator

    • IteratorSetting

      public IteratorSetting(int priority, String name, Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass, Map<String,String> properties)
      Constructs an iterator setting using the provided name and the provided class's name for the scan scope with the provided parameters.
      Parameters:
      priority - The priority for the iterator (see setPriority(int))
      name - The distinguishing name for the iterator
      iteratorClass - The class for the iterator
      properties - Any properties for the iterator
      Since:
      1.6.0

    • IteratorSetting

      public IteratorSetting(DataInput din) throws IOException
      Throws:
      IOException
      Since:
      1.5.0

  • Method Details

    • getPriority

      public int getPriority()
      Get layer at which this iterator applies. See setPriority(int) for how the priority is used.
      Returns:
      the priority of this Iterator

    • setPriority

      public void setPriority(int priority)
      Set layer at which this iterator applies.
      Parameters:
      priority - determines the order in which iterators are applied (system iterators are always applied first, then user-configured iterators, lowest priority first)

    • getName

      public String getName()
      Get the iterator's name.
      Returns:
      the name of the iterator

    • setName

      public void setName(String name)
      Set the iterator's name. Must be a simple alphanumeric identifier. The iterator name also may not contain a dot/period.

    • getIteratorClass

      public String getIteratorClass()
      Get the name of the class that implements the iterator.
      Returns:
      the iterator's class name

    • setIteratorClass

      public void setIteratorClass(String iteratorClass)
      Set the name of the class that implements the iterator. The class does not have to be present on the client, but it must be available to all tablet servers.

    • addOption

      public void addOption(String option, String value)
      Add another option to the iterator.
      Parameters:
      option - the name of the option
      value - the value of the option

    • removeOption

      public String removeOption(String option)
      Remove an option from the iterator.
      Parameters:
      option - the name of the option
      Returns:
      the value previously associated with the option, or null if no such option existed

    • addOptions

      public void addOptions(Set<Map.Entry<String,String>> propertyEntries)
      Add many options to the iterator.
      Parameters:
      propertyEntries - a set of entries to add to the options

    • addOptions

      public void addOptions(Map<String,String> properties)
      Add many options to the iterator.
      Parameters:
      properties - a map of entries to add to the options

    • getOptions

      public Map<String,String> getOptions()
      Get the configuration parameters for this iterator.
      Returns:
      the properties

    • clearOptions

      public void clearOptions()
      Remove all options from the iterator.

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

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

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • readFields

      public void readFields(DataInput din) throws IOException
      Specified by:
      readFields in interface org.apache.hadoop.io.Writable
      Throws:
      IOException
      Since:
      1.5.0
      See Also:
      • Writable

    • write

      public void write(DataOutput dout) throws IOException
      Specified by:
      write in interface org.apache.hadoop.io.Writable
      Throws:
      IOException
      Since:
      1.5.0
      See Also:
      • Writable