Package org.elasticsearch.script

Class ScriptContext<FactoryType>

  • public final class ScriptContext<FactoryType>
extends java.lang.Object
    The information necessary to compile and run a script. A ScriptContext contains the information related to a single use case and the interfaces and methods necessary for a ScriptEngine to implement.

    There are at least two (and optionally a third) related classes which must be defined.

    The InstanceType is a class which users of the script api call to execute a script. It may be stateful. Instances of the InstanceType may be executed multiple times by a caller with different arguments. This class must have an abstract method named execute which ScriptEngine implementations will define.

    The FactoryType is a factory class returned by the ScriptService when compiling a script. This class must be stateless so it is cacheable by the ScriptService. It must have one of the following:

    • An abstract method named newInstance which returns an instance of InstanceType
    • An abstract method named newFactory which returns an instance of StatefulFactoryType

    The StatefulFactoryType is an optional class which allows a stateful factory from the stateless factory type required by the ScriptService. If defined, the StatefulFactoryType must have a method named newInstance which returns an instance of InstanceType.

    Both the FactoryType and StatefulFactoryType may have abstract methods to indicate whether a variable is used in a script. These method should return a boolean and their name should start with needs, followed by the variable name, with the first letter uppercased. For example, to check if a variable doc is used, a method boolean needsDoc() should be added. If the variable name starts with an underscore, for example, _score, the needs method would be boolean needs_score().

    • Field Summary

      Fields 
      Modifier and Type Field Description
      java.lang.Class<FactoryType> factoryClazz
      A factory class for constructing script or stateful factory instances.
      java.lang.Class<?> instanceClazz
      A class that is an instance of a script.
      java.lang.String name
      A unique identifier for this context.
      java.lang.Class<?> statefulFactoryClazz
      A factory class for construct script instances.

    • Constructor Summary

      Constructors 
      Constructor Description
      ScriptContext​(java.lang.String name, java.lang.Class<FactoryType> factoryClazz)
      Construct a context with the related instance and compiled classes.

    • Method Summary

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • name

        public final java.lang.String name
        A unique identifier for this context.

      • factoryClazz

        public final java.lang.Class<FactoryType> factoryClazz
        A factory class for constructing script or stateful factory instances.

      • statefulFactoryClazz

        public final java.lang.Class<?> statefulFactoryClazz
        A factory class for construct script instances.

      • instanceClazz

        public final java.lang.Class<?> instanceClazz
        A class that is an instance of a script.

    • Constructor Detail

      • ScriptContext

        public ScriptContext​(java.lang.String name,
                     java.lang.Class<FactoryType> factoryClazz)
        Construct a context with the related instance and compiled classes.