Top Description Fields Methods
org.intellij.lang.annotations

public @Interface Flow

extends Annotation
Annotations
@Retention:CLASS
@Target:PARAMETER, METHOD
Imports
java.lang.annotation.ElementType, .Retention, .RetentionPolicy, .Target

This annotation assists the 'Data flow to this' feature by describing data flow from the method parameter to the corresponding container (e.g. ArrayList.add(item)) or from the container to the method return value (e.g. Set.toArray()) or between method parameters (e.g. System.arraycopy(array1, 0, array2, length))

Field Summary

Modifier and TypeField and Description
public static final String
public static final String
public static final String
public static final String
public static final String

Method Summary

Modifier and TypeMethod and Description
public String
source()

Denotes the source of the data flow.

public boolean
sourceIsContainer()

true if the data source is container and we should track not the expression but its contents.

public String
target()

Denotes the destination of the data flow.

public boolean
targetIsContainer()

true if the data target is container and we should track not the expression but its contents.

Inherited from java.lang.annotation.Annotation:
annotationTypeequalshashCodetoString

Field Detail

DEFAULT_SOURCEback to summary
public static final String DEFAULT_SOURCE
DEFAULT_TARGETback to summary
public static final String DEFAULT_TARGET
RETURN_METHOD_TARGETback to summary
public static final String RETURN_METHOD_TARGET
THIS_SOURCEback to summary
public static final String THIS_SOURCE
THIS_TARGETback to summary
public static final String THIS_TARGET

Method Detail

sourceback to summary
public String source()

Denotes the source of the data flow.
Allowed values are:

  • THIS_SOURCE - Means that the data flows from this container.
    E.g. annotation for java.util.List method get(index) means the method reads contents of list and returns it.
    @Flow(source = THIS_SOURCE) T get(int index);
  • this.Field name - means that the data flows from this container some (synthetic) field.
    E.g. annotation for java.util.Map.keySet() method here means that it returns data from the map from the field named "keys".
    @Flow(source = "this.keys") Set<K> keySet();
By default, the source() value is:
  • THIS_SOURCE if the method was annotated, e.g.
    @Flow(sourceIsContainer=true, targetIsContainer=true) Object[] Collection.toArray()
    Here the annotation tells us that java.util.Collection.toArray() method
    reads the contents of this collection (source=THIS_SOURCE by default) and passes it outside.
  • Corresponding argument if the method parameter was annotated, e.g.
    void List.add(@Flow(targetIsContainer=true) E item)
    Here the annotation tells us that java.util.List.add(E item) method
    takes the argument (source="item" by default) and passes it to this collection.
sourceIsContainerback to summary
public boolean sourceIsContainer()

true if the data source is container and we should track not the expression but its contents.
E.g. the java.util.ArrayList constructor takes the collection and stores its contents:
ArrayList(

@Flow(sourceIsContainer=true, targetIsContainer=true) Collection<? extends E> collection 
)
By default it's false.
targetback to summary
public String target()

Denotes the destination of the data flow.
Allowed values are:

  • THIS_TARGET - Means that the data flows inside this container (of the class the annotated method belongs to).
    E.g. annotation for java.util.List method add(element) means the method takes the argument and passes it to this collection.
    boolean add(@Flow(target=THIS_TARGET, targetIsContainer=true) E element);
  • Parameter name - means the data flows to this parameter.
    E.g.
    void arraycopy(@Flow(sourceIsContainer=true, target="dest", targetIsContainer=true) Object src, int srcPos, Object dest, int destPos, int length)
    means that java.lang.System.arraycopy() method takes its first argument and passes it to the "dest" parameter.
  • this.Field name - means that the data flows to this container in some (synthetic) field.
    E.g. annotation for java.util.Map.put(key, value) method here means that it takes the argument 'key' and stores the data in some (hidden) field named "keys".
    V put(@Flow(target = "this.keys", targetIsContainer=true) K key, V value);
By default, the target() value is:
  • THIS_TARGET if the parameter was annotated, e.g.
    void List.set(int index, @Flow(targetIsContainer=true) E element)
    Here the annotation tells us that java.util.List.set(index, element) method
    reads its second argument 'element' and passes it to this collection (target=THIS_TARGET by default).
  • RETURN_METHOD_TARGET if the method was annotated, e.g.:
    @Flow(sourceIsContainer=true) E List.remove(int index)
    Here the annotation tells us that java.util.List.remove(int index) method
    returns the data from its collection (target=RETURN_METHOD_TARGET by default).
targetIsContainerback to summary
public boolean targetIsContainer()

true if the data target is container and we should track not the expression but its contents.
E.g. the java.lang.System.arraycopy() method parameter 'dest' is actually an array:
void arraycopy(@Flow(sourceIsContainer=true, target="dest", targetIsContainer=true) Object src, int srcPos, Object dest, int destPos, int length)
By default it's false.