org.apache.juneau

Class BeanTraverseSession

java.lang.Object

org.apache.juneau.Session

org.apache.juneau.BeanSession

org.apache.juneau.BeanTraverseSession

Direct Known Subclasses:

JsonSchemaGeneratorSession, SerializerSession

public class BeanTraverseSession
extends BeanSession

Session that lives for the duration of a single use of BeanTraverseContext.

Used by serializers and other classes that traverse POJOs for the following purposes:

• Keeping track of how deep it is in a model for indentation purposes.
• Ensuring infinite loops don't occur by setting a limit on how deep to traverse a model.
• Ensuring infinite loops don't occur from loops in the model (when detectRecursions is enabled.

This class is NOT thread safe. It is typically discarded after one-time use although it can be reused within the same thread.

Field Summary

Fields

Modifier and Type	Field and Description
int	indent The current indentation depth into the model.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BeanTraverseSession(BeanTraverseContext ctx, BeanSessionArgs args) Create a new session using properties specified in the context.

Method Summary

Modifier and Type	Method and Description
protected int	getInitialDepth() Configuration property: Initial depth.
ObjectMap	getLastLocation() Returns information used to determine at what location in the parse a failure occurred.
protected int	getMaxDepth() Configuration property: Max traversal depth.
protected ClassMeta<?>	getOptionalType(ClassMeta<?> cm) Returns the inner type of an Optional.
protected Object	getOptionalValue(Object o) If the specified object is an Optional, returns the inner object.
protected String	getStack(boolean full) Returns the current stack trace.
protected boolean	isDetectRecursions() Configuration property: Automatically detect POJO recursions.
protected boolean	isIgnoreRecursions() Configuration property: Ignore recursion errors.
protected boolean	isOptional(ClassMeta<?> cm) Same as ClassMeta.isOptional() but gracefully handles a null ClassMeta.
protected void	onError(Throwable t, String msg, Object... args) Logs a warning message.
protected void	pop() Pop an object off the stack.
protected ClassMeta<?>	push(String attrName, Object o, ClassMeta<?> eType) Push the specified object onto the stack.
protected void	setCurrentClass(ClassMeta<?> currentClass) Sets the current class being traversed for proper error messages.
protected void	setCurrentProperty(BeanPropertyMeta currentProperty) Sets the current bean property being traversed for proper error messages.
ObjectMap	toMap() Returns the properties defined on this bean context as a simple map for debugging purposes.
protected boolean	willRecurse(String attrName, Object o, ClassMeta<?> cm) Returns true if BeanTraverseContext.BEANTRAVERSE_detectRecursions is enabled, and the specified object is already higher up in the traversal chain.

Methods inherited from class org.apache.juneau.BeanSession

_class, checkForWarnings, convertToMemberType, convertToMemberType, convertToType, convertToType, convertToType, getArgsClassMeta, getBeanClassVisibility, getBeanConstructorVisibility, getBeanDictionaryClasses, getBeanFieldVisibility, getBeanFilters, getBeanMeta, getBeanMethodVisibility, getBeanRegistry, getBeanTypePropertyName, getBeanTypePropertyName, getBpi, getBpro, getBpwo, getBpx, getClassMeta, getClassMeta, getClassMetaForObject, getClassMetaForObject, getExamples, getImplClasses, getLocale, getMediaType, getNotBeanClasses, getNotBeanPackagesNames, getNotBeanPackagesPrefixes, getPojoSwaps, getPropertyNamer, getSchema, getStringBuilder, getTimeZone, getTimeZoneId, isBean, isBean, isBeanMapPutReturnsOldValue, isBeansRequireDefaultConstructor, isBeansRequireSerializable, isBeansRequireSettersForGetters, isBeansRequireSomeProperties, isDebug, isFluentSetters, isIgnoreInvocationExceptionsOnGetters, isIgnoreInvocationExceptionsOnSetters, isIgnorePropertiesWithoutSetters, isIgnoreUnknownBeanProperties, isIgnoreUnknownNullBeanProperties, isSortProperties, isUseEnumNames, isUseInterfaceProxies, isUseJavaBeanIntrospector, newBean, newBean, newBeanMap, newBeanMap, object, returnStringBuilder, string, toArray, toBeanMap, toBeanMap

Methods inherited from class org.apache.juneau.Session

addToCache, addToCache, addWarning, getClassProperty, getFromCache, getInstanceArrayProperty, getInstanceProperty, getLogger, getProperties, getProperty, getProperty, getProperty, getPropertyKeys, getWarnings, hasProperty, hasWarnings, toString

Methods inherited from class java.lang.Object

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

Field Detail

indent

public int indent

The current indentation depth into the model.

Constructor Detail

BeanTraverseSession

protected BeanTraverseSession(BeanTraverseContext ctx,
                              BeanSessionArgs args)

Create a new session using properties specified in the context.

Parameters:

ctx - The context creating this session object. The context contains all the configuration settings for this object. Can be null.

args - Runtime arguments. These specify session-level information such as locale and URI context. It also include session-level properties that override the properties defined on the bean and serializer contexts.

Method Detail

setCurrentProperty

protected final void setCurrentProperty(BeanPropertyMeta currentProperty)

Sets the current bean property being traversed for proper error messages.

Parameters:

currentProperty - The current property being traversed.

setCurrentClass

protected final void setCurrentClass(ClassMeta<?> currentClass)

Sets the current class being traversed for proper error messages.

Parameters:

currentClass - The current class being traversed.

push

protected final ClassMeta<?> push(String attrName,
                                  Object o,
                                  ClassMeta<?> eType)
                           throws BeanRecursionException

Push the specified object onto the stack.

Parameters:

attrName - The attribute name.

o - The current object being traversed.

eType - The expected class type.

Returns:

The ClassMeta of the object so that instanceof operations only need to be performed once (since they can be expensive).

Throws:

BeanRecursionException - If recursion occurred.

willRecurse

protected final boolean willRecurse(String attrName,
                                    Object o,
                                    ClassMeta<?> cm)
                             throws BeanRecursionException

Returns true if BeanTraverseContext.BEANTRAVERSE_detectRecursions is enabled, and the specified object is already higher up in the traversal chain.

Parameters:

attrName - The bean property attribute name, or some other identifier.

o - The object to check for recursion.

cm - The metadata on the object class.

Returns:

true if recursion detected.

Throws:

BeanRecursionException - If recursion occurred.

pop

protected final void pop()

Pop an object off the stack.

isOptional

protected final boolean isOptional(ClassMeta<?> cm)

Same as ClassMeta.isOptional() but gracefully handles a null ClassMeta.

Parameters:

cm - The meta to check.

Returns:

true if the specified meta is an Optional.

getOptionalType

protected final ClassMeta<?> getOptionalType(ClassMeta<?> cm)

Returns the inner type of an Optional.

Parameters:

cm - The meta to check.

Returns:

The inner type of an Optional.

getOptionalValue

protected final Object getOptionalValue(Object o)

If the specified object is an Optional, returns the inner object.

Parameters:

o - The object to check.

Returns:

The inner object if it's an Optional, null if it's null, or else the same object.

onError

protected void onError(Throwable t,
                       String msg,
                       Object... args)

Logs a warning message.

Parameters:

t - The throwable that was thrown (if there was one).

msg - The warning message.

args - Optional MessageFormat-style arguments.

getStack

protected String getStack(boolean full)

Returns the current stack trace.

Parameters:

full - If true, returns a full stack trace.

Returns:

The current stack trace.

getLastLocation

public final ObjectMap getLastLocation()

Returns information used to determine at what location in the parse a failure occurred.

Returns:

A map, typically containing something like {line:123,column:456,currentProperty:"foobar"}

isDetectRecursions

protected final boolean isDetectRecursions()

Configuration property: Automatically detect POJO recursions.

Returns:

true if recursions should be checked for during traversal.

See Also:

BeanTraverseContext.BEANTRAVERSE_detectRecursions

isIgnoreRecursions

protected final boolean isIgnoreRecursions()

Configuration property: Ignore recursion errors.

Returns:

true if when we encounter the same object when traversing a tree, we set the value to null.
Otherwise, a BeanRecursionException is thrown with the message "Recursion occurred, stack=...".

See Also:

BeanTraverseContext.BEANTRAVERSE_ignoreRecursions

getInitialDepth

protected final int getInitialDepth()

Configuration property: Initial depth.

Returns:

The initial indentation level at the root.

See Also:

BeanTraverseContext.BEANTRAVERSE_initialDepth

getMaxDepth

protected final int getMaxDepth()

Configuration property: Max traversal depth.

Returns:

The depth at which traversal is aborted if depth is reached in the POJO tree.
If this depth is exceeded, an exception is thrown.

See Also:

BeanTraverseContext.BEANTRAVERSE_maxDepth

toMap

public ObjectMap toMap()

Description copied from class: Session

Returns the properties defined on this bean context as a simple map for debugging purposes.

Overrides:

toMap in class BeanSession

Returns:

A new map containing the properties defined on this context.