Package org.apache.juneau

Class BeanTraverseSession

java.lang.Object

org.apache.juneau.ContextSession

org.apache.juneau.BeanSession

org.apache.juneau.BeanTraverseSession

Direct Known Subclasses:

JsonSchemaGeneratorSession, SerializerSession

public class BeanTraverseSession
extends BeanSession

ContextSession 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.

Notes:

• This class is not thread safe and is typically discarded after one use.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	BeanTraverseSession.Builder	Builder class.

Field Summary

Fields

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

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	BeanTraverseSession(BeanTraverseSession.Builder builder)	Constructor.

Method Summary

Modifier and Type	Method	Description
final int	getInitialDepth()	Initial depth.
final JsonMap	getLastLocation()	Returns information used to determine at what location in the parse a failure occurred.
final int	getMaxDepth()	Max traversal depth.
protected final ClassMeta<?>	getOptionalType(ClassMeta<?> cm)	Returns the inner type of an Optional.
protected final 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.
final boolean	isDetectRecursions()	Automatically detect POJO recursions.
final boolean	isIgnoreRecursions()	Ignore recursion errors.
protected static final boolean	isOptional(ClassMeta<?> cm)	Same as ClassMeta.isOptional() but gracefully handles a null ClassMeta.
protected final boolean	isRoot()	Returns true if we're processing the root node.
protected void	onError(Throwable t, String msg, Object... args)	Logs a warning message.
protected final void	pop()	Pop an object off the stack.
protected FluentMap<String,Object>	properties()	Returns the properties on this bean as a map for debugging.
protected final ClassMeta<?>	push(String attrName, Object o, ClassMeta<?> eType)	Push the specified object onto the stack.
protected final void	setCurrentClass(ClassMeta<?> currentClass)	Sets the current class being traversed for proper error messages.
protected final void	setCurrentProperty(BeanPropertyMeta currentProperty)	Sets the current bean property being traversed for proper error messages.
protected final boolean	willExceedDepth()	Returns true if we're about to exceed the max depth for the document.
protected final boolean	willRecurse(String attrName, Object o, ClassMeta<?> cm)	Returns true if BeanTraverseContext.Builder.detectRecursions() is enabled, and the specified object is already higher up in the traversal chain.

Methods inherited from class org.apache.juneau.BeanSession

addWarning, convertToMemberType, convertToMemberType, convertToType, convertToType, convertToType, create, getAnnotationProvider, getArgsClassMeta, getBeanClassVisibility, getBeanConstructorVisibility, getBeanDictionary, getBeanFieldVisibility, getBeanMeta, getBeanMethodVisibility, getBeanRegistry, getBeanTypePropertyName, getBeanTypePropertyName, getClassMeta, getClassMeta, getClassMetaForObject, getClassMetaForObject, getLocale, getMediaType, getNamePropertyName, getNotBeanClasses, getNotBeanPackagesNames, getPropertyNamer, getSwaps, getTimeZone, getTimeZoneId, isBean, isBean, isBeanMapPutReturnsOldValue, isBeansRequireDefaultConstructor, isBeansRequireSerializable, isBeansRequireSettersForGetters, isBeansRequireSomeProperties, isFindFluentSetters, isIgnoreInvocationExceptionsOnGetters, isIgnoreInvocationExceptionsOnSetters, isIgnoreMissingSetters, isIgnoreUnknownBeanProperties, isIgnoreUnknownNullBeanProperties, isSortProperties, isUseEnumNames, isUseInterfaceProxies, isUseJavaBeanIntrospector, newBean, newBean, newBeanMap, newBeanMap, newGenericMap, object, string, toArray, toBeanMap, toBeanMap, toBeanMap

Methods inherited from class org.apache.juneau.ContextSession

checkForWarnings, getContext, getSessionProperties, getWarnings, isDebug, toString

Methods inherited from class java.lang.Object

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

Field Details

indent

public int indent

The current indentation depth into the model.

Constructor Details

BeanTraverseSession

protected BeanTraverseSession(BeanTraverseSession.Builder builder)

Constructor.

Parameters:

builder - The builder for this object.

Method Details

getInitialDepth

public final int getInitialDepth()

Initial depth.

Returns:

The initial indentation level at the root.

See Also:

• BeanTraverseContext.Builder.initialDepth(int)

getLastLocation

public final JsonMap 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"}

getMaxDepth

public final int getMaxDepth()

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.Builder.maxDepth(int)

isDetectRecursions

public final boolean isDetectRecursions()

Automatically detect POJO recursions.

Returns:

true if recursions should be checked for during traversal.

See Also:

• BeanTraverseContext.Builder.detectRecursions()

isIgnoreRecursions

public final boolean isIgnoreRecursions()

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.Builder.ignoreRecursions()

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.

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.

isOptional

protected static 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.

isRoot

protected final boolean isRoot()

Returns true if we're processing the root node.

Must be called after push(String, Object, ClassMeta) and before pop().

Returns:

true if we're processing the root node.

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.

pop

protected final void pop()

Pop an object off the stack.

properties

protected FluentMap<String,Object> properties()

Description copied from class: ContextSession

Returns the properties on this bean as a map for debugging.

Overrides:

properties in class BeanSession

Returns:

The properties on this bean as a map for debugging.

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.

setCurrentClass

protected final void setCurrentClass(ClassMeta<?> currentClass)

Sets the current class being traversed for proper error messages.

Parameters:

currentClass - The current class being traversed.

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.

willExceedDepth

protected final boolean willExceedDepth()

Returns true if we're about to exceed the max depth for the document.

Returns:

true if we're about to exceed the max depth for the document.

willRecurse

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

Returns true if BeanTraverseContext.Builder.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.