A table of known extensions, searchable by name or field number. When parsing a protocol message that might have extensions, you must provide an ExtensionRegistry in which you have registered any extensions that you want to be able to parse. Otherwise, those extensions will just be treated like unknown fields.

For example, if you had the .proto file:

option java_class = "MyProto";

message Foo {
  extensions 1000 to max;
}

extend Foo {
  optional int32 bar;
}

Then you might write code like:

ExtensionRegistry registry = ExtensionRegistry.newInstance();
registry.add(MyProto.bar);
MyProto.Foo message = MyProto.Foo.parseFrom(input, registry);

Background:

You might wonder why this is necessary. Two alternatives might come to mind. First, you might imagine a system where generated extensions are automatically registered when their containing classes are loaded. This is a popular technique, but is bad design; among other things, it creates a situation where behavior can change depending on what classes happen to be loaded. It also introduces a security vulnerability, because an unprivileged class could cause its code to be called unexpectedly from a privileged class by registering itself as an extension of the right type.

Another option you might consider is lazy parsing: do not parse an extension until it is first requested, at which point the caller must provide a type to use. This introduces a different set of problems. First, it would require a mutex lock any time an extension was accessed, which would be slow. Second, corrupt data would not be detected until first access, at which point it would be much harder to deal with it. Third, it could violate the expectation that message objects are immutable, since the type provided could be any arbitrary message class. An unprivileged user could take advantage of this to inject a mutable object into a message belonging to privileged code and create mischief.

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	ExtensionRegistry.DescriptorIntPair A (GenericDescriptor, int) pair, used as a map key.
public static class	ExtensionRegistry.ExtensionInfo A (Descriptor, Message) pair, returned by lookup methods.

Field Summary

Modifier and Type	Field and Description
pack-priv static final ExtensionRegistry	EMPTY_REGISTRY
private final Map<String, ExtensionRegistry.ExtensionInfo>	immutableExtensionsByName
private final Map<ExtensionRegistry.DescriptorIntPair, ExtensionRegistry.ExtensionInfo>	immutableExtensionsByNumber
private final Map<String, ExtensionRegistry.ExtensionInfo>	mutableExtensionsByName
private final Map<ExtensionRegistry.DescriptorIntPair, ExtensionRegistry.ExtensionInfo>	mutableExtensionsByNumber

Inherited from com.google.protobuf.ExtensionRegistryLite:: EMPTY_REGISTRY_LITE EXTENSION_CLASS_NAME

Constructor Summary

Access	Constructor and Description
private	ExtensionRegistry()
private	ExtensionRegistry(ExtensionRegistry other)
pack-priv	ExtensionRegistry(boolean empty)

Method Summary

Modifier and Type	Method and Description
public void	add(final Extension<?, ?> extension) Add an extension from a generated file to the registry.
public void	add(final GeneratedMessage.GeneratedExtension<?, ?> extension) Add an extension from a generated file to the registry.
public void	add(final Descriptors.FieldDescriptor type) Add a non-message-type extension to the registry by descriptor.
public void	add(final Descriptors.FieldDescriptor type, final Message defaultInstance) Add a message-type extension to the registry by descriptor.
private void	add(final ExtensionRegistry.ExtensionInfo extension, final Extension.ExtensionType extensionType)
public ExtensionRegistry.ExtensionInfo	findExtensionByName(final String fullName) Deprecated Deprecated.
public ExtensionRegistry.ExtensionInfo	findExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber) Deprecated Deprecated.
public ExtensionRegistry.ExtensionInfo	Returns: Information about the extension if found, or `null` otherwise. findImmutableExtensionByName(final String fullName) Find an extension for immutable APIs by fully-qualified field name, in the proto namespace.
public ExtensionRegistry.ExtensionInfo	Returns: Information about the extension if found, or `null` otherwise. findImmutableExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber) Find an extension by containing type and field number for immutable APIs.
public ExtensionRegistry.ExtensionInfo	Returns: Information about the extension if found, or `null` otherwise. findMutableExtensionByName(final String fullName) Find an extension for mutable APIs by fully-qualified field name, in the proto namespace.
public ExtensionRegistry.ExtensionInfo	Returns: Information about the extension if found, or `null` otherwise. findMutableExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber) Find an extension by containing type and field number for mutable APIs.
public Set<ExtensionRegistry.ExtensionInfo>	Returns: Information about the extensions found, or `null` if there are none. getAllImmutableExtensionsByExtendedType(final String fullName) Find all extensions for immutable APIs by fully-qualified name of extended class.
public Set<ExtensionRegistry.ExtensionInfo>	Returns: Information about the extensions found, or `null` if there are none. getAllMutableExtensionsByExtendedType(final String fullName) Find all extensions for mutable APIs by fully-qualified name of extended class.
public static ExtensionRegistry	getEmptyRegistry() Hides com.google.protobuf.ExtensionRegistryLite.getEmptyRegistry. Get the unmodifiable singleton empty instance.
public ExtensionRegistry	getUnmodifiable() Overrides com.google.protobuf.ExtensionRegistryLite.getUnmodifiable. Returns an unmodifiable view of the registry.
pack-priv static ExtensionRegistry.ExtensionInfo	newExtensionInfo(final Extension<?, ?> extension)
public static ExtensionRegistry	newInstance() Hides com.google.protobuf.ExtensionRegistryLite.newInstance. Construct a new, empty instance.

Inherited from com.google.protobuf.ExtensionRegistryLite:: add add findLiteExtensionByNumber isEagerlyParseMessageSets resolveExtensionClass setEagerlyParseMessageSets

Field Detail

EMPTY_REGISTRY	back to summary
pack-priv static final ExtensionRegistry EMPTY_REGISTRY

immutableExtensionsByName	back to summary
private final Map<String, ExtensionRegistry.ExtensionInfo> immutableExtensionsByName

immutableExtensionsByNumber	back to summary
private final Map<ExtensionRegistry.DescriptorIntPair, ExtensionRegistry.ExtensionInfo> immutableExtensionsByNumber

mutableExtensionsByName	back to summary
private final Map<String, ExtensionRegistry.ExtensionInfo> mutableExtensionsByName

mutableExtensionsByNumber	back to summary
private final Map<ExtensionRegistry.DescriptorIntPair, ExtensionRegistry.ExtensionInfo> mutableExtensionsByNumber

Constructor Detail

ExtensionRegistry	back to summary
private ExtensionRegistry()

ExtensionRegistry	back to summary
private ExtensionRegistry(ExtensionRegistry other)

ExtensionRegistry	back to summary
pack-priv ExtensionRegistry(boolean empty)

Method Detail

add	back to summary
public void add(final Extension<?, ?> extension) Add an extension from a generated file to the registry.

add	back to summary
public void add(final GeneratedMessage.GeneratedExtension<?, ?> extension) Add an extension from a generated file to the registry.

add	back to summary
public void add(final Descriptors.FieldDescriptor type) Add a non-message-type extension to the registry by descriptor.

add	back to summary
public void add(final Descriptors.FieldDescriptor type, final Message defaultInstance) Add a message-type extension to the registry by descriptor.

add	back to summary
private void add(final ExtensionRegistry.ExtensionInfo extension, final Extension.ExtensionType extensionType)

findExtensionByName back to summary

findExtensionByName	back to summary
public ExtensionRegistry.ExtensionInfo findExtensionByName(final String fullName) Deprecated Deprecated. Use `findImmutableExtensionByName(String)` instead. Annotations @Deprecated

public ExtensionRegistry.ExtensionInfo findExtensionByName(final String fullName)

Deprecated

Deprecated. Use findImmutableExtensionByName(String) instead.

Annotations

@Deprecated

findExtensionByNumber back to summary

findExtensionByNumber	back to summary
public ExtensionRegistry.ExtensionInfo findExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber) Deprecated Deprecated. Use `findImmutableExtensionByNumber(Descriptors.Descriptor, int)` Annotations @Deprecated

public ExtensionRegistry.ExtensionInfo findExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber)

Deprecated

Deprecated. Use findImmutableExtensionByNumber(Descriptors.Descriptor, int)

Annotations

@Deprecated

findImmutableExtensionByName back to summary

findImmutableExtensionByName	back to summary
public ExtensionRegistry.ExtensionInfo findImmutableExtensionByName(final String fullName) Find an extension for immutable APIs by fully-qualified field name, in the proto namespace. i.e. `result.descriptor.fullName()` will match `fullName` if a match is found. Returns:ExtensionRegistry.ExtensionInfo Information about the extension if found, or `null` otherwise.

public ExtensionRegistry.ExtensionInfo findImmutableExtensionByName(final String fullName)

Find an extension for immutable APIs by fully-qualified field name, in the proto namespace. i.e. result.descriptor.fullName() will match fullName if a match is found.

Returns:ExtensionRegistry.ExtensionInfo: Information about the extension if found, or null otherwise.

findImmutableExtensionByNumber back to summary

findImmutableExtensionByNumber	back to summary
public ExtensionRegistry.ExtensionInfo findImmutableExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber) Find an extension by containing type and field number for immutable APIs. Returns:ExtensionRegistry.ExtensionInfo Information about the extension if found, or `null` otherwise.

public ExtensionRegistry.ExtensionInfo findImmutableExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber)

Find an extension by containing type and field number for immutable APIs.

Returns:ExtensionRegistry.ExtensionInfo: Information about the extension if found, or null otherwise.

findMutableExtensionByName back to summary

findMutableExtensionByName	back to summary
public ExtensionRegistry.ExtensionInfo findMutableExtensionByName(final String fullName) Find an extension for mutable APIs by fully-qualified field name, in the proto namespace. i.e. `result.descriptor.fullName()` will match `fullName` if a match is found. Returns:ExtensionRegistry.ExtensionInfo Information about the extension if found, or `null` otherwise.

public ExtensionRegistry.ExtensionInfo findMutableExtensionByName(final String fullName)

Find an extension for mutable APIs by fully-qualified field name, in the proto namespace. i.e. result.descriptor.fullName() will match fullName if a match is found.

Returns:ExtensionRegistry.ExtensionInfo: Information about the extension if found, or null otherwise.

findMutableExtensionByNumber back to summary

findMutableExtensionByNumber	back to summary
public ExtensionRegistry.ExtensionInfo findMutableExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber) Find an extension by containing type and field number for mutable APIs. Returns:ExtensionRegistry.ExtensionInfo Information about the extension if found, or `null` otherwise.

public ExtensionRegistry.ExtensionInfo findMutableExtensionByNumber(final Descriptors.Descriptor containingType, final int fieldNumber)

Find an extension by containing type and field number for mutable APIs.

Returns:ExtensionRegistry.ExtensionInfo: Information about the extension if found, or null otherwise.

getAllImmutableExtensionsByExtendedType back to summary

getAllImmutableExtensionsByExtendedType	back to summary
public Set<ExtensionRegistry.ExtensionInfo> getAllImmutableExtensionsByExtendedType(final String fullName) Find all extensions for immutable APIs by fully-qualified name of extended class. Note that this method is more computationally expensive than getting a single extension by name or number. Returns:Set<ExtensionRegistry.ExtensionInfo> Information about the extensions found, or `null` if there are none.

public Set<ExtensionRegistry.ExtensionInfo> getAllImmutableExtensionsByExtendedType(final String fullName)

Find all extensions for immutable APIs by fully-qualified name of extended class. Note that this method is more computationally expensive than getting a single extension by name or number.

Returns:Set<ExtensionRegistry.ExtensionInfo>: Information about the extensions found, or null if there are none.

getAllMutableExtensionsByExtendedType back to summary

getAllMutableExtensionsByExtendedType	back to summary
public Set<ExtensionRegistry.ExtensionInfo> getAllMutableExtensionsByExtendedType(final String fullName) Find all extensions for mutable APIs by fully-qualified name of extended class. Note that this method is more computationally expensive than getting a single extension by name or number. Returns:Set<ExtensionRegistry.ExtensionInfo> Information about the extensions found, or `null` if there are none.

public Set<ExtensionRegistry.ExtensionInfo> getAllMutableExtensionsByExtendedType(final String fullName)

Find all extensions for mutable APIs by fully-qualified name of extended class. Note that this method is more computationally expensive than getting a single extension by name or number.

Returns:Set<ExtensionRegistry.ExtensionInfo>: Information about the extensions found, or null if there are none.

getEmptyRegistry	back to summary
public static ExtensionRegistry getEmptyRegistry() Hides com.google.protobuf.ExtensionRegistryLite.getEmptyRegistry. Get the unmodifiable singleton empty instance.

getEmptyRegistry

back to summary

public static ExtensionRegistry getEmptyRegistry()

Hides com.google.protobuf.ExtensionRegistryLite.getEmptyRegistry.

Get the unmodifiable singleton empty instance.

getUnmodifiable	back to summary
public ExtensionRegistry getUnmodifiable() Overrides com.google.protobuf.ExtensionRegistryLite.getUnmodifiable. Returns an unmodifiable view of the registry. Annotations @Override

getUnmodifiable

back to summary

public ExtensionRegistry getUnmodifiable()

Overrides com.google.protobuf.ExtensionRegistryLite.getUnmodifiable.

Returns an unmodifiable view of the registry.

Annotations

@Override

newExtensionInfo	back to summary
pack-priv static ExtensionRegistry.ExtensionInfo newExtensionInfo(final Extension<?, ?> extension)

newInstance	back to summary
public static ExtensionRegistry newInstance() Hides com.google.protobuf.ExtensionRegistryLite.newInstance. Construct a new, empty instance.

newInstance

back to summary

public static ExtensionRegistry newInstance()

Hides com.google.protobuf.ExtensionRegistryLite.newInstance.

Construct a new, empty instance.

com.google.protobuf back to summary

private final Class ExtensionRegistry.DescriptorIntPair

Class Inheritance

extends Object

java.lang.Object
com.google.protobuf.ExtensionRegistry.DescriptorIntPair

A (GenericDescriptor, int) pair, used as a map key.

Field Summary

Modifier and Type	Field and Description
private final Descriptors.Descriptor	descriptor
private final int	number

Constructor Summary

Access	Constructor and Description
pack-priv	DescriptorIntPair(final Descriptors.Descriptor descriptor, final int number)

Method Summary

Modifier and Type	Method and Description
public boolean	equals(final Object the reference object with which to compare. obj) Overrides java.lang.Object.equals. Indicates whether some other object is "equal to" this one.
public int	hashCode() Overrides java.lang.Object.hashCode. Returns a hash code value for the object.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll toString wait wait wait

Field Detail

descriptor	back to summary
private final Descriptors.Descriptor descriptor

number	back to summary
private final int number

Constructor Detail

DescriptorIntPair	back to summary
pack-priv DescriptorIntPair(final Descriptors.Descriptor descriptor, final int number)

Method Detail

equals back to summary

equals	back to summary
public boolean equals(final Object obj) Overrides java.lang.Object.equals. Doc from java.lang.Object.equals. Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`. It is transitive: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Parameters obj:Object the reference object with which to compare. Returns:boolean `true` if this object is the same as the obj argument; `false` otherwise. Annotations @Override

public boolean equals(final Object obj)

Overrides java.lang.Object.equals.

Doc from java.lang.Object.equals.

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

It is reflexive: for any non-null reference value x, x.equals(x) should return true.
It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters

obj:Object: the reference object with which to compare.

Returns:boolean

true if this object is the same as the obj argument; false otherwise.

Annotations

@Override

hashCode back to summary

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Doc from java.lang.Object.hashCode. Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by `java.util.HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Returns:int a hash code value for this object. Annotations @Override

public int hashCode()

Overrides java.lang.Object.hashCode.

Doc from java.lang.Object.hashCode.

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by java.util.HashMap.

The general contract of hashCode is:

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns:int

a hash code value for this object.

Annotations

@Override

com.google.protobuf back to summary

public final Class ExtensionRegistry.ExtensionInfo

Class Inheritance

extends Object

java.lang.Object
com.google.protobuf.ExtensionRegistry.ExtensionInfo

A (Descriptor, Message) pair, returned by lookup methods.

Field Summary

Modifier and Type	Field and Description
public final Message	defaultInstance A default instance of the extension's type, if it has a message type.
public final Descriptors.FieldDescriptor	descriptor The extension's descriptor.

Constructor Summary

Access	Constructor and Description
private	ExtensionInfo(final Descriptors.FieldDescriptor descriptor)
private	ExtensionInfo(final Descriptors.FieldDescriptor descriptor, final Message defaultInstance)

Method Summary

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

defaultInstance	back to summary
public final Message defaultInstance A default instance of the extension's type, if it has a message type. Otherwise, `null`.

descriptor	back to summary
public final Descriptors.FieldDescriptor descriptor The extension's descriptor.

Constructor Detail

ExtensionInfo	back to summary
private ExtensionInfo(final Descriptors.FieldDescriptor descriptor)

ExtensionInfo	back to summary
private ExtensionInfo(final Descriptors.FieldDescriptor descriptor, final Message defaultInstance)

public Class ExtensionRegistry

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private final Class ExtensionRegistry.DescriptorIntPair

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public final Class ExtensionRegistry.ExtensionInfo

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail