Class Internal

public final class Internal

The classes contained within are used internally by the Protocol Buffer library and generated message implementations. They are public only because those generated messages do not reside in the protobuf package. Others should not use this class directly.

Inheritance

java.lang.Object > Internal

Static Fields

EMPTY_BYTE_ARRAY

public static final byte[] EMPTY_BYTE_ARRAY

An empty byte array constant used in generated code.

Field Value
TypeDescription
byte[]

EMPTY_BYTE_BUFFER

public static final ByteBuffer EMPTY_BYTE_BUFFER

An empty byte array constant used in generated code.

Field Value
TypeDescription
ByteBuffer

EMPTY_CODED_INPUT_STREAM

public static final CodedInputStream EMPTY_CODED_INPUT_STREAM

An empty coded input stream constant used in generated code.

Field Value
TypeDescription
CodedInputStream

Static Methods

<T>getDefaultInstance(Class<T> clazz)

public static T <T>getDefaultInstance(Class<T> clazz)
Parameter
NameDescription
clazzClass<T>
Returns
TypeDescription
T

byteArrayDefaultValue(String bytes)

public static byte[] byteArrayDefaultValue(String bytes)

Helper called by generated code to construct default values for bytes fields.

This is like #bytesDefaultValue, but returns a byte array.

Parameter
NameDescription
bytesString
Returns
TypeDescription
byte[]

byteBufferDefaultValue(String bytes)

public static ByteBuffer byteBufferDefaultValue(String bytes)

Helper called by generated code to construct default values for bytes fields.

This is like #bytesDefaultValue, but returns a ByteBuffer.

Parameter
NameDescription
bytesString
Returns
TypeDescription
ByteBuffer

bytesDefaultValue(String bytes)

public static ByteString bytesDefaultValue(String bytes)

Helper called by generated code to construct default values for bytes fields.

This is a lot like #stringDefaultValue, but for bytes fields. In this case we only need the second of the two hacks -- allowing us to embed raw bytes as a string literal with ISO-8859-1 encoding.

Parameter
NameDescription
bytesString
Returns
TypeDescription
ByteString

copyByteBuffer(ByteBuffer source)

public static ByteBuffer copyByteBuffer(ByteBuffer source)

Create a new ByteBuffer and copy all the content of source ByteBuffer to the new ByteBuffer. The new ByteBuffer's limit and capacity will be source.capacity(), and its position will be 0. Note that the state of source ByteBuffer won't be changed.

Parameter
NameDescription
sourceByteBuffer
Returns
TypeDescription
ByteBuffer

equals(List<byte[]> a, List<byte[]> b)

public static boolean equals(List<byte[]> a, List<byte[]> b)

Helper method for implementing Message#equals(Object) for bytes field.

Parameters
NameDescription
aList<byte[]>
bList<byte[]>
Returns
TypeDescription
boolean

equalsByteBuffer(ByteBuffer a, ByteBuffer b)

public static boolean equalsByteBuffer(ByteBuffer a, ByteBuffer b)

Helper method for implementing Message#equals(Object) for bytes field.

Parameters
NameDescription
aByteBuffer
bByteBuffer
Returns
TypeDescription
boolean

equalsByteBuffer(List<ByteBuffer> a, List<ByteBuffer> b)

public static boolean equalsByteBuffer(List<ByteBuffer> a, List<ByteBuffer> b)

Helper method for implementing Message#equals(Object) for bytes field.

Parameters
NameDescription
aList<ByteBuffer>
bList<ByteBuffer>
Returns
TypeDescription
boolean

hashBoolean(boolean b)

public static int hashBoolean(boolean b)

Helper method for implementing Message#hashCode() for booleans. See Also: Boolean#hashCode()

Parameter
NameDescription
bboolean
Returns
TypeDescription
int

hashCode(byte[] bytes)

public static int hashCode(byte[] bytes)

Helper method for implementing Message#hashCode() for bytes field.

Parameter
NameDescription
bytesbyte[]
Returns
TypeDescription
int

hashCode(List<byte[]> list)

public static int hashCode(List<byte[]> list)

Helper method for implementing Message#hashCode() for bytes field.

Parameter
NameDescription
listList<byte[]>
Returns
TypeDescription
int

hashCodeByteBuffer(ByteBuffer bytes)

public static int hashCodeByteBuffer(ByteBuffer bytes)

Helper method for implementing Message#hashCode() for bytes field.

Parameter
NameDescription
bytesByteBuffer
Returns
TypeDescription
int

hashCodeByteBuffer(List<ByteBuffer> list)

public static int hashCodeByteBuffer(List<ByteBuffer> list)

Helper method for implementing Message#hashCode() for bytes field.

Parameter
NameDescription
listList<ByteBuffer>
Returns
TypeDescription
int

hashEnum(Internal.EnumLite e)

public static int hashEnum(Internal.EnumLite e)

Helper method for implementing Message#hashCode() for enums.

This is needed because java.lang.Enum#hashCode() is final, but we need to use the field number as the hash code to ensure compatibility between statically and dynamically generated enum objects.

Parameter
NameDescription
eInternal.EnumLite
Returns
TypeDescription
int

hashEnumList(List<? extends Internal.EnumLite> list)

public static int hashEnumList(List<? extends Internal.EnumLite> list)

Helper method for implementing Message#hashCode() for enum lists.

Parameter
NameDescription
listList<? extends com.google.protobuf.Internal.EnumLite>
Returns
TypeDescription
int

hashLong(long n)

public static int hashLong(long n)

Helper method for implementing Message#hashCode() for longs. See Also: Long#hashCode()

Parameter
NameDescription
nlong
Returns
TypeDescription
int

isValidUtf8(byte[] byteArray)

public static boolean isValidUtf8(byte[] byteArray)

Like #isValidUtf8(ByteString) but for byte arrays.

Parameter
NameDescription
byteArraybyte[]
Returns
TypeDescription
boolean

isValidUtf8(ByteString byteString)

public static boolean isValidUtf8(ByteString byteString)

Helper called by generated code to determine if a byte array is a valid UTF-8 encoded string such that the original bytes can be converted to a String object and then back to a byte array round tripping the bytes without loss. More precisely, returns true whenever:


 Arrays.equals(byteString.toByteArray(),
     new String(byteString.toByteArray(), "UTF-8").getBytes("UTF-8"))
 

This method rejects "overlong" byte sequences, as well as 3-byte sequences that would map to a surrogate character, in accordance with the restricted definition of UTF-8 introduced in Unicode 3.1. Note that the UTF-8 decoder included in Oracle's JDK has been modified to also reject "overlong" byte sequences, but currently (2011) still accepts 3-byte surrogate character byte sequences.

See the Unicode Standard,
Table 3-6. UTF-8 Bit Distribution,
Table 3-7. Well Formed UTF-8 Byte Sequences.

As of 2011-02, this method simply returns the result of ByteString#isValidUtf8(). Calling that method directly is preferred.

Parameter
NameDescription
byteStringByteString

the string to check

Returns
TypeDescription
boolean

whether the byte array is round trippable

stringDefaultValue(String bytes)

public static String stringDefaultValue(String bytes)

Helper called by generated code to construct default values for string fields.

The protocol compiler does not actually contain a UTF-8 decoder -- it just pushes UTF-8-encoded text around without touching it. The one place where this presents a problem is when generating Java string literals. Unicode characters in the string literal would normally need to be encoded using a Unicode escape sequence, which would require decoding them. To get around this, protoc instead embeds the UTF-8 bytes into the generated code and leaves it to the runtime library to decode them.

It gets worse, though. If protoc just generated a byte array, like: new byte[] {0x12, 0x34, 0x56, 0x78} Java actually generates code which allocates an array and then fills in each value. This is much less efficient than just embedding the bytes directly into the bytecode. To get around this, we need another work-around. String literals are embedded directly, so protoc actually generates a string literal corresponding to the bytes. The easiest way to do this is to use the ISO-8859-1 character set, which corresponds to the first 256 characters of the Unicode range. Protoc can then use good old CEscape to generate the string.

So we have a string literal which represents a set of bytes which represents another string. This function -- stringDefaultValue -- converts from the generated string to the string we actually want. The generated code calls this automatically.

Parameter
NameDescription
bytesString
Returns
TypeDescription
String

toByteArray(String value)

public static byte[] toByteArray(String value)

Helper method to get the UTF-8 bytes of a string.

Parameter
NameDescription
valueString
Returns
TypeDescription
byte[]

toStringUtf8(byte[] bytes)

public static String toStringUtf8(byte[] bytes)

Helper method to convert a byte array to a string using UTF-8 encoding.

Parameter
NameDescription
bytesbyte[]
Returns
TypeDescription
String