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java.lang.Objectcom.google.protobuf.Internal
public 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.
Nested Class Summary | |
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static interface |
Internal.EnumLite
Interface for an enum value or value descriptor, to be used in FieldSet. |
static interface |
Internal.EnumLiteMap<T extends Internal.EnumLite>
Interface for an object which maps integers to Internal.EnumLite s. |
Field Summary | |
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static byte[] |
EMPTY_BYTE_ARRAY
An empty byte array constant used in generated code. |
static java.nio.ByteBuffer |
EMPTY_BYTE_BUFFER
An empty byte array constant used in generated code. |
Constructor Summary | |
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Internal()
|
Method Summary | |
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static byte[] |
byteArrayDefaultValue(java.lang.String bytes)
Helper called by generated code to construct default values for bytes fields. |
static java.nio.ByteBuffer |
byteBufferDefaultValue(java.lang.String bytes)
Helper called by generated code to construct default values for bytes fields. |
static ByteString |
bytesDefaultValue(java.lang.String bytes)
Helper called by generated code to construct default values for bytes fields. |
static java.nio.ByteBuffer |
copyByteBuffer(java.nio.ByteBuffer source)
Create a new ByteBuffer and copy all the content of source
ByteBuffer to the new ByteBuffer. |
static boolean |
equals(java.util.List<byte[]> a,
java.util.List<byte[]> b)
Helper method for implementing MessageLite#equals() for bytes field. |
static boolean |
equalsByteBuffer(java.nio.ByteBuffer a,
java.nio.ByteBuffer b)
Helper method for implementing MessageLite#equals() for bytes
field. |
static boolean |
equalsByteBuffer(java.util.List<java.nio.ByteBuffer> a,
java.util.List<java.nio.ByteBuffer> b)
Helper method for implementing MessageLite#equals() for bytes
field. |
static int |
hashBoolean(boolean b)
Helper method for implementing MessageLite#hashCode() for
booleans. |
static int |
hashCode(byte[] bytes)
Helper method for implementing MessageLite#hashCode() for bytes field. |
static int |
hashCode(java.util.List<byte[]> list)
Helper method for implementing MessageLite#hashCode() for bytes field. |
static int |
hashCodeByteBuffer(java.nio.ByteBuffer bytes)
Helper method for implementing MessageLite#hashCode() for bytes
field. |
static int |
hashCodeByteBuffer(java.util.List<java.nio.ByteBuffer> list)
Helper method for implementing MessageLite#hashCode() for bytes
field. |
static int |
hashEnum(Internal.EnumLite e)
Helper method for implementing MessageLite#hashCode() for enums. |
static int |
hashEnumList(java.util.List<? extends Internal.EnumLite> list)
Helper method for implementing MessageLite#hashCode() for
enum lists. |
static int |
hashLong(long n)
Helper method for implementing MessageLite#hashCode() for longs. |
static boolean |
isValidUtf8(byte[] byteArray)
Like isValidUtf8(ByteString) but for byte arrays. |
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. |
static java.lang.String |
stringDefaultValue(java.lang.String bytes)
Helper called by generated code to construct default values for string fields. |
static byte[] |
toByteArray(java.lang.String value)
Helper method to get the UTF-8 bytes of a string. |
static java.lang.String |
toStringUtf8(byte[] bytes)
Helper method to convert a byte array to a string using UTF-8 encoding. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
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public static final byte[] EMPTY_BYTE_ARRAY
public static final java.nio.ByteBuffer EMPTY_BYTE_BUFFER
Constructor Detail |
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public Internal()
Method Detail |
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public static java.lang.String stringDefaultValue(java.lang.String bytes)
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.
public static ByteString bytesDefaultValue(java.lang.String bytes)
This is a lot like stringDefaultValue(java.lang.String)
, 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.
public static byte[] byteArrayDefaultValue(java.lang.String bytes)
This is like bytesDefaultValue(java.lang.String)
, but returns a byte array.
public static java.nio.ByteBuffer byteBufferDefaultValue(java.lang.String bytes)
This is like bytesDefaultValue(java.lang.String)
, but returns a ByteBuffer.
public static java.nio.ByteBuffer copyByteBuffer(java.nio.ByteBuffer source)
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.
public static boolean isValidUtf8(ByteString byteString)
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.
byteString
- the string to check
public static boolean isValidUtf8(byte[] byteArray)
isValidUtf8(ByteString)
but for byte arrays.
public static byte[] toByteArray(java.lang.String value)
public static java.lang.String toStringUtf8(byte[] bytes)
public static int hashLong(long n)
MessageLite#hashCode()
for longs.
Long.hashCode()
public static int hashBoolean(boolean b)
MessageLite#hashCode()
for
booleans.
Boolean.hashCode()
public static int hashEnum(Internal.EnumLite e)
MessageLite#hashCode()
for enums.
This is needed because 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.
public static int hashEnumList(java.util.List<? extends Internal.EnumLite> list)
MessageLite#hashCode()
for
enum lists.
public static boolean equals(java.util.List<byte[]> a, java.util.List<byte[]> b)
MessageLite#equals()
for bytes field.
public static int hashCode(java.util.List<byte[]> list)
MessageLite#hashCode()
for bytes field.
public static int hashCode(byte[] bytes)
MessageLite#hashCode()
for bytes field.
public static boolean equalsByteBuffer(java.nio.ByteBuffer a, java.nio.ByteBuffer b)
MessageLite#equals()
for bytes
field.
public static boolean equalsByteBuffer(java.util.List<java.nio.ByteBuffer> a, java.util.List<java.nio.ByteBuffer> b)
MessageLite#equals()
for bytes
field.
public static int hashCodeByteBuffer(java.util.List<java.nio.ByteBuffer> list)
MessageLite#hashCode()
for bytes
field.
public static int hashCodeByteBuffer(java.nio.ByteBuffer bytes)
MessageLite#hashCode()
for bytes
field.
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