Package io.protostuff

Class ByteString

java.lang.Object
io.protostuff.ByteString

public final class ByteString extends Object
Immutable array of bytes.
  • Field Details

    • bytes

      private final byte[] bytes
    • EMPTY_STRING

      public static final String EMPTY_STRING
      Empty String.
      See Also:
    • EMPTY_BYTE_ARRAY

      public static final byte[] EMPTY_BYTE_ARRAY
      Empty byte array.
    • EMPTY

      public static final ByteString EMPTY
      Empty ByteString.
    • hash

      private volatile int hash
  • Constructor Details

    • ByteString

      private ByteString(byte[] bytes)
  • Method Details

    • wrap

      static ByteString wrap(byte[] bytes)
    • getBytes

      byte[] getBytes()
    • writeTo

      public static void writeTo(OutputStream out, ByteString bs) throws IOException
      Writes the bytes to the OutputStream.
      Throws:
      IOException
    • writeTo

      public static void writeTo(DataOutput out, ByteString bs) throws IOException
      Writes the bytes to the DataOutput.
      Throws:
      IOException
    • writeTo

      public static void writeTo(Output output, ByteString bs, int fieldNumber, boolean repeated) throws IOException
      Writes the bytes to the Output.
      Throws:
      IOException
    • toString

      public String toString()
      Overrides:
      toString in class Object
    • byteAt

      public byte byteAt(int index)
      Gets the byte at the given index.
      Throws:
      ArrayIndexOutOfBoundsException - index is < 0 or >= size
    • size

      public int size()
      Gets the number of bytes.
    • isEmpty

      public boolean isEmpty()
      Returns true if the size is 0, false otherwise.
    • copyFrom

      public static ByteString copyFrom(byte[] bytes, int offset, int size)
      Copies the given bytes into a ByteString.
    • copyFrom

      public static ByteString copyFrom(byte[] bytes)
      Copies the given bytes into a ByteString.
    • copyFrom

      public static ByteString copyFrom(String text, String charsetName)
      Encodes text into a sequence of bytes using the named charset and returns the result as a ByteString.
    • copyFromUtf8

      public static ByteString copyFromUtf8(String text)
      Encodes text into a sequence of UTF-8 bytes and returns the result as a ByteString.
    • copyTo

      public void copyTo(byte[] target, int offset)
      Copies bytes into a buffer at the given offset.
      Parameters:
      target - buffer to copy into
      offset - in the target buffer
    • copyTo

      public void copyTo(byte[] target, int sourceOffset, int targetOffset, int size)
      Copies bytes into a buffer.
      Parameters:
      target - buffer to copy into
      sourceOffset - offset within these bytes
      targetOffset - offset within the target buffer
      size - number of bytes to copy
    • toByteArray

      public byte[] toByteArray()
      Copies bytes to a byte[].
    • asReadOnlyByteBuffer

      public ByteBuffer asReadOnlyByteBuffer()
      Constructs a new read-only java.nio.ByteBuffer with the same backing byte array.
    • toStringUtf8

      public String toStringUtf8()
      Constructs a new String by decoding the bytes as UTF-8.
    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object
    • equals

      public static boolean equals(ByteString bs, ByteString other, boolean checkHash)
      Returns true if the contents of both match.
    • equals

      public boolean equals(byte[] data)
      Returns true if the contents of the internal array and the provided array match.
    • equals

      public boolean equals(byte[] data, int offset, int len)
      Returns true if the contents of the internal array and the provided array match.
    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object
    • stringDefaultValue

      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.

    • bytesDefaultValue

      public static ByteString bytesDefaultValue(String bytes)
      Helper called by generated code to construct default values for bytes fields.

      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.

    • byteArrayDefaultValue

      public static byte[] byteArrayDefaultValue(String bytes)
      Helper called by generated code to construct default values for byte array fields.

      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.