Package org.apache.beam.sdk.coders

Class StringUtf8Coder

java.lang.Object
org.apache.beam.sdk.coders.Coder<String>
org.apache.beam.sdk.coders.StructuredCoder<String>
org.apache.beam.sdk.coders.AtomicCoder<String>
org.apache.beam.sdk.coders.StringUtf8Coder
All Implemented Interfaces:
Serializable
public class StringUtf8Coder extends AtomicCoder<String>
A Coder that encodes Strings in UTF-8 encoding. If in a nested context, prefixes the string with an integer length field, encoded via a VarIntCoder.
See Also:

  • Method Details

    • of

      public static StringUtf8Coder of()

    • encode

      public void encode(String value, OutputStream outStream) throws IOException
      Description copied from class: Coder
      Encodes the given value of type T onto the given output stream. Multiple elements can be encoded next to each other on the output stream, each coder should encode information to know how many bytes to read when decoding. A common approach is to prefix the encoding with the element's encoded length.
      Specified by:
      encode in class Coder<String>
      Throws:
      IOException - if writing to the OutputStream fails for some reason

    • encode

      public void encode(String value, OutputStream outStream, Coder.Context context) throws IOException
      Description copied from class: Coder
      Encodes the given value of type T onto the given output stream in the given context.
      Overrides:
      encode in class Coder<String>
      Throws:
      IOException - if writing to the OutputStream fails for some reason

    • decode

      public String decode(InputStream inStream) throws IOException
      Description copied from class: Coder
      Decodes a value of type T from the given input stream in the given context. Returns the decoded value. Multiple elements can be encoded next to each other on the input stream, each coder should encode information to know how many bytes to read when decoding. A common approach is to prefix the encoding with the element's encoded length.
      Specified by:
      decode in class Coder<String>
      Throws:
      IOException - if reading from the InputStream fails for some reason

    • decode

      public String decode(InputStream inStream, Coder.Context context) throws IOException
      Description copied from class: Coder
      Decodes a value of type T from the given input stream in the given context. Returns the decoded value.
      Overrides:
      decode in class Coder<String>
      Throws:
      IOException - if reading from the InputStream fails for some reason

    • verifyDeterministic

      public void verifyDeterministic()
      Description copied from class: AtomicCoder
      Throw Coder.NonDeterministicException if the coding is not deterministic.

      In order for a Coder to be considered deterministic, the following must be true:

      • two values that compare as equal (via Object.equals() or Comparable.compareTo(), if supported) have the same encoding.
      • the Coder always produces a canonical encoding, which is the same for an instance of an object even if produced on different computers at different times.
      .

      Unless overridden, does not throw. An AtomicCoder is presumed to be deterministic

      Overrides:
      verifyDeterministic in class AtomicCoder<String>

    • consistentWithEquals

      public boolean consistentWithEquals()
      Returns true if this Coder is injective with respect to Object.equals(java.lang.Object).

      Whenever the encoded bytes of two values are equal, then the original values are equal according to Objects.equals(). Note that this is well-defined for null.

      This condition is most notably false for arrays. More generally, this condition is false whenever equals() compares object identity, rather than performing a semantic/structural comparison.

      By default, returns false.

      Overrides:
      consistentWithEquals in class Coder<String>
      Returns:
      true. This coder is injective.

    • getEncodedTypeDescriptor

      public TypeDescriptor<String> getEncodedTypeDescriptor()
      Description copied from class: Coder
      Returns the TypeDescriptor for the type encoded.
      Overrides:
      getEncodedTypeDescriptor in class Coder<String>

    • getEncodedElementByteSize

      public long getEncodedElementByteSize(String value) throws Exception
      Returns the size in bytes of the encoded value using this coder.
      Overrides:
      getEncodedElementByteSize in class Coder<String>
      Returns:
      the byte size of the UTF-8 encoding of the string or, in a nested context, the byte size of the encoding plus the encoded length prefix.
      Throws:
      Exception