Package org.apache.avro.io

Class JsonEncoder

java.lang.Object
org.apache.avro.io.Encoder
org.apache.avro.io.ParsingEncoder
org.apache.avro.io.JsonEncoder
All Implemented Interfaces:
Flushable, Parser.ActionHandler
public class JsonEncoder extends ParsingEncoder implements Parser.ActionHandler
An Encoder for Avro's JSON data encoding.

Construct using EncoderFactory.

JsonEncoder buffers output, and data may not appear on the output until Flushable.flush() is called.

JsonEncoder is not thread-safe.

  • Field Details

    • isEmpty

      protected BitSet isEmpty
      Has anything been written into the collections?

  • Method Details

    • flush

      public void flush() throws IOException
      Specified by:
      flush in interface Flushable
      Throws:
      IOException

    • isIncludeNamespace

      public boolean isIncludeNamespace()

    • setIncludeNamespace

      public void setIncludeNamespace(boolean includeNamespace)

    • configure

      public JsonEncoder configure(OutputStream out) throws IOException
      Reconfigures this JsonEncoder to use the output stream provided.

      If the OutputStream provided is null, a NullPointerException is thrown.

      Otherwise, this JsonEncoder will flush its current output and then reconfigure its output to use a default UTF8 JsonGenerator that writes to the provided OutputStream.

      Parameters:
      out - The OutputStream to direct output to. Cannot be null.
      Returns:
      this JsonEncoder
      Throws:
      IOException
      NullPointerException - if out is null

    • configure

      public JsonEncoder configure(OutputStream out, boolean autoflush) throws IOException
      Reconfigures this JsonEncoder to use the output stream provided.

      If the OutputStream provided is null, a NullPointerException is thrown.

      Otherwise, this JsonEncoder will flush its current output and then reconfigure its output to use a default UTF8 JsonGenerator that writes to the provided OutputStream.

      Parameters:
      out - The OutputStream to direct output to. Cannot be null.
      Returns:
      this JsonEncoder
      Throws:
      IOException
      NullPointerException - if out is null

    • writeNull

      public void writeNull() throws IOException
      Description copied from class: Encoder
      "Writes" a null value. (Doesn't actually write anything, but advances the state of the parser if this class is stateful.)
      Specified by:
      writeNull in class Encoder
      Throws:
      IOException

    • writeBoolean

      public void writeBoolean(boolean b) throws IOException
      Description copied from class: Encoder
      Write a boolean value.
      Specified by:
      writeBoolean in class Encoder
      Throws:
      IOException

    • writeInt

      public void writeInt(int n) throws IOException
      Description copied from class: Encoder
      Writes a 32-bit integer.
      Specified by:
      writeInt in class Encoder
      Throws:
      IOException

    • writeLong

      public void writeLong(long n) throws IOException
      Description copied from class: Encoder
      Write a 64-bit integer.
      Specified by:
      writeLong in class Encoder
      Throws:
      IOException

    • writeFloat

      public void writeFloat(float f) throws IOException
      Description copied from class: Encoder
      Write a float.
      Specified by:
      writeFloat in class Encoder
      Throws:
      IOException

    • writeDouble

      public void writeDouble(double d) throws IOException
      Description copied from class: Encoder
      Write a double.
      Specified by:
      writeDouble in class Encoder
      Throws:
      IOException

    • writeString

      public void writeString(Utf8 utf8) throws IOException
      Description copied from class: Encoder
      Write a Unicode character string.
      Specified by:
      writeString in class Encoder
      Throws:
      IOException

    • writeString

      public void writeString(String str) throws IOException
      Description copied from class: Encoder
      Write a Unicode character string. The default implementation converts the String to a Utf8. Some Encoder implementations may want to do something different as a performance optimization.
      Overrides:
      writeString in class Encoder
      Throws:
      IOException

    • writeBytes

      public void writeBytes(ByteBuffer bytes) throws IOException
      Description copied from class: Encoder
      Write a byte string.
      Specified by:
      writeBytes in class Encoder
      Throws:
      IOException

    • writeBytes

      public void writeBytes(byte[] bytes, int start, int len) throws IOException
      Description copied from class: Encoder
      Write a byte string.
      Specified by:
      writeBytes in class Encoder
      Throws:
      IOException

    • writeFixed

      public void writeFixed(byte[] bytes, int start, int len) throws IOException
      Description copied from class: Encoder
      Writes a fixed size binary object.
      Specified by:
      writeFixed in class Encoder
      Parameters:
      bytes - The contents to write
      start - The position within bytes where the contents start.
      len - The number of bytes to write.
      Throws:
      IOException

    • writeEnum

      public void writeEnum(int e) throws IOException
      Description copied from class: Encoder
      Writes an enumeration.
      Specified by:
      writeEnum in class Encoder
      Parameters:
      e - the enumeration to write
      Throws:
      IOException

    • writeArrayStart

      public void writeArrayStart() throws IOException
      Description copied from class: Encoder
      Call this method to start writing an array. When starting to serialize an array, call Encoder.writeArrayStart(). Then, before writing any data for any item call Encoder.setItemCount(long) followed by a sequence of Encoder.startItem() and the item itself. The number of Encoder.startItem() should match the number specified in Encoder.setItemCount(long). When actually writing the data of the item, you can call any Encoder method (e.g., Encoder.writeLong(long)). When all items of the array have been written, call Encoder.writeArrayEnd(). As an example, let's say you want to write an array of records, the record consisting of a Long field and a Boolean field. Your code would look something like this: 
       out.writeArrayStart();
 out.setItemCount(list.size());
 for (Record r : list) {
   out.startItem();
   out.writeLong(r.longField);
   out.writeBoolean(r.boolField);
 }
 out.writeArrayEnd();
      Specified by:
      writeArrayStart in class Encoder
      Throws:
      IOException

    • writeArrayEnd

      public void writeArrayEnd() throws IOException
      Description copied from class: Encoder
      Call this method to finish writing an array. See Encoder.writeArrayStart() for usage information.
      Specified by:
      writeArrayEnd in class Encoder
      Throws:
      IOException

    • writeMapStart

      public void writeMapStart() throws IOException
      Description copied from class: Encoder
      Call this to start a new map. See Encoder.writeArrayStart() for details on usage. As an example of usage, let's say you want to write a map of records, the record consisting of a Long field and a Boolean field. Your code would look something like this: 
       out.writeMapStart();
 out.setItemCount(list.size());
 for (Map.Entryinvalid input: '<'String, Record> entry : map.entrySet()) {
   out.startItem();
   out.writeString(entry.getKey());
   out.writeLong(entry.getValue().longField);
   out.writeBoolean(entry.getValue().boolField);
 }
 out.writeMapEnd();
      Specified by:
      writeMapStart in class Encoder
      Throws:
      IOException

    • writeMapEnd

      public void writeMapEnd() throws IOException
      Description copied from class: Encoder
      Call this method to terminate the inner-most, currently-opened map. See Encoder.writeArrayStart() for more details.
      Specified by:
      writeMapEnd in class Encoder
      Throws:
      IOException

    • startItem

      public void startItem() throws IOException
      Description copied from class: Encoder
      Start a new item of an array or map. See Encoder.writeArrayStart() for usage information.
      Overrides:
      startItem in class ParsingEncoder
      Throws:
      IOException

    • writeIndex

      public void writeIndex(int unionIndex) throws IOException
      Description copied from class: Encoder
      Call this method to write the tag of a union. As an example of usage, let's say you want to write a union, whose second branch is a record consisting of a Long field and a Boolean field. Your code would look something like this: 
       out.writeIndex(1);
 out.writeLong(record.longField);
 out.writeBoolean(record.boolField);
      Specified by:
      writeIndex in class Encoder
      Throws:
      IOException

    • doAction

      public Symbol doAction(Symbol input, Symbol top) throws IOException
      Description copied from interface: Parser.ActionHandler
      Handle the action symbol top when the input is sought to be taken off the stack.
      Specified by:
      doAction in interface Parser.ActionHandler
      Parameters:
      input - The input symbol from the caller of advance
      top - The symbol at the top the stack.
      Returns:
      null if advance() is to continue processing the stack. If not null the return value will be returned by advance().
      Throws:
      IOException