public abstract Class Decoder

Processes the next block of an array and returns the number of items in the block and let's the caller read those items.

Exceptions

AvroTypeException:

When called outside of an array context

Processes the next block of map entries and returns the count of them. Similar to arrayNext. See readMapStart for details.

Exceptions

AvroTypeException:

When called outside of a map context

Reads and returns the size of the first block of an array. If this method returns non-zero, then the caller should read the indicated number of items, and then call arrayNext to find out the number of items in the next block. The typical pattern for consuming an array looks like:

  for(long i = in.readArrayStart(); i != 0; i = in.arrayNext()) {
    for (long j = 0; j < i; j++) {
      read next element of the array;
    }
  }

Exceptions

AvroTypeException:

If this is a stateful reader and array is not the type of the next value to be read

Reads a boolean value written by Encoder#writeBoolean.

Exceptions

AvroTypeException:

If this is a stateful reader and boolean is not the type of the next value to be read

Reads a byte-string written by Encoder#writeBytes. if old is not null and has sufficient capacity to take in the bytes being read, the bytes are returned in old.

Exceptions

AvroTypeException:

If this is a stateful reader and byte-string is not the type of the next value to be read

Reads a double written by Encoder#writeDouble.

Exceptions

AvroTypeException:

If this is a stateful reader and is not the type of the next value to be read

Reads an enumeration.

Returns:int

The enumeration's value.

Exceptions

AvroTypeException:

If this is a stateful reader and enumeration is not the type of the next value to be read.

Reads fixed sized binary object.

Parameters

bytes:byte[]

The buffer to store the contents being read.

start:int

The position where the data needs to be written.

length:int

The size of the binary object.

Exceptions

AvroTypeException:

If this is a stateful reader and fixed sized binary object is not the type of the next value to be read or the length is incorrect.

A shorthand for readFixed(bytes, 0, bytes.length).

Exceptions

AvroTypeException:

If this is a stateful reader and fixed sized binary object is not the type of the next value to be read or the length is incorrect.

Reads a float written by Encoder#writeFloat.

Exceptions

AvroTypeException:

If this is a stateful reader and is not the type of the next value to be read

Reads the tag of a union written by Encoder#writeIndex.

Exceptions

AvroTypeException:

If this is a stateful reader and union is not the type of the next value to be read

Reads an integer written by Encoder#writeInt.

Exceptions

AvroTypeException:

• If encoded value is larger than 32-bits
• If this is a stateful reader and int is not the type of the next value to be read

Reads a long written by Encoder#writeLong.

Exceptions

AvroTypeException:

If this is a stateful reader and long is not the type of the next value to be read

Reads and returns the size of the next block of map-entries. Similar to readArrayStart. As an example, let's say you want to read a map of records, the record consisting of an Long field and a Boolean field. Your code would look something like this:

Map m = new HashMap();
Record reuse = new Record();
for (long i = in.readMapStart(); i != 0; i = in.readMapNext()) {
  for (long j = 0; j < i; j++) {
    String key = in.readString();
    reuse.intField = in.readInt();
    reuse.boolField = in.readBoolean();
    m.put(key, reuse);
  }
}

Exceptions

AvroTypeException:

If this is a stateful reader and map is not the type of the next value to be read

"Reads" a null value. (Doesn't actually read anything, but advances the state of the parser if the implementation is stateful.)

Exceptions

AvroTypeException:

If this is a stateful reader and null is not the type of the next value to be read

Reads a char-string written by Encoder#writeString.

Exceptions

AvroTypeException:

If this is a stateful reader and char-string is not the type of the next value to be read

Reads a char-string written by Encoder#writeString.

Exceptions

AvroTypeException:

If this is a stateful reader and char-string is not the type of the next value to be read

Used for quickly skipping through an array. Note you can either skip the entire array, or read the entire array (with readArrayStart), but you can't mix the two on the same array. This method will skip through as many items as it can, all of them if possible. It will return zero if there are no more items to skip through, or an item count if it needs the client's help in skipping. The typical usage pattern is:

  for(long i = in.skipArray(); i != 0; i = i.skipArray()) {
    for (long j = 0; j < i; j++) {
      read and discard the next element of the array;
    }
  }

Exceptions

AvroTypeException:

If this is a stateful reader and array is not the type of the next value to be read

Discards a byte-string written by Encoder#writeBytes.

Exceptions

AvroTypeException:

If this is a stateful reader and byte-string is not the type of the next value to be read

Discards fixed sized binary object.

Parameters

length:int

The size of the binary object to be skipped.

Exceptions

AvroTypeException:

If this is a stateful reader and fixed sized binary object is not the type of the next value to be read or the length is incorrect.

Support for quickly skipping through a map similar to skipArray. As an example, let's say you want to skip a map of records, the record consisting of an Long field and a Boolean field. Your code would look something like this:

for (long i = in.skipMap(); i != 0; i = in.skipMap()) {
  for (long j = 0; j < i; j++) {
    in.skipString(); // Discard key
    in.readInt(); // Discard int-field of value
    in.readBoolean(); // Discard boolean-field of value
  }
}

Exceptions

AvroTypeException:

If this is a stateful reader and array is not the type of the next value to be read

Discards a char-string written by Encoder#writeString.

Exceptions

AvroTypeException:

If this is a stateful reader and char-string is not the type of the next value to be read