public interface MessageLite extends MessageLiteOrBuilderAbstract interface implemented by Protocol Message objects.
This interface is implemented by all protocol message objects. Non-lite messages additionally implement the Message interface, which is a subclass of MessageLite. Use MessageLite instead when you only need the subset of features which it supports -- namely, nothing that uses descriptors or reflection. You can instruct the protocol compiler to generate classes which implement only MessageLite, not the full Message interface, by adding the follow line to the .proto file:
option optimize_for = LITE_RUNTIME;
This is particularly useful on resource-constrained systems where the full protocol buffers runtime library is too big.
Note that on non-constrained systems (e.g. servers) when you need to link in lots of protocol
definitions, a better way to reduce total code footprint is to use optimize_for =
CODE_SIZE. This will make the generated code smaller while still supporting all the same
features (at the expense of speed). optimize_for = LITE_RUNTIME is best when you only
have a small number of message types linked into your binary, in which case the size of the
protocol buffers runtime itself is the biggest problem.
Implements
MessageLiteOrBuilderMethods
getParserForType()
public abstract Parser<? extends MessageLite> getParserForType()Gets the parser for a message of the same type as this message.
| Returns | |
|---|---|
| Type | Description |
Parser<? extends com.google.protobuf.MessageLite> | |
getSerializedSize()
public abstract int getSerializedSize()Get the number of bytes required to encode this message. The result is only computed on the first call and memoized after that.
If this message requires more than Integer.MAX_VALUE bytes to encode, the return value will be smaller than the actual number of bytes required and might be negative.
| Returns | |
|---|---|
| Type | Description |
int | |
newBuilderForType()
public abstract MessageLite.Builder newBuilderForType()Constructs a new builder for a message of the same type as this message.
| Returns | |
|---|---|
| Type | Description |
MessageLite.Builder | |
toBuilder()
public abstract MessageLite.Builder toBuilder()Constructs a builder initialized with the current message. Use this to derive a new message from the current one.
| Returns | |
|---|---|
| Type | Description |
MessageLite.Builder | |
toByteArray()
public abstract byte[] toByteArray()Serializes the message to a byte array and returns it. This is just a trivial wrapper
around #writeTo(CodedOutputStream).
If this message requires more than Integer.MAX_VALUE bytes to encode, the behavior is unpredictable. It may throw a runtime exception or truncate or slice the data.
| Returns | |
|---|---|
| Type | Description |
byte[] | |
toByteString()
public abstract ByteString toByteString()Serializes the message to a ByteString and returns it. This is just a trivial wrapper
around #writeTo(CodedOutputStream).
If this message requires more than Integer.MAX_VALUE bytes to encode, the behavior is unpredictable. It may throw a runtime exception or truncate or slice the data.
| Returns | |
|---|---|
| Type | Description |
ByteString | |
writeDelimitedTo(OutputStream output)
public abstract void writeDelimitedTo(OutputStream output)Like #writeTo(OutputStream), but writes the size of the message as a varint before
writing the data. This allows more data to be written to the stream after the message without
the need to delimit the message data yourself. Use Builder#mergeDelimitedFrom(InputStream) (or the static method
YourMessageType.parseDelimitedFrom(InputStream)) to parse messages written by this method.
| Parameter | |
|---|---|
| Name | Description |
output | OutputStream |
| Exceptions | |
|---|---|
| Type | Description |
IOException | |
writeTo(CodedOutputStream output)
public abstract void writeTo(CodedOutputStream output)Serializes the message and writes it to output. This does not flush or close the
stream.
| Parameter | |
|---|---|
| Name | Description |
output | CodedOutputStream |
| Exceptions | |
|---|---|
| Type | Description |
IOException | |
writeTo(OutputStream output)
public abstract void writeTo(OutputStream output)Serializes the message and writes it to output. This is just a trivial wrapper around
#writeTo(CodedOutputStream). This does not flush or close the stream.
NOTE: Protocol Buffers are not self-delimiting. Therefore, if you write any more data to the stream after the message, you must somehow ensure that the parser on the receiving end does not interpret this as being part of the protocol message. This can be done e.g. by writing the size of the message before the data, then making sure to limit the input to that size on the receiving end (e.g. by wrapping the InputStream in one which limits the input). Alternatively, just use #writeDelimitedTo(OutputStream).
| Parameter | |
|---|---|
| Name | Description |
output | OutputStream |
| Exceptions | |
|---|---|
| Type | Description |
IOException | |