linux-china / jackson-datatype-protobuf Goto Github PK

Jackson module that adds support for serializing and deserializing Google's Protocol Buffers to and from JSON.

To use module on Maven-based projects, use following dependency:

<dependency>
  <groupId>com.hubspot.jackson</groupId>
  <artifactId>jackson-datatype-protobuf</artifactId>
  <version><!-- see table below --></version>
</dependency>

There are separate versions based on which version of Jackson you are using, see the table below:

Registration is done as follows:

ObjectMapper mapper = new ObjectMapper();
mapper.registerModule(new ProtobufModule());

after which functionality is available for all normal Jackson operations.

Protobuf 3 specifies a canonical JSON representation (available here). This library conforms to that representation with a few exceptions:

• int64, fixed64, uint64 are written as JSON numbers instead of strings
• Any objects don't have any special handling, so the value will be a base64 string, and the type URL field name is typeUrl instead of @type

Support has been dropped for com.google.protobuf:protobuf-java:2.x, but you can use an older release if necessary:

• 0.9.10-jackson2.9-proto2
• 0.9.10-jackson2.8-proto2
• 0.9.10-jackson2.7-proto2
• 0.9.10-preJackson2.7-proto2

This library assumes that field names in proto files will be lowercase with underscores, as is recommended by the protobuf style guide: https://developers.google.com/protocol-buffers/docs/style#message-and-field-names

Use underscore_separated_names for field names – for example, song_name.

If your field names don't match this convention, you may need to set a PropertyNamingStrategy on your ObjectMapper for things to work as expected. For example, if your proto field names are camel case, you could configure your ObjectMapper to use PropertyNamingStrategy.LOWER_CAMEL_CASE.