Package io.modelcontextprotocol.json

Class McpJsonDefaults

java.lang.Object
io.modelcontextprotocol.json.McpJsonDefaults
public class McpJsonDefaults extends Object
This class is to be used to provide access to the default McpJsonMapper and to the default JsonSchemaValidator instances via the static methods: getMapper() and getSchemaValidator().

The initialization of (singleton) instances of this class is different in non-OSGi environments and OSGi environments. Specifically, in non-OSGi environments the McpJsonDefaults class will be loaded by whatever classloader is used to call one of the existing static get methods for the first time. For servers, this will usually be in response to the creation of the first McpServer instance. At that first time, the mcpMapperServiceLoader and mcpValidatorServiceLoader will be null, and the McpJsonDefaults constructor will be called, creating/initializing the mcpMapperServiceLoader and the mcpValidatorServiceLoader...which will then be used to call the ServiceLoader.load method.

In OSGi environments, upon bundle activation SCR will create a new (singleton) instance of McpJsonDefaults (via the constructor), and then inject suppliers via the setMcpJsonMapperSupplier and setJsonSchemaValidatorSupplier methods with the SCR-discovered instances of those services. This does depend upon the jars/bundles providing those suppliers to be started/activated. This SCR behavior is dictated by xml files in OSGi-INF directory of mcp-core (this project/jar/bundle), and the jsonmapper and jsonschemavalidator provider jars/bundles (e.g. mcp-json-jackson2, mcp-json-jackson3, or others).