Metadata Format (Metadata Format) _ Spring Boot3.4.0-SNAPSHOT中文文档(官方文档中文翻译)|Spring 教程 —

This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Boot 3.3.4!spring-doc.cn

Configuration metadata files are located inside jars under META-INF/spring-configuration-metadata.json. They use a JSON format with items categorized under either “groups” or “properties” and additional values hints categorized under "hints", as shown in the following example:spring-doc.cn

{"groups": [
	{
		"name": "server",
		"type": "org.springframework.boot.autoconfigure.web.ServerProperties",
		"sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties"
	},
	{
		"name": "spring.jpa.hibernate",
		"type": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties$Hibernate",
		"sourceType": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties",
		"sourceMethod": "getHibernate()"
	}
	...
],"properties": [
	{
		"name": "server.port",
		"type": "java.lang.Integer",
		"sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties"
	},
	{
		"name": "server.address",
		"type": "java.net.InetAddress",
		"sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties"
	},
	{
		  "name": "spring.jpa.hibernate.ddl-auto",
		  "type": "java.lang.String",
		  "description": "DDL mode. This is actually a shortcut for the \"hibernate.hbm2ddl.auto\" property.",
		  "sourceType": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties$Hibernate"
	}
	...
],"hints": [
	{
		"name": "spring.jpa.hibernate.ddl-auto",
		"values": [
			{
				"value": "none",
				"description": "Disable DDL handling."
			},
			{
				"value": "validate",
				"description": "Validate the schema, make no changes to the database."
			},
			{
				"value": "update",
				"description": "Update the schema if necessary."
			},
			{
				"value": "create",
				"description": "Create the schema and destroy previous data."
			},
			{
				"value": "create-drop",
				"description": "Create and then destroy the schema at the end of the session."
			}
		]
	}
]}

Each “property” is a configuration item that the user specifies with a given value. For example, server.port and server.address might be specified in your application.properties/application.yaml, as follows:spring-doc.cn

Propertiesspring-doc.cn
YAMLspring-doc.cn

server.port=9090
server.address=127.0.0.1

server:
  port: 9090
  address: 127.0.0.1

The “groups” are higher level items that do not themselves specify a value but instead provide a contextual grouping for properties. For example, the server.port and server.address properties are part of the server group.spring-doc.cn

It is not required that every “property” has a “group”. Some properties might exist in their own right.

Finally, “hints” are additional information used to assist the user in configuring a given property. For example, when a developer is configuring the spring.jpa.hibernate.ddl-auto property, a tool can use the hints to offer some auto-completion help for the none, validate, update, create, and create-drop values.spring-doc.cn

It is not required that every “property” has a “group”. Some properties might exist in their own right.

Group Attributes

The JSON object contained in the groups array can contain the attributes shown in the following table:spring-doc.cn

Name Type Purpose

Name	Type	Purpose
`name`spring-doc.cn	Stringspring-doc.cn	The full name of the group. This attribute is mandatory.spring-doc.cn
`type`spring-doc.cn	Stringspring-doc.cn	The class name of the data type of the group. For example, if the group were based on a class annotated with `@ConfigurationProperties`, the attribute would contain the fully qualified name of that class. If it were based on a `@Bean` method, it would be the return type of that method. If the type is not known, the attribute may be omitted.spring-doc.cn
`description`spring-doc.cn	Stringspring-doc.cn	A short description of the group that can be displayed to users. If no description is available, it may be omitted. It is recommended that descriptions be short paragraphs, with the first line providing a concise summary. The last line in the description should end with a period (`.`).spring-doc.cn
`sourceType`spring-doc.cn	Stringspring-doc.cn	The class name of the source that contributed this group. For example, if the group were based on a `@Bean` method annotated with `@ConfigurationProperties`, this attribute would contain the fully qualified name of the `@Configuration` class that contains the method. If the source type is not known, the attribute may be omitted.spring-doc.cn
`sourceMethod`spring-doc.cn	Stringspring-doc.cn	The full name of the method (include parenthesis and argument types) that contributed this group (for example, the name of a `@ConfigurationProperties` annotated `@Bean` method). If the source method is not known, it may be omitted.spring-doc.cn

Group Attributes

Property Attributes

Hint Attributes

Repeated Metadata Items