本文主要參考官文文檔。主要目的方便版本升級使用复凳，對于需要升級部分進行翻譯溯乒，對于新增特性等后續(xù)部分未做處理

1杠娱、Upgrading from Spring Boot 2.5

1.1 在Spring Boot 2.4棄用的代碼

在Spring Boot 2.4中棄用的類、方法和屬性將在這個版本中被移除。升級前請確保沒有使用被棄用注解的方法胚迫。

1.2 默認禁止循環(huán)引用

缺省情況下，現(xiàn)在禁止bean之間的循環(huán)引用唾那。如果您的應(yīng)用程序由于' BeanCurrentlyInCreationException '而啟動失敗访锻，強烈建議您更新配置以打破依賴循環(huán)。如果不能這樣做闹获，可以通過設(shè)置spring.main.allow-circular-references=true 期犬，或者在SpringApplication 和SpringApplicationBuilder 上使用新的setter方法旭蠕。這將恢復2.5的行為并自動嘗試打破依賴循環(huán)丹墨。

1.3 基于PathPattern的Spring MVC路徑匹配策略

根據(jù)注冊的Spring MVC處理程序映射匹配請求路徑的默認策略已經(jīng)從 AntPathMatcher 變?yōu)?PathPatternParser。使用PathPatternParser時使鹅，不支持自定義調(diào)度servlet路徑(spring.mvc.servlet.path)茎用。
如果你正在使用Spring Security遣总，你應(yīng)該檢查你的mvcMatchers 的使用睬罗，以確保你的匹配器繼續(xù)滿足你的需求。對于AntPathMatcher, authorizeRequests.mvcMatchers("hello").permitAll() '將授予對' /hello '的訪問權(quán)限旭斥。更精確地匹配 PathPatternParser需要使用authorizeRequests.mvcMatchers("/hello").permitAll()(注意前導/)來代替容达。
如果你需要將默認值切換回AntPathMatcher，你可以設(shè)置 spring.mvc.pathmatch.matching-strategy=ant-path-matcher 垂券。

執(zhí)行器端點現(xiàn)在也使用基于 PathPattern 的URL匹配花盐。注意，執(zhí)行器端點的路徑匹配策略不能通過配置屬性進行配置菇爪。如果您正在使用Actuator和Springfox算芯，這可能會導致應(yīng)用程序無法啟動。請參見Springfox本期的詳細信息凳宙。

1.4 Actuator Env InfoContributor默認禁用

缺省情況下熙揍，env 信息貢獻者現(xiàn)在是禁用的。該貢獻者公開了Spring Environment 中任何名稱以 info開頭的屬性氏涩。如果您有任何以info 開頭的屬性届囚，并希望它們顯示在InfoEndpoint中，請將management.info.env.enabled=true 是尖。

1.5 Application Startup

記錄到ApplicationStartup 的 spring.boot.application.running啟動步驟已被重命名為spring.boot.application.ready意系。如果你正在處理從FlightRecorderApplicationStartup或 BufferingApplicationStartup 生成的文件，你將需要使用新的名稱饺汹。

1.6 Web資源配合

直接注入Resources 不再有效蛔添，因為這個配置已經(jīng)在WebProperties中得到了協(xié)調(diào)。如果你需要訪問這些信息兜辞，你需要注入WebProperties來代替迎瞧。

1.7 Dependency Management移除

JBoss Transaction SPI

Dependency management for org.jboss:jboss-transaction-spi has been removed. If you are using org.jboss:jboss-transaction-spi you should define your own dependency management that meets your application’s needs.

Nimbus DS

Dependency management for com.nimbusds:oauth2-oidc-sdk and com.nimbusds:nimbus-jose-jwt has been removed. If you are using Spring Security you should rely on the versions that it will pull in as transitive dependencies. If you are not using Spring Security you should define your own dependency management that meets your application’s needs.

HAL Browser

Dependency management for org.webjars:hal-browser has been removed. If you are using org.webjars:hal-browser you should define your own dependency management that meets your application’s needs.

1.8 Prometheus版本屬性

控制Prometheus版本的屬性已從prometheus-pushgateway.version 更改為prometheus-client.version。這是為了反映出該屬性管理Prometheus客戶端中每個模塊的版本弦疮，而不僅僅是pushgateway夹攒。

1.9 嵌入式Mongo

要使用嵌入式mongo，spring.mongodb.embedded.version 必須設(shè)置的屬性胁塞。這有助于確保MongoDB 版本咏尝。這有助于確保嵌入式支持使用的MongoDB版本與您的應(yīng)用程序?qū)⒃谏a(chǎn)中使用的MongoDB版本相匹配。

1.10 Oracle數(shù)據(jù)庫驅(qū)動依賴管理

Oracle數(shù)據(jù)庫驅(qū)動程序的依賴管理已經(jīng)簡化啸罢。如果你仍然依賴舊的 com.oracle.ojdbc groupId编检，你需要升級到 com.oracle.database.jdbcgroupId，因為我們已經(jīng)刪除了前者的依賴管理扰才。

1.11 Flyway Vault相關(guān)屬性移除

Flyway的7.12版本將vault相關(guān)的設(shè)置移到了一個閉源擴展中允懂。不幸的是，這妨礙了Spring Boot對它們進行配置衩匣。結(jié)果蕾总，對應(yīng)的spring.flyway.vault-secrets, spring.flyway.vault-token, 和spring.flyway.vault-url的屬性已被刪除粥航。如果您是Flyway Teams用戶，可以通過FlywayConfigurationCustomizer bean, FluentConfigiguration.getExtensionConfiguration 和Vault ApiExtension配置設(shè)置生百。

1.12 WebFlux Session 屬性

spring.webflux.session屬性組已棄用递雀，并已遷移到server.reactive.session。舊的屬性將繼續(xù)工作蚀浆，但如果可能缀程，您應(yīng)該遷移到新的屬性。

1.13 Elasticsearch 屬性整合

用于配置Elasticsearch客戶端的配置屬性已經(jīng)得到了統(tǒng)一市俊。以前杨凑，配置阻塞高級REST客戶端和響應(yīng)式REST客戶機的許多常用屬性在 spring.elasticsearch.rest 和 spring.data.elasticsearch.clients.reactive中重復。

如果您正在使用阻塞REST客戶端摆昧，下表列出了舊屬性及其替換項:

1.14 Spring Data Couchbase不在考慮使用注解@Persistent

為了使默認行為與Spring Data Couchbase保持一致撩满， @Persistent注解類型不再被考慮。如果您依賴于該注解据忘，則可以使用@Document 代替鹦牛。

1.15 Maven Build Info’s Default Time

Maven插件的構(gòu)建信息支持現(xiàn)在使用 project.build.outputTimestamp屬性作為默認的構(gòu)建時間。如果未設(shè)置該屬性勇吊，則使用構(gòu)建會話的開始時間。和以前一樣窍仰，時間可以通過設(shè)置為off來完全禁用汉规。

1.16 Records and @ConfigurationProperties

如果你在一個Java 16類中使用 @ConfigurationProperties ，并且該類只有一個構(gòu)造函數(shù)驹吮，那么它就不再需要用 @ConstructorBinding注解了针史。如果你的類有多個構(gòu)造函數(shù)， @ConstructorBinding 仍然應(yīng)該用來標識用于屬性綁定的構(gòu)造函數(shù)碟狞。

1.17 Deferred OpenID Connect Discovery

對于使用 spring-security-oauth2-resource-server配置了OpenID連接issuer-uri的資源服務(wù)器應(yīng)用程序啄枕，Spring Boot現(xiàn)在會自動配置SupplierJwtDecoder 而不是NimbusJwtDecoder。這就啟用了Spring Security的惰性O(shè)IDC發(fā)現(xiàn)支持族沃，從而提高了啟動時間频祝。類似地，對于響應(yīng)式應(yīng)用程序脆淹，ReactiveSupplierJwtDecoder 是自動配置的常空。

1.18 Kafka 3.0

Spring Boot 2.6升級到Apache Kafka 3.0旨在默認啟用最強的交付保證。由于一個Kafka bug盖溺，這些更改直到Kafka 3.0.1 (Spring Boot 2.6.5使用Kafka 3.0.1)才完全到位漓糙。
啟用冪等會導致一些問題，例如在升級時出現(xiàn) ClusterAuthorizationException烘嘱。如果你遇到問題昆禽，想要禁用冪等(Kafka 3.0.1之前的默認值)蝗蛙，設(shè)置以下屬性:

spring.kafka.producer.properties.enable.idempotence=false

1.19 最低要求的變化

無。

2醉鳖、New and Noteworthy

Check the configuration changelog for a complete overview of the changes in configuration. |

SameSite Cookie Attribute Servlet Support

You can now configure SameSite attributes on session cookies for servlet applications using the server.servlet.session.cookie.same-site property. This works with auto-configured Tomcat, Jetty and Undertow servers.

In addition, the CookieSameSiteSupplier interface can be used if you want to apply a SameSite attribute to other cookies. See the updated documentation for more details and some example code.

Reactive Server Session Properties

The session properties supported for reactive servers (previously under spring.webflux.session) have been expanded with this release. The new properties are available under server.reactive.session and now offer parity with the servlet versions.

Pluggable Sanitization Rules

Spring Boot sanitizes sensitive values present in the /env and /configprops endpoints. While it was possible to configure which properties get sanitized via configuration properties, users might want to apply sanitization rules based on which PropertySource the property originated from. For example, Spring Cloud Vault uses vault to store encrypted values and load them into the Spring environment. Since all values are encrypted, it would make sense to blank the values of every key in an entire property source. Such sanitization customizations can be configured by adding a @Bean of type SanitizingFunction.

Java Runtime Information

The info endpoint can now expose Java Runtime information under the java key, as shown in the following example:

{
  "java": {
    "vendor": "BellSoft",
    "version": "17",
    "runtime": {
      "name": "OpenJDK Runtime Environment",
      "version": "17+35-LTS"
    },
    "jvm": {
      "name": "OpenJDK 64-Bit Server VM",
      "vendor": "BellSoft",
      "version": "17+35-LTS"
    }
  }
}

To expose this information in the info endpoint’s response, set the management.info.java.enabled property to true.

Build Info Property Exclusions

It’s now possible to exclude specific properties from being added to the build-info.properties file generated by the Spring Boot Maven or Gradle plugin.

Maven users can exclude the standard group, artifact, name, version or time properties using the <excludeInfoProperties> tag. For example, to exclude the version property the following configuration can be used:

<configuration>
    <excludeInfoProperties>
        <excludeInfoProperty>version</excludeInfoProperty>
    </excludeInfoProperties>
</configuration>

Gradle users can use null values with the properties block of the DSL:

task buildInfo(type: org.springframework.boot.gradle.tasks.buildinfo.BuildInfo) {
    destinationDir project.buildDir
    properties {
        version = null
    }
}

Health Support

Additional Path on Main or Management Port

Health groups can be made available at an additional path on either the main or management port. This is useful in cloud environments such as Kubernetes, where it is quite common to use a separate management port for the actuator endpoints for security purposes. Having a separate port could lead to unreliable health checks because the main application might not work properly even if the health check is successful. A typical configuration would have all the actuator endpoints on a separate port and health groups that are used for liveness and readiness available at an additional path on the main port.

Composite Contributor Include/Exclude Support

Health groups can be configured to include/exclude parts of a CompositeHealthContributor. This can be done by specifying the fully qualified path to the component. For example, a component spring which is nested inside a composite named test, can be included using test/spring.

Metrics Support

Application Startup

Auto-configuration exposes two metrics related to application startup:

• application.started.time: time taken to start the application.

• application.ready.time: time taken for the application to be ready to service requests.

Disk Space

Micrometer’s DiskSpaceMetrics are now auto-configured. disk.free and disk.total metrics are provided for the partition identified by the current working directory. To change the path that is used, define your own DiskSpaceMetrics bean.

Task Execution and Scheduling

Micrometer’s ExecutorServiceMetrics are now auto-configured for all ThreadPoolTaskExecutor and ThreadPoolTaskScheduler beans, as long as the underlying ThreadPoolExecutor is available. Metrics are tagged with the name of the executor derived from its bean name.

Jetty Connection and SSL

Micrometer’s JettyConnectionMetrics are now auto-configured. Additionally, when server.ssl.enabled is set to true, Micrometer’s JettySslHandshakeMetrics are also auto-configured.

Exporting to the Dynatrace v2 API

Support for exporting metrics to the Dynatrace v2 API has been added. With a local OneAgent running on the host, a dependency on io.micrometer:micrometer-registry-dynatrace is all that is required. Without a local OneAgent, the management.metrics.export.dynatrace.uri and management.metrics.export.dynatrace.api-token properties must be configured. Other settings that are specific to the v2 API can be configured using the management.metrics.export.dynatrace.v2 properties. Please refer to the updated reference documentation for further details.

Docker Image Building Support

Additional Image Tags

The Maven and Gradle plugins now support applying additional tags to a generated image after it is built using a tags configuration parameter.

See the updated Gradle and Maven reference documentation for more details.

Network Configuration

A network configuration parameter has been added to the Maven plugin spring-boot:build-image goal and the Gradle bootBuildImage task. This parameter can be used to configure the network driver used by the container that runs the Cloud Native Buildpacks builder process.

Cache Configuration

The Maven and Gradle plugins now support customizing the names of the volumes used to cache layers contributed to a built image by buildpacks using buildCache and launchCache configuration parameters.

See the updated Gradle and Maven reference documentation for more details.

Auto-configuration for Spring Data Envers

Auto-configuration for Spring Data Envers is now provided. To use it, add a dependency on org.springframework.data:spring-data-envers and update your JPA repositories to extend from RevisionRepository.

Redis Connection Pooling

Redis (both Jedis and Lettuce) will now automatically enable pooling when commons-pool2 is on the classpath. Set spring.redis.jedis.pool.enabled or spring.redis.lettuce.pool.enabled to false to disable pooling if required.

Auto-configuration for spring-rabbit-stream

Auto-configuration for Spring AMQP’s new spring-rabbit-stream module has been added. A StreamListenerContainer is auto-configured when the spring.rabbitmq.listener.type property is set to stream. The spring.rabbitmq.stream.* properties can be used to configure access to the broker and spring.rabbitmq.listener.stream.native-listener can be used to enable native listener support.

Support for PEM format in Kafka SSL Properties

Previously, Kafka only supported file-based key and trust stores for SSL. With KIP-651, it is now possible to use the PEM format. Spring Boot has added the following properties that allow configuring SSL certificates and private keys using the PEM format:

• spring.kafka.ssl.key-store-key

• spring.kafka.ssl.key-store-certificate-chain

• spring.kafka.ssl.trust-store-certificates

Improved Configuration of the Maven Plugin’s Start Goal

The Maven Plugin’s start goal has been made more configurable from the command line. Its wait and maxAttempts properties can be specified using spring-boot.start.wait and spring-boot.start.maxAttempts respectively.

Auto-configured Spring Web Service Server Tests

A new annotation, @WebServiceServerTest, that can be used to test Web Service @Endpoint beans has been introduced. The annotation creates a test slice containing @Endpoint beans and auto-configures a MockWebServiceClient bean that can be used to test your web service endpoints.

MessageSource-based Interpolation of Bean Validation Messages

The application’s MessageSource is now used when resolving {parameters} in constraint messages. This allows you to use your application’s messages.properties files for Bean Validation messages. Once the parameters have been resolved, message interpolation is completed using Bean Validation’s default interpolator.

Using WebTestClient for Testing Spring MVC

Developers could use WebTestClient to test WebFlux apps in mock environments, or any Spring web app against live servers. This change also enables WebTestClient for Spring MVC in mock environments: classes annotated with @AutoConfigureMockMvc can get injected a WebTestClient. This makes our support complete, you can now use a single API to drive all your web tests!

Spring Integration PollerMetadata Properties

Spring Integration PollerMetadata (poll unbounded number of messages every second) can now be customized with spring.integration.poller.* configuration properties.

Support for Log4j2’s Composite Configuration

Log4j2’s composite configuration is now supported. To use it, configure the logging.log4j2.config.override property with a comma-separated list of secondary configuration files that will override the main configuration. The main configuration is sourced from Spring Boot’s defaults, a well-known standard location such as log4j2.xml, or the location specified by the logging.config property as before.

Dependency Upgrades

Spring Boot 2.6 moves to new versions of several Spring projects:

• Spring Security 5.6

• Spring Data 2021.1

• Spring HATEOAS 1.4

• Spring Kafka 2.8

• Spring AMQP 2.4

• Spring Session 2021.1.0

Numerous third-party dependencies have also been updated, some of the more noteworthy of which are the following:

• Apache Kafka 3.0

• Artemis 2.19

• Cassandra Driver 4.13

• Commons DBCP 2.9

• Commons Pool 2.11

• Couchbase Client 3.2.2

• Elasticsearch 7.15

• Flyway 8.0.5

• Hibernate 5.6

• JUnit Jupiter 5.8

• Jedis 3.7

• Kafka 3.0

• Kotlin 1.6

• Liquibase 4.5

• Micrometer 1.8

• Mockito 4.0

• MongoDB 4.4

• Postgresql 42.3

• QueryDSL 5.0

• SnakeYAML 1.29

• Thymeleaf Layout Dialect 3.0

Miscellaneous

Apart from the changes listed above, there have also been lots of minor tweaks and improvements including:

• The failure analysis for a NoSuchMethodError now includes information about the location from which the calling class was loaded.

• A ClientResourcesBuilderCustomizer bean can now be defined to customize Lettuce’s ClientResources will retaining the default auto-configuration.

• Configuration properties for Flyway’s detectEncoding, failOnMissingLocations, and ignoreMigrationPatterns configuration settings have been added.

• A custom ResourceLoader to be used by the application can be provided when creating a SpringApplicationBulder.

• A WebSessionIdResolver can now be defined to customize the resolver that will be used by the auto-configured WebSessionManager.

• Any RSocketConnectorConfigurer beans are now automatically applied to the auto-configured RSocketRequester.Builder.

• spring-boot-configuration-processor can now generate metadata for classes annotated with Lombok’s @Value.

• A new server.tomcat.reject-illegal-header configuration property can be set to true to configure Tomcat to accept illegal headers.

• When using Stackdriver, labels can now be configured on the monitor resource by setting management.metrics.export.stackdriver.resource-labels.* configuration properties.

• @EntityScan now supports comma-separated values in its basePackages attribute.

• A new configuration property, server.netty.idle-timeout, that can be used to control Reactor Netty’s idle timeout has been added.

• The location from which Devtools loads its global settings can now be configured using the spring.devtools.home system property or the SPRING_DEVTOOLS_HOME environment variable.

• The setter methods on RabbitTemplateConfigurer are now public

• The heapdump endpoint is now supported on OpenJ9 where it will produce a heap dump in PHD format.

• New configuration properties are now supported for multipart support in WebFlux, under spring.webflux.multipart.*

• Any ContainerCustomizer bean is now called to configure the auto-configured Spring AMQP MessageListenerContainer

• Jackson’s default leniency can be configured using the spring.jackson.default-leniency property.

• Distribution statistic’s expiry and buffer length are now configurable.

• Command Latency metrics for Lettuce are now auto-configured.

• Disk space metrics can be configured with one or more paths using the management.metrics.system.diskspace.paths property.

• Users can take control over the Redis auto-configuration by providing a RedisStandaloneConfiguration bean.

• The URLs of all available data sources is now logged when the H2 console is auto-configured.

• A new configuration property, spring.integration.management.default-logging-enabled, can be used to disable Spring Integration’s default logging by setting its value to false.

• Auto-configuration for UserDetailsService will now back off in the presence of an AuthenticationManagerProvider bean.

Deprecations in Spring Boot 2.6.0

• AbstractDataSourceInitializer has been deprecated in favor of DataSourceScriptDatabaseInitializer. Similarly, subclasses of AbstractDataSourceInitializer have been deprecated in favour of new DataSourceScriptDatabaseInitializer-based equivalents.

• SpringPhysicalNamingStrategy has been deprecated in favor of Hibernate 5.5’s CamelCaseToUnderscoresNamingStrategy

• Three methods on AbstractApplicationContextRunner have been deprecated in favor of new RunnerConfiguration-based equivalents

• The started and running methods in SpringApplicationRunListener have been replaced with versions that accept a Duration.

• Constructors in ApplicationStartedEvent and ApplicationReadyEvent have been replaced with versions that accept a Duration.

• The EnvironmentEndpoint.sanitize has been deprecated for removal.