Spring Boot 用來簡化 Spring 應用開發,約定大於配置,去繁從簡,just run 就能建立一個獨立的、產品級別的應用。css
背景:html
J2EE 笨重的開發、繁多的配置、低下的開發效率、複雜的部署流程、第三方技術集成難度大。java
解決:react
優勢:git
SpringBoot 官網 | SpringBoot 官方文檔 | SpringBoot-2.1.3.RELEASE 源碼下載(其它版本直接修改連接版本號便可)github
一、使用 maven 建立一個 java 項目,依賴以下:web
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.3.RELEASE</version> <relativePath/> </parent> <groupId>com.zze.learning</groupId> <artifactId>springboot_helloworld</artifactId> <version>1.0-SNAPSHOT</version> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <!--這個插件,能夠將應用打包成一個可執行的 jar 包--> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
二、編寫 SpringMVC 控制器:redis
package com.zze.springboot.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; @Controller public class TestController { @RequestMapping("/test") @ResponseBody public String test(){ return "hello world"; } }
三、編寫主程序:spring
package com.zze.springboot; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication // 標註一個主程序類,說明這是一個 Spring Boot 應用 public class TestApplication { public static void main(String[] args) { // Spring 應用啓動 SpringApplication.run(TestApplication.class, args); } }
四、執行主程序:mongodb
控制檯:
瀏覽器訪問 localhost:8080/test:
五、咱們還能夠經過 maven 將程序打成一個 jar 包,直接經過 java 命令啓動:
CMD:
瀏覽器訪問 localhost:8080/test:
這個 HelloWorld 程序也可使用官網幫助生成,點擊使用。
父項目
首先,咱們引入了一個父項目:
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.3.RELEASE</version> <relativePath/> </parent>
而這個父項目也有一個父項目:
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>2.1.3.RELEASE</version> <relativePath>../../spring-boot-dependencies</relativePath> </parent>
這個父項目是真正管理 SpringBoot 應用中的全部依賴版本,它能夠稱爲 SpringBoot 的版本管理中心,因此之後咱們導入它管理的依賴是不須要聲明版本的。
場景啓動器
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency>
spring-boot-starter:SpingBoot 場景啓動器。SpringBoot 將全部功能場景都抽取出來,作成一個個 starter (場景啓動器),只須要在項目中引入這些 starter 相關場景的全部依賴都會導入進來,要使用什麼功能就導入什麼場景啓動器。下面是 SpringBoot 提供的一些場景啓動器:
Name | Description | Pom |
---|---|---|
Core starter, including auto-configuration support, logging and YAML |
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Starter for JMS messaging using Apache ActiveMQ |
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Starter for using Spring AMQP and Rabbit MQ |
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Starter for aspect-oriented programming with Spring AOP and AspectJ |
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Starter for JMS messaging using Apache Artemis |
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Starter for using Spring Batch |
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Starter for using Spring Framework’s caching support |
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Starter for using Spring Cloud Connectors which simplifies connecting to services in cloud platforms like Cloud Foundry and Heroku |
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Starter for using Cassandra distributed database and Spring Data Cassandra |
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Starter for using Cassandra distributed database and Spring Data Cassandra Reactive |
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Starter for using Couchbase document-oriented database and Spring Data Couchbase |
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Starter for using Couchbase document-oriented database and Spring Data Couchbase Reactive |
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Starter for using Elasticsearch search and analytics engine and Spring Data Elasticsearch |
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Starter for using Spring Data JDBC |
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Starter for using Spring Data JPA with Hibernate |
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Starter for using Spring Data LDAP |
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Starter for using MongoDB document-oriented database and Spring Data MongoDB |
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Starter for using MongoDB document-oriented database and Spring Data MongoDB Reactive |
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Starter for using Neo4j graph database and Spring Data Neo4j |
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Starter for using Redis key-value data store with Spring Data Redis and the Lettuce client |
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Starter for using Redis key-value data store with Spring Data Redis reactive and the Lettuce client |
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Starter for exposing Spring Data repositories over REST using Spring Data REST |
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Starter for using the Apache Solr search platform with Spring Data Solr |
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Starter for building MVC web applications using FreeMarker views |
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Starter for building MVC web applications using Groovy Templates views |
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Starter for building hypermedia-based RESTful web application with Spring MVC and Spring HATEOAS |
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Starter for using Spring Integration |
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Starter for using JDBC with the HikariCP connection pool |
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Starter for building RESTful web applications using JAX-RS and Jersey. An alternative to |
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Starter for using jOOQ to access SQL databases. An alternative to |
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Starter for reading and writing json |
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Starter for JTA transactions using Atomikos |
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Starter for JTA transactions using Bitronix |
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Starter for using Java Mail and Spring Framework’s email sending support |
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Starter for building web applications using Mustache views |
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Starter for using Spring Security’s OAuth2/OpenID Connect client features |
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Starter for using Spring Security’s OAuth2 resource server features |
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Starter for using the Quartz scheduler |
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Starter for using Spring Security |
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Starter for testing Spring Boot applications with libraries including JUnit, Hamcrest and Mockito |
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Starter for building MVC web applications using Thymeleaf views |
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Starter for using Java Bean Validation with Hibernate Validator |
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Starter for building web, including RESTful, applications using Spring MVC. Uses Tomcat as the default embedded container |
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Starter for using Spring Web Services |
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Starter for building WebFlux applications using Spring Framework’s Reactive Web support |
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Starter for building WebSocket applications using Spring Framework’s WebSocket support |
package com.zze.springboot; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication // 標註一個主程序類,說明這是一個 Spring Boot 應用 public class TestApplication { public static void main(String[] args) { // Spring 應用啓動 SpringApplication.run(TestApplication.class, args); } }
@SpringBootApplication :標註在某個類上說明這個類是 SpringBoot 的主配置類,SpringBoot 就應該運行這個類的 main 方法來啓動 SpringBoot 應用。查看它,發現它實際上是一個組合註解:
@Target({ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) @Documented @Inherited @SpringBootConfiguration @EnableAutoConfiguration @ComponentScan( excludeFilters = {@Filter( type = FilterType.CUSTOM, classes = {TypeExcludeFilter.class} ), @Filter( type = FilterType.CUSTOM, classes = {AutoConfigurationExcludeFilter.class} )} ) public @interface SpringBootApplication {
@SpringBootConfiguration :標註在某個類上,表示這是一個 SpringBoot 的配置類。而它也是一個組合註解:
@Target({ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) @Documented @Configuration public @interface SpringBootConfiguration {
@Configuration :Spring 配置類上來標註這個註解。它實際上是容器中的一個組件:
@Target({ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) @Documented @Component public @interface Configuration {
@Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @Documented @Inherited @AutoConfigurationPackage @Import(AutoConfigurationImportSelector.class) public @interface EnableAutoConfiguration {
@Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @Documented @Inherited @Import(AutoConfigurationPackages.Registrar.class) public @interface AutoConfigurationPackage {
@Import(AutoConfigurationPackages.Registrar.class) :Spring 底層註解,給容器中導入組件。導入的組件由 AutoConfigurationPackages.Registrar.class 決定,使用這個類會將所標識類(即: com.zze.springboot.TestApplication 類)所在包及子包下的全部類掃描到 Spring 容器。
@Target({ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) @Documented public @interface Import {
# Initializers org.springframework.context.ApplicationContextInitializer=\ org.springframework.boot.autoconfigure.SharedMetadataReaderFactoryContextInitializer,\ org.springframework.boot.autoconfigure.logging.ConditionEvaluationReportLoggingListener # Application Listeners org.springframework.context.ApplicationListener=\ org.springframework.boot.autoconfigure.BackgroundPreinitializer # Auto Configuration Import Listeners org.springframework.boot.autoconfigure.AutoConfigurationImportListener=\ org.springframework.boot.autoconfigure.condition.ConditionEvaluationReportAutoConfigurationImportListener # Auto Configuration Import Filters org.springframework.boot.autoconfigure.AutoConfigurationImportFilter=\ org.springframework.boot.autoconfigure.condition.OnBeanCondition,\ org.springframework.boot.autoconfigure.condition.OnClassCondition,\ org.springframework.boot.autoconfigure.condition.OnWebApplicationCondition # Auto Configure org.springframework.boot.autoconfigure.EnableAutoConfiguration=\ org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\ org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\ org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration,\ org.springframework.boot.autoconfigure.batch.BatchAutoConfiguration,\ org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration,\ org.springframework.boot.autoconfigure.cassandra.CassandraAutoConfiguration,\ org.springframework.boot.autoconfigure.cloud.CloudServiceConnectorsAutoConfiguration,\ org.springframework.boot.autoconfigure.context.ConfigurationPropertiesAutoConfiguration,\ org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration,\ org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration,\ org.springframework.boot.autoconfigure.couchbase.CouchbaseAutoConfiguration,\ org.springframework.boot.autoconfigure.dao.PersistenceExceptionTranslationAutoConfiguration,\ org.springframework.boot.autoconfigure.data.cassandra.CassandraDataAutoConfiguration,\ org.springframework.boot.autoconfigure.data.cassandra.CassandraReactiveDataAutoConfiguration,\ org.springframework.boot.autoconfigure.data.cassandra.CassandraReactiveRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.cassandra.CassandraRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.couchbase.CouchbaseDataAutoConfiguration,\ org.springframework.boot.autoconfigure.data.couchbase.CouchbaseReactiveDataAutoConfiguration,\ org.springframework.boot.autoconfigure.data.couchbase.CouchbaseReactiveRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.couchbase.CouchbaseRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchAutoConfiguration,\ org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchDataAutoConfiguration,\ org.springframework.boot.autoconfigure.data.elasticsearch.ElasticsearchRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.jdbc.JdbcRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.ldap.LdapRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration,\ org.springframework.boot.autoconfigure.data.mongo.MongoReactiveDataAutoConfiguration,\ org.springframework.boot.autoconfigure.data.mongo.MongoReactiveRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.mongo.MongoRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration,\ org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.solr.SolrRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration,\ org.springframework.boot.autoconfigure.data.redis.RedisReactiveAutoConfiguration,\ org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration,\ org.springframework.boot.autoconfigure.data.rest.RepositoryRestMvcAutoConfiguration,\ org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration,\ org.springframework.boot.autoconfigure.elasticsearch.jest.JestAutoConfiguration,\ org.springframework.boot.autoconfigure.elasticsearch.rest.RestClientAutoConfiguration,\ org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration,\ org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration,\ org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration,\ org.springframework.boot.autoconfigure.h2.H2ConsoleAutoConfiguration,\ org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration,\ org.springframework.boot.autoconfigure.hazelcast.HazelcastAutoConfiguration,\ org.springframework.boot.autoconfigure.hazelcast.HazelcastJpaDependencyAutoConfiguration,\ org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration,\ org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration,\ org.springframework.boot.autoconfigure.influx.InfluxDbAutoConfiguration,\ org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration,\ org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration,\ org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration,\ org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration,\ org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration,\ org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration,\ org.springframework.boot.autoconfigure.jdbc.XADataSourceAutoConfiguration,\ org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration,\ org.springframework.boot.autoconfigure.jms.JmsAutoConfiguration,\ org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration,\ org.springframework.boot.autoconfigure.jms.JndiConnectionFactoryAutoConfiguration,\ org.springframework.boot.autoconfigure.jms.activemq.ActiveMQAutoConfiguration,\ org.springframework.boot.autoconfigure.jms.artemis.ArtemisAutoConfiguration,\ org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration,\ org.springframework.boot.autoconfigure.jersey.JerseyAutoConfiguration,\ org.springframework.boot.autoconfigure.jooq.JooqAutoConfiguration,\ org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration,\ org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration,\ org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration,\ org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration,\ org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration,\ org.springframework.boot.autoconfigure.mail.MailSenderAutoConfiguration,\ org.springframework.boot.autoconfigure.mail.MailSenderValidatorAutoConfiguration,\ org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration,\ org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration,\ org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration,\ org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration,\ org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration,\ org.springframework.boot.autoconfigure.quartz.QuartzAutoConfiguration,\ org.springframework.boot.autoconfigure.reactor.core.ReactorCoreAutoConfiguration,\ org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration,\ org.springframework.boot.autoconfigure.security.servlet.SecurityRequestMatcherProviderAutoConfiguration,\ org.springframework.boot.autoconfigure.security.servlet.UserDetailsServiceAutoConfiguration,\ org.springframework.boot.autoconfigure.security.servlet.SecurityFilterAutoConfiguration,\ org.springframework.boot.autoconfigure.security.reactive.ReactiveSecurityAutoConfiguration,\ org.springframework.boot.autoconfigure.security.reactive.ReactiveUserDetailsServiceAutoConfiguration,\ org.springframework.boot.autoconfigure.sendgrid.SendGridAutoConfiguration,\ org.springframework.boot.autoconfigure.session.SessionAutoConfiguration,\ org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientAutoConfiguration,\ org.springframework.boot.autoconfigure.security.oauth2.client.reactive.ReactiveOAuth2ClientAutoConfiguration,\ org.springframework.boot.autoconfigure.security.oauth2.resource.servlet.OAuth2ResourceServerAutoConfiguration,\ org.springframework.boot.autoconfigure.security.oauth2.resource.reactive.ReactiveOAuth2ResourceServerAutoConfiguration,\ org.springframework.boot.autoconfigure.solr.SolrAutoConfiguration,\ org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration,\ org.springframework.boot.autoconfigure.task.TaskSchedulingAutoConfiguration,\ org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration,\ org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration,\ org.springframework.boot.autoconfigure.transaction.jta.JtaAutoConfiguration,\ org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration,\ org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration,\ org.springframework.boot.autoconfigure.web.embedded.EmbeddedWebServerFactoryCustomizerAutoConfiguration,\ org.springframework.boot.autoconfigure.web.reactive.HttpHandlerAutoConfiguration,\ org.springframework.boot.autoconfigure.web.reactive.ReactiveWebServerFactoryAutoConfiguration,\ org.springframework.boot.autoconfigure.web.reactive.WebFluxAutoConfiguration,\ org.springframework.boot.autoconfigure.web.reactive.error.ErrorWebFluxAutoConfiguration,\ org.springframework.boot.autoconfigure.web.reactive.function.client.ClientHttpConnectorAutoConfiguration,\ org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration,\ org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration,\ org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration,\ org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration,\ org.springframework.boot.autoconfigure.web.servlet.HttpEncodingAutoConfiguration,\ org.springframework.boot.autoconfigure.web.servlet.MultipartAutoConfiguration,\ org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration,\ org.springframework.boot.autoconfigure.websocket.reactive.WebSocketReactiveAutoConfiguration,\ org.springframework.boot.autoconfigure.websocket.servlet.WebSocketServletAutoConfiguration,\ org.springframework.boot.autoconfigure.websocket.servlet.WebSocketMessagingAutoConfiguration,\ org.springframework.boot.autoconfigure.webservices.WebServicesAutoConfiguration,\ org.springframework.boot.autoconfigure.webservices.client.WebServiceTemplateAutoConfiguration # Failure analyzers org.springframework.boot.diagnostics.FailureAnalyzer=\ org.springframework.boot.autoconfigure.diagnostics.analyzer.NoSuchBeanDefinitionFailureAnalyzer,\ org.springframework.boot.autoconfigure.jdbc.DataSourceBeanCreationFailureAnalyzer,\ org.springframework.boot.autoconfigure.jdbc.HikariDriverConfigurationFailureAnalyzer,\ org.springframework.boot.autoconfigure.session.NonUniqueSessionRepositoryFailureAnalyzer # Template availability providers org.springframework.boot.autoconfigure.template.TemplateAvailabilityProvider=\ org.springframework.boot.autoconfigure.freemarker.FreeMarkerTemplateAvailabilityProvider,\ org.springframework.boot.autoconfigure.mustache.MustacheTemplateAvailabilityProvider,\ org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAvailabilityProvider,\ org.springframework.boot.autoconfigure.thymeleaf.ThymeleafTemplateAvailabilityProvider,\ org.springframework.boot.autoconfigure.web.servlet.JspTemplateAvailabilityProvider
J2EE的總體解決方案和自動配置都在 spring-boot-autoconfigure-2.1.3.RELEASE.jar 中。
IDE 都支持使用 Spring 的項目建立嚮導快速建立一個 SpringBoot 項目(需聯網環境下)。下面以 IDEA 爲例。
一、新建模塊,選中 「Spring Initializr」 項:
二、輸入座標,默認選擇 「Maven Project」:
三、可直接勾選要導入的場景:
四、點擊「Finish」,完成:
默認生成的 SpringBoot 項目:
static:保存全部的靜態資源,例如:js、css、images 等。
templates:保存全部的模板頁面;(SpringBoot 以 jar 包方式嵌入Tomcat,默認不支持 JSP 頁面,可以使用模板引擎如:freemarker、thymeleaf)。
application.properties:SpringBoot 應用的配置文件,能夠修改一些默認設置。