SpringBoot高级
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SpringBoot自定配置
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SpringBoot事件监听
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SpringBoot流程分析
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SpringBoot监控
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SpringBoot部署
1-SpringBoot自动配置-Condition-1
Condition是Spring4.0后引入的条件化配置接口，通过实现Condition接口可以完成有条件的加载相应的Bean
@Conditional要配和Condition的实现类（ClassCondition）进行使用
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ClassCondition
public class ClassCondition implements Condition { /** * * @param context 上下文对象。用于获取环境，IOC容器，ClassLoader对象 * @param metadata 注解元对象。 可以用于获取注解定义的属性值 * @return */ @Override public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) { //1.需求： 导入Jedis坐标后创建Bean //思路：判断redis.clients.jedis.Jedis.class文件是否存在 boolean flag = true; try { Class<?> cls = Class.forName("redis.clients.jedis.Jedis"); } catch (ClassNotFoundException e) { flag = false; } return flag; } }
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UserConfig
@Configuration public class UserConfig { @Bean @Conditional(ClassCondition.class) public User user(){ return new User(); } }
测试
@SpringBootApplication public class SpringbootConditionApplication { public static void main(String[] args) { //启动SpringBoot的应用，返回Spring的IOC容器 ConfigurableApplicationContext context = SpringApplication.run(SpringbootConditionApplication.class, args); Object user = context.getBean("user"); System.out.println(user); } }
2-SpringBoot自动配置-Condition-2
需求：将类的判断定义为动态的。判断哪个字节码文件存在可以动态指定。
自定义条件注解类
import org.springframework.context.annotation.Conditional; import java.lang.annotation.*; @Target({ElementType.TYPE, ElementType.METHOD}) @Retention(RetentionPolicy.RUNTIME) @Documented @Conditional(ClassCondition.class) public @interface ConditionOnClass { String[] value(); }
注意：此处@ConditionOnClass为自定义注解
@Configuration public class UserConfig { @Bean //@Conditional(ClassCondition.class) @ConditionOnClass("com.alibaba.fastjson.JSON") public User user(){ return new User(); } @Bean @ConditionalOnProperty(name = "itcast",havingValue = "itheima") public User user2(){ return new User(); } }
测试User对象的创建
@SpringBootApplication public class SpringbootConditionApplication { public static void main(String[] args) { //启动SpringBoot的应用，返回Spring的IOC容器 ConfigurableApplicationContext context = SpringApplication.run(SpringbootConditionApplication.class, args); Object user = context.getBean("user"); System.out.println(user); } }
查看条件注解源码
SpringBoot 提供的常用条件注解：
ConditionalOnProperty：判断配置文件中是否有对应属性和值才初始化Bean
ConditionalOnClass：判断环境中是否有对应字节码文件才初始化Bean
ConditionalOnMissingBean：判断环境中没有对应Bean才初始化Bean
3-SpringBoot自动配置-切换内置web服务器
查看继承关系图
排除Tomcat服务器
pom文件中的排除依赖效果
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <!--排除tomcat依赖--> <exclusions> <exclusion> <artifactId>spring-boot-starter-tomcat</artifactId> <groupId>org.springframework.boot</groupId> </exclusion> </exclusions> </dependency> <!--引入jetty的依赖--> <dependency> <artifactId>spring-boot-starter-jetty</artifactId> <groupId>org.springframework.boot</groupId> </dependency>
4-SpringBoot自动配置-Enable注解原理
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SpringBoot不能直接获取在其他工程中定义的Bean
演示代码：
springboot-enable工程
/** * @ComponentScan 扫描范围：当前引导类所在包及其子包 * * com.itheima.springbootenable * com.itheima.config * //1.使用@ComponentScan扫描com.itheima.config包 * //2.可以使用@Import注解，加载类。这些类都会被Spring创建，并放入IOC容器 * //3.可以对Import注解进行封装。 */ //@ComponentScan("com.itheima.config") //@Import(UserConfig.class) @EnableUser @SpringBootApplication public class SpringbootEnableApplication { public static void main(String[] args) { ConfigurableApplicationContext context = SpringApplication.run(SpringbootEnableApplication.class, args); //获取Bean Object user = context.getBean("user"); System.out.println(user); } }
pom中引入springboot-enable-other
<dependency> <groupId>com.itheima</groupId> <artifactId>springboot-enable-other</artifactId> <version>0.0.1-SNAPSHOT</version> </dependency>
springboot-enable-other工程
UserConfig
@Configuration public class UserConfig { @Bean public User user() { return new User(); } }EnableUser注解类
import org.springframework.context.annotation.Import; import java.lang.annotation.*; @Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @Documented @Import(UserConfig.class) public @interface EnableUser { } **原因**：@ComponentScan 扫描范围：当前引导类所在包及其子包
原因：@ComponentScan 扫描范围：当前引导类所在包及其子包
三种解决方案：
1.使用@ComponentScan扫描com.itheima.config包
2.可以使用@Import注解，加载类。这些类都会被Spring创建，并放入IOC容器
3.可以对Import注解进行封装。
重点：Enable注解底层原理是使用@Import注解实现Bean的动态加载
5-SpringBoot自动配置-@Import详解
@Enable*底层依赖于@Import注解导入一些类，使用@Import导入的类会被Spring加载到IOC容器中。而@Import提供4中用法：
①导入Bean
②导入配置类
③导入 ImportSelector 实现类。一般用于加载配置文件中的类
④导入 ImportBeanDefinitionRegistrar 实现类。
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导入Bean @Import(User.class)
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导入配置类 @Import(UserConfig.class)
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导入 ImportSelector 实现类 @Import(MyImportSelector.class)
MyImportSelector
public class MyImportSelector implements ImportSelector { @Override public String[] selectImports(AnnotationMetadata importingClassMetadata) { return new String[]{"com.itheima.domain.User", "com.itheima.domain.Role"}; } }
导入 ImportBeanDefinitionRegistrar 实现类。@Import({MyImportBeanDefinitionRegistrar.class})
public class MyImportBeanDefinitionRegistrar implements ImportBeanDefinitionRegistrar { @Override public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) { AbstractBeanDefinition beanDefinition = BeanDefinitionBuilder.rootBeanDefinition(User.class).getBeanDefinition(); registry.registerBeanDefinition("user", beanDefinition); } }
/** Import4中用法： * 1. 导入Bean * 2. 导入配置类 * 3. 导入ImportSelector的实现类。 * 4. 导入ImportBeanDefinitionRegistrar实现类 */ //@Import(User.class) //@Import(UserConfig.class) //@Import(MyImportSelector.class) //@Import({MyImportBeanDefinitionRegistrar.class}) @SpringBootApplication public class SpringbootEnableApplication { public static void main(String[] args) { ConfigurableApplicationContext context = SpringApplication.run(SpringbootEnableApplication.class, args); /*//获取Bean Object user = context.getBean("user"); System.out.println(user);*/ /*User user = context.getBean(User.class); System.out.println(user); Role role = context.getBean(Role.class); System.out.println(role);*/ /* Object user = context.getBean("user"); System.out.println(user);*/ Map<String, User> map = context.getBeansOfType(User.class); System.out.println(map); } }
@EnableAutoConfiguration中使用的是第三种方式：@Import(AutoConfigurationImportSelector.class)
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@EnableAutoConfiguration 注解内部使用 @Import(AutoConfigurationImportSelector.class)来加载配置类。
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配置文件位置：META-INF/spring.factories，该配置文件中定义了大量的配置类，当 SpringBoot 应用启动时，会自动加载这些配置类，初始化Bean
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并不是所有的Bean都会被初始化，在配置类中使用Condition来加载满足条件的Bean
7-SpringBoot自动配置-自定义starter步骤分析
需求：自定义redis-starter。要求当导入redis坐标时，SpringBoot自动创建Jedis的Bean。
步骤：
①创建 redis-spring-boot-autoconfigure 模块
②创建 redis-spring-boot-starter 模块,依赖 redis-spring-boot-autoconfigure的模块
③在 redis-spring-boot-autoconfigure 模块中初始化 Jedis 的 Bean。并定义META-INF/spring.factories 文件
④在测试模块中引入自定义的 redis-starter 依赖，测试获取 Jedis 的Bean，操作 redis。
<!--引入configure-->
<dependency>
<groupId>com.itheima</groupId>
<artifactId>redis-spring-boot-autoconfigure</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
@ConfigurationProperties(prefix = "redis") public class RedisProperties { private String host = "localhost"; private int port = 6379; public String getHost() { return host; } public void setHost(String host) { this.host = host; } public int getPort() { return port; } public void setPort(int port) { this.port = port; } }
创建RedisAutoConfiguration自动配置类
@Configuration @EnableConfigurationProperties(RedisProperties.class) public class RedisAutoConfiguration { /** * 提供Jedis的bean */ @Bean public Jedis jedis(RedisProperties redisProperties) { return new Jedis(redisProperties.getHost(), redisProperties.getPort()); } }
在resource目录下创建META-INF文件夹并创建spring.factories
注意：”\ “是换行使用的
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.itheima.redis.config.RedisAutoConfiguration
在springboot-enable工程中引入自定义的redis的starter
<!--自定义的redis的starter-->
<dependency>
<groupId>com.itheima</groupId>
<artifactId>redis-spring-boot-starter</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
在SpringbootEnableApplication启动类中测试
Jedis jedis = context.getBean(Jedis.class); System.out.println(jedis);
redis.port=6666
使用注解完成有条件加载配置类
@Configuration @EnableConfigurationProperties(RedisProperties.class) @ConditionalOnClass(Jedis.class) public class RedisAutoConfiguration { /** * 提供Jedis的bean */ @Bean @ConditionalOnMissingBean(name = "jedis") public Jedis jedis(RedisProperties redisProperties) { System.out.println("RedisAutoConfiguration...."); return new Jedis(redisProperties.getHost(), redisProperties.getPort()); } }
Java中的事件监听机制定义了以下几个角色：
①事件：Event，继承 java.util.EventObject 类的对象
②事件源：Source ，任意对象Object
③监听器：Listener，实现 java.util.EventListener 接口 的对象
SpringBoot 在项目启动时，会对几个监听器进行回调，我们可以实现这些监听器接口，在项目启动时完成一些操作。
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ApplicationContextInitializer、
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SpringApplicationRunListener、
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CommandLineRunner、
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ApplicationRunner
自定义监听器的启动时机：MyApplicationRunner和MyCommandLineRunner都是当项目启动后执行，使用@Component放入容器即可使用
MyApplicationRunner
/** * 当项目启动后执行run方法。 */ @Component public class MyApplicationRunner implements ApplicationRunner { @Override public void run(ApplicationArguments args) throws Exception { System.out.println("ApplicationRunner...run"); System.out.println(Arrays.asList(args.getSourceArgs())); } }
MyCommandLineRunner
@Component public class MyCommandLineRunner implements CommandLineRunner { @Override public void run(String... args) throws Exception { System.out.println("CommandLineRunner...run"); System.out.println(Arrays.asList(args)); } }
MyApplicationContextInitializer的使用要在resource文件夹下添加META-INF/spring.factories
org.springframework.context.ApplicationContextInitializer=com.itheima.springbootlistener.listener.MyApplicationContextInitializer
@Component public class MyApplicationContextInitializer implements ApplicationContextInitializer { @Override public void initialize(ConfigurableApplicationContext applicationContext) { System.out.println("ApplicationContextInitializer....initialize"); } }
public class MySpringApplicationRunListener implements SpringApplicationRunListener { public MySpringApplicationRunListener(SpringApplication application, String[] args) { } @Override public void starting() { System.out.println("starting...项目启动中"); } @Override public void environmentPrepared(ConfigurableEnvironment environment) { System.out.println("environmentPrepared...环境对象开始准备"); } @Override public void contextPrepared(ConfigurableApplicationContext context) { System.out.println("contextPrepared...上下文对象开始准备"); } @Override public void contextLoaded(ConfigurableApplicationContext context) { System.out.println("contextLoaded...上下文对象开始加载"); } @Override public void started(ConfigurableApplicationContext context) { System.out.println("started...上下文对象加载完成"); } @Override public void running(ConfigurableApplicationContext context) { System.out.println("running...项目启动完成，开始运行"); } @Override public void failed(ConfigurableApplicationContext context, Throwable exception) { System.out.println("failed...项目启动失败"); } }
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判断是否是Web环境
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执行监听器
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准备环境
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打印banner：可以resource下粘贴自定义的banner
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创建context
refreshContext(context);
①导入依赖坐标
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency>
{ "_links":{ "self":{ "href":"http://localhost:8080/actuator", "templated":false }, "health":{ "href":"http://localhost:8080/actuator/health", "templated":false }, "health-component-instance":{ "href":"http://localhost:8080/actuator/health/{component}/{instance}", "templated":true }, "health-component":{ "href":"http://localhost:8080/actuator/health/{component}", "templated":true }, "info":{ "href":"http://localhost:8080/actuator/info", "templated":false } } }
http://localhost:8080/actuator/info
在application.properties中配置
info.name=lucy
info.age=99
http://localhost:8080/actuator/health
开启健康检查详细信息
management.endpoint.health.show-details=always
{ "status":"UP", "details":{ "diskSpace":{ "status":"UP", "details":{ "total":159579508736, "free":13558104064, "threshold":10485760 } }, "redis":{ "status":"UP", "details":{ "version":"2.4.5" } } } }
开启所有endpoint
在application.properties中配置：
management.endpoints.web.exposure.include=*
开启所有endpoint的返回结果：
{ "_links":{ "self":{ "href":"http://localhost:8080/actuator", "templated":false }, "auditevents":{ "href":"http://localhost:8080/actuator/auditevents", "templated":false }, "beans":{ "href":"http://localhost:8080/actuator/beans", "templated":false }, "caches-cache":{ "href":"http://localhost:8080/actuator/caches/{cache}", "templated":true }, "caches":{ "href":"http://localhost:8080/actuator/caches", "templated":false }, "health-component-instance":{ "href":"http://localhost:8080/actuator/health/{component}/{instance}", "templated":true }, "health":{ "href":"http://localhost:8080/actuator/health", "templated":false }, "health-component":{ "href":"http://localhost:8080/actuator/health/{component}", "templated":true }, "conditions":{ "href":"http://localhost:8080/actuator/conditions", "templated":false }, "configprops":{ "href":"http://localhost:8080/actuator/configprops", "templated":false }, "env":{ "href":"http://localhost:8080/actuator/env", "templated":false }, "env-toMatch":{ "href":"http://localhost:8080/actuator/env/{toMatch}", "templated":true }, "info":{ "href":"http://localhost:8080/actuator/info", "templated":false }, "loggers":{ "href":"http://localhost:8080/actuator/loggers", "templated":false }, "loggers-name":{ "href":"http://localhost:8080/actuator/loggers/{name}", "templated":true }, "heapdump":{ "href":"http://localhost:8080/actuator/heapdump", "templated":false }, "threaddump":{ "href":"http://localhost:8080/actuator/threaddump", "templated":false }, "metrics-requiredMetricName":{ "href":"http://localhost:8080/actuator/metrics/{requiredMetricName}", "templated":true }, "metrics":{ "href":"http://localhost:8080/actuator/metrics", "templated":false }, "scheduledtasks":{ "href":"http://localhost:8080/actuator/scheduledtasks", "templated":false }, "httptrace":{ "href":"http://localhost:8080/actuator/httptrace", "templated":false }, "mappings":{ "href":"http://localhost:8080/actuator/mappings", "templated":false } } }
SpringBoot Admin 有两个角色，客户端(Client)和服务端(Server)。
以下为创建服务端和客户端工程步骤：
admin-server：
①创建 admin-server 模块
②导入依赖坐标 admin-starter-server
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-starter-server</artifactId>
</dependency>
③在引导类上启用监控功能@EnableAdminServer
@EnableAdminServer @SpringBootApplication public class SpringbootAdminServerApplication { public static void main(String[] args) { SpringApplication.run(SpringbootAdminServerApplication.class, args); } }
admin-client：
①创建 admin-client 模块
②导入依赖坐标 admin-starter-client
<dependency>
<groupId>de.codecentric</groupId>
<artifactId>spring-boot-admin-starter-client</artifactId>
</dependency>
③配置相关信息：server地址等
# 执行admin.server地址 spring.boot.admin.client.url=http://localhost:9000 management.endpoint.health.show-details=always management.endpoints.web.exposure.include=*
④启动server和client服务，访问server
SpringBoot 项目开发完毕后，支持两种方式部署到服务器：
①jar包(官方推荐)
②war包
更改pom文件中的打包方式为war
修改启动类
import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.builder.SpringApplicationBuilder; import org.springframework.boot.web.servlet.support.SpringBootServletInitializer; @SpringBootApplication public class SpringbootDeployApplication extends SpringBootServletInitializer { public static void main(String[] args) { SpringApplication.run(SpringbootDeployApplication.class, args); } @Override protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) { return builder.sources(SpringbootDeployApplication.class); } }
指定打包的名称
<build>
<finalName>springboot</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
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