Spring Boot

一、Hello World

1. 起步

package com.wrq.boot.controller;
@Controller
public class HelloController {
 @ResponseBody
 @RequestMapping("/hello")
 public String hello(){
 return "hello world!";
 }
}

package com.wrq.boot;
@SpringBootApplication
public class BootApplication {
	public static void main(String[] args) {
		//应用启动起来
		SpringApplication.run(BootApplication.class, args);
	}
}

 . ____ _ __ _ _
 /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/ ___)| |_)| | | | | || (_| | ) ) ) )
 ' |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot :: (v1.5.19.BUILD-SNAPSHOT)
2019年01月14日 00:35:00.020 INFO 18196 --- [ main] com.wrq.boot.BootApplication : Starting BootApplication on DESKTOP-IJ41H0K with PID 18196 (D:\Java\Project\Spring-Boot-Notes\boot\target\classes started by wangqian in D:\Java\Project\Spring-Boot-Notes\boot)
2019年01月14日 00:35:00.026 INFO 18196 --- [ main] com.wrq.boot.BootApplication : No active profile set, falling back to default profiles: default
2019年01月14日 00:35:00.203 INFO 18196 --- [ main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@e50a6f6: startup date [Mon Jan 14 00:35:00 CST 2019]; root of context hierarchy
2019年01月14日 00:35:04.984 INFO 18196 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8081 (http)
2019年01月14日 00:35:05.048 INFO 18196 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2019年01月14日 00:35:05.048 INFO 18196 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.37
2019年01月14日 00:35:05.396 INFO 18196 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2019年01月14日 00:35:05.396 INFO 18196 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 5205 ms
2019年01月14日 00:35:05.880 INFO 18196 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/]
2019年01月14日 00:35:05.890 INFO 18196 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2019年01月14日 00:35:05.891 INFO 18196 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2019年01月14日 00:35:05.891 INFO 18196 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2019年01月14日 00:35:05.892 INFO 18196 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2019年01月14日 00:35:06.666 INFO 18196 --- [ main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@e50a6f6: startup date [Mon Jan 14 00:35:00 CST 2019]; root of context hierarchy
2019年01月14日 00:35:06.854 INFO 18196 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/hello]}" onto public java.lang.String com.wrq.boot.controller.HelloController.hello()
2019年01月14日 00:35:06.863 INFO 18196 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2019年01月14日 00:35:06.865 INFO 18196 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2019年01月14日 00:35:06.946 INFO 18196 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2019年01月14日 00:35:06.946 INFO 18196 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2019年01月14日 00:35:07.009 INFO 18196 --- [ main] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2019年01月14日 00:35:07.278 INFO 18196 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2019年01月14日 00:35:07.347 INFO 18196 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080(http)
2019年01月14日 00:35:07.357 INFO 18196 --- [ main] com.wrq.boot.BootApplication : Started BootApplication in 8.343 seconds (JVM running for 9.312)

#修改端口
server.port=8081

@RestController
public class HelloController {
 @RequestMapping("/hello")
 public String hello(){
 return "hello world!";
 }
}

@ResponseBody
@Controller
public class HelloController {
 @RequestMapping("/hello")
 public String hello(){
 return "hello world!";
 }
}

2. 注解区别?

3. 依赖讲解

<parent>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-parent</artifactId>
	<version>1.5.19.BUILD-SNAPSHOT</version>
	<relativePath/> <!-- lookup parent from repository -->
</parent>

<dependency>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter</artifactId>
</dependency>

<!--添加这个依赖,@ResponseBody @RequestMapping-->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<!--绑定配置文件处理器,配置文件进行绑定的时候就会有提示-->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-configuration-processor</artifactId>
	<optional>true</optional>
</dependency>

<!-- 将应用打包成一个可执行Jar包,直接使用java -jar xxxx的命令来执行 -->
	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

二、配置文件

1. 配置文件

YAML (YAML Ain't Markup Language)

简单介绍

配置实例

<server>
 <port>8081</port>
</server>

server:
 port: 8081

2. YAML语法

基本语法

server:
 port: 8081
 path: /hello // 冒号后面的空格不要拉下

值的写法

普通的值

name: "wang \n qian" // 输出:wang 换行 qian

对象

frends:
 lastName: zhang
 age: 20

frends:{ lastName: zhang,age: 18 }

Map

maps: {k1: v1,k2: v2}

数组

pets: // var onj = {pets: ['cat','pig','dog']}
 - cat
 - pig
 - dog

pets:[cat, pig, dog]

配置文件获取

package com.wrq.boot.bean;
@Component
@ConfigurationProperties(prefix = "persion")
public class Persion {
 private String name;
 private int age;
 private double weight;
 private boolean boss;
 private Date birth;
 private Map<String,Object> maps;
 private List<Object> list;
 private Dog dog;
 
 此处,这个bean的getter、setter和tostring方法已经省略,千万不能忽略!
 
}

@Component
// @ConfigurationProperties(prefix = "persion")
public class Persion {
 @value("${persion.name}") // $()读取配置文件、环境变量中的值
 private String name;
 @value("#{11*2}") // #{SpEL} 采用表达式
 private int age;
 @value("true") // 直接赋值
 private boolean boos;
}

package com.wrq.boot.bean; 
public class Dog { // 用作Persion中的属性
 private String name;
 private int age;
 此处,这个bean的getter、setter和tostring方法已经省略,千万不能忽略!
}

persion:
 name: 王大锤
 age: 18
 weight: 125
 boss: false
 birth: 2018年5月5日
 maps: {k1: v1,k2: v2}
 list:
 - wangli
 - wangbai
 dog:
 name: xiaogou
 age: 2

persion.name = 王大锤
persion.age = 18
persion.weight = 125
persion.boss = false
persion.birth = 2018年5月5日
persion.maps.k1 = v1
persion.maps.k2 = v2
persion.dog.name = xiaogou
persion.dog.age = 15

package com.wrq.boot;
@RunWith(SpringRunner.class)
@SpringBootTest
public class BootApplicationTests {
	@Autowired
	Persion persion;
	@Test
	public void contextLoads() {
		System.out.print(persion);
	}
}

控制台打印:
application.yml的结果:
Persion{name='王大锤', age=18, weight=125.0, boss=false, birth=Sat May 05 00:00:00 CST 2018, maps={k1=v1, k2=v2}, list=[wangli, wangbai], dog=Dog{name='xiaogou', age=2}}
application.properties的结果:
Persion{name='ï¿1⁄2ï¿1⁄2Ǭ', age=18, weight=125.0, boss=false, birth=Sat May 05 00:00:00 CST 2018, maps={k2=v2, k1=v1}, list=[wangli, wangbai], dog=Dog{name='xiaogou', age=15}}

注解比较

@Component
@ConfigurationProperties(prefix = "persion") // 如果使用的是@value注入值时,无法使用校验
@Validated // 添加此注解
public class Persion {
 
 @Email // 配置文件书写的属性必须是邮箱格式,不符合报错!
 private String name;
 
}

@value("${persion.maps}") // 由于使用的是@value,无法获取配置文件中的map
private Map<String,Object> maps;

@PropertySource

persion.name = 王弟弟
persion.age = 18
persion.weight = 125
persion.boss = false
persion.birth = 2018年5月5日
persion.maps.k1 = v1
persion.maps.k2 = v2
persion.dog.name = xiaogou
persion.dog.age = 15

package com.wrq.boot.bean;
@Component
@PropertySource(value = {"classpath:persion.properties"})
@ConfigurationProperties(prefix = "persion")
public class Persion {
 private String name;
 private int age;
 private double weight;
 private boolean boss;
 private Date birth;
 private Map<String,Object> maps;
 private List<Object> list;
 private Dog dog;
 
 此处,这个bean的getter、setter和tostring方法已经省略,千万不能忽略!
}

@ImportResource

package com.wrq.boot.service;
/**
 * Created by wangqian on 2019年1月12日.
 */
public class HelloService {
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
 <bean id="helloService" class="com.wrq.boot.service.HelloService"></bean>
</beans>

package com.wrq.boot;
@RunWith(SpringRunner.class)
@SpringBootTest
public class BootApplicationTests {
	@Autowired
	ApplicationContext ioc;
	@Test
	public void testConfig() {
		boolean b = ioc.containsBean("helloService");
		System.out.print(b);
	}
}

package com.wrq.boot;
@ImportResource(locations = {"classpath:bean.xml"}) // 通过此配置是bean.xml生效
@SpringBootApplication
public class BootApplication {
	public static void main(String[] args) {
		//应用启动起来
		SpringApplication.run(BootApplication.class, args);
	}
}

package com.wrq.boot.config;
/**
 * Created by wangqian on 2019年1月12日.
 */
@Configuration
public class MyConfig {
 // 将方法的返回值添加到容器之中,并且容器中这个组件的id就是方法名
 @Bean
 public HelloService helloService(){
 System.out.print("通过@Bean给容器添加组件了..");
 return new HelloService();
 }
}

3. 配置文件占位符

随机数

${random.value}
${random.int}
${random.long} 
${random.uuid} 
${random.int(10)}
${random.int[1024,65536]}

属性配置占位符

persion.name = 王弟弟${random.uuid}
persion.age = ${random.int}
persion.dog.name = ${persion.name}_dog

4. Profile 多环境支持

1. 多Profile的方式

# 激活application-dev.properties配置文件
spring.profiles.active=dev

server.port=8082

2019年01月12日 20:46:09.345 INFO 14404 --- [main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8082 (http)

2. 多文档块的方式

server:
 port: 8081
spring:
 profiles:
 active: dev 
---
spring: 
 profiles: dev
server:
 port: 8083
---
spring:
 profiles: prod
server:
 port: 8084

3. 激活指定Profile

# 激活application-dev.properties配置文件
spring.profiles.active=dev

server:
 port: 8081
spring:
 profiles:
 active: dev 
---
spring: 
 profiles: dev
server:
 port: 8083

Program arguments:--spring.profiles.active=dev

VM options:-Dspring-profiles-active=dev

java -jar spring-boot-project-config.jar --spring.profiles.active=dev

5. 配置文件优先级

优先级

默认配置

java -jar boot-config-position-xxxxxx.jar --spring.config.location=D:/application.properties

6. 外部配置加载顺序

java -jar boot-config-position-xxxxxx.jar --server.port // 多个配置用空格隔开

7. 自动配置原理

=========================
AUTO-CONFIGURATION REPORT
=========================
Positive matches:
-----------------
 DispatcherServletAutoConfiguration matched:
 - @ConditionalOnClass found required class 'org.springframework.web.servlet.DispatcherServlet'; @ConditionalOnMissingClass did not find unwanted class (OnClassCondition)
 - @ConditionalOnWebApplication (required) found 'session' scope (OnWebApplicationCondition)
Negative matches:
-----------------
 ActiveMQAutoConfiguration:
 Did not match:
 - @ConditionalOnClass did not find required classes 'javax.jms.ConnectionFactory', 'org.apache.activemq.ActiveMQConnectionFactory' (OnClassCondition)

三、日志处理

1. 日志框架

2. SLF4j的使用

框架使用

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class HelloWorld {
 public static void main(String[] args) {
 Logger logger = LoggerFactory.getLogger(HelloWorld.class);
 logger.info("Hello World");
 }
}

遗留问题

3. Sping Boot日志关系

<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter</artifactId>
</dependency>

<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-logging</artifactId>
</dependency>

graph LR
spring-boot-starter-logging-->logback-classic
logback-classic-->logback-core
spring-boot-starter-logging-->jul-to-slf4j
jul-to-slf4j-->slf4j-api
spring-boot-starter-logging-->log4j-over-slf4j
log4j-over-slf4j-->slf4j-api
spring-boot-starter-logging-->jcl-over-slf4j
jcl-over-slf4j-->slf4j-api

<dependency>
 <groupId>org.springframework</groupId>
 <artifactId>spring-core</artifactId>
	 <exclusions>
	 <exclusion>
 <groupId>commons-logging</groupId>
 <artifactId>commons-logging</artifactId>
		</exclusion>
	 </exclusions>
</dependency>

4. 日志使用

默认配置

 . ____ _ __ _ _
 /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/ ___)| |_)| | | | | || (_| | ) ) ) )
 ' |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot :: (v1.5.19.BUILD-SNAPSHOT)
2019年01月13日 22:50:22.392 INFO 2364 --- [ main] com.wrq.boot.BootApplication : Starting BootApplication on DESKTOP-IJ41H0K with PID 2364 (D:\Java\Project\Spring-Boot-Notes\boot-logging\target\classes started by wangqian in D:\Java\Project\Spring-Boot-Notes\boot-logging)
2019年01月13日 22:50:22.393 INFO 2364 --- [ main] com.wrq.boot.BootApplication : No active profile set, falling back to default profiles: default
2019年01月13日 22:50:22.394 DEBUG 2364 --- [ main] o.s.boot.SpringApplication : Loading source class com.wrq.boot.BootApplication

使用与级别

@RunWith(SpringRunner.class)
@SpringBootTest
public class BootLoggingApplicationTests {
	Logger logger = LoggerFactory.getLogger(getClass());
	@Test
	public void contextLoads() {
		logger.trace("trace追踪信息");
		logger.debug("debug调试信息");
		logger.info("info日志信息");
		logger.warn("warn警告信息");
		logger.error("error报错信息");
		
	}
}

2019年01月13日 23:17:56.731 INFO 2624 --- [ main] c.wrq.boot.BootLoggingApplicationTests : info日志信息
2019年01月13日 23:17:56.732 WARN 2624 --- [ main] c.wrq.boot.BootLoggingApplicationTests : warn警告信息
2019年01月13日 23:17:56.745 ERROR 2624 --- [ main] c.wrq.boot.BootLoggingApplicationTests : error报错信息

修改级别

logging.level.com.wrq=trace // 把com.wrq包下面类的日志都设成trace级别

2019年01月13日 23:24:06.449 TRACE 18136 --- [ main] c.wrq.boot.BootLoggingApplicationTests : trace追踪信息
2019年01月13日 23:24:06.449 DEBUG 18136 --- [ main] c.wrq.boot.BootLoggingApplicationTests : debug调试信息
2019年01月13日 23:24:06.449 INFO 18136 --- [ main] c.wrq.boot.BootLoggingApplicationTests : info日志信息
2019年01月13日 23:24:06.749 WARN 18136 --- [ main] c.wrq.boot.BootLoggingApplicationTests : warn警告信息
2019年01月13日 23:24:06.749 ERROR 18136 --- [ main] c.wrq.boot.BootLoggingApplicationTests : error报错信息

修改日志输出方式

logging.level.com.wrq = trace
# 不指定路径,当前项目下生成springboot.log日志
#logging.file=springboot.log
# 当D盘下生成springboot.log日志
#logging.file=D:/springboot.log
# 在当前磁盘的根路径下创建spring文件夹和里面的log文件夹,使用spring.log作为默认的日志文件名
logging.path=/spring/log
# 在控制台输出的日志的格式
logging.pattern.console=%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n
# 在指定文件中输出的日志的格式
logging.pattern.file=%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n
# 日志输出格式: %d表示日期时间, %thread表示线程名, %-5level:级别从左显示5个字符宽度 %logger{50} 表示logger名字最长50个字符,否则按照句点分割。 %msg:日志消息, %n是换行符

指定日志文件

<!-- logback-spring.xml配置文件中:-->
<layout class="ch.qos.logback.classic.PatternLayout">
 <springProfile name="dev"> <!-- dev环境下采用下方输出方式 -->
 <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} --- [%thread] %-5level %logger{50} - %msg%n</pattern>
 </springProfile>
 <springProfile name="!dev"> <!-- 非dev环境下采用下方输出方式 -->
 <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} ---- [%thread] %-5level %logger{50} - %msg%n</pattern>
 </springProfile>
</layout>

切换日志

四、Web实战

1. 创建项目

步骤

思考

2. 静态资源映射规则

1) 第一种规则

public void addResourceHandlers(ResourceHandlerRegistry registry) {
 if(!this.resourceProperties.isAddMappings()) {
 logger.debug("Default resource handling disabled");
 } else {
 Integer cachePeriod = this.resourceProperties.getCachePeriod();
 if(!registry.hasMappingForPattern("/webjars/**")) {
 this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{"/webjars/**"}).addResourceLocations(new String[]{"classpath:/META-INF/resources/webjars/"}).setCachePeriod(cachePeriod));
 }
 String staticPathPattern = this.mvcProperties.getStaticPathPattern();
 if(!registry.hasMappingForPattern(staticPathPattern)) {
 this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{staticPathPattern}).addResourceLocations(this.resourceProperties.getStaticLocations()).setCachePeriod(cachePeriod));
 }
 }
 }

<dependency>
 <groupId>org.webjars</groupId>
 <artifactId>jquery</artifactId>
 <version>2.1.1</version>
</dependency>

org.webjars:jquery:2.1.1
 ->jquery-2.1.1.jar
 ->META-INF
 ->maven
 ->resources
 ->webjars
 ->jquery
 ->2.1.1
 ->jquery.js
 ->jquery.min.js

2) 第二种规则

3) 第三种规则

4) 第四种规则

5) 自定义静态文件夹路径

spring.resources.static.locations=classpath:/hell,classpath:/wrq/

3. 模板引擎

1) 常见的模板引擎

2) 使用模板引擎

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

<properties>
 <thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
 <thymeleaf-layout-dialect.version>2.1.1</thymeleaf-layout-dialect.version>
</properties>

4. Thymeleaf使用

@ConfigurationProperties(prefix = "spring.thymeleaf")
public class ThymeleafProperties {
	private static final Charset DEFAULT_ENCODING = Charset.forName("UTF-8");
	private static final MimeType DEFAULT_CONTENT_TYPE = MimeType.valueOf("text/html");
	public static final String DEFAULT_PREFIX = "classpath:/templates/";
	public static final String DEFAULT_SUFFIX = ".html";
	
	// 只需要把HTML放在classpath:/templates/,Thymeleaf就会自动解析渲染

package com.wrq.boot.controller;
@Controller
public class HelloController {
 // 此处并没有@ResponseBody注解
 @RequestMapping("/success")
 public String hello () {
 return "success";
 }
}

<html xmlns:th="http://www.thymeleaf.org">

package com.wrq.boot.controller;
@Controller
public class HelloController {
 @RequestMapping("/success")
 public String hello (Map<String ,Object> map) {
 map.put("Hello","World"); // 传递过去一个值
 return "success";
 }
}

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
 <meta charset="UTF-8">
 <title>Title</title>
</head>
<body>
<div th:text="${Hello}">模板引擎获取不到值</div>
</body>
</html>

5. Thymeleaf语法

6. Sping MVC自动配置

7. 如何修改Sping Boot的默认配置

@Bean
@ConditionalOnMissingBean
public HttpMessageConverters messageConverters() {}

8. 扩展Spring MVC

<mvc:view‐controller path="/hello" view‐name="success"/> 
<mvc:interceptors>
 <mvc:interceptor> 
 <mvc:mapping path="/hello"/> <bean></bean>
 </mvc:interceptor>
</mvc:interceptors>

package com.wrq.boot.config;
@Configuration
public class ConfigController extends WebMvcConfigurerAdapter {
 /**
 * 访问 http://localhost:8080/helloMan 跳转到success.html
 * @param registry
 */
 @Override
 public void addViewControllers(ViewControllerRegistry registry) {
 registry.addViewController("/helloMan").setViewName("success");
 }
}

9. 完全掌控Spring MVC

package com.wrq.boot.config;
@EnableWebMvc // 添加此注解将会全面掌控Spring MVC
@Configuration
public class ConfigController extends WebMvcConfigurerAdapter {
 /**
 * 访问 http://localhost:8080/helloMan 跳转到success.html
 * @param registry
 */
 @Override
 public void addViewControllers(ViewControllerRegistry registry) {
 registry.addViewController("/helloMan").setViewName("success");
 }
}

@Import(DelegatingWebMvcConfiguration.class)
public @interface EnableWebMvc {

@Configuration public class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport {

@Configuration
@ConditionalOnWebApplication @ConditionalOnClass({ Servlet.class, DispatcherServlet.class, WebMvcConfigurerAdapter.class})
//容器中没有这个组件的时候,这个自动配置类才生效
@ConditionalOnMissingBean(WebMvcConfigurationSupport.class)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE+10)
@AutoConfigureAfter({DispatcherServletAutoConfiguration.class,
ValidationAutoConfiguration.class})
public class WebMvcAutoConfiguration {

10. 增删改查Demo

// resources->i18n->login_en_US.properties(login_zn_CN.properties)
spring.messages.basename=i18n.login // 设置国际化资源文件的基础名(去掉语言国家代码的) 

@Bean
@ConditionalOnMissingBean
@ConditionalOnProperty(prefix = "spring.mvc", name = "locale")
public LocaleResolver localeResolver() {
	if (this.mvcProperties
			.getLocaleResolver() == WebMvcProperties.LocaleResolver.FIXED) {
		return new FixedLocaleResolver(this.mvcProperties.getLocale());
	}
	AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver();
	localeResolver.setDefaultLocale(this.mvcProperties.getLocale());
	return localeResolver;
}

spring.thymeleaf.cache=false

public class LoginHandlerIntercepter implements HandlerInterceptor {
 @Override
 public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
 Object username = request.getSession().getAttribute("LoginUser");
 if(username != null){
 return true;
 } else {
 request.setAttribute("msg", "没有权限,请登录");
 request.getRequestDispatcher("/index.html").forward(request,response);
 return false;
 }
 }
 @Override
 public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
 }
 @Override
 public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
 }
}

@Configuration
public class ConfigController extends WebMvcConfigurerAdapter {
 @Bean
 public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){
 WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter(){
 @Override
 public void addViewControllers(ViewControllerRegistry registry) {
 registry.addViewController("/index.html").setViewName("login");
 registry.addViewController("/").setViewName("login");
 registry.addViewController("/main.html").setViewName("dashboard");
 }
 @Override
 public void addInterceptors(InterceptorRegistry registry) {
 // 静态资源:Spring Boot已经做好了资源映射,我们用管。
 registry.addInterceptor(new LoginHandlerIntercepter()).addPathPatterns("/**")
 .excludePathPatterns("/","/index.html","/user/login");
 }
 };
 return adapter;
 }
}

1、抽取公共片段 
<div th:fragment="copy"> 
 &copy; 2011 The Good Thymes Virtual Grocery 
</div> 
2、引入公共片段 
<div th:insert="~{footer :: copy}">
</div>
~{templatename::selector}:模板名::选择器 ~{templatename::fragmentname}:模板名::片段名 
3、默认效果: 
insert的公共片段在div标签中 
如果使用th:insert等属性进行引入,可以不用写~{} 
行内写法可以加上:[[~{}]];[(~{})];

引入片段:
<footer th:fragment="copy">
 &copy; 2011 The Good Thymes Virtual Grocery
</footer>
引入方式:
<body>
 <div th:insert="footer :: copy"></div>
 <div th:replace="footer :: copy"></div>
 <div th:include="footer :: copy"></div>
</body>
引入效果:
<body>
 ...
 <div>
 <footer>
 &copy; 2011 The Good Thymes Virtual Grocery
 </footer>
 </div>
 <footer>
 &copy; 2011 The Good Thymes Virtual Grocery
 </footer>
 <div>
 &copy; 2011 The Good Thymes Virtual Grocery
 </div>
</body>

11. 错误处理机制

@Value("${error.path:/error}")
private String path = "/error"; // 系统出现错误发送 /error 请求

@Controller
@RequestMapping("${server.error.path:${error.path:/error}}")
public class BasicErrorController extends AbstractErrorController {
...
@RequestMapping(produces = "text/html") // 浏览器发送的请求到这个方法处理,返回HTML
	public ModelAndView errorHtml(HttpServletRequest request,
			HttpServletResponse response) {
		HttpStatus status = getStatus(request);
		Map<String, Object> model = Collections.unmodifiableMap(getErrorAttributes(
				request, isIncludeStackTrace(request, MediaType.TEXT_HTML)));
		response.setStatus(status.value());
		ModelAndView modelAndView = resolveErrorView(request, response, status, model);
		return (modelAndView != null) ? modelAndView : new ModelAndView("error", model);
	}
	@RequestMapping
	@ResponseBody // JSON,其他客户端来到这个方法处理
	public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
		Map<String, Object> body = getErrorAttributes(request,
				isIncludeStackTrace(request, MediaType.ALL));
		HttpStatus status = getStatus(request);
		return new ResponseEntity<Map<String, Object>>(body, status);
	}

private ModelAndView resolve(String viewName, Map<String, Object> model) {
 //默认SpringBoot可以去找到一个页面? error/404 
		String errorViewName = "error/" + viewName;
		//模板引擎可以解析这个页面地址就用模板引擎解析 
		TemplateAvailabilityProvider provider = this.templateAvailabilityProviders
				.getProvider(errorViewName, this.applicationContext);
		if (provider != null) {
		//模板引擎可用的情况下返回到errorViewName指定的视图地址 
			return new ModelAndView(errorViewName, model);
		}
		 //模板引擎不可用,就在静态资源文件夹下找errorViewName对应的页面 error/404.html 
		return resolveResource(errorViewName, model);
	}

12. 定制错误页面

@ControllerAdvice
public class MyExceptionHandler {
 // 浏览器和其他客户端返回的都是Json
 @ResponseBody
 @ExceptionHandler(UserIsNoExist.class) // 自定义异常UserIsNoExist的处理方法
 public Map<String, Object> handlerException (Exception e) {
 HashMap<String, Object> map = new HashMap<>();
 map.put("code", "用户不存在");
 map.put("message", e.getMessage());
 return map;
 }
}

@ControllerAdvice
public class MyExceptionHandler {
 /**
 * 请求 /error 这个时候就会调用Spring Boot默认配置的组件处理
 */
 @ExceptionHandler(UserIsNoExist.class)
 public String handlerException (Exception e) {
 HashMap<String, Object> map = new HashMap<>();
 request.setAttribute("javax.servlet.error.status_code", 500);
 map.put("code", "用户不存在");
 map.put("message", e.getMessage());
 return "forward:/error";
 }
}

@ControllerAdvice
public class MyExceptionHandler {
 @ExceptionHandler(UserIsNoExist.class)
 public String handlerException (Exception e, HttpServletRequest request) {
 HashMap<String, Object> map = new HashMap<>();
 /**
 * 必须自定义状态码,如何不自定义无法跳转到我们自己创建的5xx和4xx的错误页面
 */
 request.setAttribute("javax.servlet.error.status_code", 500);
 map.put("code", "用户不存在");
 map.put("message", e.getMessage());
 // 把自定义的map放到request域里面,然后再去请求 /error ,接下来会去DefaultErrorAttributes
 request.setAttribute("ext", map);
 return "forward:/error";
 }
}

@Component
public class MyErrorAttributes extends DefaultErrorAttributes{
 // 返回值的map就是页面和json能获取所有的字段
 @Override
 public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes, boolean includeStackTrace) {
 Map<String, Object> map = super.getErrorAttributes(requestAttributes, includeStackTrace);
 Map<String, Object> ext = (Map<String, Object>)
 // 刚刚传递过来的值 
 requestAttributes.getAttribute("ext", 0);
 map.put("ext", ext);
 return map;
 }
}

五、嵌入式Servlet容器

1. 修改Servlet容器配置

#通用的servlet配置
server.port=8081
server.context-path=/crud
#tomcat的设置
servlet.tomcat.xxx

package com.wrq.boot.config;
@Configuration
public class ConfigController extends WebMvcConfigurerAdapter {
 /**
 * 通过下面的bean实现自定义嵌入式容器配置
 * @return
 */
 @Bean EmbeddedServletContainerCustomizer embeddedServletContainerCustomizer() {
 return new EmbeddedServletContainerCustomizer() {
 @Override
 public void customize(ConfigurableEmbeddedServletContainer container) {
 container.setPort(8086);
 }
 };
 }
}

2. 注册三大组件:Servlet、Filter、Listener

@Configuration
public class MyConfigController {
 @Bean
 public ServletRegistrationBean testServlet() {
 // 访问 /servlet 的时候就会调用 TestServlet
 ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new TestServlet(), "/servlet");
 return servletRegistrationBean;
 }
}

 @Bean
public FilterRegistrationBean filterRegistrationBean () {
 FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
 filterRegistrationBean.setFilter(new TestFilter());
 filterRegistrationBean.setUrlPatterns(Arrays.asList("/helloMan","/filter"));
 return filterRegistrationBean;
}

@Bean 
public ServletListenerRegistrationBean myListener(){ 
ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>(new MyListener()); 
return registrationBean; 
}

@Bean(name = DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME)
@ConditionalOnBean(value = DispatcherServlet.class, name = DEFAULT_DISPATCHER_SERVLET_BEAN_NAME)
public ServletRegistrationBean dispatcherServletRegistration(
		DispatcherServlet dispatcherServlet) {
	ServletRegistrationBean registration = new ServletRegistrationBean(
			dispatcherServlet, this.serverProperties.getServletMapping());
// 默认拦截:/ 所有请求;包静态资源,但是不拦截jsp请求 /*会拦截jsp 
//可以通过server.servletPath来修改SpringMVC前端控制器默认拦截的请求路径 
	registration.setName(DEFAULT_DISPATCHER_SERVLET_BEAN_NAME);
	registration.setLoadOnStartup(
			this.webMvcProperties.getServlet().getLoadOnStartup());
	if (this.multipartConfig != null) {
		registration.setMultipartConfig(this.multipartConfig);
	}
	return registration;
}

3. 切换Servlet容器

graph LR
spring-boot-starter-web-->sping-boot-starter-tomcat
sping-boot-starter-tomcat-->tomcat-embed-core
tomcat-embed-core-->tomcat-annotations-api
sping-boot-starter-tomcat-->tomcat-embed-el
sping-boot-starter-tomcat-->tomcat-embed-el-websocket

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
	<exclusion>
		<artifactId>spring-boot-starter-tomcat</artifactId>
		<groupId>org.springframework.boot</groupId>
	</exclusion>
</exclusions>
</dependency>
<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-jetty</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
	<exclusion>
		<artifactId>spring-boot-starter-tomcat</artifactId>
		<groupId>org.springframework.boot</groupId>
	</exclusion>
</exclusions>
</dependency>
<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-undertow</artifactId>
</dependency>

4. 自动配置原理以及启动原理

5. 使用外部的Servlet容器

<!-- 意思是已经提供了tomcat的环境,打包不需要携带 -->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-tomcat</artifactId>
	<scope>provided</scope>
</dependency>

public class ServletInitializer extends SpringBootServletInitializer {
	@Override
	protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
		return application.sources(BootExternalContainerApplication.class);
	}
}

6. 外部容器的相关原理

五、Docker

1. 什么是Docker?

2. Docker的核心概念

3. Docker的使用

六、数据访问

1. 简介

2. JDBC

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

spring:
 datasource:
 username: root
 password: admin
 url: jdbc:mysql://localhost:3306/jdbc?characterEncoding=utf-8
 driver-class-name: com.mysql.jdbc.Driver

原理

/**
* Generic DataSource configuration.
*/
@ConditionalOnMissingBean(DataSource.class)
@ConditionalOnProperty(name = "spring.datasource.type")
static class Generic {
 // 使用DataSourceBuilder创建数据源,利用反射创建相关的数据源,并绑定相关属性。
	@Bean
	public DataSource dataSource(DataSourceProperties properties) {
		return properties.initializeDataSourceBuilder().build();
	}
}

自动执行建表语句

schema‐*.sql、data‐*.sql 
1. 默认规则:schema.sql,schema‐all.sql,放在类路径下,启动就会执行文件中的语句
2. 在yml中可以使用下面配置指定位置
schema:
 ‐ classpath:department.sql

操作数据库

@Bean // /容器中注入了 JdbcTemplate 的bean
@Primary
@ConditionalOnMissingBean(JdbcOperations.class)
public JdbcTemplate jdbcTemplate() {
	return new JdbcTemplate(this.dataSource);
}

@Controller
public class HelloController {
 @Autowired
 JdbcTemplate jdbcTemplate;
 @ResponseBody
 @RequestMapping("/hello")
 public List hello () {
 List<Map<String, Object>> maps = jdbcTemplate.queryForList("select * from department");
 return maps;
 }
}

3. 配置数据源

<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
 <groupId>com.alibaba</groupId>
 <artifactId>druid</artifactId>
 <version>1.1.10</version>
</dependency>

spring:
 datasource:
 username: root
 password: admin
 url: jdbc:mysql://localhost:3306/jdbc?characterEncoding=utf-8
 driver-class-name: com.mysql.jdbc.Driver
 type: com.alibaba.druid.pool.DruidDataSource
# 下面的配置如果想生效需要自己配置
 initialSize: 5
 minIdle: 5
 maxActive: 20
 maxWait: 60000
 timeBetweenEvictionRunsMillis: 60000
 minEvictableIdleTimeMillis: 300000
 validationQuery: SELECT 1 FROM DUAL
 testWhileIdle: true
 testOnBorrow: false
 testOnReturn: false
 poolPreparedStatements: true

initialSize: 5
minIdle: 5
maxActive: 20
maxWait: 60000
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: SELECT 1 FROM DUAL
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true

@Configuration
public class Config {
 // 把配置文件中spring.datasource.initialSize等属性和DruidDataSource中属性进行绑定
 @ConfigurationProperties(prefix = "spring.datasource")
 @Bean
 public DruidDataSource druidDataSource () {
 return new DruidDataSource();
 }
}

@Configuration
public class DruidConfig {
 /**
 * spring.datasource中的配置和DruidDataSource中的属性绑定
 * @return
 */
 @ConfigurationProperties(prefix = "spring.datasource")
 @Bean
 public DruidDataSource druidDataSource () {
 return new DruidDataSource();
 }
 /**
 * 配置Druid的监控 
 * 1、配置一个管理后台的Servlet,拦截登陆
 * @return
 */
 @Bean
 public ServletRegistrationBean statViewServlet(){
 ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");
 Map<String,String> initParams = new HashMap<>();
 initParams.put("loginUsername","admin");
 initParams.put("loginPassword","123456");
 initParams.put("allow",""); // 允许所有访问
 servletRegistrationBean.setInitParameters(initParams);
 return servletRegistrationBean;
 }
 // 配置一个web监控的filter,哪些请求会被监控,哪些排除。
 @Bean
 public FilterRegistrationBean webStatFilter() {
 FilterRegistrationBean bean = new FilterRegistrationBean(new WebStatFilter());
 Map<String,String> initParams = new HashMap<>();
 initParams.put("exclusions","*.js,*.css,/druid/*");
 bean.setInitParameters(initParams);
 bean.setUrlPatterns(Arrays.asList("/*"));
 return bean;
 }
}

4. 整合MyBatis-注解版

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
	<groupId>org.mybatis.spring.boot</groupId>
	<artifactId>mybatis-spring-boot-starter</artifactId>
	<version>1.3.2</version>
</dependency>
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
 <groupId>com.alibaba</groupId>
 <artifactId>druid</artifactId>
 <version>1.1.10</version>
</dependency>

spring:
 datasource:
# 数据源基本配置
 username: root
 password: 123456
 driver-class-name: com.mysql.jdbc.Driver
 url: jdbc:mysql://localhost:3306/mybatis
 type: com.alibaba.druid.pool.DruidDataSource
# 数据源其他配置
 initialSize: 5
 minIdle: 5
 maxActive: 20
 maxWait: 60000
 timeBetweenEvictionRunsMillis: 60000
 minEvictableIdleTimeMillis: 300000
 validationQuery: SELECT 1 FROM DUAL
 testWhileIdle: true
 testOnBorrow: false
 testOnReturn: false
 poolPreparedStatements: true
# 配置监控统计拦截的filters,去掉后监控界面sql无法统计,'wall'用于防火墙
 filters: stat,wall,log4j
 maxPoolPreparedStatementPerConnectionSize: 20
 useGlobalDataSourceStat: true
 connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

@Configuration
public class DruidConfig {
 /**
 * spring.datasource中的配置和DruidDataSource中的属性绑定
 * @return
 */
 @ConfigurationProperties(prefix = "spring.datasource")
 @Bean
 public DruidDataSource druidDataSource () {
 return new DruidDataSource();
 }
 /**
 * 配置Druid的监控
 * 1、配置一个管理后台的Servlet,拦截登陆
 * @return
 */
 @Bean
 public ServletRegistrationBean statViewServlet(){
 ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");
 Map<String,String> initParams = new HashMap<>();
 initParams.put("loginUsername","admin");
 initParams.put("loginPassword","123456");
 initParams.put("allow",""); // 允许所有访问
 servletRegistrationBean.setInitParameters(initParams);
 return servletRegistrationBean;
 }
 // 配置一个web监控的filter,哪些请求会被监控,哪些排除。
 @Bean
 public FilterRegistrationBean webStatFilter() {
 FilterRegistrationBean bean = new FilterRegistrationBean(new WebStatFilter());
 Map<String,String> initParams = new HashMap<>();
 initParams.put("exclusions","*.js,*.css,/druid/*");
 bean.setInitParameters(initParams);
 bean.setUrlPatterns(Arrays.asList("/*"));
 return bean;
 }
}

public class Department {
 private Integer id;
 private String departmentName;
 // getter、setter方法已经省略
}

@Mapper
public interface DepartmentMapper {
 @Select("select * from department where id=#{id}")
 public Department getDeptById(Integer id);
 @Delete("delete from department where id=#{id}")
 public int deleteDeptById(Integer id);
 /**
 * Options注解:当插入一条数据后生成id,这个新生成的id会再次封装进来。
 * 加了Options注解,把插入的数据再返回的时候会把刚刚生成的id封装进去
 * @param department
 * @return
 */
 @Options(useGeneratedKeys = true,keyProperty = "id")
 @Insert("insert into department(departmentName) values(#{departmentName})")
 public int insertDept(Department department);
 @Update("update department set departmentName=#{departmentName} where id=#{id}")
 public int updateDept(Department department);
}

@Controller
public class DepartmentController {
 @Autowired
 private DepartmentMapper departmentMapper;
 @ResponseBody
 @RequestMapping(value = "/dept/{id}",method = RequestMethod.GET)
 public Department getDepartment(@PathVariable("id") Integer id){
 return departmentMapper.getDeptById(id);
 }
 /**
 * mapper中不添加Options注解,返回的json的id为空,加了Options注解,把插入的数据再返回的时候会把刚刚生成的id封装进去
 * @param department
 * @return
 */
 @ResponseBody
 @RequestMapping(value = "/dept", method = RequestMethod.GET)
 public Department insertDepartment(Department department){
 departmentMapper.insertDept(department);
 return department;
 }
}

@org.springframework.context.annotation.Configuration
public class MyBatisConfig {
 @Bean
 public ConfigurationCustomizer configurationCustomizer(){
 return new ConfigurationCustomizer() {
 @Override
 public void customize(Configuration configuration) {
 // 开启驼峰命名
 configuration.setMapUnderscoreToCamelCase(true);
 }
 };
 }
}

4. 整合MyBatis-配置版

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
	<groupId>org.mybatis.spring.boot</groupId>
	<artifactId>mybatis-spring-boot-starter</artifactId>
	<version>1.3.2</version>
</dependency>
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
 <groupId>com.alibaba</groupId>
 <artifactId>druid</artifactId>
 <version>1.1.10</version>
</dependency>

spring:
 datasource:
# 数据源基本配置
 username: root
 password: 123456
 driver-class-name: com.mysql.jdbc.Driver
 url: jdbc:mysql://localhost:3306/mybatis
 type: com.alibaba.druid.pool.DruidDataSource
# 数据源其他配置
 initialSize: 5
 minIdle: 5
 maxActive: 20
 maxWait: 60000
 timeBetweenEvictionRunsMillis: 60000
 minEvictableIdleTimeMillis: 300000
 validationQuery: SELECT 1 FROM DUAL
 testWhileIdle: true
 testOnBorrow: false
 testOnReturn: false
 poolPreparedStatements: true
# 配置监控统计拦截的filters,去掉后监控界面sql无法统计,'wall'用于防火墙
 filters: stat,wall,log4j
 maxPoolPreparedStatementPerConnectionSize: 20
 useGlobalDataSourceStat: true
 connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

@Configuration
public class DruidConfig {
 /**
 * spring.datasource中的配置和DruidDataSource中的属性绑定
 * @return
 */
 @ConfigurationProperties(prefix = "spring.datasource")
 @Bean
 public DruidDataSource druidDataSource () {
 return new DruidDataSource();
 }
 /**
 * 配置Druid的监控
 * 1、配置一个管理后台的Servlet,拦截登陆
 * @return
 */
 @Bean
 public ServletRegistrationBean statViewServlet(){
 ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");
 Map<String,String> initParams = new HashMap<>();
 initParams.put("loginUsername","admin");
 initParams.put("loginPassword","123456");
 initParams.put("allow",""); // 允许所有访问
 servletRegistrationBean.setInitParameters(initParams);
 return servletRegistrationBean;
 }
 // 配置一个web监控的filter,哪些请求会被监控,哪些排除。
 @Bean
 public FilterRegistrationBean webStatFilter() {
 FilterRegistrationBean bean = new FilterRegistrationBean(new WebStatFilter());
 Map<String,String> initParams = new HashMap<>();
 initParams.put("exclusions","*.js,*.css,/druid/*");
 bean.setInitParameters(initParams);
 bean.setUrlPatterns(Arrays.asList("/*"));
 return bean;
 }
}

package com.wrq.boot.bean;
public class Employee {
 private Integer id;
 private String lastName;
 private Integer gender;
 private String email;
 private Integer dId;
 ...
}

@Mapper
public interface EmployeeMapper {
 public Employee getEmpById(Integer id);
 public void insertEmp(Employee employee);
}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
 PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
 <settings>
 <setting name="mapUnderscoreToCamelCase" value="true"/>
 </settings>
</configuration>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.wrq.boot.mapper.EmployeeMapper">
 <select id="getEmpById" resultType="com.wrq.boot.bean.Employee">
 SELECT * FROM employee WHERE id=#{id}
 </select>
 <insert id="insertEmp" >
 INSERT INTO employee(lastName,email,gender,d_id) VALUES (#{lastName},#{email},#{gender},#{dId})
 </insert>
</mapper>

mybatis:
 config-location: classpath:mybatis/mybatis-config.xml
 mapper-locations: classpath:mybatis/mapper/*.xml

@RestController
public class EmployeeController {
 @Autowired
 private EmployeeMapper employeeMapper;
 @GetMapping("/emp/{id}")
 public Employee getEmployee(@PathVariable("id") Integer id){
 return employeeMapper.getEmpById(id);
 }
}

4. 整合JPA

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<scope>runtime</scope>
</dependency>

spring:
 datasource:
 username: root
 password: admin
 url: jdbc:mysql://localhost:3306/jpa?characterEncoding=utf-8
 driver-class-name: com.mysql.jdbc.Driver
 jpa:
 hibernate:
 ddl-auto: update
 show-sql: true

//使用JPA注解配置映射关系
@Entity //告诉JPA这是一个实体类(和数据表映射的类)
@Table(name = "tbl_user") //@Table来指定和哪个数据表对应;如果省略默认表名就是user;
public class User {
 @Id //这是一个主键
 @GeneratedValue(strategy = GenerationType.IDENTITY)//自增主键
 private Integer id;
 @Column(name = "last_name", length = 50) //这是和数据表对应的一个列
 private String lastName;
 @Column //省略默认列名就是属性名
 private String email;
 ...
}

package com.wrq.boot.repository;
public interface UserRepository extends JpaRepository<User,Integer> {
}

package com.wrq.boot.controller;
@RestController
public class UserController {
 @Autowired
 UserRepository repository;
 @GetMapping("/user/{id}")
 public User getUser (@PathVariable("id") Integer id){
 User one = repository.findOne(id);
 return one;
 }
 @GetMapping("/user")
 public User insertUser(User user){
 User save = repository.save(user);
 return save;
 }
}