springboot笔记

1. 外部资源properties的几种导入方式

1.1 使用注解直接在实体类上赋值

@Component
public class student {
    @Value("sss")
    private String name;
    @Value("13")
    private int age;
    private boolean happy;
    private Map<String,Object> maps;
    private List<Object> list;

    public student() {
    }

    public student(String name, int age, boolean happy, Map<String, Object> maps, List<Object> list) {
        this.name = name;
        this.age = age;
        this.happy = happy;
        this.maps = maps;
        this.list = list;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public boolean isHappy() {
        return happy;
    }

    public void setHappy(boolean happy) {
        this.happy = happy;
    }

    public Map<String, Object> getMaps() {
        return maps;
    }

    public void setMaps(Map<String, Object> maps) {
        this.maps = maps;
    }

    public List<Object> getList() {
        return list;
    }

    public void setList(List<Object> list) {
        this.list = list;
    }

    @Override
    public String toString() {
        return "student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", happy=" + happy +
                ", maps=" + maps +
                ", list=" + list +
                '}';
    }
}

1.2 通过yaml赋值，在实体类中引用

@ConfigurationProperties(prefix="student") springboot通过这个寻找到配置文件的yaml

@Component
@ConfigurationProperties(prefix="student")
public class Student {

    private String name;
    private int age;
    private boolean happy;
    private Map<String,Object> maps;
    private List<Object> list;

student:
  name: sss
  age: 3
  happy: false
  maps: {k1: v1,k2: v2}
  list:
    - 1
    - 2
    - 3

1.3 通过properties赋值

@PropertySource(value = "classpath:application.properties")

@Component
//@ConfigurationProperties(prefix="student")
@PropertySource(value = "classpath:application.properties")
public class Student {
    @Value("${name}")
    private String name;
    @Value("${age}")
    private int age;
    private boolean happy;
    private Map<String,Object> maps;
    private List<Object> list;

name=axj
age=1100000

2. JSR303校验

3. 多环境下的资源选择

通过spring.profiles.active=xxx

application.xxx.properties

3.1 通过yaml

使用 - - -去分开 得到另一个块

4. SpringBoot Web开发

4.1 静态资源导入

• webjars localhost:8080/webjars
• public，static，/**，resources localhost:8080/

优先级: resources>static>public

5. thymeleaf

依赖：

<dependency>
	<groupId>org.thymeleaf</groupId>
	<artifactId>thymeleaf-spring5</artifactId>
</dependency>
<dependency>
	<groupId>org.thymeleaf.extras</groupId>
	<artifactId>thymeleaf-extras-java8time</artifactId>
</dependency>

命名空间：xmlns:th=“www.thymeleaf.org”

Spring官方文档：找到我们对应的版本

docs.spring.io/spring-boot…

6 MVC自动装配

官网阅读

在进行项目编写前，我们还需要知道一个东西，就是SpringBoot对我们的SpringMVC还做了哪些配置，包括如何扩展，如何定制。

只有把这些都搞清楚了，我们在之后使用才会更加得心应手。途径一：源码分析，途径二：官方文档！

地址 ：docs.spring.io/spring-boot…

Spring MVC Auto-configuration
// Spring Boot为Spring MVC提供了自动配置，它可以很好地与大多数应用程序一起工作。
Spring Boot provides auto-configuration for Spring MVC that works well with most applications.
// 自动配置在Spring默认设置的基础上添加了以下功能：
The auto-configuration adds the following features on top of Spring’s defaults:
// 包含视图解析器
Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans.
// 支持静态资源文件夹的路径，以及webjars
Support for serving static resources, including support for WebJars 
// 自动注册了Converter：
// 转换器，这就是我们网页提交数据到后台自动封装成为对象的东西，比如把"1"字符串自动转换为int类型
// Formatter：【格式化器，比如页面给我们了一个2019-8-10，它会给我们自动格式化为Date对象】
Automatic registration of Converter, GenericConverter, and Formatter beans.
// HttpMessageConverters
// SpringMVC用来转换Http请求和响应的的，比如我们要把一个User对象转换为JSON字符串，可以去看官网文档解释；
Support for HttpMessageConverters (covered later in this document).
// 定义错误代码生成规则的
Automatic registration of MessageCodesResolver (covered later in this document).
// 首页定制
Static index.html support.
// 图标定制
Custom Favicon support (covered later in this document).
// 初始化数据绑定器：帮我们把请求数据绑定到JavaBean中！
Automatic use of a ConfigurableWebBindingInitializer bean (covered later in this document).

/*
如果您希望保留Spring Boot MVC功能，并且希望添加其他MVC配置（拦截器、格式化程序、视图控制器和其他功能），则可以添加自己
的@configuration类，类型为webmvcconfiguer，但不添加@EnableWebMvc。如果希望提供
RequestMappingHandlerMapping、RequestMappingHandlerAdapter或ExceptionHandlerExceptionResolver的自定义
实例，则可以声明WebMVCregistrationAdapter实例来提供此类组件。
*/
If you want to keep Spring Boot MVC features and you want to add additional MVC configuration 
(interceptors, formatters, view controllers, and other features), you can add your own 
@Configuration class of type WebMvcConfigurer but without @EnableWebMvc. If you wish to provide 
custom instances of RequestMappingHandlerMapping, RequestMappingHandlerAdapter, or 
ExceptionHandlerExceptionResolver, you can declare a WebMvcRegistrationsAdapter instance to provide such components.

// 如果您想完全控制Spring MVC，可以添加自己的@Configuration，并用@EnableWebMvc进行注释。
If you want to take complete control of Spring MVC, you can add your own @Configuration annotated with @EnableWebMvc.