1.Lombok
1.基本介绍
2.应用实例
1.pom.xml 引入Lombok,使用版本仲裁
<!--导入springboot父工程-->
<parent>
<artifactId>spring-boot-starter-parent</artifactId>
<groupId>org.springframework.boot</groupId>
<version>2.5.3</version>
</parent>
<dependencies>
<!--配置maven项目场景启动器,自动导入和web相关的包-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--引入Lombok,使用版本仲裁-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
2.@Data注解说明
- 相当于Getter, Setter, RequiredArgsConstructor, ToString, EqualsAndHashCode,Value这些注解的组合
- 主要记住Getter, Setter,ToString
package lombok;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;/**
* Generates getters for all fields, a useful toString method, and hashCode and equals implementations that check
* all non-transient fields. Will also generate setters for all non-final fields, as well as a constructor.
*
* Equivalent to {@code @Getter @Setter @RequiredArgsConstructor @ToString @EqualsAndHashCode}.
*
* Complete documentation is found at the project lombok features page for @Data.
*
* @see Getter
* @see Setter
* @see RequiredArgsConstructor
* @see ToString
* @see EqualsAndHashCode
* @see lombok.Value
/
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.SOURCE)
public @interface Data {
/*
* If you specify a static constructor name, then the generated constructor will be private, and
* instead a static factory method is created that other classes can use to create instances.
* We suggest the name: “of”, like so:
*
*
* public @Data(staticConstructor = “of”) class Point { final int x, y; }
*
*
* Default: No static constructor, instead the normal constructor is public.
*
* @return Name of static ‘constructor’ method to generate (blank = generate a normal constructor).
*/
String staticConstructor() default “”;
}
3.@RequiredArgsConstructor注解说明(不常用)
4.@NoArgsConstructor无参构造器
5.@AllArgsConstructor全参构造器
注意事项:
- 当使用全参构造器时,默认的无参构造器会消失
- 如果还想要无参构造器就需要使用无参构造器的注解
6.两种使用Lombok的方式
1.需要Getter, Setter,ToString,无参构造器
- @Data
2.需要使用Getter, Setter,ToString,无参构造器,全参构造器
- @Data
- @AllArgsConstructor
- @NoArgsConstructor
3.在IDEA中安装Lombok插件解锁扩展注解
1.安装插件
2.扩展注解:日志输出
1.代码实例
2.会在日志中输出
2.Spring Initailizr(不推荐)
1.基本介绍
2.通过IDEA方式创建
1.新创建一个项目
2.进行配置
3.创建成功
3.通过官网创建
1.进入官网
2.配置完之后选择
3.最后会生成一个.zip文件,解压之后在IDEA中打开即可
4.第一次使用自动配置爆红
3.yaml
1.基本说明
2.yaml基本语法
3.yaml数据类型
1.字面量
2.对象
3.数组
4.yaml应用实例
1.创建一个新的maven项目
2.pom.xml引入依赖并刷新maven
<!--导入springboot父工程-->
<parent>
<artifactId>spring-boot-starter-parent</artifactId>
<groupId>org.springframework.boot</groupId>
<version>2.5.3</version>
</parent>
<dependencies>
<!--配置maven项目场景启动器,自动导入和web相关的包-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--引入Lombok,使用版本仲裁-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
3.编写两个bean
1.Car.java
package com.sun.springboot.bean;
import lombok.Data;
import org.springframework.stereotype.Component;
/**
* @author 孙显圣
* @version 1.0
*/
@Data //getter,setter,tostring,无参构造
@Component
public class Car {
private String name;
private Double price;
}
2.Monster.java
package com.sun.springboot.bean;
import lombok.Data;
import org.springframework.stereotype.Component;
import java.util.*;
/**
* @author 孙显圣
* @version 1.0
*/
@Data
@Component
public class Monster {
private Integer id;
private String name;
private Integer age;
private Boolean isMarried;
private Date birth;
private Car car;
private String[] skill;
private List<String> hobby;
private Map<String, Object> wife;
private Set<Double> salaries;
private Map<String, List<Car>> cars;
}
4.HiController.java 接受请求
package com.sun.springboot.controller;
import com.sun.springboot.bean.Monster;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/**
* @author 孙显圣
* @version 1.0
*/
@RestController
public class HiController {
@Resource
private Monster monster;
@RequestMapping("/monster")
public Monster monster() {
return monster;
}
}
5.主程序Application.java
package com.sun.springboot;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/**
* @author 孙显圣
* @version 1.0
*/
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class);
}
}
6.运行主程序(目前返回的值是空的)
7.创建yaml文件(后缀也可以是yml) resources/application.yml
monster: #前缀
id: 100
name: 牛魔王
age: 500
isMarried: false
birth: 2000/11/11
8.绑定数据到Monster类
9.解决报错
1.因为使用@Configuration注解导致的问题
2.在pom.xml中添加依赖即可
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<!--防止将该依赖传递到其他模块-->
<optional>true</optional>
</dependency>
3.运行主程序
10.完整yml文件
monster: #前缀
id: 100
name: 牛魔王
age: 500
isMarried: false
birth: 2000/11/11
#对象类型
# car: {name: 宝马, price: 1000} #行内格式
car:
name: 奔驰
price: 3000
#数组类型
# skill: [芭蕉扇, 牛魔拳] #行内格式
skill:
- 牛魔王
- 芭蕉扇
#list类型
# hobby: [白骨精, 美人鱼]
hobby:
- 白骨精
- 牛魔王
#map类型
# wife: {no1: 牛魔王, no2: 猪八戒}
wife:
no1: 白骨精
no2: 铁扇公主
#set类型
# salaries: [1, 2, 3]
salaries:
- 4
- 5
- 6
#map<String, List<Car>>类型
cars:
car1: [
{name: 奔驰, price: 400},
{name: 奔驰, price: 400}
]
car2: [
{name: 奔驰, price: 400},
{name: 奔驰, price: 400}
]
# cars: {car1: [{name: 奔驰, price: 200}, {name: 奔驰, price: 200}],
# car2: [{name: 奔驰, price: 200}, {name: 奔驰, price: 200}]}
11.结果展示
12.yaml注意事项和细节说明
1.注意事项
- application.properties和application.yml如果有相同前缀值的绑定,则application.properties优先级高
- 字符串无需加引号,但是加引号也没有问题
- yaml配置文件如果不提示字段信息,则导入依赖即可
- 如果添加依赖还不显示字段信息则安装YAML插件
2.细节说明
- 其实不需要记住什么yaml的类型,只要能跟java对应上即可
- 如果是对象或者map,则表示方式是
- 换行key: value
- {key1: value1, key2: value2}
- 如果是数组或list,则表示方式是
- 换行- value
- [value1, value2]