SpringBoot绑定复杂类型自定义参数（List/Map/Set/自定义对象等）YML

应用场景

在开发中，我们经常需要把一些随时可能变化的属性配置到配置文件中，这样耦合性低，方便维护。Spring Boot在这方面为我们提供了很大的便捷，我们可以很轻易的将properties、yml、yaml中配置的属性绑定到JAVA实体类上。

*注意事项

• 您需要保证您需要绑定参数的这个类是被Spring IOC容器所管理的
• 您这个需要绑定参数的类至少需要具有set方法，不然无法绑定（但不会报错，下面演示中使用的lombok提供get、set方法等）
• 您在使用这个类的时候也应该是遵循Spring 依赖注入的规范

代码解释：请看下面的代码：我创建了一个Configuration类(我使用了Lombok提供get、set方法等)，他有一个静态内部类：Properties，这个内部类我用来作为“配置类出现”，为它绑定属性。所以我用@Component注解将它交给IOC容器管理，又由于我的Configuration类需要注入Properties“配置类”，所以我也将Configuration类交给了IOC容器管理，在Configuration中使用@Resource注解注入了Properties,而print方法作为测试方法，我为它加了@PostConstruct注解（在依注入完成之后自动执行，方便查看测试结果）

package com.scfenzhi.config;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
/**
* @Author: Yi Dai
* @Email: 484201132@qq.com
* @CreateTime: 2022-01-15 15:51
* @Company: Sichuan Fenzhi International Trade Co., LTD
* @Description:
*/
@Component
public class Configuration {
@Resource
private Properties properties;
@Data
@Component
@ConfigurationProperties(prefix = "configuration.properties")
private static class Properties {
}
@PostConstruct
public void print() {
System.out.println(properties);
}
}


基本数据类型及字符串类型

Java代码

package com.scfenzhi.config;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
/**
* @Author: DaiYi
* @Email: 484201132@qq.com
* @CreateTime: 2022-01-15 15:51
* @Company: Sichuan Fenzhi International Trade Co., LTD
* @Description:
*/
@Component
public class Configuration {
@Resource
private Properties properties;
@Data
@Component
@ConfigurationProperties(prefix = "configuration.properties")
private static class Properties {
private byte byteType;
private short shortType;
private int intType;
private long longType;
private float floatType;
private double doubleType;
private boolean booleanType;
private char chatType;
private String str1;
private String str2;
private String str3;
}
@PostConstruct
public void print() {
System.out.println(properties);
}
}


yaml代码

configuration:
properties:
byte-type: 1
short-type: 1
int-type: 1
long-type: 1
float-type: 1.0F
double-type: 1.0D
boolean-type: true
chat-type: 97
str1: haha
str2: 'heihei'
str3: "xixixi"


输出结果

Configuration.Properties(byteType=1, shortType=1, intType=1, lOngType=1, floatType=1.0, doubleType=1.0, booleanType=true, chatType=a, str1=haha, str2=heihei, str3=xixixi)

特别注意：

• 绑定char类型时，您可以选择使用字符表码表中的数值来代替字符(比如我上面的97就表示字母a)，当然，您也可以使用字面量表示，如chat-type: a，值您也可以选择用单引号或者双引号包裹起来。这并不会报错。
• 绑定String类型时，您可以选择不用引号或者使用单引号，甚至双引号也可以，都不会报错。在有特殊字符的情况下，使用引号可能是个不错的选择。
• 绑定boolean类型参数时，您不仅可以使用true、false来表示。您还可以用on或者off表示(on=true,off=false)
• 绑定float类型或者double类型时，您可以选择在值的后面加一个标识符标识类型，如1.0f表示这是float类型，1.0D表示这是double类型，大小写均可。但是比较坑的是，long类型是不能加L或者l标识符的，这会报错：

Failed to bind properties under ‘configuration.properties.long-type’ to long:
Property: configuration.properties.long-type
Value: 1L
Origin: class path resource [application.yml] - 89:16
Reason: failed to convert java.lang.String to long (caused by java.lang.NumberFormatException: For input string: “1L”)

对象类型（自定义对象）

Java代码

package com.scfenzhi.config;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
/**
* @Author: Yi Dai
* @Email: 484201132@qq.com
* @CreateTime: 2022-01-15 15:51
* @Company: Sichuan Fenzhi International Trade Co., LTD
* @Description:
*/
@Component
public class Configuration {
@Resource
private Properties properties;
@Data
@Component
@ConfigurationProperties(prefix = "configuration.properties")
private static class Properties {
private User user;
}
@Data
private static class User {
private int id;
private String username;
private boolean gender;
}
@PostConstruct
public void print() {
System.out.println(properties);
}
}


yaml代码(写法一)

configuration:
properties:
user: { id: 1001,username: Yi Dai,gender: false }


yaml代码(写法二)

configuration:
properties:
user:
id: 1001
username: Yi Dai
gender: on


输出结果

两种写法输出结果一致

Configuration.Properties(user=Configuration.User(id=1001, username=Yi Dai, gender=true))

数组类型

Java代码

package com.scfenzhi.config;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
/**
* @Author: Yi Dai
* @Email: 484201132@qq.com
* @CreateTime: 2022-01-15 15:51
* @Company: Sichuan Fenzhi International Trade Co., LTD
* @Description:
*/
@Component
public class Configuration {
@Resource
private Properties properties;
@Data
@Component
@ConfigurationProperties(prefix = "configuration.properties")
private static class Properties {
private String[] stringArray;
private User[] userArray;
}
@Data
private static class User {
private int id;
private String username;
private boolean gender;
}
@PostConstruct
public void print() {
System.out.println(properties);
}
}


yaml代码（写法一）

configuration:
properties:
string-array: [ Yi Dai,Guoxu Li ]
user-array: [ { id: 1001,username: Yi Dai,password: 123456a,gender: true },{ id: 1002,username: Guoxu Li,password: 123456b,gender: off } ]



yaml代码（写法二）

configuration:
properties:
string-array:
- Yi Dai
- Guoxu Li
user-array:
- id: 1001
username: Yi Dai
password: 123456a
gender: true
- id: 1002
username: Guoxu Li
password: 123456b
gender: off



输出结果

两种写法输出结果一致

Configuration.Properties(stringArray=[Yi Dai, Guoxu Li], userArray=[Configuration.User(id=1001, username=Yi Dai, gender=true), Configuration.User(id=1002, username=Guoxu Li, gender=false)])

特别注意：

• 在采用写法二绑定数组时，您应该注意每个元素都要换行，且-标识符后面应该有一个空格

集合类型

Java代码

package com.scfenzhi.config;
import lombok.Data;
import lombok.ToString;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* @Author: DaiYi
* @Email: 484201132@qq.com
* @CreateTime: 2022-01-15 15:51
* @Company: Sichuan Fenzhi International Trade Co., LTD
* @Description:
*/
@ToString
@Component
public class Configuration {
@Resource
private Properties properties;
@Data
@Component
@ConfigurationProperties(prefix = "configuration.properties")
private static class Properties {
private List stringList;
private Set integerSet;
private Map stringIntegerMap;
}
@PostConstruct
public void print() {
System.out.println(properties);
}
}


yaml代码（写法一）

configuration:
properties:
string-list: [ YiDai,'Guoxu Li',"Yaxin Zhang" ]
integer-set: [ 1,3,5,7,9 ]
string-integer-map: { Dai: 18 , "Li": 23,'Zhang': 19 }


yaml代码（写法二）

configuration:
properties:
string-list:
- Yi Dai
- 'Guoxu Li'
- "Yaxin Zhang"
integer-set:
- 1
- 3
- 5
- 7
- 9
string-integer-map:
Dai: 18
"Li": 23
'Zhang': 19


输出结果

Configuration.Properties(stringList=[YiDai, Guoxu Li, Yaxin Zhang], integerSet=[1, 3, 5, 7, 9], stringIntegerMap={Dai=18, Li=23, Zhang=19})

特别注意：

• 在采用第二种写法绑定map时，您应该注意，此时不是数组了，不能在每一项前面加-标识符，如果您加了，这会导致结果的前面多了索引值和一个.，如：0.Dai=18。
• 绑定map时（无论何种写法），如果您的key是String类型的，那么存在一个问题，就是您多个字符之间的空格会被自动去除（加引号也不好使），但value不会。
• List集合默认创建java.util.ArrayList
• Set集合默认创建java.util.LinkedHashSet
• Map集合默认创建java.util.LinkedHashMap

复杂类型

Java代码

package com.scfenzhi.config;
import lombok.Data;
import lombok.ToString;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* @Author: DaiYi
* @Email: 484201132@qq.com
* @CreateTime: 2022-01-15 15:51
* @Company: Sichuan Fenzhi International Trade Co., LTD
* @Description:
*/
@ToString
@Component
public class Configuration {
@Resource
private Properties properties;
@Data
@Component
@ConfigurationProperties(prefix = "configuration.properties")
private static class Properties {
private User user;
private List userList;
private Set userSet;
private Map userMap;
}
@Data
private static class User {
private Integer id;
private String username;
private Boolean gender;
private Car car;
}
@Data
private static class Car {
private Double price;
private String brand;
}
@PostConstruct
public void print() {
System.out.println(properties);
}
}


yaml代码（写法一）

configuration:
properties:
user: { id: 1001, username: Yi Dai,gender: true,car: { price: 1,brand: '宝驴' } }
user-list: [ { id: 1001, username: Yi Dai,gender: true,car: { price: 1,brand: '宝驴' } },{ id: 1002, username: Yaxin Zhang,gender: false,car: { price: 2,brand: '玛莎拉驴' } } ]
user-set: [ { id: 1001, username: Yi Dai,gender: true,car: { price: 1,brand: '宝驴' } },{ id: 1002, username: Yaxin Zhang,gender: false,car: { price: 2,brand: '玛莎拉驴' } } ]
user-map: { 1001: { id: 1001, username: Yi Dai,gender: true,car: { price: 1,brand: '宝驴' } },1002: { id: 1002, username: Yaxin Zhang,gender: false,car: { price: 2,brand: '玛莎拉驴' } } }



yaml代码（写法二）

configuration:
properties:
user:
id: 1001
username: Yi Dai
gender: true
car:
price: 1
brand: 宝驴
user-list:
- id: 1001
username: Yi Dai
gender: true
car:
price: 1
brand: 宝驴
- id: 1002
username: Yaxin Zhang
gender: false
car:
price: 1
brand: 玛莎拉驴
user-set:
- id: 1001
username: Yi Dai
gender: true
car:
price: 1
brand: 宝驴
- id: 1002
username: Yaxin Zhang
gender: false
car:
price: 1
brand: 玛莎拉驴
user-map:
1001:
id: 1001
username: Yi Dai
gender: true
car:
price: 1
brand: 宝驴
1002:
id: 1002
username: Yaxin Zhang
gender: false
car:
price: 1
brand: 玛莎拉驴


输出结果

两种方式都能正常绑定

Configuration.Properties(user=Configuration.User(id=1001, username=Yi Dai, gender=true, car=Configuration.Car(price=1.0, brand=宝驴)), userList=[Configuration.User(id=1001, username=Yi Dai, gender=true, car=Configuration.Car(price=1.0, brand=宝驴)), Configuration.User(id=1002, username=Yaxin Zhang, gender=false, car=Configuration.Car(price=2.0, brand=玛莎拉驴))], userSet=[Configuration.User(id=1001, username=Yi Dai, gender=true, car=Configuration.Car(price=1.0, brand=宝驴)), Configuration.User(id=1002, username=Yaxin Zhang, gender=false, car=Configuration.Car(price=2.0, brand=玛莎拉驴))], userMap={1001=Configuration.User(id=1001, username=Yi Dai, gender=true, car=Configuration.Car(price=1.0, brand=宝驴)), 1002=Configuration.User(id=1002, username=Yaxin Zhang, gender=false, car=Configuration.Car(price=2.0, brand=玛莎拉驴))})

• 由于是松散绑定，所以您可以选择将属性名之间的多个单词的分割符改为下划线(_)