文章目录
示例工具版本使用 @ConfigurationProperties 的步骤使用 @ConfigurationProperties 的前缀使用 @ConfigurationProperties 与 @Bean 一起使用使用 @ConfigurationProperties 与Object, List, Map 和 Array 属性1. Object Properties2. List Properties3. Map Properties4. Array Properties输出效果 使用 @ConfigurationProperties 与 @EnableConfigurationProperties使用 @Validated 和 @ConfigurationPropertiesMavenYAML 文件参考文献源码下载Spring Boot@ConfigurationProperties是用于外部化配置的注解。
为了将属性文件中的属性值注入到一个类中，我们可以在类的层面上添加@ConfigurationProperties与原型注释（如@Component），或者在@Configuration类中的@Bean方法中添加@ConfigurationProperties。
@ConfigurationProperties用于绑定和验证来自属性文件（如.properties文件）的外部属性。
@ConfigurationProperties有以下可选元素:
ignoreInvalidFields: 忽略无效字段的布尔值。
ignoreUnknownFields: 忽略未知字段的布尔值。
prefix: 要绑定到此对象的属性的前缀。
value: 要绑定到此对象的属性的前缀。
为了使用@ConfigurationProperties从属性文件注入值，我们的类必须创建类属性的setter方法。在这里，我们将详细讨论使用@ConfigurationProperties并举例说明。
示例工具版本
Java 11Spring 5.1.7.RELEASESpring Boot 2.1.5.RELEASEHibernate Validator 6.0.16Maven 3.5.2使用 @ConfigurationProperties 的步骤
找到使用@ConfigurationProperties注解的步骤。
1.创建一个带有@ConfigurationProperties和@Component注释的类。在这里，我们的类中有字符串和整数属性。
Team.java
package com.concretepage;import org.springframework.boot.context.properties.ConfigurationProperties;import org.ponent;@Component@ConfigurationPropertiespublic class Team {private String team;private int teamSize;private String teamLeader;//Setters and Getterspublic String toString() {return "Team:" + team + " - " + teamSize + " - " + teamLeader;}}
创建类字段的setter方法是使用@ConfigurationProperties的必要条件。
2.多个单词的属性名称如teamSize可以在属性文件中绑定属性名称如teamSize或team-size或team_size。找到属性文件。
myteam.properties
team=XYZ Teamteam-size=3team-leader=Mahesh
3.在配置类中，使用@PropertySource注解导入.property文件。
AppConfig.java
package com.concretepage;import org.springframework.context.annotation.Configuration;import org.springframework.context.annotation.PropertySource;@Configuration@PropertySource("classpath:myteam.properties")public class AppConfig {}
所有上述属性值都将绑定到Team类，相应地，我们可以根据需要将这个类注入到任何其他类并获取值。
4.现在运行该应用程序。
MySpringBootApp.java
package com.concretepage;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.ApplicationContext;@SpringBootApplicationpublic class MySpringBootApp {public static void main(String[] args) {final ApplicationContext ctx = SpringApplication.run(MySpringBootApp.class, args);final Team team = ctx.getBean(Team.class);System.out.println("--- Team ---");System.out.println(team);}}
输出
--- Team ---Team:XYZ Team - 3 - Mahesh
使用 @ConfigurationProperties 的前缀
我们可以在@ConfigurationProperties注解中使用前缀元素。如果属性文件的属性以前缀开始，就可以在@ConfigurationProperties中进行配置。找到属性文件。
myteam.properties
app.team=XYZ Teamapp.team-size=3app.team-leader=Mahesh
我们可以看到，属性已经以前缀app字开头。我们需要在@ConfigurationProperties中对其进行配置，将这些值注入到Team类中。
Team.java
@Component@ConfigurationProperties(prefix="app")public class Team {private String team;private int teamSize;private String teamLeader;//Setters and Getterspublic String toString() {return "Team:" + team + " - " + teamSize + " - " + teamLeader;}}
使用 @ConfigurationProperties 与 @Bean 一起使用
我们可以将@ConfigurationProperties与@Bean以及@Component注解一起使用。
在上面的例子中，我们已经将@ConfigurationProperties与@Component一起使用。
这里我们将创建一个例子来使用@ConfigurationProperties和@Bean。
我们需要在方法层面上使用@ConfigurationProperties和@Bean。找到这个例子。
AppConfig.java
package com.concretepage;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.context.annotation.PropertySource;@Configuration@PropertySource({"classpath:myteam.properties", "classpath:project-util.properties"})public class AppConfig {@Bean@ConfigurationProperties(prefix="project") public Project getProject() {return new Project();}}
Project.java
package com.concretepage;public class Project {private String projectName;private int size;private String manager;//Setters and getters public String toString() {return "Project:" + projectName + " - " + size + " - " + manager;}}
project-util.properties
project.project-name=PQR Projectproject.size=10project.manager=John
使用 @ConfigurationProperties 与Object, List, Map 和 Array 属性
在上面的例子中，我们已经看到了如何将简单的属性与一个类绑定。
现在我们将提供使用@ConfigurationProperties绑定Object、List、Map和Array属性的例子。
myteam.properties
app.team=XYZ Teamapp.team-size=3app.team-leader=Mahesh#Object pany.name=ABC pany.ceo=pany.location=Delhi#List propertiesapp.employees[0].name=Amarapp.employees[0].designation=Developerapp.employees[0].age=25app.employees[1].name=Akbarapp.employees[1].designation=Testerapp.employees[1].age=23app.employees[2].name=Anthonyapp.employees[2].designation=Designerapp.employees[2].age=27#Map Propertiesapp.technologies.BACKEND=Javaapp.technologies.FRONTEND=Angularapp.technologies.DATABASE=Oracle#Array Propertiesapp.clients[0]=A Clientapp.clients[1]=B Clientapp.clients[2]=C Client
AppConfig.java
@Configuration@PropertySource({"classpath:myteam.properties", "classpath:project-util.properties"})public class AppConfig {------}
Team.java
@Component@ConfigurationProperties(prefix="app")public class Team {private String team;private int teamSize;private String teamLeader;private Company company;private List<Employee> employees;private Map<String, String> technologies;private String[] clients;//Setters and Getterspublic String toString() {return "Team:" + team + " - " + teamSize + " - " + teamLeader;}}
1. Object Properties
myteam.properties
#Object pany.name=ABC pany.ceo=pany.location=Delhi
Team.java
@Component@ConfigurationProperties(prefix="app")public class Team {------private Company company;public Company getCompany() {return company;}public void setCompany(Company company) {pany = company;}------}
Company.java
package com.concretepage;public class Company {private String name;private String ceo;private String location;//Setters and Getterspublic String toString() {return "Company:" + name + " - " + ceo + " - " + location;}}
2. List Properties
myteam.properties
#List propertiesapp.employees[0].name=Amarapp.employees[0].designation=Developerapp.employees[0].age=25app.employees[1].name=Akbarapp.employees[1].designation=Testerapp.employees[1].age=23app.employees[2].name=Anthonyapp.employees[2].designation=Designerapp.employees[2].age=27
Team.java
@Component@ConfigurationProperties(prefix="app")public class Team {------private List<Employee> employees;public List<Employee> getEmployees() {return employees;}public void setEmployees(List<Employee> employees) {this.employees = employees;}------}
Employee.java
package com.concretepage;public class Employee {private String name;private String designation;private int age;//Setters and Getterspublic String toString() {return "Employee:" + name + " - " + designation + " - " + age;}}
3. Map Properties
myteam.properties
#Map Propertiesapp.technologies.BACKEND=Javaapp.technologies.FRONTEND=Angularapp.technologies.DATABASE=Oracle
Team.java
@Component@ConfigurationProperties(prefix="app")public class Team {------private Map<String, String> technologies;public Map<String, String> getTechnologies() {return technologies;}public void setTechnologies(Map<String, String> technologies) {this.technologies = technologies;}------}
4. Array Properties
myteam.properties
#Array Propertiesapp.clients[0]=A Clientapp.clients[1]=B Clientapp.clients[2]=C Client
Team.java
@Component@ConfigurationProperties(prefix="app")public class Team {------private String[] clients;public String[] getClients() {return clients;}public void setClients(String[] clients) {this.clients = clients;}------}
输出效果
现在让我们运行演示应用程序。
MySpringBootApp.java
package com.concretepage;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.ApplicationContext;@SpringBootApplicationpublic class MySpringBootApp {public static void main(String[] args) {final ApplicationContext ctx = SpringApplication.run(MySpringBootApp.class, args);final Team team = ctx.getBean(Team.class);System.out.println("--- Team ---");System.out.println(team);System.out.println("--- Team Employee---");team.getEmployees().forEach(e -> System.out.println(e));System.out.println("--- Technologies ---");System.out.println(team.getTechnologies().size());team.getTechnologies().forEach(((t, v) -> System.out.println(t + " - " + v)));System.out.println("--- Company ---");System.out.println(team.getCompany());System.out.println("--- Clients ---");for (String c : team.getClients()) {System.out.println(c);}System.out.println("--- Project ---");final Project project = ctx.getBean(Project.class);System.out.println(project);}}
输出
--- Team ---Team:XYZ Team - 3 - Mahesh--- Team Employee---Employee:Amar - Developer - 25Employee:Akbar - Tester - 23Employee:Anthony - Designer - 27--- Technologies ---3FRONTEND - AngularDATABASE - OracleBACKEND - Java--- Company ---Company:ABC Ltd - Narendra - Delhi--- Clients ---A ClientB ClientC Client--- Project ---Project:PQR Project - 10 - John
使用 @ConfigurationProperties 与 @EnableConfigurationProperties
假设我们有一个用@ConfigurationProperties注解的类，但它没有用@Component注解，或者它不是一个Spring bean。
在这种情况下，为了使用@ConfigurationProperties从属性文件中注入值，我们将@EnableConfigurationProperties注解与@SpringBootApplication一起使用，并将@ConfigurationProperties注解的类指定为@EnableConfigurationProperties。
找到这个例子。这里我们从Team.java中删除了@Component。
Team.java
@ConfigurationProperties(prefix="app")public class Team {private String team;private int teamSize;private String teamLeader;private Company company;private List<Employee> employees;private Map<String, String> technologies;private String[] clients;//Setters and Getterspublic String toString() {return "Team:" + team + " - " + teamSize + " - " + teamLeader;}}
现在要启用@ConfigurationProperties的工作，我们需要使用@EnableConfigurationProperties注解与@SpringBootApplication结合起来，并指定上述类到其中。
MySpringBootApp.java
package com.concretepage;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.context.properties.EnableConfigurationProperties;import org.springframework.context.ApplicationContext;@SpringBootApplication@EnableConfigurationProperties(Team.class)public class MySpringBootApp {public static void main(String[] args) {final ApplicationContext ctx = SpringApplication.run(MySpringBootApp.class, args);------}}
使用 @Validated 和 @ConfigurationProperties
使用@ConfigurationProperties从属性文件注入到类中的值可以用Spring的@Validated注解来验证。
Team.java
package com.concretepage;import java.util.List;import java.util.Map;import javax.validation.constraints.NotBlank;import javax.validation.constraints.NotEmpty;import javax.validation.constraints.NotNull;import javax.validation.constraints.Size;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.format.annotation.NumberFormat;import org.ponent;import org.springframework.validation.annotation.Validated;@Component@ConfigurationProperties(prefix="app")@Validatedpublic class Team {@NotBlankprivate String team;@NumberFormatprivate int teamSize;@Size(max=30)private String teamLeader;@NotNullprivate Company company;@NotEmptyprivate List<Employee> employees;@NotEmptyprivate Map<String, String> technologies;private String[] clients;//Setters and Getterspublic String toString() {return "Team:" + team + " - " + teamSize + " - " + teamLeader;}}
Maven
找到我们示例中使用的Maven配置。
pom.xml
<parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.1.5.RELEASE</version><relativePath /></parent><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><dependency><groupId>org.hibernate.validator</groupId><artifactId>hibernate-validator</artifactId><version>6.0.16.Final</version></dependency></dependencies>
YAML 文件
找到与示例中使用的属性文件等效的YAML文件。
application.yml
app:team:XYZ Teamteam-size:3team-leader:Maheshemployees:- name:Amardesignation:Developerage:25- name:Akbardesignation:Testerage:23- name:Anthonydesignation:Designerage:27technologies:BACKEND:JavaFRONTEND:AngularDATABASE:Oracleclients:- A Client- B Client- C Clientcompany:name:ABC Ltdceo:Narendralocation:Delhiproject:project-name:PQR Projectsize:10manager:John
参考文献
【1】Spring @ConfigurationProperties Doc
【2】Spring Boot @ConfigurationProperties Example
源码下载
spring-boot-configurationproperties.zip
