Spring Boot @ConfigurationProperties
是外部化配置的注解。要将属性值从属性文件注入到类中,我们可以在类级别添加 @ConfigurationProperties
,并使用诸如 @Component
之类的构造型注解,或者将 @ConfigurationProperties
添加到 @Configuration
类中的 @Bean
方法中。 @ConfigurationProperties
用于绑定和验证来自属性文件(如 .properties
文件)的外部属性。 @ConfigurationProperties
具有以下可选元素。
ignoreInvalidFields:忽略无效字段的布尔值。
ignoreUnknownFields:忽略未知字段的布尔值。
prefix:绑定到此对象的属性的前缀。
value:绑定到此对象的属性的前缀。
要使用 @ConfigurationProperties
从属性文件中注入值,我们的类必须创建类属性的 setter 方法。在这里,我们将通过示例详细讨论使用 @ConfigurationProperties
。
找到使用 @ConfigurationProperties
注解的步骤。
1. 创建一个使用 @ConfigurationProperties
和 @Component
注解的类。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.springframework.stereotype.Component;
@Component
@ConfigurationProperties
public class Team {
private String team;
private int teamSize;
private String teamLeader;
//Setters and Getters
public String toString() {
return "Team:" + team + " - " + teamSize + " - " + teamLeader;
}
}
创建类字段的 setter 方法必须与 @ConfigurationProperties
一起使用。
2.teamSize
等多个单词的属性名可以绑定属性文件中的teamSize
或team-size
或team_size
等属性名。找到属性文件。
myteam.properties
team=XYZ Team
team-size=3
team-leader=Mahesh
3. 在配置类中,使用 @PropertySource
注解导入 .properties
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 {
}
以上所有属性值都将绑定到 Team
类,因此我们可以根据需要将该类注入任何其他类并获取值。
4. 现在运行应用程序。
MySpringBootApp.java
package com.concretepage;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
@SpringBootApplication
public 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
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头,则可以在 @ConfigurationProperties
中进行配置。找到属性文件。
myteam.properties
app.team=XYZ Team
app.team-size=3
app.team-leader=Mahesh
我们可以看到属性以前缀 app
开头。我们需要在 @ConfigurationProperties
中配置它以在 Team
类中注入这些值。
Team.java
@Component
@ConfigurationProperties(prefix="app")
public class Team {
private String team;
private int teamSize;
private String teamLeader;
//Setters and Getters
public String toString() {
return "Team:" + team + " - " + teamSize + " - " + teamLeader;
}
}
我们可以将 @ConfigurationProperties
与 @Bean
以及 @Component
注解一起使用。在上面的例子中,我们使用了 @ConfigurationProperties
和 @Component
。在这里,我们将创建一个使用 @ConfigurationProperties
和 @Bean
的示例。
我们需要在方法级别使用 @ConfigurationProperties
和 @Bean
。找到例子。
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 Project
project.size=10
project.manager=John
在上面的示例中,我们已经看到了如何将简单属性与类绑定。现在我们将提供使用 @ConfigurationProperties
绑定 Object、List、Map 和 Array 属性的示例。
myteam.properties
app.team=XYZ Team
app.team-size=3
app.team-leader=Mahesh
#Object properties
app.company.name=ABC Ltd
app.company.ceo=Narendra
app.company.location=Delhi
#List properties
app.employees[0].name=Amar
app.employees[0].designation=Developer
app.employees[0].age=25
app.employees[1].name=Akbar
app.employees[1].designation=Tester
app.employees[1].age=23
app.employees[2].name=Anthony
app.employees[2].designation=Designer
app.employees[2].age=27
#Map Properties
app.technologies.BACKEND=Java
app.technologies.FRONTEND=Angular
app.technologies.DATABASE=Oracle
#Array Properties
app.clients[0]=A Client
app.clients[1]=B Client
app.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 Getters
public String toString() {
return "Team:" + team + " - " + teamSize + " - " + teamLeader;
}
}
1。对象属性
myteam.properties
#Object properties
app.company.name=ABC Ltd
app.company.ceo=Narendra
app.company.location=Delhi
Team.java
@Component
@ConfigurationProperties(prefix="app")
public class Team {
------
private Company company;
public Company getCompany() {
return company;
}
public void setCompany(Company company) {
this.company = company;
}
------
}
Company.java
package com.concretepage;
public class Company {
private String name;
private String ceo;
private String location;
//Setters and Getters
public String toString() {
return "Company:" + name + " - " + ceo + " - " + location;
}
}
2。列出属性
myteam.properties
#List properties
app.employees[0].name=Amar
app.employees[0].designation=Developer
app.employees[0].age=25
app.employees[1].name=Akbar
app.employees[1].designation=Tester
app.employees[1].age=23
app.employees[2].name=Anthony
app.employees[2].designation=Designer
app.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 Getters
public String toString() {
return "Employee:" + name + " - " + designation + " - " + age;
}
}
3 Map属性
myteam.properties
#Map Properties
app.technologies.BACKEND=Java
app.technologies.FRONTEND=Angular
app.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。数组属性
myteam.properties
#Array Properties
app.clients[0]=A Client
app.clients[1]=B Client
app.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;
}
------
}
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;
@SpringBootApplication
public 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 - 25
Employee:Akbar - Tester - 23
Employee:Anthony - Designer - 27
--- Technologies ---
3
FRONTEND - Angular
DATABASE - Oracle
BACKEND - Java
--- Company ---
Company:ABC Ltd - Narendra - Delhi
--- Clients ---
A Client
B Client
C Client
--- Project ---
Project:PQR Project - 10 - John
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 Spring bean。在这种情况下,要使用 @ConfigurationProperties
从属性文件中注入值,我们将 @EnableConfigurationProperties
注解与 @SpringBootApplication
结合使用,并将 @ConfigurationProperties
注解类指定为 @EnableConfigurationProperties
。
找到例子。这里我们从 Team.java
中删除 @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 Getters
public String toString() {
return "Team:" + team + " - " + teamSize + " - " + teamLeader;
}
}
现在要启用 @ConfigurationProperties
,我们需要将 @EnableConfigurationProperties
注解与 @SpringBootApplication
结合使用,并为其指定上面的类。
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 @ConfigurationProperties
从属性文件注入到类的值可以使用 Spring @Validated
注解进行验证。
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.springframework.stereotype.Component;
import org.springframework.validation.annotation.Validated;
@Component
@ConfigurationProperties(prefix="app")
@Validated
public class Team {
@NotBlank
private String team;
@NumberFormat
private int teamSize;
@Size(max=30)
private String teamLeader;
@NotNull
private Company company;
@NotEmpty
private List<Employee> employees;
@NotEmpty
private Map<String, String> technologies;
private String[] clients;
//Setters and Getters
public String toString() {
return "Team:" + team + " - " + teamSize + " - " + teamLeader;
}
}
找到我们示例中使用的 Maven。
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>
找到与我们示例中使用的属性文件等效的 YAML 文件。
application.yml
app:
team:XYZ Team
team-size:3
team-leader:Mahesh
employees:
- name:Amar
designation:Developer
age:25
- name:Akbar
designation:Tester
age:23
- name:Anthony
designation:Designer
age:27
technologies:
BACKEND:Java
FRONTEND:Angular
DATABASE:Oracle
clients:
- A Client
- B Client
- C Client
company:
name:ABC Ltd
ceo:Narendra
location:Delhi
project:
project-name:PQR Project
size:10
manager:John
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原文链接 : https://www.concretepage.com/spring-boot/spring-boot-configurationproperties
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