Spring读取配置文件

配置文件

application.properties

message.name = haha
message.number = 1
message.title = java

1. @Value

@Value("${message.name}")
String name;

@Value("${message.number}")
int number;

@Value("${message.title}")
String title;

@Test
public void contextLoads() {
    System.out.println(name + number + title);    // 输出：haha1java
}

2. @ConfigurationProperties读取配置文件并与 bean 绑定

创建一个MessageProperties类，在该类上加了 @Component 注解，我们可以像使用普通 bean 一样将其注入到类中使用。

@Component
@ConfigurationProperties(prefix = "message")
public class MessageProperties {
    private String name;
    private int number;
    private String title;

    public String getName() {
        return name;
    }

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

    public int getNumber() {
        return number;
    }

    public void setNumber(int number) {
        this.number = number;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    @Override
    public String toString() {
        return "MessageProperties{" +
                "name='" + name + '\'' +
                ", number=" + number +
                ", title='" + title + '\'' +
                '}';
    }
}

使用时，注入刚才注册的bean

@Autowired
private MessageProperties messageProperties;

@Test
public void contextLoads() {
    System.out.println(messageProperties.toString());//MessageProperties{name='haha', number=1, title='java'}
}

3. @ConfigurationProperties读取配置文件，但不与bean 绑定

@ConfigurationProperties(prefix = "message")
public class MessageProperties {
    private String name;
    private int number;
    private String title;

    public String getName() {
        return name;
    }

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

    public int getNumber() {
        return number;
    }

    public void setNumber(int number) {
        this.number = number;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    @Override
    public String toString() {
        return "MessageProperties{" +
                "name='" + name + '\'' +
                ", number=" + number +
                ", title='" + title + '\'' +
                '}';
    }
}

使用时，在要使用MessageProperties的地方使用@EnableConfigurationProperties注解注册我们的配置bean

@EnableConfigurationProperties(MessageProperties.class)
public class ReadpropertiesApplicationTests {
    @Autowired
    private MessageProperties messageProperties;

    @Test
    public void contextLoads() {
        System.out.println(messageProperties.toString());//MessageProperties{name='haha', number=1, title='java'}
    }
}

参考

• https://github.com/Snailclimb/springboot-guide/blob/master/docs/basis/read-config-properties.md