类型安全配置：@ConfigurationProperties

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@ConfigurationProperties可以看作@Value的升级版，通过该注解可将配置文件中的属性和一个Bean关联，从而实现类型安全的配置

一、添加依赖包

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-configuration-processor</artifactId>
	<optional>true</optional>
</dependency>

二、配置文件设置属性（application.yml）

author:
  name: 猴子哥哥
  age: 28

注：application.properties中容易中文乱码问题

三、配置Bean

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@Component
@ConfigurationProperties(prefix = "author")
public class AuthorConfig {
    private String name;
    private Integer age;

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("AuthorConfig{");
        sb.append("\"name\":\"")
                .append(name).append('\"');
        sb.append(",\"age\":")
                .append(age);
        sb.append('}');
        return sb.toString();
    }
}

四、注解源码及说明

package org.springframework.boot.context.properties;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import org.springframework.core.annotation.AliasFor;

/**
 * Annotation for externalized configuration. Add this to a class definition or a
 * {@code @Bean} method in a {@code @Configuration} class if you want to bind and validate
 * some external Properties (e.g. from a .properties file).
 * <p>
 * Note that contrary to {@code @Value}, SpEL expressions are not evaluated since property
 * values are externalized.
 *
 * @author Dave Syer
 * @see ConfigurationPropertiesBindingPostProcessor
 * @see EnableConfigurationProperties
 */
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ConfigurationProperties {

	/**
	 * The name prefix of the properties that are valid to bind to this object. Synonym
	 * for {@link #prefix()}. A valid prefix is defined by one or more words separated
	 * with dots (e.g. {@code "acme.system.feature"}).
	 * @return the name prefix of the properties to bind
	 */
	@AliasFor("prefix")
	String value() default "";

	/**
	 * The name prefix of the properties that are valid to bind to this object. Synonym
	 * for {@link #value()}. A valid prefix is defined by one or more words separated with
	 * dots (e.g. {@code "acme.system.feature"}).
	 * @return the name prefix of the properties to bind
	 */
	@AliasFor("value")
	String prefix() default "";

	/**
	 * Flag to indicate that when binding to this object invalid fields should be ignored.
	 * Invalid means invalid according to the binder that is used, and usually this means
	 * fields of the wrong type (or that cannot be coerced into the correct type).
	 * @return the flag value (default false)
	 */
	boolean ignoreInvalidFields() default false;

	/**
	 * Flag to indicate that when binding to this object unknown fields should be ignored.
	 * An unknown field could be a sign of a mistake in the Properties.
	 * @return the flag value (default true)
	 */
	boolean ignoreUnknownFields() default true;

}

1）prefix=value：配置文件中的前缀
2）ignoreInvalidFields：是否忽略类型不一致的属性
3）ignoreUnknownFields：是否忽略属性名称对应不上的属性