延伸:以后除了可以为实体类注入属性,还可以为配置类注入相关的配置信息
1.编写实体类
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@Component @ConfigurationProperties (prefix = "person" ) public class Person { private String lastName; private Integer age; private Boolean boss; private Date birth; private Map<String,Object> maps; private List<Object> lists; private Dog dog; @Override public String toString() { return "Person{" + "lastName='" + lastName + '\ '' + ", age=" + age + ", boss=" + boss + ", birth=" + birth + ", maps=" + maps + ", lists=" + lists + ", dog=" + dog + '}' ; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this .lastName = lastName; } public Integer getAge() { return age; } public void setAge(Integer age) { this .age = age; } public Boolean getBoss() { return boss; } public void setBoss(Boolean boss) { this .boss = boss; } public Date getBirth() { return birth; } public void setBirth(Date birth) { this .birth = birth; } public Map<String, Object> getMaps() { return maps; } public void setMaps(Map<String, Object> maps) { this .maps = maps; } public List<Object> getLists() { return lists; } public void setLists(List<Object> lists) { this .lists = lists; } public Dog getDog() { return dog; } public void setDog(Dog dog) { this .dog = dog; } } |
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@Component
表示将当前类的创建工作交给Spring容器管理
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@ConfigurationProperties (prefix = “person”) |
用于表示该类需要读取的配置信息,prefix用于指示读取哪一个配置信息
Person类依赖了一个Dog类,如下:
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public class Dog { private String name; private Integer age; @Override public String toString() { return "Dog{" + "name='" + name + '\ '' + ", age=" + 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; } } |
2.编写yml文件
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@ConfigurationProperties (prefix = “person”) |
Person类的这个注解就会去找yml中对应的配置信息
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person: lastName: zhangsan age: 18 boss: false birth: 2017/12/12 maps: {k1: v1,k2: v2} lists: - lisi - zhaoliu - wangwu dog: name: 小狗 age: 2 |
3.测试
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@RunWith (SpringRunner. class ) @SpringBootTest public class SpringbootQuickStartApplicationTests { @Autowired Person person; @Test public void demo1() { System.out.println(person); } } |
4.结果
注意:有可能中文在这个地方打印会出现乱码,原因是yml的编码和java文件的编码不一样导致,我们需要将其配成一致的编码,如都设置成utf-8。
5.可以不用@ConfigurationProperties(prefix = “person”)注解方式
使用@Value的方式注入属性值
@Value注解等价于:
以三个属性字段为例
我们既可以从配置文件取值,也可以通过字面量直接赋值,当属性值少的时候这种方式特别方便。
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@Value ( "${person.lastName}" ) private String lastName; @Value ( "${person.age}" ) private Integer age; @Value ( "true" ) private Boolean boss; |
效果如下,由于只注入了三个属性,其余属性则为空
6.@ConfigurationProperties(prefix = “person”)
默认是从主配置文件中读取相关信息,我们可以使用
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@PropertySource (value = {“配置文件的路径”}) |
来指定需要读取的配置文件
6.1写一个dog.properties配置Dog类的相关配置信息
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dog.name=puppy dog.age= 24 |
6.2为Dog类注入属性
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@PropertySource (value = { "classpath:dog.properties" }) @Component @ConfigurationProperties (prefix = "dog" ) public class Dog { private String name; private Integer age; |
6.3效果
以上为个人经验,希望能给大家一个参考,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/qq_38041105/article/details/106981444