Springboot_yaml
给实体类属性赋值
方式一
注解实现,@Component
实现被spring接管,@Value
赋值,@Autowired
实现自动装配
@Component
public class Dog {
@Value("旺财")
private String name;
@Value("2")
private Integer age;
public Dog() {
}
public Dog(String name, Integer age) {
this.name = name;
this.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;
}
@Override
public String toString() {
return "Dog{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}
@SpringBootTest
class Springboot02ConfigApplicationTests {
@Autowired
private Dog dog;
@Test
void contextLoads() {
System.out.println(dog);
}
}
方式二
@Component
实现被spring接管,在.yaml配置文件给实体类people属性赋值
通过@ConfigurationProperties(prefix = "people")
与.yaml配置文件进行绑定,实现注入
@Component
@ConfigurationProperties(prefix = "people")
public class People {
private String name;
private Integer age;
private Boolean happy;
private Date birth;
private Map<String,Object> map;
private List<Object> list;
private Dog dog;
public People() {
}
public People(String name, Integer age, Boolean happy, Date birth, Map<String, Object> map, List<Object> list, Dog dog) {
this.name = name;
this.age = age;
this.happy = happy;
this.birth = birth;
this.map = map;
this.list = list;
this.dog = dog;
}
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;
}
public Boolean getHappy() {
return happy;
}
public void setHappy(Boolean happy) {
this.happy = happy;
}
public Date getBirth() {
return birth;
}
public void setBirth(Date birth) {
this.birth = birth;
}
public Map<String, Object> getMap() {
return map;
}
public void setMap(Map<String, Object> map) {
this.map = map;
}
public List<Object> getList() {
return list;
}
public void setList(List<Object> list) {
this.list = list;
}
public Dog getDog() {
return dog;
}
public void setDog(Dog dog) {
this.dog = dog;
}
@Override
public String toString() {
return "People{" +
"name='" + name + '\'' +
", age=" + age +
", happy=" + happy +
", birth=" + birth +
", map=" + map +
", list=" + list +
", dog=" + dog +
'}';
}
}
在添加@ConfigurationProperties
后会爆红,是因为缺少依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
people:
name: fan
age: 18
happy: true
birth: 2023/1/10
map: {k1: v1,k2: v2}
list:
- code
- music
- girl
dog:
name: 黑子
age: 3
@SpringBootTest
class Springboot02ConfigApplicationTests {
@Autowired
private People people;
@Test
void contextLoads() {
System.out.println(people);
}
}
yaml中也可以使用SpEL表达式
people:
name: fan
age: ${random.int} # 可以随机取一些值
happy: true
birth: 2023/1/10
map: {k1: v1,k2: v2}
hello: 六七
list:
- code
- music
- girl
dog:
name: ${people.hello:旺财} # 如果存在people.hello,则取它,否则赋值旺财
age: 3
对比小结
@Value这个使用起来并不友好!我们需要为每个属性单独注解赋值,比较麻烦;
1、@ConfigurationProperties只需要写一次即可 , @Value则需要每个字段都添加
2、松散绑定:这个什么意思呢? 比如我的yaml中写的last-name,这个和lastName是一样的, - 后面跟着的字母默认是大写的。这就是松散绑定。
3、JSR303数据校验 , 这个就是我们可以在字段是增加一层过滤器验证 , 可以保证数据的合法性
4、复杂类型封装,yaml中可以封装对象 , 使用value就不支持
结论:
-
配置yml和配置properties都可以获取到值 , 强烈推荐 yml;
-
如果我们在某个业务中,只需要获取配置文件中的某个值,可以使用一下 @value;
-
如果说,我们专门编写了一个JavaBean来和配置文件进行一一映射,就直接@configurationProperties,不要犹豫!
JSR303数据校验
使用前在想要校验的类上添加注解@Validated
常见参数
@NotNull(message="名字不能为空")
private String userName;
@Max(value=120,message="年龄最大不能查过120")
private int age;
@Email(message="邮箱格式错误")
private String email;
空检查
@Null 验证对象是否为null
@NotNull 验证对象是否不为null, 无法查检长度为0的字符串
@NotBlank 检查约束字符串是不是Null还有被Trim的长度是否大于0,只对字符串,且会去掉前后空格.
@NotEmpty 检查约束元素是否为NULL或者是EMPTY.
Booelan检查
@AssertTrue 验证 Boolean 对象是否为 true
@AssertFalse 验证 Boolean 对象是否为 false
长度检查
@Size(min=, max=) 验证对象(Array,Collection,Map,String)长度是否在给定的范围之内
@Length(min=, max=) string is between min and max included.
日期检查
@Past 验证 Date 和 Calendar 对象是否在当前时间之前
@Future 验证 Date 和 Calendar 对象是否在当前时间之后
@Pattern 验证 String 对象是否符合正则表达式的规则
.......等等
除此以外,我们还可以自定义一些数据校验规则