【Springboot学习】从零开始学习Springboot（四）

yaml语法

• 使用双引号时可以使用转义字符

数组

一种写法

#数组
like:
  - a
  - b
  - c
#对象数组
like:
  - name: hh # - 为元素
    age: 18
  - name: aa
    age: 17

 另一种简约写法

#数组
likes: [足球,篮球]
#对象数组
likes: [ { hh:a , ll:b } , { hh:c , ll:d } ]

yaml数据读取

单个数据读取

 后端代码

@RestController
@RequestMapping(value="/books")
public class BookController {

    @Value("${test1.test}")
    private int test00;
    
    @GetMapping
    public String getById(){
        System.out.println("springboot is running");
        return "springboot is running"+test00;
    }
}

yaml

//yaml
test1:
  test: 0

效果

使用Environment对象读取全部配置信息

后端代码

@RestController
@RequestMapping(value="/books")
public class BookController {

    @Value("${test5}")
    private String abc;
    
    @GetMapping
    public String getById(){
        System.out.println("springboot is running");
        System.out.println(env.getProperty("test5"));
        return "springboot is running"+abc;
    }
}

 yaml

test4: abcd
test5: ${test4}efg

效果

yaml特定属性引用

需要引用的数据

test10:
  test101: test101.
  test102: 102
  test103: test103@test.test

处理步骤

1. 定义特定的类来封装yaml文件对应的数据

   public class MyTest {
       private String test101;
       private String test102;
       private String test103;
   
       @Override
       public String toString() {
           return "MyTest{" +
                   "test101='" + test101 + '\'' +
                   ", test102='" + test102 + '\'' +
                   ", test103='" + test103 + '\'' +
                   '}';
       }
   
       public String getTest101() {
           return test101;
       }
   
       public void setTest101(String test101) {
           this.test101 = test101;
       }
   
       public String getTest102() {
           return test102;
       }
   
       public void setTest102(String test102) {
           this.test102 = test102;
       }
   
       public String getTest103() {
           return test103;
       }
   
       public void setTest103(String test103) {
           this.test103 = test103;
       }
   }

2. 定义为spring管控的bean
3. 指定加载的数据
4. 打印对象

   @RestController
   @RequestMapping(value="/books")
   public class BookController {
       @Autowired
       private  MyTest my;
   
       @GetMapping
       public String getById(){
           System.out.println("springboot is running");
           System.out.println(env.getProperty("test5"));
   
           return "springboot is running"+my;
       }
   }

测试结果

yaml属性引用

后端代码

@RestController
@RequestMapping(value="/books")
public class BookController {
    @Value("${test5}")
    private String abc;

    @GetMapping
    public String getById(){
        System.out.println("springboot is running");
        return "springboot is running"+abc;
    }
}

yaml

test4: abcd
test5: ${test4}efg

效果