Spring Boot：使用 @Value 或 @ConfigurationProperties 从 yaml 读取列表

Spring Boot: read list from yaml using @Value or @ConfigurationProperties

提问by Marged

I want to read a list of hosts from a yaml file (application.yml), the file looks like this:

我想从 yaml 文件 (application.yml) 中读取主机列表，文件如下所示：

cors:
    hosts:
        allow: 
            - http://foo1/
            - http://foo2/
            - http://foo3/

(Example 1)

（示例 1）

My class used defines the value like this:

我使用的类定义了这样的值：

@Value("${cors.hosts.allow}")   
List<String> allowedHosts;

But reading fails as Spring complains about this:

但是阅读失败，因为 Spring 抱怨这个：

java.lang.IllegalArgumentException: Could not resolve placeholder 'cors.hosts.allow' in string value "${cors.hosts.allow}"

java.lang.IllegalArgumentException：无法解析字符串值“${cors.hosts.allow}”中的占位符“cors.hosts.allow”

When I change the file like this the property can be read but naturally it does not contain the list but only one entry:

当我像这样更改文件时，可以读取该属性，但自然它不包含列表，而只包含一个条目：

cors:
    hosts:
        allow: http://foo1, http://foo2, http://foo3

(I know that I could read the values as a single line and split them by ","but I do not want to go for a workaround yet)

（我知道我可以将这些值作为一行读取并将它们拆分，","但我还不想寻求解决方法）

This does not work either (although I think this should be valid according to snakeyamls docs):

这也不起作用（尽管我认为根据snakeyamls docs这应该是有效的）：

cors:
    hosts:
        allow: !!seq [ "http://foo1", "http://foo2" ] 

(Skipping the !!seqand just using the [/ ]is a failure too)

（跳过!!seq并仅使用[/]也是失败的）

I read the suggestion herewhich involves using @ConfigurationPropertiesand transferred the example to Java and used it with the yaml file you see in Example1:

我在这里阅读了建议，其中涉及使用@ConfigurationProperties示例并将其传输到 Java，并将其与您在示例 1 中看到的 yaml 文件一起使用：

@Configuration
@EnableWebMvc
@ConfigurationProperties(prefix = "cors.hosts")
public class CorsConfiguration extends WebMvcConfigurerAdapter {
    @NotNull
    public List<String> allow;
...

When I run this I get this complaint:

当我运行这个时，我收到了这个投诉：

org.springframework.validation.BindException: org.springframework.boot.bind.RelaxedDataBinder$RelaxedBeanPropertyBindingResult: 1 errors Field error in object 'cors.hosts' on field 'allow': rejected value [null]; codes [NotNull.cors.hosts.allow,NotNull.allow,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [cors.hosts.allow,allow]; argumen ts []; default message [allow]];

org.springframework.validation.BindException: org.springframework.boot.bind.RelaxedDataBinder$RelaxedBeanPropertyBindingResult: 1 个错误字段“允许”对象“cors.hosts”中的字段错误：拒绝值 [null]；代码 [NotNull.cors.hosts.allow,NotNull.allow,NotNull]; 参数 [org.springframework.context.support.DefaultMessageSourceResolvable: 代码 [cors.hosts.allow,allow]; 参数 ts []; 默认消息 [允许]];

I searched for other means to have my CORS hosts configurable and found this Spring Boot issuebut as this is not yet finished I can't use it as a solution. All of this is done with Spring Boot 1.3 RC1

我搜索了其他方法来配置我的 CORS 主机并发现了这个Spring Boot 问题，但由于尚未完成，我无法将其用作解决方案。所有这些都是通过 Spring Boot 1.3 RC1 完成的

回答by JeanValjean

It's easy, the answer is in this docand also in this one

这很容易，答案是在这个文档，并在这一个

So, you have a yaml like this:

所以，你有一个这样的 yaml：

cors:
    hosts:
        allow: 
            - http://foo1/
            - http://foo2/
            - http://foo3/

Then you first bind the data

然后你先绑定数据

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

import java.util.List;

@Component
@ConfigurationProperties(prefix="cors.hosts")
public class AllowedHosts {
    private List<String> HostNames; //You can also bind more type-safe objects
}

Then in another component you just do

然后在另一个组件中，您只需执行

@Autowired
private AllowedHosts allowedHosts;

And you are done!

你已经完成了！

回答by Ahmet Vehbi Olga?

use comma separated values in application.yml

在 application.yml 中使用逗号分隔值

corsHostsAllow: http://foo1/, http://foo2/, http://foo3/

java code for access

用于访问的java代码

@Value("${corsHostsAllow}")    
String[] corsHostsAllow

I tried and succeeded ;)

我尝试并成功了;)

回答by Sanim

I have been able to read list from properties like below way-

我已经能够从像下面这样的属性中读取列表-

Properties-

特性-

cors.hosts.allow[0]=host-0
cors.hosts.allow[1]=host-1

Read property-

读取属性-

@ConfigurationProperties("cors.hosts")
public class ReadProperties {
    private List<String> allow;

    public List<String> getAllow() {
       return allow;
    }
    public void setAllow(List<String> allow) {
        this.allow = allow;
    }
}

回答by sean teng

I met the same problem, But solved, give you my solution

我遇到了同样的问题，但解决了，给你我的解决方案

exclude-url: >
  /management/logout,
  /management/user/login,
  /partner/logout,
  /partner/user/login

success in the version of Spring boot 2.1.6.RELEASE

Spring boot 2.1.6.RELEASE版本成功