有没有方法从YAML映射值到对象列表

Question

​正如我在这篇文章中看到的，我正试图从YAML文件创建一个服务器对象列表，但是使用Micronaut。

我的YAML文件具有以下配置：

server:
    -
        name: "Server 1"
        flow: "both"
        environment: "test"
    -
        name: "Server 2"
        flow: "both"
        environment: "production"

我的POJO是：

package dev.renansouza.server;

public class Server {

    private String name;
    private String flow;
    private String environment;

    public Server() {}

    public Server(String name, String flow, String environment) {
        this.name = name;
        this.flow = flow;
        this.environment = environment;
    }

    public String getName() {
        return name;
    }

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

    public String getFlow() {
        return flow;
    }

    public void setFlow(String flow) {
        this.flow = flow;
    }

    public String getEnvironment() {
        return environment;
    }

    public void setEnvironment(String environment) {
        this.environment = environment;
    }

    @Override
    public String toString() {
        return "Servers -> name: " + name + " flow: " + flow + " environment: " + environment;
    }

}

我的服务是：

package dev.renansouza.server;

import io.micronaut.context.annotation.ConfigurationProperties;

import javax.annotation.PostConstruct;
import javax.inject.Singleton;

import java.util.ArrayList;
import java.util.List;

import static dev.renansouza.server.ServerService.PREFIX;

@Singleton
@ConfigurationProperties(PREFIX)
public class ServerService {

    public static final String PREFIX = "server";

    private List<Server> networkRules = new ArrayList<>();

    @PostConstruct
    public void init() {
        for(Server s : this.getServers()) {
            System.out.println(s);
        }
    }

    public List<Server> getServers() {
        return this.networkRules;
    }
}

我在系统上设置了一个断点。出来println行并以调试方式启动应用程序，但什么也没发生。

我需要做任何额外的配置吗？

Answer 1

查看项目https://github.com/jeffbrown/renansouzaproperties.

https://github.com/jeffbrown/renansouzaproperties/blob/master/src/main/resources/application.yml

micronaut:
    application:
        name: renansouzaproperties
server:
    Server 1:
        flow: both
        environment: test
    Server 2:
        flow: both
        environment: production

https://github.com/jeffbrown/renansouzaproperties/blob/master/src/main/java/renansouzaproperties/Server.java

package renansouzaproperties;

import io.micronaut.context.annotation.EachProperty;
import io.micronaut.context.annotation.Parameter;

@EachProperty("server")
public class Server {
    private String name;
    private String flow;
    private String environment;

    public Server(@Parameter String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

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

    public String getFlow() {
        return flow;
    }

    public void setFlow(String flow) {
        this.flow = flow;
    }

    public String getEnvironment() {
        return environment;
    }

    public void setEnvironment(String environment) {
        this.environment = environment;
    }

    @Override
    public String toString() {
        return "Servers -> name: " + name + " flow: " + flow + " environment: " + environment;
    }
}

https://github.com/jeffbrown/renansouzaproperties/blob/master/src/main/java/renansouzaproperties/DemoController.java

package renansouzaproperties;

import io.micronaut.http.annotation.Controller;
import io.micronaut.http.annotation.Get;
import io.micronaut.http.HttpStatus;

import java.util.List;

@Controller("/demo")
public class DemoController {

    private List<Server> serverList;

    public DemoController(List<Server> serverList) {
        this.serverList = serverList;
    }

    @Get("/")
    public HttpStatus index() {
        for(Server server: serverList) {
            System.out.println(server);
        }
        return HttpStatus.OK;
    }
}

如果启动应用程序并向发送请求http://localhost:8080/demo您将看到如下输出，表明已创建所需的服务器实例：

Servers -> name: server 1 flow: both environment: test
Servers -> name: server 2 flow: both environment: production

我意识到，您的问题明确地询问了yaml中的列表，本例没有使用列表，但从其他注释和您发布的示例代码来看，您似乎并不真正需要yaml中的列表。如果您真的希望在yaml中列出一个列表，那么也有一种方法可以做到这一点。如果这真的是你需要的，请告诉我。

我希望这有帮助。