如何在YAML文件中为简单的POJO定义映射？

Question

我使用snakeYaml将某些配置/属性值解析为Configuration对象。

我的yaml文件看起来像这样-

#Thread
batchLimit: 1000
threadCountLimit: 2

#Some More Config
key: value

#MAP
keyMapping: <What goes here?>

我的配置类看起来像这样-

public class Configuration{
  int batchlimit;
  int threadCountLimit;
  ...
  Map<String,String> keyMapping;
}

如何在YAML文件中定义keyMapping，使其直接通过SnakeYAML读取？

Answer 1

下面是它的外观：

#MAP
keyMapping: 
    key1: value1
    key2: value2

通常，YAML格式自然支持键-值对。看看下面的教程(仅举个例子)：https://github.com/Animosity/CraftIRC/wiki/Complete-idiot's-introduction-to-yaml

或者只是搜索"yaml地图“来获取更多细节。

Answer 2

带有键值对的Yaml文件"AppParams.yml“：

someConfig:
    key1: value1
    key2: value2

POJO：

public class ApplicationParameters {
    private Map<String, String> someConfig;

    public ApplicationParameters() {
    }

    public Map<String, String> getSomeConfig() {
        return someConfig;
    }

    public void setSomeConfig(Map<String, String> someConfig) {
        this.someConfig = someConfig;
    }
}

读者：

ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
File paramFile = new File("AppParams.yml");
ApplicationParameters applicationParameters = mapper.readValue(paramFile, ApplicationParameters.class);

Map<String, String> someConfig = applicationParameters.getSomeConfig();

String key1Value = someConfig.get("key1");    //returns "value1"

上面的示例在POM.xml中使用了以下依赖项：

 <dependencies>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.9.8</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.8</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.dataformat</groupId>
        <artifactId>jackson-dataformat-yaml</artifactId>
        <version>2.9.8</version>
    </dependency>
</dependencies>