尝试使用jackson将平面yaml文件转换为java中的hashmap。

Question

我正在尝试转换一个扁平的yaml文件，如下所示

aramex: "Aramex"
aramex_cash_on_delivery: "Aramex COD"
australia_post: "Australia Post"
boxberry_delivery: "Boxberry Delivery"
boxberry_locker: "Boxberry Pickup and Postamats"
boxit_delivery: "BoxIt Home Delivery"
boxit_locker: "BoxIt Locker & Store Pickup"
chronopost: "Chronopost"

到hashmap中，这样我就可以直接从键访问它，而不必维护额外的文件。

例如：

map.get("aramex"); // should return "Aramex"

我更希望我不需要向pojo添加属性，因为这对我来说是更多的维护。有没有什么例子可以说明杰克逊是怎么做到的呢？

Answer 1

我最终使用了如下的yaml文件：

shipping_options:
  aramex: "Aramex"
  aramex_cash_on_delivery: "Aramex COD"
  australia_post: "Australia Post"
  boxberry_delivery: "Boxberry Delivery"
  boxberry_locker: "Boxberry Pickup and Postamats"

像这样的pojo：

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonInclude;
import java.util.Map;

import com.fasterxml.jackson.annotation.JsonProperty;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;

@Data
@Builder
@AllArgsConstructor
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
public class ShippingOptions {
  @JsonProperty("shipping_options")
  Map<String, String> shippingOptions;
}

以及获取密钥的代码：

public static String getShippingOptionValue(String key) throws IOException {
    String baseDir = System.getProperty("user.dir");
    String filePath = baseDir + "/src/test/resources/shippingoptions.yaml";
    File yaml = new File(filePath);
    ObjectMapper mapper = new ObjectMapper(new YAMLFactory());
    mapper.findAndRegisterModules();
    ShippingOptions shippingOptions = null;
    try {
      shippingOptions = mapper.readValue(yaml, ShippingOptions.class);
    } catch (FileNotFoundException e) {
      log.info("file could not be found {}", filePath);
    } catch (IOException e) {
      log.info("could not load shipping options from {}", filePath);
      throw new IOException("shipping options YAML file was unable to be converted by Jackson {}", e);
    }
    assert shippingOptions != null;
    String value = shippingOptions.getShippingOptions().get(key);
    log.info("Shipping option retrieved was {}", value);
  }

希望这能帮助到一些人。