當映射到POJO中的Double型別欄位時，JacksonObjectMapper將Integer值轉換為null-有解無憂

請多多包涵。我瀏覽了很多鏈接，但找不到適合我的案例的解決方案。我需要幫助。

注意：我無法更改 JSON 請求（在測驗中表示為地圖）

這是我的 POJO：

public class TestModelWithDoubleField {
    private Double frequency;

    public Double getFrequency(){
        return frequency;
    }

    /**
     * @param frequency the frequency to set
     */
    public void setFrequency(Double frequency) {
        this.frequency = frequency;
    }

    /**
     * @param frequency the frequency to set
     */
    @JsonIgnore
    public void setFrequency(Integer frequency) {
        if(frequency != null) {
            setFrequency(new Double(frequency));
        }
    }
}

這是失敗的測驗：

@Test
public void testWithIntegerValueConvertToDoubleFieldInPOJO() throws IOException {
    final Map<String, Integer> map = new HashMap<>();
    map.put("frequency", 900);
    TestModelWithDoubleField pojo = objectMapper.convertValue(map, TestModelWithDoubleField.class);
    Assert.assertNotNull(pojo);
    Assert.assertNotNull(pojo.getFrequency());   //-> This is giving output as null. Hence fails.
}

在線路Assert.assertNotNull(pojo.getFrequency());頻率為零。因此測驗失敗。

我希望它自動轉換為它的 Double 型別。穿上@JsonIgnore另一個二傳手也不起作用。

任何從該地圖中獲取有效物件的方法都可以。

uj5u.com熱心網友回復：

只需添加@JsonProperty("frequency")所需的二傳手。你甚至不需要@JsonIgnore另一個。

public static class TestModelWithDoubleField
{
  private Double frequency;

  public Double getFrequency()
  {
      return frequency;
  }

  /**
   * @param frequency the frequency to set
   */
  @JsonProperty("frequency")
  public void setFrequency(Double frequency)
  {
      this.frequency = frequency;
  }

  /**
   * @param frequency the frequency to set
   */
  public void setFrequency(Integer frequency)
  {
      if(frequency != null)
      {
          setFrequency(new Double(frequency));
      }
  }
}

uj5u.com熱心網友回復：

只需洗掉該public void setFrequency(Integer frequency)方法，它就會起作用：

public class TestModelWithDoubleField {
    private Double frequency;

    public Double getFrequency(){
        return frequency;
    }

    public void setFrequency(Double frequency){
        this.frequency = frequency;
    }
}

由于您無法洗掉該public void setFrequency(Integer frequency)方法，因此您可以通過將其他 setter@JsonProperty定義為 Jackson 使用的 setter 來注釋其他 setter ：

public class TestModelWithDoubleField {
    private Double frequency;

    public Double getFrequency(){
        return frequency;
    }

    @JsonProperty
    public void setFrequency(Double frequency) {
        this.frequency = frequency;
    }

    public void setFrequency(Integer frequency) {
        if(frequency != null) {
            setFrequency(new Double(frequency));
        }
    }
}

轉載請註明出處，本文鏈接：https://www.uj5u.com/shujuku/337283.html

標籤：爪哇弹簧靴杰克逊杰克逊数据绑定

上一篇：想要模擬屬于另一個類的依賴項

下一篇：Springboot、javascript和websocket的CORS錯誤