杰克逊阵列到 Pojo 不只在 Android 上工作

Posted 2023-04-19

【中文标题】杰克逊阵列到 Pojo 不只在 Android 上工作

【英文标题】：Jackson Array to Pojo Not Working Only on Android

【发布时间】：2019-12-17 03:05:15

【问题描述】：

我想将 json 数组转换为 POJO，它在 JVM 上运行但在 android 上失败

这是我的pojo：

package com.binance.api.client.domain.market;

import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;

@JsonFormat(shape = JsonFormat.Shape.ARRAY)
@JsonPropertyOrder()
@JsonIgnoreProperties(ignoreUnknown = true)

public class Lilin 
    public Long openTime;

    public String open;

    public String high;

    public String low;

    public String close;

    public String volume;

    public Long closeTime;

    public String quoteAssetVolume;

    public Long numberOfTrades;

    public String takerBuyBaseAssetVolume;

    public String takerBuyQuoteAssetVolume;

然后手动测试一下：

public void testCandlestickDeserializer() 
        final String candlestickJson = "[\n" +
                "    1499040000000,\n" +
                "        \"0.01634790\",\n" +
                "        \"0.80000000\",\n" +
                "        \"0.01575800\",\n" +
                "        \"0.01577100\",\n" +
                "        \"148976.11427815\",\n" +
                "        1499644799999,\n" +
                "        \"2434.19055334\",\n" +
                "        308,\n" +
                "        \"1756.87402397\",\n" +
                "        \"28.46694368\",\n" +
                "        \"17928899.62484339\"\n" +
                "        ]";
        ObjectMapper mapper = new ObjectMapper();
        try 
            Lilin candlestick = mapper.readValue(candlestickJson, Lilin.class);
            System.out.println(candlestick);
         catch (IOException e) 
            System.err.println(e);
        
    

在 JVM 上尝试没有错误，但在 Android 上运行时出现此错误：

Cannot deserialize value of type `java.lang.Long` from String "0.01634790": not a valid Long value

@JsonPropertyOrder() 注释似乎在 Android 上无法正常工作

【参考方案1】：

您可能错过了定义属性排序，例如来自文档：

例子：

// ensure that "id" and "name" are output before other properties
@JsonPropertyOrder( "id", "name" )
// order any properties that don't have explicit setting using alphabetic order

@JsonPropertyOrder(alphabetic=true)
//This annotation may or may not have effect on deserialization: for basic JSON handling there is no effect, but for other supported data types (or structural conventions) there may be.

来源：https://fasterxml.github.io/jackson-annotations/javadoc/2.2.0/com/fasterxml/jackson/annotation/JsonPropertyOrder.html

【讨论】：

谢谢，添加@JsonPropertyOrder("openTime", "open", "high", "low", "close", "volume","closeTime","quoteAssetVolume","numberOfTrades","takerBuyBaseAssetVolume","takerBuyQuoteAssetVolume") 现在可以使用了