Jackson JSON字段映射大小写？

Question

我不清楚jackson是如何处理映射字段中的大写字母的。如果有人能帮忙，我将不胜感激。

{"user":{"username":"[e-mail]","password":"pwd","sendercompid":"COMPID","service":{"host":"address","port":6666,"service":"S1","serviceAsString":"s1"}},"MDReqID":"ghost30022","NoRelatedSym":1,"Symbol":["GOOG"],"MarketDepth":"0","NoMDEntryTypes":3,"MDEntryType":["0","1","2"],"SubscriptionRequestType":"1","AggregatedBook":"N"}:

上面是我的json，下面是我的例外。。。

com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "MDReqID" (class com.myco.qa.fixrest.MarketDataRequest), not marked as ignorable (10 known properties: , "mdreqID", "marketDepth", "user", "subscriptionRequestType", "aggregatedBook", "mdentryType", "symbol", "mdupdateType", "noRelatedSym", "noMDEntryTypes"])

上面是我的例外，下面是我的班级。。。

public class MarketDataRequest {
    private User user;
    private String MDReqID;
    private char SubscriptionRequestType;
    private int MarketDepth;
    private int MDUpdateType;
    private char AggregatedBook;
    private int NoMDEntryTypes;
    private ArrayList<Character> MDEntryType;
    private int NoRelatedSym;
    private ArrayList<String> Symbol;

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public String getMDReqID() {
        return MDReqID;
    }

    public void setMDReqID(String MDReqID) {
        this.MDReqID = MDReqID;
    }

    public char getSubscriptionRequestType() {
        return SubscriptionRequestType;
    }

    public void setSubscriptionRequestType(char subscriptionRequestType) {
        SubscriptionRequestType = subscriptionRequestType;
    }

... 等等

Answer 1

在与收到的JSON字符串中的属性名称匹配的setter上添加@JsonProperty：

@JsonProperty("MDReqID")
public void setMDReqID(String MDReqID) {
    this.MDReqID = MDReqID;
}

此外，添加@JsonProperty注释到getter中，以便您的输出以传统格式显示：

@JsonProperty("mDReqID")
public String getMDReqID() {
    return MDReqID;
}

现在，您可以随意命名变量：

private String mdReqID;

Answer 2

你也可以

@JsonNaming(PropertyNamingStrategy.UpperCamelCaseStrategy.class)

在类上大写JSON消息中的所有属性名称

Answer 3

由于setter方法被命名为setMDReqID（...）Jackson假设变量被命名为mDReqID，因为命名约定Java（变量应该以小写字母开头）。

如果你真的想要一个大写字母，在setter上使用@JsonProperty注释（或者-对于序列化-在getter上），如下所示：

@JsonProperty("MDReqID")
public void setMDReqID(String MDReqID) {
    this.MDReqID = MDReqID;
}