在 Java 中使用 GSON 使用 HashMap 成员 JSON 解码自定义类

发布于 2024-10-26 11:54:29 字数 1631 浏览 0 评论 0原文

我有以下类：

class IndexItem {
    private String word;
    private HashMap<String, Integer> docs;
    private Integer total;

    public IndexItem(String word) {
        this.total = 0;
        this.docs = new HashMap<String, Integer>();
        this.word = word;
    }

    public IndexItem() {
        this.total = 0;
        this.docs = new HashMap<String, Integer>();
        this.word = "";
    }
}

我还有使用 GSON 从该类实例之一编码的以下 JSON 字符串：

{"word":"refer","docs":{"c84ada58bb47e7ee8fab14d6d0ae1978.html":7,"7664010c28b7366813f52b30fd683f43.html":6,"a51ed147e16ea44244d7362367caeb4e.html":2},"total":15}

我尝试运行以下命令来解码该字符串：

IndexItem item = new Gson().fromJson(jsonStr, IndexItem.class);

当我尝试运行它时，我收到以下错误消息：

Exception in thread "main" com.google.gson.JsonParseException: 
  The JsonDeserializer MapTypeAdapter failed to deserialized 
  json object
    {"c84ada58bb47e7ee8fab14d6d0ae1978.html":7,"7664010c28b7366813f52b30fd683f43.html":6,"a51ed147e16ea44244d7362367caeb4e.html":2} 
    given the type class java.util.HashMap
at  
   com.google.gson.JsonDeserializerExceptionWrapper.deserialize(JsonDeserializerExceptionWrapper.java:63)
at
com.google.gson.JsonDeserializationVisitor.invokeCustomDeserializer(JsonDeserializationVisitor.java:88)
at 
com.google.gson.JsonObjectDeserializationVisitor.visitFieldUsingCustomHandler(JsonObjectDeserializationVisitor.java:116)

我是新的转向 GSON，并且已经很长时间没有接触 Java 了。所以我的问题是：

有没有办法让 GSON 解码我的类中的 HashMap？还是我的做法是错误的，应该采取不同的方法？如果是这样，我应该去哪里寻找？

原文

I have the following class:

class IndexItem {
    private String word;
    private HashMap<String, Integer> docs;
    private Integer total;

    public IndexItem(String word) {
        this.total = 0;
        this.docs = new HashMap<String, Integer>();
        this.word = word;
    }

    public IndexItem() {
        this.total = 0;
        this.docs = new HashMap<String, Integer>();
        this.word = "";
    }
}

I also have the following JSON string encoded from one of this classes instances using GSON:

{"word":"refer","docs":{"c84ada58bb47e7ee8fab14d6d0ae1978.html":7,"7664010c28b7366813f52b30fd683f43.html":6,"a51ed147e16ea44244d7362367caeb4e.html":2},"total":15}

I tried running the following command to decode this string:

IndexItem item = new Gson().fromJson(jsonStr, IndexItem.class);

And I get the following error message when I try running it:

Exception in thread "main" com.google.gson.JsonParseException: 
  The JsonDeserializer MapTypeAdapter failed to deserialized 
  json object
    {"c84ada58bb47e7ee8fab14d6d0ae1978.html":7,"7664010c28b7366813f52b30fd683f43.html":6,"a51ed147e16ea44244d7362367caeb4e.html":2} 
    given the type class java.util.HashMap
at  
   com.google.gson.JsonDeserializerExceptionWrapper.deserialize(JsonDeserializerExceptionWrapper.java:63)
at
com.google.gson.JsonDeserializationVisitor.invokeCustomDeserializer(JsonDeserializationVisitor.java:88)
at 
com.google.gson.JsonObjectDeserializationVisitor.visitFieldUsingCustomHandler(JsonObjectDeserializationVisitor.java:116)

I am new to GSON and haven't dealt with Java in a long time. So my question is:

Is there a way to get GSON to decode the HashMap in my class? OR am I going about this all wrong and should take a different approach? If so where should I look?

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