Question

我正在尝试将json字符串转换为bean对象，如下所示 -

 PinsRequestTo objPinsRequestTo = new PinsRequestTo();
 objPinsRequestTo = new Gson().fromJson(pinMessageJson, PinsRequestTo.class);

My Bean对象如下

 public class PinsRequestTo {
   private String message;
   private JsonArray keypattern_id_list;

   public String getMessage() {
       return message;
   }

   public void setMessage(String message) {
       this.message = message;
   }

   public JsonArray getKeypattern_id_list() {
       return keypattern_id_list;
   }

   public void setKeypattern_id_list(JsonArray keypattern_id_list) {
       this.keypattern_id_list = keypattern_id_list;
   }
}

json字符串如下

{
 "keypattern_id_list":["C0000011MSZPIN2015010760417236","C0000011MSZPIN2015010760294357"]
}

我在此过程中遇到异常，如下所示

com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was BEGIN_ARRAY at line 2 column 25
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:176)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.read(ReflectiveTypeAdapterFactory.java:93)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:172)
at com.google.gson.Gson.fromJson(Gson.java:795)
at com.google.gson.Gson.fromJson(Gson.java:761)
at com.google.gson.Gson.fromJson(Gson.java:710)
at com.google.gson.Gson.fromJson(Gson.java:682)
......
......

我想用Json字符串中的数组设置PinsRequestTo的属性keypattern_id_list。我该怎么办。如果还有其他方法，请告诉我。

提前致谢

Answer 1

在 PinsRequestTo 类中将keypattern_id_list变量类型从JsonArray更改为List<String>，然后它应如下所示：

public class PinsRequestTo {
    private String message;
    private List<String> keypattern_id_list;

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public List<String> getKeypattern_id_list() {
        return keypattern_id_list;
    }

    public void setKeypattern_id_list(List<String> keypattern_id_list) {
        this.keypattern_id_list = keypattern_id_list;
    }

    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("PinsRequestTo [message=").append(message)
                .append(", keypattern_id_list=").append(keypattern_id_list)
                .append("]");
        return builder.toString();
    }
}

和反序列化逻辑如下：

String pinMessageJson = "{\"keypattern_id_list\":[\"C0000011MSZPIN2015010760417236\",\"C0000011MSZPIN2015010760294357\"]}";

PinsRequestTo objPinsRequestTo = new Gson().fromJson(pinMessageJson, PinsRequestTo.class);
System.out.println(objPinsRequestTo);

这是print语句的输出：

PinsRequestTo [message=null, keypattern_id_list=[C0000011MSZPIN2015010760417236, C0000011MSZPIN2015010760294357]]

gson的maven依赖是：

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.2.2</version>
</dependency>

在将json字符串转换为bean对象gson（）。fromJson（）方法时，抛出“Expected BEGIN_OBJECT但是BEGIN_ARRAY”

1 个答案: