Question

嗨我在使用带有键和值作为用户定义对象的Map时从json转换为Object时遇到问题，下面是说明问题的示例。

错误：线程“main”com.google.gson.JsonSyntaxException中出现异常： java.lang.IllegalStateException：预期为BEGIN_OBJECT但是为STRING 在第1栏第70栏

Employee.java

public class Employee {
    private String employeeId;
    private Map<AddreessKey, Address> addressMap = new HashMap<AddreessKey, Address>();
   //Setters and getters
  }

AddressKey.java

public class AddreessKey {
   private String addressId;
   private String addressName;
  //Getters and Setters

}

Address.Java

public class Address {
    private String street;
    private String home;
//Getters and Setters 
}

Test.java

public class Test {
    public static void main(String[] args) {
       Employee e=new Employee();
       e.setEmployeeId("1");

     Map<AddreessKey, Address> ax=new HashMap<AddreessKey, Address>();

     AddreessKey key=new AddreessKey();
     key.setAddressId("1");
     key.setAddressName("HOME");

     Address value=new Address();
     value.setHome("home");
     value.setStreet("street");

     ax.put(key, value);

     e.setAddressMap(ax);

    //Converting to Json
    String json=new Gson().toJson(e);

   //Getting Problem When converting back to object
   //If I use Any Wrapper class or String class as key instead of object (AddreesKey), No issues when converting back to object.
  //When i use object I am getting the problem

  Employee emp=new Gson().fromJson(json,Employee.class);


  }
}

先谢谢，我希望我的问题很清楚。

Answer 1

我运行了您的代码并找到了修复程序：

Gson gson = new GsonBuilder().enableComplexMapKeySerialization().create(); e.setAddressMap(ax); String json=gson.toJson(e); System.out.println(" JSON :: " + json); Employee emp=gson.fromJson(json,Employee.class);

另外，请务必使用gson v2.3.1 如果这不适合你，请告诉我。

HTH。

Gson转换问题使用Key和Value时，两者都是用户定义的对象

1 个答案: