Java 无法为Product.class调用无参数构造函数

我在android应用程序中使用GSON和Volley库进行联网，但在使用GSON将Json响应转换为模型类时，我发现以下错误：

88-2006/ E/Volley﹕ [121] NetworkDispatcher.run: Unhandled exception java.lang.RuntimeException: Unable to invoke no-args constructor for class [Lcom.example.model.Product;. Register an InstanceCreator with Gson for this type may fix this problem.
    java.lang.RuntimeException: Unable to invoke no-args constructor for class [Lcom.example.model.Product;. Register an InstanceCreator with Gson for this type may fix this problem.

以下是我正在使用的POJO类： Product.java

public class Product {

    private String status;

    private List<Result> results = new ArrayList<Result>();

    private Pagination pagination;
    public Product(){}

    // getters and setters
}

Result.java

public class Result {

    private String id;

    private Properties properties;
    public Result{}

}

Properties.java

public class Properties {

    private String qbcode;

    private String name;

    private String purchasedate;

    private String vendor;

    private String thumbnail;
    public Properties(){}
}

我已经检查了与此相同的现有问题，根据我发现的答案，我在所有类中添加了no-arg构造函数，但仍然出现错误，请帮助我解决此问题

Json字符串：

{
  "status" : "OK",
  "results" : [ {
    "id" : "IzIzOjE=",
    "properties" : {
      "qbcode" : "IN-1-1",
      "name" : "Test Name",
      "purchasedate" : "2015-05-21",
      "vendor" : "Test Vendor",
      "thumbnail" : "http://en.wikipedia.org/static/images/project-logos/enwiki.png"
    }
  }, {
    "id" : "IzIzOjI=",
    "properties" : {
      "qbcode" : "IN-1-2",
      "name" : "Test Name",
      "purchasedate" : "2015-05-21",
      "vendor" : "Test Vendor",
      "thumbnail" : "http://en.wikipedia.org/static/images/project-logos/enwiki.png"
    }
  }, {
    "id" : "IzIzOjM=",
    "properties" : {
      "qbcode" : "IN-1-3",
      "name" : "Test Name",
      "purchasedate" : "2015-05-21",
      "vendor" : "Test Vendor",
      "thumbnail" : "http://en.wikipedia.org/static/images/project-logos/enwiki.png"
    }
  },{
    "id" : "IzIzOjU=",
    "properties" : {
      "qbcode" : "IN-1-5",
      "name" : "Test Name",
      "purchasedate" : "2015-05-21",
      "vendor" : "Test Vendor",
      "thumbnail" : "http://en.wikipedia.org/static/images/project-logos/enwiki.png"
    }
  } ],
  "pagination" : {
    "first" : "/list?size=20",
    "previous" : "/list?start=IzIzOjE=&size=20",
    "next" : "/list?start=IzIzOjQx&size=20",
    "last" : "/list?start=IzIzOjYx&size=20"
  }
}

---

为所有类添加默认构造函数。例如：

public class Product{

    public Product(){
    }

}

---

问题解决了，我对Gson做了一个愚蠢的调用，因为我获得了一个包含其他类（Result.class等）列表的Product类，但我正在发送Product[].class转换为Gson，因此引发异常。

您的模型具有私有属性，您必须为同一模型创建setter，或使用所有参数创建构造函数，如下所示：

public class Product {

    private String status;
    private List<Result> results = new ArrayList<Result>();
    private Pagination pagination;

    public void setStatus(String status) {
        this.status = status;
    }

    public void setResults(List<Result> results) {
        this.results = results;
    }

    public void setPagination(Pagination pagination) {
        this.pagination = pagination;
    }
}

公共类产品{
私有字符串状态；
私有列表结果=新建ArrayList（）；
私有分页分页；
公共无效设置状态（字符串状态）{
这个状态=状态；
}
公共void setResults（列出结果）{
这个结果=结果；
}
公共无效设置分页（分页分页）{
this.pagination=分页；
}
}

或

公共类产品{
私有字符串状态；
私有列表结果=新建ArrayList（）；
私有分页分页；
公共产品（字符串状态、列表结果、分页分页）{
这个状态=状态；
这个结果=结果；
this.pagination=分页；
}
}

请同时包含json数据。您是否已在所有类中添加了标准构造函数（无参数构造函数）？您是否已将无参数构造函数公开？@SachinGupta我已编辑我的问题我已添加了默认构造函数，但仍收到相同的错误检查此答案：

public class Product {

    private String status;
    private List<Result> results = new ArrayList<Result>();
    private Pagination pagination;

    public void setStatus(String status) {
        this.status = status;
    }

    public void setResults(List<Result> results) {
        this.results = results;
    }

    public void setPagination(Pagination pagination) {
        this.pagination = pagination;
    }
}

public class Product {

    private String status;
    private List<Result> results = new ArrayList<Result>();
    private Pagination pagination;

    public Product(String status, List<Result> results, Pagination pagination) {
        this.status = status;
        this.results = results;
        this.pagination = pagination;
    }

}