用这个建实体类：{ "ret": 0, "msg": "打印成功", "data": "UA", "success": true }

下面是一个可能的实体类的示例代码：

public class Response {
    private int ret;
    private String msg;
    private String data;
    private boolean success;

    public int getRet() {
        return ret;
    }

    public void setRet(int ret) {
        this.ret = ret;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public String getData() {
        return data;
    }

    public void setData(String data) {
        this.data = data;
    }

    public boolean isSuccess() {
        return success;
    }

    public void setSuccess(boolean success) {
        this.success = success;
    }
}

这个实体类对应的 JSON 数据如下：

{
    "ret": 0,
    "msg": "打印成功",
    "data": "UA",
    "success": true
}

你可以根据实际需要修改实体类的属性名称和类型。