使用Gson序列化POJO

Question

我使用GSON序列化POJO －更改对象之前和之后。

由Struts2设置的更改后的名称（称为A）可以轻松地序列化到Json。

虽然更改前的POJO无法通过iBatis（称为B）从数据库中获取，但无法进行序列化。

错误消息显示：忘记注册类型适配器？

我已经阅读了Gson API。 但是我不认为为每个POJO注册一个类型适配器是一个好主意，是什么使B无法序列化？

我为POJO编写了一个clone（），从B克隆的对象也可以完成。

这令人困惑...有人可以回答我吗？

更改之前（B的克隆）：

{"id":"6429B5329C544711A9848AF243D10E4E","idType":"未选择","firstDate":"Feb 29, 2012 12:00:00 AM","name":"testetes","gender":"男","phone":"553223","city":"未选择","ocup":"未选择","nation":"未选择","famStru":"未选择","infSouc":"未选择","creater":"EE4783A6272A4B62A5CC68DB3C11FE1E","createDate":"Feb 29, 2012 12:00:00 AM","purpose":"未选择","education":"未选择","income":"未选择","cars":"未选择","acptCarpRent":"未选择","acptCarpPrice":"未选择","handStand":"未选择","intentHouse":"未选择","intentArea":"未选择","intentLayout":"未选择","nextDate":"Mar 7, 2012 12:00:00 AM","wuyeType":"未选择","attentionPro":"958B9E093A84415B901900C2DA25C712","ordinaryTraffic":"未选择","attentionPoint":"未选择","buyDate":"未选择","cityArea":"未选择","lastUpdate":"Feb 29, 2012 12:00:00 AM","lastModifier":"EE4783A6272A4B62A5CC68DB3C11FE1E","saler":"A4FB4877DC2945E980477544A955B57F","state":"意向","status":"0"}

修改后（A）：

{"id":"6429B5329C544711A9848AF243D10E4E","idType":"未选择","firstDate":"Feb 29, 2012 12:00:00 AM","visitMode":"","name":"testetes","gender":"男","telPhone":"","phone":"553223","fax":"","adrs":"","postCode":"","email":"","workUnit":"","city":"未选择","media_id":"","ocup":"未选择","idNum":"","nation":"未选择","famStru":"未选择","infSouc":"未选择","createDate":"Feb 29, 2012 12:00:00 AM","idAdr":"","purpose":"未选择","education":"未选择","income":"未选择","cars":"未选择","acptCarpRent":"未选择","acptCarpPrice":"未选择","handStand":"未选择","intentHouse":"未选择","intentArea":"未选择","intentLayout":"未选择","customerDetail":"","wuyeType":"未选择","attentionPro":"958B9E093A84415B901900C2DA25C712","ordinaryTraffic":"未选择","attentionPoint":"未选择","buyDate":"未选择","cityArea":"未选择","lastUpdate":"Mar 11, 2012 2:58:04 PM","lastModifier":"00000000000000000000000000000000","saler":"A4FB4877DC2945E980477544A955B57F","state":"意向"}

Answer 1

听起来您的POJO属于客户类型？ 克隆对象时，您正在创建一个新的Customer，Gson可以对其进行序列化。 但是，当您从数据库中获取同一对象时，它不是标准的Customer对象。 相反，它是一个包含一些持久性信息的子类，例如对象的类。

可能最简单的解决方案是使用Gson的@Expose批注。 如果使用new GsonBuilder().excludeFieldsWithoutExposeAnnotation().create()创建Gson对象，则可以使用@Expose标记要序列化的每个Customer字段。 其他任何字段，包括持久性框架的子类的字段，都不会被序列化。

Answer 2

布兰登是对的。 如果您不想使用任何注释或修改POJO类，这是另一个解决方案。 这可能对其他任何人都有帮助。

Type typeOfSrc = new TypeToken<A>() {}.getType(); //this helps for generic one.
gson.toJson(obj, typeOfSrc); or gson.toJson(obj, A.class);