Java – serialize POJOs using gson

I use gson to serialize POJOs – objects before and after changes

The changed (called a) set by struts 2 can be easily serialized as JSON

Although the pre - change POJOs obtained from the database through ibatis (called B) cannot be serialized

The error message says: forgot to register the type adapter?

I have read the gson API But I don't think it's a good idea to register a type adapter for each POJO What makes b unable to serialize?

I wrote a clone () for my POJO, which can also clone objects from B

It's confusing... Can anyone answer me?

Before change (clone of B):

{"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,"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,"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,"lastModifier":"EE4783A6272A4B62A5CC68DB3C11FE1E","saler":"A4FB4877DC2945E980477544A955B57F","state":"意向","status":"0"}

After change:

{"id":"6429B5329C544711A9848AF243D10E4E","visitMode":"","telPhone":"","fax":"","adrs":"","postCode":"","email":"","workUnit":"","media_id":"","idNum":"","idAdr":"","customerDetail":"","lastUpdate":"Mar 11,2012 2:58:04 PM","lastModifier":"00000000000000000000000000000000","state":"意向"}

Solution

Sounds like your POJO is of customer type? When you clone your object, you are creating a new customer, and gson can serialize it well However, when getting the same object from DB, it is not a standard customer object Instead, it is a subclass that contains some persistence information, such as the class of an object

Perhaps the simplest solution is to use gson's @ expose annotation If you use the new gsonbuilder() excludeFieldsWithoutExposeAnnotation(). Create() creates a gson object, you can use @ expose to mark each customer field to be serialized Any other fields, including those of subclasses of the persistence framework, are not serialized