Tidy up a little bit of feeling useful knowledge

1, often using jquery to get the tag inside the value Val (), or HTML (), text () and so on, once want to get all the HTML elements of the tag including their own also used to operate, query for half a day found $ ("#lefttr1"). Prop ("outerHTML" To

2, encountered this error, after the discovery is missing the primary key error.

3. Jsonmappingexception:no suitable constructor found,reate the default constructor for your POJO class

Both of these errors may be caused by a failure to create a constructor.

4, Java.lang.OutOfMemoryError:PermGen SPAC memory is not enough to solve by Baidu memory shortage

5, could not the load an entity may be the database and entity corresponding field inconsistent

Tidy up a little bit of feeling useful knowledge