The requirement is that the user can write an article, therefore I choose type Text for the content field inside mysql database. How can I convert
Since you're using JPA, use the Lob annotation (and optionally the Column annotation). Here is what the JPA specification says about it:
9.1.19 Lob Annotation
A
Lobannotation specifies that a persistent property or field should be persisted as a large object to a database-supported large object type. Portable applications should use theLobannotation when mapping to a database Lob type. The Lob annotation may be used in conjunction with theBasicannotation. A Lob may be either a binary or character type. The Lob type is inferred from the type of the persistent field or property, and except for string and character-based types defaults to Blob.
So declare something like this:
@Lob
@Column(name="CONTENT", length=512)
private String content;