configure Smart tips (DTD file config)

configure Smart tips (DTD file config)
window -> preferences -> xml -> XML Catalog -> Add ->


i.e. 
configuration.xml
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">


Location: local file which download from "http://mybatis.org/dtd/mybatis-3-config.dtd"
Key: -//mybatis.org//DTD Config 3.0//EN


i.e.
mapper.xml
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">


Location: local file which download from "http://mybatis.org/dtd/mybatis-3-mapper.dtd"
Key: -//mybatis.org//DTD Mapper 3.0//EN


then: reopen the xml file use xml style, then can use dtd smart tips.