public interface sqler<s,a,r> { void setsql(s sql); void setargs(a args); r getresult();}public interface argscreator<a> { a createargs();}
假设需要两个接口进行协作,但如果只这样定义,无法获得类型检查,因此,可以这样定义
public interface sqler<s,a,r> { void setsql(s sql); void setargs(a args); r getresult();}public interface argscreator<a,e extends sqler<?,a,?>> { a createargs();}