Java格式字符串的语法可能会变得复杂,例如：
"|%1$-10s|%2$-10s|%3$-20s|\n"
有人创建一个流畅的DSL来帮助构建这些格式字符串似乎已经成熟(类似于Jooq对sql的作用).
这样的事情存在吗？
解决方法
您可以使用
fluflu(一种流畅的API生成器)创建这样的API,其灵感来自
jOOQ’s API和
jOOQ’s underlying API design techniques.
Fluflu提供使用APT工具处理的注释,以从API实现生成流畅的API.注释模拟有限状态机.这是他们的维基的一个例子：
@Fluentize(className = "CoreClass",startState = "State0",startMethod = "start")
public abstract class ToBeFluentized implements Cloneable {
@Transitions({
@Transition(from = "State0",end = true),@Transition(from = "State1",end = true)
})
public void end() {
}
protected String with = null;
protected List<byte[]> b = new LinkedList<>();
@Transition(from = { "State0","State1" },to = "State0")
public abstract ToBeFluentized with(
@AssignTo("with") String a,@AddTo("b") byte[] b
);
@Transition(from = "State1",to = "State0")
public ToBeFluentized z() {
return this;
}
Set<Integer> j = new HashSet<>();
@Transition(from = "State1",to = "State1",name="a")
public abstract ToBeFluentized z(@AddTo("j") int j);
@Transition(from = "State0",to = "State1")
public ToBeFluentized a() {
return this;
}
@Transition(from = "State0",to = "State1")
public ToBeFluentized b() {
return this;
}
@Transition(from = "State0",to = "State1")
public ToBeFluentized vari(String... strings) {
return this;
}
}
然后可以这样使用：
State0 c = CoreClass.start().a().z();
State0 d = c.b().with("z","z".getBytes());
State0 e = c.b().with("q",new byte[]{0,1});
d.end();
e.end();
当然,您仍然需要编写实现:-)