Java/Groovy：創建並讀取兩個對象的列表

Question

如何定義和遍歷兩個對象（Foo，Bar）的列表？

我試了一下：

// create 
def fooBar = new ArrayList<Foo, Bar>() 
fooBar.add(new Foo()) 
fooBar.add(new Bar()) 
fooBar.add(new Foo()) // << shouldn't be allowed or overwrite first foo 

def fooBars = new ArrayList<List<Foo, Bar>>() 
fooBars << fooBar 

// read 
fooBars.each { fooBar -> 
    def foo = fooBar[0] 
    def bar = fooBar[1] 
    // do something with foo and bar 
} 

我想要什麼：

// pseudo code 
def fooBar = new ???<Foo, Bar>() 
fooBar.set(new Foo()) 
fooBar.set(new Bar()) 

def fooBars = new ArrayList<???>() 
fooBars << fooBar 

fooBars.each { fooBar -> 
    def foo = fooBar[???] // 0, 'foo', ..? 
    def bar = fooBar[???] 
    // do something with foo and bar 
} 

如果創建我自己的FooBar的類是解決我沒事，我只是希望有一個更簡單的解決方案。