我正在编写自定义地图,它有自定义的Pair数组,并且地图使用Pair进行操作。它们是通用的,我不知道它们的类型,可能是整数、字符串或双精度浮点数。因此,我不能使用ArrayList,这对我来说是禁止的。
在map的等价函数中: 我正在做: FMap
但编译器报错:
public class FMap<K, V> {
private FPair<K, V>[] data;
int capacity=23;
int used=0;
public FMap(int cap){
super();
capacity=cap;
used =0;
data = new FPair[ capacity];
for(int i=0; i< data.length; ++i)
data[i] = new FPair<K, V>();
}
但编译器报错:
javac -g -Xlint BigramDyn.java
./TemplateLib/FMap.java:23: warning: [rawtypes] found raw type: FPair
data = new FPair[capacity];
^
missing type arguments for generic class FPair<A,B>
where A,B are type-variables:
A extends Object declared in class FPair
B extends Object declared in class FPair
./TemplateLib/FMap.java:23: warning: [unchecked] unchecked conversion
data = new FPair[capacity];
^
required: FPair<K,V>[]
found: FPair[]
where K,V are type-variables:
K extends Object declared in class FMap
V extends Object declared in class FMap
2 warnings
如果我使用 data = new FPair<K, V>[capacity]
而不是 data = new FPair[capacity]
编译器会提示:
TemplateLib/FMap.java:23: error: generic array creation
data = new FPair<K,V>[capacity];
^
1 error
在map的等价函数中: 我正在做: FMap
FMap<K,V> otherPair = (FMap<K,V>) other;
但编译器报错:
./TemplateLib/FMap.java:34: warning: [unchecked] unchecked cast
FMap<A,B> otherPair = (FMap<A,B>) other;
^
required: FMap<A,B>
found: Object
where A,B are type-variables:
A extends Object declared in class FMap
B extends Object declared in class FMap
1 warning