JAVA核心技术卷一，泛型例子

对于这段代码，很多网友充满了质疑，首先有很多，不细心的，没有写Pair类，就进行编译。

肯定编译不过的，Pair类在其他代码的前两页。

还有这里，写出了泛型的特点。通过几个构造函数，和参数的变化，解释了，泛型。

package pair1;


public class Pair<T>{
private T first;
private T second;
public Pair(){
first = null;
second = null;
}

public Pair(T first, T second){
this.first = first;
this.second = second;

}

public T getFirst(){
return first;
}
public T getSecond(){
return second;
}

public void setFirst(T newValue){
first = newValue;

}

public void setSecond(T newValue){
second = newValue;

}



}

package pair1;

public class ArrayAlg {
public static Pair<String> minmax(String[] a){
if(a == null || a.length == 0)
return null;
String min = a[0];
String max = a[0];
for(int i = 1; i < a.length; i++){
if(min.compareTo(a[i]) > 0)
min = a[i];
if(max.compareTo(a[i]) < 0)
max = a[i];
}

return new Pair<>(min, max);
}

}

package pair1;


public class PairTest1 {


public static void main(String[] args) {
// TODO Auto-generated method stub
String[] words = {"Mary", "had", "a", "little", "lamb"};
Pair<String> mm = ArrayAlg.minmax(words);
System.out.println("min = " + mm.getFirst());
System.out.println("min = " + mm.getSecond());
}


}