java实现队列-链表存储

创建一个节点类

public class G {
    int height;
    String name;

    G next;

    public G(int height, String name) {
        this.height = height;
        this.name = name;
    }

    public G() {
    }

    @Override
    public String toString() {
        return "G{" +
                "height=" + height +
                ", name='" + name + ''' +
                '}';
    }
}

创建链表

public class Glist {
    private G front;
    private G rear;
    private int size;



    public G getFront() {
        return front;
    }

    public void setFront(G front) {
        this.front = front;
    }

    public G getRear() {
        return rear;
    }

    public void setRear(G rear) {
        this.rear = rear;
    }

    public int getSize() {
        return size;
    }

    public void setSize(int size) {
        this.size = size;
    }

    
    public Glist() {
        rear=front=null;
    }

    
    public boolean isEmpty(){
        return ((front==null&rear==null)?true:false);
    }

    
    public void enList(G g){
        if(isEmpty()){
            rear=front=g;
        }else{
            rear.next=g;
            rear=g;
        }
        size++;
    }

    
    public G deList(){
        G g1;
        if(isEmpty()){
            throw new RuntimeException("队列为空");
        }else {
            g1=front;
            front=g1.next;
            g1.next=null;
            size--;
        }
        if(size==0){
            front=rear;
        }
        return g1;
    }

    
    public static void main(String[] args) {
        Glist g1=new Glist();
        G s1=new G(4,"sfgsf");
        G s2=new G(5,"sfgsf");
        G s3=new G(6,"sfgsf");
        G s4=new G(7,"sfgsf");
        g1.enList(s1);
        g1.enList(s2);
        g1.enList(s3);
        System.out.println(g1.deList().toString());
        System.out.println(g1.getSize());
        System.out.println(g1.deList().toString());
        System.out.println(g1.getSize());

        System.out.println(g1.deList().toString());
        System.out.println(g1.getSize());


    }
}

总结
1.判断队列是否为空时：rear和font都为空时，队列才为空。
2.在列添加第一个元素时：头指针和尾指针要指向同一个元素（没有头结点的队列）；