public interface List {
    public Object getElement(int index) throws Exception;
    public void doInsert(Object obj,int index) throws Exception;
    public void doDelete(int index) throws Exception;
}

public class SequenceList implements List{
    static final int DEFUALTLENTH=10;
    int maxSize;//最大数组长度
    int size;//当前长度
    Object[] list;//对象数组
    
    //顺序表初始化方法
    public void init(int size1){
        maxSize = size1;//这个表的长度为size1
        list = new Object[size1];
    }
    //无参构造方法
    public SequenceList() {
        init(DEFUALTLENTH);
    }
    //有参构造方法
    public SequenceList(int size2){
        init(size2);
    }

    @Override
    public Object getElement(int index) throws Exception {
        if(size==0 || index<0 || index>=size){
            System.out.println("参数不正确");
        }
        if(size == maxSize){
            System.out.println("");
        }
        return list[index];
    }

    @Override
    public void doInsert(Object obj,int index) throws Exception {
        if(index<0 || index>size+1){
            System.out.println("参数错误");
        }
        if(size == maxSize){
            System.out.println("线性表已满，无法插入");
        }
        for(int i=size-1;i>index-1;i--){
            list[i+1]=list[i];//指定位置之后的元素都后移一位
        }
        list[index] = obj;
        size++;
    }

    @Override
    public void doDelete(int index) throws Exception {
        if(index<0||index>=size){
            System.out.println("参数错误");
        }
        if(index<size){
            for(int i=size-1;i>index;i--){
                list[i-1] = list[i];
            }
        }
        size--;
        
    }
    

}

public class ListTest {
    public static void main(String args[]){
        SequenceList seq = new SequenceList(20);
        try {
            seq.doInsert("aa", 1);
            seq.doInsert("bb", 2);
            seq.doInsert("cc", 3);
            for(int j=0;j<seq.size;j++){
            System.out.println(seq.getElement(j));}
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
}

public class StudentList {
   public static void main(String args[]){
	   SequenceList seqList = new SequenceList(30);
	   try {
		seqList.doInsert(new Student(1,"小米","女",23), seqList.size);//每次插入，都在表的最后一位插入
		seqList.doInsert(new Student(2, "小徐", "男", 22), seqList.size);
		for(int i=0;i<seqList.size;i++){
			System.out.println("第"+(i+1)+"学生信息为："+seqList.getElement(i).toString());
		}
	} catch (Exception e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
   }
}
class Student{
	private int id;
	private String name;
	private String gender;
	private int age;

	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getGender() {
		return gender;
	}
	public void setGender(String gender) {
		this.gender = gender;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "student [id=" + id + ", name=" + name + ", gender=" + gender
				+ ", age=" + age + "]";
	}
	public Student(int sid,String name,String gender,int age){
		this.id = sid;
		this.name = name;
		this.gender = gender;
		this.age = age;
	}
	
}