自制数据结构（容器）-java开发用的最多的ArrayList和HashMap

 
public class MyArrayList<E> {
		    private int capacity = 10;
		    private int size = 0;
		    private E[] values = null;  
 
		    @SuppressWarnings("unchecked")
		    public MyArrayList() {
		        values = (E[]) new Object[capacity];
		    }  
 
		    @SuppressWarnings("unchecked")
		    public MyArrayList(int capacity) {
		        this.capacity = capacity;
		        values = (E[]) new Object[this.capacity];
		    }  
 
		    public void put(E e) {
		        if (e == null) {
		            throw new RuntimeException("The value should not be null.");
		        }
		        if (size >= capacity) {
		            enlargeCapacity();
		        }
		        values[size] = e;
		        size++;
		    }  
 
		    public E get(int index) {
		        if (index >= size) {
		            throw new RuntimeException("The index:" + index + " is out of band.");
		        }
		        return values[index];
		    }  
 
		    public void remove(int index) {
		        if (index >= size) {
		            throw new RuntimeException("The index:" + index + " is out of band.");
		        }
		        for (int i = index; i < size - 1; i++) {
		            values[i] = values[i + 1];
		        }
		        values[size - 1] = null;
		        size--;
		    }  
 
		    @SuppressWarnings("unchecked")
		    private void enlargeCapacity() {
		        capacity = capacity * 2;
		        E[] tmpValues = (E[]) new Object[capacity];
		        System.arraycopy(values, 0, tmpValues, 0, size);
		        values = tmpValues;
		    }  
 
		    public String toString() {
		        StringBuilder sb = new StringBuilder();
		        sb.append("[");
		        for (int i = 0; i < size; i++) {
		            sb.append(values[i]).append(",");
		        }
		        if (size > 0) {
		            sb.deleteCharAt(sb.length() - 1);
		        }
		        sb.append("]");
		        return sb.toString();
		    }
		    /**
		     * @param args
		     */
		    public static void main(String[] args) {
		        MyArrayList<Integer> myList = new MyArrayList<Integer>();
		        for(int i=0;i<1000;i++){
		        	myList.put(i);
		        }
		        System.out.println(myList.toString());
		    }  
 
	}