genericslab.java

来自「一步 教你学会java 完成一个完整的SWT系统 是本人学习java」· Java 代码 · 共 41 行

import java.util.*;

public class GenericsLab {
	
	public static void main( String[] args ) {


		List sList  = new LinkedList();
		List iList = new LinkedList();

		// In the next line create a generic List iterator - from the iList

	        iList.add(new Integer(1));
		iList.add(new Integer(2));

		sList.add(new String("Hello"));
		sList.add(new String("World"));

                // Add an Integer to list that contains only String 
		sList.add(new Integer(1));

        	// Create a generic List iterator for the iList
		Iterator genericIterator = iList.iterator();  

		while(genericIterator.hasNext()) {

			// Illegal cast caught at runtime.
			String item = (String)genericIterator.next();
		}

		genericIterator = sList.iterator();
		// No guarantee of homogeneous containers.
		while (genericIterator.hasNext()) {
			// fail at runtime due to heterogeneous set
			String item = (String)genericIterator.next();
		}

	}
}