Collection 接口 & List 接口

package com.imooc.collection;
/**
* 课程类
* @author Monica
*
*/
public class Course {
public String id;
public String name;
public Course(String id,String name){
this.id = id;
this.name = name;
}
public Course(){

}
}

package com.imooc.collection;

import java.util.HashSet;
import java.util.Set;
/**
* 学生类
* @author Monica
*
*/

public class Student {
public String id;
public String name;
public Set<Course> courses;
public Student(String id,String name){
this.id = id;
this.name = name;
this.courses = new HashSet<Course>();//set接口调用
}
}

package com.imooc.collection;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

public class ListTest {
/**
* 用于存放备选课程的List
*/
public List coursesToSelect;

public ListTest(){
this.coursesToSelect = new ArrayList();
}
/**
* 用于往coursesToSelect中添加备选课程
*/
public void testAdd(){
//创建一个课程对象，并通过调用add方法，添加到备选课程List中
Course cr1 = new Course("1","数据结构");
coursesToSelect.add(cr1);
//取出元素  get方法
Course temp = (Course)coursesToSelect.get(0);
System.out.println("添加了课程："+temp.id+":"+temp.name);

Course cr2 = new Course("2","C语言");//提供索引位置，插入元素
coursesToSelect.add(0, cr2);
Course temp2 = (Course)coursesToSelect.get(0);
System.out.println("添加了课程："+temp2.id+":"+temp2.name);

coursesToSelect.add(cr1);
//取出元素  get方法
Course temp0 = (Course)coursesToSelect.get(2);
System.out.println("添加了课程："+temp.id+":"+temp.name);

//以下方法会抛出数组下标越界异常
//Course cr3 = new Course("3","Test");
//coursesToSelect.add(4,cr3);数组越界

Course[] course = {new Course("3","离散数学"),new Course("4","汇编语言")};
coursesToSelect.addAll(Arrays.asList(course));
Course temp3 = (Course)coursesToSelect.get(3);
Course temp4 = (Course)coursesToSelect.get(4);

System.out.println("添加了两门课程："+temp3.id+":"+temp3.name+";"+temp4.id+":"+temp4.name);

Course[] course2 = {new Course("5","高等数学"),new Course("6","大学英语")};
coursesToSelect.addAll(2,Arrays.asList(course2));
Course temp5 = (Course)coursesToSelect.get(2);
Course temp6 = (Course)coursesToSelect.get(3);

System.out.println("添加了两门课程："+temp5.id+":"+temp5.name+";"+temp6.id+":"+temp6.name);

}
/**
* 取得List中的元素的方法
* @param args
*/
public void testGet(){
//通过集合的
int size = coursesToSelect.size();
System.out.println("有如下课程待选：");
for(int i = 0; i<size;i++){
Course cr = (Course)coursesToSelect.get(i);
System.out.println("课程："+cr.id+":"+cr.name);
}
}
/**
* 迭代器遍历List方法
* @param args
*/
public void testIterator(){
//通过集合的迭代器访问
System.out.println("有如下课程待选（通过迭代器访问）：");
Iterator it = coursesToSelect.iterator();
while(it.hasNext()){
Course cr = (Course)it.next();
System.out.println("课程："+cr.id+":"+cr.name);
}
}
/**
* 通过for each方法访问集合元素
* @param args
*/
public void testForEach(){
System.out.println("有如下课程待选（通过for each访问）：");
for(Object obj:coursesToSelect){
Course cr = (Course)obj;
System.out.println("课程："+cr.id+":"+cr.name);
}
}
/**
* 修改List中的元素
* @param args
*/
public void testModify(){
coursesToSelect.set(4, new Course("7","毛概"));
}
/**
* 删除List中的元素
* @param args
*/
public void testRemove(){
Course cr = (Course)coursesToSelect.get(4);
System.out.println("我是课程："+cr.id+":"+cr.name+"我即将被删除");
coursesToSelect.remove(cr);
System.out.println("成功删除课程！");
testForEach();
}
public void testRemoves(){
System.out.println("即将删除4位置上的元素");
coursesToSelect.remove(4);
System.out.println("成功删除课程！");
testForEach();
}
public static void main(String[] args){
ListTest lt = new ListTest();
lt.testAdd();
lt.testGet();
lt.testIterator();
lt.testForEach();
lt.testModify();
lt.testForEach();
lt.testRemove();
}
}

package com.imooc.collection;

public class ChildCourse extends Course {

}

package com.imooc.collection;

import java.util.ArrayList;
import java.util.List;

public class TestGeneric {
/**
* 带有泛型——Course，的List类型属性
*/
public List<Course> courses;
//实例化
public TestGeneric(){
this.courses = new ArrayList<Course>();
}
public void testAdd(){
Course cr1 = new Course("1","大学语文");
courses.add(cr1);
//泛型集合中，不能添加泛型规定的类型及其子类型以外的对象，否则会报错！
//courses.add("能否添加一些奇怪的东西呢？");
Course cr2 = new Course("2","Java基础");
courses.add(cr2);
}
/**
* 测试循环遍历
*/
public void testForEach(){
for(Course cr:courses){
System.out.println(cr.id+":"+cr.name);
}
}

/**
* 泛型集合可以添加泛型的子类型的对象实例
* @param args
*/
public void testChild(){
ChildCourse ccr = new ChildCourse();
ccr.id = "3";
ccr.name = "我是子类型的课程对象实例";
courses.add(ccr);
}
/**
* 泛型不能使用基本类型
* @param args
*/
public void testBasicType(){
List<Integer> list = new ArrayList<Integer>();
list.add(1);
System.out.println("基本类型必须使用包装类作为泛型！"+list.get(0));
}
public static void main(String[] args) {
// TODO Auto-generated method stub
TestGeneric tg = new TestGeneric();
tg.testAdd();
tg.testForEach();
tg.testChild();
tg.testForEach();
tg.testBasicType();

}

}