public void testAdd(){
  //add方法一
  Course cr1 = new Course("1", "课程一");
  coursesToSelect.add(cr1);
  Course temp = (Course)coursesToSelect.get(0);
  System.out.println("添加了课程:"+temp.id+":"+temp.name);
  //add方法二，添加到指定位置
  Course cr2 = new Course("2", "课程二");
  coursesToSelect.add(0, cr2);;
  Course temp2 = (Course)coursesToSelect.get(0);
  System.out.println("添加了课程:"+temp2.id+":"+temp2.name);
  //addAll数组添加方法一
  Course[] cr34 = {new Course("3", "课程三"), new Course("4", "课程四")};
  coursesToSelect.addAll(Arrays.asList(cr34));//添加数组的方法
  Course temp3 = (Course)coursesToSelect.get(2);
  Course temp4 = (Course)coursesToSelect.get(3);
  System.out.println("添加了两门课程:"+temp3.id+":"+temp3.name+
    ";"+temp4.id+":"+temp4.name);
  //addAll数组添加方法二，添加到指定位置
  Course[] cr56 = {new Course("5", "课程五"), new Course("6", "课程六")};
  coursesToSelect.addAll(2, Arrays.asList(cr56));
  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(){
  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);
  }
 }

/**
  * 通过迭代器来遍历List
  * @param args
  */
 public void testIterator(){
  Iterator it = coursesToSelect.iterator();
  System.out.println("有如下课程待选(迭代器)：");
  while(it.hasNext()){
   Course cr = (Course)it.next();//Iterator的next方法
   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(for each)：");
  for(Object obj:coursesToSelect){
   Course cr = (Course)obj;//取出的元素一致都为Object类型，需要强转
   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", "课程七"));
 }

/**
  * 删除List中的元素
  * @param args
  */
 public void testRemore(){
  Course cr = (Course)coursesToSelect.get(4);
  System.out.println("我是课程："+cr.id+"："+cr.name+"，我即将被删除了");
  coursesToSelect.remove(cr);
  System.out.println("删掉了。。");
  testForEach();//方法内部调用方法
 }

public void testRemore(){
  Course[] courses={(Course)coursesToSelect.get(3),(Course)coursesToSelect.get(4)};
  System.out.println("我是课程：3,4，我即将被删除了");
  coursesToSelect.removeAll(Arrays.asList(courses)); 
  System.out.println("删掉了。。");
  testForEach();//方法内部调用方法
 }

private String id;
public String getId(){
 return id;
}
public String setId(){
 this.id=id;
}