对List中的某个属性进行排序

1.Student的Bean如下：

public class Student {

	private int age;

	private String name;

	private String weight;

	public String getWeight() {
		return weight;
	}

	public void setWeight(String weight) {
		this.weight = weight;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

2.按照List中对象的Int类型属性进行排序

   /**
	 * 按照List中的某个Int类型的属性进行排序
	 * @param list
	 */
	@SuppressWarnings("unchecked")
	public static void sortIntMethod(List list){
	    Collections.sort(list, new Comparator(){
			@Override
			public int compare(Object o1, Object o2) {
				Student stu1=(Student)o1;
				Student stu2=(Student)o2;
				if(stu1.getAge()>stu2.getAge()){
					return 1;
				}else if(stu1.getAge()==stu2.getAge()){
					return 0;
				}else{
					return -1;
				}
			}	    	
	    });
	    System.out.println("/////////////排序之后///////////////");
	    for(int i=0;i<list.size();i++){
	    	Student st=(Student)list.get(i);
	    	System.out.println("st.age="+st.getAge()+",st.name="+st.getName());
	    }
	}

3.按照List中对象的String类型的属性进行排序
1)方法一：

  /**
	 * 按照List中的某个String类型的属性进行排序
	 * @param list
	 */
	@SuppressWarnings("unchecked")
	public static void sortStringMethod(List list){
	    Collections.sort(list, new Comparator(){
			@Override
			public int compare(Object o1, Object o2) {
				Student stu1=(Student)o1;
				Student stu2=(Student)o2;
				return stu1.getName().compareTo(stu2.getName());
			}	    	
	    });
	    System.out.println("/////////////排序之后///////////////");
	    for(int i=0;i<list.size();i++){
	    	Student st=(Student)list.get(i);
	    	System.out.println("st.age="+st.getAge()+",st.name="+st.getName());
	    }
	}

2)方法二：
使用java.text.RuleBasedCollator来实现，用来执行区分语言环境的String 比较:

/**
	 * 按照List中的某个String类型的属性进行排序
	 * @param list
	 */
	@SuppressWarnings("unchecked")
	public static void sortByRuleBasedCollator(List list){
		Collections.sort(list, new Comparator(){
			@Override
			public int compare(Object o1, Object o2) {
			    return ((java.text.RuleBasedCollator)java.text.Collator.getInstance(java.util.Locale.CHINA)).compare(((Student)o1).getName(), ((Student)o2).getName());
			}		
		});
		System.out.println("/////////////排序之后///////////////");
	    for(int i=0;i<list.size();i++){
	    	Student st=(Student)list.get(i);
	    	System.out.println("st.age="+st.getAge()+",st.name="+st.getName());
	    }
	}

4.测试排序的方法

        @SuppressWarnings("unchecked")
	public static void main(String[] args) {

		ArrayList list=new ArrayList();
		Student t1=new Student();
		t1.setAge(35);
		t1.setName("wanglei");
		list.add(t1);

		Student t2=new Student();
		t2.setAge(4);
		t2.setName("lisi");
		list.add(t2);

		Student t3=new Student();
		t3.setAge(56);
		t3.setName("zhonghua");
		list.add(t3);

		Student t4=new Student();
		t4.setAge(39);
		t4.setName("waanglei");
		list.add(t4);
		System.out.println("/////////////排序之前///////////////");
		for(int i=0;i<list.size();i++){
	    	Student st=(Student)list.get(i);
	    	System.out.println("st.age="+st.getAge()+",st.name="+st.getName());
	    }
                //按照List中的某个Int类型的属性进行排序
		sortIntMethod(list);
		//按照List中的某个String类型的属性进行排序
		sortStringMethod(list);	
	}

5.结果
1)按照List中对象的Int类型属性进行排序的结果：

[img]http://dl.iteye.com/upload/attachment/426678/148bfae1-7707-3ec4-a07e-4af09482fed9.png[/img]

2)按照按照List中对象的String类型的属性进行排序的结果：

[img]http://dl.iteye.com/upload/attachment/426680/f3ca78bf-c241-3c2e-9252-fee3f030dca7.png[/img]