List按指定字段排序

项目中经常有对List按某个字段进行排序,这里写了个通用的方法,仅供参考:

public class SortList<T> {
	/**
	 * @param targetList 目标排序List
	 * @param sortField 排序字段
	 * @param sortMode 排序方式
	 */
	@SuppressWarnings({ "unchecked", "rawtypes" })
	public void sort(List<T> targetList, final String sortField, final String sortMode) {
		Collections.sort(targetList, new Comparator() {
			public int compare(Object obj1, Object obj2) { 
				int retVal = 0;
				try {
					Method method1 = ((T)obj1).getClass().getMethod(sortField, null);
					Method method2 = ((T)obj2).getClass().getMethod(sortField, null);
					if (sortMode != null && "desc".equals(sortMode)) {
						retVal = method2.invoke(((T) obj2), null).toString().compareTo(method1.invoke(((T) obj1), null).toString()); // 倒序
					} else {
						retVal = method1.invoke(((T) obj1), null).toString().compareTo(method2.invoke(((T) obj2), null).toString()); // 正序
					}
				} catch (Exception e) {
					throw new RuntimeException();
				}
				return retVal;
			}
		});
	}
	
	/**
	 * 测试方法
	 * @param args
	 */
	public static void main(String[] args) {
		List<Person> targetList = new ArrayList<Person>();
		targetList.add(new Person("zhangsan",11));
		targetList.add(new Person("lisi",12));
		targetList.add(new Person("wangwu",13));
		System.out.println("排序前: " + targetList);
		
		SortList<Person> sortList = new SortList<Person>();
		sortList.sort(targetList, "getAge", "desc");
		
		System.out.println("排序后：" +targetList);
	}
}

class Person {
	private String name;
	private int age;

	public Person() {

	}

	public Person(String name, int age) {
		this.name = name;
		this.age = age;
	}

	public String getName() {
		return name;
	}

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

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}
	
	public String toString(){
		return "name: " + this.name + ",age: " + this.age;
	}
}