JAVA：List<T> 排序

package *;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class JavaTest {
	
	public static void main(String[] args) {
		class UserInfo {
			private String name;
			private String age;
			public String getName() {
				return name;
			}
			public void setName(String name) {
				this.name = name;
			}
			public String getAge() {
				return age;
			}
			public void setAge(String age) {
				this.age = age;
			}
			@Override
			public String toString() {
				return "UserInfo [name=" + name + ", age=" + age + "]";
			}
		}
		
	  	class UserInfoCompartor implements Comparator<UserInfo> {
	  		public int compare(UserInfo o1, UserInfo o2) {
	  			long deNum = Long.parseLong(o2.getAge()) - Long.parseLong(o1.getAge());
	  			return deNum > 0? 1 : deNum < 0? -1 : 0;
	  		}
	  	}
		
		List<UserInfo> userInfos = new ArrayList<UserInfo>();
		for (int i = 0; i < 5; i++) {
			UserInfo userInfo = new UserInfo();
			userInfo.setAge("2"+i);
			userInfo.setName("Google:" +i);
			userInfos.add(userInfo);
		}
		
		System.out.println("Before: " + userInfos);
		Collections.sort(userInfos, new UserInfoCompartor());
		System.out.println("After: " + userInfos);
	}
}

Before: [UserInfo [name=Google:0, age=20], UserInfo [name=Google:1, age=21], UserInfo [name=Google:2, age=22], UserInfo [name=Google:3, age=23], UserInfo [name=Google:4, age=24]]
After: [UserInfo [name=Google:4, age=24], UserInfo [name=Google:3, age=23], UserInfo [name=Google:2, age=22], UserInfo [name=Google:1, age=21], UserInfo [name=Google:0, age=20]]