Java中List类的contains和indexOf方法的使用及区别

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

public class Temp 
{
	public static void main(String[] args) throws Exception
	{
		List<String> list = new ArrayList<String>();
		for (int i = 0; i < 10; i++) {
			list.add(String.valueOf(i));
		}
		//使用contains
		System.out.println(list.contains("5"));
		//使用indexOf
		System.out.println(list.indexOf("5"));
		System.out.println(list.indexOf(new String("5")));
		
		List<People> peoples = new ArrayList<People>();
		People a  = new People("a");
		People b  = new People("b");
		People newa  = new People("a");
		peoples.add(a);
		peoples.add(b);
		//使用contains
		System.out.println(peoples.contains(newa));
		//使用indexOf
		System.out.println(peoples.indexOf(newa));
	}
}
class People{
	private String name;
	
	/**
	 * @param name
	 */
	public People(String name) {
		this.name = name;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		People other = (People) obj;
		if (name == null) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		return true;
	}

	/**
	 * @return the name
	 */
	public String getName() {
		return name;
	}
	
}

//使用contains
System.out.println(peoples.contains(a));
//使用indexOf
System.out.println(peoples.indexOf(a));