Java中怎样实现字符串截取

/**

	 * str.indexOf()查找下标

	 * substring();//字符串截取

	 * length();//字符串长度

	 * */

	@Test

	public void funB() {

		String mail = "tony@tedu.com";

		int aa = mail.indexOf("@");

		System.out.println("@所在位置："+aa);

		System.out.println("mail长度："+mail.length());

		System.out.println("邮箱用户名："+mail.substring(0, aa));

		System.out.println(mail.substring(aa+1));

		System.out.println("邮箱用户名："+mail.substring(aa, mail.length()));

	}