Java截取字符串的方法

public static void main(String args[]) {  //以该字符第一次出现，开始截取  //String str="abc.def";  //String str="abc.def.sdfsdf.fsdfd.ddddd.ggggg.ttttt";  //String str1=str.substring(str.indexOf(".")+1, str.length());  //以该字符出现的最后一次，开始截取  String str="http://wxj.videocc.net/wxj/images/2014/12/i3jwci4j.jpg";  String str1=str.substring(str.lastIndexOf("/")+1, str.length());  //截取后面5个字符  // String str="http://wxj.videocc.net/wxj/images/2014/12/i3jwci4j.jpg";  //String str1 = str.substring(str.length()-5,str.length());  System.out.println(str1);}