JAVA按字节截取字符串（适用于Unicode）

/* Author:lxrmido Website:buzhuanggeek.com Edit:GVIM_073 Date:2011/09/10 */ import javax.swing.*; class hw_7{ public static void main(String[] args){ String str = JOptionPane.showInputDialog(null, "请输入待截取的字符串："); String bytess = JOptionPane.showInputDialog(null, "请输入要截取的字节数："); while(!(bytess.matches("\\d+"))){ bytess = JOptionPane.showInputDialog(null, "输入有误，请重新输入要截取的字节数："); } int bytes = Integer.parseInt(bytess); int index = 0; int endindex = 0; char strc[] = str.toCharArray(); for(int i:strc){ if(i > 256){ if((index == bytes) || (index == bytes-1)){ break; } index += 2; endindex ++; }else{ if(index == bytes){ break; } index ++; endindex ++; } } JOptionPane.showMessageDialog(null, "截取的字符串为："+ str.substring(0, endindex)); System.exit(0); } }