找出字符串中第一个匹配项的下标

package com.cjh.str;

import java.io.StringBufferInputStream;

public class Str1 {
	public static void main(String[] args) {
		//字符串匹配
		System.out.println(strStr("aaacaaab","aaab"));
	}
	
	public static int strStr(String str1, String str2) {
		char[] origin = str1.toCharArray(); //原始字符串
		char[] pattern = str2.toCharArray(); //模式字符串
		int i=0, j=0;
		while(i <= origin.length - pattern.length) {
			for (j = 0; j < pattern.length; j++) {
				if (pattern[j] != origin[i+j]) {
					break;
				}
			}
			if (j == pattern.length) {
				return i;
			}
			i++;
		}
		return -1;
	}
}