字符串替换算法【java】

public class StringReplace {

	/**
	 * 字符串替换
	 * @param srcString
	 * @param oldString
	 * @param newString
	 * @return
	 */
	public String replace(String srcString, String oldString, String newString) {
		if(srcString == null) {
			return null;
		}
		char[] lineChars = srcString.toCharArray();
		char[] newStringChars = newString.toCharArray();
		int oldLength = oldString.length();
		StringBuffer buf = new StringBuffer(lineChars.length); //用于存储替换后的字符串
		
		int i = 0;
		int j = i;
		while((i = srcString.indexOf(oldString,i)) >= 0){
			buf.append(lineChars, j, i-j).append(newStringChars);
			i += oldLength;
			j = i;
		}
		buf.append(lineChars, j, lineChars.length - j); //拼接源字符串后面剩下的字符串
		return buf.toString();
	}
	
	public static void main(String[] args) {
	   StringReplace mp = new StringReplace();
	   String str = "xbn_sxsghdhs我是中国人xxshjsh中国s_sx我爱中国China...;;;XH_sx()8jsdh*^_sxghdgshd";
	   long start = System.nanoTime();
	   System.out.println(mp.replace(str, "_sx", "$$$"));
	   System.out.println(System.nanoTime() - start);
	   
	   String str1 = "xbn_sxsghdhs我是中国人xxshjsh中国s_sx我爱中国China...;;;XH_sx()8jsdh*^_sxghdgshd";
	   start = System.nanoTime();
	   System.out.println(str1.replace("_sx", "$$$"));
	   System.out.println(System.nanoTime() - start);
	   
	   String str2 = "%gsfg^gsgh*jChinanxj&^&bbsnakkIloveChina*#KChina#@wdschiaChina";
	   start = System.nanoTime();
	   System.out.println(mp.replace(str2, "China", "中国"));
	   System.out.println(System.nanoTime() - start);
	   
	   start = System.nanoTime();
	   System.out.println(str2.replace("China", "中国"));
	   System.out.println(System.nanoTime() - start);
	}
}

 

评论

1 楼 cccoooccooco 2014-03-01  

测了下，效率很高啊。谢谢分享。