public String replace(String text, String oldStr, String newStr) {
int oldLen = oldStr.length();
int k = 0;
while (k + oldLen <= text.length()) {// 检测到字符串末尾
k = text.indexOf(oldStr, k);// 从k处查找oldStr,并返回位置
if (k == -1)// 若查不到,则跳出
return text;
// 若有,则将其替换为newStr
int i = k + oldLen;
text = text.substring(0, k) + newStr
+ text.substring(i, text.length());
}
return text;
}