java 截取某个字符之前或之后的字符串

String filePath = "group1/M00/00/02/wKgBil9QhcOAZkm5AAJ-5AaXPtQ147.jpg"; // 截取点前的字符串 String path = filePath.substring(0, filePath.indexOf(".")); // 截取点后的字符串 String suffix = filePath.substring(path.length() + 1); // 拼接成缩略图地址 String file = path + "_500x500." + suffix;