java判断一个文件是否为二进制文件的方法

public static boolean isBinary(File file) 
{
boolean isBinary = false;
try {
FileInputStream fin = new FileInputStream(file);
long len = file.length(); 
for (int j = 0; j < (int) len; j++) {
int t = fin.read();
if (t < 32 && t != 9 && t != 10 && t != 13) {
isBinary = true;
break;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return isBinary;
}