src/org/nutz/lang/util/Disks.java
public static String absolute(String path) {
        return absolute(path, ClassTools.getClassLoader(), Encoding.defaultEncoding());
    }
public static String absolute(String path) {
        return absolute(path, ClassTools.getClassLoader(), Encoding.defaultEncoding());
    }
获取一个路径的绝对路径。如果该路径不存在，则返回null

@param path
路径
@return 绝对路径