获取用户根目录，不在tomcat目录下

 public static String getApkFilePath(){
        StringBuilder sb = new StringBuilder();
        File file = new File(System.getProperty("user.dir"));
        String vFilePath = file.getParent();
        file = new File(vFilePath);
        String fileRealPath = file.getParent();
        sb.append(fileRealPath);
//        D:\Program Files\apache-tomcat-7.0.67-work\apache-tomcat-7.0.67\bin
        sb.append(System.getProperties().getProperty("file.separator"));
        sb.append("apkFile");
        sb.append(System.getProperties().getProperty("file.separator"));
        return sb.toString();
    }