android的U盘能写入的方法

第一部:在assets中添加一张platform.xml 第二步:在代码中写入一下代码 (A):private String path = ""; /** 配置文件路径 */ private String xmlPath = ""; private String xPath=""; /** * @description 检查配置文件是否存在,不存在则新建,拷贝assets下的配置文件 * @author * @date */ private void checkFileExists() { path = FileUtil.getSDCardDir(this).getAbsolutePath() + Constant.SOURCE_FILE_PATH; xmlPath = path + File.separator + Constant.Select_CONFIG_FILE_NAME; xPath=path+File.separator+Constant.Select_CONFIG_FILE_NAMES; Log.d(TAG, "xmlpath:"+xmlPath); File file = new File(path); if (file.mkdirs()) { Log.d("", "文件目录创建成功"); } File xmlfile = new File(xmlPath); if (!xmlfile.exists()) { FileUtil.copyAssetsDataToSDCard(this, Constant.Select_CONFIG_FILE_NAME, path); Log.d("", "The file copies to SDCard successfully!"); } else { Log.d("", "The file already exists!"); } } (B): private static String TMP_PATH = "/sdcard/mount.txt"; private static String mMountPiont = null; private static boolean mWriteable = false; public static String getSystemMountPiont() { DataInputStream dis = null; if (mMountPiont == null) { try { RootCmd.execRootCmd("mount > " + TMP_PATH); // Runtime.getRuntime().exec("mount > " + TMP_PATH); dis = new DataInputStream(new FileInputStream(TMP_PATH)); String line = null; int index = -1; while ( (line = dis.readLine()) != null ) { index = line.indexOf(" /system "); if (index > 0) { mMountPiont = line.substring(0, index); if (line.indexOf(" rw") > 0) { mWriteable = true; Log.i(TAG, "/system is writeable !"); } else { mWriteable = false; Log.i(TAG, "/system is readonly !"); } break; } } } catch (Exception e) { e.printStackTrace(); } finally { if (dis != null) { try { dis.close(); } catch (IOException e1) { e1.printStackTrace(); } dis = null; } File f = new File(TMP_PATH); if (f.exists()) { f.delete(); } } } if (mMountPiont != null) { Log.i(TAG, "/system mount piont: " + mMountPiont); } else { Log.i(TAG, "get /system mount piont failed !!!"); } return mMountPiont; } (C:)public boolean moveSystemUIapkFile() { getSystemMountPiont(); try { Process p; p = Runtime.getRuntime().exec("su"); // Attempt to write a file to a root-only DataOutputStream os = new DataOutputStream(p.getOutputStream()); Log.d(TAG, "MOUNTPOINT:"+mMountPiont); if (mMountPiont != null && RootCmd.haveRoot()) { os.writeBytes("mount -o remount,rw "+ mMountPiont +" /system\n"); os.writeBytes("cd /system/etc/permissions\n"); os.writeBytes("rm -f platform.xml\n"); os.writeBytes("cp "+ xmlPath+" /system/etc/permissions\n"); os.writeBytes("chmod 644 /system/etc/permissions/platform.xml\n"); os.writeBytes("mount -o remount,ro "+ mMountPiont +" /system\n"); os.writeBytes("exit\n"); os.flush(); os.close(); p.waitFor(); return true; } } catch (Exception e) { Log.d("MdriverApp","moveSystemUIapkFile",e); } return false; }