android I/O

   本文主要涉及一些文件的保存、复制；

复制文件代码:

public void copyFile(String oldPath, String newPath) {
           try {
               File oldfile = new File(oldPath);
               boolean can_read=oldfile.canRead();//判断是否可读?
              System.out.println(can_read);
               if (oldfile.exists()) { //文件存在时
                   InputStream inStream = new FileInputStream(oldPath); //读入原文件
                  @SuppressWarnings("resource")
                FileOutputStream fs = new FileOutputStream(newPath);//新建输出流
                   byte[] buffer = new byte[1444];
                   inStream.read(buffer);
                   fs.write(buffer);
                /*  while ( (byteread = inStream.read(buffer)) != -1) {  //如果到了流的末尾会返回-1
                       bytesum += byteread; //字节数 文件大小   得到字节总数
                       fs.write(buffer, 0, byteread);   //从buffer中写入byteread
                 }*/
                  inStream.close();
      }
         }
           catch (Exception e) {
               System.out.println("复制单个文件操作出错");
        e.printStackTrace();

    }

}

写入也可以用被注释的部分。

如下是我自己学习时候，先把一个字符串写入zhao.txt然后再从里面读出来，输出显示。这里先把字符串转换成“UTF-8”编码，读取的时候也要转换：

try {

      String    version="good";

    @SuppressWarnings("resource")
    FileOutputStream version_write=new FileOutputStream(savefile);

        version_write.write(version.getBytes("UTF-8"));}//写入
    catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

      try {
    @SuppressWarnings("resource")
    FileInputStream version_read=new FileInputStream(savefile);
           byte[] version_byte=new byte[1024];
      version_read.read(version_byte);//读出编码

      String ru=EncodingUtils.getString(version_byte, "UTF-8");//解码
     System.out.println(ru);//输出显示

} catch (FileNotFoundException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}