android下大文件分割上传

1. 由于android自身的原因，对大文件(如影视频文件)的操作很容易造成OOM，即：Dalvik堆内存溢出，利用文件分割将大文件分割为小文件可以解决问题。

• 文件分割后分多次请求服务。

  //文件分割上传
      public  void cutFileUpload(String fileType,String filePath)
      {
          try
          {
              FileAccessI fileAccessI = new FileAccessI(filePath, 0);
              Long nStartPos = 0l;
              Long length = fileAccessI.getFileLength();
              int mBufferSize = 1024 * 100; //每次处理1024 * 100字节
              byte[] buffer = new byte[mBufferSize];
              FileAccessI.Detail detail;
              long nRead = 0l;
              String vedioFileName = Usual.f_getUUID(); //分配一个文件名
              long nStart = nStartPos;
              int i = 0;
              while (nStart < length)
              {
                  detail = fileAccessI.getContent(nStart);
                  nRead = detail.length;
                  buffer = detail.b;
                  JSONObject mInDataJson = new JSONObject();
                  mInDataJson.put("a", "282");
                  mInDataJson.put("FileName", vedioFileName);
                  mInDataJson.put("start", nStart); //服务端获取开始文章进行写文件
                  mInDataJson.put("filetype", fileType);
                  nStart += nRead;
                  nStartPos = nStart;
                  String url = UsualA.f_getXmlSOAUrl(UsualA.mServiceFastByteUrl, "n.uploadvedio", mInDataJson.toString(),
                          "282");
                  HttpFastUtil.f_httpPostByte(url, buffer, false);
              }
          }
          catch (Exception e)
          {
          }

• 文件分割类

  package ishitong.mppsp.android.util;
  
  import java.io.*;
  
  public class FileAccessI implements Serializable
  {
  
      RandomAccessFile oSavedFile;
      long nPos;
  
  
      public FileAccessI() throws IOException
      {
          this("", 0);
      }
      public FileAccessI(String sName, long nPos) throws IOException
      {
          oSavedFile = new RandomAccessFile(sName, "rw");//创建一个随机访问文件类，可读写模式
          this.nPos = nPos;
          oSavedFile.seek(nPos);
      }
      public synchronized int write(byte[] b, int nStart, int nLen)
      {
          int n = -1;
          try
          {
              oSavedFile.write(b, nStart, nLen);
              n = nLen;
          }
          catch (IOException e)
          {
              e.printStackTrace();
          }
          return n;
      }
      //每次读取102400字节
      public synchronized Detail getContent(long nStart)
      {
          Detail detail = new Detail();
          detail.b = new byte[102400];
          try
          {
              oSavedFile.seek(nStart);
              detail.length = oSavedFile.read(detail.b);
          }
          catch (IOException e)
          {
              e.printStackTrace();
          }
          return detail;
      }
  
  
      public class Detail
      {
  
          public byte[] b;
          public int length;
      }
  
      //获取文件长度
      public long getFileLength()
      {
          Long length = 0l;
          try
          {
              length = oSavedFile.length();
          }
          catch (IOException e)
          {
              // TODO Auto-generated catch block
              e.printStackTrace();
          }
          return length;
      }
  }

• 服务端获得分割的文件，利用RandomAccessFile进行文件整理

  /**
       * 音视频图片处理
       * @param mStr
       * @return
       * @throws Exception
       */
      public static String f_uploadVedio(String mStr) throws Exception
      {
          String mResult = Usual.mEmpty;
          String fileType = Usual.mEmpty;
          int startPosL = 0;
          RandomAccessFile oSavedFile = null;
          JSONObject jsonObject = new JSONObject(mStr);
          String vedioJsonStr = jsonObject.getString("VEDIO");
          byte[] vedioBytes = Usual.f_fromBase64String(vedioJsonStr);
          startPosL = (Integer) jsonObject.get("start"); //接收客户端的开始位置(文件读取到的字节大小)
          fileType = (String)jsonObject.getString("filetype");
          String fileName = (String)jsonObject.getString("FileName");
          if(fileType.equals("picture"))
          {
              oSavedFile = new RandomAccessFile("E:\"+fileName+".jpg","rw");
          }
          else if(fileType.equals("photo"))
          {
              oSavedFile = new RandomAccessFile("E:\"+fileName+".jpg","rw");
          }
          else if(fileType.equals("voice"))
           {
              oSavedFile = new RandomAccessFile("E:\"+fileName+".mp3","rw");
          }
          else if(fileType.equals("video")) 
          {
              oSavedFile = new RandomAccessFile("E:\"+fileName+".mp4", "rw");
          }
          //设置标志位,标志文件存储的位置
          oSavedFile.seek(startPosL);
          oSavedFile.write(vedioBytes);
          oSavedFile.close();
          mResult = "000";
          return mResult;
      }