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;
       }