java和android文件下载断点续传概要.docx
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java和android文件下载断点续传概要
java和android文件下载
packagecom.example.filetest;
importjava.io.File;
importjava.io.FileNotFoundException;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.RandomAccessFile;
import.HttpURLConnection;
import.MalformedURLException;
import.URL;
importjava.security.KeyManagementException;
importjava.security.KeyStoreException;
importjava.security.NoSuchAlgorithmException;
importjava.security.UnrecoverableKeyException;
/*importmons.httpclient.DefaultHttpMethodRetryHandler;
importmons.httpclient.cookie.CookiePolicy;
importmons.httpclient.methods.GetMethod;
importmons.httpclient.params.HttpMethodParams;*/
importorg.apache.http.Header;
importorg.apache.http.HttpException;
importorg.apache.http.HttpResponse;
importorg.apache.http.HttpStatus;
importorg.apache.http.client.ClientProtocolException;
importorg.apache.http.client.HttpClient;
importorg.apache.http.client.methods.HttpGet;
importorg.apache.http.conn.ClientConnectionManager;
importorg.apache.http.conn.scheme.PlainSocketFactory;
importorg.apache.http.conn.scheme.Scheme;
importorg.apache.http.conn.scheme.SchemeRegistry;
importorg.apache.http.conn.ssl.SSLSocketFactory;
importorg.apache.http.impl.client.DefaultHttpClient;
importorg.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;
importorg.apache.http.message.BasicHeader;
importorg.apache.http.params.BasicHttpParams;
importorg.apache.http.params.HttpConnectionParams;
importandroid.content.Context;
importandroid.graphics.Bitmap;
importandroid.graphics.BitmapFactory;
import.ConnectivityManager;
import.NetworkInfo;
importandroid.text.TextUtils;
importandroid.util.Log;
publicclassNetDownlodUtils{
publicinterfaceDownloadCallback{
voidonStart（longdownloaded,longfileSize）;
voidonProgress（intprogress,longdowloaded,longfileSize）;
voidOnFinished（booleancompleted,longfileSize,Stringremark）;
}
privatefinalstaticintTIMEOUT_CONNECTION=15*1000;
privatefinalstaticintTIMEOUT_SOCKET=15*1000;
privatefinalstaticintRETRY_TIME=2;
publicstaticfinalStringUTF_8="UTF-8";
privatestaticfinalStringTAG="NetDownlodUtils";
/**
*下载文件，实现断点续传，添加range到header
*@paramurl
*@paramdestFile
*@return
*/
publicstaticFiledownloadBreakpointContinuingly（Stringurl,FiledestFile,DownloadCallbackcb）{
RandomAccessFileraf=null;
InputStreaminput=null;
longfileSize=0;
StringerrorMsg=null;
try{
Log.d（TAG,"Startingdownloadfile:
"+destFile+",url:
"+url）;
newFile（destFile.getParent（））.mkdirs（）;
fileSize=getDownloadFileSize（url）;
destFile.createNewFile（）;
raf=newRandomAccessFile（destFile,"rw"）;
longdownloaded=raf.length（）;
if（cb!
=null）{
cb.onStart（downloaded,fileSize）;
}
Log.d（TAG,"shoulddownloadrestfilesize:
"+（fileSize-downloaded））;
HttpGetget=getHttpGet（url,raf.length（）,-1）;
HttpResponseresponse=getHttpClient（）.execute（get）;
intcode=response.getStatusLine（）.getStatusCode（）;
Log.d（TAG,"downloadfilereturncode:
"+code）;
if（code==HttpStatus.SC_PARTIAL_CONTENT）{
raf.seek（destFile.length（））;
errorMsg="HttpStatus.SC_PARTIAL_CONTENT";
}elseif（code==HttpStatus.SC_NOT_FOUND）{
errorMsg="HttpStatus.SC_NOT_FOUND";
returnnull;
}elseif（code!
=HttpStatus.SC_OK）{
errorMsg="code!
=HttpStatus.SC_OK!
!
code="+code;
returnnull;
}
longrestFileSize=response.getEntity（）.getContentLength（）;
Log.d（TAG,"trydownloadrestfilesize="+restFileSize）;
//TODO最好先检查存储空间，面的写数据失败
input=response.getEntity（）.getContent（）;
bytedata[]=newbyte[4096];
intcount;
while（（count=input.read（data））!
=-1）{
raf.write（data,0,count）;
intprogress=fileSize==0?
0:
（int）（raf.length（）*100/fileSize）;
if（cb!
=null）{
cb.onProgress（progress,raf.length（）,fileSize）;
}
}
}catch（Exceptione）{
e.printStackTrace（）;
Log.w（TAG,e.toString（））;
}finally{
try{
input.close（）;
}catch（IOExceptione）{
e.printStackTrace（）;
}
try{
raf.close（）;
}catch（IOExceptione）{
e.printStackTrace（）;
}
if（cb!
=null）{
cb.OnFinished（true,fileSize,errorMsg）;
}
}
returndestFile;
}
/**
*实现断点续传，添加range到header
*注意点：
range区间不能指定end，否则在某些情况下（如阿里云服务器）不生效），不指定end绘制解把文件读完整
*@paramurl
*@paramstart
*@return
*/
protectedstaticHttpGetgetHttpGet（Stringurl,longstart,longend）{
HttpGethttpGet=newHttpGet（url）;
if（start>=0）{
StringBufferrange=newStringBuffer（"bytes="+start+"-"）;
if（end>start）{
range.append（end）;
}
HeaderheaderRange=newBasicHeader（"Range",range.toString（））;
Log.d（TAG,"rangeheader:
"+headerRange）;
httpGet.addHeader（headerRange）;
}
returnhttpGet;
}
/**
*如果尚未知道文件的下载大小，则先主动获取一下
*/
privatestaticlonggetDownloadFileSize（Stringurl）{
longfileSize=0;
try{
HttpGetget=getHttpGet（url,0,-1）;
fileSize=getHttpClient（）.execute（get）.getEntity（）.getContentLength（）;
}catch（ClientProtocolExceptione）{
e.printStackTrace（）;
}catch（IOExceptione）{
e.printStackTrace（）;
}
returnfileSize;
}
publicstaticNetworkInfogetNetworkInfo（Contextcontext）{
ConnectivityManagerconnectivityManager=（ConnectivityManager）context
.getSystemService（Context.CONNECTIVITY_SERVICE）;
NetworkInfonetworkInfo=connectivityManager.getActiveNetworkInfo（）;
returnnetworkInfo;
}
publicstaticbooleanisNetConnected（Contextcontext）{
if（context!
=null）{
NetworkInfoni=getNetworkInfo（context）;
returnni!
=null&&ni.isAvailable（）&&ni.isConnected（）;
}
returnfalse;
}
/**
*getnettypename:
cmwap/cmnet/wifi/uniwap/uninet/ctnet/ctwap
*@paramcontext
*@return
*/
publicstaticStringgetNetWorkTypeName（Contextcontext）{
StringnetworkType=null;
try{
NetworkInfonetworkInfo=getNetworkInfo（context）;//NULL
if（networkInfo!
=null&&networkInfo.isAvailable（））{
StringtypeName=networkInfo.getTypeName（）;//MOBILE/WIFI
if（!
"MOBILE".equalsIgnoreCase（typeName））{
networkType=typeName;
}else{
networkType=networkInfo.getExtraInfo（）;//cmwap/cmnet/wifi/uniwap/uninet
if（networkType==null）{
networkType=typeName+"#[]";
}
}
}
}catch（Exceptione）{
e.printStackTrace（）;
}
returnnetworkType;
}
publicstaticBitmapgetNetBitmap（Stringurl）{
returndownloadNetBitmap（url）;
}
publicstaticInputStreamdownloadNetStream（Stringurl）{
InputStreaminput=null;
intretryTimes=0;
do{
try{
HttpURLConnectioncon=（HttpURLConnection）newURL（url）.openConnection（）;
con.setDoInput（true）;
con.connect（）;
input=con.getInputStream（）;
intmaxSize=con.getContentLength（）;
Log.i（TAG,"maxSize=="+maxSize）;
returninput;
}catch（MalformedURLExceptione）{
e.printStackTrace（）;
}catch（Exceptione）{
e.printStackTrace（）;
}
if（input==null）{
retryTimes++;
if（retryTimestry{
Thread.sleep（1000）;
Log.i（TAG,"downloadNetStreamretryTimes="+retryTimes）;
}catch（InterruptedExceptione1）{
}
continue;
}
}
}while（retryTimesreturninput;
}
publicstaticBitmapdownloadNetBitmap（Stringurl）{
Bitmapbitmap=null;
InputStreaminStream=null;
try{
inStream=downloadNetStream（url）;
if（inStream!
=null）{
bitmap=BitmapFactory.decodeStream（inStream）;
}
}catch（OutOfMemoryErrore3）{
e3.printStackTrace（）;
}catch（Exceptione）{
e.printStackTrace（）;
}finally{
if（inStream!
=null）{
try{
inStream.close（）;
}catch（IOExceptione）{
e.printStackTrace（）;
}
}
}
returnbitmap;
}
publicstaticvoidsaveStreamToFiles（Contextcontext,InputStreamis,
StringfileName）{
if（is==null）
return;
byte[]buffer=newbyte[1024];
intlen=-1;
try{
FileOutputStreambos=context.openFileOutput（fileName,
Context.MODE_PRIVATE）;
while（（len=is.read（buffer））!
=-1）{
bos.write（buffer,0,len）;
bos.flush（）;
}
if（bos!
=null）{
bos.close（）;
}
is.close（）;
}catch（FileNotFoundExceptione）{
e.printStackTrace（）;
}catch（IOExceptione）{
e.printStackTrace（）;
}
}
publicstaticBitmapgetHttpBitmap（Stringurl）{
HttpClienthttpClient=null;
HttpGethttpGet=null;
InputStreaminStream=null;
Bitmapbmp=null;
intretryTimes=0;
try{
do{
try{
httpClient=getHttpClient（）;
httpGet=getHttpGetMethod（url,null,null）;
HttpResponseres=httpClient.execute（httpGet）;
intstatusCode=res.getStatusLine（）.getStatusCode（）;
if（statusCode!
=HttpStatus.SC_OK）{
thrownewException（"errorstatusCode="+statusCode）;
}
inStream=res.getEntity（）.getContent（）;
bmp=BitmapFactory.decodeStream（inStream）;
inStream.close（）;
break;
}catch（OutOfMemoryErrore3）{
e3.printStackTrace（）;
}catch（HttpExceptione）{
e.printStackTrace（）;
}catch（IOExceptione）{
e.printStackTrace（）;
}catch（Exceptione）{
e.printStackTrace（）;
}
if（bmp==null）{
retryTimes++;
if（retryTimestry{
Thread.sleep（1000）;
Log.w（TAG,"downloadBitmapretryTimes="+retryTimes）;
}catch（InterruptedExceptione3）{
}
continue;
}
}
}while（retryTimes}catch（Exceptione）{
e.printStackTrace（）;
}finally{
httpClient=null;
}
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