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http断点续传简单实现(java)

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/* <udp:s3#T  
**SiteFileFetch.java y?Fh%%uNr  
*/ wgI$'tI  
package NetFox; r?V\X7` +  
import java.io.*; XnV|{X%]U  
import java.net.*; [|uAfp5R  
bCc^)o/w  
2Xgn[oI{  
public class SiteFileFetch extends Thread { j2tw`*S+  
.wYx_  
#2Mz.=#G  
SiteInfoBean siteInfoBean = null; //文件信息Bean 1<pbO:r  
long[] nStartPos; //开始位置 9KD2C>d<  
long[] nEndPos; //结束位置 F5&4x"c  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 M="%NxuS  
long nFileLength; //文件长度 |PTL!>ym2  
boolean bFirst = true; //是否第一次取文件 Kkdd}j  
boolean bStop = false; //停止标志 ~(G]-__B<  
File tmpFile; //文件下载的临时信息 ]J m9D=  
DataOutputStream output; //输出到文件的输出流 Jg |/*Or  
1+Ja4`o,iS  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) PK!=3fK4\F  
public SiteFileFetch(SiteInfoBean bean) throws IOException %xkqiI3Ff  
{ Nqewtn9n  
siteInfoBean = bean; ;k!bv|>n  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =DvnfT<  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 6BNOF66kH  
if(tmpFile.exists ()) 980[]&(  
{ 0M-Zp[w\-  
bFirst = false; lbTz  
read_nPos(); Pg7W:L7  
} {v<Ig{{V  
else NCl$vc;,  
{ _9""3O  
nStartPos = new long[bean.getNSplitter()]; qvhTc6oH  
nEndPos = new long[bean.getNSplitter()]; +X"TiA7{j  
} //f[%j*>  
d),@&MSN  
_8DY9GaE  
,$7LMTVDrE  
} \d%&_rp  
(Q\QZu@  
IiS1ubNtZ  
public void run() XR]]g+Z  
{ bG;vl; C  
//获得文件长度 pA"pt~6  
//分割文件 *cq#>rN  
//实例FileSplitterFetch &I<R|a  
//启动FileSplitterFetch线程 1 NLawi6  
//等待子线程返回 c;B Q$je}  
try{ hFyN|Dqhds  
if(bFirst) 3zMmpeq  
{ ,|?B5n&  
nFileLength = getFileSize(); "n:L<F,g  
if(nFileLength == -1) Nbuaw[[iz  
{ l4v)tV~  
System.err.println("File Length is not known!"); : :e=6i  
} yV=hi?f-[V  
else if(nFileLength == -2) R-bICGSE  
{ ^7~=+0cF]  
System.err.println("File is not access!"); 82efqzT  
} M'R^?Jjb  
else JwxI8Pi*y  
{ l{_>?]S5  
for(int i=0;i<nStartPos.length;i++) _QkU,[E  
{ [&3G `8hY  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); *M6M'>Tin  
} dcYUw]  
for(int i=0;i<nEndPos.length-1;i++) 0'c<EJ  
{ W~Eq_J?I  
nEndPos = nStartPos[i+1]; 5 -5qm[.;  
} +SZ#s :#SE  
nEndPos[nEndPos.length-1] = nFileLength; W5EB+b49KM  
} *.n9D  
} n[ AJ'A{  
/ QSK$ZDC  
/N{xFt/?  
//启动子线程 ) l0=j b  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )TVyRYZ1  
for(int i=0;i<nStartPos.length;i++) %l5Uy??Z  
{ 6(<M.U_ft  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [{f{E  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /'!F \ kz  
nStartPos,nEndPos,i); /$/\$f$  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oC^-" (#  
fileSplitterFetch.start(); V)_mo/D!D  
} d=Q0 /sI&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gV$Lfkz  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q J@XVN4   
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q@r8V&-<  
nEndPos = " + nFileLength); -8#Of)W  
// fileSplitterFetch[nPos.length-1].start(); L+9a4/q  
OI::0KOv  
0waQw7 E  
//等待子线程结束 +wS?Z5%mU  
//int count = 0; n)^B0DnIk  
//是否结束while循环 W 29@`93  
boolean breakWhile = false; bUU_NqUf*3  
^W3xw[{  
GwxfnC Ki9  
while(!bStop) 83OOM;'  
{ E{(7]Wri  
write_nPos(); 87r#;ND  
Utility.sleep(500); Y{f;qbEQH'  
breakWhile = true; AdKv!Ta5b  
$:{uF#  
FJ}/g ?  
for(int i=0;i<nStartPos.length;i++) -]A,SBs  
{ f0O"Hm$Z  
if(!fileSplitterFetch.bDownOver) vqJiMa j@Z  
{ [Xg?sdQCI  
breakWhile = false; jaFBz&P/#  
break; '\[GquK;P  
} doW_v u  
} Rm&i"  
if(breakWhile) [?.k8;k  
break; Go= MG:`  
>#)^4-e  
8%U+y0j6b  
//count++; Nd%,V  
//if(count>4) |36d<b Io  
// siteStop(); (w6024~  
} &Plc  
P I)lJ\  
^R! qxSj  
System.err.println("文件下载结束!"); &?#V*-;^  
} zL+jlUkE  
catch(Exception e){e.printStackTrace ();} VK[^v;  
} %8DU}}Rj  
Z[[q W f  
a[ 1^)=/DM  
//获得文件长度 9h9 jS~h  
public long getFileSize() >DP9S@W  
{ SRRqIQz  
int nFileLength = -1; 4%Z!*W*  
try{ 0L S,(v4  
URL url = new URL(siteInfoBean.getSSiteURL()); tMR&>hM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &z+nNkr?yN  
httpConnection.setRequestProperty("User-Agent","NetFox"); W.'#pd  
zn@<>o8hU  
sn+g#v9e  
int responseCode=httpConnection.getResponseCode(); +vIpt{733  
if(responseCode>=400) {P&{+`sov  
{ Hbn%CdDk1  
processErrorCode(responseCode); A,Wwt [Qw  
return -2; //-2 represent access is error 3X=9$xw_  
} Ub2t7MU  
k Pi%RvuQ  
jhgS@g=@ZC  
String sHeader; A<fKO <d  
ikX"f?Q;S2  
DvB!- |ek  
for(int i=1;;i++) _~/F-  
{ (~q.YJ'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w$[&ejFb  
//Utility.log(in.readLine()); Yd'Fhvo8  
sHeader=httpConnection.getHeaderFieldKey(i); $P&{DOiKS  
if(sHeader!=null) Y3=5J\d!a  
{ wI8  
if(sHeader.equals("Content-Length")) e=Ko4Ao2y  
{ c<bV3,  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .ZQD`SRrI  
break; Ne#FBRu5  
} N-Fs-uB  
} o@:${> jw  
else MdXOH$ ps  
break; ndg1E;>  
} 0)F.Y,L  
} E)sC:oO  
catch(IOException e){e.printStackTrace ();} v=5H,4UMA  
catch(Exception e){e.printStackTrace ();} -LzkM"  
A0X'|4I  
QTr) r;Tro  
Utility.log(nFileLength); J>Pc@,y  
!z? &  
V6Z~#=EQ  
return nFileLength; 3E9 )~$  
} QiH>!Ssw  
-&q@|h'  
wN NXUW  
//保存下载信息(文件指针位置) B|d-3\sn  
private void write_nPos() e~oh%l^C72  
{ pPL)!=o!  
try{ d ~#B,+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $40G$w  
output.writeInt(nStartPos.length); Lb]!TOl  
for(int i=0;i<nStartPos.length;i++) B7x( <!B  
{ 'Em3;`/C*+  
// output.writeLong(nPos); >0F)^W?  
output.writeLong(fileSplitterFetch.nStartPos); =csh=V@s  
output.writeLong(fileSplitterFetch.nEndPos); ,3XlX(P  
} i%@blz:_Y  
output.close(); H 48YX(HI  
} i+qt L3  
catch(IOException e){e.printStackTrace ();} *kY JwO^  
catch(Exception e){e.printStackTrace ();} |j}D2q=  
} A_e&#O  
c,CcKy;+  
.;\uh$c  
//读取保存的下载信息(文件指针位置) ($nQmr;t  
private void read_nPos() !;3hN$5  
{ <-6f}wN  
try{ o5B]?ekpq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0tKVo]EK  
int nCount = input.readInt(); 5GK> ~2c(  
nStartPos = new long[nCount]; ;!S i_b2  
nEndPos = new long[nCount]; ?K\r-J!Y  
for(int i=0;i<nStartPos.length;i++) t:x"]K  
{ _-|/$ jZ  
nStartPos = input.readLong(); .oS[ DTn5S  
nEndPos = input.readLong(); DD5cUlOSu  
} T)MX]T  
input.close(); M!YGv   
} Pm7lP5  
catch(IOException e){e.printStackTrace ();} T mK[^  
catch(Exception e){e.printStackTrace ();} S5BS![-QK  
} ).)^\  
2= Y8$-  
8-_atL  
private void processErrorCode(int nErrorCode) r^7eK)XA_  
{ HV&i! M@T  
System.err.println("Error Code : " + nErrorCode); f AY(ro9Q(  
} 8e5imei  
$D='NzE/  
i>7]9gBm1q  
//停止文件下载 .sjv"D"  
public void siteStop() NR,R.N^[  
{ NQxx_3*4O  
bStop = true; e ?7y$H-  
for(int i=0;i<nStartPos.length;i++) eZ]>;5  
fileSplitterFetch.splitterStop(); Yl&bv#[z  
shD4";8*@  
2]y Hxo/6  
} /PVx  
} bE,#,  
//负责部分文件的抓取 AJ>$`=  
**FileSplitterFetch.java J%]5C}v \  
*/ #qu;{I#W3  
package NetFox; 6?ky~CV  
jM-7  
DUSQh+C  
import java.io.*; L&KL]n  
import java.net.*; d/3bE*gr  
bk0<i*ju7(  
/2''EF';  
public class FileSplitterFetch extends Thread { !UR3`Xk  
![!,i\x  
l, 9r d[  
String sURL; //File URL *0vRVlYf  
long nStartPos; //File Snippet Start Position XqU0AbQ  
long nEndPos; //File Snippet End Position p1[|5r5Day  
int nThreadID; //Thread's ID Lf:#koaC  
boolean bDownOver = false; //Downing is over 6B]i}nFH{+  
boolean bStop = false; //Stop identical 7|"l/s9,  
FileAccessI fileAccessI = null; //File Access interface <00nu'Ex1v  
TV|Z$,6l  
^F qs,^~W  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XTA:Y7"O  
{ 2I3H?Lrx!m  
this.sURL = sURL; # F6<N]i  
this.nStartPos = nStart; vTo+jQs^  
this.nEndPos = nEnd; @#*{* S8  
nThreadID = id; 3kh!dL3D  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KMG}VG   
} jd2 p~W  
KYyoN  
L8Q/!+K  
public void run() U\W$^r,  
{ {3SK|J`  
while(nStartPos < nEndPos && !bStop) _>)@6srC  
{ #V)l>  
y<~(}xsHh  
:#\jx  
try{ Lctp=X4  
URL url = new URL(sURL); .76Z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,S m?2<  
httpConnection.setRequestProperty("User-Agent","NetFox"); WZjR^ 6  
String sProperty = "bytes="+nStartPos+"-"; K47.zu  
httpConnection.setRequestProperty("RANGE",sProperty); xb"e'Zh  
Utility.log(sProperty); P8H2v_)X&  
C?MKb D=K  
\acGSW .c  
InputStream input = httpConnection.getInputStream(); ~[kI! [  
//logResponseHead(httpConnection); 1FG"Ak}D  
*3h_'3yo@  
m&#D~  
byte[] b = new byte[1024]; Y9 Bk$$#\  
int nRead; &4%78K\  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JaR!9GVN7  
{ AFeFH.G6Jr  
nStartPos += fileAccessI.write(b,0,nRead); .g7\+aiTUd  
//if(nThreadID == 1) t8;nP[`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -O r\  
} -<AGCiLz  
[g}0.J`_  
BlM(Q/z  
Utility.log("Thread " + nThreadID + " is over!"); #)i+'L8  
bDownOver = true; >I0 a$w  
//nPos = fileAccessI.write (b,0,nRead); ?%lfbZ  
} D(Q]ddUi'  
catch(Exception e){e.printStackTrace ();} &os:h] C  
} +.rE|)BPy  
} (]VY==t~  
<]_[o:nOP  
G8MLg#  
//打印回应的头信息 ]l3Y=Cl  
public void logResponseHead(HttpURLConnection con) $"}[\>e*{  
{ sPl3JP&s  
for(int i=1;;i++) $Y\7E/T  
{ .81 ~ K[  
String header=con.getHeaderFieldKey(i); ?5^DQ|Hg ^  
if(header!=null) dB QCr{7  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )>iPx.hVSS  
Utility.log(header+" : "+con.getHeaderField(header)); q0['!G%["  
else .$Yp~  
break; O%aHQL%Sz  
} fQ -IM/z  
} k! x`cp  
l<(jm{q?u  
"ub0}p4V  
public void splitterStop() L$"pk{'  
{ 5d# 73)x$  
bStop = true; Z^%HDB9^  
} ~zvZK]JoX  
G_WHW(8   
H;DjM;be  
} )(c%QWz  
Df]*S  
'z=d&K  
/* r;>.*60AT  
**FileAccess.java Hq?dqg'%~  
*//文件访问(定位,写) ~EvGNnTL  
package NetFox; x cZF_elt7  
import java.io.*; 9T1 - {s R  
n;:C{5  
6JR FYgI  
public class FileAccessI implements Serializable{ rd=+[:7L  
I= cayR  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vTWm_ed+^  
RandomAccessFile oSavedFile; A^zd:h-  
long nPos; +=nWB=iCb  
gkca{BJ   
}gE^HH'  
public FileAccessI() throws IOException Qv]rj]%  
{ >LPIvmT4D?  
this("",0); xX Dj4j,  
} Y'#uZA3KA  
kP^=  
U8,pe;/ln`  
public FileAccessI(String sName,long nPos) throws IOException j6L(U~%  
{ 6* 0vUy*"  
oSavedFile = new RandomAccessFile(sName,"rw"); _?eT[!oO8  
this.nPos = nPos; #)iPvV'  
oSavedFile.seek(nPos); oR3t vw.  
} A!}Ps"Z  
gg Nvm  
d'b9.ki\  
public synchronized int write(byte[] b,int nStart,int nLen) (CJx Y(1K  
{ PSyUC#;  
int n = -1; VssWtL  
try{ k-)Ls~#+  
oSavedFile.write(b,nStart,nLen); ,3!4 D^  
n = nLen; 8PWEQ<ev7>  
} ,K|UUosS-#  
catch(IOException e) 8`90a\t'Z  
{ Nu'ox. V  
e.printStackTrace (); rFp>A`TJ  
} BPVOBL@   
1jaK N*  
r @ !  
return n; e{ *yV#Wl  
} ofPv?_@  
}02(Y!Gh  
Wv ~&Qh}  
} n9R0f9:*  
z*9 ke  
9n"MNedqH  
/* T8yMaC  
**SiteInfoBean.java QV4FA&f&  
*/ M|{NC`fa  
package NetFox; ) t CNp  
:H+8E5  
oArJ%Y>  
public class SiteInfoBean { Jb-.x_Bf  
~qK/w0=j  
& x_ #zN]  
private String sSiteURL; //Site's URL tf[)| /M  
private String sFilePath; //Saved File's Path G&"O)$h  
private String sFileName; //Saved File's Name p./0N.  
private int nSplitter; //Count of Splited Downloading File ;WgUhA ;q  
OB*V4Yv  
?/my G{E  
public SiteInfoBean() G.PRPl  
{//nSplitter的缺省值为5 v *`M3jb  
//default value of nSplitter is 5 @[Q`k=h$  
this("","","",5); 9PMIF9"   
} 'g3T'2"`5  
mkl^2V13~  
\N$)Q.M  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A~ _2"  
{ O~Bh(_R&  
sSiteURL= sURL; vTTXeS-b  
sFilePath = sPath; [AA}P/iW  
sFileName = sName; i83[':  
this.nSplitter = nSpiltter; d[XMQX  
`*D"=5G+  
MH9vg5QKp  
} )4m`Ya,E3  
PTqia!  
r4<aEj;l  
public String getSSiteURL() l5\V4  
{ p@[ fZj  
return sSiteURL; 8@RtL,[d  
} q6<P\CSHy<  
%l6E0[   
;mvVo-r*q  
public void setSSiteURL(String value) iRbe$v&N  
{ "/mt uU3rt  
sSiteURL = value; <HzL%DX  
} ?_cOU@n  
]vP}K   
_A] )q  
public String getSFilePath() Vu=/<;-N  
{ z^z`{B  
return sFilePath; 8ZLHN',  
} 7D4tuXUq2  
@BF1X.4-+  
#sDb611}#  
public void setSFilePath(String value) `E?0jQ  
{ [[zN Aq)"  
sFilePath = value;  bLAHVi<.  
}  qLP/z  
%.?V\l  
a @d 15CN  
public String getSFileName() 3?@6QcHl{  
{ i7e6lC  
return sFileName; f-71`Pyb  
} L+(ng  
%^vT7c>  
WmN( (  
public void setSFileName(String value) ]bY]YNt{7]  
{ "aCAA#$J  
sFileName = value; x3Y)l1gh  
} 2\QsF,@`YU  
q$mc{F($D  
#/f~LTE  
public int getNSplitter() Z0m`%(MJa  
{ lM{ fld  
return nSplitter; ii-AE L  
} +E_yEH7_)  
% hvK;B?Y|  
5<R m{  
public void setNSplitter(int nCount) T9H*]LxK  
{  1/2cb-V  
nSplitter = nCount; jWv'`c  
} _Uq' N0U  
} $i5J}  
=4a:)g'  
(r kg0  
/* Wi'}d6c  
**Utility.java q*3keB;X  
*/ @XV&^l -  
package NetFox; E<[ s+iX  
A>1$?A8Q  
kzDN(_<1  
public class Utility { EN2SI+  
UI+6\ 3  
^hmV?a:Y  
public Utility() r(46jV.sD:  
{ 0!_?\)X  
{YzCgf  
'#V@a  
} _>R aw  
h<`aL;.g  
//线程睡眠 Y(.e e%;,  
public static void sleep(int nSecond) {;c'@U  
{ :aej.>I0  
try{ -}|L<~  
Thread.sleep(nSecond); KBmOi  
}  % D  
catch(Exception e) O {1" I  
{ EIg~^xK  
e.printStackTrace (); 'Oue 1[  
} QL WnP-  
} gHrs|6q9  
^H3N1eC,`F  
//日志 c MXv  
public static void log(String sMsg) qTr P@F4`g  
{ Q=`yPK>{$N  
System.err.println(sMsg); ;7QXs39S  
} -AdDPWn  
0\P5=hD)K  
>.d/@3 '  
public static void log(int sMsg) b0{i +R  
{  ?<EzILM  
System.err.println(sMsg); si]VM_w6  
} nn_O"fZi  
} ]?tRO  
-WlYHW  
c$Kc,`2m7  
/* #1DEZ4]jjY  
**TestMethod.java e0zP LU}  
*/ Z8 #nu  
package NetFox; 7~e,"^>T  
&Q883A J  
w\bwa!3Y  
public class TestMethod { )4L2&e`k)(  
^ ` y7JXI:  
nF<K84  
public TestMethod() uL`#@nI  
{ ///xx/weblogic60b2_win.exe !C#oZU]P  
try{ f+cb83}n]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QxYm3x5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t0m;tb bg  
SiteFileFetch fileFetch = new SiteFileFetch(bean); q? ' 4&  
fileFetch.start(); .gx^L=O:  
} Zv;nY7B  
catch(Exception e){e.printStackTrace ();} h;gc5"mG  
{aY) Qv}  
_;j1g%  
} 8tx*z"2S  
NP T-d  
DM^0[3XuV5  
public static void main(String[] args) tYu<(Z(l)  
{ 'x*C#mt  
new TestMethod(); bY" zK',m  
} xsZG(Tz  
} x77L"5g  
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