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http断点续传简单实现(java)

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/* p +T&9  
**SiteFileFetch.java hf?^#=k^  
*/ cw5YjQ8 9  
package NetFox; jSG jv>  
import java.io.*; :%>8\q>UX  
import java.net.*; M`>W'<  
M:I,j  
F}AbA pTv  
public class SiteFileFetch extends Thread { =d5!O~}r>  
W^Rb~b^?  
J.nVEqLZ  
SiteInfoBean siteInfoBean = null; //文件信息Bean xlwsZm{V  
long[] nStartPos; //开始位置 /7lkbL  
long[] nEndPos; //结束位置 iit`'}+U  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 N)!v-z,k  
long nFileLength; //文件长度 I !(yU  
boolean bFirst = true; //是否第一次取文件 ; zvnDox  
boolean bStop = false; //停止标志 /y!Vs`PZ!  
File tmpFile; //文件下载的临时信息 }w-`J5Eq#  
DataOutputStream output; //输出到文件的输出流 >bZ#  
qXhrK /  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) OK)0no=OAK  
public SiteFileFetch(SiteInfoBean bean) throws IOException X,fTzkGj  
{ IWWFl6$-  
siteInfoBean = bean; kdHql>0  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); f9Xw]G9  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %om7h$D =`  
if(tmpFile.exists ()) E1C8yIF  
{ >WDpBn:  
bFirst = false; gK<-*v  
read_nPos(); h4qR\LX  
} gU~)(|Nu.  
else 19rUvgC{M  
{ # _7c>gn  
nStartPos = new long[bean.getNSplitter()]; %nCUct@c  
nEndPos = new long[bean.getNSplitter()]; ?hmb"^vlG  
} @s@  
1(?J>{-lw  
9Ac t<( V  
-24.[E/5  
} &q< 8tTW5  
t<k8.9 M$  
(s3%1OC[  
public void run() BdKtpje  
{ FO5SXwx  
//获得文件长度 5`uS<[vA  
//分割文件 i3"sAr P"|  
//实例FileSplitterFetch "_K 6=  
//启动FileSplitterFetch线程 /iN\)y#u1  
//等待子线程返回 sXa8(xc  
try{ 64vSJx>u  
if(bFirst) yT n@p(J  
{ b910Z?B^L  
nFileLength = getFileSize(); bpx=&74,6m  
if(nFileLength == -1) KCT8Q!\  
{ -,;Ep'  
System.err.println("File Length is not known!"); <^\r9Qxl  
} \nHlI=!P  
else if(nFileLength == -2) :A'!u r=\  
{ kwL) &@  
System.err.println("File is not access!"); Ih7Eq/iu  
} ry\']\k  
else o{he) r6)_  
{ q"Md)?5N  
for(int i=0;i<nStartPos.length;i++) #K l2K4  
{ z3C^L  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,$]q2aL  
} N93E;B  
for(int i=0;i<nEndPos.length-1;i++) _tk5?9Ykn  
{ vck$@3*  
nEndPos = nStartPos[i+1]; ) G{v>Z ,  
} 3XnXQ/({  
nEndPos[nEndPos.length-1] = nFileLength; UIl_& |  
} TUaK:*x*  
} [:QMnJ  
(*RybKoaA  
l(5-Cr  
//启动子线程 ;Wa{q.)  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &~%@QC/  
for(int i=0;i<nStartPos.length;i++) N>R%0m<e  
{ ie(7m| .  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (<l2 ^H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v'!Nt k  
nStartPos,nEndPos,i); 3+-(;>>\  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q]wM/7  
fileSplitterFetch.start(); wuzz%9;@B  
} XNU qZ-M :  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RFJ;hh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FZ9<Q  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^kr)U8  
nEndPos = " + nFileLength); W/>?1+r.Z  
// fileSplitterFetch[nPos.length-1].start(); iy]}1((hR  
$3TTHS o  
i .N1Cvp&  
//等待子线程结束 7fay:_  
//int count = 0; $vBU}~l7  
//是否结束while循环 (L >[,YO9  
boolean breakWhile = false; UTQKlwPa  
 9+QrTO  
5E!m! nBZ  
while(!bStop) B`scuLl3  
{ ]M(mq`K  
write_nPos(); sZ"U=6R  
Utility.sleep(500); [kOA+\v  
breakWhile = true; /[? F1Q  
~vGtNMQg  
`z_7[$\~  
for(int i=0;i<nStartPos.length;i++) EKPTDKut  
{ ;J(,F:N  
if(!fileSplitterFetch.bDownOver) rcZ SC3  
{ eeU$uR  
breakWhile = false; jw[BtRW  
break; XKX,7  
} 4Aew )   
} n^\;*1%$c@  
if(breakWhile) &=Zg0Q  
break; />Vx*^u8Hz  
HY4E  
F2$bUY  
//count++;  <%D"eD  
//if(count>4) X`n0b<  
// siteStop(); b 0b9#9x  
} qffSq](D.  
f_!`~`04  
L~{Vt~H9"  
System.err.println("文件下载结束!"); &H&P)Px*_  
} k |3(dXLG  
catch(Exception e){e.printStackTrace ();} o#P3lz  
} {p|%hhTK%  
/:` i%E  
WKl'  
//获得文件长度 kqW<e[  
public long getFileSize() 6b70w @P!  
{ huJq#5?  
int nFileLength = -1; Sz|CreFK16  
try{ +.]}f}Y  
URL url = new URL(siteInfoBean.getSSiteURL()); G}#/`]o!K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +MZO%4  
httpConnection.setRequestProperty("User-Agent","NetFox"); qW~ R-g]  
cIvYfgIo9  
e=l5j"gq  
int responseCode=httpConnection.getResponseCode(); ~H|LWCU)K8  
if(responseCode>=400) RLz`aBT  
{ ZQ9oZHUm  
processErrorCode(responseCode); _S2^;n?  
return -2; //-2 represent access is error h ^h-pd  
} GR ?u?-  
U|7Qw|I7  
|3:=qpT-  
String sHeader; 8I\eromG  
$U1kP?pR  
Ws*PMK.0  
for(int i=1;;i++) < }wAP_y  
{ n [Xzo}  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ik5jwfz  
//Utility.log(in.readLine()); s#4ew}  
sHeader=httpConnection.getHeaderFieldKey(i); Zng` oFD  
if(sHeader!=null) O;0<^M/0G  
{ U`9\P2D`/  
if(sHeader.equals("Content-Length")) GHJ=-9{YL  
{ < mK  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ' ?G[T28  
break; ,(0XsBL  
} [k~+(.2I  
} oT)VOkFq  
else [du>ff  
break; '<D`:srV  
} B~;LBgpp  
} `Kc %S^C'  
catch(IOException e){e.printStackTrace ();} [Ht."VxR  
catch(Exception e){e.printStackTrace ();} FPMSaN P  
2Z`$  
U aj`  
Utility.log(nFileLength); 2]NAs9aZ  
+ %#MrNM'  
\8*,&ak%  
return nFileLength; ,AbKxT f2  
} :@>br+S  
9U<)_E<y  
SZ2q}[o`R  
//保存下载信息(文件指针位置) } C{}oLz  
private void write_nPos() Q)6wkY+!  
{ d0A\#H_&  
try{ \ ~LU 'j  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Iq0 #A5U%  
output.writeInt(nStartPos.length); 9{%g-u \  
for(int i=0;i<nStartPos.length;i++) L.0} UXd  
{ :Q r7:$S^  
// output.writeLong(nPos); P"=UI$HN  
output.writeLong(fileSplitterFetch.nStartPos); bN4&\d*u#  
output.writeLong(fileSplitterFetch.nEndPos); KBr5bcm4u  
} Wt+y-ES  
output.close(); LA+$_U"Jk  
} 2rj/wakd  
catch(IOException e){e.printStackTrace ();} R )d99j^"  
catch(Exception e){e.printStackTrace ();} )qyx|D  
} ~f=6?5.wa  
dx13vZ3[U  
g;-+7ViIr  
//读取保存的下载信息(文件指针位置) G{f`K^  
private void read_nPos() g2aT`=&Z  
{ n.a=K2H:V  
try{ nrS[7~  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,dZ H$  
int nCount = input.readInt(); (]}x[F9l  
nStartPos = new long[nCount]; cPx ~|,)l  
nEndPos = new long[nCount]; \ L9?69B~  
for(int i=0;i<nStartPos.length;i++) V8nz-DL{  
{ nG},v%  
nStartPos = input.readLong(); :n+y/6 *  
nEndPos = input.readLong(); B15O,sL&W  
} @7Rt4}g  
input.close();  ?+ -/';  
} FI`nRFq)C  
catch(IOException e){e.printStackTrace ();} (pE\nuA\  
catch(Exception e){e.printStackTrace ();} 7TV>6i+7  
} %;<k(5bhGJ  
J\xz^%p  
ycrh5*g  
private void processErrorCode(int nErrorCode) )'j_D<  
{ )l!J$X+R  
System.err.println("Error Code : " + nErrorCode); h{W$ fZc<  
} Y|m_qB^_  
qD(fYOX{C  
rysP)e  
//停止文件下载 )e|$K= D  
public void siteStop() k+WO &g*|  
{ *#Lsjk~_-  
bStop = true; G>=9gSLM  
for(int i=0;i<nStartPos.length;i++) s<Ex"+  
fileSplitterFetch.splitterStop(); ReI=4Jq11  
N?a1sdR  
P&[Ft)`  
} :jk)(=^  
} ~{7zm"jN  
//负责部分文件的抓取 'ZGT`'ri  
**FileSplitterFetch.java hF{x')(#l  
*/ jU]]:S4xD/  
package NetFox; `P^u:  
{k_ PMl0G  
o%V @D'w  
import java.io.*; [!J @a  
import java.net.*; Q? <-`7  
&TP:yA[  
L,C? gd@"  
public class FileSplitterFetch extends Thread { xta}4:d-Y  
X+dR<GN+YX  
;g: UE  
String sURL; //File URL 'A@qg^e:`  
long nStartPos; //File Snippet Start Position }g>dn  
long nEndPos; //File Snippet End Position HF &h  
int nThreadID; //Thread's ID KjFZ  
boolean bDownOver = false; //Downing is over ig{A[7qN  
boolean bStop = false; //Stop identical iUeV5cB  
FileAccessI fileAccessI = null; //File Access interface --in+  
C2+{U  
?(5o@Xq  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U6c)"^\  
{ gt =j5  
this.sURL = sURL; XGE 2J  
this.nStartPos = nStart; xb4Pt`x)rS  
this.nEndPos = nEnd; ]> nPqL  
nThreadID = id; |MTpU@`p5  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ruZYehu1W  
} uSABh ^  
pT("2:)x  
V*6l6-y~Ih  
public void run() l;XU#6{  
{ $Cz1C  
while(nStartPos < nEndPos && !bStop) 42b.7E  
{ &u+yM D  
0M$#95n  
2wB.S_4"-<  
try{ Mam8\  
URL url = new URL(sURL); OD  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vC{ h2A  
httpConnection.setRequestProperty("User-Agent","NetFox"); \ V[;t-  
String sProperty = "bytes="+nStartPos+"-"; \@Ee9C 13  
httpConnection.setRequestProperty("RANGE",sProperty); p&i. )/  
Utility.log(sProperty); J"%8:pL  
%==G+S{  
N7e`6d!  
InputStream input = httpConnection.getInputStream(); ~gu=x&{  
//logResponseHead(httpConnection); I*^5'N'  
44\!PYf7  
6N9 c<JC  
byte[] b = new byte[1024]; b->eg 8|  
int nRead; W*YxBn4  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lemVP'cn  
{ p Tcbq  
nStartPos += fileAccessI.write(b,0,nRead); *-?Wcz  
//if(nThreadID == 1) 3.Ji5~  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yuwc$Qp)  
} 7#~4{rjg  
|w=Ec#)t4  
S-isL4D.Z  
Utility.log("Thread " + nThreadID + " is over!"); gzVtxDh  
bDownOver = true; S4L-/<s[*  
//nPos = fileAccessI.write (b,0,nRead); DW1@<X  
} <(fdHQD!7>  
catch(Exception e){e.printStackTrace ();} Xl#Dw bx  
} Wu4ot0SZ  
} 25aNC;J  
d2RnQA  
SXQ@;= ]xV  
//打印回应的头信息 "Owct(9  
public void logResponseHead(HttpURLConnection con) rVUUH!  
{ 0yn[L3x7  
for(int i=1;;i++) n%F-cw  
{ py]KTRzy  
String header=con.getHeaderFieldKey(i); lwVk(l Z  
if(header!=null) i*X{^A73"  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y^ QKp"  
Utility.log(header+" : "+con.getHeaderField(header)); As0 B\  
else E[S? b=^  
break; Iha[G u  
} ;xfO16fNk  
} 3FFaEl  
(@+h5@J[`I  
1hR (N  
public void splitterStop() Y!Drb-U?;  
{ -^yXLa;D  
bStop = true; kB8 Mi  
} N*Yy&[  
2R~6<W+&:>  
ndr)3tuYu  
} s8^~NX(xdy  
88 {1mA,v  
fO6[!M(  
/* xPt*CB  
**FileAccess.java 7skljw(  
*//文件访问(定位,写) ZT6V/MD7T.  
package NetFox; 0x\2 #i  
import java.io.*; 7!p LK&_  
(qUK7$  
3 -tO;GKb  
public class FileAccessI implements Serializable{ :V-k'hm &  
69Nw/$  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 80|onP\L  
RandomAccessFile oSavedFile; [9OSpq  
long nPos; (VyA6a8  
8"x9#kyU<3  
(_K_`5d;QI  
public FileAccessI() throws IOException 6a*83G,k  
{ kae2 73"  
this("",0); ?mMW*ico  
} vs +QbI6>-  
-j&Vtr  
.Rvf/-e  
public FileAccessI(String sName,long nPos) throws IOException }S */b1  
{ ZZ("-#?  
oSavedFile = new RandomAccessFile(sName,"rw"); #F!Kxks  
this.nPos = nPos; fz3lR2~G  
oSavedFile.seek(nPos); {(}yG_Q]!  
} *hF^fxLbl  
09d9S`cS\  
<#y*h8IZ@t  
public synchronized int write(byte[] b,int nStart,int nLen) wX0l?xdI  
{ _8^0!,j  
int n = -1; Q ]"jD#F  
try{ =2%VZE7Vm  
oSavedFile.write(b,nStart,nLen); $e BQH  
n = nLen; v5T`K=qC  
} \,R!S/R#  
catch(IOException e) MU1E_"Z)  
{ ;'}'5nO=$  
e.printStackTrace (); !" E-\cc'  
} (9]6bd  
zT7"VbP  
(~&w-w3  
return n; BqB |Fo  
} Ns<?b;aK  
q jz3<`7-  
d; =u  
} !^iwQ55e2A  
_{$fA6C  
4&{!M _  
/* &s8<6P7  
**SiteInfoBean.java #by Jqy&e  
*/ ?v4E<iXs  
package NetFox; K(VW%hV1  
d2~l4IL)~  
_R^y\1Qu  
public class SiteInfoBean { ARF\fF|<2  
1k[GuG%/K  
6{=_718l`  
private String sSiteURL; //Site's URL vk'rA{x  
private String sFilePath; //Saved File's Path 8eJE>g1J  
private String sFileName; //Saved File's Name ,q#2:b<E  
private int nSplitter; //Count of Splited Downloading File l^W uS|G[  
MQ`%``  
HCj> ,^<h  
public SiteInfoBean() mI"D(bx\  
{//nSplitter的缺省值为5 ` 1+%}}!$u  
//default value of nSplitter is 5 VRbQdiZ{  
this("","","",5); [b/o$zR  
} Yw)Fbt^  
-bS)=L  
&RO7{,`  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '#D8*OP^  
{ Y: psZ  
sSiteURL= sURL; I^_NC&m  
sFilePath = sPath; ()\jCNLT  
sFileName = sName; 9I .^LZ"  
this.nSplitter = nSpiltter; yMxTfR  
TH4\HY9qa?  
(0L=AxH  
} 68e[:wf  
"^Rv#  
YQd:M%$  
public String getSSiteURL() wL3,g2-L  
{ $a(`ve|  
return sSiteURL; 1~\M!SQ)  
} |m;L?)F<  
ER^QV(IvP8  
>o/95xk2  
public void setSSiteURL(String value) e |V]  
{ %tmp  
sSiteURL = value; (3;@^S4&w  
} zzIr2so  
~<)vKk  
#xT!E:W '  
public String getSFilePath() }x:f%Z5h  
{ gXy -Mpzp  
return sFilePath; gU;&$  
} ss iokLE  
V.=lGhi  
b>11h  
public void setSFilePath(String value) ;ME)Og  
{ LFf`K)q  
sFilePath = value; QyGnDomQ  
} ;Vu5p#,O<M  
RMP9y$~3pU  
(9C<K<  
public String getSFileName() Kat&U19YH  
{ 42+#<U7T  
return sFileName; A.En+-[\  
} QDTNx!WL  
Kq)MTlP0g  
I#G0, &Gv  
public void setSFileName(String value) Eu,`7iQ?(  
{ pqR\>d 0  
sFileName = value; 3BQ!qO17^d  
} Q5a)}6-5  
yI3kvh  
BRv x[u  
public int getNSplitter() T .n4TmF  
{ 1^G{tlA-  
return nSplitter; eQDX:b  
} 3EK9,:<Cf  
u2iXJmM*  
s'\$t  
public void setNSplitter(int nCount) (gXN%rsY  
{ Vba.uKNjk  
nSplitter = nCount; (zcLx;N  
} M(Zc^P}N  
} I#rubAl  
_$s> c!t,#  
IV`%V+ f  
/* D(]E/k@ ;~  
**Utility.java & ,hr8  
*/ YY5!_k  
package NetFox; y~ rX l  
`T&jPA9eY  
z(13~38+  
public class Utility { wvby?MhPY  
z rfUQO  
O7G"sT1Dv  
public Utility() kcuzB+  
{ 7h9U{4r: M  
19UN*g3(  
y1f:?L-z  
} 1;F`c`0<  
vVxD!EL  
//线程睡眠 s1j{x&OSq  
public static void sleep(int nSecond) g(E"4M@t!  
{ t^tmz PWA  
try{ gm"#:< )  
Thread.sleep(nSecond); b #fTAC;<  
} Ea $aUORm  
catch(Exception e) (eWPis[  
{ 23]Y<->Eu<  
e.printStackTrace (); OF U/gaO~  
} {KL5GowH  
} ,  X{>  
Zu*K-ep"  
//日志 sW@krBxMv  
public static void log(String sMsg) 6<76H  
{ ~NcQ1.  
System.err.println(sMsg); #]Y>KX2HG  
} mN_Z7n;^eh  
/RnTQ4   
#FxPj-3(ix  
public static void log(int sMsg) jM)C4ii.-$  
{ <n"C,  
System.err.println(sMsg); Nf41ZT~  
} \;X+X,M  
} 5\fCd|  
zg)sd1@  
x2Lq=zwJ  
/* &HZmQ>!R D  
**TestMethod.java RO(TvZ0pE  
*/ D<$XyP  
package NetFox; /iaf ^ >  
C~% 1w%nn  
~a9W3b4j  
public class TestMethod { T1WWK'  
*iA4:EIP  
]e?x# <S  
public TestMethod() -V.d?A4"  
{ ///xx/weblogic60b2_win.exe !D^c3d  
try{ `{v?6:G:Q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); BqK(DH^9N  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8jlLUG:g  
SiteFileFetch fileFetch = new SiteFileFetch(bean); yY).mxRN  
fileFetch.start(); ;E^K.6  
} ZJW[?V\5=  
catch(Exception e){e.printStackTrace ();} >/$Fh:R-  
/#NYi,<{X  
W!Gdf^Yy<  
} (.Y/  
rh*sbZ68>E  
1Tp/MV/>  
public static void main(String[] args) $g9**b@  
{ oPf)be| #  
new TestMethod(); KL,/2 (  
} _*M42<wcO  
} g`^X#-!(  
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