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http断点续传简单实现(java)

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/* 1@=po)Hnp  
**SiteFileFetch.java C2)2)  
*/ k-""_WJ~^  
package NetFox; C"]^Q)aJN  
import java.io.*; sUm'  
import java.net.*; W+1^4::+  
B,fo(kG  
& "B=/-(  
public class SiteFileFetch extends Thread { Nl1D o:PY  
D7qOZlX16  
.XhrCi Z  
SiteInfoBean siteInfoBean = null; //文件信息Bean 4I5Y,g{6+  
long[] nStartPos; //开始位置 Ld-_,-n  
long[] nEndPos; //结束位置 IdxzE_@  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W'TaBuCb  
long nFileLength; //文件长度 G<;*SYAb  
boolean bFirst = true; //是否第一次取文件 S>; 5[l 4  
boolean bStop = false; //停止标志 9 JK Ew  
File tmpFile; //文件下载的临时信息 HLHz2-lI  
DataOutputStream output; //输出到文件的输出流 x3eZ^8^1}  
f'3$9x  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) VgS_s k  
public SiteFileFetch(SiteInfoBean bean) throws IOException rk)`\=No  
{ ,wdD8ZT'Ip  
siteInfoBean = bean; 9@)O_@=  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ##4HYQ%E  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); t<?,F  
if(tmpFile.exists ()) Y:)e(c"A  
{ B^jc3 VsR  
bFirst = false; fa2kG&, _  
read_nPos(); S`m]f5u|  
} U|j`e5)  
else "8zDbdK  
{ ^L&iR0  
nStartPos = new long[bean.getNSplitter()]; w^0nqh  
nEndPos = new long[bean.getNSplitter()]; K,:N   
} 63x?MY6  
ges J/I  
'(jG[ry&T  
Lbb0_-']  
} QnX(V[  
%C_HXr@  
',5 ky{  
public void run() =zs`#-^8  
{ n>U5R_T  
//获得文件长度 2jCfT>`3  
//分割文件 KdbHyg<4  
//实例FileSplitterFetch H~z`]5CN  
//启动FileSplitterFetch线程 PRE|+=w$  
//等待子线程返回 VBcPu  
try{ QUQ'3  
if(bFirst) `,*5wBC  
{ 1D!<'`)AY  
nFileLength = getFileSize(); I ?.^ho  
if(nFileLength == -1) LvYB7<zk>  
{ m/EFHS49  
System.err.println("File Length is not known!"); 4#hSJ(~7S  
} J`1rJ  
else if(nFileLength == -2) V,N%;iB}  
{ t}tEvh  
System.err.println("File is not access!"); G?Hdq;  
} ~gRf:VXX=_  
else jsi!fx2Rm  
{ @bP)406p  
for(int i=0;i<nStartPos.length;i++) i,9)\1R  
{ 7EO_5/cY  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); cq4I pe  
} >Wg hn:^  
for(int i=0;i<nEndPos.length-1;i++) ls)%c  
{ {h`uV/5@`  
nEndPos = nStartPos[i+1]; >`ZyG5  
}  | (_  
nEndPos[nEndPos.length-1] = nFileLength; HT1!5  
} \=0Vi6!Mc  
} ZO c)  
o J;$sj  
rguCp}r  
//启动子线程 Gjo`&#  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u!qP  
for(int i=0;i<nStartPos.length;i++) h>OfOx/{q9  
{ 2x0<&Xy#P  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hODWB&b  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'Ne@e)s9  
nStartPos,nEndPos,i); 0}q uG^%_  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aPbE;" f  
fileSplitterFetch.start(); Q^txVUL  
} dL )<% o  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), LTx,cP  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0F><P?5  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \.#>=!Ie  
nEndPos = " + nFileLength); )U{Qj5W+F  
// fileSplitterFetch[nPos.length-1].start(); NGOfb  
K~uq,~  
-5QZJF2~  
//等待子线程结束 = 6\^%  
//int count = 0; )~ h}  
//是否结束while循环 d <JM36j?  
boolean breakWhile = false; :1KpGj*F  
(,Df^4%7  
< F+l  
while(!bStop) C/6V9;U  
{ QbpFE)TYJ|  
write_nPos(); D]Xsvv #  
Utility.sleep(500); 5 5c|O  
breakWhile = true; w %BL  
M}v/tRI  
54li^   
for(int i=0;i<nStartPos.length;i++) +pn N!:q  
{ cY.bO/&l  
if(!fileSplitterFetch.bDownOver) ><HE;cVg?  
{ l}sjD[2  
breakWhile = false; W'+:'_{j:  
break; n3 r3"~i  
} j Dv{/ )  
} _8UDT^?8,  
if(breakWhile) u.Tcg^v  
break; L.0mk_&  
]G< Vg5  
v9O~@v{=  
//count++; Q%mB |i|  
//if(count>4) ':m,)G5&  
// siteStop(); m<"WDU?y;  
} HYSIN^<oy  
tr}Loq\y  
*CTlOy  
System.err.println("文件下载结束!"); `t'W2X  
} { W{]L:  
catch(Exception e){e.printStackTrace ();}  0$fpIz  
} N `F~n%N  
7X'u6$i  
R2]Z kg  
//获得文件长度 dP]\Jo=Yh  
public long getFileSize() `W/>XZl+t  
{ ]R9HyCl&a6  
int nFileLength = -1; 5 -RsnF  
try{ 6h,(wo3Y  
URL url = new URL(siteInfoBean.getSSiteURL()); j@uOOhy  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e@* EzvO  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?\s+EE&-  
K':;%~I  
o@i#|kx,  
int responseCode=httpConnection.getResponseCode(); ?[Q3q4  
if(responseCode>=400) yx&51G$  
{ ;8{4!S&b  
processErrorCode(responseCode); C-6F]2:  
return -2; //-2 represent access is error lHe{\N[C  
} $ Kncvu  
Zu("#cA.H  
c?&X?<  
String sHeader; s6.M\^  
@Y<bwv  
;{tj2m,  
for(int i=1;;i++) |My4SoOF  
{ !1{e|p 7  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %Ax3;g#  
//Utility.log(in.readLine()); 3e;^/kf<9  
sHeader=httpConnection.getHeaderFieldKey(i); Vi]W|bP  
if(sHeader!=null) Rww{:R  
{ kN4{13Qs*  
if(sHeader.equals("Content-Length")) 6'G6<8 >-  
{ .|b$NM  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K<ft2anY5  
break; n+q!l&&  
} OJ5#4qJ[  
} !()$8  
else wL 4dTc  
break; }Nm#q@o$P  
} jiS_G%G  
}  fc-iAj  
catch(IOException e){e.printStackTrace ();} %Iv,@}kvT+  
catch(Exception e){e.printStackTrace ();} S:oi< F  
,J^b0@S  
"haL  
Utility.log(nFileLength); qr4pR-Gdr  
yvH A7eq*"  
YS@ypzc/  
return nFileLength; J1I ;Jgql(  
} ERE)A-8  
X"e5 Y!:M-  
dP<=BcH>f  
//保存下载信息(文件指针位置) EGzzHIZ`!  
private void write_nPos() ( b~T]3Es  
{ 6qoyiT%P&  
try{ [] `&vWZ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); QaS7z#/?.  
output.writeInt(nStartPos.length); h WtVWVNL  
for(int i=0;i<nStartPos.length;i++) 2ZMb<b4H  
{ 33ef/MElD$  
// output.writeLong(nPos); 6dN7_v)  
output.writeLong(fileSplitterFetch.nStartPos); -vR5BMy=  
output.writeLong(fileSplitterFetch.nEndPos); '\ey<}?5V  
} B9$jSD  
output.close(); lpeEpI/gM  
} TKY*`?ct  
catch(IOException e){e.printStackTrace ();} ,t9^j3Ixg  
catch(Exception e){e.printStackTrace ();} y 4I6  
} q6SXWT'Sa  
MVTMwwO\[  
IE&!YP(U(  
//读取保存的下载信息(文件指针位置) Vp*KfS]  
private void read_nPos() v99B7VH4  
{ uRRQyZ  
try{ ,PuL{%PXu  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r1.nTO%  
int nCount = input.readInt(); $.PuK~}  
nStartPos = new long[nCount]; 'y2nN=CN  
nEndPos = new long[nCount]; uK$9Ll{lk  
for(int i=0;i<nStartPos.length;i++) q[`]D7W "  
{ !tMuuK?IL=  
nStartPos = input.readLong(); BJB^m|b)  
nEndPos = input.readLong(); g-H N  
} P+PR<ZoI{f  
input.close(); Xti[[sJ  
} K/b_22]CC  
catch(IOException e){e.printStackTrace ();} s(%oTKjt  
catch(Exception e){e.printStackTrace ();} ;8*`{F[  
} q<[_T  
iZNts%Y]  
{VvqO7A  
private void processErrorCode(int nErrorCode) -UdEeZz.  
{ [}/LD3  
System.err.println("Error Code : " + nErrorCode); u7\J\r4,+  
} (?`kYTw7g'  
{QZUDPPR  
*4xat:@{{  
//停止文件下载 SHbtWq}T  
public void siteStop() ~\.w^*$#Y  
{ M?:c)&$]D  
bStop = true; OK6] e3UO  
for(int i=0;i<nStartPos.length;i++) ;04Ldb1{|3  
fileSplitterFetch.splitterStop(); e8]\U/  
8V)^R(\;  
r>"   
} *x])Y~oQ  
} ?^$MRa:D  
//负责部分文件的抓取 oA7;.:3  
**FileSplitterFetch.java V7[zAq  
*/ LbG_z =A  
package NetFox; J'fQW<T4wU  
jbu8~\"  
8p9bCE>\  
import java.io.*; #u"k~La  
import java.net.*; j>x-"9N  
T[uiPs /xD  
S<u-n8bv  
public class FileSplitterFetch extends Thread { =p?WBZT|:  
4EZ9hA9+  
n9A7K$ZD@  
String sURL; //File URL bQP{|  
long nStartPos; //File Snippet Start Position ->O2I?  
long nEndPos; //File Snippet End Position W#BM(I  
int nThreadID; //Thread's ID x~{;TZa[I  
boolean bDownOver = false; //Downing is over 5ish\"  
boolean bStop = false; //Stop identical {%{ `l-  
FileAccessI fileAccessI = null; //File Access interface PSVc+s[Q+V  
`v}%33$hA  
8J~1-;  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !Mim@!5M  
{ &f^l ^K 5:  
this.sURL = sURL; Jn3 An  
this.nStartPos = nStart; *l;B\=KR  
this.nEndPos = nEnd; $Y_i4(  
nThreadID = id; 1jPJw3"3h  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &S]@Ot<z  
} F;[T#N:~  
7.@TK&  
%]6~Eq%s  
public void run() @@rEs40  
{ ,0~9dS   
while(nStartPos < nEndPos && !bStop) P=&o%K,:f  
{ <Ib[82PU  
vab@-=%k  
tBT<EV{ G  
try{ d&u]WVU  
URL url = new URL(sURL); o{EC&-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iMFgmM|  
httpConnection.setRequestProperty("User-Agent","NetFox"); E%v?t1>/  
String sProperty = "bytes="+nStartPos+"-"; Wg0g/  
httpConnection.setRequestProperty("RANGE",sProperty); Ns0cgCrhX  
Utility.log(sProperty); )+"'oY$]}  
|t) }VM%  
!x>%+&c>k  
InputStream input = httpConnection.getInputStream(); iNWo"=J  
//logResponseHead(httpConnection); \uq/x^?yo  
~7t$MF.  
,4,V4 N  
byte[] b = new byte[1024]; /K{9OT@>  
int nRead; ""h)LUrl  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )a3J9a;ZS0  
{ L%$|^T=%  
nStartPos += fileAccessI.write(b,0,nRead); E+tB&  
//if(nThreadID == 1) RJH,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .8uz 6~  
} bY2 C]r(n  
_s$_Sa ;  
RZ7( J  
Utility.log("Thread " + nThreadID + " is over!"); .tmiQ.  
bDownOver = true; N!x =eC  
//nPos = fileAccessI.write (b,0,nRead); 6uKMCQ=h  
} e9Pk"HHl  
catch(Exception e){e.printStackTrace ();} ~-t>z  
} UMp/ \&0  
} A@D2+fS  
e)IpPTj#  
ym/fFm6h  
//打印回应的头信息 KdUnD4d  
public void logResponseHead(HttpURLConnection con) rVa?JvDO=  
{ |?,[@z _,  
for(int i=1;;i++) 7`H 1f]d  
{ 6^n0[7  
String header=con.getHeaderFieldKey(i); k@D0 {z  
if(header!=null) I3:[= ,5  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (?kl$~&|  
Utility.log(header+" : "+con.getHeaderField(header)); l|+BC  
else ?D)<,  
break; TLf9>= OVh  
} x]{E)d"!  
} qG/fE'(j&  
pdb1GDl0q  
CGP3qHrXt  
public void splitterStop() Bo+DJizu  
{ _l], "[d  
bStop = true; T y@=yA17  
} ,j ',x\  
).HDru-2  
*tX{MSYW  
} 9Sq%s&  
%q322->Z  
hv$m4,0WB  
/* f8<o8*`7  
**FileAccess.java R%H$%cnj  
*//文件访问(定位,写) b7\ cxgRq  
package NetFox; \zkw2*t  
import java.io.*; $hVYTy~}  
]PP:oriWl  
" ;w}3+R  
public class FileAccessI implements Serializable{ MfBdNdox7  
gbStAr.  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A +w v-~3  
RandomAccessFile oSavedFile; FNQX7O52  
long nPos; {8EW)4Hf  
~; OYtz  
25|8nfeC5  
public FileAccessI() throws IOException @l(vYJ:f  
{ T\# *S0^  
this("",0); Ekm7 )d$  
} 6V+ qnUk  
nCvPB/-  
]43bere  
public FileAccessI(String sName,long nPos) throws IOException (5Tvsw`  
{ }^K/?dM  
oSavedFile = new RandomAccessFile(sName,"rw"); }T0K^Oe+eS  
this.nPos = nPos; p(m1O70 C  
oSavedFile.seek(nPos); qy!Ou3^  
} YIp-Y}6  
wj|x:YZ*  
>7U>Yh  
public synchronized int write(byte[] b,int nStart,int nLen) j#6|V]l  
{ &MgeYpd  
int n = -1; \hP=-J[~C  
try{ jN+N(pIi.o  
oSavedFile.write(b,nStart,nLen); X7|.T0{=x  
n = nLen; QI[}(O7#6  
} 0gF!!m  
catch(IOException e) cM&'[CI  
{ HT_TP q  
e.printStackTrace (); Y/8K;U|  
} 2o[IHO]  
GfyX'(ge  
|\uYv|sT  
return n; bv dR"G  
} Er:?M_ev  
=S]a&*M  
Px'!;  
} F[7x*-NO-  
` e{BId  
B7-RU<n  
/* 9f}XRz  
**SiteInfoBean.java dj[apuiF  
*/ 4*UP. r@  
package NetFox; :PnSQjV:  
8C.!V =@\  
I]J*BD#n.  
public class SiteInfoBean { /=#~  
!m{2WW-  
9-bG<`v\E  
private String sSiteURL; //Site's URL Lg`Jp&Kg  
private String sFilePath; //Saved File's Path , Ut Hc]  
private String sFileName; //Saved File's Name [ij,RE7,T  
private int nSplitter; //Count of Splited Downloading File g>7Y~_}  
{lzG*4?  
gw3NS8 A+  
public SiteInfoBean() z]$j7dp  
{//nSplitter的缺省值为5  D\T!4q'Q  
//default value of nSplitter is 5 X`\:_|  
this("","","",5); qGPb  
} %bX0 mN  
MdhT!?  
R/<=mZ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,i ++fOnQ  
{ L,-u.vV  
sSiteURL= sURL; JAn1{<Ky  
sFilePath = sPath; ]s|lxqP  
sFileName = sName; G\Q9IcJ0dY  
this.nSplitter = nSpiltter; Inuc(_I  
?Nl"sVCo  
>e8JK*Blz  
} bv\ A,+  
0B0G2t&hr  
?SUQk55w  
public String getSSiteURL() T2Z[AvNXFk  
{ <e6=% 9  
return sSiteURL; {=At#*=A  
} }NX\~S"  
liNON  
Q.(51]'  
public void setSSiteURL(String value) 1BD6 l2y  
{ + >sci  
sSiteURL = value; VvgN3e[  
} $M]%vG  
A"/aGCG0z  
>7>7/7=O  
public String getSFilePath() %9c|%#3  
{ +X!+'>  
return sFilePath; .9\Cy4_qSd  
} Jc~E"x  
J7a-CI_Tf  
~! Lw1]&  
public void setSFilePath(String value) .w FU:y4r  
{ z(d4)z 8'6  
sFilePath = value; lfMH1llx  
} .g-3e"@  
{u]CHN`%Z  
TSyzdnMvz  
public String getSFileName() o#d$[oa  
{ L/k40cEI^z  
return sFileName; WX*cICb5  
} mvf _@2^  
hrlCKL&  
O~Uw&Bq  
public void setSFileName(String value) _XN~@5elrC  
{ F|]rA*2u  
sFileName = value; 9c5!\m1  
} oBUh]sR{.  
&8Wlps`  
]b\WaS8I  
public int getNSplitter() Rk[8Bd?  
{ iH _"W+dq  
return nSplitter; *7vue"I*Z  
} ^X;JT=r  
.xv ^G?GG  
Z)v)\l9d  
public void setNSplitter(int nCount) 0P:F97"1,  
{ 'j /q76uXV  
nSplitter = nCount; <<BQYU)Ig  
} lIy/;hIc  
} cJ4S!  
)K.R\]XR  
uf0^E3H  
/* V9$-twhu  
**Utility.java :A$wX$H01  
*/ ArdJ."  
package NetFox; 8c?8X=|D7  
Alh?0Fk3)  
v j@V !j?  
public class Utility { ) hPVX()O!  
s{%fi*  
6(5c7R#  
public Utility() }` @?X"r  
{ ks^|>  
0- Yeu5A  
$pBr &,  
} ^k9rDn/AW  
\1khyF'  
//线程睡眠 ]*h&hsS 0  
public static void sleep(int nSecond) |x[$3R1@  
{ r2)pAiTM*  
try{  bn|DRy  
Thread.sleep(nSecond); A@ { !:_55  
} ][ N) 2_^M  
catch(Exception e) /op/g]O}  
{ RQJ9MG w  
e.printStackTrace (); G32_FQ$ b  
} n=SzF(S[M  
} :6sGX p  
'XME?H:q a  
//日志 z7$}#)Z7  
public static void log(String sMsg) 6 cr^<]v!  
{ Uc>LFX& -B  
System.err.println(sMsg); o[H\{a>  
} |<2JQ[]  
iqlVlm>E  
IM|Se4;x  
public static void log(int sMsg) @%keTTZ  
{ O^Dc&w  
System.err.println(sMsg); m>+A*M8  
} Bzwx0c2VY8  
} qIUC2,&g  
zVn*!c  
GHqBnE{B  
/* vzQyE0T/  
**TestMethod.java @Yb Z 8Uc  
*/ Hm<M@M$aG  
package NetFox; -<12~HKK::  
-{r!M(47  
,$SkaTBe  
public class TestMethod { mKMGdN~  
jFS 'I*1+  
se"um5N-  
public TestMethod() (h%|;9tF  
{ ///xx/weblogic60b2_win.exe *%]+sU  
try{ iu+zw[f  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QDl)92z  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %j!z\pa  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?\l!]vu*  
fileFetch.start(); ^S:cNRSW"  
} <(ubZ  
catch(Exception e){e.printStackTrace ();} sd]0Hx[  
{m>~`   
sL;z"N@PK  
} SIJ# ?0,  
V&$  J;  
t P At?  
public static void main(String[] args) G<Th<JF)Q  
{ k^~@9F5k  
new TestMethod(); gA|!$ EAM  
} ~&vA_/M  
} `mQP{od?"?  
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