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http断点续传简单实现(java)

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/* oGJ*Rn)Z  
**SiteFileFetch.java zY1s7/$ i  
*/ RrO0uadmn  
package NetFox; 5i4V5N>3  
import java.io.*; 77xq/c[)  
import java.net.*; i[2bmd!H  
`*" H/QG  
(zs4#ja2,  
public class SiteFileFetch extends Thread { p2Dh3)&  
< g3du~  
rQcRjh+E H  
SiteInfoBean siteInfoBean = null; //文件信息Bean >d{dZD}  
long[] nStartPos; //开始位置 5e#&"sJ.1  
long[] nEndPos; //结束位置 8R\>FNk;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 \]T=j#.S$  
long nFileLength; //文件长度 *^@#X-NG  
boolean bFirst = true; //是否第一次取文件 2&.n  
boolean bStop = false; //停止标志 =sE2}/g  
File tmpFile; //文件下载的临时信息 . 0 s[{x  
DataOutputStream output; //输出到文件的输出流 b46[fa   
hgweNRTh!  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) .# 6n  
public SiteFileFetch(SiteInfoBean bean) throws IOException \K?(  
{ c Pq Dsl3  
siteInfoBean = bean; X-)RU?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .:{h{@a  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); r=~WMDCz@  
if(tmpFile.exists ()) 4{;8:ax&w  
{ %NT`C9][  
bFirst = false; 1p7cv~#95  
read_nPos(); Nm6Z|0S  
} VqK%^  
else 8_a$kJJ2  
{ + mfe*'AU  
nStartPos = new long[bean.getNSplitter()]; Uvjdx(fY[a  
nEndPos = new long[bean.getNSplitter()]; \~@[QGKN  
} *xE"8pN/  
.3lGX`d{  
Mw"xm9(Q  
{W5ydHXy  
} j+DE|Q&]I  
bA@ /B'  
H96BqNoO  
public void run() RzA2*]%a  
{ K*R)V/B/l  
//获得文件长度 `fBG~NDw  
//分割文件 <w0NPrS]  
//实例FileSplitterFetch -{X<*P4p  
//启动FileSplitterFetch线程 ixIV=#  
//等待子线程返回 |SGgy|/a#  
try{ (Wd_G-da  
if(bFirst) << 3 a<I  
{ :+~KPn>w5  
nFileLength = getFileSize(); W@I 02n2 H  
if(nFileLength == -1) q>_vE{UB  
{ =n@F$/h  
System.err.println("File Length is not known!"); aO8c h  
} D JLiZS  
else if(nFileLength == -2) vkd[: CC  
{ B4]AFRI  
System.err.println("File is not access!"); , CJAzGBS  
} )W&o?VRfO  
else GWF/[%  
{ qbS'|--wH  
for(int i=0;i<nStartPos.length;i++) &/Eg2  
{ QS3U)ZO$@  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]43alf F#  
} uYFMv=>j  
for(int i=0;i<nEndPos.length-1;i++) d"#gO,H0  
{ C%giv9a  
nEndPos = nStartPos[i+1]; wYZT D*A2h  
} u~s Sk  
nEndPos[nEndPos.length-1] = nFileLength; iO!27y  
} weNzYMf%  
} "pt+Fe|@c;  
Dt.0YKF  
aSc{Ft/O  
//启动子线程 6!P`XTTE  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yiiyqL*E  
for(int i=0;i<nStartPos.length;i++) T}C2e! _O  
{ 7#QLtU  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OnZF6yfN=3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a%Uw;6|{  
nStartPos,nEndPos,i); }$o*  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1hl]W+9  
fileSplitterFetch.start(); B\\6#  
} Lp_$?MCD.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `/z_rqJ0CL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k@#5$Ejc2  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EE+`i%  
nEndPos = " + nFileLength); UQ/qBbn  
// fileSplitterFetch[nPos.length-1].start();  s[3e=N  
$:Rn;  
FY$fV"s  
//等待子线程结束 gX[|;IZ0o  
//int count = 0; 4|`Yz%'  
//是否结束while循环 )h#]iGVN}  
boolean breakWhile = false; h@=7R  
puOC60zI  
K*~]fy  
while(!bStop) _@Y"$V]=Vt  
{ n5|l|#c$N  
write_nPos(); COR;e`%,  
Utility.sleep(500); CdY8 #+"  
breakWhile = true; ]<1HM"D  
!lAD q|$  
_2b9QP p  
for(int i=0;i<nStartPos.length;i++) !BDUv(  
{ 2K;#Evn'j  
if(!fileSplitterFetch.bDownOver) Z1M>-[j)  
{ iZaeoy  
breakWhile = false; "NDxgJ%J35  
break; X 7=fX~s  
} *I0Tbc O  
} J1bA2+5.*e  
if(breakWhile)  ?>af'o:  
break; &-M]xo ^  
f|U0s  
baee?6  
//count++; +iy7e6P  
//if(count>4) ` @8`qXg  
// siteStop(); X APYpBgm  
} ~4\,&HH  
VU|;:  
Wqra8u#  
System.err.println("文件下载结束!"); oBA`|yW{U  
} D==Mb~  
catch(Exception e){e.printStackTrace ();} 5!Bktgk.  
} ' _dzcN,z  
K$H <}e3  
piOXo=9H.  
//获得文件长度 ,w{m3;]_%  
public long getFileSize() UNDi_6Dy   
{ XF}rd.K:  
int nFileLength = -1; q_ %cbAcD  
try{ $+cAg >  
URL url = new URL(siteInfoBean.getSSiteURL()); lv]quloT  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f6!D L<  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6 {}JbRNf  
HG%Z "d  
Tv5g`/e=Ej  
int responseCode=httpConnection.getResponseCode(); mf' ]O,  
if(responseCode>=400) ; dd Q/  
{ S_v(S^x6  
processErrorCode(responseCode); `Gd$:qV  
return -2; //-2 represent access is error !g>.i`  
} ]u#JuX  
&.Q8Mi aT  
|%1?3Mpn  
String sHeader; fQ+\;iAU  
cX:HD+wO  
u=r`t(Z1H  
for(int i=1;;i++) [Il~K  
{ /\Z J   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ""{|3XJe  
//Utility.log(in.readLine()); Wkzs<y"  
sHeader=httpConnection.getHeaderFieldKey(i); BI2; ex  
if(sHeader!=null) ~>5#5!}@*  
{ at|g%$%  
if(sHeader.equals("Content-Length")) :B|Dr v  
{ 7\XE,;4>  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9b;A1gu  
break; QvLZg  
} -"Q-H/qh  
} 9 [jTs3l:  
else 5,pSg  
break; 'Z&;uv,l  
} e-5?p~>  
} nmFC%p)4  
catch(IOException e){e.printStackTrace ();}  npp[@*~  
catch(Exception e){e.printStackTrace ();} 9bJQT'<R  
(\a6H2z8l  
^YvB9XN  
Utility.log(nFileLength); g~S)aU\:,  
kforu!C  
@kFu*"  
return nFileLength; FP^{=0  
} R?66b{O  
DJ@|QQ  
>TjJA #  
//保存下载信息(文件指针位置) AoaN22  
private void write_nPos() !@A#=(4R4  
{ fP HLXg5s  
try{ 7=XL!:P  
output = new DataOutputStream(new FileOutputStream(tmpFile)); %7hB&[ 5  
output.writeInt(nStartPos.length); J*fBZ.NO  
for(int i=0;i<nStartPos.length;i++) ILwn&[A0  
{ &<pKx!  
// output.writeLong(nPos); aj\nrD1  
output.writeLong(fileSplitterFetch.nStartPos); =~KsS }`1,  
output.writeLong(fileSplitterFetch.nEndPos); !yOeW0/2[  
} Avlz=k1*  
output.close(); C\ZkGX  
} !? 5U|  
catch(IOException e){e.printStackTrace ();} qTQ!jN  
catch(Exception e){e.printStackTrace ();} "xRBE\B  
} oslJC$cy'  
a`(a)9i  
q2rUbU_A(  
//读取保存的下载信息(文件指针位置) x]|+\1  
private void read_nPos() m~hoE8C$  
{ ULH0'@BJ  
try{ TBrGA E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }MbH3ufC  
int nCount = input.readInt(); U`|0 jJ  
nStartPos = new long[nCount]; v%{.A)  
nEndPos = new long[nCount]; %wptZ"2M  
for(int i=0;i<nStartPos.length;i++) \C^;k%{LV  
{ ra N)8w}-  
nStartPos = input.readLong(); qmy%J  
nEndPos = input.readLong(); z*$q8Z&7rg  
} ,m<H-gwa  
input.close(); dq1:s1  
} #-% A[7Cdp  
catch(IOException e){e.printStackTrace ();} X>YsQrK(ig  
catch(Exception e){e.printStackTrace ();} JwnQ0 e  
} RP5+d  
gk[{2HgN  
VdSv  
private void processErrorCode(int nErrorCode) WKz> !E%  
{ -u!FOD/  
System.err.println("Error Code : " + nErrorCode); %M|,b!eF  
} >>i@r@  
A5'NGt  
ORXm&z)  
//停止文件下载 wa=uUM_4u^  
public void siteStop() 3@Z#.FV~C[  
{ #@@Mxr'F  
bStop = true; _p-t<ytnh  
for(int i=0;i<nStartPos.length;i++) vsWHk7 9  
fileSplitterFetch.splitterStop(); h N2:d1f0  
wkqX^i7ls  
S [h];eM  
} %?^6).aEK  
} NLPkh,T:  
//负责部分文件的抓取 :j')E`#   
**FileSplitterFetch.java &!aAO(g  
*/ <s5qy-  
package NetFox; + Q=1AXe  
`LAR@a5i  
##Q/I|  
import java.io.*; [.hyZ}B  
import java.net.*; h_1T,f (  
 c gzwx  
uXDq~`S  
public class FileSplitterFetch extends Thread { g,o?q:FL  
'0y9MXRT  
"<_0A f]  
String sURL; //File URL iRg7*MQu  
long nStartPos; //File Snippet Start Position I):!`R.,  
long nEndPos; //File Snippet End Position DypFl M*  
int nThreadID; //Thread's ID %>-@K|:gS  
boolean bDownOver = false; //Downing is over N>(g?A; Z+  
boolean bStop = false; //Stop identical :ISMPe3'  
FileAccessI fileAccessI = null; //File Access interface P&m\1W(  
7XKY]|S,'  
kg@>;(V&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }g#&Q0  
{ t5)+&I2  
this.sURL = sURL; Hqnxq  
this.nStartPos = nStart; c|F[.;cR  
this.nEndPos = nEnd; XNQAi (!GS  
nThreadID = id; [V'QrcCF  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^Q*atU  
} OO?]qZa1  
Xc"&0v%;#  
[aI]y =v  
public void run() lrf v+  
{ B+^(ktZp@  
while(nStartPos < nEndPos && !bStop) \AL f$88>@  
{ h~{aGo  
N]KxAttt  
/%_OW@ ?  
try{ '13ZX:  
URL url = new URL(sURL); (b'B%rFO  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [7_56\G4  
httpConnection.setRequestProperty("User-Agent","NetFox"); |#6QThK  
String sProperty = "bytes="+nStartPos+"-"; upj]6f"(  
httpConnection.setRequestProperty("RANGE",sProperty); .h0b~nI>>  
Utility.log(sProperty); &>e-(4Xu  
[mEql,x3  
U=hlu  
InputStream input = httpConnection.getInputStream(); Y"-^%@|p  
//logResponseHead(httpConnection); =+ t^f  
s"Pf+aTW  
n,B,"\fw  
byte[] b = new byte[1024]; >^XBa*4;Y  
int nRead; P/EM :  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J|'7_0OAx  
{ F u&EhGm6  
nStartPos += fileAccessI.write(b,0,nRead); L\y;LSTU  
//if(nThreadID == 1) 6c^e\0q  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /axIIfx-  
} ui(^k $  
s'kDk2r  
%Y!Yvw^&P(  
Utility.log("Thread " + nThreadID + " is over!"); /dv<qp  
bDownOver = true; el:9wq  
//nPos = fileAccessI.write (b,0,nRead); 5@^ dgq  
} bdGIF'p%  
catch(Exception e){e.printStackTrace ();} [D*UT#FM  
} @as"JAN  
} kcb.Wz~=  
JyR/1 W  
R+&jD;U{  
//打印回应的头信息 Oft4- 4$E  
public void logResponseHead(HttpURLConnection con) "M|zv  
{ hKzSgYxP=t  
for(int i=1;;i++) tv!_e$CR  
{ a'!zG cT  
String header=con.getHeaderFieldKey(i); Qt vYv!  
if(header!=null) [HCAmnb  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); detwa}h[0  
Utility.log(header+" : "+con.getHeaderField(header)); f4L`.~b'hb  
else TEDAb >  
break; KiJT!moB  
} O(+phRwJ  
} }:Z#}8  
H,N)4;F<c  
=m5SK5vLKT  
public void splitterStop() gn3jy^5  
{ Nbp!teH6  
bStop = true; ?B :a|0pf  
} 'Ysx=  
R'S0 zp6  
hAHq\  
} +[5.WC7J  
I4&::y^ C  
F'hHK.tT  
/* 8T(e.I  
**FileAccess.java P;k0W>~k  
*//文件访问(定位,写) z )HD`Ho  
package NetFox; h,Q3oy\s1  
import java.io.*; QR1{ w'c  
d> {nQF;c  
PssMTEf  
public class FileAccessI implements Serializable{ 7EXI6jGJ|  
)c8j}  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 otk}y8  
RandomAccessFile oSavedFile; U#3J0+!  
long nPos; sP ls zC[  
+|tC'gCnV  
N5 $c]E  
public FileAccessI() throws IOException =+AS/Jq  
{ Vb9',a?#n  
this("",0); .nyfYa+  
} 1&e} ms  
=C~/7N,lW]  
b!)<-|IK  
public FileAccessI(String sName,long nPos) throws IOException TC<@e<-%Sq  
{ C:Hoq(  
oSavedFile = new RandomAccessFile(sName,"rw"); Zfyo-Wk  
this.nPos = nPos; qG<$Ajiin  
oSavedFile.seek(nPos); &gjF4~W]  
} qbv#I;  
q `pP$i:  
|^A;&//  
public synchronized int write(byte[] b,int nStart,int nLen) .jj$Kh q]  
{ QR>gt;  
int n = -1; U*3uq7  
try{ 5< ja3  
oSavedFile.write(b,nStart,nLen); zL\OB?)5J  
n = nLen; *6} N =Z  
} hcyM6:}  
catch(IOException e) /c,(8{(O  
{ -=(!g&0  
e.printStackTrace (); Dq)j:f#QM  
} z`\F@pX%wC  
|m2X+s9  
DG?"5:Zd  
return n; Ps 8%J;  
} CP6LHkM9  
Qci4J  
{uHU]6d3qy  
} =KR NvW  
f aLtdQi  
b?Ki;[+O  
/* {Lm~r+ U  
**SiteInfoBean.java &\Amn?Iq  
*/ 8HP6+c%  
package NetFox; 6,9o>zT%H  
~j<+k4I~  
3"P }n  
public class SiteInfoBean { Yh>]-SCw  
1 CHeufQ  
Ry|!pV  
private String sSiteURL; //Site's URL 8KRba4[  
private String sFilePath; //Saved File's Path f/V 2f].  
private String sFileName; //Saved File's Name 7P9=)$(EH  
private int nSplitter; //Count of Splited Downloading File ldp%{"ZZ  
L@gWzC~?Q  
LU9A#  
public SiteInfoBean() "70WUx(\t  
{//nSplitter的缺省值为5 W>O~-2  
//default value of nSplitter is 5 gmm|A9+tv  
this("","","",5); W]nSR RWco  
} |<GDUwC_;  
VP6ZiQ|  
yUp,NfS]o  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |M+<m">E  
{ rs~wv('  
sSiteURL= sURL; ObiT-D?)g  
sFilePath = sPath; g]c6& Y,#  
sFileName = sName; {\(L%\sV@  
this.nSplitter = nSpiltter; ]GRWnif  
3.qTLga|}  
lg b?)=  
} 3%E74 mOcD  
y>aZXa  
.<Zy|1 4  
public String getSSiteURL() c.j$9=XLBG  
{ ,JEF GI{  
return sSiteURL; D)d~3`=#  
} >>5NX"{  
;W^o@*i{>  
#cCL.p"]  
public void setSSiteURL(String value) u5Ftu?t  
{ >2Kh0rIH  
sSiteURL = value; VL*ovD%-  
} Et/&^&=\-  
!Uq^7Mw  
@0SC"CqM  
public String getSFilePath() TEaJG9RU>v  
{ uNHF'?X  
return sFilePath; R>(@Z M&  
} 1Y]TA3:  
J52 o g4l  
 0gfA#|'  
public void setSFilePath(String value) 7=DjI ~  
{ Y k5 }`d!:  
sFilePath = value; 48*Do}l]  
} LH@j8YB5u  
Yx>"bv  
A$a1(8H  
public String getSFileName() n2fbp\I  
{ <Ce2r"U1e  
return sFileName; $]A/ o(  
} !OuWPH. :  
&Y^WP?HS  
yfC^x%d7G  
public void setSFileName(String value) 1hziXC0WY  
{ th&[Nt7  
sFileName = value; ;asP4R=  
} Q J7L7S  
l!g]a2x*  
$.[#0lCI  
public int getNSplitter() kVy\b E0o  
{ a@0BBihz  
return nSplitter; 6%VV,$p  
} gw}Mw  
~mR'Q-hi<  
Z>^pCc\lH  
public void setNSplitter(int nCount) `2PLWo  
{ Ed ,D8ND  
nSplitter = nCount; 4M^G`WA}t9  
} 1 %,a =,v  
} b/Xbs0q  
ME=/|.}D<  
Vl2XDkhq  
/* Rh>}rGvCUN  
**Utility.java Ey4z.s'-l  
*/ V@\%)J'g  
package NetFox; @`,1:  
-%I2[)F<  
B0ndcB-  
public class Utility { QQV~?iW{~  
izx#3u$P  
X 51Yfr  
public Utility() iT)z_  
{ T0]*{k(FR  
]7/ b/J  
eVM/uDD  
} dF~8XYo  
>~Qr  
//线程睡眠 /mK?E5H'r1  
public static void sleep(int nSecond) &zuG81F6  
{ KR%{a(V;7  
try{ '_$uW&{NI  
Thread.sleep(nSecond); h)Ff2tX  
} !0dNQ[$82  
catch(Exception e) A+UU~?3y  
{ Vo"RO$%ow*  
e.printStackTrace (); ^'ryNa;"  
} Q pmsOp|  
} s\P2Bp_{  
Ck /F9(  
//日志 G7CG~:3h+  
public static void log(String sMsg)  ]$,UPR/3  
{ UA yC.$!  
System.err.println(sMsg); m{7(PHpw  
} Ogp"u b8  
\~5C7^_  
S*sT] J`!  
public static void log(int sMsg) !Lh^oPT"I  
{ E.U_W  
System.err.println(sMsg); O/!bG~\Y  
} ]7rj/l$ u  
} 8zBWIi  
3ux0 Jr2yT  
:hI@AA>g  
/* QzAK##9bfa  
**TestMethod.java =dx1/4bZl|  
*/ ykFJ%sw3X  
package NetFox; %/rMg"f:  
V._(q^  
Ii:>xuF&  
public class TestMethod { j6g[N4xr  
A mwa)  
{H{X[p8  
public TestMethod() #-GJ&m8  
{ ///xx/weblogic60b2_win.exe XduV+$ 03  
try{ E(i[o?  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EFc-foN  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g9Yz*Nee<  
SiteFileFetch fileFetch = new SiteFileFetch(bean); f +hjC  
fileFetch.start(); 8Y#\xzod  
} "{D|@Bc  
catch(Exception e){e.printStackTrace ();} h48SItY  
E!O\87[  
{$1J=JbE  
} >G'SbQ8  
jU5}\oP@  
Q(o!iI:Gts  
public static void main(String[] args) g38&P3/  
{ ,p9i%i  
new TestMethod(); I=!rbF;Z  
} l]]l  
} mP(kcMT "  
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