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http断点续传简单实现(java)

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/* .m?~TOR  
**SiteFileFetch.java {^W,e ^:  
*/ skz]@{38  
package NetFox; f~FehN7  
import java.io.*; `z_7[$\~  
import java.net.*; m0Syxb  
O->eg  
Fnpn_O XlH  
public class SiteFileFetch extends Thread { X u):.0I  
4Aew )   
n\-_i2yy  
SiteInfoBean siteInfoBean = null; //文件信息Bean CFm1c1%Hg  
long[] nStartPos; //开始位置 HF: T]n,  
long[] nEndPos; //结束位置 0f%:OU5Y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 =&pN8PEn\  
long nFileLength; //文件长度 cN7z(I0[  
boolean bFirst = true; //是否第一次取文件 nV3 7` I  
boolean bStop = false; //停止标志 ;p 5v3<PC  
File tmpFile; //文件下载的临时信息 *Qx|5L!_  
DataOutputStream output; //输出到文件的输出流 r0deBRM  
\( <{)GpBi  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) WKl'  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5TneuGD  
{ L"h@`3o|  
siteInfoBean = bean; 3DAGW"F  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); `b")Bx|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); SrtVoe[  
if(tmpFile.exists ()) /iy*3P,`  
{ I'9s=~VfY,  
bFirst = false; 8Wx@[!  
read_nPos(); {[5L96RH%  
} _S2^;n?  
else (oitCIV  
{ k,R~oSA'n  
nStartPos = new long[bean.getNSplitter()]; !@Sf>DM"  
nEndPos = new long[bean.getNSplitter()]; te*Y]-&I|/  
} q 9brpbg_  
5Ue^>8-  
rrY{Jf9>  
R;E"Qdt  
} Gr#rM/AfCK  
,AbKxT f2  
{?f^  
public void run() _%Jl&0%q  
{ "26B4*  
//获得文件长度 dI0bTw|s/  
//分割文件 \ ~LU 'j  
//实例FileSplitterFetch rF'^w56  
//启动FileSplitterFetch线程 {1@4}R4  
//等待子线程返回 *%N7QyO`I  
try{ c_z/At;4  
if(bFirst) 7 xp1\j0  
{ pl#o!j(i  
nFileLength = getFileSize(); 6PJJ?}P^1  
if(nFileLength == -1) CS;W)F  
{ ^KZAYB9C  
System.err.println("File Length is not known!"); g;-+7ViIr  
} g2aT`=&Z  
else if(nFileLength == -2) Xrj(,|  
{ @r/Id{pCI  
System.err.println("File is not access!"); :nKsZ1bX  
} pKxX{i1l  
else nG},v%  
{ DYAwQ"i;6  
for(int i=0;i<nStartPos.length;i++)  &6\r  
{ ?79SPp)oo  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 5xMA~I0c  
} 7TV>6i+7  
for(int i=0;i<nEndPos.length-1;i++) yul<n>X|  
{ Th~3mf #  
nEndPos = nStartPos[i+1]; i9&K  
} *X=@yB*aK  
nEndPos[nEndPos.length-1] = nFileLength; Y|m_qB^_  
} y/X:=d6"  
} zj9bSDVL(  
+Q SxYV  
yhSk"e'G  
//启动子线程 s<Ex"+  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FI?gT  
for(int i=0;i<nStartPos.length;i++) I 9{40_  
{ n&0mz1rw  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _[}G(<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }[>RxHd  
nStartPos,nEndPos,i); a1 4 6kq  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +,&m7L  
fileSplitterFetch.start(); V17>j0Ev$W  
} zB#_:(1qK  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nd$H 3sf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~rgf{oGz  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K/f>f;c  
nEndPos = " + nFileLength); MB ]#%g&  
// fileSplitterFetch[nPos.length-1].start(); !dfS|BA]  
Jh37pI  
a&$Zpf!!  
//等待子线程结束 Smq r q  
//int count = 0; o,?!"*EP  
//是否结束while循环 t{/:(Nu  
boolean breakWhile = false; =oo[ Eyr  
cm@jt\D  
Np.no$_  
while(!bStop) &u+yM D  
{ 5z1\#" B[  
write_nPos(); ZhhI@_sz  
Utility.sleep(500); vC{ h2A  
breakWhile = true;  FovE$Dj]  
^~ Ekg:`  
%==G+S{  
for(int i=0;i<nStartPos.length;i++) XMt u"K  
{ -Nsk}Rnk*  
if(!fileSplitterFetch.bDownOver) lq:]`l,6@  
{ 8K|J:[7  
breakWhile = false; 1pd 9s8CA  
break; 8h*t55  
} r0)JUc}Fyq  
} <_"B}c/2$  
if(breakWhile) c*N50%=4  
break; |w=Ec#)t4  
seu ~'s-  
?TIV2m^?  
//count++; <KKDu$W|T  
//if(count>4) Wt>J`  
// siteStop(); TG1P=g5h  
} tS?a){^:c  
qOW#Q:T  
"Owct(9  
System.err.println("文件下载结束!"); fZ[kh{|  
} ^`tk/#h\9F  
catch(Exception e){e.printStackTrace ();} +C'XS{K,#  
} `-4'/~G  
9Hu d|n  
-7k[Vg?  
//获得文件长度 C`dkD0_  
public long getFileSize() ;xfO16fNk  
{ zm3-C%:Bw  
int nFileLength = -1; YnSbw3U.I  
try{ ar Q)%W  
URL url = new URL(siteInfoBean.getSSiteURL()); <O.Kqk* nq  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +fM&su=wl  
httpConnection.setRequestProperty("User-Agent","NetFox");  #;`Oj  
M~als3  
88 {1mA,v  
int responseCode=httpConnection.getResponseCode(); VKy5=2&  
if(responseCode>=400) y`4{!CEyLW  
{ b6|Z"{TI _  
processErrorCode(responseCode); $`pd|K`  
return -2; //-2 represent access is error )u0O_R  
} e8oKn&  
S`=n&'  
[9OSpq  
String sHeader; dXl]Pe|v  
8"x9#kyU<3  
I FsE!oDs4  
for(int i=1;;i++) Y.>kO  
{ J@QdieW6  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _%{0?|=  
//Utility.log(in.readLine()); 'G8 ?'u_)  
sHeader=httpConnection.getHeaderFieldKey(i); *<IR9.~{6%  
if(sHeader!=null) 4@6 <  
{ fz3lR2~G  
if(sHeader.equals("Content-Length")) +Qs!Nhsq  
{ LKx`v90p  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vG~+r<:  
break; } ~F~hf>s  
} mZ7B<F[qV  
} -(9O6)Rs$  
else G6V/SaD  
break; 3 CM^j<9  
} [/cIUQ  
} [(ygisqt  
catch(IOException e){e.printStackTrace ();} mw4JQ\  
catch(Exception e){e.printStackTrace ();} *g_w I%l  
eLV.qLBUs  
Ns<?b;aK  
Utility.log(nFileLength); 8}BS2C%P  
W pN.]x  
RBE7485  
return nFileLength; +AoP{ x$Ia  
} =u=Kw R  
uE`r/=4  
NEV p8)w  
//保存下载信息(文件指针位置) XQ?fJWLU  
private void write_nPos() ^"x<)@X  
{ 'Jydu   
try{ >b48>@~bY  
output = new DataOutputStream(new FileOutputStream(tmpFile)); <bUXC@3W  
output.writeInt(nStartPos.length); z)}!e,7  
for(int i=0;i<nStartPos.length;i++) JoJukoy}F  
{ 6+3$:?  
// output.writeLong(nPos); ^m%52Tm h  
output.writeLong(fileSplitterFetch.nStartPos); u,o1{% O  
output.writeLong(fileSplitterFetch.nEndPos); . I==-|  
} -bS)=L  
output.close(); Fp%Ln(/m  
} sbnjy"Z%  
catch(IOException e){e.printStackTrace ();} dZ]Rqr _!  
catch(Exception e){e.printStackTrace ();} ,Dp0fauJ  
} rF] +,4  
{eQWO.C{  
Ur!~<4GO  
//读取保存的下载信息(文件指针位置) "^Rv#  
private void read_nPos() :(, mL2[  
{ ? ?[g}>  
try{ `PlOwj@u0`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1e}8LH7  
int nCount = input.readInt(); y=Q!-~5|fF  
nStartPos = new long[nCount]; %tmp  
nEndPos = new long[nCount]; XAuI7e  
for(int i=0;i<nStartPos.length;i++) "9XfQ"P  
{ (=c1  
nStartPos = input.readLong(); vzXag*0  
nEndPos = input.readLong(); .H~YI  
} ,_ .v_  
input.close(); O0hu qF$K  
} (Rd$VYuf  
catch(IOException e){e.printStackTrace ();} >jTp6tu,  
catch(Exception e){e.printStackTrace ();} dRaOGm)  
} P^)q=A8Z#  
sKL:p3r  
)9L/sKz  
private void processErrorCode(int nErrorCode) O!&,5Dy  
{ :P+\p=  
System.err.println("Error Code : " + nErrorCode); f p[,C1U  
} [L(h G a  
M 2q"dz   
)L5i&UK.  
//停止文件下载 cWLqU  
public void siteStop() ;\{`Ci\  
{ '@=PGpRF  
bStop = true;  L,LNv  
for(int i=0;i<nStartPos.length;i++) V/%~F6e  
fileSplitterFetch.splitterStop(); Z(GfK0vU  
(zcLx;N  
](jFwxU  
} Log|%P\  
} ,d_Gn!  
//负责部分文件的抓取 F]+~x/!  
**FileSplitterFetch.java \6!W05[ Q  
*/ D Ml?o:l  
package NetFox; *rh,"Zo  
ZH 6\><My  
kcuzB+  
import java.io.*; "Cz<d w]D  
import java.net.*; ~O6\6$3b5E  
('[TLHP  
9KuD(EJS  
public class FileSplitterFetch extends Thread { n/4i|-^  
+&=?BC}L9^  
jp2Q 9Z  
String sURL; //File URL Ond'R'3\E  
long nStartPos; //File Snippet Start Position c1XX~8  
long nEndPos; //File Snippet End Position \cJa;WM>  
int nThreadID; //Thread's ID {KL5GowH  
boolean bDownOver = false; //Downing is over ci9R.U)  
boolean bStop = false; //Stop identical )Kd%\PP  
FileAccessI fileAccessI = null; //File Access interface na+d;h*~y  
~@W*r5/  
Wr?'$:  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ca<"  
{ <%?#AVU[  
this.sURL = sURL; k@mVxnC  
this.nStartPos = nStart; ` uCIXb  
this.nEndPos = nEnd; 2{|$T2?e  
nThreadID = id; dtt~ Bd  
fileAccessI = new FileAccessI(sName,nStartPos);//定位  ;q>9W,jy  
} s%4M$ e  
"Zv~QwC  
0E`1HP"b  
public void run() s#9Ui#[=h  
{ , E )|y4  
while(nStartPos < nEndPos && !bStop) rVnd0K  
{ $.%rAa_H  
O[@ q%&_  
]b?9zeT*'l  
try{ )RgGcHT@  
URL url = new URL(sURL);  >w6taX  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *XOJnyC_H  
httpConnection.setRequestProperty("User-Agent","NetFox"); xGk6n4Gg  
String sProperty = "bytes="+nStartPos+"-"; V N{NA+I  
httpConnection.setRequestProperty("RANGE",sProperty); \c,pEXG  
Utility.log(sProperty); dq;|?ESP  
5K%SL1N  
qy1F* kY  
InputStream input = httpConnection.getInputStream(); g`^X#-!(  
//logResponseHead(httpConnection); .wA+S8}S  
+EXJ\wy  
VSX@e|Nj  
byte[] b = new byte[1024]; ^ <`(lyph  
int nRead; Ga>uFb}W~  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U @v*0  
{ )::>q5c  
nStartPos += fileAccessI.write(b,0,nRead); h"mi"H^o  
//if(nThreadID == 1) z+}QZ >  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'wasZ b<^  
} /wShUR{  
EI~"L$?  
^>x|z.  
Utility.log("Thread " + nThreadID + " is over!"); N;oQ^B'  
bDownOver = true; aVs(EHF  
//nPos = fileAccessI.write (b,0,nRead); 9I7\D8r  
} :,12")N  
catch(Exception e){e.printStackTrace ();} 8F(h*e_?  
} g1E~+@  
} 85:NFa@J  
1F'1>Bu~  
s'aip5P  
//打印回应的头信息 bu7'oB~:V^  
public void logResponseHead(HttpURLConnection con) %=we `&  
{ U6ZR->:  
for(int i=1;;i++) '+>fFM,*B  
{ w.\w1:d  
String header=con.getHeaderFieldKey(i); 63|+2-E2Q  
if(header!=null) l- pe4x  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d,vNem-Z*L  
Utility.log(header+" : "+con.getHeaderField(header));  MTER(L  
else @oF$LMD  
break;  9fnA  
} AUVgPXOwd  
} /M~!sPW&?  
qSqI7ptA\  
<:/&&@2  
public void splitterStop() V-I(WzR9y  
{ @$"J|s3M  
bStop = true; p9U?!L!y  
} &c(WE RW?-  
u cwnA  
-4w=s|#.\  
} Xv <G-N4  
YIt& >  
,oxcq?7#4  
/* $8USyGi3J  
**FileAccess.java (iJ1 ;x  
*//文件访问(定位,写) h eaRX4  
package NetFox; Tu{&v'!j6  
import java.io.*; X8dR+xd  
%<?0apO  
;4M><OS!  
public class FileAccessI implements Serializable{ R+q"_90_  
RCTQhTy=  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x83 !C}4:  
RandomAccessFile oSavedFile; @~<j&FTT  
long nPos; <Llp\XcZ  
fP tm0.r  
S-31-Zjw  
public FileAccessI() throws IOException WwF~d+>|C  
{ IW8+_#d  
this("",0); I)q,kP@yY  
} 4Wy <?O2  
/( .6bv  
ms($9Lv/  
public FileAccessI(String sName,long nPos) throws IOException {mWui9 %M  
{ ] sz3]"2  
oSavedFile = new RandomAccessFile(sName,"rw"); kt[:@Nda9  
this.nPos = nPos; )&era ` e[  
oSavedFile.seek(nPos); P o jmC  
} {GvTfZfp  
/vY_Y3k#  
}?cGf- c  
public synchronized int write(byte[] b,int nStart,int nLen) c`lJu_  
{ ;fw1  
int n = -1; /&u<TJ4  
try{ 2f U$J>Y  
oSavedFile.write(b,nStart,nLen); Ngr/QL]Q  
n = nLen; ve ~05mg  
} nf 1#tlIJd  
catch(IOException e) K.G$]H  
{ f:g,_|JD$  
e.printStackTrace (); y%sroI('y  
} 7'wS\/e4a  
&U+ _ -Ph  
!R*-R.%  
return n; Auy_K?he]  
} 8Qh#)hiW!  
g }laG8  
iv phlw  
} @ S<-d  
 tvXW  
Z5c~^jL$-  
/* pLMRwgzr  
**SiteInfoBean.java g8!wb{8?s  
*/ f84:hXo6  
package NetFox; oG$)UTzGc  
izKfU?2]X@  
 )>D+x5o]  
public class SiteInfoBean { ,!V]jP)  
p8s:g~ W  
Z/^  u  
private String sSiteURL; //Site's URL "cTncL  
private String sFilePath; //Saved File's Path MNH1D! }  
private String sFileName; //Saved File's Name >3awn*N  
private int nSplitter; //Count of Splited Downloading File 0!z@2[Pe66  
;q0uE:^ S  
b':|uu*/  
public SiteInfoBean() /7!""{1\\  
{//nSplitter的缺省值为5 $3Z-)m  
//default value of nSplitter is 5 x8;`i$  
this("","","",5); DK0.R]&4(  
} mMMQ|ea  
ExHKw~y9  
A:<;M@q !  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [~:-&  
{ 2,aPr:]  
sSiteURL= sURL; C"lJl k9g^  
sFilePath = sPath; jGrN\D?h  
sFileName = sName; UpXz&k  
this.nSplitter = nSpiltter; $+}+zZX5  
-@>BHC  
&C>/L;  
} )otb>w5  
L6>pGx  
TpA\9N#$  
public String getSSiteURL() :';L/x>  
{ vzF5xp.  
return sSiteURL; [![%9'+P  
} ??hJEE  
[sW.CK= 3  
4@.|_zY  
public void setSSiteURL(String value) ^\B :R,  
{ iqnJ~g  
sSiteURL = value; P;PQeXKw  
} `Q+moX  
V|)>{Xdn  
~) ?  
public String getSFilePath() }HEvr)v9  
{ \:> Wpqw  
return sFilePath; eT'nl,e|  
} 5>J=YLq  
1Y_w5dU  
A?TBtAe  
public void setSFilePath(String value) )Qm[[pnj  
{ uS&| "*pR  
sFilePath = value; q P ;A}C  
} \.XLcz  
?=GXqbS"  
(wc03,K^  
public String getSFileName() ,wKe fpV;5  
{ QZ `tNq :/  
return sFileName; BQ^H? jo  
} 569}Xbc/  
-st7_3  
39 {{7(hh  
public void setSFileName(String value) ,fEO> i  
{ *%Qn{x  
sFileName = value; lCW8<g^  
} o`khz{SU:  
BF{w)=@/'  
)hwV`2>l  
public int getNSplitter() ?}Z1(it0  
{ M>jtFP <S  
return nSplitter; P?BGBbC  
} X\p,%hk \  
(2?G:+C 7  
RkF D*E$  
public void setNSplitter(int nCount) &iN--~}!$  
{ >]'yK!a?  
nSplitter = nCount; ~.PP30 '  
} ,? E&V_5  
} OT %nrzP  
bg|!'1bD`5  
eMK+X \  
/* AvR2_  
**Utility.java TJ?g%  
*/ uhN%Aj\iu(  
package NetFox; 0;,IKXK6X  
Dc~,D1xWj  
F2(q>#<_  
public class Utility { ]IJRnVp%  
/R X1UQ.s  
wLuv6\E  
public Utility() M8w5Ob  
{ S)He$B$pp  
(_* wt]"'  
3`9{T>  
} '+<(;2Z vL  
Ju@Q6J5  
//线程睡眠 0f ER*.F  
public static void sleep(int nSecond) ')+0nPV  
{ %u?HF4S'  
try{ Fb2%!0i  
Thread.sleep(nSecond); ~;-9X|  
} us?&:L|!=  
catch(Exception e) SM[{BH<  
{ IL7`0cN(  
e.printStackTrace (); 7J>Gd  
} n)8Yj/5  
} ]T O/kl/  
$awi>#[  
//日志 wh 0<Uv  
public static void log(String sMsg) Vu0 KtG9  
{ ?y},,  
System.err.println(sMsg); x )5V.q  
} #i QX 6WF  
HN5W@5m: .  
z?8~[h{i%  
public static void log(int sMsg) uMXc0fs!$  
{ 3bC yTZk  
System.err.println(sMsg); OQ_stE2i  
} [nN7qG  
} 5''*UFIF1  
>AD =31lq  
[2$4|;7  
/* !7lj>BA>  
**TestMethod.java ^<V9'Ut   
*/ ^Uw[x\%#gD  
package NetFox; ?`sy%G  
o|S)C<w  
q/@dR{-  
public class TestMethod { RcY[rnI6  
t\U$8l_;  
-@%%*YI>  
public TestMethod() e]W0xC-  
{ ///xx/weblogic60b2_win.exe jy$@a%FD  
try{ #*IVlchA"B  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,^T]UHRO  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u,i]a#K  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,j9 80/  
fileFetch.start(); K\=8eg93Z  
} J2Et-Cz1  
catch(Exception e){e.printStackTrace ();} /MMtTB H  
=v2%Vs\7k  
\&|CM8A  
} nW;kcS*A  
UKB_Yy^Y  
D(Ix!G/  
public static void main(String[] args) G\H q/4  
{ 4!%]fg}Um  
new TestMethod(); i*tv,f.(  
} 9{J?HFw*;  
} _\AUQ{  
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