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http断点续传简单实现(java)

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/* zT+ "Z(oz,  
**SiteFileFetch.java 7-("pp YX=  
*/ @d_9NOmNT  
package NetFox; QP7N#mh  
import java.io.*; G]RFGwGt  
import java.net.*; -7u_\XFk  
-Ic<.ix  
-GZ:}<W 6+  
public class SiteFileFetch extends Thread { zn#lFPj12  
-'rb+<v  
hh8U/dVk*  
SiteInfoBean siteInfoBean = null; //文件信息Bean  Q5 =  
long[] nStartPos; //开始位置 F@<^  
long[] nEndPos; //结束位置 "sJ@_lp  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 }e-D&U  
long nFileLength; //文件长度 ffG1QvC|M  
boolean bFirst = true; //是否第一次取文件 cpu|tK.t  
boolean bStop = false; //停止标志 q85 4k+C  
File tmpFile; //文件下载的临时信息 3(3-#MD0  
DataOutputStream output; //输出到文件的输出流 N[&(e d=  
U-pBat.$'C  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) UL0n>Wa5  
public SiteFileFetch(SiteInfoBean bean) throws IOException iJSyi;l|  
{ >uR;^B5m  
siteInfoBean = bean; eCwR }m?_  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); {)wl`mw3  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?o`fX wE  
if(tmpFile.exists ()) gr\vC  
{ C)BVsHT4  
bFirst = false; ^2LqKo\T  
read_nPos(); QRHM#v S  
} cF}9ldc  
else HY,VJxR[  
{ |vY|jaV}  
nStartPos = new long[bean.getNSplitter()]; :u|F>e  
nEndPos = new long[bean.getNSplitter()]; q8H9au&/  
} hx hs>eY  
>o5eyi  
;\ gat)0n%  
Y@MFH>*  
} AH|'{  
J5SOPG  
cv9-ZOxJ  
public void run() Xp~O?2:3l  
{ +^3 *Y"6Z  
//获得文件长度 )NnkoCNeE  
//分割文件 lin  
//实例FileSplitterFetch O5dBI_  
//启动FileSplitterFetch线程 (d#W3  
//等待子线程返回 ]~7xq)28  
try{ 9M7Wlx2  
if(bFirst) uO4R5F|tL  
{ Y0g6zHk7  
nFileLength = getFileSize(); zv~b-Tp  
if(nFileLength == -1) xPMX\aI|l  
{ @] 3`S  
System.err.println("File Length is not known!"); LX7<+`aa  
} ZG)6{WS  
else if(nFileLength == -2) ~QU\kZ7Z  
{ `! _mIh}  
System.err.println("File is not access!"); X;d 1@G  
} vg\fBHzn  
else ?<~P)aVVj  
{ wj9 Hh  
for(int i=0;i<nStartPos.length;i++) `g'z6~c7n  
{ 5Eu`1f?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Z[9f8/6<b  
} seA=7c5E  
for(int i=0;i<nEndPos.length-1;i++) /OeOL3Y  
{ tx]!|x" F  
nEndPos = nStartPos[i+1]; YQaL)t$0  
} %kL]-Z  
nEndPos[nEndPos.length-1] = nFileLength; 9` G}GU]@}  
} w C-x'  
} T^H`$;\  
*wV`7\@  
Z(hRwIOF  
//启动子线程 I ka V g L  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >:P-3#e*  
for(int i=0;i<nStartPos.length;i++) CM 8Ub%  
{ Jqqt@5Ni  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g&O!w!T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +A<7:`sO  
nStartPos,nEndPos,i); p"Q V| `  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '/@i} digf  
fileSplitterFetch.start(); 7F8>w 7Y]  
} iQz c$y^,9  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 54%h)dLDy  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /igbn  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v,Yz\onB^  
nEndPos = " + nFileLength); gF&HJF 0x  
// fileSplitterFetch[nPos.length-1].start(); ju(QSZ|;  
*.zC9Y,  
y])z,#%ED  
//等待子线程结束 U_Am Riy  
//int count = 0; :{x    
//是否结束while循环 MXynv";<H  
boolean breakWhile = false; z5 :53,`D'  
B8 R&Q8Q  
ci`N ,&:R  
while(!bStop) ^spASG -o  
{ ;{ESo?$*  
write_nPos(); -](3iPy}  
Utility.sleep(500); WxS$yUu  
breakWhile = true; N>',[4pJ|  
$GX9-^og=T  
B2)SNhF2Y  
for(int i=0;i<nStartPos.length;i++) ?#VkzT  
{ tkf^sGgNO  
if(!fileSplitterFetch.bDownOver) *Zz hN]1  
{ LAv!s/O$=  
breakWhile = false; |oTA $bln  
break; Fo GSCg%  
} z>O=. Ku6  
} #<gD@Jybu  
if(breakWhile) nHIW_+<Mf  
break; crRYgr  
v9l|MI15V  
l5l#LsaQb  
//count++; jfsbvak  
//if(count>4) >UB ozmF=\  
// siteStop(); !T1)tGrH  
} !z?;L_Lb  
~19&s~  
QxeK-x^  
System.err.println("文件下载结束!"); mY!&*nYn|  
} ,B$m8wlI|  
catch(Exception e){e.printStackTrace ();} 8? &!@3n  
} h}f l:J1C  
h0Ilxa   
PVX23y;  
//获得文件长度 eC*-/$D  
public long getFileSize() 5)<}a&;{  
{ {%XDr,myd  
int nFileLength = -1; dnstm@0k  
try{  ~ A4_  
URL url = new URL(siteInfoBean.getSSiteURL()); #~:@H&f790  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o :_'R5  
httpConnection.setRequestProperty("User-Agent","NetFox"); d/&~IR  
SMbhJ}\O  
<wO8=bem  
int responseCode=httpConnection.getResponseCode(); Fq #;  
if(responseCode>=400) c_)lTI4  
{ w $z]Z-  
processErrorCode(responseCode); L(\o66a-rV  
return -2; //-2 represent access is error bs\7 juHt  
} OjBg$f~0F  
E~'QC  
>e9xM Gv  
String sHeader; gukKa  
4: S-  
3NxwQ,~  
for(int i=1;;i++) +G lb  
{ Nm,9xq  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 88M$mjx  
//Utility.log(in.readLine()); Yb Dz{m  
sHeader=httpConnection.getHeaderFieldKey(i); Zh 3hCxXa  
if(sHeader!=null) }pL#C  
{ Sz'JOBp  
if(sHeader.equals("Content-Length")) ad'C&^o5  
{ dEWI8Q]  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I-o |~  
break;  ylBjuD+  
} i9quP"<9  
} 3Fl!pq]  
else <hM`]/J55  
break; I+_u?R)$  
} } 2P,Z6L  
} Z{spo=  
catch(IOException e){e.printStackTrace ();} [{cMEV&  
catch(Exception e){e.printStackTrace ();} OAd}#R\U  
Uh8c!CA8:\  
"[p-Iy1  
Utility.log(nFileLength); \1cJ?/$_Of  
DW.vu%j^[  
{G(N vf,K]  
return nFileLength; LFT)_DG7(  
} vILq5iR  
3v7*@(y  
H3qM8_GUA  
//保存下载信息(文件指针位置) |% xgob  
private void write_nPos() C J#1j>  
{ ^E`SR6_cmj  
try{ |XoW Z,K  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ph|\%P`>%  
output.writeInt(nStartPos.length); PcQqdU^!  
for(int i=0;i<nStartPos.length;i++) nK;c@!~pS  
{ EG3?C  
// output.writeLong(nPos); 92)e/t iP  
output.writeLong(fileSplitterFetch.nStartPos); @?\[M9yK  
output.writeLong(fileSplitterFetch.nEndPos); =}7[ypQM`]  
} mu#  a  
output.close(); (_$'e%G0  
} E4dN,^_ F!  
catch(IOException e){e.printStackTrace ();} '+*{u]\  
catch(Exception e){e.printStackTrace ();} FCMV1,  
} + 4*jO5EZ  
:{ Q[kYj  
";$rcg"%X  
//读取保存的下载信息(文件指针位置) qZ|>{^a*  
private void read_nPos() @ob4y  
{  (zL(  
try{ }[m,HA<j  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tNbZ{=I>  
int nCount = input.readInt(); f hS4Gb_  
nStartPos = new long[nCount]; ^P !} "  
nEndPos = new long[nCount]; K|g+W t^tQ  
for(int i=0;i<nStartPos.length;i++) qKL mL2O  
{ 3T7,Y(<V  
nStartPos = input.readLong(); ;R8pVj!1f  
nEndPos = input.readLong(); ,ThN/GkSC  
} ;u "BCW  
input.close(); G>yTv`-  
} :Lze8oY(D}  
catch(IOException e){e.printStackTrace ();} 0281"aO  
catch(Exception e){e.printStackTrace ();} c-gpO|4>  
} POtwT">z  
6o!Y^^/U  
HbXYinG%  
private void processErrorCode(int nErrorCode) smTPca)7s  
{ hxQx$  
System.err.println("Error Code : " + nErrorCode); EvQMt0[?EW  
} zUCtH*  
<W<>=vDzyE  
9C2DW,?  
//停止文件下载 k-N` h  
public void siteStop() N|53|H  
{ [c_o.`S_\  
bStop = true; d"Aer  
for(int i=0;i<nStartPos.length;i++) 27q=~R}  
fileSplitterFetch.splitterStop(); "Gh5 ^$w?j  
ql_GN[c/  
uiQRRT  
} (h3f$  
} ?z$^4u3  
//负责部分文件的抓取 IGC:zZ~z  
**FileSplitterFetch.java Gl@}b\TB  
*/ JNZ  O7s  
package NetFox; mM6X0aM  
f7_EqS=(  
E+$%88  
import java.io.*; M!j: 2dT"  
import java.net.*; B(TE?[ #  
# 2qDn^s  
,q|;`?R;  
public class FileSplitterFetch extends Thread { CV )v6f  
SZ'2/#R>  
[@LA<Z_  
String sURL; //File URL U 3UDA  
long nStartPos; //File Snippet Start Position \2Atm,#4  
long nEndPos; //File Snippet End Position xYUC|c1Q9  
int nThreadID; //Thread's ID XzF-g*e  
boolean bDownOver = false; //Downing is over OPtFz6   
boolean bStop = false; //Stop identical ,KyG^;Riy  
FileAccessI fileAccessI = null; //File Access interface :G\X  
>.X& v  
?\7$63gBH  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i,z^#b7JQ  
{ $63_* 9  
this.sURL = sURL; VwKo)zH  
this.nStartPos = nStart; ljw(cUM  
this.nEndPos = nEnd; N&]GP l0  
nThreadID = id; 6b6rM%B.oD  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EFqYEDXW  
} 7I0[Ii  
S(\<@S&  
w#Di  
public void run() MJDW-KL-  
{ 44p?x8(z*  
while(nStartPos < nEndPos && !bStop) 8,^2'dK34  
{ V^[B=|56  
Q]v><  
n |e=7?H8  
try{ 9J $"Qt5;6  
URL url = new URL(sURL); Q6lC:cB<  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aHR&6zj4  
httpConnection.setRequestProperty("User-Agent","NetFox"); rOyKugHe  
String sProperty = "bytes="+nStartPos+"-"; T}55ZpS C&  
httpConnection.setRequestProperty("RANGE",sProperty); h .%)RW?  
Utility.log(sProperty); ^^FqN;  
@cC@(M~Ru  
9H6%\#rw  
InputStream input = httpConnection.getInputStream(); 6hX[5?}  
//logResponseHead(httpConnection); {/E_l  
lC AD $Ia~  
~p* \|YC  
byte[] b = new byte[1024]; s=BJ7iU_68  
int nRead; zZ*\v  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^0fe:ac;  
{ Y$\c_#/]  
nStartPos += fileAccessI.write(b,0,nRead); RP1sQ6$  
//if(nThreadID == 1) r]<?,xx [  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )'3V4Z&  
} % r>v^1Vo  
n&N>$c,T27  
!x@3U^${  
Utility.log("Thread " + nThreadID + " is over!"); V[RsSZx =  
bDownOver = true; dtDT^~  
//nPos = fileAccessI.write (b,0,nRead); zHu w[  
} \zMx~-2oN  
catch(Exception e){e.printStackTrace ();} _Q=h3(ZI  
} w$1B|7tX;2  
} ];63QJU  
.FWi$B';  
5%K(tRc|  
//打印回应的头信息 ucwUeRw,  
public void logResponseHead(HttpURLConnection con) JMVh\($,x  
{ Sz'H{?"  
for(int i=1;;i++) )ld`2) 4  
{ 1[k.apn  
String header=con.getHeaderFieldKey(i); *MM8\p_PuT  
if(header!=null) OS]FGD3a  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N6thbH@  
Utility.log(header+" : "+con.getHeaderField(header)); z1vSt[s  
else i~sW_f+  
break; 7~ =r9-&G  
} sG K7Uy  
} WTX!)H6Zv  
d"U'\ID2y  
! a!^'2  
public void splitterStop() 3:ELYn  
{ V|`w/P9g4  
bStop = true; g3Z"ri~!G  
} eX3|<Bf  
3@8Zy:[8<  
kl[Jt)"4@  
} oa q!<lI  
dm`:']?  
U0fr\kM  
/* z5q(  
**FileAccess.java c)B <d#  
*//文件访问(定位,写) 9JBVG~m+  
package NetFox; 25wvB@0&  
import java.io.*; >uy(N  
;/s##7qf  
3"HX':8x  
public class FileAccessI implements Serializable{ $dkkgsw 7  
^w6~?'}  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GEbm$\  
RandomAccessFile oSavedFile; m&{%6  
long nPos; A=bBI>GEYP  
{O"N2W  
oF {u  
public FileAccessI() throws IOException & T&>4I!'M  
{ g), t  
this("",0); OkfnxknZ|  
} |:)ARH6l#  
{T'M4y=)i  
_<m yM2z  
public FileAccessI(String sName,long nPos) throws IOException yDmx)^En  
{ \l71Q/y6u`  
oSavedFile = new RandomAccessFile(sName,"rw"); H*R4AE0  
this.nPos = nPos; XZH\HK)K-]  
oSavedFile.seek(nPos); k?VH4 yA  
} .z}*!   
Ux b>)36I  
W0;MGBfb  
public synchronized int write(byte[] b,int nStart,int nLen) (_Ky' .  
{ 1!p7N$QR  
int n = -1; 4KnrQ-D  
try{ $-p#4^dg  
oSavedFile.write(b,nStart,nLen); kpLx?zW--q  
n = nLen; TJ+,G4z  
} >^ TcO  
catch(IOException e) {}DoRp q=  
{ :{'%I#k2  
e.printStackTrace (); .X;D I<K  
} Qoom[@$  
6u [ B}%l  
.g8db d  
return n; r";;Fk#5  
} y|2y! &o,!  
@l %x;`E  
y\@INA^  
} 1T/ 72+R0  
r"bV{v  
4ztU) 1  
/* \Jm^XXgS  
**SiteInfoBean.java >})W5Y+  
*/ z 8y.@<6  
package NetFox; y41,T&ja  
5Zy%Nam'gN  
AZf$XHP2  
public class SiteInfoBean { +XoY@|Djd  
TS49{^d$  
H tAO9  
private String sSiteURL; //Site's URL `g^bQ x  
private String sFilePath; //Saved File's Path .Hm1ispq  
private String sFileName; //Saved File's Name b<\aJb{2  
private int nSplitter; //Count of Splited Downloading File tr@)zM GB  
 @s7wKk  
j:P(,M[  
public SiteInfoBean() @G?R (  
{//nSplitter的缺省值为5 DTo P|P  
//default value of nSplitter is 5 2 i97  
this("","","",5); <}('w/  
} b/6!>qMMk%  
#iVr @|,  
ePscSMx&  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v0u, :eZ4  
{ UJ7{FN=@t  
sSiteURL= sURL; cllnYvr3  
sFilePath = sPath; :7[4wQDt4  
sFileName = sName; f <pJ_  
this.nSplitter = nSpiltter; r O-=):2  
u`Abko<D  
':#DROe!  
} :)DvZxHE@  
ZIs=%6""&  
Apbgm[m|{  
public String getSSiteURL() RhD   
{ z#Db~  
return sSiteURL; P&5kO;ia  
} Yx':~  
nNpXkI:  
't n-o  
public void setSSiteURL(String value) UoOxGo  
{ <RJ+f-  
sSiteURL = value; (,;4f7\  
} /j"aOLL|  
x9i^ _3Z  
q"Th\? }%  
public String getSFilePath() 6L,"gF<n  
{ s7"5NU-  
return sFilePath; s}g3*_"  
} tf4clzSTa  
]:}x 4O#  
6oy[0hj  
public void setSFilePath(String value) /0(c-Dv  
{ BNq6dz$J  
sFilePath = value; ;X%8I$Ba,  
} C8AR ^F W  
.Zm de*b  
*^i"q\n5(  
public String getSFileName() 1HBWOV7z.?  
{ bEB9J- Q  
return sFileName; +O!4~k^  
} 8 Az|SJ<  
{Y1&GO;  
9"cyZO  
public void setSFileName(String value) Ws;X;7tS  
{ vpz l{  
sFileName = value; e`bP=7`0  
} D8\9nHUD`  
7g-{ <d  
;YY nIb(  
public int getNSplitter() sfzDE&>'  
{ 0 `$fs.4c  
return nSplitter; Z=9gok\  
} &}!AjA)  
SlI wLv^  
2U& +K2  
public void setNSplitter(int nCount) x<1t/o  
{ yM# %UeZ\  
nSplitter = nCount; OPJ(ub  
} 6[\1Nzy>  
} \JDxN  
$%.,=~W7  
j026CVL  
/* [ @9a  
**Utility.java @B Muov  
*/ =F/EzS  
package NetFox; / 5y _ <  
V>& 1;n  
Yd]  
public class Utility { a^7QHYJ6  
b]g#mQ  
ccwz:7r  
public Utility() `Ln1g@  
{ 6 jU ?~  
8f>v[SQ"  
iM M s3  
} ?\_vqW  
lY[\eQ 1:  
//线程睡眠 Qb8Z+7  
public static void sleep(int nSecond) o]@'R<F(u  
{ K)GpQ|4:<  
try{ 58t~? 2E  
Thread.sleep(nSecond); tY%T  
} p<c1$O*  
catch(Exception e) &"d :+!4h  
{ vDCbD#.6  
e.printStackTrace (); JfRqOEP4Y  
} iz3Hoj  
} uLr-!T  
=Y*zF>#lP  
//日志 5h6-aQU[  
public static void log(String sMsg) i4lB ]k  
{ &n]]OPo  
System.err.println(sMsg); g=jB'h?  
} <vd}oiB@  
85BB{ T;  
}c=YiH,o  
public static void log(int sMsg) EpK7VW  
{ m O"Rq5  
System.err.println(sMsg); =yZ6$ hK  
} R0e!b+MZ.  
} C:z7R" yj  
IwR=@Ne8  
B$MHn?  
/* p~OX1RBI  
**TestMethod.java \_MWZRMc5  
*/ n^` `)"  
package NetFox; #rQT)n  
\jr-^n]  
#g~]2x  
public class TestMethod { zz #IY'dwT  
&?# YjU"  
#>2cfZ`6'J  
public TestMethod() JPpNCC.b  
{ ///xx/weblogic60b2_win.exe \`W8#fob  
try{ _ME?o  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rh T!8dTk  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 74a k|(!  
SiteFileFetch fileFetch = new SiteFileFetch(bean); * yGlX[  
fileFetch.start(); WnhH]WY  
} Rm Q>.?  
catch(Exception e){e.printStackTrace ();} ge#P(Itz  
7-mo\jw<  
{BZ0x2  
} rBZ00}  
vy5I#q(k  
g{JH5IZ~  
public static void main(String[] args) [6)vD@  
{ V o%GO 9b;  
new TestMethod(); = Q"(9[Az  
} O^IS:\JX&  
} 3 <Zo{;  
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