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http断点续传简单实现(java)

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/* `7Ug/R<  
**SiteFileFetch.java -zfoRU v  
*/ CmC0k-%w  
package NetFox; xxX/y2\  
import java.io.*; CMVS W6  
import java.net.*; `| 9Ku  
$C_M&O}  
Pn WD}'0V  
public class SiteFileFetch extends Thread { 3;/?q  
F|eu<^"$ H  
\2DE ==M)P  
SiteInfoBean siteInfoBean = null; //文件信息Bean }C6@c1myq-  
long[] nStartPos; //开始位置 Q7Ij4  
long[] nEndPos; //结束位置 c?6d2jH.  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 \KM|f9-b  
long nFileLength; //文件长度 F-0UdV  
boolean bFirst = true; //是否第一次取文件 H^(L90  
boolean bStop = false; //停止标志 v[#)GB _5  
File tmpFile; //文件下载的临时信息 cdp0!W4Gi  
DataOutputStream output; //输出到文件的输出流 D1"7s,Hmu  
/8eW@IO.F  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) C ?7X"~ ~  
public SiteFileFetch(SiteInfoBean bean) throws IOException I6dm@{/:>  
{ d79N-O-  
siteInfoBean = bean; s44iEh=V(I  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ,b' 4CF  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); aWvd`qA9r  
if(tmpFile.exists ()) moO _-@i  
{ 'h *Zc}Q:  
bFirst = false; TlPVHJyt  
read_nPos(); n(&*kfk  
} * BOBH;s  
else ~mH+DV3  
{ Jp ]T9W\  
nStartPos = new long[bean.getNSplitter()]; XVUf,N,  
nEndPos = new long[bean.getNSplitter()]; $L{7%]7QC  
} ^ }#f()  
j[DIz@^  
\C/z%Hf7-  
g _ M-F  
} 6E+=Xi  
&BgU:R,  
,P@QxnQ   
public void run() R;THA!  
{ JSjYC0e  
//获得文件长度 q|{tQJfYg  
//分割文件 k>{-[X,/OV  
//实例FileSplitterFetch Z=9dMND  
//启动FileSplitterFetch线程 .cR*P<3O  
//等待子线程返回 60PYCqWc  
try{ BX$hAQ(6Q  
if(bFirst) `Cj,HI_/*  
{ `^%GN8d}nm  
nFileLength = getFileSize(); "6V_/u5M;=  
if(nFileLength == -1) hEOJb @:R  
{ $FCw$+w  
System.err.println("File Length is not known!"); ^Kw(& v  
} /=M.-MU2  
else if(nFileLength == -2) v MWC(m  
{ faVS2TN4  
System.err.println("File is not access!"); s^PmnFR  
} Y'_ D<Mp  
else g{a d0.y,  
{ {Gkn_h-^  
for(int i=0;i<nStartPos.length;i++) &7F&}7*c  
{ \X opU"  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 7SHo%b A  
} Gg+YfY_  
for(int i=0;i<nEndPos.length-1;i++) n\~yX<;X3  
{ m|dF 30~A  
nEndPos = nStartPos[i+1]; rk|a'&  
} CjZ6NAHc  
nEndPos[nEndPos.length-1] = nFileLength; '#f?#(  
} ~~dfpW_"  
} IMR$x(g= F  
{G.{a d  
6QptKXu7  
//启动子线程 EG1x  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s}!"a8hU`  
for(int i=0;i<nStartPos.length;i++) *2:Yf7rvI+  
{ m t.,4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4`0;^K.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +-k`x0v  
nStartPos,nEndPos,i); 3mA/Nu_  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ib(,P3  
fileSplitterFetch.start(); -9Xw]I#QR  
} p,^>*/O>  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dh,7iQ s  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |ZuDX87  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \]GGVI ;u  
nEndPos = " + nFileLength); "b;k.Fx  
// fileSplitterFetch[nPos.length-1].start(); Q2R>lzB  
~p!QSRu~,b  
s.e y!ew  
//等待子线程结束 ^ N_`^m  
//int count = 0; ZArf;&8  
//是否结束while循环 n(# c`t*  
boolean breakWhile = false; @f'AWeJ2  
;@O(z*14@  
%w%zv2d  
while(!bStop) JgZdS-~  
{ "U{mMd!9L  
write_nPos(); qZc)Sa.S  
Utility.sleep(500); Ot"(uW4$[  
breakWhile = true; dK7 ^  
8Nv-/VQ/b  
y7 <(,uT  
for(int i=0;i<nStartPos.length;i++) /^WE@r[:  
{ )xbqQW7%0+  
if(!fileSplitterFetch.bDownOver) 7dx4~dF  
{ rr6"Y&v  
breakWhile = false; Z~B+*HF  
break; 1r&AB!Z #  
} IT7:QEfKU  
} l>33z_H^  
if(breakWhile) ";58B} ki  
break; _"`/^L`Q?  
P:vX }V |[  
k.ww-nH  
//count++; j[BgP\&,  
//if(count>4) !-@SS>  
// siteStop(); wf^cyCR0  
} _4De!q0(  
UvoG<;  
0$(jBnE  
System.err.println("文件下载结束!"); 4>d[qr*<  
} A'w2GC{.  
catch(Exception e){e.printStackTrace ();} 4O9tx_<JG  
} *,_2hvlz  
!DCVoc]pV  
LE Jlo%M  
//获得文件长度 /Ir 7 DZK  
public long getFileSize() 7YSuB9{M  
{ ]lC4+{V  
int nFileLength = -1; <4SF~i  
try{ ~n)]dFy  
URL url = new URL(siteInfoBean.getSSiteURL()); gS0,')w  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NdaM9a#TZ  
httpConnection.setRequestProperty("User-Agent","NetFox"); m}sh I8S  
jR }*bIzv  
_qdWQFuM  
int responseCode=httpConnection.getResponseCode(); ^O?l9(=/u  
if(responseCode>=400) Z7ZWf'o  
{ aj+zmk~-  
processErrorCode(responseCode); :  ,|=Q}  
return -2; //-2 represent access is error (u$!\fE-et  
} c lq <$-  
8VKb*  
bK6, saN>  
String sHeader; an #jZ[  
:Fq2x_IUE  
ei(| 5h  
for(int i=1;;i++) R#r h  
{ \Gv-sA  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s"gKonwI2  
//Utility.log(in.readLine()); 15RI(BN   
sHeader=httpConnection.getHeaderFieldKey(i); H d96[Uo  
if(sHeader!=null) iFXUKGiV  
{ 4d,qXSKty  
if(sHeader.equals("Content-Length")) h:eN>yW  
{ w`2_6[,9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g5?r9e  
break; ~r7DEy|+  
} "`H=AX0  
} >I R` ]  
else pU[a[  
break; |8b$x| B  
} n C\(+K1%  
} =aX1:Z  
catch(IOException e){e.printStackTrace ();} OsDp88Bc  
catch(Exception e){e.printStackTrace ();} bUpmU/ RW  
f4qS OVv  
w`w ` q'  
Utility.log(nFileLength); \f ~u85  
LD7? .  
w;g)Iy6x  
return nFileLength; O p!  
} <<~lV5  
^*j[&:d  
j58Dki->.  
//保存下载信息(文件指针位置) PkZf(=-X  
private void write_nPos() 6T5A31 Q  
{ %`8KG(F^  
try{ AiR%MD  
output = new DataOutputStream(new FileOutputStream(tmpFile)); c9>8IW  
output.writeInt(nStartPos.length); j X^&4f  
for(int i=0;i<nStartPos.length;i++) !c3Qcva  
{ vgd}09y  
// output.writeLong(nPos); loAfFK>g  
output.writeLong(fileSplitterFetch.nStartPos); (dw3'W  
output.writeLong(fileSplitterFetch.nEndPos); OoA5!HEh  
} g%KGF)+H  
output.close(); 5G dY7t_1  
} t\E-6u  
catch(IOException e){e.printStackTrace ();} Il tg0`  
catch(Exception e){e.printStackTrace ();} S0X.8Bq  
} ^$T!@ +:  
&z 1|  
^loF#d= s  
//读取保存的下载信息(文件指针位置) |R:v<  
private void read_nPos() ~50y-  
{ BdRE*9.0  
try{ FN8=YUYK%  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o>QFd x  
int nCount = input.readInt(); PAO[Og,-  
nStartPos = new long[nCount]; H@OrX  
nEndPos = new long[nCount]; C_g"omw40  
for(int i=0;i<nStartPos.length;i++) rA>A=,  
{ fS'k;r*r  
nStartPos = input.readLong(); +A.a~Stt  
nEndPos = input.readLong(); @8x6#|D  
} 3e!a>Gl*  
input.close(); UlLM<33_)  
} JXD?a.vy^q  
catch(IOException e){e.printStackTrace ();} 2!"\;/  
catch(Exception e){e.printStackTrace ();} O_%PBgcJr  
} @pEO@bbg>  
EzeDShN=J  
0YTtA]|`4  
private void processErrorCode(int nErrorCode) -sGWSC  
{ {R6Zwjs  
System.err.println("Error Code : " + nErrorCode); hIg, 0B  
} .P0Qs&i  
?Pok-90  
c=U$$|qHV  
//停止文件下载 6#lC(ko'  
public void siteStop() $=S'#^Z  
{ cVv4gQD\  
bStop = true; (tz_D7c$F  
for(int i=0;i<nStartPos.length;i++) 8 MACbLY  
fileSplitterFetch.splitterStop(); WPh |~]by<  
m}'t'l4 c  
6=`m   
} kxKnmB#m-  
} aZ`_W|  
//负责部分文件的抓取 olQ8s *  
**FileSplitterFetch.java odn97,A  
*/ ^QL/m\zq@%  
package NetFox; OKLggim{  
GwIfGixqH  
JWm^RQ  
import java.io.*; fuIv,lDA  
import java.net.*; \Z7([Gh  
o\:f9JL  
=-s20mdj  
public class FileSplitterFetch extends Thread { f 7QUZb\  
M b /X@51  
$'mB8 S  
String sURL; //File URL Ubos#hP  
long nStartPos; //File Snippet Start Position gP hw.e""  
long nEndPos; //File Snippet End Position +e3WwUx  
int nThreadID; //Thread's ID o- e,  
boolean bDownOver = false; //Downing is over [C~)&2wh>  
boolean bStop = false; //Stop identical 35]G_\  
FileAccessI fileAccessI = null; //File Access interface >cr_^(UW&  
zL!~,B8C  
(gJ )]/n  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .8uwg@yD  
{ Dy!bj  
this.sURL = sURL; 5}l#zj  
this.nStartPos = nStart; 7)6Yfa]I%  
this.nEndPos = nEnd; lVp~oZC6[  
nThreadID = id; h9OL%n 7m'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +qW w-8  
} :Kc0ak)<n  
1&dsQ, VDl  
|% YzGgp7  
public void run() :,z3 :PL  
{ zt>_)&b  
while(nStartPos < nEndPos && !bStop) _2Xu1q.6~5  
{ _=^hnv  
U"Ob@$ROFy  
LkZo/K~  
try{ He_(JXTP  
URL url = new URL(sURL); $?JLCa  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'V9aB5O&  
httpConnection.setRequestProperty("User-Agent","NetFox"); E<G@LT  
String sProperty = "bytes="+nStartPos+"-"; i7!mMO8]  
httpConnection.setRequestProperty("RANGE",sProperty); ZT6X4 Z  
Utility.log(sProperty); :iOHc-x  
gW pT:tX-  
qLi1yH  
InputStream input = httpConnection.getInputStream(); 9xS`@ "`  
//logResponseHead(httpConnection); ;>8TNB e!  
@p` CAB  
JE:n`l/p  
byte[] b = new byte[1024]; zam0(^=  
int nRead; gl\$jDC9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Zow^bzy4  
{ !m:PBl5  
nStartPos += fileAccessI.write(b,0,nRead); 4l!Yop0h  
//if(nThreadID == 1) Y l3[~S  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'UG}E@G  
} ]! J3?G  
{$TB#=G  
~TK^aM  
Utility.log("Thread " + nThreadID + " is over!"); l:Xf(TLa  
bDownOver = true; Nb9V/2c;V  
//nPos = fileAccessI.write (b,0,nRead); OVo  
} Jz3<yQ-  
catch(Exception e){e.printStackTrace ();} e]B<\i\T  
} LY cSMuJ  
} 64?$TT  
3 !w>"h0(  
@`+$d=rO`  
//打印回应的头信息 Cy> +j{%!  
public void logResponseHead(HttpURLConnection con) <[f2ZS6  
{ ~U*N'>'=)  
for(int i=1;;i++) VGUDUM.8  
{ 714nUA872  
String header=con.getHeaderFieldKey(i); e4H0<h }{  
if(header!=null) e%0#"6}  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OZ0%;Y0  
Utility.log(header+" : "+con.getHeaderField(header)); Tvw2py q  
else 1~u\]Zi=D  
break; `xAJy5  
} xr3PO?:  
} 1Y"qQp  
Ri6 br  
c1!/jTX$  
public void splitterStop() jG ;(89QR/  
{ b0=AQ/:  
bStop = true; jL).B&  
} @.@#WHde  
i-vJ&}}  
tsC|R~wW  
} eKti+n.  
VP[!ji9P   
5$Q`P',*Ua  
/* %c2i.E/G  
**FileAccess.java " /-v 9  
*//文件访问(定位,写) x[@3;_'K  
package NetFox; QAnfxt6  
import java.io.*; R/xCS.yl}  
{Qmb!`F  
/2V',0  
public class FileAccessI implements Serializable{ Wv/5#_  
ea}KxLC`,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;|1P1H-W~M  
RandomAccessFile oSavedFile; r_Yl/WW  
long nPos; `a-T95IFy  
'n.9qxY;  
$=SYssg7La  
public FileAccessI() throws IOException WY~[tBi\  
{ 1L qJ@v0  
this("",0); rL/7wa  
} He;%6OG{  
]H'82a  
ddhTr i'f  
public FileAccessI(String sName,long nPos) throws IOException 3evfX[V#  
{ \gv x)S11  
oSavedFile = new RandomAccessFile(sName,"rw"); ?o'arxCxZn  
this.nPos = nPos; qc"/T16M]  
oSavedFile.seek(nPos); yVv3S[J  
} Z'bMIdV  
%--5bwZi  
4\WkXwoqQO  
public synchronized int write(byte[] b,int nStart,int nLen) buyz>IC P  
{ vrx3O  
int n = -1; CnA)>4E*'  
try{ emIbGkH  
oSavedFile.write(b,nStart,nLen); Pg C]@Q%  
n = nLen; G"sc;nT  
} m 4LM10  
catch(IOException e) RA67w&  
{ E?o8'r  
e.printStackTrace (); pra&A2Y\  
} +mv%z3"j;  
b#j5fEY  
#T`+~tW'|  
return n; j" .6  
} [+7X&B  
[kkcV5I-  
n}kz&,  
} D|#(zjl@  
?y@pR e$2  
'2{o_<m  
/* nE%qm -  
**SiteInfoBean.java V7i`vo3Cc  
*/ hIr^"kVK  
package NetFox; ~Nh7C b _  
o-Arfc3Q  
;H|M)z#[Z  
public class SiteInfoBean { 5LH ]B  
q8]k]:r  
# TF  
private String sSiteURL; //Site's URL D$ z!wV  
private String sFilePath; //Saved File's Path C}E ea~  
private String sFileName; //Saved File's Name \ .s".aA  
private int nSplitter; //Count of Splited Downloading File X/749"23  
7s3<}  
Nuq/_x  
public SiteInfoBean() XL9lB#v^  
{//nSplitter的缺省值为5 a8$pc>2E  
//default value of nSplitter is 5 7J/3O[2  
this("","","",5); th|Q NG  
} aX:$Q }S  
6* w;xf  
_ RT}Ee}Y  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nzDY!Y  
{ mn` Ae=  
sSiteURL= sURL; HEN9D/O=  
sFilePath = sPath; U %l{>*q  
sFileName = sName; (Cd `~*5  
this.nSplitter = nSpiltter; ,r4af<  
a@1gMZc*  
`r Ql{$9IC  
} ? GW3E  
e0 EJ[bG  
F4Z0g*^x  
public String getSSiteURL() ,/9|j*9H  
{ Jq)k?WS  
return sSiteURL; x|5/#H  
} 5P x_vtqP  
Xw5" JE!.  
i[J',  
public void setSSiteURL(String value) %R>MSSjvr  
{ VvKH]>*  
sSiteURL = value; `#U6`[[  
} +__Rk1CVh  
S0yT%V  
na)ceN2h  
public String getSFilePath() T94$}- 5/)  
{  1qF.0  
return sFilePath; XwMC/]lK<  
} 1cega1s3xR  
H R  
ysPW<  
public void setSFilePath(String value) 24fWj?A|^  
{ { q<l]jn9  
sFilePath = value; f^ qQ 5N  
} TmiQq'm[b  
[XK"$C]jHJ  
&5<lQ1  
public String getSFileName() EbHeP  
{ 2$=HDwv  
return sFileName; @hPbD?)M  
} Ja1*a,],L  
mHy]$Z  
2BY:qz%:  
public void setSFileName(String value) lhU#/}Z  
{ &D#v0!e~x  
sFileName = value; X(9Ff=0.~  
} EzaOg|  
~MX@-Ff  
^y,ip=<5\3  
public int getNSplitter() 3ssio-X  
{ p"Y=  
return nSplitter; H Vy^^$  
} 0a5P@;"a  
MRc^lYj{  
19_F\32  
public void setNSplitter(int nCount) 5YasD6l  
{ zD'gGxM1  
nSplitter = nCount; Jo ^ o`9  
} ?}.(k/  
} {U9jA_XX  
Df9}YI ;?  
 Bv3v;^  
/* ;DTNw=  
**Utility.java <Jx{Uv  
*/ "O`;zC  
package NetFox; ?W(f%/B#  
yLP0w^Q  
M<729M  
public class Utility { IP3-lru  
>*MB_m2|  
6dh PqL  
public Utility() Velmq'n  
{ foeVjL:T  
1 /`>Eh  
Dcf`+?3  
} [Zf<r1m  
Jc+U$h4  
//线程睡眠 3^\y>  
public static void sleep(int nSecond) Y'P8`$  
{ {BF\G%v;+  
try{ S.z;Bm  
Thread.sleep(nSecond);  7)T+!>  
} b#M<b.R)  
catch(Exception e) *QVE>{  
{ \r2w@F{C  
e.printStackTrace (); T]xGE   
} =%p"oj]:  
} M\%{!Wzo8  
ocMf}"  
//日志 4 R]|  
public static void log(String sMsg) > h9U~#G=  
{ tv0xfAV  
System.err.println(sMsg); g 0L 4  
} <j>@Fg#q  
,-Na'n  
wcOAyo5(n  
public static void log(int sMsg) $2.DZ  
{ z(xvt>  
System.err.println(sMsg); 8P 8"dN[  
} $#!~K2$  
} #SdaTMLFf  
86Rit!ih  
VlEkT9^:  
/* & 2b f  
**TestMethod.java R8 KL4g-d  
*/ ><=af 9T  
package NetFox; [Xrq+O,  
cE3co(j  
5IepVS(>?v  
public class TestMethod { g^idS:GtX5  
;9~z_orNQZ  
}yw\+fc  
public TestMethod() {*2A% }S  
{ ///xx/weblogic60b2_win.exe U{x'@/Ld  
try{ kB 2bT}  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sw&Qks? V  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v6GWD}HH,  
SiteFileFetch fileFetch = new SiteFileFetch(bean);  u32<=Q[  
fileFetch.start(); zb<+x(0y"  
} &$=F $  
catch(Exception e){e.printStackTrace ();} WM#!X!Vo  
AIeYy-f  
@.0,k a,X  
} "n\!y~:  
&.}zZ/  
] !H<vR$8  
public static void main(String[] args) H\S,^)drJ?  
{ 29GiNy+ob  
new TestMethod(); m4iR '~L}  
} ]mc,FlhU@  
} h3:,Gbyap  
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