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http断点续传简单实现(java)

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/* D\^mh{q(  
**SiteFileFetch.java +iqzj-e&e[  
*/ 4|&_i)S-Y  
package NetFox; ::p%R@?  
import java.io.*; QE|x[?7e,!  
import java.net.*; 7@R^B=pb  
LC7%Bfn!  
o2D;EUsNX  
public class SiteFileFetch extends Thread { 0.\}D:x(z  
x) jc  
?8qN8rk^+  
SiteInfoBean siteInfoBean = null; //文件信息Bean K=! C\T"I%  
long[] nStartPos; //开始位置  :yw8_D3  
long[] nEndPos; //结束位置 "!Qi$ ]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 b@S~ =  
long nFileLength; //文件长度 D GL=\  
boolean bFirst = true; //是否第一次取文件 wg+[T;0S  
boolean bStop = false; //停止标志 j #~ S"t  
File tmpFile; //文件下载的临时信息 XRmE  
DataOutputStream output; //输出到文件的输出流 \_(|$Dhq  
nx(jYXVT  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 0.S7uH%"  
public SiteFileFetch(SiteInfoBean bean) throws IOException C#V_Gb  
{ 4T6: C?V  
siteInfoBean = bean; 0GW69 z  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5yyc 0UG  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); F}.R -j#  
if(tmpFile.exists ()) ;}lsD1S:  
{ J%]5C}v \  
bFirst = false; )<%CI#s#  
read_nPos(); ^-L nO%h?  
} n&!q9CR`  
else ~Ede5Vg!!2  
{ #@' B\!<@=  
nStartPos = new long[bean.getNSplitter()]; JXjH}C  
nEndPos = new long[bean.getNSplitter()]; ^RE[5h6^q  
} 4k9$' k  
Kum" }ux  
.HN4xL  
*k,{[b  
} t7yvd7  
Py?e+[cN  
|{ =Jp<} s  
public void run() I s|_  
{ ~z^49Ys:  
//获得文件长度 ;?q-]J?  
//分割文件 j115:f  
//实例FileSplitterFetch 9K;g\? 3  
//启动FileSplitterFetch线程 F~0iJnF  
//等待子线程返回 M6ZXq6J  
try{ >;]S+^dXY  
if(bFirst) Hh%"  
{ i%GiWanG  
nFileLength = getFileSize(); Z`f?7/"B  
if(nFileLength == -1) /U,(u9bq  
{ u aYI3w@^  
System.err.println("File Length is not known!"); F >H\F@Wl  
} Wv%F^(R7  
else if(nFileLength == -2) DQ}&J  
{ o=RxQk1N  
System.err.println("File is not access!"); TV|Z$,6l  
} r:PYAb=g  
else 37biRXqLH  
{ aTfc>A;  
for(int i=0;i<nStartPos.length;i++) .:XXc  
{ ~1XC5.*-  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); nI4oQE  
} z0x^HDAeC  
for(int i=0;i<nEndPos.length-1;i++) ^?_MIS`4N  
{ h@]{j_$u  
nEndPos = nStartPos[i+1]; CfO{KiM(2  
} P'SGt  
nEndPos[nEndPos.length-1] = nFileLength; z}iz~WZ  
} <>(v~a]  
} M1]w0~G  
y<*\D_J  
A8QUfg@uK~  
//启动子线程 k.})3~F-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nltOX@P-  
for(int i=0;i<nStartPos.length;i++) U\W$^r,  
{ 1cx%+-  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TD-B\ @_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P)LQ=b}V#;  
nStartPos,nEndPos,i); wz@[rMf  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,gW$m~\  
fileSplitterFetch.start(); '"XVe+.O  
} P9R-41!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |z8_]o+|r1  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C8do8$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eY%Ep=J  
nEndPos = " + nFileLength); JvEW0-B^l,  
// fileSplitterFetch[nPos.length-1].start(); 3UF^Ff<wo  
EuA352x  
lfG',hlI;  
//等待子线程结束 O$x +>^  
//int count = 0; xnJ#}-.7  
//是否结束while循环 z:N?T0b(  
boolean breakWhile = false; aO}p"-'  
mI\[L2x  
>l=jJTJ;q  
while(!bStop) rLY I\  
{ I. Xbowl  
write_nPos(); Hq~SRc~  
Utility.sleep(500); ?r*}1WsH  
breakWhile = true; ' R2*3<  
=(~*8hJ  
a^^OI|?  
for(int i=0;i<nStartPos.length;i++) Ted tmX$  
{ <WbO&;%  
if(!fileSplitterFetch.bDownOver) S;/pm$?/  
{ !]9qQ7+R%  
breakWhile = false; yRD tPK"E-  
break; O'(D:D?  
} s'd\"WaQV  
} 6;@:/kl t  
if(breakWhile) _RS CyV  
break; f =A#:d  
\ [M4[Qlq  
"rc QS H  
//count++; [w-# !X2y  
//if(count>4) ?!$Dr0r  
// siteStop(); 0'Qvis[kt  
} dtj b(*x  
82V;J 8T?  
hD7vjg& Z  
System.err.println("文件下载结束!"); !HtW~8|:  
} oA:`=f%\  
catch(Exception e){e.printStackTrace ();} GO*D4<#u  
} BlM(Q/z  
U ]B-B+-  
arS@l<79  
//获得文件长度 5E 9R+N  
public long getFileSize() Bk@EQdn  
{ pc QkJ F  
int nFileLength = -1; jwuSne  
try{ {9) HB:  
URL url = new URL(siteInfoBean.getSSiteURL()); {%RwZ'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ooCfr?E  
httpConnection.setRequestProperty("User-Agent","NetFox"); b\kA  
kIe)ocJg  
-G#m'W&  
int responseCode=httpConnection.getResponseCode(); Eg2SC?5  
if(responseCode>=400) {lUaN0O:  
{ Z 0v&AD=  
processErrorCode(responseCode); &T ^bv*P  
return -2; //-2 represent access is error % .ss  
} '|*e4n  
$"}[\>e*{  
_ /Eg_dQ~@  
String sHeader; e2>AL  
>5TXLOYZ  
)4hA Fy6l  
for(int i=1;;i++) .81 ~ K[  
{ ~]9EhC'l  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %h;1}SFl0  
//Utility.log(in.readLine()); TTWiwPo59  
sHeader=httpConnection.getHeaderFieldKey(i); |+JC'b?,  
if(sHeader!=null) ccx0aC3@I  
{ bj_/  
if(sHeader.equals("Content-Length")) Z.rhM[*+0C  
{ >z% WW&Z'  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~BE=z:  
break; :~ &#9  
}  tO D}&  
} fQ -IM/z  
else *+00  
break; oMYZ^b^  
} ixoN#'y<"  
} 7{k?" NF  
catch(IOException e){e.printStackTrace ();} SL\15`[{  
catch(Exception e){e.printStackTrace ();} fP8bWZ{  
C*1 1?B[  
'$ z@40u  
Utility.log(nFileLength); SLH;iqPT  
83aWMmA(1  
^>eV}I5ak  
return nFileLength; u6:$AA  
} +1\t 0P24  
G_WHW(8   
fEt BodA)  
//保存下载信息(文件指针位置) T{N8 K K  
private void write_nPos() *iyc,f^w  
{ jR+k x:+  
try{ NSR][h_  
output = new DataOutputStream(new FileOutputStream(tmpFile)); #BgiDLh  
output.writeInt(nStartPos.length); +CXq41g"c  
for(int i=0;i<nStartPos.length;i++) {d)L0KXK  
{ hvA|d=R(  
// output.writeLong(nPos); m%.[|sZ3EM  
output.writeLong(fileSplitterFetch.nStartPos); gO@LJ  
output.writeLong(fileSplitterFetch.nEndPos); uu>R)iTQ%S  
} Zw<<p|{)<  
output.close(); ?+%bEZ`  
} N| P?!G-=  
catch(IOException e){e.printStackTrace ();} FF|M7/[~  
catch(Exception e){e.printStackTrace ();} [o7Qr?RN  
} =+[` 9  
F[)tg#}@G  
g&8-X?^Q  
//读取保存的下载信息(文件指针位置) tbfwgK  
private void read_nPos() 6uk}4bdvq  
{ TQ%F\@"  
try{ %ZDO0P !/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sWKdqs  
int nCount = input.readInt(); =8"xQ>D62  
nStartPos = new long[nCount]; r029E-  
nEndPos = new long[nCount]; 0< }BSv  
for(int i=0;i<nStartPos.length;i++) ,,Ivey!kL  
{ YOA)paq+  
nStartPos = input.readLong(); ?V(+Cc  
nEndPos = input.readLong(); 6!;D],,"#.  
} k\g:uIsv$  
input.close(); vWL| vR  
} ZG~d<kM&8s  
catch(IOException e){e.printStackTrace ();} 9ESV[  
catch(Exception e){e.printStackTrace ();} .&8a ;Q?c  
} $ERiBALN:  
!HP=Rgh  
I%B\Wy/j^  
private void processErrorCode(int nErrorCode) UA*Kuad  
{ ep*8*GmP  
System.err.println("Error Code : " + nErrorCode); FMWM:  
} ,#%I$  
l|;]"&|_]c  
VtGZB3  
//停止文件下载 _?eT[!oO8  
public void siteStop() aB`jFp-  
{ T#[#w*w/  
bStop = true; R D?52\  
for(int i=0;i<nStartPos.length;i++)  NfmHa  
fileSplitterFetch.splitterStop(); $s 'n]]Wq  
g8" H{u  
n?9FJOqi  
} C 5e;U  
} 7*He 8G[W  
//负责部分文件的抓取 =j{Kxnv  
**FileSplitterFetch.java 3~Ap1_9  
*/ ["<'fq;PJ  
package NetFox; #%V+- b(  
QiJ  
lnF{5zc  
import java.io.*; LyL(~Jc|  
import java.net.*; ktp<o.f[  
+AFBTJ  
<\P `<  
public class FileSplitterFetch extends Thread { g0-rQA  
)l`VE_(|  
0ZZ Wj%  
String sURL; //File URL wyLyPJv  
long nStartPos; //File Snippet Start Position \eRct_  
long nEndPos; //File Snippet End Position Nx E=^ v  
int nThreadID; //Thread's ID QUh`kt(E  
boolean bDownOver = false; //Downing is over .8;0O M  
boolean bStop = false; //Stop identical "^Y zHq6  
FileAccessI fileAccessI = null; //File Access interface P'*Fd3B#A=  
uH[:R vC0  
xLgZtLt9  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \5Y<UJ Ki  
{ da@W6Ovx  
this.sURL = sURL; 2(Aw  
this.nStartPos = nStart; GR_caP  
this.nEndPos = nEnd; n9-WZsc1  
nThreadID = id; vF/wV'Kk  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 e0<O6  
} nyBT4e  
Zq5~M bldh  
9\0$YY%  
public void run() yD@eT:lyi  
{ 5du xW>D  
while(nStartPos < nEndPos && !bStop) fVdu9 l  
{ eo.B0NZsF  
yM,Y8^  
D_`NCnYG  
try{ J"TF@7{p  
URL url = new URL(sURL); X}g3[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,,BWWFg~  
httpConnection.setRequestProperty("User-Agent","NetFox"); w6pXF5ur>  
String sProperty = "bytes="+nStartPos+"-"; 3e1P!^'\  
httpConnection.setRequestProperty("RANGE",sProperty); w"? RbA  
Utility.log(sProperty); LC\U6J't1  
Z9Z\2t  
MIb [}w=  
InputStream input = httpConnection.getInputStream(); <d >!%  
//logResponseHead(httpConnection); Q X-n l~  
ru4M=D  
;V?d;O4u  
byte[] b = new byte[1024]; pbw{EzM  
int nRead; {-%8RSK=<  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z%\&n0  
{ e^$JGh2  
nStartPos += fileAccessI.write(b,0,nRead); ]b:>7_la  
//if(nThreadID == 1) 9Hd_sNUu\  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y*p02\)  
} II Amx[ b  
c5: X$k\  
Z[eWey_  
Utility.log("Thread " + nThreadID + " is over!"); 2( m#WK7>F  
bDownOver = true; sz%_9;`dpL  
//nPos = fileAccessI.write (b,0,nRead); mkl^2V13~  
} cv7:5P  
catch(Exception e){e.printStackTrace ();} C2\zbC[qm  
} A~ _2"  
} *N"CV={No  
n=|% H'U  
C7DwA/$D  
//打印回应的头信息 <XN=v!2;  
public void logResponseHead(HttpURLConnection con) NCl@C$W9q  
{ d`~~Ww1  
for(int i=1;;i++) n 8 K6m(  
{ E%W w)P  
String header=con.getHeaderFieldKey(i); &~2I Fp  
if(header!=null) 0=K8 nxdx  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MH9vg5QKp  
Utility.log(header+" : "+con.getHeaderField(header)); TPak,h(1  
else ww #kc!'  
break; Ivj=?[c|  
} 4I&Mdt<^D  
} u8M_2r  
DuIXv7"[  
 WjCxTBI  
public void splitterStop() A7|L|+ ?  
{ "F6gV;{Bt  
bStop = true; /bPs0>5  
} G=SMz+z  
76KNgV)3  
={+8jQqi1  
} b&dv("e 4  
-Mz [S  
DUh\x>^  
/* Ez-Q'v(9  
**FileAccess.java ge<D}6GQ  
*//文件访问(定位,写) ._Ww  
package NetFox; _l"nwEs  
import java.io.*; SD<a#S\o  
lk[Y6yE  
JodD6 ;P  
public class FileAccessI implements Serializable{ Ks@c wY  
s~9n13z  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Vu=/<;-N  
RandomAccessFile oSavedFile; C,GZ  
long nPos; t,IOq[Vtk  
8ZLHN',  
xV 2C4K  
public FileAccessI() throws IOException qZ&~&f|>e  
{ v^vi *c  
this("",0); 4d-(:  
} ODhq `?(N  
xwi6#>  
`E?0jQ  
public FileAccessI(String sName,long nPos) throws IOException x~wS/y  
{ -a&<Un/  
oSavedFile = new RandomAccessFile(sName,"rw"); 4e#$ -V   
this.nPos = nPos; w6WPfy(/2  
oSavedFile.seek(nPos); )%3T1 D/  
} j@ D,2B;  
.T3 m%n  
XM,slQ  
public synchronized int write(byte[] b,int nStart,int nLen) q b/}&J7+  
{ o. ;Vrc  
int n = -1; ^_<|~  
try{ o:fe`#t  
oSavedFile.write(b,nStart,nLen); RAP-vVh/C  
n = nLen; y&-QLX L  
} nosD1sS.K8  
catch(IOException e) B4wRwrVI>  
{ [ ~2imS  
e.printStackTrace (); j49Uj}:j  
} $LFL4Q  
2J8:_Ql3I  
u+KZ. n/  
return n; J9p4\=9  
} H;l_;c`  
-Ou.C7ol  
r$}C<a[U  
} m!ueqV"  
7t:tS7{}  
stBe ^C  
/* Z0m`%(MJa  
**SiteInfoBean.java sA77*T  
*/ v{fcQb  
package NetFox; ii-AE L  
>3Q|k{97  
?1a9k@[t  
public class SiteInfoBean { ne/JC(  
F_jHi0A  
%0N HU`j  
private String sSiteURL; //Site's URL $2L6:&.P,  
private String sFilePath; //Saved File's Path 6CIzT.  
private String sFileName; //Saved File's Name -p.\fvip  
private int nSplitter; //Count of Splited Downloading File ZcQu9XDIt  
DQm%=ON7  
e)g &q'O  
public SiteInfoBean() n=vDEX:'  
{//nSplitter的缺省值为5 *{!Y_FrL  
//default value of nSplitter is 5 hW< v5!,  
this("","","",5); "cPg_-n  
} z+yIP ?s}(  
Jt@lH  
RbXR/Rd  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O6R)>Y4  
{ |f#hGk6  
sSiteURL= sURL; pX?3inQP%(  
sFilePath = sPath; v/.'st2%  
sFileName = sName; f,KB BBbG  
this.nSplitter = nSpiltter; cN8Fn4gq  
'in%Gii  
v#d\YV{I  
} %gh#gH   
N}K [Q=  
IrqM_OjC  
public String getSSiteURL() oDz|%N2s|  
{ DylO;+  
return sSiteURL; C; N6",s!  
} YAOfuas]j  
jk03 Hd  
b j`\;_oo  
public void setSSiteURL(String value) YcN|L&R.  
{ E,}{iqAb  
sSiteURL = value; 7|DG1p9C  
} v{VF>qE P  
og5VB  
)hXTgUZa  
public String getSFilePath() Gl1XRNy C  
{ 6FA+q YSV  
return sFilePath; o8 JOpD  
} < $0is:]  
4a+gM._+O  
b-sN#'TDg  
public void setSFilePath(String value) dm4Q'u  
{ ` 3qf}=Z`  
sFilePath = value; <m]0!ii  
} d-D,Gx]>$  
yx :^*/  
ZH_$Q$9  
public String getSFileName() (?7=,A7^  
{ ^w60AqR8  
return sFileName; oLT#'42+H  
} L7-BuW}&  
1 :p'  
ew~Z/ A   
public void setSFileName(String value) >v.f H6P,}  
{  Sfz1p  
sFileName = value; +[!S[KE  
} S\g9 @g.  
I'4(Ibl+  
73;Y(uh9  
public int getNSplitter() Q[biy{(b8  
{ Jr2yn{s=S  
return nSplitter; ^v'kEsE^*  
} CUu Owx6%  
4 XjwU`  
wtTy(j,9  
public void setNSplitter(int nCount) .h-mFcjy  
{ Fv pU]  
nSplitter = nCount; ^l!SIu  
}   3%kUj  
} 4>*=q*<V5E  
.| 4P :r  
4v\HaOk  
/* "?NDN4l*  
**Utility.java s6,~J F^  
*/ Wigt TAh4  
package NetFox; bC `<A  
Z-PB CU  
'~D4%WKT  
public class Utility { $0_K&_5w~  
%Jt35j@Ee  
.9nqJ7]  
public Utility() yE8D^M|g  
{ !kovrvM6F  
ba|xf@=&  
K81X32Lm'  
} d`^3fr'.4A  
J:@gmo`M;V  
//线程睡眠 |g&V? lI  
public static void sleep(int nSecond) Lv%3 jj  
{ {N4 'g_  
try{ 4z0gyCAC A  
Thread.sleep(nSecond); .l1x~(  
} Nn LK!Q  
catch(Exception e) [ohLG_9  
{ FS1\`#Bm)  
e.printStackTrace (); 0cS$S Mn{  
} %R0 Wq4}  
} Hd~g\  
Lh[0B.g<  
//日志 ihrf/b  
public static void log(String sMsg) fDy*dp4z  
{ uy {O   
System.err.println(sMsg); Hr?lRaV  
} A8'RM F1  
^Arv6kD,  
`MI\/oM@  
public static void log(int sMsg) tbS hSbj  
{ Cn~VJ,l g  
System.err.println(sMsg); LYD iqOrx  
} 4 Ej->T.  
} TKB8%/_p  
n _K1%  
d{S'6*`D  
/* c4fH/-  
**TestMethod.java YV.' L  
*/ *yhA8fJ  
package NetFox; Z@zo~*o  
v"k ? e  
^*ZaqMA  
public class TestMethod { :uCwWv   
EO!,rB7I  
w6vbYPCN  
public TestMethod() KuJ)alD;1  
{ ///xx/weblogic60b2_win.exe }4C_r'd6  
try{  S_P&Fv  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6>]_H(z7  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V4,Gt ]4  
SiteFileFetch fileFetch = new SiteFileFetch(bean); rfwJLl/  
fileFetch.start(); )\1>)BJq  
} ~B;}jI]d[  
catch(Exception e){e.printStackTrace ();} w%])  
(<Cq_K w  
t\Vng0  
} )E9!m  
2.v{W-D[  
AU9C#;JD  
public static void main(String[] args) jEBn"]\D  
{ q;e b  
new TestMethod(); |5~Oh`w  
} rI$NNk'A  
} >?^oxB"<Gc  
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