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http断点续传简单实现(java)

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/* DjY8nePyE  
**SiteFileFetch.java >d#3|;RY  
*/ 5lGQ#r  
package NetFox; 7"#f!.E  
import java.io.*; d)\2U{  
import java.net.*; |88CBiu}  
uj)yk*  
d bCNhbN(  
public class SiteFileFetch extends Thread { Oc#>QZ3  
^}hJL7O'  
GtC7^ Z&E  
SiteInfoBean siteInfoBean = null; //文件信息Bean =)(0.E  
long[] nStartPos; //开始位置 C\OECVT  
long[] nEndPos; //结束位置 pp<E))&R  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 JwB"\&'1ZS  
long nFileLength; //文件长度 cu)U7  
boolean bFirst = true; //是否第一次取文件 -A}zJBcR  
boolean bStop = false; //停止标志 Vu%n&uF  
File tmpFile; //文件下载的临时信息 Y KY2Cw  
DataOutputStream output; //输出到文件的输出流 rmsQt  
0 k9<&  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) q~j)W$k  
public SiteFileFetch(SiteInfoBean bean) throws IOException UoHd-  
{ {tc57jsr  
siteInfoBean = bean; 0Q`&inwh  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); j|mv+O  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Z&-tMai;  
if(tmpFile.exists ()) 1\y@E  
{ w763 zi{  
bFirst = false; !j0_ cA  
read_nPos(); [3kl^TE  
} +mLD/gK`  
else 7k'gt/#up  
{ &sdx`,  
nStartPos = new long[bean.getNSplitter()]; _KN: o10U  
nEndPos = new long[bean.getNSplitter()]; Ev{MCu1!6  
} w:Ra7ExP  
iy}xICt  
Q(e{~ ]*  
O5M2`6|As  
} D#ZPq,f  
J+|/-{g  
-x{&an=  
public void run() 6A?8tm/0  
{ F\-Si!~oOz  
//获得文件长度 lov%V*tL  
//分割文件 x9&p!&*&IT  
//实例FileSplitterFetch >azEed<B  
//启动FileSplitterFetch线程 6} #"qqnx  
//等待子线程返回 I|T7+{5z  
try{ l!:^6i  
if(bFirst) lm*g Gy1i  
{ 2T?TM! \Q  
nFileLength = getFileSize(); zqf[Z3  
if(nFileLength == -1) o,*=$/or  
{ +?Ez} BP  
System.err.println("File Length is not known!"); m8+:=0|$  
} 8SZK:VE@  
else if(nFileLength == -2) [S0mY["  
{ !D;c,{Oz  
System.err.println("File is not access!"); ?A&%Cwj  
} G|*G9nQ  
else XXm'6xD-  
{ xNIGO/uI~  
for(int i=0;i<nStartPos.length;i++) #A )Ab%r8"  
{ 7]Rk+q2:  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); u{Ak:0G7  
} $UC{"0  
for(int i=0;i<nEndPos.length-1;i++) X3yS5wh d(  
{ }LQC.!  
nEndPos = nStartPos[i+1]; qnXTNs ?b  
} |IN[uQ  
nEndPos[nEndPos.length-1] = nFileLength; d@ (vg  
} AG>\aV"b  
} Du!._  
yLqF ,pvO  
b i~=x  
//启动子线程 +GeWg` \=  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `*k@4.J{  
for(int i=0;i<nStartPos.length;i++) 'Wp @b678  
{ dp<$Zw8BE  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vBoO'l9'M  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9yL6W'B!  
nStartPos,nEndPos,i); `ET& VV  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oM-[B h]A  
fileSplitterFetch.start(); Sc_5FX\Yx  
} `HyF_m>\  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J^:n* C  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M4:s;@qZ.  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l!@ 1u^v2  
nEndPos = " + nFileLength); (O0byu}  
// fileSplitterFetch[nPos.length-1].start(); E}YI WTX  
9!#EwPD$#  
gr+Pl>C{  
//等待子线程结束 M*`hDdS  
//int count = 0; $r15gfne>  
//是否结束while循环 30d#Lq  
boolean breakWhile = false; Mk5RHDh  
$3\,h; y  
YlKFw|=  
while(!bStop) Y.-S=Y   
{ T5e^J"   
write_nPos(); q.T:0|  
Utility.sleep(500); H,K`6HH  
breakWhile = true; ?1w"IjUS  
a g;dc  
FN\GE\H  
for(int i=0;i<nStartPos.length;i++) pkk4h2Ah  
{ "dtlME{Bx  
if(!fileSplitterFetch.bDownOver) $^h?:L:1n  
{ Y;_T=  L  
breakWhile = false; -Qb0:]sV#  
break; =/}X$,@2  
} /b%Q[ Ck_  
} I`^YAbnb  
if(breakWhile) }-nU3{1  
break; H~Uq?!=b  
wOg,SMiq  
%{'4. ,  
//count++; q qvF-mDN  
//if(count>4) A[JM4x   
// siteStop(); ir&.Z5=  
} #jP/k.  
yU_9a[$V  
L~&" aF/b  
System.err.println("文件下载结束!");  zy>}L #  
} .8H}Lf\  
catch(Exception e){e.printStackTrace ();} (0C&z/  
} AC4 l<:Yh  
x~+-VF3/  
mi^hvks<  
//获得文件长度 S^j,f'2  
public long getFileSize() jQ$BPEG&X  
{ s|2}2<+  
int nFileLength = -1; 0>@[o8  
try{ $ $4W}Ug3U  
URL url = new URL(siteInfoBean.getSSiteURL()); c-*2dV[@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6+PGwCS  
httpConnection.setRequestProperty("User-Agent","NetFox"); (h,Ws-O  
<L&eh&4c  
F,pCR7o>  
int responseCode=httpConnection.getResponseCode(); [:B*6FXMN~  
if(responseCode>=400) 88o:NJ}_  
{ m UgRm]  
processErrorCode(responseCode); XTo8,'UaP  
return -2; //-2 represent access is error E {>`MNj  
} GV6mzD@ <  
q-IWRb0j%a  
m =k%,J_  
String sHeader; F1c&0*_A  
I%xn,u  
Xw^X&Pp  
for(int i=1;;i++) &t_h'JX&  
{ c#pj:f*H  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o^GC=Aca`  
//Utility.log(in.readLine()); 1JeJxzv>C  
sHeader=httpConnection.getHeaderFieldKey(i); [hnK/4!  
if(sHeader!=null) r\xXU~$9v  
{ KY+]RxX  
if(sHeader.equals("Content-Length")) o0`q#>7!_b  
{ j04/[V)  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GAp!nix6h  
break; LdEE+"Jw  
} /^ 4"Qv\@/  
} VQ<5%+  
else VGZ6  
break; UH20n{_:  
} Ub)M*Cq0(o  
} aQ|hi F}  
catch(IOException e){e.printStackTrace ();} 8*Zvr&B,G  
catch(Exception e){e.printStackTrace ();} tIGs>, a=  
M&[b.t*  
F$yeF^\g  
Utility.log(nFileLength); Pux)>q] C  
@T7PZB&xnl  
c<tmj{$  
return nFileLength; :e2X/tl#  
} 968^ "T#  
Eem g  
$?f]ZyZr.  
//保存下载信息(文件指针位置) =P]GPEz_  
private void write_nPos() 5~l2!PY  
{ PEzia}m  
try{ gZ`DT  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `bqzg  
output.writeInt(nStartPos.length); |Fp'/~|w2d  
for(int i=0;i<nStartPos.length;i++) 7I3:u+  
{ .bfST.OA  
// output.writeLong(nPos); H,|YLKg-|  
output.writeLong(fileSplitterFetch.nStartPos); b:Dg}  
output.writeLong(fileSplitterFetch.nEndPos); / O)6iJ  
} >{XScxaB`  
output.close(); %wW'!p-<  
} >'Hx1;  
catch(IOException e){e.printStackTrace ();} -u~eZ?(!Ye  
catch(Exception e){e.printStackTrace ();} /qXzOd  
} xA-jvu9@  
0;cuX@A/a?  
OX3Xy7  
//读取保存的下载信息(文件指针位置) Ja [#[BJ?  
private void read_nPos() FL&dv  
{ ImHU:iR[J-  
try{ a}yR p  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VDn:SGj5  
int nCount = input.readInt(); )7AM3%z1?  
nStartPos = new long[nCount]; <kbnu7?a*  
nEndPos = new long[nCount]; q+%!<]7X  
for(int i=0;i<nStartPos.length;i++)  MYx88y  
{ 4)nt$fW  
nStartPos = input.readLong(); aAcKwCGq\  
nEndPos = input.readLong(); 3:AU:  
} #90c$ dc  
input.close(); 1eiw3WU;  
} - 0DZ::  
catch(IOException e){e.printStackTrace ();} h2;l1 G,  
catch(Exception e){e.printStackTrace ();} QgZJ`G--  
} vJThU$s-  
?*+1~m>  
3#mE( `|P  
private void processErrorCode(int nErrorCode) [gn[nP9  
{ vHc#m@4o  
System.err.println("Error Code : " + nErrorCode); {u4i*udG`)  
} `^%@b SE(  
"XB4yExy  
w%2ziwgh  
//停止文件下载 UR,?!rJ^B  
public void siteStop() ^U{P3 %uZ  
{ ;@4sd%L8V  
bStop = true; vX.]hp5~  
for(int i=0;i<nStartPos.length;i++) )Ga8`t"  
fileSplitterFetch.splitterStop(); PW)8aLU  
6sy,A~e  
.hne)K%={y  
} qK-qcPLsl  
} L!vWRwZwC  
//负责部分文件的抓取 K0 QH?F  
**FileSplitterFetch.java +.K*n&  
*/ S}mm\<=1  
package NetFox; CjV7q y  
$eMK{:$O  
eI?HwP{m  
import java.io.*; zzE]M}s  
import java.net.*; b"3uD`  
y($EK(cb  
3P`WPph  
public class FileSplitterFetch extends Thread { G<fS (q  
wt\m+!u`  
tNB%eb{  
String sURL; //File URL =h7[E./U1  
long nStartPos; //File Snippet Start Position |?yE^$a  
long nEndPos; //File Snippet End Position xD^wTtT  
int nThreadID; //Thread's ID pJ6Jx(  
boolean bDownOver = false; //Downing is over Rdj8 *f  
boolean bStop = false; //Stop identical ?sE@]]z  
FileAccessI fileAccessI = null; //File Access interface {83C,C-  
O!,Ca1N  
UQnBqkE  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jm+ blB^%K  
{ jJ<;2e~OW  
this.sURL = sURL; +K&?)?/=  
this.nStartPos = nStart; *?p ^6vO  
this.nEndPos = nEnd; [9J:bD  
nThreadID = id; r;'i<t{P  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sX!3_ '-  
} Wt"ww~h`(  
z6 a,0&;-L  
Q!`)e@r  
public void run() iel-<(~   
{ nfa_8  
while(nStartPos < nEndPos && !bStop) [\a:4vDAbi  
{ cB<O.@  
|zh +  
|+u+)C  
try{ ot0U-G(  
URL url = new URL(sURL); A`IHP{aB  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \*Ts)EW  
httpConnection.setRequestProperty("User-Agent","NetFox"); &M$Bt} <  
String sProperty = "bytes="+nStartPos+"-"; yYM_lobn  
httpConnection.setRequestProperty("RANGE",sProperty); r(]98a]o~  
Utility.log(sProperty); _tA7=*@8  
%6N)G!P  
S7Znz@  
InputStream input = httpConnection.getInputStream(); C_-%*]*,j  
//logResponseHead(httpConnection); drbe#FObX  
6N&| 2:U  
ovB=Zm  
byte[] b = new byte[1024]; CuIqh BW!  
int nRead; f&f`J/(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9QC< E|  
{ .(JE-upJ"  
nStartPos += fileAccessI.write(b,0,nRead); hRa\1Jt>a  
//if(nThreadID == 1) jmSt?M0.xV  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *!i,?vn  
} Etw~*  
& \JLTw  
4`$5 _} j!  
Utility.log("Thread " + nThreadID + " is over!"); O/(3 87=U  
bDownOver = true; Shs')Zs bv  
//nPos = fileAccessI.write (b,0,nRead); nT#37v  
} &yB%QX{3  
catch(Exception e){e.printStackTrace ();} =,O /,2)  
} g%ZdIKj!  
} Bj; [  
UmYD]  
1E8$% 6VV  
//打印回应的头信息 /9P^{ OZ;y  
public void logResponseHead(HttpURLConnection con) A 0 S8Dh$  
{ 6={IMkmA  
for(int i=1;;i++) RXUA!=e  
{ 7,f:Qi@g  
String header=con.getHeaderFieldKey(i); PBCb0[\  
if(header!=null) J_|7$ l/  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4C6=77Jr  
Utility.log(header+" : "+con.getHeaderField(header)); =Y/}b\9`T  
else q)NXyy4BT  
break; DQ%`v =  
} c!.=%QY  
} K4_~ruhr  
N`f!D>b:dn  
Rq"VB.ef&{  
public void splitterStop() dJloH)uJZ>  
{ Ih(:HFRMq6  
bStop = true; $|rCrak;  
} ={\![{L  
fBf]4@{  
C?8PT/  
} I; ^xAd3G  
3T"2S[gT  
VIb;96$Or  
/* 92s4u3 L;  
**FileAccess.java BO[+E' 2  
*//文件访问(定位,写) @8QFP3\1  
package NetFox; R_t~UTfI;  
import java.io.*; "tfn?n0  
yVT&rQ"{  
hJecCOA)'  
public class FileAccessI implements Serializable{ >9 q]>fJ  
G!nl'5|y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mp!YNI  
RandomAccessFile oSavedFile; < }<#W/  
long nPos; km9Gwg/zT  
SRP5P,-y  
nWKO8C>  
public FileAccessI() throws IOException ,m2A p\l  
{ hT.4t,wa8  
this("",0); EV:_Kx8fP  
} Vp|2wlFE-  
0Ulxp  
:8](&B68gE  
public FileAccessI(String sName,long nPos) throws IOException @m5O{[euj<  
{ (}9cD^F0n  
oSavedFile = new RandomAccessFile(sName,"rw"); $$k7_rs  
this.nPos = nPos; r5D jCV"  
oSavedFile.seek(nPos); <9=zP/Q  
} X'YfjbGo  
n>u.3w L  
wYZy e^7  
public synchronized int write(byte[] b,int nStart,int nLen) W/b"a?wE{  
{ s.f`.o  
int n = -1; d&/^34gn  
try{ )C'G2RV  
oSavedFile.write(b,nStart,nLen); X7t 5b7  
n = nLen; =9kj? u~  
} ]\[m=0K  
catch(IOException e) jn.R.}TT  
{ @<hF.4,]  
e.printStackTrace (); ;gZwQ6)i  
} 2b; rr  
&r&;<Q  
V*~1,6N [  
return n; ,h3269$J  
} J@oEV=L  
?R dmKA  
='7er.~\  
} K#_~ !C4L  
:&xz5c`"04  
83mlZ1jQz  
/* ev~dsk6k  
**SiteInfoBean.java m"96:v  
*/ $Sp*)A]E`  
package NetFox; !Sh^LYqn  
b7?U8/#'  
p>2||  
public class SiteInfoBean { 59&T/  
ST[2]   
9zXu6<|qrL  
private String sSiteURL; //Site's URL ^</65+OT+  
private String sFilePath; //Saved File's Path 'CP/ymf/a  
private String sFileName; //Saved File's Name b=6MFPbg  
private int nSplitter; //Count of Splited Downloading File SZCF3m&pz  
aO~s i=  
%1Vu=zCAW  
public SiteInfoBean() v[0DE*p  
{//nSplitter的缺省值为5 E"Ya-8d=  
//default value of nSplitter is 5 kWzuz#  
this("","","",5); j lYD~)  
} )2iM<-uB  
A8=e?%  
[5>S-Z  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \[Sm2/9v  
{ s`$NW^']  
sSiteURL= sURL; =gxgS<bde  
sFilePath = sPath; 4^ d+l.F  
sFileName = sName; <_##YSGh,  
this.nSplitter = nSpiltter; _myg._[  
F Q8RK~?`  
xi '72  
} ti$oZ4PpF  
N&6_8=3z  
Z7tU0  
public String getSSiteURL() .`oJcJ  
{ b &\3ps  
return sSiteURL; jF%)Bhn(  
} r Iya\z1W  
@4 zi]v  
I-RdAVB/Ep  
public void setSSiteURL(String value) D6&mf2'u  
{ FRl3\ZDqrb  
sSiteURL = value; 'hwV   
} U%mkhWn  
[}W^4,  
6F|Hg2tpz  
public String getSFilePath() DFt=%aV[  
{ _hAj2%SL  
return sFilePath; 0EL\Hd  
} ({;P#qCX  
7\7Brw4  
yt/20a  
public void setSFilePath(String value) 6%\7.h  
{ SREDM  
sFilePath = value; Tf&f`/  
} `jD8(}_  
/|4Q9=  
OqfhCNAY  
public String getSFileName() Bo\a  
{ WUE)SVf  
return sFileName; ^kCk^D-Gz  
} 'Z*\1Ci  
u)q2YLK8  
e3yorQ][  
public void setSFileName(String value) KuIt[oM  
{ e.)yV'%L  
sFileName = value; }};j2  
} 1kB'sc3N!  
SQO>}#qm  
Bi9 N  
public int getNSplitter() { 4_I7r  
{ d-6sC@PB  
return nSplitter; ,wwU` U  
} f7EIDFX>pt  
&^CL] &/  
2.fyP"P L  
public void setNSplitter(int nCount) T[Z <bW~0  
{ 2]of SdM  
nSplitter = nCount; ,XWay%8{E  
} G"T;l"TAt8  
} ,\sR;=svK  
w6WGFQ_%  
R`Ys;g/!  
/* <;$Sa's,LE  
**Utility.java :wv :#EaH  
*/ _1w.B8Lyz@  
package NetFox; E)&NP}k-P  
1=9qAp;?o  
r+{!@`dYi  
public class Utility { #hy5c,}>  
ugIm:bg&  
38x[Ad4%  
public Utility() ^D ]7pe  
{ ~>}dse  
U<ku_(2"#  
mr{k>Un\  
} Y0P}KPD  
bl:a&<F  
//线程睡眠 ZXssvjWQV}  
public static void sleep(int nSecond) 4*N@=v  
{ [3{:H"t  
try{ M(.uu`B  
Thread.sleep(nSecond); )[y!m9Vn  
} JqVBT+:  
catch(Exception e) _H^^2#wc/  
{ HobGl0<y  
e.printStackTrace (); N[+o[%A  
} |?;"B:0  
} ohQz%?r  
YO.`l~ v  
//日志 Y5h)l<P>B  
public static void log(String sMsg) ]HNT(w@  
{ )M&Azbu  
System.err.println(sMsg); }2iKi(io*  
} +YQ)}v  
#"=yQZ6Y  
MYDf`0{$_a  
public static void log(int sMsg) (x1"uy7_  
{ k$$S!qi#  
System.err.println(sMsg); 0] :*v?  
} J-eA,9J  
} 9:CVN@E  
J]=aI>Ow  
3%vx' 1h[  
/* ?vht~5'  
**TestMethod.java T(sG.%  
*/ 1eE]4Z4Q  
package NetFox; JhMrm%  
$.r}g\43P  
X_0{*!v8  
public class TestMethod { oSu|Yn  
Ru9pb~K  
6?<`wGs(  
public TestMethod() , IMT '*  
{ ///xx/weblogic60b2_win.exe EvH(Po h  
try{ 7b7%(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (_%JF[W  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $dVgFot  
SiteFileFetch fileFetch = new SiteFileFetch(bean);  hZss  
fileFetch.start(); G +nY}c  
} [kp7LA"`  
catch(Exception e){e.printStackTrace ();} %CsTB0Y7n,  
HAI1%F236  
Q8gdI  
} JX2 |  
b]so9aCz  
"b1R5(Ar  
public static void main(String[] args) K;ry4/Vap  
{ ^;bGP.!p  
new TestMethod(); 35@Ibe~  
} e%@[d<Ta\  
}  4s1kZ`e  
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