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http断点续传简单实现(java)

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/* 6 }qNH29  
**SiteFileFetch.java E,u@,= j  
*/ xhj A!\DS  
package NetFox; !YsL x[+  
import java.io.*; =?0o5|u]  
import java.net.*; l)HF4#Bs  
.P9ALJP(b  
XNf%vC>  
public class SiteFileFetch extends Thread { k P>G4$e_v  
X@5!I+u\L  
XQ%*U=)s  
SiteInfoBean siteInfoBean = null; //文件信息Bean a@lvn/b2  
long[] nStartPos; //开始位置 tlQ3 BKp  
long[] nEndPos; //结束位置 4)*8&  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 S;MS,R  
long nFileLength; //文件长度 d9sl(;r  
boolean bFirst = true; //是否第一次取文件 T Jp(  
boolean bStop = false; //停止标志 QrHI}r  
File tmpFile; //文件下载的临时信息 [F*t2 -ta  
DataOutputStream output; //输出到文件的输出流 = %\;7  
2r,K/'  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 'h.{fKG]ME  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5L"{J5R}  
{ g(>;Z@Y  
siteInfoBean = bean; /H^=`[Mr  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); / \!hW-+]W  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ;Pnz4Y4|eU  
if(tmpFile.exists ()) aYkm]w;C  
{ wH3FCfvm  
bFirst = false; /4<eI 3Z  
read_nPos(); |/Am\tk#13  
} uw&GXOzew9  
else 0:@:cz=#*  
{ .&T JSIx$  
nStartPos = new long[bean.getNSplitter()]; n Uz 2~z  
nEndPos = new long[bean.getNSplitter()]; q!$?G]-%  
} lnEc5J@c>i  
~}z{RE($v  
M4XnuFGB[w  
"$;=8O5O  
} "/[-U;ck  
2d>kc2=*  
KtA0 8?B  
public void run() w6'o<=  
{ nMNAn}~*M  
//获得文件长度 h$_Wh(  
//分割文件 &-470Z%/  
//实例FileSplitterFetch !r,ZyJU  
//启动FileSplitterFetch线程 Ts:3_4-k  
//等待子线程返回 "O<JVC{m  
try{ 7,d^?.~S  
if(bFirst) `f}}z5  
{ cH.T6u_%  
nFileLength = getFileSize(); |g}! F-  
if(nFileLength == -1) zT6ng#  
{ tV9BVsN  
System.err.println("File Length is not known!"); $Ud-aRlD  
} @ZK#Y){  
else if(nFileLength == -2) E tWpBg  
{ fJtJ2xi  
System.err.println("File is not access!"); xO`w| k  
} {  KE[8n  
else muwXzN(KX  
{ p^Kp= z  
for(int i=0;i<nStartPos.length;i++) vtc} )s\  
{ U#gHc:$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); l[.*X  
} >&f .^p  
for(int i=0;i<nEndPos.length-1;i++) :CV!:sUm  
{ T?I&n[Y|  
nEndPos = nStartPos[i+1]; 36s[hg  
} pv~XZ(J.1  
nEndPos[nEndPos.length-1] = nFileLength; c (O+s/  
} 7]_UZ)u  
} Ro*$7j0!Hf  
4tz8^z[Kw  
kzZtKN9Az  
//启动子线程 C0[Rf.*  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^)m]j`}IGb  
for(int i=0;i<nStartPos.length;i++) @#c(4}^ <w  
{ f#pT6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w;vp X>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =iC5um:  
nStartPos,nEndPos,i); r*C:)z .}  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q*+@"tk<  
fileSplitterFetch.start(); E j@M\  
} s1<_=sfnT  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y%Ui)UMnw]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B08q/ qi  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f&bY=$iff  
nEndPos = " + nFileLength); [Qa0uM#SU  
// fileSplitterFetch[nPos.length-1].start(); s[)2z3  
%L+/GtxK  
;Z:z'';Lm  
//等待子线程结束 ;TD<\1HJT=  
//int count = 0; >V;JI;[  
//是否结束while循环 XtRfzqg?K  
boolean breakWhile = false; 12])``9  
X&0m$x  
CsS0(n(x  
while(!bStop) 0I* ^VGZ  
{ Z`v6DfK}  
write_nPos(); O66\s q  
Utility.sleep(500); u`$,S& Er  
breakWhile = true; %?J\P@  
2/RK pl &  
e<dFvMO  
for(int i=0;i<nStartPos.length;i++) dt{ |bQLu3  
{ <~!7?ak  
if(!fileSplitterFetch.bDownOver) Pk T&zSQA  
{ W%hdS<b  
breakWhile = false; i)Vqvb0Q  
break; b{)9 ?%_  
} Hq8<g$  
} J\b,rOIf  
if(breakWhile) \/$T 3f`x  
break; ptQr8[FA  
#!u P >/  
G5egyP;  
//count++; BoG/Hd.S  
//if(count>4) Mcj4GjV6:"  
// siteStop(); TD].*9  
} JXUnhjB,B  
B3@   
d*khda;Vj  
System.err.println("文件下载结束!"); z[b,:G  
} %+|k>?&z7  
catch(Exception e){e.printStackTrace ();} fu}NH \{  
} aCcBmc  
S&}7jRH1  
EShc1KPqc  
//获得文件长度 *E+2E^B  
public long getFileSize() }OJ*o  
{ `sQ\j Nu  
int nFileLength = -1; - y{*U1[  
try{ >~_y\  
URL url = new URL(siteInfoBean.getSSiteURL()); 9G` 2t~%  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "zc@(OA[z  
httpConnection.setRequestProperty("User-Agent","NetFox"); $TU=^W)X  
d?Gf T$1  
!p >a,8w  
int responseCode=httpConnection.getResponseCode(); nS"K dPM  
if(responseCode>=400) o<1e-  
{ GBzC<e#  
processErrorCode(responseCode); s+(%N8B  
return -2; //-2 represent access is error TDBWYppM  
} BWFl8 !_X  
/p~"?9b[ i  
D{Y~ kV|  
String sHeader; w5gN8ZF3  
A9qCaq{  
^+oi|y  
for(int i=1;;i++) vC E$)z'"  
{ m~1{~'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); TC?kuQI  
//Utility.log(in.readLine()); ?{?mAb c  
sHeader=httpConnection.getHeaderFieldKey(i); 7'S/hV%  
if(sHeader!=null) R[LVx-e7'  
{ w(8q qU+\  
if(sHeader.equals("Content-Length")) 1 >jG*tr  
{ `I,A7b  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O*d&H;;  
break; wXPNfV<(2  
} FXV=D_G}  
} #x1AZwC  
else q -M&f@Il  
break; >"jV8%!sM  
} /*`BGNkYY  
} ~"\sL;B  
catch(IOException e){e.printStackTrace ();} Ziu f<X{  
catch(Exception e){e.printStackTrace ();} nQdNXv<(  
k(C?6Gfj  
'!Ps4ZTn_  
Utility.log(nFileLength); T~cq=i|O  
$^ (q0zR~l  
>hoIJZP,  
return nFileLength; X_C9Z  
} ;_amgRP7$  
TP{lt6wws(  
a3?Dtoy'  
//保存下载信息(文件指针位置) -b~MQ/, 2  
private void write_nPos() ih.UzPg  
{ </t_<I0{  
try{ 1 iS9f~  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `]\4yTd  
output.writeInt(nStartPos.length); 'G>Ejh@t  
for(int i=0;i<nStartPos.length;i++) 7U:,:=  
{ 2_vE  
// output.writeLong(nPos); BnvUPDT&  
output.writeLong(fileSplitterFetch.nStartPos); VD/Wl2DK  
output.writeLong(fileSplitterFetch.nEndPos); 96]lI3 c  
} WLiY:X(+|  
output.close(); r/HKxXT  
} s#`%c({U|  
catch(IOException e){e.printStackTrace ();} SW (7!`  
catch(Exception e){e.printStackTrace ();} {.bLh 0  
} aQCbRS6  
vY *p][$  
r=n|MT^O  
//读取保存的下载信息(文件指针位置) :>nk63V (  
private void read_nPos() ioi0^aM  
{ VxjEKc  
try{ Fly@"W4a  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); '&Q_5\Tn  
int nCount = input.readInt(); g,Kb9['  
nStartPos = new long[nCount]; _Jk-nZgn  
nEndPos = new long[nCount]; SOb17:o3|  
for(int i=0;i<nStartPos.length;i++) $JqdI/s  
{ ~53E)ilB  
nStartPos = input.readLong(); [T"oqO4%]  
nEndPos = input.readLong(); ^8.R 'Yq  
} Tr)a6Cf  
input.close(); l"}W $3]u$  
} z~4L=tA(  
catch(IOException e){e.printStackTrace ();} ^c< <I-o|  
catch(Exception e){e.printStackTrace ();} ?Ee?Ol?i2  
} }E]`ly<Z  
aBr%"&Z.MG  
c[!e*n!y  
private void processErrorCode(int nErrorCode) Ptzha?}OZ  
{ DG8$zl5  
System.err.println("Error Code : " + nErrorCode); {5.,gb@6  
} *`ehI_v :  
V J){@  
n]ar\f  
//停止文件下载 d`StBXG!  
public void siteStop() R" 5/  
{ ~Cks)mJs  
bStop = true; / Zz2=gDY  
for(int i=0;i<nStartPos.length;i++) qz E/n   
fileSplitterFetch.splitterStop(); QoDWR5*^D  
a: iIfdd4'  
hOfd<k\A  
} +hY/4Tx<  
} gwThhwR  
//负责部分文件的抓取 U'";  
**FileSplitterFetch.java 6TfL|W<  
*/ jt"p Js'  
package NetFox; eWqJ2Tt  
9Lk.\.  
EM vV  
import java.io.*; LAw X9q`  
import java.net.*; uWx/V+w  
PHfGl  
;Bc f~[ErM  
public class FileSplitterFetch extends Thread { (z2)<_bXJ  
PfnhE>[>cf  
LN?T$H  
String sURL; //File URL !aa^kcEjnL  
long nStartPos; //File Snippet Start Position q*DR~Ov  
long nEndPos; //File Snippet End Position i.cSD%*  
int nThreadID; //Thread's ID uFSgjWJ#~  
boolean bDownOver = false; //Downing is over %!(6vm>8  
boolean bStop = false; //Stop identical ]!YzbvoR  
FileAccessI fileAccessI = null; //File Access interface <2A4}+p:  
W}Nd3  
2r?g|< :  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q5lRc=.b[  
{ =_%:9FnQ0  
this.sURL = sURL; wIx Lr{  
this.nStartPos = nStart; K_]LK  
this.nEndPos = nEnd; t@}<&{zk  
nThreadID = id; ~rpYZLH/:0  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 XZd !c Ff  
} F!pUfF,&  
F__DPEAc_  
WHbvb3'  
public void run() ?aSL'GI  
{ 3WPMS/  
while(nStartPos < nEndPos && !bStop) VxjHB?)  
{ &9o @x]) @  
AKa{C f  
"kP.Kx!  
try{ L2{tof  
URL url = new URL(sURL); GgA =EdJn  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M*t@Q|$:  
httpConnection.setRequestProperty("User-Agent","NetFox"); E'XF n'  
String sProperty = "bytes="+nStartPos+"-"; e{=7,DRH<  
httpConnection.setRequestProperty("RANGE",sProperty); &JfyXM[]  
Utility.log(sProperty); mWmDH74  
^Xa-)Pu  
9!2KpuWji  
InputStream input = httpConnection.getInputStream(); r}f -.Fo  
//logResponseHead(httpConnection); 7dPA>5"XD  
%=#&\ldPS  
(~}l?k  
byte[] b = new byte[1024]; ]YevO(  
int nRead; rZJp>Q)s  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G9E?   
{ g^B 6N F  
nStartPos += fileAccessI.write(b,0,nRead); N_C\L2  
//if(nThreadID == 1) \hi{r@k>}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p@cPm8L3  
} M_9|YjwS  
_ esFx  
aMv  
Utility.log("Thread " + nThreadID + " is over!"); sB7DF<91  
bDownOver = true; D3XQ>T[*q  
//nPos = fileAccessI.write (b,0,nRead); -.^Mt.)  
} %NeKDE  
catch(Exception e){e.printStackTrace ();} jy&p_v1  
} Fi7pq2  
} ,{'~J @  
^4s#nf:}  
?[XH`c,  
//打印回应的头信息 z w5EaY  
public void logResponseHead(HttpURLConnection con) vf5[x!4  
{ Em4TEv  
for(int i=1;;i++) {\]SvoJnJ  
{ mT!~;] RrF  
String header=con.getHeaderFieldKey(i); F>^k<E?,C  
if(header!=null) w?Q@"^IL  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); IDLA-Vxo  
Utility.log(header+" : "+con.getHeaderField(header)); s)]|zu0"Ku  
else OmU.9PDg-  
break; ;y HA.}  
} s?0r\cc|:  
} QQC0uta`  
.Z/"L@  
"G`)x+<~Z8  
public void splitterStop() vtL)  
{ )}paQmy#  
bStop = true; y99G3t  
} i&_sbQ^  
l8^^ O   
X^aujK^@  
} RCxqqUS\C  
bZ3CJ f&mE  
|$1j;#h  
/* #wC4$y<>  
**FileAccess.java H2k>E}`  
*//文件访问(定位,写) !_x-aro3<  
package NetFox; xss D2*l  
import java.io.*; apw8wL2  
j5$Sm  
q=96Ci_a  
public class FileAccessI implements Serializable{ C}+(L3Z  
jriliEz;f  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 j4G,Z4  
RandomAccessFile oSavedFile; Q%t8cJ L  
long nPos; &,e@pvc3  
/j S  
Cs*u{O  
public FileAccessI() throws IOException {BKI8vy  
{ n'M}6XUw  
this("",0); :+[q `  
} 9KAXc(-  
^[qmELW#7  
OM, uR3,  
public FileAccessI(String sName,long nPos) throws IOException p=Vm{i7  
{ eRv3ZHH  
oSavedFile = new RandomAccessFile(sName,"rw"); s \kkD *  
this.nPos = nPos; -Tz/ZOJ  
oSavedFile.seek(nPos); :T'"%_d5  
}  Rl 6E  
.^Ek1fi.  
nnr(\r~  
public synchronized int write(byte[] b,int nStart,int nLen) Qz/=+A/4  
{ )9@Ftzg|  
int n = -1; uV%7|/fD  
try{ m _:ib}  
oSavedFile.write(b,nStart,nLen); D$ `yxc  
n = nLen; M4')gG;  
} 1}V_:~7  
catch(IOException e) #]:nQ (  
{ 4'X^YBm  
e.printStackTrace (); fmloh1{4  
} }|A%2!Q}  
#kV= ;(lq  
%Xp}d5-  
return n; F!SmCE(0x  
} ,T1 t`  
eqjl$QWPJS  
r!#a.  
} L4Kkbt<x  
eOLS  
nk6xavQji  
/* r[~K m5  
**SiteInfoBean.java vT[%*)`  
*/ D+"5R5J",  
package NetFox; /4=O^;   
e'7!aysj  
#M8"b]oh6  
public class SiteInfoBean { >B~p[wh0  
vsES`  
C\EV $U,  
private String sSiteURL; //Site's URL QEtZ]p1H@  
private String sFilePath; //Saved File's Path ea7v:#O[S  
private String sFileName; //Saved File's Name BH%eu 7`t  
private int nSplitter; //Count of Splited Downloading File tR2IjvmsX  
lm@<i4%$F  
^#"!uCq]gM  
public SiteInfoBean() oOJN?97!k  
{//nSplitter的缺省值为5 E#_}y}7JY  
//default value of nSplitter is 5 m2VF}% EIr  
this("","","",5); ~":?})  
} "-^TA_XfI  
S W  
4$vya+mAk5  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L!/USh:IP  
{ qW7S<ouh  
sSiteURL= sURL; Pk*EnA)  
sFilePath = sPath; 5z#>>|1>#  
sFileName = sName; -*tP_=-Dg  
this.nSplitter = nSpiltter; J^1w& 40  
9Y*6AaKE6  
mDj:w#q  
} dr:)+R  
V&NOp  
^$yr-p%-  
public String getSSiteURL() [l'~>  
{ PsLuyGR.<  
return sSiteURL; 7eh}Je8  
} AA yzT*^  
UyIjM;X  
JNk ]$ xz  
public void setSSiteURL(String value) Az" 3f  
{ r#^X]  
sSiteURL = value; [}d 3 u!  
} I_Oa<J\+  
3LX<&."z  
ly6?jVJ  
public String getSFilePath() b ~v  
{ Q{mls  
return sFilePath; f'R^MX2  
} ~@L$}Eu  
PZH]9[H  
[)9bR1wh  
public void setSFilePath(String value) Dth<hS,2J  
{ b6oPnP_3P  
sFilePath = value; {v~&.|  
} 8a e]tX5$  
}%_x T  
?u 9) GJO[  
public String getSFileName() t</Kel|D  
{ ;>|:I(l;  
return sFileName; 9k2HP]8=[{  
} E jBEZL|_  
E%jOJA  
g24)GjDi  
public void setSFileName(String value) I@ }:} 8t  
{ D='/-3f!F]  
sFileName = value; $5cLhi"`  
} 9 `J`(  
=^=9z'u"=  
g"xLS}Al  
public int getNSplitter() JTl 37j  
{  {EZ ;  
return nSplitter; 1 dI  
} -twIF49  
QTK \"  
OsvAm'B  
public void setNSplitter(int nCount) HIi"zo=V  
{ 5K{(V^88F  
nSplitter = nCount; %^gT.DsX-  
} %+FM$xyJ  
} =@V4V} ?  
~SP.&>Q>  
t3v*P6  
/* 0O"GI33Mg  
**Utility.java c3i|q@ k  
*/ e +4p__TmZ  
package NetFox; ^/mQo`[G  
9?bfZF4A=  
BalOph4M[  
public class Utility { ?i)-K?4Sb  
BxO2w1G  
u\&oiwSIP  
public Utility() n4(w?,w }  
{ ANp4yy+  
W[j =!o  
9j$ OU@N 8  
} <`*6;j.&  
u=#LY$  
//线程睡眠 (= uwx#  
public static void sleep(int nSecond) ?GB($D=Y'&  
{ cV)fe`Gg  
try{ ,t61IU3"  
Thread.sleep(nSecond); t*e+[  
} +5? s Yp\  
catch(Exception e) j\!zz  
{ :14O=C  
e.printStackTrace (); c{rX7+bN  
} zO9|s}J8q  
} Z]uN9c  
l yO_rZT  
//日志 $vlgiJ&f  
public static void log(String sMsg) u%VO'}Gz  
{ f![x7D$  
System.err.println(sMsg); k[y{&f,  
} c@5fiRPv!  
REnRpp$  
^X"G~#v=q  
public static void log(int sMsg) |C7GI[P  
{ X\X  
System.err.println(sMsg); =n9adq  
} T* -*U /  
} @\u)k  
%jKR\f G  
@Eqc&v!O  
/* <s]K~ Vo  
**TestMethod.java ,^:Zf|V  
*/ Xdq2.:\  
package NetFox; T1\Xz-1  
}_@cqx:n^  
 6:ZqS~-  
public class TestMethod { #}:VZ2Z  
"g>uNtt~  
( F0.lDZ  
public TestMethod() XrFyN(p  
{ ///xx/weblogic60b2_win.exe XuoI19V[  
try{ `lN1u'(:  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ud`V"X  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :4]&R9J>o  
SiteFileFetch fileFetch = new SiteFileFetch(bean); xm/v :hl=  
fileFetch.start(); }@SZ!-t%rD  
} ~k|~Q\   
catch(Exception e){e.printStackTrace ();} dH#S69>  
=qCVy:RL4  
(U/6~r'.L  
} ;9=9D{-4+  
)&se/x+  
QRgWzaI  
public static void main(String[] args) C&zgt :q6}  
{ z})H$]:$  
new TestMethod(); 1g2%f9G  
} j)'V_@  
} %q2dpzNW  
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