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http断点续传简单实现(java)

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/* Fc~G*Gz~Z|  
**SiteFileFetch.java Hn|W3U  
*/ )4yP(6|lx  
package NetFox; 8dGsV5"*  
import java.io.*; BI1M(d#1L"  
import java.net.*; NJUKH1lIhR  
GWA"!~Hu  
I Dohv[#  
public class SiteFileFetch extends Thread { b}[S+G-9W  
3Z!%td5n  
1EyN |m|  
SiteInfoBean siteInfoBean = null; //文件信息Bean k# [!; <  
long[] nStartPos; //开始位置 <LHhs <M'  
long[] nEndPos; //结束位置 S,#1^S  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 OW7  
long nFileLength; //文件长度  YKyno?m  
boolean bFirst = true; //是否第一次取文件 {w@qFE'b  
boolean bStop = false; //停止标志 o`bch? ]  
File tmpFile; //文件下载的临时信息 xye-Z\-t  
DataOutputStream output; //输出到文件的输出流 g6GkA.!X$  
'!HTE` Aj  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) po| Ux`u  
public SiteFileFetch(SiteInfoBean bean) throws IOException `2lS@  
{ n6/Ous  
siteInfoBean = bean; (Ou%0 KW  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); GAz -yCJp  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); lA^1}  
if(tmpFile.exists ()) b9b Ivjm_  
{ M5dYcCDE  
bFirst = false; OUX7 *_  
read_nPos(); v=U<exM6%  
} 02;jeZ#z  
else /0s1;?  
{ a=z] tTs4  
nStartPos = new long[bean.getNSplitter()]; M(%H  
nEndPos = new long[bean.getNSplitter()]; >B BV/C'9  
} )(iv#;ByL  
g`XngRb|j  
OF-k7g7  
~tDYo)hH8  
} RRL{a6(?  
@!8aZB3odt  
VY?9|};f  
public void run() YF%gs{  
{ T &ZQ ie/  
//获得文件长度 n;g'?z=hy  
//分割文件 5ZCu6 A  
//实例FileSplitterFetch CIudtY(:  
//启动FileSplitterFetch线程 Fr9/TI  
//等待子线程返回 w,UE0i9I  
try{ J4Gzp~{  
if(bFirst) b^o4Q[  
{ cgnNO&  
nFileLength = getFileSize(); )U/jD  
if(nFileLength == -1) R9J!}az'  
{ ZpTDM1ro  
System.err.println("File Length is not known!"); #Hw|P  
} ?CpVA  
else if(nFileLength == -2) YT\`R  
{ &g`&#IRz  
System.err.println("File is not access!"); TW|K.t@5#H  
} N /4E ~^2  
else 2+1ybOwb  
{ V9c.(QY|f  
for(int i=0;i<nStartPos.length;i++) Myq8`/_  
{ DT-VxF6h  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `TrWtSwv  
} 9LR=>@Z  
for(int i=0;i<nEndPos.length-1;i++) K-RmB4WI  
{ Et=Pr+Q{c  
nEndPos = nStartPos[i+1]; %OQdUH4x  
} X9x`i  
nEndPos[nEndPos.length-1] = nFileLength; .-gJS-.c  
} D,#UJPyg  
} H$![]Ujq  
waMF~#PJlt  
}7 N6n Zj`  
//启动子线程 NxP(&M(  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &:&'70Ya  
for(int i=0;i<nStartPos.length;i++) lC<;Q*Y  
{ ' zyw-1  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i|:!I)(lh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e3I""D{)[=  
nStartPos,nEndPos,i); /jv/qk3i  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5.rAxdP  
fileSplitterFetch.start(); D|uvgu2  
} -TUJ"ep]QJ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c_8&4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <WXVUEea  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x,B] J4  
nEndPos = " + nFileLength); 'uL4ezTtA  
// fileSplitterFetch[nPos.length-1].start(); (x=$b(I  
F*72g)hVh  
RQVu~7d[  
//等待子线程结束 3j7FG%\  
//int count = 0; b8WtNVd  
//是否结束while循环 cu!%aM,/<-  
boolean breakWhile = false; jn(x-fj6R  
c 1YDln  
"@Vyc6L  
while(!bStop) *22Vc2[i;  
{ xyL"U*  
write_nPos(); Z.VKG1e}  
Utility.sleep(500); tv#oEM9esl  
breakWhile = true; kK &w5'  
WzIUHNn'I  
IJ^~,+  
for(int i=0;i<nStartPos.length;i++) 'a#lBzu\b  
{ BP/nK.  
if(!fileSplitterFetch.bDownOver) p2vN=[g9)  
{ J%"BCbxW~B  
breakWhile = false; 0|&@)`  
break; @MSmg3 &  
} lQ 8hY$  
} g'.OzD  
if(breakWhile) br I;}m  
break; rA~f68h|  
Z?)g'n  
7;jD>wp 9D  
//count++; "O34 E?ql.  
//if(count>4) 6bm7^e(  
// siteStop(); ,#Z%0NLe  
} [LoQYDku  
HP# SR';E  
(W}F\P  
System.err.println("文件下载结束!"); WZQ2Mi<&1'  
} c'oiW)8;A  
catch(Exception e){e.printStackTrace ();} $ XjijD9R  
} :ld~9  
{'b;lA]0  
5m8u:6kQu  
//获得文件长度 )/RG-L  
public long getFileSize() 4'QX1p  
{ q G%Y& P  
int nFileLength = -1; x|O7}oj  
try{ v,w af`)J  
URL url = new URL(siteInfoBean.getSSiteURL()); Giyh( DL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {&5lZ<nu8A  
httpConnection.setRequestProperty("User-Agent","NetFox"); m8sd2&4  
.}==p&(  
f-%M~:  
int responseCode=httpConnection.getResponseCode(); \jfK']P/H  
if(responseCode>=400) (/:m*x*6  
{ {JE [  
processErrorCode(responseCode); IkCuw./  
return -2; //-2 represent access is error "6B@V=d  
} %8*:VR  
PaCC UF  
BA@E  
String sHeader; 8t!jo.g  
J!:BCjRdw  
 ?eS;Yc  
for(int i=1;;i++) YBt=8`r  
{ 64B.7S88  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =B}IsBn'J  
//Utility.log(in.readLine()); ng}C$d . I  
sHeader=httpConnection.getHeaderFieldKey(i); +?J  N_aR  
if(sHeader!=null) )Zq'r L<  
{ A@V$~&JCL5  
if(sHeader.equals("Content-Length")) g,,wG k  
{ #9,8{ O"  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g+#<;Gbpe  
break; Xm#W}Y'  
} Xg dBLb  
} /4x\}qvU  
else [F6 )Z[uG  
break; 'K7\[if{  
} M%E<]H2;S  
} M<-Q8 a~  
catch(IOException e){e.printStackTrace ();} D ,kxB~  
catch(Exception e){e.printStackTrace ();} #`iEbiSq  
HE&)N clY  
Fm`*j/rq  
Utility.log(nFileLength); {$8+n::  
~/rD _K  
{H)7K.hQN  
return nFileLength; >7W)iwF  
} ]IV{;{E)  
x}/jh  
JSL&` `  
//保存下载信息(文件指针位置) }#ink4dK:  
private void write_nPos() @2E52$zu  
{ )Cy>'l*Og7  
try{ hF'VqJS  
output = new DataOutputStream(new FileOutputStream(tmpFile)); u@Hz7Q} P  
output.writeInt(nStartPos.length); $_S-R 3L\  
for(int i=0;i<nStartPos.length;i++) #)'Iqaq7  
{ ^yW['H6V  
// output.writeLong(nPos); d6n_Hpxw^  
output.writeLong(fileSplitterFetch.nStartPos); :E9pdx+  
output.writeLong(fileSplitterFetch.nEndPos); /EjXyrn2  
} )Rn\6ka  
output.close(); gX" -3w  
} \c2x udU  
catch(IOException e){e.printStackTrace ();} #D9.A7fCc5  
catch(Exception e){e.printStackTrace ();} \,13mB6  
} i^DMnvV.  
[FBS|v#T  
NK0'\~7&  
//读取保存的下载信息(文件指针位置) 7r;1 6"  
private void read_nPos() J4+K)gWB  
{ 'V]C.`9c  
try{ (WHg B0{  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OlT8pG5Oa  
int nCount = input.readInt(); L\#YFf  
nStartPos = new long[nCount]; >6S7#)0T  
nEndPos = new long[nCount]; %`i*SF(gV  
for(int i=0;i<nStartPos.length;i++) 8\s#law  
{ p7QZn.,=u  
nStartPos = input.readLong(); /?;'y,(Q  
nEndPos = input.readLong(); fXMY.X>f  
} p_I^7 $  
input.close(); Gazva/e  
} P*KIk~J  
catch(IOException e){e.printStackTrace ();} t+v %%N_  
catch(Exception e){e.printStackTrace ();} o< @![P  
} rd7p$e=i  
-Cyo2wk  
xt}.0dC!/%  
private void processErrorCode(int nErrorCode) O}i+ 1  
{ ,8r?C!m]  
System.err.println("Error Code : " + nErrorCode); Jg$<2CR&  
} LDQ,SS,  
FO*Gc Z  
}||u {[  
//停止文件下载 {&+M.Xn  
public void siteStop() {D[6=\ F  
{ k9%o{Uzy  
bStop = true; t`B@01;8A  
for(int i=0;i<nStartPos.length;i++) T +vo)9w  
fileSplitterFetch.splitterStop(); 0si1:+t-[+  
:\[l~S  
X,G<D}  
} NK qI x  
} 4s 7 RB  
//负责部分文件的抓取 wQG?)aaM  
**FileSplitterFetch.java ,ayEZ#4.m  
*/ glLVT i  
package NetFox; V8/4:Va7 s  
q=pRe-{  
jJIP $  
import java.io.*; x*H#?.E  
import java.net.*; +j{Cfv$do  
Il [~  
!JXiTI!  
public class FileSplitterFetch extends Thread { ~vz%I^xW  
1r=cCM  
A,F~*LXm  
String sURL; //File URL :(]fC~G~  
long nStartPos; //File Snippet Start Position p q`uB  
long nEndPos; //File Snippet End Position ,NQ!d4 ~D  
int nThreadID; //Thread's ID F `7 v  
boolean bDownOver = false; //Downing is over g ` s|]VNt  
boolean bStop = false; //Stop identical 0!,uo\`  
FileAccessI fileAccessI = null; //File Access interface =.z;:0]'n  
Wxj_DTi[1"  
j{lurb)y  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %M`48TW)  
{ fHd[8{;P:  
this.sURL = sURL; :|n[zjK/S  
this.nStartPos = nStart; {.2\}7.c  
this.nEndPos = nEnd; JaUzu3*=  
nThreadID = id; '^TeV=  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *b>RUESF  
} `,6|6.8#  
V22z-$cb  
sQ`G'<!  
public void run() ;mEn@@{  
{ O q$_ q  
while(nStartPos < nEndPos && !bStop) UF7h{V})  
{ f|,Kh1{e  
{_N9<i{T  
7_\F$bp`  
try{ P7F"#R0QB  
URL url = new URL(sURL); kBZ1)?   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q3WI @4  
httpConnection.setRequestProperty("User-Agent","NetFox"); d1/WUKmbZ  
String sProperty = "bytes="+nStartPos+"-"; by<@\n2B:U  
httpConnection.setRequestProperty("RANGE",sProperty); ir<e^a  
Utility.log(sProperty); "`ftcJUd  
{A/^;X{N^  
8;?4rrS  
InputStream input = httpConnection.getInputStream(); =sk[I0W  
//logResponseHead(httpConnection); ~1+6gG  
zx%WV@O9  
GqHW.s5  
byte[] b = new byte[1024]; 5hmfdj6  
int nRead; Kkp dcc  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0Ncpi=6  
{ |^l_F1+w  
nStartPos += fileAccessI.write(b,0,nRead); {V/>5pz4e  
//if(nThreadID == 1) \Wfw\x0.  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [uU!\xe  
} AY5iTbL1  
@?<[//1  
T)gulP  
Utility.log("Thread " + nThreadID + " is over!"); ^7y t>  
bDownOver = true; 3'.@aMA@  
//nPos = fileAccessI.write (b,0,nRead); bVUIeX'  
} n/skDx TE  
catch(Exception e){e.printStackTrace ();} #B5,k|"/,M  
} o{y}c->  
} ?)1Y|W'Rv  
xoo,}EY  
K\2{SjL:B  
//打印回应的头信息 I Id4w~|  
public void logResponseHead(HttpURLConnection con) FL{?W(M  
{ 5Rl\& G\  
for(int i=1;;i++) f7a4E+}  
{ gbuh04#~  
String header=con.getHeaderFieldKey(i); Jx5`0?  
if(header!=null) J>  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); esJ7#Gxt  
Utility.log(header+" : "+con.getHeaderField(header)); i#V(oSx  
else tq59w  
break; sA,bR|  
} 1x|3|snz)  
} &MSU<S?1  
}>h n  
nq{/fD(2  
public void splitterStop() dO8 2T3T  
{ LJ[zF~4#  
bStop = true; B)Y[~4o  
} cR3d& /_,U  
es*$/A  
Dylm=ZZa  
} F_*']:p  
W q<t+E[  
y`va6 %u{  
/* CI{2(.n4  
**FileAccess.java S-Y{Vi"2  
*//文件访问(定位,写) P{9:XSa%  
package NetFox; R->x_9y-R  
import java.io.*; |4mvB2r  
=#u4^%i)  
!ekByD  
public class FileAccessI implements Serializable{ #zl1#TC{(  
~^obf(N`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `2 <:$]  
RandomAccessFile oSavedFile; itzUq,T  
long nPos; FC1rwXL(  
jUm-!SK}q  
A5Hx $.Z  
public FileAccessI() throws IOException 6nk }k]Ji  
{ ^f,4=-  
this("",0); !Axe}RD'  
} !}!KT(% %  
:C_/K(Rkl  
(C. $w  
public FileAccessI(String sName,long nPos) throws IOException 1(Is 7  
{ nNCR5&,q  
oSavedFile = new RandomAccessFile(sName,"rw"); zgGysjV  
this.nPos = nPos; w80X~  
oSavedFile.seek(nPos); K(?V]Mxl6  
} Q("m*eMRt  
uU 7 <8G  
WPRk>j  
public synchronized int write(byte[] b,int nStart,int nLen) ;JkIZ8!  
{ DKS1Sm6d0  
int n = -1; 3 ZOD2: (  
try{ A1p~K*[[  
oSavedFile.write(b,nStart,nLen); %f'pAc|#  
n = nLen; f![] :L  
} dT0W8oL  
catch(IOException e) sLA.bp.O  
{ 4<($ZN8  
e.printStackTrace (); ^^v3iCT  
} J,Ki2'=  
50MM05aC  
Tm`@5  
return n; rT` sY  
} xq;>||B  
>2s6Y  
:=B.)]F.)  
} E.*hY+kGZ  
vt5w(}v(  
wG)e8,#  
/* G Uu8 N  
**SiteInfoBean.java 9^!.!%6O$  
*/ f4p*!e  
package NetFox; 'KjH|u  
XdJD"|,h  
8~(,qU8-N  
public class SiteInfoBean { \r IOnZ.WK  
Hpix:To  
,&,%B|gT]  
private String sSiteURL; //Site's URL 1R}9k)JQ  
private String sFilePath; //Saved File's Path n=-vOa%  
private String sFileName; //Saved File's Name ]izHn;+  
private int nSplitter; //Count of Splited Downloading File ) r.Wge  
m^oG9&";  
LhAN( [  
public SiteInfoBean() 1vq2`lWpx  
{//nSplitter的缺省值为5 9C \}bT  
//default value of nSplitter is 5 ]lA}5  
this("","","",5); 2@MpWj4  
} rS>.!DiYr,  
1#N`elm  
7D<Aa?cv_l  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _t-6m2A  
{ 3YLK?X8  
sSiteURL= sURL; P1OYS\  
sFilePath = sPath; drAJ-ii  
sFileName = sName; :WWHEZK  
this.nSplitter = nSpiltter; h.?<( I  
jlb8<xIC]  
_i ztQ78  
} p8 S~`fjV  
N_ ODr]L  
Dl.< (/  
public String getSSiteURL() Vb? wwx7=  
{ /HUT6B  
return sSiteURL; 2(!W 9#]  
} fP<== DK  
,$!fyi[;C  
P>q~ocq<  
public void setSSiteURL(String value) U>kaQ54/  
{ (A2ga):Pk  
sSiteURL = value; jk`U7 G*  
} IsT}T}p,t  
NCg("n,jx  
2XyyU}.$  
public String getSFilePath() >0SG]er@  
{ z>+CMH5L)  
return sFilePath; F lVG,Z  
} M5*Ln-qt(a  
lFuW8G,-f@  
k @fxs]Y_L  
public void setSFilePath(String value) )r"R  
{ Z<|x6%  
sFilePath = value; B[mZQ&Gz`a  
} vV"YgN:  
.K^gh$z!  
q>%.zc[x  
public String getSFileName() rui 8x4c  
{ BT(eU*m-  
return sFileName; ,r3`u2)  
} EQoK\.; G~  
I.t)sf,  
DBy%"/c  
public void setSFileName(String value) ,MHK|8!  
{ [6K[P3UZx  
sFileName = value; |9i[*]  
} 9k93:#{WE  
M%jR`qVFg.  
L7lpOy4k  
public int getNSplitter() M`7lYw\Or!  
{ @ebY_*  
return nSplitter; N\s-{7K  
} k3LHLJZ#  
YO.ddy*59  
nCV7(ldmH  
public void setNSplitter(int nCount) `+."X1  
{ Q-iBK*-w  
nSplitter = nCount; I<W<;A  
} kN*I_#  
} ?w'03lr%  
P7X3>5<;q  
9h+T O_T@F  
/* Le-t<6i-V#  
**Utility.java wg k[_i  
*/ 3 q8S  
package NetFox; ^Et^,I:`  
L09r|g4Z  
N:KM8PZ&~  
public class Utility { hw`pi6  
w$]wd`N}  
A]%*ye"NT  
public Utility() PXl%"O%d  
{ !mVq+_7]  
2.{zf r  
vytO8m%U  
} 7#&Q-3\:  
J}-e9vK-#  
//线程睡眠 4F -<j!  
public static void sleep(int nSecond) $Ups9pQ  
{ i6FJG\d  
try{ /Aw@2 6  
Thread.sleep(nSecond); =yRv *C  
} x'G_z_<V  
catch(Exception e) Q`O~f<a  
{ bO('y@)X  
e.printStackTrace (); r|z B?9Q  
} G ` eU   
} >,Zn~8&Z  
RP 6<#tq,  
//日志 j:8Pcx  
public static void log(String sMsg) k8+U0J_{'  
{ SEWdhthP  
System.err.println(sMsg); k:mW ,s|a  
} :"nh76xg<  
 Ew;AYZX  
l"h6e$dP  
public static void log(int sMsg) /,< s9 :  
{ p? w^|V  
System.err.println(sMsg); Ai:, cY5%  
} -U7,~z  
} |rgPHRX^Hn  
".pQM.T  
1(i%nX<U  
/* _K!)0p  
**TestMethod.java 1'\s7P  
*/ -) +B!"1  
package NetFox; t,A=B(W  
g^#,!e  
J_<6;#  
public class TestMethod { X_3hh}=  
oZL# *Z(h  
"ChJR[4@  
public TestMethod() 2J)  
{ ///xx/weblogic60b2_win.exe 6@:<62!;  
try{ D)[(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pOB<Bx5t  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E8lq2r=  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^@Qc!(P  
fileFetch.start(); W%MS,zkAE  
} +T,0,^ *  
catch(Exception e){e.printStackTrace ();} LOwd mj  
3<1x>e2nT  
L|'B*  
} 05jjLM'e  
zG%'Cw)8  
bx-:aC)]2  
public static void main(String[] args) ssH[\i  
{ IO2@^jup  
new TestMethod(); oe=1[9T"  
} s=K?-O  
} u{sb^cmy  
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