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http断点续传简单实现(java)

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/* /fEXAk  
**SiteFileFetch.java q}lSnWY[[  
*/ HvU)GJ u b  
package NetFox; yCVBG  
import java.io.*; :nn'>  
import java.net.*; xMu6PM<l  
-`JY] H  
N_U D7P1  
public class SiteFileFetch extends Thread { Ex{]<6UAu  
`K.yE0^i  
o>h>#!e  
SiteInfoBean siteInfoBean = null; //文件信息Bean G5Nub9_*X  
long[] nStartPos; //开始位置 y+_U6rv[  
long[] nEndPos; //结束位置 4ai3@f5  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W3#L!&z_wK  
long nFileLength; //文件长度 5Dd;?T>  
boolean bFirst = true; //是否第一次取文件 Z(cgI5Pu  
boolean bStop = false; //停止标志 VEk|lX;2  
File tmpFile; //文件下载的临时信息 .)Q'j94Q  
DataOutputStream output; //输出到文件的输出流 >jIc/yEYKI  
f3O'lc3  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }OZfsYPz}T  
public SiteFileFetch(SiteInfoBean bean) throws IOException 0n%`Xb0q  
{ x :s-\>RcA  
siteInfoBean = bean; 3zkq'lZ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); d4U_Wu&  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -#@;-2w  
if(tmpFile.exists ()) 0&)4^->c  
{ \_oHuw  
bFirst = false; Zv_<*uzKZ  
read_nPos(); x$t=6@<]  
} 8w4.|h5FP  
else G!uxpZ   
{ wS*UXF&f  
nStartPos = new long[bean.getNSplitter()]; te_D  ,  
nEndPos = new long[bean.getNSplitter()]; .$rcTZ  
} G9]GK+@&F  
'?nhpT^  
u<[Y6m  
l%fl=i~oN  
} >8c9-dTmf  
4f+Ke*^[RA  
6 [IiJhVL  
public void run() "xKJ?8   
{ ;)*Drk*t,  
//获得文件长度 4^ A\w  
//分割文件 6Yu8ReuL  
//实例FileSplitterFetch _F$?Z  
//启动FileSplitterFetch线程 :DEZ$gi  
//等待子线程返回 L))(g][;  
try{ zc_3\N  
if(bFirst) 8V@3T/}  
{ @YRBZ6FH  
nFileLength = getFileSize(); Xg"=,j2  
if(nFileLength == -1) Gh.02  
{ LY7'wONx  
System.err.println("File Length is not known!"); 1]"b.[P>  
} rTcH~s D`  
else if(nFileLength == -2) Z+4J4Ka^!(  
{ d]<tFx>CQW  
System.err.println("File is not access!"); p ^Ruf?>  
} q;U[f6JjE  
else }Q*8QV  
{ :%{8lanO  
for(int i=0;i<nStartPos.length;i++) -Rmz`yOq}  
{ MCvjdc3:  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 3>Yec6Hs  
} 3OTSLF/  
for(int i=0;i<nEndPos.length-1;i++) #'8E%4  
{ 6<2 7}S  
nEndPos = nStartPos[i+1]; -LF^u;s8&S  
} Tg[+K+b  
nEndPos[nEndPos.length-1] = nFileLength; qzXch["So  
} Gg/K  
} zKR_P{W>^  
m]85F^R0  
aX~7NslR  
//启动子线程 ^ `!6Yax?  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5 gE  
for(int i=0;i<nStartPos.length;i++) oY &r76  
{ W n|w~{d{  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v vFX\j3  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h4]yIM `8d  
nStartPos,nEndPos,i); nlKWZYv  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l+@NjZGm<  
fileSplitterFetch.start(); 3S Dw-k  
} {epsiHK@tK  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3AWg43L7  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *9G;n!t  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |[0|j/V%O  
nEndPos = " + nFileLength); 0nC%tCV'  
// fileSplitterFetch[nPos.length-1].start(); cxVnlgq1  
,+0_kndR  
jZ)1]Q2  
//等待子线程结束 {'JoVJKv  
//int count = 0; 0q81H./3  
//是否结束while循环 &<4Jyhm:o  
boolean breakWhile = false; V^"5cW  
/Ue~W, |  
2x0[@cT i?  
while(!bStop) V5m4dQ>t  
{ S?&ntUah  
write_nPos(); %1S;y  
Utility.sleep(500); (JOge~U  
breakWhile = true; 1aKY+4/G  
-(dc1?COi  
[W` _`  
for(int i=0;i<nStartPos.length;i++) 2\_}81 hM  
{ /K1YDq<=  
if(!fileSplitterFetch.bDownOver) v. !L:1@I.  
{ H_Vf _p?  
breakWhile = false; v#F .FK  
break; JpN+'/  
} 0P z"[  
} N,L$+wm  
if(breakWhile) C/!kMMh>vV  
break; nF]lSg&]X  
so1% MV  
.,I^)8c  
//count++; Bf.@B0\  
//if(count>4) Ft'?43J  
// siteStop(); Y'wQ(6ok  
} yi PMJ  
aVEg%8  
;BsyN[bF  
System.err.println("文件下载结束!"); w!7Hl9BW  
} ZJ1 %  
catch(Exception e){e.printStackTrace ();} !A qSG-  
} R]H/Jv\'  
}9=VhC%J  
z^bv)u  
//获得文件长度 *Mk5*_  
public long getFileSize() It&$R`k  
{ mGb,oj7l  
int nFileLength = -1; g,*LP  
try{ @uApm~}  
URL url = new URL(siteInfoBean.getSSiteURL()); 63 F@F t  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Eu2@%2}P  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;.+sz(:hm  
I'm.+(1m,  
f!AcBfaLr  
int responseCode=httpConnection.getResponseCode(); =c:K(N qL  
if(responseCode>=400) 1$H*E~  
{ N$i!25F`  
processErrorCode(responseCode); yP. ,Dh s  
return -2; //-2 represent access is error jt=%oa  
} \b6H4aQii  
M|xd9kA^  
1%g%I8W%  
String sHeader; 4CCtLHb  
MF69n,(o  
j&~`H:=E  
for(int i=1;;i++) =f4>vo}@k  
{  [,JUC<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VXX7Y? !  
//Utility.log(in.readLine()); P :zZ  
sHeader=httpConnection.getHeaderFieldKey(i); nB>C3e  
if(sHeader!=null) j#6@ cO'`  
{ 2[zFKK  
if(sHeader.equals("Content-Length")) = wEU+R_#o  
{ _9*3Mr)2N  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^VabXGzo#  
break; [M?'N w/[S  
} :@K 1pAh4  
} r2"B"%;  
else UaG })  
break; d.>Zn?u4L  
} G*`Y~SJp  
} a*/%EP3  
catch(IOException e){e.printStackTrace ();} u4hC/!  
catch(Exception e){e.printStackTrace ();} ;d5d$Np@m&  
uf q9+}  
Q6%dM'fR  
Utility.log(nFileLength); s 1~&PH^  
{{N*/ E^  
@~1}n/  
return nFileLength; 3M~*4  
} J?DJA2o  
JlaT -j  
H+lBb$  
//保存下载信息(文件指针位置) o>~xrV`E  
private void write_nPos() m}`!FaB #  
{ nz+k ,  
try{ U}hQVpP#  
output = new DataOutputStream(new FileOutputStream(tmpFile)); )a99@`L\P  
output.writeInt(nStartPos.length); T3H\KRe6  
for(int i=0;i<nStartPos.length;i++) {_[\k^98>  
{ t:$^iUrx  
// output.writeLong(nPos); z"D'rHxy  
output.writeLong(fileSplitterFetch.nStartPos); Lgr(j60s  
output.writeLong(fileSplitterFetch.nEndPos); ;fi H=_{us  
} 2":{3=oW~  
output.close(); %OT} r  
} {&3{_Ml  
catch(IOException e){e.printStackTrace ();} :9?y-X  
catch(Exception e){e.printStackTrace ();} u?xXZ]_u-  
} 4 s&9A/&pC  
$OGTHJA  
$<DcbJW  
//读取保存的下载信息(文件指针位置) m6wrG`-di  
private void read_nPos()  {@E(p4W  
{ ^&8FwV]  
try{ >tGl7Ov  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )+L.$h  
int nCount = input.readInt(); 1>)q 5D  
nStartPos = new long[nCount]; ZlEQzL~  
nEndPos = new long[nCount]; _4^#VD#f  
for(int i=0;i<nStartPos.length;i++) .0=VQU  
{ mssCnr;  
nStartPos = input.readLong(); 4C]>{osv  
nEndPos = input.readLong(); V;@kWE>3  
} qE:/~Q0  
input.close(); wg.TCT2  
} "fH"U1Bw  
catch(IOException e){e.printStackTrace ();} lJ>OuSd  
catch(Exception e){e.printStackTrace ();} n=_jmR1  
} `bAOhaB,/  
25R6>CXsi  
#]SiS2lM#  
private void processErrorCode(int nErrorCode) J!+)v  
{ T #OrsJdu  
System.err.println("Error Code : " + nErrorCode); 4s_|6{ANS  
} QtSJ9;eP  
ZkA05wPZ#  
(,P6cWt}"  
//停止文件下载 _-6IB>  
public void siteStop() /l6r4aO2=  
{ J n~t>?  
bStop = true; zLt7jxx  
for(int i=0;i<nStartPos.length;i++) B QxU~s  
fileSplitterFetch.splitterStop(); .=`r?#0  
))NiX^)8^  
SJ0IEPk  
} P,RdY M06  
} #^i.[7p  
//负责部分文件的抓取 (6g;FD:"6  
**FileSplitterFetch.java ,RXfJh  
*/ F4X0DRC,G  
package NetFox; D #Ku5~j  
N0mP EF2  
#0uD&95<  
import java.io.*; +-$Hx5  
import java.net.*; ~[*\YN);  
42B_8SK  
6R=dg2tKT  
public class FileSplitterFetch extends Thread { V!&O5T(~  
MGbl-,]  
+!6dsnr8  
String sURL; //File URL #Y>os3]  
long nStartPos; //File Snippet Start Position I7C*P~32{n  
long nEndPos; //File Snippet End Position RX\l4H5;  
int nThreadID; //Thread's ID IN!,|)8s  
boolean bDownOver = false; //Downing is over %pd-{KR  
boolean bStop = false; //Stop identical hW Va4  
FileAccessI fileAccessI = null; //File Access interface t^')ST  
!Zi_4 .(4  
UB9n7L(@c  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }.S4;#|hw  
{ Xg^9k00C  
this.sURL = sURL; Tm) (?y  
this.nStartPos = nStart; -ufO,tJRLL  
this.nEndPos = nEnd; tqYwP Sr  
nThreadID = id; &i{>Li  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3*<?'O7I0  
} 5vSJjhS  
&:@)ro CR  
|G(9mnZ1  
public void run() iD"9,1@~n  
{ 0 v> *P*  
while(nStartPos < nEndPos && !bStop) ~jOn)jBRZ  
{ 9snc *<  
kKlcK_b;  
DnI31!+y  
try{ p*ic@n*G  
URL url = new URL(sURL); yE{(Ebm  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hT DFIYV  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;&$Nn'~a  
String sProperty = "bytes="+nStartPos+"-"; a 9H^e<g  
httpConnection.setRequestProperty("RANGE",sProperty); [G#PK5C  
Utility.log(sProperty); !M*$p Qi}  
1[U`,(C1  
sCrOdJ6|  
InputStream input = httpConnection.getInputStream(); %xuJQuCqf  
//logResponseHead(httpConnection); .KeZZLH  
i"Z  
z7$,m#tw  
byte[] b = new byte[1024]; PYhRP00}M  
int nRead; q  W"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JIH6!  
{ u301xc,N<z  
nStartPos += fileAccessI.write(b,0,nRead); fFiFS\''V  
//if(nThreadID == 1)  |Ym3.hz  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); umJ!j&(  
} 41oXOB  
ymo].  
)Bo]+\2  
Utility.log("Thread " + nThreadID + " is over!"); :41Ch^\E  
bDownOver = true; zxhE9 [`*e  
//nPos = fileAccessI.write (b,0,nRead); /Y_)dz^@  
} ~A-Y%P  
catch(Exception e){e.printStackTrace ();} yR'%UpaE  
} kl+^0i  
} !=SBeq  
(_.0g}2  
E#A%aLp0E  
//打印回应的头信息 D.:6X'hp  
public void logResponseHead(HttpURLConnection con) aEvW<jHh  
{ kh5VuXpe  
for(int i=1;;i++) )/mBq#ZS  
{ d")TH3pG  
String header=con.getHeaderFieldKey(i); A.wuB  
if(header!=null) y c:y}"  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k[<Uxh%  
Utility.log(header+" : "+con.getHeaderField(header)); @q/E)M?  
else "x~su?KiA  
break; >Y 8\I  
} ]mZN18#  
} \&#IK9x{  
:rzq[J^  
5'%nLW7;O  
public void splitterStop() Nay&cOz  
{ S:YQVj  
bStop = true; dHO8 bYBH  
} .sBwJZ  
W^8MsdM  
^=.QQo||B  
} =,w(D~ps  
bZf}m=C!  
W^"C|4G}  
/* 1wTPT,k  
**FileAccess.java @{LD_>R  
*//文件访问(定位,写) NR9=V  
package NetFox; l)K8.(2  
import java.io.*; Ef2i#BoZ  
sn-P&"q  
/O {iL:`  
public class FileAccessI implements Serializable{ 'J1!P:tJ  
)1iqM]~;B  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rjWn>M  
RandomAccessFile oSavedFile; IDn$w^"  
long nPos; +JlPQ~5  
SDHJX8Hq  
u?%FD~l:uU  
public FileAccessI() throws IOException /+JHnedK  
{ ,We'A R3X  
this("",0); -.t/c}a#  
} ]X\p\n'@j  
'MK"*W8QRM  
?&_u$Nn  
public FileAccessI(String sName,long nPos) throws IOException }[mLtv%&  
{ Zp qb0ro  
oSavedFile = new RandomAccessFile(sName,"rw"); ~pWV[oUD  
this.nPos = nPos; :N#8|;J1Fl  
oSavedFile.seek(nPos); ["N_t:9I  
} kR/Etm5_  
3;Y 9<  
@|6#]&v`  
public synchronized int write(byte[] b,int nStart,int nLen) $az9Fmta  
{ +"GBuNh  
int n = -1; bx._,G  
try{ |y.^F3PE  
oSavedFile.write(b,nStart,nLen); U-:"Wx%G  
n = nLen; wY xk[)&Y  
} * &O4b3R  
catch(IOException e) 5KgAY;|  
{ @O9wit.  
e.printStackTrace (); Qr9@e Q1Pp  
} q5#6PYIq  
tFvXVfml  
PUbfQg  
return n; U%V4@iz~\m  
} cTa$t :K@  
6R#.AD\  
PTP0 _|K  
} ##5e:<c&[  
G}LOQ7  
_ZHDr[  
/* sa w  
**SiteInfoBean.java c@|f'V4  
*/ )zAATBb4.  
package NetFox; &hu3A)%  
,R[<+!RS  
vB Vg/  
public class SiteInfoBean { n= A}X4^  
d A>6  
',m!L@7M5  
private String sSiteURL; //Site's URL bR*} s/  
private String sFilePath; //Saved File's Path RXw }Tb/D8  
private String sFileName; //Saved File's Name &|I{ju_  
private int nSplitter; //Count of Splited Downloading File -58Sb"f  
S5/p3;O\c  
qlm7eS"sy  
public SiteInfoBean() o7kQ&w   
{//nSplitter的缺省值为5 #ja6nt8GC  
//default value of nSplitter is 5 J*D3=5&  
this("","","",5); s)~Wcp'+M:  
} $J9/AFzO"  
Pj ^O8  
->r udRQ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mt\pndTy7!  
{ fRK=y+gl@  
sSiteURL= sURL; ~u-_DOA  
sFilePath = sPath; 7;@o]9W  
sFileName = sName; <tgfbY^nL  
this.nSplitter = nSpiltter; nj=nSD  
v9MliD'  
XM~eocn  
} iLk"lcX  
gQ$0 |0O  
6QePrf  
public String getSSiteURL() FV\$M6 _  
{ oD 3Q{ e  
return sSiteURL; ZmaGp* Wj  
} yC\!6pg  
C:ntr=3J  
so_^%) gdJ  
public void setSSiteURL(String value) &I7T ?  
{ 1xjw=  
sSiteURL = value; nJR(lXWO  
} GsiT!OP]y  
U.c~l,5%"  
6ANA oWg*  
public String getSFilePath() ZO& F15$P  
{ PMZ*ECIJU  
return sFilePath; q DPl( WXb  
} 8I<LZ{a10  
% |G"ZPO?  
LX</xI08W  
public void setSFilePath(String value) |vY|jaV}  
{ :u|F>e  
sFilePath = value; q8H9au&/  
} hx hs>eY  
>o5eyi  
^w*&7.Z  
public String getSFileName() Y@MFH>*  
{ AH|'{  
return sFileName; J5SOPG  
} d=/a{lP\  
>x8~?)7z  
VWW(=j  
public void setSFileName(String value) O#`y;%  
{ ,B$e'KQ  
sFileName = value; 1i}p?sU  
} pykRi#[UrX  
nmoC(| r  
t'*2)U  
public int getNSplitter() /_i]bM7W  
{ S#l)|c_~  
return nSplitter; -~_;9[uV  
} $: qrh66  
O4T_p=Xc  
Idr|-s%l6'  
public void setNSplitter(int nCount) ;fB!/u  
{ w"AO~LF  
nSplitter = nCount; v<E_n;@9k  
} ZmZ7E]c  
} r?}L^bK  
ew1bb K>  
&?M'(` ~  
/* =' &TqiIv"  
**Utility.java l-M .C8N  
*/ 7%yP5c B  
package NetFox; QA#Jx  
)]{&  
Q#}c5TjVr  
public class Utility { $}.#0c8I  
' eH Fa  
M4K>/-9X+V  
public Utility() a]=j  
{ 85#+_}#  
?}<Wmy2A  
&NK6U  
} j,v2(e5:  
m-R`(  
//线程睡眠 yD( v_J*  
public static void sleep(int nSecond) _Sult;y"u  
{ ^i6`w_/  
try{ XT\Q"=FD  
Thread.sleep(nSecond); \"l/D?+Q  
} 2$1D+(5;  
catch(Exception e) 0]2@T=*kTY  
{ l%v2O'h  
e.printStackTrace (); vR'rYDtU@  
} 0ae}!LO  
} \g:Bg%43h  
e`;U9Z  
//日志 &I?d(Z=:\  
public static void log(String sMsg) kRB2J3Nt.  
{ %-3wR@  
System.err.println(sMsg); no8FSqLUS~  
} B8 R&Q8Q  
ci`N ,&:R  
^spASG -o  
public static void log(int sMsg) CxJH)H$  
{ -](3iPy}  
System.err.println(sMsg); NXdT"O=P  
} b0[H{q-z{X  
} yA^+<uz}  
|=#uzp7*  
eG%Q 3h  
/* =R0#WMf$@  
**TestMethod.java %$zX a%A  
*/ dwmZ_m.  
package NetFox; |"k+j_/+  
o '!WW  
5+Hw @CY3  
public class TestMethod { c8M'/{4rH  
TbR!u:J  
 ui1h M  
public TestMethod() fC!+"g55  
{ ///xx/weblogic60b2_win.exe R2dCp|6A  
try{ -+&sPrQ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xv?'*2J  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !KmSLr7xU  
SiteFileFetch fileFetch = new SiteFileFetch(bean); g:fzf>oQ>p  
fileFetch.start(); !z?;L_Lb  
} =l1O9/\9  
catch(Exception e){e.printStackTrace ();} O"f|gc)GLz  
THz=_L6  
IW- BY =C  
} ,B$m8wlI|  
L=<{tzTc  
;p/$9b.0:  
public static void main(String[] args) $qfNEAmDf\  
{ PVX23y;  
new TestMethod(); eC*-/$D  
} Gcd'- 1  
} 2JLXDkZ  
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