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http断点续传简单实现(java)

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/* SsA;T5:6  
**SiteFileFetch.java fr'M)ox1  
*/ s vn[c*  
package NetFox; {#q']YDe`  
import java.io.*; y e!Bfz>  
import java.net.*; EM/NT/  
f@l6]z{.L  
jB }O6u[%  
public class SiteFileFetch extends Thread { &d`T~fl|  
0z?b5D;  
QFoZv+|  
SiteInfoBean siteInfoBean = null; //文件信息Bean n<MMO=+bg  
long[] nStartPos; //开始位置 XfA3Ez,}  
long[] nEndPos; //结束位置 zM6 yUEg  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 70_T;K6  
long nFileLength; //文件长度 CCKg,v  
boolean bFirst = true; //是否第一次取文件 G%)?jg@EA  
boolean bStop = false; //停止标志 >Bp%~8f  
File tmpFile; //文件下载的临时信息 xO'I*)  
DataOutputStream output; //输出到文件的输出流 8xhXS1  
GZT}aMMSJ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }C>Q  
public SiteFileFetch(SiteInfoBean bean) throws IOException '|^LNAx  
{ dJ\6m!Mp  
siteInfoBean = bean; g!n1]- 1  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ,oe e'  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); PJj{5,#@3  
if(tmpFile.exists ()) ^|}C!t+  
{ 2{s ND  
bFirst = false; bHlG(1uf  
read_nPos(); qG"|,bA  
} }]vj"!?a  
else }@yvw*c  
{ m}.ru)^p  
nStartPos = new long[bean.getNSplitter()]; Hxr2Q]c?u  
nEndPos = new long[bean.getNSplitter()]; /R#-mY  
} I Vy,A7f  
Bc}<B:q%b  
j)\&#g0u6  
7'FDI`e[  
} THH rGvb  
3(P^PP8  
a:@9GmtV&  
public void run() vy/U""w`  
{ &QE^i%6>\  
//获得文件长度 ';V(sRU@  
//分割文件 I^Ichn  
//实例FileSplitterFetch vZ 4Z+;.  
//启动FileSplitterFetch线程 Y~1}B_  
//等待子线程返回 jIE>t5 fy  
try{ k Fv\V   
if(bFirst) 7UHqiA`L  
{ ih `/1n  
nFileLength = getFileSize(); Z_' %'&Y  
if(nFileLength == -1) T Uhp  
{ *pP"u::S  
System.err.println("File Length is not known!"); `.;7O27A^%  
} cb&y8!ci~  
else if(nFileLength == -2) m6V1m0M  
{ 5X&<+{bX  
System.err.println("File is not access!"); Bir }X  
} R+]p -NI^  
else %9M; MK  
{ r0G#BPgdR  
for(int i=0;i<nStartPos.length;i++) d_J?i]AP|'  
{ DjOFfD\MF  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); B0=:A  
} 2a.NWJS  
for(int i=0;i<nEndPos.length-1;i++) pALB[;9g  
{ )xQxc.  
nEndPos = nStartPos[i+1]; M)Rp+uQ  
} hM\QqZFyp  
nEndPos[nEndPos.length-1] = nFileLength; ~m!>e])P?X  
} qq-&z6;$  
} =D5@PHpv(  
p@i U}SUaE  
X2@mQ&n  
//启动子线程 w GZ(bKyO  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =\4w" /Y  
for(int i=0;i<nStartPos.length;i++) {N5g52MN  
{ 7~\Dzcfk"P  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4:r^6m%%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zq!2);,  
nStartPos,nEndPos,i); $Fz/&;KX!  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !Go(8`>  
fileSplitterFetch.start(); VK`_ Qc#B  
} :EgdV  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CW\o>yh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /p\Ymq  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yD1*^~loJ  
nEndPos = " + nFileLength); 2DQ'h}BI  
// fileSplitterFetch[nPos.length-1].start(); u-UUF  
?^BsR  
1@)]+* F*z  
//等待子线程结束 {DN c7G  
//int count = 0; SNvK8,"g  
//是否结束while循环 *(?YgV  
boolean breakWhile = false; O#O~A |  
BT>*xZLpS  
u;J=g  
while(!bStop) @<vDR">  
{ 0IDHoNaT<  
write_nPos(); 0O-p(L=  
Utility.sleep(500); 6$PfX.Fh  
breakWhile = true; OD\x1,E)I  
*XH?|SV  
Byldt  
for(int i=0;i<nStartPos.length;i++) o*p7/KvoT  
{ Xz]}cRQ[  
if(!fileSplitterFetch.bDownOver) aS~k.^N  
{ 6/4OFvL1  
breakWhile = false; "vLqYc4$  
break; ^Jnp\o>  
} R2]?9\II  
} Jq6p5jr"  
if(breakWhile) W[^XG\  
break; Rp`}"x9  
l^$:R~gS  
LV8,nTYvE  
//count++; d,<ctd  
//if(count>4) }i[i{lKj  
// siteStop(); t ?bq ~!X  
} /SMp`Q88  
Y2<#%@%4  
ULU ]k#  
System.err.println("文件下载结束!"); d0-}Xl  
} pbqa  
catch(Exception e){e.printStackTrace ();} =1yUH9\,b  
} &}T`[ d_Z  
)>\Ne~%  
?\vJ8H[bD  
//获得文件长度 E}NX+ vYF  
public long getFileSize() r}hj,Sq'  
{ -8 &f=J)  
int nFileLength = -1; ?-@h Nrx  
try{ ^[zF_df  
URL url = new URL(siteInfoBean.getSSiteURL()); <R3S{ ty  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FNc[2sI  
httpConnection.setRequestProperty("User-Agent","NetFox");  o{-PT'  
Nq*\{rb  
0w+hf3K+:  
int responseCode=httpConnection.getResponseCode(); bO2$0!=I  
if(responseCode>=400) k9^P#l@p  
{ $%1[<}<  
processErrorCode(responseCode); Q8:u1$}  
return -2; //-2 represent access is error U +mx@C_  
} JC=Bxv  
8: s3Q`O  
|AFF*]e S  
String sHeader; )3)L  
H>M%5bj  
(^Nf;E  
for(int i=1;;i++) kJDMIh|g  
{ tAc;O[L  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (5yg\3Jvp  
//Utility.log(in.readLine()); XLmbpEh  
sHeader=httpConnection.getHeaderFieldKey(i); Opjt? ]  
if(sHeader!=null) 3tr?-l[N\  
{ H[>_LYZ8  
if(sHeader.equals("Content-Length")) }Bc6:a  
{ ~7~nU>Vv  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sS-5W-&P{T  
break; c&0IJ7fZG  
} 8<]> q  
} &)bar.vw/  
else 6eS#L21*  
break; :=i0$k<E/  
} @L0wd>  
} t#P)KcWOt  
catch(IOException e){e.printStackTrace ();} q>Q|:g&:  
catch(Exception e){e.printStackTrace ();} siD Sm  
.5 dZaI)  
k*-+@U"+  
Utility.log(nFileLength); |fw+{f  
"%.#/!RG  
;^rZ"2U l  
return nFileLength; CiMy_`H  
} ]AHUo;(f%  
x&9 I2"  
F5MWxAS,>  
//保存下载信息(文件指针位置) s#d# *pgzh  
private void write_nPos() ZnJnjW PQ  
{ x(t} H8q  
try{ 55!9U:{  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^ MddfBwk  
output.writeInt(nStartPos.length); =} vG|  
for(int i=0;i<nStartPos.length;i++) ;<MaCtDt  
{ (O<lVz@8  
// output.writeLong(nPos); Zy!\=-dSm  
output.writeLong(fileSplitterFetch.nStartPos); Cog:6Gnw  
output.writeLong(fileSplitterFetch.nEndPos); c3 wu&*p{  
} +m+HC(Z  
output.close(); %hTe%(e  
} Jp= (Q]ab  
catch(IOException e){e.printStackTrace ();} |/<iydP  
catch(Exception e){e.printStackTrace ();} .7kVC  
} #); 6+v  
i5AhF\7F9  
-_314j=`/  
//读取保存的下载信息(文件指针位置) +QHhAA$  
private void read_nPos() >K &b,o,[  
{ KK] >0QAY  
try{ d9^=#ot  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V!Joh5=a  
int nCount = input.readInt(); +'KM~c?]  
nStartPos = new long[nCount]; SjJUhTb  
nEndPos = new long[nCount]; 7P\sn<  
for(int i=0;i<nStartPos.length;i++) FcWu#}.p}  
{ Cu?$!|V  
nStartPos = input.readLong(); &1?Q]ZRp  
nEndPos = input.readLong(); qh&K{r*T  
} 6g.@I!j E  
input.close(); )b-G2< kb  
} >eEf|tKO  
catch(IOException e){e.printStackTrace ();} FCP5EN  
catch(Exception e){e.printStackTrace ();} A{c6XQR~z  
} |BW956fBU  
}YSH8d  
6 XG+YIG6w  
private void processErrorCode(int nErrorCode) -[7.VP   
{ nut7b  
System.err.println("Error Code : " + nErrorCode); Kp&d9e{ Yc  
} +Rh'VZJs  
X<?;-HrS;  
|aVv Lz  
//停止文件下载 z[k2&=c  
public void siteStop() brVT  
{ :heJ5* !,  
bStop = true; A%2!Hr  
for(int i=0;i<nStartPos.length;i++) jG^~{7#  
fileSplitterFetch.splitterStop(); ze ua`jQ  
y7w>/7q  
Jg Xbs+.  
} Z g'[.wov  
} h]=chz  
//负责部分文件的抓取 <B fwR$  
**FileSplitterFetch.java rcbixOT  
*/ C4G)anT  
package NetFox; t^[{8,N  
L{Th>]X  
4Cfwz-Qo  
import java.io.*; zH_q6@4  
import java.net.*; NKGCz|- 9  
JBYQ7SsAS0  
dKMuo'H'%  
public class FileSplitterFetch extends Thread { 2cDC6rul  
Wu}Co  
"E8!{  
String sURL; //File URL LNg1q1 P3  
long nStartPos; //File Snippet Start Position dHu]wog  
long nEndPos; //File Snippet End Position !uZ+r%  
int nThreadID; //Thread's ID l-Xxv  
boolean bDownOver = false; //Downing is over RS:0xN\JN  
boolean bStop = false; //Stop identical MVj@0W33m  
FileAccessI fileAccessI = null; //File Access interface Z/I!\  
eGE%c1H9a  
6JL 7ut  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException | -R::gm  
{ f>'7~69  
this.sURL = sURL; t"L:3<U7  
this.nStartPos = nStart; \Dc\H )  
this.nEndPos = nEnd; 42C:cl} ."  
nThreadID = id; ZD<,h` lZ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *dQRs6  
} P``hw=L  
d-* 9tit  
a=J?[qrx  
public void run() C VUDN2  
{ s,}<5N]U  
while(nStartPos < nEndPos && !bStop) sDF J  
{ :vr,@1c  
CJC|%i3  
f&`*x t/  
try{ h1Lp:@:|  
URL url = new URL(sURL); \uYUX~}i"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >hhd9  
httpConnection.setRequestProperty("User-Agent","NetFox"); 646ye Q1  
String sProperty = "bytes="+nStartPos+"-"; M&K@><6k,k  
httpConnection.setRequestProperty("RANGE",sProperty); ufJFS+?  
Utility.log(sProperty); IQ_0[  
-`RJ k(  
Y!`?q8z$G  
InputStream input = httpConnection.getInputStream(); V.4j?\#%  
//logResponseHead(httpConnection); 5[3hw4  
GWW@8GNI  
zZxP= c  
byte[] b = new byte[1024]; T'V(%\w  
int nRead; ]`NbNr]K  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *Z]| Z4Q/`  
{ GWhZ Mj  
nStartPos += fileAccessI.write(b,0,nRead); i-<=nD&?t  
//if(nThreadID == 1) A`r9"([-A  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kgIWgk%  
} <,GHy/u\  
1t0F J@)*  
EK'&S=]  
Utility.log("Thread " + nThreadID + " is over!"); TM}F9!*je  
bDownOver = true; D6vn3*,&  
//nPos = fileAccessI.write (b,0,nRead); 7^; OjO@8  
} )&9 =)G  
catch(Exception e){e.printStackTrace ();} N!v@!z9Mu  
} ArEpH"}@  
} y(R*Z^c}d,  
!G,$:t1-=V  
I>xB.$A  
//打印回应的头信息 EH:1Z*|Z{\  
public void logResponseHead(HttpURLConnection con) q^cFD  
{ C0W~Tk\C2  
for(int i=1;;i++) &SM$oy#?  
{ ^M9oTNk2  
String header=con.getHeaderFieldKey(i); P=@lkF!\#  
if(header!=null) GKSy|z  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q.XsY.{  
Utility.log(header+" : "+con.getHeaderField(header)); ,dp?'_q {  
else pxbNeqK@p  
break; vP4Ij  
} s,k1KTXg<B  
} IX(yajc[~M  
=, 0a3D6b  
g#:XN  
public void splitterStop() GW#kaqC1  
{ :2My|3H\  
bStop = true; z]YhQIU4n8  
} ob7_dWAG  
AN>`M?EQ  
B#MW`7c  
} >2:Sv1T  
c 2@@Rd~M  
{XXNl)%  
/* S=g-&lK  
**FileAccess.java OgS8.wX  
*//文件访问(定位,写) $iPN5@F  
package NetFox; *\WI!%  
import java.io.*; `Y;gMrp  
@e,Zmx  
wUeOD.;#F  
public class FileAccessI implements Serializable{ |BkY"F7m9  
{t:ND  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w'0M>2   
RandomAccessFile oSavedFile; 0%F.]+6[O4  
long nPos; PQ]9xzOg[  
AL7O-D  
O-5U|wA  
public FileAccessI() throws IOException h yKg=Foq  
{ E?mp6R]}%  
this("",0); Q75^7Ga_  
} ?<?C*W_  
KUutC :  
e W)I}z +{  
public FileAccessI(String sName,long nPos) throws IOException W~F/ZrT3A  
{ a~7osRmp0  
oSavedFile = new RandomAccessFile(sName,"rw"); 1.H!A@  
this.nPos = nPos; RG3G},Q   
oSavedFile.seek(nPos); Q $0%~`t  
} bW^QH-t  
3x0wk9lND  
yTt (fn:;  
public synchronized int write(byte[] b,int nStart,int nLen) -C}59G8  
{ BmFME0  
int n = -1; O`jA-t  
try{ S1`0d9ds#  
oSavedFile.write(b,nStart,nLen); `_A?a_[*  
n = nLen; PJ@,01  
} *UoHzaIqz  
catch(IOException e) "T%'Rp`j|  
{ p.] .M"A  
e.printStackTrace (); AV4HX\`{P0  
} cu^*x/0,  
TY\"@(Q|G  
 KdJx#Lc  
return n; Mgs|*u-5  
} K!K"}%/_  
XHM"agrhSQ  
W+ '}O<  
} }l?_Cfvu  
U<Y'.!  
W7=_u+0d  
/* (OcNC/9  
**SiteInfoBean.java )v{41sM+  
*/ -xu.=n@,  
package NetFox; by]|O  
<1+6O[>{  
~: <@`  
public class SiteInfoBean { ,(27p6!  
v6-~fcX0G  
' xZPIj+  
private String sSiteURL; //Site's URL K}<!{/fi)  
private String sFilePath; //Saved File's Path %)Uvf`Xhh4  
private String sFileName; //Saved File's Name h_chZB'  
private int nSplitter; //Count of Splited Downloading File E D^rWE_  
-f2`qltjb  
0#fG4D_  
public SiteInfoBean() UX'NJ1f  
{//nSplitter的缺省值为5 -0o6*?[Z  
//default value of nSplitter is 5 0 ;_wAk  
this("","","",5); JX/4=..  
} _#D\*0J  
d<Q+D1  
iynS4]`U  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EKd3$(^   
{ Gz|%;  
sSiteURL= sURL; x~9z`d{!  
sFilePath = sPath; Ipz 1+ #s'  
sFileName = sName; d6@jEa-  
this.nSplitter = nSpiltter; c`i=(D<  
oUvk2]H  
<%>n@A  
} 7{^4 x#NO  
XBQ<  
;IuK2iDt<  
public String getSSiteURL() CxA\yG3L&  
{ 7vpN 6YP  
return sSiteURL; -j`!(IJ  
} Wbn[Q2h5  
( OyY_`  
$JhZ'Z  
public void setSSiteURL(String value) k=mT!  
{ uH&,%k9GVK  
sSiteURL = value; {eswe  
} :DMHezaU  
-RH4y 2  
Z&]+A,  
public String getSFilePath() s1Tl.p5  
{ j[/SXF\=  
return sFilePath; ]opW; |{e  
} qHR^0&  
Cl9SPz  
RZ|HwYG  
public void setSFilePath(String value) 1t[;`iZ  
{ fATA%eA8;  
sFilePath = value; H6ky)kF&  
} HZDaV&)@  
YQ @dl  
\)otu\3/  
public String getSFileName() uRm_  
{ >'ksXA4b  
return sFileName; Wj4^W<IO  
} !2Xr~u7a  
rv,NQZ  
6MQs \J6.  
public void setSFileName(String value) 1<W4>~,wj  
{ ,qe]fo >  
sFileName = value; 5BU%%fBJ.  
} Ig02M_  
=XMD+  
hJ;f1dZ7}  
public int getNSplitter() s!@=rq  
{ {UdcX~\~  
return nSplitter; x&R9${e%  
} h0F0d^W.  
P /c Q1  
Zk/' \(5  
public void setNSplitter(int nCount) '9-axIj70  
{ O&#S4]Y   
nSplitter = nCount; `;5VH]V  
} "%oH@ =  
} _K0izKTA.  
HPtTv}l  
ASKAgU"h  
/* X,WQ'|rC  
**Utility.java <JL\?)}n  
*/ s- ,=e  
package NetFox; `Di ^6UK(  
fiE>H~  
G2CZwm{/f  
public class Utility { ka5#<J7<p  
}uF[Ra  
?W[J[cb  
public Utility() Qp kKVLi  
{ R`@8.]cpPy  
q+A<g(Xu  
i?GfY C2q  
} a^*cZ?Ta  
<XQN;{xSa  
//线程睡眠 a=J@y K  
public static void sleep(int nSecond) iK5]y+@8  
{ +{,N X  
try{ a>o"^%x  
Thread.sleep(nSecond); KTG:I@|C  
} '}jf#C1$c  
catch(Exception e) BIxV|\k  
{ h8f!<:rTS  
e.printStackTrace (); '1W!xQ}E  
} IajD;V  
} (KT38RhA  
1MbY7!?PG  
//日志 R'Kt=.s<  
public static void log(String sMsg) &mN'Tk  
{ pU?{0xZH  
System.err.println(sMsg); 81GQijq  
} >_;kTy,  
6 gj]y^}  
|av*!i5Q  
public static void log(int sMsg) oLgg  
{ Km6Ub?/7o  
System.err.println(sMsg); K0tV'Ml#"  
} i\t753<Ys  
} xS= _yO9-  
<8u>_o6  
o3Mf:;2cC  
/* BZovtm3 E  
**TestMethod.java $Y8>_6%+T  
*/ /xl4ohL$a  
package NetFox; @v>l[6]>^  
Mw/?wtW  
vuYO\u+ud  
public class TestMethod { N]B)Fb  
VZ\O9lD  
^oS$>6|  
public TestMethod() uQH%.A  
{ ///xx/weblogic60b2_win.exe }x*7l`1  
try{ Ct4LkmD  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lV P9=  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2>F\&  
SiteFileFetch fileFetch = new SiteFileFetch(bean); R'rTE  
fileFetch.start(); >%-Hj6%  
} !Tv?%? 2l  
catch(Exception e){e.printStackTrace ();} CPVzX%=  
ZU=,f'bU  
r eGm>  
} ^'m\D;  
*6:v}#b[  
^#]c0  
public static void main(String[] args) ?nQ_w0j  
{ ~j=xiP  
new TestMethod(); ):e+dt  
} AT"!{Y "H  
} Vwjk[ DOL  
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