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http断点续传简单实现(java)

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/* "TZq")-  
**SiteFileFetch.java <r%K i`u(p  
*/ lZFu|(  
package NetFox; '-iEbE  
import java.io.*; @HT\Y%E  
import java.net.*; =|3BkmO  
yx-{Pj X   
b!<_ JOL2.  
public class SiteFileFetch extends Thread { s :vNr@TS  
"<,lqIqA;  
N5Js.j>z  
SiteInfoBean siteInfoBean = null; //文件信息Bean _&gi4)q  
long[] nStartPos; //开始位置 z7K{ ,y  
long[] nEndPos; //结束位置 *ap,r&]#F  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 (q)}`1d'  
long nFileLength; //文件长度 7]=&Q4e4  
boolean bFirst = true; //是否第一次取文件 z.vQ1~s  
boolean bStop = false; //停止标志 C@(@n!o:!  
File tmpFile; //文件下载的临时信息 Z 3BwbH  
DataOutputStream output; //输出到文件的输出流 ?&B8:<qy;L  
6'qkD<  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ;pnF%co9  
public SiteFileFetch(SiteInfoBean bean) throws IOException j=WxtMS  
{ coP->&(@U#  
siteInfoBean = bean; +m=b "g  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); qeZG/\,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); l:HQ@FX  
if(tmpFile.exists ()) aZ#FKp^8H  
{ rRTKF0+  
bFirst = false; ]so/AdT9hA  
read_nPos(); m`yvZ4K!  
} >m%_`68  
else byHc0ktI\  
{ -y`Pm8  
nStartPos = new long[bean.getNSplitter()]; c&['T+X  
nEndPos = new long[bean.getNSplitter()]; c_/BS n  
} 5Rbl.5. A  
!np_B0`  
|t,sK aL  
,=/9Ld2w9  
} uGU 2  
0.MB;gm:  
^<;W+dWdU  
public void run() AHf 9H?  
{ tUu ' gs|  
//获得文件长度 7e_4sxg'(3  
//分割文件 ~ua(Qm  
//实例FileSplitterFetch xIdb9hm<  
//启动FileSplitterFetch线程 JrP`u4f_  
//等待子线程返回 )g pN 5TDd  
try{ Gu;40)gm  
if(bFirst) U/>I! 7oe  
{ ;-db/$O  
nFileLength = getFileSize(); d$ouH%^cGu  
if(nFileLength == -1) x]^d'o:cDP  
{ /s?%ft#-9o  
System.err.println("File Length is not known!"); >6es 5}  
} @iz Onc:  
else if(nFileLength == -2) ,NO[Piok  
{ ^ u$gO3D  
System.err.println("File is not access!"); Bm~^d7;Cw  
} `?VK(<w0q  
else Gb')a/  
{ %bcf% 7  
for(int i=0;i<nStartPos.length;i++) P`tOL#UeZL  
{ &4Z8df!  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); >d 5-if  
} Ha v&vV  
for(int i=0;i<nEndPos.length-1;i++) 7qC /a c  
{ gS(3m_  
nEndPos = nStartPos[i+1]; CL<-3y*  
} '}cSBbl&/n  
nEndPos[nEndPos.length-1] = nFileLength; :ez76oGyc  
} $z=a+t *  
} ~d*Q{v~3  
Th_@'UDa  
Agd"m4!  
//启动子线程 p$,7qGST  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {O+T`; =)L  
for(int i=0;i<nStartPos.length;i++) Laj/~Ru6  
{ 1P)K@j  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pH~\~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %1&X+s3  
nStartPos,nEndPos,i); G^'We6<  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g;l K34{  
fileSplitterFetch.start(); kNuvJ/St  
} 6(rm%c  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8\J$\Edv  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l;-2hZ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZayJllaq^  
nEndPos = " + nFileLength);  |Iy;_8c  
// fileSplitterFetch[nPos.length-1].start(); {$S"S j  
!(*&P  
m"L^tSD~  
//等待子线程结束 LWrYK i  
//int count = 0; ("`"?G  
//是否结束while循环 d=1\=d/K  
boolean breakWhile = false; :6n4i$  
VgPlIIHh5  
WUS%4LL(  
while(!bStop) _'p/8K5)=  
{ 0>[]Da}  
write_nPos(); T m"B  
Utility.sleep(500); b>5* G1  
breakWhile = true; D;sG9Hky  
0hY3vBQ!  
4KH'S'eR  
for(int i=0;i<nStartPos.length;i++) (-<hx~  
{ wOH:'sk["  
if(!fileSplitterFetch.bDownOver) Q g/Rw4[  
{ x(?Rm,  
breakWhile = false; E8C8kH]  
break; mJ%^`mrI  
} <*vR_?!  
} F`KXG$  
if(breakWhile) KKwM\   
break; u ?V}pYX  
@@ j\OR  
1_7p`Gxt[/  
//count++; 2K4Xu9-i:b  
//if(count>4) 0MpW!|E  
// siteStop(); B9l~Y/3|  
} -axKnfj  
auI`'O`/  
\LUW?@gLa  
System.err.println("文件下载结束!"); .QY>@b\  
} 7<LuL  
catch(Exception e){e.printStackTrace ();} E2|M#Y  
} Av.`'.b  
@de  ZZ  
j6s j2D  
//获得文件长度 1<:5b%^c  
public long getFileSize() &wQ<sVQ0$  
{ Cuylozj$&  
int nFileLength = -1; r'ilJ("  
try{ "d}']M?-h  
URL url = new URL(siteInfoBean.getSSiteURL()); =lv(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ll}_EUF|  
httpConnection.setRequestProperty("User-Agent","NetFox"); :E{)yT  
e@c8Ce|0  
Qfp4}a=  
int responseCode=httpConnection.getResponseCode(); ^5Y<evjm  
if(responseCode>=400) wmpQF<  
{ "IS; o o$g  
processErrorCode(responseCode); ,3rsjoKhd  
return -2; //-2 represent access is error &$ }6:  
} eP (*.  
q AVypP?J  
8K^#$,.."  
String sHeader; C;ab-gh  
YdV.+v(30  
 Z/Wf  
for(int i=1;;i++) |Ja5O  
{ em7L `,  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pPxgjX  
//Utility.log(in.readLine()); M19O^P>[  
sHeader=httpConnection.getHeaderFieldKey(i); 0aq{Y7sYU  
if(sHeader!=null) Cw^iA U  
{ /.s L[X-G  
if(sHeader.equals("Content-Length")) '`tFZfT  
{ 5xT, O  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ud"_[JtGM  
break; .NWsr*Tel  
} `]]m$  
} Sj)?!  
else _G`Q2hf"5  
break; =Crl{Ax  
} %#fjtbeB  
} aQH]hLvs  
catch(IOException e){e.printStackTrace ();} zM8 jjB  
catch(Exception e){e.printStackTrace ();} k %{q q v  
!C4)P3k  
2K3j3|T  
Utility.log(nFileLength); nUs=PD3)  
G;u 6p  
3]iw3M  
return nFileLength; ZT"vVX- )G  
} o^5UHFxTCB  
uih8ZmRt  
lhQMR(w^  
//保存下载信息(文件指针位置) `4ga~Ch  
private void write_nPos() [6\O <-?  
{ Li8/GoJW-T  
try{ f x:vhEX  
output = new DataOutputStream(new FileOutputStream(tmpFile)); b4$g$()  
output.writeInt(nStartPos.length); 1A93ol=  
for(int i=0;i<nStartPos.length;i++) MF$Dx| Tcj  
{ 2./ z6jXW_  
// output.writeLong(nPos); EWl9rF@I  
output.writeLong(fileSplitterFetch.nStartPos); ">B&dNrt  
output.writeLong(fileSplitterFetch.nEndPos); |+~P; fG  
} O*2{V]Y @  
output.close(); +-x+c: IxA  
} Lcg1X3$G  
catch(IOException e){e.printStackTrace ();} uR=*q a  
catch(Exception e){e.printStackTrace ();} N f?\O@  
} 2/ )~$0  
{y|.y~vW  
f% 8n?f3;u  
//读取保存的下载信息(文件指针位置) Dd OK&  
private void read_nPos() 8\)4waz$  
{ 3Zz_wr6  
try{ dr8Q>(ZY  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %U<lS.i  
int nCount = input.readInt(); 7u1o>a %9  
nStartPos = new long[nCount]; hQ)?LPUB  
nEndPos = new long[nCount]; g}?39?o4  
for(int i=0;i<nStartPos.length;i++) 8eCh5*_$  
{ amQiH!}8R  
nStartPos = input.readLong(); H>\l E2  
nEndPos = input.readLong(); }If,O  
} "T8b.ng  
input.close(); t& yuo E  
} W;X:U.  
catch(IOException e){e.printStackTrace ();} [ P*L`F  
catch(Exception e){e.printStackTrace ();} ee<'j~{A  
} ?<OE|nb&  
](+u'8  
@Rd`/S@  
private void processErrorCode(int nErrorCode) E)'T;%  
{ Sw{rNzh%$  
System.err.println("Error Code : " + nErrorCode); C:!&g~{cKi  
} fX LsLh+~D  
B|>eKI  
I]#x0?D  
//停止文件下载 Qc Xw -  
public void siteStop() R{B5{~m>W@  
{ U~|)=+%O  
bStop = true; :p1_ij]ND  
for(int i=0;i<nStartPos.length;i++) Oxi^&f||`  
fileSplitterFetch.splitterStop(); *EU1`q*  
`y"a>gHC  
3!KyO)8  
} Ngrj@_J  
} S>[&]  
//负责部分文件的抓取 W Emh  
**FileSplitterFetch.java |>JRJ"CFE  
*/ U d+6=Us{  
package NetFox; U,< ?]h  
DI :  
`'rvDaP  
import java.io.*; xM&`>`;^e  
import java.net.*; 8P%Jky&(  
EBmkKiI;  
?;rRR48T9E  
public class FileSplitterFetch extends Thread { 9:!V":8q  
{FN CC*=  
%zjyZ{=  
String sURL; //File URL t4zKI~cO  
long nStartPos; //File Snippet Start Position }.A \;FDyj  
long nEndPos; //File Snippet End Position {o %OG/!1  
int nThreadID; //Thread's ID ;A?86o'?  
boolean bDownOver = false; //Downing is over ^Y"|2 :  
boolean bStop = false; //Stop identical oPxh+|0?  
FileAccessI fileAccessI = null; //File Access interface I_`$$-|  
6(B[(Af  
aO *][;0  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7$kTeKiP  
{ +W|VCz  
this.sURL = sURL; 7MX5hZF"  
this.nStartPos = nStart; :<6gP(  
this.nEndPos = nEnd; _nIt4l7  
nThreadID = id; kc[<5^b5  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q$B|a5a?  
} pQCW6X  
_o6Zj1p  
ib(4Y%U6~  
public void run() 7] >z e  
{ P.Qz>c^-C  
while(nStartPos < nEndPos && !bStop) )9 {!=k  
{ D' h%.  
za5E{<0  
a;G>56iw  
try{ 70A* !v  
URL url = new URL(sURL); /6'5uP   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )4FW~o<i  
httpConnection.setRequestProperty("User-Agent","NetFox"); l=>FoJf!*<  
String sProperty = "bytes="+nStartPos+"-"; Pu2cU5n  
httpConnection.setRequestProperty("RANGE",sProperty); JIMi~mEiN  
Utility.log(sProperty); Tu=~iQ  
fp$U%uj  
2()/l9.O'  
InputStream input = httpConnection.getInputStream(); Y-v6M3$  
//logResponseHead(httpConnection); ^B'N\[  
$btk48a7  
P\2x9T  
byte[] b = new byte[1024]; N}\3UHtO  
int nRead; $*+`;PG-  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?fvK<0S`  
{ 810uxw{\  
nStartPos += fileAccessI.write(b,0,nRead); Nf9$q| %!  
//if(nThreadID == 1) %xwtG:IKEV  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zRA,Yi4;+  
} ugQySg>  
GOY!()F  
T:VFyby\w  
Utility.log("Thread " + nThreadID + " is over!"); Y-P?t+l  
bDownOver = true; xU;Q ~(  
//nPos = fileAccessI.write (b,0,nRead); 5J*h7  
} A~ wVY  
catch(Exception e){e.printStackTrace ();} *qw//W   
} ByW,YKMy  
} =BgQ Ss/^c  
Nk$OTDwP  
z?g\w6  
//打印回应的头信息 y.WEO>   
public void logResponseHead(HttpURLConnection con) BA`K,#Ft7  
{ QzD8 jk#  
for(int i=1;;i++) 'zx1kq1  
{ `;3fnTI:1  
String header=con.getHeaderFieldKey(i); ()EiBl(kWk  
if(header!=null) b[my5O l  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ka| 8 _C^z  
Utility.log(header+" : "+con.getHeaderField(header)); FrQRHbp3  
else hR~~k~84  
break; -Z&9pI(3R~  
} ^r^)  &]  
} LVNJlRK  
)C#b83  
e~Z>C>J  
public void splitterStop() cy( WD#^  
{ Y~-P9   
bStop = true; !WQS.&  
}  uzaD K  
h$a% PaVf  
!^(?C@TQ  
} S0p[Kt  
oz/Nx{bg  
q,2 +\i  
/* eGlPi|  
**FileAccess.java dW"=/UW  
*//文件访问(定位,写) bK#SxV  
package NetFox; E) z=85;_p  
import java.io.*; gOLN7K-)  
\ _l4li  
4I!g?Moh  
public class FileAccessI implements Serializable{ GiS:Nq`$(  
DuI>z?bS  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节  /wT<p  
RandomAccessFile oSavedFile; J1g+H2  
long nPos; g#b9xTG J^  
r2G38/K  
Df5!z\dx  
public FileAccessI() throws IOException #b wGDF  
{ #$ooV1E  
this("",0); gnN"6r1  
}  rBUWzpE"  
z=yE- I{  
><i: P*ht  
public FileAccessI(String sName,long nPos) throws IOException E_-QGE/1  
{ FW)VyVFmk  
oSavedFile = new RandomAccessFile(sName,"rw"); OAo;vC:^  
this.nPos = nPos; ;DX g  
oSavedFile.seek(nPos); e6gLYhf&  
} ToX--w4  
V_/.]zQA  
Y1R?, 5  
public synchronized int write(byte[] b,int nStart,int nLen) Yan}H}Oq  
{ 9Yd"Y-   
int n = -1; ;b_l/T(  
try{ ?Sr7c|a2  
oSavedFile.write(b,nStart,nLen); > PK 6CR  
n = nLen; u\Y3h:@u  
} H*HL:o-[  
catch(IOException e) SZ1yy["  
{ 6_g:2=6S  
e.printStackTrace ();  L30$  
} $8WWN} OC  
\>[k0<  
b} FhC"'i  
return n; %ty`Oa2  
} 7KL@[  
mI'&!@WG  
-car>hQq  
} +t%1FkI\  
EhAaaG  
3?e~J"WXC5  
/* c8LMvL  
**SiteInfoBean.java Vw]!Kb7tA  
*/ eY[kUMo  
package NetFox; d9up! k  
QJ+Ml  
dngG=  
public class SiteInfoBean { #Q'#/\5  
*vzEfmN:d  
IG&twJR  
private String sSiteURL; //Site's URL uHq;z{ 2GI  
private String sFilePath; //Saved File's Path 8]D0)  
private String sFileName; //Saved File's Name P^AI*tH"m  
private int nSplitter; //Count of Splited Downloading File 1gQ_76Yck  
#I1q,fm  
>t{-_4Yv?  
public SiteInfoBean() #>6Jsnv1  
{//nSplitter的缺省值为5 X0Wx\xDg[  
//default value of nSplitter is 5 +ZOKfX  
this("","","",5); =Cd{bj.8  
} P$Q,t2$A  
 +;-ZU  
zx5#eMD  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |DYgc$2pN  
{ G=]ox*BY  
sSiteURL= sURL; 0S96x}]J B  
sFilePath = sPath; q%LjOPE V  
sFileName = sName; [* M':  
this.nSplitter = nSpiltter; BA[ uO3\4  
#p ;O3E@  
V!l?FOSZ  
} 4n"6<cO5q  
6-z(34&N  
) "Z6Q5k^  
public String getSSiteURL() Kq5i8L=u  
{ #Vu;R5GZ}  
return sSiteURL; 1'N<ITb  
} C]Y%dQh+a  
%o 5'M^U  
iI>7I<_  
public void setSSiteURL(String value) W1521:  
{ IXG@$O?y/  
sSiteURL = value; N0%q 66]1  
} #0PZa$kM(o  
n =WH=:&  
2Z5_@Y  
public String getSFilePath() )|_L?q#w!'  
{ a?yU;IKJ  
return sFilePath; {1qr6P,"  
} 1[J|AkN  
F 2Y!aR  
 S'\e"w  
public void setSFilePath(String value) Npi) R)  
{ =?Ui(?tI  
sFilePath = value; Kv2S&P|jXM  
} |]9L#  
zk"8mTg  
 i CLH  
public String getSFileName() TW|- 0  
{ vZW[y5   
return sFileName; 8+J>jZ  
} plp-[eKcD  
J.'%=q(Sb  
ANNVE},  
public void setSFileName(String value) 9ln=f=  
{ )ki Gk}2  
sFileName = value; ^`B;SSV  
} =H3tkMoi2  
#4JLWg  
z1]nC]2  
public int getNSplitter() ;rF[y7\  
{ r<4j;"lQK  
return nSplitter; Oet+$ b  
} .rITzwgB  
1= 7ASS9  
UhrRB  
public void setNSplitter(int nCount) m"'} {3$%  
{ CmV &+C$V%  
nSplitter = nCount; !\$V?*p7  
} W+/_0GgQ3  
} _m[DieR  
>:4`y"0  
SZyORN  
/* -U\'Emu4  
**Utility.java $dXx@6fP  
*/ -jy0Kl/p  
package NetFox; Fe4>G8uuwn  
ca,W:9#.xn  
IRwtM'%0  
public class Utility { -- FzRO{D  
JSi0-S[Y{  
V.z8 ]iG  
public Utility() wMj #.Jh  
{ 8Y.9%@  
9^ZtbmUf  
dJ m9''T')  
} ~D>pu%F  
KX]!yA  
//线程睡眠 g&y^r/  
public static void sleep(int nSecond) Eh ";irE  
{ $xbW*w  
try{ k}Q<#   
Thread.sleep(nSecond); I8j:{*h  
} kaXq.  
catch(Exception e) IhBc/.&RL  
{ p7@R+F\.};  
e.printStackTrace (); ~!5=o{wy  
} &e@)yVLL  
} 2jC`'8  
:>2wVN&\c  
//日志 !& >`  
public static void log(String sMsg)  u\L}B!  
{ ^a_a%ws  
System.err.println(sMsg); 4k-Ak6s  
} 8\!E )M|4  
BjsT 9?6W/  
qSB&Q0T  
public static void log(int sMsg) J (?qk  
{ * dw.Ug  
System.err.println(sMsg); bY=[ USgps  
} C[G+SA1&W  
} |Rz.Pt6  
DegbjqZ#  
/ De~K+w7o  
/* GaG>0 x   
**TestMethod.java 8>,w8(Nt  
*/ `H6~<9r  
package NetFox; 3>-h- cpMX  
#$- E5R;x  
&.\7='$F  
public class TestMethod { >#x[qX  
=uH2+9.  
{V2"Pym?  
public TestMethod() ]FZPgO'G  
{ ///xx/weblogic60b2_win.exe y'`/^>.  
try{  '2*OrY  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &<]f-  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B(++*#T!^m  
SiteFileFetch fileFetch = new SiteFileFetch(bean); P .m@|w&.K  
fileFetch.start(); .Mb[j1L^  
} ur\6~'l4  
catch(Exception e){e.printStackTrace ();} dY S(}U  
!T][c~l  
`.@sux!lu  
} YE{ [f@i0  
.{h"0<x  
BZ?Ck[E]Z  
public static void main(String[] args) |cf-S8pwY  
{ ;na%*G`  
new TestMethod(); q\?s<l63  
} > 0MP[  
} $TXxhd 6  
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