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http断点续传简单实现(java)

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/* 8,|kao:  
**SiteFileFetch.java F[MFx^sT{  
*/ R-14=|7a-  
package NetFox; 7Yy ;  
import java.io.*; #z42C?V  
import java.net.*; sq]F;=[5  
r<\u6jF  
@]0%L0u  
public class SiteFileFetch extends Thread { .]Z"C&"N]  
DNi+"[~&P  
[Qr"cR^  
SiteInfoBean siteInfoBean = null; //文件信息Bean DwF hK*  
long[] nStartPos; //开始位置 :KO2| v\  
long[] nEndPos; //结束位置 P2Y^d#jO  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W l4%GB  
long nFileLength; //文件长度 -qoH,4w  
boolean bFirst = true; //是否第一次取文件 (sj,[  
boolean bStop = false; //停止标志 `mqMLo *  
File tmpFile; //文件下载的临时信息 ce(#2o&`  
DataOutputStream output; //输出到文件的输出流 pk~WrqK}  
E"0>yl)  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Ho%CDz z  
public SiteFileFetch(SiteInfoBean bean) throws IOException 05[SC}MCA  
{ M3AXe]<eC1  
siteInfoBean = bean; xC?h2hIt  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); T0 {Lq:  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); @pxcpXCy  
if(tmpFile.exists ()) =">NQ)98u  
{ I_BJH'!t  
bFirst = false; Debv4Gr;^  
read_nPos(); .^g p?  
} KmF]\:sMD  
else uq{ beC  
{ g=rbPbu  
nStartPos = new long[bean.getNSplitter()]; DI%saw  
nEndPos = new long[bean.getNSplitter()]; <uJ@:oWG7  
} 7 d vnupLh  
#Dac~>a'  
(#'>(t(4  
9B4&m|g  
} n*$ g]G$  
U6VKMxSJ  
ME dWLFf  
public void run() Ls%MGs9PI  
{ [!z,lY>  
//获得文件长度 +qoRP2  
//分割文件 7Ix973^  
//实例FileSplitterFetch f5r0\7y0  
//启动FileSplitterFetch线程 1"g<0 W  
//等待子线程返回 M}Sv8D]I  
try{ wj+*E6o-n  
if(bFirst) :%.D78&  
{ 8_8l.!~  
nFileLength = getFileSize(); oQ#8nu{k  
if(nFileLength == -1) RpF&\x>  
{ v1[29t<I!  
System.err.println("File Length is not known!"); <q SC#[xu  
} pUTr!fR  
else if(nFileLength == -2) +0~YP*I`/  
{ ,)XLq8  
System.err.println("File is not access!"); ;fJ.8C  
} s CRdtP  
else 9UkBwS`  
{ $k?>DP 4  
for(int i=0;i<nStartPos.length;i++) g ?k=^C  
{ : 'c&,oLY  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); T |p"0b A  
} M{\I8oOg  
for(int i=0;i<nEndPos.length-1;i++) *Uh!>Iv;  
{ 25T18&R  
nEndPos = nStartPos[i+1]; '7/)Ot(  
} ;r8X.>P*  
nEndPos[nEndPos.length-1] = nFileLength; Rv=YFo[B  
} yr6V3],Tp  
} <[phnU^ 8  
%;/P&d/  
%RVZD#zr  
//启动子线程 pI[uUu7O  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >Q/Dk7#  
for(int i=0;i<nStartPos.length;i++) pJ=#zsE0  
{ n?Q|)2 2  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !W\+#ez  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C+]I@Go'Tk  
nStartPos,nEndPos,i); 2/f}S?@   
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s.#`&Sd>  
fileSplitterFetch.start(); @co S+t  
} B[}6-2<>?C  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >usL*b0%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 43w}qY1  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S @Y39  
nEndPos = " + nFileLength); lFk R=!?=  
// fileSplitterFetch[nPos.length-1].start(); .d*8C,  
@d_M@\r=j  
.X&9Q9T=#  
//等待子线程结束 &[9709 (=  
//int count = 0; 0"R|..l/  
//是否结束while循环 z{543~Og59  
boolean breakWhile = false; _GPe<H  
YR70BOxK  
KoRV %@I  
while(!bStop) 7^Uv7< pw  
{ yu|>t4#GT  
write_nPos(); JC"z&ka  
Utility.sleep(500); [Pp'Ye~K@c  
breakWhile = true; rOYx b }1  
AX INThJ  
@iiT<  
for(int i=0;i<nStartPos.length;i++) )+^+s d  
{ jdN` mosJ  
if(!fileSplitterFetch.bDownOver) ^q&x7Kv%  
{ <aw[XFg  
breakWhile = false; u +hX  
break; mq l Z?-  
} km(Po}  
} im8CmQ  
if(breakWhile) S/ *E,))m  
break; W_=f'yb:E  
(:_$5&i7  
dr(*T  
//count++; VVZ'i.*_3?  
//if(count>4) 4*L_)z&4;  
// siteStop(); 7$b1<.WX  
} K9[UB  
1oS/`)  
7pd$\$  
System.err.println("文件下载结束!"); _$'ashF  
} >z03{=sAN  
catch(Exception e){e.printStackTrace ();} W!X@  
} [ 3Gf2_  
b 6p|q_e  
7/H)Az@i45  
//获得文件长度 r$1Qf}J3=  
public long getFileSize() KXy6Eno  
{ *hx  
int nFileLength = -1; sx%[=g+<2(  
try{ 2T35{Q!=F  
URL url = new URL(siteInfoBean.getSSiteURL()); 8m MQ[#0:}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -@s#uA h  
httpConnection.setRequestProperty("User-Agent","NetFox"); @- xjfC\d  
/(cPfZZ  
QY/w  
int responseCode=httpConnection.getResponseCode(); pb}*\/s  
if(responseCode>=400) }pYqWTG  
{ \Z/@C lCm  
processErrorCode(responseCode); WLT"ji0w2  
return -2; //-2 represent access is error Wc#24:OKe3  
} 6t$8M[0-U  
y0#2m6u  
"x-j~u?  
String sHeader; UfGkTwoo=  
=  [E  
3n _htgcv  
for(int i=1;;i++) <YY14p  
{ t# i #(H  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QV!up^Zso  
//Utility.log(in.readLine()); fVlB=8DNk&  
sHeader=httpConnection.getHeaderFieldKey(i); }tz7b#  
if(sHeader!=null) 0S"MC9beg  
{ ;I}fBZ 3  
if(sHeader.equals("Content-Length")) l **X^+=$  
{ se)TzI^]b@  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )e{aN+  
break; "sTRS*  
} (>Em^(&  
} d0D] Q  
else rp$'L7lrX  
break; @dK Tx#gZ  
} >7|VR:U?B  
} eFgA 8kY)  
catch(IOException e){e.printStackTrace ();} uT"rq:N  
catch(Exception e){e.printStackTrace ();} jd: 6:Fm  
j%kncGS  
dN q$}  
Utility.log(nFileLength); ;l+Leex  
L0,'mS  
vP&(-a  
return nFileLength; *@5@,=d  
} 5! {D!  
]Ze1s02(  
c{|p.hd  
//保存下载信息(文件指针位置) 4s- !7  
private void write_nPos() Y<OFsWYY  
{ lxx2H1([  
try{ -n 1 v3  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ui~>SN>s  
output.writeInt(nStartPos.length); 79gT+~z   
for(int i=0;i<nStartPos.length;i++) uRvP hkqm  
{ o!Zb0/AP)  
// output.writeLong(nPos); pBHRa?Y5  
output.writeLong(fileSplitterFetch.nStartPos); J1k>07}|  
output.writeLong(fileSplitterFetch.nEndPos); ftb\0,-   
} Q ,g\  
output.close(); 3] Ct6  
} ?,z}%p  
catch(IOException e){e.printStackTrace ();} oH@78D0A  
catch(Exception e){e.printStackTrace ();} IGl9 g_18  
} KlEpzJ98  
Jy)/%p~  
C|bET  
//读取保存的下载信息(文件指针位置) _BufO7 `.  
private void read_nPos() ("KF'fp&M2  
{ 1 MFbQs^  
try{ 5P2K5,o|n~  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 81F9uM0  
int nCount = input.readInt(); &oNAv-m^GD  
nStartPos = new long[nCount]; \z$= K  
nEndPos = new long[nCount]; E .h*g8bXe  
for(int i=0;i<nStartPos.length;i++) :gv"M8AP  
{ CIWO7bS  
nStartPos = input.readLong(); *. t^MP  
nEndPos = input.readLong(); Gv&V|7-f0  
} iZmcI;?u  
input.close(); PCA4k.,T  
} ?,/ }`3Vw  
catch(IOException e){e.printStackTrace ();} Ry&6p>-  
catch(Exception e){e.printStackTrace ();} P}iE+Z 3  
} G@0&8  
4+n\k  
k6^Z~5 Sy  
private void processErrorCode(int nErrorCode) (7Qo  
{ y =@N|f!  
System.err.println("Error Code : " + nErrorCode); , gHDx  
} [g,}gyeS(  
vO=fP_  
)7@0[>  
//停止文件下载 !-bB559Nv  
public void siteStop() $G>.\t  
{ HW|IILFB  
bStop = true; $b\P|#A  
for(int i=0;i<nStartPos.length;i++) al0L&z\  
fileSplitterFetch.splitterStop(); }Z>)DN=+  
~&O%N  
[QTV9  
} *hrd5na  
} iso4]>LF  
//负责部分文件的抓取 Ac6=(B  
**FileSplitterFetch.java Vl]>u+YqE  
*/ 'qi}|I  
package NetFox; Tw% 3p=  
E^PB)D(.  
J,G lIv.A  
import java.io.*; 6zkaOA46V  
import java.net.*; $kgVa^  
^8tEach  
<{pz<io)  
public class FileSplitterFetch extends Thread { wr4:Go`  
c,22*.V/  
=;k|*Ny  
String sURL; //File URL -di o5a  
long nStartPos; //File Snippet Start Position !wNO8;(  
long nEndPos; //File Snippet End Position ]9L oZ)  
int nThreadID; //Thread's ID 4 :=]<sc,  
boolean bDownOver = false; //Downing is over 'yth'[  
boolean bStop = false; //Stop identical *I'yH8Fcn  
FileAccessI fileAccessI = null; //File Access interface 598i^z{~0%  
.543N<w  
zX~MC?,W1  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yVc(`,tZ(  
{ edV\-H5<  
this.sURL = sURL; 4YHY7J  
this.nStartPos = nStart; % nIf)/2g  
this.nEndPos = nEnd; *A< 5*Db:F  
nThreadID = id; b[yiq$K/  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2tLJU  Z1  
} 5r_|yu  
:EH=_"  
:LTN!jj  
public void run() G`zm@QL  
{ zJXplvaL;  
while(nStartPos < nEndPos && !bStop) C7vxw-o|&p  
{ xpI wrJO  
b\ PgVBf9  
Y~Ifj,\  
try{ ':}\4j&{E  
URL url = new URL(sURL); +{>=^9%X  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fLVAKn  
httpConnection.setRequestProperty("User-Agent","NetFox"); >MK98(F  
String sProperty = "bytes="+nStartPos+"-"; ]{kPrey  
httpConnection.setRequestProperty("RANGE",sProperty); i&k7-<  
Utility.log(sProperty); L(o15  
BC]?0 U  
rbQR,Nf2x  
InputStream input = httpConnection.getInputStream(); 4~=l}H>&  
//logResponseHead(httpConnection); fQ98(+6  
0Qd:`HF[  
or]IZ2^n  
byte[] b = new byte[1024]; _rYkis^ u  
int nRead; zT[!o j7  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Il.K"ll  
{ vI]N^j2%  
nStartPos += fileAccessI.write(b,0,nRead); 1U\z5$V  
//if(nThreadID == 1) vFsLY  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ETLD$=iS  
} "] iB6  
.~}1+\~5  
EzIGz[  
Utility.log("Thread " + nThreadID + " is over!"); go"Hf_  
bDownOver = true; 0;ji65  
//nPos = fileAccessI.write (b,0,nRead); ;6 wA"  
} sC;+F*0g  
catch(Exception e){e.printStackTrace ();} 5Ph4<f` L~  
} ;GI&lpKK  
} *4Izy14e  
l+R+&b^  
@o6L6Y0Naa  
//打印回应的头信息 E!#WnSpnK  
public void logResponseHead(HttpURLConnection con) ^H' \"9;7  
{ _y3Xb`0a  
for(int i=1;;i++) '=6\v!  
{ 9mFE?J  
String header=con.getHeaderFieldKey(i); <9%R\_@$H  
if(header!=null) L:8q8i  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RGU\h[  
Utility.log(header+" : "+con.getHeaderField(header)); A4ygW:  
else ""D 4s  
break; 'eX '  
} h-D }'R  
} h*Pc=/p  
6DWgl$[[  
T n}s*<=V  
public void splitterStop() 4g7)iL^#~  
{ !L8#@BjU  
bStop = true; !3v1bGk  
} \_U$"/$4VH  
U3:j'Su4H?  
e*n@j  
} ;Q&5,< N)j  
s!e3|pGS  
))i}7 chc  
/* -o.:P>/  
**FileAccess.java Rx|;=-8zg  
*//文件访问(定位,写) pO.2<  
package NetFox; 6Kb1~jY  
import java.io.*; +&"zU GTIc  
4 N7^?  
|B2+{@R  
public class FileAccessI implements Serializable{ .y,0[i V N  
IyPnp&_  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f>Jr|#k  
RandomAccessFile oSavedFile; SC])?h-Fw  
long nPos; 7fX<511(  
HOh!Xcu  
d&s9t;@=  
public FileAccessI() throws IOException B !=F2  
{ C=4Qlt[`  
this("",0); 4X(H ;  
} 19KQlMO.G  
(/*]?Ehd  
y Ej^=pw  
public FileAccessI(String sName,long nPos) throws IOException ~<OSYb  
{ R+,u^;\  
oSavedFile = new RandomAccessFile(sName,"rw"); Q&| \r  
this.nPos = nPos; QW~1%`  
oSavedFile.seek(nPos); QS]1daMIK<  
} e01epVR;  
r_;N t  
VgC2+APg  
public synchronized int write(byte[] b,int nStart,int nLen) _W'-+,  
{ _M5|Y@XN-  
int n = -1; 3CGp`~Zf  
try{ qH6>!=00  
oSavedFile.write(b,nStart,nLen); l/ ;  
n = nLen; x*&|0n.D  
} 'D"C4;X  
catch(IOException e) W#C*5@8  
{ eS mLf*\G  
e.printStackTrace (); f_Av3  
} df#$ 9 -  
5=?\1`e1[  
0f>5(ek  
return n; =;&yd';k  
} <)-Sj,  
tWa) _y  
M8b;d}XL  
} r7,t";?>  
*6F[t.Or  
Gvqxi|  
/* q,eVjtF  
**SiteInfoBean.java 8j\cL'  
*/ .oUTqki  
package NetFox; |:<f-j7t~  
!|S43i&p  
I \JGs@I   
public class SiteInfoBean { s^uS1  
Z//+Gw<'  
vf%&4\ib  
private String sSiteURL; //Site's URL }\:Nu Tf  
private String sFilePath; //Saved File's Path 0C6-GKbZ  
private String sFileName; //Saved File's Name CxG#"{&  
private int nSplitter; //Count of Splited Downloading File #c?j\Y9nz  
4 bH^":i(  
Uu(SR/R}  
public SiteInfoBean() os={PQRD  
{//nSplitter的缺省值为5 04l!:Tp,  
//default value of nSplitter is 5 %H&@^Tt a  
this("","","",5); \EtQ5T*u  
} QKN+>X  
5BKt1%Pg  
T iiWp!mX  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b8SHg^}  
{ 4 f'V8|QM{  
sSiteURL= sURL; 5Qn '  
sFilePath = sPath; Zk"eA'"\  
sFileName = sName; CtAwBQO  
this.nSplitter = nSpiltter; ~W+kiTsD?  
n}G|/v<  
QYjsDL><  
} 9:1Q1,-i!-  
K&70{r  
{~s DYRX  
public String getSSiteURL() t@N=kV  
{ a$"Hvrj  
return sSiteURL; oxkoA  
} ~r`9+b[9{  
V(6Z3g  
e`TH91@  
public void setSSiteURL(String value) #( jw!d&  
{ V7P&%oz{C  
sSiteURL = value; !0@Yplj  
} W 7\f1}]H  
D.Q=]jOs  
Dg?70v <a  
public String getSFilePath() *q".-u!D[  
{ `-l6S  
return sFilePath; 4V COKx  
} OJ$]V,Z00x  
?$^2Umt 0  
-~ Mb  
public void setSFilePath(String value) Vz)`nmO}5\  
{ b6F4>@gjg  
sFilePath = value; Rh{zH~oZ  
} 4V==7p x(  
$!(pF  
{{MRELipW  
public String getSFileName() 7MHKeLq  
{ @I/]D6 ~"  
return sFileName; pxf$ 1  
} U,q\em R  
5nO% Ke=  
YmgLzGk`  
public void setSFileName(String value) :1^R9yWA4  
{ Y2SJ7  
sFileName = value; (egzH?  
} #KXa&C  
Mt5PaTjj  
kO{s^_qR^c  
public int getNSplitter() rZ^v?4Z\  
{ ,o,I5>`  
return nSplitter; RYl>  
} uVDa^+=  
oDYRQozo>  
S.q].a  
public void setNSplitter(int nCount) r*_ZJ*h[  
{ :WL'cJ9a  
nSplitter = nCount; :!b'Vk  
} p>;_e(  
} P2'DD 3   
WT`4s  
sZm$|T0  
/* I=9!Rs(QF  
**Utility.java (tGY%oT"  
*/ -3lb@ 6I6  
package NetFox; ' n$ %Ls}S  
}HYjA4o\A  
] Ww?QhJ  
public class Utility { '@CR\5 @  
~\3kx]^10  
ZMLg;-T.&4  
public Utility() B7<Kc  
{ w{90`  
&0(  
r~nsN*t  
} z2hc.29t  
S^<g_ q  
//线程睡眠 <u:WlaS  
public static void sleep(int nSecond) ?zJOh^  
{ "0k8IVwp  
try{ 4bJZmUb  
Thread.sleep(nSecond); VA%Un,5h  
} lmSo8/%T  
catch(Exception e) 4[-*~C|W5  
{ >ap1"n9k  
e.printStackTrace (); ?8mlZ X9C  
} t 6^l`6:p  
} \7 NpT}dj  
:C8$Xi_i}  
//日志  ?k|H3;\  
public static void log(String sMsg) 'EfR|7m  
{ $4T2z-  
System.err.println(sMsg); eD Z8w  
} Pv+5K*"7Cg  
~w;]c_{.b  
AkT<2H|4  
public static void log(int sMsg) N#_GJSG_|  
{ .ol'.t ,S  
System.err.println(sMsg); \Ro^*4B  
} FsGlJ   
} z5X~3s\dP  
fn/7wO$!  
?[MsQQd~  
/* =@5x"MOz  
**TestMethod.java Vax^8 -  
*/ ?`Y\)'}   
package NetFox; W Qc>  
')$NfarQ.  
A[YpcG'9  
public class TestMethod { ACK1@eF  
0G2g4DSKD  
%,*G[#*&  
public TestMethod() |uH%6&\  
{ ///xx/weblogic60b2_win.exe vkRi5!bR  
try{ xT)psM'CL  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /)rkiwp  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B,(Heg  
SiteFileFetch fileFetch = new SiteFileFetch(bean); y9|K|xO[  
fileFetch.start(); 1Fi86  
} !"TZ:"VZU  
catch(Exception e){e.printStackTrace ();} l#wdpD a{  
;*[9Q'lI*  
5b6s4ZyV  
} N|2y"5  
4E:bp   
8%~t  
public static void main(String[] args) r CRgzC  
{ AP\ofLmq  
new TestMethod(); m!OMrZ%)}  
} J:F^ #gW  
} 7CB#YP?E  
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