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http断点续传简单实现(java)

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/* 3Qv9=q|[b  
**SiteFileFetch.java `T2DGv  
*/ YS9)%F=X  
package NetFox; ieEt C,U  
import java.io.*; <1sUK4nQ,  
import java.net.*; f:t5`c.  
Nde1`W]:  
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public class SiteFileFetch extends Thread { }&ew}'*9)  
+ZwTi!W  
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SiteInfoBean siteInfoBean = null; //文件信息Bean q<g!bW%  
long[] nStartPos; //开始位置 W.7u6F`  
long[] nEndPos; //结束位置 ~8Ef`zL  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 g[{rX4~|  
long nFileLength; //文件长度 $iy(+}  
boolean bFirst = true; //是否第一次取文件 \<=.J`o{  
boolean bStop = false; //停止标志 SZgan  
File tmpFile; //文件下载的临时信息 v<} $d.&*  
DataOutputStream output; //输出到文件的输出流 ' #r^W2  
wzI*QXV2s  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) /X\:3P  
public SiteFileFetch(SiteInfoBean bean) throws IOException d/?0xLW  
{ +zFEx%3^  
siteInfoBean = bean; RCGpZyl  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); B<!wh  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 6 1K:SXj  
if(tmpFile.exists ()) xiQd[[(sM  
{ n{F&GE="  
bFirst = false; oW/H8q<wY  
read_nPos(); 0c#|LF_  
} # f{L;  
else b@1";+(27  
{ WoMMAo~  
nStartPos = new long[bean.getNSplitter()]; ;xE1#ZT  
nEndPos = new long[bean.getNSplitter()]; }Tk*?tYt  
} B{_-k  
k*T&>$k}^  
s[/)v:  
LTio^uH  
} ?Qh[vcF7`  
<d hBO  
k$K>ml/h  
public void run() v.]W{~PI2V  
{ )0@&pEObm  
//获得文件长度 1\Vp[^#Vx  
//分割文件 V^p XbDRl  
//实例FileSplitterFetch cU=/X{&Om  
//启动FileSplitterFetch线程 2W`<P2IA  
//等待子线程返回 o7 X5{  
try{ H Ff9^  
if(bFirst) ZGWZ2>k  
{  AQz&u  
nFileLength = getFileSize(); t.m C q 4{  
if(nFileLength == -1) GI*2*m!u  
{ a{8g9a4  
System.err.println("File Length is not known!"); N u9+b"Wr  
} J|I&{  
else if(nFileLength == -2) &l1CE1 9<  
{ ~bk+JK- >  
System.err.println("File is not access!"); E./Gt.Na  
} lw 9 rf4RF  
else * d[sja+  
{ AVv 8Hhd  
for(int i=0;i<nStartPos.length;i++) HTUY|^^D  
{ g JMv  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); -7l)mk  
} W_N!f=HW  
for(int i=0;i<nEndPos.length-1;i++) J#& C&S 2  
{ CpF&Vy K  
nEndPos = nStartPos[i+1]; E#cZM>  
} vErlh:~e  
nEndPos[nEndPos.length-1] = nFileLength; rN^P//  
} !NFP=m1  
} qy|si4IU8,  
0FD+iID  
LK[%}2me  
//启动子线程 /_*L8b  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u0& dDZ  
for(int i=0;i<nStartPos.length;i++) DR6 OR B7  
{ KUqD<Jj?  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #r_&Q`!eU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *b0f)y3RV  
nStartPos,nEndPos,i); \;s mH;m  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v(tr:[V  
fileSplitterFetch.start(); 0Bpix|mq  
}  $VCWc#  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hd}"%9p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [8QE}TFic  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lE?F Wt  
nEndPos = " + nFileLength); _:tisr{  
// fileSplitterFetch[nPos.length-1].start(); aGz <Yip  
\WeGO.i-  
`o~9a N  
//等待子线程结束 D 4\T`j:  
//int count = 0; }TCOm_Y/qL  
//是否结束while循环 Vi~F Q  
boolean breakWhile = false; c|'hs   
]+B#SIC;  
Sgt@G=_o  
while(!bStop) [=Yfdh M8S  
{ f`j RLo*L  
write_nPos(); >aZ$x/U+Iw  
Utility.sleep(500); YrR}55V,  
breakWhile = true; MyOdWD&7  
:h&*<!O2B`  
IYy2EK[s  
for(int i=0;i<nStartPos.length;i++) o|nj2.  
{ WBA0! g98  
if(!fileSplitterFetch.bDownOver) ? 1g<] ?  
{ %@{);5[  
breakWhile = false; m*BtD-{  
break; PQ2u R  
} 5UwaBPj4  
} m3k}Q3&6Z  
if(breakWhile) yp=2nU"o  
break; TWC^M{e  
.s_wP  
m(Cn'@i`"0  
//count++; zX!zG<<K  
//if(count>4) W)F2X0D>  
// siteStop(); (s,*soAN  
} L44-: 3  
*fq=["O  
_AQ :<0/#  
System.err.println("文件下载结束!"); ~h;c3#wuc  
} qPpC)6-Q  
catch(Exception e){e.printStackTrace ();} eA>O<Z1>  
} AO9F.A<T5  
/0 ,#c2aq  
4b8!LzKS  
//获得文件长度 )jp#|#h  
public long getFileSize() Ftm%@S?  
{ G1Cn[F;e  
int nFileLength = -1; p3*}!ez4  
try{ "6n~, $  
URL url = new URL(siteInfoBean.getSSiteURL()); DY6wp@A  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S*:b\{[f>  
httpConnection.setRequestProperty("User-Agent","NetFox"); N`/6 By  
2Ni$ (`"  
~?dPF;.6_  
int responseCode=httpConnection.getResponseCode(); )L`0VTw'M  
if(responseCode>=400) a Kb2:1EQ  
{ &gkloP @  
processErrorCode(responseCode); S@zsPzw  
return -2; //-2 represent access is error RaAi9b[/S  
} gQ*0Mk  
UGEC_  
g!<@6\RB  
String sHeader; Xi5ZQo!t  
>(u=/pp=:  
bzmT.!  
for(int i=1;;i++) <?,o {  
{ ~xu<xy@E  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p SASMc@  
//Utility.log(in.readLine()); cp2e,%o  
sHeader=httpConnection.getHeaderFieldKey(i); @q2Yka  
if(sHeader!=null) `w]=x e  
{ VVvV]rU~  
if(sHeader.equals("Content-Length")) ]xA;*b;| h  
{ 4_`+&  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); DPi%[CRH  
break; DVRE;+Jt  
} 1A">tgA1  
} N>7INK  
else '>Y"s|  
break; ]~)FMWQz-  
} ld4QhZia  
} 6Ez}A|i  
catch(IOException e){e.printStackTrace ();} N/Z3 EF_  
catch(Exception e){e.printStackTrace ();} {Os$Uui37\  
9~<HTH  
O(h4;'/E  
Utility.log(nFileLength); kh 1 7  
rFSLTbTf  
!SD?  
return nFileLength; LqPn$rZ|$  
} B+wSLi(  
bJ]g2C7`36  
I' ej?~  
//保存下载信息(文件指针位置) 7Xm pq&g  
private void write_nPos() SPe Se/  
{ 0CQ\e1S,#  
try{ [(5;jUmF@  
output = new DataOutputStream(new FileOutputStream(tmpFile)); V(A6>0s$|  
output.writeInt(nStartPos.length); //\ORJd  
for(int i=0;i<nStartPos.length;i++)  Jt.dR6,  
{ fnG&29x  
// output.writeLong(nPos); ,+KZn}>  
output.writeLong(fileSplitterFetch.nStartPos); 9@#Z6[=R,  
output.writeLong(fileSplitterFetch.nEndPos);  "C B*  
} ngcXS2S_  
output.close(); h2zuPgz,  
} YL=?Nk/  
catch(IOException e){e.printStackTrace ();} l];,)ddD9  
catch(Exception e){e.printStackTrace ();} OOGqtA;  
} kz(%8qi8&  
A jr]&H4  
MZB0vdx  
//读取保存的下载信息(文件指针位置) +g<2t,  
private void read_nPos() Y{B|*[xM  
{ 9Y- Sqk+  
try{ .ZFs+8qU>  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); * 'WzIk2  
int nCount = input.readInt(); 3205gI,  
nStartPos = new long[nCount]; ;+g p#&i`  
nEndPos = new long[nCount]; 7KnZ  
for(int i=0;i<nStartPos.length;i++) KY<>S/  
{ ec[S?-  
nStartPos = input.readLong(); :se o0w]  
nEndPos = input.readLong(); z[B*sbS  
} &7!&]kA+  
input.close(); RRqHo~*0  
} 0PI C|  
catch(IOException e){e.printStackTrace ();} nKp='>Th  
catch(Exception e){e.printStackTrace ();} R)"Ds}1G  
} ce\]o^4  
OWx YV$  
{O*WLZ{0  
private void processErrorCode(int nErrorCode) CDQ}C=4  
{ 9Ruj_U  
System.err.println("Error Code : " + nErrorCode); <->Nex  
} ,OsFv}v7  
l Ot3^`  
7c1xB.g   
//停止文件下载 !s06uh  
public void siteStop() fHCLsI  
{ dq28Y$9~  
bStop = true; XMd-r8yYr  
for(int i=0;i<nStartPos.length;i++) s"#JBw\7  
fileSplitterFetch.splitterStop(); NDEltG(  
.8S6;xnkC  
w7cciD|  
} _nOJ.G  
} Sg(fZ' -  
//负责部分文件的抓取 L!Iu\_{q  
**FileSplitterFetch.java 9}Ud'#E  
*/ laG@SV  
package NetFox; NK2Kw{c"iI  
v*SSc5gFG  
3zo]*6p0  
import java.io.*; 9bR lSb@  
import java.net.*; k3h,c;  
Mo\LFxx>4{  
_]a8lr+_-  
public class FileSplitterFetch extends Thread { CpNnywDRwU  
/L\ ]t  
+dw$IMwb  
String sURL; //File URL fCdd,,,}  
long nStartPos; //File Snippet Start Position \Y&*sfQ  
long nEndPos; //File Snippet End Position &^3KF0\Q  
int nThreadID; //Thread's ID l2QO\O I9m  
boolean bDownOver = false; //Downing is over Dj}n!M`2I  
boolean bStop = false; //Stop identical i_Dv+^&zV  
FileAccessI fileAccessI = null; //File Access interface D 's'LspQ  
}CnqJ@>C5  
SIv8EMGo  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 99w;Q 2k  
{ <NZ^*]  
this.sURL = sURL; xdb9oH  
this.nStartPos = nStart; 7\m.xWX e  
this.nEndPos = nEnd; <7N8L  
nThreadID = id; ,S 5tkTa  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1ThONrxu  
} .|[ZEXq  
fmyyQ|]O"  
Bf33%I~  
public void run() >=Hm2daN  
{ lPF(&pP  
while(nStartPos < nEndPos && !bStop) vH/ z|<  
{ P=PcO>  
UmYReF<<_  
t)P5bQ+$u9  
try{ -6a4H?L  
URL url = new URL(sURL); k~f3~-"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GWo^hIfJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); os6p1"_\f  
String sProperty = "bytes="+nStartPos+"-"; S-V)!6\cK  
httpConnection.setRequestProperty("RANGE",sProperty); [SGt ~bRJ  
Utility.log(sProperty); c&r8q]u  
Gh}k9-L  
mi9BC9W(  
InputStream input = httpConnection.getInputStream(); M,xhQ{eBY  
//logResponseHead(httpConnection); KNT(lA0s  
q] g'rO'  
EOJk7  
byte[] b = new byte[1024]; (qd$wv^ h  
int nRead; 4a3Xz,[(a  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \l!^6G|c  
{ /N6sH!w  
nStartPos += fileAccessI.write(b,0,nRead); pW ]+a0j  
//if(nThreadID == 1) tYV%izE  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `L p3snS  
} Z* eb  
Sh'>5z2  
Hik8u!#P  
Utility.log("Thread " + nThreadID + " is over!"); _~!*|<A_  
bDownOver = true; 6&/H XqP  
//nPos = fileAccessI.write (b,0,nRead); 8 tq6.%\  
} ?^]29p_  
catch(Exception e){e.printStackTrace ();} 46(Vq|  
} Ar&]/X,WG  
} wn*<.s  
XrR@cDNx{  
DVCO( fz  
//打印回应的头信息 }#~@HM>6Z  
public void logResponseHead(HttpURLConnection con) Y4*ezt:;Q  
{ v&g(6~b_>  
for(int i=1;;i++) n{vp&  
{ |lH~nU.*  
String header=con.getHeaderFieldKey(i); q~*3Bk~  
if(header!=null) s+Qm/ h2  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); .5=Qf vi*  
Utility.log(header+" : "+con.getHeaderField(header)); RqTW$94RD  
else mq~rD)T  
break; W[S4s/)mg  
} A WlR" p2  
} nLK%5C  
U9:?d>7  
:x e/7-  
public void splitterStop() gb 6 gIFq;  
{ 2w`kh=  
bStop = true; BNU]NcA#*,  
} C6Qnn@waYb  
d;(&_;  
n 99>oh  
} :UjHP}s  
aYQ!`mS::M  
q^}QwJw  
/* cVv>"oF;~*  
**FileAccess.java )W^Wqa8mG|  
*//文件访问(定位,写) p"^^9'`=  
package NetFox; uS :3Yo  
import java.io.*; ) *:<3g!  
2!QS&i  
l'YpSO~l7  
public class FileAccessI implements Serializable{ c_b^t09  
x#yL&+'?Mj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <qH>[ \  
RandomAccessFile oSavedFile; f:L%th  
long nPos; n y6-_mA]  
(bH*i\W  
7NG^X"N{Ul  
public FileAccessI() throws IOException ` c~:3^?9d  
{ (mXV5IM  
this("",0); e"en ma\_  
} 4)Y=)#=  
`T  $lTP  
nIVPh99  
public FileAccessI(String sName,long nPos) throws IOException PQAN,d  
{ NC::;e  
oSavedFile = new RandomAccessFile(sName,"rw"); D6Ov]E:fa  
this.nPos = nPos; Q1V4bmM  
oSavedFile.seek(nPos); qA:CV(Z  
} #tG/{R  
m;o \.s  
N3E Qq~lX  
public synchronized int write(byte[] b,int nStart,int nLen) +GMM&6<  
{ :pQZ)bF  
int n = -1; (PU0\bGA  
try{ ry}CND(nB  
oSavedFile.write(b,nStart,nLen); 2vWJ|&|p  
n = nLen; {>>ozB.  
} /Kb7#uq  
catch(IOException e) 8^j u=  
{ B&|F9Z6D  
e.printStackTrace (); l<)(iU  
} bnLvJ]i)  
P7d" E  
m *8[I  
return n; l){l*~5zl2  
} Q(gu ";&  
s&Y~ 48{  
-?<wvUbR{  
} R{)Sv| +`  
D8slSX`6j  
7 }(LO^,A  
/* nab:y(]$/  
**SiteInfoBean.java %b'ic  
*/ hu[=9#''$  
package NetFox; <QT u"i  
[qlq&?"  
]OZZPo  
public class SiteInfoBean { HH+NNSRO  
#B:J7&@fn  
iyrUY  
private String sSiteURL; //Site's URL V| z|H$-  
private String sFilePath; //Saved File's Path y!GjC]/  
private String sFileName; //Saved File's Name *ghkw9/  
private int nSplitter; //Count of Splited Downloading File K,%H*1YKK  
i}ypEp  
Fgxh?Wd9  
public SiteInfoBean() HY9H?T  
{//nSplitter的缺省值为5 +pc_KR  
//default value of nSplitter is 5 N:[m,U9a  
this("","","",5); VkhZt7]K}B  
} g"( vl-Uw  
,XCC#F(d1  
4JFi|oK0H  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PTIC2  
{ }qT @.  
sSiteURL= sURL; ui`xgR\6Rh  
sFilePath = sPath; z,}1K!  
sFileName = sName; O\pqZ`E=s  
this.nSplitter = nSpiltter; r vVU5zA4H  
 >>Hsx2M  
-w=rNlj  
} Pk[f_%0  
"2+>!G RQ  
FyJI@PZdI-  
public String getSSiteURL() v<_}Br2I[  
{ ww nc  
return sSiteURL; 2{!'L'km  
} 3X*;.'#Z  
's@v'u3  
IK(G%dDw  
public void setSSiteURL(String value) ,ZV<o!\  
{ gWqmK/.U.0  
sSiteURL = value; 7xB#)o53  
} VXZdRsV8T  
*pw:oTO  
+`u]LOAyP=  
public String getSFilePath() 6g29!F`y  
{ ;5ugnVXu  
return sFilePath; 0aSN 8  
} WW0N"m'  
c%>t(ce`Tl  
s2_j@k?%  
public void setSFilePath(String value) Lg|j0-"N  
{ l Vo](#W  
sFilePath = value; HGfYL')Z  
} Dd<gYPC  
B{H;3{0  
Q/\ <rG4  
public String getSFileName() qc|;qPj   
{ [ hm/B`t*e  
return sFileName; 2$yKa5SaX  
} WTA0S}pT  
>*,Zc  
T5B~CC'6  
public void setSFileName(String value) KArf:d  
{ RR{]^g51  
sFileName = value; <d# 9d.<  
} y mY,*Rb  
jkQv cU  
vlw2dY@^  
public int getNSplitter() tNjb{(eO\h  
{ U&C\5N]  
return nSplitter; u Zz^>* b  
} '1~mnmiP  
)_ NQ*m  
Ik>sd@X*|  
public void setNSplitter(int nCount) !\JG]2 \  
{ #E5Sc\,  
nSplitter = nCount; fxI>FhU_  
}  h#^IT  
} yf*MG&}  
{[hV ['Awv  
%g5weiFM  
/* kMo;<Z  
**Utility.java  .r[DqC  
*/ ?q7V B  
package NetFox; r9%4q4D?>9  
MkC25  
7Nh6 `  
public class Utility { 0 !E* >  
28d:  
r|fJ~0z  
public Utility() R5X<8(4p  
{ !a[ voUS  
IJD'0/R'c  
Fb*^GH)J  
} |D$U{5}Mv  
@+syD  
//线程睡眠 ]8htJ]<|Q  
public static void sleep(int nSecond) YMIDV-  
{ uWG'AmK_#E  
try{ 7{D +\i  
Thread.sleep(nSecond); Iu 2RK  
} -qs.'o ;2  
catch(Exception e) qe"5&cc1  
{ wDem }uO  
e.printStackTrace (); 5G_*T  
} Xleoh2&M  
} +@cf@}W6QC  
4^w>An6  
//日志 r1}OlVbK  
public static void log(String sMsg) Cm JI"   
{ {p 9y{$  
System.err.println(sMsg); A>%fE 6FY  
} jXGr{n  
)cUc}Avg}  
7eQ7\,^H  
public static void log(int sMsg) jzI\Q{[m'  
{ HMgZ& v  
System.err.println(sMsg); 00%$?Fyk  
} lk}R#n$  
} "%A/bv\u  
w I #_r_  
o8KlY?hX  
/* w<J$12 "p+  
**TestMethod.java $* b>c:  
*/ }f^K}*sK$5  
package NetFox; t<|=-  
r7C  m  
NX@TWBn%  
public class TestMethod { UB.FX  
@-kzSm  
{Ylj]  
public TestMethod() =XQ3sk6U  
{ ///xx/weblogic60b2_win.exe %a8'6^k  
try{ ^^jF*)DT@  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s]5wzbFO  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $Fc*^8$ryC  
SiteFileFetch fileFetch = new SiteFileFetch(bean); qk~QcVg  
fileFetch.start(); Gd%6lab  
} nl*{@R.q @  
catch(Exception e){e.printStackTrace ();} ;?=nr5;q  
5>KAVtYvc  
E0ud<'3<  
} :n0(gB  
QMy;?,  
[5)1 4% x  
public static void main(String[] args) y"cK@sOo  
{ S N?jxQ  
new TestMethod(); #8;^ys1f  
} z ]o&^Q  
} y<BiR@%,7  
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