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http断点续传简单实现(java)

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/* 4!-/m7%eF  
**SiteFileFetch.java  $kxu-  
*/ k: z)Sw  
package NetFox; "XU)(<p  
import java.io.*; U(hIT9  
import java.net.*; $Q=S`z=  
^g"%:4zO  
ZSLvr-,D  
public class SiteFileFetch extends Thread { *EFuK8 ;  
<ti,Wn.  
e1ExB#  
SiteInfoBean siteInfoBean = null; //文件信息Bean <jh=W9.N_  
long[] nStartPos; //开始位置 <9S5  
long[] nEndPos; //结束位置 /Nhc|x6zQ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 x}OJ~Yk]  
long nFileLength; //文件长度 NOl/y@#  
boolean bFirst = true; //是否第一次取文件 E=ObfN"ge  
boolean bStop = false; //停止标志 "!:)qVL^  
File tmpFile; //文件下载的临时信息 tV2o9!N4  
DataOutputStream output; //输出到文件的输出流 /#[mV(k  
NZ% v{?  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) b{.Y?.U  
public SiteFileFetch(SiteInfoBean bean) throws IOException KB gFS%-W  
{ UW{C`^?=B  
siteInfoBean = bean; -+:t%A?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); R=S)O.*R  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); EfX,0NqT  
if(tmpFile.exists ()) cEK#5   
{ aX*7tRn_%  
bFirst = false; $]4o!Z  
read_nPos(); +9.GNu  
} y]uBVn'u  
else }-p-(  
{ #r@>.S=U]  
nStartPos = new long[bean.getNSplitter()]; PVrNS7 Rk/  
nEndPos = new long[bean.getNSplitter()]; Qa"4^s  
} "J 2v8c  
& z5:v-G?  
dA0o{[o=  
fjm 3X$tR  
} tQ)l4Y 8  
>KJE *X@s  
A" IaFXB  
public void run() S"@@BQ#mf  
{ &Zo+F]3d  
//获得文件长度 D 75;Y;E  
//分割文件 \OkJX_7  
//实例FileSplitterFetch E4<#6q  
//启动FileSplitterFetch线程 g+-^6UG  
//等待子线程返回 dlMjy$/T  
try{ w^[:wzF0  
if(bFirst) '_" S/X +v  
{ <WL] (-9I:  
nFileLength = getFileSize(); ?8q4texf[  
if(nFileLength == -1) A9z3SJ\vXl  
{ xiF}{25a  
System.err.println("File Length is not known!"); v3cLU7bi?2  
} /Y [ b8f  
else if(nFileLength == -2) $I9U.~*  
{ nQG<OVRClS  
System.err.println("File is not access!"); yjM!M|  
} 8L*#zaSAf  
else WPPD vB  
{ DK|/|C}6  
for(int i=0;i<nStartPos.length;i++) iAXF;'|W  
{ 8]WcW/1r !  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); s 4n<k]d  
} i1!Y {  
for(int i=0;i<nEndPos.length-1;i++) &0OH:P%  
{ B. #-@  
nEndPos = nStartPos[i+1]; >bg{  
} hfs QAa  
nEndPos[nEndPos.length-1] = nFileLength; .GvZv>  
} {T3wOi  
} X @X`,/{X  
iN2591S  
ucUu hS5  
//启动子线程 #_zj5B38E  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jIWX6  
for(int i=0;i<nStartPos.length;i++) T;3B_ lu]  
{ /Ur]U w  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rj-4K@a8#N  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^O**ZndB/  
nStartPos,nEndPos,i); Cf@N>N#t)  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3vEwui-5  
fileSplitterFetch.start(); +xNq8yS  
} I<S*"[nV  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u89Q2\z~"M  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )Zrn?KM  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |Rb8 / WX  
nEndPos = " + nFileLength); #2%8@?_-M  
// fileSplitterFetch[nPos.length-1].start(); *\^(-p~M  
pK)!o  
q[c^`5  
//等待子线程结束 F`o"t]AD-a  
//int count = 0; * K0aR!  
//是否结束while循环 f_IsY+@  
boolean breakWhile = false; -90X^]  
%/RT}CBBsW  
c\rP"y|S};  
while(!bStop) rC6EgWt<V  
{ wLo<gA6;  
write_nPos(); 8>DX :`  
Utility.sleep(500); cq8JpSB(  
breakWhile = true; kM3#[#6$!  
Jv~^hN2  
s_U--y.2r(  
for(int i=0;i<nStartPos.length;i++) %\!@$]3q  
{ {Vf].l:kn  
if(!fileSplitterFetch.bDownOver) xxpzz(S ]A  
{ I1JF2" {c  
breakWhile = false; mA5sK?W  
break; \Lm`jU(:l  
} "f-HOd\=  
} M?I^`6IOc8  
if(breakWhile) {ApjOIxk  
break; H2CpZK'  
gVs@T'  
P@U2Q%\  
//count++; 5zH_yZ@+  
//if(count>4) Om2w+yU  
// siteStop(); 66scBi_d  
} O?iLLfs  
] m #*4  
i_p-|I:hQ  
System.err.println("文件下载结束!"); a!, X@5  
} G1wJ]ar  
catch(Exception e){e.printStackTrace ();} 7~VDk5Z6  
} m5cRHo<9Y  
n"nfEA3{`  
"FLiSz%ME  
//获得文件长度 K/8TwB?I  
public long getFileSize() I\|.WrMNi  
{ cPX^4d~9  
int nFileLength = -1; {6>$w/+~  
try{ *Z3b6X'e  
URL url = new URL(siteInfoBean.getSSiteURL()); B\+uRiD8w  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MZ>Q Rf  
httpConnection.setRequestProperty("User-Agent","NetFox"); k!d<2Qp W  
[NbW"Y7  
Cw~fP[5XMF  
int responseCode=httpConnection.getResponseCode(); t_\&LMD  
if(responseCode>=400) H"wIa8A  
{  Rp6q)  
processErrorCode(responseCode); =|H.r9-PK6  
return -2; //-2 represent access is error V2$M`|E  
} '|G8yojz  
[x -<O:r=P  
{N@Pk[!  
String sHeader; G}@a]EGm  
)g`~,3G  
~Sx\>wBlc  
for(int i=1;;i++) 6ck%M#v  
{ 6u{%jSA>D\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]6,D 9^{;  
//Utility.log(in.readLine()); 3]kN9n{  
sHeader=httpConnection.getHeaderFieldKey(i); 40 zO4  
if(sHeader!=null) mcxD#+H 3  
{ )QI#szv6  
if(sHeader.equals("Content-Length")) 7nZ3u _~  
{ Nwk^r75lq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \Npvm49  
break; ow#8oUf=  
} ]N:Wt2  
} E|W7IgS  
else Us% _'}(/U  
break; ?h,.1Tb  
} KIY9?B=+  
} o 9d|XY_  
catch(IOException e){e.printStackTrace ();} ul!q)cPb{  
catch(Exception e){e.printStackTrace ();} X#o;`QM  
_.SpU`>/f  
[<nd+3E  
Utility.log(nFileLength); )-25?B  
`tl-] ^Y2  
fP llN8n  
return nFileLength; qf{HGn_9~1  
} mv(/M t  
^grDP*;W  
ulfs Z:  
//保存下载信息(文件指针位置) #p-\Y7f  
private void write_nPos() *pyC<4W  
{ ?5wsgP^  
try{ .p(r|5(b  
output = new DataOutputStream(new FileOutputStream(tmpFile)); WZ UeW*#=  
output.writeInt(nStartPos.length); LVdtI  
for(int i=0;i<nStartPos.length;i++) nIqF:6/  
{ A:5P  
// output.writeLong(nPos); X,D ]S@  
output.writeLong(fileSplitterFetch.nStartPos); w{GEWD{&  
output.writeLong(fileSplitterFetch.nEndPos); kB=5=#s  
} %Lq}5zB  
output.close(); ypx`!2Q$  
} A>\3FeU>UC  
catch(IOException e){e.printStackTrace ();} (R(NEN  
catch(Exception e){e.printStackTrace ();} Bk5ft4v-  
} i*mI-l  
}sp?@C,Z  
AnpO?+\HF  
//读取保存的下载信息(文件指针位置) ,_K:DSiB  
private void read_nPos() Uh'W d_?  
{ >2NsBS(  
try{ YB(8 T"  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k7M{+X6[  
int nCount = input.readInt(); UU ' 9  
nStartPos = new long[nCount]; Y]i:$X]C?X  
nEndPos = new long[nCount]; W9{y1,G9  
for(int i=0;i<nStartPos.length;i++) m<!CF3g  
{ #hXuGBZEI  
nStartPos = input.readLong(); !04 ^E  
nEndPos = input.readLong(); pqe%tRH{  
} FA;B :O@:'  
input.close(); JvS ~.g1  
} KVoM\ttP  
catch(IOException e){e.printStackTrace ();} AOx8OiqE:  
catch(Exception e){e.printStackTrace ();} 'Y]<1M>.g  
} n,{  
${`q!  
GqgJ]m  
private void processErrorCode(int nErrorCode) e' |c59E  
{ 2hTsjJ!'  
System.err.println("Error Code : " + nErrorCode); (A-Uo   
} y|3!E>Up  
'Z nJd j  
etk|%%J  
//停止文件下载 oUB9)C~  
public void siteStop() mFE7#OM  
{ p$<){,R  
bStop = true; <)oxs ]<  
for(int i=0;i<nStartPos.length;i++) 4}] In/yA  
fileSplitterFetch.splitterStop(); !k#N] 9D3  
|@hyGu-H+  
@Y#TWt#  
} :^]Fp UY  
} ^b*ub(5Ot  
//负责部分文件的抓取 am/D$ (l1  
**FileSplitterFetch.java 2SKtdiY  
*/ ;`Z>^.CB  
package NetFox; B9'2$s+Z;  
S}K-\[i?  
'Y/8gD~.  
import java.io.*; eYPIZ{S7h  
import java.net.*; Gz7,g Y  
&+/$~@OK  
Zm#,Ike?#  
public class FileSplitterFetch extends Thread { ""jl  
RI BB*  
+:u &]  
String sURL; //File URL NSQ)lSW,;  
long nStartPos; //File Snippet Start Position M* dou_Q  
long nEndPos; //File Snippet End Position FQcm =d_s  
int nThreadID; //Thread's ID Z-aB[hE  
boolean bDownOver = false; //Downing is over Q|f)Awe$  
boolean bStop = false; //Stop identical :kXxxS  
FileAccessI fileAccessI = null; //File Access interface zF&_9VNk=c  
q\Z9.T+Qo  
%@%~<U)W  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;!EEzR.  
{ ppO!v?  
this.sURL = sURL; *k0;R[IAV  
this.nStartPos = nStart; aI\]R:f,  
this.nEndPos = nEnd; A \Z_br  
nThreadID = id; G ahY+$L,  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c43&[xP Lz  
} q4Y'yp`?K;  
~:-V<r,pe  
axv-U dE;  
public void run() "rw'mogRL  
{ 7Q aZ|\c  
while(nStartPos < nEndPos && !bStop) A$TF a:O|  
{ d)0 hAdh  
@! jpJ}  
N Q }5'  
try{ :oJ!9\5  
URL url = new URL(sURL); UQjZhH  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R I]x=  
httpConnection.setRequestProperty("User-Agent","NetFox"); $EZr@n  
String sProperty = "bytes="+nStartPos+"-"; h5[.G!  
httpConnection.setRequestProperty("RANGE",sProperty); ^_o:Ddz?l"  
Utility.log(sProperty); = Ru q  
!1P<A1K  
t0)hd X  
InputStream input = httpConnection.getInputStream(); mm N $\2  
//logResponseHead(httpConnection); 5(y Q-/6C+  
~bfjP2 g  
l{. XhB  
byte[] b = new byte[1024]; 5NMju!/  
int nRead; X{qa|6S,F  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'WwD$e0=  
{ 7Y^2JlZu=  
nStartPos += fileAccessI.write(b,0,nRead); 'zuA3$SR  
//if(nThreadID == 1) dV"Kx  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &I/C^/F&  
} i.+#a2   
AUR{O  
5ma~Pjt8}  
Utility.log("Thread " + nThreadID + " is over!"); hy@e(k|S]U  
bDownOver = true; > Cx;h=  
//nPos = fileAccessI.write (b,0,nRead); _Tf0L<A'R  
} z!^3%kJJ>  
catch(Exception e){e.printStackTrace ();} MUp{2_RA  
} /fxv^C82yv  
} -yY]0  
?gS~9jgcd  
u~27\oj,  
//打印回应的头信息 ~<=wTns!  
public void logResponseHead(HttpURLConnection con) 8uB6C0,6?  
{ *w1R>  
for(int i=1;;i++) M532>+A]Za  
{ *)i+c{~  
String header=con.getHeaderFieldKey(i); HE3x0H}o>  
if(header!=null) Il!#]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tEllkHyef  
Utility.log(header+" : "+con.getHeaderField(header)); 6CzN[R}  
else k7bfgb {  
break; 3 yM!BTlX  
} "C]_pWk  
} _^Q =n>G  
1$uO%  
9K#U<Q0b'  
public void splitterStop() )7iYx{n  
{ @. KFWAm  
bStop = true; fMZc_dsW9  
} YGkk"gFIA  
~)!vhdBe  
[1.>9ngj  
} ](^BQc  
iR4!X()  
t%30B^Ii%K  
/* 2@pEuB3$?!  
**FileAccess.java 2L?Pw   
*//文件访问(定位,写) B6]M\4v  
package NetFox; y3mJO[U0 a  
import java.io.*; 9 X87"  
yv.(Oy  
EN~ha:9  
public class FileAccessI implements Serializable{ hkR Jqta)  
q=uJ^N  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mV'^4by  
RandomAccessFile oSavedFile; )Jd{WC.  
long nPos; m#t  
(J\Qo9Il  
3AarRQWsn  
public FileAccessI() throws IOException 1EA}[x  
{ m-}6DN  
this("",0); ZbLN:g}  
} _iW-i  
/Wm3qlv  
4(}V$#^+  
public FileAccessI(String sName,long nPos) throws IOException (khMjFOg  
{ {#uf#J|  
oSavedFile = new RandomAccessFile(sName,"rw"); 5\P3JoH:Yg  
this.nPos = nPos; W8s/"  
oSavedFile.seek(nPos); h%(0|  
} oA $]%  
I=wA)Bli1p  
X5Ff2@."y|  
public synchronized int write(byte[] b,int nStart,int nLen) ^[-3qi  
{ \d"M&-O  
int n = -1; Mj-B;r  
try{  tvvRHvL  
oSavedFile.write(b,nStart,nLen); t[?O*>  
n = nLen; u7ER  
} /km'#f)/  
catch(IOException e) $eUJd Aetk  
{ **lT ' D  
e.printStackTrace (); # >L^W7^  
} *heX[D &>)  
wU bLw  
>EIV`|b$h  
return n; 9Y-6e0B:  
} RF.8zea{O`  
;l2pdP4jf  
pbb6?R,  
} F5;x>;r  
<ooRpn  
*[[TDduh&  
/* <)$b=z  
**SiteInfoBean.java <MoKTP-<  
*/ @mrGG F  
package NetFox; LzJNQd'  
!)TO2?,^  
,mW-O!$3W  
public class SiteInfoBean { 8t Ef>  
G/5]0]SO  
0'.7dzz  
private String sSiteURL; //Site's URL \3v}:E+3  
private String sFilePath; //Saved File's Path ITu5Y"x  
private String sFileName; //Saved File's Name \Z%V)ZRi=  
private int nSplitter; //Count of Splited Downloading File ImVHX~ qHJ  
.|9o`mF7  
74q |FQ  
public SiteInfoBean() 4w-P%-4  
{//nSplitter的缺省值为5 I4"U/iL51  
//default value of nSplitter is 5 G Za<  
this("","","",5); U:o(%dk  
} A('_.J=  
pJ 7="n  
*ioVLt,:R  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C [h^bBq  
{ qC aM]Y  
sSiteURL= sURL; X6g{qzHg_  
sFilePath = sPath; B '"RKs]  
sFileName = sName; 5Myp#!|x:  
this.nSplitter = nSpiltter; N3}jLl/  
=/jCDY  
H%AC *,  
} >k{KwFB^S  
e+=P)Zp/  
YjM_8@ <  
public String getSSiteURL() >m;*Zk`  
{ '-[~I>o%  
return sSiteURL; p+>vX X  
} YKT=0   
Pwh0Se5Z  
9:tn! <^=I  
public void setSSiteURL(String value) #fR~ 7 KR  
{ XY1e eB-  
sSiteURL = value; nm597WeZp  
} 8hx 3pvmk  
Rg?m$$X`  
~9KxvQzt  
public String getSFilePath() 1-M\K^F  
{ \P` mV9P  
return sFilePath; CnA0^JX  
} 6#rj3^]  
j >wT-s  
`K^j:fE7n  
public void setSFilePath(String value) 8P#jC$<  
{ DNN60NX 5Q  
sFilePath = value; ?g21U97Q  
} Y$SwQ;wl  
y! lEGA7  
Os# V=P  
public String getSFileName() J_=42aHO  
{ M)1? $'Aq  
return sFileName; T8ftBIOi  
} ^5yFb=2  
lB Y"@N  
L~])?d  
public void setSFileName(String value) 3\Ma)\>R\-  
{ [Q=NGHB1/  
sFileName = value; K!MIA  
} |tkhsQ-;  
`>mT/Rmb@  
LYv$U;*+  
public int getNSplitter() ^Q'^9M2)  
{ A=5A8B1  
return nSplitter; jK{)gO  
} \:/ :S"-  
3Y}X7-|)Z  
CQ+WBTiC  
public void setNSplitter(int nCount) {IlX@qWr  
{ +80yyn#  
nSplitter = nCount; s}pn5zMp:8  
} ,?Bo x  
} ~A5MzrvIO2  
s$s]D\N  
e viv,  
/* .jfkOt?2  
**Utility.java _ IqUp Y  
*/ Jn>6y:s  
package NetFox; C/w!Y)nB=  
Xt!%W    
lQolE P.pc  
public class Utility { zu~E}  
wSMP^kG  
/5y*ZIq]e  
public Utility() ]^63n/Twj  
{ 2sOV3~bB  
  vZQ'  
>lRa},5(  
} ]ctlK'.  
*0 0K3  
//线程睡眠 ?1z." &  
public static void sleep(int nSecond) uD2v6x236  
{ Ris5) *7  
try{ g`}+K U  
Thread.sleep(nSecond); QQ5G?E  
} b@yGa%Gz@  
catch(Exception e) -2dk8]KB]  
{ <3;Sq~^  
e.printStackTrace (); ) DzbJ}  
} ,c%>M^d  
} 7n1@m_7O  
)K4A-9pC  
//日志 j(`L)/|O  
public static void log(String sMsg) ].j;d2xT\  
{ m&H@f:  
System.err.println(sMsg); #sOkD  
} ItZqLUJ m  
Fnnk }I}  
1%?J l~M  
public static void log(int sMsg) J1?)z+t9~  
{ PN!NB.  
System.err.println(sMsg); >^8=_i !  
} =c-,uW11[  
} 1?6;Oc^  
[HKTXF{n  
f\ wP}c'  
/* d{UyiZm\  
**TestMethod.java ^b{w\HZ  
*/ Wn(pz)+Y  
package NetFox; c({V[eGY  
JO4rU- n  
Pw^ lp'dO  
public class TestMethod { ZR~ *Yofy  
wz-#kH5?  
HbRDa  
public TestMethod() p/4\O  
{ ///xx/weblogic60b2_win.exe '\ $2+*  
try{ 4v"9I(  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |z!Y,zaX  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0u]!C"VX  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Xgge_`T9  
fileFetch.start(); ] Fx9!S  
} 1]L 0r  
catch(Exception e){e.printStackTrace ();} C0xj M0  
hcvWf\4'#q  
>i>%@  
} rpk )i:k\  
U{2[n F  
~ >af"<  
public static void main(String[] args) eB`7C"Z  
{ ohFUy}y  
new TestMethod(); - I$qe Xy  
} 6gLk?^.  
} t,mD{ENm&  
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