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http断点续传简单实现(java)

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/* R9gK>}>Y  
**SiteFileFetch.java X )d7y  
*/ vukI`(#  
package NetFox; MyZ@I7Fb,  
import java.io.*; //VgPl  
import java.net.*; Ip]-OVg  
heiIb|z  
MyAS'Ki  
public class SiteFileFetch extends Thread { 8$<jd^w  
L.bR\fE   
xZt]s3?  
SiteInfoBean siteInfoBean = null; //文件信息Bean xtL_,ug  
long[] nStartPos; //开始位置 I9Af\ k|^  
long[] nEndPos; //结束位置 {20^abUAS  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 G"0YCi#I|  
long nFileLength; //文件长度 +\G/j]3f  
boolean bFirst = true; //是否第一次取文件 $trvNbco  
boolean bStop = false; //停止标志 [ Y.3miE  
File tmpFile; //文件下载的临时信息 7Zp'}Om<I  
DataOutputStream output; //输出到文件的输出流 ),5^bl/  
%qRbl4  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) hdtb.u~  
public SiteFileFetch(SiteInfoBean bean) throws IOException 2SEfEkk  
{ uiDK&@RS  
siteInfoBean = bean; $-Q,@Bztq  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); j}Lt"r2F  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 8D[P*?O  
if(tmpFile.exists ()) bb[.Kvq5  
{ &Cp)\`[y  
bFirst = false; oqOv"yLJ:  
read_nPos(); 0V ,R|Ln  
} j[Uul#  
else )~;=0O |X  
{ =7ul,  
nStartPos = new long[bean.getNSplitter()]; _7? o/Q?F%  
nEndPos = new long[bean.getNSplitter()]; `s(T (l  
} 8r(S=dA  
B25@6   
6-U|e|e  
IQxY]0\uf6  
} +[Nc";Oy  
J2 {?P cs  
jSp4eq  
public void run() "WR)a`$UR  
{ B ?96d'A  
//获得文件长度 n; ;b6s5  
//分割文件 hu.c&Q>  
//实例FileSplitterFetch Au,xIe!t  
//启动FileSplitterFetch线程 XZhuV<  
//等待子线程返回 Z?|\0GR+`5  
try{ 2V7x  
if(bFirst) >Du5B&41  
{ W-zD1q~0?  
nFileLength = getFileSize(); AGkk|`  
if(nFileLength == -1) 1\t}pGSOeh  
{ ;g$s`l/ 4  
System.err.println("File Length is not known!"); 4.2qt  
} )B.NV<m  
else if(nFileLength == -2) K*jV=lG  
{ 6=a($s!   
System.err.println("File is not access!"); )MqF~[k<-  
} 9MA/nybI  
else S@;>lw,s!  
{ &*iar+vr  
for(int i=0;i<nStartPos.length;i++) is?H1V~8`$  
{ 2 >G"A  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 289teU  
} rCqcl  
for(int i=0;i<nEndPos.length-1;i++) i{TErJ{}e  
{ W#!![JDc  
nEndPos = nStartPos[i+1]; tep_g4CQR_  
} X+"8yZz3?  
nEndPos[nEndPos.length-1] = nFileLength; pv8"E?9,k  
} ?<VahDBS+A  
} W zYy<  
[Dd?c,5AD  
9NLO{kN  
//启动子线程 f@lRa>Z(Fm  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gK7j~.bb"  
for(int i=0;i<nStartPos.length;i++) <_&tP=h  
{ %tiFx:F+  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j4RM'_*G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ym6zNb8 bQ  
nStartPos,nEndPos,i); Rr+Y::E  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); . fq[>zG'&  
fileSplitterFetch.start(); @*jd.a`  
} x"0*U9f  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "pTyQT9P  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [X[d`@rXv  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (5Q,d [B  
nEndPos = " + nFileLength); J/Ki]T9  
// fileSplitterFetch[nPos.length-1].start(); /Y|oDfv  
6'd=% V  
vQCRs!A  
//等待子线程结束 =B O} hk  
//int count = 0; UV8,SSDTV  
//是否结束while循环 aW$( lf2;  
boolean breakWhile = false; 1!<k-vt  
SA s wP  
<*u[<  
while(!bStop) hp?hb-4l  
{ * bx%hX  
write_nPos(); /N(L52mz  
Utility.sleep(500); DP`$gd  
breakWhile = true; 9Cbf[\J!bq  
n)$T zND  
}|>mR];  
for(int i=0;i<nStartPos.length;i++) OpeK-K  
{ >en,MT|  
if(!fileSplitterFetch.bDownOver) sS#Lnj^`%  
{ 16=tHo8|  
breakWhile = false; qXO@FW]  
break; \P% E1c#  
} X,d`-aKO\y  
} bf ]W_I]B  
if(breakWhile) b}63?.M{  
break; 7kapa59  
{iiHeSD  
dX|(n.}  
//count++; </0@7  
//if(count>4) apQ` l^  
// siteStop(); }Jkz0JY~  
} & xOEp  
d;UP|c>2  
ZnDI J&S  
System.err.println("文件下载结束!"); t>;u;XY!;  
} !ckmNE0  
catch(Exception e){e.printStackTrace ();} Cw"Y=`  
} ]H8,}  
Z^w11}  
k@r%>Ul@  
//获得文件长度 R/ 5aIh  
public long getFileSize() ~_^#/BnAl  
{ pj?wQ'  
int nFileLength = -1; D9 `J||]E  
try{ WO{V,<;  
URL url = new URL(siteInfoBean.getSSiteURL()); )`5k fj  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8,Iil:w  
httpConnection.setRequestProperty("User-Agent","NetFox"); [>l 2E  
!#P|2>>u  
)i@j``P  
int responseCode=httpConnection.getResponseCode(); kc#<Gr&Z&  
if(responseCode>=400) KICy! "af  
{ f S-(Kmh  
processErrorCode(responseCode); R zG7Xr=t  
return -2; //-2 represent access is error Q; DN*  
} LJ7Qwh_",  
C" vj#Tx  
O_@  
String sHeader; +dd\_\  
-olD!zKS  
20glz(  
for(int i=1;;i++) HPM ggRs  
{ CMk0(sztU_  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8%-+@ \=  
//Utility.log(in.readLine()); pRS+vV3  
sHeader=httpConnection.getHeaderFieldKey(i); g *}M;"  
if(sHeader!=null) iDp'M`(6h  
{ @uru4>1_dy  
if(sHeader.equals("Content-Length")) t As@0`x9  
{ t+C9QXY  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); vFuf{ @P  
break; ID+ o6/V8  
} j*2Q{ik>J  
} 9='a9\((mH  
else "`Y.N$M`k  
break; 6:Eu[PE~w  
} Nr24Rv  
} 1;O%8sp&  
catch(IOException e){e.printStackTrace ();} \^=Wp'5R  
catch(Exception e){e.printStackTrace ();} rof&O   
<G d?,}\  
tl.I:A5L  
Utility.log(nFileLength); R.KqTEs<k  
s{I Xth6  
]xJ5}/  
return nFileLength; 8=XfwwWHy<  
} g.3 . C?  
879x(JII  
gDY+'6m;  
//保存下载信息(文件指针位置) wD(1Sr5n  
private void write_nPos() %Pl 7FHfB  
{ \?n4d#=$o  
try{ 3I|&}+Z6  
output = new DataOutputStream(new FileOutputStream(tmpFile)); hN(sz  
output.writeInt(nStartPos.length); vkFfHzR$  
for(int i=0;i<nStartPos.length;i++) U%E6"Hg  
{ B.:DW3  
// output.writeLong(nPos); F_KPhe$  
output.writeLong(fileSplitterFetch.nStartPos); m|tE3 UBNv  
output.writeLong(fileSplitterFetch.nEndPos); (``EBEn  
} eh`sfH  
output.close(); y^M ~zOe  
} HiTn5XNf  
catch(IOException e){e.printStackTrace ();} )9(Mt _  
catch(Exception e){e.printStackTrace ();} () l#}H`m  
} UkO L7M  
`R}q&|o7<  
^]iIvIp  
//读取保存的下载信息(文件指针位置) ; E Nhy  
private void read_nPos() ('SA9JG  
{ H.sYy-_]F  
try{ ?kOtK  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .f+ul@o  
int nCount = input.readInt(); VBHDI{HzRv  
nStartPos = new long[nCount]; 43i@5F]  
nEndPos = new long[nCount]; +9 Uo<6}  
for(int i=0;i<nStartPos.length;i++) ROWb:tX}  
{ PS*=MyNa  
nStartPos = input.readLong(); P[;<,U;'HO  
nEndPos = input.readLong(); (:JX;<-  
} zli@XZ#  
input.close(); -2)6QKh~D  
} %t*_Rtz\o  
catch(IOException e){e.printStackTrace ();} j3<|X  
catch(Exception e){e.printStackTrace ();} P>*B{fi^  
} ]u;Ma G=;  
SGuR-$U`)  
^qn,b/>L  
private void processErrorCode(int nErrorCode) <=]wh|D  
{ .X D.'S  
System.err.println("Error Code : " + nErrorCode); 4Dd@&N  
} p};B*[ki  
PL+j;V(<  
B%~hVpm,eM  
//停止文件下载 d0@&2hO  
public void siteStop() jFa{h!  
{ ; O6Ez-"  
bStop = true; JG]67v{F  
for(int i=0;i<nStartPos.length;i++) n^HKf^]  
fileSplitterFetch.splitterStop(); xq U@87[_  
{_ &*"bK  
NJ^H"FLS:  
} 0^5*@vt  
} &#keI.,  
//负责部分文件的抓取 ;zMZ+GZ?;+  
**FileSplitterFetch.java : h"Bf@3  
*/ z0@{5e$#Y  
package NetFox; Y|*a,H"_  
/< OoZf+[  
Gr1WBYK  
import java.io.*; hKG)* Q  
import java.net.*; ]c67zyX=%  
*,hg+?lZ  
4,nUCT  
public class FileSplitterFetch extends Thread { 2J>v4EWC  
;9WS#>o  
=vd9mb-  
String sURL; //File URL !Vtj:2PQL  
long nStartPos; //File Snippet Start Position yvQRr75  
long nEndPos; //File Snippet End Position m$ubxI)  
int nThreadID; //Thread's ID SxAZ2|/-  
boolean bDownOver = false; //Downing is over !foiGZ3g  
boolean bStop = false; //Stop identical ~>j5z&:&  
FileAccessI fileAccessI = null; //File Access interface z0yPBt1W  
&bIE"ZBjt  
v;%>F)I  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;ui=7[ Us  
{ GKT^rc-YT-  
this.sURL = sURL; vs*Q {  
this.nStartPos = nStart; cft'%IEs  
this.nEndPos = nEnd; w=|"{-ijo  
nThreadID = id; Te\i;7;4u  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bhqV2y*'  
} +dw=)A#/  
%^zGM^PD  
+\Zr\fOe|%  
public void run() jDyG~de  
{ <i!:{'%  
while(nStartPos < nEndPos && !bStop) ZQ MK1  
{ xE0'eC5n^  
A9D vU)1  
h)~i ?bq!/  
try{ 1kX>sajp~  
URL url = new URL(sURL); :!cNkJa  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0q !  
httpConnection.setRequestProperty("User-Agent","NetFox"); dXBXV>rbB  
String sProperty = "bytes="+nStartPos+"-"; ;7 F'xz"  
httpConnection.setRequestProperty("RANGE",sProperty); 3|Vh[iAa\  
Utility.log(sProperty); $-J=UT2m  
s|q]11r+H  
n0T>sE -9  
InputStream input = httpConnection.getInputStream(); axpn*(yE  
//logResponseHead(httpConnection); !! \O B6  
9 M<3m  
01br l^5K  
byte[] b = new byte[1024]; 5 `Mos  
int nRead; f,s1k[w/;  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vs:x3)m5j  
{ 1>"Yw|F-|3  
nStartPos += fileAccessI.write(b,0,nRead); |B` mWZ'"  
//if(nThreadID == 1) N H$!<ffz  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `#Yv(a2TY  
} 3<:m;F*#  
:5 zXW;s  
Y`tv"v2  
Utility.log("Thread " + nThreadID + " is over!"); J Gpy$T{t  
bDownOver = true; K7jz*|2  
//nPos = fileAccessI.write (b,0,nRead); dJYW8pcKT  
} vf&Sk`  
catch(Exception e){e.printStackTrace ();} q>^x ,:L  
} E$?:^ausu  
} 4w)aAXK  
A2xfNY<  
hp< NVST  
//打印回应的头信息 IFd2r;W8  
public void logResponseHead(HttpURLConnection con) :}[RDF?  
{ 08pG)_L  
for(int i=1;;i++) # 1#?k  
{ l^WPv/}?  
String header=con.getHeaderFieldKey(i); YS|Ve*t(L=  
if(header!=null) &|j^?ro6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _go1gf7  
Utility.log(header+" : "+con.getHeaderField(header)); {r.yoI4e  
else B?|url6h  
break; 6t0-u~  
} E5EAk6  
} F/(z3Kf  
_1sjsGp>  
%Q2<bj]  
public void splitterStop() l^"HcP6  
{ >qT4'1S*g  
bStop = true; bFt$u]Yvo  
} Kz`g Q|S  
D3MRRv#  
qL 0{w7  
} {:!CA/0Jx  
D$OUy}[2`.  
q/N1q&  
/* cf7UV6D g  
**FileAccess.java re-;s  
*//文件访问(定位,写) 4#c-?mh_  
package NetFox; DGY?4r7>y  
import java.io.*; ='"hB~[  
xD|CQo}:  
<Jwx|  
public class FileAccessI implements Serializable{ U<"@@``+N  
cIJqF.k  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x_K8Gr#Z0  
RandomAccessFile oSavedFile; ^o@N.+`&<  
long nPos; S~+er{,ht4  
=Co[pt  
8U$(9X  
public FileAccessI() throws IOException %x2_njDd  
{ Qv`Lc]'  
this("",0); j4fv-{=$  
} G7yR&x^  
%0<-5&GE  
m\];.Da  
public FileAccessI(String sName,long nPos) throws IOException f'>270pH  
{ HT: p'Yyi  
oSavedFile = new RandomAccessFile(sName,"rw"); }bZcVc2  
this.nPos = nPos; f#mcW L1}  
oSavedFile.seek(nPos); 4* vV9*'!  
} #,4CeD|(D,  
<PayP3E  
A3Lfh6O  
public synchronized int write(byte[] b,int nStart,int nLen) 0M=U >g)  
{ 6_.K9;Gd  
int n = -1; NGYUZ\m  
try{ (r]3tGp  
oSavedFile.write(b,nStart,nLen); 4-wCk=I  
n = nLen; 9AGf4tuy  
} 0';U3:=i,  
catch(IOException e) 0<{zW%w  
{ qyx  '  
e.printStackTrace (); JTw3uM, e  
} 9t1aR*b&@  
L#|, _j=9  
"{&?t}rj+  
return n; Bn5O;I13  
} e9 `n@  
Xaca=tsO  
=DT7]fU  
} "0&+ `7  
-ST[!W V  
#:5vN-9?  
/* )U~,q>H+ %  
**SiteInfoBean.java Rpi@^~aPE  
*/ E[Rd= /P6  
package NetFox; ;ZSJ-r  
\"X<\3z2  
%O! ~!'  
public class SiteInfoBean { :JEzfI1  
n'&Cr0{  
B}(+\Q$I  
private String sSiteURL; //Site's URL $GR 3tLzK:  
private String sFilePath; //Saved File's Path %DKQ   
private String sFileName; //Saved File's Name 6^Q Bol  
private int nSplitter; //Count of Splited Downloading File BfcpB)N&.K  
qNH= W?T8.  
+ \DGS  
public SiteInfoBean() ZP]l%6\.  
{//nSplitter的缺省值为5 7<ZP(I5X  
//default value of nSplitter is 5 ?0{8fGM4  
this("","","",5); 78iu<L+If  
} Yb~[XS |p  
?_!} lg  
";&5@H|  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w=]bj0<A=  
{ c']3N  
sSiteURL= sURL;  u Z(vf  
sFilePath = sPath; uh][qMyLM  
sFileName = sName; &at^~ o  
this.nSplitter = nSpiltter; {GTOHJ2  
xcF:moL  
`<0{U]m  
} tML[~AZh  
J<<Ph  
H\zV/1~Y  
public String getSSiteURL() wNHvYu lI  
{ WB: NV=&^  
return sSiteURL; wRa$b  
} LQ7.RK  
+zU[rhMk'  
]dx6E6A,  
public void setSSiteURL(String value) 'Mfn:n+  
{ QO0#p1fom'  
sSiteURL = value; W+F^(SC\  
} O% 1X[  
f.Uvf^T}2  
N^)\+*tf1  
public String getSFilePath() 5#DtaVz  
{ @Kx@ 2#~b  
return sFilePath; !9B`  
} M<4tjVQ6  
+@U}gk;#c  
-HE@wda  
public void setSFilePath(String value) |f :1Br  
{ x&ngCB@O  
sFilePath = value; 7j9X<8 *  
} ?89K [D|  
F5hOKUjv  
Wfw6(L  
public String getSFileName() SuO@LroxTB  
{ jD`p;#~8  
return sFileName; mbij& 0  
} ODggGB`H`  
wM]j#  
*dTI4k  
public void setSFileName(String value) 4Jf6uhaE  
{ F2B9Q_>P  
sFileName = value; ^Yz.}a##w2  
} ~{8X$xs  
[m}58?0~x  
>+9f{FP 9  
public int getNSplitter() l"C)Ia&/  
{ ^lt;K{  
return nSplitter; MPexc5_  
} K&\3j-8^  
H{XD>q.  
QSaJb?I  
public void setNSplitter(int nCount) mYE8]4  
{ g[#4`Q<.  
nSplitter = nCount; O%>FKU>(?  
} +&U{>?.u  
} ~O;'],#Co  
3 ;N+5*-  
B!;qz[]I  
/* YgeU>I|v  
**Utility.java y [pU8QSt  
*/ Sh]g]xR  
package NetFox; "#3p=}]  
Qd{h3K^hlu  
{m<NPtp910  
public class Utility { GC<zL }  
8|*=p4_fn  
M_ GN3  
public Utility() ,.g9HO/R1  
{ B?-~f^*,jG  
x+X^K_*  
&ND8^lR=Y;  
} _LOV&83O(  
)(aj  
//线程睡眠 K<3$>/|  
public static void sleep(int nSecond) #Q6.r.3@x  
{ A18&9gY  
try{ 7p!w(N?s  
Thread.sleep(nSecond); C4`u3S  
} ,o_Ur.UJ  
catch(Exception e) knPo"GQW  
{ z1WF@ Ej  
e.printStackTrace (); h|DKD.  
} !R`)S7!  
} QIcg4\d%s  
gOE3x^X*{  
//日志 6?CBa]QG  
public static void log(String sMsg) _BA2^C':c{  
{ 3 E~d  
System.err.println(sMsg); ? 7H'#l  
} :Hn*|+'  
U'Xw'?Uj  
rLy <3  
public static void log(int sMsg) '%D$|)  
{ }`SXUM_sD`  
System.err.println(sMsg); Yy_o*Ozq  
} n1Y3b~E?E  
} c T[.T#I  
@ k`^Z5tN  
=36e&z-#  
/* N~w4|q!]  
**TestMethod.java +Y:L4`  
*/ wl*"Vagb  
package NetFox; g.cD3N  
CUS^j  
2Sq+w;/  
public class TestMethod { l9 K 3E<g  
c1,dT2:=  
jv"^_1  
public TestMethod() 49BLJ|:P?  
{ ///xx/weblogic60b2_win.exe q$;'Fy%oy  
try{ Tath9wlv6;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ice7J2r_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OfR\8hAY  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ic"n*SZa  
fileFetch.start(); R/yOy ^<  
} 7Y8B \B)w  
catch(Exception e){e.printStackTrace ();} V!'N:je  
3,snx4q (  
e<wRA["  
} 4E Hb  
xELnik_L2  
$J~~.PUXQ  
public static void main(String[] args) A0NNB%4|/  
{ >};6>)0  
new TestMethod(); ]g>@r.Nc  
} YzcuS/~x  
} "4{_amgm&<  
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