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http断点续传简单实现(java)

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/* 5S EyAhB  
**SiteFileFetch.java 2.>WR~ \  
*/ \@}G'7{  
package NetFox; '=Z]mi/aw  
import java.io.*; PXRkK63  
import java.net.*; t{ R\\j  
/qd5{%:  
!*tV[0 i2  
public class SiteFileFetch extends Thread { P"%QFt,  
RI[=N:C^  
hT0[O  
SiteInfoBean siteInfoBean = null; //文件信息Bean =Lc!L !(,b  
long[] nStartPos; //开始位置 `+\6;nM  
long[] nEndPos; //结束位置 &&daQg4Ha  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 v/m} {&K  
long nFileLength; //文件长度 <y}9Twdy  
boolean bFirst = true; //是否第一次取文件 jGSY$nt9  
boolean bStop = false; //停止标志 F+m%PVW:  
File tmpFile; //文件下载的临时信息 <?>1eU%  
DataOutputStream output; //输出到文件的输出流 VK]cZ%)  
4!</JZX~$  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Xv&&U@7  
public SiteFileFetch(SiteInfoBean bean) throws IOException W0 n?S "  
{ Sf>#Zqj/  
siteInfoBean = bean; a7fFp 9l!  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); sP'U9l  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _ g8CvH)?!  
if(tmpFile.exists ()) g!\H^d4  
{ }mYxI^n  
bFirst = false; [pRRBMho  
read_nPos(); sOyL  
} w!eY)p<  
else V"Sa9P{y"  
{ :u9OD` D  
nStartPos = new long[bean.getNSplitter()]; tgVMgu  
nEndPos = new long[bean.getNSplitter()]; !\}X?G f  
} chE}TK  
{44#<A<  
+Zg@X.z  
q21l{R{Y  
} *yZ `aKfH  
YctWSfh  
(UB?UJc  
public void run() KSAE!+  
{ (uVL!%61k  
//获得文件长度 t }YT+S  
//分割文件 *6bO2LO"  
//实例FileSplitterFetch 2j;9USZ p  
//启动FileSplitterFetch线程 'N3)>!Y:8  
//等待子线程返回 eev-";c  
try{ B2,c_[UZ.  
if(bFirst) q|g>;_  
{ 8CUlE-R5  
nFileLength = getFileSize(); bP Q=88*  
if(nFileLength == -1) 6E#znRi6IE  
{ ^~;"$=Wf  
System.err.println("File Length is not known!"); 7|PB6h3  
} Ii&\LJ  
else if(nFileLength == -2) Z0[d;m*  
{ ]Zz.n5c  
System.err.println("File is not access!"); ueyQ&+6r  
} ntntB{t  
else , .E>  
{ !<3!ORFO  
for(int i=0;i<nStartPos.length;i++) 0Lf4 ^9N  
{ RKPX*(i~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); pft-.1py  
}  :Y Ki  
for(int i=0;i<nEndPos.length-1;i++) +# 3e<+!F  
{ '.wb= C  
nEndPos = nStartPos[i+1]; |->C I  
}  tE#;$Ss  
nEndPos[nEndPos.length-1] = nFileLength; \^1S:z  
} hXh nJ  
} Ae[fW97  
4a=QTq0p  
aka)#0l .  
//启动子线程 akF T 0@9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7^7Jh&b)/  
for(int i=0;i<nStartPos.length;i++) #U(kK(uO  
{ hv`I`[/J  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 63i&<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ms#rvn!J  
nStartPos,nEndPos,i); p,.6sk  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aJ QzM  
fileSplitterFetch.start(); suS[P?4  
} @THa[|(S  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PJ YUD5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wF9L<<&B  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O 6ph_$nt.  
nEndPos = " + nFileLength); ~F^tLi!5  
// fileSplitterFetch[nPos.length-1].start(); M1icj~Jr  
PIAE6,*  
ed2r<H$  
//等待子线程结束 !QpOrg  
//int count = 0; /9=r.Vxh  
//是否结束while循环 \zc R7 5  
boolean breakWhile = false; as(/ >p  
l8khu)\n4R  
la}cGZ; p.  
while(!bStop) fy$?~Ji &  
{ Eq%f`Qg+1E  
write_nPos(); .1}1e;f-  
Utility.sleep(500); 84!Hd.H  
breakWhile = true; UiVGOQq  
d_Jj&:"l  
:dqZM#$d  
for(int i=0;i<nStartPos.length;i++) Gj?$HFa  
{ 6?Kl L [~  
if(!fileSplitterFetch.bDownOver) inFS99DKx  
{ l/,la]!T  
breakWhile = false; qW`?,N)r  
break; @C<ofg3E  
} &)jq3  
} \1SC:gN*#  
if(breakWhile) i),bAU!+m  
break; ap8q`a{j^  
4l7 Ny\J  
K iEmvC  
//count++; d@p#{ -  
//if(count>4) Wb>;L@jB7  
// siteStop(); 1_b*j-j  
} 14"+ctq  
7{]dh+)  
i)'tt9f$  
System.err.println("文件下载结束!"); p="0Y<2l  
} J?dLI_{ <  
catch(Exception e){e.printStackTrace ();} v<t?t<|J  
} e_|Z&  
4i PVpro  
KIcIYCBz  
//获得文件长度 Z+u.LXc|c  
public long getFileSize() qvLh7]sbK:  
{ yVgC1-8i*  
int nFileLength = -1; KIi:5Y  
try{ "g)V&Lx#X  
URL url = new URL(siteInfoBean.getSSiteURL()); \ @ fKKb|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xr{Ym99E$  
httpConnection.setRequestProperty("User-Agent","NetFox"); aU~?&]  
E%DT;1  
3%bhW9H%  
int responseCode=httpConnection.getResponseCode(); ] j8bv3  
if(responseCode>=400) 4y#XX[2Wj  
{ -pIz-*  
processErrorCode(responseCode); `IEA  
return -2; //-2 represent access is error haY]gmC  
} _-lE$ O  
Aj|->Y  
|g.CS$'#Nt  
String sHeader;  |iI dm  
bU}v@Uk  
x\U[5d   
for(int i=1;;i++) x1?mE)n]  
{ _U}vKm  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .1q}mw   
//Utility.log(in.readLine()); hHhDs>tB  
sHeader=httpConnection.getHeaderFieldKey(i); p#{y9s4h  
if(sHeader!=null) J8!2Tt  
{ Q#G xo  
if(sHeader.equals("Content-Length")) i6KB\W2  
{ m$_b\^we  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J_ h.7V  
break; I8YUq   
} -iS^VzI|I  
} tj'~RQvO  
else ROmmak(y8  
break; lKw-C[  
} B ,cFvS  
} 4~&3.1  
catch(IOException e){e.printStackTrace ();} |$b8(g$s)  
catch(Exception e){e.printStackTrace ();} y]0O"X-G  
GdcXU:J /  
>x JzV  
Utility.log(nFileLength); !8[T*'LJ-  
4`,7 tj  
`hZh}K^  
return nFileLength; 9xO@_pkX  
} M2|!,2  
H7GI`3o  
AU3Rz&~  
//保存下载信息(文件指针位置) [B# XA}w  
private void write_nPos() 0\{dt4nW&O  
{ fj;ZGbg-O  
try{ OemY'M? ZQ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0-S.G38{  
output.writeInt(nStartPos.length); |y[I!JdR  
for(int i=0;i<nStartPos.length;i++) V:Gy pY)  
{ ewU*5|*[  
// output.writeLong(nPos); ?W{+[OXs  
output.writeLong(fileSplitterFetch.nStartPos); XZ~kXE;B(  
output.writeLong(fileSplitterFetch.nEndPos); .Pponmy  
} Ba@~:  
output.close(); Q $}#&  
} \0x>#ygX  
catch(IOException e){e.printStackTrace ();} XZb=;tYo  
catch(Exception e){e.printStackTrace ();} o6px1C:  
} @T~XwJ~  
y\Aa;pL)RQ  
Tc/^h 4xH  
//读取保存的下载信息(文件指针位置) 12z!{k7N  
private void read_nPos() oj - `G  
{ le\-h'D  
try{ *,4rYb7I w  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pE&G]ZC  
int nCount = input.readInt(); V ml 6\X  
nStartPos = new long[nCount]; >) u;X  
nEndPos = new long[nCount]; D{6 y^@/  
for(int i=0;i<nStartPos.length;i++) `P;r[j"  
{ }bv+^#  
nStartPos = input.readLong(); PPB/-F]rr  
nEndPos = input.readLong(); !iKW1ks  
} ID2->J  
input.close(); ~ tA ^K  
} 5[jcw`  
catch(IOException e){e.printStackTrace ();} .oyAi||  
catch(Exception e){e.printStackTrace ();} P|<V0 Vs.  
} "00j]e.  
P!W%KobZ7|  
7P+1W \  
private void processErrorCode(int nErrorCode) a#=d{/ ab  
{ Y7.+ Ma#|  
System.err.println("Error Code : " + nErrorCode); x 4+WZYv3  
} YWK0.F,8a  
=U3S"W %  
;[}OZt  
//停止文件下载 f%,S::%Ea  
public void siteStop() \Nt 5TG_  
{ y>y2,x+[  
bStop = true; ?Ts]zO%%Z  
for(int i=0;i<nStartPos.length;i++) T;92M}\  
fileSplitterFetch.splitterStop(); uaF-3  
K<e #y!  
yMz#e0k  
} R%WY!I8C  
} KMj\A d  
//负责部分文件的抓取 }#FV{C]  
**FileSplitterFetch.java v`Jt+?I  
*/ wHj 1+W  
package NetFox; 9 8|sWI3 B  
o1ZVEvp  
jg710.v:  
import java.io.*; tTy!o=  
import java.net.*; 5v)^4( )  
V1]GOmXz  
r >'tE7W9  
public class FileSplitterFetch extends Thread { Zo<)r2|O.  
<a"(B*bBd  
>[;W ~*  
String sURL; //File URL -wXeue},>  
long nStartPos; //File Snippet Start Position Mp`$1Ksn  
long nEndPos; //File Snippet End Position &u2;S?7m  
int nThreadID; //Thread's ID ,p d -hu  
boolean bDownOver = false; //Downing is over GQtNk<?$I  
boolean bStop = false; //Stop identical i!%bz  
FileAccessI fileAccessI = null; //File Access interface tn5%zJ#+  
$xWwI( SaB  
]3O&8,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /*qRbN  
{ TmG);B}  
this.sURL = sURL; 7%Y`j/  
this.nStartPos = nStart; 2t\0vV2)/O  
this.nEndPos = nEnd; [Arf!W-QG  
nThreadID = id; a<<4gXx  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]@#9B>v=  
} ^v; )6a2  
Y)1/f EM  
`j>5W<5q\  
public void run() ^cYB.oeu  
{ %]4Tff  
while(nStartPos < nEndPos && !bStop) ,m=G9QcN  
{ EB[T 5{  
)q=F_:$  
_eKO:Y[e  
try{ m.K cTM%j  
URL url = new URL(sURL); 9r?Z'~,Za  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )dkU4]  
httpConnection.setRequestProperty("User-Agent","NetFox"); VmqJMU>.  
String sProperty = "bytes="+nStartPos+"-"; qdix@ @  
httpConnection.setRequestProperty("RANGE",sProperty); l(Rn=?  
Utility.log(sProperty); uyWheR  
b(0<,r8  
.$&^yp  
InputStream input = httpConnection.getInputStream(); G,)zn9X  
//logResponseHead(httpConnection); S~Gse+*  
CPOH qK`k  
XQy`5iv  
byte[] b = new byte[1024]; /pj[c;aO  
int nRead; J~2SGXH)^?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~m6=s~Vn  
{ gK rUv0&F  
nStartPos += fileAccessI.write(b,0,nRead); Z mJ<h&  
//if(nThreadID == 1) n~ *|JJ*`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nQiZ6[L  
} ?8-Am[xH  
;M3%t=KV  
]>X_E%`G<b  
Utility.log("Thread " + nThreadID + " is over!"); `dZ|Ko%k  
bDownOver = true; .TGw+E1k  
//nPos = fileAccessI.write (b,0,nRead); (DiduSJ  
} )=5 &Q  
catch(Exception e){e.printStackTrace ();} Pu3oQDldV  
} [~9UsHfH  
} O52 /fGt  
x"b'Pmw  
DG;7+2U  
//打印回应的头信息 C8-7XQ=B:b  
public void logResponseHead(HttpURLConnection con) oai=1vt@  
{ |oPRP1F-;e  
for(int i=1;;i++) N9w"Lb  
{ w)EY j+L  
String header=con.getHeaderFieldKey(i); (uC8M,I\  
if(header!=null) fu5L)P^T  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]}v]j`9m%  
Utility.log(header+" : "+con.getHeaderField(header)); b}K,wAx  
else y#GHmHeh  
break; Cy;UyZ  
} OH t)z.  
} i\sBey ND"  
>bW=oTFz  
T-] {gc  
public void splitterStop() ? Lg(,-:  
{ KwL_ae6fV  
bStop = true; d/; tq  
} cw<I L  
*z~,|DQ(A  
Cab.a)o  
} \BnU ?z  
F rc  kA  
& P-8_I  
/* *JJ8\R&P0  
**FileAccess.java jYp!?%!  
*//文件访问(定位,写) ?%6oM  
package NetFox; {+67<&g  
import java.io.*; ~IhM(Q*mO!  
m]n2wmE3n  
.!o]oM U/  
public class FileAccessI implements Serializable{ J0!V(  
1B;2 ~2X  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RcYUO*  
RandomAccessFile oSavedFile; R l ]x:  
long nPos; IJ Jp5[w  
E{\CE1*  
$lxpwO  
public FileAccessI() throws IOException gC1LQ!:;Oi  
{ OijuOLt  
this("",0); h3@tZL#g  
} ~q ^o|?  
OFtaOjsyUa  
jqaX|)8|$  
public FileAccessI(String sName,long nPos) throws IOException m'"r<]pB*4  
{ Skt-5S#  
oSavedFile = new RandomAccessFile(sName,"rw"); ,U\ s89  
this.nPos = nPos; $?56 i4  
oSavedFile.seek(nPos); n4{%M  
} ~(R=3  
5 bI :xL}  
K%J?'-  
public synchronized int write(byte[] b,int nStart,int nLen) -.h)CM@L  
{  vD#U+  
int n = -1; (=!At)O  
try{ {[!<yUJ`S#  
oSavedFile.write(b,nStart,nLen); ,`HweIq(  
n = nLen; t.( `$  
} n#">k%bD  
catch(IOException e) E;a,].  
{ T~E;@weR  
e.printStackTrace (); " aG6u^%  
} (  cs  
V#ELn[k  
jSp&\Wjb  
return n; uRb48Qy2  
} ]yPK}u  
 R0Vt_7  
Eg)24C R 4  
} (%B{=w}8  
`H! (hMMV  
?, pwYT0g  
/* NTu |cX\R  
**SiteInfoBean.java j=O+U _w  
*/ T1d@=&0"  
package NetFox; vFk@  
. Vb|le(7  
@ [;'b$T$  
public class SiteInfoBean { 64u(X^i  
G=cRdiy`C  
%E_Y4Oe1  
private String sSiteURL; //Site's URL +@rFbsyJ.  
private String sFilePath; //Saved File's Path 5=?P 6I_$G  
private String sFileName; //Saved File's Name hQ|mow@Zmz  
private int nSplitter; //Count of Splited Downloading File 5k0iVpjQ  
_m9k2[N!  
"B3jq^  
public SiteInfoBean() AY52j  
{//nSplitter的缺省值为5 IS]A<}j/-  
//default value of nSplitter is 5 HUx`RX0>  
this("","","",5); b=EI?XwJ  
} !P{ /;Q  
|Y!^E % *  
cNd&C'/N  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `Q*`\-8J  
{ JQKXbsXS  
sSiteURL= sURL; F7<mm7BGZ  
sFilePath = sPath; }eLApFHEDg  
sFileName = sName; RW&o3_Ua  
this.nSplitter = nSpiltter; <SNr\/aCRi  
*F( qg%1+  
'UX^]  
} eX$KH;M  
toY_1  
V48_aL  
public String getSSiteURL() c[-N A  
{ 7rdmj[vu  
return sSiteURL; Nr*l3Z>LD  
}  LgF?1?  
"pDU v^ie  
2 ,nhs,FZ  
public void setSSiteURL(String value) Ic&~iqQ  
{ uj3`M9  
sSiteURL = value; #2^0z`-\_z  
} F${sEtH  
WXxnOLJr  
2Z{?3mAb;  
public String getSFilePath() 4XAB_Q  
{ j55_wx@cA  
return sFilePath; ajycYk9<m  
} }uDpf0;^  
F$8:9eL,T  
bhUE!h<  
public void setSFilePath(String value) &n1Vv_Lb  
{ Y^]n>X  
sFilePath = value; o`CM15d*7o  
} RFbf2s\t  
"[ S[vkI  
x;W!sO@$  
public String getSFileName() qXtC7uNj$  
{ cpk\;1&t  
return sFileName; =Z.0-C>W  
} ?eTZ>o.p/  
}C @xl9S"  
[7><^?t V  
public void setSFileName(String value) diXWm-ZKL  
{ #f(a,,Uu'  
sFileName = value; "7sv@I_j  
} BQfnoF  
QI[WXx p  
uT]$R  
public int getNSplitter() c%5P|R~g]p  
{ f_ MK4  
return nSplitter; q#j[0,^ $  
} ?sHZeWZ(  
g}`g>&l5  
"vk]y  
public void setNSplitter(int nCount) %scw]oF  
{ V n_&q6Pa  
nSplitter = nCount; ?*V\ -7jg  
} 1V`-D8-?  
} mZU L}[xf  
5"h4XINZ  
6KGT?d  
/* -|'@ :cIZ  
**Utility.java -Jd7  
*/ Z+V%~C1  
package NetFox; i@:^b_  
-$!r+4|q  
 2l,>x  
public class Utility { | K|AUI  
y3j$?o M  
nO yG7:  
public Utility() JA{kifu0+  
{ 1!1,{\9%  
RV@B[:  
(w-"1(  
} K cex%.  
*ssw`}yE'  
//线程睡眠 C1A  X  
public static void sleep(int nSecond) uNy-r`vg  
{ ->qRGUW  
try{ JRBz/ j  
Thread.sleep(nSecond); + _ehzo97  
} 12i`82>;  
catch(Exception e) r7VBz_Q  
{ ]|F`;}7  
e.printStackTrace (); Eet/l]e#a  
} =0&XdxX  
} H.?`90IQ  
4r;le5@  
//日志 pKXSJ"Xo  
public static void log(String sMsg) \ MuKS4  
{ #HL$`&m  
System.err.println(sMsg); ZWGelZP~  
} b w1s?_P  
{31X  
)[Rwc#PA;  
public static void log(int sMsg) G l/3*J  
{ 2G|}ENC  
System.err.println(sMsg); )2"WC\%  
} @}jg5}  
} yq, qS0Fo  
&T-:`(  
"viZ"/ ~6  
/* 8;~,jZ s  
**TestMethod.java W' Y<iA  
*/ {B=64,D^7R  
package NetFox; YeJTB}  
`!N.1RP _  
Wv5=$y  
public class TestMethod { >mQD/U  
a%y*e+oM  
NjS<DzKhK  
public TestMethod() {<IHiB35q  
{ ///xx/weblogic60b2_win.exe K4Ed]hX  
try{ e]1) _;b*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dg^s$2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \B 8j9  
SiteFileFetch fileFetch = new SiteFileFetch(bean); &: LE]w  
fileFetch.start(); W SvhC  
} ;t N@  
catch(Exception e){e.printStackTrace ();} v3~`1MM  
r *N@%T  
6I~M8Lo ;  
} M+-odLltw  
`-s]d q  
|@rf#,hTDp  
public static void main(String[] args) XR=ebl  
{ b7'A5]X  
new TestMethod(); cooicKS7  
} *W=1yPP  
} {'P?wv  
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