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http断点续传简单实现(java)

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/* f[ywC$en  
**SiteFileFetch.java }l2JXf55  
*/ 2-6-kS)c  
package NetFox; T<?;:MO88  
import java.io.*; :=8vy  
import java.net.*; 5u8Sxfm",  
f ;Dz(~ hw  
>w'6ZDA*X  
public class SiteFileFetch extends Thread { 04"hQt{[  
_96&P7  
n-Xj>  
SiteInfoBean siteInfoBean = null; //文件信息Bean I F@M  
long[] nStartPos; //开始位置  e?7paJ  
long[] nEndPos; //结束位置 | jkmh6  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 3_>R's8P  
long nFileLength; //文件长度 1Li@O[%X<  
boolean bFirst = true; //是否第一次取文件 t>[r88v  
boolean bStop = false; //停止标志 68SM br  
File tmpFile; //文件下载的临时信息 jL8zH  
DataOutputStream output; //输出到文件的输出流 C+mU_g>  
:8ZxOwwv  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) DjKjEZHgM  
public SiteFileFetch(SiteInfoBean bean) throws IOException 6IX!9I\sT  
{ uu:)jxi  
siteInfoBean = bean; |bk*Lgkzw  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); f.= E.%  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 2*M*<p=v  
if(tmpFile.exists ()) x EBjfn  
{ ,jn?s^X6Dj  
bFirst = false;  /F_ :@#H  
read_nPos(); ^ WNJQg'  
} S|[UEU3FpB  
else (TE2t7ab|M  
{ $o/>wgQY-  
nStartPos = new long[bean.getNSplitter()]; JvDsr0]\#  
nEndPos = new long[bean.getNSplitter()]; [a3 0iE  
} )>fi={!=c  
{ZcZ\Q;6  
j#&  
=(ZGaZ}  
} <-F"&LI{<  
xeI{i{8  
QP#Wfk(C  
public void run() a5-\=0L~  
{ L9T u>4  
//获得文件长度 pd#/;LT  
//分割文件 )hug<D *h  
//实例FileSplitterFetch HhL%iy1  
//启动FileSplitterFetch线程 aM~fRra7  
//等待子线程返回 =lwS\mNs  
try{ zqh{=&Tjx  
if(bFirst) f[I c hCwX  
{ lIz_0rE  
nFileLength = getFileSize(); z(3"\ ^T  
if(nFileLength == -1) { rT`*P~  
{ j;)6uia*A  
System.err.println("File Length is not known!"); ]D%k)<YK  
} ;X(n3F  
else if(nFileLength == -2) C~qhwwh  
{ ??Zmj:8E'  
System.err.println("File is not access!"); D.(G9H  
} &r%*_pX  
else %K"%Qm=Tl  
{ <^U(ya  
for(int i=0;i<nStartPos.length;i++) G+uiZ (p>  
{ [.X%:H+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &._!)al  
} n5.>;N.*  
for(int i=0;i<nEndPos.length-1;i++) ~7pjk  
{ |a{]P=<q  
nEndPos = nStartPos[i+1]; :OCux Sc%5  
} d|]O<]CG_  
nEndPos[nEndPos.length-1] = nFileLength; 4_+Pv6  
} [+g@@\X4  
} ,:4DN&<  
jJZsBOW[8  
m>ycN  
//启动子线程 V=&,^qZ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  7E`(8i  
for(int i=0;i<nStartPos.length;i++) T-C#xmY(  
{ ulf/C%t,R  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xGfD z*t  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zpqGh  
nStartPos,nEndPos,i); z,FTsR$x  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @b\ S.  
fileSplitterFetch.start(); *Ca)RgM  
} c%@~%IGF  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _i[)$EgFm  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cEc,eq|  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lVdT^"~3  
nEndPos = " + nFileLength); ,6;xr'[o*  
// fileSplitterFetch[nPos.length-1].start(); Xexe{h4t_>  
vo ;F;  
&3Z. #*  
//等待子线程结束 +'/}[1q1/T  
//int count = 0; *fi;ZUPW3  
//是否结束while循环 @GQ8q]N:<  
boolean breakWhile = false; ]A72) 1  
oL Vtu5  
/;&+ < }  
while(!bStop) BwJ^_:(p~  
{ c~UAr k S  
write_nPos(); u:$x6/t  
Utility.sleep(500); ; ,=h59`  
breakWhile = true; ]}[Yf  
wB>S\~i  
b"M`@';+  
for(int i=0;i<nStartPos.length;i++) K- I\P6R`  
{ :X1cA3c!  
if(!fileSplitterFetch.bDownOver) g&+Y{*Gp  
{ T5S g2a1&  
breakWhile = false; tB7K&ssi  
break; &.Latx  
} /Y[o=Uyl  
} 3`k[!!   
if(breakWhile) FU\/JF.j  
break; ?orhJS  
0^9:KZ.!  
b>QM~mq3^I  
//count++; cc41b*ci$  
//if(count>4) "65||[=8  
// siteStop(); /&$"}Z6z  
} Ty3CBR{6  
5'X74`  
(@ fa~?v>@  
System.err.println("文件下载结束!"); y98JiNq  
} i)7n c  
catch(Exception e){e.printStackTrace ();} DhLr^Z!h3;  
} EK?@Z.q+  
mN\%f J7  
goDV2 alC^  
//获得文件长度 Yz=h"Zr  
public long getFileSize() M!Z*QY."P  
{ }UKgF.  
int nFileLength = -1; jVad)2D  
try{ cX %:  
URL url = new URL(siteInfoBean.getSSiteURL()); |Bx||=z`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F1gt3 ae  
httpConnection.setRequestProperty("User-Agent","NetFox"); V(;55ycr  
-(\1r2 Y  
x0\e<x9s  
int responseCode=httpConnection.getResponseCode(); 3s`V)aXP  
if(responseCode>=400) 48tcgFg[  
{ /a[V!<"R  
processErrorCode(responseCode); [)#u<lZ<~  
return -2; //-2 represent access is error t_dcV%=  
} qDnCn H  
+ a-wv  
5vD3K! \u  
String sHeader; xwPI  
"jL1. 9%"  
I&L.;~  
for(int i=1;;i++) (n=9c%w  
{ "^;#f+0  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j4;Du>obQ  
//Utility.log(in.readLine()); \U/v;Ijf  
sHeader=httpConnection.getHeaderFieldKey(i); _*s~`jn{H  
if(sHeader!=null) QVIcb ;&:}  
{ h&lyxYZ+T$  
if(sHeader.equals("Content-Length")) /~40rXH2C  
{ {7vgHutp  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :?HSZocf  
break; \V]t!mZ-}l  
} ,-@xq.D  
} C<_ Urnmn  
else h`=r )D  
break; A9 U5,mOz  
} jcE Msc  
} p-.Ri^p   
catch(IOException e){e.printStackTrace ();} '%R<"  
catch(Exception e){e.printStackTrace ();} 8tU>DJ}0  
swt tp`  
C(G(^_6  
Utility.log(nFileLength); jDR')ascn  
H4t)+(:D'  
d$w(-tV42  
return nFileLength; ^f9>l;Lb  
} z. 'Fv7  
>-b&v$  
wb b*nL|P  
//保存下载信息(文件指针位置) H"eS<eT  
private void write_nPos() nE_Cuc>K\  
{ >?z:2@Q)B  
try{ FC{})|yh }  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $!f !,fw+  
output.writeInt(nStartPos.length); 42&v % ;R  
for(int i=0;i<nStartPos.length;i++) *ot> WVB  
{ `?l3Ct*  
// output.writeLong(nPos); "# !D|[h0  
output.writeLong(fileSplitterFetch.nStartPos); 2`EVdl7B]  
output.writeLong(fileSplitterFetch.nEndPos); ;`DD}j`  
} tAERbiH  
output.close(); K4:  $=  
} 3A_G=WaED  
catch(IOException e){e.printStackTrace ();} vB.l0!c\e_  
catch(Exception e){e.printStackTrace ();} @OzMiN  
} Or7 mD  
[ 7g><  
uAUp5XP|Z  
//读取保存的下载信息(文件指针位置) #.H}r6jqs  
private void read_nPos() $E\^v^LW  
{ h$>wv`  
try{ 'S*k_vuN  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eNbpwne  
int nCount = input.readInt(); 1fH<VgF`  
nStartPos = new long[nCount]; 6kN:*  
nEndPos = new long[nCount]; L_Q S0_1  
for(int i=0;i<nStartPos.length;i++) -\4zwIH  
{ 7b,(\Fm  
nStartPos = input.readLong(); Q,gLi\siI  
nEndPos = input.readLong(); {]^O:i"  
} 7CGyC[[T~  
input.close(); s9@Sd  
} r{_>ldjq  
catch(IOException e){e.printStackTrace ();} H>XFz(LWh  
catch(Exception e){e.printStackTrace ();} zU&L.+   
} KnGTcoXg_  
 .t =  
'1Y\[T*  
private void processErrorCode(int nErrorCode) eVJ^\z:4  
{ }gv8au<  
System.err.println("Error Code : " + nErrorCode); Z.1> kZ  
} q9]IIv  
6~xBi(m`  
d|lpec  
//停止文件下载 Rko M~`CT  
public void siteStop() A%X X5*  
{ UE.4q Y_7  
bStop = true; wNYg$d0M  
for(int i=0;i<nStartPos.length;i++) T^:fn-S}=  
fileSplitterFetch.splitterStop(); ac8P\2{"  
!q' 4D!I  
bm# (?  
} ++jAz<46  
} tU :EN;H  
//负责部分文件的抓取 =r 9r~SR#  
**FileSplitterFetch.java b~w=v_[(I  
*/ ;+/o?:AH  
package NetFox; }t%W1UJ  
*F`A S>  
m@Rtlb  
import java.io.*; 'xE _Cj  
import java.net.*; mJ}opy!{;  
 Vzl^Ka'  
S/tIwG ~e3  
public class FileSplitterFetch extends Thread { gckI.[!b  
/.z;\=;[n!  
Ul+Mo&y-  
String sURL; //File URL )]htm&q5  
long nStartPos; //File Snippet Start Position aZ|=(]  
long nEndPos; //File Snippet End Position )"+2Z^1-  
int nThreadID; //Thread's ID >e,mg8u6$  
boolean bDownOver = false; //Downing is over om h{0jA0  
boolean bStop = false; //Stop identical )#iq4@)|g  
FileAccessI fileAccessI = null; //File Access interface ,yd=e}lQx  
9DQa PA6  
cV{o?3<:B  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kwpK1R4zs  
{ x1&W^~  
this.sURL = sURL; Pr ]Ka  
this.nStartPos = nStart; Av'GB  
this.nEndPos = nEnd; Yz$3;  
nThreadID = id; y|wlq3o  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `;l.MZL!  
} }a AH  
d;mx<i=/  
&0zT I?c  
public void run() )Gw~XtB2  
{ zOgTQs"ZH  
while(nStartPos < nEndPos && !bStop) -#!x|ne  
{ jh2t9SI~  
N- H^lqD  
Z[__"^}  
try{ A+J*e  
URL url = new URL(sURL); K"j_>63)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); } :=Tm]S  
httpConnection.setRequestProperty("User-Agent","NetFox"); 'R`tLN  
String sProperty = "bytes="+nStartPos+"-"; r%:+$aIt  
httpConnection.setRequestProperty("RANGE",sProperty); $Iv2j">3)  
Utility.log(sProperty); Tm_B^ W}  
]0hrRA`  
r}[7x]sP  
InputStream input = httpConnection.getInputStream(); <S?ddp2  
//logResponseHead(httpConnection); AdRX`[ik  
Q'_z<V  
AKMm&(fh%  
byte[] b = new byte[1024]; b4^`DHRu6  
int nRead; !*6CWV0  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >D201&*G%  
{ {ZY+L;eg1  
nStartPos += fileAccessI.write(b,0,nRead); b& 1`NO  
//if(nThreadID == 1) J{^RkGF  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b#7{{@H  
} ( =~&+z  
$!&*xrrNM  
]?*I9  
Utility.log("Thread " + nThreadID + " is over!"); "Ph^BU Ab  
bDownOver = true; q.,JVGMS  
//nPos = fileAccessI.write (b,0,nRead); |2{wG 4  
} 5^^XQ?"  
catch(Exception e){e.printStackTrace ();} OS8q( 2z?s  
} Y>'|oygHA  
} !%$`Eq)M^7  
" Hd|7F'u=  
Qxj JN^Q  
//打印回应的头信息 {%_L=2n6  
public void logResponseHead(HttpURLConnection con) As>_J=8} 3  
{ W.kM7z>G  
for(int i=1;;i++) XQw>EZdj_N  
{ Ja9e^`i;  
String header=con.getHeaderFieldKey(i); _%QhOY5tv"  
if(header!=null) =:~R=/ZXk  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K4kMM*D  
Utility.log(header+" : "+con.getHeaderField(header)); hdrm!aBd  
else *QH28%^  
break; |P%Jw,}]9  
} =Q\r?(Iy  
} Dc,I7F|%  
jYKor7KTqT  
%$b:X5$Z  
public void splitterStop() >p"c>V& 8  
{ ?!+MM&c-n  
bStop = true; R6(oZph  
} >D4# y  
&G-!qxe  
/HaHH.e  
} i*Z" Me  
"yS _s  
s=;uc] 9g  
/* @<elq'2  
**FileAccess.java R#I0|;q4|p  
*//文件访问(定位,写) r[*Vqcz  
package NetFox; k=jk`c{<[  
import java.io.*; X"fb;sGT  
h%uZYsK  
ye,>A.  
public class FileAccessI implements Serializable{ oaIi2=Tf  
++^l]8  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MB~=f[cUnd  
RandomAccessFile oSavedFile; 0E3[N:s  
long nPos; 7Mg=b%IYs  
;;#qmGoE  
: qd`zG3  
public FileAccessI() throws IOException 'ZDp5pCC;  
{ 24z< gO  
this("",0); f,kZ\Ia'r  
}  PoxK{Y  
\nPEyw,U  
X\bOz[\  
public FileAccessI(String sName,long nPos) throws IOException  J4f i'  
{ Utnr5^].2O  
oSavedFile = new RandomAccessFile(sName,"rw"); ,F,X ,  
this.nPos = nPos; *%%g{ 3$  
oSavedFile.seek(nPos); R#%(5-Zu#R  
} iO|se:LY<  
@$[?z9ck"  
W04@!_) <  
public synchronized int write(byte[] b,int nStart,int nLen) tMf}   
{ MkfBu W;)  
int n = -1; jIC_[  
try{ old(i:2  
oSavedFile.write(b,nStart,nLen); l`#4KCL(  
n = nLen; S[PE$tYT#t  
} w n/_}]T  
catch(IOException e) 8%A#`)fb  
{ u{['<r;I  
e.printStackTrace (); u)}$~E>  
} A kC1z73<  
Lr$go6s  
J}v}~Cv  
return n; C~2F9Pg  
} QdF5Cwf4  
6-$jkto  
p<2L.\6"  
} E8$20Ue  
D$ dfNiCH  
6e9,PS  
/* }B\a<0L/  
**SiteInfoBean.java Ve}(s?hU5  
*/ f$e[u E r  
package NetFox; [ 9 {*94M  
oHd FMD@  
Mo?~_|}  
public class SiteInfoBean { ]zE;Tw.S  
_aGOb;h  
%b&". mN  
private String sSiteURL; //Site's URL {o_X`rgrL  
private String sFilePath; //Saved File's Path $WyD^|~SF  
private String sFileName; //Saved File's Name vQosPS_2L  
private int nSplitter; //Count of Splited Downloading File G&D7a/G\  
H?<N.Dq  
n0r+A^]  
public SiteInfoBean() C7lH]`W|/  
{//nSplitter的缺省值为5 IUE~_7  
//default value of nSplitter is 5 @$S+Ne[<  
this("","","",5); zMbN;tu  
} F, W~,y  
'&x#rjo#  
ZZ2vvtlyG  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )97SnCkal  
{ sGy eb5c  
sSiteURL= sURL; :o0JY= 5  
sFilePath = sPath; UK595n;P  
sFileName = sName; fkuLj%R  
this.nSplitter = nSpiltter; B~]k#Ot)  
QLXN*c  
e- :yb^  
} #p P[xE"Y  
jN{Xfjmfv  
QS%%^+E2  
public String getSSiteURL() K-bD<X  
{ F"&~*m^+  
return sSiteURL; G,?hp>lj  
} 'Y*E<6:  
xf<at->  
pWy=W&0~qf  
public void setSSiteURL(String value) !nqUBa  
{ $@z5kwx:P  
sSiteURL = value; (!ZM{Js%  
} ^8 zR  
OVm\  
*@Lp`thq  
public String getSFilePath() ;nep5!s;<  
{ VPO N-{=`  
return sFilePath; 2/vMoVT,  
} AP68V  
-m)X]]~C  
>"|B9Woc  
public void setSFilePath(String value) GR&z,  
{ \]</w5 Pi,  
sFilePath = value; 6g 5#TpCh  
} 8K.R=  
J2::'Hw*s  
iIMd!Q.)@  
public String getSFileName() D&od?3}E  
{ !Fca~31R'  
return sFileName; Gr7=:+0n|P  
} uD}2<$PP  
_Tf4WFu2  
*AG#316  
public void setSFileName(String value) 5* j?E  
{ ;|p BFKx  
sFileName = value; <vUbv   
} wfNk=)^$  
y+X2Pl  
]"t@-PFX<  
public int getNSplitter() + ,%&e  
{ Q9~*<I> h;  
return nSplitter; 1$D_6U:H0  
} oI=fx Sjd  
0O9Ni='Tn  
|%J{RA  
public void setNSplitter(int nCount) >hPQRd  
{ ,VCyG:dw  
nSplitter = nCount; v9:9E|,U+  
} ur3(HL  
} kddZZA3`  
q#T/  
QIB\AAclO  
/* +@94;me  
**Utility.java Yn@lr6s  
*/ 6%t1bM a  
package NetFox; byLft 1  
ePr&!Tz#  
/LvRP yj@  
public class Utility { $* AYcy7  
eZSNNgD<:  
5 MN8D COF  
public Utility() ;LG#.~f  
{ e4!:c^?  
<g1hxfKx5  
t/cY=Wp  
} ht2\y&si  
t; 4]cg:_  
//线程睡眠 Bk*F_>X"  
public static void sleep(int nSecond) _JHd9)[  
{ eM$sv9?  
try{ d Vj_8>  
Thread.sleep(nSecond); *A"~m !=  
} =T(6#"  
catch(Exception e) "t (p&;d  
{ # WAZ9,t  
e.printStackTrace (); qv]}$WU  
} 4x  
} E~]R2!9  
)/pU.Z/  
//日志 zG ^$"f2  
public static void log(String sMsg) 43mP]*=A  
{ MRb-H1+Xf  
System.err.println(sMsg); Y8m1M-#w  
} J%x\=Sv  
SZ,YS 4M  
<kGU,@6PF  
public static void log(int sMsg) L1cI`9  
{ =p*]Az  
System.err.println(sMsg); | N[<x@  
} BI3@|,._N  
} lu<xv  
Nv(9N-9r  
7]blrN]  
/* | #47O  
**TestMethod.java H."EUcE{  
*/ 9~p[  
package NetFox; ti I.W  
)}"wesNo".  
^Wt*  
public class TestMethod { ^pQCNKLBY  
#vti+A~n,4  
aqj@Cjk4Z  
public TestMethod() Uk^B"y_  
{ ///xx/weblogic60b2_win.exe (oEC6F  
try{ uTKD 4yig  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X*{2[+<o  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); orWbU UC  
SiteFileFetch fileFetch = new SiteFileFetch(bean); B56L1^ 7  
fileFetch.start(); ]sE?ezu  
} ?u" 4@  
catch(Exception e){e.printStackTrace ();} AlAYiUw{  
*Zt#U#  
D/vOs[X o,  
} ^eo|P~w g  
u~WVGjoQ  
" @v <Bk  
public static void main(String[] args) '}B+r@YCN  
{ Rb%8)t x  
new TestMethod(); P<M?Qd 1.  
} +yk24 ` >  
} ZWc]$H?  
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