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http断点续传简单实现(java)

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/* }x(Ewr  
**SiteFileFetch.java 4StoEgFS  
*/ :3.!?mOe2  
package NetFox; $i"IOp  
import java.io.*; t2RL|$>F1  
import java.net.*; 4'GosQ85  
%WAaoR&u  
^+rI=c 0  
public class SiteFileFetch extends Thread { f2G 3cg~H  
3fdqFJ O  
zp:EssO=Q  
SiteInfoBean siteInfoBean = null; //文件信息Bean 0+6=ag%  
long[] nStartPos; //开始位置 `IH*~d]  
long[] nEndPos; //结束位置 3eR c>^wh  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 iKA}??5e  
long nFileLength; //文件长度 ,FWsgqL{l  
boolean bFirst = true; //是否第一次取文件 Z^6qxZJ7  
boolean bStop = false; //停止标志 @ w?,7i-S  
File tmpFile; //文件下载的临时信息 ;(Kj-,>  
DataOutputStream output; //输出到文件的输出流 { \ ]KYI0  
(\M+E tU<9  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) UIK4]cYC'  
public SiteFileFetch(SiteInfoBean bean) throws IOException u -A_l<K  
{ h_\OtoRa  
siteInfoBean = bean; h4N&Yb fo  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); JGQ)/(  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Fr)6<9%xVm  
if(tmpFile.exists ()) @H61^K<  
{ aqKrf(Rv  
bFirst = false; !;M5.Y1j&"  
read_nPos(); Yk=2ld;;  
} @f`s%o  
else PXo^SHJ+gt  
{ UX@8  
nStartPos = new long[bean.getNSplitter()]; !]l;n Fd  
nEndPos = new long[bean.getNSplitter()]; j71RlS73  
} qv)%)n  
J8?V1Ad{  
>N-l2?rE  
".sRi  
} kS< 9cy[O  
nJcY>Rp?  
QS%t:,0lp  
public void run() z@U5  
{ UNyk, #4  
//获得文件长度 8]&\FA8  
//分割文件 _ pO1XM  
//实例FileSplitterFetch Hgbrlh  
//启动FileSplitterFetch线程 9@wmngvM*Y  
//等待子线程返回 ]:svR@E  
try{ O7z5,-  
if(bFirst) {9XQ~t"m^  
{ H&uh$y@  
nFileLength = getFileSize(); s7s@!~  
if(nFileLength == -1) lX/:e=  
{ wG X\ub#!  
System.err.println("File Length is not known!"); Bj* M W  
}  |Fe*t  
else if(nFileLength == -2) Huf;A1.  
{ F5%IsAH  
System.err.println("File is not access!"); AYv7- !Yk  
} Ypwn@?xeP  
else 5E0dX3-  
{ `qhZZ{s)1U  
for(int i=0;i<nStartPos.length;i++) pReSvF}}C  
{ :|\)=4  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); w:/QB-`%  
} 2-beq<I  
for(int i=0;i<nEndPos.length-1;i++) RSBk^  
{ zszx~LSvIT  
nEndPos = nStartPos[i+1]; h~s h!W8  
} =O>E>Q  
nEndPos[nEndPos.length-1] = nFileLength; :Hj #1-U  
} `gz/?q  
} Xk}\-&C7  
i Ie{L-Na  
S3ZI C\2  
//启动子线程 gXe`G( w  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Le*gdoW.  
for(int i=0;i<nStartPos.length;i++) Yz ? 8n  
{ !YIW8SP)  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H0-v^H>^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), La r9}nx0  
nStartPos,nEndPos,i); SHRn $<  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WB3YN+Xl3  
fileSplitterFetch.start(); Lc_cB`  
} );d"gv(]D  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4rUOk"li  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0gH;y+\=*  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e@{Rlz   
nEndPos = " + nFileLength); #sM*<2vj  
// fileSplitterFetch[nPos.length-1].start(); DhN<e7c`  
*H~&hs>k  
3M5wF6nY[[  
//等待子线程结束  I}u&iV`  
//int count = 0; Y'76!Y  
//是否结束while循环 `_!R;f  
boolean breakWhile = false; oW3|b2D  
m-lTXA(  
<v3pI!)x  
while(!bStop) 1@xdzKua1  
{ zo:NE0 0  
write_nPos(); o<Qt<*  
Utility.sleep(500); Zw_'u=r >  
breakWhile = true; naVbcY  
F<J`1 :  
<jG[ z69)  
for(int i=0;i<nStartPos.length;i++) ]MnQ3bWq"j  
{ 2k!4oVUN  
if(!fileSplitterFetch.bDownOver) f0+vk'Z  
{ .zsY VtK  
breakWhile = false; W{fNZb'  
break; \WxBtpbQ B  
} nhRpb9f`1@  
} "x O+  
if(breakWhile) f7:}t+d  
break; iJS7g  
f0 kz:sZ9  
J$i.^|hE/  
//count++; C/MQY:X4  
//if(count>4) J=b 'b%  
// siteStop(); R)6"P?h._4  
} .+&M,% x  
yaPx=^&  
WJy\{YAG  
System.err.println("文件下载结束!"); j[Gg[7q{y  
} |z?c>.  
catch(Exception e){e.printStackTrace ();} vQy+^deW  
} z/wwe\ a5  
3L9@ELY4  
}!N/?A5  
//获得文件长度 p{AX"|QM"  
public long getFileSize() ;*cCaB0u  
{ FT\%=>{  
int nFileLength = -1; "6gBbm  
try{ p\DSFB  
URL url = new URL(siteInfoBean.getSSiteURL()); 4@QR2K|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <[?ZpG  
httpConnection.setRequestProperty("User-Agent","NetFox"); f([d/  
Y(=A HmR  
Qcn;:6_&W  
int responseCode=httpConnection.getResponseCode(); h !?rk|  
if(responseCode>=400) |IDZMd0  
{ -Eoq#ULvR  
processErrorCode(responseCode); L| ;WE=  
return -2; //-2 represent access is error eIQ@){lJ-]  
} eU\XAN#@  
tgY/8& $M  
{RI)I  
String sHeader; 1} ~`g ED  
D B(!*6#?  
1 0^FfwRfM  
for(int i=1;;i++) YT6dI"48  
{ O]KQ]zN  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); slaH2}$xR  
//Utility.log(in.readLine()); ~~q>]4>  
sHeader=httpConnection.getHeaderFieldKey(i); 38GZ_ z}r  
if(sHeader!=null) s7,D}Zz  
{ 1rON8=E  
if(sHeader.equals("Content-Length")) 0cq<!{d  
{ z fu)X!t^  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U:bnX51D4  
break; b4 Pa5 w  
} #3?}MC  
} D# gC-,  
else klnk{R.>|  
break; S|F:[(WaM  
} 6zI}?KZf  
} /7x1Z*Hg  
catch(IOException e){e.printStackTrace ();} gux?P2f  
catch(Exception e){e.printStackTrace ();} <`WcI`IA b  
d>V#?1$h  
F?t;bV  
Utility.log(nFileLength);  3Hi8=*  
7"1]5\p^g  
$g),|[ x+(  
return nFileLength; \2CEEs'  
} Yr[& *>S  
i&{%} ==7  
L_o/fTz4  
//保存下载信息(文件指针位置) :*s@L2D6  
private void write_nPos() D 9UM8Hxi  
{ k 7:Z\RGy  
try{ U+zntB  
output = new DataOutputStream(new FileOutputStream(tmpFile)); V[n,fEPBr  
output.writeInt(nStartPos.length); ja6V*CWb  
for(int i=0;i<nStartPos.length;i++) qg:EN~E#  
{ sG\K$GP!  
// output.writeLong(nPos); u<4bOJn({  
output.writeLong(fileSplitterFetch.nStartPos); }}Z2@}  
output.writeLong(fileSplitterFetch.nEndPos); j4u ["O3  
} | ^G38  
output.close(); e;2A{VsD8  
} >`p? CE  
catch(IOException e){e.printStackTrace ();} MGY0^6yK5  
catch(Exception e){e.printStackTrace ();} i!gS]?*DH  
} 5vJxhBm/  
HiBI0)N}  
i.\ e/9]f  
//读取保存的下载信息(文件指针位置) iB`EJftI!  
private void read_nPos() zrf tF2U  
{ _!_1=|[  
try{ =2}V=E/85  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); zRbY]dW  
int nCount = input.readInt(); z#1"0Ks&P  
nStartPos = new long[nCount]; 20}w . V  
nEndPos = new long[nCount]; {h PB%  
for(int i=0;i<nStartPos.length;i++) UZ#oaD8H6  
{ Vf<q-3q  
nStartPos = input.readLong(); ;e< TEs  
nEndPos = input.readLong(); %NM={X|'  
} Y[H769  
input.close(); M8/:PmR<  
} !qU1RdZ  
catch(IOException e){e.printStackTrace ();} \+=`o .2  
catch(Exception e){e.printStackTrace ();} i<):%[Q)>  
} |* ^LsuFb  
{ {:Fs  
jw`05rw:  
private void processErrorCode(int nErrorCode) t=9f:,I$  
{ OzwJ 52  
System.err.println("Error Code : " + nErrorCode); x,zYNNx5g  
} 1vxQ`)a  
o\]U;#YD  
]^T-X/v9  
//停止文件下载 bE{Y K  
public void siteStop() T]nAz<l),  
{ -/V(Z+dj  
bStop = true; H5 V>d  
for(int i=0;i<nStartPos.length;i++) *C<;yPVc  
fileSplitterFetch.splitterStop(); >oO]S]W  
Z4rk$K'=1w  
dfKGO$}V  
} Ow.DBL)x'>  
} r/HTkXs I  
//负责部分文件的抓取 O6vxp?:^  
**FileSplitterFetch.java /|<S D.:  
*/ jM @N<k  
package NetFox; [`s0 L#  
R PoBF~>  
@0]WMI9B"B  
import java.io.*; j/fniyJ)  
import java.net.*; fGqX dlP  
9t6c*|60#n  
RRV%g!  
public class FileSplitterFetch extends Thread { 8A.7q  
\$*CXjh3G  
gPT_}#_GxM  
String sURL; //File URL N5,LHO  
long nStartPos; //File Snippet Start Position cjJfxD&q  
long nEndPos; //File Snippet End Position I:G8B5{J  
int nThreadID; //Thread's ID '^>} =f  
boolean bDownOver = false; //Downing is over J-<_e??  
boolean bStop = false; //Stop identical C\~}ySQc.e  
FileAccessI fileAccessI = null; //File Access interface *OznZIn  
BAY e:0  
I`H&b& .`  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8V 4e\q  
{ xPPA8~Dm*  
this.sURL = sURL; Y0T:%  
this.nStartPos = nStart; af %w|M  
this.nEndPos = nEnd; AU}kIm_+  
nThreadID = id; VsAJ2g9L  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d&raHF*  
} 5RFro^S9E  
o{`x:  
1*2ycfa  
public void run() CuvY^["  
{ XsQ81j.  
while(nStartPos < nEndPos && !bStop) EJ#I7_  
{ 1n[)({OQ  
8.n#@%  
vxTn  
try{ _:=\h5}8  
URL url = new URL(sURL); HbI{Xf[6LP  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,;Wm>V)o  
httpConnection.setRequestProperty("User-Agent","NetFox"); `bfUP s  
String sProperty = "bytes="+nStartPos+"-"; wjwCs`  
httpConnection.setRequestProperty("RANGE",sProperty); U4fv$gV  
Utility.log(sProperty); 1W{oj  
6j XDLI  
n:OXv}pv  
InputStream input = httpConnection.getInputStream(); GdI,&| /  
//logResponseHead(httpConnection); -X!<$<\y;  
7@\.()  
$"W[e"Q  
byte[] b = new byte[1024]; bs?\ )R5/  
int nRead; ,v K%e>e&  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ">CRFee0  
{ m+;U,[%[*E  
nStartPos += fileAccessI.write(b,0,nRead); q,L>PN+W  
//if(nThreadID == 1) el*|@#k}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j \jMN*dmV  
} %W\NYSm  
%%}l[W  
H=C~h\me?  
Utility.log("Thread " + nThreadID + " is over!"); :rQDA =Ps  
bDownOver = true; <<u]WsW{C  
//nPos = fileAccessI.write (b,0,nRead); M$%ON>K q  
} &uRT/+18W3  
catch(Exception e){e.printStackTrace ();} _>\33V-?b  
} PiM(QR  
} i@nRZ$K  
?V8Fgd  
XXum2eA  
//打印回应的头信息 s_/@`kd{  
public void logResponseHead(HttpURLConnection con) v77UE"4|c  
{ 2=fM\G  
for(int i=1;;i++) QOktIH  
{ dxAGO(  
String header=con.getHeaderFieldKey(i); jn|NrvrX  
if(header!=null) nMzt_IlI  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5@%Gq)z5  
Utility.log(header+" : "+con.getHeaderField(header)); \ YF@r7  
else 4;J.$  
break; >~Zj  
} X}(X\rp  
} [-VH%OM  
j!i* &  
8xAIn>,_  
public void splitterStop() oQ r.cKD ?  
{ STjb2t,a  
bStop = true; d.~ns4bt9  
} A?#i{R  
xjbI1qCfe  
JseKqJ?g  
} 8iaMr278W  
&?bsBqpN  
~/K&=xE  
/* T90O.]S  
**FileAccess.java *W\3cS  
*//文件访问(定位,写) Zqm%qm:  
package NetFox; X5/j8=G H`  
import java.io.*; 'uL$j=vB  
yg'CL/P  
vw!7f|Pg ~  
public class FileAccessI implements Serializable{ 8iY.!.G#|  
GBb8 }lx  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jy.L/s  
RandomAccessFile oSavedFile; 'XKfKv >;  
long nPos; A"M;kzAfHM  
z_xy*Iif  
9_5>MmiB  
public FileAccessI() throws IOException 6jc5B#  
{ b}Gm{;s!  
this("",0); L]z8'n,  
} 1$E[`` n  
/]z #V'  
153*b^iDBh  
public FileAccessI(String sName,long nPos) throws IOException 18%$Z$K,  
{ VdM Ksx`r  
oSavedFile = new RandomAccessFile(sName,"rw"); _@XueNU1hS  
this.nPos = nPos; T DR|*Cs  
oSavedFile.seek(nPos); A}9^,C$#  
} v1yB   
h/\ Zq  
OXM=@B<"  
public synchronized int write(byte[] b,int nStart,int nLen) S;Sy.Lp  
{ l H_pG~  
int n = -1; K\Q4u4DjbJ  
try{ E]~ #EFc  
oSavedFile.write(b,nStart,nLen); z.hq2v  
n = nLen; U9`Co&Z2  
} 4uO88[=  
catch(IOException e) xM<aQf\j  
{ ?SYmsaSr5  
e.printStackTrace (); ,x&WE@tD |  
} 0N!rIz  
N~v<8vJq`  
l^bak]9 1  
return n; h~sTi  
} >wqWIw.w>  
+76ao7d.  
-:_3N2U=+  
} y{(Dv}   
09vVCM;DY  
j-J/yhWO&  
/* <bW~!lv  
**SiteInfoBean.java 3'L =S  
*/ `dX0F=Ag?  
package NetFox; XLiwE$:t%  
Xbx=h^S  
VSUWX1k4%  
public class SiteInfoBean { F# 9^RA)9  
e`LvHU_0  
A?n5;mvq#  
private String sSiteURL; //Site's URL M*T!nwb  
private String sFilePath; //Saved File's Path imM#zy  
private String sFileName; //Saved File's Name s^PsA9EAn  
private int nSplitter; //Count of Splited Downloading File %8 DI)n#H  
e:MbMj6`  
!} x-o`a5  
public SiteInfoBean() VPO~veQ  
{//nSplitter的缺省值为5 s."N7F  
//default value of nSplitter is 5 It2:2  
this("","","",5); >f&L7@  
} H0B=X l[  
]!"7k_  
N8x&<H  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MR4k#{:w  
{ '.%Omc  
sSiteURL= sURL; 0RSzDgX  
sFilePath = sPath; 3e-E/6zH6  
sFileName = sName; }3WP:Et  
this.nSplitter = nSpiltter;  Jc]k\U  
S Cn)j:gH;  
eFy {VpO+  
} >*B59+1P  
+,7vbs3  
_I,GH{lhI  
public String getSSiteURL() k`'*niz  
{ ZjY?T)WE9  
return sSiteURL; fWIWRsy%  
} -+2A@kmEJ  
!YO'u'4<aK  
8qfXc ^6  
public void setSSiteURL(String value) 1n6%EC|X  
{ `{IL.9M!f  
sSiteURL = value; ON>l%Ae4G  
} hH05p!2  
3H>\hZ  
w4Hq|N1-Y  
public String getSFilePath() kbH@h2Ww  
{ l  LBzY`j  
return sFilePath; %ib7)8Ki0  
} yP` K [/  
.*+jD^Gr  
=l] lwA -  
public void setSFilePath(String value) <dXeP/1w`  
{ nsq7dhq  
sFilePath = value; uB6Mj dp6  
} ;/ |tU o$  
c;a<nTLn  
f\RTO63|O  
public String getSFileName() tK#/S+l  
{ ?} E M,  
return sFileName; s`v$r,N0  
} #tw_`yh  
;Vf{3  
Azr|cKu]  
public void setSFileName(String value) sC2NFb-+&  
{ Q_0_6,Opb  
sFileName = value; ?V~vP%1  
} R7h3O0@!  
f?16%Rk<  
u35"oLV6}#  
public int getNSplitter() m9D Tz$S.  
{ `]l|YQz\  
return nSplitter; rmWs o b  
} BT$Oh4y4  
GlC(uhCpV  
Oi@|4mo  
public void setNSplitter(int nCount) 79o=HiOF99  
{ Qs#;sy W@~  
nSplitter = nCount; NweGK  
} 0$=U\[og  
} QOPh3+.5  
s%~Nx3,  
*]Cyc<  
/* (4C)] RHQ  
**Utility.java n\BV*AH  
*/ c7WOcy@M  
package NetFox; xh25 *y  
VP~%,=  
T#I}w\XlhP  
public class Utility { ]ab q$Y'  
_)YB*z5  
QvOl-Lfc  
public Utility() q@ wX=  
{ e5; YY  
*1:kIi7_  
Qs8yJH`v  
} OCCC' k  
`JGW8 _  
//线程睡眠 Y9st3  
public static void sleep(int nSecond) bB*cd!7y  
{ fgF@ x  
try{ 3.ShAL  
Thread.sleep(nSecond); ,K PrUM}  
} m?8o\|i,  
catch(Exception e) pQ4HX)<P  
{ Mdp'u$^!  
e.printStackTrace (); `@u9 fx.  
} -?IF'5z  
} G"Ey%Q2K  
'9&@?P;  
//日志 Q?`s4P)14o  
public static void log(String sMsg) :RBeq,QaO  
{ 0Xn,q]@Z  
System.err.println(sMsg); t9lf=+%s  
} EF9Y=(0|  
B=}QgXg  
3e\IRF xzb  
public static void log(int sMsg) ^\yz`b(A0  
{ ?Ho>  
System.err.println(sMsg); OekE]`~w  
} 'bg'^PN>z  
} C?<-`$0  
<KoOJMx(  
[W3sveqj&  
/* e$rPXRf  
**TestMethod.java T+%P+  
*/ #)S&Z><<  
package NetFox; <R_)[{ 7  
"%_T7 A ![  
<w?k<%( 4  
public class TestMethod { ;W\?lGOs{  
(_gt!i{h  
Y\4B2:Qd9  
public TestMethod() )N\B C  
{ ///xx/weblogic60b2_win.exe 2)QZYgfh  
try{ 5rQu^6&  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KAu>U3\/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'coY`B; 8  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3RFU  
fileFetch.start(); 53bVhPGv  
} 2 zX9c<S=5  
catch(Exception e){e.printStackTrace ();} =&FaMR2  
jL'R4z  
lWP]}Uy=5~  
} l%2 gM7WMY  
n5tsaU;  
(W[]}k ;  
public static void main(String[] args) z;N`jqo   
{ rc"8N<D  
new TestMethod(); Q j|tD+<  
} z('t#J!b  
} HoeW6UV  
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