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http断点续传简单实现(java)

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/* iY.~N#Q  
**SiteFileFetch.java I>G)wRpfR'  
*/ QT^( oog=  
package NetFox; E2%7v  
import java.io.*; H$\?D+xlf  
import java.net.*; hoSk  
s7T=/SC54  
2yeq2v   
public class SiteFileFetch extends Thread { !YAkHrF`[0  
H${Ym BG  
v  mw7H  
SiteInfoBean siteInfoBean = null; //文件信息Bean r|0C G^:C  
long[] nStartPos; //开始位置 Re,0RM\  
long[] nEndPos; //结束位置 ^!Bpev  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ,gD30Pylz  
long nFileLength; //文件长度 mX,#|qLf  
boolean bFirst = true; //是否第一次取文件 "ZT=[&2  
boolean bStop = false; //停止标志 v-OGY[|97  
File tmpFile; //文件下载的临时信息 $0cMrf@  
DataOutputStream output; //输出到文件的输出流 =oiY'}%(i  
b*.)m  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) #v~zf@<KLB  
public SiteFileFetch(SiteInfoBean bean) throws IOException |!IJ/ivEgw  
{ d5sG t#   
siteInfoBean = bean; BWw7o{d  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); |%zhwDQ.  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); lWnV{/q\X  
if(tmpFile.exists ()) TSE(Kt  
{ xZ4\.K\f]  
bFirst = false; >+1^XeeS  
read_nPos(); c WK@O>  
} \U~ggg0h  
else RTF{<,E.UX  
{ /j3oHi$  
nStartPos = new long[bean.getNSplitter()]; }qb z&%R  
nEndPos = new long[bean.getNSplitter()]; s?OGB}  
} F"B!r-J  
?Vt$  
`b9oH^}n j  
0Dh a1[=  
} :gQc@)jZ(*  
G++kU o<  
B}r@xz  
public void run() D.$EvUSK<.  
{ Xb|hP  
//获得文件长度 X ,T^(p  
//分割文件 li NPXS+  
//实例FileSplitterFetch 2evM|Dj  
//启动FileSplitterFetch线程 ^{Syg;F=  
//等待子线程返回 XXe7w3x{  
try{ ,0#OA* 0B  
if(bFirst) $OjsaE %  
{ i.K}(bo;b  
nFileLength = getFileSize(); ]T zN*6o  
if(nFileLength == -1) }yB@?  
{ !j7b7<wR  
System.err.println("File Length is not known!"); G)b]uX  
} %!YsSk,   
else if(nFileLength == -2) W,wg@2  
{ KJ'MK~g  
System.err.println("File is not access!"); :5@7z9 >  
} =X% D;2  
else |L]dJ<  
{ lzuPE,h  
for(int i=0;i<nStartPos.length;i++) x-%nnC6e  
{ h"ZF,g;a  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |vEfE{  
} p aMw88*u  
for(int i=0;i<nEndPos.length-1;i++) *%8,G'"r?  
{ %tQIKjsVaY  
nEndPos = nStartPos[i+1]; M c@p~5!M  
} -4GSGR'L&y  
nEndPos[nEndPos.length-1] = nFileLength; |,}QhR  
} ]G|@F :  
} _L# Tp  
Blaj07K  
r>osa3N'  
//启动子线程 <_42h|-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q^0K8>G^  
for(int i=0;i<nStartPos.length;i++) c}rRNS$F  
{ ;{HxY98Q  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mP:mzmUw  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5HOhk"  
nStartPos,nEndPos,i); ;5 IS58L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X>*zA?:  
fileSplitterFetch.start(); G.<9K9K  
} C'zMOR6c  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tx5@r;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gs0,-)  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :%!SzI?  
nEndPos = " + nFileLength); Txp~&a03  
// fileSplitterFetch[nPos.length-1].start(); _VY]  
%/S BJ  
)Dqv&^  
//等待子线程结束 3c-ve$8u~  
//int count = 0; I94;1(Cs%  
//是否结束while循环 F}.Af=<Q  
boolean breakWhile = false; 39k P)cD  
nz>A\H  
$dwv1@M2  
while(!bStop) %iJ6;V 4  
{ r-[z!S  
write_nPos(); pCpj#+|_)  
Utility.sleep(500); aIqNNR  
breakWhile = true; dIM:U :c  
7&HP2r  
HjV^6oP  
for(int i=0;i<nStartPos.length;i++) 1f}S:Z  
{ jp[QA\  
if(!fileSplitterFetch.bDownOver) tP3H7Yl! g  
{ ?(g kk YI  
breakWhile = false; 4&`66\p;  
break; I~q}M!v~  
} %t<Y6*g  
} <v5toyA  
if(breakWhile) EH,uX{`e  
break; /~AwX8X  
(& ~`!]  
<GoE2a4Va  
//count++; n.7 $*9)#  
//if(count>4) Q jQJ "  
// siteStop(); sPd5f2'  
} gHox{*hb[  
mZq*o<kTA  
=8tdu B  
System.err.println("文件下载结束!"); W^y F5  
} *DG*&Me  
catch(Exception e){e.printStackTrace ();} =}Cb?C[;  
} wv?`3:co  
dC.uK^FuJ  
9&2kuLp?P  
//获得文件长度 <(^-o4Cl  
public long getFileSize() xRaYm  
{ WP}__1!%u  
int nFileLength = -1; 4Y-9W2s  
try{ o +aB[+  
URL url = new URL(siteInfoBean.getSSiteURL()); qrt+{5/t  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H;$w^Tr  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5[Q44$a{  
B}?/oZW 4  
&/7GhZRt  
int responseCode=httpConnection.getResponseCode(); k+s<;{  
if(responseCode>=400) Mq*Sp UR  
{ !N)oi $T%  
processErrorCode(responseCode); Qh{=Z^r  
return -2; //-2 represent access is error  gu"Agct4  
} VvoJ85  
aC%0jJ<eo  
2b3*zB*@V  
String sHeader; *nH?o* #  
Zj}DlNkVu  
|d,1mmv@K  
for(int i=1;;i++) g[eI-J+F  
{ y"){?  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (:hPT-1  
//Utility.log(in.readLine()); Gt 2rJ<>  
sHeader=httpConnection.getHeaderFieldKey(i); }. ,xhF[  
if(sHeader!=null) 3w^q0/ GD  
{ i\`[0dfY  
if(sHeader.equals("Content-Length")) O %)+ w  
{ @&2T0UB  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bBDgyFSI <  
break; *1elUI2Rg  
} &Nec(q<  
} *Qyw _Q  
else }Y-f+qX*  
break; V;)'FJ)]  
} AS8T!  
} 40:YJ_n  
catch(IOException e){e.printStackTrace ();} |Yk23\!  
catch(Exception e){e.printStackTrace ();} }"3L>%Q5  
\x|(`;{  
2 3>lE}^G  
Utility.log(nFileLength); 778L[wYe  
JBg",2w |C  
fTH?t_e  
return nFileLength; 6}|/~n  
} x9@%L{*  
Omh(UHZBB  
u2!8'-Ai  
//保存下载信息(文件指针位置) 2{&|%1Jg  
private void write_nPos() @gTpiV2  
{ 7OW;o mT`  
try{ Oj<2_u  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~ae68&L6  
output.writeInt(nStartPos.length); ){gOb  
for(int i=0;i<nStartPos.length;i++) vqL{~tR  
{ 2|Tt3/Rn  
// output.writeLong(nPos); w*bVBuX s  
output.writeLong(fileSplitterFetch.nStartPos); Y&gfe8%5N  
output.writeLong(fileSplitterFetch.nEndPos); KAUYE^  
} 2RM1-j ($  
output.close(); %DRDe  
} H|,{^b@9  
catch(IOException e){e.printStackTrace ();} {5_*f)$[H  
catch(Exception e){e.printStackTrace ();} e348^S&rG  
} 40@KL$B=  
E}a3.6)p  
$p9XXZ"*  
//读取保存的下载信息(文件指针位置) 9jvg[ H  
private void read_nPos() SX F F  
{ Ufo- AeQo  
try{ O|gb{  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iPkG=*Ip(%  
int nCount = input.readInt(); W<9G wMU  
nStartPos = new long[nCount]; X;}_[ =-  
nEndPos = new long[nCount]; fA+M/}=  
for(int i=0;i<nStartPos.length;i++) c85B-/  
{ c%B=TAs5c  
nStartPos = input.readLong(); 4CN8>J'-  
nEndPos = input.readLong(); |-e=P9,  
} IA+>dr  
input.close(); se)I2T{J  
} QZwRg&d<o  
catch(IOException e){e.printStackTrace ();} C-2n2OM.  
catch(Exception e){e.printStackTrace ();} -(1e!5_-@  
} b< [eBXe  
}  g  
0 TS:o/{(a  
private void processErrorCode(int nErrorCode) t@4vEKw?.X  
{ )}6:Ke)  
System.err.println("Error Code : " + nErrorCode); zZE?G:isR  
} _wX'u,HrC  
rre;HJGEL  
| _S9U|  
//停止文件下载 ,p 'M@[  
public void siteStop() O&X-)g=  
{ 95(VY)_6#A  
bStop = true; {+`ep\.$&  
for(int i=0;i<nStartPos.length;i++) S[ 2`7'XV  
fileSplitterFetch.splitterStop(); Sa<R8X' J  
dm.3.xXq  
s%/0WW0y^  
} 8zY)0  
} ( NiuAy  
//负责部分文件的抓取 rhUZ9Fdv  
**FileSplitterFetch.java }Rf } iG  
*/ jEI!t^#  
package NetFox; 1yKf=LZ^  
S63L>p|ml  
[hiOFmMJZ-  
import java.io.*; :Z+(H+lyZ  
import java.net.*; ^.<IT"  
Uz62!)  
VSSiuo'5w  
public class FileSplitterFetch extends Thread { N4D_ 43jz  
i?|SC=  
A&t}s #3  
String sURL; //File URL Lh. L~M1X  
long nStartPos; //File Snippet Start Position \(A>~D8Fo  
long nEndPos; //File Snippet End Position   () SG  
int nThreadID; //Thread's ID , n EeI&  
boolean bDownOver = false; //Downing is over ;aFQP:l/  
boolean bStop = false; //Stop identical pFG~XW  
FileAccessI fileAccessI = null; //File Access interface *]H ./a:1  
Nls|R  
~7Jc;y&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'uPqe.#?  
{ lOE bh  
this.sURL = sURL; mqE&phF,  
this.nStartPos = nStart; ; aMMI p  
this.nEndPos = nEnd; cq!> B{  
nThreadID = id; `"D7XC0x  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c(eu[vj:  
} #6YNgJNk  
>o[T#U  
2h/` RefHJ  
public void run() _x>u "w  
{ 3*'!,gK~[  
while(nStartPos < nEndPos && !bStop) FB</~ g  
{ +V0uH pm  
\@80Z5?n  
Uh7kB`2  
try{ %iX +"  
URL url = new URL(sURL); sDwSEg>#B  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bZKK' d$I  
httpConnection.setRequestProperty("User-Agent","NetFox"); Jl4zj>8~  
String sProperty = "bytes="+nStartPos+"-"; }2{%V^D)r  
httpConnection.setRequestProperty("RANGE",sProperty); 1ITa6vjS  
Utility.log(sProperty); yqAw7GaBN  
fa6L+wt4O  
 %RJW@~!  
InputStream input = httpConnection.getInputStream(); ;1o"Oij  
//logResponseHead(httpConnection); cy? EX~s4  
%f^TZ,q$  
|M+ !O93  
byte[] b = new byte[1024]; .E@yB`AR  
int nRead; iaR'):TD  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \K>6-0r|  
{ i|2Q}$3t2  
nStartPos += fileAccessI.write(b,0,nRead); _E?(cWC  
//if(nThreadID == 1) 9BF #R<}h  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .m4K ]^m  
} 0Uybh.dC  
udw5A*Ls  
^6obxwVG  
Utility.log("Thread " + nThreadID + " is over!"); j:fL_1m  
bDownOver = true; bhFzu[B  
//nPos = fileAccessI.write (b,0,nRead); PDtaL  
} gB&'MA!  
catch(Exception e){e.printStackTrace ();} > ^D10Nf*  
} 2avSsN{^  
} B!9<c9/ P]  
*}LYMrP  
TMq\}k-I5  
//打印回应的头信息 I*'QD)  
public void logResponseHead(HttpURLConnection con) "y62Wo6m)  
{ rs<UWk<q  
for(int i=1;;i++) gx #TRp}-  
{  O'_D*?  
String header=con.getHeaderFieldKey(i); 3F<My+J  
if(header!=null) )5p0fw  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cnQ( G$kh  
Utility.log(header+" : "+con.getHeaderField(header)); tEZ@v(D  
else Azu$F5G!n  
break; #W* 5=Cf  
} vJK0>":G  
} yn`H}@`k  
N^:)U"9*e  
\V}?K0#bt  
public void splitterStop() 8NA2C.gOZ  
{ ;CFI*Wfp  
bStop = true; h=?#D0  
} P!1y@R>Ln  
l2._Z Py  
B`9'COw  
} vz/.*u  
ub7|'+5  
jDOB (fE  
/* 4E<iIA\x  
**FileAccess.java RCgZ GP  
*//文件访问(定位,写) t4~Bn<=  
package NetFox; "0pu_  
import java.io.*; eG=Hyc  
4f'1g1@$  
AEp|#H' >  
public class FileAccessI implements Serializable{ E&#cU}ErN  
(TgLCT[@T  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `ZC_F! E  
RandomAccessFile oSavedFile; p0>W}+8fF  
long nPos; dXg.[|S*  
qwoF4_VN  
|W:xbtPNy  
public FileAccessI() throws IOException ko2?q  
{  MV'q_{J  
this("",0); 7vF+Di(B  
} F4`ud;1H  
lhZXq!2p  
P uYAoKG  
public FileAccessI(String sName,long nPos) throws IOException "**Tw'  
{ =c8xg/  
oSavedFile = new RandomAccessFile(sName,"rw"); Psm5J80}n  
this.nPos = nPos; >cpT_M&C,  
oSavedFile.seek(nPos); iGlg@  
} +" |?P  
62)Qr  
"}fJ 2G3  
public synchronized int write(byte[] b,int nStart,int nLen) td@I ;d2  
{ Y=6569U2  
int n = -1; sVWOh|O[W  
try{ g3B%}!|  
oSavedFile.write(b,nStart,nLen); |zd+ \o  
n = nLen; ( y0  
} =#L\fe)q)  
catch(IOException e) vLCyT=OB`  
{ 57@6O-t-  
e.printStackTrace (); g6aIS^mU  
} 2 8>  
\Hb"bv  
gV~_m  
return n; [/E|n[Bx  
} 5y^I~"_ i  
'rl?'~={p  
kZ5;Fe\*  
} aN UU' [  
ERTjY%A  
q8 &\;GK|  
/* o{]2W `0r  
**SiteInfoBean.java $Iz*W]B!  
*/ '< =77yDg  
package NetFox; h8XoF1wuw  
TF_wT28AU2  
yjE $o?A  
public class SiteInfoBean { pf% yEz  
{HO,d{{  
3R>"X c  
private String sSiteURL; //Site's URL OV2/?  
private String sFilePath; //Saved File's Path WQiIS0BJ *  
private String sFileName; //Saved File's Name \JLea$TM:  
private int nSplitter; //Count of Splited Downloading File ~v>3lEGn*  
@b&_xT  
@6"+x  
public SiteInfoBean() M!R=&a=Z  
{//nSplitter的缺省值为5 n:"0mWnL$y  
//default value of nSplitter is 5 joA>-k04  
this("","","",5); 3D}Pa  
} _s18^7  
imc1rY!~'  
N(J'h$E  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J7pF*2  
{ H-iCaXT  
sSiteURL= sURL; \RS0mb  
sFilePath = sPath; W"!{f  
sFileName = sName; 1<G,0Lt  
this.nSplitter = nSpiltter; S'(IG m4  
,K15KN.'  
k 1l K`p  
} O03N$ Jq A  
P"{yV?CNg  
:sX4hZK =G  
public String getSSiteURL() zDf96eK  
{ Q_6v3no1  
return sSiteURL; m1D,#=C,_  
} PDpuHHB  
e}NB ,o  
R$x(3eyx  
public void setSSiteURL(String value) kq*IC&y  
{ r ?<?0j  
sSiteURL = value; GdM|?u&s"  
} cwE?+vB  
=4uO"o  
"^)$MAZ  
public String getSFilePath() W0S\g#  
{ " 1h~P,  
return sFilePath; Am<){&XT ]  
} z s\N)LyM  
'soll[J  
8iPA^b|sz{  
public void setSFilePath(String value) =)%~QK {Y  
{ `j4OKZ  
sFilePath = value; E~S~Ld%  
} YRu/KUT$ 7  
l'1_Fb  
v2ab84 C*  
public String getSFileName() WtlLqD!_D  
{ To;r#h  
return sFileName; r.' cjUs  
} F!RP *  
# ';b>J  
bwK1XlfD.s  
public void setSFileName(String value) cS>xT cj  
{ 8aY}b($*ZI  
sFileName = value; n{!=gR.v.  
} !]MGIh#u  
=.IAd< C  
au+ a7~0~  
public int getNSplitter() 'DUY f5nF  
{ ahR-^^'$  
return nSplitter; -+Z&O?pSH  
} #;\tgUQ  
t?FPmbj v  
#Wt1Ph_;  
public void setNSplitter(int nCount) RaA7 U   
{ <%"CQT6g %  
nSplitter = nCount; Ku8qn \2"  
} T9AFL;1  
} `L"l{^cH  
t x1(6V&l;  
mW#p&{  
/* G C@U['  
**Utility.java ~g&Gi)je  
*/ ?V})2wwP  
package NetFox; 9j1 tcT  
N lB%Qu  
vl5r~F  
public class Utility { 5xc-MkIRL  
GTW5f  
?r R, h{~  
public Utility() AA K}t6  
{ nn/_>%Y  
&Fl* ,  
\)BDl  
} 88+J(^y>  
L)_L#]Yy  
//线程睡眠 `BY&&Bv#?  
public static void sleep(int nSecond) =)2!qoE  
{ y_Nn%(j  
try{ PxgLt2dXa  
Thread.sleep(nSecond); lR3JyYY{X  
} Z"a]AsG/Q#  
catch(Exception e) G `JXi/#`  
{ xkkW?[&  
e.printStackTrace (); G 4 C 7  
} !J+< M~o}  
} QfsTUAfR  
#zw 'H9l  
//日志 }P"JP[#E\  
public static void log(String sMsg) VK?c='zg  
{ \B D'"  
System.err.println(sMsg); 30$Q5]T  
} .{LJ  
f m'Qif q^  
Ov9kD0S  
public static void log(int sMsg) hh"=|c  
{ ,a?$F1Z-  
System.err.println(sMsg); .+hM1OF`x  
} 7I<];j  
} j%OnLTZ  
*27*&&=)H  
& l NHNu[  
/* +BE_K_56  
**TestMethod.java >L>t$1hXM  
*/ 7nL3+Pq  
package NetFox; jaI mO  
tL~?)2uEN  
@}@J$ g  
public class TestMethod { f")*I  
Um9]X@z  
? $LKn2C  
public TestMethod() b_T?jCyW  
{ ///xx/weblogic60b2_win.exe 4`#3p@-  
try{ DEkFmmw   
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1f^4J~{  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |KxFi H  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {JlW1;Jc7  
fileFetch.start(); pC'GKk 8  
} D#n^U `\if  
catch(Exception e){e.printStackTrace ();} ;n,@[v  
2v6QUf  
px1{=~V/  
} }$ZcC_  
idr,s\$>  
*n=NBkq%/!  
public static void main(String[] args) Ll !J!{  
{ l[q%1-N  
new TestMethod(); v8xNtUxN  
} tj_+0J$sw:  
} d8? }69:h  
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