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http断点续传简单实现(java)

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/* "m{,~'x  
**SiteFileFetch.java c:83LZ  
*/ ^$%Z! uz  
package NetFox; )Qm[[pnj  
import java.io.*; "uLjIIl  
import java.net.*; )XQ`M?**M  
? muzU.h"z  
5unG#szq  
public class SiteFileFetch extends Thread { g~UUP4<$"  
4h6k`ie!$  
5 ,0d  
SiteInfoBean siteInfoBean = null; //文件信息Bean `RMI(zI3g.  
long[] nStartPos; //开始位置 DoC(Z)o  
long[] nEndPos; //结束位置 QZ `tNq :/  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 3Rm#-T s  
long nFileLength; //文件长度 iVB^,KQ@  
boolean bFirst = true; //是否第一次取文件 V8=Y@T,  
boolean bStop = false; //停止标志 $4jell  
File tmpFile; //文件下载的临时信息 +7Kyyu)y@  
DataOutputStream output; //输出到文件的输出流 ( *G\g=D  
M.h`&8  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) *`( <'Z  
public SiteFileFetch(SiteInfoBean bean) throws IOException T ^A b!O  
{ BF{w)=@/'  
siteInfoBean = bean; = sAn,ri  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); p8wyEHB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 2tayP@$  
if(tmpFile.exists ()) \b[9ebME  
{ )a}"^1  
bFirst = false; \U%#nU{  
read_nPos(); %iJ%{{f`  
} (2?G:+C 7  
else W:i?t8y\y  
{ X5YiFLH>y\  
nStartPos = new long[bean.getNSplitter()]; ThW,Y" l  
nEndPos = new long[bean.getNSplitter()]; @1zQce>  
} K}[>T(0E  
ck#"*] ,  
,? E&V_5  
9>/wUQs!]  
} iE0ab,OF  
\3Oij^l 0  
@|ye qy_:  
public void run() 2?Ye*-  
{ ry};m_BY  
//获得文件长度 v+6@ cC  
//分割文件 N__H*yP  
//实例FileSplitterFetch !gwjN_ZJ^  
//启动FileSplitterFetch线程 3E}EBJLsZ  
//等待子线程返回 Dj\e@?Y  
try{ DjMf,wX-{  
if(bFirst) (Lh#`L?x  
{ s!/TU{8J  
nFileLength = getFileSize(); vUC!fIG  
if(nFileLength == -1) /R X1UQ.s  
{ O!D/|.Q#%  
System.err.println("File Length is not known!"); u% 2<\:~j  
} ]L2Oz  
else if(nFileLength == -2) elJ)4Em  
{ 9ykM3  
System.err.println("File is not access!"); "s W-_j]  
} 3`9{T>  
else .AV)'j#6P  
{ a :SQ16_?  
for(int i=0;i<nStartPos.length;i++)  Z:2I/  
{ 33:DH}  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); P+e KZo  
} m}VM+=  
for(int i=0;i<nEndPos.length-1;i++) i5hD#  
{ G@S&1=nj3  
nEndPos = nStartPos[i+1]; ~;-9X|  
} 9?+9UlJ7K  
nEndPos[nEndPos.length-1] = nFileLength; mzL[/B#>M  
} ]O:M$ $  
} _i}wK?n  
L{ gE'jCC  
,xJrXPW  
//启动子线程 rl:KJ\*D  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b syq*  
for(int i=0;i<nStartPos.length;i++) G,&%VQ3P>  
{ iNcZ)m/  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5IVksg  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :lcea6iO  
nStartPos,nEndPos,i); 9T2xU3UyY  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?y},,  
fileSplitterFetch.start(); _17|U K|N  
} uK*Nu^  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BpAB5=M0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B7Ntk MK  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5,+\`!g  
nEndPos = " + nFileLength); )J/HkOj"V  
// fileSplitterFetch[nPos.length-1].start(); uMXc0fs!$  
.uZ7 -l  
@^nu #R  
//等待子线程结束 _3Q8n|  
//int count = 0; Mjpo1dw  
//是否结束while循环 @b!"joEy  
boolean breakWhile = false; A3P9.mur  
k/Mp6<?C:  
~M ?|Vn  
while(!bStop) 1`r| op},  
{ t7#lsd`_  
write_nPos(); .I?@o8'x  
Utility.sleep(500); c $;\i  
breakWhile = true; TmEY W<  
y93k_iq$S  
!MZw#=D`  
for(int i=0;i<nStartPos.length;i++) ateUpGM QU  
{ q/@dR{-  
if(!fileSplitterFetch.bDownOver) [_DPxM=V  
{ Xer@A;c  
breakWhile = false; 7-iIay1h"  
break; lhn8^hOJ/  
}  :,]S}R  
} +KK$0pL  
if(breakWhile) jy$@a%FD  
break; ayp b  
5P^U_  
_&{%Wc5W~F  
//count++; D\L!F6taS  
//if(count>4) |:iEfi]j  
// siteStop(); ~P1_BD(  
} !oSLl.fQd  
4-4?IwS  
G^h_ YjR`*  
System.err.println("文件下载结束!"); QrjDF>   
} i3V/`)iz  
catch(Exception e){e.printStackTrace ();} Hw_o w?  
} \&|CM8A  
?_4^le[;  
:F|\Ij0T  
//获得文件长度 *c]KHipUIS  
public long getFileSize() <,39_#H?F3  
{ W04av_u 5  
int nFileLength = -1; P;foK)AM  
try{ 4!%]fg}Um  
URL url = new URL(siteInfoBean.getSSiteURL()); NXoK@Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VK .^v<Yo  
httpConnection.setRequestProperty("User-Agent","NetFox"); w-FnE}"l  
ySX/=T:<;  
XSD%t8<LO  
int responseCode=httpConnection.getResponseCode(); xe:' 8J6L  
if(responseCode>=400) FUTn  
{ f'/ KMe%<  
processErrorCode(responseCode); 2ChWe}f  
return -2; //-2 represent access is error /5a;_  
} cK}Pf+r>  
,7/ _T\d<  
hTS|_5b  
String sHeader; ]mkJw3  
`"<2)yq?  
p]f&mBO*  
for(int i=1;;i++) $4j^1U`~)K  
{ )h"Fla  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }""p)Y&  
//Utility.log(in.readLine()); XeUprN  
sHeader=httpConnection.getHeaderFieldKey(i); 8fO8Dob]\Y  
if(sHeader!=null) J%P)%yX  
{ S=9E@(]  
if(sHeader.equals("Content-Length")) G.jQX'%4QG  
{ t[O+B 6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rc~Y=m   
break; ,?=KgG1i  
} E`E'<"{Yd  
} : ^(nj7D  
else H1UL.g%d=  
break; Z`xyb>$  
} !LSs9_w  
} Q_lu`F|  
catch(IOException e){e.printStackTrace ();} ?[SVqj2-  
catch(Exception e){e.printStackTrace ();} ./iXyta  
9eSRCLhgD  
wixD\t59X  
Utility.log(nFileLength); rgR?wXW]jE  
 # eEvF  
g~R/3cm4  
return nFileLength; [t}):}~F|  
} 2]Fu 1  
 GVp  
d=n h  
//保存下载信息(文件指针位置) Gc}0]!nrW9  
private void write_nPos() =tq7z =k  
{ {{zua- F  
try{ BD4"pcr  
output = new DataOutputStream(new FileOutputStream(tmpFile)); /$*; >4=>f  
output.writeInt(nStartPos.length); p2a?9R  
for(int i=0;i<nStartPos.length;i++) a@k.$  
{ ,lP7 ri  
// output.writeLong(nPos); #Y: ~UVV  
output.writeLong(fileSplitterFetch.nStartPos); U,ELqi\  
output.writeLong(fileSplitterFetch.nEndPos); 3:O+GQ*  
} W :>J864!  
output.close(); mS7E_A8  
}  uE"2kn  
catch(IOException e){e.printStackTrace ();} ]-rczl|o  
catch(Exception e){e.printStackTrace ();} WhenwQT  
} scmto cm  
3DI^y` av  
G4);/#  
//读取保存的下载信息(文件指针位置) ;>/ipnx  
private void read_nPos() /MqP[*L  
{ Si[eAAd' :  
try{ $l43>e{E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v['AB4  
int nCount = input.readInt(); af^@ .$ |  
nStartPos = new long[nCount]; Yoe les-  
nEndPos = new long[nCount]; nO:HB.&@  
for(int i=0;i<nStartPos.length;i++) X@eg<]'m  
{ W9+h0A-  
nStartPos = input.readLong(); y8D 8Y8B  
nEndPos = input.readLong(); * T\>  
} $uTlbAuv  
input.close(); X%35XC.n  
} & ]%\.m  
catch(IOException e){e.printStackTrace ();} - YAO3  
catch(Exception e){e.printStackTrace ();} K wQXA'  
} +}\29@{W  
i 63?"  
vnF g%M!  
private void processErrorCode(int nErrorCode) M+\rX1T  
{ >pa\n9=Q^  
System.err.println("Error Code : " + nErrorCode); r5Wkc$  
} YBeZN98Nt  
ju r1!rg%  
FqL`Kt  
//停止文件下载 6O]Xhe0d@  
public void siteStop() @ikUM+A {  
{ (c 1u{  
bStop = true; pO5v*oONz+  
for(int i=0;i<nStartPos.length;i++) l`oT:  
fileSplitterFetch.splitterStop(); QM7[O]@  
A>[hC{  
%oMWcgsdJi  
} i<0D Z_rub  
} =nw,*q +  
//负责部分文件的抓取 YcEtgpz@  
**FileSplitterFetch.java "@aq@mY@  
*/ 55(J&q  
package NetFox; WNl&v]   
Ae3,W  
Am]2@ESUP  
import java.io.*; VoWA tNU  
import java.net.*; m]Hb+Y=;h  
o8iig5bp  
oPp!*$V  
public class FileSplitterFetch extends Thread { Qs~d_;  
Bi$ 0{V Z8  
HIQ]"Hl  
String sURL; //File URL Q>##hG:m  
long nStartPos; //File Snippet Start Position 5+J 64_  
long nEndPos; //File Snippet End Position t*5z1T?  
int nThreadID; //Thread's ID @G7w(>_T3  
boolean bDownOver = false; //Downing is over QZ6[*_Z6  
boolean bStop = false; //Stop identical Ax :3}  
FileAccessI fileAccessI = null; //File Access interface 4o)(d=q  
C+ZQB)gn  
)R8%wk?2  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A!Knp=Gw  
{ TB ;3`  
this.sURL = sURL; qr7 X-[&  
this.nStartPos = nStart; >Iu]T{QNO  
this.nEndPos = nEnd; u4`mQ6  
nThreadID = id; +R3\cRM  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3(cU)  
} A%.J%[MVz  
Q:'qw#P/C  
'Wo?%n  
public void run() ocb%&m ;i  
{ !hwzKm=%N  
while(nStartPos < nEndPos && !bStop) ^aGZJiyJ  
{ l{M;PaJ`}  
)Ix-5084  
@>qx:jx(-S  
try{ D|u^8\'.  
URL url = new URL(sURL); '-$))AdD  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wUh3Hd'  
httpConnection.setRequestProperty("User-Agent","NetFox"); -lJx%9>  
String sProperty = "bytes="+nStartPos+"-"; y|&.v <  
httpConnection.setRequestProperty("RANGE",sProperty); BnKP7e  
Utility.log(sProperty); wrZ7Sr!/V  
e|2vb GQ  
yEMX`  
InputStream input = httpConnection.getInputStream(); !D.= 'V  
//logResponseHead(httpConnection); i}v}K'`  
7.w *+Z>z  
*u:;:W&5y  
byte[] b = new byte[1024]; ;:#?~%7>  
int nRead; oi33{#%t  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^&f{beU9  
{ *qeic e%E  
nStartPos += fileAccessI.write(b,0,nRead); =DeHxPv}f  
//if(nThreadID == 1) SH@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  ?.4yg(  
} Fi,e}j=2f  
XhHel|!g:  
v#FJ+  
Utility.log("Thread " + nThreadID + " is over!"); {ar5c&<  
bDownOver = true; 'xLM>6[wz  
//nPos = fileAccessI.write (b,0,nRead); ,v$2'm)V  
} ~#HH;q_7m  
catch(Exception e){e.printStackTrace ();} GFASF,+  
} X+?Il)Bv  
} knNhN=hG+  
T:w2  
\]L::"![?  
//打印回应的头信息 ;PP_3`  
public void logResponseHead(HttpURLConnection con) X]3l| D  
{ =hZ&66  
for(int i=1;;i++) ft~|  
{ CPF>^Mp#  
String header=con.getHeaderFieldKey(i); xdFP$Y~ogy  
if(header!=null) UY}9  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X\c1q4oB[  
Utility.log(header+" : "+con.getHeaderField(header)); PsF- 9&_  
else @1J51< x  
break; z$I[kR%I{  
} N+C%Z[gt[  
} >Rl0%!  
O]$*EiO\  
h;4y=UU  
public void splitterStop() P!)7\.7  
{ eCPKpVhP  
bStop = true; % +t  
} m<,y-bQ*(  
z1{E:~f  
?:{0  
} mCC:}n"#  
"2vNkO##  
=hOj8;2  
/* B4\:2hBq  
**FileAccess.java ]|((b/L3  
*//文件访问(定位,写) hX'z]Am<  
package NetFox; _4XoUE\\  
import java.io.*; `ohF?5J,  
-Z/6;2Q  
%(dV|,|v  
public class FileAccessI implements Serializable{ Gct&}]3pm  
0%q ctZy  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 YP .%CD(K  
RandomAccessFile oSavedFile; 3u"J4%zg|L  
long nPos; \ eyQo>(  
NXWIE4T>*^  
QvK]<HEr  
public FileAccessI() throws IOException 6>LQGO  
{ ,,wyydG  
this("",0); N#-kk3!Z;  
} ]'1N_m]?  
ZhJ|ZvJ  
+*:x#$phx  
public FileAccessI(String sName,long nPos) throws IOException _I -0,  
{ 0%&fUz36E6  
oSavedFile = new RandomAccessFile(sName,"rw"); [6/%V>EM  
this.nPos = nPos; T`RQUJO  
oSavedFile.seek(nPos); B 4*X0x  
} 63y':g  
hNR >Hy\  
1Hk<_no5  
public synchronized int write(byte[] b,int nStart,int nLen) "z(fBnv  
{ 4?*"7t3  
int n = -1; i}$N&  
try{ 0=(-8vwd  
oSavedFile.write(b,nStart,nLen); WO \lny!  
n = nLen; I%zo>s6  
} 8G[Y9A(bmP  
catch(IOException e) t UAY]BJ*s  
{ (8m\#[T+R  
e.printStackTrace (); %unK8z  
} 1,;qXMhK`;  
H/v37%p7  
*C:q _/  
return n; HS5Ug'\446  
} WKYA9BaR  
}v(H E%~}  
\.{pZMM  
} ?+}E  
9>$%F;JP44  
|qudJucV  
/* w4< u@L  
**SiteInfoBean.java |"tV["a  
*/ 6!}m$Dvt~  
package NetFox; ETH#IM8J  
~_l: b  
BGh8\2  
public class SiteInfoBean { WX[dM }L  
>`,#%MH#  
EK-bvZ  
private String sSiteURL; //Site's URL l`5}i|4KTW  
private String sFilePath; //Saved File's Path o y%g{,V  
private String sFileName; //Saved File's Name Q&U= jX  
private int nSplitter; //Count of Splited Downloading File n.H`1@  
Lw2YP[CR  
abk:_  
public SiteInfoBean() 0wE8Gm G  
{//nSplitter的缺省值为5 FUTyx"   
//default value of nSplitter is 5 px(1Ppb9  
this("","","",5); Nm :|C 3_I  
} *}WqYqOow  
xzf)_ <  
"F.J>QBd  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ewff(e9  
{ V{aIhH>P  
sSiteURL= sURL; G?/8&%8  
sFilePath = sPath; XuAc3~HAd  
sFileName = sName; [?r\b  
this.nSplitter = nSpiltter; 0#[Nfe*  
Z(`K6`KM  
* jNu?$  
} '~6CGqU*  
%$-3fj7  
/)<7$  
public String getSSiteURL() U?m?8vhR6(  
{ lV*&^Q8.  
return sSiteURL; )d a8 Ru  
} _"e( ^yiK  
`fE:5y  
n#AH@`&i  
public void setSSiteURL(String value) JU`'?b  
{ XXdMppoR  
sSiteURL = value; 9*Mg<P"  
} y]z#??  
B!C32~[  
3G0\i!*t  
public String getSFilePath() [8g\pPQ  
{ !~DkA7i55  
return sFilePath; i*rv_G|(Zj  
} +( 7vmC.  
KE1@z]  
]tV{#iIJ*  
public void setSFilePath(String value) *xNjhR]7v  
{ HDG"a&$   
sFilePath = value; FQ&VM6_  
} SxQDqoA~  
;@\J scNJ|  
x~,?Zj)n?C  
public String getSFileName() ^rb7`s#G  
{ |&*rSp2iH  
return sFileName; _5 -"<  
} ^O9m11  
\nt'I;f  
WED7]2>  
public void setSFileName(String value) =7Gi4X%  
{ fH{$LjH(  
sFileName = value; xo3)ds X  
} Ppn ZlGQ6  
E)SOcM)  
$w}aX0dK&  
public int getNSplitter() % ieAY-<"  
{ Z.f<6<gF  
return nSplitter; J\},o|WI  
} ( {62GWnn_  
4p g(QeR  
s0'U[]  
public void setNSplitter(int nCount) wY)GX  
{ nr6[rq  
nSplitter = nCount; C /VXyl@o  
} PU\q.y0R  
} rMx_ <tXX  
AYtcN4\/  
U}5KAi 9Z  
/* |-?b)yuAz  
**Utility.java c'4 \F9  
*/ x?$Y<=vT  
package NetFox; ITOGD  
N^>g= Ub  
:zZM&r>  
public class Utility { g9`ytWmM  
#_5+kBA+>'  
!kYmrj**  
public Utility() 'Pn`V{a  
{ v:ZD}Q_  
cA^7}}?e  
z#!Cg*K(  
} sVf7g?  
&Vm[5XW  
//线程睡眠 .5zJ bZ9  
public static void sleep(int nSecond) ;]e"bX  
{ V)@scB|>,  
try{ N($]))~3&  
Thread.sleep(nSecond); =sJHnWL[  
} [C#pMLp,~  
catch(Exception e) j|w+=A1  
{ 27gm_ *  
e.printStackTrace (); B)iJH  
} -4a&R=%p  
} YRXe j  
l#:Q V:  
//日志 Z/;SR""wa  
public static void log(String sMsg) O`| ri5d  
{ s!\L1E  
System.err.println(sMsg); M>#S z  
} 8gdOQ=a  
G 3x1w/L  
k#M W>  
public static void log(int sMsg) UJ&,9}L8  
{ N:zSJW`1  
System.err.println(sMsg); #,pLVt<  
}  )BB a  
} C <)&qx3  
Ved:w^ ,  
lD XH<W?  
/* %;gWl1&5  
**TestMethod.java Lr&tpB<  
*/ ]y$C6iUY*  
package NetFox; >skS`/6  
wm4e:&  
.YlM'E*X  
public class TestMethod { K a jyQ"j  
U9s y]7  
S] a$w5ZP  
public TestMethod() bvKi0-  
{ ///xx/weblogic60b2_win.exe YWdvL3Bgk,  
try{ _X/`4 G  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CSs6Vm!=  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :4TcCWG  
SiteFileFetch fileFetch = new SiteFileFetch(bean); _XtY/7n  
fileFetch.start(); <k1gc,*  
} >oNs_{  
catch(Exception e){e.printStackTrace ();} w5Z3e^g  
"/=x u|  
WBdb[N6\  
} K} @:>;* 9  
pcG q  
l+,rc*-j0  
public static void main(String[] args) Gz:a1-x  
{ S7*:eo  
new TestMethod(); 5 Da( DA  
} [d}1Cq=_  
} \~>#<@h  
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