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http断点续传简单实现(java)

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/* "Zm**h.t  
**SiteFileFetch.java go >*n\  
*/ ntR@[)K  
package NetFox; kZ7\zbN>  
import java.io.*; $;7,T~{  
import java.net.*; w=Ai?u  
4efIw<1_  
$/*1 9 e~  
public class SiteFileFetch extends Thread { HYU-F_|N=  
KmS$CFsGL  
(mbC! !>  
SiteInfoBean siteInfoBean = null; //文件信息Bean _ 3@[S F  
long[] nStartPos; //开始位置 `o/G0~T)  
long[] nEndPos; //结束位置 [PG#5.jwQ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 DwSB(O#X  
long nFileLength; //文件长度 qLC_p)  
boolean bFirst = true; //是否第一次取文件 $d0xJxM  
boolean bStop = false; //停止标志 LX f r  
File tmpFile; //文件下载的临时信息 @jh\yjrW  
DataOutputStream output; //输出到文件的输出流 <14,xYpE  
[0c7fH`8V  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) wHx@&Tp  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5rp,xk!  
{ oKyl2jg+,  
siteInfoBean = bean; (h {"/sR  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); CCoT  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); HGycF|]2  
if(tmpFile.exists ()) ?{=& Ro  
{ rtM29~c>@  
bFirst = false; )M3} 6^s]  
read_nPos(); xXb7/.*qE  
} B ]*v{?<W  
else T{ WJf-pI  
{ ZkWX4?&OMt  
nStartPos = new long[bean.getNSplitter()]; WAq)1gwN  
nEndPos = new long[bean.getNSplitter()]; wFbw3>'a9  
} `-_kOxe3  
PFR64HK2  
OVq(ulwi+  
2/o_,k  
} ^*?mb)  
QC\r|RXW  
#su R[K*S  
public void run() Z$*m=]2  
{ ,8.Fd|#L  
//获得文件长度 813t=A  
//分割文件 (1%O;D.*?{  
//实例FileSplitterFetch  N>V\  
//启动FileSplitterFetch线程 ,zF^^,lO7  
//等待子线程返回 Cx~,wk;=  
try{ ZNfQM&<d  
if(bFirst) eewlK]  
{ gn-@OmIs  
nFileLength = getFileSize(); hl} iw_e  
if(nFileLength == -1) cQzUR^oq,  
{ cnw?3/J  
System.err.println("File Length is not known!"); H8!; XB  
}  " fXs!  
else if(nFileLength == -2) Pk ?M~{S  
{ 4H9mKR  
System.err.println("File is not access!"); i<\WRzVT  
} #'y4UN  
else Dpb prT7_  
{ _ASyGmO{  
for(int i=0;i<nStartPos.length;i++) .n\j<Kq  
{ 6 uS;H]nd<  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,vDSY N6  
} /Fj*sS8  
for(int i=0;i<nEndPos.length-1;i++) 8*x/NaH /\  
{ \Gl>$5np  
nEndPos = nStartPos[i+1]; `8 Ann~Z|k  
} PAD&sTjE*  
nEndPos[nEndPos.length-1] = nFileLength; jjT)3 c:J[  
} qs$w9I  
} 5M v<8P~  
QZwZ4$jkiO  
tkIpeL[d  
//启动子线程 1[] 9EJ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; GI5#{-)  
for(int i=0;i<nStartPos.length;i++) R$m?aIN  
{ |S6L[Uo  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Au10]b  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <D`VFSEJ  
nStartPos,nEndPos,i); a&z$4!wQB  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .;J6)h  
fileSplitterFetch.start(); vu@@!cT6e  
} [,yYr  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )BeB xo7lv  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )+ (GE  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gmUX 2x(  
nEndPos = " + nFileLength); vqhu%ZyP  
// fileSplitterFetch[nPos.length-1].start(); _uL8TC ^  
^ *1hz<  
0/5{v6_rG  
//等待子线程结束 (jI_Dk;  
//int count = 0; {Gvv^.H7  
//是否结束while循环 IkP; i_|  
boolean breakWhile = false; GMKY1{   
P>nz8NRq  
'T+v&M  
while(!bStop) nPR*mbW  
{ cI\&&<>SlG  
write_nPos(); Oil~QAd,  
Utility.sleep(500); oiRrpS\T.  
breakWhile = true; ^Lc, w  
fB= j51Lw  
&{e:6t  
for(int i=0;i<nStartPos.length;i++) v"YaMbu  
{ YH,u*.I^/  
if(!fileSplitterFetch.bDownOver) !g[UFw  
{ LjySO2  
breakWhile = false; kInU,/R*  
break; kXN8hU}iq  
} R ~?9+  
} G`r/ tesW  
if(breakWhile) 9GgXX9K  
break; QB5,Vfoux  
@bIZ0tr4  
bLSUF`-z  
//count++; {k uC+~R  
//if(count>4) 3~EPX`#[W  
// siteStop(); }X9G(`N(}  
} @/8O@^  
z3p TdUt  
8 3Tv-X  
System.err.println("文件下载结束!"); r7+Ytr  
} VmON}bb[zz  
catch(Exception e){e.printStackTrace ();} MlV3qM@  
} B=)tq.Q7  
ih=O#f|  
)mu[ye"p  
//获得文件长度 BIxjY!!"  
public long getFileSize() m\f}?t  
{ Ksff]##H  
int nFileLength = -1; rqTsKrLe  
try{ IFbN ]N0  
URL url = new URL(siteInfoBean.getSSiteURL()); x31Jl{x8\?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .23Yqr'zT  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?wVq5^ e  
YP`/dX"4  
FO:k >F  
int responseCode=httpConnection.getResponseCode(); | Zj=E$  
if(responseCode>=400) s x2\  
{ +[":W?j  
processErrorCode(responseCode); ~COd(,ul  
return -2; //-2 represent access is error >Yx,%a@~R  
} !bBx'  
mvu$  
y4%[^g~-  
String sHeader; %\B@!4]  
M7.H;.?  
~j yl  
for(int i=1;;i++) \hD jZ  
{ /Jc54d  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )@_5}8  
//Utility.log(in.readLine()); vw*,_f  
sHeader=httpConnection.getHeaderFieldKey(i); -r%k)4_  
if(sHeader!=null) ^=arKp,?5  
{ Vrt*,R&  
if(sHeader.equals("Content-Length")) aa&\HDh*  
{ ;4<!vVf e  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <"Yx}5n.  
break; Q\ pI\]p:  
} Z$y~:bz  
} $O9,Gvnxx  
else % U|4%P  
break; C zxF  
} "H|hN  
} lNx:_g:SrZ  
catch(IOException e){e.printStackTrace ();} Su]p6B  
catch(Exception e){e.printStackTrace ();} |W*i'E   
Vi>`g{\  
<KrfM  
Utility.log(nFileLength); b,lIndj#  
8F/JOtkGMt  
64l(ru<  
return nFileLength; ;uaZp.<um&  
} MX s]3M  
I` q"  
6]fz;\DgP  
//保存下载信息(文件指针位置) .&rL>A2U  
private void write_nPos() N4u-tlA  
{ h 6juX'V  
try{ ~y>NJM>1  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^v&)z ,  
output.writeInt(nStartPos.length); B qcFbY  
for(int i=0;i<nStartPos.length;i++) Ja{[T  
{ fBnlB_}e  
// output.writeLong(nPos); u5A$VRMN  
output.writeLong(fileSplitterFetch.nStartPos); S3sxK:  
output.writeLong(fileSplitterFetch.nEndPos); vJsx_ i\i  
} a H *5(E]  
output.close(); 1? Im"  
} -op(26:W<  
catch(IOException e){e.printStackTrace ();} UgD&tD0fp  
catch(Exception e){e.printStackTrace ();} I2)#."=Ew  
} fcisDu8n  
)<vuv9=k\%  
6$ ag<  
//读取保存的下载信息(文件指针位置) ;` ! j~  
private void read_nPos() ?y2v?h"  
{ L)3JTNiB  
try{ ^ ^k]2oG  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %ql2 XAY  
int nCount = input.readInt(); ,2]a<0m  
nStartPos = new long[nCount]; Qn`Fq,uvL  
nEndPos = new long[nCount]; v|wO qS  
for(int i=0;i<nStartPos.length;i++) .NT9dX  
{ -$o4WSd~  
nStartPos = input.readLong(); 5?-@}PL!Y  
nEndPos = input.readLong(); {xCqz0  
} G'(8/os{  
input.close(); n0opb [?  
} 0l2@3}e  
catch(IOException e){e.printStackTrace ();} fu{.Ir  
catch(Exception e){e.printStackTrace ();} ~c${?uf   
} "w:?WS  
!c;BOCqa  
M1J77LfS8  
private void processErrorCode(int nErrorCode) a$]i8AeG  
{ .y>G/8_i  
System.err.println("Error Code : " + nErrorCode); o$k9$H>Na  
} u9D#5NvGs  
>_SqM!^v  
 TgvBy  
//停止文件下载 siD/`T&  
public void siteStop() oE&#Tl?Vt  
{ ObSRd$M  
bStop = true; aLO'.5 ~^  
for(int i=0;i<nStartPos.length;i++) Gk]6WLi  
fileSplitterFetch.splitterStop(); ?(>fB2^  
eY8rm  
d< b,].  
} [6f(3|"  
} .a7!*I#g  
//负责部分文件的抓取 j S<."a/n  
**FileSplitterFetch.java WbGN 5?9Q  
*/ @q+X:K5b  
package NetFox; 1[4 0\sM  
PEPf=sm  
v-!^a_3Ui  
import java.io.*; Og<nnq  
import java.net.*; A_2oQ*  
L<Q>:U.@\  
)GR4U8<>g  
public class FileSplitterFetch extends Thread { TcOmBKps'  
@y(<4kLz  
CC,CKb  
String sURL; //File URL Ms14]M[\  
long nStartPos; //File Snippet Start Position 4Bk9d\z  
long nEndPos; //File Snippet End Position C(}N*e1  
int nThreadID; //Thread's ID w=QW8q?  
boolean bDownOver = false; //Downing is over KYR64[1  
boolean bStop = false; //Stop identical :Hq#co  
FileAccessI fileAccessI = null; //File Access interface `w EAU7m:  
9;R'Xo=y  
L'r gCOJ<  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UB,:won  
{ a}[ 1*_G  
this.sURL = sURL; @k3xk1*  
this.nStartPos = nStart; ]h?p3T$h  
this.nEndPos = nEnd; N^%7  
nThreadID = id; o+F < r#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5LzP0F U  
} aM|;3j1p  
.^V9XN{'a  
l#fwNM/F  
public void run() tFu"h1  
{ Qz`v0"'w  
while(nStartPos < nEndPos && !bStop) 6D/K=-   
{ Q|(G -  
m#`1.5%  
d'k99(vy  
try{ v`Yj)  
URL url = new URL(sURL); 5DmW5w'p  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LGq T$ O|  
httpConnection.setRequestProperty("User-Agent","NetFox"); !z2KQ 4C  
String sProperty = "bytes="+nStartPos+"-"; &9F(C R  
httpConnection.setRequestProperty("RANGE",sProperty); 1fqJtP6  
Utility.log(sProperty); T_Cj=>L  
>b2wFo/em  
U o[\1)  
InputStream input = httpConnection.getInputStream(); ZK5 wZU  
//logResponseHead(httpConnection); #D-Ttla  
HUalD3 \  
'g:.&4x_w  
byte[] b = new byte[1024]; 0bl8J5Ar5  
int nRead; D.*o^{w|  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k nljc^  
{ 74fE%;F  
nStartPos += fileAccessI.write(b,0,nRead); QE+HL8c^s  
//if(nThreadID == 1) L~{3W  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W]I+Rlv)U  
} Wgb L9'}B  
@G^m+-  
Dbw{E:pq  
Utility.log("Thread " + nThreadID + " is over!"); +d=w%r)  
bDownOver = true; [Zne19/  
//nPos = fileAccessI.write (b,0,nRead); =XFyEt  
} z -uW,  
catch(Exception e){e.printStackTrace ();} %<{1 N|  
} MJ<jF(_=  
}  6h?)x  
+;bP.[Z  
B3&C=*y  
//打印回应的头信息 {ep.So6  
public void logResponseHead(HttpURLConnection con) X.eocy  
{ ?,w9e|  
for(int i=1;;i++)  }~Ir &   
{ 97vQM  
String header=con.getHeaderFieldKey(i); S!h=HE  
if(header!=null) Ogu";p(  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %r]V:d+  
Utility.log(header+" : "+con.getHeaderField(header)); J*4T| #0  
else A,4Z{f83  
break; -+y3~^EYm,  
} 2 2@w:  
} n;e.N:p  
sFw;P`  
g17 fge6%  
public void splitterStop() O96%U$W  
{ "f:_(np,  
bStop = true; Ou{VDE  
} zg$NrI&  
/" @cv{  
=F09@C,  
} }#2I/dn  
7V-uQ)*  
i2E@5 v=|Y  
/* v(;n|=O  
**FileAccess.java `]F#j ]"  
*//文件访问(定位,写) Y2}m/7aF  
package NetFox; 7)*q@  
import java.io.*; #|K5ma  
|O{kv}Y Z  
`JcWH_[  
public class FileAccessI implements Serializable{ xM?tdQ~VHY  
6 -BC/  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^#]eCXv  
RandomAccessFile oSavedFile; cUr5x8<W).  
long nPos; 7{p6&xXx  
HL%|DCo  
,L\>mGw  
public FileAccessI() throws IOException t'[`"pp=  
{ S]?I7_  
this("",0); c~u91h?  
} BBa!l e9P  
{R?VB!dR  
")9jt^  
public FileAccessI(String sName,long nPos) throws IOException H3+P;2 {  
{ 465?,EpS  
oSavedFile = new RandomAccessFile(sName,"rw"); vF9fXY=  
this.nPos = nPos; V^< Zs//7  
oSavedFile.seek(nPos); pYh\l.@qf  
} DDe`Lb%%  
_8e0vi!~2  
GYtp%<<9;  
public synchronized int write(byte[] b,int nStart,int nLen) ] QJ7q}  
{ wQYW5X  
int n = -1; f1|&umJ$  
try{ =g$%jM>35  
oSavedFile.write(b,nStart,nLen); cToT_Mk  
n = nLen; ^bECX<,H  
} '#>(JN5\  
catch(IOException e) uQg&]bSv  
{ "Ug+# ;}p$  
e.printStackTrace (); 7MIrrhk  
} +iw4>0pi  
o\X|\nUk  
MH=Ld=i  
return n; p. KT=dZT  
} g/gaPc*86  
u5tUm  
nnCz!:9p  
} '^(qlCI  
D{6<,#P{w  
M=4`^.Ocm  
/* T!-ly7-`  
**SiteInfoBean.java w[#*f?at~  
*/ aa}U87]k  
package NetFox; M:oZk&cs  
f=- R<l  
VYkUUp  
public class SiteInfoBean { @_ Tq>tOr&  
=l>=]O~h  
VyWzb  
private String sSiteURL; //Site's URL n$<n Yr`X  
private String sFilePath; //Saved File's Path ,,;vG6^a  
private String sFileName; //Saved File's Name  NG?g(  
private int nSplitter; //Count of Splited Downloading File T>w;M?`9K  
8Yf=)  
cC9haxW  
public SiteInfoBean() DK1{Z;Z  
{//nSplitter的缺省值为5 %rO)w?  
//default value of nSplitter is 5 0~e6\7={  
this("","","",5); Ehq [4}  
} |OIU)53A-  
p5J!j I=  
95Q^7oI  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,3Nna:~f  
{ ?;ZnD(4?  
sSiteURL= sURL; $`<-;kI  
sFilePath = sPath; !*o{xq   
sFileName = sName; { }P~nP  
this.nSplitter = nSpiltter; w`[`:H_z  
5 Q,j+  
9>;CvR  
} &t}6sD9o  
&}d5'IRT  
f<>CSjQ4c  
public String getSSiteURL() fzUG1|$e  
{ Nb)Mh  
return sSiteURL; ( ; _AP.  
} ie7P^:T|+  
Nt687  
dg&GMo  
public void setSSiteURL(String value) S2EV[K8#  
{ o0TB>DX$`  
sSiteURL = value; 0@RVM|  
} =b>e4I@  
Fi# 9L  
MJU*Sq  
public String getSFilePath() 68~5Dx  
{ Zi<(>@z2  
return sFilePath; DuIgFp  
} py6O\` \  
`t+;[G>ZE  
FBa- gm<9  
public void setSFilePath(String value) 4GS:kfti  
{ I>lblI$7  
sFilePath = value; 37 *2/N2  
} X39%O'  
,_ @) IN  
Uurpho_~  
public String getSFileName() h{^MdYJ  
{ "g5MltH  
return sFileName; NT{ 'BJ  
} izLB4pk$  
[XkWPx`  
B?ipo,2~{  
public void setSFileName(String value) Nzb=h/;  
{ k0 D):  
sFileName = value; =)J )xH!N  
} rdH^"(  
?(M]'ia{  
G> s qfYkK  
public int getNSplitter() mteQRgC  
{ {"O-/* f+(  
return nSplitter; r(<91~Ww  
} 3gv?rJV  
r9p ((ir  
I_|W'%N]  
public void setNSplitter(int nCount) Nhtc^DX  
{ fC/P W`4Ae  
nSplitter = nCount; B^.:dn  
} d"S\j@  
} _p<wATv?7t  
%&wi@ *#  
:0p$r pJP  
/* HC"yC;_  
**Utility.java y2nT)nL  
*/ ]'Gz~Z%>F  
package NetFox; K{XE|g  
sTvw@o *  
>AWWwq -  
public class Utility { @*WrHoa2N  
=FQH5iSd  
L }R-|  
public Utility() 10tTV3`IM  
{ a[=ub256S  
Wr8}=\/  
KK4rVb:-  
} [Bj\h7 G  
w8F`RRHEE  
//线程睡眠 'fZ\uMdTx  
public static void sleep(int nSecond) hJ?PV@xy  
{ XE#$|Z  
try{ ycf)*0k  
Thread.sleep(nSecond); 2B+qS'OT  
} T%E/k# )q  
catch(Exception e) 9ZDbZc  
{ [}5mi?v  
e.printStackTrace (); E`|vu*l7  
} g|j15&x  
} /&l4 sF1  
34L1Gxf  
//日志 .]N`]3$=  
public static void log(String sMsg) "O_)~u  
{ 0iKAg  
System.err.println(sMsg); !:v7SRUXb  
} $Qxy@vU  
HTSk40V  
m@YK8 c#$  
public static void log(int sMsg) !P gwFJ  
{ ?>My&yB  
System.err.println(sMsg); +mYK  
} T-x}o  
} Kp19dp}'b  
#P {|7}jk  
;,xM*  
/* s\ Ln  
**TestMethod.java /Eu|Jg=I  
*/ >uFFTik  
package NetFox; whFJ]  
4ZkaH(a1  
Xm<|m#  
public class TestMethod { +]Ev  
DeI3(o7  
B/Ltb^a  
public TestMethod() s0DT1s&  
{ ///xx/weblogic60b2_win.exe 'f8'|o)  
try{ ;_0frX  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [MF&x9Ss?%  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *hh9 K  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 83VFBY2q  
fileFetch.start(); #VsS C1  
} BE!l{  
catch(Exception e){e.printStackTrace ();} 2I 7|hZ,  
)!;20Po  
-op)X>  
} !t?5U_on  
Lz!H@)-mr  
Zh_3ydMD1  
public static void main(String[] args) ((M>To_l  
{ <`NtTG  
new TestMethod(); [kMWsiZ  
} P1 |3%#c  
} lHE \Z`  
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