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http断点续传简单实现(java)

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/* a#$N%=j  
**SiteFileFetch.java X{`1:c'x  
*/ q~j)W$k  
package NetFox; ~}K{e  
import java.io.*; /22nLc;/Cx  
import java.net.*; |U EC  
$2QYxY9s  
3-iD.IAUm@  
public class SiteFileFetch extends Thread { *,0+RASvq  
S@Iw;V  
#~S>K3(  
SiteInfoBean siteInfoBean = null; //文件信息Bean i-]U+m*  
long[] nStartPos; //开始位置 TtZ}"MPZ  
long[] nEndPos; //结束位置 AX;c}0g  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 9n"V\e_R  
long nFileLength; //文件长度 eIJ[0c b}  
boolean bFirst = true; //是否第一次取文件 I>aGp|4  
boolean bStop = false; //停止标志 6A?8tm/0  
File tmpFile; //文件下载的临时信息 Lc%xc`n8B  
DataOutputStream output; //输出到文件的输出流 x9&p!&*&IT  
'BhwNuW\"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) M$H`^Pv  
public SiteFileFetch(SiteInfoBean bean) throws IOException \E77SO,$  
{ `BjR.xMv  
siteInfoBean = bean; f3 vF"O  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Pj&A=  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [S0mY["  
if(tmpFile.exists ()) SO_>c+Dw  
{ q/x/N5HU  
bFirst = false; [,b)YjO~Xd  
read_nPos(); @vt$MiOi  
} 3ev -Iqz  
else WqQU@sA  
{ Ha)np  
nStartPos = new long[bean.getNSplitter()]; 5gshKmt_  
nEndPos = new long[bean.getNSplitter()]; Cfv]VQQE  
} {OP~8e"  
y42#n  
>pdnCv_c  
/[{auUxSX  
} V%51k{  
'Wp @b678  
]]PE#DDg  
public void run() V{ |[oIp  
{ > c:Zx!  
//获得文件长度 PIxjM>  
//分割文件 8wmQ4){  
//实例FileSplitterFetch QNpu TZn#Q  
//启动FileSplitterFetch线程 l!@ 1u^v2  
//等待子线程返回 Z0\Iyc G  
try{ 9!#EwPD$#  
if(bFirst) R6P\T\~E  
{ 2(+P[(N1,  
nFileLength = getFileSize(); 12OlrU  
if(nFileLength == -1) ~OCZz$qA  
{ iRt*A6`m+  
System.err.println("File Length is not known!"); q3+8]-9|5  
} b#='^W3  
else if(nFileLength == -2) %b?uW] j:  
{ ix*muVBj.  
System.err.println("File is not access!"); + zp0" ,2B  
} " " %#cDR  
else "dtlME{Bx  
{ W.[BPR  
for(int i=0;i<nStartPos.length;i++) 6t m \L  
{ m\-PU z&C  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 5@f5S0 Y  
} l"\uf(0K  
for(int i=0;i<nEndPos.length-1;i++) @GeHWv  
{ %{'4. ,  
nEndPos = nStartPos[i+1]; vpLMhf`  
} wW5Yw i  
nEndPos[nEndPos.length-1] = nFileLength; T*+A.G@L"  
} D^?_"wjW  
} (STx$cya  
1<,/ -H  
V^rW?Do  
//启动子线程 mH\@QdF  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rQj~[Y.c  
for(int i=0;i<nStartPos.length;i++) S(t{&+Wc  
{ Y /lN@  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RxG^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ri+U0[e3  
nStartPos,nEndPos,i); DsQ/aG9c%  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ac\W\=QvB  
fileSplitterFetch.start(); mx}E$b$<CY  
} OKPJuV`y6  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d)KF3oA  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1);  `{}@@]  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r/PKrw sC  
nEndPos = " + nFileLength); . #U}q 7X  
// fileSplitterFetch[nPos.length-1].start(); c#pj:f*H  
ny1 \4C  
PAoX$q  
//等待子线程结束 w~N-W8xNR  
//int count = 0; j04/[V)  
//是否结束while循环 w+_Wc~f  
boolean breakWhile = false; hk;bk?:m  
RGp'b  
f:vD`Fz1  
while(!bStop) sFElD ]|  
{ /b{HG7i\  
write_nPos(); ~6d5zI4\  
Utility.sleep(500); fS I%c3  
breakWhile = true; Le&;g4%  
eP= j.$  
oEIqA  
for(int i=0;i<nStartPos.length;i++) l%<c6;  
{ sykFSPy`'  
if(!fileSplitterFetch.bDownOver) %U?)?iZdL  
{ oAz<G  
breakWhile = false; )4ncutb  
break; , ` o+ ?  
} HNMBXXf, B  
} g1V)$s 7  
if(breakWhile) (\& 62B1  
break; $G3@< BIN  
5"gL.Ez  
ZNL5({lv  
//count++; }Vl^EAR  
//if(count>4) g;G5 r&T  
// siteStop(); 5hz_P+Q  
} !*bdG(pK  
^ItAW$T]F  
vgAFuQi(  
System.err.println("文件下载结束!"); 2sun=3qb  
} L[. <o{  
catch(Exception e){e.printStackTrace ();} u){S$</  
} /7vE>mSY  
(9'be\  
6t$N78U  
//获得文件长度 w4A#>;Qu*  
public long getFileSize() BS.=  
{ fTgbF{?xh  
int nFileLength = -1; {aIZFe}B  
try{ 8Fx]koP.  
URL url = new URL(siteInfoBean.getSSiteURL()); 3?^NN|xg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?Cc :)  
httpConnection.setRequestProperty("User-Agent","NetFox"); JMePI%#8  
:D4];d>1  
e^WqJ7j  
int responseCode=httpConnection.getResponseCode(); UM\}aq=,  
if(responseCode>=400) qK-qcPLsl  
{ vv* |F  
processErrorCode(responseCode); r0uJ$/!  
return -2; //-2 represent access is error R8ZD#,;  
} rXDJ:NP  
I4:rie\hjC  
5"uNj<.V  
String sHeader; tWX7dspx/  
f}blB?e  
`#p< rfe  
for(int i=1;;i++) C[0MA ,^  
{ e# <4/FR  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ());  ]CIe~q  
//Utility.log(in.readLine());  +Lhe,  
sHeader=httpConnection.getHeaderFieldKey(i); f-&ATTx`J  
if(sHeader!=null) :mn(0 R~  
{ $>![wZ3  
if(sHeader.equals("Content-Length")) T+(M8 qb  
{ n{$}#NdV  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lJlhl7  
break; ?(>k,[n  
} G ~A$jStm  
} Q-3r}jJe  
else XJ O[[G`  
break; BPh".RJ  
} uct=i1+ fE  
} V07VwVD  
catch(IOException e){e.printStackTrace ();} re/xs~  
catch(Exception e){e.printStackTrace ();} .Nk}Z9L]k  
{x9j_/R  
R qn WtE  
Utility.log(nFileLength); 3Qk/ Ll  
[0wP\{%  
^glX1 )  
return nFileLength; m^'~&!ba  
} rykj2/O  
3hH>U%`-  
el}hcAY/RP  
//保存下载信息(文件指针位置) Q7L)f71i  
private void write_nPos() *!i,?vn  
{ " cNg :  
try{ & \JLTw  
output = new DataOutputStream(new FileOutputStream(tmpFile)); K[*h+YO  
output.writeInt(nStartPos.length); Shs')Zs bv  
for(int i=0;i<nStartPos.length;i++) z1kBNOr  
{ ::v;)VdX+*  
// output.writeLong(nPos); ^)Smv\Md  
output.writeLong(fileSplitterFetch.nStartPos); 4{Q$!O>  
output.writeLong(fileSplitterFetch.nEndPos); JaA&eT|  
} ]F !'M  
output.close(); J`4Z<b53  
} -!@H["  
catch(IOException e){e.printStackTrace ();} UE\%e9<l  
catch(Exception e){e.printStackTrace ();} N`f!D>b:dn  
} DE'Xq6#PK  
Ih(:HFRMq6  
SwyaYK  
//读取保存的下载信息(文件指针位置) h] <GTWj  
private void read_nPos() s;anP0-O  
{ ?0 HR(N(z!  
try{ J 0&zb'1  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0K&_D)  
int nCount = input.readInt(); $I\))*a  
nStartPos = new long[nCount]; xT:qe  
nEndPos = new long[nCount]; WfRVv3Vm  
for(int i=0;i<nStartPos.length;i++) MgHOj   
{ uPI v/&HA  
nStartPos = input.readLong(); [SK2x4  
nEndPos = input.readLong(); ,;9ak-$8p  
} 2=jd;2~  
input.close(); \)FeuLGL9  
} f#*h^91x  
catch(IOException e){e.printStackTrace ();} Jw2B&)k/  
catch(Exception e){e.printStackTrace ();} Y,3z-Pa=@  
} 9 aY'0wa  
W^^K0yn`@  
^!q 08`0  
private void processErrorCode(int nErrorCode) &/ \O2Aw8  
{ X'YfjbGo  
System.err.println("Error Code : " + nErrorCode); Xq+!eOT  
} .UNF~}^H  
g7 .7E6%H  
N<p5p0  
//停止文件下载 sGXp}{E9  
public void siteStop() <l* agH-.3  
{ @~JB\j9  
bStop = true; 7bctx_W&6  
for(int i=0;i<nStartPos.length;i++) 0eQ~#~j&  
fileSplitterFetch.splitterStop();  aeEw#  
pGO|~:E/L  
lF0K=L  
} Gtj (  
} 9 yh9HE  
//负责部分文件的抓取 z8 hTZU  
**FileSplitterFetch.java "9c.CI  
*/ Q2JdO 6[96  
package NetFox; 6Hc H'nmeN  
p>2||  
;n% ]*v  
import java.io.*; ST[2]   
import java.net.*; pem3G5 `g=  
'CP/ymf/a  
r^?)F?n!  
public class FileSplitterFetch extends Thread { `'z(--J}`  
\4[c}l  
FZ[@])B  
String sURL; //File URL *>H M$.?Q  
long nStartPos; //File Snippet Start Position CBiU#h q  
long nEndPos; //File Snippet End Position <dju6k7uz  
int nThreadID; //Thread's ID B'WCN&N  
boolean bDownOver = false; //Downing is over 7P3 <o!YA  
boolean bStop = false; //Stop identical Ha46U6_'h  
FileAccessI fileAccessI = null; //File Access interface hgTM5*fD}  
XNc"kp? z  
\>*MMe  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [VY8?y  
{ r Iya\z1W  
this.sURL = sURL; ig2{lEkF  
this.nStartPos = nStart; hQgk.$g  
this.nEndPos = nEnd; 2ApDpH`fiJ  
nThreadID = id; ga4/,   
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F/Rng'l  
} _n-VgPRn  
&{-oA_@  
,!o\),N  
public void run() t9Enk!@  
{ sD LVYD  
while(nStartPos < nEndPos && !bStop) _&k'j)rg  
{ X_lUD?y  
bE7(L $UF  
R&u)=~O\5  
try{ e67c:Z  
URL url = new URL(sURL); -XS+Uv  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R-r+=x&  
httpConnection.setRequestProperty("User-Agent","NetFox"); KuIt[oM  
String sProperty = "bytes="+nStartPos+"-"; @+0@BO1 2  
httpConnection.setRequestProperty("RANGE",sProperty); Ze$^UR  
Utility.log(sProperty); u+2 xrzf  
<Um1h:^   
}aHB$}"!  
InputStream input = httpConnection.getInputStream(); ..P=D <'f  
//logResponseHead(httpConnection); x'E'jh%  
TIK/%T  
N>&{Wl'y\  
byte[] b = new byte[1024]; ImUQ*0  
int nRead; dCf'\ @<<  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) htUy2v#V  
{ >cwJl@wx-  
nStartPos += fileAccessI.write(b,0,nRead); p=8M0k  
//if(nThreadID == 1) jQ.>2-;H9  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EuKrYY]g  
} 'Yaf\Hp  
LW83Y/7  
^D ]7pe  
Utility.log("Thread " + nThreadID + " is over!"); boC>N   
bDownOver = true; ct2_N  
//nPos = fileAccessI.write (b,0,nRead); p?Z+z  
} 2 Ft0C2  
catch(Exception e){e.printStackTrace ();} t7C!}'g&'  
} 9}%~w(P  
} %KabyvOl)  
.-C+0L1j  
mFgb_Cd  
//打印回应的头信息 haEZp6Z  
public void logResponseHead(HttpURLConnection con) d+YVyw.z  
{ 7(A G]  
for(int i=1;;i++) ]HNT(w@  
{ q_9N+-?{7  
String header=con.getHeaderFieldKey(i); )9A<fwpN  
if(header!=null) J[& 7,}  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #GDh/t2@  
Utility.log(header+" : "+con.getHeaderField(header)); 3&a*]  
else zCj*:n  
break; ]Vf8mkDGO  
} Q ^1#xBd  
} ?vht~5'  
vjs|!O=oH  
!~|"LA!jn  
public void splitterStop() ySr091Q  
{ &geOFe}R  
bStop = true; :N*q;j>  
} Sq?6R}q%  
O9qKwn;q(  
:r vO8.\  
} T_(e(5  
FM;;x(sg  
~Me&cT8  
/* Yn[EI7D  
**FileAccess.java WoClTb>F  
*//文件访问(定位,写) HAI1%F236  
package NetFox; fr,CH{Uq  
import java.io.*; R uFu,H-  
8,H#t@+MT  
%`s9yRk9>E  
public class FileAccessI implements Serializable{ HkfSx rTgQ  
I).^,%>Z)  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "u,~yxYWl  
RandomAccessFile oSavedFile; P60]ps!M  
long nPos; t;e]L'z@:  
2\z`G  
HhQPgjZ/  
public FileAccessI() throws IOException )qe$rD;N  
{ soQv?4  
this("",0); 4Ow Vt&  
} z hR_qW+  
>ihe|WN  
*\~kjZ 3  
public FileAccessI(String sName,long nPos) throws IOException +}G>M=t::  
{ AVevYbucB  
oSavedFile = new RandomAccessFile(sName,"rw"); ++p& x{  
this.nPos = nPos; Tm~#wL +r  
oSavedFile.seek(nPos); p-(ADQS  
} "` ?W u  
{L2Gb(YLW  
7"CH\*%  
public synchronized int write(byte[] b,int nStart,int nLen) ! 4^L $  
{ R=Ly49  
int n = -1; C"m0"O>  
try{ HU'`kimWb  
oSavedFile.write(b,nStart,nLen); n]ppO U|[  
n = nLen; ^)0{42!]  
} kmwrv -W  
catch(IOException e) 6'sFmC  
{ <GFB'`L  
e.printStackTrace (); <hF~L k ,  
} hDkqEkq1R  
%ucmJ-< y#  
b8b PK<  
return n; 9:Z~}yX  
} +KwF U  
/ jL{JF>I  
5_tK3Q8?  
} m+gG &`&u  
)'I<xx'1  
iN9!?Ov_  
/* *ej o6>  
**SiteInfoBean.java v%8-Al^G  
*/ Y"\T*lKa  
package NetFox; 1oW]O@R  
fvBC9^3  
uxJiec`&  
public class SiteInfoBean { 6pz:Lfd80  
xY}j8~k  
<n~g+ps  
private String sSiteURL; //Site's URL ;eEtdoy  
private String sFilePath; //Saved File's Path Nm:<rI,^  
private String sFileName; //Saved File's Name ;51!a C  
private int nSplitter; //Count of Splited Downloading File 7u3b aM  
ib=^ tK  
@U.}Ei  
public SiteInfoBean() _TcQ12H 5<  
{//nSplitter的缺省值为5 I EsD=  
//default value of nSplitter is 5 0}C}\1  
this("","","",5); Y&Vbf>Hi+  
} T^H) lC#R  
o?hw2-mH  
|/Q."d  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) OuIW|gIu0  
{ LYT<o FE-  
sSiteURL= sURL; cZ2, u,4  
sFilePath = sPath; b6$A@b  
sFileName = sName; W oG  
this.nSplitter = nSpiltter; pO+wJ|f  
a|{<#<6n(  
eS%6 h U b  
} O*Pe [T5x'  
;}9Ws6#XQs  
cZF;f{t  
public String getSSiteURL() r|BKp,u9  
{ b020U>)v  
return sSiteURL; #"YWz)8  
} GIl{wd  
@y2Bq['  
eOO*gM=  
public void setSSiteURL(String value) ,r,;2,;6nd  
{ bD[W~ku  
sSiteURL = value; 5{f/H] P  
} Bq =](<>>  
sWzXl~JbF  
DQXx}%Px  
public String getSFilePath() Uy'ZL(2  
{ EGO@`<"h  
return sFilePath; BqAwo  
} _^$b$4)  
g {wPw  
! r\ktX  
public void setSFilePath(String value) `.Q3s?1F  
{ RwHXn]1  
sFilePath = value; ?bi^h/ f  
} @  MoMU  
I}3K,w/7mi  
Ev ,8?  
public String getSFileName() ^Iq.0E9_  
{ z]_CFo1'l  
return sFileName; 5 : >  
} :WTvP$R  
Z'M@DY/fdK  
SvJ8Kl OV  
public void setSFileName(String value) U.jMK{  
{ UZ0O j5B.  
sFileName = value; NT:>.~ah@&  
} !-Q!/?  
U^S:2  
)Em,3I/.l  
public int getNSplitter() ~/[N)RFD  
{ 82l";;n4p  
return nSplitter; v)pWx0l=  
} f}d@G/L  
(Gs g+c   
zOp"n\  
public void setNSplitter(int nCount) (jMp`4P  
{ CBHWMetJ*  
nSplitter = nCount; ~<R~Q:T  
} 2l%iXK[  
} P3>2=qK"E(  
^ZBkt7  
B}T72!a  
/* Pk2 "\y@q/  
**Utility.java @35]IxD  
*/ 0nn# U  
package NetFox; |%9~W^b  
6?~pjMV  
m8`A~  
public class Utility { pswppC6f  
3N\X{za  
%QkvBg*  
public Utility() 1yf&ck1R  
{ SS-   
7MfvU|D[d/  
Vt>E\{@[t  
} W5 }zJ)x  
m 9Q{ )?J7  
//线程睡眠 .!! yj,bQz  
public static void sleep(int nSecond) ?whp _  
{ T[J_/DE@  
try{ 0eIR)#j*  
Thread.sleep(nSecond); -z94>}Z=  
} J0o[WD$A x  
catch(Exception e) IS~oyFS  
{ "b;?2_w:E  
e.printStackTrace (); W3kilhZ  
} MDt4KD+bZ  
} wVB8PO8  
VI{1SIhfa  
//日志 P'';F}NwfX  
public static void log(String sMsg) !Ai;S  
{ \zU R9h  
System.err.println(sMsg); P*Nl3?T  
} 8iB}a\]B  
>@o*v*25  
9EW 7,m{A  
public static void log(int sMsg) 9`{cX  
{ *G38N]|u6  
System.err.println(sMsg); LgYzGlJp  
} Ig2VJs;  
} $6[]c)(  
L K$hV"SYb  
sh RvwE[  
/* w6tY6bf}  
**TestMethod.java >#Y q&@G  
*/ hB4.tMgZ  
package NetFox; muLTYgaM  
l;fH5z  
!.A>)+AK  
public class TestMethod { PC5FfX  
JP]K\nQx'  
}HzZj;O^2>  
public TestMethod() b~p <   
{ ///xx/weblogic60b2_win.exe ( KrIMZ  
try{ iJK9-k~  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hV%l}6yS&  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zq#o8))4X  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $}829<gh7  
fileFetch.start(); HD>{UU?  
} _<8y^ymo  
catch(Exception e){e.printStackTrace ();} okW3V}/x/z  
aNz%vbh\  
&N#)(rQ1  
} ^/,s$dj  
w K+2;*bI  
pfG:P rZ  
public static void main(String[] args) QZY (S*Up  
{ UTz;Sw?~hw  
new TestMethod(); "T'!cy  
} `@90b 4u  
} q:'(1y~  
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