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http断点续传简单实现(java)

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/* "/#=8_f  
**SiteFileFetch.java ukInS:7  
*/ #a$k3C  
package NetFox; lx)Bj6  
import java.io.*; fzk^QrB  
import java.net.*;  l,lfkm  
CRh.1-  
'ZiTjv ]  
public class SiteFileFetch extends Thread { ab!Cu8~v  
F\Z|JCA  
SQS PdR+  
SiteInfoBean siteInfoBean = null; //文件信息Bean VfFXH,j  
long[] nStartPos; //开始位置 GN=ugP 9  
long[] nEndPos; //结束位置 @OB7TI_/   
FileSplitterFetch[] fileSplitterFetch; //子线程对象 CI8bHY$  
long nFileLength; //文件长度 >Ohh) $  
boolean bFirst = true; //是否第一次取文件 810pJ  
boolean bStop = false; //停止标志 wG-lR,glb  
File tmpFile; //文件下载的临时信息 `B%IHr  
DataOutputStream output; //输出到文件的输出流 p~evPTHnrX  
\46 'j.  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) xIb"8,N  
public SiteFileFetch(SiteInfoBean bean) throws IOException ->u}b?aF  
{ U;q GUqI  
siteInfoBean = bean; v>!tws5e  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); {gkY:$xnrG  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 9sId2py]W  
if(tmpFile.exists ()) Z`jSpgWR  
{ r9vO(m~  
bFirst = false; rG t/ /6  
read_nPos(); 6!|/(~  
} 71I: P|.>  
else ; `Vbl_"L  
{ 4UISuYg'  
nStartPos = new long[bean.getNSplitter()]; >OotgJnhC  
nEndPos = new long[bean.getNSplitter()]; Z'cL"n\9R]  
} K1oSoD8c  
Qw@_.I  
vFx0B?  
-"} mmTa*<  
} Q|] 9  
mh :eUFe  
Fu$JI8  
public void run() huTWoMU  
{ n]< >$  
//获得文件长度 Xf/qUao  
//分割文件 _Z0O]>KH  
//实例FileSplitterFetch #[ TOe  
//启动FileSplitterFetch线程 )r`F}_CEL  
//等待子线程返回 8w\ZY>d   
try{ *f*o ,~8V1  
if(bFirst) \-nbV#{  
{ )d =8)9B  
nFileLength = getFileSize(); @\}w8  
if(nFileLength == -1) T:|PSJc0  
{ <ZXK}5SZ#  
System.err.println("File Length is not known!"); TJ`Jqnh  
} XnNU-UCX  
else if(nFileLength == -2) }}q_QD_  
{ Xt$o$V  
System.err.println("File is not access!"); C#tY};t  
} ^- H  
else hTS?+l  
{ [39  
for(int i=0;i<nStartPos.length;i++) [R%Pf/[Fr  
{ Ra-%,cS  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); RKtU@MX49  
} .DN)ck:e;  
for(int i=0;i<nEndPos.length-1;i++) Y| 2Gj(*8  
{ V")u y&Ob  
nEndPos = nStartPos[i+1]; gu|cQ2xV  
} UgC{  
nEndPos[nEndPos.length-1] = nFileLength; gBPYGci2F  
} (-bLP  
} ? f>pKe  
2J1YrHj3  
/xh/M@G3  
//启动子线程 1 [D,Mu%E  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NB#-W4NA  
for(int i=0;i<nStartPos.length;i++) syB.Z-Cpd  
{ 3?Tk[m1b  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Dqg~g|(Q<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G\ m`{jv  
nStartPos,nEndPos,i); .j l|? o  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tMOhH #  
fileSplitterFetch.start(); i286`SLU  
} 7 yp}  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q3P*&6wA  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >u/ T`$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <xO" E%t  
nEndPos = " + nFileLength); wu`P=-  
// fileSplitterFetch[nPos.length-1].start(); D\9-MXc1  
a%NSL6  
pe@j`Sm:Ej  
//等待子线程结束 9LK<u$C  
//int count = 0; {OGv1\ol&  
//是否结束while循环 k]] e8>  
boolean breakWhile = false; pdEUDuX  
"+k^8ki  
wzNGL{3  
while(!bStop) aPH6R<G  
{ o3kVcX^  
write_nPos(); e>~7RN  
Utility.sleep(500); ^R;rrn{^  
breakWhile = true; xp;CYr"1}  
/j(3 ~%]o4  
k*"FMJG_  
for(int i=0;i<nStartPos.length;i++) O$, bNu/g  
{ ZMn~QU_5  
if(!fileSplitterFetch.bDownOver) (sN;B)  
{ 'rSP@  
breakWhile = false; IuN:*P  
break; 0.kQqy~5  
} i-E/#zni  
} FAbl5VW'  
if(breakWhile) :W*']8 M-  
break; _=ziw|zI  
w\(; >e@  
$CP_oEb  
//count++; , HHCgN  
//if(count>4) C'oNGOEd  
// siteStop(); , 3p$Z  
} #24 eogo~  
;:#g\|(<+  
% >}{SS  
System.err.println("文件下载结束!"); \$[; d:9j  
} ML-?#jNa<  
catch(Exception e){e.printStackTrace ();} dWDM{t\}\  
} \Zbi`;m?  
{ZR>`'^:  
vAH`tPi>  
//获得文件长度 KDEcR  
public long getFileSize() =*Ru 2  
{ FdFN4{<QZ  
int nFileLength = -1; |xX>AMZc)D  
try{ 3S h#7"K3  
URL url = new URL(siteInfoBean.getSSiteURL()); Qk h}=3u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gK+/wTQ%  
httpConnection.setRequestProperty("User-Agent","NetFox"); R^ &nBwp  
H){lXR/#u  
+x_9IvaW&?  
int responseCode=httpConnection.getResponseCode(); 29~Bu5  
if(responseCode>=400) 2Pz)vnV"  
{ NU{`eM  
processErrorCode(responseCode); N"Mw1R4  
return -2; //-2 represent access is error ux=0N]lc  
} A$;"9F@  
%IhUQ6  
*!- J"h  
String sHeader; }<KQ +  
F* h\#?  
9?L,DThQ  
for(int i=1;;i++) KVA~|j B  
{ AttS?TZr  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &m8Z3+Ea  
//Utility.log(in.readLine()); D g~L"  
sHeader=httpConnection.getHeaderFieldKey(i); dub %fs  
if(sHeader!=null) [44C`x[8M+  
{  V9cKl[  
if(sHeader.equals("Content-Length")) GT3 ?)g{Z  
{ 4ht+u  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uqFYa bU  
break; bz4TbGg]  
} ^j>w<ljzz  
} TeXt'G=M  
else /lqVMlz\77  
break; 2ms@CQy(00  
} _oBJ'8R\  
} \Uh$%#}.  
catch(IOException e){e.printStackTrace ();} GO<,zOqvU  
catch(Exception e){e.printStackTrace ();} "B"Yfg[  
m2h@*  
*%;+3SV  
Utility.log(nFileLength); A1uo@W  
`Eq~W@';Q0  
{Xw6p  
return nFileLength; f tE2@}  
} Ptj[9R  
/.>8e%)  
{ M&Vh]  
//保存下载信息(文件指针位置) "2 "gTS  
private void write_nPos() I/V lH:o  
{ _&xi})E^O]  
try{ lU&[){  
output = new DataOutputStream(new FileOutputStream(tmpFile)); KYN{Dh]-}  
output.writeInt(nStartPos.length); I`-N]sf^  
for(int i=0;i<nStartPos.length;i++)  @& fAR2  
{ Rt=zqfJ  
// output.writeLong(nPos);  roNRbA]  
output.writeLong(fileSplitterFetch.nStartPos); j,@@[{tu  
output.writeLong(fileSplitterFetch.nEndPos); Ap)[;_9BD  
} f9FEH7S68  
output.close(); Fh0cOp(  
} waRK$/b (  
catch(IOException e){e.printStackTrace ();} ^Pp2T   
catch(Exception e){e.printStackTrace ();} Z36C7 kw  
} 7 S 6@[-E  
|b^+= "  
CYFi_6MFl  
//读取保存的下载信息(文件指针位置) /t"F Z#  
private void read_nPos() O4lHR6M2  
{ vn"+x_  
try{ i0/RvrLc  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Pua| Z x  
int nCount = input.readInt(); {>rGe#Vu  
nStartPos = new long[nCount]; wR]jJb F  
nEndPos = new long[nCount]; !]*Cwbh. u  
for(int i=0;i<nStartPos.length;i++) ?=#vp /  
{ o +KDK{MD  
nStartPos = input.readLong(); yMVlTO  
nEndPos = input.readLong(); #|R#/Yc@Bv  
} kACgP!~/1  
input.close(); K0xka[x=(  
} YggeKN  
catch(IOException e){e.printStackTrace ();} C(@#I7G  
catch(Exception e){e.printStackTrace ();} 05PRlz *x=  
} jqv"8S5  
CaE1h9  
RJhafUJ zH  
private void processErrorCode(int nErrorCode) OPe3p {]  
{ )oAxt70  
System.err.println("Error Code : " + nErrorCode); lNRGlTD%  
} SR8)4:aKW  
Q!*}^W  
|S0nR<x-M  
//停止文件下载 1~aP)q  
public void siteStop() o4PJ9x5R!  
{ ~4^~w#R  
bStop = true; n> tru L  
for(int i=0;i<nStartPos.length;i++) [~&yLccN  
fileSplitterFetch.splitterStop(); ~OSgpM#O!T  
b<bj5m4fz>  
[Rxbb+,U  
} p'f8?jt  
} 7H!/et?S,  
//负责部分文件的抓取 Q /zlU@  
**FileSplitterFetch.java ;eY.4/*R  
*/ !> 2kH  
package NetFox; E>I\m!ue  
)Bw}T  
rZ#ZY  
import java.io.*; HzQ Y\Y6  
import java.net.*; iKM!>Fi  
$s]vZ(H  
ZULnS*V;5  
public class FileSplitterFetch extends Thread { ! %X#;{  
zN3b`K. i  
Uu_Es{@  
String sURL; //File URL @ Cd#\D|  
long nStartPos; //File Snippet Start Position -~] q?k?  
long nEndPos; //File Snippet End Position A~)#  
int nThreadID; //Thread's ID AC&)FY  
boolean bDownOver = false; //Downing is over mxEn iy  
boolean bStop = false; //Stop identical ^g SZzJ5  
FileAccessI fileAccessI = null; //File Access interface  $+  
i9koh3R\  
'B\7P*L"p  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f Hd|tl  
{ %5$)w;p.$'  
this.sURL = sURL; mJNw<T4!/  
this.nStartPos = nStart; E^4}l2m_  
this.nEndPos = nEnd; ;_p$5GVR|  
nThreadID = id; w&[&ZDsK  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;V0^uB.z  
} W"n0x8~sV  
K 7 OIT2-  
?>/9ae^Bw  
public void run() 7SJR_G6,{  
{ .L@gq/x)  
while(nStartPos < nEndPos && !bStop) #1De#uZ  
{ NH'Dz6K5  
zvbO q  
bY UG4+rD  
try{ \k 6'[ln  
URL url = new URL(sURL); H):(8/> (  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %WF]mF T_  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,n3e8qd  
String sProperty = "bytes="+nStartPos+"-"; _J"fgxW  
httpConnection.setRequestProperty("RANGE",sProperty); aY-7K._</  
Utility.log(sProperty); Fs(FI\^  
0fzHEL  
y|/[;  
InputStream input = httpConnection.getInputStream(); =1Hn<Xay0  
//logResponseHead(httpConnection); p?2^JJpUb  
\,S4-~(:!  
/b7]NC%  
byte[] b = new byte[1024]; 92x)Pc^D  
int nRead; ]?%S0DO*  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g{^~g  
{ +Ly@5y"  
nStartPos += fileAccessI.write(b,0,nRead); b4&l=^:e=  
//if(nThreadID == 1) ?DGg.2f  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E?- ~*T  
} HA74s':FN  
0[])wl  
&u2H^ j  
Utility.log("Thread " + nThreadID + " is over!"); x n=#4:f  
bDownOver = true; %uw7sGz\  
//nPos = fileAccessI.write (b,0,nRead); p1UYkmx[  
} UvR.?js(O  
catch(Exception e){e.printStackTrace ();} sBk|KG  
} AO238RC!:  
} <?F-v  
[Ob09#B%:5  
|Iknk,  
//打印回应的头信息 kvG.?^ v  
public void logResponseHead(HttpURLConnection con) {l"(EeW6)  
{ ua E,F^p  
for(int i=1;;i++) GL%)s?   
{ )FN\jo!!.  
String header=con.getHeaderFieldKey(i); z HT#bP:o  
if(header!=null) #/> a`Ur_  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wk#cJ`wG;  
Utility.log(header+" : "+con.getHeaderField(header)); lVCnu> 8  
else $0R5 ]]db)  
break; y$+=>p|d.^  
} KM"BHaSkF  
} jO-T1P']Y  
@ZRg9M:N  
DwGRv:&HH  
public void splitterStop() 1~Z   
{ K@%gvLa\  
bStop = true; 1 -$+@Xl  
} 2wu\.{6Zp  
dVg'v7G&V(  
Ma4eu8  
} R"j<C13;%  
CG;+Z-"X  
g:Q:cSg<  
/* {n&GZG"f  
**FileAccess.java Id1de>:;  
*//文件访问(定位,写) orOq5?3  
package NetFox; EU Z7?4o  
import java.io.*;  ~)F_FS  
osc A\r  
%(|-+cLW+  
public class FileAccessI implements Serializable{ 8DX5bB  
7 0PGbAD  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m>|7&l_  
RandomAccessFile oSavedFile; k[)/,1  
long nPos; AZf69z  
BiDyr  
|ZC'a!  
public FileAccessI() throws IOException T% GR{mp  
{ <Sr:pm  
this("",0); B}nT>Ub  
} &dPUd ~&EL  
Yxy!&hPLv:  
m&yHtnt  
public FileAccessI(String sName,long nPos) throws IOException :|8!w  
{ gF`hlYD  
oSavedFile = new RandomAccessFile(sName,"rw"); Xvk+1:D  
this.nPos = nPos; $&!|G-0'  
oSavedFile.seek(nPos); <*+[E!oi  
} U o aWI2  
-g:i'e  
g}S%D(~  
public synchronized int write(byte[] b,int nStart,int nLen) f:t j   
{ FY-eoq0O3  
int n = -1; yY{  
try{ YeVo=hYH@  
oSavedFile.write(b,nStart,nLen); EEMRy  
n = nLen; E62_k 0q  
} Ls+vWfF=#  
catch(IOException e) ej7L-~lxQ  
{ zKI1  
e.printStackTrace (); n1aOpz6`  
} dd6%3L{cn  
\%B7M]P  
qQIX:HWDKZ  
return n; 8)M WC:  
} !@*= b1  
{6%-/$LX  
)c?nh3D  
} 4;@L#Pzt  
Z +O< IF%  
<EdNF&S-  
/* w+Gav4  
**SiteInfoBean.java 2R ^6L@fw  
*/ _0ZU I^#  
package NetFox; _T7XCXEk   
}346uF7C  
Bz|/TV?X(  
public class SiteInfoBean {  3bJ|L3G  
I-=Ieq"R9  
_k;HhLj`  
private String sSiteURL; //Site's URL 2G<XA  
private String sFilePath; //Saved File's Path u%6b|M@P  
private String sFileName; //Saved File's Name LM 1Vsh<  
private int nSplitter; //Count of Splited Downloading File 7G7"Zule*j  
s}yN_D+V  
TA8  
public SiteInfoBean() O OXP1L  
{//nSplitter的缺省值为5 -%Ce  
//default value of nSplitter is 5 =d iGuI B  
this("","","",5); rg=Ym.  
} 4?+jvVq  
aL&9.L|1 g  
NTO.;S|2%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]>ndFE6kl  
{ dc_2nF  
sSiteURL= sURL; P RNq8nmxC  
sFilePath = sPath; ; xQhq*  
sFileName = sName; n ywC]T  
this.nSplitter = nSpiltter; ep0dT3&  
<r(D\rmD  
:6&#u.\u  
} ]"?<y s  
/1D.Ud^  
i)Q d>(v  
public String getSSiteURL() 5sj$XA?5  
{ =;F7h @:  
return sSiteURL; FD~ U F;VQ  
} ;g;1<? [  
LU8:]zOY  
3lEP:Jp  
public void setSSiteURL(String value) aT+w6{%Z  
{ /d/]#T[Z9  
sSiteURL = value; i2;,\FI@t%  
} Vg :''!4t2  
P}>>$$b\Yi  
Ab:ah 7!  
public String getSFilePath() ,rF!o_7  
{ G:wO1f6  
return sFilePath; 3OY(L`  
} &}|`h8JA]K  
@?;)x&<8?3  
JoZzX{eu"  
public void setSFilePath(String value) :Bu)cy#/[  
{ _meW9)B  
sFilePath = value; sY?wQ:  
} rx@i .+  
!, rF(pz  
D~|q^Ms,%  
public String getSFileName() 5*Qzw[[=  
{ Y7 K2@257  
return sFileName; k7L4~W  
} R~|(]#com  
${}9/(x/^  
2- (}=N  
public void setSFileName(String value)  B@*!>R  
{ :#{0yno)H  
sFileName = value; k,; (`L  
} *J >6i2M,u  
yF_/.mI  
_34%St!lg  
public int getNSplitter() @v!#_%J  
{ {x[C\vZsi]  
return nSplitter; 4x?I,cAN  
} o>T+fBHE  
y\[* mgl:  
,2i1 4H  
public void setNSplitter(int nCount) fY #Yn  
{ ne3t|JZ  
nSplitter = nCount; l Ft&cy2  
} tp }Bz&V  
} wlslG^^(!  
Fg'{K%t4  
,^ dpn  
/* \" m&WFm  
**Utility.java Nez '1  
*/ x{GFCy7  
package NetFox; so| U&`G  
<X5ge>.  
$fT#Wva-\d  
public class Utility { ,t9CP  
-mo4`F  
-7o-d-d F  
public Utility() ac966<#  
{ _\= /~>Xl  
4cJ/XgX  
*,*XOd:3TL  
} |}/KueZ  
Qw|y%Td8r  
//线程睡眠 RzFxO  
public static void sleep(int nSecond) Jw^my4  
{ UlKg2p  
try{ L'"c;FF02i  
Thread.sleep(nSecond); BO6XY90(  
} ,9ew75Jl  
catch(Exception e) E @Rb+8},"  
{ U!RIeC  
e.printStackTrace (); a5d_= :S ;  
} TV0Y{x*~iH  
} PGVp1TQ  
oR7f3';?6  
//日志  Bs>S2]  
public static void log(String sMsg) "T<7j.P?  
{ 5LU7}v~/  
System.err.println(sMsg); sqjDh  
} huR ^l  
N+H[Y4c?F&  
*A")A.R  
public static void log(int sMsg) w vI v+Q9  
{ ed3wj3@  
System.err.println(sMsg); %\)AT"  
} }g|9P SbJ  
} / T_v8 {D  
0 N0< 4b  
O#>,vf$  
/* :!fY;c?  
**TestMethod.java 1]A\@(  
*/ "d M-3o<  
package NetFox; |<y1<O>F  
[(.lfa P  
f'`y-]"V5)  
public class TestMethod { Mpk7$=hjc  
a"Ly9ovW  
O0bOv S  
public TestMethod() 1:./f|m  
{ ///xx/weblogic60b2_win.exe I?%#`Rvu  
try{ iU=:YPE+ .  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B)0;gWK  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,W/Y@ScC  
SiteFileFetch fileFetch = new SiteFileFetch(bean); z U *Mk  
fileFetch.start(); AXnKhYlu  
} (OavgJ+Y  
catch(Exception e){e.printStackTrace ();} D$w?  
-$@'@U  
hQNUA|Q=%  
} h7m$P^=U  
&Wk:>9]Jrb  
@ Yo*h"s  
public static void main(String[] args) 9\kEyb$F=  
{ 04}c_XFFE  
new TestMethod(); Y;dqrA>@  
} ]~ S zb  
} nf:wJ-;*  
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