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http断点续传简单实现(java)

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/* cxSHSv 1;  
**SiteFileFetch.java u%z'.#r;a  
*/ #2ta8m),  
package NetFox; MooH`2Fd  
import java.io.*; 6A]I" E]5  
import java.net.*; 6P717[  
DMG'8\5C  
.Vnb+o  
public class SiteFileFetch extends Thread { 4 xbWDu]  
=dA] nM  
-i{_$G8W/c  
SiteInfoBean siteInfoBean = null; //文件信息Bean #U L75  
long[] nStartPos; //开始位置 >wmHCOL:  
long[] nEndPos; //结束位置 C 4C /  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ^U5N!"6R  
long nFileLength; //文件长度 }aE'  
boolean bFirst = true; //是否第一次取文件 xO>z )3A  
boolean bStop = false; //停止标志 %|}*xMQ  
File tmpFile; //文件下载的临时信息 '#3FEo  
DataOutputStream output; //输出到文件的输出流 Y=G`~2Pr=  
x cAs}y}  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) dLb$3!3  
public SiteFileFetch(SiteInfoBean bean) throws IOException }#ta3 x  
{ IS(F_< .  
siteInfoBean = bean; QR"+fzOL  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 9G SpDc  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 4sQm"XgE  
if(tmpFile.exists ()) sU&v B:]~  
{ ?<3 d Fb  
bFirst = false; 9AhA"+?  
read_nPos(); m=@xZw<  
} k6ry"W3  
else o^X3YaS)  
{  mih}?oi  
nStartPos = new long[bean.getNSplitter()]; ,:L^vG@*  
nEndPos = new long[bean.getNSplitter()]; v5a\}S<(  
} Ly8=SIZ   
bHRn}K+<}c  
!`?i>k?Q E  
( `bb1gz  
} $%DoLpE>  
N~=PecQ  
0*5Jq#5  
public void run() "o`?-bQ:  
{ 2yn"K|  
//获得文件长度 E-C]<{`O  
//分割文件 %M1l[\N  
//实例FileSplitterFetch P7=`P  
//启动FileSplitterFetch线程 (["kbPma  
//等待子线程返回 NO[A00m|OL  
try{ +&VY6(Zj+*  
if(bFirst) m0ra  
{ }YdC[b$j^  
nFileLength = getFileSize(); &2XH.$Q  
if(nFileLength == -1) i4i9EvWp  
{ U&])ow):  
System.err.println("File Length is not known!"); !;&\n3-W  
} PVlC j  
else if(nFileLength == -2) 5?`4qSUz  
{ V{oFig 6  
System.err.println("File is not access!"); +`Q]p" G  
} )r{Wj*u  
else >Z_;ZMu)  
{ tkk8b6%h?p  
for(int i=0;i<nStartPos.length;i++) o"X..m<  
{ pp(09y`]  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =Mwuhk|*  
} q:)PfP+  
for(int i=0;i<nEndPos.length-1;i++) KZ[TW,Gw  
{ |s/N ?/qi  
nEndPos = nStartPos[i+1]; Nkj$6(N=zJ  
} U"8Hw@  
nEndPos[nEndPos.length-1] = nFileLength; #2%V  
} W|fE]RY  
} h.#:7d(g  
8Snv, Lb`^  
A+Isk{d  
//启动子线程 td%J.&K_*'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pd&KAu|<`  
for(int i=0;i<nStartPos.length;i++) )-5eIy  
{ )-[$m%  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WZ6{9/%:  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5`fUR/|[  
nStartPos,nEndPos,i); zo@vuB.  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vv,<#4d  
fileSplitterFetch.start(); QAxy?m,'  
} %XukiA+  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }(u:K}8  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PRiE2Di2S  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kZ@UQ{>`  
nEndPos = " + nFileLength); wg0_J<y]  
// fileSplitterFetch[nPos.length-1].start(); PUO7Z2  
S>T ;`,  
+|dL R*s  
//等待子线程结束 };rp25i  
//int count = 0; _ s}aF  
//是否结束while循环 In?+  
boolean breakWhile = false; w=_^n]`R  
5TpvJ1G  
,^e2ma|z  
while(!bStop) b(|&e  
{ :F"IOPfU5[  
write_nPos(); Conik`  
Utility.sleep(500); =\2gnk~  
breakWhile = true; am? k  
 tM\BO0  
=PA?6Bm  
for(int i=0;i<nStartPos.length;i++) t|oIzjKE/  
{ !l#aq\:}~e  
if(!fileSplitterFetch.bDownOver) i?pd|J  
{ Dom]w.W5  
breakWhile = false; ,\ 1X\  
break; KNN{2thy `  
} I$sXbM;z=  
} hfIP   
if(breakWhile) } x r0m+/  
break; V Zbn@1  
_XP}f x7$C  
mYo~RXKGF  
//count++; L9e<hRZ$  
//if(count>4) 3HuocwWbz  
// siteStop(); *ezMS   
} ^#e|^]] L  
[[T6X9  
Ump Hae  
System.err.println("文件下载结束!"); \41/84BA  
} .9ZK@xM&?  
catch(Exception e){e.printStackTrace ();} 'vt Jl  
} c0e[vrP:  
 V0A>+  
 d<xi/  
//获得文件长度 ;k@]"&t  
public long getFileSize() ^bPpcm=  
{ *A48shfO  
int nFileLength = -1; o<lmU8xB=  
try{ +UOVD:G  
URL url = new URL(siteInfoBean.getSSiteURL()); 4Dzg r,V  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P4yUm(@  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ms5qQ<0v_  
]pB5cq7o  
i75\<X  
int responseCode=httpConnection.getResponseCode(); m.ka%h$  
if(responseCode>=400) y,rdyt  
{ |9 5K  
processErrorCode(responseCode); F|+B8&-v  
return -2; //-2 represent access is error a(yWIgD\\  
} o8:9Y js  
r<(UN@T}  
l v:GiA"X  
String sHeader; 8q]"CFpa  
!.#g   
]vR Ol.  
for(int i=1;;i++) ex~"M&^  
{ }U>K>"AZl  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }@ U}c6/  
//Utility.log(in.readLine()); ;s$4/b/~  
sHeader=httpConnection.getHeaderFieldKey(i); URj)]wp/  
if(sHeader!=null) O251. hXK  
{ 8MDivr/@  
if(sHeader.equals("Content-Length")) on8$Kc  
{ /oEDA^qx  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F ]D^e{y  
break; 73!NoDxb  
} CTg79 ITYk  
} l{3zlXk3z  
else n?6^j8i  
break; _?felxG[  
} %LHt{:9.  
} )R<93`q  
catch(IOException e){e.printStackTrace ();} ,@ p4HN*  
catch(Exception e){e.printStackTrace ();} 7~1Fy{tc  
CaED(0  
R86i2',  
Utility.log(nFileLength); nt&% sM-X  
`%Kj+^|DS  
5G2ueRVb  
return nFileLength; qh}+b^Wi  
}  = v?V  
YwH Fn+  
$!p2Kf>/Q  
//保存下载信息(文件指针位置) @Jd eOL;  
private void write_nPos() 3:$@DZT$  
{ %kkDitmI{  
try{ r&v!2A]:  
output = new DataOutputStream(new FileOutputStream(tmpFile)); P^Og(F8;  
output.writeInt(nStartPos.length); B/Q>i'e  
for(int i=0;i<nStartPos.length;i++) e$ QMR.'  
{ =7kn1G.(  
// output.writeLong(nPos); ~3Qa-s;g  
output.writeLong(fileSplitterFetch.nStartPos); G]xN#O;  
output.writeLong(fileSplitterFetch.nEndPos); qD"~5vtLqQ  
} )Mflt0fp  
output.close(); NODg_J~T  
} 4\V/A+<W  
catch(IOException e){e.printStackTrace ();} Oi C|~8  
catch(Exception e){e.printStackTrace ();} N1y,~Z  
} I WT|dA >  
Oel%l Y}m3  
P^q!Pye  
//读取保存的下载信息(文件指针位置) 2Nm{.Y  
private void read_nPos() P9`CW  
{ c?c"|.-<p  
try{ x)%"i)  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *<{hLf  
int nCount = input.readInt(); &Nr+- $  
nStartPos = new long[nCount]; 1p/_U?H:|  
nEndPos = new long[nCount]; d"3x11|  
for(int i=0;i<nStartPos.length;i++) $*XTX?,'  
{ S:g6z'e1  
nStartPos = input.readLong(); L1k  
nEndPos = input.readLong(); l%i*.b(  
} -c0*  
input.close(); xjxX4_  
} Om7 '_}  
catch(IOException e){e.printStackTrace ();} E\Iz:ES^  
catch(Exception e){e.printStackTrace ();} 1"<{_&d1  
} meap;p  
pK>/c>de  
~S :8M<aB  
private void processErrorCode(int nErrorCode) g[ @Q iy  
{ D 7thLqA  
System.err.println("Error Code : " + nErrorCode); ei]Q<vT6  
} VJr~h "[  
wB[ JFy"E  
mH<|.7~0  
//停止文件下载 Yu[MNX ;G  
public void siteStop() *ZRk)  
{ 6khm@}}  
bStop = true; W8]?dL}|  
for(int i=0;i<nStartPos.length;i++) Qe9}%k6@E  
fileSplitterFetch.splitterStop(); 7<8'7<X  
j\B taC  
`X&d:!}F  
} -@'RYY=  
} %vG;'_gM B  
//负责部分文件的抓取 YD~(l-?"  
**FileSplitterFetch.java &d!ASa  
*/ >N~jlr|  
package NetFox; pZc`!f"  
PCBV6Y7r  
m60hTJ?N)  
import java.io.*; ^6CPC@B1  
import java.net.*; axXR-5c  
`B3YP1  
#H8QX5b)  
public class FileSplitterFetch extends Thread { YAi@EvzCVy  
9(a*0H  
Q"LlBp>t|#  
String sURL; //File URL _$}@hD*R~  
long nStartPos; //File Snippet Start Position 0@&;JMh6<  
long nEndPos; //File Snippet End Position ^d9o \  
int nThreadID; //Thread's ID ^@'zQa  
boolean bDownOver = false; //Downing is over 8-O: e  
boolean bStop = false; //Stop identical *TxR2pC}  
FileAccessI fileAccessI = null; //File Access interface 0J5$ Yw1'F  
8l?@ o  
PIsXX#`7;  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4!M0)Nix  
{ WUx2CK2N  
this.sURL = sURL; yaI jXv  
this.nStartPos = nStart; --`W1!jI@  
this.nEndPos = nEnd; Sn;q:e3i{A  
nThreadID = id; nu16L$ ]  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P^BSl7cT  
} 3[kl` *`  
ZGd7e.u=  
#g Rns  
public void run() rO,n~|YJ  
{ 7B)@ aUj$  
while(nStartPos < nEndPos && !bStop) d5W =?  
{ $M4C4_oPy  
fL&e^Q  
<z wI@i  
try{ 'HWPuWW  
URL url = new URL(sURL); Ojp|/yd^YL  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iA"H*0  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ei@al>.\  
String sProperty = "bytes="+nStartPos+"-"; ef:Zi_o   
httpConnection.setRequestProperty("RANGE",sProperty); !-B|x0fs  
Utility.log(sProperty); }OgZZ8-_M  
ab_EH}j1\q  
vb\R~%@T,  
InputStream input = httpConnection.getInputStream(); f(-3d*g  
//logResponseHead(httpConnection); d\ Xijy  
dpcv'cRfw  
r?Pk}Q  
byte[] b = new byte[1024]; $! UEpQ  
int nRead; p1\E C#Q  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <2w 41QZX  
{ UzkX;UA  
nStartPos += fileAccessI.write(b,0,nRead); l_ &T)Ei  
//if(nThreadID == 1) ?d)eri8,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YQ}IE[J}v  
} c/G^}d%  
0t00X/  
?,!C0ts  
Utility.log("Thread " + nThreadID + " is over!"); qd [Z\B  
bDownOver = true; UO>S2u  
//nPos = fileAccessI.write (b,0,nRead); `?(9Bl  
} O~F8lQ  
catch(Exception e){e.printStackTrace ();} %e=UYBj"  
} l]P3oB}Yo  
} *3y:Wv T>  
f87lm*wZ  
s|Zv>Qt  
//打印回应的头信息 $Mqw)X&q  
public void logResponseHead(HttpURLConnection con) ARid   
{ kc"SUiy/  
for(int i=1;;i++) [PU0!W;  
{ !~f!O"n)3r  
String header=con.getHeaderFieldKey(i); #_fL[j&  
if(header!=null) ,09d"7`X  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gG46hO-M%x  
Utility.log(header+" : "+con.getHeaderField(header)); y/Q,[Uzk\  
else +q~dS.  
break; &qeM YYY  
} ;c>IM]  
} 4p/d>DTiM  
4ko(bW#jL  
Bf6\KI<V2  
public void splitterStop() 'uF"O"*  
{ Q-f?7*>  
bStop = true; Gn?<~8a  
} z_ia3k<  
>z69r0)>  
cpBTi  
} !W45X}/o  
oyo V1jO  
Z|$OPMLX  
/* }JBLzk5|  
**FileAccess.java {o.i\"x;  
*//文件访问(定位,写) +# tmsv]2  
package NetFox; VH$hQPP5d  
import java.io.*; M!b"c4|<  
p3{ 3[fDx  
Ba]^0Y u  
public class FileAccessI implements Serializable{ vBjrI*0  
wO ?A/s  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,qO2D_  
RandomAccessFile oSavedFile; RE75TqYW  
long nPos; [>U =P`  
NYp46;  
3n=ftkI  
public FileAccessI() throws IOException %u02KmV.  
{ 5Qgh\4  
this("",0); =LMM]'no,  
} T0P_&E@X  
f^kH[C  
=GSe$f?  
public FileAccessI(String sName,long nPos) throws IOException 5IiZnG u  
{ d,caOE8N  
oSavedFile = new RandomAccessFile(sName,"rw"); JQ]A"xTIa*  
this.nPos = nPos; WkR=(dss8  
oSavedFile.seek(nPos); )Fh5*UC  
} \L{V|}"X  
 q<Zza  
k'JfXrW<!  
public synchronized int write(byte[] b,int nStart,int nLen) O;?Nz:/q  
{ uu+)r  
int n = -1; * k ^?L  
try{ :f5"w+  
oSavedFile.write(b,nStart,nLen); M[7$cfp-Y~  
n = nLen; ,fW%Qv  
} L4-v'Z;  
catch(IOException e) t bEJyA  
{ H|*Ual  
e.printStackTrace (); rc+}KO  
} &F#K=R| .j  
x C+TO  
i-*ZW:  
return n; %?z8*G]M  
} Ea\Khf]2  
p;<brwN  
@Lf-=9  
} g<$q#l~4xH  
TQg~I/  
%#$K P  
/* }MXC0Z~si  
**SiteInfoBean.java MGE8S$Z  
*/ QNe siV0MI  
package NetFox; .-HwT3  
- HiRXB  
8Xjp5  
public class SiteInfoBean { 2\J-7o=P  
ErXzKf  
u</LgOP`-  
private String sSiteURL; //Site's URL <P1yA>=3`  
private String sFilePath; //Saved File's Path :M _N  
private String sFileName; //Saved File's Name G"|`&r@  
private int nSplitter; //Count of Splited Downloading File %$ CV?K$C  
cHjnuL0fsy  
q aZQ1<e  
public SiteInfoBean() p]erk  
{//nSplitter的缺省值为5 ] g]^^  
//default value of nSplitter is 5 Vx*O^cM  
this("","","",5); ].r~?9'/  
} {IA3`y~  
::R5F4  
 \qj(`0HG  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !)$e+o^W  
{ @\s*f7  
sSiteURL= sURL; S5>?j n1  
sFilePath = sPath; ATscP hk  
sFileName = sName; c1aIZ  
this.nSplitter = nSpiltter; [h[@? 8vB  
e> -fI_+b  
h"$)[k~  
} ptMDhMVW  
e-Ma8+X\  
iininITOS{  
public String getSSiteURL() Hx#1TqC /  
{ K|sk]2.  
return sSiteURL; h1REL^!c  
} OH/!Ky\@  
6Mh"{N7  
#Q'j^y 7=z  
public void setSSiteURL(String value) q)PLc{NO  
{ ;nbV-<e  
sSiteURL = value; wlsq[x P  
} My<.^~  
2D)B%nM[  
'B yB1NL  
public String getSFilePath() It:,8  
{ 5u=>~yK+  
return sFilePath; X([p0W 9V(  
} :` >bh  
{j[a'Gb  
JBk >|q"  
public void setSFilePath(String value) 7 tQ?av  
{ 8@A}.:  
sFilePath = value; wU(!fw\  
} b>]k=zd  
^ DCBL&I  
]@{l<ExP  
public String getSFileName() 9oQ$w?=#$  
{ PT39VI =  
return sFileName; )0?u_Z]w9  
} -]<<}@NF  
Q4ZKgcC  
@id!F<+%oD  
public void setSFileName(String value) AjD? _DPc  
{ ,s`4k?y  
sFileName = value; 4@r76v}{  
} G3dA`3  
4t,f$zk  
_qa9wK/  
public int getNSplitter() A9Icn>3?`(  
{ F[KM0t!  
return nSplitter; *aW:Z6N  
} V@o#" gZ  
{5 Sy=Y  
D6,Ol4d  
public void setNSplitter(int nCount) kX%vTl7F  
{ g&I|@$\  
nSplitter = nCount; ; ,n}>iTE  
} _E2W%N  
} {PKf]m  
r T_J6F5J  
rT(b t~Z  
/* yb6gYN  
**Utility.java X wIKpr8  
*/ <f#pS[A  
package NetFox; P,@/ap7J  
~JHEr48  
)F+wk"`+6  
public class Utility { p|g7Z  
G@P+M1c  
0+T:};]  
public Utility() mJZB@m u?  
{ -QK- w>  
xX.kKEo"d  
]Z?jo#F  
} .z[#j]k  
y({lE3P  
//线程睡眠 pi5DDK  
public static void sleep(int nSecond) SZvp %hS0  
{ ipyc(u6Z5  
try{ L)c]i'WZ  
Thread.sleep(nSecond); a66Ns7Rb  
} (_]D\g~  
catch(Exception e) W`uq,r0Xsy  
{ ;FJFr*PM  
e.printStackTrace (); [>KnMi=o)  
} p z\8Bp}yo  
} HCT+.n6  
KAgxIz!^-1  
//日志 |$g} &P8;  
public static void log(String sMsg) *!pn6OJ"Q}  
{ fp}5QUm-  
System.err.println(sMsg); N}nE?|N=5  
} o)n= n!A  
0#CmB4!<O  
WO6R04+WV  
public static void log(int sMsg) qM<CBcON  
{ m 48Ab`  
System.err.println(sMsg); {YG qa$+\  
} p'A43  
} \5}*;O@  
_2hZGC%&E  
@z^7*#vQv  
/* ~G1B}c]  
**TestMethod.java ~OWpk)Vq  
*/ (8~D ^N6Z  
package NetFox; a"l\_D'.K8  
yKy )%i  
k"|Fu   
public class TestMethod { .03Rp5+v  
tUt_Q;%yC  
p3>Md?e  
public TestMethod() D#A6s32a  
{ ///xx/weblogic60b2_win.exe TKQ^D  
try{ Xzl$Qc  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xck`"RU<xA  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9h/Hy aN  
SiteFileFetch fileFetch = new SiteFileFetch(bean); .>Qa3,v5  
fileFetch.start(); 3m$ck$  
} r'4Dj&9Ac  
catch(Exception e){e.printStackTrace ();} Ww"]3  
qeb}~FL"o  
H>o \C  
} [=",R&uD$  
p[ &b@U#  
=WHI/|&  
public static void main(String[] args) f[ KI T  
{ q0DRT4K  
new TestMethod(); [RY Rt/?Q  
} J=&}$  
} P| hwLM  
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