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http断点续传简单实现(java)

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/* #Rx|oSc}  
**SiteFileFetch.java Gr}lr gPS  
*/ 0oiz V;B5%  
package NetFox; 1p }:K`#{  
import java.io.*; M# a1ev  
import java.net.*; 1xsIM'&  
y3{ F\K  
##_Jz5P  
public class SiteFileFetch extends Thread { 6L4<c+v_  
B?pNF+?'z  
|| 0n%"h>i  
SiteInfoBean siteInfoBean = null; //文件信息Bean <yw(7  
long[] nStartPos; //开始位置 g*%z{w  
long[] nEndPos; //结束位置 Kg>ehn4S@  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 6Qh@lro;y  
long nFileLength; //文件长度 SoPiEq  
boolean bFirst = true; //是否第一次取文件 N:nhS3N<L  
boolean bStop = false; //停止标志 m.EIMuj  
File tmpFile; //文件下载的临时信息 M>LgEc-v67  
DataOutputStream output; //输出到文件的输出流 4k4 d%  
G,fh/E+  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) \[yg f6#[  
public SiteFileFetch(SiteInfoBean bean) throws IOException DLBHZ?+!  
{ C0v1x=(xiM  
siteInfoBean = bean; }?KfL$@$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ]sL)[o  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); K#_x.: <J  
if(tmpFile.exists ()) ecIZ +G)k  
{ & Y Y^Bd#  
bFirst = false; 6L}}3b h  
read_nPos(); _jCk)3KO  
} 'PK;Fg\  
else |'ML )`c[  
{ 7ea<2va,  
nStartPos = new long[bean.getNSplitter()]; \:vHB!2E  
nEndPos = new long[bean.getNSplitter()]; @eOD+h'  
} HJ^SqSm  
yNU.<d 5  
|18h p  
jPc"qER!  
} IVdM}"+  
9hn+eU  
, tb\^  
public void run() DITo.PU  
{ Ae[Na:G+  
//获得文件长度 {2,vxGi  
//分割文件 Z\. n6  
//实例FileSplitterFetch _'Rzu'$`  
//启动FileSplitterFetch线程 %8hjMds  
//等待子线程返回 &Ay[mZQ 7  
try{ 97 eEqI$#  
if(bFirst) 7xU6Ll+p  
{ *3Qwmom  
nFileLength = getFileSize(); oQ:.pq{T  
if(nFileLength == -1) su\iUi  
{ ;%W]b  
System.err.println("File Length is not known!"); YkuFt>U9,  
} 7G]v(ay  
else if(nFileLength == -2) vnr{Ekg  
{ 9Q /t+  
System.err.println("File is not access!"); x,81#=m^h  
} kVeR{i<*(  
else jRGslak;  
{ 734f &2  
for(int i=0;i<nStartPos.length;i++) 0s'h2={iI  
{ bpgvLZb>s  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); z}z 6Vg  
} T0TgV  
for(int i=0;i<nEndPos.length-1;i++) ($or@lfs  
{ Vl\8*!OL%  
nEndPos = nStartPos[i+1]; ,*MA teD  
} (<KFA,  
nEndPos[nEndPos.length-1] = nFileLength; 3Z%~WE;I  
} W{W8\  
} 1LZ[i89&%  
~;S  
DV{0|E  
//启动子线程 }huFv*<@'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {'@`: p&3r  
for(int i=0;i<nStartPos.length;i++) a2%xW_e  
{ M)6iYA%$  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B9(@ .  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D`NPU  
nStartPos,nEndPos,i); A2 9R5  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dtx3;d<NsJ  
fileSplitterFetch.start(); L'L[Vpx  
} euiP<[|h=  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -~] q?k?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A~)#  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AC&)FY  
nEndPos = " + nFileLength); mxEn iy  
// fileSplitterFetch[nPos.length-1].start(); M~ eXC  
aM7=>  
)eD9H*mq  
//等待子线程结束 (J 1:J  
//int count = 0; GTuxMg`  
//是否结束while循环 nr]:Y3KyxX  
boolean breakWhile = false; sOqT*gwr:  
hZ`<ID  
{|{;:_.>  
while(!bStop) 'zhv#&O  
{ l9t|@9  
write_nPos(); Rl{e<>O\^  
Utility.sleep(500); nghpWODq  
breakWhile = true; xQ,My  
5RsO^2V:  
N@#,YnPI  
for(int i=0;i<nStartPos.length;i++) Lm3~< vP1e  
{ oH='\M%+  
if(!fileSplitterFetch.bDownOver) :Xi&H.k)p  
{ g^: & Dh  
breakWhile = false; u*=8s5Q[  
break; 572{DC&T  
} [nASMKK0  
} m gE r+  
if(breakWhile) ).3riR  
break; J!\oH%FJp  
pf$gvL  
4G2iT+X-  
//count++; "IN[(  
//if(count>4) Qg]+&8!*  
// siteStop(); +3F%soum95  
} =1Hn<Xay0  
p?2^JJpUb  
R8-=N+hX  
System.err.println("文件下载结束!"); ?[<#>,W  
} yu>)[|-  
catch(Exception e){e.printStackTrace ();} oJ?,X^~_  
} < Dt/JA(p  
BUS4 T#D  
VVJIJ9L&C  
//获得文件长度 9? y&/D5O  
public long getFileSize() H <9_BA?  
{ H~ E<ek'~  
int nFileLength = -1; *7o@HBbF  
try{ w ZfY~  
URL url = new URL(siteInfoBean.getSSiteURL()); q ;"/i*+3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7epil  
httpConnection.setRequestProperty("User-Agent","NetFox"); MfZamu5+F  
bae;2| w  
Y'<wE2ZL)  
int responseCode=httpConnection.getResponseCode(); 3Fw7q"  
if(responseCode>=400) :cvT/xhO  
{ G=/^]E  
processErrorCode(responseCode); #y-R*4G  
return -2; //-2 represent access is error Du #>y!  
} Cto>~pV  
c] -  
7M)<Sv  
String sHeader; E#R1  
o3$dl`'  
I0*N "07n  
for(int i=1;;i++) X-*LA*xbN  
{ fjCFJ_  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d$^ @$E2f  
//Utility.log(in.readLine()); y* :C~  
sHeader=httpConnection.getHeaderFieldKey(i); U@9v(TfV  
if(sHeader!=null) &F:%y(;{Y  
{ WjguM  
if(sHeader.equals("Content-Length")) :T{VCw:*  
{ gBr /Y}I  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S!rVq,| d  
break; ,BFw-A  
} xX|f{)<  
} =QK ucLo  
else 2H1 [ oD[  
break; _(-i46x}  
} R"j<C13;%  
} CG;+Z-"X  
catch(IOException e){e.printStackTrace ();} g:Q:cSg<  
catch(Exception e){e.printStackTrace ();} {n&GZG"f  
0V?7'Em  
U1`pY:P  
Utility.log(nFileLength); MOPHu O{^  
 ~)F_FS  
osc A\r  
return nFileLength; fZoQQ[s  
} :k-@w5(  
g/(BV7V  
*eGG6$I  
//保存下载信息(文件指针位置) -<L5;  
private void write_nPos() G5%k.IRz  
{ _0BQnzC=  
try{ jn`5{ ]D  
output = new DataOutputStream(new FileOutputStream(tmpFile)); #"8'y  
output.writeInt(nStartPos.length); \H&;.??W  
for(int i=0;i<nStartPos.length;i++) fR?'HsQg  
{ %}JSR y  
// output.writeLong(nPos); O0;mXH  
output.writeLong(fileSplitterFetch.nStartPos); +@c$n`>)  
output.writeLong(fileSplitterFetch.nEndPos); u{7->[=  
} -oTdi0P  
output.close(); p2U6B  
} "[-W(=  
catch(IOException e){e.printStackTrace ();} n0G@BE1Y=  
catch(Exception e){e.printStackTrace ();} 4V;-*:  
} U{qwhz(  
k{O bm g  
4]FS jVO  
//读取保存的下载信息(文件指针位置) !Na@T]J  
private void read_nPos() 6v74mIRn'?  
{ 2I|lY>Z  
try{ v}id/brl  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8H1&=)M=  
int nCount = input.readInt(); QeN7~ J  
nStartPos = new long[nCount]; rp^:{6O  
nEndPos = new long[nCount]; re,}}'  
for(int i=0;i<nStartPos.length;i++) q6b&b^r+H  
{ T9'HQu  
nStartPos = input.readLong(); #3tC"2MZ  
nEndPos = input.readLong(); bN6i*) }  
} )?I*zc  
input.close(); P,b&F  
} .4l cES~  
catch(IOException e){e.printStackTrace ();} ;VEKrVD  
catch(Exception e){e.printStackTrace ();} < 2fy(9y  
} =**Q\ Sl  
%%#bTyF  
<Ql2+ev6  
private void processErrorCode(int nErrorCode) 24 .'+3  
{ GvvKM=1  
System.err.println("Error Code : " + nErrorCode); 9-vQn/O^D  
} 9Fw NX  
[:}"MdU'  
UkXa mGoy3  
//停止文件下载 e+<|  
public void siteStop() ktRGl>J  
{ *yY\d.6(  
bStop = true; 2G<XA  
for(int i=0;i<nStartPos.length;i++) Sn^M[}we  
fileSplitterFetch.splitterStop(); t BG 9Mn  
;JMmr-@  
cnRgzj<ek  
} bvHQ# :}H  
} bR1Q77<G\  
//负责部分文件的抓取 7F_N{avr  
**FileSplitterFetch.java kZ]pV=\Y*  
*/ ;@:-T/=  
package NetFox; jP0TyhM  
eKLE^`2*@  
l_8ibLyo  
import java.io.*; F@#p  
import java.net.*; #3{{[i(;i  
4#.Q|vyl]"  
mg>wv[ 7  
public class FileSplitterFetch extends Thread { P!IXcPKW53  
)]LP8 J&  
/{P-WRz>  
String sURL; //File URL keG\-f  
long nStartPos; //File Snippet Start Position Dd,i^,4Gj  
long nEndPos; //File Snippet End Position -1~o~yGE  
int nThreadID; //Thread's ID AX'-}5T=  
boolean bDownOver = false; //Downing is over L "'d(MD  
boolean bStop = false; //Stop identical X<pNc6  
FileAccessI fileAccessI = null; //File Access interface 5sj$XA?5  
=;F7h @:  
FD~ U F;VQ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;g;1<? [  
{ LU8:]zOY  
this.sURL = sURL; ^QG<_Dm]  
this.nStartPos = nStart; aR'~=t&;z1  
this.nEndPos = nEnd; ori[[~OyB  
nThreadID = id; FQE(qltf,  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cct/mX2&~  
} .6I'V3:Kg  
:h/v"2uDN  
eAqpP>9n  
public void run() hy@b/Y![M  
{ M;NIcM  
while(nStartPos < nEndPos && !bStop) s?&S<k-=fr  
{ NB86+2stu  
Y"^.6  
ZR"qrCSw`  
try{ fC[~X[H  
URL url = new URL(sURL); )O$S3ojZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tA,J~|+f:  
httpConnection.setRequestProperty("User-Agent","NetFox"); HD1/1?y!@q  
String sProperty = "bytes="+nStartPos+"-"; WTjmU=<\  
httpConnection.setRequestProperty("RANGE",sProperty); vS[\ j  
Utility.log(sProperty); 8rFP*K9  
}n#$p{e$i  
=Zsxl]h   
InputStream input = httpConnection.getInputStream(); e**'[3Y  
//logResponseHead(httpConnection); *65~qAd  
( z F_<  
\hb$v  
byte[] b = new byte[1024]; Ts|;5ya5m  
int nRead; [-81s!#mkw  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^#K^WV  
{ skTtGz8R[  
nStartPos += fileAccessI.write(b,0,nRead); .7:ecFKk  
//if(nThreadID == 1) R9D2cu,{  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6+"gk(  
} &p*rEs  
X?JtEQ~>  
p,uM)LD  
Utility.log("Thread " + nThreadID + " is over!"); Q`4I a<5B  
bDownOver = true; }W[=O:p  
//nPos = fileAccessI.write (b,0,nRead); h|i b*%P_  
} rOj(THoc{  
catch(Exception e){e.printStackTrace ();} AAKc8 {  
} ,^ dpn  
} \" m&WFm  
Nez '1  
x{GFCy7  
//打印回应的头信息 so| U&`G  
public void logResponseHead(HttpURLConnection con) <X5ge>.  
{ $fT#Wva-\d  
for(int i=1;;i++) %da-/[  
{ zwP*7u$CH  
String header=con.getHeaderFieldKey(i); \%%M>4c  
if(header!=null) ;XlCd[J<  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ex@}x#3  
Utility.log(header+" : "+con.getHeaderField(header)); qK~]au:C  
else |z&7KoYK'  
break; ER@RWV 2  
} *P5/S8c  
} {a9.0N:4  
~ahu{A4Bw  
CyB4apJ  
public void splitterStop() <1:I[b  
{ {i3=N{5b  
bStop = true; x&m(h1h  
} $(08!U  
mv`b3 $  
nPl,qcyY  
} ?P#\ CW  
%|f@WxNrU  
~x@V"rxGw  
/* F[F  NtZ  
**FileAccess.java olXfR-2>1  
*//文件访问(定位,写) |  >yc|W  
package NetFox; 9}42s+  
import java.io.*; J~ +p7S  
f.E{s*z>  
qzLD  
public class FileAccessI implements Serializable{ xgM\6e  
#SjCKQ~  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 De>,i%`Q,D  
RandomAccessFile oSavedFile; -lq`EB +  
long nPos; 0m\( @2E  
HzuG- V  
m`Z.xIA7;  
public FileAccessI() throws IOException g:p` .KuB  
{ +JXn   
this("",0); A_2lG!! 6  
} v;}MHl  
CP$,fj  
~3-+~y=o~  
public FileAccessI(String sName,long nPos) throws IOException ?[WUix;  
{ -yu$Mm  
oSavedFile = new RandomAccessFile(sName,"rw"); {!wd5C@  
this.nPos = nPos; U7,.L  
oSavedFile.seek(nPos); `bn@;7`X  
} -*-"kzgd  
Ys?0hd<cn  
A8AeM `  
public synchronized int write(byte[] b,int nStart,int nLen) 1-.i^Hal  
{ R mo'3  
int n = -1; 4<5*HpW  
try{ %rEP.T\i  
oSavedFile.write(b,nStart,nLen); 9VIAOky-  
n = nLen; 2Qc_TgWF  
} 3RcnoXX_  
catch(IOException e) Wg8*;dvtM  
{ %N\8!aXnf  
e.printStackTrace (); ) :Px`] 5  
} f'qM?GlET  
lR`.V0xA   
 /7Q9(}  
return n; _6YfPk+  
} 1Vz3N/AP%?  
{?A/1q4rr  
8)83j6VF  
} ^?A>)?Sq  
E5*pD*#  
0 U#m7j  
/* <Skf n`).  
**SiteInfoBean.java xf|C{XV@H  
*/ -KG1"g,2  
package NetFox; gh `_{l  
ofgNL .u  
Y 7?q `  
public class SiteInfoBean { o0dD  
(&_^1  
YhN:t?  
private String sSiteURL; //Site's URL 58`Dcx,yJ  
private String sFilePath; //Saved File's Path %/_E8GE  
private String sFileName; //Saved File's Name +vV?[e  
private int nSplitter; //Count of Splited Downloading File 0[8uuqV[cB  
fN9uSnu  
TIF  =fQ  
public SiteInfoBean() Wi~?2-!  
{//nSplitter的缺省值为5 }b{7+ + Ah  
//default value of nSplitter is 5 +]~}kvk:  
this("","","",5); hxw6^EA  
} gnf4H V~  
U0N6\+  
;:Tb_4Hr  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8\PI1U  
{ b/E3Kse?  
sSiteURL= sURL; *h pS/g/3\  
sFilePath = sPath; muhu` k`C  
sFileName = sName; -f?,%6(1  
this.nSplitter = nSpiltter; 1].m4vC  
3S%/>)k  
TpHzf3.I  
} U_UN& /f  
Ksk[sf?J&  
F9r|EU#;  
public String getSSiteURL() 'S9jMyZrZ  
{ !?K#f?x<?  
return sSiteURL; !|mzu1S  
} }"/>,  
0^F!-b^z  
e Dpt1  
public void setSSiteURL(String value) SI=7$8T5=5  
{ WP^wNi ~>  
sSiteURL = value; v[jg|s&6"  
} 3wPUP+)c7  
>3I|5kZ6  
wzY{ii  
public String getSFilePath() 1>umf~%Wa  
{ [LV>z  
return sFilePath; vSCJ xSt#e  
} 8LY^>.  
)d{fDwrx1  
[<jU$93E  
public void setSFilePath(String value) Yq{R*HO  
{ V~$?]Z%_  
sFilePath = value; UI~hB4V$]  
} 0])[\O`j  
8}Q 2!,9Q  
Q0g^%  
public String getSFileName() S2#@j#\  
{ aeEio;G1  
return sFileName; '<6DLtZl  
} [88PCA:  
EbJc%%c  
XXXQAY-,C  
public void setSFileName(String value) YmHu8H_Q  
{ o,/wE  
sFileName = value; z0&Y_Up+5  
} ,y}~rYsP%  
\Y6r !D9  
6yC4rX!a  
public int getNSplitter() ROO@EQ#`Z  
{ E+$D$a  
return nSplitter; <2N=cH'  
} u $D%Iz  
[7,q@>:CS  
_auFt"n  
public void setNSplitter(int nCount) ~*e@^Nv)v  
{ gIKQip<  
nSplitter = nCount; 3MDs?qx>s  
} HI[Pf%${  
} WfYG#!}x  
a/[)A _-  
l;B  
/* `(E$-m-~jH  
**Utility.java bzECNi5^  
*/ a&7uRR26  
package NetFox; VDiW9]  
p@oz[017/J  
OMBH[_  
public class Utility { 1I40N[PE)  
X,}(MW  
Q!r` G  
public Utility() Zb:Z,O(vn  
{ jVqpokWH  
COHook(:  
/-+hMYe  
} 7j88^59  
thE9fr/  
//线程睡眠 K87yQOjPv  
public static void sleep(int nSecond) F?qg?1v B|  
{ s(r4m/  
try{ KxWm63"  
Thread.sleep(nSecond); -&lD0p>*g  
} vx}BT H  
catch(Exception e) >Sb3]$$  
{ s@ 6Jz\<E  
e.printStackTrace (); "/%o'Fq  
} 2WE01D9O  
} 1*.*\4xo  
pnXwE-c_  
//日志 sD|}? 7  
public static void log(String sMsg) p =-~qBw  
{ IsDwa qd|  
System.err.println(sMsg); ]<S{3F=  
} oc#hAjB.  
b.RFvq5Z  
S 8)!70  
public static void log(int sMsg) yI^7sf7k  
{ R*2F)e\|  
System.err.println(sMsg); .Ad9(s  
} \9`.jB~<  
} *Rxn3tR7  
Rr}m(e=  
gMp' S  
/* 3 rR1/\  
**TestMethod.java `$q0fTz  
*/ qqys`.  
package NetFox; 9_ZGb"(Lj  
\ _?d?:#RD  
T1'\!6_5  
public class TestMethod { 5=R]1YI~$  
 GInw7  
ZZi|0dG4;  
public TestMethod() &y7xL-xP  
{ ///xx/weblogic60b2_win.exe +k[w)7Q  
try{ ls~9qkAyLx  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #)3 B  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "2p\/VfA  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~YByyJG   
fileFetch.start(); dnh~An 9  
} N|3#pHm@  
catch(Exception e){e.printStackTrace ();} }Kn l  
7k00lKA\w  
@uanej0q7  
} |*Oi:)qt  
}Yc5U,A;  
P'DcNMdw  
public static void main(String[] args) DO( 3hIj  
{ :6/$/`I0W  
new TestMethod(); ^;tB,7:*V  
} lS#^v#uS  
} q([{WZ:6Oq  
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