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http断点续传简单实现(java)

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/* GuU-< *u(d  
**SiteFileFetch.java NFEr ,n  
*/ ov,s]g83  
package NetFox; hB.8\-}QMq  
import java.io.*; #\m.3!Hcr  
import java.net.*; rnhLv$  
0LL0\ly]  
,iP YsW]5  
public class SiteFileFetch extends Thread { ~B"HI+:\L  
;NdH]a {  
}k%6X@  
SiteInfoBean siteInfoBean = null; //文件信息Bean S!=R\_{u$  
long[] nStartPos; //开始位置 IBJNs$  
long[] nEndPos; //结束位置 2xO[ ?fR  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 = wDXlAQ  
long nFileLength; //文件长度 r.zgLZ}3&V  
boolean bFirst = true; //是否第一次取文件 [(#)9/3,  
boolean bStop = false; //停止标志 # M/n\em"X  
File tmpFile; //文件下载的临时信息 Wd)\r.pJ  
DataOutputStream output; //输出到文件的输出流 !JrKTB%  
hZ e{Ri  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 8Z9>h:c1  
public SiteFileFetch(SiteInfoBean bean) throws IOException 'ZMh<M[  
{ f7Nmvla[q  
siteInfoBean = bean; _%D7D~2r|  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); e8xq`:4Y  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); <%uEWb)  
if(tmpFile.exists ()) ?VE'!DW  
{ o(Z~J}l({  
bFirst = false;  AkS16A  
read_nPos(); 54>0Dv??H  
} H OWpTu(  
else Fovah4q%V  
{ bs)wxU`Q*  
nStartPos = new long[bean.getNSplitter()]; a"U3h[;$y  
nEndPos = new long[bean.getNSplitter()]; -sJD:G,%  
} H<i!C|AF  
E:**gvfq  
8o%Vn'^t  
+)q ,4+K%}  
} @#,/6s7?  
c8uw_6#r(D  
k"DZ"JC  
public void run() GyQFR?  
{ W9w(a:~hY  
//获得文件长度 u]Vt>Ywu  
//分割文件 q%kCTw  
//实例FileSplitterFetch  eu$VKLY*  
//启动FileSplitterFetch线程 vJ'22)n  
//等待子线程返回 -kLBq :M  
try{ C$+Q,guM  
if(bFirst) K a(B&.  
{ '{ =F/q  
nFileLength = getFileSize(); P`Ku. ONQ  
if(nFileLength == -1) ^lV}![do!  
{ V>)/z|[  
System.err.println("File Length is not known!"); MSM8wYcD  
} B;=Z^$%T  
else if(nFileLength == -2) }a5TY("d9H  
{ y<- ]'Yts  
System.err.println("File is not access!"); gtMR/P:S  
} Fik ;hB  
else "0;WYw?  
{ A)n_ST0  
for(int i=0;i<nStartPos.length;i++) k0V]<#h87  
{ r7R'beiH  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); z3S"1L7  
} =h-E N_[  
for(int i=0;i<nEndPos.length-1;i++) \D z? h  
{ /FXvrH(  
nEndPos = nStartPos[i+1]; F6yFKNK!n  
} pI K:$eN!/  
nEndPos[nEndPos.length-1] = nFileLength; fG>3gS6&  
} *Ts$Hj[  
} Q}B]b-c+E  
\a;xJzc9  
-avxH?;?7  
//启动子线程 UwS7B~  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Iga +8k  
for(int i=0;i<nStartPos.length;i++) Y2l;NSWU  
{ aIa<,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '1 2*'Q+{+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RDDA^U7y#  
nStartPos,nEndPos,i); uNuFD|aQ.  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T=-UcF  
fileSplitterFetch.start(); y-.{){uaD  
} \v-I<"::  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), au50%sA~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U'" #jT  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [#@lsI  
nEndPos = " + nFileLength); qtAt=` s  
// fileSplitterFetch[nPos.length-1].start(); --l UEo~  
^rq\kf*]  
xOShO"4Z   
//等待子线程结束 xP_%d,  
//int count = 0; *Xk5H,:  
//是否结束while循环 |33t5}we  
boolean breakWhile = false; a~LA&>@  
9;{(.K  
c8mh#T bl  
while(!bStop) .gC.T`/m  
{ iLBORT !;  
write_nPos(); 3^ UoK  
Utility.sleep(500); _p:n\9k  
breakWhile = true; k6(</uRj  
[Y*>x2X  
Rjq\$aY}%  
for(int i=0;i<nStartPos.length;i++) Wu{_QuAB  
{ dI%jR&.e;  
if(!fileSplitterFetch.bDownOver) ZPE-  
{ em,1Yn?  
breakWhile = false; d*Mqs}8  
break; ;[ Dxk$"  
} iQ Xlz] '  
} Yn [ F:Z  
if(breakWhile) {c3FJ5:  
break; %Jh( 5  
*Lz'<=DLoW  
8 f~x\.  
//count++; w`8H=Hf  
//if(count>4) l+2NA4s  
// siteStop(); P]^OSPRg  
} !Q~>)$Cf^  
D['J4B  
)s:kQ~+  
System.err.println("文件下载结束!"); |0}Xb|+  
} T\p>wiY2|F  
catch(Exception e){e.printStackTrace ();} )_C>hWvo_  
} /hqn>t  
Z_bVCe{  
1-^D2B[-  
//获得文件长度 y[l{ UBue:  
public long getFileSize() I>nYI|o1  
{ Ek `bPQ5  
int nFileLength = -1;  .GJbrz  
try{ ly34aD/p~,  
URL url = new URL(siteInfoBean.getSSiteURL()); q 6UZ`9&z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lbt8S.fx  
httpConnection.setRequestProperty("User-Agent","NetFox"); D1-w>Y#  
]s5e[iS  
R2~y<^.V`Y  
int responseCode=httpConnection.getResponseCode(); 5>%^"f  
if(responseCode>=400) U`3?bhzua  
{ x^)?V7[t  
processErrorCode(responseCode); xa'U_]m  
return -2; //-2 represent access is error vzfMME17  
} m4OnRZYlw  
-E6av|c,F  
)!rD&l$tE  
String sHeader; ?/MkH0[G=  
LvS5N)[  
Ws3z-U>j  
for(int i=1;;i++) Wf "$  
{ S)zw[m  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `_)9eGQ  
//Utility.log(in.readLine()); U}X'RCM  
sHeader=httpConnection.getHeaderFieldKey(i); JXkx!X_{  
if(sHeader!=null) vjGJRk|XED  
{ =/a`X[9vI  
if(sHeader.equals("Content-Length")) 0$`pYW]  
{ ] +%`WCr9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z6M5 '$\y  
break; Y1r'\@L w  
} vA:ZR=)F  
} 9A4n8,&sm  
else v `/nX->  
break; 3O*iv{-&  
} *>qc6d@'  
} Z ;~%!  
catch(IOException e){e.printStackTrace ();} viU}  
catch(Exception e){e.printStackTrace ();} B=>Xr!pM!  
BTr;F]W  
1yF9zKs&_  
Utility.log(nFileLength); Y9f7~w^s  
-eV*I >G  
,^mEi  
return nFileLength; y~]D402Cx  
} zF FYl7]  
rN#9p+t$  
\ CcVk"/  
//保存下载信息(文件指针位置) LEnv/t6U  
private void write_nPos() y'2w*?  
{ "'``O~08/  
try{ [V?HK_~  
output = new DataOutputStream(new FileOutputStream(tmpFile)); lrHN6:x(Y4  
output.writeInt(nStartPos.length); GNmP_N  
for(int i=0;i<nStartPos.length;i++) Em Ut/]  
{ ] g9SUFM  
// output.writeLong(nPos); .yUD\ZGJ u  
output.writeLong(fileSplitterFetch.nStartPos); R6 ej  
output.writeLong(fileSplitterFetch.nEndPos); Kk=>"?&  
} V]Ccj\Oi  
output.close(); w-)JCdS6Tb  
} {-7ovH?  
catch(IOException e){e.printStackTrace ();} `R (N3  
catch(Exception e){e.printStackTrace ();} w_`;Mn%p  
} Tg@G-6u0c  
.Gr"| uII  
3nhQ^zqf  
//读取保存的下载信息(文件指针位置) 9({ 9r[U  
private void read_nPos() ;6 d-+(@  
{ )N^fSenFBn  
try{ c{D<+XM  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]S?G]/k}  
int nCount = input.readInt(); 2.);OFk+  
nStartPos = new long[nCount]; 7?k3jDK  
nEndPos = new long[nCount]; W=S^t_F  
for(int i=0;i<nStartPos.length;i++) ^o C>,%7  
{ qrOesSdc  
nStartPos = input.readLong(); j3w~2q"r  
nEndPos = input.readLong(); ~IO'"h'w  
} &=%M("IlD  
input.close(); ;A"i.:ZT  
} q2B'R   
catch(IOException e){e.printStackTrace ();} w H=7pS"s  
catch(Exception e){e.printStackTrace ();} b?Q$UMAbH  
} h Ks  
Wn;%B].I  
'^7Z]K<v  
private void processErrorCode(int nErrorCode) ||cI~qg  
{ :G9d,B7*  
System.err.println("Error Code : " + nErrorCode); dwvc;f-  
} Gl{2"!mt=  
&u"mFweS  
$@{ d\@U  
//停止文件下载 90J WU$K  
public void siteStop() )knK'H(  
{ %T<c8w}dP  
bStop = true; 1M_6X7PH  
for(int i=0;i<nStartPos.length;i++) [}Rs  
fileSplitterFetch.splitterStop(); .{;RJ:O  
>PdrLwKS  
pkG8g5(w  
} BB1_EdoG  
} 0V"(}!=2a  
//负责部分文件的抓取 s&WE'  
**FileSplitterFetch.java Qd3ppJn  
*/ NV} fcZ  
package NetFox; SJ8 ~:"\P  
{KTZSs $n  
hQzT =0  
import java.io.*; o4rf[.z  
import java.net.*; bTYR=^9  
CIwI1VR^  
_,Q -)\  
public class FileSplitterFetch extends Thread { i[33u p  
Mp5Z=2l5  
.Q</0*sp  
String sURL; //File URL ed/ "O gA  
long nStartPos; //File Snippet Start Position =y?Aeqq\fl  
long nEndPos; //File Snippet End Position p*zTuB~e<  
int nThreadID; //Thread's ID @1k-h;`,  
boolean bDownOver = false; //Downing is over tnb'\}Vn  
boolean bStop = false; //Stop identical E7SmiD@)  
FileAccessI fileAccessI = null; //File Access interface n*AN/LBp  
N^[MeG,8  
5P);t9O6  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ho%%voJBS  
{ b\NY!)B  
this.sURL = sURL; bWCtRli}  
this.nStartPos = nStart; #'#@H  
this.nEndPos = nEnd; *gwo.s  
nThreadID = id; Xe ^NVF  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h^H)p`[Gme  
} A}uWy^w  
SrMfd7H8f  
X*)DpbWd  
public void run() L`w_Q2{sv  
{ [4])\q^q  
while(nStartPos < nEndPos && !bStop) HR'F  
{ PGTjOkx  
bI;u};v  
Xa U ^^K  
try{ o|s|Wm x>u  
URL url = new URL(sURL); wUS w 9xg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }&l%>P  
httpConnection.setRequestProperty("User-Agent","NetFox"); dZd]p8  
String sProperty = "bytes="+nStartPos+"-"; /5>A 2y  
httpConnection.setRequestProperty("RANGE",sProperty); \3 rgwbF  
Utility.log(sProperty); T%TO?[cN  
8X\":l:  
0w2<2grQ  
InputStream input = httpConnection.getInputStream(); H7{kl  
//logResponseHead(httpConnection); }mk z_P(Z  
( ~>-6Nb 5  
*MCkezW7{  
byte[] b = new byte[1024]; tg2+Z\0)4g  
int nRead; -?)z@Lc  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZoqE,ucH  
{ 2tp95E`(O  
nStartPos += fileAccessI.write(b,0,nRead); *2m{i:3  
//if(nThreadID == 1) #("E) P  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5G#2#Al(F  
} ~P-^An^  
8hX /~-H  
SmP&wNHQf  
Utility.log("Thread " + nThreadID + " is over!"); c`)[-  
bDownOver = true; k#5Qwxu`  
//nPos = fileAccessI.write (b,0,nRead); &x[V<Gq  
} :{#w-oC>6P  
catch(Exception e){e.printStackTrace ();} a0wpsl iF  
} vWYU'_=  
} ^{O1+7d[.  
_6sSS\  
V$  MMK  
//打印回应的头信息 Ez^wK~  
public void logResponseHead(HttpURLConnection con) Q"GZh.m  
{ Lnltt86  
for(int i=1;;i++) 9iK%@k  
{ 5.U|CL  
String header=con.getHeaderFieldKey(i); 0*/[z~Z-1  
if(header!=null) 7  nawnS  
//responseHeaders.put(header,httpConnection.getHeaderField(header));  OJ# d  
Utility.log(header+" : "+con.getHeaderField(header)); 1|7t q  
else b5%T)hn=  
break; Q,>]f@m  
} {@X)=.Zf  
} _s0;mvz'  
S1*xM  
@$|bMH*1:  
public void splitterStop() [jKhC<t}  
{ JjH141 n%D  
bStop = true; &UX:KW`=  
} \2 `|eo  
gCI{g. [I!  
h}GzQry1  
} Up1e4mNL  
/V>yF&p  
`+T"^{ Z  
/* 6PRP&|.#  
**FileAccess.java AUm5$;o,/  
*//文件访问(定位,写) y?xFF9W@H  
package NetFox; Zx%6pZ(.  
import java.io.*; e:;u_ be~  
r )f+j@KF  
! X<dN..  
public class FileAccessI implements Serializable{ {60U6n  
eh6=-  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^" UZ.@sq'  
RandomAccessFile oSavedFile; k4~2hD<|  
long nPos; u_%L~1+'  
G@6F<L~$1  
EpH\;25u  
public FileAccessI() throws IOException z CFXQi  
{ FWQNO(  
this("",0); `z6I][Uf  
} bb`8YF+?'  
Uizg.<.  
j:'8yFi_  
public FileAccessI(String sName,long nPos) throws IOException 43BqNQ0  
{ D'\gy$9m1  
oSavedFile = new RandomAccessFile(sName,"rw"); ]9$^=z%SE  
this.nPos = nPos; o+FDkqEN  
oSavedFile.seek(nPos); WKONK;U+7  
} }Gh95HwE  
O g!SFg*  
 M_f.e!?  
public synchronized int write(byte[] b,int nStart,int nLen) @@#h-k%k-  
{ 6{?B`gm7g  
int n = -1; C.?~D*Q  
try{ cFloaCz  
oSavedFile.write(b,nStart,nLen); 9<1dps=c  
n = nLen; q3/ 0xN+?  
} Xny{8Oo<1?  
catch(IOException e) '>#8 F.  
{ ,^&amWey  
e.printStackTrace (); ->a |  
} Ox&]{  
8QFg6#"O  
C"g bol^  
return n; )cBO_  
} lWk/vj<5  
cPPTGpqw  
%HcCe[d5l  
} A$W~R  
_+}#  
Q-y`IPtA<  
/* J*+[?FXRL  
**SiteInfoBean.java Ew*SA  
*/ u\o~'Jz  
package NetFox; {Z^q?~zC[  
e# z#bz2<  
$'93:9tg  
public class SiteInfoBean { wYN/ }>M  
3?bTs =  
N<T@GQwkS  
private String sSiteURL; //Site's URL `clp#l.ii  
private String sFilePath; //Saved File's Path M.fA5rJ^  
private String sFileName; //Saved File's Name IQQ QB  
private int nSplitter; //Count of Splited Downloading File $9?<mP2-*  
hf< [$B  
@5*$yi 'Cp  
public SiteInfoBean() dc,qQM  
{//nSplitter的缺省值为5 -s9()K(vZG  
//default value of nSplitter is 5 #,Cz+ k*4  
this("","","",5); sTw+.m{F  
} ^_\%?K_u  
:HkX sZ  
"*ww>0[  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y@2yV(m)o  
{ ?OVje9  
sSiteURL= sURL; #.@-ng6C  
sFilePath = sPath; o4nDjFhh  
sFileName = sName; 7(C:ty9  
this.nSplitter = nSpiltter; #i=k-FA)H  
;2l|0:  
W?D-&X^ny  
} nG0R1<  
(0^ZZe`# j  
)_SpY\J  
public String getSSiteURL() p;.M .  
{ 0n*D](/NK  
return sSiteURL; lwm 9gka  
} )F,z pGG  
%`}nP3  
@IV,sz e  
public void setSSiteURL(String value) qpV"ii  
{ LyRW\\z2  
sSiteURL = value; I*H($ a  
} QVo>Uit   
1\-r5e; BE  
x%T.0@!8  
public String getSFilePath() 8~ u/gM  
{ f-Zi!AGh>  
return sFilePath; h}4yz96WD  
} K>G.HN@  
h`f$]_c  
Ik-E_U2  
public void setSFilePath(String value) y'(a:.%I  
{ V E?Aa  
sFilePath = value; $0|`h)&  
} )Bu#ln"  
ji.T7wn1u  
5:(/k\9+yv  
public String getSFileName() "<&) G{  
{ DcN!u6sJ  
return sFileName; ~]SCf@pRk  
} DGNn#DP  
P=R-1V  
zJov*^T-C  
public void setSFileName(String value) yX/{eX5dr  
{ $N\k*=  
sFileName = value; &pW2R}  
} lN*beOj  
7QRkXs  
fGoJP[ae  
public int getNSplitter() wU|jw(  
{ ic}mru  
return nSplitter; k%V YAON  
} p4D.nB8  
J T6}m  
RoNE7|gF:  
public void setNSplitter(int nCount) 6B+?X5-6DH  
{ nWA>u J5  
nSplitter = nCount; w@pJ49  
} /  QT>"  
} P=l 7m*m  
*P8CzF^>\&  
X0]{8v%  
/* ~ +h4i'  
**Utility.java G|u)eW  
*/ wsB  
package NetFox; "RgP!  
AkCy C1  
a(X V~o  
public class Utility { c#TV2@   
U9jdb9 |  
{.ypZ8JU  
public Utility() 5+yy:#J]  
{ 'I$kDM mwh  
\>x1#Vr>#V  
aJ}hlM>  
} oU se~  
Q]e]\J  
//线程睡眠 @km4qJZ  
public static void sleep(int nSecond) e$/y ~!  
{ kU,g=+ 2J  
try{ >>|47ps3  
Thread.sleep(nSecond); kW0ctGFYlf  
} YQb503W"d~  
catch(Exception e) r dCs  
{ bOSqD[?  
e.printStackTrace (); NF7  
} z/fSs tN  
} ,&y_^-|d  
70 Ph^e)  
//日志 r6GXmr  
public static void log(String sMsg) 6\k~q.U@XI  
{ &hrMpD6z6i  
System.err.println(sMsg); +\$c_9|C+  
} !{fu(E  
c\/-*OYr<  
_>ZC;+c?  
public static void log(int sMsg) Kp^"<%RT  
{ ix$ ^1(  
System.err.println(sMsg); >'4$g7o,  
} 'T$Cw\F&  
} T?RN} @D  
-xbs'[  
cQ'x]u_  
/* mE_%  
**TestMethod.java h=\1ZQKC)  
*/ I L,lXB<  
package NetFox; v|KIVBkbT  
:W6'G@ p  
]=9 d'WL  
public class TestMethod { {]dG 9  
\GQRpJ#h1  
WP?]"H  
public TestMethod() "a9j2+9  
{ ///xx/weblogic60b2_win.exe 2vU-9p {  
try{  P_'{|M<?  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P (DEf(  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -%| ] d ;  
SiteFileFetch fileFetch = new SiteFileFetch(bean); [+QyKyhTO  
fileFetch.start(); `wZ  
} y5F"JjQAa  
catch(Exception e){e.printStackTrace ();} Hpa6; eT  
w,up`W7,  
K\xnQeS<W  
} bRrS d:e  
`JY+3d,Ui  
E)`0(Z:E  
public static void main(String[] args) Z=Cw7E  
{ w>8kBQ?b  
new TestMethod(); &-{%G=5~e%  
} M$Bb,s  
} 6212*Z_Af  
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