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http断点续传简单实现(java)

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/* .>#X*u  
**SiteFileFetch.java Sf*1Z~P|  
*/ QNbV=*F?  
package NetFox; Ls<^z@I  
import java.io.*; \!LIqqX  
import java.net.*; aAKwC01?  
6|uv+$  
*T6*Nxs0k  
public class SiteFileFetch extends Thread { +~(SeTY  
9]C%2!Ur,  
B/O0 ~y!n  
SiteInfoBean siteInfoBean = null; //文件信息Bean AjVX  
long[] nStartPos; //开始位置 e dTFk$0  
long[] nEndPos; //结束位置 a\-AGG{2/X  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 7f] qCZ<0V  
long nFileLength; //文件长度 +[vI ocu  
boolean bFirst = true; //是否第一次取文件 ,>!%KYD/f  
boolean bStop = false; //停止标志 I'`90{I  
File tmpFile; //文件下载的临时信息 x52#md-Z  
DataOutputStream output; //输出到文件的输出流 Ty<."dyPW  
unKPqc%q=n  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) A=W:}szt]  
public SiteFileFetch(SiteInfoBean bean) throws IOException _mWVZ1P  
{ ]*?lgwE  
siteInfoBean = bean; {x{~%)-  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 7F2 WmMS  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); XEegUTs  
if(tmpFile.exists ()) p<[MU4  
{ ) >te|@}o  
bFirst = false; j)ME%17  
read_nPos(); R1$s1@3I|  
} %@9c'6  
else UpaF>,kM  
{ 71n3d~!O>  
nStartPos = new long[bean.getNSplitter()]; qCkC 2Fy(  
nEndPos = new long[bean.getNSplitter()]; v]Fw~Y7l!  
} "%}24t%  
S=}1k,I  
_?> x{![  
'Zs3b4n8  
} {o SdVRI  
6l'J!4*qY  
U ,NGV0  
public void run() YdDP;, DA  
{ fUMjLA|*I<  
//获得文件长度 iGPrWe@.  
//分割文件 OxQ5P;O  
//实例FileSplitterFetch W_L*S4 ~  
//启动FileSplitterFetch线程 w_h{6Kc<  
//等待子线程返回 FI,K 0sO/|  
try{ jB<B_"  
if(bFirst) P!Brw72  
{ Q5c3C &$6  
nFileLength = getFileSize(); QLH!>9Ch  
if(nFileLength == -1) !RP0W  
{ en>n\;U  
System.err.println("File Length is not known!"); > ^=n|%  
} /W GD7\G'8  
else if(nFileLength == -2) q68CU~i*  
{ JC0#pU;  
System.err.println("File is not access!"); yh2)Pc[  
} S B~opN  
else zLgc j(;  
{  5@DCo  
for(int i=0;i<nStartPos.length;i++) Mw3$QRM  
{ E{0e5.{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); in K]+H]{  
} +BeA4d8b  
for(int i=0;i<nEndPos.length-1;i++) DIABR%0  
{ 0W0GSDx  
nEndPos = nStartPos[i+1]; D6~KLSKm  
} ;A4qE W  
nEndPos[nEndPos.length-1] = nFileLength; |a#=o}R_  
} "cyRzQ6EH  
} iX o(  
Atb`Q'Yrw  
K@<*m!%<2  
//启动子线程 b@c(Nv  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AyWdJ<OU  
for(int i=0;i<nStartPos.length;i++) ~s-bA#0S  
{ #W6 6`{>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;*'I&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8 :WN@  
nStartPos,nEndPos,i); h/oun2C  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fv7]1EO.  
fileSplitterFetch.start(); [n2zdiiBd  
} Qo :vAv  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,,H;2xYf  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F!3p )?  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~5&B#Sm[G  
nEndPos = " + nFileLength); #K0/ >W  
// fileSplitterFetch[nPos.length-1].start(); )w~1VcnJEp  
tA^+RO4  
T$`m!mQ4  
//等待子线程结束 S{?l/*Il*_  
//int count = 0; aGBd~y@e  
//是否结束while循环 'z^'+}iyv  
boolean breakWhile = false; xT+#K5  
^^&H:q  
 LtH j  
while(!bStop) -<g[P_#  
{ e`co:HO`#  
write_nPos(); e/cHH3 4  
Utility.sleep(500); rrR"2WuGO  
breakWhile = true; <o9AjASv\,  
)u+O~Y95&i  
k,$/l1D  
for(int i=0;i<nStartPos.length;i++) 8!0fT}  
{ 1$1>cuu  
if(!fileSplitterFetch.bDownOver) &a4FGzR#  
{ #q K.AZi  
breakWhile = false;  Cu5_OJ  
break; cpl Ny?UIC  
} Ux1j+}y  
} -8l(eDm"m  
if(breakWhile) q_6lD~~q^  
break; sZ~03QvkT  
|||m5(`S  
VXiU5n^  
//count++; )sW!s3>S>  
//if(count>4) )Nqx=ms[(!  
// siteStop(); |{(JUXo6K  
} |$6Ten[B#  
Zo-,TKgY'  
@sG*u >   
System.err.println("文件下载结束!"); U# [T!E  
} +pq) 7  
catch(Exception e){e.printStackTrace ();} yZ 7)|j  
} Vpp$yM&?  
.rG~\Ws  
w_o+;B|I  
//获得文件长度 oexTz[  
public long getFileSize() YhNrg?nS  
{ P>u2""c  
int nFileLength = -1; )5n0P Zi  
try{ \9@}0}%`  
URL url = new URL(siteInfoBean.getSSiteURL()); P5h*RV>oS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?mM:oQH+>  
httpConnection.setRequestProperty("User-Agent","NetFox"); X31%T"  
0C.5Qx   
4CchE15  
int responseCode=httpConnection.getResponseCode(); \pkK >R  
if(responseCode>=400) jygUf|  
{ EZ{{p+e ^  
processErrorCode(responseCode); [TQYu:e  
return -2; //-2 represent access is error [L7s(Zs>  
} tK[o"?2y  
%,1TAmJfHa  
PY C  
String sHeader; P=1K u|k  
WY QVe_<z:  
QnOs8%HS-  
for(int i=1;;i++) 50|nQ:u,  
{ ( tq);m&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \ a7m!v  
//Utility.log(in.readLine()); IJKdVb~   
sHeader=httpConnection.getHeaderFieldKey(i); c~/poFj  
if(sHeader!=null) n $N M  
{ S"@6,  
if(sHeader.equals("Content-Length")) 5FuV=Yuc  
{ A(uo%QE|  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U+#^>}wc  
break; sVFX(yx0  
} Xs|d#WbX  
} *;McX  
else 9{U@s  
break; 0[fBP\H"Wr  
} @`+\v mfD  
} ^7ID |uMr  
catch(IOException e){e.printStackTrace ();} ^!C  
catch(Exception e){e.printStackTrace ();} x^c,cV+*  
c%O97J.5b  
}"nm3\Df  
Utility.log(nFileLength); FeS ,TQ4j  
S&-F(#CF^  
H"A@Q.'  
return nFileLength; l" ~ CAw;  
} L4T\mP7D7*  
|A,.mOT  
'5*&  
//保存下载信息(文件指针位置) `KLr!<i()  
private void write_nPos() N-b'O`C  
{ fj['M6+wd  
try{ R\X;`ptT  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \2[tM/+Bs  
output.writeInt(nStartPos.length); %-fS:~$  
for(int i=0;i<nStartPos.length;i++) p %.Adxx  
{ p<h(  
// output.writeLong(nPos); bC"h7$3  
output.writeLong(fileSplitterFetch.nStartPos); Ac{TqiIv  
output.writeLong(fileSplitterFetch.nEndPos); 2Mq@5n  
} _t;^\"\  
output.close(); z>0$SBQ-  
} cZ !$XXA`  
catch(IOException e){e.printStackTrace ();} }@jJv||  
catch(Exception e){e.printStackTrace ();} qhG2j;  
} ">_|!B&wb^  
^K::g)  
O(-6Zqk8Q  
//读取保存的下载信息(文件指针位置) ^8bc<c:P  
private void read_nPos() >'=9sCi  
{ %Qb}z@>fJk  
try{ tUZfQ  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G9xO>Xp^Al  
int nCount = input.readInt(); LttA8hf5q?  
nStartPos = new long[nCount]; js;YSg{m  
nEndPos = new long[nCount]; +A1*e+/b\  
for(int i=0;i<nStartPos.length;i++) gBWr)R  
{ =Ez@kTvOs  
nStartPos = input.readLong(); |H,WFw1%}  
nEndPos = input.readLong(); [>_zV.X  
} 9bRUN<  
input.close(); GutiqVP:B  
} =aQlT*n%3  
catch(IOException e){e.printStackTrace ();} DWx;cP8[  
catch(Exception e){e.printStackTrace ();} gaNe\  
} 8 "NPj0  
+t*I{X(  
e2G;_:  
private void processErrorCode(int nErrorCode) pRxVsOb  
{ FIAmAZH}_  
System.err.println("Error Code : " + nErrorCode); % jf|efxo  
} pbqk  
T*Ge67  
4JXvP1`  
//停止文件下载 -G?IXgG  
public void siteStop() fWWB]h  
{ GV ) "[O  
bStop = true; ts_|7Ev  
for(int i=0;i<nStartPos.length;i++) xT* 3QwK  
fileSplitterFetch.splitterStop(); Khv}q.)F  
C|g1:#0  
]oz>/\!  
} qf ]le]J  
} fuCt9Kjo<  
//负责部分文件的抓取 E@)'Z6r1  
**FileSplitterFetch.java 3}3b@:<  
*/ ;gu4~LQw  
package NetFox; |9.J?YP8 (  
H/Ql  
 Y%y  
import java.io.*; O[L#|_BnEO  
import java.net.*; HE_UHv  
B]b/(Q+  
z0a`*3 -2  
public class FileSplitterFetch extends Thread { }M"])B I  
"Dq^r9  
=+?OsH v  
String sURL; //File URL s S3RK  
long nStartPos; //File Snippet Start Position W?!rqo2SP  
long nEndPos; //File Snippet End Position K5^zu`19  
int nThreadID; //Thread's ID LH @B\ mS  
boolean bDownOver = false; //Downing is over 9M1DE  
boolean bStop = false; //Stop identical ~ Al3Dv9x  
FileAccessI fileAccessI = null; //File Access interface .q:6F*,1M  
ZdY$NpR,  
Btr>ek  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Hd7Vp:KM  
{ _akjgwu  
this.sURL = sURL; v+trHdSBYE  
this.nStartPos = nStart; cUd>ah v  
this.nEndPos = nEnd; 8'qlg|{!~  
nThreadID = id; j"pyK@v2B  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (Uu5$q(  
} omPxU2Jw  
/CKnXU;  
r}Gku0Hu_E  
public void run() 0 "TPY(n  
{ 'Ox "YE  
while(nStartPos < nEndPos && !bStop) #)48dW!n  
{ *wd=&Z^19  
L *|P'  
@;y@Hf'Jv  
try{ [ybK  
URL url = new URL(sURL); o /1+ }f  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =WZ9|e  
httpConnection.setRequestProperty("User-Agent","NetFox"); j` * bz-  
String sProperty = "bytes="+nStartPos+"-"; -k2|`t _  
httpConnection.setRequestProperty("RANGE",sProperty); ?|}qT05  
Utility.log(sProperty); d ( ru5*p  
;l0%yg/}  
%BMlc m7Ec  
InputStream input = httpConnection.getInputStream(); :f_oN3F p  
//logResponseHead(httpConnection); 0yMHU[):~  
%z-so?gF  
7Lj:m.0O^  
byte[] b = new byte[1024]; n;vZY  
int nRead; Bf+~&I#E  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6CGk*s  
{ ![vy{U.:`  
nStartPos += fileAccessI.write(b,0,nRead); g3Hi5[-H  
//if(nThreadID == 1) X_bB6A6  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8WpNlB+:{  
} \h0+` ;Q  
M%Vp_ 0  
KjF8T7%  
Utility.log("Thread " + nThreadID + " is over!"); %gSmOW2.c^  
bDownOver = true; !Z{7X ^  
//nPos = fileAccessI.write (b,0,nRead); Vu4LC&q  
} \`2EfYJ{  
catch(Exception e){e.printStackTrace ();} lZ2g CZ  
} ]-a/)8  
} [TqX"@4NS  
u}_x   
C8)s6  
//打印回应的头信息 ni )G  
public void logResponseHead(HttpURLConnection con) tux`-F  
{ "A~D(1K  
for(int i=1;;i++) 8ql<7RTM!  
{ 4OO^%`=)M'  
String header=con.getHeaderFieldKey(i); 1~2+w]-kU  
if(header!=null) P%vouC0W  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Zn Rj}y  
Utility.log(header+" : "+con.getHeaderField(header)); KiE'O{Y  
else >Lo'H}[pF  
break; M)wNu  
} Rp:I&f$Hk/  
} (sH4 T>  
9U3}_  
E(1G!uu<  
public void splitterStop() CQ Ei(ty  
{ a~JZc<ze  
bStop = true; v/$<#2|  
} U%#Vz-r  
4&e<Sc64  
maQxU(  
} e8xNZG;  
jJ2{g> P0P  
xH,e$t#@@~  
/* 0lOan  
**FileAccess.java 4W E)2vkS  
*//文件访问(定位,写) $ER$|9)KD  
package NetFox; _Vt9ckaA  
import java.io.*; e85E+S%  
MAX?,- x  
meThjCC  
public class FileAccessI implements Serializable{ Z R~2Y?Wt9  
Y=<zR9f`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #KHj.Vg  
RandomAccessFile oSavedFile; B !rb*"[  
long nPos; VtU2&  
M-+!z5 q~d  
*qm>py`O  
public FileAccessI() throws IOException =dQF}-{!  
{ P9S)7&+DL  
this("",0); '%TD#!a  
} dPV<:uO  
5*90t{#  
mT|r:Yr:  
public FileAccessI(String sName,long nPos) throws IOException qkC{IBN92  
{ Q MX  
oSavedFile = new RandomAccessFile(sName,"rw"); 5s4x%L (~}  
this.nPos = nPos; 6~?yn-Z  
oSavedFile.seek(nPos); Gtvbm  
} fmLDufx  
}~0}B[Rf  
Y$|KY/)H)  
public synchronized int write(byte[] b,int nStart,int nLen) j~9Y0jz_  
{ }y(cv}8Y  
int n = -1; KxFA@3  
try{ c2s73i z  
oSavedFile.write(b,nStart,nLen); o(D_ /]'8  
n = nLen; @|OGxQoC  
} L$,Kdpj  
catch(IOException e) cmd7-2  
{ "s`#` '  
e.printStackTrace (); *kj+6`:CPs  
} ox";%|PP1  
$0~1;@`rQ6  
~0Zy$L/D  
return n; N!\1O,  
} EVLDP\w{  
*rV{(%\m  
R.GDCGAL  
} N];K  
p"*xye x  
cb. -AlqQ  
/* *W 04$N  
**SiteInfoBean.java lm+s5}*%o  
*/ )! k l:  
package NetFox; Qdc)S>gp  
6]HMhv  
VPVg \K{  
public class SiteInfoBean { 7kMO);pO  
NKVLd_f k  
X@A8~ kj1  
private String sSiteURL; //Site's URL j~9![s!  
private String sFilePath; //Saved File's Path V9>$M=  
private String sFileName; //Saved File's Name VjeF3pmBa  
private int nSplitter; //Count of Splited Downloading File 3?!c<^"e  
]&='E.f  
e_S,N0  
public SiteInfoBean() jF#Dc[*  
{//nSplitter的缺省值为5 d@Wze[M?0  
//default value of nSplitter is 5 }p8iq  
this("","","",5); mK^E@uxN  
} j:^gmZ;J  
WK{F  
f|j<Mj+\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?+{_x^  
{ G6\`Iy68/v  
sSiteURL= sURL; S]&aDg1y}  
sFilePath = sPath; lXVh`+X/l  
sFileName = sName; - Sn]`  
this.nSplitter = nSpiltter; B_3N:K Y 9  
UzV78^:,iD  
'@^mesMG  
} QUz4 Kt  
cF"}}c1*M  
<:StZ{o;  
public String getSSiteURL() * COC&  
{ wkJ@#jD*[  
return sSiteURL; g/w <T+v  
} iBKH\em/  
od&wfwk(  
dI%Nwl%  
public void setSSiteURL(String value) _.m|Ml,`{  
{ D'UIxc8  
sSiteURL = value;  |vBy=:  
} :"K9(XKKU  
fzN?X=  
y (%y'xBP  
public String getSFilePath() 4 *. O%  
{ P_.AqEH  
return sFilePath; <(45(6fQ  
} vI"BNC*Q1  
}YU\}T-P  
owA.P-4  
public void setSFilePath(String value) fM(~>(q&  
{ "|E'E"_1  
sFilePath = value; @F|pKf:M+  
} -AB0uMot  
>YcaFnY  
{]4Zpev  
public String getSFileName() OgzKX>N`A  
{ gA]3h8%w  
return sFileName; Xhpcu1nA  
} JI&.d:  
$h  >rs  
~bw=;xF{3  
public void setSFileName(String value) i G%R'/*  
{ :=:m4UJb  
sFileName = value; AO(z l*4  
} TALiH'w6|e  
>h$Q%w{V  
-6e^`c6{  
public int getNSplitter() D]WrPWL8v  
{ e0]%ko"  
return nSplitter; 7gRR/&ZK  
} P9jSLM  
qv<^%7gq  
rG%8ugap  
public void setNSplitter(int nCount) ZT<VDcP{  
{ ~sNBklK  
nSplitter = nCount; (543`dqAmC  
} tLP Er@  
} _C,9c7K4  
`r %lB  
P!XO8X 1F  
/* Ggbz  
**Utility.java R}D[ z7  
*/ nPjK=o`KR  
package NetFox; @z`eqG,']  
EZZE(dq@gf  
qCF&o7*oN  
public class Utility { x+[ATZ([  
#[Rs&$vQm  
&_\;p-1:  
public Utility() RW<4",  
{ &<- S-e  
UUGX@  
FgMQ=O2  
} bicbCC6kC  
'oUTY *  
//线程睡眠 Fx:4d$>;  
public static void sleep(int nSecond) <00=bZzX  
{ SErh"~[  
try{ 2dDhO  
Thread.sleep(nSecond); WwxV} ?Cf+  
} @c).&7  
catch(Exception e) yqP=6   
{ x4v&%d=M  
e.printStackTrace (); lWUQkS  
} eWr6@  
} p!\ GJ a",  
1yFIIj:^|  
//日志 G7r.Jm^q  
public static void log(String sMsg) g`)0 wP  
{ l9 &L$,=  
System.err.println(sMsg); Z tc\4  
} lcVG<*gf-  
$v5 >6+-n  
~JP3C5q  
public static void log(int sMsg) *] !r T&E  
{ .fS{j$  
System.err.println(sMsg); 9ZuKED  
} CV2#G*  
} gJ>#HEkMB  
u~~ ~@p  
.9UrWBW\I  
/* Qkc 9X0J!  
**TestMethod.java B[t>T>~  
*/ 3#eAXIW[  
package NetFox; -vc ,O77z"  
+x<OyjY5?]  
L^K,YlNBR  
public class TestMethod { bgkBgugZhX  
:m>Vp  
_9?v?mL5;  
public TestMethod() 5f2=`C0_  
{ ///xx/weblogic60b2_win.exe  \+:`nz3m  
try{ OLoo#HW  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cg9*+]rc  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =)a %,H  
SiteFileFetch fileFetch = new SiteFileFetch(bean); q#\B}'I{  
fileFetch.start(); OjrZ6  
} i`?yi-R&  
catch(Exception e){e.printStackTrace ();} \[%_ :9eq  
RMdU1@  
j]aIJbi  
} G3h"Eo?>g  
p(9[*0.};  
XV,ce~ro[  
public static void main(String[] args) IYa(B+nB)  
{ e*d lGK3l  
new TestMethod(); dJlK'zK  
} U8@P/Z9  
} p&D7&Sb[  
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