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http断点续传简单实现(java)

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/* TRG(W^<F  
**SiteFileFetch.java H`4H(KWm  
*/ gkUG*Zw  
package NetFox; }9fH`C/m  
import java.io.*; gH- e0134%  
import java.net.*; G.K3'^_  
<Gzy*1 Q&  
m`UNdFS  
public class SiteFileFetch extends Thread { Z~o*$tF/  
)AOD~T4s7  
!Y_"q^5GG'  
SiteInfoBean siteInfoBean = null; //文件信息Bean TDg#O!DUF  
long[] nStartPos; //开始位置 }~dXz?{p8  
long[] nEndPos; //结束位置 ' >[KVvm  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 q4vu r>m6  
long nFileLength; //文件长度 10 dVV[=  
boolean bFirst = true; //是否第一次取文件 +F ~;Q$T  
boolean bStop = false; //停止标志 uf,4GPo,  
File tmpFile; //文件下载的临时信息 N$J)Ow  
DataOutputStream output; //输出到文件的输出流 a#W:SgE?Y  
wL,b.]  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }*l V  
public SiteFileFetch(SiteInfoBean bean) throws IOException fAWjk&9  
{ ,YFuMek  
siteInfoBean = bean; We3*WsX\  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); GqhnE>  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Nd/iMV6V;  
if(tmpFile.exists ()) p2|c8n==  
{ B?c9cS5Mj  
bFirst = false; ITh1|yP  
read_nPos(); W5?F?Dp!v  
} z<rdxn,9  
else w[PWJ! <  
{ HbF.doXK  
nStartPos = new long[bean.getNSplitter()]; MrjET!`.jC  
nEndPos = new long[bean.getNSplitter()]; /zn|?Y[  
} PPT"?lt*&  
)NZ6!3[@  
I ,Q"<? &  
>L/Rf8j&  
} !o &+  
k%#`{#n i  
VtF^; f  
public void run() }(O/y-  
{ !_s|h@  
//获得文件长度 hNUAwTH6  
//分割文件 dz.]5R  
//实例FileSplitterFetch iC&=-$vu  
//启动FileSplitterFetch线程 HTI1eLZ2  
//等待子线程返回 c+AZ(6O ?\  
try{ 1(M0C[P  
if(bFirst) )'\Jp 7*3  
{ mnL \c'  
nFileLength = getFileSize(); (utm+*V,  
if(nFileLength == -1) LU4\&fd  
{ <5/r  
System.err.println("File Length is not known!"); h{.KPK\  
} 2}]6~i  
else if(nFileLength == -2) AY:3o3M  
{ 8 f%@:}H  
System.err.println("File is not access!"); ` 1DJwe2  
} 2;%DE<Z  
else )F&@ M;2p'  
{ =If% m9  
for(int i=0;i<nStartPos.length;i++) C1P{4 U  
{ 7P9n. [  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 1Nw&Z0MI  
} ?UQVmE&  
for(int i=0;i<nEndPos.length-1;i++) y|q4d(P.  
{ d9|dHJf  
nEndPos = nStartPos[i+1]; #/@U|g  
} ([UuO}m-  
nEndPos[nEndPos.length-1] = nFileLength; AL! ^1hCF  
} c&)H   
} Jl&bWp^3  
j11\t  
,Ihuo5>/z  
//启动子线程 [6BL C{2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /7*jH2  
for(int i=0;i<nStartPos.length;i++) zB\g'F/  
{ 8-cG[/|0  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sl|s#+Z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _3tHzDSG#  
nStartPos,nEndPos,i);  m3 ;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wq_c^Ioy  
fileSplitterFetch.start(); &T]+g8''  
} UT [7 J  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m\7-/e2 a  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #h ;j2  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WM: ~P$%cx  
nEndPos = " + nFileLength); 28SlFu?  
// fileSplitterFetch[nPos.length-1].start(); rui}a=rs  
hSaS2RLF  
9:A>a3KOH  
//等待子线程结束 '*!R gbj;  
//int count = 0; *jGB/ y  
//是否结束while循环 [6 wI22  
boolean breakWhile = false; [V{JuG;s  
x +|Fw d  
PqPLy  
while(!bStop) "%urT/F v&  
{ %H>vMR-,~  
write_nPos(); |`s}PcV  
Utility.sleep(500); 66D<Up'K  
breakWhile = true; wc)[r~On(5  
*x`z5_yfO  
[ar:zl V8  
for(int i=0;i<nStartPos.length;i++) 4DEsB)%X  
{ cGkl=-oQ'  
if(!fileSplitterFetch.bDownOver) R%aH{UhE`  
{ b@^M|h.Va  
breakWhile = false; lZ0+:DaP2  
break; T;GBZR%  
} V-A^9AAPm  
} qh0)~JL4   
if(breakWhile) &o^wgmS   
break; /`\-.S9  
vPmP<c)cb  
h@Ea$1'e,  
//count++; 7E Y~5U/4  
//if(count>4) \bQ|O7s  
// siteStop(); 7;;W{W%  
} ro@Zbm;P  
#i ?@S$  
N$pwTyk  
System.err.println("文件下载结束!"); H24g+<Tv  
} POH >!lHu  
catch(Exception e){e.printStackTrace ();} qS&PMQ"$  
} rZu_"bcJ  
W euV+}\b  
`m3@mJ!>\  
//获得文件长度 90sMS]a  
public long getFileSize() V==' 7n  
{ FtM7+>Do.  
int nFileLength = -1; z"}k\B-5  
try{ jm RYL("  
URL url = new URL(siteInfoBean.getSSiteURL()); X]cB `?vR  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }Bc'(2A;,  
httpConnection.setRequestProperty("User-Agent","NetFox"); ol!o8M%Q  
KblOP{I  
kjaz{&P  
int responseCode=httpConnection.getResponseCode(); n#z^uq|v  
if(responseCode>=400) |GK [I  
{ ^ eM=h  
processErrorCode(responseCode); rctn0*MP  
return -2; //-2 represent access is error qqw6p j  
} T~"tex]  
oCy52Bm.!  
HZ 8 j[kO  
String sHeader; :N8D1e-a  
<kLY1 EILM  
8S]Mf*~S'  
for(int i=1;;i++) &M>S$+I n  
{ e7,iO#@:m  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Redp'rXT<h  
//Utility.log(in.readLine()); a:zx&DwM  
sHeader=httpConnection.getHeaderFieldKey(i); FAM`+QtNw  
if(sHeader!=null) pal))e! B  
{ FVY,CeA.  
if(sHeader.equals("Content-Length")) WU<#_by g  
{ H7Y}qP5X  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C| Mh<,~ E  
break; +V2a|uvEc  
} rA` zuYo  
} LvWU %?  
else >=U $s@  
break; U&u7d$ANP  
} )[p8  
} #> CN,eiZ  
catch(IOException e){e.printStackTrace ();} 6\5U%~78  
catch(Exception e){e.printStackTrace ();} > 7;JZuVo  
w-B\AK?}  
d[~c-G6  
Utility.log(nFileLength); |o!<@/iH=  
X[@>1tl  
* uEU9fX  
return nFileLength; S BFhC  
} `b\4h/~  
^iV@NVP  
z7<^aS  
//保存下载信息(文件指针位置) N->;q^  
private void write_nPos() 2CmeO&(Qf*  
{ < ht >>  
try{ Phb<##OB  
output = new DataOutputStream(new FileOutputStream(tmpFile)); T&R`s+7  
output.writeInt(nStartPos.length); n|,Es!8:o  
for(int i=0;i<nStartPos.length;i++) 2~ 'Q#(  
{ #m$H'O[WG\  
// output.writeLong(nPos); xje{ kx#  
output.writeLong(fileSplitterFetch.nStartPos); yLDHJ}R  
output.writeLong(fileSplitterFetch.nEndPos); ,7j`5iq[m  
}  fx;5j;  
output.close(); r#Pd@SV  
} 8U;!1!+ 7)  
catch(IOException e){e.printStackTrace ();} z?  {#/  
catch(Exception e){e.printStackTrace ();} Ev^Xs6 }"  
} dHp6G^Y  
L1F){8[  
 vo::y"  
//读取保存的下载信息(文件指针位置) {#[a4@B0  
private void read_nPos() "Q/3]hc.  
{ ?0?'  
try{ PN.6BJvu  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kBONP^xI  
int nCount = input.readInt(); A%GJ|h,i  
nStartPos = new long[nCount]; IcQ?^9%{  
nEndPos = new long[nCount]; Z(<ul<?r  
for(int i=0;i<nStartPos.length;i++) piId5Gx7  
{ D>|:f-Z6Z  
nStartPos = input.readLong(); AGv;8'`  
nEndPos = input.readLong(); .s!:p pwl  
} v,M2|x\r}  
input.close(); t[Q^Xp  
} +$UfP(XmH  
catch(IOException e){e.printStackTrace ();} 'P~*cr ?A  
catch(Exception e){e.printStackTrace ();} {'b8;x8h  
} O Z#?  
`3+U6>U [  
^M80 F7  
private void processErrorCode(int nErrorCode) t%TZu>(1O  
{ ^#=L?e  
System.err.println("Error Code : " + nErrorCode); H!Od.$ZIX  
} }!d}febk_  
xO.7cSqgw  
$(NfHIX  
//停止文件下载 ~Fx[YPO,  
public void siteStop() <pE G8_{}  
{ o?b%L  
bStop = true; 5sE^MS1  
for(int i=0;i<nStartPos.length;i++) {c J6Lq&  
fileSplitterFetch.splitterStop(); h)<R#xw  
)ld7^G  
%/^d]#  
} #>,cc?H-  
} 1z`,*eD7  
//负责部分文件的抓取 !;xE7w  
**FileSplitterFetch.java }Sh-4:-D  
*/ O[`Ob6Q{F  
package NetFox; l~=iUZW<  
:rj78_e9  
7'8O*EoB'  
import java.io.*; -m @s 9k  
import java.net.*; 1]<!Xuk^f  
9F-k:hD |  
W+eN%w5  
public class FileSplitterFetch extends Thread { ;+jp,( 7  
{jVFlKP>  
\8$`:3,@  
String sURL; //File URL OM.^>=  
long nStartPos; //File Snippet Start Position M ?3N  
long nEndPos; //File Snippet End Position kzmt'/L8  
int nThreadID; //Thread's ID [yyV`&  
boolean bDownOver = false; //Downing is over o2|(0uN'  
boolean bStop = false; //Stop identical VsmL#@E  
FileAccessI fileAccessI = null; //File Access interface +sI.GWQ_:  
a(7ryl~c=  
xC{NIOYn'  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~3%3{a a  
{ U\ L"\N7  
this.sURL = sURL; Z\L@5.*ydE  
this.nStartPos = nStart; _qg6( X  
this.nEndPos = nEnd; %b?Pasf.  
nThreadID = id; &-* nr/xT  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z`*cI   
} $"i690  
vq s~a7E-P  
G<z)Ydh_  
public void run() @Dy.HQ~  
{ ;FmSL#]I  
while(nStartPos < nEndPos && !bStop) wY95|QS  
{ c`+ITNV  
"tR.'F[n4P  
zb" hy"hKw  
try{ Qx6/Qa S?  
URL url = new URL(sURL); K$.zO4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); moR]{2Cd{  
httpConnection.setRequestProperty("User-Agent","NetFox"); vhHMxOZ;  
String sProperty = "bytes="+nStartPos+"-"; n1t(ns|  
httpConnection.setRequestProperty("RANGE",sProperty); Q*8-d9C  
Utility.log(sProperty); hG@ys5  
`[KhG)Y7t  
TH|hrL;:8  
InputStream input = httpConnection.getInputStream(); e !yw"Cf*  
//logResponseHead(httpConnection); [1*/lt|+p  
-1:Z^&e/  
$imx-H`|  
byte[] b = new byte[1024]; c{Kl?0#[  
int nRead;  (2li:1j  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nADd,|xD3  
{ /ZDc=>)~  
nStartPos += fileAccessI.write(b,0,nRead); {X$Mwqhpp;  
//if(nThreadID == 1)  SoX V  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mig3.is  
} X W)A~wPBs  
=5`@:!t7  
 ~Hs{(7   
Utility.log("Thread " + nThreadID + " is over!"); dO[4}FZ$  
bDownOver = true; gp)ds^  
//nPos = fileAccessI.write (b,0,nRead); `VsGa  
} Lm|X5RVq  
catch(Exception e){e.printStackTrace ();} X2[cR;;'  
} j 7 URg>i0  
} nrIL_  
!cb#fl  
uE j6A  
//打印回应的头信息 J7GsNFL  
public void logResponseHead(HttpURLConnection con) fYy.>m+P1  
{ ^0Q*o1W  
for(int i=1;;i++) ^W D$ gd  
{ @>5<m'}2  
String header=con.getHeaderFieldKey(i); }^[@m#  
if(header!=null) zRu`[b3u<  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dLf8w>i`T  
Utility.log(header+" : "+con.getHeaderField(header)); tTH%YtG  
else jyhzLu  
break; / yi:Q0  
} a1SOC=.M;  
} BUinzW z{a  
mj=|oIMwT  
BA-nxR  
public void splitterStop() 14!J\`rI  
{ =on!&M  
bStop = true; GiXde}bm  
} fZ}Y(TG/  
%>2t=)T  
?MM3LA! <  
} df *#?Ok  
.4> s2  
t5X lR]` w  
/* ]?(F'&  
**FileAccess.java n-3j$x1Ne  
*//文件访问(定位,写) C-u/{CP  
package NetFox; Ok&>[qu  
import java.io.*; HY;?z `=  
%uVJL z  
_|3TC1N$n  
public class FileAccessI implements Serializable{ X'7S|J6s  
jHH  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 MuV0;K \  
RandomAccessFile oSavedFile; SRN9(LN  
long nPos; ]t)M}^w  
*g4Cy 8$  
]A$^ l,  
public FileAccessI() throws IOException Treh{s  
{ e[mhbFf-  
this("",0); ,'CWt]OS'  
} 7&V^BW  
|.O!zRm  
h5rP]dbhXU  
public FileAccessI(String sName,long nPos) throws IOException R.IUBw5;/  
{ J xm9@,  
oSavedFile = new RandomAccessFile(sName,"rw"); 07Q[L'}y@  
this.nPos = nPos; "P5bYq%0v  
oSavedFile.seek(nPos); $H-D9+8 7  
} 1{x~iZa  
ZT"|o\G^Q  
7. 9s.*  
public synchronized int write(byte[] b,int nStart,int nLen) ynZ[c8.  
{ ;K\N  
int n = -1; C6UMc} 9h  
try{ ?w37vsN  
oSavedFile.write(b,nStart,nLen); '$h @  
n = nLen; D4Y!,7WEVt  
} CKt|c!3 7  
catch(IOException e) ESxC{ "  
{ /~l/_Jct@G  
e.printStackTrace (); }&T<wm!  
} Of7) A  
)^f9[5ee  
ix7 e] )m(  
return n; ]9&q'7*L  
} "Dl9<EZ  
?ey&Un"  
6!%d-Z7)  
} b^,Mw8KsO  
_SIs19"lR  
+GYMJK`S+  
/* 0uIV6LI  
**SiteInfoBean.java 2r}uE\GN  
*/ \W`}L  
package NetFox; J'ZFIT_>  
FW)^O%2s  
I0w@S7  
public class SiteInfoBean { '!^E92  
N _~KZQ11^  
Uty(sDtu  
private String sSiteURL; //Site's URL q"+ q  
private String sFilePath; //Saved File's Path K>R;~ o  
private String sFileName; //Saved File's Name Md>f  
private int nSplitter; //Count of Splited Downloading File `}9 1S  
a|P~LMPM  
YKe0:cWc  
public SiteInfoBean() 85|95P.<  
{//nSplitter的缺省值为5 +# RlX3P  
//default value of nSplitter is 5 }.MoDR3\  
this("","","",5); oBj>9I;  
} c7g.|R  
X4 }`>  
=EcIXDzC>  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p_5>?[TW:  
{ 1 x\VdT  
sSiteURL= sURL; \_gp50(3  
sFilePath = sPath; o7Cnyy#:  
sFileName = sName; lv00sa2z  
this.nSplitter = nSpiltter; ~w1{zxs  
fs rg2:kQ  
N{^>MRK=5  
} l|vWeBs  
n=G>y7b  
BK(pJNBh  
public String getSSiteURL() sm2p$3v  
{ xS~yH[k  
return sSiteURL; 7"n)/;la  
} 6)#- 5m  
kj{rk^x  
| or 8d>,  
public void setSSiteURL(String value) V#zhG AMy.  
{ 3{Ek-{ 9  
sSiteURL = value; nb0 Py>4  
} vn0cKz@  
cXb @H#  
A]Q1&qM%  
public String getSFilePath() mEB2RLCM  
{ |5O >>a()  
return sFilePath; Et}C`vZ+Ve  
} ~mXZfG/D  
l:zU_J6  
.#=j <&  
public void setSFilePath(String value) ;.nP%jD  
{ FVsu8z u  
sFilePath = value; X(r)Z\  
} *Z]5!$UpC  
j8[`~p b  
'R4>CZ%jV  
public String getSFileName() 1Lm].tq  
{ I~p8#<4#b  
return sFileName; _.d}lK3$2  
} \3H<z@;  
(30<oE{  
t$]&,ucW#  
public void setSFileName(String value) i{ t TUA  
{ qJ{r!NJJ 8  
sFileName = value; ;[TljcbS  
} 943I:, B  
L4YVH2`0)  
JCw{ ?^F"  
public int getNSplitter() (orrX Ez  
{ |5 oKq'(b  
return nSplitter; {yvb$ND|j{  
} Y!++C MzU  
QL)>/%yU  
1DEO3p  
public void setNSplitter(int nCount) <a8#0ojm  
{ O`wYMng)  
nSplitter = nCount; qDby!^ryc  
} a. h?4+^bN  
} CS~=Z>6EjA  
./"mn3U  
*Rz{44LP&  
/* ,U6*kvHS6  
**Utility.java +(;8@"u  
*/ jd ["eI  
package NetFox; o"'iX UJ  
%B#hb<7}  
OJMvn'y  
public class Utility { R&6n?g6@/V  
N4I^.k<-A  
<A#5v\{.;~  
public Utility() G_V.H \w  
{ =ud `6{R  
 M*d-z  
wXc,FD$  
} ~?FK ; (  
n_<mPU  
//线程睡眠 o;ik Z*+*  
public static void sleep(int nSecond) :fxWz%t  
{ mWNR(()v  
try{ S 3R|8?|  
Thread.sleep(nSecond); CdX`PQ  
} >j&1?M2C  
catch(Exception e) R<Z^L~)  
{ $Llta,ULE  
e.printStackTrace (); .D+RLO z  
} F|ETug n  
} 3H1Pp*PH  
.|T2\M  
//日志 ?ouV  
public static void log(String sMsg) HDyQzCG,  
{ fucUwf\_  
System.err.println(sMsg); {UP'tXah  
} aQ&uC )w  
`koOp  
|}Q( F+cL  
public static void log(int sMsg) Af`z/:0<  
{ W&<g} N+  
System.err.println(sMsg); fCLcU@3W?  
} Gu2_dT  
} Y;8 >=0ye  
V?=TVI*k  
8|w-XR  
/* F#6cF=};@  
**TestMethod.java /E)9v$!  
*/ L*P_vCC  
package NetFox; }qG#N  
,aI,2U91  
d;{y`4p)s  
public class TestMethod { (/'h4KS@  
KZ]r8  
.%_)*NUZ  
public TestMethod() $)Wb#B  
{ ///xx/weblogic60b2_win.exe @\ }sb]  
try{ TfL4_IAG.  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X&s7% ]n+  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :ztyxJv1  
SiteFileFetch fileFetch = new SiteFileFetch(bean); CQ<8P86gt  
fileFetch.start(); ai4PM b$p  
} 7UnzIe  
catch(Exception e){e.printStackTrace ();} /M:H9Z8!  
V7P6zAJy  
t')h{2&&!2  
} `Z:3` 7c  
;J'OakeVO  
c )03Ms4 D  
public static void main(String[] args) z4g+2f7h-X  
{ eO'xkm  
new TestMethod(); )`<6taKx@n  
} @YCv  
} zHV|-R  
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