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http断点续传简单实现(java)

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/* h|mh_T{+  
**SiteFileFetch.java }4ijLX>b  
*/ i;y<gm"  
package NetFox; 724E(?>J  
import java.io.*; }E[S%W[  
import java.net.*; -lRXH7|X  
L{N9h1]  
$T tCVR  
public class SiteFileFetch extends Thread { nYY@+%` ]z  
BM& 95p   
j! iimdq  
SiteInfoBean siteInfoBean = null; //文件信息Bean Uc!} D  
long[] nStartPos; //开始位置 "X's>uM  
long[] nEndPos; //结束位置 '{QbjG%<P  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 FGG Fi(  
long nFileLength; //文件长度 |L.QIr,jCC  
boolean bFirst = true; //是否第一次取文件 66fvS}x  
boolean bStop = false; //停止标志 5'?K(Jdmp  
File tmpFile; //文件下载的临时信息 _OZrH(8  
DataOutputStream output; //输出到文件的输出流 acdaDY  
|s+[489g'6  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) eEb(TG~,Y  
public SiteFileFetch(SiteInfoBean bean) throws IOException J1YP-:  
{ Eh#W*Bg  
siteInfoBean = bean; !3v!BJ#+,&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); M-,vX15S  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Z<;<!+,  
if(tmpFile.exists ()) fMlxtj+5   
{ rg "W1m[k  
bFirst = false; ",(-AU!a)h  
read_nPos(); VzA~w` $d  
} :-xp'_\L  
else hdQ[=PH)  
{ 5.0BaVwi  
nStartPos = new long[bean.getNSplitter()]; =PP]LDlJs  
nEndPos = new long[bean.getNSplitter()]; 0yfmQ=,X  
} &7,Kv0j}  
CSRcTxH  
CA7tI >y_  
MM3X! tq  
} uwsGtgd&  
Z`o}xV  
[~` ; .7~  
public void run() A 7'dD$9  
{ J )oa:Q  
//获得文件长度 cT`x,2  
//分割文件 Yl% Ra1  
//实例FileSplitterFetch O`g44LW2n  
//启动FileSplitterFetch线程 IfF<8~~E  
//等待子线程返回 AH;0=<n  
try{ rOm)s'  
if(bFirst) 7h<B:~(K  
{ b&"=W9(V  
nFileLength = getFileSize(); BLgmF E2  
if(nFileLength == -1) Y 6K<e:Y  
{ cAM1\3HWT"  
System.err.println("File Length is not known!"); 'M=(5p  
} w[I%Id;E  
else if(nFileLength == -2) 8|.( Y  
{ HB\<nK  
System.err.println("File is not access!"); (^ZC8)0i(  
} aAh")B2  
else c|X.&<lX  
{ q@~N?$>  
for(int i=0;i<nStartPos.length;i++) -A(] ",*J  
{ 1 9$ufod  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); puG$\D-[  
} *^bqpW2$q  
for(int i=0;i<nEndPos.length-1;i++) R;.zS^LL  
{ sEt5!&  
nEndPos = nStartPos[i+1]; y>'^<xk  
} @OZW1p  
nEndPos[nEndPos.length-1] = nFileLength; cR[)[9}  
} W#$ pt>h)  
} -\b~R7VQ  
YT+fOndjaF  
)7<JGzBZ1  
//启动子线程 tbJB0T|G  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w}zl=w{G  
for(int i=0;i<nStartPos.length;i++) KV k 36;$  
{ ld -c?  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5u'"m<4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^Jcs0c @\  
nStartPos,nEndPos,i); y&-wb'==p  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lsCD%P  
fileSplitterFetch.start(); S) Sv4Qm  
} H[U$4 %t  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !lG5BOJM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); G#ZU^%$M,  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H2 5Mx>|d  
nEndPos = " + nFileLength); Z Mids"Xdf  
// fileSplitterFetch[nPos.length-1].start(); DPw"UY:  
w 6+X{  
1"RO)&  
//等待子线程结束  &~:b &  
//int count = 0; EjV,&7o)  
//是否结束while循环 iIA5ylf{E  
boolean breakWhile = false; dms R>Q  
..UmbJJ.u  
fLA!oeq{&}  
while(!bStop) sn '#]yM  
{ j#$ R.  
write_nPos(); Q@6OIE  
Utility.sleep(500); G4{ zt3{  
breakWhile = true; PCF!Y(l  
B4bC6$Lg  
*>h"}e41  
for(int i=0;i<nStartPos.length;i++) p 2It/O  
{ x[U/ 8#f&  
if(!fileSplitterFetch.bDownOver) "X4OUk  
{ c}kZ x1  
breakWhile = false; A1Ia9@=Mf  
break; S75wtz)e  
} hn{]Q@(I  
} >0~|iRySi  
if(breakWhile) r&@#,g  
break; 75v 5/5zRn  
1q0DOf]!T  
RJYuyB  
//count++; fdc ?`4  
//if(count>4) 'e^,#L_!o  
// siteStop(); y/k6gl[`  
} IeLG/ fB  
R$X1Q/#md  
Q#Q]xJH  
System.err.println("文件下载结束!"); N`1:U 4}  
} 2>p K  
catch(Exception e){e.printStackTrace ();} 58\Rl  
} bq/ m?;  
{P"$;_Y"<  
D+lzISp~e  
//获得文件长度 +ObP[F  
public long getFileSize() >&6pBtC_  
{ [tGAo/  
int nFileLength = -1; D^yZ!}Kl  
try{ -'BC*fVr  
URL url = new URL(siteInfoBean.getSSiteURL()); 0ubT/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _W'>?e0i  
httpConnection.setRequestProperty("User-Agent","NetFox"); CMB:%  
`% k9@k .  
6*8"?S'  
int responseCode=httpConnection.getResponseCode(); J@PwN^`  
if(responseCode>=400) ~CIA6&  
{ ) (unL`y  
processErrorCode(responseCode); fDt#<f 4;  
return -2; //-2 represent access is error 6My=GByC  
} xy)Y)yp  
u&yAMWl  
qgg/_H:;w  
String sHeader; nd*9vxM  
23?\jw3w  
Wjc1EW!2x  
for(int i=1;;i++) bRT1~)  
{ Cj"+` C)l  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^ cpQ*Fz  
//Utility.log(in.readLine()); >a7OE=K  
sHeader=httpConnection.getHeaderFieldKey(i); 8dgI&t  
if(sHeader!=null) /?uA{/8  
{ JJ`RF   
if(sHeader.equals("Content-Length")) I4 {uw ge  
{ yqR2^wZ%r  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c]LE9<G  
break; <wWZ]P 2]  
} qp3J/(F  
} nt. A X  
else &?UIe]  
break; -x)Oo`  
} 2 Z K:S+c  
} Y5?*=eM  
catch(IOException e){e.printStackTrace ();} *"Yz"PK  
catch(Exception e){e.printStackTrace ();} ,rj_P  
Qz)1wf'y  
xj`ni G  
Utility.log(nFileLength); .|W0B+Z8  
&x6Z=|Ers  
E0; }e  
return nFileLength; Br^4N9  
} tS#=I.ET  
&XAG| #  
nAIV]9RAZ%  
//保存下载信息(文件指针位置) 29{Ep   
private void write_nPos() 0,$eiY)u$  
{ ~2u~}v5m7  
try{ 1AMxZ (e  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9RA~#S|(T  
output.writeInt(nStartPos.length); ~,[-pZ <  
for(int i=0;i<nStartPos.length;i++) :U;n?Zu S  
{ Y~z3fd  
// output.writeLong(nPos); Ua0fs|t1v  
output.writeLong(fileSplitterFetch.nStartPos); '-C%?*ku  
output.writeLong(fileSplitterFetch.nEndPos); vF yl,S5A  
} +e VWTRG  
output.close(); _~~:@fy  
} wJ#fmQXKJ5  
catch(IOException e){e.printStackTrace ();} WqQAt{W/<  
catch(Exception e){e.printStackTrace ();} &j=Fx F9o  
} n7-|\p!xP6  
z H$^.1  
) H=}bqn  
//读取保存的下载信息(文件指针位置) 8T"C]  
private void read_nPos() yF2|w=!  
{ tg =ClZ-  
try{ Y'K+O  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t8SvU  
int nCount = input.readInt(); ]^aOYtKX  
nStartPos = new long[nCount]; /zxLnT; 5  
nEndPos = new long[nCount]; dJyf.VJ  
for(int i=0;i<nStartPos.length;i++) X*f#S:kiNU  
{ C>l{_J)n  
nStartPos = input.readLong(); Su" 9`  
nEndPos = input.readLong(); T%0vifoQ_$  
} o[Ojl .r<  
input.close(); I ACpUB  
} V9aGo#  
catch(IOException e){e.printStackTrace ();} iA*^`NMaT  
catch(Exception e){e.printStackTrace ();} ^na8d's:  
} ]?KTw8j}  
MR4e.+#E  
}/)vOUcEd  
private void processErrorCode(int nErrorCode) ^3~+|A98M  
{ 2J7= O^$?  
System.err.println("Error Code : " + nErrorCode); bm/pLC6%.  
} cyYsz'i m  
XS:W{tL!  
X}"Ic@8  
//停止文件下载 D*7JE  
public void siteStop() Y)~Y;;/G  
{ tYb8a  
bStop = true; >4I,9TO  
for(int i=0;i<nStartPos.length;i++) Gg'sgn   
fileSplitterFetch.splitterStop(); JH3$G,:zM  
+=.>9  
hG1\  
} %{M_\Ae#  
} IQz"FH?  
//负责部分文件的抓取 {jyI7 r#X  
**FileSplitterFetch.java {WokH;a/  
*/ kH;DAphk  
package NetFox; =[A5qwyv  
ai,\'%N  
&8=wkG%  
import java.io.*; JSXJlau  
import java.net.*; %@C(H%obWd  
V2Iq k]V%y  
FKYPkFB  
public class FileSplitterFetch extends Thread { <jt_<p +  
u.\FNa  
#kGgz O  
String sURL; //File URL U`)\|\NY  
long nStartPos; //File Snippet Start Position C:r@)Mhq  
long nEndPos; //File Snippet End Position ?+3vK=Rf}  
int nThreadID; //Thread's ID +#* F"k(  
boolean bDownOver = false; //Downing is over .\Z/j  
boolean bStop = false; //Stop identical kHWW\?O  
FileAccessI fileAccessI = null; //File Access interface 2EO WbN}M  
R7'6#2y  
x}^ :Bs+j  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IBP3  
{ mGZJ$|  
this.sURL = sURL; g=ehAg  
this.nStartPos = nStart; u92);1R  
this.nEndPos = nEnd; <@F.qMl  
nThreadID = id; bQ%6z}r  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ig-V^P  
} `(- nSQ  
Np2I*l6W  
;`")3~M3*  
public void run() )GT*HJR(vc  
{ g3V bP  
while(nStartPos < nEndPos && !bStop) .Iu8bN(L`  
{ ~mSW.jy}=-  
R #f*QXv  
n'?AZ4&z  
try{ 9N+3S2sBx&  
URL url = new URL(sURL); =D>,s)}o3;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H[WsHq;T+9  
httpConnection.setRequestProperty("User-Agent","NetFox"); Uzi.CYVs%  
String sProperty = "bytes="+nStartPos+"-"; ol[sX=5 *  
httpConnection.setRequestProperty("RANGE",sProperty); |2L|Zp&  
Utility.log(sProperty); o"kVA;5<G  
96(3ilAt  
g36:OK"  
InputStream input = httpConnection.getInputStream(); cVV@MC  
//logResponseHead(httpConnection); %#_"I e  
Pv#Oea?  
(&Kv]--  
byte[] b = new byte[1024]; m{v*\e7 P  
int nRead; @V\ u<n  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R^p'gQc$   
{ \X*Es.;|x  
nStartPos += fileAccessI.write(b,0,nRead); |>Ld'\i8  
//if(nThreadID == 1) ^y,Ex;6o  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Za110oF  
} ~M c'~:{O  
]NEr]sc-"F  
S^8C\ E  
Utility.log("Thread " + nThreadID + " is over!"); VYR<x QA  
bDownOver = true; L2sUh+'|  
//nPos = fileAccessI.write (b,0,nRead); o^efeI  
} gTM*td(~^  
catch(Exception e){e.printStackTrace ();} $q|-9B  
} 7^oO N+=d  
} |#b]e|aP  
Yy 8? X9r.  
n%S%a >IQj  
//打印回应的头信息 >fq]c  
public void logResponseHead(HttpURLConnection con) sQ}E4Iq1#S  
{ ; _K3/:  
for(int i=1;;i++) G(3wI}  
{ )K}-z+$)k  
String header=con.getHeaderFieldKey(i); mfW}^mu  
if(header!=null) q+Ec|Xd e  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L*8U.{NY  
Utility.log(header+" : "+con.getHeaderField(header)); _'*Vcu`Y  
else t?aOZps  
break; s+-V^{Ht  
} {i^F4A@=Z  
} {V^|9j:\K  
G`e!WvC  
R<<U(.E  
public void splitterStop() e0$.|+  
{ cr`NHl/XF  
bStop = true; p9y@5z  
} Bjp4:;Bb  
`DFo:w!k  
A"}Ib'  
} &}rmDx  
Z}AhDIw!G  
;Tec)Fl  
/* e~ZxDAd  
**FileAccess.java t?(fDWd|-  
*//文件访问(定位,写) W; zzc1v  
package NetFox; ?u4t;  
import java.io.*; 'lMDlTU O  
P!yOA_)as  
m S4N%Q  
public class FileAccessI implements Serializable{ /8? u2 q  
h J H  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LTTMxiq[*  
RandomAccessFile oSavedFile; M{jJ>S{g  
long nPos; 4M )oA|1w  
$vLGX>H  
q&kG>  
public FileAccessI() throws IOException zN&m-nrw  
{  X@Bg_9\i  
this("",0); m7|S'{+!  
} +Ym#!"  
E*vh<C  
|%g)H,6c  
public FileAccessI(String sName,long nPos) throws IOException ]p@q.P  
{ )B9/P>c  
oSavedFile = new RandomAccessFile(sName,"rw"); ^ AJ_  
this.nPos = nPos; +7 mUX  
oSavedFile.seek(nPos); ELZ@0,  
} @x@wo9<Fc  
UZ;FrQ(l{  
=lmelo#m&  
public synchronized int write(byte[] b,int nStart,int nLen) GD1L6kVd1  
{ 2[CHiB*>  
int n = -1; rM`z2*7%d  
try{ H-qbgd6&>R  
oSavedFile.write(b,nStart,nLen); jfU$qo!gi  
n = nLen; 717OzrF}A?  
} }1mkX\wWP  
catch(IOException e) .^wBv 'Y  
{ = G>Y9Sc  
e.printStackTrace (); +,zV [\  
} tRbZX{  
2t;3_C  
qV)hCc/ ~  
return n; i.0d>G><@  
} `Ip``I#A  
20w4 '@sq  
zmhAeblA  
} w$0*5n>)  
re fAgS!=q  
6t{G{ ]  
/* 4xF}rm  
**SiteInfoBean.java cp&1yB   
*/ s_P[lbHt.  
package NetFox; * >k6n5%  
KP_7h/e  
zHD 8 \*  
public class SiteInfoBean { u`"Y!*[ -  
qGi\*sc>x  
d~KTUgH'<  
private String sSiteURL; //Site's URL GA"vJFQ  
private String sFilePath; //Saved File's Path 0v|qP  
private String sFileName; //Saved File's Name `-g$ 0lm7  
private int nSplitter; //Count of Splited Downloading File XPLm`Q|1#t  
qu0 q LM  
^ f[^.k$3d  
public SiteInfoBean() y/>Nx7C0=2  
{//nSplitter的缺省值为5 BKK@_B"  
//default value of nSplitter is 5 mGo NT  
this("","","",5); 63'L58O  
} 5R6QZVc  
7#j9"*  
,U~in)\ U  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %ed TW[C`  
{ P! P` MX  
sSiteURL= sURL; DAy|'%rF1-  
sFilePath = sPath; Y=@iD\u  
sFileName = sName; *i"Mu00b  
this.nSplitter = nSpiltter; p\}!uS4 (  
l-2lb&n  
#!>`$  
} 0x # V   
{KSy I#  
1ZXRH;J40  
public String getSSiteURL() PHMp, z8  
{ | Pqs)Mb]  
return sSiteURL; ypNeTR$4  
} ; hU9_e  
CoV @{Pi  
.uB[zJc  
public void setSSiteURL(String value) C't%e  
{ 6n/KL  
sSiteURL = value; ;x&3tN/I  
} Hp@cBj_@P2  
*fSX3Dk  
X{iidTW`xv  
public String getSFilePath() @ev^e !B  
{ *-'`Ea  
return sFilePath; oJZ0{^  
} 0 ke1KKy/d  
O]l-4X#8F  
qnzNJ_ `R  
public void setSFilePath(String value) Q'[~$~&`  
{ ?sxf_0*  
sFilePath = value; w$`u_P|@E:  
} I.o3Old  
(kx>\FIK*  
 HS|x  
public String getSFileName() fN 1:'d  
{ qJ$S3B  
return sFileName; R(2MI}T  
} BT(G9 Pj;  
w_YY~Af  
yCv"(fNQ  
public void setSFileName(String value) z u1gP/  
{ V{{UsEVO  
sFileName = value; II.Wa&w}  
} M+4S>Sjw  
th=45y"C  
?hW(5]p|  
public int getNSplitter() `U;V-  
{ ^fM=|.?  
return nSplitter; d_98%U+u  
} N]|U-fN\  
=OR&,xt  
5a* Awv}  
public void setNSplitter(int nCount) ,-> P+m5  
{ ND5E`Va5R  
nSplitter = nCount; *JaFt@ x  
} C,u;l~zz  
} #elaz8 5  
\)PS&Y8n  
U4Pk^[,p1G  
/* $P&27  
**Utility.java U9AtC.IG!  
*/ CjA}-ee  
package NetFox; w2tkJcQ3  
.sUL5`  
vaZ?>94  
public class Utility { BimM)4g  
a[gN+DX%L  
r3.v^  
public Utility() qxD<mZ@-R0  
{ wSs78c=  
;<`  
z yI4E\  
} x[%% )[d  
;}k_2mr~  
//线程睡眠 {XYf"ONi  
public static void sleep(int nSecond) $Vm J[EF1  
{ 3K_!:[  
try{ J~G"D-l<9/  
Thread.sleep(nSecond); QLTE`t5w3'  
} i)e)FhEY6  
catch(Exception e) SiJX5ydz  
{ q}5&B =2pM  
e.printStackTrace (); upH%-)%'  
} /XW,H0pR  
} 2qkC{klC^M  
4U:+iumy2  
//日志 >l5JwwG  
public static void log(String sMsg) z~a]dMs"(P  
{ mH3{<^Z6  
System.err.println(sMsg); >JhIRf  
} d>7bwG+k  
g:c @  
fmq^AnKd  
public static void log(int sMsg) FkT % -I  
{ jfrUOl'l  
System.err.println(sMsg); 'w7{8^Z2  
} {EupB?  
} B6vmBmN  
';7|H|,F  
8 _[f#s`)  
/* Qod2m$>wp}  
**TestMethod.java c[0$8F>  
*/ z'X_ s.9F  
package NetFox; :ui1]its4  
]# T9v06w  
WJL,L[XC  
public class TestMethod { P.1iuZ "w  
]j:Ikb}  
ByZ.!~  
public TestMethod() 63- YWhs;  
{ ///xx/weblogic60b2_win.exe Bj7\{x,?  
try{ z*>CP  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )u&_}6z  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9~mi[l~  
SiteFileFetch fileFetch = new SiteFileFetch(bean); `0Q:d'  
fileFetch.start(); ;7<a0HZ5!  
} j|(bDa4\  
catch(Exception e){e.printStackTrace ();} z:R2Wksg  
4%j&]PASa1  
|qNrj~n@  
} LGCL*Qbsg  
_?_Svx2  
<FK7Rz:4T  
public static void main(String[] args) 0+:.9*g=k  
{ @]#+`pZ4A  
new TestMethod(); x{*!"a>  
} S8vmXlD  
} C12 7he  
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