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http断点续传简单实现(java)

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/* Dp|y&x!  
**SiteFileFetch.java 4:<74B  
*/ eqD|3YX  
package NetFox; -g8G47piX:  
import java.io.*; K!^x+B|  
import java.net.*; $%!'c# F  
zr%2oFeX,  
In)8AK(Hw  
public class SiteFileFetch extends Thread { $/</J]2`;  
FbB^$ ]*  
h-u63b1"?  
SiteInfoBean siteInfoBean = null; //文件信息Bean [#$:X+lw  
long[] nStartPos; //开始位置 7Pspx'u  
long[] nEndPos; //结束位置 {HPKp&kl  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Ft)7Wx" S  
long nFileLength; //文件长度 ?EF[OyE  
boolean bFirst = true; //是否第一次取文件 M]&F1<  
boolean bStop = false; //停止标志 Xy[O  
File tmpFile; //文件下载的临时信息 ) jBPt&  
DataOutputStream output; //输出到文件的输出流 @]yd Wd  
Z 4,nl  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) @q0\oG4L  
public SiteFileFetch(SiteInfoBean bean) throws IOException (0/g)gW  
{ %>^CD_[eO  
siteInfoBean = bean; @{16j# 'R  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 9xL8 ];-  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Htd-E^/  
if(tmpFile.exists ()) KhK:%1po  
{ Gkci_A*  
bFirst = false; sd|5oz )  
read_nPos(); UMsJg7~  
} "&(.Z(  
else S*,DX~vig  
{ BUR96YN.  
nStartPos = new long[bean.getNSplitter()]; `j+aAxJ=\  
nEndPos = new long[bean.getNSplitter()]; Wt=QCutt  
}  WK;X6`  
T:$a x  
. 7WNd/WG  
W@<(WI3  
} e<wA["^  
C-Y~T;53  
@H%)!f]zWt  
public void run() `)e5pK  
{  hUy"XXpr  
//获得文件长度 82ay("ZY  
//分割文件 HD^Ou5YB  
//实例FileSplitterFetch f5p>oXo4b  
//启动FileSplitterFetch线程 Pi|WOE2  
//等待子线程返回 ;"/[gFD5u  
try{ C+ \c(M a  
if(bFirst) UYJMW S=  
{ u0^Vy#@_  
nFileLength = getFileSize(); TC7&IqT  
if(nFileLength == -1) 7Gg3$E+#*  
{ B->3/dp2c'  
System.err.println("File Length is not known!"); )BI6nU  
} QN`K|,}H^  
else if(nFileLength == -2) D; xRgHn  
{ ~,j52obR6Z  
System.err.println("File is not access!"); *d%"/l^0  
} @'UbTB!  
else YC(7k7  
{ pW{Q%"W  
for(int i=0;i<nStartPos.length;i++) O  |45r   
{ J_PAWW  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); kpT>xS^6<  
} _}8hE v  
for(int i=0;i<nEndPos.length-1;i++) GQ=Zp3[  
{ OCR`1  
nEndPos = nStartPos[i+1]; ~<[$.8*  
} }G8gk"st  
nEndPos[nEndPos.length-1] = nFileLength; z4 GcS/3K  
} y.h2hv]Bc  
} 7.V'T=@x3)  
 6/u]r  
)-yJKmV  
//启动子线程 9g %1^$R  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *4]u?R  
for(int i=0;i<nStartPos.length;i++) KZ8Hp=s  
{ kD_Ac{{<  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y#aL]LxZE  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }_,\yC9F  
nStartPos,nEndPos,i); T!-*;yu  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +qN}oyL  
fileSplitterFetch.start(); |"}F cS y  
} Vf28R,~m  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MR")  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0PfjD  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B49: R >  
nEndPos = " + nFileLength); 0j{Rsy   
// fileSplitterFetch[nPos.length-1].start(); =K#5I<x  
Ka\h a  
(<bYoWrK#  
//等待子线程结束 v)+E!"R3.  
//int count = 0; jh7-Fl`  
//是否结束while循环 I8ZBs0sfF{  
boolean breakWhile = false; zG IxmJ.  
1f 3c3PJ  
[)efh9P*  
while(!bStop) S($8_u$U  
{ Oy(f h%k#  
write_nPos(); <Z b~tYp  
Utility.sleep(500); pl#2J A8  
breakWhile = true; !{u`}:\  
l\f /(&,  
Nuc;Y  
for(int i=0;i<nStartPos.length;i++) \mK;BWg)  
{ aMU0BS"   
if(!fileSplitterFetch.bDownOver) Gm`#0)VC  
{ B/Jz$D  
breakWhile = false; h7 r *5E  
break; 0^lCZ,uq;  
} 38<Z=#S  
} DxM$4  
if(breakWhile) KM-d8^\:  
break; 1>~bzXY#  
0H9UM*O  
G4&vrM,f  
//count++; pL [JGn  
//if(count>4) \&!qw[;O  
// siteStop();  =1MVF  
} e]9Z]a2  
P/!W']OO  
\ 8v^ hb  
System.err.println("文件下载结束!"); qV$\E=%fhM  
} [SKN}:D  
catch(Exception e){e.printStackTrace ();} 0Dt-!Q7  
} Ji#eA[  
PTS dW~3  
gZf8/Tp\z  
//获得文件长度 @PL.7FM<v  
public long getFileSize() " ""k}M2A  
{ #Sc9&DfX  
int nFileLength = -1; 634OH*6  
try{ -P6Z[ V%  
URL url = new URL(siteInfoBean.getSSiteURL()); -~_[2u^3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [r#m +R"N  
httpConnection.setRequestProperty("User-Agent","NetFox"); TSKT6_IJw  
-I0J-~#  
v\Y8+dD  
int responseCode=httpConnection.getResponseCode(); N^Hj%5  
if(responseCode>=400) #c%F pR4  
{ : L+%5Jq  
processErrorCode(responseCode); |Cm6RH$(  
return -2; //-2 represent access is error ?hmuAgOtbh  
} ;Yve m  
vojXo|c  
`s8o2"12  
String sHeader; %,UTFuM`  
@ogj -ol&  
d-cW47  
for(int i=1;;i++) @|PUet_pb  
{ Y@y"bjK \  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h!mx/Hx  
//Utility.log(in.readLine()); 5 W!#,jz  
sHeader=httpConnection.getHeaderFieldKey(i); &_$0lI DQ  
if(sHeader!=null) XW.k%H4@  
{ ipe8U1Sc  
if(sHeader.equals("Content-Length")) KvH t`  
{ -#Ys67,4N  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XI+GWNAmJ  
break; d:Oo5t)MN  
} / # d^  
} K (,MtY*  
else z2lT4SAv+  
break; 34,'smHi%  
} RT. %\)))  
} M%YxhuT0  
catch(IOException e){e.printStackTrace ();} j#jwK(:]  
catch(Exception e){e.printStackTrace ();} L0)w~F ?m  
x=03 WQ8  
Z<iK(?@O  
Utility.log(nFileLength); $|tk?Sps  
skYHPwJdW  
)UtK9;@"  
return nFileLength; R; ui 4wg6  
} T/PmT:Qg `  
 {DD #&B  
Pm]lr|Q{I  
//保存下载信息(文件指针位置) ..R JHa6B  
private void write_nPos() CofTTYl  
{ Qv<p$Up6  
try{ 8,IQ6Or|-2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1k]L,CX  
output.writeInt(nStartPos.length); KF6N P  
for(int i=0;i<nStartPos.length;i++) &Oc `|r*  
{ `GSl}A  
// output.writeLong(nPos); 5,pEJ>dDD3  
output.writeLong(fileSplitterFetch.nStartPos); r PTfwhs  
output.writeLong(fileSplitterFetch.nEndPos); <iBn-EG l>  
} ^u2x26].  
output.close(); / */"gz%  
} }qJ`nN8  
catch(IOException e){e.printStackTrace ();} /BN=Kl]  
catch(Exception e){e.printStackTrace ();} }G "EdhSl  
} icQQLSU5  
($Op*bR  
$DaQM'-  
//读取保存的下载信息(文件指针位置) :r2d%:h%2  
private void read_nPos() }KYOde@  
{ voFg6zoV_  
try{ kxR!hA8wv4  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JAM]neKiX  
int nCount = input.readInt(); dOK]Su  
nStartPos = new long[nCount]; )%b 5uZ  
nEndPos = new long[nCount]; Vry*=X &Q  
for(int i=0;i<nStartPos.length;i++) 2r!- zEV  
{ qnb/zr)p  
nStartPos = input.readLong(); hE E1i  
nEndPos = input.readLong(); +^jm_+  
} J7sH]  
input.close(); (Y*9 [hm  
} -Mf-8zw8G  
catch(IOException e){e.printStackTrace ();} w5yX~8UzJ  
catch(Exception e){e.printStackTrace ();} 0|]d^bo  
} ">M&/}4  
3ZN\F  
Fn0 |v66  
private void processErrorCode(int nErrorCode) Ct^=j@g  
{ N{}8Zh4op  
System.err.println("Error Code : " + nErrorCode); V(XZ7<& {  
} >l #D9%  
>5E1y!  
0_AIKJrL  
//停止文件下载 {>PEl; ,-  
public void siteStop() LqO=wK~  
{ cml~Oepf  
bStop = true; aI=Q_}8-  
for(int i=0;i<nStartPos.length;i++) DAg*  
fileSplitterFetch.splitterStop(); ,)N/2M\B-  
'? -N  
`A5n6*A7  
} acar-11_o/  
} .S1MxZhbP  
//负责部分文件的抓取 ]jPP]Z:y  
**FileSplitterFetch.java Q/]o'_[vW  
*/ <o[3*59  
package NetFox; e2BC2K0  
}#; .b'`  
FhPCFmmUT  
import java.io.*; z,hBtq:-$  
import java.net.*; 2s> BNWTU  
v,8Q9<=O  
T@`Al('  
public class FileSplitterFetch extends Thread { y<wd~!>Ubu  
-/0aGqY  
^16zZ*  
String sURL; //File URL h@'CmIZc  
long nStartPos; //File Snippet Start Position X$@qs9?)^  
long nEndPos; //File Snippet End Position !! )W`  
int nThreadID; //Thread's ID _~D#?cFY6  
boolean bDownOver = false; //Downing is over Zy.ls&<:  
boolean bStop = false; //Stop identical C@\5%~tW+  
FileAccessI fileAccessI = null; //File Access interface s[dIWYs#  
fBh/$    
@|sBnerE  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,!LY:pMK  
{ U* c'xoP  
this.sURL = sURL; Fq!_VF^r  
this.nStartPos = nStart; C(h Td%  
this.nEndPos = nEnd; H3`.Y$z  
nThreadID = id; ~'0ZW<X.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )n 1[#x^I  
} *9w-eK1{  
r{84Y!k~*  
q_ryW$/_  
public void run() c`UFNNm=  
{ 5W&L cBB  
while(nStartPos < nEndPos && !bStop) z]C=nXb k  
{ 3:8p="$F  
'-J<ib t  
r:g_mMvB  
try{ '?Q"[e  
URL url = new URL(sURL); &['x+vL9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~ iQBgd@D^  
httpConnection.setRequestProperty("User-Agent","NetFox"); ](8F]J ,  
String sProperty = "bytes="+nStartPos+"-"; 1|!)*!hu  
httpConnection.setRequestProperty("RANGE",sProperty); %l#X6jkt  
Utility.log(sProperty); T9!NuKfur  
om9'A=ZU  
e=s85!  
InputStream input = httpConnection.getInputStream(); c#`IF6qj  
//logResponseHead(httpConnection); dFhyT.Y?  
vF pKkS343  
7jQVm{{.  
byte[] b = new byte[1024]; wHQ$xO;vD'  
int nRead; =au!rda  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6Z' K1  
{ I{WP:]"Yf  
nStartPos += fileAccessI.write(b,0,nRead); bd-iog(  
//if(nThreadID == 1) l?rLadvc  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); | 5:2?S2R  
} o1?-+P/  
}p)Hw2  
>SL mlK  
Utility.log("Thread " + nThreadID + " is over!"); NP.i,H  
bDownOver = true; C984Ee  
//nPos = fileAccessI.write (b,0,nRead); W[a"&,okqO  
} '6e4rn{  
catch(Exception e){e.printStackTrace ();} )G?\{n-  
} 98O]tL+k/u  
} GCiG50Z=  
u*W! !(P/  
zJl;| E".  
//打印回应的头信息 *]h"J]  
public void logResponseHead(HttpURLConnection con) 2<p@G#(  
{ Eu "8IM!%-  
for(int i=1;;i++) =<m!% /I  
{ QxxPImubB  
String header=con.getHeaderFieldKey(i); ?6nB=B)/  
if(header!=null) QT73=>^B  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =Ry8E2NuM  
Utility.log(header+" : "+con.getHeaderField(header)); Fj2z$   
else cQ1Axs TO  
break; -$:*!55:j  
}  ;Ss!OFK  
} /\uopa  
jAue+ tB  
)!cucY  
public void splitterStop() x3#:C=  
{ p~=z)7% e'  
bStop = true; ov H'_'  
} 7CSz  
:@"o.8p   
Hm!"%  
} ;~djbo0,X  
Uf ]$I`T#  
<H-kR\HF  
/* MMC$c=4"  
**FileAccess.java QA;,/iw`  
*//文件访问(定位,写) S5, u| H  
package NetFox; ebNRZJ?C,  
import java.io.*; m[Ihte->  
0*tnJB  
|4P8N{ L>O  
public class FileAccessI implements Serializable{ ZI qXkD  
*{j;LA.BR#  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <Opw"yY&q]  
RandomAccessFile oSavedFile; (|o @  
long nPos; \lQI;b;$  
do.>Y}d  
::iYydpM  
public FileAccessI() throws IOException %e0X-tXcmX  
{  [ OUV!o  
this("",0); 77sG;8HE  
} vO&X<5?Qc  
kONn7Itbu  
7][fciZN  
public FileAccessI(String sName,long nPos) throws IOException #I.~+M  
{ }vx,i99W?  
oSavedFile = new RandomAccessFile(sName,"rw"); $joGda  
this.nPos = nPos; &qSf ~7/  
oSavedFile.seek(nPos); 6SE^+@jR  
} =54D#,[B  
hCF_pt+  
F%&lM[N%  
public synchronized int write(byte[] b,int nStart,int nLen) jPZ+~:m+  
{ n7~4*B  
int n = -1; B[EOz\?=m  
try{ 4g2`[<S  
oSavedFile.write(b,nStart,nLen); %saP>]o  
n = nLen; }qoId3iY!7  
} lxgfi@@+h  
catch(IOException e) ~MC 5rOA  
{ 59SL mj  
e.printStackTrace (); B hx.q,X  
} mLkp*?sfC  
'jE/Tre^  
(jhi<eV  
return n; KWD{_h{R  
} yHC[8l8%  
X"`[&l1  
_z%~ m2SP  
} bXc*d9]  
lX2:8$?X  
O43"-  
/* R[m{"2|,Lc  
**SiteInfoBean.java =-/'$7R,  
*/ {dxl8~/I  
package NetFox; H Q[  
<oT1&C{  
B6TE9IoSb8  
public class SiteInfoBean { .bP8Z =  
bx{njo1Mr  
_K{- 1ZYsi  
private String sSiteURL; //Site's URL v?6*n >R  
private String sFilePath; //Saved File's Path d*04[5`  
private String sFileName; //Saved File's Name $|&<cenMT  
private int nSplitter; //Count of Splited Downloading File 'U ZzH$h  
"s]  
XRQ1Uh6  
public SiteInfoBean() [_3&  
{//nSplitter的缺省值为5 Zos.WS#  
//default value of nSplitter is 5 >b9J!'G,(  
this("","","",5); lDKyD`WKnZ  
} mS;WNlm\  
'q~<ZO  
40`Qsv0#  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aJjUy%  
{ /=AFle2(  
sSiteURL= sURL; 3)o>sp)Ji$  
sFilePath = sPath; [.xc`CF  
sFileName = sName; SB('Nqih  
this.nSplitter = nSpiltter; 6)ZaK  
3dbaCusT$  
:*[mvF  
} 4 $Kzh  
._A4 :  
]3='TN8aQF  
public String getSSiteURL() h@1/  
{ =L1%gQJJ&  
return sSiteURL; )!E:  
} L;vglS=l;  
cmU0=js.  
BQ[R)o  
public void setSSiteURL(String value) `W_&^>yl  
{ 9ei'oZ  
sSiteURL = value; \h s7>5O^K  
} \}kR'l  
gpzFY"MS=  
.mqMzV  
public String getSFilePath() NX(+%EBcA  
{ %x@bP6d[  
return sFilePath; Eul3 {+]  
} '~f*O0_  
Ei+lVLoC  
ht6}v<x.eA  
public void setSFilePath(String value) 6(htpT%J  
{ CKe72OC  
sFilePath = value; gp 11/ .  
} Q7F4OS5b  
m8F \ESL  
e]; IQ|  
public String getSFileName() |E$q S)y  
{ }W!w  
return sFileName; a;U)#*(5|v  
} +lFBH(o]X  
cp~6\F;c  
HA}q.L]#  
public void setSFileName(String value) ?z-nY,'^uq  
{ W=+AU!%  
sFileName = value; f>cUdEPBb  
} |?^N@  
*KiY+_8>  
>j ].`T  
public int getNSplitter() s?1Aj<  
{ hv>Xr=RE  
return nSplitter; %" mki>  
} lWJYT <kt  
x30|0EHYl[  
A0;{$/  
public void setNSplitter(int nCount) fU%Ys9:wU  
{ yV L >Ie/  
nSplitter = nCount; . 8ikcs  
} ^!k_"C)B  
} H=WB6~8)  
?5lO1(  
n!X%i+|4x  
/* HpUJ_pZ  
**Utility.java o.|36#Fa  
*/ QKvaTy#  
package NetFox; uX{g4#eG  
TPkP5w  
A~k: m0MX  
public class Utility { 7TypzgXNe  
H|j]uLZ  
'|v<^EH  
public Utility() zT/woiyB`  
{ =c#mR" 1  
|t3}>+"?z  
|FlB#  
} RhF< {U.  
mKV31wvK}  
//线程睡眠 pK_zq  
public static void sleep(int nSecond) rij%l+%@#  
{ iny/K/5bf  
try{ %zEy.7Ux  
Thread.sleep(nSecond); %'=TYvB 2  
} U Lq`!1{   
catch(Exception e) QJR},nZ3  
{ O)&ME  
e.printStackTrace (); uP8 cW([  
} tx+P@9M_Aq  
} }waZGJLN  
}> C?Zx*  
//日志 t)k;5B`> &  
public static void log(String sMsg) egfd=z=2un  
{ 4 PU@W o  
System.err.println(sMsg); D0S^Msk9L  
} ~WV1t][  
k@n L(2  
"OkZ [E)  
public static void log(int sMsg) ix?Z:pIS0  
{ :c )R6=v  
System.err.println(sMsg); UaQW<6+  
} z1tCSt}7f  
} *?Wr^T  
r,vSDHb`j  
h.- o$+Sa  
/* =bvLMpa  
**TestMethod.java qf [J-"o  
*/ 7+[L6q/K  
package NetFox; o ?.VW/"  
XJS^{=/  
_wW"Tn]  
public class TestMethod { $mf6!p4  
ci 22fw0  
m<cv3dbZo  
public TestMethod() Xfg?\j/  
{ ///xx/weblogic60b2_win.exe ^y|`\oyqwN  
try{ *8%uXkMm  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V!+<  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fbah~[5}  
SiteFileFetch fileFetch = new SiteFileFetch(bean); '?{L gj^R  
fileFetch.start(); -I#<?=0B  
} m,w^,)  
catch(Exception e){e.printStackTrace ();} }>YEtA  
@fVz *  
K3rsew n  
} 6BXZGE  
pm=s  
UK@hnQU8`  
public static void main(String[] args) yB;K|MXy?  
{ =3 ;! 5P  
new TestMethod(); `VglE?M  
} ?$/W3Xn0%  
} w0<1=;_%  
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