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http断点续传简单实现(java)

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/* -e51 /lhpd  
**SiteFileFetch.java $Zi {1w  
*/ 0ly6  |:  
package NetFox; gpbdK?  
import java.io.*; MD 0d  
import java.net.*; INCanE`+  
!t)uRJ   
{)Zz4  
public class SiteFileFetch extends Thread { g p9;I*!  
a*,V\l|6  
2*-qEUl1  
SiteInfoBean siteInfoBean = null; //文件信息Bean :E|+[}|  
long[] nStartPos; //开始位置 RLw/~  
long[] nEndPos; //结束位置 ;8]Hw a1!  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 vl`St$$|  
long nFileLength; //文件长度 \WUCm.w6\%  
boolean bFirst = true; //是否第一次取文件 )>rYp )  
boolean bStop = false; //停止标志  W"~"R  
File tmpFile; //文件下载的临时信息 Q\^BOdX^`  
DataOutputStream output; //输出到文件的输出流 8M['-  
tuo'Uk)  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) :K \IS`  
public SiteFileFetch(SiteInfoBean bean) throws IOException \u/=?b  
{ N>j*{]OY+{  
siteInfoBean = bean; <qoPBm])  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); c!$~_?]  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); FGo)] U  
if(tmpFile.exists ()) >^f]Lgp  
{ /PBK:B  
bFirst = false; a5]]AkvA  
read_nPos(); !$-QWKD4  
} Ej@N}r>X  
else C0>)WVCK  
{ Z 2uU'T  
nStartPos = new long[bean.getNSplitter()]; Hw#yw g  
nEndPos = new long[bean.getNSplitter()]; P6'0:M@5  
} ~4S6c=:  
o:%;AOcl  
Kna@K$6{w=  
rG B*a8  
} .KYDYdoS'  
^'vWv C  
:bP <H  
public void run() SwH#=hg  
{ H[/^&1P  
//获得文件长度 >BMtR0  
//分割文件 ~c=*Y=)LG  
//实例FileSplitterFetch :r_/mzR#  
//启动FileSplitterFetch线程 rN~V^k  
//等待子线程返回 ~VF?T~Kr_  
try{ Bo*Wm w  
if(bFirst) *u34~v16,  
{ 4Gh%PUV#  
nFileLength = getFileSize(); 51>OwEf<R  
if(nFileLength == -1) ,v*\2oG3^  
{ U,`F2yD/!  
System.err.println("File Length is not known!"); BQ~\p\  
} {*Qx^e`h$.  
else if(nFileLength == -2) `LWbL*;Y0  
{ y|#Fu  
System.err.println("File is not access!"); \FIOFbwe  
} z)FGbX  
else !`dn# j  
{ rIj B{X{Z  
for(int i=0;i<nStartPos.length;i++) nlx~yUXL4  
{ d:n .Vp  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); )5U7w  
} ; JHf0  
for(int i=0;i<nEndPos.length-1;i++) *_uGzGB&G  
{ `$VnB  
nEndPos = nStartPos[i+1]; kPp7;U2A  
} 6)3pnhG9  
nEndPos[nEndPos.length-1] = nFileLength; |=Pw -uk  
} ^+dL7g?+  
} eG5xJA^  
KlRIJOS  
eKqo6P:#f  
//启动子线程 O/f+B}W  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qP[jtRIN  
for(int i=0;i<nStartPos.length;i++) L8KMMYh[  
{ (Mt-2+"+  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f@xjNm*'Z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &m@DK>  
nStartPos,nEndPos,i); v}"DW?  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~w$ ^`e!]  
fileSplitterFetch.start(); LZ~}*}jy  
} @yn1#E,  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I6 Q{ Axy  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :W1B"T<  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4"%LgV`  
nEndPos = " + nFileLength); )>^!X$`3  
// fileSplitterFetch[nPos.length-1].start(); sMWNzt  
y)+l U  
h!]=)7x;  
//等待子线程结束 NB)22 %  
//int count = 0; yUFT9bD  
//是否结束while循环 ,S=ur%  
boolean breakWhile = false; Md1ePp]  
oei2$uu  
#; >v,Jo  
while(!bStop) ]KRw[}z  
{ 2xpI|+ a%  
write_nPos(); |VML.u:N  
Utility.sleep(500); n]P,5  
breakWhile = true; w:[\G%yQ  
FO xZkU\e=  
l>jNBxB|/A  
for(int i=0;i<nStartPos.length;i++) 4Y}{?]>pu  
{ Z[zRZ2'i5  
if(!fileSplitterFetch.bDownOver) >iI-Cs7TD  
{ .d%CD`8!  
breakWhile = false; @7,k0H9Moa  
break; rW0-XLbL5H  
} |jTRIMj%,_  
} : ]~G9]R`  
if(breakWhile) ~myY-nEY  
break; xEqr3(  
R"qxT.P(  
`"qSr%|  
//count++; XlU`jv+  
//if(count>4) W v!%'IB  
// siteStop(); ]*vv=@"`e  
} 4xD`Z_U  
:5BVVa0oR  
QNgfvy  
System.err.println("文件下载结束!"); 4Yya+[RY  
} }:hN}*H  
catch(Exception e){e.printStackTrace ();} /}$D&KwYg  
} 7 y'2  
aqN6.t  
J`d;I#R%c  
//获得文件长度 ._US8  
public long getFileSize() +I r  
{ C7 T}:V](q  
int nFileLength = -1;  F'9#dR?  
try{ FWDAG$K@0  
URL url = new URL(siteInfoBean.getSSiteURL()); C{U"Nsu+1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'o]8UD(  
httpConnection.setRequestProperty("User-Agent","NetFox"); zP|^) h5  
Y4I;-&d's  
pt=H?{06  
int responseCode=httpConnection.getResponseCode(); ]}0QrD  
if(responseCode>=400) &Z 6s\r%  
{ *VgiJ  
processErrorCode(responseCode); C0%yGLh&  
return -2; //-2 represent access is error SK;c D>)  
} o==:e  
3DS&-rN  
Iju9#b6  
String sHeader; F!&$Z .  
:"I!$_E'  
yJ?S7+b  
for(int i=1;;i++) q=`i  
{ Dt=@OZW  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0 pPSg9  
//Utility.log(in.readLine()); :2(U3~3:  
sHeader=httpConnection.getHeaderFieldKey(i); 8zzY;3^h;  
if(sHeader!=null) `(o:;<&3  
{ -]k vM  
if(sHeader.equals("Content-Length")) ;HoBLxb P  
{ .l$:0a  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h0)Dj( C  
break; k}FmdaPI'  
} I::|d,bR!  
} |!E: [UH  
else JBt2R=  
break; H[D<G9:  
} F;sZc,Y,^  
} 1j?+rs+o-  
catch(IOException e){e.printStackTrace ();} .6[7D  
catch(Exception e){e.printStackTrace ();} /l1OC(hm  
VHqHG`}:  
/Xk-xg+U  
Utility.log(nFileLength); 25{-GaB  
+Fa!<txn  
^c|_%/  
return nFileLength; &r)[6a$fW  
} 1V:I }~\  
iqr/MB,W  
v,^W& W.  
//保存下载信息(文件指针位置) Z|$M 9E  
private void write_nPos() x ?24oO  
{ 1U6 z2i+y  
try{ &hu>yH>j  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~kFL[Asnaf  
output.writeInt(nStartPos.length); !\5w<*p8  
for(int i=0;i<nStartPos.length;i++) liU8OXBl  
{ ]I'dnd3e  
// output.writeLong(nPos); O QGKH6q  
output.writeLong(fileSplitterFetch.nStartPos); y,s`[=CT  
output.writeLong(fileSplitterFetch.nEndPos); h yK&)y?~  
} i8->3uB  
output.close(); ,9Si 3vn  
} D1R$s*{  
catch(IOException e){e.printStackTrace ();} _9:r4|S  
catch(Exception e){e.printStackTrace ();} 2mEvoWnJ  
} a&RH_LjM  
I>JBGR`j  
MUn(ZnQy|  
//读取保存的下载信息(文件指针位置) |ya.c\}q  
private void read_nPos() ohna1a^  
{ qsWy <yL+  
try{ 75^AO>gt   
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5D eo}(3  
int nCount = input.readInt(); ez<V  
nStartPos = new long[nCount]; 2"6bz^>}  
nEndPos = new long[nCount]; ]Bj2;<@y  
for(int i=0;i<nStartPos.length;i++) LS]0p#  
{ E.N  
nStartPos = input.readLong(); #f<3[BLx  
nEndPos = input.readLong(); S`8Iu[Ma  
} 76cLf~|d~  
input.close(); 50""n7I<%  
} H)+QkQb}  
catch(IOException e){e.printStackTrace ();} w)C5XX30;  
catch(Exception e){e.printStackTrace ();} /V GI@"^v  
} uH]oHh!}j  
c{ ([U  
rXP~k]tC  
private void processErrorCode(int nErrorCode) _;M3=MTM9  
{ ,pIh.sk7s*  
System.err.println("Error Code : " + nErrorCode); /mXxj93UA  
} lFl(Sww!\  
# /Bg5:  
% :h %i|  
//停止文件下载 6=:s3I^  
public void siteStop() `I.pwst8i-  
{ d}Q% I  
bStop = true; Q_>W!)p Gz  
for(int i=0;i<nStartPos.length;i++) R,ZG?/#uM9  
fileSplitterFetch.splitterStop(); k(he<-GF\  
jn(%v]  
F1meftK  
} N "}N>xe2  
} J6Vx7  
//负责部分文件的抓取 s'|t2`K("  
**FileSplitterFetch.java !<24Cy  
*/ $*|M+ofQ  
package NetFox; cj9C6Y!  
m!5Edo-;<  
u}b%-:-  
import java.io.*; gxx#<=`  
import java.net.*; ,Qs%bq{t  
LcZ|A;it  
[5!dO\-[  
public class FileSplitterFetch extends Thread { (9R;-3vY:S  
Gk]ZP31u  
t{s*,X\b  
String sURL; //File URL k!Q{u2  
long nStartPos; //File Snippet Start Position eR0$CTSw  
long nEndPos; //File Snippet End Position flT6y-d  
int nThreadID; //Thread's ID XO+rg&Pu  
boolean bDownOver = false; //Downing is over /,`OF/%  
boolean bStop = false; //Stop identical WdH/^QvTP  
FileAccessI fileAccessI = null; //File Access interface qVfl6q5  
tuLNGU  
T<-_#}.Hn  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ss%1{s~ok  
{ ~Up{zRD"B  
this.sURL = sURL; 4(p`xdr}K  
this.nStartPos = nStart; s VHk;:e>x  
this.nEndPos = nEnd; n*Uk<_WA  
nThreadID = id; .G#li(NWH  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hD=.rDvO  
} |c^?tR<  
1je j7p>K  
`nKN|6o#x  
public void run() ^=5x1<a9$  
{  +IO>%  
while(nStartPos < nEndPos && !bStop) H8B$# .  
{ AgZ?Ry  
GC:q6}  
@$~IPg[J  
try{ n}I?.r@e  
URL url = new URL(sURL); &gPP# D6A  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "F%JZO51  
httpConnection.setRequestProperty("User-Agent","NetFox"); [q U v|l1  
String sProperty = "bytes="+nStartPos+"-"; vxHFNGI  
httpConnection.setRequestProperty("RANGE",sProperty); r! HXhl  
Utility.log(sProperty); X =%8*_  
7f4O~4.[i  
:eSsqt9]9  
InputStream input = httpConnection.getInputStream(); N#2ldY *  
//logResponseHead(httpConnection); =YTcWB  
- Z`RKR8C  
H>A6VDu  
byte[] b = new byte[1024]; vENf3;o0  
int nRead; mf)+ 5On  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "i\#L`TkzX  
{ A&bj l[s  
nStartPos += fileAccessI.write(b,0,nRead); a]T&-#c,}  
//if(nThreadID == 1) BjeD4  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lm=;Y6'`N  
} X fqhD&g  
fP V n;  
U3N9O.VC  
Utility.log("Thread " + nThreadID + " is over!"); n{i,`oQ"  
bDownOver = true; Z Cjw)To(  
//nPos = fileAccessI.write (b,0,nRead); U2A 82;Z  
} )9:5?,SO  
catch(Exception e){e.printStackTrace ();} (v%24bv  
}  RQb}t,  
} @1Q-.54a  
`/ayg:WSU  
P/girce0  
//打印回应的头信息 hd u2?v@  
public void logResponseHead(HttpURLConnection con) 8M@'A5]  
{ [d8Q AO1;)  
for(int i=1;;i++) tw>2<zmSi%  
{ zD79M  
String header=con.getHeaderFieldKey(i); p*&0d@'r  
if(header!=null) ?UZt30|1  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z sTtSM\Ac  
Utility.log(header+" : "+con.getHeaderField(header)); +)iMJ]>  
else z8'1R6nq  
break; M{Z ;7n'  
} m$kQbPlatN  
} lOk8VlH<h  
{VL@U$'oI  
pX ^^0  
public void splitterStop() QCF'/G  
{ ^w.hI5ua)  
bStop = true; ~?AEtl#&"  
} C=/B\G/.9  
{^ b2nOMv  
^Aq0<  
} G$+v |z  
Zn'tNt/  
uI)twry]@  
/* RI0^#S_{  
**FileAccess.java B-R#?Xn:!I  
*//文件访问(定位,写) sa(.Anmlj  
package NetFox; ~vFa\7sf  
import java.io.*; ( %\7dxiK  
$+!dP{   
@)?]u U"L  
public class FileAccessI implements Serializable{ lGl'A}]#$  
AQlB_ @ b  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &(rWl`eTY`  
RandomAccessFile oSavedFile; `X6JZxGyd  
long nPos; &$F<]]&  
Jpj=d@Of70  
vRmn61  
public FileAccessI() throws IOException jdP )y]c  
{ LdV&G/G-#D  
this("",0); S{rltT-  
} rP3HR 5  
&0Yg:{k$  
.p&@;fZ  
public FileAccessI(String sName,long nPos) throws IOException 8Ojqm#/f  
{ K>@yk9)vi  
oSavedFile = new RandomAccessFile(sName,"rw"); HUi?\4  
this.nPos = nPos; #]kjyT0  
oSavedFile.seek(nPos); ttzNv>L,  
} 6<._^hyq  
"6$V1B0KW  
MC}t8L=  
public synchronized int write(byte[] b,int nStart,int nLen) XH"+oW  
{ /x6p  
int n = -1; a/sjW  
try{ `hi=y BO  
oSavedFile.write(b,nStart,nLen); D(#f`Fj;  
n = nLen; G@[8P?M=Z  
}  5&&4-  
catch(IOException e) 2J ZR"P  
{ &X$T "Dp  
e.printStackTrace (); =_7wd*,  
} Ey&H?OFiP  
%9J@##+  
N{;!xI v  
return n; <v:VA!]  
} ;]>kp^C#  
/kW Z 8Z  
/ (&E  
} {^VtD  
jT{T#_  
.f\LzZ-I:  
/* H}^'  
**SiteInfoBean.java K4c:k; V  
*/ !Zz;;Z  
package NetFox; eqo0{e  
q$Gs;gz^(  
9%/hoA)  
public class SiteInfoBean { 9y7N}T6  
Z*%;;&?  
:Ha/^cC/3  
private String sSiteURL; //Site's URL L"bOc'GfQ  
private String sFilePath; //Saved File's Path B$4*U"tk  
private String sFileName; //Saved File's Name rFRcK>X\L  
private int nSplitter; //Count of Splited Downloading File 5)k8(kH  
nw+~:c  
 0#,a#P  
public SiteInfoBean() rbw$=bX}  
{//nSplitter的缺省值为5 ?[D3 -4  
//default value of nSplitter is 5 )ZG;.j  
this("","","",5); 9wgB J Jl7  
} rf.pT+g.P  
WRh5v8Wz0  
q2qi~}l  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D*XrK0#Z`  
{ YG "Ta|@5  
sSiteURL= sURL; Dp@XAyiA[  
sFilePath = sPath; D BT4 W/  
sFileName = sName; n ~t{]if"  
this.nSplitter = nSpiltter; =kjKK  
Ot=jwvw  
o>el"0rn.h  
} l& :EKh  
/sE,2X*BT  
D JP6Z  
public String getSSiteURL() 4"d,=P.{  
{ p@ <Q?  
return sSiteURL; /x<g$!`X  
} o-,."|6  
54 lD+%E  
8Sbz)X  
public void setSSiteURL(String value) SQp|  
{ 6EqA Y`y  
sSiteURL = value; %go2tv:|W  
} LU1I `E  
ZlT }cA/n  
LCF}Y{  
public String getSFilePath() s\*L5{kiSl  
{ {15j'Qwm  
return sFilePath; !b8V&<  
} o3J#hQrl  
-t`kb*O3`  
<_EKCk  
public void setSFilePath(String value)  N5 ME_)  
{ g}an 5a  
sFilePath = value; rTPgHK]?l  
} 7CIN!vrC|1  
K$"#SZEi  
AjzTszByu  
public String getSFileName() (lk9](;L  
{ ]\E"oZ  
return sFileName;  5NU{y+  
} j\2Qe %d  
SSK}'LQ  
?=u?u k<-  
public void setSFileName(String value) )M0YX?5A R  
{ r`H}f#.KR  
sFileName = value; agIqca;  
} DUp`zW;B  
wk(25(1q  
Y:^hd809  
public int getNSplitter() Hon2;-:]{]  
{ |'^s3i&w  
return nSplitter; %iyc1]w{  
} 1\}vU  
DfXkLOGik  
5`;SI36"  
public void setNSplitter(int nCount) 4TtC~#D:  
{ 3I)~;>meo  
nSplitter = nCount; N*Y[[N(  
} K-qWT7<  
} X5 vMY  
,jU>V]YC  
GQ2GcX(E(  
/* aZ#FKp^8H  
**Utility.java rRTKF0+  
*/ |IgR1kp+.  
package NetFox; Xp<q`w0I,  
&@~K8*tmK  
y>o:5':;'  
public class Utility { UXm_-/&b9  
,d"T2Hy  
&<&tdShI  
public Utility() jqUVERbc  
{ #s)f3HU>  
o9kJ90{D=  
,K5K?C$k  
}  H.5 6  
73Dxf -  
//线程睡眠 !:{Qbv&T  
public static void sleep(int nSecond) wNB?3v{n  
{ ^<;W+dWdU  
try{ 'L/)9.29  
Thread.sleep(nSecond); .N(R~_  
} 7e_4sxg'(3  
catch(Exception e) ~ua(Qm  
{ -[mmT'sS  
e.printStackTrace (); JrP`u4f_  
} )g pN 5TDd  
} pdu1 kL  
.K C* (}-  
//日志 7HkO:/  
public static void log(String sMsg) TWP@\ BQ  
{ >A Ep\ *  
System.err.println(sMsg); D  T5d]MU  
} u>XXKlW:  
Fh~9(Y#  
*5'8jC"2g  
public static void log(int sMsg) YPK@BmAdE  
{ rZKh}E  
System.err.println(sMsg); -l[H]BAMXy  
} 5Tsz|k  
} "x$@^  
,&[o:jTk  
I4Do$&9<D  
/* CD1Ma8I8  
**TestMethod.java SKG U)Rn;  
*/ Np\NStx2  
package NetFox; snbXAx1L  
SSe;&Jk2d  
={g"cx  
public class TestMethod { Et6j6gmif  
Ey@^gHku\  
yg\QtWW M  
public TestMethod() D+T/ Z)  
{ ///xx/weblogic60b2_win.exe G|cjI*  
try{ ,Yag! i>;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ar-Vu{`  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FPc `J  
SiteFileFetch fileFetch = new SiteFileFetch(bean); <IrhR,@M,L  
fileFetch.start(); Q%CrB>|@  
} Q Xd`P4a  
catch(Exception e){e.printStackTrace ();} (Mc{nFqS  
W ?x~"-*  
fh#:j[R4e  
} Df"PNUwA"  
w1Bkz\95  
r CJ$Pl9R  
public static void main(String[] args) *`a$6F7m4  
{ tP_.-//  
new TestMethod(); C  eEhe  
} f]*;O+8$LN  
} enk`I$Xx  
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