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http断点续传简单实现(java)

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/* yM-3nwk  
**SiteFileFetch.java [j^c&}0  
*/ }|!9aojr  
package NetFox; Da8{==  
import java.io.*; o\7q!  
import java.net.*; |g}~7*+i  
H(k-jAO,  
:UdH}u!Ek  
public class SiteFileFetch extends Thread { 6}9`z8  
*)4 `"D  
dN)!B!*aI  
SiteInfoBean siteInfoBean = null; //文件信息Bean b`Agb <x"  
long[] nStartPos; //开始位置 xIh,UW#  
long[] nEndPos; //结束位置 F;@A2WD  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 :Z'q1kW@"  
long nFileLength; //文件长度 `zZGL&9m`  
boolean bFirst = true; //是否第一次取文件 2%F!aeX  
boolean bStop = false; //停止标志 $IU|zda8  
File tmpFile; //文件下载的临时信息 A(<"oAe|  
DataOutputStream output; //输出到文件的输出流 21\t2<"  
?c!W*`yP  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) !WD~zZ|  
public SiteFileFetch(SiteInfoBean bean) throws IOException !W ,pjW%Y  
{ hi(u L>\  
siteInfoBean = bean; MH8Selnv  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); sF=8E8qa   
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $6 A91|ZSQ  
if(tmpFile.exists ()) hz8Z)xjJ V  
{ IhYTK%^96  
bFirst = false; QTNE.n<?  
read_nPos(); S@'yuAe*G  
} J6VG j=/  
else ~>]/1JFz  
{ `p. O  
nStartPos = new long[bean.getNSplitter()]; 9 yE   
nEndPos = new long[bean.getNSplitter()]; z]J pvw`p  
} )K+ Tvx3(m  
~dO&e=6Hk  
p*^[ ~}N  
TT0~41&l  
} w[V71Iej  
o/U"'FP  
QNzx(IV@  
public void run() ^:c"%<"='  
{ HYkZMVH{  
//获得文件长度 w u  
//分割文件 i1kTP9  
//实例FileSplitterFetch Apfs&{Uy  
//启动FileSplitterFetch线程 Lb>UraUvL  
//等待子线程返回 z^q ~|7  
try{ JN Ur?+g  
if(bFirst) A]FjV~PB  
{ 8@f=GJf  
nFileLength = getFileSize(); 0y"Ra%Y  
if(nFileLength == -1) pM^r8kIH  
{ EZ.|6oug\  
System.err.println("File Length is not known!"); Ao:<aX,=  
} @sV6g?{tI  
else if(nFileLength == -2) Ak\w)!?s  
{ ?5>Ep:{+/  
System.err.println("File is not access!"); $ 4& )  
} \2K_"5  
else 5V^+;eO  
{ TZ]D6.mD  
for(int i=0;i<nStartPos.length;i++) jd&kak  
{ .-6B6IEI_"  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); yE\dv)(<  
} *)2& gQ&%+  
for(int i=0;i<nEndPos.length-1;i++) f_&bwfbo  
{ U#jbii6e  
nEndPos = nStartPos[i+1]; \*C}[D  
} d4h, +OU  
nEndPos[nEndPos.length-1] = nFileLength; ?G#T6$E8  
} 5Z`9L| 3d  
} 3+%c*}KC~  
V ?10O  
V=@M!;'<  
//启动子线程 fh1rmet&Ts  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !i|]OnJY  
for(int i=0;i<nStartPos.length;i++) k lRS:\dW  
{ U(.3[x  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s5s'$|h"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o+H;ZGT5H  
nStartPos,nEndPos,i); kc3dWWPe  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BtyBZ8P;e  
fileSplitterFetch.start(); y8$TU;  
} BJM_kKH  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), llf|d'5Nl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k0=$mmmPY  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eQ}o;vJN  
nEndPos = " + nFileLength); )V}u}5  
// fileSplitterFetch[nPos.length-1].start(); YlZe  
TZT1nj"n  
S z3@h"  
//等待子线程结束 8( ^;h2O!  
//int count = 0; Vp;^_,  
//是否结束while循环 hJ+;N  
boolean breakWhile = false; ;OlC^\e  
24TQl<H{  
Z;^UY\&X  
while(!bStop) z;dD }Fo  
{ xwwy9:ze*l  
write_nPos(); q L6Rs  
Utility.sleep(500); B rGaCja  
breakWhile = true; @ (UacFO  
ddDl~&}o  
, qj  
for(int i=0;i<nStartPos.length;i++) 8+Y+\XZG  
{ k{/2vV[`]  
if(!fileSplitterFetch.bDownOver) 4uW}.7R'  
{ ZiBTe,;  
breakWhile = false; aj1o   
break; }";\8  
} FbMX?T"yH  
} `TM[7'  
if(breakWhile) PYldqY   
break; wG1A]OJl1  
sLE@Cm]k  
:%M[|Fj  
//count++; q M( n]{H  
//if(count>4) E\5cb[Y  
// siteStop(); ~.;S>o[  
} 2;@#i*\Y  
S!0ocS!t  
2TN+ (B#Z!  
System.err.println("文件下载结束!"); K)|#FRPM u  
} y{~l&zrl  
catch(Exception e){e.printStackTrace ();} ~ {sRK  
} FF:Y7wXW  
hjB G`S#  
 fL9R{=I%  
//获得文件长度 >gAq/'.Q  
public long getFileSize() X G fLi  
{ Jsee8^_~  
int nFileLength = -1; &8R%W"<K  
try{ Ol4 )*/oZ  
URL url = new URL(siteInfoBean.getSSiteURL()); 7xAzd# c?=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T<*i($ [  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]| oh1q  
|A_yr/f  
5}3Q}o#  
int responseCode=httpConnection.getResponseCode(); r2A(GUz  
if(responseCode>=400) _ukKzY  
{ S$q:hXZ#e  
processErrorCode(responseCode); |I7-7d-; /  
return -2; //-2 represent access is error &P>wIbE  
} vmI]N  
\>NjeMuWU  
C<CE!|sfr  
String sHeader; Sr)rKc  
/esSM~*H  
Fy N@mX  
for(int i=1;;i++) >jjuWO3T  
{ ~c7}eTJd"  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 45l/)=@@B  
//Utility.log(in.readLine()); ,?;q$Xoi  
sHeader=httpConnection.getHeaderFieldKey(i); @; ayl  
if(sHeader!=null) \HFeEEKH  
{ yyJ4r}TE  
if(sHeader.equals("Content-Length")) $a(EF 6  
{ LGq}wxq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *h Ph01  
break; :. B};;N  
} =/MAKi}g  
} uGl +"/uDu  
else 1P&XG@  
break; [nBlHI;&  
} o >bf7+D  
} E<;C@B  
catch(IOException e){e.printStackTrace ();} (v*$ExF  
catch(Exception e){e.printStackTrace ();} C.dN)?O  
Hk%m`|Z  
T!eb=oy  
Utility.log(nFileLength); '7}s25[{\  
ETe,RY  
SlvQ)jw%  
return nFileLength; az3rK4g  
} TfK$tTkM  
c,;-[sn  
Kl~jcq&z  
//保存下载信息(文件指针位置) %76N$`{u  
private void write_nPos() <N^2|*3  
{ E7^r3#s  
try{ ZiodJ"r  
output = new DataOutputStream(new FileOutputStream(tmpFile)); +~RiCZt  
output.writeInt(nStartPos.length); {4tJT25  
for(int i=0;i<nStartPos.length;i++) rwr>43S5<3  
{ -%"Kxe  
// output.writeLong(nPos); TGu`r>N51  
output.writeLong(fileSplitterFetch.nStartPos); Hw[u Sv8  
output.writeLong(fileSplitterFetch.nEndPos); 2'W3:   
} t>><|~wp  
output.close(); e"P>b? OY  
} !Y/$I?13Z  
catch(IOException e){e.printStackTrace ();} u$d T^c  
catch(Exception e){e.printStackTrace ();} 5F$ elW  
} n\&[^Q#b|  
PO5/j  
~7T]l1]W%  
//读取保存的下载信息(文件指针位置) ?)k;.<6  
private void read_nPos() ]Ow A>fb  
{ HkFoyy  
try{ +s.r!?49+  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WPiQ+(pt  
int nCount = input.readInt(); Im i)YC  
nStartPos = new long[nCount]; 7HzO_u%H1  
nEndPos = new long[nCount]; %{g<{\@4(;  
for(int i=0;i<nStartPos.length;i++) Y ## ftQ  
{ V~` ?J6  
nStartPos = input.readLong(); }6MHIr=o  
nEndPos = input.readLong(); E9t[Mb %0  
} _v:t$k#sN  
input.close(); _oxhS!.*  
} 4~=/CaG~  
catch(IOException e){e.printStackTrace ();} {Sm^F  
catch(Exception e){e.printStackTrace ();} 8C3oj  
} XqMJe'%r  
E$dPu  
{H{u[XR[z  
private void processErrorCode(int nErrorCode) 7<DlA>(oUX  
{ hDI_qZ  
System.err.println("Error Code : " + nErrorCode); { [ QCuR  
} $TS4YaJ%  
wB~Ag$~  
f"j~{b7  
//停止文件下载 fvg jqiT  
public void siteStop() Ub!MyXd{q  
{ ;:NW  
bStop = true; G$&SlJZEk  
for(int i=0;i<nStartPos.length;i++) f]N2(eM  
fileSplitterFetch.splitterStop(); #]pFE.o  
/pni_-l*  
aj;OG^(!2_  
} !2>MaV1,  
} -E_lwK  
//负责部分文件的抓取 ~ {OBRC  
**FileSplitterFetch.java gwwYz]'d>r  
*/ udYk 6  
package NetFox; <Uf?7  
]G m"U!h*  
| wuUH  
import java.io.*; c+P.o.k;  
import java.net.*; luAmq+  
Ao>] ~r0  
cC@B\Q  
public class FileSplitterFetch extends Thread { >.^/Z/[.L  
_s{on/u  
co^kP##Y  
String sURL; //File URL Bbk=0+ ^8I  
long nStartPos; //File Snippet Start Position ^ 'W<|  
long nEndPos; //File Snippet End Position .=rS,Tpo  
int nThreadID; //Thread's ID hJ[Z~PC\T0  
boolean bDownOver = false; //Downing is over iOk^RDG+  
boolean bStop = false; //Stop identical T 2Uu/^  
FileAccessI fileAccessI = null; //File Access interface 0~2~^A#]\  
$e>(M&9,  
z2:^Qg  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {uVvo=3  
{ '*K}$+l  
this.sURL = sURL; Se*o{V3s$  
this.nStartPos = nStart; );X &J:-l+  
this.nEndPos = nEnd; ro:B[XE  
nThreadID = id; `a *_b9  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <7-Qn(m,  
} WBcnE( zF  
w Q!C9Gp3e  
Z]U"i1lA  
public void run() UqJ}5{rt  
{ 1?k{jt~  
while(nStartPos < nEndPos && !bStop) A{3VTe4TV  
{ -.XICKz  
&z'N Q !uV  
Vqr#%. N  
try{ -nM=^ i4)  
URL url = new URL(sURL); Aun X[X9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,ddoII  
httpConnection.setRequestProperty("User-Agent","NetFox"); s#phs `v  
String sProperty = "bytes="+nStartPos+"-"; wrtJ8O(  
httpConnection.setRequestProperty("RANGE",sProperty); 9 GEMmo3  
Utility.log(sProperty); Ph{7S43  
# !:u*1  
dY|~"6d)  
InputStream input = httpConnection.getInputStream(); 6M sVV_/  
//logResponseHead(httpConnection); 8OV;&Z,x  
~8fy qE$  
X*4iNyIs_  
byte[] b = new byte[1024];  Xaz`L  
int nRead; H > Y0R  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $@WqM$  
{ ;^fGQ]`4  
nStartPos += fileAccessI.write(b,0,nRead); 8\V  
//if(nThreadID == 1) Vp"=8p#k  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l:' 0  
} i -kj6N5  
#ZzFAt  
f}1B-  
Utility.log("Thread " + nThreadID + " is over!"); ">-J+ST%  
bDownOver = true; 6A$  Y]u  
//nPos = fileAccessI.write (b,0,nRead); WR5@S&fU`  
} *?l-:bc]  
catch(Exception e){e.printStackTrace ();} [Un~]E.'J  
} F},#%_4  
} 1]DPy+  
n:TWZ.9  
*O5Ysk^|  
//打印回应的头信息 _lK+/"-l  
public void logResponseHead(HttpURLConnection con) NA=I7I@  
{ .zm/GtOV@  
for(int i=1;;i++) uD'GI  
{ ca@?-)  
String header=con.getHeaderFieldKey(i); %1\MW+  
if(header!=null) QGC%, F"+  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KR49Y>s<  
Utility.log(header+" : "+con.getHeaderField(header)); W##~gqZ/  
else Es7+bFvsE8  
break; uT\|jv,  
} Xc>M_%+ R  
} L lNd97Z  
,\%qERk  
G C#s;X  
public void splitterStop() mi`jY0e2  
{ O7})1|>1  
bStop = true; 3RbPc8($Y  
} 9/yE\p .  
z\kiYQ6kA  
8.Z9 i  
} {S$]I)tV  
Z)Zc9SVC  
Z<Rhn  
/* _Hp[}sv4)  
**FileAccess.java Yg~$1b@  
*//文件访问(定位,写) t[|aM-F&>  
package NetFox; lx)Bj6  
import java.io.*; >Q-"-X1  
u]<_6;_  
?as1^~  
public class FileAccessI implements Serializable{ =N~*`5|rk  
nS` :)#;  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X+$IaLfCxD  
RandomAccessFile oSavedFile; 810pJ  
long nPos; Q)s`~G({P  
Zr#\>h'c  
<rbzsn"a  
public FileAccessI() throws IOException X:Iam#H  
{ m\DI6O"u'  
this("",0); "C~Zl&3  
} LJ{P93aq`^  
6!|/(~  
4\pUA4  
public FileAccessI(String sName,long nPos) throws IOException <l`xP)] X  
{ i2y E-sgF  
oSavedFile = new RandomAccessFile(sName,"rw"); A?;KfVq  
this.nPos = nPos; Yp@i{$IUW  
oSavedFile.seek(nPos); VX+:C(m~  
} D\LXjEm e.  
"T~ce@  
c*N>7IF,  
public synchronized int write(byte[] b,int nStart,int nLen) ~6!TMVr  
{ H\^zp5/  
int n = -1; ?}Y;/Lwx  
try{ |qq7vx  
oSavedFile.write(b,nStart,nLen); i9=*ls^Cx  
n = nLen; NN"!kuM  
} 0<$t9:dq  
catch(IOException e) av:9kPKm  
{ 6)#=@i` \  
e.printStackTrace (); )ePQN~#K}  
} 7|Bg--G1  
U:+wt}-T"  
NU/:jr.W#  
return n; =*'K'e>P3  
} gQ;1SY!  
w\{oOlE  
+)U>mm,  
} <UE-9g5?G  
I?~iEO\nh  
rI;84=v2&9  
/* n/vKxtW  
**SiteInfoBean.java UR' P,  
*/ sF!nSr  
package NetFox; 6Sr}I,DG  
/5&' U!:+  
96]!*}  
public class SiteInfoBean { 01&J7A2  
Y-y<gW  
'\4 @  
private String sSiteURL; //Site's URL ` Clh;  
private String sFilePath; //Saved File's Path d7i 0'R  
private String sFileName; //Saved File's Name j" ~gEGfK  
private int nSplitter; //Count of Splited Downloading File TBr@F|RXiO  
G~FAChI8![  
e>~7RN  
public SiteInfoBean() :}{,u6\  
{//nSplitter的缺省值为5 l 4e`-7  
//default value of nSplitter is 5 (sN;B)  
this("","","",5); %5rC`9^  
} bS"zp6Di  
:W*']8 M-  
`p\@b~GM  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #a|.cm>6  
{ x !^u$5c  
sSiteURL= sURL; C'oNGOEd  
sFilePath = sPath; p8_ CY[U  
sFileName = sName; YIZ+BVa  
this.nSplitter = nSpiltter; S3F8Chk5  
#dEMjD  
MzX4/*ba  
} dWDM{t\}\  
B kh1VAT  
d^W1;0  
public String getSSiteURL() ml\2%07  
{ 9}*<8%PSt,  
return sSiteURL; lVR a{._m  
} .!Qo+(  
p"ElO,\  
[r f.&  
public void setSSiteURL(String value) hQPNxpe  
{ 4o``t]  
sSiteURL = value; R}J}Q b  
} LktH*ePO  
ne-; gTP;  
f\]splL  
public String getSFilePath() O;m@fS2%3  
{ at5>h   
return sFilePath; =}^J6+TVL  
} 3qNLosm#M  
# @~HpqqR  
7ElU5I<S  
public void setSFilePath(String value) }=T=Z#OgH  
{ s%xhT  
sFilePath = value; 7w?V0pLwn8  
} yG..B  
IqrT@jgN-  
SoPiEq  
public String getSFileName() "2 "gTS  
{ *Tyr  
return sFileName; |jT^[q(z  
} Li8$Rb~q  
*uG!U%jY)  
kD.KZV  
public void setSFileName(String value) %$Aqbd  
{ |<sf:#YzY&  
sFileName = value; Z[Wlyb0  
} fD'/#sA#'  
nz^nptw  
g^1r0.Sp{8  
public int getNSplitter() Z;hyi'rPJ  
{ r,5-XB  
return nSplitter; t)LU\!  
} brntE:  
: (cb2j(C  
0f1H8zV  
public void setNSplitter(int nCount) .>P~uZiX!  
{ XTV0Le\f  
nSplitter = nCount; im=5{PbJ^  
} g^jJ8k,7(  
} $57\u/(  
z OtkC3hY  
T)8p:}P!  
/* H.:9:I[n  
**Utility.java aVP5%  
*/ /9pbnzn  
package NetFox; V7:\q^$  
0 sZwdO  
Lx%:t YZ  
public class Utility { GMBJjP&R]  
EY~7oNfc`R  
RK-x?ZYH'  
public Utility() gwiR/(1  
{ /l ^y}o %?  
YZ< NP  
e8{^f]5  
} FuuS"G,S  
`y2ljIWJ  
//线程睡眠 gKWzFnW  
public static void sleep(int nSecond) VG)="g[%)  
{ P{cos&X|  
try{ -KiRj!v|  
Thread.sleep(nSecond); 8"i/wMP]  
} HyEa_9  
catch(Exception e) ?I[h~vr6.  
{ \-OC|\{32  
e.printStackTrace (); Rboof`pVt  
} Y%g "Y  
} <(YF5Xm6$h  
\45(#H<$  
//日志 IcFK,y%1  
public static void log(String sMsg) 9#Y2`p T  
{ &DLhb90  
System.err.println(sMsg); Sph*1c(R  
} >)^N J2Fd  
]G*$W+G]  
DWrbp  
public static void log(int sMsg) >rw"Rd'  
{ _R74/|  
System.err.println(sMsg); 3]^'  
} \f"1}f  
} cy3M^_5B<  
<HF-2?`  
o?wt$j-  
/* {y6C0A*  
**TestMethod.java EwQae(PpA  
*/ K]<u8eF  
package NetFox; Q]#Z9H  
KO&:06V{  
KjOi(YUnq7  
public class TestMethod { yW("G-Nm  
>vVw!.fJ  
X NE+(Bt  
public TestMethod() e+@xs n3  
{ ///xx/weblogic60b2_win.exe b_vTGl1_6  
try{ jdM=SBy7q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k[9A,N^lZB  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aZKXD! 4  
SiteFileFetch fileFetch = new SiteFileFetch(bean); cPuHLwwYf  
fileFetch.start(); CH;;V3  
} 4AHL3@x  
catch(Exception e){e.printStackTrace ();} C:GvP>  
/{X_ .fv<v  
d>!p=O`>{q  
} Q2c*.Y  
0S.?E.-&0  
x=,8[W#XT  
public static void main(String[] args) -H\,2FO  
{ C[YnrI!  
new TestMethod(); z-@ -O  
} LgHJo-+>  
} yvxl_*Ds8  
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