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http断点续传简单实现(java)

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/* rY 0kzD/  
**SiteFileFetch.java !_EaF`oh(  
*/ Mbt}G|;8H7  
package NetFox; I1H} 5 bf3  
import java.io.*; >UP{= `  
import java.net.*; X>n\@rTo  
B"-gK20vY  
Whf7J'  
public class SiteFileFetch extends Thread { GS%i<HQ3  
,@_$acm  
suh@  
SiteInfoBean siteInfoBean = null; //文件信息Bean n.[0#Ur&}  
long[] nStartPos; //开始位置 <eObQ[mQ  
long[] nEndPos; //结束位置 Bh9O<|E  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !Cm<K*c"&E  
long nFileLength; //文件长度 %'}L.OvG  
boolean bFirst = true; //是否第一次取文件 _L6WbRu|  
boolean bStop = false; //停止标志 MNE{mV(  
File tmpFile; //文件下载的临时信息 ^8mF0K&  
DataOutputStream output; //输出到文件的输出流 GP %83T  
nt/+?Sj  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类)  Yfk){1  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5$r`e+Nf'  
{ I[~EQ {Iz  
siteInfoBean = bean; 6AZJ,Q\E@  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ]7QRelMiz+  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); B%v2)+?@  
if(tmpFile.exists ()) X(-e-:B4;  
{ Y* #'Gh,  
bFirst = false; 9.KOrg5}L  
read_nPos(); :qV}v2  
} ;CU<\  
else *0 ;DCUv  
{ -%&_LE9ZtS  
nStartPos = new long[bean.getNSplitter()]; -fl?G%:(!0  
nEndPos = new long[bean.getNSplitter()]; FtUOgL)|  
} |g5B==KI  
;;zKHS  
rf+'U9  
VrF(0,-Z`3  
} avR4#bfc  
_E e`Uk  
{gE19J3  
public void run() 5Rv6+d  
{ s!\uR.  
//获得文件长度 Y$%/H"1bk  
//分割文件 *E<%db C2  
//实例FileSplitterFetch `<Z5/;a5W  
//启动FileSplitterFetch线程 #clPao?r  
//等待子线程返回 xw*T? !r=V  
try{ G>?hojvi  
if(bFirst) FhgO5@BO  
{ x1m J&D  
nFileLength = getFileSize(); +Y!9)~f}7X  
if(nFileLength == -1) KzeTf?G  
{ %}+!%A.3  
System.err.println("File Length is not known!"); 8K! l X  
} ~q]+\qty4  
else if(nFileLength == -2) ^h+<Q%'a'  
{ f>)k<-<yj  
System.err.println("File is not access!"); r\y~ :  
} oYNP,8r^  
else u>Z0ug6x  
{ Epm\ =s  
for(int i=0;i<nStartPos.length;i++) 3~"G(UP  
{ fF208A7U I  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ^|@t2Rp@  
} h+k:G9;sS  
for(int i=0;i<nEndPos.length-1;i++) +OFq=M  
{ `A@{})+  
nEndPos = nStartPos[i+1]; ^CUeq"GYoZ  
} N|c;Qzl  
nEndPos[nEndPos.length-1] = nFileLength; D6,rb 9  
} 4@PH5z  
} !>B|z=  
,?GEL>F  
 {g?$u  
//启动子线程 8(UUc>g  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^Bw2y&nN  
for(int i=0;i<nStartPos.length;i++) U2=l; R{  
{ ,K Ebnk|i  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  Z(p kj  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }EmNSs`$r  
nStartPos,nEndPos,i); 'AN3{  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hm|8ydNs  
fileSplitterFetch.start(); 6[kp#  
} Z 6^AO=3  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c>~"Z-VtX  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `;-K/)/x  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "?|sC{'C4j  
nEndPos = " + nFileLength); +0mU)4n/  
// fileSplitterFetch[nPos.length-1].start();  4I7}  
nwh7DU i  
&MnS( 82L  
//等待子线程结束 >3V{I'^^-  
//int count = 0; T]d9tX-  
//是否结束while循环 h#9X0u7j  
boolean breakWhile = false; M]YK]VyG  
Z@fMU2e=Z  
u1F@VV{  
while(!bStop) Jg=[!j0(  
{ )CQ'kHT<e  
write_nPos(); z=>U>  
Utility.sleep(500); <A +VS  
breakWhile = true; 59:Xu%Hp  
'Z#8]YP`  
~"89NVk"  
for(int i=0;i<nStartPos.length;i++) (]0JI1 d  
{ 8^CdE*a  
if(!fileSplitterFetch.bDownOver) =Jfo=`da  
{ tgy*!B6a~  
breakWhile = false; 4QODuyl2H  
break; !Mp.jE  
} k3::5&  
} qc_c&  
if(breakWhile) ZI4[v>  
break; :@zz5MB5@  
g$<Sh.4A  
Md_S};!QN6  
//count++; v'(p."g  
//if(count>4) bcFG$},k  
// siteStop(); e[f}Lxln  
} Y.&nxT95=  
>[;+QVr;  
@l:\0cO  
System.err.println("文件下载结束!"); OnE#8*8  
} iB1"aE3  
catch(Exception e){e.printStackTrace ();} 1e.V%!Xk  
} m,KG}KX  
XVcY?_AS#  
(LzVWz m  
//获得文件长度 Lu,72i0O ^  
public long getFileSize() Tg|0!0qD]F  
{ &GF@9BXI3  
int nFileLength = -1; zi l^^wT0J  
try{ hw/ :  
URL url = new URL(siteInfoBean.getSSiteURL()); oUrNz#U  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vvk1 D(  
httpConnection.setRequestProperty("User-Agent","NetFox"); @&(0]kZ6  
{2Jo|z  
rnW(<t"  
int responseCode=httpConnection.getResponseCode(); rM/Ona2x  
if(responseCode>=400) KECo7i=e  
{ &5:83#*Oj  
processErrorCode(responseCode); {%W'Zx  
return -2; //-2 represent access is error y/57 >.3  
} I;xrw?=\L  
g,Z8I;A^  
IzPnbnS}  
String sHeader; CX/ _\0 G4  
d>[=]  
k I  
for(int i=1;;i++) (/TYET_H  
{ ]t$wK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &`+tWL6L  
//Utility.log(in.readLine()); gXZl3  
sHeader=httpConnection.getHeaderFieldKey(i); hKo& ZWPq  
if(sHeader!=null) pRyePxCDj)  
{ $m{-I=  
if(sHeader.equals("Content-Length")) E(]39B"i  
{ }pqnF53  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F(+,M~  
break; g{{DC )>  
} a=n* }.  
} aQzDOeTi  
else ,gAa9  
break; oD1rt>k  
} fS9TDy  
} aX CVC<l  
catch(IOException e){e.printStackTrace ();} u7  s-  
catch(Exception e){e.printStackTrace ();} Msj(>U&}+  
ejs_ ?  
%l{0z<  
Utility.log(nFileLength); a`/\0~  
>Pa&f20Hp  
IZ?+c@t  
return nFileLength; FfEP@$  
} CshYUr -  
[_kis  
WBc,/lgZ  
//保存下载信息(文件指针位置) ux>wa+XFa  
private void write_nPos() cV8Bl="gqe  
{ O^/z7,  
try{ p1}umDb%  
output = new DataOutputStream(new FileOutputStream(tmpFile)); rjk{9u1a"  
output.writeInt(nStartPos.length); G,o5JL"t  
for(int i=0;i<nStartPos.length;i++) JK.<(=y\  
{ $W}YXLFj?  
// output.writeLong(nPos); 4Wsp PHj  
output.writeLong(fileSplitterFetch.nStartPos); 1nGpW$Gx  
output.writeLong(fileSplitterFetch.nEndPos); 2h=QJgpCG  
} n:dnBwY  
output.close(); f%#q}vK-  
} (r Tn6[ *  
catch(IOException e){e.printStackTrace ();} lqaOLZH  
catch(Exception e){e.printStackTrace ();} ,u.G6"<  
} jimWLF5Q5"  
&Ul8h,qw  
o/dj1a~U  
//读取保存的下载信息(文件指针位置) y}5:CZ  
private void read_nPos() ULT,>S6r  
{ -!Ov{GHr0  
try{ y6#AL<W@=  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Mg pjC`  
int nCount = input.readInt(); $c^,TAN  
nStartPos = new long[nCount]; 3.0t5F<B  
nEndPos = new long[nCount]; pUV4oyGV   
for(int i=0;i<nStartPos.length;i++) Uw!N;QsC  
{ Pi/V3D) B  
nStartPos = input.readLong(); kH4xP3. i  
nEndPos = input.readLong(); $X\deJ1Hi  
} )\O;Rt(  
input.close(); I 0vJJP#  
} 8cKP_Ec  
catch(IOException e){e.printStackTrace ();} n?a?U:  
catch(Exception e){e.printStackTrace ();} Q}zd!*  
} 1@}s:  
.#Vup{.  
Al}D~6MD  
private void processErrorCode(int nErrorCode) S:= _o  
{ !_i;6UVG  
System.err.println("Error Code : " + nErrorCode); nNc>nB1  
} V'iT>  
 Y%zYO  
[\BLb8  
//停止文件下载 B!j7vXM2  
public void siteStop() .X.,.vHx  
{ $R&K-;D/8  
bStop = true; v?O6|0#x  
for(int i=0;i<nStartPos.length;i++) GS)4,.  
fileSplitterFetch.splitterStop(); Kry^ 47"  
L9} %tEP  
B'}pZOa[Wb  
} n.l7V<1  
} G4<M@ET  
//负责部分文件的抓取 a[ Y\5Ojm  
**FileSplitterFetch.java hI6Tp>b*~  
*/ H$M{thW  
package NetFox; BJ*8mKi h  
G2 {R5F !  
>{1 i8 b@  
import java.io.*; n=iL6Yu(  
import java.net.*; =zsA@UM0  
,^n5UA`PK  
&x.n>O  
public class FileSplitterFetch extends Thread { YQ$Wif:@(n  
nBg  tK  
nhImO@Q:  
String sURL; //File URL E{8-VmY  
long nStartPos; //File Snippet Start Position Sv>bU4LHf  
long nEndPos; //File Snippet End Position bdYx81  
int nThreadID; //Thread's ID ~q,Wj!>Ob  
boolean bDownOver = false; //Downing is over Rm&4Pku  
boolean bStop = false; //Stop identical han S8  
FileAccessI fileAccessI = null; //File Access interface hd%O\D?  
/6@$^paB  
s`dwE*~  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >HRL@~~Z  
{ W*WSjuFr2  
this.sURL = sURL; J#) %{k_  
this.nStartPos = nStart; X%R)  
this.nEndPos = nEnd; U$m[{r2M  
nThreadID = id; {8e4TD9E0  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :pw6#yi8`  
} \R|qXB $  
q /eod  
tO~o-R  
public void run() g^)8a;/c  
{ oR@1/lV  
while(nStartPos < nEndPos && !bStop) (yO8G-Z0  
{ 'z$!9ufY,  
Aa!#=V1d  
.T*89cEu  
try{ j 21>\K!p  
URL url = new URL(sURL); a0)]W%F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LB\+*P6QM  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;=lQMKx0  
String sProperty = "bytes="+nStartPos+"-"; @!KG;d:l  
httpConnection.setRequestProperty("RANGE",sProperty); UZ-[vD1n  
Utility.log(sProperty); n eBcS[  
/I~(*X  
$,8}3R5}  
InputStream input = httpConnection.getInputStream(); J/>9w  
//logResponseHead(httpConnection); ["BD,mB  
Xf%wW[~  
zL=PxFw0  
byte[] b = new byte[1024]; ,/Al'  
int nRead; s<'WTgy1i  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #McX  
{ X*< !_3  
nStartPos += fileAccessI.write(b,0,nRead); i-M<_62c  
//if(nThreadID == 1) (_nU}<y_i  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &pFP=|Pq  
} %d^ =$Q  
LA4,o@V`  
vT;~\,M  
Utility.log("Thread " + nThreadID + " is over!"); d Z P;f^^  
bDownOver = true; `%$l b:e  
//nPos = fileAccessI.write (b,0,nRead); w\%AR1,rs  
} tk66Ggi[K  
catch(Exception e){e.printStackTrace ();} fD~f_Wr  
} 8c<OX!  
} a"!r]=r  
+L-(Lz[p  
!)HB+yr  
//打印回应的头信息 il~A(`+YO  
public void logResponseHead(HttpURLConnection con) Jl-:@[;  
{ 2@>#?c7  
for(int i=1;;i++) LB/1To  
{ bF c %  
String header=con.getHeaderFieldKey(i); fp2uk3Bm[  
if(header!=null) & d@N3y  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [;$9s=:[  
Utility.log(header+" : "+con.getHeaderField(header)); ;t \C!A6  
else I`uOsZBO/  
break; _5H0<%\  
} UE 1tm  
} !~-@p?kW/  
4%>2 >5  
v O@7o  
public void splitterStop() EeDK ^W8N  
{ gT#hF]c:  
bStop = true; _Eus7  
} xi}3)5  
OY,iz  
|*JMCI@Mz  
} GEJy?$9   
d 6zfP1lQ  
G%XjDxo$I  
/* !BEl6h  
**FileAccess.java ftccga  
*//文件访问(定位,写) OYj~"-3y)  
package NetFox; _.+2sm   
import java.io.*; Wq"^{  
,A;wLI  
nRh.;G  
public class FileAccessI implements Serializable{ q4]Qvf>  
fT0+i nRG  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C o,"  
RandomAccessFile oSavedFile; >{ .|Ng4K  
long nPos; Fh~ pB>t  
L%31>)8  
6rh^?B  
public FileAccessI() throws IOException H57wzG{xG  
{ Xo ,U$zE  
this("",0); nrJW.F]S8[  
} s/0~!0  
8=WX`*-uH  
(dQsR sA  
public FileAccessI(String sName,long nPos) throws IOException ]<:qMLg  
{ _g%h:G&^  
oSavedFile = new RandomAccessFile(sName,"rw"); hZ UnNQ  
this.nPos = nPos; 6a4-VX5  
oSavedFile.seek(nPos); @0fiui_  
} Fg^Z g\X3  
3<X*wVi)NN  
4&wwmAp^  
public synchronized int write(byte[] b,int nStart,int nLen) g%%j"Cz1  
{ f6JC>Np  
int n = -1; k'PNfx\K  
try{ `c/mmS  
oSavedFile.write(b,nStart,nLen); fB`7f $[  
n = nLen; o>@9[F,h+  
} U%l<48@8  
catch(IOException e) RZTC+ylj  
{ i1DJ0xC]  
e.printStackTrace (); A?ij  
} \ 3FOI  
M1_1(LSU  
u8b^DB#+W  
return n; Bw4 _hlm  
} 'WcP+4c  
{7d\du&G  
V[avV*;3i  
} *7^w}v+.  
4j}uVGi{e  
?vV&tqnx%  
/* ^8{:RiN6e~  
**SiteInfoBean.java i~uoK7o|G  
*/ ]=jpqxlx  
package NetFox; OG{vap)  
D0 ,t,,L  
2F|06E'  
public class SiteInfoBean { q#*b4q {  
!z |a+{  
k?qd -_sC  
private String sSiteURL; //Site's URL T}y@ a^#  
private String sFilePath; //Saved File's Path {O (@}  
private String sFileName; //Saved File's Name ["SD'  
private int nSplitter; //Count of Splited Downloading File 0)E`6s#M  
<S(`e/#[  
7(]M`bBH  
public SiteInfoBean() H@V+Q}  
{//nSplitter的缺省值为5 T56%3i  
//default value of nSplitter is 5 #6F/:j;  
this("","","",5); Qcs >BOV~  
} *S] K@g  
N)o/}@]6  
qZ rv2dT  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IT0 [;eqR  
{ \4"01:u'  
sSiteURL= sURL; mH5[(?   
sFilePath = sPath; 95b65f  
sFileName = sName; SZL('x,"^  
this.nSplitter = nSpiltter; mFW/xZwR,5  
?b3({P  
QRAw#  
} >SaT?k1E  
n}toUqUnk\  
,,CheRO  
public String getSSiteURL() &b!|Y  
{ B| .8+Q  
return sSiteURL; =`KV),\  
} 3p#BEH<re  
iw0|A  
~#nbD-*#  
public void setSSiteURL(String value) uJu#Vr:m  
{ MT(G=r8  
sSiteURL = value; 7MhN>a;A\  
} y)0wM~E;2  
MfK}DEJK,  
{p)=#Jd`.P  
public String getSFilePath() 2y@y<38  
{ N]7#Q.(~  
return sFilePath; 0uwe,;   
} Y0ouLUlI  
\p{$9e;8yT  
^>tqg^  
public void setSFilePath(String value) o.x<h";  
{ :%kJ9zW  
sFilePath = value; @zAav>  
} 6qq{JbK  
3W.5 [;}  
'1[Bbs  
public String getSFileName() Q|i`s=|  
{ O&ZVu>`g  
return sFileName; Yo a|.2f  
} jp viX#\S_  
*$EcP`K$  
T<S_C$O  
public void setSFileName(String value) X+;{&Efrl  
{ k(%h{0'  
sFileName = value; w;8VD`>[|  
} M;zJ1  
~Lf>/w  
4Up \_  
public int getNSplitter() !Ng~;2GoA  
{ HYWKx><   
return nSplitter;  v+qHH8  
} +?R !  
=b[q<p\  
Df_*W"(v  
public void setNSplitter(int nCount) VFjNrngl  
{ ZZ@1l  
nSplitter = nCount; |8s45g>  
} \o=YsJ8U  
} 8CN~o|uN  
#Ss lH  
*h Z{>  
/* 3tAX4DnYrq  
**Utility.java MaQ`7U5 |e  
*/ v''F\V )  
package NetFox; /FW{>N1   
U5pg<xI  
G'0]m-)dw  
public class Utility { #Y;tobB  
?VP07 dQTe  
H;=++Dh  
public Utility() RY9h^q*  
{ N9jSiRJ  
aK4ZH}XHE"  
``9`Xq  
} =BNS3W6  
[7*$Sd  
//线程睡眠 4E~!$Ustx  
public static void sleep(int nSecond) 04wO9L;  
{ 1 wB2:o<  
try{ HA W57N  
Thread.sleep(nSecond); xXn2M*g  
} P K9BowlW  
catch(Exception e) Ki{]5Rz  
{ <QZ X""  
e.printStackTrace (); PS3%V_2  
} ?84B0K2N s  
} $TR#-q  
V-.Nc#  
//日志 B jsF5~+\  
public static void log(String sMsg) jpI=B  
{ wrmbOT  
System.err.println(sMsg); $(JB"%S8c  
} 9m:G8j'  
t!JD]j>q  
(TQhO$,  
public static void log(int sMsg) C#Y_La  
{ u~VvGLFf5,  
System.err.println(sMsg); c"x-_Uk  
} ];VJ54  
} "O j2B|:s&  
6-vQQ-\  
- BE.a<  
/* &ytnoj1L(  
**TestMethod.java =%IBl]Z!"  
*/ cc_v4d{x  
package NetFox; gHe%N? '  
QGI_aU  
E,g5[s@  
public class TestMethod { r"aJ&~8::W  
\$%q< _l  
u/g4s (a  
public TestMethod() }8,[B50  
{ ///xx/weblogic60b2_win.exe |E =8  
try{ TU(w>v  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g9K7_T #W  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5);  01;  
SiteFileFetch fileFetch = new SiteFileFetch(bean); iD-,C`  
fileFetch.start(); u iEAi  
} 6}xFE]Df-Y  
catch(Exception e){e.printStackTrace ();} ^g eC?m  
}:f \!b  
;S_\- ]m&g  
} =n7 3bm  
~!A*@a C  
E` aAPk_ y  
public static void main(String[] args) ;4] sP^+  
{ k~+(X|!5w  
new TestMethod(); }'.k  
} nm.~~h+8M  
} h..D1(M  
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