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http断点续传简单实现(java)

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/* :1Xz4wkWS*  
**SiteFileFetch.java q CC.^8  
*/ S/hQZHZHg,  
package NetFox; Ux!p8  
import java.io.*; `6(S^P  
import java.net.*; IVnHf_PzF  
.bl/*s  
%bn jgy  
public class SiteFileFetch extends Thread { yf.~XUk^  
 M mj;-u  
|*eZD-f  
SiteInfoBean siteInfoBean = null; //文件信息Bean 8P\G }  
long[] nStartPos; //开始位置 5X$jl;6  
long[] nEndPos; //结束位置 e`_LEv  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 St9?RD{4;  
long nFileLength; //文件长度 QD&`^(X1p  
boolean bFirst = true; //是否第一次取文件 w$iX.2|9%u  
boolean bStop = false; //停止标志 ,5p(T_V/  
File tmpFile; //文件下载的临时信息 |Pax=oJ\M  
DataOutputStream output; //输出到文件的输出流 %)8}X>xq  
=_*Zn(>t`  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) '?' l;#^i<  
public SiteFileFetch(SiteInfoBean bean) throws IOException wh`"w7br  
{ nsC3  
siteInfoBean = bean; Xf]d. :  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); k/_ 59@)  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); )T2Caqs2  
if(tmpFile.exists ()) z6\UGSL  
{ ;%9|k U  
bFirst = false; |$Sedzj'  
read_nPos(); [#vH'y  
} a$OE0zn`  
else R$<&ie6UQ  
{ {*" |#6-  
nStartPos = new long[bean.getNSplitter()]; M#6W(|V/  
nEndPos = new long[bean.getNSplitter()]; K#d`Hyx  
} k@J&IJ  
,AFu C <  
BoWg0*5xb  
;7V%#-  
} ~L\z8[<C  
C`9+6T  
$szqy?i 0?  
public void run() pofie$  
{ u'DRN,h+  
//获得文件长度 g-bK|6?yz  
//分割文件 lvz7#f L~  
//实例FileSplitterFetch DV-d(@`K  
//启动FileSplitterFetch线程 ^"2J]&x`G  
//等待子线程返回 @o _}g !9=  
try{ t\,PB{P:J  
if(bFirst) zu{P#~21  
{ *)T^Ch D,  
nFileLength = getFileSize(); HCs?iJ  
if(nFileLength == -1) WPMSm<[  
{ E,U+o $  
System.err.println("File Length is not known!"); <0&*9ZeD  
} JIOR4'9  
else if(nFileLength == -2) WiR(;m<g  
{ )23H1  
System.err.println("File is not access!"); .}TZxla0Zr  
} 6j]0R*B7`Q  
else om z  
{ 3$>1FoSk  
for(int i=0;i<nStartPos.length;i++) )yZ^[uJ}3C  
{ /]Md~=yNp  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); K!Y71_#  
} qi D@'Va\  
for(int i=0;i<nEndPos.length-1;i++) :>f )g  
{ %RRNJf}z  
nEndPos = nStartPos[i+1]; 3ym',q  
} YfKdR"i+.  
nEndPos[nEndPos.length-1] = nFileLength; :bq8N@P/  
} s)D;a-F  
} D'PI1 0t  
ZG8DIV\D7  
'4Bm;&6M  
//启动子线程 vw/J8'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `e&Suyf4B  
for(int i=0;i<nStartPos.length;i++) 2-v%`fA  
{ sBg.u  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~P **O~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -zeG1gr3  
nStartPos,nEndPos,i); 0pd'93C  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Moza".fiN  
fileSplitterFetch.start(); pO3SUOP  
} V&2l5v  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v$wIm,j  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $G@5qxcV  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B%6)}Nl[  
nEndPos = " + nFileLength); #h ]g?*}OJ  
// fileSplitterFetch[nPos.length-1].start(); `dN@u@[\ks  
y??XIsF  
_Q4)X)F  
//等待子线程结束 0~/_|?]`7  
//int count = 0; &n:.k}/P  
//是否结束while循环 }|NCboM^_  
boolean breakWhile = false; 9qzHS~l  
f r6 fj  
5Yq@;e  
while(!bStop) VjZ|$k  
{ T:yE(OBf  
write_nPos(); . 3T3E X|G  
Utility.sleep(500); A$0fKko  
breakWhile = true; 7ZWgf"1j  
&d^m 1  
F{;((VboN  
for(int i=0;i<nStartPos.length;i++) je=a/Y=%U{  
{ >_T-u<E  
if(!fileSplitterFetch.bDownOver) >U27];}y  
{ .p" xVfi6  
breakWhile = false; vV-`jsq20H  
break; Pw"-S?`(  
} 9EibIOD^/  
} Y&Z.2>b  
if(breakWhile) cU!vsdR3  
break; =MDys b&:  
@<EO`L)Z  
ar+9\  
//count++; jasy<IqT!{  
//if(count>4) 1?+St`+{B-  
// siteStop(); 60?%<oJ oH  
} d S V8q ,D  
i2SR{e8:GF  
>@ .  
System.err.println("文件下载结束!"); Ry6@VQ"NLb  
} >e5 qv(y]  
catch(Exception e){e.printStackTrace ();} wgGl[_)  
} }y gD3:vN7  
CryBwm  
t&e{_|i#+  
//获得文件长度 4zFW-yy  
public long getFileSize() e^1Twz3z  
{ ,/|T-Ka  
int nFileLength = -1; $X,D(  
try{ Vp@?^imL  
URL url = new URL(siteInfoBean.getSSiteURL()); A_q3KB!$=+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1\I}2;  
httpConnection.setRequestProperty("User-Agent","NetFox"); $kp{Eg '  
8VXH+5's  
p9{mS7R9T  
int responseCode=httpConnection.getResponseCode(); 8[{ Vu0R  
if(responseCode>=400) ^SrJu:Q_  
{ j*r{2f4Rt  
processErrorCode(responseCode); BR;D@R``}  
return -2; //-2 represent access is error /jJw0 5;L  
} WCixKYq  
bY~pc\V:`w  
k~1?VQ+?M  
String sHeader; amY!qg0P*  
9InVQCf2J  
u.xnOcOH!  
for(int i=1;;i++) S;`A{Mow  
{ .U]-j\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v):Or'$~M  
//Utility.log(in.readLine()); Y`a3tO=Pd  
sHeader=httpConnection.getHeaderFieldKey(i); r3UUlR/Do  
if(sHeader!=null) t;\Y{`  
{ ePo}y])2  
if(sHeader.equals("Content-Length")) ##"HF  
{ YT(AUS5n  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aAUvlb  
break; 7J<5f)  
} + ksVtG,  
} 6(ol1 (U  
else 0flRh)[J  
break; A2Gevj?F$  
} 7hPY_W y  
} *gWwALGo5  
catch(IOException e){e.printStackTrace ();} {3aua:q  
catch(Exception e){e.printStackTrace ();} HN|%9{VeB  
)\$|X}uny&  
R8'RA%O9J  
Utility.log(nFileLength); 0n{=%Q  
pFjK}J OF  
}*]-jWt1J\  
return nFileLength; C;^X[x%h7$  
} Qzw;i8n{  
]~siaiN[  
$6poFo)U+  
//保存下载信息(文件指针位置) e$rZ5X  
private void write_nPos() u]UOSfn  
{ 92oFlEJ  
try{ hp|YE'uYT  
output = new DataOutputStream(new FileOutputStream(tmpFile)); >fQMXfoY  
output.writeInt(nStartPos.length); 1bwOm hkS  
for(int i=0;i<nStartPos.length;i++) ysY*k`5  
{ :^h$AWR^f  
// output.writeLong(nPos); uoh7Sz5!^  
output.writeLong(fileSplitterFetch.nStartPos); |P?*5xPB  
output.writeLong(fileSplitterFetch.nEndPos); 6(-N FnT  
} 63IM]J  
output.close(); O?#7N[7  
} e$Pj.>-<=  
catch(IOException e){e.printStackTrace ();} 5\VWCI  
catch(Exception e){e.printStackTrace ();} $/Uq0U  
} a0H+.W+]  
l+0oS'`V*L  
5]:U9ts#  
//读取保存的下载信息(文件指针位置)  o-B$J?  
private void read_nPos() g *+>H1}  
{ a/xn'"eli  
try{ PXNuL&   
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0?|<I{z2  
int nCount = input.readInt(); ysnx3(+|  
nStartPos = new long[nCount]; Q S;f\'1bb  
nEndPos = new long[nCount]; yyTnL 2Y9  
for(int i=0;i<nStartPos.length;i++) nKj7.,>;:<  
{ {(Es(Sb}c  
nStartPos = input.readLong(); XC#oB~K'  
nEndPos = input.readLong(); ]JQULE)  
} dft!lBN  
input.close(); ":N9(}9  
} >9Vn.S  
catch(IOException e){e.printStackTrace ();} <<O$ G7c  
catch(Exception e){e.printStackTrace ();} SOaoo^,O  
} zX i 'kB  
i SQu#p@  
1s;S aq+  
private void processErrorCode(int nErrorCode) a(ZcmYzXU  
{ w5 Li&m  
System.err.println("Error Code : " + nErrorCode); gbD KE{  
} H3oFORh  
pT6$DB#  
%E;'ln4h&,  
//停止文件下载 Zx>=tx}  
public void siteStop() 86a\+Kz%%L  
{ 9} .z;prz  
bStop = true; 8zq=N#x  
for(int i=0;i<nStartPos.length;i++) NvX[zqNP_R  
fileSplitterFetch.splitterStop(); }c:M^Ff  
J] r^W)O  
u9p$YJ  
} 'dc#F3  
} +1!ia]  
//负责部分文件的抓取 >=w)x,0yX  
**FileSplitterFetch.java %\:Wi#w>  
*/ 4?01s-Y  
package NetFox; xN'I/@ kb  
&BSn?  
;mi%F3  
import java.io.*; w&.a QGR#  
import java.net.*; +aAc9'k   
_)iCa3z  
y8xE 6i  
public class FileSplitterFetch extends Thread { V|R,!UND  
b7ZSPXV  
62NsJ<#>  
String sURL; //File URL pTuS*MYz  
long nStartPos; //File Snippet Start Position 2B`JGFcdcB  
long nEndPos; //File Snippet End Position iU:cW=W|M\  
int nThreadID; //Thread's ID K@%].:  
boolean bDownOver = false; //Downing is over TkF[x%o  
boolean bStop = false; //Stop identical z0 Z%m@  
FileAccessI fileAccessI = null; //File Access interface ez[Vm:2K  
-tU'yKhn  
Ew$C ;&9  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1AFA=t:]p  
{ 2 ? 4!K.  
this.sURL = sURL; @E8+C8'  
this.nStartPos = nStart; YchH~m|  
this.nEndPos = nEnd; 4 H&#q>  
nThreadID = id; O33 `+UV"W  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x|29L7i  
} e~(5%CO>#j  
7x8  yxE  
K|s, ru  
public void run() DIUjn;>k8  
{ VG~Vs@c(  
while(nStartPos < nEndPos && !bStop) ]K%!@O!  
{ /<BI46B\  
nT)vNWT=  
Ht&Y C<X  
try{ NZz8j^  
URL url = new URL(sURL); D3K8F@d  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =?`c=z3~i$  
httpConnection.setRequestProperty("User-Agent","NetFox"); 7o}J%z  
String sProperty = "bytes="+nStartPos+"-"; FE;x8(;W8  
httpConnection.setRequestProperty("RANGE",sProperty); ,"0 :3+(8;  
Utility.log(sProperty); N4HqLh23H  
|vzl. ^"-  
M"To&?OI  
InputStream input = httpConnection.getInputStream(); !Xw5<J3L-  
//logResponseHead(httpConnection); uXl3k:_n  
BfiD9ka-z  
9(<@O%YU  
byte[] b = new byte[1024]; k~z Iy;AZ  
int nRead; Qe(:|q _  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _h1mF<\ X^  
{ S`Rs82>  
nStartPos += fileAccessI.write(b,0,nRead); T&7qC=E#5  
//if(nThreadID == 1) 6D_D';o  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MnW+25=N  
} -`6+UkOV[x  
%e} Saf  
""~ajy  
Utility.log("Thread " + nThreadID + " is over!"); UJ6v(:z <  
bDownOver = true; Eu04e N  
//nPos = fileAccessI.write (b,0,nRead); "@8li^  
} zT-_5uZQ  
catch(Exception e){e.printStackTrace ();} FHI ;)wn=  
} 2^yU ~`#  
} ;i+#fQO7Q  
\Y}8S/]  
SMK_6?MZ  
//打印回应的头信息 A&jlizN7  
public void logResponseHead(HttpURLConnection con) Aq7osU1B  
{ "g8M0[7e3  
for(int i=1;;i++) uY'HT|@:{  
{ @U}1EC{A  
String header=con.getHeaderFieldKey(i); FzC'G57Kl  
if(header!=null) \dQNLLg/  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c~ V*:$F  
Utility.log(header+" : "+con.getHeaderField(header)); .#pU=v#/[  
else 3=ymm^  
break; v|2T%y_ u  
} }RqK84K  
} *CHX  
*~i ])4  
L*JjG sTH  
public void splitterStop()  ; 4~hB  
{ cYt!n5w~W  
bStop = true; N]sAji*  
} HyWCMK6b  
u;c?d!E  
J-hbh  
} wD)XjX  
V "h +L7T  
L;I]OC^J  
/* }`~+]9 <   
**FileAccess.java wAW5 Z0D  
*//文件访问(定位,写) C3YT1tK  
package NetFox; [q #\D  
import java.io.*; uW36;3[f#1  
 kPLxEwl  
:6\qpex  
public class FileAccessI implements Serializable{ @I!0-OjL  
b1?'gn~  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RrQJ/ts7}  
RandomAccessFile oSavedFile; B0]~el  
long nPos; &KRX[2  
`+Q%oj#FF  
WI-1)1t  
public FileAccessI() throws IOException y_lU=(%Jd  
{ SI-Ops~e  
this("",0); OpYY{f  
} g7W"  
v^ V itLC  
w&T9;_/  
public FileAccessI(String sName,long nPos) throws IOException [3|P7?W/  
{ :&9s,l   
oSavedFile = new RandomAccessFile(sName,"rw"); W|63Ir67  
this.nPos = nPos; V[Ui/M!9Z  
oSavedFile.seek(nPos); HCC#j9UN6  
} o:Sa, !DK  
?2Py_gkf  
u5f9Jw}  
public synchronized int write(byte[] b,int nStart,int nLen) rCdu0 gYT  
{ + @s"zp;F  
int n = -1; !." D]i;  
try{ YGC L2Y  
oSavedFile.write(b,nStart,nLen); {[?(9u7R  
n = nLen; ExL0?FemWV  
} q6V>zi  
catch(IOException e) CdjI`  
{ .jjG(L  
e.printStackTrace (); *mvlb (' &  
} % ^1V4  
;,:`1UI  
Q:d]imw!O  
return n; ,M ^<CJ  
} >V8-i`  
=R$u[~Xl2X  
Ls+2Zbh  
} o9yJf#-En  
_H7x9 y=  
q ,]L$  
/* }Sh?S]]`  
**SiteInfoBean.java p}pjfG  
*/ eiaFaYe\  
package NetFox; rlSeu5X6  
q Y? j#fzi  
^ EQ<SCh  
public class SiteInfoBean { }-2 2XYh  
i#Bf"W{F  
r1{@Ucw2  
private String sSiteURL; //Site's URL ~H<6gN<j(.  
private String sFilePath; //Saved File's Path 9`X\6s  
private String sFileName; //Saved File's Name 3<f}nfB%r?  
private int nSplitter; //Count of Splited Downloading File >7T'OC  
,K"U> &  
:vQrOn18p  
public SiteInfoBean() `MN4uC  
{//nSplitter的缺省值为5 By",rD- r  
//default value of nSplitter is 5 A>;bHf@  
this("","","",5); ?(F6#"/E  
} ep)n_!$OH"  
Y0dEH^I  
Y>dzR)~3[  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E`usknf>l  
{ /cQueUME`  
sSiteURL= sURL; +RMSA^  
sFilePath = sPath; jTtu0Q|  
sFileName = sName; }"P|`"WW  
this.nSplitter = nSpiltter; CMG&7(MR  
)|R)Q6UJ  
IT7wT+  
} :tB1D@Cb6  
{14fA)`%  
{{D)YldtA  
public String getSSiteURL() H.|#c^I  
{ m_?~OL S  
return sSiteURL; PI:4m%[  
} lH x^D;m6  
):68%,  
BB!THj69a6  
public void setSSiteURL(String value) Ms5ap<q#  
{ 6azGhxh  
sSiteURL = value; n,V[eW#m'L  
} L:pYn_  
[P=Jw:E  
p;59?  
public String getSFilePath() 8:c-k|CX  
{ Bs_s&a>  
return sFilePath; fF$<7O)+]  
} vMi;+6'n>  
tqvN0vY5  
6xe*E[#k\  
public void setSFilePath(String value) dGYn4i2k?  
{ .9on@S  
sFilePath = value; ['X]R:3h  
} Pmr5S4Ka  
@fZ,.2ar  
b9KP( _  
public String getSFileName() 3LJ+v5T~  
{ L%*!`TN  
return sFileName; av}k)ZT_  
} +eWQa`g  
_(W+S`7Z  
'8RsN-w  
public void setSFileName(String value) *v jmy/3  
{ E"\<s3  
sFileName = value; @w#-aGJO  
} xaq-.IQAM$  
=r?hg GWe  
;v)JnbsH}  
public int getNSplitter() 67JA=,EE  
{ _JzEGpeG  
return nSplitter; VuhGx:Xl  
} Gv!2f  
vsCCB}7\  
iW]j9}t  
public void setNSplitter(int nCount) )0.kv2o.  
{ KVoS C @w  
nSplitter = nCount;  acajHs  
} P%V'4p c  
} 0rQMLx  
>a!/QMh  
m)ky*"(  
/* Q 04al=  
**Utility.java vjbASFF0=  
*/ !_]Y~[  
package NetFox; tVYF{3BhA  
O40?{v'  
SB;&GHq"n  
public class Utility { !fV+z%:  
?qv !w~m<  
0cv{  
public Utility() -P(efYk  
{ gDQ^)1k  
bQzZy5,  
!j8FIY'[  
} ,Q3T Tno ,  
:(E@Gf  
//线程睡眠 QGMV}y  
public static void sleep(int nSecond) 2 ~dE<}  
{ A6  
try{ NJ%P/\ C  
Thread.sleep(nSecond); on!,c>nNa  
} z 4e7PW|  
catch(Exception e) SpIv#?  
{  g T6z9  
e.printStackTrace (); %e8@*~h@  
} Eh)fnqs_d}  
} 3p$?,0ELH  
0.Q Ujw  
//日志 PF0_8,@U  
public static void log(String sMsg) s-NX o  
{ #JqB ;'\  
System.err.println(sMsg); Gf%~{@7=u  
} xBj 9y u  
(fhb0i-  
"syI#U{  
public static void log(int sMsg) ]]HNd7Vh  
{ "-M p_O]  
System.err.println(sMsg); SjK  
} FBG4pb9=~  
} OMk y$d#  
i:dR\|B  
\Zb;'eDv  
/* 2/U.| *mH  
**TestMethod.java 1wii8B6  
*/ i}(LqcYU  
package NetFox; xPdG*OcX!  
Q1lyj7c#x  
l&[O  
public class TestMethod { 1Te %F+7  
y1z4ik)Sd@  
|o7[|3:M  
public TestMethod() IM*y|UHt  
{ ///xx/weblogic60b2_win.exe )J=!L\  
try{ j<upRS,$  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PhLn8jNti  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yER(6V'\iQ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); @ 8(q$  
fileFetch.start(); {.`vs;U  
} 53_Hl]#qZ  
catch(Exception e){e.printStackTrace ();} K&u_R  
:S]%6gb8G  
#{0HYg?(f  
} ~ZaY!(R<  
]dVGUG8  
'I|v[G$l  
public static void main(String[] args) " > ypIR<  
{ t[HE6ea  
new TestMethod(); #Bze,?@  
} u$z`   
} Brw@g8w-X  
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