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http断点续传简单实现(java)

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/* @6UtnX'd  
**SiteFileFetch.java ?;,;  
*/ h~>1 -T8  
package NetFox; }StzhV{GS  
import java.io.*; akvi^]x  
import java.net.*; m]jA(  
EL~$7 J  
IWE([<i}i[  
public class SiteFileFetch extends Thread { mI8EeMa{  
`Na()r$T  
( eKgc  
SiteInfoBean siteInfoBean = null; //文件信息Bean aMI;; iL^  
long[] nStartPos; //开始位置 LhO\a  
long[] nEndPos; //结束位置 0%bCP/  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 NQqw|3  
long nFileLength; //文件长度 )M0`dy{1  
boolean bFirst = true; //是否第一次取文件 5t:Zp\$+`  
boolean bStop = false; //停止标志 &ZD@-"@  
File tmpFile; //文件下载的临时信息 8xB-cE  
DataOutputStream output; //输出到文件的输出流 u[)X="-e#  
dWn6-es  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) B''yW{  
public SiteFileFetch(SiteInfoBean bean) throws IOException ^ 9+ Qxv  
{ v*.R<- X:  
siteInfoBean = bean; )=f}vHg$  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); &>qUT]w  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 7$<pdayd  
if(tmpFile.exists ()) &m3-][ !n  
{ RQ E]=N  
bFirst = false; cb_C2+%8NA  
read_nPos(); CtY-Gs  
} kQ>2W5o-d-  
else }{F)Ren  
{ Pk;w.)kT  
nStartPos = new long[bean.getNSplitter()]; QYbB\Y  
nEndPos = new long[bean.getNSplitter()]; H?"M&mF  
} Ovt]3`U9J  
P3Ql[ 2  
cH&)Iz`f  
[ K?  
} ;^/ruf[t  
Rs=Fcvl  
8;gi8Y  
public void run() [r`KoHwdm  
{ Ke4oLF2  
//获得文件长度 wNi%u{T  
//分割文件 "-f]d~P>  
//实例FileSplitterFetch k^}[+IFJ  
//启动FileSplitterFetch线程 -f|/#1  
//等待子线程返回 SNqSp.>-U"  
try{ 1NP  
if(bFirst) e]1=&:eX#d  
{ Owf!dMA;nF  
nFileLength = getFileSize(); kZF]BPh.  
if(nFileLength == -1) \oPe" k=  
{ _4>DuklH,  
System.err.println("File Length is not known!"); w"0$cL3  
} br=e+]C Y)  
else if(nFileLength == -2) !sX$?P%U  
{ a[hF2/*  
System.err.println("File is not access!"); w9Yx2  
} k*A(7qQA`4  
else Ij(dgY  
{ XEiVs\) G  
for(int i=0;i<nStartPos.length;i++) &m--}  
{ 5x@ U<  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); h.tj8O1  
} eY 3:Nl^  
for(int i=0;i<nEndPos.length-1;i++) ]L~z9)  
{ }4>u_)nt  
nEndPos = nStartPos[i+1]; ^x&x|ckR!  
} wwl,F=| Y  
nEndPos[nEndPos.length-1] = nFileLength; u [qy1M0  
} U,2OofLM  
} "22./vWV|i  
R"OT&:0/  
d_ =K (}eR  
//启动子线程 v.W!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "5eD >!  
for(int i=0;i<nStartPos.length;i++) lB27Z}   
{ ?`TJ0("z"  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &m5^ YN$b  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L@\t] ~  
nStartPos,nEndPos,i); #N`'hPD}  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]MYbx)v)  
fileSplitterFetch.start(); ;d<XcpK}  
} TU?n;h#TZ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Lx- %y'P  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8nI~iN?"   
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [g}^{ $`  
nEndPos = " + nFileLength); N,w6  
// fileSplitterFetch[nPos.length-1].start(); VQ!4( <XD  
9]3l'  
r5&c!b\  
//等待子线程结束 ScJ:F-@>  
//int count = 0; ]yKwH 9sl  
//是否结束while循环 L^e*_q2d:>  
boolean breakWhile = false; 2>"{El|PbN  
u0R[TA3  
.:H'9QJg  
while(!bStop) %;4#?.W8  
{ _3 [E$Lg  
write_nPos(); "|i1A R:I  
Utility.sleep(500); 5S? "<+J'  
breakWhile = true; UP-2{zb |?  
9>+>s ?IgK  
x/1FQ>n:9  
for(int i=0;i<nStartPos.length;i++) zpT{!V  
{ |g7)A?2J~  
if(!fileSplitterFetch.bDownOver) [vtDtwL  
{ ?bd!JW bg`  
breakWhile = false; <;i&-,  
break; Z2{$FN  
} 5%S5*c6BD  
} NZ`6iK-V_  
if(breakWhile) {;bec%pq0  
break; w+rw<,u%  
'_g&!zi8~  
W=2.0QmW  
//count++; IF>v -Z  
//if(count>4) ? Zv5iI  
// siteStop(); &/EZn xl  
} akw:3+`  
\yymp70w  
%|@?)[;  
System.err.println("文件下载结束!"); R(Vd[EGY  
} CWs;1`aP  
catch(Exception e){e.printStackTrace ();} yq3"VFh3d  
} ?_pd#W=!  
,S(_YS^m  
jM*wm~4>@  
//获得文件长度 IAd ^$9  
public long getFileSize() .*k!Zl*  
{ ;2 o{ 6  
int nFileLength = -1; Y\!:/h]E&  
try{ ~l+~MB  
URL url = new URL(siteInfoBean.getSSiteURL()); ^umHuAAE  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ahd{f!  
httpConnection.setRequestProperty("User-Agent","NetFox"); M]\"]H?  
oQyMs>g  
T5~Qfl?Y  
int responseCode=httpConnection.getResponseCode(); #oGvxc7  
if(responseCode>=400) ziW[qH {  
{ KJ?/]oLr0  
processErrorCode(responseCode); TuMZHB7h;  
return -2; //-2 represent access is error yyR@kOGga  
} Zfu" 8fX  
K6<1&  
w*SFQ_6YE  
String sHeader; tORDtMM9+  
,38bT#p:,r  
/9y'UKl7[  
for(int i=1;;i++) !x:w2  
{ RAyR&p  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0txSF^x  
//Utility.log(in.readLine()); lSId<v?C>  
sHeader=httpConnection.getHeaderFieldKey(i); x^F2Ywp%  
if(sHeader!=null) '.&,.E&{$  
{ Q[O U`   
if(sHeader.equals("Content-Length")) BcGQpv&x  
{ /`x|-9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D/{Spw@  
break; _ )^n[_E  
} Qzk/oH s  
} b!37:V\#}  
else X>jwjRK $  
break; q33!X!br  
} r52,f%nlm  
} uP ?gGo  
catch(IOException e){e.printStackTrace ();} [/t/694  
catch(Exception e){e.printStackTrace ();} !as<UH"\  
S4~;bsSx  
gk6j5 $Y"<  
Utility.log(nFileLength); ^?[^o\/@R  
Z42v@?R.!W  
EZiGi[t7  
return nFileLength; &4MVk3SLx#  
} : [vp.vw}/  
;lWy?53=@  
[dL?N  
//保存下载信息(文件指针位置) 1[`l`Truz  
private void write_nPos() nBiA=+'v  
{ s.dn~|a  
try{ d0Kg,HB  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?t.?f`(|  
output.writeInt(nStartPos.length); Hp> J,m(*  
for(int i=0;i<nStartPos.length;i++) L{CHAVkV  
{ zck |jhJ6  
// output.writeLong(nPos); f<'&_*7,|t  
output.writeLong(fileSplitterFetch.nStartPos); N<Q}4%^c  
output.writeLong(fileSplitterFetch.nEndPos); 4_I,wG@  
} VF==F_l  
output.close(); "Lpt@g[HF  
} ZCJ8I  
catch(IOException e){e.printStackTrace ();} v:T` D  
catch(Exception e){e.printStackTrace ();} 7erao-  
} .}y Lz  
#WpO9[b>  
Z*e7W O.  
//读取保存的下载信息(文件指针位置) t@19a6:Co  
private void read_nPos() nt[0krG  
{ .r*b+rc;]  
try{ U ._1'pW  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =yNHJHRA#  
int nCount = input.readInt(); 't_=%^ q  
nStartPos = new long[nCount]; c!\y\r  
nEndPos = new long[nCount]; $BBfsaJPT  
for(int i=0;i<nStartPos.length;i++) ptq{$Y{_  
{ u]MF r2  
nStartPos = input.readLong(); G7/LYTT)  
nEndPos = input.readLong(); Z/RUrYeb  
} Tx_(^K  
input.close(); ]R>k0X.V  
} b~1p.J4  
catch(IOException e){e.printStackTrace ();} YL=k&Q G  
catch(Exception e){e.printStackTrace ();} !<6wrOMaO  
} +m7 x>ie)  
6$dm-BI  
$xZk{ rK  
private void processErrorCode(int nErrorCode) f"0H9  
{ Y@\5gZ&T  
System.err.println("Error Code : " + nErrorCode); o%9>elOju  
} -MEz`7c~  
Gf]s?J^a  
IFTW,9hh  
//停止文件下载 #"yf^*wX  
public void siteStop() =K>Z{% i  
{ I2DmM"-|  
bStop = true; aQmL=9  
for(int i=0;i<nStartPos.length;i++) B+DRe 8  
fileSplitterFetch.splitterStop(); \j;uN#)28  
cnPX vD^kY  
(MIw$)#^  
} R39R$\  
} 5)o IPHXw  
//负责部分文件的抓取 B:r-')!0$#  
**FileSplitterFetch.java g^4FzJ  
*/ =U2Te  
package NetFox; .}<B*e=y  
"AK3t' jF*  
jr l6):x  
import java.io.*; E\*",MGL  
import java.net.*; 9cmJD5OO  
2!3&Ub#FO  
q5W'P>  
public class FileSplitterFetch extends Thread { l>(G3l Iw  
`pMI[pLZe  
2* L/c-  
String sURL; //File URL fBOPd =  
long nStartPos; //File Snippet Start Position >C}RZdO~  
long nEndPos; //File Snippet End Position r=Q5=(hn  
int nThreadID; //Thread's ID _Usg`ax-  
boolean bDownOver = false; //Downing is over *&0Hz{|  
boolean bStop = false; //Stop identical ` j<tI6[e  
FileAccessI fileAccessI = null; //File Access interface ?^vZ{B)&0E  
f,a %@WT  
yrs3`/  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U[D<%7f  
{ ZtLn*M  
this.sURL = sURL; ggTjd"|)  
this.nStartPos = nStart; ncdr/(`  
this.nEndPos = nEnd; .am*d|&+G  
nThreadID = id; {|E7N"Qzg  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,h._iO)I^  
} y4L9Cxvs  
NFc8"7Mz}  
A,e^bM  
public void run() _MEv*Q@o  
{ 'X,V  
while(nStartPos < nEndPos && !bStop) \veL5  
{ EG.C2]Fi  
R7{hoqI2  
4"{wga~%/  
try{ .Cus t  
URL url = new URL(sURL); \8D~,$,``|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UG_0Y8$  
httpConnection.setRequestProperty("User-Agent","NetFox"); k>CtWV5B  
String sProperty = "bytes="+nStartPos+"-"; Z :+#3.4$3  
httpConnection.setRequestProperty("RANGE",sProperty); 8!SiTOzR?  
Utility.log(sProperty); >[@d&28b%  
pb Ie)nK  
o?FUVK  
InputStream input = httpConnection.getInputStream(); ( `+Z'Y  
//logResponseHead(httpConnection); (d#Z-w-  
SXz([Z{)  
}aM`Jp-O  
byte[] b = new byte[1024]; w0Y%}7  
int nRead; wS0bk<(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?&m]du#6  
{ \Agg6tY r  
nStartPos += fileAccessI.write(b,0,nRead);  vB*oI~<  
//if(nThreadID == 1) 8!6*|!,:?n  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %Ab_PAw  
} 3raA^d3!?  
^b %8_?2m  
J"%}t\Q  
Utility.log("Thread " + nThreadID + " is over!"); T_[\(K`w!  
bDownOver = true; oLMi vy4  
//nPos = fileAccessI.write (b,0,nRead); CWQ2iu<_0  
} m5aaY  
catch(Exception e){e.printStackTrace ();} ?\M6P?tpo&  
} zpqNmxmF  
} # :w2Hf6Q  
J6ShIPc  
A_~5|  
//打印回应的头信息 MjC%6%HI  
public void logResponseHead(HttpURLConnection con) %:?QE ;  
{ xN8JrZE&  
for(int i=1;;i++) Jk`)`94 I  
{ ok2~B._+;  
String header=con.getHeaderFieldKey(i); 2] G$6H  
if(header!=null) X$iJ|=vW  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i%4k5[f.:  
Utility.log(header+" : "+con.getHeaderField(header)); H<}eoU.  
else :&)/vq  
break; >o#wP  
} 'a^tL[rLP1  
} ]UT|BE4v  
TeCpT2!5j  
.<^Y E%  
public void splitterStop() /'fDXSdP  
{ {WeXURp&nF  
bStop = true; `lezJ (Xm  
} {FY[|:Cp  
=e8L7_;  
n o+tVm|  
} )2Ru!l#  
YQdX>k  
$YY)g$  
/* .]s( c!{y  
**FileAccess.java 9XqAjez\  
*//文件访问(定位,写) \Fg6b6  
package NetFox; #x@lZ!Y  
import java.io.*; etMh=/NFV  
2qMsa>~  
{a8^6dm*E  
public class FileAccessI implements Serializable{ ]j2v"n  
Pph8"`mv.m  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i6#]$B  
RandomAccessFile oSavedFile; T) tZU?  
long nPos; ;GFB@I@  
s[2ZxCrCw  
)1nCw  
public FileAccessI() throws IOException #3yw   
{ 83ic@[  
this("",0); "=\_++  
} 6eYf2sZ;J  
_ c ]3nzIr  
66@3$P%1p  
public FileAccessI(String sName,long nPos) throws IOException s7nX\:Bw:  
{ 9me}&Fdr  
oSavedFile = new RandomAccessFile(sName,"rw"); W({TC  
this.nPos = nPos; j-`X_8W  
oSavedFile.seek(nPos); ~J>gVg%66  
} =Cy>$/H64  
tK|9qs<%  
4!~ .6cp3  
public synchronized int write(byte[] b,int nStart,int nLen) Qj<{oZp&  
{ YG 5Z8@kH  
int n = -1; 0SY f<$  
try{ Jhsv2,8 {  
oSavedFile.write(b,nStart,nLen); q X%vRf0  
n = nLen; n~)HfY  
} rH&r6Xv[  
catch(IOException e) s'aV qB  
{ q bZ,K@0  
e.printStackTrace (); ?(/j<,m^  
} s |gD  
u2-@?yt  
nz(q)"A  
return n; me:|!lI7YU  
} &xBK\  
3_\{[_W  
2@3.xG  
} $TA6S+  
gJ3OK!/  
jxnQG A  
/* En,)}yI  
**SiteInfoBean.java ^\[LrPq e  
*/ 12tJrS*Z  
package NetFox; ? %+VG  
y^!E "  
cF_;hD|YZ  
public class SiteInfoBean { FS`vK`'  
Dpdn%8+Z  
<cDKGd  
private String sSiteURL; //Site's URL C](z#c~c  
private String sFilePath; //Saved File's Path i'Y'HI  
private String sFileName; //Saved File's Name 6i]Nr@1C  
private int nSplitter; //Count of Splited Downloading File Z[k#AgC)  
[EmOA.6  
"s>fV9YyZ  
public SiteInfoBean() 2fzKdkJhe  
{//nSplitter的缺省值为5 %R5Com  
//default value of nSplitter is 5 fys5-1@-p  
this("","","",5); xz"Z3B  
} ke}Y 2sB  
,yk PQzO  
"B9[cDM&  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,l$NJt   
{ $AA~]'O>6:  
sSiteURL= sURL; my\o P(e\  
sFilePath = sPath; :T7?  
sFileName = sName; H ~[LJ5x  
this.nSplitter = nSpiltter; `!nJS|  
9U|<q  
y8w0eq94  
} msc 1^2  
 's>#8;X  
,C{^`Bk-W  
public String getSSiteURL() 6wb^*dD92  
{ b8N[."~:  
return sSiteURL; ).NcLJw_  
} W&+y(Z-t  
%XJQ0CE<(  
w.J%qWJq  
public void setSSiteURL(String value) GSz @rDGY  
{ k-WHHoU>o  
sSiteURL = value; Qj 6gg  
} cc|CC Zl  
a[1sA12  
:cc[Jco@w  
public String getSFilePath() }rz dm9  
{ xdd:yrC   
return sFilePath; ~~C6)N~1  
} GA|/7[I}  
i>Z|6 5  
Lw>-7)  
public void setSFilePath(String value) [1z{T(dh  
{ brg":V1a  
sFilePath = value; j|VXC(6 P,  
} 81g9ZV(4  
Ro'jM0(KE  
gB]C&Q  
public String getSFileName()  6Xdtr  
{  d?:`n 9`  
return sFileName; r0F_;  
} 5oz>1  
[AXsnpa/C  
6xQ"bFm  
public void setSFileName(String value) sA/,+aM  
{ <9ma(PFa  
sFileName = value; )K{o<m~WAo  
} ;#3ekl{-g  
\s=QiPK  
IWAj Mwo  
public int getNSplitter() X_D6eYF  
{ >9-Dd)<  
return nSplitter; 0jBKCu  
} MWBXs7 5I  
W`#gpi)7N  
xME(B@j  
public void setNSplitter(int nCount) mR"uhm}q  
{ $"Afy)Ir  
nSplitter = nCount; fO*)LPen.z  
} " Wp   
} }%eDEM  
&oA~ Tx  
k_]\(myq  
/* 5B%w]n  
**Utility.java GGCqtA^@7d  
*/ Js/N()X  
package NetFox; 6hZ.{8e0  
YVoao#!  
z~F37]W3[  
public class Utility { {3_Gjb5\\4  
}A-{6Qe  
f[x~)=  
public Utility() V {p*z  
{ x@h tx?   
J;S-+  
rB,ldy,f  
} >gr<^$  
C?,*U  
//线程睡眠 M3ZOk<O<R  
public static void sleep(int nSecond) A*hZv|$0  
{ T-^0:@5o9  
try{ sr\cVv")  
Thread.sleep(nSecond); UanEzx%  
} W/sY#"  
catch(Exception e) RF:04d  
{ \UOm]z  
e.printStackTrace (); j(sLK &  
} 47KNT7C  
} GSP?X$E  
YNI;h%w  
//日志 yx2z%E  
public static void log(String sMsg) YV-j/U{&  
{ 1DUb [W8  
System.err.println(sMsg); a~,Kz\Tt  
} F'1k<V?  
sMP:sCRC  
#00D?nC  
public static void log(int sMsg) ^ESUMXb  
{ `g--QR  
System.err.println(sMsg); \6{LR&  
} +s ULo  
} $%Z3;:<Uf-  
*#zS^b n  
m~;B:LN<  
/* CI^[I\$&  
**TestMethod.java \0nlPXk?G  
*/ })P O7:  
package NetFox; d .p'pGL  
 c-5Ysg  
;= a_B1"9u  
public class TestMethod { B[CA 5Ry  
44~hw:   
zZ: xEc  
public TestMethod() U9 bWU'  
{ ///xx/weblogic60b2_win.exe 33 : @*  
try{ ypl G18  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D*QYKW=)  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0'`S,  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6lsEGe  
fileFetch.start(); `"c'z;  
} $Zxt&a  
catch(Exception e){e.printStackTrace ();}  t!jYu<P  
"TNVD"RLY  
QXs8:;T  
} q6R Eh;$  
Cc Y7$D  
NO2(vE  
public static void main(String[] args) Vc _:*  
{ W qE '(  
new TestMethod(); !>3LGu,  
} ;}K62LSR  
} -%,"iaO  
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