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http断点续传简单实现(java)

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/* ZFL~;_r  
**SiteFileFetch.java q2E_ A  
*/ wIt}dc  
package NetFox; F JyT+  
import java.io.*; sO@Tf\d  
import java.net.*; UaeXY+O  
:vbW  
O\ r0bUPE  
public class SiteFileFetch extends Thread { {P_.~0pc*  
6i/(5 nQ  
26h21Z16q  
SiteInfoBean siteInfoBean = null; //文件信息Bean b ]KBgZ  
long[] nStartPos; //开始位置 b \2 ds,  
long[] nEndPos; //结束位置 ~4'$yWG  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 FZn w0tMq  
long nFileLength; //文件长度 3!]rmZ-W  
boolean bFirst = true; //是否第一次取文件 xA*<0O\V  
boolean bStop = false; //停止标志 > ~O.@|  
File tmpFile; //文件下载的临时信息 tWc Hb #  
DataOutputStream output; //输出到文件的输出流 VOLj>w  
gPPkT"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) RA L~!"W  
public SiteFileFetch(SiteInfoBean bean) throws IOException  @q) d  
{ P&Vv/D  
siteInfoBean = bean; nu%*'.  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); wibNQ`4k  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); cvL;3jRo  
if(tmpFile.exists ()) [ 4)F f  
{ =I_'.b  
bFirst = false; |A(Iti{v  
read_nPos(); tCt#%7J;a  
} +ZP7{%  
else i83OOV$1J  
{ f/?P514h  
nStartPos = new long[bean.getNSplitter()]; r~['VhI!;E  
nEndPos = new long[bean.getNSplitter()]; sW\!hW1*x  
} Z% UP6%  
,ig/s2ZG6X  
$XH^~i;  
Eu3E-K@y  
} Q~9^{sHZjP  
`R^gU]Z,  
C3g_! dUs  
public void run() VIf.q)_k  
{ ;O,jUiQ  
//获得文件长度 hhvyf^o   
//分割文件 4*;MJ[|  
//实例FileSplitterFetch K|=A:  
//启动FileSplitterFetch线程 q) KKvO  
//等待子线程返回 !&E-}}<  
try{ vl)l'  
if(bFirst) jPkn[W# 6  
{ ?a]mDx>xh  
nFileLength = getFileSize(); owv[M6lbD  
if(nFileLength == -1) YS_; OFsd  
{ dPRra{  
System.err.println("File Length is not known!"); Wd ELV3  
} *LY8D<:zs  
else if(nFileLength == -2) U6s[`H3I{  
{ f|(M.U-  
System.err.println("File is not access!"); 6Kz,{F@  
} I]q% 2ie  
else \~wMfP8  
{ d0> zS  
for(int i=0;i<nStartPos.length;i++) 9lE_nc  
{ >yDZw!C  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); F:DrX_O%  
} _)-o1`*-  
for(int i=0;i<nEndPos.length-1;i++) \fe]c :  
{ d#wVLmKZ  
nEndPos = nStartPos[i+1]; q@2siI~W  
} f*8DCh!r"  
nEndPos[nEndPos.length-1] = nFileLength; /Z4et'Lo  
} Dvln/SBk  
} 69.NPy@  
TD_Oo-+\  
<#HYqR',  
//启动子线程 hE-M$LmN@  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /qw.p#  
for(int i=0;i<nStartPos.length;i++) QS`]  
{ 1h5 Akq  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C7AUsYM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }(u ol  
nStartPos,nEndPos,i); 9N3eN  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gQ.Sa j $  
fileSplitterFetch.start(); FVBYo%Ap  
} x,Vr=FB  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kU`r)=1"  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2J;g{95z  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /Ci<xmP  
nEndPos = " + nFileLength); ;A[Q2(w+  
// fileSplitterFetch[nPos.length-1].start(); $ME)#(  
Kc(FX%3LU  
0m ? )ROaJ  
//等待子线程结束 :BT q!>s  
//int count = 0; syK^<xa  
//是否结束while循环 TS5Q1+hWHV  
boolean breakWhile = false; 3R V R  
&+R?_Ooibk  
ehY5!D1Q  
while(!bStop) Rlirs-WQ  
{ :U x_qB  
write_nPos(); HpnWo DM  
Utility.sleep(500); Z%\,w(o[h  
breakWhile = true; GPkpXVm  
#LOwGJ$yVz  
40 0#v|b  
for(int i=0;i<nStartPos.length;i++) v.5+7,4  
{ )dSi/  
if(!fileSplitterFetch.bDownOver) 4X|zmr:A  
{ xN%K^Tree  
breakWhile = false; :\U{_@?`%  
break; g=o4Q< #^y  
} B7vpsSL  
} @s^-.z  
if(breakWhile) RpYERAgT  
break; o _H`o&xr  
)\^-2[;  
$, '*f?d  
//count++; ~u+9J}  
//if(count>4) N}YkMJy  
// siteStop(); ~e.L.,4QZ8  
} gPc=2  
t&DEb_"De  
jF*j0PkNdb  
System.err.println("文件下载结束!"); 29q _BR *:  
} ~F7gP{r  
catch(Exception e){e.printStackTrace ();} iG?[<1~  
} dC4'{ n|7  
4xJQ!>6  
6S\8$  
//获得文件长度 {FTqu.  
public long getFileSize() @xZR9Z8]L  
{ RCLeA=/N@0  
int nFileLength = -1; L&OwPd  
try{ 61 ~upQaR  
URL url = new URL(siteInfoBean.getSSiteURL()); t&Og$@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BL58] P84  
httpConnection.setRequestProperty("User-Agent","NetFox"); xAP+FWyV  
$u6 3]rypm  
'[O;zJN;  
int responseCode=httpConnection.getResponseCode(); h`.&f  
if(responseCode>=400) y18Y:)DkL  
{ &G$Ucc `  
processErrorCode(responseCode); KCDE{za  
return -2; //-2 represent access is error W+1^4::+  
} B,fo(kG  
Jpo (Wl  
D7qOZlX16  
String sHeader; kz7(Z'pw  
4I5Y,g{6+  
/JU.?M35  
for(int i=1;;i++) Oz#{S:24M+  
{ vSLtFMq^(  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G<;*SYAb  
//Utility.log(in.readLine()); sFTy(A/  
sHeader=httpConnection.getHeaderFieldKey(i); ji,kkipY?w  
if(sHeader!=null) RY*U"G0#w  
{ 5i{j' {_(8  
if(sHeader.equals("Content-Length")) EDs\,f}  
{ _t}WsEQ+P  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B4 8={  
break; $ o#V#  
} 8SS|a  
} [;sRV<  
else HiJE}V;Vq  
break; E q+_&Wk  
} 7i1q wRv  
} 7 x?<*T  
catch(IOException e){e.printStackTrace ();} @gXx1hEg  
catch(Exception e){e.printStackTrace ();} b*Q&CL  
GNJj=1Lsd  
R_S.tT!  
Utility.log(nFileLength); ?#Q #u|~  
lCHO;7YHX  
*s iFj CN<  
return nFileLength; $a ` G  
} <yg F(  
&XUiKnNW  
Yp2eBgo"  
//保存下载信息(文件指针位置) >~+ELVB&  
private void write_nPos() {P#|zp4C{  
{ &Z|P2dI  
try{ CQDkFQq-dq  
output = new DataOutputStream(new FileOutputStream(tmpFile)); -1ub^feJ,  
output.writeInt(nStartPos.length); *bpD`s @  
for(int i=0;i<nStartPos.length;i++) 6/dI6C!  
{ Tkgs]q79  
// output.writeLong(nPos); IRqy%@)  
output.writeLong(fileSplitterFetch.nStartPos); 9490o:s  
output.writeLong(fileSplitterFetch.nEndPos); )TM4R)r%)9  
} 3%=~) 7cF  
output.close(); zT?D<XW>1  
} DrK{}uM  
catch(IOException e){e.printStackTrace ();} y Fq&8 x<X  
catch(Exception e){e.printStackTrace ();} =[jXe  
} hqkz^!rp  
\:F_xq  
_``=cc  
//读取保存的下载信息(文件指针位置) ^@NU}S):yN  
private void read_nPos() pIKPXqA  
{ ,U dVNA  
try{ 4x[S\,20  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !brf(-sr)  
int nCount = input.readInt(); t}/( b/VD  
nStartPos = new long[nCount]; x `)&J B  
nEndPos = new long[nCount]; [Cv/{f3]u{  
for(int i=0;i<nStartPos.length;i++) I?G :p+  
{ YQA ,f#  
nStartPos = input.readLong(); Q#[9|A9  
nEndPos = input.readLong(); l_%6  
} g_COp "!~9  
input.close(); Q6I:"2u1  
} n#_$\ p>Yd  
catch(IOException e){e.printStackTrace ();}  | (_  
catch(Exception e){e.printStackTrace ();} HT1!5  
} A1zjPG&]  
"wh , Ue  
q;)JISf.  
private void processErrorCode(int nErrorCode) 0v$~90)  
{ $z*'fXg  
System.err.println("Error Code : " + nErrorCode); T0rG M  
} h>OfOx/{q9  
85xR2<:  
hODWB&b  
//停止文件下载 'Ne@e)s9  
public void siteStop() 0}q uG^%_  
{ aPbE;" f  
bStop = true; e.V:)7Uc  
for(int i=0;i<nStartPos.length;i++) PBkt~=j  
fileSplitterFetch.splitterStop(); ,{?%m6.lE  
}Y36C.@H  
vn"{I&L+w0  
} (0y~%J  
} WlBc.kFck  
//负责部分文件的抓取 oIj#>1~c%  
**FileSplitterFetch.java A '];`  
*/ {fn!'  
package NetFox; :1KpGj*F  
9|CN8x-  
LOV)3{m  
import java.io.*; H\tUpan6fy  
import java.net.*; Jz *;q~  
\7'{g@C(  
$43qME  
public class FileSplitterFetch extends Thread { &m:uO^-D  
/{--+ C  
>]5P 3\AQV  
String sURL; //File URL W#WVfr  
long nStartPos; //File Snippet Start Position Whf.fK  
long nEndPos; //File Snippet End Position _X"N1,0  
int nThreadID; //Thread's ID **gXvTqI  
boolean bDownOver = false; //Downing is over dQR-H7U  
boolean bStop = false; //Stop identical Qhcu>r a  
FileAccessI fileAccessI = null; //File Access interface ?]Xpi3k  
|R\>@Mg#B  
bY QRBi  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A#'8X w|  
{ G<rHkt@[  
this.sURL = sURL; #d2.\X}A"3  
this.nStartPos = nStart; z]D69O b  
this.nEndPos = nEnd; FZE"7ec>m  
nThreadID = id; Bad:n o\W  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O~K>4 ax  
} tc{s B\&-  
!6Mo]xh  
O2dW6bt  
public void run() )*x6 FfTUd  
{ u-G+ j)  
while(nStartPos < nEndPos && !bStop) Jd^,]  
{ GKc`xIQ  
Qtv&ijFC  
i5?q,_  
try{ h Pa_VrH  
URL url = new URL(sURL); I- >Ss},U  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qfRH5)k  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5 -RsnF  
String sProperty = "bytes="+nStartPos+"-"; 6h,(wo3Y  
httpConnection.setRequestProperty("RANGE",sProperty); j@uOOhy  
Utility.log(sProperty); e@* EzvO  
?\s+EE&-  
/9p wZ%:<  
InputStream input = httpConnection.getInputStream(); !fR3 (=oN  
//logResponseHead(httpConnection); +8d1|cB"  
 l(tOe  
Z+. '>  
byte[] b = new byte[1024]; #O} ,`[<  
int nRead; 0-yp,G  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .j<]mUY  
{ TXvI4"&  
nStartPos += fileAccessI.write(b,0,nRead); K\6u9BYG  
//if(nThreadID == 1) !sW(wAy?o  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s %\-E9 T  
} [o+q>|q  
y0.8A-2:  
.Cl:eu,]  
Utility.log("Thread " + nThreadID + " is over!"); !1{e|p 7  
bDownOver = true; q0R -7O(  
//nPos = fileAccessI.write (b,0,nRead); ,a]?S^:y]  
} NDlF0f  
catch(Exception e){e.printStackTrace ();} q ]e`9/U  
} O% KsD[W;  
} (~wqa 3  
X1-'COQS%&  
g+>(dnX  
//打印回应的头信息 qUGC" <W  
public void logResponseHead(HttpURLConnection con) };jN\x?&q  
{ (VEpVn3{  
for(int i=1;;i++) e MY<uqdw  
{ ah0`KxO]  
String header=con.getHeaderFieldKey(i); xQXXC|T  
if(header!=null) 8hJ%JEzga  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RA'M8:$  
Utility.log(header+" : "+con.getHeaderField(header)); $jI3VB  
else >$7v ;Q  
break; f"SD/]q-  
} m\r@@!  
} ![_*(8v}S  
\T:i{.i  
6BbGA*%{  
public void splitterStop() |G,tlchprs  
{ "(z5{z?S  
bStop = true; vyX\'r.~7  
} r6} |hpJ8  
Q)" Nu.m &  
c[4i9I3v  
} VE {3}S  
EGzzHIZ`!  
( b~T]3Es  
/* 6ZG+ZHUC&  
**FileAccess.java !1DKLQ  
*//文件访问(定位,写) nv%rJy*w[  
package NetFox; fW3(&@  
import java.io.*; I]<_rN8~o  
B!_mC<*4`X  
#W'HR  
public class FileAccessI implements Serializable{ > BY&,4r  
1&)?JZhg  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nvJf/90$  
RandomAccessFile oSavedFile; ]?+p5;{y4  
long nPos; !K}~/9Z=m  
(ehK?6[  
`W:%mJd9  
public FileAccessI() throws IOException >x+6{^}Q>  
{ o` ZQd,3  
this("",0); Avd ^  
} )d1_Wm#B  
,PuL{%PXu  
r1.nTO%  
public FileAccessI(String sName,long nPos) throws IOException )ufg9"\  
{ luuX2Mx>o  
oSavedFile = new RandomAccessFile(sName,"rw"); "2P&X  
this.nPos = nPos; WEQ1 Seq  
oSavedFile.seek(nPos); +HeTtFo{M  
} /F-qP.<D,r  
57zSu3v4Y  
[los dnH^?  
public synchronized int write(byte[] b,int nStart,int nLen) -o[x2u~n\  
{ =;3Sx::=  
int n = -1; ?_$=l1vf  
try{ y?m/*hh`  
oSavedFile.write(b,nStart,nLen); G_{&sa  
n = nLen; 6@e+C;j =  
} 8U>B~9:JO  
catch(IOException e) L[H5NUG!  
{ KJ=6n%6  
e.printStackTrace (); ^xHTWg%9  
} v'qG26  
Co9QW/'i  
hMUs" <.  
return n; GCX G/k?w:  
} #Jn_c0  
p|jV{P  
Wi2WRJdyu  
}  , ^;)<[  
=aA+~/~8%  
=aj/,Q]  
/* X*39c b(b  
**SiteInfoBean.java ng:9 l3 x  
*/ ph[#QHB  
package NetFox; wS+ ^K  
Q`D~5ci  
YW`,v6  
public class SiteInfoBean { (TwnkXrR,  
"@d[h,TM  
wsN?[=l{s  
private String sSiteURL; //Site's URL /VzI'^  
private String sFilePath; //Saved File's Path IOoz^/'  
private String sFileName; //Saved File's Name j!4et;  
private int nSplitter; //Count of Splited Downloading File a1.Ptf eW|  
_$f9]bab  
]*FVz$>XM  
public SiteInfoBean() vj\dA2!~  
{//nSplitter的缺省值为5 U{z9>  
//default value of nSplitter is 5 *@Y3oh}S  
this("","","",5); 6s\Kt3=  
} .k9{Yv0  
7J|VD#DE$Y  
I8<,U!$  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !+4cqO  
{ 0 79'(%  
sSiteURL= sURL; H(2]7dRS%  
sFilePath = sPath; Xn,v]$M!  
sFileName = sName; k.^co I5  
this.nSplitter = nSpiltter; (+u39NQV  
J-) XQDD  
\XM^oE#G  
} ZAUQJS 91E  
;._7jFj.  
8&~~j7p,  
public String getSSiteURL() k^%B5  
{ )m{Ye0!RD  
return sSiteURL; AUNQA  
} m-DsY  
P=&o%K,:f  
9Xl5@%uz?z  
public void setSSiteURL(String value) & jczO-R^  
{ +|@rD/I6  
sSiteURL = value; l)w Hl%p  
} J.dLPKU;-  
t|!j2<e  
t" 7yNs(I  
public String getSFilePath() .G(llA}  
{ f0<%&2ym  
return sFilePath; ]oV{t<0a  
} QgD g}\P  
P=+nB*hG  
]%Nlv(  
public void setSFilePath(String value) H_Kj7(=&>  
{ ?wF'<kEH  
sFilePath = value; |),'9  
} +sx 8t  
J}@z_^|"mJ  
VY"9?2?/  
public String getSFileName() Ra/Ukv_v  
{ RJH,  
return sFileName; .8uz 6~  
} bY2 C]r(n  
_s$_Sa ;  
RZ7( J  
public void setSFileName(String value) mVsIAC$}8  
{ drd/jH&  
sFileName = value; )r z+'|,  
} /c-r  
^/ =#UQ*k  
b}w C|\s  
public int getNSplitter() k({\/t3i  
{ 3 M10fI?  
return nSplitter; pD2<fP_  
} 2gjGeM  
Gqcz< =/  
L9ap(  
public void setNSplitter(int nCount) zT|)uP*  
{ 9cx =@  
nSplitter = nCount; o/ mF #  
} :BukUket1e  
} he-Ji  
+ "}=d3E6  
q4$+H{xB  
/* F3lw@b3])  
**Utility.java xc:!cA{V  
*/ -;XKcS7Ue  
package NetFox; Hiv!BV|  
y}K\%;`[a  
s(LT  
public class Utility { ~i_Tw#}  
(j"(  
Rek -`ki5F  
public Utility() "ZHtR/;  
{ \[>9UC%  
FvuGup`w  
bo=ZM9  
} !.<T"8BUpv  
H,<7G;FPT  
//线程睡眠 g3sUl&K  
public static void sleep(int nSecond) b7\ cxgRq  
{ \zkw2*t  
try{ $hVYTy~}  
Thread.sleep(nSecond); ]PP:oriWl  
} 4YMX|1wd)  
catch(Exception e) )Vk6;__  
{ " ;w}3+R  
e.printStackTrace (); #W2[  
} Y'3}G<'%  
} asgF1?r  
]G}B 0u3  
//日志 's!-80sd  
public static void log(String sMsg) ExXM:1 e26  
{ _uu<4c   
System.err.println(sMsg); cj|*_}  
} u%dKig  
$7Mtt.d6  
>71&]/Rv  
public static void log(int sMsg) PS" .R_"  
{ wFIh6[3  
System.err.println(sMsg); KZ:8[d  
} /<3<. ~  
} geefnb  
2~p[7?sp'  
YIp-Y}6  
/* FM5e+$>@  
**TestMethod.java  ql&*6KZ"  
*/ zN_:nY>  
package NetFox; mN5 8r"!J  
X7|.T0{=x  
7C?.L70ZY  
public class TestMethod { MuEy>dl  
nxap\Lf  
m>e3vu  
public TestMethod() z&3]%t `C  
{ ///xx/weblogic60b2_win.exe N<_Ko+VF  
try{ snp v z1iS  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )06iV  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Zq ot{s  
SiteFileFetch fileFetch = new SiteFileFetch(bean); )yb+M ez  
fileFetch.start(); SHqyvF  
} 6=PiVwI  
catch(Exception e){e.printStackTrace ();} 4DO/rtkVq  
VAYb=4lt  
#G,XDW2"w  
} xwzT#DXGJ  
Rh] P8  
{R&ZqEo'D  
public static void main(String[] args) ;? uC=o>Z{  
{ _NdLcpBT?  
new TestMethod(); OalP1Gy  
} 2+9 2Q_+  
}  D\T!4q'Q  
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