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http断点续传简单实现(java)

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/* =[8d@d\  
**SiteFileFetch.java D1~^\)*  
*/ pgfu+K7?w  
package NetFox; &*c'uN w  
import java.io.*; Kk56/(_S  
import java.net.*; u> In(7\  
z7$}#)Z7  
g BH?l/  
public class SiteFileFetch extends Thread { <e^6.!;W  
bAdAp W  
u p7 x)w:  
SiteInfoBean siteInfoBean = null; //文件信息Bean )muv;Rf`e5  
long[] nStartPos; //开始位置 ees^O{ 8  
long[] nEndPos; //结束位置 R=DPeUy;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 8ST~$!z$  
long nFileLength; //文件长度 K;kLQ2)  
boolean bFirst = true; //是否第一次取文件 {)jk_&c7  
boolean bStop = false; //停止标志 }W)Mwu'W  
File tmpFile; //文件下载的临时信息 _/8y1) I  
DataOutputStream output; //输出到文件的输出流 (T`q++  
^K*~ <O-  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) j!"iYtgV  
public SiteFileFetch(SiteInfoBean bean) throws IOException \j/}rzo]  
{ 0I6499FQ  
siteInfoBean = bean; k@lXXII ?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ]qF<Zw7  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [j1^$n 8V  
if(tmpFile.exists ()) 4I+.^7d  
{ sF, uIr/  
bFirst = false; Xd5! Ti}  
read_nPos(); &?fvt  
} c[6zX#{`  
else lP-kZA!  
{ E{?L= ^cU  
nStartPos = new long[bean.getNSplitter()]; ~ |J*E38  
nEndPos = new long[bean.getNSplitter()]; @b>YkJDk  
} q 8tP29  
{!>E9Px  
Ed8U;U b  
C!oksI  
} RbyF#[}  
|^\ Hv5  
``/y=k/au  
public void run() hu`L v  
{ CD$u=E ]  
//获得文件长度 'XG:1Bpm  
//分割文件 h7)VJY  
//实例FileSplitterFetch u_hE7#i  
//启动FileSplitterFetch线程 cG<Q`(5~  
//等待子线程返回 s n=zh1 A  
try{ Bl:{p>-q  
if(bFirst) S]Sp Z8  
{ I>(;bNgN E  
nFileLength = getFileSize(); hG< a  
if(nFileLength == -1) h,Y{t?Of  
{ H ,01o5J  
System.err.println("File Length is not known!"); ]wJ}-#Kx  
} ZJ)3GF}4  
else if(nFileLength == -2) BvNl?A@]A  
{ v[p/c.p?i  
System.err.println("File is not access!"); {-:4O\/  
} YY1{v?[  
else [w+yQ7P  
{ OYQXi  
for(int i=0;i<nStartPos.length;i++) ?*(r1grHl  
{ ~m009  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); f]{1ZU%4  
} #r78Ym'aI  
for(int i=0;i<nEndPos.length-1;i++) 5(mCBH  
{ 5e~ j  
nEndPos = nStartPos[i+1]; S&gKgQD"Q  
} )M&I)In'  
nEndPos[nEndPos.length-1] = nFileLength; 8ItCfbqa6  
} H-nFsJ(R!c  
} EN5G:hD  
tU-#pB>H  
%N?W]vbra  
//启动子线程 z&6]vN'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n0>5'm%ES  
for(int i=0;i<nStartPos.length;i++) t1*BWY  
{ !HT>  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %B*<BgJ;4F  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ZEXj|wC  
nStartPos,nEndPos,i); +8?R+0P  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BXKlO(7  
fileSplitterFetch.start(); fwar8 i1  
} wz|Q%.%?[  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0%q{UW2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k:(e79  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k*zc5ev}  
nEndPos = " + nFileLength); 6KZ8 .m}:  
// fileSplitterFetch[nPos.length-1].start(); `W.vW8 !#  
{ c6DT  
troy^H  
//等待子线程结束 f<$K.i  
//int count = 0; Dn{19V. L  
//是否结束while循环 TA-(_jm  
boolean breakWhile = false; :_I wc=  
a{%52B"  
"'&>g4F`o  
while(!bStop) d=c1WK  
{ *cI6 &;y  
write_nPos(); 2:6Y83  
Utility.sleep(500); Aspj*CDu  
breakWhile = true; 4P-'(4I)  
;_Of`C+  
f"Vm'0r  
for(int i=0;i<nStartPos.length;i++) X,C/x)  
{ ] _]6&PZXk  
if(!fileSplitterFetch.bDownOver) -h^} jP8  
{ =4w^)'/  
breakWhile = false; S9F]!m^i  
break; )Zu Q;p  
} {TcbCjyw  
} $.x?in|_  
if(breakWhile) PL$(/Z  
break; 6LF^[b/u  
ys"mP* wD  
BW(DaNt^  
//count++; HnKF#<  
//if(count>4) V~gUMu4ot  
// siteStop(); D/%b@Ls2ze  
} l52n/w#qFB  
<EMLiiNY  
?'8MI|*l%  
System.err.println("文件下载结束!"); aaa#/OWQZ  
} uN? O*h/(  
catch(Exception e){e.printStackTrace ();} :Jsz"vCg&s  
} VQW)qOR9  
VdN+~+A:  
l2KxZteXY0  
//获得文件长度 Al-%j- j@-  
public long getFileSize() *{p& Fy55  
{ JNA}EY^2I.  
int nFileLength = -1; hvv>UC/  
try{ lLwQridFXh  
URL url = new URL(siteInfoBean.getSSiteURL()); =LeVJGF  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z6>ZV6(d2^  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]mLTF',5  
I5<#SW\a?  
5l7L@Ey  
int responseCode=httpConnection.getResponseCode(); s R0e&Y  
if(responseCode>=400) w]P7!t  
{ @x>$_:]  
processErrorCode(responseCode); x#}eC'Q  
return -2; //-2 represent access is error 3~1lVU:  
} " ih>T^|  
D 5wR?O  
HZQ3Ht3Vh  
String sHeader; ]bU'G$Qm&s  
x) qHeS  
\5pAG mgD  
for(int i=1;;i++) %dWFg<< |  
{ ~9>[U%D  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;g)Fhdy!  
//Utility.log(in.readLine()); ~[/c'3+4qn  
sHeader=httpConnection.getHeaderFieldKey(i); =K< I)2   
if(sHeader!=null) W/F4wEODY  
{ c+K=pp@  
if(sHeader.equals("Content-Length")) uJ5%JB("E  
{ UFY~D"% /  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y`_X@Q  
break; H2R^t{ w  
} {3p7`h~  
} Ch&]<#E>`  
else 87E3pe  
break;  rOf  
} Mh/>qyS *2  
} WuQ<AS=   
catch(IOException e){e.printStackTrace ();} #1hz=~YO  
catch(Exception e){e.printStackTrace ();} .AI'L|FQ%c  
v+_Y72h*a  
)B5gs%u]  
Utility.log(nFileLength); Y\9*e5?`I3  
U:p"IY#%  
$=QO_t)?  
return nFileLength; %oKc?'L0  
} xgw)`>p,W  
Bst>9V&R  
>oaEG5%d  
//保存下载信息(文件指针位置) o*ED!y7  
private void write_nPos() Lj* =*V  
{ -oT+;2\2  
try{ 7tO$'q*h  
output = new DataOutputStream(new FileOutputStream(tmpFile));  KGwL09)  
output.writeInt(nStartPos.length); \ #c+vfq  
for(int i=0;i<nStartPos.length;i++) Uht:wEr  
{ ]~ eWr2uG?  
// output.writeLong(nPos); GYmBxX87  
output.writeLong(fileSplitterFetch.nStartPos); }uj'BO2?  
output.writeLong(fileSplitterFetch.nEndPos); f<:SdtG5  
} w*kFtNBfU  
output.close(); h_"/@6  
} G9":z|  
catch(IOException e){e.printStackTrace ();} >}(*s^!k  
catch(Exception e){e.printStackTrace ();} ]8nm9qmF<  
} dnc!=Z89  
{h+E&u[zL  
$ttr_4=  
//读取保存的下载信息(文件指针位置) L"<Eov6  
private void read_nPos() BjJ gQ`X  
{ }ucg!i3C  
try{ w3UJw  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _ShJ3\,K  
int nCount = input.readInt(); CPE F,,\  
nStartPos = new long[nCount]; )@|Fh@|  
nEndPos = new long[nCount]; =C2C~Xd  
for(int i=0;i<nStartPos.length;i++) PBnn,#  
{ b<cM[GaV~  
nStartPos = input.readLong(); n.>'&<H>9  
nEndPos = input.readLong(); \-id[zKb  
} T0)y5  
input.close(); ? NK} q\$  
} fT~<C {  
catch(IOException e){e.printStackTrace ();} A'R sy6  
catch(Exception e){e.printStackTrace ();} m;1 exa  
} j!n> d  
F=c_PQO  
zX Pj7K*  
private void processErrorCode(int nErrorCode)  Q'M Ez  
{ 3!UP>,!  
System.err.println("Error Code : " + nErrorCode); 3goJ(XI  
} _j tS-CnO  
aJ@qB9(ZBe  
]}c=U@D,9  
//停止文件下载 . M $D  
public void siteStop() a{.n(M  
{ ?bA]U:  
bStop = true; 9}_f\Bs  
for(int i=0;i<nStartPos.length;i++) DYl{{L8@  
fileSplitterFetch.splitterStop(); `t2! M\)  
tqC#_[~7  
P6'I:/V  
} $QnfpM%+=  
} # =3]bg  
//负责部分文件的抓取 U<gw<[>f  
**FileSplitterFetch.java )ISTb  
*/ O, 6!`\ND  
package NetFox; r\`m[Q  
s``L?9  
oI/ThM`=q  
import java.io.*; i*>yUav"  
import java.net.*; <3CrCEPC  
w;_=$L'H&G  
7NEn+OI4  
public class FileSplitterFetch extends Thread { AV! cCQ  
,"ZlY}!Gn  
+y(h/NcQ  
String sURL; //File URL v[GHqZ  
long nStartPos; //File Snippet Start Position g/gLG:C  
long nEndPos; //File Snippet End Position N`MQHQ1  
int nThreadID; //Thread's ID ?K#$81;[  
boolean bDownOver = false; //Downing is over ;hDr+&J|  
boolean bStop = false; //Stop identical $ 7!GA9Bn  
FileAccessI fileAccessI = null; //File Access interface 0<k!F3=  
h^,a 1'  
WLb7]rCTp  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @I:&ozy }=  
{ }hxYsI"d  
this.sURL = sURL; 5Bk  
this.nStartPos = nStart; 2Mp;/b!  
this.nEndPos = nEnd; fOAb?:D  
nThreadID = id; ny}utO  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WFG/vzJ  
} rK wkj)  
PN=yf@<V3F  
:f:C*mYvu  
public void run() "Q4{6FH+mB  
{ K6oLSr+EAK  
while(nStartPos < nEndPos && !bStop) L4%LE/t|e  
{ *uR'eXW  
0jH2. d=  
f 5Oh#  
try{ ,fRb6s-  
URL url = new URL(sURL); gw:BKR'o  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u)-l+U.  
httpConnection.setRequestProperty("User-Agent","NetFox"); KivzgNz  
String sProperty = "bytes="+nStartPos+"-"; AaVlNjB  
httpConnection.setRequestProperty("RANGE",sProperty); Pip if.  
Utility.log(sProperty); <LY+" Y  
/FY_LM  
00+5a TrE  
InputStream input = httpConnection.getInputStream(); k$c!J'qL&  
//logResponseHead(httpConnection); tTal<4  
p P&~S<[  
mDUS9>  
byte[] b = new byte[1024]; A:(uK>5{Kk  
int nRead; `'`XB0vb  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vr$ [  
{ = 1C9lKm  
nStartPos += fileAccessI.write(b,0,nRead); t)h3GM  
//if(nThreadID == 1) T=vI'"w  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N{0 D<"  
} XT)@)c7j  
:M16ijkx  
"- AiC6u  
Utility.log("Thread " + nThreadID + " is over!"); ?FyA2q!  
bDownOver = true; dL>ZL1.$  
//nPos = fileAccessI.write (b,0,nRead); nm..$QL  
} Yhfk{CI  
catch(Exception e){e.printStackTrace ();} $v,_8{ !  
} xp = ]J UQ  
} %?ad.F+7  
f|!zjX`  
A]1](VQ)4  
//打印回应的头信息 u56cT/J1  
public void logResponseHead(HttpURLConnection con) cVN|5Y   
{ 7o3f5"z  
for(int i=1;;i++) *"wsMO  
{ NeH^g0Q2,g  
String header=con.getHeaderFieldKey(i); GI/o!0"_  
if(header!=null) 70@:!HI]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xQ4Q'9  
Utility.log(header+" : "+con.getHeaderField(header)); }/=_  
else Yyf8B  
break; tP3Upw"U  
} <?+ \\Z!7  
} WukD|BCC  
mSs%gL]g  
74_ji!  
public void splitterStop() zrcSPh  
{ w5p+Yx=q  
bStop = true; ;-59#S&?tB  
} bLg1Dd7Q  
#~"jo[  
iVE+c"c!2&  
} kAMt8  
czafBO6  
0oD?4gn  
/* D?$f[+  
**FileAccess.java @>?&Mw\c  
*//文件访问(定位,写) :^K|u^_>P  
package NetFox; QM=X<?m/,=  
import java.io.*; 72aj4k]^  
7+fFKZFKF  
,Ao8QN  
public class FileAccessI implements Serializable{ v q|W&  
=4G9ev 4  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J}BS/Tr}=  
RandomAccessFile oSavedFile; b1-JnEc  
long nPos; JVRK\A|R  
!I@"+oY<  
Xr-eDUEi  
public FileAccessI() throws IOException p\Jz<dkN1  
{ DEIn:d  
this("",0); )tB mSVprl  
} OX!9T.j  
e(sQgtM6  
;sDFTKf  
public FileAccessI(String sName,long nPos) throws IOException o@ }Jd0D4  
{ [E+#+-n7  
oSavedFile = new RandomAccessFile(sName,"rw"); K*>lq|i u  
this.nPos = nPos; 0EOpK%{  
oSavedFile.seek(nPos); t68h$u  
} |iJ37QIM  
fDf:Jec`[  
.Gw;]s3  
public synchronized int write(byte[] b,int nStart,int nLen) HKV]Rn  
{ CtS*"c,j  
int n = -1; nI&Tr_"tm  
try{ 72.Z E%Ue  
oSavedFile.write(b,nStart,nLen); Ygr1 S(=  
n = nLen; w[t!?(![>  
} Iq MXd K|  
catch(IOException e) to2dkU  
{ y8VLFe;  
e.printStackTrace (); "YM)bc  
} !h4L_D0  
pno]B ld'z  
zGF_ c9X  
return n; ,*Jm\u  
} w`q):yXX  
qhc3 oRe  
mJp)nF8r~  
} gq!| 0  
j'g':U  
Vv#|% ^0  
/* HsO4C)/  
**SiteInfoBean.java 6"b =aPTi  
*/ <J!#k@LY]7  
package NetFox; rfku]A$  
D=i)AZqMPp  
N;Wm{~Zhb  
public class SiteInfoBean { Tapj7/0`  
eJlTCXeZ|  
ED [` Y.;  
private String sSiteURL; //Site's URL 1--_E,Su>  
private String sFilePath; //Saved File's Path x8+W9i0[1  
private String sFileName; //Saved File's Name v@(Y:\>  
private int nSplitter; //Count of Splited Downloading File ,onOwPz  
fL>>hBCqC  
BxVo>r  
public SiteInfoBean() 0rP`BK|  
{//nSplitter的缺省值为5 bS[;d5  
//default value of nSplitter is 5 p'tB4V qT  
this("","","",5); O0[.*xG  
} !36jtKdM  
4Hc+F(  
q$7SJ.pF  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y%m^V?k  
{ )%FRBO]  
sSiteURL= sURL; c0h:Vqk-  
sFilePath = sPath; ZUPlMHc  
sFileName = sName; V~([{  
this.nSplitter = nSpiltter; JL.noV3q$  
(r78AZ  
LX5, _`B  
} '@t}8J  
?( rJ  
C{^U^>bU  
public String getSSiteURL() #[=%+*Q  
{ S&N[@G  
return sSiteURL; 9[31EiT  
} x=]PE}<E  
2?J[D7  
T-S6`^_L  
public void setSSiteURL(String value) anxZ|DE  
{  #4?Z|_j3  
sSiteURL = value; RHe'L36W  
} A"ApWJ3  
&b~if}vcb  
x"7`,W  
public String getSFilePath() MhT.Zg\  
{ <? h`  
return sFilePath; /1OzX'5f  
} 1VRe xp  
Tp-<!^o4  
$w%n\t>B  
public void setSFilePath(String value) UM[<v9NWE  
{ GO3F[ l  
sFilePath = value; Y367Jr@^N  
} =\uQGH  
wX7|a/|@  
c:>&iB-Yu  
public String getSFileName() ZoFQJJK56B  
{ 5ctH=t0  
return sFileName; N i\*<:_  
} Rd#V,[d  
B}Lz#'5_  
p:g`K# [F  
public void setSFileName(String value) gpt98:w:  
{ s{q)P1x  
sFileName = value; [ QHSCF5  
} H#zsk*=QD  
F^knlv'  
ZMFV iE;8  
public int getNSplitter() z^xrB$8 u  
{ 4^|;a0Qy]  
return nSplitter; ~D[5AXV`^  
} @t W;(8-  
UM?{ba9  
CY{`IZ  
public void setNSplitter(int nCount) (+_i^SqK  
{ ah1DuTT/G  
nSplitter = nCount; Yr7%C  
} 7*D*nY4+  
} ?=C?3R  
#:C?:RMS  
<X5'uve  
/* c(:qid  
**Utility.java C9?R*2L>  
*/ Mwm=r//  
package NetFox; N|G=n9p  
[;IW'cXNq  
Lbo8> L(  
public class Utility { "!\ON)l*  
@I`X{oAA  
GoVB1)  
public Utility() $m$tfa-  
{ =e<;B_ ~.  
y1zNF$<q  
W`$D*X0*o  
} |(mr&7O  
-]!m4xvK  
//线程睡眠 v7;zce/~  
public static void sleep(int nSecond) ,}9G|$  
{ rkp 1tv  
try{ bC[TLsh7{2  
Thread.sleep(nSecond); %j '_I\  
} Y+ZQN>  
catch(Exception e) A (:7q4  
{ ]}K\&ho2  
e.printStackTrace (); F4=+xd >0  
} 2(s+?n.N  
} Cd>GY  
x2 s%qZ#  
//日志 1-HL#y*7$  
public static void log(String sMsg) }]8n3&*  
{ D/T& 0  
System.err.println(sMsg); HkGA$  
} H,/|pP.  
35 Y#eU2]  
bzI!;P1&  
public static void log(int sMsg) zvvF 9  
{ tcovMn '  
System.err.println(sMsg); Cfizh@<  
} mPl2y3m%  
} /zB;1%m-  
lkj^<%N"r  
uVO*@Kj+  
/* 'Gn-8r+  
**TestMethod.java 3ug|H  
*/ W%/lBkP  
package NetFox; ! 11x&Db  
y:FxX8S$'e  
^H0`UKE  
public class TestMethod { fB \+.eN  
AnB]f~Yjl  
9t`Z_HwdCb  
public TestMethod() MhE'_sq  
{ ///xx/weblogic60b2_win.exe 8 *Fr=+KN  
try{ @,b:s+]rp  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bzz{ p1e  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cfb8kNn~+  
SiteFileFetch fileFetch = new SiteFileFetch(bean); x~7_`=}rO  
fileFetch.start(); )gO=5_^u*o  
} &VY(W{\eY  
catch(Exception e){e.printStackTrace ();} ?DAW~+,!7o  
1QfOD-lv  
>JN K06T  
} qr5ME/)z  
h q5=>p  
Ihe/P {t]J  
public static void main(String[] args) /+FZDRf!r  
{ fz)i9D@  
new TestMethod();  Bld%d:i  
} ,zCrix 3  
} 9.bMA<X  
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