http断点续传简单实现（java)

/* 9OV@z6
  
**SiteFileFetch.java a_V\[V{R=  
*/ _FYA? d}  
package NetFox; Hf@4p'  
import java.io.*; e`s1z|h  
import java.net.*; '9Z`y_~)G  
In^mE(8YO  
>7PQOQMW'
 
public class SiteFileFetch extends Thread { MzX&|wimb  
NJQ)Ttt  
Sz@z 0'  
SiteInfoBean siteInfoBean = null; //文件信息Bean T{k_3[{0o  
long[] nStartPos; //开始位置 Jz~:  
long[] nEndPos; //结束位置 !9WGZfK+0Y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 gK QJ^a\!  
long nFileLength; //文件长度 ;_vhKU)%J#  
boolean bFirst = true; //是否第一次取文件 9e=}PL  
boolean bStop = false; //停止标志 L?j0t*do  
File tmpFile; //文件下载的临时信息 Bd <0}  
DataOutputStream output; //输出到文件的输出流 P*A+k"DU1  
zXx/\B$&d*  
//负责整个文件的抓取，控制内部线程（FileSplitterFetch类） fJ[ ^_,O  
public SiteFileFetch(SiteInfoBean bean) throws IOException m~5 unB9  
{ Cd_@<  
siteInfoBean = bean; h/t;ZLUAZP  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); (<r)xkn  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); tg@61V?>  
if(tmpFile.exists ()) >jsY'Bm  
{ A{ ~D_q  
bFirst = false; -n&&d8G^s  
read_nPos(); 0#9H;j<Op  
} wKLYyetM!  
else e{@RBYX@+c  
{ ea"X$<s>-  
nStartPos = new long[bean.getNSplitter()]; 1hY|XZ%qd  
nEndPos = new long[bean.getNSplitter()]; | J3'#7  
} 7h}gIm7e"  
IQ@9S  
S>0%jCjW  
B{`adq?pW  
} Q?i_Nl/|  
SK\@w9#&$  
M5ZH6X@5  
public void run() Q38+`EhLA  
{ ng3ZK  
//获得文件长度 VKD
OM0{V  
//分割文件 P}}G9^  
//实例FileSplitterFetch d\JaYizp  
//启动FileSplitterFetch线程 \{@
m  
//等待子线程返回 #QoWne
Z  
try{ Eo6N'h>h  
if(bFirst) =G:Krc8w@  
{ fA
6IW(_bi  
nFileLength = getFileSize(); ~i"=:D  
if(nFileLength == -1) F<,pAxl~@  
{ 3p=Xv%xd  
System.err.println("File Length is not known!"); E:x@O8F  
} ks0Q+YW  
else if(nFileLength == -2) ?Fl}@EA#M  
{ n?fy@R  
System.err.println("File is not access!"); R%WY!I8C  
} KMj\A d  
else }#FV{C]  
{ v`Jt+?I  
for(int i=0;i<nStartPos.length;i++) wHj1+W  
{ $&as5z8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); o1ZVEvp  
} %^@l5h.lqB  
for(int i=0;i<nEndPos.length-1;i++) ^YLC{V  
{ 5v)^4( )  
nEndPos = nStartPos[i+1]; ,%TBW,>  
} r >'tE7W9  
nEndPos[nEndPos.length-1] = nFileLength; o}v<~v(  
} <a"(B*bBd  
} U3{<+vSR`  
Z<i}XCE  
v0\l~_|H  
//启动子线程 {$z54nvw$  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1%+-}yo<  
for(int i=0;i<nStartPos.length;i++) qSvV|G  
{ :hZM$4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m !*F5x  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), BYq80Vk%@  
nStartPos,nEndPos,i); mKZzSd)p  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eTa_RO,x  
fileSplitterFetch.start(); ,ErfTg&^  
} y|6n:<o  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .G[/4h :.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); G?$@6  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ='h2z"}\Bn  
nEndPos = " + nFileLength); NfvPE]S  
// fileSplitterFetch[nPos.length-1].start(); !q2zuxq!R  
=x8[%+  
61S;M8tNv  
//等待子线程结束 c*)T4n[e  
//int count = 0; % "(&a'B  
//是否结束while循环 ~bZ$ d{o^  
boolean breakWhile = false; /TpTR-\I0  
*D?_,s  
$X#y9<bW  
while(!bStop) <N vw*yA  
{ 1p}H,\o  
write_nPos(); oVvA`}  
Utility.sleep(500); Z_q+Ac{p  
breakWhile = true; .^wpfS  
c<_%KL&R  
7l53&,s   
for(int i=0;i<nStartPos.length;i++) L!
cOg8Z  
{ +Uq|Yh'Q  
if(!fileSplitterFetch.bDownOver) 6$R9Y.s>Z  
{ =-2~>B  
breakWhile = false; <,M"kF:  
break; FH=2,"A  
} 3ay},3MCV%  
}
XQy`5iv  
if(breakWhile) zV&l^.  
break; J~2SGXH)^?  
9hA`I tS  
gK rUv0&F  
//count++; = QBvU)Ki  
//if(count>4) !/}3/iU  
// siteStop(); nQiZ6[L  
}
8ZY]-%  
;M3%t=KV  
`dZ|Ko%k  
System.err.println("文件下载结束！"); .TGw+E1k  
} (DiduSJ  
catch(Exception e){e.printStackTrace ();} ?@'&<o0p#  
} aD: #AmbJ  
>&(#p@#  
)pHtsd.eP  
//获得文件长度 sM-,95H  
public long getFileSize() P 2WAnm  
{ oai=1vt@  
int nFileLength = -1; |oPRP1F-;e  
try{ GKt."[seV  
URL url = new URL(siteInfoBean.getSSiteURL()); 36=aahXd\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (uC8M,I\  
httpConnection.setRequestProperty("User-Agent","NetFox"); fu5L)P^T  
\qG?'Iy  
bIU.C|h@  
int responseCode=httpConnection.getResponseCode(); p[Po*c.b  
if(responseCode>=400) hP"2X"kz&  
{ Cy;UyZ  
processErrorCode(responseCode); q}LDFsU  
return -2; //-2 represent access is error lbHgxZ  
} 4m
vR]:G  
E.K^v/dNdq  
joe)b  
String sHeader; d/; tq  
cw<
IL  
*z~,|DQ(A  
for(int i=1;;i++) Cab.a)o  
{ \BnU?z  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :c/54Ss~  
//Utility.log(in.readLine()); uBlPwb,V  
sHeader=httpConnection.getHeaderFieldKey(i);  (Q8!5s  
if(sHeader!=null) jYp!?%!  
{ ?%6oM
 
if(sHeader.equals("Content-Length")) 4zyQ"?A~  
{ 1iF=~@Nz_  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Pe_O(  
break; ,jY:@<n  
} yT7$6x  
} .!o]oM U/  
else N68mvBe  
break; ng%[yY  
} p>tkRA?lk  
} A*OqUq/H`;  
catch(IOException e){e.printStackTrace ();} .iy4 (P4  
catch(Exception e){e.printStackTrace ();}
^+>*Y=fl  
cB uuq  
r!Eh}0bL  
Utility.log(nFileLength); w ,j*I7V  
NxHUOPAJc  
X)3(.L  
return nFileLength; JWb +  
} b G:\*1T  
p":u]Xgb  
;E.]:Ia~  
//保存下载信息（文件指针位置） "6jt$-?  
private void write_nPos() QY;(Ny/(y  
{ t{>K).'  
try{ cfIC(d  
output = new DataOutputStream(new FileOutputStream(tmpFile)); =dGp&9K,fw  
output.writeInt(nStartPos.length); pCE GZV,d@  
for(int i=0;i<nStartPos.length;i++) B7f<XBU6
>  
{ O)q4^AE$  
// output.writeLong(nPos); g#$ C8k  
output.writeLong(fileSplitterFetch.nStartPos); oP,*H6)i  
output.writeLong(fileSplitterFetch.nEndPos); n6oOknCna  
} PBn7{( x  
output.close(); +pR,BjY  
} h*fN]k6  
catch(IOException e){e.printStackTrace ();} =ANr|d  
catch(Exception e){e.printStackTrace ();} F!X0Wo=  
} @;4;72@O  
=dAAb\:  
Ih.+-!w  
//读取保存的下载信息（文件指针位置） ^77W#{Zs  
private void read_nPos() VE
gtN}  
{ ,8 4|qI  
try{ n[jXqFm!`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "u6pl);G  
int nCount = input.readInt(); rDWAZ<;;  
nStartPos = new long[nCount]; ogFo/TKM  
nEndPos = new long[nCount]; z206fF  
for(int i=0;i<nStartPos.length;i++) ia5%  
{ :Qge1/  
nStartPos = input.readLong(); tc'iKJ5)  
nEndPos = input.readLong(); x$d[Ovw-  
} h?xgOb!4  
input.close(); p7|I>8ur.  
} d'';0[W)  
catch(IOException e){e.printStackTrace ();} }k }=e  
catch(Exception e){e.printStackTrace ();} 
nYx /q  
} @\g}I`_M  
FsE
D9+/m  
!/p|~K  
private void processErrorCode(int nErrorCode) )J 'F]s  
{ 1K9.3n   
System.err.println("Error Code : " + nErrorCode); IH`Q=Pj  
} FDl/7P`b(  
C'I&<  
sx#O3*'>1  
//停止文件下载 76w[X=Fv  
public void siteStop() TDo)8+.2z  
{ )h]+cGM  
bStop = true; 7z;2J;u`n  
for(int i=0;i<nStartPos.length;i++) <W0(!<U  
fileSplitterFetch.splitterStop(); )]fiyXA  
zx$YNjeV  
b\"F6TF:  
} 6:2*<  
} Xe);LhDC  
//负责部分文件的抓取 Y~}MfRE3z  
**FileSplitterFetch.java %r[`HF>  
*/ No7-fX1B  
package NetFox; ;{I9S'  
@}q, ';H7  
li%@HdA!  
import java.io.*; 0cmd +`  
import java.net.*; /l7 %x.  
 LgF?1?  
QP'sS*saJ  
public class FileSplitterFetch extends Thread { 2 ,nhs,FZ  
Ic&~iqQ  
i*|HN"!  
String sURL; //File URL @|:fm() <  
long nStartPos; //File Snippet Start Position 8|Tqk,/pD  
long nEndPos; //File Snippet End Position *)Pm  
int nThreadID; //Thread's ID WXxnOLJr  
boolean bDownOver = false; //Downing is over )x!q;^Js9A  
boolean bStop = false; //Stop identical 5,;\zSz  
FileAccessI fileAccessI = null; //File Access interface u{4P)DIQ  
+'m9b7+v  
zLl-{Kk  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ->I.D?p  
{ FsqH:I4O  
this.sURL = sURL; vGi<" Sn7  
this.nStartPos = nStart; oZ2:%  
this.nEndPos = nEnd; NV
./p`k  
nThreadID = id; /kGWd9ujF  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Hdyl]q-(P  
} ;>7~@ K  
gxO~44"  
aA?Qr&]M  
public void run()  C O6}D  
{ 4S42h_9  
while(nStartPos < nEndPos && !bStop) $'\kK,=  
{ P.Tnq  
W7!Rf7TK  
- egTZW-  
try{ uYebRCdR  
URL url = new URL(sURL); ,9y6:W%5  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b,Eq-Z;  
httpConnection.setRequestProperty("User-Agent","NetFox"); +j: &_  
String sProperty = "bytes="+nStartPos+"-"; X8tPn_`x  
httpConnection.setRequestProperty("RANGE",sProperty); h>V6}(~;.  
Utility.log(sProperty); w~6/p  
le^Fik   
J0Yb_(w  
InputStream input = httpConnection.getInputStream(); #btz94/~O  
//logResponseHead(httpConnection); /5E0'y,|P  
>4ex5  
<Ch9"1f3,  
byte[] b = new byte[1024]; l'l&Zqd  
int nRead; ?u2\*@C  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e^*&&  
{ ~Y43`@3H:  
nStartPos += fileAccessI.write(b,0,nRead); |~
A*?6:@  
//if(nThreadID == 1) S(3h{Y"#  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E0qJ.v  
} 3sV$#l P  
=RUy4+0>F  
6`2i'flv  
Utility.log("Thread " + nThreadID + " is over!"); FqJd  
bDownOver = true; qVU<jt  
//nPos = fileAccessI.write (b,0,nRead); O\7x+^.  
} Q7u|^Gu,5  
catch(Exception e){e.printStackTrace ();} #c:@oe4v  
} =H7p&DhD[  
} OR&pGoW  
4j;IyQDvM  
qdQ4%,E[  
//打印回应的头信息 ?n<F?~  
public void logResponseHead(HttpURLConnection con) ot7f?tF2<J  
{ to13&#o  
for(int i=1;;i++) uNy-r`vg  
{ g Nz  
String header=con.getHeaderFieldKey(i); Hva!6vwO%O  
if(header!=null) JAHmmNlW  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k|xmZA*  
Utility.log(header+" : "+con.getHeaderField(header)); DzhLb8k  
else * 0K]/tn<  
break; 9V)c
f  
} ,w"cY?~<  
} Sy?^+JdM/  
trwo(p  
c2V_|
oL  
public void splitterStop() kPOk.F%)  
{ HpbwW=;V  
bStop = true; oBmv^=cH  
} mmwc'-jU:  
idBdaZg  

njd2  
} lLVD`)  
R)d_0Ng  
3B[tbU(  
/* dDiy_Q6  
**FileAccess.java &pl)E$Y  
*//文件访问(定位，写) `Zp*?  
package NetFox; (M;d*gNr  
import java.io.*; 5<X"+`=9  
atZNX1LD[/  
3q'nO-KJ  
public class FileAccessI implements Serializable{ ,6y.wNb:F  
FXk*zXn6  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v+EJ $  
RandomAccessFile oSavedFile; -DGuaUU  
long nPos; F+c8 O
 
%Lx#7bR U  
1$))@K-I  
public FileAccessI() throws IOException Q~^v=ye  
{ &hVf=We  
this("",0); a@|`!<5  
} tZ
) ,Z<  
DFfh!KKR$  
 Dt5AG  
public FileAccessI(String sName,long nPos) throws IOException "@ZwDg`  
{ TH>uL;?=  
oSavedFile = new RandomAccessFile(sName,"rw"); @6_w{6:b  
this.nPos = nPos; WjVm{7?{  
oSavedFile.seek(nPos); [)X(Qtk  
} Z>`frL  
X$%[%q8qg  
Hj-n
'XZ  
public synchronized int write(byte[] b,int nStart,int nLen) y[f%0*\B  
{ l [ m_<1L  
int n = -1; S41S+#7t*  
try{ <F}j;mX  
oSavedFile.write(b,nStart,nLen); Lz9|
"F"V  
n = nLen; iMM9a;G+  
} j~rW 2(  
catch(IOException e) Q&$2F:4f&  
{ Y}}1]}VIK  
e.printStackTrace (); </9c=GoJ  
} H(?+-72KX  
(eT9N_W  
5!i\
S[:  
return n; =f=>buD  
} {JQV~rfh`  
m,5m'9dj  
"V:RKH`  
} /.mx\_$   
|v>W  
N#OO{`":Z`  
/* $W;r S7b  
**SiteInfoBean.java NHdNCHhA>-  
*/ |em_l$oGc  
package NetFox; BN`tiPNEp  
Nc EPPl0I  
zcV~)go6  
public class SiteInfoBean { *wdNZ  
EwfL.z  
M%13b$i~f  
private String sSiteURL; //Site's URL J"eE9FLM  
private String sFilePath; //Saved File's Path RXO}mu]Iu  
private String sFileName; //Saved File's Name M&(0n?R"R  
private int nSplitter; //Count of Splited Downloading File 7 A{R0@  
P`CQ)o  
]<iD'=a  
public SiteInfoBean() wVv@   
{//nSplitter的缺省值为5 R-Tf9?)  
//default value of nSplitter is 5 TY+Rol;!  
this("","","",5); sEb*GF*.V  
} *6(/5V  
z4[8*}  
/GP:W6:6z6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /u'V>=D;f  
{ {f6~Vwf  
sSiteURL= sURL; gE&83i"  
sFilePath = sPath; & @$D(  
sFileName = sName; 1VXn`O?LW  
this.nSplitter = nSpiltter; ]|Iczg-   
UN6nh T  
DS<
E:'N  
} x1+V  
jJkc vC8d  
B%co`0$  
public String getSSiteURL() r+k~%5Ff~  
{ qaBL  
return sSiteURL; DRu#vC  
} Gd2t^tc  
b9l%5a  
!5zj+N  
public void setSSiteURL(String value) \S#![N
C  
{ DoEN`K\U  
sSiteURL = value; Cm6%wAzC  
} $.Qq:(O:6  
d-UQc2r  
Eye.#~  
public String getSFilePath() # i|pi'Ij  
{ .gwT?O,  
return sFilePath; om0g'Qa  
} >` |sBx  
35#"]l"  
w2]]##J  
public void setSFilePath(String value) Kb#
Z(C9  
{ csv;u'  
sFilePath = value; O1z
3(  
} $gcC}tX  
YLNJ4nE  
\BdQ(rm  
public String getSFileName() L8$+%Gvo  
{ 
m@` NN  
return sFileName; X./7b{Pax  
} Z2{G{]EV(  
G4K3qD#+H  
WaDdZIz4  
public void setSFileName(String value) =(as{,j  
{ D"s ]dQ$r  
sFileName = value; 68a  
} `yua?n  
Xa=oEG  
uPL|3ACS  
public int getNSplitter() 0(az80 p  
{ idP2G|Z  
return nSplitter; UV)!zgP  
} vt2A/9_Z%  
~&8bVA= .  
sG k'G573  
public void setNSplitter(int nCount) kKNrCv@64d  
{ 6tT*b@/_o  
nSplitter = nCount; CDDOm8  
} E<4'4)FHuQ  
} @]:GTrs  
^U{SUWl  
Q\GSX RP  
/* lZhd^69y  
**Utility.java j?oh~7Ki  
*/ y/6%'56u
F  
package NetFox; s% (|z  
`&)uuLn|  
~*^aCuq\  
public class Utility { >Byxb./*  
H1kxY]_/  
gK>aR ^*  
public Utility() T.#Vma  
{ L3^+`e  
5(&'/U^  
U=\!`_f':  
} ~_hn{Ous  
(GDW9:  
//线程睡眠 H6%%n X  
public static void sleep(int nSecond) CUZ ;<Pn  
{ \6c8Lqa  
try{ }*M>gvPo  
Thread.sleep(nSecond); Yuqt=\? #  
} f
g0zD:@rA  
catch(Exception e) )2y# cM*  
{ xe!6Pgcb  
e.printStackTrace (); e"ur+7  
} |qX[Dk  
} tU>?j1  
Tn 3<cO7v  
//日志 je^=gnq  
public static void log(String sMsg) $Z{Xt*  
{ 9w( Wtw'  
System.err.println(sMsg); 3YOYlb %j  
} s^Rig[  
L<M
H:  
A&/YnJ"  
public static void log(int sMsg) NE2P "mY  
{ ubQZTAx  
System.err.println(sMsg); jxNnrIA  
} c*HWH$kB  
} MWron_xg  
@Xj6h!"R  
x72T5.  
/* ;ax%H @o  
**TestMethod.java z)U/bjf  
*/ GYK&QYi,  
package NetFox; !JWZ}u
M6  
byetbt(IF  
Ym5ji$!2  
public class TestMethod { [,As;a*o  
G [$u`mxV^  
/D&7 \3}  
public TestMethod() /r@~"Rx'  
{ ///xx/weblogic60b2_win.exe h;?H4j  
try{ 1/%g VB8  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `c%{M4bF\  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x|`o7.  
SiteFileFetch fileFetch = new SiteFileFetch(bean); xN=:*#Z"pb  
fileFetch.start(); [$AOu0J  
} bAZx*qE=  
catch(Exception e){e.printStackTrace ();} !,zRg5Wp4  
TW5Pt{X=f  
N9=1<{Z  
} kcN#g-0  
z*B-`i.  
F>/"If#  
public static void main(String[] args) iW,fKXuo&y  
{ qrZ*r{3  
new TestMethod(); >* >}d%  
} RDWUy(iX  
} |v31weD8  
点击下载更多相关资料