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http断点续传简单实现(java)

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/* GN0s`'#"3%  
**SiteFileFetch.java <D}yqq@|  
*/ /Py1Q  
package NetFox; /7[U J'  
import java.io.*; >~+qU&'2  
import java.net.*; $X\deJ1Hi  
#{f%b,.yxt  
I 0vJJP#  
public class SiteFileFetch extends Thread { LZ'Y3 *  
;*+wg5|  
gPJZpaS  
SiteInfoBean siteInfoBean = null; //文件信息Bean f3;.+hJ])  
long[] nStartPos; //开始位置 bz'#YM  
long[] nEndPos; //结束位置 *@+E82D  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Z@1vJH6IbA  
long nFileLength; //文件长度 PS:"mP7n  
boolean bFirst = true; //是否第一次取文件 ",, W1]"%  
boolean bStop = false; //停止标志 6B8g MO  
File tmpFile; //文件下载的临时信息 &m5FYm\  
DataOutputStream output; //输出到文件的输出流 ^}Wk  
yiO/0nMp  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) +H**VdM6s  
public SiteFileFetch(SiteInfoBean bean) throws IOException %3kS;AaA  
{ aGz$A15#  
siteInfoBean = bean; tS[@3h  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); |#i|BVnoE  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); <>71;%e;'  
if(tmpFile.exists ()) +eUWf{(_  
{ Bx" eX>A8  
bFirst = false; (qyT,K8  
read_nPos(); u%24% Q  
} Rlwewxmr  
else ,v@C=4'm  
{ P9yg  
nStartPos = new long[bean.getNSplitter()]; n=iL6Yu(  
nEndPos = new long[bean.getNSplitter()]; =zsA@UM0  
} EK 8rV  
k1_" }B5  
N+nv#]{  
VRQD  
} YiGSFg  
c,L{Qv"n{  
Ljs4^vy <J  
public void run() v!WkPvU  
{ =6O<1<[y  
//获得文件长度 opIbs7k-  
//分割文件 w l#jSj%pd  
//实例FileSplitterFetch {b,#l]v  
//启动FileSplitterFetch线程 P9f,zM-  
//等待子线程返回 E'^$~h$  
try{ 7=`_UqCV  
if(bFirst) Cj5=UUnO  
{ @AfC$T  
nFileLength = getFileSize(); L (@".{T  
if(nFileLength == -1) EC8Fapy  
{ @Wl2E.)K;  
System.err.println("File Length is not known!"); =N^j:t  
} /cC4K\M  
else if(nFileLength == -2) N2.(0 G  
{ spG3"Eodi  
System.err.println("File is not access!"); MZWicfUy  
} c`s ]ciC  
else (yO8G-Z0  
{ 'z$!9ufY,  
for(int i=0;i<nStartPos.length;i++) N_o|2  
{ u5I#5  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); <(tnClAn  
} @g%^H)T  
for(int i=0;i<nEndPos.length-1;i++) u;Rm/.  
{ ZOzwO6(_  
nEndPos = nStartPos[i+1]; / 0ra]}[(  
} I4Rd2G_  
nEndPos[nEndPos.length-1] = nFileLength; Wagb|B\  
} /I~(*X  
} $,8}3R5}  
J/>9w  
"NvB@>S  
//启动子线程 G_v^IM#B=  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ojbms>a  
for(int i=0;i<nStartPos.length;i++) i~ITRi@  
{ 7*C>4Gs  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W%P$$x5&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), t2hI^J0y  
nStartPos,nEndPos,i); <d~IdK'\x  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F x3X  
fileSplitterFetch.start(); 5c 69M5  
} YDjjhe+  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XF i!=|F  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #4Ltw ,b^  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H$!sK  
nEndPos = " + nFileLength); /L; c -^  
// fileSplitterFetch[nPos.length-1].start(); 'q7&MM'oS^  
hwi$:[  
zOn% \  
//等待子线程结束 d 6=Z=4w  
//int count = 0; <o: O<p@6  
//是否结束while循环 Xu%8Q?]  
boolean breakWhile = false; a+ s%9l  
kn= fW1  
2'-o'z<  
while(!bStop) RN ~pC  
{ ppR; v  
write_nPos(); L8~zQV$h  
Utility.sleep(500); b@ OF  
breakWhile = true; PwS7!dzH-  
fp2uk3Bm[  
& d@N3y  
for(int i=0;i<nStartPos.length;i++) [;$9s=:[  
{ ;t \C!A6  
if(!fileSplitterFetch.bDownOver) # 5b   
{ 6g 5Lf)yG  
breakWhile = false; v{O(}@  
break; &H:2TL!  
} 'M=V{.8U  
} r%FfJM@!  
if(breakWhile) l5<&pb#b  
break; qMmhVUx  
tE]Y=x[Ux  
.*{0[  
//count++; f19'IH$n{  
//if(count>4) >*"1`vcxF  
// siteStop(); wj-z;YCV  
} d 6zfP1lQ  
@% .;}tC  
_KAg1Ww  
System.err.println("文件下载结束!"); ftccga  
} OYj~"-3y)  
catch(Exception e){e.printStackTrace ();} _.+2sm   
} Wq"^{  
,A;wLI  
VL8yL`~zc.  
//获得文件长度 3) _(t.$D  
public long getFileSize() @  Br?  
{ R@lA5w  
int nFileLength = -1; 2T3b6  
try{ ~vw$Rnotz  
URL url = new URL(siteInfoBean.getSSiteURL()); [z r2\(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N(Xg#m   
httpConnection.setRequestProperty("User-Agent","NetFox"); kA{eT  
E=RX^ 3+}  
gi JjE  
int responseCode=httpConnection.getResponseCode(); j7 \y1$w  
if(responseCode>=400) nrJW.F]S8[  
{ EzGO/uZ]  
processErrorCode(responseCode); *4O9W8Qz  
return -2; //-2 represent access is error j)Y68fKK  
} ^wMZG'/  
x2Dg92  
!f)^z9QX8  
String sHeader; wG",Obja  
f_;6uCCO  
&m{vLw  
for(int i=1;;i++) ?xYoCn}Z  
{ 8w9?n3z=}  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p(pL"  
//Utility.log(in.readLine()); 3\H0Nkubts  
sHeader=httpConnection.getHeaderFieldKey(i); OHK]=DH:M  
if(sHeader!=null) Ry"N_Fb  
{ xM D]b  
if(sHeader.equals("Content-Length")) yN9setw*,M  
{ \><v1x>;  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #jT=;G7f2  
break; R[f@g;h  
} 9 $ Ud\   
} d5l].%~  
else (<ngdf`,  
break; ~zyD=jx P9  
} k*!f@ M  
} ?~WDl j3  
catch(IOException e){e.printStackTrace ();} QRlrcauM  
catch(Exception e){e.printStackTrace ();} z~\Y*\f^Y3  
5v5K}hx  
cnR18NK  
Utility.log(nFileLength); :i/uRR  
x|U[|i,;  
/}R*'y  
return nFileLength; # mW#K  
} TA>28/U#  
*IV_evgM7  
nx|b9W<  
//保存下载信息(文件指针位置) "XWO#,Ue  
private void write_nPos() zz1]6B*eX  
{ 1D2Yued  
try{ ,&0iFUwN_  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Or"+d 5  
output.writeInt(nStartPos.length); :{M1]0 NH  
for(int i=0;i<nStartPos.length;i++) }o2e&.$4d  
{ +~!\;71:f  
// output.writeLong(nPos); oh.8WlI  
output.writeLong(fileSplitterFetch.nStartPos); #6F/:j;  
output.writeLong(fileSplitterFetch.nEndPos); Qcs >BOV~  
} *S] K@g  
output.close(); N)o/}@]6  
} faPgp  
catch(IOException e){e.printStackTrace ();} IT0 [;eqR  
catch(Exception e){e.printStackTrace ();} \4"01:u'  
} mH5[(?   
95b65f  
SZL('x,"^  
//读取保存的下载信息(文件指针位置) mFW/xZwR,5  
private void read_nPos() ?b3({P  
{ QRAw#  
try{ >SaT?k1E  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %G/j+Pf  
int nCount = input.readInt(); Vc?=cQ'c  
nStartPos = new long[nCount]; &b!|Y  
nEndPos = new long[nCount]; B| .8+Q  
for(int i=0;i<nStartPos.length;i++) =`KV),\  
{ G_)(?  
nStartPos = input.readLong(); $\vTiS'  
nEndPos = input.readLong(); ^eY% T5K   
} ;/)u/[KAv  
input.close(); MT(G=r8  
} )sG/H8  
catch(IOException e){e.printStackTrace ();} @;g|styh^  
catch(Exception e){e.printStackTrace ();} 3FhkK/@  
} 0mYKzJi  
UY`U[#  
H3Sfz'  
private void processErrorCode(int nErrorCode) P#N@W_""YD  
{ P=PVOt@ b  
System.err.println("Error Code : " + nErrorCode); *|^}=ioj*  
} 2/.I6IbL  
drW}w+ !  
Nc[[o>/Cb  
//停止文件下载 IM*T+iRKqF  
public void siteStop() YCS8qEP&  
{ dXewS_7  
bStop = true; .|x" '3#  
for(int i=0;i<nStartPos.length;i++) xe9V'wICp(  
fileSplitterFetch.splitterStop(); x'hUw*  
PBY ^m+  
mYw9lM  
} Z9k"&F ~u}  
} ,n\'dMNii  
//负责部分文件的抓取 y-=YXqj  
**FileSplitterFetch.java {Tl|>\[P  
*/ 8CN~o|uN  
package NetFox; #Ss lH  
q:X&)f  
3tAX4DnYrq  
import java.io.*; MaQ`7U5 |e  
import java.net.*; v''F\V )  
5"o)^8!>  
uszH1@g'  
public class FileSplitterFetch extends Thread { G'0]m-)dw  
U?sio%`(  
JtGBNz!"  
String sURL; //File URL z4iZE*ZS  
long nStartPos; //File Snippet Start Position ~ $QNp#dq  
long nEndPos; //File Snippet End Position FNB4YZ6  
int nThreadID; //Thread's ID VT~jgsY  
boolean bDownOver = false; //Downing is over ~L ufHbr  
boolean bStop = false; //Stop identical , \ 6*fXc  
FileAccessI fileAccessI = null; //File Access interface KQv97#n1  
Ub9p&=]h  
04wO9L;  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException > cM}M=4s  
{ |*[#Iii'  
this.sURL = sURL; ds|L'7  
this.nStartPos = nStart; wV\.NQtS  
this.nEndPos = nEnd; h0oe'Xov  
nThreadID = id; r^v1_u, 1I  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /=K(5Xd  
} /_D_W,#P  
1$#1  
O\+b1+&b3Y  
public void run() xiy=D5N.=  
{ uefrE53  
while(nStartPos < nEndPos && !bStop) E'cI}q  
{ gski:C   
xS+!/pBf"Y  
WS6;ad;|  
try{ Mpx98xcO  
URL url = new URL(sURL); 1'YUK"i  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NA!?.zn  
httpConnection.setRequestProperty("User-Agent","NetFox"); Jq*Q;}n  
String sProperty = "bytes="+nStartPos+"-"; ;wa#m1  
httpConnection.setRequestProperty("RANGE",sProperty); ~$jRn(2  
Utility.log(sProperty); :SD#>eD0  
U62Z ?nge%  
<%N*IE"q  
InputStream input = httpConnection.getInputStream(); PS3jCT  
//logResponseHead(httpConnection); O<P(UT"  
7DPxz'7):  
?3y>K!D(A  
byte[] b = new byte[1024]; GMlJM  
int nRead; Gzc`5n{"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s=>^ 8[0O  
{  OK(xG3T  
nStartPos += fileAccessI.write(b,0,nRead); i<{:J -U|  
//if(nThreadID == 1) Q%:Z&lg y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); INEE 37%  
} K]&i9`>N   
}Ud'j'QMy  
Ce/D[%  
Utility.log("Thread " + nThreadID + " is over!"); /V }Z,'+  
bDownOver = true; FA{'Ki`  
//nPos = fileAccessI.write (b,0,nRead); meYGIP:n  
} v, !`A!{D  
catch(Exception e){e.printStackTrace ();} ~NTKWRaR  
} Zg9VkL6Z6  
} CT/>x3o  
fRjp(m  
uN=f( -"  
//打印回应的头信息 VA @  
public void logResponseHead(HttpURLConnection con) vDIsawbHD  
{ QIfP%,LT  
for(int i=1;;i++) 88VI _<  
{ /*(&Dmt>  
String header=con.getHeaderFieldKey(i); D67z6jep(  
if(header!=null) Md&K#)9,(  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r72zWpF!Ss  
Utility.log(header+" : "+con.getHeaderField(header)); b%].D(qBy  
else 7ufTmz#j<  
break; `S A1V),~  
} P2F8[o!<  
} d~q7!  
(6i4N2  
40O@a:q*  
public void splitterStop() q2U?EP{8~  
{ 32Wa{LG;2  
bStop = true; 7NkMr8[}F  
} LbuhKL}VN  
KB {IWu  
WidLUv   
} y!T8(  
,n`S ,  
`neo.]  
/* 0J6* U[  
**FileAccess.java X o[GD`t  
*//文件访问(定位,写) -EE}HUP)  
package NetFox; P('bnDU  
import java.io.*; vDyGxU!#\  
fg/hUUl  
l{Et:W%|  
public class FileAccessI implements Serializable{  +F~B"a  
;(rK^*`fO  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Lb?0<  
RandomAccessFile oSavedFile; I%{ 1K+V/  
long nPos; LfJMSscfv  
S0ReT*I  
OVE?;x>n/1  
public FileAccessI() throws IOException |xT'+~u  
{ w,j;XPp  
this("",0); }@~+%_;  
} ]TN/n%\  
/4}y2JVv)  
cUO$IR)yL  
public FileAccessI(String sName,long nPos) throws IOException e-nwR  
{ !b$]D?=}  
oSavedFile = new RandomAccessFile(sName,"rw");  pLM?m  
this.nPos = nPos; nd[Ja_h  
oSavedFile.seek(nPos); l5D4 ?`|  
} GcG$>&,  
8T8]gM  
PAH#yM2Ic  
public synchronized int write(byte[] b,int nStart,int nLen)  yyGn <  
{ Tfx-h)oP3  
int n = -1; >*\yEH9"  
try{ Qjd]BX;  
oSavedFile.write(b,nStart,nLen); Zy|u5J  
n = nLen; f ~bgZ  
} P0RtS1A  
catch(IOException e) >Bu _NoM  
{ wxN&k$`a  
e.printStackTrace (); S4rm K&  
} DQ&\k'"\  
Oc-ia)v1G  
_:FD#5BZ1  
return n; )P,pW?h$  
} cM\BEh h  
mex@~VK  
+:W?:\  
} t>x!CNb'C  
WO6+r?0M2  
b;nqhO[f}  
/* P76gJ@#m  
**SiteInfoBean.java wr~Qy4 ny  
*/ [Fv_~F491  
package NetFox; deJ/3\t  
I:0dz:T7*  
a-AA$U9hj  
public class SiteInfoBean { *$3p3-  
$M~`)UeV_  
F"QJ)F  
private String sSiteURL; //Site's URL c=^69>w  
private String sFilePath; //Saved File's Path BU7QK_zT:  
private String sFileName; //Saved File's Name c[$i )\0  
private int nSplitter; //Count of Splited Downloading File Cq3Au%7  
@H^\PH?pp  
x=X&b%09  
public SiteInfoBean() Kjpsz];  
{//nSplitter的缺省值为5 l TVz'ys  
//default value of nSplitter is 5 D_G]WW8  
this("","","",5); gZ-:4G|J  
} F%4N/e'L  
#B q|^:nj  
G&`5o*).bb  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C =B a|Z  
{ ?j)#\s2  
sSiteURL= sURL; ?A~=.u@[d  
sFilePath = sPath; kWs:7jiiu  
sFileName = sName; iRqLLMrn  
this.nSplitter = nSpiltter; R]RLy#j  
SR`A]EC(V  
6q7jI )l  
} s@Loax6@B  
/iJsa&W}  
ad52a3deR  
public String getSSiteURL() OL^DuoB4q  
{ c8HETs1  
return sSiteURL; wUfPnAD.'  
} h 0)oQrY  
NRk^Z)  
O;T)u4Q&3  
public void setSSiteURL(String value) %eGD1.R  
{ M'oQ<,yW-  
sSiteURL = value; Xn5LrLM&  
} c{39,oF  
j 20m Z  
) q/brCq  
public String getSFilePath() xK4E+^ b  
{ |CK/-UG}  
return sFilePath; )Y"t$Iw"  
} `6LV XDR  
3$BO=hI/-  
jS5K:yx<  
public void setSFilePath(String value) 7|Iq4@IT  
{ <y"lL>JR  
sFilePath = value; ey\(*Tu9  
} +vPCr&40  
Zm(}~C29  
Uo[`AzD3  
public String getSFileName() Ye^xV,U@  
{ Q8h=2YL  
return sFileName; 9WHarv2@  
} ]eX(K5 A  
rP/W,! 7:K  
H>"P]Y)oX  
public void setSFileName(String value) wy:euKB~   
{ ?ZkVk=t?  
sFileName = value; q^~w:$^ U  
} E~8J<g E  
6 \ %#=GG  
Jq+@%#G  
public int getNSplitter() @[n%q.|VB  
{ EJJ&`,q  
return nSplitter; B*^QTJ  
} L:jv%;DM  
F$9+WS`c  
1-R4A7+3  
public void setNSplitter(int nCount) Bma.Uln  
{ "IWL& cH3  
nSplitter = nCount; w"A>mEex<  
} "c![s%  
} 9Z3Vf[n5\  
eO{2rV45O  
Wck WX]};S  
/* pwF])uf*{\  
**Utility.java ~c\2'  
*/ ;@n/g U  
package NetFox; qVd s 2  
)Rj?\ZUR  
cO-^#di  
public class Utility { 0_t9;;y :  
aDE}'d1qo  
^HHT>K-m  
public Utility() 8P2_/)|  
{ lO}I>yo}\  
|8{ \j*3  
2,.8 oa(  
} 4*UKR!sr  
R]o2_r7N"}  
//线程睡眠 q-e3;$  
public static void sleep(int nSecond) CZ(fP86e  
{ >-(,BfZ  
try{ 2 F ~SH  
Thread.sleep(nSecond); ,rhNXx  
} %B| Ca&  
catch(Exception e) <S0gIg`)  
{ NF7+Gp6?q  
e.printStackTrace (); )xTu|V   
} 5L\Im^  
} @X_)%Y-^O  
e^hI[LbNC  
//日志 I3Ad+]v  
public static void log(String sMsg) p >nKNd_aQ  
{ B<,AI7  
System.err.println(sMsg); Wa%p+(\<uB  
} X C '|  
<h`}I3Ao  
=z}M(<G  
public static void log(int sMsg) Ul:M=8nE%  
{ &VVvZ@X;  
System.err.println(sMsg); [kI[qByf  
} ,4(m.P10  
} WX $AOnEv  
?nf4K/IjZ!  
}/7rA)_  
/* KoFWI_(b  
**TestMethod.java YRj"]= 5N  
*/ m .^WSy  
package NetFox; ~vfPsaRh  
M7neOQHq  
ket"fXqJX  
public class TestMethod { U#4>GO;A  
a!;K+wL >  
1c$c e+n~  
public TestMethod() AHLXmQl  
{ ///xx/weblogic60b2_win.exe Lx3`.F\mG  
try{  L$[1+*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f5.Be%  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;GZ'Rb  
SiteFileFetch fileFetch = new SiteFileFetch(bean); zBqNE`  
fileFetch.start(); t>"|~T$9  
} <{.pYrn  
catch(Exception e){e.printStackTrace ();} W1O Y}2kj  
et`rPK~m  
r#^uY:T%  
} gE6{R+sp  
S2$r 6T  
eak+8URo  
public static void main(String[] args) =n M Aw&`  
{ l D]?9K29  
new TestMethod(); KocNJ TB  
} fyv S1_  
} @Sz7*p  
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