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http断点续传简单实现(java)

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/* wA6E7vi'  
**SiteFileFetch.java j`K0D65  
*/ ,?`kYPZ  
package NetFox; EQX<<x"  
import java.io.*; "-j96 KD  
import java.net.*; x(p/9$.#  
m\E=I5*/  
`cIeqp  
public class SiteFileFetch extends Thread { E,cQ9}/  
yU"#2 *C  
P% 8U  
SiteInfoBean siteInfoBean = null; //文件信息Bean 3,#v0#  
long[] nStartPos; //开始位置 Ndyo)11z  
long[] nEndPos; //结束位置 E`{DX9^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Mm1>g~o  
long nFileLength; //文件长度 s6#e?5J  
boolean bFirst = true; //是否第一次取文件 Ps;4]=c  
boolean bStop = false; //停止标志 N/<c;"o  
File tmpFile; //文件下载的临时信息 xMa9o  
DataOutputStream output; //输出到文件的输出流 l.Z+.<@  
nZG zez  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) k_?~@G[I  
public SiteFileFetch(SiteInfoBean bean) throws IOException %(H' j@D[  
{ ^NM>x Ienf  
siteInfoBean = bean; &>R:oYN  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Vr;>Im  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); +_QcLuV,  
if(tmpFile.exists ()) 25r3[gX9`  
{ '@IReMl  
bFirst = false; 2=%]Ax"R  
read_nPos(); .9Dncsnf,`  
} N9M",(WTt}  
else Vup|*d2r0E  
{ D9hq$?  
nStartPos = new long[bean.getNSplitter()]; z4zPR?%:  
nEndPos = new long[bean.getNSplitter()]; :bL^S1et  
} ?FEh9l)d\  
oq b(w+<  
|cC&,8O:{  
m Ph=bG  
} "?FBbJ  
Y{Lxo])e  
@gmo;8?k  
public void run() `-K[$V  
{ NL2D,  
//获得文件长度 I|;C} lfp  
//分割文件 W7{^/s5r  
//实例FileSplitterFetch Rm6i[y&  
//启动FileSplitterFetch线程 oZdY0nh4  
//等待子线程返回 (E~6fb "c  
try{ DJqJ6z:'  
if(bFirst) zsR5"Vi=  
{ MmFtG-  
nFileLength = getFileSize(); #&?}h)Jr'  
if(nFileLength == -1) Ll VbY=EX7  
{ bfpoX,:   
System.err.println("File Length is not known!");  ':DL  
} 09{s'  
else if(nFileLength == -2) U!E}(9 tb  
{ 563ExibH  
System.err.println("File is not access!"); N^k& 8  
} 7{9M ^.}  
else v yt|x5  
{ L|;sB=$'{  
for(int i=0;i<nStartPos.length;i++) ZF8`= D`:R  
{ FPPl^  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); P^U.VXY}  
} Vock19P  
for(int i=0;i<nEndPos.length-1;i++) 7(P4KvkI  
{ /;!I.|j  
nEndPos = nStartPos[i+1]; Xn>>hzj-x?  
} K$r)^K=s  
nEndPos[nEndPos.length-1] = nFileLength; .YP&E1lNi  
} @2hOy@V  
} }9!}T~NMs  
`)MKCw$e  
q!~DCv df  
//启动子线程 >;VZB/ d  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]Zc\si3i&  
for(int i=0;i<nStartPos.length;i++) Vl>KeZ+  
{ ~dP\0x0AB  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #B#xSmak  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3\C+g{}e  
nStartPos,nEndPos,i); 2 !9Zw$  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w@n}DCFt  
fileSplitterFetch.start(); ] ;CJ6gM~  
} <Z\{ijfvD  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {wDe#c{_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <(yAat$H  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q("4R  
nEndPos = " + nFileLength); `O;4 b#!g  
// fileSplitterFetch[nPos.length-1].start(); @P i]kWW})  
 3UKd=YsJ  
Q}a(vlZ  
//等待子线程结束 Z%=A[` 5]  
//int count = 0; 1KR4Wq@  
//是否结束while循环 <(V~eo e  
boolean breakWhile = false; kLpq{GUv:  
lvNi/jk  
$xF[j9nM  
while(!bStop) _N>#/v)Yi  
{ _+~&t9A!  
write_nPos(); >hV 2p/D  
Utility.sleep(500); JZE@W -2  
breakWhile = true; j%J>LeTca  
;18u02z^  
0"ooHP$1  
for(int i=0;i<nStartPos.length;i++) Ww#!-,*]o  
{ pF8+< T3y  
if(!fileSplitterFetch.bDownOver) k2PK4Ua_}q  
{ Z)@[N 6\?  
breakWhile = false; >ffC?5+  
break; L =M'QJl9  
} U;"J8  
} fL]jk1.Xv-  
if(breakWhile) ]^i^L  
break; whrDw1>(  
BN FYUcVP  
S_RP& +!7  
//count++; 'fk6]&-I  
//if(count>4) ?5,I`9  
// siteStop(); Y> ~jho  
} {Ve`VV5E  
pK"Z9y&  
!@ y/{~Gu  
System.err.println("文件下载结束!"); OPogH=vf  
} >l=^3B,j  
catch(Exception e){e.printStackTrace ();} IY mkZ?cW  
} HS\'{4P  
G-;EB  
?du*ITim  
//获得文件长度 jpoNTl'  
public long getFileSize() rls{~ZRl  
{ f|)~_J H  
int nFileLength = -1; vg _PMy\  
try{  x\VP X  
URL url = new URL(siteInfoBean.getSSiteURL()); 8s-X H  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `0!%jz=  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4T v=sP  
rq}xuSFI  
}m7$,'C%P  
int responseCode=httpConnection.getResponseCode(); `VDvxl@1  
if(responseCode>=400) J(= y$8xje  
{ (N)>?r@n`  
processErrorCode(responseCode); _9Rj,  
return -2; //-2 represent access is error R\/tKZJjb  
} _5$L`&  
#YK3Ogb,  
d3#e7rQ8  
String sHeader; {SRD\&J[  
lQm7`+  
8LXK3D}?3  
for(int i=1;;i++) ?|!m  
{ JRj{Q 1J  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :hR^?{9Z4>  
//Utility.log(in.readLine()); R|wS*xd,  
sHeader=httpConnection.getHeaderFieldKey(i); xj3{Ke`6  
if(sHeader!=null) FT J{  
{ p1mAoVxR  
if(sHeader.equals("Content-Length")) && PZ;  
{ 7  `c!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); YNKvR  
break; y|3("&)"S  
} 'Z#>K*  
} zG^$-L.n  
else 4%JJ} {Ff  
break; 5Nbq9YY  
} =ReSlt  
} u|D L?c>W  
catch(IOException e){e.printStackTrace ();} _g,_G  
catch(Exception e){e.printStackTrace ();} G-sQL'L[U  
D*sL&Rt][Y  
nHp$5|r<  
Utility.log(nFileLength); XJ"xMv  
'R42N3|F  
zvdIwV&oT  
return nFileLength; , E$f"  
} Q]VG6x  
i<=2 L?[.I  
6KD-nr{S  
//保存下载信息(文件指针位置) Z J1@z.  
private void write_nPos() !:tr\L {  
{ I#7H)^us  
try{ <JvYCWX`  
output = new DataOutputStream(new FileOutputStream(tmpFile)); cjd-B:l  
output.writeInt(nStartPos.length); X;#Ni}af  
for(int i=0;i<nStartPos.length;i++) 7-\wr^ll3  
{ y>d`cRy  
// output.writeLong(nPos); U!JmSP  
output.writeLong(fileSplitterFetch.nStartPos); Xf mN/j2  
output.writeLong(fileSplitterFetch.nEndPos); :lmimAMt  
} =@X?$>'  
output.close(); Y@T$O<*  
} '0&HkM{ D  
catch(IOException e){e.printStackTrace ();} W2M[w_~QE  
catch(Exception e){e.printStackTrace ();} %dhrXK5  
} P:1eWP  
TB84}  
QA)W(1  
//读取保存的下载信息(文件指针位置) |8GLS4.]t  
private void read_nPos() !0):g/2h  
{ &+ H\ST(/  
try{ I'N!j>5oX  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BuxU+  
int nCount = input.readInt(); 'AmA3x)9u  
nStartPos = new long[nCount]; y$6EEp  
nEndPos = new long[nCount]; Y/pK  
for(int i=0;i<nStartPos.length;i++) 1YU?+K  
{ ~~I]SI k{  
nStartPos = input.readLong(); AgUjC  
nEndPos = input.readLong(); =GeGlI6  
} z=8l@&hYLq  
input.close(); n,_9Eh#WD  
} yD8Qy+6L  
catch(IOException e){e.printStackTrace ();} \{ C ~B;=  
catch(Exception e){e.printStackTrace ();} <dz_7hR"  
} `FX?P`\@I  
PQz[IZ  
O<dCvH  
private void processErrorCode(int nErrorCode) 1W}k>t8?h'  
{ k ,r*xt  
System.err.println("Error Code : " + nErrorCode); s t#^pWL  
} r|/9'{!  
qQ,(O5$|  
dwiLu&]u  
//停止文件下载 vVsaGW   
public void siteStop() =eh!eZ9  
{ k RSY;V  
bStop = true; BV\~Dm]"  
for(int i=0;i<nStartPos.length;i++) :X7O4?ww  
fileSplitterFetch.splitterStop(); 2|`Mb~E;  
s= z$;1C  
n^l5M^.  
} I+jc  
} |O"Pb`V+  
//负责部分文件的抓取 'gsO}xj  
**FileSplitterFetch.java {e0aH `me  
*/ !thFayq  
package NetFox; Z0wH%o\  
U2\k7I  
H;Gs0Qi;  
import java.io.*;  Lu[Hz8  
import java.net.*; v^[!NygShs  
l SuNZY aO  
oB '5':  
public class FileSplitterFetch extends Thread { th0>u.hJ  
>km$zfM2-  
pNu?DF{ 3  
String sURL; //File URL ,I,Zl.5  
long nStartPos; //File Snippet Start Position [g+WL\1  
long nEndPos; //File Snippet End Position =OKUSHu@V  
int nThreadID; //Thread's ID L%pAEoSG  
boolean bDownOver = false; //Downing is over 7&L8zl|K  
boolean bStop = false; //Stop identical >Tn[CgH]7  
FileAccessI fileAccessI = null; //File Access interface KQ(S\  
'}F9f?  
m]{/5L  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^lK!tOeO  
{ yC!>7@m  
this.sURL = sURL; t!>0^['g4  
this.nStartPos = nStart; +|4olK$[  
this.nEndPos = nEnd; /~?[70B}E  
nThreadID = id; {%\;'&@z\  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Oj2=&uz  
} Q H>g-@  
";n%^I}  
l[nf"'  
public void run() 5\ }QOL  
{ 7CX5pRNL  
while(nStartPos < nEndPos && !bStop) a@?ebCE  
{ ma`sv<f4-!  
_~*ba+{  
7&V3f=aj6  
try{ x3jjtjf  
URL url = new URL(sURL); Dd$8{~h"G  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); azTiY@/  
httpConnection.setRequestProperty("User-Agent","NetFox"); ZMK1V)ohn  
String sProperty = "bytes="+nStartPos+"-"; kkj_k:Eah  
httpConnection.setRequestProperty("RANGE",sProperty); $u)#-X;x  
Utility.log(sProperty); |Y2n6gkH[  
bW3Ah?0N  
q1|@v#kH6  
InputStream input = httpConnection.getInputStream(); ;\T~Hc}&;  
//logResponseHead(httpConnection); u(`7F(R  
e.!~7c_z?  
o+S?j*mv@  
byte[] b = new byte[1024]; F5w=tK  
int nRead; =[gFaB_H  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V:gXP1P  
{ c&`]O\D-c  
nStartPos += fileAccessI.write(b,0,nRead); F-Ku0z]){?  
//if(nThreadID == 1) eNm Wul  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KXu1%`x=%Z  
} XhOg>  
mt-t8~A  
|%(qaPA1  
Utility.log("Thread " + nThreadID + " is over!"); !~-@sq  
bDownOver = true; ^)3=WD'!  
//nPos = fileAccessI.write (b,0,nRead); ,^@/I:  
} XKT[8o<L  
catch(Exception e){e.printStackTrace ();} \@_?mL@=  
} SMQC/t]HT  
} $@WA}\D  
n+Ng7  
cZw_^@!  
//打印回应的头信息 2d&HSW  
public void logResponseHead(HttpURLConnection con) >R\!Qk  
{ 6%&w\<(SG  
for(int i=1;;i++) 8%b-.O:_$  
{ #Jfmt~ks '  
String header=con.getHeaderFieldKey(i); A5G@u}YS5  
if(header!=null) )/bv@Am  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ek '% % %  
Utility.log(header+" : "+con.getHeaderField(header)); \6/!{D,  
else 4HGR-S/  
break; RRGs:h@;  
} k rXU*64  
} u>2opI~m  
yJ8_<A  
9}d^ll&  
public void splitterStop() +1Rz+  
{ e&9v`8}   
bStop = true; Js9 EsN%  
} _wZr`E)  
Wtflw>-  
@^b>S6d "  
} u4[rA2Bf8E  
m!Aw,*m+*  
=%;TVJk*a  
/* }y%mG&KSz  
**FileAccess.java XBTjb  
*//文件访问(定位,写) _+&/P&  
package NetFox; QEY#U|  
import java.io.*; byIP]7Ld  
{\ BFWGX  
s>ZlW:jY  
public class FileAccessI implements Serializable{ : )k|Onz  
3+I"Dm,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,WS{O6O7  
RandomAccessFile oSavedFile; l_T5KV  
long nPos; "u"?~  
tLGNYW!K  
j<A; i  
public FileAccessI() throws IOException +?0r%R%\  
{ .gw6W0\F  
this("",0); 8oP"?ew#  
} x\5\KGw16  
<T$rvS  
}DkdF  
public FileAccessI(String sName,long nPos) throws IOException fvoPV &:  
{ H$)otDOE  
oSavedFile = new RandomAccessFile(sName,"rw"); #2qv"ntW  
this.nPos = nPos; 8fQXif\z  
oSavedFile.seek(nPos); =o4McV}  
} oX6()FR  
i0[mU,  
ezr'"1Ba}  
public synchronized int write(byte[] b,int nStart,int nLen) >NBwtF>  
{ 2| ERif;)  
int n = -1; -p20UP 1I  
try{ v <E#`4{  
oSavedFile.write(b,nStart,nLen); V}q=!zz  
n = nLen; ;QQ/bM&I  
} sW@_q8lG  
catch(IOException e) xGK"`\V  
{ <{k8 K6  
e.printStackTrace (); Xm^/t#  
} o 0H.DeP  
C.hRL4+;Zm  
JE[J}-2  
return n; X@@7Qk  
} (.9H1aO46|  
;VPYWss  
ljk,R G  
} >F;yfv;  
PKt;]T0  
+HY.m+T  
/* 5Fa/Q>N  
**SiteInfoBean.java -W)8Z.  
*/ WL1$LLzN  
package NetFox; V(6Ql j7  
{o8K&XU#&t  
!]!J"!xg*  
public class SiteInfoBean { Qy| 6A@  
uS{WeL6%  
c4FU@^Vv  
private String sSiteURL; //Site's URL 8"J6(KS  
private String sFilePath; //Saved File's Path v c b}Gk  
private String sFileName; //Saved File's Name ~> 5  
private int nSplitter; //Count of Splited Downloading File AF"XsEt.e  
W^1)70<y  
8,?*eYNjb  
public SiteInfoBean() Z(o]8*;A i  
{//nSplitter的缺省值为5 DM*u;t{i  
//default value of nSplitter is 5 a |0f B4G  
this("","","",5); \.{ZgL5"  
} sm;\;MP*yH  
5OHF=wh  
X5o{d4R L  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q Pp>%iE@  
{ m7,;Hr(  
sSiteURL= sURL; C'fQ Z,r-v  
sFilePath = sPath; DV jsz  
sFileName = sName; _SQ0`=+  
this.nSplitter = nSpiltter; X6EnC57  
Mt(;7q@1c  
87:V-*8  
} 3>buZ6vh  
4>te>[  
NpF)|Ppb{  
public String getSSiteURL() P<IZ%eS3B  
{ 5t[7taLX\  
return sSiteURL; ^ &VN=Y6z  
}  uE3xzF  
p(x<h  
3Cl&1K #5  
public void setSSiteURL(String value) 420yaw/":  
{ 3("E5lI(g:  
sSiteURL = value; r[RO"Ej"  
} U7d05y'  
2B=+p83<  
,:?=j80m  
public String getSFilePath() jI,?*n<  
{ %1%@L7wP>  
return sFilePath; ]j^rJ|WTH  
} OJPi*i5*  
c:_dW;MJ0  
;F\sMf{  
public void setSFilePath(String value) >&uR=Yd  
{ ? ]hS^&  
sFilePath = value; (/3E,6gMk^  
} 6yXMre)YV  
Mg=R**s1x%  
f&`yiy_  
public String getSFileName() kDK0L3}nr]  
{ $C9['GGR  
return sFileName; VyxX5Lrj  
} rb<9/z5-  
dZ'H'm;,!  
c"^g*i2&0  
public void setSFileName(String value) xX2/uxi8  
{ *Au[{sR  
sFileName = value; #=aTSw X  
} @!2vS@f  
yo"!C?82=  
XF Wo"%}w  
public int getNSplitter() mA0|W#NB  
{ -3&mgd  
return nSplitter; ,(&5y:o  
} 4W36VtQ@E  
I"r[4>>B>0  
*aS[^iX?s  
public void setNSplitter(int nCount) EMMp4KKOx+  
{ CGJ>j}C  
nSplitter = nCount; 3B[u2o>  
} ;$rh&ET  
} %3 VToj@`>  
1agI/R  
t Ai?Bjo  
/* SoL"M[O  
**Utility.java {xJ<)^fD8  
*/ $o>6Io|D  
package NetFox; Ls(l  
udGZ%Mr_  
qq[Enf|/y  
public class Utility { Ai.^~#%X  
Bz*6M  
5u&hp  
public Utility() "y$s`n4Mj  
{ d m$iiRY  
[rtMx8T  
k|[86<&[  
} 7G5VwO  
8Xk,Nbcqt  
//线程睡眠 qBXIR }  
public static void sleep(int nSecond) yc3i> w`  
{ @sLB _f  
try{ K8g9IZ*lT  
Thread.sleep(nSecond); ]:F?k#c  
} \4roM1&[  
catch(Exception e) z)XI A)i6  
{ I<LIw8LI  
e.printStackTrace (); $%0A#&DVh  
} <+)B8I^  
} J#*R]LU|  
5qQ\H}  
//日志 F@Cxjz  
public static void log(String sMsg) "IKbb7x  
{ C#D8 E.W  
System.err.println(sMsg); anxwK47  
} Lt\=E8&rh  
OZi4S3k  
K:8. Dvn  
public static void log(int sMsg) `*HM5 1U  
{ (`FY{]Wz!  
System.err.println(sMsg); - {|  
} &Y|AX2KUC  
} /F7X"_(H  
+U*:WKdI?  
fD ?w!7f-1  
/* Jw)-6WJ!uO  
**TestMethod.java hxx`f-#=  
*/ oiNt'HQ2/  
package NetFox; dEG1[QG  
TC^fyxq  
T +~ _D  
public class TestMethod { A N 'L- E  
R?H[{A X  
&(YNz9L  
public TestMethod() 5Int,SX  
{ ///xx/weblogic60b2_win.exe t6a$ZN;  
try{ =Z}=nS?4  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,1|0]:  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !=rJ~s F/{  
SiteFileFetch fileFetch = new SiteFileFetch(bean); x|q|> dPB  
fileFetch.start(); T~b6Zu6  
} #CTHCwYo  
catch(Exception e){e.printStackTrace ();} e{7"7wn=  
( t59SY  
mVdg0  
} p|o?nI  
9Jj:d)E>o  
d+158qQOh]  
public static void main(String[] args) )w'GnUqWz  
{ 31=v US  
new TestMethod(); _&|<(m&."  
} BhCOT+i;c  
} Y[Kpd[)[v  
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