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http断点续传简单实现(java)

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/* WpkCFp  
**SiteFileFetch.java ;9)=~)  
*/ :Yi 4Ia  
package NetFox; "msPH<D  
import java.io.*; w-Q=oEt  
import java.net.*; N`vPt?@  
mE9ytFH\k  
~`0=-Qkd  
public class SiteFileFetch extends Thread { dAaxbP|  
uK[gI6M  
2W/*1K}  
SiteInfoBean siteInfoBean = null; //文件信息Bean l5U^lc  
long[] nStartPos; //开始位置 r90R~'5x9  
long[] nEndPos; //结束位置 qIO)<5\[%d  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ;F/s!bupCM  
long nFileLength; //文件长度 Wa iM\h?=#  
boolean bFirst = true; //是否第一次取文件 ciN*gwI)  
boolean bStop = false; //停止标志 ko~e*31_E  
File tmpFile; //文件下载的临时信息 Ujvk*~:  
DataOutputStream output; //输出到文件的输出流 !A+jX7Nb  
uzT>|uu$  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Nu><r  
public SiteFileFetch(SiteInfoBean bean) throws IOException 3IoN.  
{ \~T&C5  
siteInfoBean = bean; G%%5lw!y'  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); f/Q/[2t  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); u TmT'u:}  
if(tmpFile.exists ()) `t7GYmw^#  
{ 4@@gC&:Y  
bFirst = false; FCChB7c`  
read_nPos(); *{=q:E$  
} Emv9l~mIu  
else raZ0B,;eFu  
{ )+a]M1j  
nStartPos = new long[bean.getNSplitter()]; T 6=~vOzTJ  
nEndPos = new long[bean.getNSplitter()]; <7j"CcJzZ  
} GJBMaT  
@nM+*0 $d  
D Z=OZ.v  
Gx(%AB~9$  
} WAVEwA`r  
iv6bXV'N  
%vU*4mH  
public void run() 3`ze<K((  
{ _2xYDi  
//获得文件长度 okBaQH2lUl  
//分割文件 B,A\/%<  
//实例FileSplitterFetch '~pZj"uy  
//启动FileSplitterFetch线程 ZC&4uNUr  
//等待子线程返回 9}11>X  
try{ 6/|"y  
if(bFirst) 0"u=g)3  
{ -n6T^vf  
nFileLength = getFileSize(); >yr3C  
if(nFileLength == -1) .X6V>e)(3  
{ 4Gsq)i17j  
System.err.println("File Length is not known!"); S{~j5tQv^q  
} lp5 b&I_  
else if(nFileLength == -2) P}D5 j  
{ sV`XJ9e|  
System.err.println("File is not access!"); S@C"tHD  
} <##aD3)  
else P~@I`r567  
{ 'WoB\y569  
for(int i=0;i<nStartPos.length;i++) P1"g62R  
{ mz^[C7(q'(  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Q0TKM >  
} 6`)Ss5jzk  
for(int i=0;i<nEndPos.length-1;i++) NqN9  
{  83:qIfF  
nEndPos = nStartPos[i+1]; \3cg\Q+~  
} OLDEB.@  
nEndPos[nEndPos.length-1] = nFileLength; =5M '+>  
} 1i$OcN?x%  
} 6hqqZ  
T!Uf PfEI  
%* @hS`  
//启动子线程 p;{w0uld"  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6X$iTJ[\x  
for(int i=0;i<nStartPos.length;i++) fU4{4M+9"  
{ \V9);KAOj  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -257g;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3$kElq[  
nStartPos,nEndPos,i); MZSyu  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZHc;8|}  
fileSplitterFetch.start(); *q(HW  
} DZX4c2J  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5$ rV0X,O  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |( R[5q  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZRCUM"R_  
nEndPos = " + nFileLength); f8 L3+u  
// fileSplitterFetch[nPos.length-1].start(); zuBfkW95+  
^r~R]stE^  
i<{/r-w=E  
//等待子线程结束 Z/I`XPmk  
//int count = 0; A>}]=Ii/  
//是否结束while循环 bqUQadDB  
boolean breakWhile = false; LP}YH W/  
3hNb ?  
OY(znVHU  
while(!bStop) K.\-  
{ -!ERe@k(  
write_nPos(); JT 5+d ,  
Utility.sleep(500); , -S n  
breakWhile = true; n/GJ&qLi:g  
 %L gfi  
s B!2't  
for(int i=0;i<nStartPos.length;i++) `jCq`-.  
{ w3peG^4D_  
if(!fileSplitterFetch.bDownOver) 2N_9S?a3sK  
{ |} K7Q  
breakWhile = false; `H\NJ,  
break; DZ0\pp?S  
} Jf8AKj3  
} Hxd ^oE  
if(breakWhile) 8_ _C T  
break; 0qD.OF)8  
^->vUf7PX  
zGE{Z A  
//count++; ?C9>bKo*2H  
//if(count>4) iMOf];O)  
// siteStop(); TZk.h8  
} lpeo^Y}N  
g3,F+  
q"pnFK9/L  
System.err.println("文件下载结束!"); x$tzq+N  
} g].hL  
catch(Exception e){e.printStackTrace ();} =;A~$[g  
} ~b{j`T  
u+uu?.bM  
Zu%oIk  
//获得文件长度 @?"t&h  
public long getFileSize() Y{ 2xokJ N  
{ 8rsv8OO  
int nFileLength = -1; X+XbIbUuL  
try{ nzORG  
URL url = new URL(siteInfoBean.getSSiteURL()); ecy41y'~:  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &,@wLy^ T  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5Ai$1'*p  
J'y*>dW  
quw:4W>  
int responseCode=httpConnection.getResponseCode(); Li\BRlebR{  
if(responseCode>=400) _ a,XL<9I  
{ >~^##bIb  
processErrorCode(responseCode); W4(O2RU  
return -2; //-2 represent access is error [u2)kH$  
} 6 _\j_$  
ihdtq  
3$ 1 z  
String sHeader; '$n#~/#}  
> jDx-H.N  
;M Z@2CO  
for(int i=1;;i++) [M6/?4\  
{ 8?7:sfc  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iP~dH/B|v  
//Utility.log(in.readLine()); 15FGlO<<  
sHeader=httpConnection.getHeaderFieldKey(i); da&f0m U  
if(sHeader!=null) _Uz}z#jt  
{ CVFsp>+  
if(sHeader.equals("Content-Length")) T"m(V/L$W  
{ F I\V6\B/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L)ry!BuHI  
break; #FV(a~  
} o<-+y\J8K  
} v{2 Vg  
else ^~dvA)bH  
break; %U)M?UNjw  
} i@ avm7  
} "i_}\p.,X  
catch(IOException e){e.printStackTrace ();} 8h2!8'  
catch(Exception e){e.printStackTrace ();} 5K*-)F ]  
wfrWpz=FO  
-m~[z  
Utility.log(nFileLength); e?D,=A4mV"  
D0&{iZ(  
z[wk-a+w  
return nFileLength; (8(z42  
} E qva] 4  
dj76YK  
6gfdXVN5  
//保存下载信息(文件指针位置) +<ey Iw  
private void write_nPos() Up$vBE8i]  
{ X7]vXo*  
try{ <!vAqqljt  
output = new DataOutputStream(new FileOutputStream(tmpFile)); U q6..<#  
output.writeInt(nStartPos.length); t%AW0#TZ  
for(int i=0;i<nStartPos.length;i++) *7I=vro  
{ Ucnit^,  
// output.writeLong(nPos); !Jj=H()}  
output.writeLong(fileSplitterFetch.nStartPos); YtrMJ"  
output.writeLong(fileSplitterFetch.nEndPos); z {J1pH_X  
} a;Y9wn  
output.close(); $*H>n!&  
} LHWh-h(s  
catch(IOException e){e.printStackTrace ();} u[oYVpe)IG  
catch(Exception e){e.printStackTrace ();} &7X0 ;<  
} +:[dviyPt  
ca_8S8lv  
UmU=3et<Wj  
//读取保存的下载信息(文件指针位置) jL)aU> kN  
private void read_nPos() 5\tYs=>b<  
{ yXw xq(32  
try{ U<NpDjc"  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g5to0  
int nCount = input.readInt(); OX4+1@$tk  
nStartPos = new long[nCount]; EQ>bwEG  
nEndPos = new long[nCount]; .-N9\GlJ,d  
for(int i=0;i<nStartPos.length;i++) * #;rp~  
{ um&e.V)N  
nStartPos = input.readLong(); +-#| M|a  
nEndPos = input.readLong(); }h>e=<  
} w|PZSOJ  
input.close(); 4f"a/(>*  
} ]IJ.}  
catch(IOException e){e.printStackTrace ();} l(zkMR$b8  
catch(Exception e){e.printStackTrace ();} hk&p+NV!  
} nx,67u/Pb  
 N _r*Ig  
>|7&hj$  
private void processErrorCode(int nErrorCode) zT~ GBC-IX  
{ bah5 f  
System.err.println("Error Code : " + nErrorCode); Pwz^{*u]  
} VPg`vI$(X  
i4!n Oyk  
^B?koU l^  
//停止文件下载 Af0E_  
public void siteStop() a@,tf'Sr  
{ Zk}e?Grc  
bStop = true; ?#D@e5Wf  
for(int i=0;i<nStartPos.length;i++) 2#1FI0,Pa*  
fileSplitterFetch.splitterStop(); $X~=M_ W  
Qq]UEI `Go  
fC%;|V'Nd  
} xyz-T1ib  
} EGGy0ly  
//负责部分文件的抓取 XW]|Mv[M  
**FileSplitterFetch.java %_SE$>v^  
*/ ?-\KVha  
package NetFox; 8N-~.p  
kC9A  
`Xmpm4 ]  
import java.io.*; G68N@g  
import java.net.*; h/(9AO}t  
3[aJ=5  
i$:CGUb  
public class FileSplitterFetch extends Thread { x_Ais&Gc  
Punbw\9!d,  
HNjkRl)QR  
String sURL; //File URL 2 >xV&  
long nStartPos; //File Snippet Start Position Gh|1%g"gm  
long nEndPos; //File Snippet End Position b<.+WkO  
int nThreadID; //Thread's ID  |Be.r{l  
boolean bDownOver = false; //Downing is over -R7f/a8  
boolean bStop = false; //Stop identical R?|_` @@A  
FileAccessI fileAccessI = null; //File Access interface N}F G%a  
$X*$,CCIB  
//Tr=!TQu  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Bdbw!zRR$  
{ JBUJc  
this.sURL = sURL; " 31C8  
this.nStartPos = nStart; <O\z`aA'q  
this.nEndPos = nEnd; FT (EH  
nThreadID = id; *%)L?*  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vlj|[joXw  
} 4?yc/F=kI  
7 cIVK}&  
)s=z i"  
public void run() ,CM$A}7[  
{ Ha C?,  
while(nStartPos < nEndPos && !bStop) B~PF<8h5  
{ "F[VqqD  
=C3l:pGMB;  
x-Mp6  
try{ 6gR=e+  
URL url = new URL(sURL); [[ s k  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qn*c<:  
httpConnection.setRequestProperty("User-Agent","NetFox"); T. ` %1S  
String sProperty = "bytes="+nStartPos+"-"; U5Ho? `<  
httpConnection.setRequestProperty("RANGE",sProperty); >MP PYVn7  
Utility.log(sProperty); Ugdm"  
06Hn:IT18  
%] #; ~I%  
InputStream input = httpConnection.getInputStream(); Bxa],inuZ  
//logResponseHead(httpConnection); 09%eaoW  
nW drVT$  
ZA9']u%EJ  
byte[] b = new byte[1024]; BgpJ;D+N4  
int nRead; giu~"#0/F  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U.^)|IHW  
{ }lxvXVc{I  
nStartPos += fileAccessI.write(b,0,nRead); Bnxzy n  
//if(nThreadID == 1) ReK@~#hLY  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;D^)^~7dh  
} 'Ux_X:,:;  
?Y hua9  
3mm`8!R  
Utility.log("Thread " + nThreadID + " is over!"); IYQYW.`ly  
bDownOver = true; +qz)KtJS  
//nPos = fileAccessI.write (b,0,nRead); 9lD,aOb  
} l[fNftT-  
catch(Exception e){e.printStackTrace ();} q]r!5&Z  
} QKP9*dz  
} n~)Y%xe[U  
=V,'f  
@`_j't,  
//打印回应的头信息 N0qC/da1  
public void logResponseHead(HttpURLConnection con) U/iAP W4U  
{ 6=@n b3D%  
for(int i=1;;i++) Uv+pdRXn  
{ %#] T.g  
String header=con.getHeaderFieldKey(i); Qs?+vk?*h  
if(header!=null) s?6 7@\  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q[b({Vj;tG  
Utility.log(header+" : "+con.getHeaderField(header)); h3)KT+7.  
else q!H 3JL  
break; #/tdZ0  
} fF d9D=EW.  
} Bs1-UI}+  
=)zq %d?i;  
R/Y/#X^b  
public void splitterStop()  CMg83  
{ rvmI 8  
bStop = true; KOmP-q=6  
} ,X$Avdc2  
`Eu(r]:W  
Gz6GU.IyQy  
} {//F>5~[  
8uGPyH  
6szkE{-/?  
/* LNN:GD)>  
**FileAccess.java oOL3O@)w>  
*//文件访问(定位,写) Z~,.l  
package NetFox; )R +o8C  
import java.io.*; $3[cBX.=  
#y*=UV|h  
eB\r/B]  
public class FileAccessI implements Serializable{ \Zh)oUHd  
__V]HcP;  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^ 2AF:(E  
RandomAccessFile oSavedFile; D}061~zb$  
long nPos; eFnsf}(Iy  
n% ` r  
={b ]  
public FileAccessI() throws IOException ,|#>X>^FQQ  
{ R`* *!ku  
this("",0); |O)deiJRy  
}  g_>ZE  
R|CY4G j  
d=#p w*w  
public FileAccessI(String sName,long nPos) throws IOException ^i8I 1@ =  
{ #w*pWD^  
oSavedFile = new RandomAccessFile(sName,"rw"); lQsQRp  
this.nPos = nPos; {.lF~cOu  
oSavedFile.seek(nPos); E&>,B81  
} ommKf[h%i  
!U#++Zig%  
x7@WWFF>  
public synchronized int write(byte[] b,int nStart,int nLen) r~}}o o4K  
{ ) *A,L%  
int n = -1; ZM vTDH!  
try{ 6|KX8\, A@  
oSavedFile.write(b,nStart,nLen); TN %"RL  
n = nLen; bSr 'ji  
} 6oP{P_Pxi  
catch(IOException e) h3kHI?jMWG  
{ tRy D@}  
e.printStackTrace (); FR}H$R7#  
} . ?p}:  
2 &Byq  
bNROXiX  
return n; ,OKM\N ,  
} yo*iv+l  
/,Rca1W  
}K>H S\e  
} ~t:b<'/  
Qsntf.fT  
P*PL6UQ  
/* 99!{[gOv  
**SiteInfoBean.java 3] qlz?5  
*/ O&,O:b:@  
package NetFox; xplo Fw~  
s3M84wz  
O$Vm#|$sq  
public class SiteInfoBean { gFT~\3j p=  
t%U[\\ic  
A(n=kx  
private String sSiteURL; //Site's URL m"G N^V7  
private String sFilePath; //Saved File's Path "k-ov9yK  
private String sFileName; //Saved File's Name \B2d(=~4  
private int nSplitter; //Count of Splited Downloading File }iSakq'  
5b#6 Y  
* |HZ&}  
public SiteInfoBean()  j/9QV  
{//nSplitter的缺省值为5 KupMndK  
//default value of nSplitter is 5 CjQ"oQw  
this("","","",5); 5FSv"=  
} v1C.\fL  
Tq84Fn!HJ>  
T'M66kg  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q==v!"Gi|  
{ jAK{<7v4U  
sSiteURL= sURL; #tZf>zrs  
sFilePath = sPath; I/Jp,~JT*  
sFileName = sName; ,Us2UEWNv  
this.nSplitter = nSpiltter; {TncqA  
c,q"}nE8w  
d_C4B  
} t;!]z-Y>  
h)_Gxe"x  
sJb)HQ,7x  
public String getSSiteURL() DAnb.0  
{ [tqO}D  
return sSiteURL; jRG\C=&(x  
} fT3*>^Uv  
v'Vt .m&9&  
+oy&OKCa  
public void setSSiteURL(String value) |WAD $3  
{ V+qJrZ ,i  
sSiteURL = value; g6g$nY@Jm  
} hoR=%pC*  
3l%,D: ?  
{KDgK  
public String getSFilePath() 9U)t@b  
{ ahtYSz_FM  
return sFilePath; V-_/(xt*  
} Hl3)R*&'J  
WE[m@K[CR  
UQ3@@:L_  
public void setSFilePath(String value) kwHqvO!G  
{ VkpHzr[k  
sFilePath = value; k\pDJ7wF^  
} Mi}I0yhVm  
rQEi/  
:wU_-{>>2  
public String getSFileName() ESMG<vW&f  
{ *J_iXu|  
return sFileName; VD24X  
} poD \C;o"  
,?k%jcR  
_(6`{PWY  
public void setSFileName(String value) ]G0dS Fh{j  
{ '_qQrP#  
sFileName = value; rKzlK 'U  
} JzMZB"Z?  
pDq#8*q+v  
#9`rXEz  
public int getNSplitter() (`6%og#8  
{ B:-U`CHHQ  
return nSplitter; W7L+8LU;  
} 4TUtY:  
~o@\ n  
:)p)=c8%  
public void setNSplitter(int nCount) JoCA{Fa}  
{ ,;.B4  
nSplitter = nCount; EqnpMHF  
} {pDTy7!Hs  
} UP;Q=t  
ivzAlwP  
v**z$5x9  
/* kG1;]1tT#  
**Utility.java [q-;/ed  
*/ dTN$y\   
package NetFox; *bA+]&dj\  
@P:R~m2  
4.|-m.a  
public class Utility { S Pn8\2Cj  
=4tO0  
c^=R8y-N  
public Utility() :N@U[Wx0A  
{ %bP~wl~  
`c"4PU^  
k6Ihc?HL  
} gYatsFyL  
hH%,!tSx  
//线程睡眠 -J,Q;tj  
public static void sleep(int nSecond) B0oxCc/'sZ  
{ $PSY:Zz  
try{ Q.,DZp   
Thread.sleep(nSecond); |gnAqkW0  
} u#`+[AC`  
catch(Exception e) ljPq2v ]  
{ 6&89~W{  
e.printStackTrace (); yl-fbYH  
} x;]x_f z  
} &%^K,Q"  
X Orcygb2  
//日志 akT|Y4KxD  
public static void log(String sMsg) s^w\zzYb  
{ =fl%8"%N&  
System.err.println(sMsg);  SLkuT`*  
} sV u k  
v f`9*xF  
./l|8o  
public static void log(int sMsg) .APVjqG  
{ }A|))Ao|  
System.err.println(sMsg); Wo{K}  
} I:#Ok+   
} :pwa{P  
|;P^clS3  
8xgJSk  
/* q] ^,vei  
**TestMethod.java pOMgEEhfS  
*/ x;u~NKy  
package NetFox; 4O!E|/`wO  
F>N+<Z  
s~^*+kq  
public class TestMethod { td >,TW=A*  
.Gh%p`<  
lop uf/U0  
public TestMethod() B{p4G`$i1  
{ ///xx/weblogic60b2_win.exe yRC3 . [  
try{ }W$8M>l  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QY@u}&m%o  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ep mJWbU  
SiteFileFetch fileFetch = new SiteFileFetch(bean); cC%j!8!  
fileFetch.start(); R4b-M0H  
} 3jF|Ic  
catch(Exception e){e.printStackTrace ();} -#aZF2z   
'M8aW!~  
EJLQ&oH[  
} vU!8`x)  
Z:@6Lv?CN  
_gW{gLYyJ  
public static void main(String[] args) )lh8 k {  
{ QH~Jy*\+PX  
new TestMethod(); :a.0he s  
} 3B{[%#vO  
} ?,07;>&  
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