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http断点续传简单实现(java)

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/* *=AqM14 @  
**SiteFileFetch.java Hc^W%t~  
*/ #P<N^[m  
package NetFox; #]P9b@@e  
import java.io.*; ,<-G<${  
import java.net.*; !-<p,z  
|`TgX@,#9  
,:LA.o}h  
public class SiteFileFetch extends Thread { F+m }#p  
3ZEB  
MN ^Aw9U  
SiteInfoBean siteInfoBean = null; //文件信息Bean ]:>,A@7  
long[] nStartPos; //开始位置 $5x ,6[&  
long[] nEndPos; //结束位置 +M' H0-[  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 8N&+7FK  
long nFileLength; //文件长度 VTy9_~q  
boolean bFirst = true; //是否第一次取文件 \K`L3*cBKK  
boolean bStop = false; //停止标志 0:w"M<80  
File tmpFile; //文件下载的临时信息 #7ohQrP  
DataOutputStream output; //输出到文件的输出流 #$1Z  
>zAUW[]C:I  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) mKr h[nA  
public SiteFileFetch(SiteInfoBean bean) throws IOException ktIi$v  
{ %\]* OZ7  
siteInfoBean = bean; *Kdda} J+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); (e(:P~Ry  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); !?c|XdjZ  
if(tmpFile.exists ()) YIw1  
{ iQDx{m3]  
bFirst = false; vz.>~HBP  
read_nPos();  (x/k.&  
} Cj~'Lhmv'T  
else zR2B- &]H  
{ '%q$` KDb  
nStartPos = new long[bean.getNSplitter()]; 3EJt%}V$k  
nEndPos = new long[bean.getNSplitter()]; (=7Cs  
} xJ#d1[kzo  
R(q~ -3~  
:POj6j/  
"[y-+)WTG  
} ep)>X@t  
?@E!u|]K  
v`M3eh@$A  
public void run() ,^uEYT}j  
{ 8F._9U-EN  
//获得文件长度 YW7b)u Yf  
//分割文件 (1#J%  
//实例FileSplitterFetch c%MW\qx  
//启动FileSplitterFetch线程 yu;P +G  
//等待子线程返回 zux{S; :?  
try{ U&?v:&c#&n  
if(bFirst) j KoG7HH  
{ x QIq^/F0  
nFileLength = getFileSize(); ZpnxecJUJ  
if(nFileLength == -1) Q)IKOt;N]  
{ H '  
System.err.println("File Length is not known!"); Evedc*z~P  
} [PDNwh0g5  
else if(nFileLength == -2) .>WxDQIo  
{ #w' kV#  
System.err.println("File is not access!"); zzX_q(:S  
} cLLbZ=`  
else U H*r5o3  
{ Fvbh\m ~  
for(int i=0;i<nStartPos.length;i++) |a Vn&qK  
{ <$IM8Y5p+w  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ~XO Ts  
} a ?)NC  
for(int i=0;i<nEndPos.length-1;i++) /w}u3|L$  
{ =,6z4" )  
nEndPos = nStartPos[i+1]; NU5.o$  
} x8V('`}j  
nEndPos[nEndPos.length-1] = nFileLength; 9-fLz?J  
} NgP&.39U  
} ~ v|>xqWV  
%5"9</a&G  
\D*KGd]M0  
//启动子线程 @eKec1<  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hvsWs.;L'  
for(int i=0;i<nStartPos.length;i++) Z/Dx,zIR  
{ Ju1D = b  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), klT@cO-9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >JFO@O5  
nStartPos,nEndPos,i); o<pf#tifv  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sN9&,&W1  
fileSplitterFetch.start(); i#vYyVr[  
} 3sy (vC  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #Y a4ps_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @1o/0y"  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wsI`fO^A8  
nEndPos = " + nFileLength); &m)6J'q3k  
// fileSplitterFetch[nPos.length-1].start(); gG(fQ 89U"  
#P0&ewy  
ux vqMgR  
//等待子线程结束 q_A!'sm@)  
//int count = 0; `ZyI!"  
//是否结束while循环 4.[^\N  
boolean breakWhile = false; 0"  
jCOIuw  
>UiYL}'br6  
while(!bStop) _=F=`xu  
{ yerg=,$_i  
write_nPos(); Jh,]r?Bd  
Utility.sleep(500); 96( v  
breakWhile = true; e>+i>/Fn{h  
?PeJlpYzV  
 mHdA2  
for(int i=0;i<nStartPos.length;i++) {Aw#?#GPW  
{ ZxGJzakB5$  
if(!fileSplitterFetch.bDownOver) tdBm (CsN  
{ n8~N$tDU  
breakWhile = false; [1g8*j~L  
break; {6|38$Rl  
} pjKWtY@=X  
} _.tVSV p  
if(breakWhile) <\r T%f}3^  
break; 2=,lcWr  
V_ :1EBzz  
6m* QX+  
//count++; AYqX |  
//if(count>4) :~&~y-14  
// siteStop(); {f3YsM;]C  
} 1H? u Qy  
? uzRhC_)!  
x -WmMfcz&  
System.err.println("文件下载结束!"); k:t ]s_`<  
} T*Y~\~Jhu  
catch(Exception e){e.printStackTrace ();} cLpYW7vZ[  
} #xsE3Wj-X  
6M @[B|Q(  
44ek IV+?  
//获得文件长度 ,>bh$|  
public long getFileSize() vYwYQG  
{ -; s|  
int nFileLength = -1; hgYZOwQ  
try{ `uv2H$  
URL url = new URL(siteInfoBean.getSSiteURL()); M8kPj8}{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M'7f O3&|  
httpConnection.setRequestProperty("User-Agent","NetFox"); PS)4 I&;U  
kj#?whK6~  
q<xCb%#Jl  
int responseCode=httpConnection.getResponseCode(); | k&Ck  
if(responseCode>=400) !,wIQy_e4  
{ \ :%(q/v"X  
processErrorCode(responseCode); lHN5Dr  
return -2; //-2 represent access is error %P;lv*v.  
} dP9qSwTa  
 ~^NtO  
I&D5;8  
String sHeader; hQ,ch[j'  
?&8^&brwG  
2%DSUv:H%  
for(int i=1;;i++) .[]r}[lU  
{ l5S aT,%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;km`P|<U  
//Utility.log(in.readLine()); {{$Nqn,pH  
sHeader=httpConnection.getHeaderFieldKey(i); -o ^7r@6  
if(sHeader!=null) (!ux+K  
{ 3+)J @(a  
if(sHeader.equals("Content-Length")) LA!?H]  
{ [;n9:Qxf  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2,DXc30I  
break; k KaE=H-x  
} m( r,Acy6  
} NH[kNi'  
else 1T"`v tR  
break; 9g9HlB&Ze  
} zIqU,n|]s  
} T:27r8"Rh  
catch(IOException e){e.printStackTrace ();} %6|nb:Oa  
catch(Exception e){e.printStackTrace ();} ui< N[  
-RE^tW*Yy  
J?*1*h  
Utility.log(nFileLength); 3lf=b~Zi)  
/j #n  
xs{3pkTYD  
return nFileLength; JB%',J  
} vDp8__^  
2":pE U{E  
!8TlD-ZT/  
//保存下载信息(文件指针位置) %:M ^4~dc  
private void write_nPos() ,1y@Z 5wy  
{ f/U`  
try{ /MIe(,>Uh  
output = new DataOutputStream(new FileOutputStream(tmpFile)); T`9lV2x*P  
output.writeInt(nStartPos.length); 'F/~o1\.  
for(int i=0;i<nStartPos.length;i++) :N:yLd} &  
{ EuEZ D +  
// output.writeLong(nPos); OC_+("N  
output.writeLong(fileSplitterFetch.nStartPos); R}-(cc%5  
output.writeLong(fileSplitterFetch.nEndPos); %41m~Wh2  
} 4)S,3G  
output.close(); >Rl"  
} DHy q^pJ  
catch(IOException e){e.printStackTrace ();} e2AX0(  
catch(Exception e){e.printStackTrace ();} S-a]j;U  
} I5X|(0es  
&u]8IEv}u  
9)h"-H;5:  
//读取保存的下载信息(文件指针位置) )cW#Rwu_A4  
private void read_nPos() qFicBpB  
{ {dhXIs  
try{ Yz'K]M_Dq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kI,yU}<Fq  
int nCount = input.readInt(); '3R`lv   
nStartPos = new long[nCount]; ;nI] !g:  
nEndPos = new long[nCount]; M-$%Rzl_  
for(int i=0;i<nStartPos.length;i++) OyU5DoDz1  
{ Q1T$k$n  
nStartPos = input.readLong(); (j%~u&+-  
nEndPos = input.readLong(); M=8.Bp|Ye  
} 5 )A1\  
input.close(); 6`&a&%,O  
} eln)BW#  
catch(IOException e){e.printStackTrace ();} ]l;o}+`G  
catch(Exception e){e.printStackTrace ();} im${3>26  
} R#s )r  
=h-U  
h! M  
private void processErrorCode(int nErrorCode) {yBs7[Wn  
{ FXpJqlhNv  
System.err.println("Error Code : " + nErrorCode); kC:uG0sW  
} TeMHm ?1^  
mbKZJ{|4s  
ISzqEi  
//停止文件下载 5A,K6f@:g  
public void siteStop() @CNi{. RX  
{ 7dN*lks  
bStop = true; 2\)xpOj  
for(int i=0;i<nStartPos.length;i++) &r[`>B{tP  
fileSplitterFetch.splitterStop(); zU,9T  
 |{&{  
e- ~N"  
} b\ X@gq  
} #"}JdBn  
//负责部分文件的抓取 \|n- O=}=2  
**FileSplitterFetch.java M5i%jZk  
*/ XP`Nf)3{Yd  
package NetFox; ajve~8/&  
M#ZcY  
oF vfCrd  
import java.io.*; W4 t;{b  
import java.net.*; -Sq z5lo  
>R|/M`<ph  
3t.l5m Rg5  
public class FileSplitterFetch extends Thread { ov|d^)'  
f<-Jg  
oxr#7Ei0d  
String sURL; //File URL BIH-"vTy  
long nStartPos; //File Snippet Start Position T!uM+6|Y  
long nEndPos; //File Snippet End Position mR!1DQ.\<  
int nThreadID; //Thread's ID c& < Fr[AK  
boolean bDownOver = false; //Downing is over X enE^e+9  
boolean bStop = false; //Stop identical O],T,Z?z  
FileAccessI fileAccessI = null; //File Access interface V[mT<Lc  
k3~}7]O)  
3\AU 72-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b}\N;D.{  
{ <xup'n^7C  
this.sURL = sURL; #+JG(^%B  
this.nStartPos = nStart; 9q)Kfz  
this.nEndPos = nEnd; GeI-\F7b  
nThreadID = id; ]{!U@b  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5CuuG<0  
} >d@&2FTO  
i|c'Lbre`  
ht|z<XJ  
public void run() vp1941P  
{ 02Y]`CXj  
while(nStartPos < nEndPos && !bStop) xP_cQwm`1  
{ # q~e^A b  
w}L]X1#sF  
y>:N{|  
try{ FSP+?((  
URL url = new URL(sURL); bw(a6qKK  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1Vsz4P"O $  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5]~'_V  
String sProperty = "bytes="+nStartPos+"-"; ,k.3|aZE  
httpConnection.setRequestProperty("RANGE",sProperty); +ndaLhj'  
Utility.log(sProperty); Mo y <@+  
Ha(c'\T (\  
LuNc, n%  
InputStream input = httpConnection.getInputStream(); i 6R~`0>Q  
//logResponseHead(httpConnection); ()2I#  
*jLJcb*.Ap  
bW$,?8(  
byte[] b = new byte[1024]; $>G8_q  
int nRead; :Hn6b$Vy8  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ng[Ar`  
{ vhe>)h*B  
nStartPos += fileAccessI.write(b,0,nRead); [I0:=yJ+  
//if(nThreadID == 1) fA&k`L(y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); # Nk;4:[  
} 1=r#d-\tR  
oNr-Q& C,  
v;BV@E0}x  
Utility.log("Thread " + nThreadID + " is over!"); 6q*9[<8  
bDownOver = true; \"qY"V  
//nPos = fileAccessI.write (b,0,nRead); Bu#E9hJFvA  
} t 4PK}>QW  
catch(Exception e){e.printStackTrace ();} %huRsQ %}  
} l2`s! ,<>O  
} :Uz|3gq  
C`K?7v3$m  
H]P. x!I  
//打印回应的头信息 IW>T}@ |  
public void logResponseHead(HttpURLConnection con) "&%I)e^  
{ dOa+(fMe  
for(int i=1;;i++) a!ud{Dx  
{ #G .ulX  
String header=con.getHeaderFieldKey(i); 7[w,:9& }  
if(header!=null) BD68$y  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,kF1T,  
Utility.log(header+" : "+con.getHeaderField(header)); c(J!~7  
else }e!x5g   
break; ?QsQnQ  
} e_#._Pi  
} |P[w==AAf  
1jCLO}  
%+f>2U4I  
public void splitterStop() uPhK3nCGo  
{ %kv0We fs  
bStop = true; n\QgOSr<  
} ~kQA7;`j$  
.}^g!jm~h  
XJ;D=~  
} 9G9fDG#F\I  
`2'#! -  
K$>%e36Cc  
/* %4ePc-  
**FileAccess.java H!?c\7adX  
*//文件访问(定位,写) 0":ib0=  
package NetFox; M|6A0m#Q  
import java.io.*; t5[ #x4 p  
sA/pVU  
|*:'TKzNS  
public class FileAccessI implements Serializable{ ,#Iu 7di  
g>Y|9Y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *#E F sUw  
RandomAccessFile oSavedFile; 4NGA/ G  
long nPos; QFw  +cy  
:QpuO1Gu  
e91aK  
public FileAccessI() throws IOException i'4B3  
{ 6`O.!|)  
this("",0); { D^{[I  
} ~R_ztD+C(  
0KYEb%44  
F5?m6`g?  
public FileAccessI(String sName,long nPos) throws IOException M\sN@+  
{ ,u!*2cWN  
oSavedFile = new RandomAccessFile(sName,"rw"); ?kWC}k{  
this.nPos = nPos; m6TNBX  
oSavedFile.seek(nPos); >*]Hq.&8  
} X*M#FT-  
hn^<;av=  
iTFdN}U  
public synchronized int write(byte[] b,int nStart,int nLen) >ZPsjQuf"  
{ eCN })An  
int n = -1; b vS(@  
try{ |K6REkzr  
oSavedFile.write(b,nStart,nLen); )>.&N[v  
n = nLen; c\iA89msp  
} vI2^tX 9  
catch(IOException e) z8QAo\_I(  
{ ?3%` bY+3;  
e.printStackTrace (); >_o}  
} N F2/B#q  
7B b9 t  
|UK}  
return n; "$N#p5  
} }2(,K[?  
5|l* `J)  
$UgA0]q n  
} Q7R~{5r>W  
zN!ZyI$nqP  
.#1~Rz1r  
/* Qk\A c  
**SiteInfoBean.java 6b+b/>G0  
*/ l7W 6qNB  
package NetFox; Ko;{I?c  
A3|Dz&@:  
CPP` qt%f  
public class SiteInfoBean { &z>e5_.  
,_yh z0.  
x*?x=^I{  
private String sSiteURL; //Site's URL #gp,V#T  
private String sFilePath; //Saved File's Path 0Uz\H0T1  
private String sFileName; //Saved File's Name >Y #t`6,!  
private int nSplitter; //Count of Splited Downloading File rypTKT|U;  
<(-3_s6-  
 AT9q3  
public SiteInfoBean() lD"(MQV@0  
{//nSplitter的缺省值为5 r.#t63Rb  
//default value of nSplitter is 5 31rx-D8o  
this("","","",5); 3~}uqaGt  
} KcK>%%  
#bl6sa{E  
O+?<h{"  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H2um|6>  
{ 6 G3\=)  
sSiteURL= sURL; m9"n4a|:  
sFilePath = sPath; >p.O0G gg  
sFileName = sName; J(c{y]`J  
this.nSplitter = nSpiltter; |g #K]v  
J.ck~;3  
COW}o~3-4  
} $:  ]o]a  
rb1`UG"h$  
u86"Y ^d#  
public String getSSiteURL() =|I>G?g-  
{ 5m9*85Ib  
return sSiteURL; WAn~ +=Ax  
} .Fnwm}  
~$p2#AqX  
jBU4F~1y  
public void setSSiteURL(String value) $OP7l>KZY  
{ NGOqy+Ty{f  
sSiteURL = value; VUhbD  
} L ]w/P|  
Yc,7tUz#  
tQ H+)*  
public String getSFilePath() iVd.f A  
{ DwrO JIy  
return sFilePath; \'9PZ6q{  
} L+CyQq  
| fSe>uVZ  
G.( mp<-  
public void setSFilePath(String value) GKoK7qH\J  
{ 6S+U&Ce\  
sFilePath = value; /)dFK~  
} ;$a@J&  
#*TEq  
D<Z p!J1o  
public String getSFileName() DSt]{fl`P  
{ /w]!wM  
return sFileName; 2Sh  
} Er{#ziN+  
~M\I;8ne  
7}vg.hmZ  
public void setSFileName(String value) Rr!Y3)f;  
{ z,VD=Hnz  
sFileName = value; u-tQ9ioKC  
} A?`jnRo=\  
40|,*wi  
HW7; {QMg  
public int getNSplitter() ,}:G\u*Fu  
{ Gkp< o  
return nSplitter; F35#dIs`&  
} :"l-KQ0  
"h|'}7p  
Qu7T[ <  
public void setNSplitter(int nCount) `\m*+Bk[5  
{ Bf$_XG3  
nSplitter = nCount; ONCnVjZ  
} ^k Cn*&  
} .58qL-iC  
-CRra EXf8  
Y& F=t/U2  
/* =&},;VOh  
**Utility.java QjC22lW-  
*/ tqy@iEz+  
package NetFox; [xT:]Pw}  
h(F<h_  
0d3+0EN{  
public class Utility { !wWJ^Oz=  
1]}#)-  
UThB7(O,  
public Utility() !o>H1#2l  
{ sF7^qrVQP9  
[2dn\z28  
doB  
} z.6$W^  
m~>Y{F2  
//线程睡眠 9W8]8sUeG  
public static void sleep(int nSecond) 3( ]M{4j  
{ !=y]Sv~h  
try{ ^::EikpF%  
Thread.sleep(nSecond); W;1|+6x  
} IJJ%$%F/  
catch(Exception e) *#TYqCc+g  
{ .)+h H y  
e.printStackTrace (); 1pCieTz!PN  
} !bC+TYsU  
} 2jbIW*  
ZbT/$\0(6  
//日志 x)UwV  
public static void log(String sMsg) l?iSxqdT  
{ a,o_`s<  
System.err.println(sMsg); m{7^EF  
} jt@SZI`  
[|~2X>  
fGv#s X  
public static void log(int sMsg) WO6/X/#8b  
{ 4G@nZn  
System.err.println(sMsg); )XfzLF7  
} w0ZLcND{  
} ]?h`:,]  
f,z P*  
'u4ezwF;  
/* " v}pdUW  
**TestMethod.java {u[V{XIUh  
*/ 5[{*{^F4  
package NetFox; ^VT1vu %03  
>\ u<&>i  
__@zTSVb  
public class TestMethod { hCYQGx0  
4gSH(*}  
+Ug/rtK4   
public TestMethod() 81%8{yn!$"  
{ ///xx/weblogic60b2_win.exe |BZDhd9<{  
try{ idRD![!UI  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >O/ D!j|  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `Y40w#?uW  
SiteFileFetch fileFetch = new SiteFileFetch(bean); zNSu  
fileFetch.start(); I =Wc&1g  
} g`k?AM\  
catch(Exception e){e.printStackTrace ();} Q/I)V2a1i  
to"' By{9  
}%TSGC4{  
} 3E^M?N2oc  
c~ <1':  
-V % gVI[  
public static void main(String[] args) v=I|O%  
{ ]+DI.%   
new TestMethod(); *pzq.#  
} "k$JP  
} >cL{Ya}Rz  
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