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http断点续传简单实现(java)

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/* f] _'icP  
**SiteFileFetch.java  |nfMoUI  
*/ ~1{ppc+  
package NetFox; L5'?.9]  
import java.io.*; gD2P)7:  
import java.net.*;  VeSQq  
m VFo2^%v  
BOWBD@y  
public class SiteFileFetch extends Thread { u 7:Iv  
A"z9t#dv@  
74  &q2g{  
SiteInfoBean siteInfoBean = null; //文件信息Bean `FEa(Q+s  
long[] nStartPos; //开始位置 W>5[_d  
long[] nEndPos; //结束位置 TbaZFLr  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 \!xCmQ  
long nFileLength; //文件长度 [r!f&R  
boolean bFirst = true; //是否第一次取文件 ia(`3r  
boolean bStop = false; //停止标志 :a^/&LbLm  
File tmpFile; //文件下载的临时信息 ]6F\a= J  
DataOutputStream output; //输出到文件的输出流 f> bL }L  
A'.=SA2.Y  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) H~^)^6)^T  
public SiteFileFetch(SiteInfoBean bean) throws IOException '/)qI.  
{ e^'|<0J  
siteInfoBean = bean; i\O^s ]  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); )*`h)`\y  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); x[0O*ty-*<  
if(tmpFile.exists ()) S+#|j  
{ |#sOa  
bFirst = false; (k8}9[3G  
read_nPos(); +H28F_ #  
} KK6n"&TVa  
else wSw> UU  
{  6']HmM  
nStartPos = new long[bean.getNSplitter()]; j8nkNE]&   
nEndPos = new long[bean.getNSplitter()]; Lx tgf2r  
} @mmnr?_w  
$rlrR'[H  
QZtQogNy#  
rOz1tY)l0d  
} TkJ[N4'0  
R1D ;  
u`&lTJgF/O  
public void run() RWGf]V]6  
{ u88wSe<\X  
//获得文件长度 !?v_.  
//分割文件 !LzA  
//实例FileSplitterFetch G[`1Yw$  
//启动FileSplitterFetch线程 o+B)  
//等待子线程返回 @Ns[qn;9  
try{ kY @(-  
if(bFirst) z DU=2c4W9  
{ 0{g*\W*+~  
nFileLength = getFileSize(); X6",Xr! {  
if(nFileLength == -1) 1`YU9?  
{ 5 mC"8N1)  
System.err.println("File Length is not known!"); DzQ  
} l#`G4Vf  
else if(nFileLength == -2) &w#!   
{ j:xC \b47"  
System.err.println("File is not access!"); iaCV8`&q%  
} 0ZM(heQ  
else \+l*ZNYM3  
{ Yj#tF}nPC  
for(int i=0;i<nStartPos.length;i++) NcP/W>lN  
{ jj1\oyQ8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); '3Lu_]I-  
} OQ7 `n<I<)  
for(int i=0;i<nEndPos.length-1;i++) .w;kB}$YC  
{ pF4Z4?W  
nEndPos = nStartPos[i+1]; u8]FJQ*\6+  
} h693TS_N  
nEndPos[nEndPos.length-1] = nFileLength; ==&  y9e  
} 2ozh!8aL  
} %IX)+ Lp`  
6,a H[ >W  
xC,x_:R`  
//启动子线程 ~Ix2O   
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'gvR?[!t  
for(int i=0;i<nStartPos.length;i++) X!p`|i  
{ ocFk#FW  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Aeb(b+=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XzHR^^;u"*  
nStartPos,nEndPos,i); b:D92pH  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S0)JIrrHC  
fileSplitterFetch.start(); &CQO+Yr$l  
} z@i4  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -}9^$}PR  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *y!O\-\S#>  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", })H d]a  
nEndPos = " + nFileLength); !: ^q_q4  
// fileSplitterFetch[nPos.length-1].start(); %'yrIR  
<;6{R#Tuh  
"FWx;65CR  
//等待子线程结束 ,|{`(y/v  
//int count = 0; /{\ /e"5  
//是否结束while循环 ,^1zG  
boolean breakWhile = false; mK[Z#obc=  
RZzHlZ  
n7cy[%yT  
while(!bStop)  ch8a  
{ n4/Wd?#`  
write_nPos(); `8ac;b  
Utility.sleep(500); f9W:-00QD  
breakWhile = true; kFv*>>X`  
Zd6ik&S   
P[ 2!D)A  
for(int i=0;i<nStartPos.length;i++) yQiY:SH  
{ -GA F>  
if(!fileSplitterFetch.bDownOver) c]PTU2BB8  
{ lPZ(c%P  
breakWhile = false; @kWL "yy,  
break; +e-F`k  
} x#J9GP.  
} 6O As%QZ  
if(breakWhile) #$I@V4O;#  
break; WVdV:vJ-  
Uj):}xgi'  
`m7<_#Y  
//count++; "`$,qvNN  
//if(count>4) mb1mlsE  
// siteStop(); D%p*G5Bg3  
} At'CT5=  
DB5J3r81  
K*SgEkb'l  
System.err.println("文件下载结束!");  USV DDqZ  
} 1f`De`zXzr  
catch(Exception e){e.printStackTrace ();} :A8}x=K  
} m2c'r3UEu  
@- STo/  
qq/>E*~  
//获得文件长度 d:@+dS  
public long getFileSize() <+_XGOt0<  
{ >R+-mP!nj  
int nFileLength = -1; X zJ#)}f  
try{ {^WK#$]  
URL url = new URL(siteInfoBean.getSSiteURL()); @>)VQf8s1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -&Z!b!jN  
httpConnection.setRequestProperty("User-Agent","NetFox"); +/~]fI  
Xp:A;i9  
{]k#=a4  
int responseCode=httpConnection.getResponseCode(); }a7d(7  
if(responseCode>=400) (/e&m=~  
{ f#0HiE!  
processErrorCode(responseCode);  ]n!V  
return -2; //-2 represent access is error #\0m(v  
} T/_u;My;  
BJj'91B[d  
D&G6^ME  
String sHeader;  E^1yU  
rH3U;K!  
~"#0rPT  
for(int i=1;;i++) *;fTiL  
{ i#[8I-OtN/  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g8<ODU0[g  
//Utility.log(in.readLine()); h>/teHy /  
sHeader=httpConnection.getHeaderFieldKey(i); ?UtKu  
if(sHeader!=null) A2|Bbqd  
{ KD kGQh#9  
if(sHeader.equals("Content-Length")) V<QpC5  
{ b^/u9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )|~&(+Q?]  
break; }r: "X<`  
} |_;kQ(,  
} >Xn,jMUW  
else e~]P _53  
break; p&(0e,`z/  
} -9b=-K.y  
} 1bFZyD"  
catch(IOException e){e.printStackTrace ();} \p4*Q}t  
catch(Exception e){e.printStackTrace ();} .]v>LsbhF  
dn(!wC]  
kR<sSLEb  
Utility.log(nFileLength); f 2WVg;Z  
aTvyz r1  
C'JI%HnQ  
return nFileLength; TO6F  
} `<YMkp[  
QVT0.GzR  
G\sx'#Whc  
//保存下载信息(文件指针位置) w <r*&  
private void write_nPos() uw+nll*W%  
{ >z<L60S  
try{ q,P.)\0A  
output = new DataOutputStream(new FileOutputStream(tmpFile)); G_F_TNO  
output.writeInt(nStartPos.length); *~PB  
for(int i=0;i<nStartPos.length;i++) mdc?~??8  
{ A;co1,]gR  
// output.writeLong(nPos); -H6 0T,o  
output.writeLong(fileSplitterFetch.nStartPos); G*=HjLmZg  
output.writeLong(fileSplitterFetch.nEndPos); ]Jswxw  
} (HAdr5  
output.close(); ygz2bHpD~  
} Zux L2W  
catch(IOException e){e.printStackTrace ();} ;]LQ}^MP(  
catch(Exception e){e.printStackTrace ();} $bE" 3/uf  
} EXSH{P O+  
Ku[q #_7  
LphCx6f,X  
//读取保存的下载信息(文件指针位置) $<-a>~^Tp  
private void read_nPos() OLG)D#m(4/  
{ rmjuNy=(  
try{ =oSD)z1c?x  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +L09^I  
int nCount = input.readInt(); Ftyxz&-4$p  
nStartPos = new long[nCount]; zZ[kU1Fyv  
nEndPos = new long[nCount]; `{#""I^_  
for(int i=0;i<nStartPos.length;i++) AF:_&gF  
{ L'wR$  
nStartPos = input.readLong(); =c6d $  
nEndPos = input.readLong(); ^tTM 7  
} }9ulHiR  
input.close(); \n}%RD-Ce  
} ,LBj$U]e|E  
catch(IOException e){e.printStackTrace ();} R~=c1bpdq  
catch(Exception e){e.printStackTrace ();} z(A60b}  
} fHaF9o+/b  
(Nzh1ul\}  
Ic3a\FTr\  
private void processErrorCode(int nErrorCode) ^iH[ 22 b4  
{ K"l~bFCZ8  
System.err.println("Error Code : " + nErrorCode); 4zs0+d +  
} $?ss5: S  
?8753{wk  
%g?M?D8Ud3  
//停止文件下载 v} !lx)#  
public void siteStop() %RW*gUvc]  
{ (\qf>l+*  
bStop = true; 5B~]%_gZr  
for(int i=0;i<nStartPos.length;i++) ^qL<=UC.  
fileSplitterFetch.splitterStop(); <8(q.  
BiU>h.4=\(  
=bp'5h8_  
} l9QIlTc7  
} ",~ZO<P  
//负责部分文件的抓取 3XY"s"  
**FileSplitterFetch.java oyiG04H&  
*/ \>\ERVEd  
package NetFox; 7b~uU@L`  
m2m ;|rr  
,tXI*R  
import java.io.*; -medD G  
import java.net.*; $\m:}\%p  
h8WM4 PK  
X!V#:2JY  
public class FileSplitterFetch extends Thread { GYtgw9 "Y  
)-I/ej^  
]R~hzo  
String sURL; //File URL {JdXn  
long nStartPos; //File Snippet Start Position gR/?MJ(v  
long nEndPos; //File Snippet End Position 26}3  
int nThreadID; //Thread's ID q"269W:  
boolean bDownOver = false; //Downing is over |zRrGQY m  
boolean bStop = false; //Stop identical BuvnY  
FileAccessI fileAccessI = null; //File Access interface ~"*W;|)  
~APS_iG[  
,OrrGwp&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A#`$#CO  
{ e6*,MnqBh  
this.sURL = sURL; |Fx *,91  
this.nStartPos = nStart; xm=Gt$>.o  
this.nEndPos = nEnd; sw9ri}oc  
nThreadID = id; 6lpJ+A57#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mdbi@ms@  
} BJ_"FG  
InL_JobE8r  
%4R1rUrgt|  
public void run() IPTFx )]G  
{ `#ff`j|a  
while(nStartPos < nEndPos && !bStop) jBEW("4R  
{ GsO(\hR6^  
Z6b]EcP)#  
D\;5{,:d  
try{ g'!"klS93  
URL url = new URL(sURL); N*[b 26  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XlXt,  
httpConnection.setRequestProperty("User-Agent","NetFox"); Pc?"H!Hkn  
String sProperty = "bytes="+nStartPos+"-"; t!xdKX& }  
httpConnection.setRequestProperty("RANGE",sProperty); 4YY!oDN:  
Utility.log(sProperty); CY':'aWfa<  
X   
Y4N7# 5  
InputStream input = httpConnection.getInputStream(); 60n>FQ<  
//logResponseHead(httpConnection); 2WLLI8  
nWc@ufY  
e KuF7Oo  
byte[] b = new byte[1024]; 3zmbx~| =\  
int nRead; $[Ut])4 ~  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .p Mwa  
{ :W>PKW`^  
nStartPos += fileAccessI.write(b,0,nRead); =i}lh}(  
//if(nThreadID == 1) 8,F|*YA  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Aua}.Fl,  
} GwA\>qXw  
CL`+\ .  
T++q.oFc  
Utility.log("Thread " + nThreadID + " is over!"); '5Kj "aD%  
bDownOver = true; /V cbT >=  
//nPos = fileAccessI.write (b,0,nRead); 3_9CREZCl  
} FzSL[S4i  
catch(Exception e){e.printStackTrace ();} Oc,HnyV+  
} OVxg9  
} 0$b4\.0>~  
UlNiH  
<5Ll<0  
//打印回应的头信息 s1sn,?  
public void logResponseHead(HttpURLConnection con) 7}Mnv WP  
{ ;xUo(^t7>  
for(int i=1;;i++) `<P:l y.  
{ FjizPg/|!  
String header=con.getHeaderFieldKey(i); >S0kiGDV{  
if(header!=null) /oJ &\pI  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 86cnEj=   
Utility.log(header+" : "+con.getHeaderField(header)); L%3Bp/`S  
else M/lC&F(  
break; @+~>utr  
} y$di_)&g  
} eB_r.R{  
+*`kJ)uP  
K;Hgq4  
public void splitterStop() 1R yE8DdP  
{ gH,Pz  
bStop = true; h 2JmRO  
} =z"8#_3A  
t_16icF9U  
PJ&L7   
} $0OOH4  
jAcKSx$}y"  
+e.w]\}  
/* gMZ+kP`  
**FileAccess.java {jwLVKT$  
*//文件访问(定位,写) x)N QRd  
package NetFox; VR1[-OE  
import java.io.*; ? F!c"+C  
&w`DF,k|  
Sp?e!`|8  
public class FileAccessI implements Serializable{ 0WKS  
RL\?i~'KH  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <}'=@a  
RandomAccessFile oSavedFile; L<iRqayn  
long nPos; {_Ll'S  
G9am}qr  
oD9L5c)  
public FileAccessI() throws IOException A n`*![  
{ x@/:{B   
this("",0); F#) bGi  
} ~#P]NWW%.  
fI<d&5&g  
3O Ks?i3A  
public FileAccessI(String sName,long nPos) throws IOException %,<Ki]F  
{ -&]!ig5v  
oSavedFile = new RandomAccessFile(sName,"rw");   !\BM  
this.nPos = nPos; '3sySsD&O  
oSavedFile.seek(nPos); %I!2dXNFRF  
} vGPsjxk&  
#639N9a~  
dS <*DP  
public synchronized int write(byte[] b,int nStart,int nLen) d+5~^\lV  
{ kw#-\RR_c  
int n = -1; d:^B2~j  
try{ _/%,cYVc8!  
oSavedFile.write(b,nStart,nLen); eV(9I v[  
n = nLen; 0b n%L~KU  
} GP %hf{  
catch(IOException e) |#SZd Xg  
{ v@M^ukk'}  
e.printStackTrace (); /K1cP>oE  
} h7T),UL  
`F&~SU,  
u,d5/`E  
return n; )u=W?5%=}  
} y5O &9Ckw  
79d(UG'O  
XpE847!soL  
} Suo$wZ7J  
}P{Wk7#Jq  
<Q- m &  
/* ;y1/b(t  
**SiteInfoBean.java yf8kBT:&S  
*/ "8cI]~ V  
package NetFox; &|RTLGwX  
vlEW{B;)Z  
7:b.c  
public class SiteInfoBean { eMFxdtH  
{ %]imf|g.  
|KS,k|).  
private String sSiteURL; //Site's URL U-m MKRV  
private String sFilePath; //Saved File's Path ,5ZQPICF  
private String sFileName; //Saved File's Name =8<~pr-NO  
private int nSplitter; //Count of Splited Downloading File 0jjtx'F  
%+Z*-iX  
iI7ocyUv  
public SiteInfoBean() h4F%lGot  
{//nSplitter的缺省值为5 3/Z>W|w#w  
//default value of nSplitter is 5 ez*QP|F*9  
this("","","",5); t:vBVDkD  
} Sx e6&  
Qs59IZ  
!d!u{1Y&  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pPo xx"y  
{ cgQ6b.  
sSiteURL= sURL; Myiv#rQ)  
sFilePath = sPath; 66" 6>  
sFileName = sName; 8,!Oup  
this.nSplitter = nSpiltter; qz (x  
:|niFK4  
|Rhqi  
} ~ ) w4Tq  
i 61k  
,J!$Q0e  
public String getSSiteURL() ,R<9yEWm  
{ IVxZ.5:L$  
return sSiteURL; 1TGRIe)  
} *0eU_*A^zO  
ty pbwfM]  
>X05f#c"v/  
public void setSSiteURL(String value) p e+h8  
{ GbL1<P$V  
sSiteURL = value; 9jEH"`qqk  
} h3 XS t  
0*rD'?)K+  
b"N!#&O]  
public String getSFilePath() M~|7gK.m1  
{ /9I/^i~  
return sFilePath; PS[ C!s&KE  
} }58MDpOF1  
8j3Y&m4^  
NM![WvtjW  
public void setSFilePath(String value) zB`woI28  
{ ?&~q^t?u  
sFilePath = value; xSK#ovH2  
} W [K.|8ho  
Xw!\,"{s  
*pS 7,Hm  
public String getSFileName() \P?X`]NwnO  
{ ]FTi2B{}H  
return sFileName; IY#:v%U  
} 9N}\>L)_  
5Q"w{ n  
{o)pwM"@(  
public void setSFileName(String value) ^9q#,6  
{ g;8 wP5i  
sFileName = value; _J W|3q  
} er)I".|  
Xzf,S;XV~  
0zq'Nf?#3  
public int getNSplitter() S\&3t}_  
{ `;;l {8  
return nSplitter; %g.cE}^  
} uy3<2L#.  
wAprksZL#  
&gY) x{  
public void setNSplitter(int nCount) L8PX SJ  
{ tMiIlf!>p  
nSplitter = nCount; Ls9NQy  
} cpltTJFg  
} @q/g%-WNz  
Q[7i  
`/P/2{,~  
/* Wa<<"x$  
**Utility.java i!?gga  
*/ ~,HFd`  
package NetFox; iT4*~(p 3  
6- i.*!I 8  
'YNdrvz  
public class Utility { 4F~^RR"  
=W.}&  
D'#Q`H  
public Utility() 1I9v`eT4  
{ @9gZH_ur>E  
^}d]O(  
&P|[YP37_  
} x [FLV8`b|  
<s'de$[  
//线程睡眠 !-f Bw  
public static void sleep(int nSecond) *n? 1C"l  
{ {G:y?q'z  
try{ &oS$<  
Thread.sleep(nSecond); _]>1(8_N  
} FI$:R  
catch(Exception e) 'RK"/ZhqE  
{ PX 8UVA  
e.printStackTrace (); r<e%;S  
} 5XZ! yYB?  
} @%R<3!3v  
'+cI W(F?  
//日志 y~ =H`PAE  
public static void log(String sMsg) `um,S  
{ ^hC'\09=c  
System.err.println(sMsg); 2nd n8_l  
} \j>7x  
37/n"\4  
?0VR2Yb${b  
public static void log(int sMsg) yJm"vN  
{ aKbmj  
System.err.println(sMsg); %T{]l;5  
} }Q/onB t  
} AC) M2;  
jV3PTU  
=^nb+}Nz(  
/* _95296  
**TestMethod.java DYD<?._I  
*/  .w9LJ  
package NetFox; ^"/^)Lb!@M  
&N|$G8\CY  
Iry$z^  
public class TestMethod { 9B: 3Ha=  
+T+@g8S  
O<gfZ>  
public TestMethod() k&]nF,f  
{ ///xx/weblogic60b2_win.exe Z',!LK!  
try{ Ma[EgG  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {3tzr;c?  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9Eyx Ob  
SiteFileFetch fileFetch = new SiteFileFetch(bean); L[ G O6l  
fileFetch.start(); ??rS h Mu  
} 0mY Y:?v  
catch(Exception e){e.printStackTrace ();} 5AYOM=O]t  
'YNaLZ20  
=Ph8&l7~sp  
} x *eU~e_jP  
,fVD`RR(W?  
11[lc2  
public static void main(String[] args) HGDrH   
{ l90mM'[  
new TestMethod(); o\IMYT  
} 'ZfgCu)St  
} Ey46JO"  
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