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http断点续传简单实现(java)

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/* I ]ZksC  
**SiteFileFetch.java M 4E|^p=5  
*/ :sX4hZK =G  
package NetFox; "_0sW3rG  
import java.io.*; yZ-Ql1 1  
import java.net.*; K BlJJH`z{  
7q&T2?GEN  
zeshM8=  
public class SiteFileFetch extends Thread { #Xk/<It  
1* ?XI  
g;~$xXn  
SiteInfoBean siteInfoBean = null; //文件信息Bean GdM|?u&s"  
long[] nStartPos; //开始位置 KK?R|1VK9  
long[] nEndPos; //结束位置 _"t"orD6  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 =5O&4G`}  
long nFileLength; //文件长度 JLGC'mbJ  
boolean bFirst = true; //是否第一次取文件 vt#&YXu{A  
boolean bStop = false; //停止标志 FI@kE19  
File tmpFile; //文件下载的临时信息 W[LQ$uj  
DataOutputStream output; //输出到文件的输出流 'soll[J  
8iPA^b|sz{  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Jq:Wt+a  
public SiteFileFetch(SiteInfoBean bean) throws IOException !KtP> `8  
{ s( :N>K5*  
siteInfoBean = bean; ~ Ofn&[G  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 8CUl |I ~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); D1V^DbUm_  
if(tmpFile.exists ()) n){u!z)Al  
{ x|*m ok  
bFirst = false; #[]B: n6  
read_nPos(); &<Fw  
} ),@m 3wQ  
else &r!jjT  
{ _z@_.%P\  
nStartPos = new long[bean.getNSplitter()]; l]L"Ex{  
nEndPos = new long[bean.getNSplitter()]; ^V"08  
} brdY97s4  
K7ZRj\(CJv  
6n^vG/.M  
|~+bbN|b  
} NkxW*w%}l  
KkSv2 3In  
-yMD9b  
public void run() A/OGF>  
{ )gG_K$08?  
//获得文件长度 7G%^8 ce{!  
//分割文件 qJK6S4O]  
//实例FileSplitterFetch %.s"l6 W  
//启动FileSplitterFetch线程 +L pMNnl6  
//等待子线程返回 `8D'r|=`Eh  
try{ Vah.tOU  
if(bFirst) w"!zLB&9[  
{ QKh vP>  
nFileLength = getFileSize(); -V52?Hq  
if(nFileLength == -1) xKXD`-|W  
{ !I Byv%m&\  
System.err.println("File Length is not known!"); Y~ Nt9L  
} b\+9#)Up@  
else if(nFileLength == -2) Ekz)Nh)vGR  
{ JjG>$z  
System.err.println("File is not access!"); 6S?*z `v  
} #+;0=6+SM  
else gX]'RBTb  
{ :2MHx}]il  
for(int i=0;i<nStartPos.length;i++) !qJ|`o Y  
{ r%II` i  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); sX]ru^F3  
} &uxwz@RC0  
for(int i=0;i<nEndPos.length-1;i++) mTZgvPJ!  
{ \E,Fe:/g  
nEndPos = nStartPos[i+1]; ^/jALA9!  
} ipJnNy;  
nEndPos[nEndPos.length-1] = nFileLength; H_7X%TvXb  
} si|b>R&Z  
} 3EX41)u  
G8F43!<  
O\zGN/!  
//启动子线程 4vf,RjB-5  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b{lkl?@a  
for(int i=0;i<nStartPos.length;i++) df!n.&\y!  
{ AME6Zu3Y  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qGKQrb,K  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S-)%#  
nStartPos,nEndPos,i); x2H?B` 5  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x0x/2re  
fileSplitterFetch.start(); &B>YiA  
} 3}X;WE `  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )6Qk|gIu(  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OcGHMGdn  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4) ~ GHb  
nEndPos = " + nFileLength); X8=s k  
// fileSplitterFetch[nPos.length-1].start(); -( +/u .  
& l NHNu[  
XxEKv=_bc  
//等待子线程结束 6z80Y*|eJ  
//int count = 0; 3re|=_ Hy  
//是否结束while循环 '74-rL:i  
boolean breakWhile = false; N5:muh \  
y~pJ|E  
_<1uO=km6  
while(!bStop) ^gD%#3>X  
{ B?)=d,E  
write_nPos(); 4`#3p@-  
Utility.sleep(500); E>3fk  
breakWhile = true; &r Lg/UEV-  
ONw;NaE,  
*PJg~F%  
for(int i=0;i<nStartPos.length;i++) '@<aS?@!t  
{ T5+iX`#M  
if(!fileSplitterFetch.bDownOver) yPqZ ,  
{ P7i G,i  
breakWhile = false; (S[" ak  
break; $}G03G@  
} <H)I06];  
} )m Uc !TP  
if(breakWhile) F! ;0eS"xp  
break; U ExK|t  
6T5nr  
 `9  
//count++; 1&@s2ee4   
//if(count>4) 9\]%N;;Lo  
// siteStop(); <([1(SY2e  
} |NcfR"[c  
jK^'s6i#  
\=yx~c_$L  
System.err.println("文件下载结束!"); D$RQD{*  
} {1y-*@yU(  
catch(Exception e){e.printStackTrace ();} !v2D 18(  
} IZ;%lV7t  
FSqS]6b3  
U. 1Vpfy  
//获得文件长度 Ny>tJ~I  
public long getFileSize() T/" 6iv\1  
{ ~5HI9A4^  
int nFileLength = -1; c D+IMlT  
try{ rZDlPp>BPZ  
URL url = new URL(siteInfoBean.getSSiteURL()); c%aY6dQG&%  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dE+xU(\, w  
httpConnection.setRequestProperty("User-Agent","NetFox"); 05\A7.iy  
)j40hrR  
;K:)R_H  
int responseCode=httpConnection.getResponseCode(); ~h] <E  
if(responseCode>=400) g(\FG  
{ pC2r{-  
processErrorCode(responseCode); \d0R&vFHQ  
return -2; //-2 represent access is error 6=kA  
}  t]Xdzy  
i6zfr|`@  
%v\0Dm+A  
String sHeader; Vc3tKuMsiX  
;f7(d\=y  
M$z.S0"  
for(int i=1;;i++) wj/\ !V!  
{ cjU*  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m<wng2`NTv  
//Utility.log(in.readLine()); d_&R>GmR$  
sHeader=httpConnection.getHeaderFieldKey(i); *r)/.rK_  
if(sHeader!=null) u{'bd;.7  
{ B~cQl  
if(sHeader.equals("Content-Length")) #J]u3*T n|  
{ ?5nF` [rx  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^o]ZDc  
break; 7z"xjA  
} 1Fn+nDn O6  
} Z&%#,0>]  
else >C~-*M9  
break; }\`MXh's  
} `'[u%UE  
} p6]4YGw*^  
catch(IOException e){e.printStackTrace ();} o~,dkV  
catch(Exception e){e.printStackTrace ();} 5C/W_H+9iK  
A1:<-TF6^p  
etj8M y6=  
Utility.log(nFileLength); U7.3`qd"  
<Brq7:n|  
5Ya TE<G  
return nFileLength; ]S4kWq{Y  
} V2cLwQ'0  
v`MCV29!}  
}s=D,_}m  
//保存下载信息(文件指针位置) ]'=]=o~4  
private void write_nPos() j`A%(()d  
{ }<o.VY&;.  
try{ m(E-?VMHo  
output = new DataOutputStream(new FileOutputStream(tmpFile)); s_ -G`xT>{  
output.writeInt(nStartPos.length); 1+RG@Cp  
for(int i=0;i<nStartPos.length;i++) |ul25/B B  
{ 5BCXI8Ox9x  
// output.writeLong(nPos); cj@Ygc)n  
output.writeLong(fileSplitterFetch.nStartPos); *SQ hXTn  
output.writeLong(fileSplitterFetch.nEndPos); Cfu]umZLn  
} Oemi}  
output.close(); 6Yebc_, R  
} k/YEUC5  
catch(IOException e){e.printStackTrace ();} r k;k:<c  
catch(Exception e){e.printStackTrace ();} Vm6G5QwM  
} 9(DS"fgC  
a:Js i=  
W"+*%x  
//读取保存的下载信息(文件指针位置) Mib(J+Il  
private void read_nPos() [!p>Id  
{ TaeN?jc5  
try{ 5*u0VabC<  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XRCiv  
int nCount = input.readInt(); " l vPge  
nStartPos = new long[nCount]; L5! aLv#  
nEndPos = new long[nCount]; Y&KI/]ly,L  
for(int i=0;i<nStartPos.length;i++) }YWLXxb;  
{ 0Lmq?D  
nStartPos = input.readLong(); "2q}G16K  
nEndPos = input.readLong(); &{NN!X  
} g-"@%ps  
input.close(); x zu)``?  
} VV O C-:  
catch(IOException e){e.printStackTrace ();} P:vAU8d>  
catch(Exception e){e.printStackTrace ();} {/G~HoY1i  
} )WavG1  
13wO6tS k  
<QFT>#@T  
private void processErrorCode(int nErrorCode) +<7~yZ[Z8  
{  u)PB@  
System.err.println("Error Code : " + nErrorCode); &^Q-:Kxs8  
} >%5Ld`c:SD  
awh<CmcZ  
9HrT>{@  
//停止文件下载 ;X,|I)  
public void siteStop() /]m5HW(P7K  
{ S0\QZ/je  
bStop = true; U8qb2'a8  
for(int i=0;i<nStartPos.length;i++) U;u@\E@2  
fileSplitterFetch.splitterStop(); ~kPHf_B;z  
]W39HL  
$q,2VH:Ip  
} -qaJ@T+J+7  
} 5H#f;L\k  
//负责部分文件的抓取 *Z\B9mx  
**FileSplitterFetch.java } M-^A{C\%  
*/ .1<QB{4~v  
package NetFox; P}hHx<L  
t=o2:p6&  
&7_xr.c7  
import java.io.*; / r6^]grg  
import java.net.*; #&<>|m  
<y[LdB/a  
4\ R2\  
public class FileSplitterFetch extends Thread { -l)vl<}  
[Ak L6  
!m8MyZ}%  
String sURL; //File URL 4H'\nsM  
long nStartPos; //File Snippet Start Position x9Um4!/t  
long nEndPos; //File Snippet End Position l#u$w&  
int nThreadID; //Thread's ID xa#;<8 iV  
boolean bDownOver = false; //Downing is over EYWRTh  
boolean bStop = false; //Stop identical y,'M3GGl  
FileAccessI fileAccessI = null; //File Access interface vYb.Ub+  
D*.U?  
0Cd )w4C  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?e( y/  
{ K",YAfJa  
this.sURL = sURL; &iR3]FNI  
this.nStartPos = nStart; :}(Aq;}X  
this.nEndPos = nEnd; :_9MS0  
nThreadID = id; 8h"Val|qP  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 U4;r.#qw,  
} APY^A6^:j  
QS(aA*D  
;PM(q<@\  
public void run() -Uj)6PzGu  
{ ?5'EP|<  
while(nStartPos < nEndPos && !bStop) lz1RAp0R "  
{ "LZQ1P*ef$  
Bv-|#sdxm  
I!sh+e  
try{ } )D E  
URL url = new URL(sURL); UF37|+"E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b7-M'-Km0_  
httpConnection.setRequestProperty("User-Agent","NetFox");  ;;>hWAS  
String sProperty = "bytes="+nStartPos+"-"; rywui10x*  
httpConnection.setRequestProperty("RANGE",sProperty); pUbf]3 t  
Utility.log(sProperty); L_4c~4  
; '6`hZ  
9~3;upWu!  
InputStream input = httpConnection.getInputStream(); O_=2{k~s0  
//logResponseHead(httpConnection); K9-;-{qb  
/`6Y-8e2  
u NmbR8Mx  
byte[] b = new byte[1024]; Ub[SUeBGH  
int nRead; 7\(m n$  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hwb+@'o  
{ aE aU_f /  
nStartPos += fileAccessI.write(b,0,nRead); VZveNz@]r  
//if(nThreadID == 1) zD}@QoB  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X=C*PWa7  
} ?XCFR t,ol  
\e)>]C}h  
gR5 EK$  
Utility.log("Thread " + nThreadID + " is over!"); jGm`Qg{<  
bDownOver = true; ky4 ;7RK  
//nPos = fileAccessI.write (b,0,nRead); `G/%U~  
} aMv?D(Meb  
catch(Exception e){e.printStackTrace ();} 2fqg,_  
} Q]h.{nN#PK  
} 8M6 Xd]{%  
M~/Pk7CC  
b"4'*<=au  
//打印回应的头信息 '%Fg+cZN\  
public void logResponseHead(HttpURLConnection con) t+9[ki  
{ FZFYwU\~.L  
for(int i=1;;i++) QK~44;LVIJ  
{ FS'|e?WU  
String header=con.getHeaderFieldKey(i); 8-#_xsZ^;  
if(header!=null) ov3FKMG?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PI G3kJ  
Utility.log(header+" : "+con.getHeaderField(header)); g2 RrBK,  
else z6'Cz}%EP'  
break; 3#\++h]QZ  
} s+m3&(X  
} Ga<Uvr%+  
Ow" e3]}Mt  
srbES6  
public void splitterStop() hZZ  
{ 5S9i>B  
bStop = true; kh4., \'  
} e:9s%|]T  
fk*I}pDx  
KIRCye  
} H|\@[:A+  
F o k%  
1  b&<De  
/* [,bra8f[C  
**FileAccess.java ;OMR5KAz  
*//文件访问(定位,写) @GVONluyU`  
package NetFox; CE5A^,EsB  
import java.io.*; UWXl c  
02 $d  
)k^y<lC2a  
public class FileAccessI implements Serializable{ A4~- {.w=  
|l-~,eRvi5  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8(zE^W,[8"  
RandomAccessFile oSavedFile; zi^?9n),  
long nPos; d6+$[4w  
2RbK##`vC  
WrHY'  
public FileAccessI() throws IOException L*6R5i>  
{ WEaG/)y  
this("",0); 1fH2obI~X  
} 8@ZZ[9kt  
T)Y{>wT  
oNEjlV*  
public FileAccessI(String sName,long nPos) throws IOException <da-iY\5  
{ u<['9U  
oSavedFile = new RandomAccessFile(sName,"rw"); " "@kBY1C  
this.nPos = nPos; \<aR^Sj.  
oSavedFile.seek(nPos); <rihi:4K  
} {Mpx33  
~dBx<  
%f?Z/Wn  
public synchronized int write(byte[] b,int nStart,int nLen) 3<x1s2U  
{ $2E&~W %  
int n = -1; 9,?7mgZ p  
try{ un F=";9H  
oSavedFile.write(b,nStart,nLen); bu8AOtY9E-  
n = nLen; Z35(f0b  
} 12VSzIm  
catch(IOException e) S[;d\Z]~  
{ }`pxs  
e.printStackTrace (); oh0*bh  
} /:;"rnvq  
L9$`zc  
[xdi.6 %  
return n; |}o6N5)  
} cx ~XG  
~@\sN+VS  
|SfCuV#g/<  
} 7_Op(C4,nC  
.3'U(U  
#|"M  
/* (zX75QSKV  
**SiteInfoBean.java *!.anbo@?z  
*/ 8|{d1dy  
package NetFox; r i/CLq^D  
dw>1Ut{"3  
@~QI3)=s  
public class SiteInfoBean { ?j;,:n   
~f:"Q(f+  
+>ld  
private String sSiteURL; //Site's URL {%oxzdPc  
private String sFilePath; //Saved File's Path D JZ$M  
private String sFileName; //Saved File's Name sOO_J!bblP  
private int nSplitter; //Count of Splited Downloading File Aw]kQ\P&  
yNhRh>l  
e-Z ul.m  
public SiteInfoBean() @R_ON"h  
{//nSplitter的缺省值为5 .(7m[-iF!  
//default value of nSplitter is 5 +a"f)4\  
this("","","",5); *zwo="WA\t  
} aH_0EBRc  
+i~kqiy.  
T0{X,  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aH dQi,=z  
{ h0?w V5H  
sSiteURL= sURL; |=:<[FU  
sFilePath = sPath; 9&bJ]  
sFileName = sName; C~IE_E&Q`  
this.nSplitter = nSpiltter; NM"5.   
s6QD^[  
P*]hXm85[K  
} A">R-1R  
P]O=K  
&I:ZJuQ4  
public String getSSiteURL() OtbPr F5  
{ ^fQa whub  
return sSiteURL; uD?Rs`  
} F1t+D)KA>  
)O2IEwPd.  
#||D,[ _=+  
public void setSSiteURL(String value) Jflm-Hhsf  
{ J |w%n5Y  
sSiteURL = value; +{#L,0t  
} g2?yT ?  
hEFOT]P4  
26;Gt8  
public String getSFilePath() {rwT4]4  
{ F!fsW9  
return sFilePath; BV6B:=E0  
} $*:g~#bh  
N@Q_5t0bk  
a2[rY  
public void setSFilePath(String value) >Q=Q%~  
{ P;eXUF+jn  
sFilePath = value; B1A:}#  
} T!I3.  
+KaVvf  
g4y& 6!g  
public String getSFileName() I_ AFHrj  
{ (*_lLM@Cd  
return sFileName; LJ K0WWch  
} ,M~> t7+  
_'4S1  
}kF?9w  
public void setSFileName(String value) k?rJGc G  
{ ]:;dJc'  
sFileName = value; \XO'7bNu-  
} &;sW4jnt  
~6K.5t7  
R9(Yi<CC  
public int getNSplitter() ^]D+H9Tl  
{ Sx8C<S5r<  
return nSplitter; MxH |yo[  
} !b=W>5h  
*^w}SE(  
Ss0I{0  
public void setNSplitter(int nCount) fv@<  
{ /=T:W*C  
nSplitter = nCount; 7xFZJ#  
} lwz\" 8  
} a;v4R[lQ  
F+ 7*SImv6  
$fB j}\o  
/* M~n./wyC  
**Utility.java 1rS8+!9C  
*/ $ U7#3-'  
package NetFox; nEPTTp+B  
*U}ztH-+/  
zkiwFEHA=  
public class Utility { !??g:2  
K9]zUe&#w  
 fZ&' _  
public Utility() &8Z .m,s]  
{ E *IP#:R  
=ZO lE|4  
]1pB7XL  
} 1w,34*-}  
AF8:bk,R  
//线程睡眠 eco&!R[G  
public static void sleep(int nSecond) >q0%yh-  
{ IA{W-RRb  
try{ 6B*#D.fd*  
Thread.sleep(nSecond); Ndmw/ae  
} T"aE]4_  
catch(Exception e) mYj)![  
{ u:f.;?  
e.printStackTrace (); i]s%tEZ1  
} Y%?*Lj|  
} bdY:-8!3  
nt+OaXe5D  
//日志 (,tu7u{  
public static void log(String sMsg) m=+x9gL2  
{ 1;DRcVyS+  
System.err.println(sMsg); V#b=mp  
} @OGG]0 J  
fUGappb  
Zxhbnl6  
public static void log(int sMsg) YaL:6[6  
{ OScqf]H  
System.err.println(sMsg); s2GF*{  
} (KwC,0p  
} =Xg/[J%  
0:>hK\F#  
X:I2wJDs\  
/*  jr_z ?  
**TestMethod.java f0j]!g  
*/ "*.N'J\  
package NetFox; }r!+wp   
t=xEUOQAn  
qTN%9!0@9  
public class TestMethod { 9(nq 4 HvI  
cs ?WE9N  
1_#;+S  
public TestMethod() E1tCY.N{  
{ ///xx/weblogic60b2_win.exe dq`{fqGl  
try{ 8e3eQ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K!.t}s.t  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P tLWFO  
SiteFileFetch fileFetch = new SiteFileFetch(bean); AFm9"mQrw  
fileFetch.start(); Kvo&_:  
} 1^2Q`~,g  
catch(Exception e){e.printStackTrace ();} <nN.$4~X  
5OtdB'UITd  
 oC*a;o  
} #{{p4/:  
u '/)l}  
Nh_\{ &r  
public static void main(String[] args) > *VvV/UU  
{ ]wdE :k,D  
new TestMethod(); y`j=(|DV  
} zSQy  
} } `r.fD  
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