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http断点续传简单实现(java)

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/*  :S %lv  
**SiteFileFetch.java {OMg d3%14  
*/ o,Z{ w"  
package NetFox; *iX e^<6v  
import java.io.*; B\`Aojw"E?  
import java.net.*; zzpZ19"`1  
^+70<#Xc  
" BTE  
public class SiteFileFetch extends Thread { 2-If]Fc  
]hw-Bu\{  
'{?C{MK3Q  
SiteInfoBean siteInfoBean = null; //文件信息Bean YhKZ|@  
long[] nStartPos; //开始位置  NY  
long[] nEndPos; //结束位置 MLVB^<qkeH  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 j#A%q"]8  
long nFileLength; //文件长度 US&B!Q:v  
boolean bFirst = true; //是否第一次取文件 3C>qh{z"  
boolean bStop = false; //停止标志 JHV)ZOO  
File tmpFile; //文件下载的临时信息 >O9 sk  
DataOutputStream output; //输出到文件的输出流 &rq{v!=7  
i\}:hU-U  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Xg<[fwW  
public SiteFileFetch(SiteInfoBean bean) throws IOException ~fN%WZ;_  
{ UV7%4xM5v  
siteInfoBean = bean; #} ,x @]p  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ~XM[>M\qB  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 8}p8r|d!ls  
if(tmpFile.exists ()) B;zt#H4  
{ - Xupq/[,  
bFirst = false; Rhgj&4  
read_nPos(); Ibr%d2yS=  
} 8Cf|*C+_'  
else ?2J?XS>  
{ 70W"G X&  
nStartPos = new long[bean.getNSplitter()]; t={0(  
nEndPos = new long[bean.getNSplitter()]; q%3<Juq~$  
} O mMX$YID  
~9o6 W",  
lPq\=V  
oY9FK{  
} U..<iNQE5  
[IX+M#mf  
f_mhD dq  
public void run() .QWhK|(.!  
{ L^Wz vv]  
//获得文件长度 &V=7D#L  
//分割文件 6 DF  
//实例FileSplitterFetch Nud,\mXrY[  
//启动FileSplitterFetch线程 mO rWJ~=  
//等待子线程返回 7 _jE[10  
try{ !AHAS  
if(bFirst) 6Z:YT&,f  
{ C0 ) Z6  
nFileLength = getFileSize(); *7gT}O;p 5  
if(nFileLength == -1) u:P~j  
{ GlYly5F  
System.err.println("File Length is not known!"); '?Bg;Z'L%  
} \{|ImCH  
else if(nFileLength == -2) x-m/SI]_N  
{ _2Py\+$  
System.err.println("File is not access!"); `^F: -  
} _2Zp1h,  
else |H)cuZ  
{ 7qIB7_K5  
for(int i=0;i<nStartPos.length;i++) '&yg {n  
{ O12Q8Oj!0  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); @"87F{!  
} *YV S|6bs  
for(int i=0;i<nEndPos.length-1;i++) 4cgIEw[6  
{ 0irr7Y  
nEndPos = nStartPos[i+1]; ROAI9sW0  
} 4*H"Z(HP  
nEndPos[nEndPos.length-1] = nFileLength; >%%=0!,yX  
} -$k>F#  
} xF8S*,#,*  
I}0_nge  
_9If/RD  
//启动子线程 j'rS&BI G  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m2bDHQ+  
for(int i=0;i<nStartPos.length;i++) ur%$aX)  
{ y;`eDS'0.N  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wz(K*FP  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'imU `zeo  
nStartPos,nEndPos,i); p]|LV)R n  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *o?i:LE]  
fileSplitterFetch.start(); Fz"ff4Bx [  
} f05d ;  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #gZ|T M/h  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~ 9M!)\~  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;IP~Tb]&  
nEndPos = " + nFileLength); [~%`N*G  
// fileSplitterFetch[nPos.length-1].start(); &w\ I<J`T  
yXfMzG  
o#hI5  
//等待子线程结束 KX+ey8@[  
//int count = 0; C7"HQQ  
//是否结束while循环 ?-~I<f ]_  
boolean breakWhile = false; DguB  
SG]K   
WStnzVe  
while(!bStop) T 1Cs>#)  
{ '1+.t$"/tU  
write_nPos(); "Ai6<:ml  
Utility.sleep(500); 1"E\C/c  
breakWhile = true; 7>.OVh<  
! q6hC  
`lCuU~~ag  
for(int i=0;i<nStartPos.length;i++) 4br6$  
{ U6j/BJT"  
if(!fileSplitterFetch.bDownOver) [#b2%G1  
{ v<h;Di@  
breakWhile = false; ;bjnL>eW  
break; NB)t7/Us  
} F? ]N8W  
} YMzBAf  
if(breakWhile) Go8F5a@j  
break; BQrL7y  
F @SG((`  
*@M3p}',M  
//count++; /6tcSg)  
//if(count>4) 3'#%c>_  
// siteStop(); 8 njuDl  
} aj7dH5SZl  
L(o#4YH}>J  
gA:TL{X0  
System.err.println("文件下载结束!"); bx;f`8SN  
} tbur$ 00  
catch(Exception e){e.printStackTrace ();} {*xBm#  
} VTw/_Hf2p  
~ =.CTm]vf  
$$gtZ{ukQ  
//获得文件长度 0s%6n5>  
public long getFileSize() SGf9U^ds  
{ P;U@y" s  
int nFileLength = -1; aqL<v94wX  
try{ YKx 1NC  
URL url = new URL(siteInfoBean.getSSiteURL()); Jt=>-Spj  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g9V.13k  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5' \)`  
Y3o Mh,  
n<R \w''x  
int responseCode=httpConnection.getResponseCode(); lX;mhJj!  
if(responseCode>=400) eE3-t/=  
{ /$`;r2LG  
processErrorCode(responseCode); h}6_ybmZ  
return -2; //-2 represent access is error +TX/g~  
} "iek,Y}j7  
>>V&yJ_  
> V%Q O>C  
String sHeader; h6QWH  
<94WZ?{p  
|5ONFd e"0  
for(int i=1;;i++) dU+0dZdKO  
{ &o.iUk  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); otq,R6 ^  
//Utility.log(in.readLine()); g!^J,e=  
sHeader=httpConnection.getHeaderFieldKey(i); In(NF#  
if(sHeader!=null) el*9 Ih  
{ ~3 @*7B5Q  
if(sHeader.equals("Content-Length")) Czu1)y  
{ *8-p7,D  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); otnV-7)@  
break; a<p %hY3  
} +Jq`$+%C  
} !; WbOnLP  
else 1n3$V:00  
break; ~e^)q>Lb7(  
} <%?uYCD  
} Bbs 0v6&,  
catch(IOException e){e.printStackTrace ();} !R{em48D  
catch(Exception e){e.printStackTrace ();} r$DZkMue  
aL)$b  
x5vzPh`  
Utility.log(nFileLength); A2_Ls;]  
EXHR(t}e  
,%8$D-4#_  
return nFileLength; x]' H jTqX  
} %!wq:~B1  
&;U|7l~vl  
.zwVCW,u  
//保存下载信息(文件指针位置) K+> V|zKuk  
private void write_nPos() a7 )@BzF#  
{ R0IF'  
try{ M,G8*HI"  
output = new DataOutputStream(new FileOutputStream(tmpFile));  T{Hf P  
output.writeInt(nStartPos.length); Oga1u  
for(int i=0;i<nStartPos.length;i++) G5u meqYC  
{ n)CH^WHL&  
// output.writeLong(nPos); Rp eBm#E2  
output.writeLong(fileSplitterFetch.nStartPos); 'FxYMSZS$  
output.writeLong(fileSplitterFetch.nEndPos); BvJ\x)  
} I}%mfojC  
output.close(); }K;iJ~kD1  
} L8D m9}  
catch(IOException e){e.printStackTrace ();} 3N3*`?5c<  
catch(Exception e){e.printStackTrace ();} kA,4$ 2_o  
} zKMv7;s?  
l#ygb|=x  
!PI0oh  
//读取保存的下载信息(文件指针位置) !qS05  
private void read_nPos() Cz[5Ug'V  
{ ~Jxlj(" 0(  
try{ B3 .X}ys#  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2%]t3\XW  
int nCount = input.readInt(); Xv&%2-V;  
nStartPos = new long[nCount]; Gl"wEL*  
nEndPos = new long[nCount]; QpJ IDM/  
for(int i=0;i<nStartPos.length;i++) #:I^&~:  
{ !p"Kd ~  
nStartPos = input.readLong(); (xQI($Wq*M  
nEndPos = input.readLong(); 2{gwY85:  
} 2D_6  
input.close(); ++gPv}:$X  
} ZR2\ dH*  
catch(IOException e){e.printStackTrace ();} -G!6U2*#  
catch(Exception e){e.printStackTrace ();} `|JI\&z  
} I*9Gb$]=  
K"I{\/x@  
D/*vj|  
private void processErrorCode(int nErrorCode) (I!1sE!?1  
{ s)Gb!-``  
System.err.println("Error Code : " + nErrorCode); 'N|2vbi<  
} C?(y2p`d\  
w4aiI2KFq  
qs "s/$  
//停止文件下载 6T]Q.\5BZ  
public void siteStop() ~Ji>[#W K  
{ WQTendS  
bStop = true; 63SVIc~wT  
for(int i=0;i<nStartPos.length;i++) L*IU0Jy>  
fileSplitterFetch.splitterStop(); +Bn?-{h=  
KG-UW  
k=FcPF"  
} pBvo M={2!  
} sq48#5Tc^r  
//负责部分文件的抓取 ~{9x6<g!  
**FileSplitterFetch.java '%:5axg?]  
*/ R rxRa[{Z  
package NetFox; ^|r`"gOJ3  
zQ=aey%  
[(!Q-8  
import java.io.*; Zr5'TZ`$  
import java.net.*; z 3Zu C{  
 L2k;f]  
Y'?Izn b  
public class FileSplitterFetch extends Thread { Y0rf9  
fo *!a$)  
D8a)(wm  
String sURL; //File URL 5#P: "U  
long nStartPos; //File Snippet Start Position 2"zIR (  
long nEndPos; //File Snippet End Position ^?#@[4?"  
int nThreadID; //Thread's ID ]y$)%J^T  
boolean bDownOver = false; //Downing is over [;Vi~$p|Eo  
boolean bStop = false; //Stop identical rT o%=0P  
FileAccessI fileAccessI = null; //File Access interface 1X Q87~  
E8+8{ #f;  
vsjM3=  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gp%tMT I1  
{ Q4#\{" N!  
this.sURL = sURL; |%n|[LP'  
this.nStartPos = nStart; 3SmqXPOw  
this.nEndPos = nEnd; sek6+#|=  
nThreadID = id; h!ZZ2[  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ER/\ +Z#Z  
} d"z *Nb  
B6-AIPb  
gq=0L:  
public void run() Ni&,g  
{ Dy98[cL  
while(nStartPos < nEndPos && !bStop) \]Kq(k[p  
{ }'%$7vL`Ft  
UnJi& ~O  
Ua}g  
try{ //VG1@vaVX  
URL url = new URL(sURL); #@IQlqJfY7  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n (9F:N  
httpConnection.setRequestProperty("User-Agent","NetFox"); _P>1`IR  
String sProperty = "bytes="+nStartPos+"-"; l)|z2 H  
httpConnection.setRequestProperty("RANGE",sProperty); $hC~af6  
Utility.log(sProperty); W=q?tD~V  
7l[t9ON  
4U_rB9K$  
InputStream input = httpConnection.getInputStream(); o-~-F+mj#  
//logResponseHead(httpConnection); }ZxW"5oq  
jc3ExOH  
|L*6x S[  
byte[] b = new byte[1024]; rD_Ss.\^g  
int nRead; 7$;c6_se  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JiG8jB7%}  
{ =B1`R%t  
nStartPos += fileAccessI.write(b,0,nRead); T@2f&Un^  
//if(nThreadID == 1) /M5=tW#e  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "#[o?_GaJ  
} h]G6~TYI5  
3 t~X:  
avF&F  
Utility.log("Thread " + nThreadID + " is over!"); xKRfl1  
bDownOver = true; ZKVp[A  
//nPos = fileAccessI.write (b,0,nRead); [I#Q  
} b=6ZdN1  
catch(Exception e){e.printStackTrace ();} f J,8g/f8  
} *C,$W\6sz  
} 1Al=v  
:DF`A(  
;Of?fe5:  
//打印回应的头信息 Q&\ZC?y4  
public void logResponseHead(HttpURLConnection con) Tom}sFl][  
{ GA({ri  
for(int i=1;;i++) 0b!fWS?,k0  
{ \Qe'?LRu{  
String header=con.getHeaderFieldKey(i); x'VeL|  
if(header!=null) r%O rH-T  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cj,&&3sbV  
Utility.log(header+" : "+con.getHeaderField(header)); K*hf(w9="%  
else XyN`BDFi  
break; _p3WE9T  
} cx,u2~43A&  
} ,i1fv "  
%a%+!wX0x  
 M}_M_  
public void splitterStop() C={sE*&dYX  
{ ^v()iF !  
bStop = true; \J#I}-a&j  
} ^/4 {\3  
dA3`b*nC  
/jn:e"0~  
} J-HabHv  
G5C#i7cpm  
oW` *FD  
/* B)LXxdkOn  
**FileAccess.java #RsIxpc  
*//文件访问(定位,写) PDa06(t7  
package NetFox; @5uyUSt]  
import java.io.*; 7]0\[9DyJ  
"'LOaf$X  
~}FLn9@*  
public class FileAccessI implements Serializable{ lUm}nsp=X  
lW@:q04Z$  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #==[RNM%ap  
RandomAccessFile oSavedFile; JJ= ~o@|c  
long nPos; 7ipY*DT8  
5wVi{P5+  
dvH67 x  
public FileAccessI() throws IOException {ILQ CvP*  
{ aG8;,H=%,  
this("",0); cfF-e93T  
} o F,R@f  
|$i1]Dr6  
dRarNW  
public FileAccessI(String sName,long nPos) throws IOException `\}zm~  
{ zjhR9  
oSavedFile = new RandomAccessFile(sName,"rw"); 8I|1P l  
this.nPos = nPos; ]MBJ"1F  
oSavedFile.seek(nPos); TO8\4p*tE  
} P7^TRrMF  
iz$v8;w  
~=aI2(b  
public synchronized int write(byte[] b,int nStart,int nLen) s;=J'x)~%  
{ G=0}IPfp  
int n = -1; n Y.Umj  
try{ pNk,jeo  
oSavedFile.write(b,nStart,nLen); ^U|CNB%.  
n = nLen; ^Ypb"Wx8  
} |Cxip&e>  
catch(IOException e) +=lcN~U2  
{ Y=#mx3.  
e.printStackTrace (); L>K39z~,  
} n$Oky-P"  
d%"@#bB  
{yl/T:Bh&  
return n; `~s,W.Eu4  
} =Am*$wGI  
7xa@wa?!L  
>H]|A<9u(  
} g#bfY=C  
5<>R dLo  
b&_u O  
/* jmwQc&  
**SiteInfoBean.java .>\>F{#~  
*/ 0V>N#P]  
package NetFox; T3PaG\5B  
/m|&nl8"qe  
[sh"?  
public class SiteInfoBean { znDtM1sLeV  
-n$rKEC4  
y*TNJJ|  
private String sSiteURL; //Site's URL .$T:n[@  
private String sFilePath; //Saved File's Path Yk*57&QI  
private String sFileName; //Saved File's Name 0OoO cc  
private int nSplitter; //Count of Splited Downloading File DG%%]  
=Z$=-\<x0.  
kA9 X!)2w  
public SiteInfoBean() \Q BpgMi(  
{//nSplitter的缺省值为5 g{f>j d  
//default value of nSplitter is 5 [OToz~=)  
this("","","",5); HZ`G)1&)  
} qS`|=5f  
F(kRAe;  
 26klW:2*  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "vHAp55B{  
{ W Y qL  
sSiteURL= sURL; M`,Z#)Af  
sFilePath = sPath; 3Tte8]0  
sFileName = sName; #p:jKAc3  
this.nSplitter = nSpiltter; 1Z{p[\k  
%emPSBf@  
4m~stDlN  
} bT6)(lm  
)*AA9   
x;b+gIz*  
public String getSSiteURL() f4;8?  
{ 7XI4=O};&%  
return sSiteURL; 5@r Zm4U  
} fbbl92p  
EG:WE^4  
| 3/p8  
public void setSSiteURL(String value) Bv|9{:1%X}  
{ !-}*jm p<  
sSiteURL = value; UK9MWC5g9  
} o[+|n[aT)3  
V5^b6$R@  
:FgRe,D  
public String getSFilePath() ,0u0 '  
{ R~?;KJ  
return sFilePath; vrEaNT$J-  
} oL/^[TXjH  
XjM)/-w  
X;a{JjN  
public void setSFilePath(String value) A2FU}Ym0=  
{ uEO2,1+  
sFilePath = value; 2n r UE  
} H_r'q9@<>  
ZN]c>w[ )I  
4 ~|TKd{  
public String getSFileName() .6A:t? .  
{ Pj5#G0i%  
return sFileName; w0`L)f5v  
} Pw0KQUs  
hb\Y)HSp/  
(dprY1noC  
public void setSFileName(String value) ;77o%J'l  
{ .BB:7+  
sFileName = value; :[rKSA]@  
} #$^i x  
8`?j*FV7kq  
&1C9K>  
public int getNSplitter() 7CN[Z9Y^}  
{ ZUI\0qh+  
return nSplitter; QKkr~?sTO  
} p?NjxQLA  
L/+J|_J)  
,^Srd20  
public void setNSplitter(int nCount) J7] 60H#P  
{ s7.*o@G  
nSplitter = nCount; ; SM^  
} 1 3az [  
} YD.^\E4o  
:|mkI#P.  
:pu{3-n.  
/* 4gNRln-  
**Utility.java tLXw&hFk`g  
*/ 4'=N{.TtO  
package NetFox; \uPTk)oaB  
>o= p5#{  
EQhV}9  
public class Utility { #C7j|9Ew1]  
3^UsyZS)  
P&^7wud-sb  
public Utility() e[dRHl  
{ aM}"DY-_ h  
F|K4zhK  
A)\DPLAG  
} `5&V}"lB  
[1MEA;  
//线程睡眠 ! HC<aWb  
public static void sleep(int nSecond) Y-{BY5E.  
{ Czxrn2p/  
try{ cY]Y8T)  
Thread.sleep(nSecond); q,&T$Tw  
} Y--8v#t  
catch(Exception e) kw}1CXD  
{ 4^^rOi0  
e.printStackTrace (); jch8d(`?d  
} eV%bJkt.  
} Y6PA\7Y\  
xJGeIh5  
//日志 s@iCfXU  
public static void log(String sMsg) nv{4 U}&P  
{ k|C8sSH  
System.err.println(sMsg); 5z>\'a1U  
} R u-rp^a  
jdf@lb=5l  
y ]%,Y=%X  
public static void log(int sMsg) cN>i3}fq  
{ =Q/>g6  
System.err.println(sMsg); I*2rS_i[T  
} #L$ I %L"  
} xB+H7Ya  
[wG%@0\  
ljON_*  
/* hyoZh Y  
**TestMethod.java =lD]sk  
*/ 34:EpZO@  
package NetFox; 0M98y!A 5^  
a $%[!vF  
loe>"_`Cq  
public class TestMethod { lM"7 Z  
c `; LF'!  
d~8~RT2m  
public TestMethod()  RZ%X1$  
{ ///xx/weblogic60b2_win.exe A$6b=2hc>  
try{ PlUjjJU  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mkA|gM[g7  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7#3)&"j  
SiteFileFetch fileFetch = new SiteFileFetch(bean); D:EF@il  
fileFetch.start(); V~Lq, oth  
} sR .j~R  
catch(Exception e){e.printStackTrace ();} Uroj%xN  
aB'@8[]z  
(=/;rJ`q  
} MT0{hsuK9  
R*m" '|U  
= h( n+y<  
public static void main(String[] args) Ti'kn{ Zv  
{ Y sV  
new TestMethod(); D.`\ ^a  
} <DS6-y  
} N2e<Y_T  
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