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http断点续传简单实现(java)

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/* `b#/[3  
**SiteFileFetch.java XO0>t{G  
*/  dhZ Zb  
package NetFox; CdDH1[J  
import java.io.*; ^eT@!N  
import java.net.*; JOJh,8C) 6  
1$);V,DK!  
c/b%T  
public class SiteFileFetch extends Thread { r|l53I 5  
u/_Gq[Q,u  
ri#,ec|J  
SiteInfoBean siteInfoBean = null; //文件信息Bean XIqv {w  
long[] nStartPos; //开始位置 MJ1W*'9</W  
long[] nEndPos; //结束位置 ==nYe { 2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 wu;7NatHx  
long nFileLength; //文件长度 SrdE>fNbs  
boolean bFirst = true; //是否第一次取文件 qo6 1O\qm  
boolean bStop = false; //停止标志 N )'8o}E  
File tmpFile; //文件下载的临时信息 I0I_vu  
DataOutputStream output; //输出到文件的输出流 D}mo\  
F='Xj@&O  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) CKx\V+\O  
public SiteFileFetch(SiteInfoBean bean) throws IOException 4Y`! bT`  
{ c=jcvDQ6W  
siteInfoBean = bean; NR ;q`Xe-  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); '&N: S-  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 2_Pz^L  
if(tmpFile.exists ()) ^a086n  
{ !O~}, pp  
bFirst = false; GEhdk]<a7  
read_nPos(); axWM|Bw<+  
} mG>T`c|r3  
else o,g6JTh  
{ h~,x7]w6  
nStartPos = new long[bean.getNSplitter()]; }/_('q@s\  
nEndPos = new long[bean.getNSplitter()]; g!p+rq_f  
} sVE>=0TVP  
Tq9,c#}&  
#x, ]D  
)WaX2uDA?  
} _u#/u2<  
Qe7" Z  
pZc9q8j3  
public void run() R"m.&%n  
{ 7YMxr3F  
//获得文件长度 imo'(j7  
//分割文件  qJsQb  
//实例FileSplitterFetch .Q l;(Wyl  
//启动FileSplitterFetch线程 `K$:r4/[  
//等待子线程返回 )3k)2XF  
try{ /Lq;w'|I  
if(bFirst) x%b]e a  
{ U,oD44  
nFileLength = getFileSize(); 4aj[5fhb-  
if(nFileLength == -1) t9-_a5>E\}  
{ NFdJb\  
System.err.println("File Length is not known!"); &z./4X  
} z2rQ$O -#  
else if(nFileLength == -2) )fxo)GS  
{ 1i5 vW-'4  
System.err.println("File is not access!"); D /,|pC  
} tfi2y]{A  
else |M[v493\  
{ @).WIs  
for(int i=0;i<nStartPos.length;i++)  JA }S{  
{ ph Wc 8[Q  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); :GN)7|:  
} ~|X99?P  
for(int i=0;i<nEndPos.length-1;i++) ODM>Z8@W/  
{ 9)G:::8u7  
nEndPos = nStartPos[i+1]; ,$hQ(yF  
} SlH7-"Ag  
nEndPos[nEndPos.length-1] = nFileLength; ,2=UuW"K  
} ,m #@%fa  
} ;s}-X_O<  
x(C]O,  
>xxXPvM<`  
//启动子线程 0!3!?E <  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Da9*/  
for(int i=0;i<nStartPos.length;i++) <wIp$F.  
{ 6LSPPMM  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \_iH4<#>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7VEt4  
nStartPos,nEndPos,i); Ig40#pA  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yrxx+z|wR  
fileSplitterFetch.start(); 0hH Iz4(  
} m _t(rn~f6  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |_Naun=+~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o'x_g^ Y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nr 'YWW  
nEndPos = " + nFileLength); |YG)NO  
// fileSplitterFetch[nPos.length-1].start(); "wc`fg"3  
[15hci+-  
b&hF')_UOz  
//等待子线程结束 UiGUaBmF*  
//int count = 0; ~G|{q VO7A  
//是否结束while循环 '^P*F9  
boolean breakWhile = false; Y\Fuj)  
c]cO[T_gGa  
M]8eW  
while(!bStop) j8D$/  
{ z1}tC\9'%  
write_nPos(); GI'&g@?u  
Utility.sleep(500); F1Zk9%L%9$  
breakWhile = true; 4fU5RB7%  
1s^$oi}  
D{&+7C:8.  
for(int i=0;i<nStartPos.length;i++) L!G9O]WB  
{ ^>P@5gcoE(  
if(!fileSplitterFetch.bDownOver) -r6(=A  
{ Ep v3/ `I  
breakWhile = false; <.y^  
break; oKMg7 3*  
} |-cALQ  
} IdQwLt  
if(breakWhile) NO0[`jy(  
break; EmBfiuX  
f:)K  
D6pEQdX`  
//count++; i?P]}JENM  
//if(count>4) Z3u""oM/  
// siteStop(); H|(*$!~e  
} Y/:Q|HnXQ  
Bv |jo&0n  
K|Ij71  
System.err.println("文件下载结束!"); *y[~kWI  
} \8C*O{w  
catch(Exception e){e.printStackTrace ();} ]0/~6f  
} +Qb2LR  
\fQgiX  
1W6n[Xg  
//获得文件长度 r*  
public long getFileSize() sDh6 Uk  
{ %_i0go,^  
int nFileLength = -1; hQW#a]]V:  
try{ x.yb4i=Jq  
URL url = new URL(siteInfoBean.getSSiteURL()); `rOe5Zp$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;M(ehX  
httpConnection.setRequestProperty("User-Agent","NetFox"); $48[!QE  
i,U-H\p&  
Y GcY2p<  
int responseCode=httpConnection.getResponseCode(); !513rNO  
if(responseCode>=400) tM?I()Y&P  
{ FdK R{dX}  
processErrorCode(responseCode); RIVN>G[;L  
return -2; //-2 represent access is error e[py J.  
} 5qODS_Eq  
D$^7Xhk  
!&`7  
String sHeader; L>R!A3G1  
-7A!2mRiz  
(WU~e!}  
for(int i=1;;i++) 5kL#V  
{ qLktMp_  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KG./<"c  
//Utility.log(in.readLine()); Y;F,GxR}  
sHeader=httpConnection.getHeaderFieldKey(i); >5z`SZf  
if(sHeader!=null) G%x,t -  
{ K+aJ`V  
if(sHeader.equals("Content-Length")) Q*{H]  
{ -iZjs  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J~ gkGso  
break; *dn-,Q%`  
} 8aM% 9OU  
} e715)_HD  
else 66y,{t  
break; W} +6L|  
} oY#XWe8Om  
} (UiH3Q9C]%  
catch(IOException e){e.printStackTrace ();} g5TLX &Bd  
catch(Exception e){e.printStackTrace ();} dT-O8  
C(Ba r#  
@5nkI$>3z  
Utility.log(nFileLength); q~A|R   
uS+b* :  
fqp7a1qQl  
return nFileLength; (V |q\XS  
} 0BU:(o&  
*~aI>7H  
CI ]U)@\U  
//保存下载信息(文件指针位置) AXv3jH,HF  
private void write_nPos() qcoZ2VJ hh  
{ Z( clw  
try{ N`mC_)  
output = new DataOutputStream(new FileOutputStream(tmpFile)); =P+wp{?AN|  
output.writeInt(nStartPos.length); cH8H)55F  
for(int i=0;i<nStartPos.length;i++) 0eu$ oel-  
{ =GS_ G;Dz  
// output.writeLong(nPos); 74!JPOpQH  
output.writeLong(fileSplitterFetch.nStartPos); uX 5B>32  
output.writeLong(fileSplitterFetch.nEndPos);  x+j/v5  
} 5D@Q1   
output.close(); Q?'W >^*J  
} &I">{J<  
catch(IOException e){e.printStackTrace ();} oGjYCVc  
catch(Exception e){e.printStackTrace ();} Y&Nv>o_}5  
} Z-r0 D  
gZuR4Ti  
N pIlQaMo4  
//读取保存的下载信息(文件指针位置) F u=VY{U4  
private void read_nPos() i3\oy`GJ  
{ G}OrpPP  
try{ ZCq\Zk1O&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mgl' d  
int nCount = input.readInt(); 'k) P(H  
nStartPos = new long[nCount]; 6Yi,%#  
nEndPos = new long[nCount]; ZkG##Jp\>  
for(int i=0;i<nStartPos.length;i++) 4 w  
{ SodW5v a  
nStartPos = input.readLong(); ToCfLJ?{  
nEndPos = input.readLong(); YH6 K-}  
} m3ZOq B-  
input.close(); 91'^--N  
} zCN;LpbEJY  
catch(IOException e){e.printStackTrace ();} NomK(%8m$  
catch(Exception e){e.printStackTrace ();} x-P_}}K 79  
} ~1z8G>R  
NxRiEe#m  
1JY90l$ME  
private void processErrorCode(int nErrorCode) t5[JN:an  
{ J-,X0v"  
System.err.println("Error Code : " + nErrorCode); J!qEj{  
} @o.i2iG  
.oOt(K +  
}LVE^6zyk  
//停止文件下载 WxI]Fcb<  
public void siteStop() I Q`aDo-V  
{ m<;" 1<k  
bStop = true; o`]FH _  
for(int i=0;i<nStartPos.length;i++) +Gs;3jC^  
fileSplitterFetch.splitterStop(); H0:6zSsc=|  
Kd21:|!t^  
h!3Z%M  
}  0>J4O:k  
} 8TM=AV  
//负责部分文件的抓取 K*D]\/;^  
**FileSplitterFetch.java ^,r;/c9A8  
*/ NWX%0PGZ  
package NetFox; R3 =E?us!  
%Y[/Ucdm  
DD3yl\#,  
import java.io.*; Fgq*3t  
import java.net.*; 8U$UI  
~w% +y  
w9}IM149  
public class FileSplitterFetch extends Thread { W..>Ny;'3  
3m9 E2R,  
.}opmI  
String sURL; //File URL h*'5h!  
long nStartPos; //File Snippet Start Position 2]KPW*V  
long nEndPos; //File Snippet End Position 0To 5|r  
int nThreadID; //Thread's ID v2<gkCK^  
boolean bDownOver = false; //Downing is over MO+0]uh:  
boolean bStop = false; //Stop identical Ft>8 YYyU  
FileAccessI fileAccessI = null; //File Access interface l"g%vS,;`  
;qQzF  
 D -EM  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f)fw87UPc  
{ eesLTy D2_  
this.sURL = sURL; yr DYw T  
this.nStartPos = nStart; |W[rywxx  
this.nEndPos = nEnd; J@-9{<  
nThreadID = id; tG&B D\  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a,\u|T:g  
} ;Q 6e&Ips/  
p#NZ\qJ  
ZSf+5{2m  
public void run() *38\&"s4_  
{ /v<8x?=  
while(nStartPos < nEndPos && !bStop) 2,`mNjHh  
{ ;hp; Rd  
7hE=+V8  
Jk{2!uP  
try{ U}TQXYAg  
URL url = new URL(sURL); wYM{x!D  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p =O1aM  
httpConnection.setRequestProperty("User-Agent","NetFox"); NX/)Z&Fx:  
String sProperty = "bytes="+nStartPos+"-"; D~);:}}>  
httpConnection.setRequestProperty("RANGE",sProperty); "Vy\- ^  
Utility.log(sProperty); P_%l}%   
u>@G:kt8  
%gB0D8,vo  
InputStream input = httpConnection.getInputStream(); 'S>Jps@  
//logResponseHead(httpConnection); _JB3+0@  
Qk?Jy<Ra  
=v;@w$#  
byte[] b = new byte[1024]; 9&jNdB  
int nRead; 3mpjSL  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _3JTHf<+  
{ W{2y*yqY  
nStartPos += fileAccessI.write(b,0,nRead); .w"O/6."  
//if(nThreadID == 1) M6n.uho/  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DSa92:M}  
} Z 0^d o  
s_ $@N!  
VNfx>&`  
Utility.log("Thread " + nThreadID + " is over!"); }7^*%$  
bDownOver = true; j R:Fih-}  
//nPos = fileAccessI.write (b,0,nRead); (CwaO m{g  
} 6FAP *V;  
catch(Exception e){e.printStackTrace ();} /zAx`H  
} \|s/_35(  
} `UPmr50Wq  
; #  
B 8,{jwB  
//打印回应的头信息 4,8 =[  
public void logResponseHead(HttpURLConnection con) j'cS_R  
{ 1NJ|%+I  
for(int i=1;;i++) 'JVvL  
{ 3 Q;l*xu  
String header=con.getHeaderFieldKey(i); T!r7RS  
if(header!=null) T9yW# .  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %UhF=C  
Utility.log(header+" : "+con.getHeaderField(header)); G3n7x?4m  
else s"Wdbw(O'  
break; jiDYPYx;I  
} F[Up  
} m5*RB1  
6IH^rSUSK  
 su$juI{  
public void splitterStop() w0SgF/"@  
{ z9ZAY!Zhq]  
bStop = true; ;E_{Zji_e  
} -0Ek&"=Z^  
6cvm\ opH  
1:8: yFV  
} 9IMcp~zX  
e)8iPu ..  
bv0 %{u&  
/* I Cs1=  
**FileAccess.java vhW '2<(  
*//文件访问(定位,写) ?*0kQo'  
package NetFox; agzG  
import java.io.*; 7BnP,Nd"W  
kzT'  
a;sZNUSn  
public class FileAccessI implements Serializable{ =r2d{  
 ?auiq  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fy eS )  
RandomAccessFile oSavedFile; ]Ea6Z  
long nPos; .nN7*))Fj  
~%ZO8X:^  
%K4-V5f  
public FileAccessI() throws IOException iD~s,  
{ hb{(r@[WHv  
this("",0); kaLRI|hC  
} L.'N'-BV  
l/5/|UE9  
`N0E;=g  
public FileAccessI(String sName,long nPos) throws IOException ~cz t=  
{ DDEn63{  
oSavedFile = new RandomAccessFile(sName,"rw"); [iD!!{6+  
this.nPos = nPos; jn'8F$GU  
oSavedFile.seek(nPos); z&8#1'  
} ?.H*!u+9>  
j(rFORT  
53c6dl  
public synchronized int write(byte[] b,int nStart,int nLen) gQ[4{+DSf  
{ %WR  
int n = -1; %F7k| Na  
try{ Yp8$0KK  
oSavedFile.write(b,nStart,nLen); IM+PjYJ  
n = nLen; R!=XMV3$PH  
} >8##~ZuF+  
catch(IOException e) v3B ^d}+.  
{ ~H.;pJ{ 8  
e.printStackTrace (); \a#2Wm  
} 8I'?9rt2M  
bYz:gbs]4|  
!Kis,e  
return n; NNT9\JRv_  
} C^a~)r.h  
nz(OHh!}u  
;AaF;zPV  
} \n5,!,A  
8`D_"3j3g\  
[": x  
/* 1/ a,7Hl  
**SiteInfoBean.java mEGMe@37  
*/ .*Z]0~ &|  
package NetFox; .IqS}Rh  
nsPM`dz/  
{_Y\Y&#  
public class SiteInfoBean {  : 2?du  
c~V\,lcI  
mxIEg?r(  
private String sSiteURL; //Site's URL m{g{"=}YR  
private String sFilePath; //Saved File's Path yC -4wn*  
private String sFileName; //Saved File's Name C-M op,w  
private int nSplitter; //Count of Splited Downloading File 5)vXmAD/0  
l"+=z.l6;  
bvoR?D\-"  
public SiteInfoBean() xn-n{U"  
{//nSplitter的缺省值为5 #pZ3xa3R  
//default value of nSplitter is 5 8yd OS  
this("","","",5); 6l4l74  
} p(v.sP4w  
QAR<.zXvP  
(b(iL\B$D=  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MKbW^:  
{ \oi=fu=}*  
sSiteURL= sURL; *+ 7#z;  
sFilePath = sPath; ` p)#!  
sFileName = sName; 'F@'4[uda  
this.nSplitter = nSpiltter; Mqq7;w@(J  
6 R!0v8  
uB%`Bx'OW  
} # RtrHm  
=0Nd\  
'b-}KDP  
public String getSSiteURL() X0m\   
{ EfOJ%Xr[,l  
return sSiteURL; $+tkBM  
} rIXAn4,dTv  
@=$;^}JS|  
VL\6U05Z  
public void setSSiteURL(String value) | 2mEowAd  
{ |')Z;  
sSiteURL = value; z2r{AQ.&  
} kWgxswl7H  
[j5L}e!T  
Uu G;z5  
public String getSFilePath() :wIbKs.r  
{ mF "ctxE  
return sFilePath; ;&iQNXL  
} RsE+\)  
/vBpRm  
+Ta7b)  
public void setSFilePath(String value) 6%)dsTAB  
{ !4|7U\;  
sFilePath = value; 1:8ZS  
} "]sr4Jg=  
zgLm~  
P5[.2y_qM  
public String getSFileName() [ z?<'Tj  
{ o0AREZ+I  
return sFileName; r t f}4.  
} 291v R]  
<jxTI%'f59  
|S/nq_g]  
public void setSFileName(String value) =l {>-`:  
{ 5{{u #W%=  
sFileName = value; %KqXtc`O  
} `*WR[c  
u{HB5QqK  
4-s Uy  
public int getNSplitter() t; "o,T  
{ 'l2`05   
return nSplitter; 9Czc$fSSt  
} s I#K01;"  
cBU>/ zIp  
F$d`Umqs;P  
public void setNSplitter(int nCount) /']Gnt G.  
{ x6m21DWw  
nSplitter = nCount; kYx|`-PA<r  
} 0nBAO  
} zg[ksny  
d]CRvzW  
J3C"W7 94}  
/* -V(5U! ^B  
**Utility.java 3HWI;  
*/ E: #VS~  
package NetFox; 7,Nd[ oL*7  
k{uc%6s  
V0"UFy?i  
public class Utility { JWC{"6  
!YCYmxw#  
+[:}<^p?cG  
public Utility() ZVViu4]?y  
{ ^ *RmT  
q_JES4ofx  
Y8(g8RN  
} j`(o\Fd )  
N n+leM  
//线程睡眠 V*LpO 8=  
public static void sleep(int nSecond) rT <=`9^{  
{ }]kzj0m  
try{ {l! [{  
Thread.sleep(nSecond); H>k=V<  
} !DXKn\aQf  
catch(Exception e) D}Z].c@ E  
{ dYW19$W n  
e.printStackTrace (); qHklu2_%  
} I@e{>}  
} 5yuR[ VU  
njX!Ez  
//日志 [26"?};"%  
public static void log(String sMsg) YEQ}<\B\&  
{ [ q22?kT  
System.err.println(sMsg); y1B3F5  
} J1hc :I<;  
D>PB|rS@  
xrS;06$  
public static void log(int sMsg) x%5n&B  
{ )FYz*:f>&  
System.err.println(sMsg); NbSkauF~b  
} X^7bOFWE  
} zq8LQ4@ay  
[*Wq6n  
[PdatL2  
/* )lE]DG!  
**TestMethod.java `#E1FB2M  
*/ AKejWh  
package NetFox; {O[a +r.n  
N.l+9L0b  
7&qunK'  
public class TestMethod { KYZ/b8C  
]W]o6uo7  
NN>,dd3T  
public TestMethod() twq!@C  
{ ///xx/weblogic60b2_win.exe glm29hF  
try{ T32C=7  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =LC:1zn4  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q",n:=PL  
SiteFileFetch fileFetch = new SiteFileFetch(bean); lo5,E(7~h  
fileFetch.start(); $~75/  
} 'D;v>r  
catch(Exception e){e.printStackTrace ();} :dc>\kUIv  
Vr+X!DeY  
@Xts}(L  
} P{h;2b{  
Mpzt9*7R  
BRLrD/8Le  
public static void main(String[] args) cQ} ,q+GR~  
{ kl,I.2-  
new TestMethod(); `qbf_;\  
}  olB?"M=H  
} 5hF iK K7  
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