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http断点续传简单实现(java)

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/* AdCi*="m  
**SiteFileFetch.java #gHs!b-g@  
*/ tks3xS  
package NetFox; GpW5)a  
import java.io.*; Ru1I,QvCj"  
import java.net.*; ZO^Y9\L  
uTSTBI4t  
^CZ)!3qd1  
public class SiteFileFetch extends Thread { Iy2KOv@a5  
qQL]3qP  
ZO`{t1   
SiteInfoBean siteInfoBean = null; //文件信息Bean 3]*_*<D  
long[] nStartPos; //开始位置 I eQF+Xz  
long[] nEndPos; //结束位置 a0s6G3J+9  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 f/_RtOSw  
long nFileLength; //文件长度 6" s}<  
boolean bFirst = true; //是否第一次取文件 _~^JRC[q  
boolean bStop = false; //停止标志 A;pVi;7  
File tmpFile; //文件下载的临时信息 ujo3"j[b  
DataOutputStream output; //输出到文件的输出流 *1Q~/<W  
>o#5tNm  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) O{sb{kk  
public SiteFileFetch(SiteInfoBean bean) throws IOException yNw YP%"y  
{ eyx;8v cM  
siteInfoBean = bean; {5ujKQOcR  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $m.e}`7SF!  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); d[b(+sHp a  
if(tmpFile.exists ()) "R"7'sJMI  
{ 8z?q4  
bFirst = false; rUb`_W@  
read_nPos(); 4 Ar\`{c>  
} J9tQ@3{f  
else 0a#2 Lo  
{ LI>tN R~  
nStartPos = new long[bean.getNSplitter()]; rv(Qz|K@  
nEndPos = new long[bean.getNSplitter()]; 2{<5?Op  
} l P4A?J+Q  
CC(At.dd  
-SZW[T<N"  
F2;k6M@  
} s^ t1T&  
^Fy{Q*p`(  
EF7Y4lp  
public void run() rtl|zCst  
{ O23dtH  
//获得文件长度 ^%^~:<N  
//分割文件 RhJ{#G~:%  
//实例FileSplitterFetch `iX~cUQ  
//启动FileSplitterFetch线程 CM; r\,o  
//等待子线程返回 A4}6hG#  
try{ =:T pH>f*  
if(bFirst) 6cCC+*V{  
{ ^Vl{IsY  
nFileLength = getFileSize(); rKlu+/G  
if(nFileLength == -1) D ^ mfWJS  
{ X8TwMt  
System.err.println("File Length is not known!"); Ig&=(Kmr  
} 'USol<  
else if(nFileLength == -2) +doZnU,  
{ &zl=}xeA  
System.err.println("File is not access!"); PD @]2lY(  
} e8HGST`  
else MuzlUW]  
{ 1^G*)Qn5Df  
for(int i=0;i<nStartPos.length;i++) wnaT~r@U'  
{ aP}kl[W  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); YT)jBS~&  
} 5ua`5Hb;  
for(int i=0;i<nEndPos.length-1;i++) CzP?J36W^  
{ Cr?|bDv}o  
nEndPos = nStartPos[i+1]; $wL zaZL|  
} W^}fAcQKH  
nEndPos[nEndPos.length-1] = nFileLength; 0dv# [  
} 6,nws5dh  
} IMaa#8,  
5PY,}1`  
B}Q.Is5  
//启动子线程 jf_xm=n  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i%jti6z$Hr  
for(int i=0;i<nStartPos.length;i++) p 8,wr )  
{ ~x:\xQti  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sEpY&6*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m+y5Q&;f  
nStartPos,nEndPos,i); ~YQC!x  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9i hB;m'C)  
fileSplitterFetch.start(); ao2NwH##  
} oBfh1/< <a  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ElJM. a  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?`wO \>y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,BGaJ|k  
nEndPos = " + nFileLength); cg16|  
// fileSplitterFetch[nPos.length-1].start(); &L&6 y()G  
F` /mcyf  
H/qv%!/o  
//等待子线程结束 +n]z'pijb  
//int count = 0; }.j<kmd  
//是否结束while循环 drr W?U  
boolean breakWhile = false; e^;<T9Esr  
T(Q(7  
x+?P/Ckg  
while(!bStop) L>4!@L5)  
{ S;pKL,d>r  
write_nPos(); ^[]q/v'3m!  
Utility.sleep(500); ]: VR3e"H  
breakWhile = true; )U6-&-07  
"eqNd"~  
>_R,^iH"  
for(int i=0;i<nStartPos.length;i++) ="~yD[S  
{ j c%  
if(!fileSplitterFetch.bDownOver) \6]Uj+  
{ @xKfqKoqg  
breakWhile = false; 8G GC)2  
break; ,C4gA(')K  
} 9j[lr${A  
} nSMw5  
if(breakWhile) eSAB :L,K  
break; Bo)N<S_=^  
dm;C @.ML  
W3AtO  
//count++; w.AF7.X`1  
//if(count>4) puv/+!q  
// siteStop(); x{GKz#  
} rMV<}C ^  
k15fy"+Ut  
`E@TPdu  
System.err.println("文件下载结束!"); @ V_@r@A  
} .ty^k@J|]  
catch(Exception e){e.printStackTrace ();} **RW 9FU  
} ]]R!MnU:$  
khXp}p!Zm  
:6N'%LKK  
//获得文件长度 am+'j5`Ys  
public long getFileSize() D@-'<0=  
{ ~s$ jiA1  
int nFileLength = -1; !)!<. x  
try{ XIS.0]~  
URL url = new URL(siteInfoBean.getSSiteURL()); F9N/_H*+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KNI* :  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;usv/8  
f:w#r.]  
a>_Cxsb&`  
int responseCode=httpConnection.getResponseCode(); tf:4}6P1  
if(responseCode>=400) bVLuv`A/  
{ NWN Pq"  
processErrorCode(responseCode); J)148/  
return -2; //-2 represent access is error E~b Yk6  
} l^LYSZg'R8  
RyAss0Sm^  
K #f*LV5  
String sHeader; W-72&\7  
31FQ=(K  
BGe&c,feIc  
for(int i=1;;i++) [~%\:of70n  
{ r@|{mQOxa  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yjq~O~  
//Utility.log(in.readLine()); ^")SU(`  
sHeader=httpConnection.getHeaderFieldKey(i); )/B' ODa  
if(sHeader!=null) 9rd7l6$R"  
{ {I]X-+D|_  
if(sHeader.equals("Content-Length")) 7GyJmzEE  
{ L,KK{o|Eq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qjtrU#n  
break;  Z>O2  
} fw[Z7`\Q5  
} 88]UA  
else 0-N"_1k|?  
break; "b#L8kN  
} nc0!ag  
} !_ng_,J  
catch(IOException e){e.printStackTrace ();} @$e!|.{1q  
catch(Exception e){e.printStackTrace ();} 2a\?Q|1C  
Cq<a|t  
$_u9Y!  
Utility.log(nFileLength); App9um3:  
figCeJ!W4  
K<_bG<tm_  
return nFileLength; ]P5|V4FXo  
} T&/ ]|4  
LH" CIL2  
*[QFIDn:  
//保存下载信息(文件指针位置) h VQj$TA  
private void write_nPos() !:N&tuJEv  
{ 7FTf8  
try{ #cZ<[K q6  
output = new DataOutputStream(new FileOutputStream(tmpFile)); `L. kyL  
output.writeInt(nStartPos.length); [ q% Rx!L  
for(int i=0;i<nStartPos.length;i++) >@mvb@4*  
{ 7a<-}>sU  
// output.writeLong(nPos); k4AF .U`I  
output.writeLong(fileSplitterFetch.nStartPos); gXQ s)Eyv  
output.writeLong(fileSplitterFetch.nEndPos); w<0F-0:8  
} 9(CY"Tc3  
output.close(); BbV@ziL  
} o~(/Twxam  
catch(IOException e){e.printStackTrace ();} y9#r SA*  
catch(Exception e){e.printStackTrace ();} nKO4o8js{{  
} S 6|#9C&  
[s"e?Qee  
Jw b'5[R  
//读取保存的下载信息(文件指针位置) 3T|xUY)G4  
private void read_nPos() ?KKu1~a_  
{ v{T%`WuPRf  
try{ !qQ B}sAf  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?|`Ba-  
int nCount = input.readInt(); a9"1a'  
nStartPos = new long[nCount];  3 cb$g  
nEndPos = new long[nCount]; ?q %&"  
for(int i=0;i<nStartPos.length;i++) 3Aqw )B'"_  
{ X>$s>})Y  
nStartPos = input.readLong(); ^_Ap?zn  
nEndPos = input.readLong(); -fA1_ ?7S  
} ^tFbg+.  
input.close(); *MG*]\D  
} )qL UHE=  
catch(IOException e){e.printStackTrace ();} s[}4Q|s%  
catch(Exception e){e.printStackTrace ();} TGxmc37?  
} t 5{Y'  
N Qdz]o  
B}&9+2M  
private void processErrorCode(int nErrorCode) *wd@YMOP  
{ W|yF jE&dr  
System.err.println("Error Code : " + nErrorCode); xeGl}q|  
} "~|;XoMU  
Pcs62aE  
'WC> _ L  
//停止文件下载 WCpCWtmy  
public void siteStop() !gKz=-C  
{ !SxZN dv  
bStop = true; '20SoVp  
for(int i=0;i<nStartPos.length;i++) N"M?kk,  
fileSplitterFetch.splitterStop(); !VXs yH3r5  
xyvG+K&  
H ({Y  
} )}[:.Zg,3/  
} 2`ED?F68gH  
//负责部分文件的抓取 p#  4@  
**FileSplitterFetch.java n-5@<y^  
*/ n_qDg  
package NetFox; V|njgcn d  
}iZ>Gm '5  
KBO{ g:"  
import java.io.*; c@ea ;Cv  
import java.net.*; 4P(ysTuM  
[Dv6z t>  
D |lm,  
public class FileSplitterFetch extends Thread { Onqd2'%<  
&AS<2hB  
]\8{z"  
String sURL; //File URL KkF3E*q\H  
long nStartPos; //File Snippet Start Position `Qrrnq  
long nEndPos; //File Snippet End Position 2!y%nkO*  
int nThreadID; //Thread's ID -y+u0,=p.  
boolean bDownOver = false; //Downing is over UyWKE<  
boolean bStop = false; //Stop identical ENEnHu^  
FileAccessI fileAccessI = null; //File Access interface |9D;2N(&!  
"\:ZH[j  
F:P&hK  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qOi3`6LCV  
{ '~Z#h  P  
this.sURL = sURL; FV1!IE-}-  
this.nStartPos = nStart; 51Nh"JTy  
this.nEndPos = nEnd; Kr*s]O  
nThreadID = id; EA/+~ux  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2S{IZ]  
} ;44?`[oP  
qUMM}ls  
2Y+8!4^L a  
public void run() &7gE=E(M  
{ %L^S;v3  
while(nStartPos < nEndPos && !bStop) @rh1W$  
{ YnCWmlC  
X`QfOs#\  
ic+tn9f\  
try{ IIW6;jS  
URL url = new URL(sURL); S(5aJ[7Zm  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x!<?/I)X  
httpConnection.setRequestProperty("User-Agent","NetFox"); `T;M=S^y*E  
String sProperty = "bytes="+nStartPos+"-"; Hsoe?kUHF  
httpConnection.setRequestProperty("RANGE",sProperty); A^a9,T  
Utility.log(sProperty); @+S5"W  
<^Hh5kfS'  
gXR1nnK  
InputStream input = httpConnection.getInputStream(); <AzM~]"3  
//logResponseHead(httpConnection); r}gp{Pf7e  
8")1,   
Xu1tN9:oE  
byte[] b = new byte[1024]; $g|/.XH%  
int nRead; S"Q$ Ol"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T]5JsrT  
{ a*8^M\>m4  
nStartPos += fileAccessI.write(b,0,nRead); D\:~G}M  
//if(nThreadID == 1) Cu%|}xq  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N o}Ly{  
} d45JT?qg&  
=;1MpD  
8: KlU(J  
Utility.log("Thread " + nThreadID + " is over!"); 27;t,Oq}  
bDownOver = true; |<@X* #X5  
//nPos = fileAccessI.write (b,0,nRead); NA,)FmQjk  
} >F zu]G4]  
catch(Exception e){e.printStackTrace ();} >Ic)RPO9  
} (wNL,<%~  
} /lQGFLZL  
/&>6#3df-  
ZQHANr= 6  
//打印回应的头信息 ~CQYF,[Th  
public void logResponseHead(HttpURLConnection con) ?PIOuN=  
{ N'fE^jqU  
for(int i=1;;i++) %2<G3]6^U  
{ [Ng#/QXk{  
String header=con.getHeaderFieldKey(i); #^- U|~,  
if(header!=null) N1RZ  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r@3VN~  
Utility.log(header+" : "+con.getHeaderField(header)); -*sDa6L  
else uvK1gJrA)  
break; "8Ud&o  
} p;dH[NW  
} \e5bxc  
?~e 8:/@  
1/Pou)D  
public void splitterStop() @)>9l&  
{ /q4<ZS#  
bStop = true; Y~T;{&wi  
} ZJ9J*5!C  
[s-Km/  
CT@JNG$<"  
} [YY[E 7  
!3{> F"  
3_W1)vd{  
/* T`f6`1x  
**FileAccess.java ( w(GJ/g  
*//文件访问(定位,写) DFKU?#R  
package NetFox; {I|iUfy  
import java.io.*; >A#wvQl7   
`}ak;^Me  
+A 6xY  
public class FileAccessI implements Serializable{ `1F[.DdF  
=dD<[Iz6  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g&y'#,'Q~,  
RandomAccessFile oSavedFile; dUOvv/,FZT  
long nPos; l BS!=/7  
G\S\Qe{P~  
Yxye?R-:  
public FileAccessI() throws IOException utxT$1iJn~  
{ 6D,xs}j1  
this("",0); Ep/4o< N(  
} f} g)3+i  
a;J{'PHu  
!8^:19+  
public FileAccessI(String sName,long nPos) throws IOException ^GG6%=g'  
{ $ Scb8<  
oSavedFile = new RandomAccessFile(sName,"rw"); 4]jN@@  
this.nPos = nPos; 3!M;Z7qF]  
oSavedFile.seek(nPos); 0S <;T+WA  
} [Q &{#%M  
@O#4duM4Qz  
&K5wCNX1  
public synchronized int write(byte[] b,int nStart,int nLen) bE _=L=NG  
{ |?6r&bT  
int n = -1; vh3Xd\N  
try{ d?(#NP#;  
oSavedFile.write(b,nStart,nLen); pIdJ+gu(s  
n = nLen; (.a:jL$  
} 'NF_!D  
catch(IOException e) EotZ$O=  
{ :nYl]Rm  
e.printStackTrace (); `T2RaWR4=  
} i,NU%be  
} 5i0R  
L6yRN>5aE  
return n; |LA./%U  
} hM^#X,7  
!0:uM)_k  
Uj&2'>MJ$  
} !_rAAY  
U^SJWYi<Y  
vt}+d StUm  
/* bFk >IifN  
**SiteInfoBean.java So?SBh1C  
*/ yS0YWqv]6@  
package NetFox; Ub=g<MYHV  
;rWgt!l  
)O~LXK=b  
public class SiteInfoBean { F2!C^r,~L  
DK 4 8  
& .VciSq6  
private String sSiteURL; //Site's URL =!m5'$Uz>  
private String sFilePath; //Saved File's Path YG ,  
private String sFileName; //Saved File's Name :5hKE(3Q  
private int nSplitter; //Count of Splited Downloading File S05+G}[$  
`oP :F[B  
2= 'gC|&s6  
public SiteInfoBean() :4s{?IY)l  
{//nSplitter的缺省值为5 U<J4\|1?7'  
//default value of nSplitter is 5 y?j#;n0  
this("","","",5); ~*RG|4#  
} B}_*0D  
s^+h>  
I\E`xkbBu  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x!GHUz*:uz  
{ p\OUxAm  
sSiteURL= sURL; oLK-~[p  
sFilePath = sPath; $Kgw6  
sFileName = sName; PjZsMHW%  
this.nSplitter = nSpiltter; = TKu2  
Qa@b-v'by  
:U_k*9z}=  
} 8&?Kg>M  
*YmR7g|k  
Rd~-.&   
public String getSSiteURL() -N;$L~`iAt  
{ S]&f+g}&w  
return sSiteURL; P34UD:  
} 3D L7  
[4 L[.N@  
i]&C=X  
public void setSSiteURL(String value) uFQ;}k;}  
{ .CGPG,\2  
sSiteURL = value; dbM~41C6  
} =K'X:UM  
jp=z ^l  
+(n&>7 5  
public String getSFilePath() n{sF'n</  
{ )D'SfNx#{  
return sFilePath; -7E)u  
} l~P%mVC3m  
GaV6h|6_  
o2M+=O@  
public void setSFilePath(String value) Xc"l')1H  
{ "B`k  
sFilePath = value; |a9d]^  
} {*utke]}*  
3 RB+  
to9~l"n.s  
public String getSFileName() 'fpm] *ig  
{ ~[n]la  
return sFileName; [7x,&  
} C \"nlNKw  
2ZTz{|y  
7#/->Y  
public void setSFileName(String value) e4:,W+g,9  
{ s Dq{h  
sFileName = value; dy/\>hu  
} Zo$ ,{rl  
\dvzL(,  
pJ8;7u  
public int getNSplitter() yM* CA,(c  
{ WcRTv"4&  
return nSplitter; QuFzj`(  
} d^uE4F}  
_0HCtx ;  
z!`aJE/  
public void setNSplitter(int nCount) X}jWNN  
{ >O0z+tj  
nSplitter = nCount; 5e)2Jt:  
} 4pU|BL\j  
} !9 7U2L4  
VtM:~|v  
j&6O 1  
/* Mw{0A\6  
**Utility.java vP k\b 3E  
*/ tjONN(K`  
package NetFox; j%w}hGW%,  
=yT3#A~<G  
C1V:_-  
public class Utility { /NE<?t N  
}G{'Rb  
TNi4H:\  
public Utility() SynL%Y9)|,  
{ w_gFN%8  
@^q|C&j  
;i;2cq  
} ucP"<,a  
<H; z4  
//线程睡眠 `5SLo=~  
public static void sleep(int nSecond) i sK_t*  
{ fRcs@yZnS  
try{ f&=WgITa  
Thread.sleep(nSecond); -_%8Q#"  
} R=7,F6.  
catch(Exception e) v8{ jEAK  
{ eT!*_.' e  
e.printStackTrace (); v d{`*|x  
} &XvSAw+D@  
} to2#PXf]y  
'R-Ly^:Qd  
//日志 0\B31=N(  
public static void log(String sMsg) /JcfAY  
{ ,0pCc<  
System.err.println(sMsg); _ ^2\/@  
} HpXQ D;  
`/e EdqT  
pq T+lai)#  
public static void log(int sMsg) fen~k#|l  
{ DqH?:`G  
System.err.println(sMsg); `] fud{  
} $.5f-vQp  
} q HU}EEv  
Y^Y1re+}  
NMy+=GZu^  
/* `SfBT1#5G  
**TestMethod.java nt:d,H<p  
*/ ^ UDNp.6k  
package NetFox; t@#l0lu$  
Yk^clCB{A(  
&i5MRw_]]  
public class TestMethod { id?B<OM  
G~+BO'U9'G  
v'e5j``=  
public TestMethod() 6 3NhD  
{ ///xx/weblogic60b2_win.exe n OQvBc  
try{ m>:zwz< ;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $sxm MP  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,_iR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); T?4I\SG  
fileFetch.start(); LkwjEJQf  
} sX c|++  
catch(Exception e){e.printStackTrace ();} |19zjhl  
r7zS4;b  
=>m x>R`S  
} vU9j|z  
q(XO_1W0V  
 %>z)Q  
public static void main(String[] args) 05ZF>`g*  
{ Vb++K0CK  
new TestMethod(); +FBUB  
} 5*hA6Ex7  
} (/[wM>q:r  
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