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http断点续传简单实现(java)

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/* -  -G1H  
**SiteFileFetch.java =Wf@'~K0k"  
*/ `T70FsSJ  
package NetFox; Q-F9oZ*0  
import java.io.*; "7HB3?2>W  
import java.net.*; G DV-wPX  
L9T u>4  
{9Y'v  
public class SiteFileFetch extends Thread { `9ox?|iJ  
$<v_Vm?6d  
K288&D|1WU  
SiteInfoBean siteInfoBean = null; //文件信息Bean :~(im_r  
long[] nStartPos; //开始位置 0REWbcxd"  
long[] nEndPos; //结束位置 K>[H@|k\k  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 e@OA>  
long nFileLength; //文件长度 lQ/XJw  
boolean bFirst = true; //是否第一次取文件 `y}d)"!  
boolean bStop = false; //停止标志 kgz{m;R  
File tmpFile; //文件下载的临时信息 G)&'8W F5o  
DataOutputStream output; //输出到文件的输出流 ]lUu%<-;  
o(P:f)B  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) RY{tX`  
public SiteFileFetch(SiteInfoBean bean) throws IOException =FmU]DV  
{ `xUPML-  
siteInfoBean = bean; %'e(3;YI  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Y9;Mey*oW  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); (5~C _Y  
if(tmpFile.exists ()) B$l`9!,  
{ 9#<Og>t2y  
bFirst = false; 5-^%\?,x  
read_nPos(); j;)g+9`  
} R(sM(x5a`  
else 0?SLRz8  
{ $hSZ@w|IF  
nStartPos = new long[bean.getNSplitter()]; :2E1aVo4b  
nEndPos = new long[bean.getNSplitter()]; k`TJ<Dv;  
} (GG"'bYk  
ImY.HB^&  
FE}!bKh  
KeB4Pae|V  
} _m],(J=,z  
bSf(DSqx  
Zjg\jo  
public void run() 1v&Fo2ML  
{ sg{D ?zl  
//获得文件长度 :OCux Sc%5  
//分割文件 n#Roz5/U  
//实例FileSplitterFetch (:QQ7xc{}  
//启动FileSplitterFetch线程 aLi_Hrb9  
//等待子线程返回 <im<(=m9  
try{ vLuQe0l{  
if(bFirst) /y)"j#-eW  
{ A[kH_{to;  
nFileLength = getFileSize(); jJZsBOW[8  
if(nFileLength == -1) 8%<`$`FyU  
{ fm%RNAPvc  
System.err.println("File Length is not known!"); SFk#bh  
} Jv <$AI  
else if(nFileLength == -2) N?;o_^C  
{ U@MP&sdL  
System.err.println("File is not access!"); k-V I9H!,  
} ulf/C%t,R  
else iIaT1i4t.  
{ R:<@+z^A[  
for(int i=0;i<nStartPos.length;i++) _-]!;0E IV  
{ 4|N\Q=,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); YM`pNtQ  
}  p &>A5  
for(int i=0;i<nEndPos.length-1;i++) /;AZ/Ocy!  
{ 1G%PXrEj8  
nEndPos = nStartPos[i+1]; l&*)r;9  
} y?n2`l7f  
nEndPos[nEndPos.length-1] = nFileLength; UMuuf6  
} EWIc|b:  
} kLt9; <L  
;#s}b1  
2BDan^:-Av  
//启动子线程 Wi[m`#  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :z.Y$]F@  
for(int i=0;i<nStartPos.length;i++) drKjLo[y  
{ 9xn23*Fo  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S tnv>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :KSor}t  
nStartPos,nEndPos,i); vo ;F;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t-i6FS-  
fileSplitterFetch.start(); ]<T8ZA_Y;  
} Jh4&Qh|t  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3;MjO*-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xDJ+BQ<1A  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l(#ke  
nEndPos = " + nFileLength); yW^IN8fm  
// fileSplitterFetch[nPos.length-1].start(); IT`=\K/[4  
^qO=~U!{  
!UoU#YU  
//等待子线程结束 /;&+ < }  
//int count = 0; 8ts+'65|F  
//是否结束while循环 vA"niO  
boolean breakWhile = false; c5E#QV0&v~  
E0 eQ9BXh  
RO{@RhnV  
while(!bStop) iv:/g|MBI&  
{ a4( ?]ND~6  
write_nPos(); ]}[Yf  
Utility.sleep(500); kAN;S<jSE  
breakWhile = true; eR-=<0Iw;  
y[p$/$bgC5  
q{cp|#m#G  
for(int i=0;i<nStartPos.length;i++) {HHh.K  
{ r1oku0o  
if(!fileSplitterFetch.bDownOver) ]hE +$sKd  
{ .S!>9X,  
breakWhile = false; 5m^Hi} S _  
break; a-5HIY5  
} "f|(@a  
} >u5g?yzw  
if(breakWhile) AB"1(PbG  
break; 'DzBp  
8.CKH4h  
~#"7,rQp  
//count++; aLKMDiT  
//if(count>4) v0`qMBr1y  
// siteStop(); #_?TIY:h  
} 'sRg4?PT  
3G%wZ,)C  
qA/#IUi)1  
System.err.println("文件下载结束!"); mT6q}``vtG  
} /e|[SITe  
catch(Exception e){e.printStackTrace ();} Jf?S9r5Q  
} Er"R;l]xJ  
U.RW4df%E  
lMBX!9z  
//获得文件长度 \ I^nx+l  
public long getFileSize() W""*hJ  
{  O[IR|  
int nFileLength = -1; 4r1<,{gCS  
try{ NTm<6Is`  
URL url = new URL(siteInfoBean.getSSiteURL()); RQ^m6)BTo  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CYtjY~  
httpConnection.setRequestProperty("User-Agent","NetFox"); | "Jx  
j?\$G.Y  
gT(th9'+z  
int responseCode=httpConnection.getResponseCode(); d $fvg8^  
if(responseCode>=400) "($Lx  
{ 9jO`gWxV8*  
processErrorCode(responseCode); &_9YLXtMi;  
return -2; //-2 represent access is error 4[TS4p  
} VyecTU"W  
C5es2!^-]O  
"H>r-cyh  
String sHeader; 894r;UA7  
q Vm"f,ruo  
4D^ M<Xn  
for(int i=1;;i++) =`qRu  
{ #%? FM>  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -uA3Y  
//Utility.log(in.readLine()); Z}8k[*.  
sHeader=httpConnection.getHeaderFieldKey(i); ]By0Xifew  
if(sHeader!=null) |*^8~u3J"  
{ uW}Hvj;0a*  
if(sHeader.equals("Content-Length")) M=5d95*-}  
{ =U4f}W;  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &|Lh38s@$#  
break; #puQi  
} ih>a~U<  
} Z+Yeg  
else (9mbF%b  
break; VK2@2`$  
} :`0'GM" `  
} l`@0zw+  
catch(IOException e){e.printStackTrace ();} oL<BLr9>  
catch(Exception e){e.printStackTrace ();} 3ty4D2y  
k"">2#V  
"7=bL7wM&  
Utility.log(nFileLength); ;asm 0H(  
MV:W@)rg  
w4\BD&7V  
return nFileLength; P<%v +O  
} -xJX_6}A  
Ci~f#{  
tm(v~L%$>]  
//保存下载信息(文件指针位置) JY{X,?s  
private void write_nPos() tg~A}1o`0  
{ 7\IL  
try{ C,o:  
output = new DataOutputStream(new FileOutputStream(tmpFile)); VmN}FMGN  
output.writeInt(nStartPos.length); DH5bpg&T  
for(int i=0;i<nStartPos.length;i++) b,#`n  
{ 8y$5oD6g9  
// output.writeLong(nPos); m</]D WJ  
output.writeLong(fileSplitterFetch.nStartPos); }>2t&+v+  
output.writeLong(fileSplitterFetch.nEndPos); gaQ[3g  
} NW z9C=y  
output.close(); N 0+hejz  
} b -PSm=`  
catch(IOException e){e.printStackTrace ();} D=$4/D:;  
catch(Exception e){e.printStackTrace ();} kMM'[w  
} jcE Msc  
'KH lrmnr  
.iFViVZC  
//读取保存的下载信息(文件指针位置) ^6Yd}  
private void read_nPos() ~gP7s_ qr{  
{ qQ^d9EK'?~  
try{ swt tp`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]k[x9,IU\y  
int nCount = input.readInt(); E W`W~h[  
nStartPos = new long[nCount]; jDR')ascn  
nEndPos = new long[nCount]; P{?;T5ap6  
for(int i=0;i<nStartPos.length;i++) lbRzx4=\y  
{ zm> >} 5R  
nStartPos = input.readLong(); Gb;99mE  
nEndPos = input.readLong(); z&O#v9.NE|  
} elu=9d];@  
input.close(); )1WMlG  
} Z a! gbt  
catch(IOException e){e.printStackTrace ();} `19qq]  
catch(Exception e){e.printStackTrace ();} U_]=E<el  
} yE#g5V&  
4sTMgBzw  
Tr~sieL  
private void processErrorCode(int nErrorCode) rWA6X DM7  
{ I?B,sl_w  
System.err.println("Error Code : " + nErrorCode); 42&v % ;R  
} ML=eL*}l  
J,??x0GDx,  
wTxbDT@H5  
//停止文件下载 I_ONbJ9]  
public void siteStop() d PsLZ"I  
{ }MP>]8Aq  
bStop = true; ]Ko^G_Rm  
for(int i=0;i<nStartPos.length;i++) _BbvhWN&+  
fileSplitterFetch.splitterStop(); n+2%tW  
P$_&  
~(P&g7u  
} ,]ga[  
} 30s; }  
//负责部分文件的抓取 D93gH1z  
**FileSplitterFetch.java {Ur7# h5  
*/ gljo;f:  
package NetFox; V@[rf<,  
m^<p8KZ  
|jsb@  
import java.io.*; uAUp5XP|Z  
import java.net.*; |d[5l^6  
dN< , %}R  
$E\^v^LW  
public class FileSplitterFetch extends Thread { w9MoT.kI}  
M 7rIi\4K4  
zEj#arSE4  
String sURL; //File URL ?E6^!4=,  
long nStartPos; //File Snippet Start Position qw<HY$3=  
long nEndPos; //File Snippet End Position /& r|ec5  
int nThreadID; //Thread's ID TN\|fzj  
boolean bDownOver = false; //Downing is over R:M,tL-l  
boolean bStop = false; //Stop identical h$`#YNd'  
FileAccessI fileAccessI = null; //File Access interface nBkh:5E5%  
O#)jr-vXdV  
Ke!'gohv  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X3',vey  
{ A|L'ih/  
this.sURL = sURL; iPvuz7j=h  
this.nStartPos = nStart; V^TbP.  
this.nEndPos = nEnd; Ird|C[la  
nThreadID = id; 2s\BY%XY  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /,2rjJ#b  
} $5NKFJc  
py @( <  
0OnV0SIL  
public void run() vQ1 v# Z  
{ nn+_TMu  
while(nStartPos < nEndPos && !bStop) u#@RM^738d  
{ 2z\e\I  
(5a1P;_Y  
rQb7?O@-  
try{ ; b*i3*!g  
URL url = new URL(sURL); Y%@hbUc}x9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \vRd}   
httpConnection.setRequestProperty("User-Agent","NetFox"); GSi>l,y'  
String sProperty = "bytes="+nStartPos+"-"; "hQgLG  
httpConnection.setRequestProperty("RANGE",sProperty); #$E)b:xj  
Utility.log(sProperty); jo9gCP.  
((bTwx  
O$D?A2eI  
InputStream input = httpConnection.getInputStream(); uOd& XW  
//logResponseHead(httpConnection); K\u_Ji]k  
=n+ \\D  
eTbg7"waA  
byte[] b = new byte[1024]; A%X X5*  
int nRead; rS7)6h7(7  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) v-Qmx-N  
{ r^1+cwy/7P  
nStartPos += fileAccessI.write(b,0,nRead); X!>eiYK)  
//if(nThreadID == 1) r@kP*  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |ZiC`Nt  
} %S \8.  
`\CVV*hP  
SwW['c'*]B  
Utility.log("Thread " + nThreadID + " is over!"); H43MoC  
bDownOver = true; =r 9r~SR#  
//nPos = fileAccessI.write (b,0,nRead); G8J*Wnwu[K  
} 2VoKr)  
catch(Exception e){e.printStackTrace ();} KzV 2MO-$  
} aG%, cQ1  
} F(,UA+$A  
Qdf=XG5  
2=iH$v  
//打印回应的头信息 Vsnuy8~k  
public void logResponseHead(HttpURLConnection con) 5Qh?>n>*  
{ [p;E~-S  
for(int i=1;;i++) `5~3G2T  
{ B9,^mE#  
String header=con.getHeaderFieldKey(i); 5d\q-d  
if(header!=null) XYr J/!*.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); = ieag7!  
Utility.log(header+" : "+con.getHeaderField(header)); 2RM+W2!!  
else 0#*Lw }qi  
break; .6f%?oo  
} '#/G,%m<!i  
} >>{FzR  
Ch \&GzQ  
hr GH}CU"  
public void splitterStop() YXo|~p;=Y  
{ Pr ]Ka  
bStop = true; uxaYCa?  
} ^Yj xeNY  
y|wlq3o  
~m^ #FJu  
} ^ vilgg~  
L;Z0`mdz  
??60,m:]  
/* qqrq11W  
**FileAccess.java svf|\p>]H  
*//文件访问(定位,写) j z58E}  
package NetFox; ?L&|Uw+  
import java.io.*; rgmF:C  
9o*,P,j'}  
O3DmNq$dz  
public class FileAccessI implements Serializable{ 7\FXz'hA  
,JU@|`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G)v #+4  
RandomAccessFile oSavedFile; W6H,6v  
long nPos; l<0}l^C.  
+5VLw  
QTX8 L  
public FileAccessI() throws IOException w@JKl5  
{ 8{`?= &%6  
this("",0); 1$qh`<\  
} ,1OyN]f3  
c:Wze*vI ;  
om?-WJI  
public FileAccessI(String sName,long nPos) throws IOException g<{xC_J  
{ )q7UxzE+  
oSavedFile = new RandomAccessFile(sName,"rw"); m<FOu<y  
this.nPos = nPos; 8#!i[UF dj  
oSavedFile.seek(nPos); 5%sE] Y#  
} 2MZCw^s>  
Vq;dJ%sY  
;4N;D  
public synchronized int write(byte[] b,int nStart,int nLen) >h0-;  
{ M9zfT !-  
int n = -1; J+d1&Tw&  
try{ ok|qyN+  
oSavedFile.write(b,nStart,nLen); V,rq0xW  
n = nLen; 3gd&i  
} oy<WsbnS  
catch(IOException e) 8JmFi  
{ ( =~&+z  
e.printStackTrace (); V3 ~~  
} P ;IrBq6|o  
y WV#Up  
AL>$HB$  
return n; Jgnhn>dHe  
} T)r9-wOq  
 Yn8=  
C z\Ppq  
} t%F0:SH  
)iFJz/n>  
/cU<hApK  
/* Um&(&?Xf  
**SiteInfoBean.java J9~ g|5  
*/ /0Ax*919j  
package NetFox; c("_bOAT  
S)D nPjN{  
pb~pN  
public class SiteInfoBean { dAy?EO0\7  
Q-1vw6d  
r Tz$^a}/  
private String sSiteURL; //Site's URL OpHsob~  
private String sFilePath; //Saved File's Path C*P7-oE2rh  
private String sFileName; //Saved File's Name B(M6@1m_  
private int nSplitter; //Count of Splited Downloading File rtc9wu  
l\C.",CEcc  
=UV`.d2[  
public SiteInfoBean() u*hSj)vr1  
{//nSplitter的缺省值为5 Z?\>JM >;  
//default value of nSplitter is 5 B ~OZ2-~  
this("","","",5); fkac_X$7  
} *QH28%^  
1dK*y'rx  
-Z's@'*  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VNY%R,6  
{ <>Hj ;q5p  
sSiteURL= sURL; (DI>5.x"  
sFilePath = sPath; P-9<YN  
sFileName = sName; :Y[LN  
this.nSplitter = nSpiltter; <i,U )Tt^C  
)= =Jfn y  
WYr/oRO  
} aTt 12Sc  
'*3h!lW1.  
kBffF@{  
public String getSSiteURL() j:VbrR  
{ b9l;a+]d  
return sSiteURL; OLE[UXD-E  
} k?,1x~  
^0 -:G6H  
:5{wf Am  
public void setSSiteURL(String value) DP|D\+YyYA  
{ xoN3  
sSiteURL = value; i*Z" Me  
} -PfX0y9n  
mGK|ihYu  
c I4K+  
public String getSFilePath() u?}(P_9  
{ b}"N`,0dO  
return sFilePath; }|pwz   
} R#I0|;q4|p  
1]p ZrBh"E  
:>C2gS@  
public void setSFilePath(String value) 0.@&_XTPl  
{ "/wyZ  
sFilePath = value; h-[VH%  
} $ 69oV:  
=o$sxb E(  
y]f"@9G#  
public String getSFileName() 2I,^YWR  
{ 9J2NH|]c  
return sFileName; W>j!Q^?  
} M r5v<  
c_4[e5z  
^y<<>Y'I  
public void setSFileName(String value) xjKR R?  
{ G U( _  
sFileName = value; `)_dS&_\  
} r2,.abo  
a m|F?|1  
73/P&hT  
public int getNSplitter() *Qg_F6y  
{ >LOjV0K/  
return nSplitter; f}9zgWU  
} f,kZ\Ia'r  
 ']2E {V  
mj W8 Q\D  
public void setNSplitter(int nCount) aWR}R>E  
{ ,X`)ct  
nSplitter = nCount; 6">+ ~ G  
} xHD=\,{ig  
} 2#c<\s|C  
"eB$k40-  
uM_wjP  
/* @`q:IIgW  
**Utility.java h4 T5+~rw  
*/ Bu#VMk chJ  
package NetFox; wAf\|{Vn  
qVH1}9_  
.\)U@L~  
public class Utility { NQJq6S4@  
[OC5l>  
E2R&[Q"%  
public Utility() 6ZP(E^.  
{ < t,zaIi  
leTf&W  
 W\d{a(*  
} =T HpdtL  
J  IUx  
//线程睡眠 JB<Sl4  
public static void sleep(int nSecond) um!J]N^  
{ Rh_np  
try{ n\*!CXc  
Thread.sleep(nSecond); |)(VsVG&  
} E&2OD [iX  
catch(Exception e) S4Y&  
{ u)}$~E>  
e.printStackTrace (); UC]\yUK1J  
} 0IBhb(X  
} Lr$go6s  
~A'!2  
//日志 pNepC<rY  
public static void log(String sMsg) xhV O3LW'  
{ jB%lB1Q|  
System.err.println(sMsg); n<O}hM ZT  
} vHry&#Pl+  
}$SavB#SBP  
k_ & :24Lj  
public static void log(int sMsg) mr*JJF0Z  
{ ON=@ O  
System.err.println(sMsg); 7%Gwc?[x  
} J?? -j  
} g jDh?I  
K1 EynU I  
I>]oS(GNT  
/* lr>oYS0  
**TestMethod.java 5m\<U`  
*/ 8']M^|1  
package NetFox;  M+||rct  
q&s3wDl/  
,(d) Qg  
public class TestMethod { Wbr|_W  
!t$'AoVBq  
2Rw&C6("w  
public TestMethod() sFT.Oxg<  
{ ///xx/weblogic60b2_win.exe \<JSkr[h!"  
try{ >s>1[W@*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 52:HNA\E/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]O+Ma}dxz:  
SiteFileFetch fileFetch = new SiteFileFetch(bean); #5cEV'm;  
fileFetch.start(); +ga k#M"n\  
} HHDl8lo  
catch(Exception e){e.printStackTrace ();} DFZkh^PFd  
I`-8Air5f  
5na~@-9p  
} ;RDh ~EV  
@XLy7_}  
` Q|*1  
public static void main(String[] args) [Dk=? +  
{ KHe=O1 %QO  
new TestMethod(); *X'Y$x>f  
} adCU61t  
} -lbm* -(  
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