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http断点续传简单实现(java)

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/* ~fD\=- S1  
**SiteFileFetch.java ^ wZx=kas  
*/ H%l-@::+$  
package NetFox; U 5j4iz'  
import java.io.*; * FEJ5x  
import java.net.*; *ilVkV"U  
}[|9vF"g.y  
L7 <30"7  
public class SiteFileFetch extends Thread { LyvR].p=5*  
{_(R?V]w,  
'vt Jl  
SiteInfoBean siteInfoBean = null; //文件信息Bean +`"Tn`O  
long[] nStartPos; //开始位置 a Tm R~k  
long[] nEndPos; //结束位置 zx8@4?bK  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 M {'(+a[  
long nFileLength; //文件长度 s% R,]q  
boolean bFirst = true; //是否第一次取文件 4|%Y09"lv  
boolean bStop = false; //停止标志 FsOJmWZ  
File tmpFile; //文件下载的临时信息 1!)'dL0mI  
DataOutputStream output; //输出到文件的输出流 r$4d4xtK  
0OG 3#pE  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 71E~~$  
public SiteFileFetch(SiteInfoBean bean) throws IOException Yg5o!A  
{ F(/<ADx  
siteInfoBean = bean; H1?C:R  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); @^ta)Ev  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _VgFuU$h  
if(tmpFile.exists ()) W.{+0xx  
{ Qh8pOUD0l}  
bFirst = false; }U>K>"AZl  
read_nPos(); /YPG_,lRA  
} =os!^{p7>  
else *B@#A4f"  
{ QhTn9S:D  
nStartPos = new long[bean.getNSplitter()]; r@i)Sluf  
nEndPos = new long[bean.getNSplitter()]; 5G'2 Wby'#  
} _?felxG[  
hJ%$Te  
x{!+ 4W;S  
gI RZkT`  
} ]==7P;_-  
ZB$yEW]]~  
.i )K#82  
public void run() T,/<'cl"  
{ tr0kTW$Ad  
//获得文件长度 r&v!2A]:  
//分割文件 RFe># o  
//实例FileSplitterFetch )~$ejS  
//启动FileSplitterFetch线程 O['[_1n_u]  
//等待子线程返回 *h?}~!AjY  
try{ ODpAMt"  
if(bFirst) ,=@WE> ip  
{ e :ub]1I=  
nFileLength = getFileSize(); 2XUIC^<@s  
if(nFileLength == -1) 2Nm{.Y  
{ w D6QN  
System.err.println("File Length is not known!");  iSX:H;  
} tycVcr \(  
else if(nFileLength == -2) rOUQg_y  
{ 8&+u+@H  
System.err.println("File is not access!"); l%i*.b(  
} 3S>rc0]6  
else $LU|wW  
{ D}ZPgt#   
for(int i=0;i<nStartPos.length;i++) / a}N6KUi  
{ A2PeI"y  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ':\bn:;  
} wB[ JFy"E  
for(int i=0;i<nEndPos.length-1;i++) Bbb":c6w0  
{ t > 64^nS  
nEndPos = nStartPos[i+1]; _-v$fDrz  
} %6V=G5+W  
nEndPos[nEndPos.length-1] = nFileLength; n0':6*oGW  
} $b_~  
} ^h`rA"F\  
Ms%C:KG  
t08[3Q&  
//启动子线程 8_rd1:t5  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -=u9>S)!c  
for(int i=0;i<nStartPos.length;i++) ^#w9!I{4.  
{ .lz= MUR  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {@" F/G+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O15~\8#'  
nStartPos,nEndPos,i); _|{pO7x]oG  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7{rRQ~s&g9  
fileSplitterFetch.start(); PIsXX#`7;  
} VdL }$CX$  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UG]5Dxk  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ej(w{vl  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Sc]h^B^7  
nEndPos = " + nFileLength); q^[SN  
// fileSplitterFetch[nPos.length-1].start(); IPY[x|  
RHt~:D3*  
.MxMBrM  
//等待子线程结束 eX^ F^(   
//int count = 0; H Mfhe[A?  
//是否结束while循环 'EU|w,GL}  
boolean breakWhile = false; -K5u5l}  
s*kSl:T @O  
3"6-X_  
while(!bStop) Op iVQr:  
{  ixF  
write_nPos(); \#'m([<e  
Utility.sleep(500);  !h* F58  
breakWhile = true; g$Ns u:L  
wH qbTA  
tlmfDQD  
for(int i=0;i<nStartPos.length;i++) &<5oDdC  
{ wpJfP_H  
if(!fileSplitterFetch.bDownOver) iM{aRFL  
{ $K~ t'wr  
breakWhile = false; Y &*nj`n  
break; _ 3jY,*  
} 0^ $6U  
} ::k/hP9.^  
if(breakWhile) R<8!lQ4s  
break; &qeM YYY  
^:m7Qd?Z[  
)u5+<OG}=  
//count++; ->U9u lTC  
//if(count>4) \&X*-T[]j  
// siteStop(); !bIhw}^C*  
} !W45X}/o  
G9a6 $K)b  
Ha20g/ UN.  
System.err.println("文件下载结束!"); H5p&dNO  
} >[gNQJ6  
catch(Exception e){e.printStackTrace ();} g E;o_~  
} I>3]VR i  
/%T d(  
=!|= Y@  
//获得文件长度 c7(Lk"G8  
public long getFileSize() %u02KmV.  
{ -85W/%  
int nFileLength = -1; kG$U  
try{ A"~4|`W  
URL url = new URL(siteInfoBean.getSSiteURL()); O0 ,=@nw8.  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,[<+7  
httpConnection.setRequestProperty("User-Agent","NetFox"); c0u1L@tj  
xnD"LK  
eww/tGa  
int responseCode=httpConnection.getResponseCode(); u~q6?*5  
if(responseCode>=400) rRzc"W}K+  
{ "s5[w+,R  
processErrorCode(responseCode); rW B/#m  
return -2; //-2 represent access is error i-*ZW:  
} }IGoPCV|  
_Kf8,|+  
?."YP[;  
String sHeader; Y('?Z]  
MGE8S$Z  
 c 1o8   
for(int i=1;;i++) XPQY*.l&.  
{ n!$zO{P  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .DG`~Fpk  
//Utility.log(in.readLine()); w9]HJ3qi  
sHeader=httpConnection.getHeaderFieldKey(i); ;G|#i? JJ  
if(sHeader!=null) x,:DL)$1  
{ Dlqvz|X/  
if(sHeader.equals("Content-Length")) Z b}U 4  
{ P}8cSX9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IB\O[R$x  
break; (utk)  
} Q"F" 13  
} ~KP@wD~  
else )/cf%  
break; h h7unHt-  
} 92XG|CWX  
} Cm%|hk>fQ  
catch(IOException e){e.printStackTrace ();} #sM`>KG6T1  
catch(Exception e){e.printStackTrace ();} x@#aOf4<U  
xVN(It7g  
-]<<}@NF  
Utility.log(nFileLength); s a{x.2/o}  
"DvhAEM  
H7%q[O  
return nFileLength; D=@bPB>  
} e?_uJh"  
H/}W_ h^^  
V@o#" gZ  
//保存下载信息(文件指针位置) oLIgj,k{*  
private void write_nPos() EslHml#  
{ O-&^;]ieJ  
try{ ]w_JbFmT  
output = new DataOutputStream(new FileOutputStream(tmpFile)); T~8kKw  
output.writeInt(nStartPos.length); @%BsQm  
for(int i=0;i<nStartPos.length;i++) z1nKj\AM2  
{ XaF;IS@A  
// output.writeLong(nPos); >|aVGY  
output.writeLong(fileSplitterFetch.nStartPos); Fv<3VKueK[  
output.writeLong(fileSplitterFetch.nEndPos); 5Nl?Km~  
} b_f"(l8'S  
output.close(); y({lE3P  
} I,W `s  
catch(IOException e){e.printStackTrace ();} Y<h6m]H  
catch(Exception e){e.printStackTrace ();} >i"WKd=  
} *alifdp  
+GncQs y  
Pk>S;KT.  
//读取保存的下载信息(文件指针位置) n0Qp:_2z  
private void read_nPos() _Kbj?j  
{ >X xHp  
try{ ^l<!:SS  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~r_2V$sC2  
int nCount = input.readInt(); kB.CeG]tk  
nStartPos = new long[nCount]; 4~Y?*|G]m  
nEndPos = new long[nCount]; $+PyW( r  
for(int i=0;i<nStartPos.length;i++) ^#IE t#  
{ Z1Qv>@u  
nStartPos = input.readLong(); vCXmu_S4^>  
nEndPos = input.readLong(); j^WYM r,  
} `F]  
input.close(); m41%?uC/  
} N.0g%0A.D  
catch(IOException e){e.printStackTrace ();} @vB-.XU  
catch(Exception e){e.printStackTrace ();} ahQY-%>  
} B]vR=F}*  
mkhWbzD'S  
0X4)=sJP  
private void processErrorCode(int nErrorCode) CO9PQ`9+  
{ mHV{9J  
System.err.println("Error Code : " + nErrorCode); "vg.{  
} z~==7:Os  
E-($Xc  
d!4TwpIgx  
//停止文件下载 QBGjH^kL  
public void siteStop() .YWkFTlZ+  
{ `SOQPAnK+;  
bStop = true; |a a\t  
for(int i=0;i<nStartPos.length;i++) seRf q&  
fileSplitterFetch.splitterStop(); ,RM8D)m\  
#p7gg61  
cTS.yN({G  
} <QO1Yg7}  
} REYvFx?i  
//负责部分文件的抓取 ck%YEMs  
**FileSplitterFetch.java Tl'wA^~H  
*/ LnKgT1  
package NetFox; wu><a!3`=o  
FRajo~H  
0[M2LF!m  
import java.io.*; 6)*B%$?x  
import java.net.*; )Tp"l"(G  
 @;$cX2  
3;VH'hh_  
public class FileSplitterFetch extends Thread { g1}:;VG=  
?|/K(}  
^_g%c&H  
String sURL; //File URL :o8|P  
long nStartPos; //File Snippet Start Position f6yj\qq]  
long nEndPos; //File Snippet End Position 0nL #-`S  
int nThreadID; //Thread's ID 71Za!3+  
boolean bDownOver = false; //Downing is over |JF,n~n  
boolean bStop = false; //Stop identical U,Uy0s2r  
FileAccessI fileAccessI = null; //File Access interface D)?%kNeA  
{9-9!jN{"  
( H&HSs  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?jUgDwc(w  
{ ZO cpF1y  
this.sURL = sURL; 8<mloM-4  
this.nStartPos = nStart; 9#:fQ!3`  
this.nEndPos = nEnd; az:}RE3o  
nThreadID = id; >l><d!hw  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yo->mD  
} DbLo{mFEIj  
R!QR@*N  
JbL3/h]  
public void run() 036m\7+Qj  
{ (lS[a  
while(nStartPos < nEndPos && !bStop) gaz",kK<  
{ `^[Tu 1  
V0Oqq0\  
fdX|t "oz  
try{ 8 yi#] 5`Q  
URL url = new URL(sURL); >'W,8F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A+8)VlE\  
httpConnection.setRequestProperty("User-Agent","NetFox"); "qF/7`e[  
String sProperty = "bytes="+nStartPos+"-"; h)ZqZ'k$  
httpConnection.setRequestProperty("RANGE",sProperty); 6xtgnl#T  
Utility.log(sProperty); COu5Tu^  
21tv(x  
<=GZm}/]N  
InputStream input = httpConnection.getInputStream(); IB| 6\uKn  
//logResponseHead(httpConnection); &U?4e'N)T  
zJW2F_  
MXfyj5K  
byte[] b = new byte[1024]; g[1>|Ax`'  
int nRead; aReJ@  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7F0J*M  
{ )Cj1VjAg  
nStartPos += fileAccessI.write(b,0,nRead); tmq?h%O>  
//if(nThreadID == 1) og35Vs0  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EK=0oy[  
} ru2M"]T  
9%|skTgIqH  
!KOa'Ic$V  
Utility.log("Thread " + nThreadID + " is over!"); z"yW):X  
bDownOver = true; Miw=2F  
//nPos = fileAccessI.write (b,0,nRead); ],0I`!\  
} R/"-r^j  
catch(Exception e){e.printStackTrace ();} K/Yeh<_&  
} R|8L'H+1x  
} (0Br`%!F  
X)hpbHa  
 rn( drG  
//打印回应的头信息 2;"vF9WMm  
public void logResponseHead(HttpURLConnection con) 6M7GPHah  
{ N atC}k  
for(int i=1;;i++) 1G12FV>M  
{ 3bezYk  
String header=con.getHeaderFieldKey(i); =dHdq D  
if(header!=null) +J C"@  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9-{+U,3)  
Utility.log(header+" : "+con.getHeaderField(header)); @0PWbs$  
else v\8v'EDP  
break; tlD^"eq4:  
} /v<Gt%3X  
} iOhX\@&  
\F`>zY2$%  
~E8/m_> rU  
public void splitterStop() ,7s+-sRG  
{ 6l2O>V  
bStop = true; Wd!Z`,R  
} k=kkF"  
v)O].Hd  
n(#yGzq  
} `a[fC9  
zQ,M795@EA  
vv2[t  
/* E A55!  
**FileAccess.java X=f%!  
*//文件访问(定位,写) vs+aUT C\  
package NetFox; `5oXf  
import java.io.*; 4zhh **]B  
C :sgT6  
?R sPAL  
public class FileAccessI implements Serializable{ p>J@"?%^  
6A =k;do  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N$t<&5 +  
RandomAccessFile oSavedFile; LcA7f'GVK  
long nPos; <3j`Z1J  
x<rS2d-Y  
t OJyj49^a  
public FileAccessI() throws IOException j -"34  
{ N8kNi4$mp=  
this("",0); 2/A*\  
} =~W=}  
nvwf!iU6  
^C~R)M:C  
public FileAccessI(String sName,long nPos) throws IOException j$s/YI:  
{ WPpO(@sn  
oSavedFile = new RandomAccessFile(sName,"rw"); #ucb  
this.nPos = nPos; 8b-mW>xsA  
oSavedFile.seek(nPos); %LmsywPPp  
} P4{~fh(  
b+arnKo1fk  
A1Uy|Dl  
public synchronized int write(byte[] b,int nStart,int nLen) kMLJa=]$  
{ Gl|n}wo$  
int n = -1; #l- 0$  
try{ S#yGqN0i  
oSavedFile.write(b,nStart,nLen); @VG@|BQWa  
n = nLen; |dqESl,2  
} dXM8iP  
catch(IOException e) 0n kC%j  
{ P{QHG 3  
e.printStackTrace (); ?GhMGpd Mq  
} {{M/=WqC  
v)gMNzt  
-$g~,dIwj  
return n; #%E^cGfY  
} P?|\Ig1Gk  
3pW4Ul@e  
#QcRN?s  
} ns\I Y<Yo  
Hsv)] %p  
j[w=pF,o  
/* -gt ?5H h  
**SiteInfoBean.java L%\Wt1\[  
*/ m2l9([u=^  
package NetFox; 1t^9.!$@y  
]e"!ZR?XJ  
LdNpb;*  
public class SiteInfoBean { \SO)|M>.a  
'yA/sZ  
~$[fG}C.K  
private String sSiteURL; //Site's URL -gba&B+D"  
private String sFilePath; //Saved File's Path Tl[*(| /C  
private String sFileName; //Saved File's Name h2Th)&Fb>  
private int nSplitter; //Count of Splited Downloading File 0pEM0M  
tH *|  
.{`C>/"}  
public SiteInfoBean() pO:]3qv  
{//nSplitter的缺省值为5 A4#F AFy  
//default value of nSplitter is 5 PO6yE r  
this("","","",5); tAJ}36 aG  
} ~re}6-?  
GQA\JYw|oY  
6hYz^}2g  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '2<r{  
{ (6a<{  
sSiteURL= sURL; +By'6?22  
sFilePath = sPath; i}v.x  
sFileName = sName; ZxT E(BQv  
this.nSplitter = nSpiltter; CZeZk  
62_k`)k  
l*&N<Yu  
} Kn@#5MC rU  
H2#o X  
g9VY{[ V  
public String getSSiteURL() $m*Gu:#xm&  
{ NjEi.]L*fX  
return sSiteURL; s9nPxC&A  
} {R@V  
"uIaKb  
Fc\]*  
public void setSSiteURL(String value) 0\ (:y^X  
{ /PTRe5-7  
sSiteURL = value; LOfw #+]d  
} V8B4e4F  
<n#X~}i)  
-XV+F@`Md  
public String getSFilePath() YkB@fTTS  
{ *. |%uf.  
return sFilePath; {b4`\ I@<  
} ml1%C%  
!R\FCAW[x  
$'Mf$h  
public void setSFilePath(String value) +#BOWz  
{ QNU~G3  
sFilePath = value;  ]gcOMC  
} 0]c&K  
r W[;3yMf  
miQ*enZi  
public String getSFileName() o|z@h][(l(  
{ wxh\CBxG  
return sFileName; UiH7  
} a6DR' BC  
QE[<Y3M  
<Jhd%O  
public void setSFileName(String value) }5oI` 9VT  
{ OR~ui[w  
sFileName = value; lRg?||1ik  
} #vV]nI<MF.  
A[;deHg=  
vQi=13Pw  
public int getNSplitter() 5<ruN11G  
{ Y#68_%[  
return nSplitter; n Ab~  
} &F~d~;G"q  
\vT~2Y(K  
<5z!0m-G  
public void setNSplitter(int nCount) ^*.$@M  
{ VM\R-[  
nSplitter = nCount; <>\|hno}  
} raPOF6-_rH  
} J Ah!#S(  
8~C}0H  
*GE6zGdN  
/* ! s =$UC  
**Utility.java C 6 \  
*/ Ie^Ed`  
package NetFox; :zKW[sF  
:gwmk9LZ  
?tjEXg>ny  
public class Utility { (rBsh6@)  
cl^UFl f[  
%@a;q?/?Nd  
public Utility() 9S]pC?N]E  
{ ^vd$j-kjTP  
}=bzUA`C  
2T2<I/")O  
} (v/L   
^R@)CIQ  
//线程睡眠 pE<a:2J  
public static void sleep(int nSecond) fL2P6N@  
{ " C0dZ  
try{ $EFS_*<X  
Thread.sleep(nSecond); C:Rs~@tl  
} geyCS3 :p  
catch(Exception e) .Bl:hk\  
{ jV*10kM<  
e.printStackTrace (); LD[\eJ _  
} 45.ks.  
} md{nHX&  
 ?pEPwc  
//日志 rogy`mh\r2  
public static void log(String sMsg) r[Pp[ g-J  
{ O.Pp*sQ^  
System.err.println(sMsg); 85&7WAco"B  
} UiV#w#&P  
3<XuJ1V&  
Nxe1^F33  
public static void log(int sMsg) L-?ty@-i  
{ +C!GV.q[  
System.err.println(sMsg); WZ ?>F  
} ~2rQ80_  
} F?2UHcs  
*RS/`a;,  
}'wZ)N@  
/* ?=Ceo#Er  
**TestMethod.java ((]i}s0S  
*/ Ich^*z(F$  
package NetFox; M2cGr  
cu>(;=  
)@DDs(q=i  
public class TestMethod { 5;KJ0N*-  
&mtt,]6C_  
{?lndBP<  
public TestMethod() }d; 2[fR)  
{ ///xx/weblogic60b2_win.exe J(}PvkA  
try{ $`GlXiV  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LGuZp?"  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $Z)u04;&@  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Szt2 "AR  
fileFetch.start(); ^=^\=9" b  
} `oNJ=,p  
catch(Exception e){e.printStackTrace ();} 4Lg ,J9  
9 l~D}5e7  
1A'eH:$  
} bj@sci(1?  
a6 vej  
!0lk}Uzkh  
public static void main(String[] args) C[%Qg=<  
{ M`al~9  
new TestMethod(); D*2*FDGI  
} J/P[9m30[  
} V/H+9+B7Im  
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