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http断点续传简单实现(java)

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/* >JS\H6  
**SiteFileFetch.java 'GQ1;9A57  
*/ /tA$ 'tZ  
package NetFox; M]!\X6<_  
import java.io.*; R?+Eo(0q,  
import java.net.*; eJ)Bs20Q  
g. f!Uc{  
Mo &Ia6^  
public class SiteFileFetch extends Thread { #O]F5JB  
&w:"e'FG`  
VA4vAF  
SiteInfoBean siteInfoBean = null; //文件信息Bean R6dw#;6{I  
long[] nStartPos; //开始位置 =%Gecj  
long[] nEndPos; //结束位置 n|NI]Qi*  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 R?1;'pvpa[  
long nFileLength; //文件长度 X obiF  
boolean bFirst = true; //是否第一次取文件 $f>Mz|j  
boolean bStop = false; //停止标志 W-=~Afy  
File tmpFile; //文件下载的临时信息 ^te9f%>$l  
DataOutputStream output; //输出到文件的输出流 CZE5RzG  
t)g1ICt  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) AM##:4   
public SiteFileFetch(SiteInfoBean bean) throws IOException D9e"E1f+"  
{ e%x$Cb:znn  
siteInfoBean = bean; }txHuq1Q.  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); K"eR 6_ k  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $;7?w-.  
if(tmpFile.exists ()) ;3Fgy8 T  
{ eB/3MUz1  
bFirst = false; VJD$nh #M5  
read_nPos(); N::_JH? ^=  
} `y0ZFh1>X  
else 5ejdf  
{ gm8L5c V  
nStartPos = new long[bean.getNSplitter()]; BMU~1[r  
nEndPos = new long[bean.getNSplitter()]; ~FH''}3:3  
} ]eb9Fq:N7  
E& T9R2Y  
9C[3w[G~C  
Zp@p9][C  
} Rb<aCX  
3s\2 9gq  
hnL"f[p@gC  
public void run() LYGFE jS[  
{ V!c{%zd  
//获得文件长度 Ia)wlA02S  
//分割文件 j9%u&  
//实例FileSplitterFetch U/yYQZ\)  
//启动FileSplitterFetch线程 0KnlomuH2  
//等待子线程返回 ckP&N:tC  
try{ ko im@B  
if(bFirst) 1 dz&J\|E#  
{ b'Z#RIb  
nFileLength = getFileSize(); $q DH  
if(nFileLength == -1) Gw!jYnU  
{ /+2^xEIjE  
System.err.println("File Length is not known!"); @`k!7? Sq  
} =Z2U  
else if(nFileLength == -2) en!cu_]t  
{ 6 )0$UW  
System.err.println("File is not access!"); WXNJc  
} IyOujdKa  
else ?Z( 6..&  
{ QYVT"$=  
for(int i=0;i<nStartPos.length;i++) [sFD-2y  
{ {4CkF \  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); eN>=x40  
} "pdG%$  
for(int i=0;i<nEndPos.length-1;i++) _zJY1cr  
{ :Ff1Js(Z  
nEndPos = nStartPos[i+1]; -#3B>VY  
} 9g"a`a?c  
nEndPos[nEndPos.length-1] = nFileLength; \PU|<Ru.  
} Y!i4P#4+q  
}  tAP~  
H h$D:ZO  
| g> K$m^  
//启动子线程 fcr\XCG7U  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !K'kkn,h  
for(int i=0;i<nStartPos.length;i++) :b^tu 8E  
{ (BMFGyE3  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cf<i"   
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vwZ2kk!|i  
nStartPos,nEndPos,i); qB3 SQ:y  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [>;U1Wt  
fileSplitterFetch.start(); 0u QqPF t  
} b,D+1'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), & @^|=>L  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); DDN#w<#  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5Tb93Q@c  
nEndPos = " + nFileLength); }OI;M^5L  
// fileSplitterFetch[nPos.length-1].start(); 65=i`!f  
N#C,_ k  
#`); UAf  
//等待子线程结束 7O;v5k~iQ  
//int count = 0; u_e}m>[S  
//是否结束while循环 h<6@&yzp  
boolean breakWhile = false; ?t'O\n)M  
j9) Z'L  
:v Pzw!  
while(!bStop) F_zs"ex/  
{ TaG'?  
write_nPos(); 3@KX|-  
Utility.sleep(500); |6"zIHvtc  
breakWhile = true; D"bLJ j/!  
xO'1|b^&  
/=lrdp!a  
for(int i=0;i<nStartPos.length;i++) 3Q~ng2Wv%  
{ puL1A?Y8UM  
if(!fileSplitterFetch.bDownOver)  -"\z|OQ  
{ bf'@sh%W  
breakWhile = false; 9FX'Uws  
break; 4ZQX YwfC|  
} P[8`]=  
} [US.n +G6  
if(breakWhile) fwf]1@#   
break; FX+Ra@I!  
HMS9_#[kE  
fE|([ ` !  
//count++; M!,$i  
//if(count>4) Y=x]'3}^  
// siteStop(); 7zgU>$i  
} $a(wM1S4  
[FAoC3 k-h  
+<"sC+2  
System.err.println("文件下载结束!"); 9-Qu b+0o  
} IpB0~`7YI  
catch(Exception e){e.printStackTrace ();} |mc!v*O  
} x>!#8?-h  
Av _1cvR:  
PLw;9^<  
//获得文件长度 p(v+j_ak  
public long getFileSize() ^E{~{  
{ *'QD!Tc  
int nFileLength = -1; @Ej{sC!0T  
try{ i.)k V B  
URL url = new URL(siteInfoBean.getSSiteURL()); Jf|J":S  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F[l{pc "C  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]{0 2!  
F9]GEBLr  
{O]Cj~}  
int responseCode=httpConnection.getResponseCode(); DKF`uRvGN:  
if(responseCode>=400) )4D |sN  
{ &xj?MgdNL  
processErrorCode(responseCode); = = cAL"Z  
return -2; //-2 represent access is error 8qrE<RHU@  
} i?A4uyYwS  
:jT1=PfL  
{Tm31f(oD  
String sHeader; ](aXZ<,  
Z '/:  
]Yp;8#:1  
for(int i=1;;i++) bs kG!w  
{ -nV]%vJ$R}  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :&/'rMi<T  
//Utility.log(in.readLine()); #:v|/2   
sHeader=httpConnection.getHeaderFieldKey(i); w=rh@S]  
if(sHeader!=null) =CFO]9  
{ >IJH#>i  
if(sHeader.equals("Content-Length")) :,fs' !  
{ 8)\ ?6C  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;xN 4L  
break; 38 tRb"3zP  
} dK#:io[Nz  
} lN<vu#  
else TXv3@/>ZlG  
break; E"b+Q  
} y['$^T?oP  
} {uM*.]  
catch(IOException e){e.printStackTrace ();} 'Wn'BRXq3  
catch(Exception e){e.printStackTrace ();} \@N8[  
^Cst4=:W  
!.?2zp~  
Utility.log(nFileLength); quTM|>=_R  
^r?ZrbSbz  
}Cvf[H1+  
return nFileLength; VA&_dU]*  
} jav7V"$  
>KNiMW^V  
]t=m  
//保存下载信息(文件指针位置) K pDKIi  
private void write_nPos() MD1n+FgTu  
{ QaH32(iH  
try{ 5*/~) wN\U  
output = new DataOutputStream(new FileOutputStream(tmpFile)); -v/1R1$e1  
output.writeInt(nStartPos.length); Ovxs+mQ  
for(int i=0;i<nStartPos.length;i++) Nz'fMdaX,  
{ pi*cO  
// output.writeLong(nPos); N<zD<q  
output.writeLong(fileSplitterFetch.nStartPos); *Ew`Fm H  
output.writeLong(fileSplitterFetch.nEndPos); (oBvpFP33  
} bg'Qq|<U  
output.close(); o+*YX!]#L  
} p`fUpARA!  
catch(IOException e){e.printStackTrace ();} F/tGk9v  
catch(Exception e){e.printStackTrace ();} AU -,  
} A_tdtN<  
Q( U+o-  
&GGJ=c\  
//读取保存的下载信息(文件指针位置) |C301ENZ  
private void read_nPos() 8d?r )/~  
{ jdiH9]&U  
try{ _D1Uc|  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7?9QlUO  
int nCount = input.readInt(); !i,Eo-[Z  
nStartPos = new long[nCount]; vO`~rUA  
nEndPos = new long[nCount]; v-B{7 ~=#Z  
for(int i=0;i<nStartPos.length;i++) <U%4$83$  
{ U>H"N1  
nStartPos = input.readLong(); r7+"i9  
nEndPos = input.readLong(); 7hQXGY,q  
} InBnU`(r  
input.close(); sG7G$G*ta!  
} WWhAm{m  
catch(IOException e){e.printStackTrace ();} h6Ovl  
catch(Exception e){e.printStackTrace ();} o,>9|EMQZ  
} Z@2^> eC  
(HbA?Aja  
mM0VUSy  
private void processErrorCode(int nErrorCode) S~()A*5  
{ wX Z"}uT<}  
System.err.println("Error Code : " + nErrorCode); uH="l.u  
} F$.h+v   
Rsd~t_a1  
lHerEv<ja  
//停止文件下载 O?L6Ues  
public void siteStop() He vZ}.  
{ a> qB k})  
bStop = true; (yA`h@@WS  
for(int i=0;i<nStartPos.length;i++) v7gs $'Q  
fileSplitterFetch.splitterStop(); /*Iq,"kGz  
$ha,DlN  
]s_,;PGU  
} bca4'`3\|  
} $$F iCMI  
//负责部分文件的抓取 /|Z_Dy  
**FileSplitterFetch.java i ]x_W@h  
*/ ) rw!. )  
package NetFox; xs,,)jF(u  
CoZOKRoaH  
^%ZbjJ7|j  
import java.io.*; IJ\4S  
import java.net.*; q>|&u  
"QSmxr  
/M!b3bmA  
public class FileSplitterFetch extends Thread { qQjd@J}^  
$0 ]xeD0X  
>vQ8~*xd  
String sURL; //File URL 8! eYax   
long nStartPos; //File Snippet Start Position OD[q u  
long nEndPos; //File Snippet End Position lldNIL6B%  
int nThreadID; //Thread's ID M5 \flE2  
boolean bDownOver = false; //Downing is over SG \6qE~  
boolean bStop = false; //Stop identical *).u:>D4  
FileAccessI fileAccessI = null; //File Access interface AS4mJ UU9  
4}4cA\B:n  
tE'^O< K  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DpQ\q;  
{ =T!eyGE  
this.sURL = sURL; 59Lc-JJ  
this.nStartPos = nStart; p{|!LcSU$2  
this.nEndPos = nEnd; f[}(E  
nThreadID = id; %9vl  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 DwmK?5p  
} sg`   
(yrN-M4~t  
:3b.`s(M  
public void run() cY mgJBG  
{ Th_PmkvC  
while(nStartPos < nEndPos && !bStop) B@w/wH  
{ /_SQKpic  
ibH!bS{  
^?J3nf{  
try{ HTz5LAe~b7  
URL url = new URL(sURL); ZSWZz8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;gGq\c  
httpConnection.setRequestProperty("User-Agent","NetFox"); or,:5Z  
String sProperty = "bytes="+nStartPos+"-"; wxJu=#!M  
httpConnection.setRequestProperty("RANGE",sProperty); =E.!Ff4~(  
Utility.log(sProperty); MB7`'W  
~Uw;6VXV1  
.jUM'; l  
InputStream input = httpConnection.getInputStream(); rjK]zD9  
//logResponseHead(httpConnection); )E|{.K  
H2lQ(Y+H  
; DXsPpZC  
byte[] b = new byte[1024]; ff&jR71E  
int nRead; -wa"&Q  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @yM$Et5  
{ @U+#@6  
nStartPos += fileAccessI.write(b,0,nRead); /|0xOiib  
//if(nThreadID == 1) p0rmcP1Ln  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  LXoZ.3S  
} F[(ocxQZ3  
E)%D LZ  
+pPfvE`  
Utility.log("Thread " + nThreadID + " is over!"); ?wP/l  
bDownOver = true; `G0k)eW  
//nPos = fileAccessI.write (b,0,nRead); BItH0r7  
} RDfv D|}VN  
catch(Exception e){e.printStackTrace ();} (/7b8)g  
} o_8Wnx^  
} &%]v0QK  
iC{(vL0P+  
H-rxn  
//打印回应的头信息 NX4G;+6  
public void logResponseHead(HttpURLConnection con) c=,HLHpFO(  
{ Al1_\vx7  
for(int i=1;;i++) n:|a;/{I]9  
{ ]"/SU6#4:  
String header=con.getHeaderFieldKey(i); E+ctiVL  
if(header!=null) 8eVy*h2:=  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gky+.EP.  
Utility.log(header+" : "+con.getHeaderField(header)); ZIN1y;dJ  
else ,eGguNA9  
break; GKc?  
} 7KesfH?  
} u*f`\vs  
/W GD7\G'8  
q68CU~i*  
public void splitterStop() L{&>,ww  
{ N5c*#lHI  
bStop = true; jG~-V<&  
} :i4AkBNK  
0K'{w]Q  
5vFM0  
} $l2`@ia"  
9a[1s|>w-  
0W0GSDx  
/* v w 6$v  
**FileAccess.java `dw">z,  
*//文件访问(定位,写) egK~w8`W%  
package NetFox; "cyRzQ6EH  
import java.io.*; (gnN </%  
Atb`Q'Yrw  
XV/7K "  
public class FileAccessI implements Serializable{ ~s-bA#0S  
7]} I  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R?zlZS.~  
RandomAccessFile oSavedFile; idB1%?<  
long nPos; eL>wKu:r  
-:95ypi  
j!@T@ 8J  
public FileAccessI() throws IOException ~/X8Hy!-  
{ vf zC2  
this("",0); XHxJzYMc  
} >?1GJ5]\s  
udT0`6l;  
fF(AvMsO  
public FileAccessI(String sName,long nPos) throws IOException DXG`%<ZMn  
{ ZJF"Yo  
oSavedFile = new RandomAccessFile(sName,"rw"); %%F, G  
this.nPos = nPos; Ell14Iki  
oSavedFile.seek(nPos); m 62Zta  
} w[F})u]E  
v-N4&9)%9  
O}%E SAB  
public synchronized int write(byte[] b,int nStart,int nLen) s >:gL,%c  
{ /Yb8= eM  
int n = -1; tmOy"mq67  
try{ *xJ]e.  
oSavedFile.write(b,nStart,nLen); `v@Z|rv,  
n = nLen; X&HYWH'@,  
} - . o,bg  
catch(IOException e) Fm=jgt3wv8  
{ ia3Q1 9r  
e.printStackTrace (); :1Nc6G  
} etT9}RbQ  
\?oT.z5VG&  
z Ohv>a  
return n;  71@kIJI  
} CcW3o"=4  
A +=#  
2<9K}Of  
} z{&Av  
ZJW8S  
uB^"A ;0v  
/* %19~9Tw  
**SiteInfoBean.java  pdm(7^  
*/ ,}\LC;31,  
package NetFox; ^SsdM#E  
tH&eKM4G  
[<5/s$,i  
public class SiteInfoBean { yZ 7)|j  
Vpp$yM&?  
dH.Fb/7f  
private String sSiteURL; //Site's URL hxj\  
private String sFilePath; //Saved File's Path l?$X.Cw X  
private String sFileName; //Saved File's Name 6eUGE4NF(  
private int nSplitter; //Count of Splited Downloading File M*bsA/Z  
w>\oz  
j94~c YV  
public SiteInfoBean() O'B3sy  
{//nSplitter的缺省值为5 +,,dsL  
//default value of nSplitter is 5 .wp[uLE  
this("","","",5); cLp_\\  
} 5 =8v\q?)c  
G~DHNO6  
50dN~(;p  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IP$eJL[&D"  
{ rz,,ku4qt  
sSiteURL= sURL; 8\9W:D@"x  
sFilePath = sPath; kP}l"CN4  
sFileName = sName; Y'jgp Vt  
this.nSplitter = nSpiltter; 9mp`LT  
~CHcbEWk)W  
|EdEV*.ej  
} n:B){'S  
%z.V$2  
y`8U0TE3R  
public String getSSiteURL() Ym"^Ds}  
{ I L7kpH+y  
return sSiteURL; Du +_dr^4  
} QHja4/  
WF*j^ %5  
?$ov9U_  
public void setSSiteURL(String value) Dq%} ({+  
{ )7!,_r  
sSiteURL = value; %QrOEs  
} ^!C  
x^c,cV+*  
c%O97J.5b  
public String getSFilePath() }"nm3\Df  
{ !SE  
return sFilePath; `n-/~7  
} J"< h#@`  
FeS ,TQ4j  
}f_@@#KB?  
public void setSFilePath(String value) RhmkpboucC  
{ J @~g>   
sFilePath = value; o3\^9-jmp  
} 6iXV  
?./fVoA]V  
+w(6#R8u5  
public String getSFileName() \!jz1`]&{  
{ IY6Qd4157  
return sFileName; TD*AFR3Oz  
} ^tSwAanP\  
h?;03>6A&]  
A@?-"=h}  
public void setSFileName(String value) x4>"m(&%  
{ -6WSYpHV  
sFileName = value; AxH`4=3<  
} BMQ4i&kF|  
x5xMr.vm  
}@jJv||  
public int getNSplitter() qhG2j;  
{ ReD]M@;  
return nSplitter; 4 ;)t\9cy_  
} ^\ln8!;  
^8bc<c:P  
YahW%mv`d  
public void setNSplitter(int nCount) T`j {2  
{ 55TFBDc  
nSplitter = nCount; pO fw *lD  
} Het>G{  
} 6C<GYzzo  
%XBTN  
N"RPCd_  
/* XYD-5pG  
**Utility.java b;*'j9ly  
*/ <Piq?&VX[  
package NetFox; ZybfqBTD&c  
Wl=yxJu_(  
TG8U=9qt  
public class Utility { m5] a  
*kZH~]  
(4RtoYWW  
public Utility() 7!(/7U6rP  
{ pRxVsOb  
~*\ *8U@7  
"Xwsu8~  
} G(shZ=fq  
3G 5xIr6   
//线程睡眠 (RrC<5"  
public static void sleep(int nSecond) o(> #}[N}  
{ Z  eY *5m  
try{ 1#;^ Z3  
Thread.sleep(nSecond); =_3rc\0  
} b&QI#w  
catch(Exception e) SYQP7oG9oQ  
{ KRn[(yr`%  
e.printStackTrace (); yKK9b  
} wxBZ+UP_  
} xzfugW  
XV4aR3n{Q  
//日志 ~#VDJ[Z  
public static void log(String sMsg) _ MB/p  
{ m~W[,7NE0&  
System.err.println(sMsg); #u+qV!4  
} f-H"|9  
b KIL@AI  
%qE"A6j  
public static void log(int sMsg) FL^t} vA  
{ VK,{Mu=.9  
System.err.println(sMsg); {[/A?AV;F  
} *qLk'<  
} mea} 9]c  
@x A^F%(  
:yi} CM4  
/* |=~mRqG  
**TestMethod.java lfd-!(tXD  
*/ v$JW7CKA  
package NetFox; v+trHdSBYE  
cUd>ah v  
jLO$[c`;  
public class TestMethod { j"pyK@v2B  
5! +{JTXa  
n) D  
public TestMethod() 3QVUWhJ  
{ ///xx/weblogic60b2_win.exe +O8zVWr  
try{ BG.8 q4[  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T*C F5S  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z!fbc#L6  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ypemp=+(r  
fileFetch.start(); -`z%<)!Y  
} >o`+j$j  
catch(Exception e){e.printStackTrace ();} UH+#Nel+!  
qkp0'f*}  
$T66%wX  
} o /1+ }f  
0Y0`$   
X&rsWk  
public static void main(String[] args) <4@8T7  
{ m#O; 1/P  
new TestMethod(); (]&B' 1b  
} 9H:J&'Xi7  
} Zy?!;`c*{  
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