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http断点续传简单实现(java)

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/* 7"K^H]6u30  
**SiteFileFetch.java W_}/O'l{  
*/ 4U{m7[  
package NetFox; +*.1}r&  
import java.io.*; 0Cq!\nzz  
import java.net.*;  d1bhJK  
w+=Q6]FxJ  
[b;Uz|o  
public class SiteFileFetch extends Thread { -l[jEJS}  
(}jL_E  
<+q$XL0  
SiteInfoBean siteInfoBean = null; //文件信息Bean enumK\  
long[] nStartPos; //开始位置 |^ iA6)Q  
long[] nEndPos; //结束位置 y\z > /q  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 A{(T'/~"  
long nFileLength; //文件长度 41}/w3Z4  
boolean bFirst = true; //是否第一次取文件 DxfMqH[vs  
boolean bStop = false; //停止标志 ls @5^g  
File tmpFile; //文件下载的临时信息 Ay%:@j(E  
DataOutputStream output; //输出到文件的输出流 }p{;^B  
*8UYSA~v  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) yoU2AMH2D^  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1R^4C8*B  
{ @ef$b?wg  
siteInfoBean = bean; t:T?7-XIE  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Nb1J ~v  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); oyW00]ka  
if(tmpFile.exists ()) &^+3er rO  
{ u`6/I#q`  
bFirst = false;  i6 L  
read_nPos(); F`srE6H  
} |D<+X^0'  
else *l-`<.  
{ m^A]+G#/  
nStartPos = new long[bean.getNSplitter()]; )Mi'(C;  
nEndPos = new long[bean.getNSplitter()]; ` FxtLG,F  
} U`1l8'W}:#  
4+Ti7p06&\  
F.0d4:A+  
VVLIeJ(*XT  
} H"D 5 e  
Azn:_4O  
-|[~sj-p  
public void run() ?Pnx ~m{%*  
{ fYn{QS?  
//获得文件长度 Q S;F+cmTh  
//分割文件 B{PLIisc  
//实例FileSplitterFetch 9P0yv3  
//启动FileSplitterFetch线程 Pgev)rh[  
//等待子线程返回 /RqhykgZ  
try{ l5HWZs^  
if(bFirst)  #>bT<  
{ X HQh4W3  
nFileLength = getFileSize(); ppFYc\&=  
if(nFileLength == -1) n ,1tD  
{ 6(.H3bu  
System.err.println("File Length is not known!"); 1J'pB;.]s  
} =qX*]  
else if(nFileLength == -2) $',3Pv  
{ ^ $wJi9D6  
System.err.println("File is not access!");  "l2bx  
} $}4K`Iu  
else 2&x7W*  
{ oZ-FF'  
for(int i=0;i<nStartPos.length;i++) GA ik;R  
{ tN}c0'H  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); _>i|s|aW  
} T3rn+BxF7  
for(int i=0;i<nEndPos.length-1;i++) 6l[G1KkV  
{ @'HT;Q!\Vd  
nEndPos = nStartPos[i+1]; Y%h}U<y  
} |Ng"C`$oqv  
nEndPos[nEndPos.length-1] = nFileLength; 5m`[MBt2g  
} 6F-JK1i  
} J[r^T&o  
<A{y($  
pn s+y  
//启动子线程 1MV@5j  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !;+U_j'Pg  
for(int i=0;i<nStartPos.length;i++) (H1lqlVWV#  
{ ] R<FKJ[  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2Y;!$0_rv  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8nsZ+,@+[  
nStartPos,nEndPos,i); ]738Z/)^  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3cHtf  
fileSplitterFetch.start(); uP Rl[tS0  
} /n8 psj  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pg!`SxFD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1I \tu  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yLB~P7K  
nEndPos = " + nFileLength); `oVB!eapl  
// fileSplitterFetch[nPos.length-1].start(); 48k 7/w\  
Uz $ @(C  
RJ*F>2  
//等待子线程结束 f@x_#ov  
//int count = 0; \n;g2/VjO  
//是否结束while循环  mmcdtVe  
boolean breakWhile = false; _4!{IdR  
&SrGh$:X  
UM`nq;>  
while(!bStop) X(b1/lzA  
{ ig$jKou F  
write_nPos(); x5PPu/  
Utility.sleep(500); /6jGt'^U  
breakWhile = true; wibwyzo  
<N-=fad]  
QXB|!'  
for(int i=0;i<nStartPos.length;i++) "qgu$N4/>  
{ {NV:|M!  
if(!fileSplitterFetch.bDownOver) 9#fp_G;=  
{ f)U6p  
breakWhile = false; y<v|X2  
break; T g{UK  
} lvx]jd\  
} c>rKgx  
if(breakWhile) \kyM}5G(<0  
break; Vpw[B.v  
5Edo%Hd6  
C/y(E |zC$  
//count++; {( dP  
//if(count>4) 44j,,k  
// siteStop(); cafsMgrA  
} }U i_ynZ!  
7O9n!aJ  
 ;b|  
System.err.println("文件下载结束!"); '{CWanTPi  
} B#:E?a;{  
catch(Exception e){e.printStackTrace ();} L&'l3|  
} L:i+}F;M)s  
}biCQ*{'  
MISE C[/  
//获得文件长度 @sdS 0pC  
public long getFileSize() 19) !$Hl  
{ R|-j]Ne  
int nFileLength = -1; V pH|R  
try{ dxntGH< O  
URL url = new URL(siteInfoBean.getSSiteURL()); EZ `}*Yrd  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mV%h[~-  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]Ly8s#<g]N  
D Kq-C%  
? o sfL  
int responseCode=httpConnection.getResponseCode(); QheDF7'z  
if(responseCode>=400) A'`P2Am  
{ a-:pJE.'p  
processErrorCode(responseCode); 716hpj#*  
return -2; //-2 represent access is error z 7@ 'CJ  
} q}e]*]dJZ  
 +xq=<jy  
BJ2Q2W W  
String sHeader; d{3I.$ThH  
^9s"FdB]24  
~Zu}M>-^c,  
for(int i=1;;i++) Z>&K&ttJ  
{ 97(n\Wt 2  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W%WC(/hor  
//Utility.log(in.readLine()); {>A 8g({i  
sHeader=httpConnection.getHeaderFieldKey(i); k5C>_( A  
if(sHeader!=null) {<r`5  
{ G_0)oC@Jl:  
if(sHeader.equals("Content-Length")) `;e^2  
{ Q8 4t9b  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;!:F#gahv  
break; rX:1_q`xA  
} x~nQm]@`h  
} n{3| E3  
else L*v93;|s  
break; \wFhTJY  
} C-&#r."L  
} K]9tc)  
catch(IOException e){e.printStackTrace ();} tbY  SK  
catch(Exception e){e.printStackTrace ();} =:;YTie  
xp(mB7;:  
HI z9s4Y_  
Utility.log(nFileLength); ZRUh/<\[  
7fUi?41XA  
I IYLA(  
return nFileLength; AsD1-$  
} )#Y|ngZ_>  
UFos E|r:  
gn364U a  
//保存下载信息(文件指针位置) @ E >eq.m  
private void write_nPos() 6z PV'~q  
{ o;%n,S8J|^  
try{ unpfA#&!"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); YyG~#6aCh  
output.writeInt(nStartPos.length); ~ J%m  
for(int i=0;i<nStartPos.length;i++) A=W5W5l(>  
{ \ x:_*`fU  
// output.writeLong(nPos); Up'."w_zE  
output.writeLong(fileSplitterFetch.nStartPos); XQ4dohGCP  
output.writeLong(fileSplitterFetch.nEndPos); c_t7RWV}  
} 2=Jmi?k  
output.close(); 7f[8ED[4  
} z(#=tC|  
catch(IOException e){e.printStackTrace ();} aam1tm#Q  
catch(Exception e){e.printStackTrace ();} -}N Ab^d  
} 8.PXTOhVL  
Z5yt]-WN&  
T4l-sJ'|  
//读取保存的下载信息(文件指针位置) k-io$  
private void read_nPos() O.dux5lfBd  
{ .\)--+(  
try{ ,b.kw}k  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r,QJG$ Jo  
int nCount = input.readInt(); #%;<FFu\  
nStartPos = new long[nCount]; Q.*'H_Y  
nEndPos = new long[nCount]; V2lp7"  
for(int i=0;i<nStartPos.length;i++) UP5%C;  
{ ^GrNfB[Qu  
nStartPos = input.readLong(); xu`d`!Tx  
nEndPos = input.readLong(); Vvx a.B  
} G#^m<G^M  
input.close(); an pJAB:1  
} 7=L:m7T  
catch(IOException e){e.printStackTrace ();} )H.ubM1  
catch(Exception e){e.printStackTrace ();} EUJ1RhajF  
} .QNjeMu.  
}k4`  
Z3Bo@`&?  
private void processErrorCode(int nErrorCode) (/To?`  
{ wVlSjk  
System.err.println("Error Code : " + nErrorCode); O7! fI'R  
} =%:JjgKc*t  
t%0r"bTi  
:v|r=#OI  
//停止文件下载 ](]*]a4ss  
public void siteStop() $:xF)E  
{ u XaL  
bStop = true; 3- 4Nad  
for(int i=0;i<nStartPos.length;i++) W dei`u[  
fileSplitterFetch.splitterStop(); iH($rSE  
~+7ad$   
+#^sy>  
} rE!G,^_{  
} Y'3k E  
//负责部分文件的抓取 D!81(}p  
**FileSplitterFetch.java v$qpcu#o  
*/ !E4E'I=]N  
package NetFox; Nck!z8  
i!s~kk  
f0:EQYYZ  
import java.io.*; v=dKcruR:  
import java.net.*; e5]&1^+  
4W[AXDS  
p,3go[9X:R  
public class FileSplitterFetch extends Thread { Z5"!0B^ j  
6GvhEulYR  
#L|JkBia  
String sURL; //File URL -='8_B/75  
long nStartPos; //File Snippet Start Position ~e,f)?  
long nEndPos; //File Snippet End Position >DSNKU+j  
int nThreadID; //Thread's ID ~gSF@tz@  
boolean bDownOver = false; //Downing is over &':UlzG  
boolean bStop = false; //Stop identical /zChdjz  
FileAccessI fileAccessI = null; //File Access interface 4SX3c:>  
MR^umLM88  
KIXwx98  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o06A=4I  
{ 'vqj5YTj  
this.sURL = sURL; i{%z  
this.nStartPos = nStart; ?,A}E|jZ  
this.nEndPos = nEnd; I{i:B  
nThreadID = id; D5o+ 0R  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 03i?"MvNo  
} 6Cop#kW#  
<k!mdj)  
8=ukS_?Vy  
public void run() +?4*,8Tmmz  
{ > Z.TM=qj  
while(nStartPos < nEndPos && !bStop) Eg287B  
{ ?NL&x  
CuV=C Ay>  
4\ uZKv@,  
try{ <lg"M;&Ht  
URL url = new URL(sURL); aPcGI  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {9m!UlTtw  
httpConnection.setRequestProperty("User-Agent","NetFox"); *il]$i  
String sProperty = "bytes="+nStartPos+"-"; 0ECO/EuCg  
httpConnection.setRequestProperty("RANGE",sProperty); n $D}0wSM/  
Utility.log(sProperty); A>&>6O4  
Bd N{[2  
ZmYa.4'L  
InputStream input = httpConnection.getInputStream(); 4iL.4Uj{N  
//logResponseHead(httpConnection); 7cOg(6N  
^`hI00u(  
OuYE-x2]x"  
byte[] b = new byte[1024]; %WJ\'@O\  
int nRead; ;%b <uV  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -.+KCt G$+  
{ Y]`lEq%  
nStartPos += fileAccessI.write(b,0,nRead); A~yw8v5UF  
//if(nThreadID == 1) : . FfE  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Kq@m?h  
} !h`cXY~ w  
9;xL!cy  
w<I5@)i|  
Utility.log("Thread " + nThreadID + " is over!"); *`QdkVER  
bDownOver = true; ~L4*b *W  
//nPos = fileAccessI.write (b,0,nRead); Wq[=}qh~  
} 47(1V/r  
catch(Exception e){e.printStackTrace ();} e&FX7dsyy  
} h M1&A  
} mZ& \3m=  
/64^5DjTh  
toYg$IV  
//打印回应的头信息 R4Gg|Bh  
public void logResponseHead(HttpURLConnection con) #h #mOJ5  
{ #1,>Qnl  
for(int i=1;;i++) EP*["fx  
{ !4b; >y=m  
String header=con.getHeaderFieldKey(i); 7-G'8t  
if(header!=null) cfy/*|  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5,=B1  
Utility.log(header+" : "+con.getHeaderField(header)); X&FuqB  
else aQym= 6 %e  
break; bdsHA2r`s  
} Ilt L@]e  
} .T62aJ   
X T)hPwg.  
#P,[fgNy  
public void splitterStop() }77=<N br  
{ `pv89aO  
bStop = true; kVG6\<c]  
} 9 FFfRIVY  
F~d7;x =g  
Y/eN)  
} )2<B$p  
]%Q]C 8[C  
71n uTE%!  
/* i"\AyKiJ  
**FileAccess.java BF1O|Q|d6  
*//文件访问(定位,写) ,$zSJzS  
package NetFox; #G4~]Qml  
import java.io.*; Fh!!T%5>C  
\aJ-q?=  
CrwcYzrRWl  
public class FileAccessI implements Serializable{ j O5:{%  
ym,Ot1  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `Hp.%G(  
RandomAccessFile oSavedFile; l)!woOt  
long nPos; ^hYR5SX  
&Ow?Hd0  
^1FZ`2u;  
public FileAccessI() throws IOException ;P0Y6v3  
{ ? /|@ #&  
this("",0); Zy+QA>d|  
} g]PLW3  
fE7a]R EK  
Rcx'a:k  
public FileAccessI(String sName,long nPos) throws IOException uB#B\i  
{ C$re$9U  
oSavedFile = new RandomAccessFile(sName,"rw"); >-@{vyoOy  
this.nPos = nPos; % OfDTs  
oSavedFile.seek(nPos); y\f8Ird  
} *a0I  Z  
>"$-VY6i  
c:,{ O 0 #  
public synchronized int write(byte[] b,int nStart,int nLen) PuoJw~^h  
{ .T$9Q Ar5  
int n = -1; !y2h`ZAZ  
try{ d`q)^  
oSavedFile.write(b,nStart,nLen); (!&O4C5  
n = nLen; XX5(/#  
} +n.j.JP"X  
catch(IOException e) 4[V6so0  
{ *d,n2a#n5  
e.printStackTrace (); hb8@br  
} K&P{2Hndr  
*~oDP@[S  
-Fw4;&>  
return n; b Ho?Rw!.  
} RKJWLofX&  
JjO/u>A3;7  
@Q1F#IU  
} $O</akn;  
\,IDLXqp  
HgBEV  
/* yI)fu^  
**SiteInfoBean.java t T/*ZzMq#  
*/ 6;c{~$s~[  
package NetFox; YU\t+/b  
*[5#g3  
zB7dCw  
public class SiteInfoBean { ={D B  
Ko1?jPE  
T+{'W  
private String sSiteURL; //Site's URL #?d>S;)+  
private String sFilePath; //Saved File's Path Ywb)h^{!  
private String sFileName; //Saved File's Name kC#B7*[RM  
private int nSplitter; //Count of Splited Downloading File Ex&RR< 5  
(i~%4w=  
D '_#?%3^  
public SiteInfoBean() Yiw^@T\H`  
{//nSplitter的缺省值为5 ~~E=E;9  
//default value of nSplitter is 5 8; N}d)*O  
this("","","",5); owVUL~  
} ] j?Fk$C  
cFNtY~(b  
4a-F4j'  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e5\1k#@  
{ #Q)w$WR  
sSiteURL= sURL; M@z/ gy^  
sFilePath = sPath; Hx/Vm`pRyX  
sFileName = sName; l:C0:m%  
this.nSplitter = nSpiltter; J0)WRn"h  
S gsR;)2  
=,;3z/k%  
} `2~Ea_Z  
X OtS+p  
(%IstR|u:  
public String getSSiteURL() H.S|njn:r  
{ w8@|b}  
return sSiteURL; 'eXw`kw(  
} u= i^F|  
2&f=4b`Z  
WW/m /+  
public void setSSiteURL(String value) 2/gj@>dt  
{ T`DlOi]Z_  
sSiteURL = value; ^?0,G>I%-  
} F(n))`(  
",@g  
Xg#([}b  
public String getSFilePath() ]6 7wk  
{ |,~A9  
return sFilePath; L}pFb@  
} PbH]K$mj{"  
n>+W]I&E  
[5:7 WqB  
public void setSFilePath(String value) @wZ_VE7B  
{ sbhEZ#7#  
sFilePath = value; ^/YAokj  
} vu \Dx9  
QlXF:Gx"=  
]b$,.t5  
public String getSFileName() .B n2;nO  
{ i-W2!;G  
return sFileName; $1 \!Oe[i  
} .F|WQ7Mu  
PG]mwaj])  
lL f01sa4  
public void setSFileName(String value) ]/naH#8G  
{ J}u1\Id%  
sFileName = value; \ku{-^7  
} kpUU'7Q  
a2FIFWvW  
3"%44'  
public int getNSplitter() xeh|u"5  
{ PiQs><FK8  
return nSplitter; Nr+1N83S}  
} |*a>6y  
^%@.Vvz<  
 ?wY.B  
public void setNSplitter(int nCount) gJv^v`X  
{ {vlh ,0~  
nSplitter = nCount; Oz7v hOU  
} 1 niTkop  
} #-,`4x$m|  
GlZDuU  
Kf5p* AI  
/* RuuU}XQ  
**Utility.java wfzb:Aig`  
*/ ]<= t  
package NetFox; sVnu Sm  
#nhAW  
g?M69~G$:x  
public class Utility { FeMu`|2  
( #Aq*2Z.  
;OyM~T gI  
public Utility() /_(Dq8^g@  
{ '>$A7  
tB7aHZ|  
[J 3;U6  
} =@MKU  
? xs0J  
//线程睡眠 "YZ`g}sG  
public static void sleep(int nSecond) :gt wvM7/B  
{ R[t[M}q  
try{ ~ $&  
Thread.sleep(nSecond); =)bc/309  
} RwKN  
catch(Exception e) Q+dI,5YF  
{ R/|o?qTrj  
e.printStackTrace (); `lzH:B  
} `,"Jc<R7Z  
} 56dl;Z)  
oPir]` re  
//日志 w{IqzmPiH  
public static void log(String sMsg) -nSqB{s!SD  
{ >6 q@Tr  
System.err.println(sMsg); j>23QPG`6U  
} KS_d5NvYl  
Q0-~&e_'  
w6 .HvH-@?  
public static void log(int sMsg) `r V,<  
{ |<$O5b'  
System.err.println(sMsg); kA0 ^~  
} Lf9h;z>#  
} +\Q@7Lj  
f*Bc`+G  
yvvR%]!.  
/* ER+[gT1CQ  
**TestMethod.java uy~j$lrn  
*/ v\C+G[MV 7  
package NetFox; E{J;-+t  
b"b!&u  
<s >SnOD  
public class TestMethod { ;7hr8?M|  
$Izk]o;X~  
_De;SB %V  
public TestMethod() hZy*E[i  
{ ///xx/weblogic60b2_win.exe 3t'K@W?AJh  
try{ 5KzU&!Zh9  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '%N p9Iqt  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N 1rrKyL!$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); COafVlJ,l  
fileFetch.start(); \D=B-dREq  
} [<hiOB  
catch(Exception e){e.printStackTrace ();} B7;MY6h#  
" B1' K8  
[cq>QMW  
} b3H;Ea?^^<  
DS yE   
\b->AXe8  
public static void main(String[] args) Y/gCtSF  
{ 2S3F]fG0  
new TestMethod(); B!0[LlF+  
} y\x<!_&D  
} Cpl)byb  
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