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http断点续传简单实现(java)

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/* FEZ6X  
**SiteFileFetch.java #wd \&  
*/ \}Wkj~IX  
package NetFox; 0!VLPA:  
import java.io.*; X or ,}. w  
import java.net.*; 4l1=l#\S  
w2,T.3DT  
=%u|8Ea*`  
public class SiteFileFetch extends Thread { NY;UI (<]  
q7]WR(e  
qB39\j  
SiteInfoBean siteInfoBean = null; //文件信息Bean MU e 'xK  
long[] nStartPos; //开始位置 xh6x B|Z  
long[] nEndPos; //结束位置 9j2I6lGQ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 |)4$\<d  
long nFileLength; //文件长度 __fR #D  
boolean bFirst = true; //是否第一次取文件 Y) h%<J  
boolean bStop = false; //停止标志 8 (KfX%  
File tmpFile; //文件下载的临时信息 ~76.S  
DataOutputStream output; //输出到文件的输出流 C~;0A!@]Y  
bsP ;  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) y;Zfz~z  
public SiteFileFetch(SiteInfoBean bean) throws IOException mce`1Tjw  
{ ^sOm7S{  
siteInfoBean = bean; YJ^ lM\/<  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); h]MVFn{  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); u`'z~N4}  
if(tmpFile.exists ()) }H#t( 9,U  
{ #rpqt{m l  
bFirst = false; :I'Ezxv|  
read_nPos(); -Wn.@bz6B  
} xI4I1"/  
else u/[]g+  
{ *D{/p/|[  
nStartPos = new long[bean.getNSplitter()]; i-FUAR  
nEndPos = new long[bean.getNSplitter()]; tN{t-xUgk  
} @NNLzqqY  
5An0D V5  
N Sh.g #  
u0Erz0*G4  
} xs I/DW  
mCt>s9a)H  
7L+X\oaB  
public void run() BXo|CITso  
{ Qkib;\2  
//获得文件长度 WhZaq  
//分割文件 ?Bzi#Z  
//实例FileSplitterFetch tv OAN|+F  
//启动FileSplitterFetch线程 G; [A Q:Iy  
//等待子线程返回 UBi4itGD  
try{ $vLV< y07  
if(bFirst) ,/:a77  
{ &7T H V  
nFileLength = getFileSize(); P082.:q"  
if(nFileLength == -1) 2E2}|: ||&  
{ rH9}nL  
System.err.println("File Length is not known!"); bX H^Bm  
} 0#[f2X62B  
else if(nFileLength == -2) VDKS_n  
{ Uo}&-$B  
System.err.println("File is not access!"); D i'u%r  
} '= <`@  
else <gdgcvd  
{ b H?qijrC  
for(int i=0;i<nStartPos.length;i++) V0Z7o\-J  
{ Hm VTfH'  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); daIL> c"  
} b'1d<sD  
for(int i=0;i<nEndPos.length-1;i++) , imvA5  
{ n+qVT4o  
nEndPos = nStartPos[i+1]; ewrWSffe  
} EO&ACG  
nEndPos[nEndPos.length-1] = nFileLength; /HuYduGdP  
} ZGpTw[5ql  
} nbASpa(  
pRwGv  
O_Rcd&<mr  
//启动子线程 U[QD!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  aoDD&JE  
for(int i=0;i<nStartPos.length;i++) E^ok`wfO  
{ F>QT|  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `f+8WPJPZ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r^A#[-VyNP  
nStartPos,nEndPos,i); = b<<5N s  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N4H+_g|  
fileSplitterFetch.start(); Yc82vSG'  
} iEpq*Qj  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;:4P'FWm^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d%lHa??/ h  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =*g$#l4  
nEndPos = " + nFileLength);  l}0V+  
// fileSplitterFetch[nPos.length-1].start(); [9O~$! <%  
E,LYS"%_  
F[kW:-ne@Z  
//等待子线程结束 V`\f+Uu  
//int count = 0; `cP'~OT  
//是否结束while循环 E ;!<Z4  
boolean breakWhile = false; *?bk?*?s  
AM[jL'r|  
%R|"Afa=  
while(!bStop) Q*:h/Lhb&  
{ vV.~76AD5  
write_nPos(); 6%kJDY.  
Utility.sleep(500); S&3X~jD(1  
breakWhile = true; =~hsKBt*  
%XI"<Y\yL  
Wzqb>.   
for(int i=0;i<nStartPos.length;i++) `(,*IK a  
{ adI!W-/R:  
if(!fileSplitterFetch.bDownOver) 8pPC 9ew\=  
{ ^.#X<8hr  
breakWhile = false; < m enABN4  
break; M%&A.j[  
} KR=d"t Qw  
} 2]D$|M?$~  
if(breakWhile) 'cZMRR c <  
break; RM&H!E<#  
b6nZ55 h  
$>r>0S#+\&  
//count++; ^m_^  
//if(count>4) #*$_S@  
// siteStop(); 0\'Q&oTo  
} "J pTE \/  
{?*<B=c  
TF=k(@9J?  
System.err.println("文件下载结束!"); * -KJh_  
} j/H>0^  
catch(Exception e){e.printStackTrace ();} c6,s+^^  
} i_=?eUq%q/  
%o@['9U[j  
vm\wO._  
//获得文件长度 9q1HSJ1)  
public long getFileSize() 5wH54g j}  
{ ]3t1=+  
int nFileLength = -1; ]$~Fzs  
try{ I7dm \|#  
URL url = new URL(siteInfoBean.getSSiteURL()); 2.LJp}>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #zS1Z f^KP  
httpConnection.setRequestProperty("User-Agent","NetFox"); Vvm=MBgN  
h `\$sT!Z  
nn@^K6  
int responseCode=httpConnection.getResponseCode(); U!&_mD# c  
if(responseCode>=400) _F`$ d2  
{ !/Iq{2LX  
processErrorCode(responseCode); P +dA~2k  
return -2; //-2 represent access is error Y=vVxVI\  
} mRhd/|g*  
><NI'q*cQ  
)MWUS;O<  
String sHeader; A%Bgp?B  
[1{SY=)  
6<x~Mk'u)  
for(int i=1;;i++) Xhcn]  
{ qH#r-  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zoZ<)x=;  
//Utility.log(in.readLine()); ic*->-!  
sHeader=httpConnection.getHeaderFieldKey(i); erx 5j\  
if(sHeader!=null) L*g. 6+2  
{ ZV'$k\  
if(sHeader.equals("Content-Length")) lWx  
{ %G;0T;0L  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I|,pE**T  
break; Y5dD|]F|  
} No`|m0 :j  
} GE1i+.+-.  
else /g_9m  
break; %#~((m1  
} n*4lz^LR  
} oZTgN .q  
catch(IOException e){e.printStackTrace ();} 4k8*E5cx  
catch(Exception e){e.printStackTrace ();} bIgh@= 2  
P$Z}  
z]kwRWe`j  
Utility.log(nFileLength); Y3-gUX*w0  
25 CZmsg  
x_*%*H  
return nFileLength; ^SZw`]  
} %*wzO9w4  
!^m%O0DT  
B:4Ka]{YO  
//保存下载信息(文件指针位置) I @ 2uF-  
private void write_nPos() pO%{'%RA  
{ Ve{n<{P  
try{ C ye T]y  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4/S=5r}  
output.writeInt(nStartPos.length); Hd9XfU  
for(int i=0;i<nStartPos.length;i++) Ju!(gh  
{ [r)e P({  
// output.writeLong(nPos); +l`65!"  
output.writeLong(fileSplitterFetch.nStartPos); 'Qa5n\HX$  
output.writeLong(fileSplitterFetch.nEndPos); eD%H XGe  
} 96d~~2p  
output.close(); -fE.<)m=!  
} /~De2mq1   
catch(IOException e){e.printStackTrace ();} bEm7QgV{X  
catch(Exception e){e.printStackTrace ();} *5_V*v6  
} ~q)u(W C|  
.XXW|{  
7R}9oK_I  
//读取保存的下载信息(文件指针位置) uG!:Z6%p  
private void read_nPos() /F.Wigv  
{ ,P{mk%=9  
try{ xH-X|N  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f-Jbs`(+  
int nCount = input.readInt(); )qL&%xz  
nStartPos = new long[nCount]; :ygWNK[ 6D  
nEndPos = new long[nCount]; >ys[I0bo  
for(int i=0;i<nStartPos.length;i++) ! QM.P t7c  
{ j~;;l!({i  
nStartPos = input.readLong(); H~noJIw#  
nEndPos = input.readLong(); OS-sk!  
} ^W~p..DF  
input.close(); &(EHq  
} j[I`\"  
catch(IOException e){e.printStackTrace ();} T*?s@$)m4  
catch(Exception e){e.printStackTrace ();} V A<5uk04K  
} FmEc`N9\v  
} bH$O%  
z-dFDtiA  
private void processErrorCode(int nErrorCode) -w1@!Sdd  
{ J'b<z.OW  
System.err.println("Error Code : " + nErrorCode); > _ <'D  
} @@@=}!<H=  
=pcF:D#+  
&?0:v`4Y  
//停止文件下载 >-.e AvD  
public void siteStop() !v|FT. T`  
{ O}Hf62"  
bStop = true; fH\X  
for(int i=0;i<nStartPos.length;i++) $= B8qZ+  
fileSplitterFetch.splitterStop();  8"%RCE  
-'`TL$  
K_~h*Yc  
} <[Q3rJ  
} Xd<t5{bD!  
//负责部分文件的抓取 S4N(cn&  
**FileSplitterFetch.java ('O}&F1  
*/ ZrO!L_/  
package NetFox; +x=)/;:  
?^i1_v7 Bi  
0V$k7H$Z  
import java.io.*; 4[yIOs  
import java.net.*; ?WUF!Jk  
DZ$` 4;C[  
W#'c 5:m 4  
public class FileSplitterFetch extends Thread { VA] e  
lx |5?P  
,E;;wdIt  
String sURL; //File URL 0p(L'  
long nStartPos; //File Snippet Start Position ,HB2 hHD  
long nEndPos; //File Snippet End Position .pPm~2]z  
int nThreadID; //Thread's ID R!(ZMRMn  
boolean bDownOver = false; //Downing is over >(r{7Qg  
boolean bStop = false; //Stop identical ht=P\E  
FileAccessI fileAccessI = null; //File Access interface g13 rx%-  
cc}Key@D  
0nJE/JZ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iD`d99f8O  
{ l[Q:}y  
this.sURL = sURL; K4Sk+ v  
this.nStartPos = nStart; yNg9X(U  
this.nEndPos = nEnd; $P z`$~  
nThreadID = id; ,CvG 20>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <eN_1NTH_  
} @%/]Q<<q  
j}1zdA  
mYxyWB  
public void run() "{D6J809  
{ |4(~%| 8{  
while(nStartPos < nEndPos && !bStop) G{Yz8]m  
{ 3S*AxAeg  
Yd EptAI  
8uNULob  
try{ kDvc" ,SD#  
URL url = new URL(sURL); 0NDftcB]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N8toxRu  
httpConnection.setRequestProperty("User-Agent","NetFox"); TlZT1H  
String sProperty = "bytes="+nStartPos+"-"; =(v^5  
httpConnection.setRequestProperty("RANGE",sProperty); O.G'?m<: #  
Utility.log(sProperty); O.`Jl%  
k o;>#::  
=U8Ek;Drp  
InputStream input = httpConnection.getInputStream(); );V2?G`/  
//logResponseHead(httpConnection); *N'K/36;  
{-3LIO  
)s_n  
byte[] b = new byte[1024]; cD*}..-/4  
int nRead; lot%N(mB`  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ub1hHA*)  
{ %`MQmXgM  
nStartPos += fileAccessI.write(b,0,nRead); !RB)_7  
//if(nThreadID == 1) <"N_j]wD  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s m,VYYs  
} {n#k,b&9B  
E>b2+;Jv  
r3E!dTDWq  
Utility.log("Thread " + nThreadID + " is over!"); G!w"{Bk?9  
bDownOver = true; /1N6X.Zb  
//nPos = fileAccessI.write (b,0,nRead); uvDzKMw~R  
} &QRE"_g  
catch(Exception e){e.printStackTrace ();} qgIb/6;xQ  
} +gd4\ZG  
} ca i <,3H  
zgx&Pte  
6E(Qx~i L  
//打印回应的头信息 Y8M]Lwj  
public void logResponseHead(HttpURLConnection con) }En  
{ !+>v[(OzM  
for(int i=1;;i++) qm/Q65>E  
{ :NJ_n6E  
String header=con.getHeaderFieldKey(i); pl@O N"=[  
if(header!=null) ,B?~-2cCz  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )?+$x[f!*  
Utility.log(header+" : "+con.getHeaderField(header)); vgY3L  
else Z;9>S=w!  
break; ^b:( jI*l  
} ;!:U((wv  
} :w}{$v}#D;  
T134ZXqqz  
ojYbR<jn9  
public void splitterStop() 'z76 Sa  
{ sn7AR88M;  
bStop = true; f}g\D#`]/  
} Lg8nj< TF  
*I}`dC[  
'iLpE7  
} 4tL<q_  
~ wg:!VWA)  
X%yO5c\l2  
/* ]7-&V-Ct*  
**FileAccess.java F, U*yj  
*//文件访问(定位,写) SGb;!T *  
package NetFox; J>fQNW!{  
import java.io.*; +"9hWb5  
RMMd#/A@}  
W3`>8v1?o  
public class FileAccessI implements Serializable{ zJe#m|Z  
f{SB1M   
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @`\VBW  
RandomAccessFile oSavedFile; OL4z%mDZi  
long nPos; LU!dN"[k  
&-(463  
3u%{dGa  
public FileAccessI() throws IOException 3?Y2L  
{ +P.+_7+:  
this("",0); ^C2\`jLMY  
} U,nEbKJgk  
+`?Y?L^ J  
WJI[9@^I~  
public FileAccessI(String sName,long nPos) throws IOException [O: !(G je  
{ SG6sw]x  
oSavedFile = new RandomAccessFile(sName,"rw"); j*~T1i  
this.nPos = nPos; L^Jk=8  
oSavedFile.seek(nPos); =zwOq(Bh W  
} ~-wPP{!  
jxYc2  
(O0Urm  
public synchronized int write(byte[] b,int nStart,int nLen) R|i/lEq  
{ H'Yh2a`!o  
int n = -1; sz9L8f2  
try{ CI3XzH\IX*  
oSavedFile.write(b,nStart,nLen); Z7 E  
n = nLen; bWOS `5  
} re> rr4@  
catch(IOException e) ?%H):r  
{ _X@v/sAy  
e.printStackTrace (); cQ9q;r`%  
} {Zp\^/  
Nk {XdrY  
V!)O6?l  
return n; T#bu V  
} ZvcJK4hi  
g-Pwp[!qkf  
Web|\CH  
} OyqNLR  
fu~ +8CE.  
Bn>8&w/P  
/* `a9L%z  
**SiteInfoBean.java ZE%YXG  
*/ ~o n(3|$  
package NetFox; b(9FZ]7S  
>I=2!C1w  
ZJlEKib%2  
public class SiteInfoBean { x W92ch+t  
Wb S4pdA  
>[X{LI(_<<  
private String sSiteURL; //Site's URL 6~*9;!th  
private String sFilePath; //Saved File's Path 4DTzSy:x  
private String sFileName; //Saved File's Name G7D2{J{1  
private int nSplitter; //Count of Splited Downloading File ;E'"Ks[GH  
[Y`,qB<B  
9{:O{nl  
public SiteInfoBean() eI@ q|"U  
{//nSplitter的缺省值为5 ,^S@EDq  
//default value of nSplitter is 5 !0N7^Z"gtz  
this("","","",5); iOG[>u0h  
} ?&Pg2]g<  
*cyeO*  
a ^%"7Ri  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @)K%2Y`  
{ M,ir`"s  
sSiteURL= sURL;  C:G8c[  
sFilePath = sPath; %Q!`NCe+[  
sFileName = sName; x\QY@9  
this.nSplitter = nSpiltter; 2.d|G `  
t='# |');  
cW+t#>' r  
} ,K^4fL$C;3  
Oh4AsOj@  
`c'W-O/  
public String getSSiteURL() Yq/.-4 y  
{ hTwA%  
return sSiteURL; 'g9"Qv?0{`  
} [V}S <Xp  
]D,MiDph  
5aa<qtUjH  
public void setSSiteURL(String value) j^`hzh3S  
{ A19;1#$=  
sSiteURL = value; A4ISNM7R[  
} J/3_C6UZ  
'TA UE{{  
Z y_V9j[n  
public String getSFilePath() M?;y\vS?.  
{ +&["HoKg}&  
return sFilePath; b=/curl&  
} cCR+D.F  
Dr6A ,3B  
c5mZG7-  
public void setSFilePath(String value) U"50_O  
{ +d|mR9^([  
sFilePath = value; asC_$tsMe  
} +CI1V>6^  
?Mee 6  
'FYJMIs  
public String getSFileName() *s;|T?~i  
{ O2"gj"D  
return sFileName; vp.ZK[/`  
} O-4C+?V  
r:]1 O*  
@9&P~mo/  
public void setSFileName(String value) t3+Py7qv  
{ SI8%M=P>  
sFileName = value; gsn)Wv$h  
} 1 1cWy+8D  
07hF2[i  
~ Uo)0  
public int getNSplitter() }Nb8}(6  
{ 72,rFYvpK  
return nSplitter; EKp@9\XBC  
} \.g\Zib )  
@UdfAyL  
lqb/eN9(t  
public void setNSplitter(int nCount) IVW1]y  
{ i.:. Y  
nSplitter = nCount; ~i.k$XGA  
} $2%f 8&  
} _$>pw<  
yOvm`9  
lq"f[-8a2q  
/* BAO|)~1Pd  
**Utility.java 0T>H)c6:\  
*/ 72veLB  
package NetFox; 5 B=^v#m  
P#:?ok  
wYlf^~#"  
public class Utility { J6jwBo2m  
u~)`&1{%  
Y\0}R,]a-  
public Utility() U w4>v:  
{ qn,O40/]  
f$'2}'.!$  
S'HnBn /  
} ko^\ HSXl  
eW>3XD4  
//线程睡眠 XerbUkZ  
public static void sleep(int nSecond) 95<EN (oUD  
{ %2V-~.Ro6  
try{ Rml2"9"`  
Thread.sleep(nSecond);  RD tU43  
} Q#IG;  
catch(Exception e) nQ GQWg`  
{ FV,4pi  
e.printStackTrace (); ,y%3mR_~  
} _Ob@`  
} Iz[@^IUx=  
jM:Y' l]  
//日志 mYU9 trHV  
public static void log(String sMsg) |] Qg7m,O  
{ _uJ"m8Tl  
System.err.println(sMsg); a[2vjFf#C  
} X<R?uI?L  
jVH|uX"M5Y  
2[gFkyqe  
public static void log(int sMsg)  ykrr2x  
{ ujJI 1I  
System.err.println(sMsg); ` }3qhar  
} yAN=2fZm  
} G"T',~  
Z;h<6[(  
A*|cdY]HP  
/* [le)P$#z  
**TestMethod.java O 1oxZj <  
*/ vF?5].T  
package NetFox; [ 4;Ii  
qp}Ma8+  
'<0J@^vZ  
public class TestMethod { a {ab*tM  
}^(}HBT  
XO <y +  
public TestMethod() /\) a  
{ ///xx/weblogic60b2_win.exe @x/T&67k  
try{ N4*G{g  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cJgBI(S5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,TRTRb;  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~8m=1)A{(  
fileFetch.start(); jLJ1u/l>;  
} Jxqh )l  
catch(Exception e){e.printStackTrace ();} F]m gmYD%  
$3,ryXp7  
d(:3   
} H'qG/@u-l  
=YG _z^'  
` gW<M  
public static void main(String[] args) mm5$> [%U  
{ Uje|`<X  
new TestMethod(); ,/O[=9l36R  
} v2,%K`pAU  
} QKE9R-K TE  
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