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http断点续传简单实现(java)

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/* KQ2jeJ/pj  
**SiteFileFetch.java ~"8)9&  
*/ n Wb0S  
package NetFox; D/Hob  
import java.io.*; |n q}#  
import java.net.*; V>:ubl8j0l  
]}HuK#  
mrId`<L5l{  
public class SiteFileFetch extends Thread { 6ujePi <U  
#P5tTCM  
T Z_](%  
SiteInfoBean siteInfoBean = null; //文件信息Bean 7FvtWE*  
long[] nStartPos; //开始位置 ar[*!:!  
long[] nEndPos; //结束位置 =6^phZ(  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 tZqy \_G  
long nFileLength; //文件长度 fLR\@f  
boolean bFirst = true; //是否第一次取文件 a534@U4,  
boolean bStop = false; //停止标志 f]37Xl%I  
File tmpFile; //文件下载的临时信息 C">w3#M%  
DataOutputStream output; //输出到文件的输出流 a[A9(Ftn  
EH~XN9b  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) I'>r  
public SiteFileFetch(SiteInfoBean bean) throws IOException Y!nxHRE  
{ ! C|VX,w  
siteInfoBean = bean; gy6Pf4Yo  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); t-3y`31i.  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); *9I/h~I  
if(tmpFile.exists ()) <{k r5<  
{ &(t/4)IZox  
bFirst = false; c]!Yb-  
read_nPos(); 0OAHD'  
} < rqFBq 8  
else r'~^BLT`#  
{ Kt\#|-{CH-  
nStartPos = new long[bean.getNSplitter()]; ~.L\f%<  
nEndPos = new long[bean.getNSplitter()]; WC *e#QP  
} '980.  
W*/0[|n*  
J8:f9a:|M  
xIb^x=|h  
} zf}X%tp  
>YuiCf?c7  
,sln0  
public void run() o:8*WCiqrN  
{ Qkq9oZ  
//获得文件长度 .uwD;j +#  
//分割文件 2c4x=%  
//实例FileSplitterFetch Q{"QpVY8  
//启动FileSplitterFetch线程 sm>5n_Vw  
//等待子线程返回 i1k#WgvZR  
try{ [mJmT->  
if(bFirst) FEzjP$  
{ ubZcpqm?Q  
nFileLength = getFileSize(); f!n0kXVu6U  
if(nFileLength == -1) *D6X&Hg&5  
{ rj> _L  
System.err.println("File Length is not known!");  Q  
} 5y%-K=d  
else if(nFileLength == -2) i>}aQ:&^0  
{ 8,m3]Lg  
System.err.println("File is not access!"); %}0B7_6B+@  
} JLFZy\  
else qTD^Vz V  
{ ]31UA>/TI  
for(int i=0;i<nStartPos.length;i++) \n`)>-  
{ +M/1,&  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); _0: }"!Gq  
} GoTJm}[N P  
for(int i=0;i<nEndPos.length-1;i++) l6O8:XI  
{ Y&JK*d  
nEndPos = nStartPos[i+1]; a][QY1E@?  
} wSwDhOX=  
nEndPos[nEndPos.length-1] = nFileLength; xJSK"  
} W$bQS!7y  
} EBl?oN7E  
dqu+-43I|  
DtrR< &m  
//启动子线程 q+}KAk|]V  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $VRVM Y [q  
for(int i=0;i<nStartPos.length;i++) !CO1I-yL  
{ |>U:Pb(  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Sq Y$\&%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?!Bf# "TY  
nStartPos,nEndPos,i); mIy|]e`SJ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <*'%Xgm  
fileSplitterFetch.start(); Gi=s|vt  
} ]dj W^C]94  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CfMCc:8mL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {Jx-Zo>'  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |0Y: /uL#)  
nEndPos = " + nFileLength); 7yM"G$  
// fileSplitterFetch[nPos.length-1].start(); eGF+@)K1"  
X{YY)}^  
1;8%\r[|5^  
//等待子线程结束 R5KOai!  
//int count = 0; ^/V>^9CZ  
//是否结束while循环 >L_nu.x  
boolean breakWhile = false; q<Sb>M/\,  
gFQ\zOlY8a  
f}%paE"  
while(!bStop) :Ou[LF.O  
{ b:6NVHb%  
write_nPos(); f2f2&|7  
Utility.sleep(500); (.Th?p%>7  
breakWhile = true; vi1 D<  
)oU%++cdo  
Wq}Y|0c  
for(int i=0;i<nStartPos.length;i++)  'K7m!y  
{ 9z9\pXFQ  
if(!fileSplitterFetch.bDownOver) &Fg|52  
{ bMp[:dw`y  
breakWhile = false; rQb=/@-  
break; \fD)|   
} 5HqvSfq>?  
} !CGpE=V  
if(breakWhile) Z&![W@m@0N  
break; A6Vb'Gqv{  
S8Ec.]T   
9(AY7]6  
//count++; `$oy4lDKQ  
//if(count>4) p`I[3/$3  
// siteStop(); m*f"Y"B.1I  
} R$;TX^r'o&  
\jx3Fs:Q  
mp z3o\n  
System.err.println("文件下载结束!"); ~JO.h$1C  
} <jBRUa[j_  
catch(Exception e){e.printStackTrace ();} @4n>I+6*&  
} Z}.ZTEB  
Z{1B:aW  
9+3 VK  
//获得文件长度 B lqISyrY  
public long getFileSize() c7RQ7\  
{ iU AY  
int nFileLength = -1; my#\(E+  
try{ R[@}Lg7+v  
URL url = new URL(siteInfoBean.getSSiteURL()); Zpz3 ?VM(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ilAhw4A  
httpConnection.setRequestProperty("User-Agent","NetFox"); d0;?GQYn:  
V)P8w#,  
<,\U,jU _  
int responseCode=httpConnection.getResponseCode(); ^9kx3Pw?8  
if(responseCode>=400) 4eJR=h1  
{ (p<pF].  
processErrorCode(responseCode); }b/P\1#z  
return -2; //-2 represent access is error Nnq1&j"m  
} iUk#hLLC  
(%mV,2|:20  
Z58{YCY  
String sHeader; ]J@-,FFC  
D"%>  
I5 qrHBJ >  
for(int i=1;;i++) l]OzE-*$b  
{ z"Mk(d@-E  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m"QDc[^Ge  
//Utility.log(in.readLine()); Xt +9z  
sHeader=httpConnection.getHeaderFieldKey(i); Q!_d6-*u  
if(sHeader!=null) (>NZYPw^3  
{ aemi;61T\  
if(sHeader.equals("Content-Length")) +}PN+:yV  
{ Je}0KW3G9L  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @_1cY#!  
break; m.<u !MI  
} Qxk& J  
} o4wSt6gBcJ  
else @0d"^  
break; MzDosr3:  
} b'Km-'MtH  
} "p7nngn~  
catch(IOException e){e.printStackTrace ();} y G3aF(  
catch(Exception e){e.printStackTrace ();} B{*{9!(l9  
Gr#3GvL  
(|NCxey  
Utility.log(nFileLength); lqKj;'  
#'0Yzh]qc  
6q6xqr:W  
return nFileLength; *QV"o{V  
} ambr}+}  
,Vw>3|C  
hS&l4 \I'Z  
//保存下载信息(文件指针位置) ,~DV0#"  
private void write_nPos() ZvMU3])u  
{ um}q@BU  
try{ &BRa5`  
output = new DataOutputStream(new FileOutputStream(tmpFile)); iaLZ|\`3a  
output.writeInt(nStartPos.length); PjH'5Y  
for(int i=0;i<nStartPos.length;i++) Wky9w r:g  
{ -$DfnAh  
// output.writeLong(nPos); 2`TV(U@  
output.writeLong(fileSplitterFetch.nStartPos); c+ e~BN  
output.writeLong(fileSplitterFetch.nEndPos); AV7#,+p%G  
} Fk^N7EJ:$  
output.close(); *UJ4\  
} }>d  
catch(IOException e){e.printStackTrace ();} ,Aai-AGG@  
catch(Exception e){e.printStackTrace ();} {M5t)-  
} {_/o' 6  
/;Hr{f jl{  
~f[ Y;  
//读取保存的下载信息(文件指针位置) k5Fj "U  
private void read_nPos() kwL|gO1L  
{ 7eju%d  
try{ >7zC-3  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *tgu@9b  
int nCount = input.readInt(); tW/g0lC%  
nStartPos = new long[nCount]; 8|)^m[c&  
nEndPos = new long[nCount]; F"UI=7:o  
for(int i=0;i<nStartPos.length;i++) 40pz<-B  
{ ;81,1 Ie<~  
nStartPos = input.readLong(); 8-B7_GoJ+B  
nEndPos = input.readLong(); c!/ +0[  
} v"W*@7<`S  
input.close(); zQG{j\  
} `Z8k#z'bN  
catch(IOException e){e.printStackTrace ();} 1 l"2 ~k  
catch(Exception e){e.printStackTrace ();} r PK.Q)g  
} bWAa: r  
7J!s"|VS  
FK593z  
private void processErrorCode(int nErrorCode) | @$I<  
{ .<F46?HS  
System.err.println("Error Code : " + nErrorCode); `SsoRPW&$  
} 7XK0vKmW3  
8hD[z}  
Cj<8r S4+  
//停止文件下载 tP7<WGHd/  
public void siteStop() {MSE}|A\V  
{ 4P k%+l  
bStop = true; XFvl  
for(int i=0;i<nStartPos.length;i++) L_RVHvA=M/  
fileSplitterFetch.splitterStop(); 6UuN-7z!"  
]LUcOR  
tVEe)QX  
} ws+'*7  
} ^`'\eEa  
//负责部分文件的抓取  o+'|j#P  
**FileSplitterFetch.java 5P%#5Yr2  
*/ d#a/J.Z$A  
package NetFox; Y=O+d\_W  
rR-[CT  
M|mfkIk0MB  
import java.io.*; ]}XDDPbZ}  
import java.net.*; $Gv@lZ@=  
ld@+p  
eIY`RMo (  
public class FileSplitterFetch extends Thread { /*T^7Y&  
"TZY)\{L  
"!V`_ S;  
String sURL; //File URL ]s AuL!  
long nStartPos; //File Snippet Start Position Z%]K,9K  
long nEndPos; //File Snippet End Position G?'^"ae"Z  
int nThreadID; //Thread's ID r|u[36NmA  
boolean bDownOver = false; //Downing is over zR?R,k)m  
boolean bStop = false; //Stop identical jRU: un4  
FileAccessI fileAccessI = null; //File Access interface N*}soMPV^.  
N68$b#9Ry  
k`8O/J  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t4_yp_  
{ <@KIDZYC  
this.sURL = sURL; <&l$xn  
this.nStartPos = nStart; ~ p? ArZb  
this.nEndPos = nEnd; XNWtX-[ ^@  
nThreadID = id; e^>>" tr  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~3?-l/$  
} V%r`v%ktF  
!q\=e@j-i  
S F*C'  
public void run() <v|"eq}  
{ 4k<o  
while(nStartPos < nEndPos && !bStop) @)6b  
{ Lc{arhN  
@"MYq#2c$  
M/=36{,w-  
try{ ly17FLJ].  
URL url = new URL(sURL); P\7*ql`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FT- .gi0  
httpConnection.setRequestProperty("User-Agent","NetFox"); )bOfs*S  
String sProperty = "bytes="+nStartPos+"-"; GHcx@||C?  
httpConnection.setRequestProperty("RANGE",sProperty); 5lG\ Z?  
Utility.log(sProperty); at_*Zh(  
'Z4}O_5_  
]u|v7}I4  
InputStream input = httpConnection.getInputStream(); f47]gtB-  
//logResponseHead(httpConnection); EVX3uC}{  
ju{Y6XJ)  
B-rE8 \  
byte[] b = new byte[1024]; b?i+nh qI  
int nRead; CvY+b^;  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g %f5hy  
{ *#XZ*Ga  
nStartPos += fileAccessI.write(b,0,nRead); &L+uu',M0c  
//if(nThreadID == 1) \Mg_Q$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1n8[fgz  
} H~+A6g]T  
z!"vez  
4|`>}Nu  
Utility.log("Thread " + nThreadID + " is over!"); \9VF)Y.ke  
bDownOver = true; Q6qW?*Y  
//nPos = fileAccessI.write (b,0,nRead); (4+P7Z,Nc  
} \sAaVdZJH(  
catch(Exception e){e.printStackTrace ();} 'ztOl`I5V  
} lI=<lmM0|/  
} (SBhU:^h  
90<g=B  
{-\U)&6#v  
//打印回应的头信息 MNd\)nX  
public void logResponseHead(HttpURLConnection con) ."$t&[;s  
{ - eG~  
for(int i=1;;i++) %lHHTZ{+  
{ G tI )O}  
String header=con.getHeaderFieldKey(i); :25LQf^nz  
if(header!=null) 7Bp7d/R-  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y!#-[K:  
Utility.log(header+" : "+con.getHeaderField(header));  rL{R=0  
else !{lH*  
break; XDemdMy$  
} Z10Vx2B  
} k7CKl;Fck  
|"gL {De  
y@3p5o9lv-  
public void splitterStop() t%lat./yT  
{ rm[C{Pn  
bStop = true; >$4# G)s  
} $d?W1D<A  
G\@pg;0|y  
ljKIxSvCFp  
} m-Eh0Zl>Z  
dz_S6o ]  
R*[sO*h\k  
/* =fcg4h5(  
**FileAccess.java KxkBP/`3Q  
*//文件访问(定位,写) b7QE  
package NetFox; Za:j;u Y  
import java.io.*; 1r;zA<<%R  
*&NP?-E  
:o'x?]  
public class FileAccessI implements Serializable{ `L'g<VK;  
RxP H[7oZ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yix[zfQt0  
RandomAccessFile oSavedFile; 6zi>Q?] 1  
long nPos; <CyU9`ye  
]q]xU,  
n=.P46|  
public FileAccessI() throws IOException G!q[NRu  
{ G *CPj^O  
this("",0); W7S~~  
} FnO@\{M"A  
UkL1h7}a\  
R BYhU55B  
public FileAccessI(String sName,long nPos) throws IOException o`bc/3!  
{ Og\k5.! ,  
oSavedFile = new RandomAccessFile(sName,"rw"); 9bM\ (s/  
this.nPos = nPos; <Riz!(G  
oSavedFile.seek(nPos); Ir9GgB  
} M et]|&  
V@ >(xe7  
Cr.YSW g)4  
public synchronized int write(byte[] b,int nStart,int nLen) 0,%{r.\S  
{ KF. {r  
int n = -1; 4{P+p!4  
try{ "_{NdV|a  
oSavedFile.write(b,nStart,nLen); /I%z7f91O  
n = nLen; n4K!Wv&u  
} \Vyys[MMY8  
catch(IOException e) #<*Vc6pC  
{ ~t6q-P  
e.printStackTrace (); $^]K611w9  
} =Hi@q "  
^hIdmTf6  
Z8|<%1Kge  
return n; }v ZOPTP  
} *1)>He$qL  
GJ ^c^`  
WK{`_c U^  
} 51|ky-  
~>u .d  
cQU/z"?+  
/* EeuYRyK  
**SiteInfoBean.java xRh 22z  
*/ j ZXa R  
package NetFox; aO'#!k*R  
N^L@MR-  
8 x{Owj:Q  
public class SiteInfoBean { .biq)L e  
4#$#x=:  
? #K|l*  
private String sSiteURL; //Site's URL ]E`<8hRB  
private String sFilePath; //Saved File's Path Pe,>ny^J1  
private String sFileName; //Saved File's Name lTx_E#^s  
private int nSplitter; //Count of Splited Downloading File ^m>4<~/  
^6s im2  
c!6D{(sfh  
public SiteInfoBean() Itl8#LpLM  
{//nSplitter的缺省值为5 l1+l@r\  
//default value of nSplitter is 5 f"MID6  
this("","","",5); + :MSY p  
} -  x  
$RD~,<oEm  
v] m/$X2  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -,J<X\  
{ {2\Y%Y'}*  
sSiteURL= sURL; R<|\Z@z  
sFilePath = sPath; SI7rTJ]/  
sFileName = sName; 1NZ"\9=U  
this.nSplitter = nSpiltter; F y+NJSG  
n$i X6Cd  
=?i?-6M  
} &W<7!U:2m  
#ArrQeO 5_  
6h:QSVfx  
public String getSSiteURL() n Bu!2c  
{ ?@64gdlwq  
return sSiteURL; H/,KY/>i  
} eaw!5]huu  
^m\o(R  
Kd\0nf6  
public void setSSiteURL(String value) 1/DtF  
{ j\y;~ V  
sSiteURL = value; Ymut]`dX  
} @C;1e7  
+f3Rzx]  
opcanl9pSW  
public String getSFilePath() Hm-#Mpw  
{ Xoj"rR9|  
return sFilePath; !>`Q]M`  
} mF7 Ak&So^  
G~9m,l+  
]2AOW}=  
public void setSFilePath(String value) @Z5q2Q  
{ k/K)nH@)  
sFilePath = value; RXgb/VR  
} AWO)]rM  
[txOh!sxD  
;UdM8+^/V]  
public String getSFileName() B,>02EZ  
{ V DFgu  
return sFileName; vq$6e*A  
} `PWKA;W$0  
yV^Yp=f_  
4]d^L>  
public void setSFileName(String value) IwyA4Ak Ru  
{ wkg4I.  
sFileName = value; |#Gxqq'  
} -gn0@hS0  
!=9x=  
so-5%S  
public int getNSplitter() 'Ru(`" 1|  
{ qCs/sW  
return nSplitter; I%T+H[,  
} pbMANZU[  
(,Y[2_Zv  
{lI}a8DP  
public void setNSplitter(int nCount) 6)INr,d  
{ YvY|\2^K  
nSplitter = nCount; =z1Lim-  
} ~ #jQFyOh  
} H%_^Gy8f  
7oZ :/6_>  
\u[x<-\/6  
/* &V38)83a  
**Utility.java H<Sn p)  
*/ SmXoNiM"y  
package NetFox;  Z-@nXt  
Aztrq  
|Ajd$+3  
public class Utility { z "@^'{.l  
 9q;O`&  
!BQt+4G7  
public Utility() $QJ3~mG2  
{ *i"9D:  
xm m,- u  
o/AG9|()4  
} ~j!n`#.\  
i"Jy>'  
//线程睡眠 P\"kr?jZP  
public static void sleep(int nSecond) T?3Q<[SmI  
{ J=A)]YE  
try{ [S6u:;7  
Thread.sleep(nSecond); fUw:jE xz  
} }?[];FB  
catch(Exception e) gM96RY  
{ NaR} 0  
e.printStackTrace (); t{})6  
} ,,H5zmgA  
} VDxm|7  
EX)&|2w  
//日志 Ez1eGPVr  
public static void log(String sMsg) 9< mMU:  
{ Wn<?_}sa|z  
System.err.println(sMsg); A7 RI&g v5  
} *HrEh;3^J  
}*x1e_m}H  
b(K"CL\p  
public static void log(int sMsg) /k.0gYD  
{ 'F W?   
System.err.println(sMsg); #*(}%!rD*  
} ;4 O[/;i  
} OVLVsNg  
rS@/@jKZE  
[6VB&   
/* Z`TfS+O6  
**TestMethod.java 1/$PxQ  
*/ -2hirA<^  
package NetFox; c>bns/f  
! ._q8q\  
&}DfIP<  
public class TestMethod { y##h(y  
.}__XWK5  
CW1l;uwtU  
public TestMethod() 9p_?t'&>q  
{ ///xx/weblogic60b2_win.exe @a8lF$<  
try{ Tm" H9  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oidZWy  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b0~r/M;J  
SiteFileFetch fileFetch = new SiteFileFetch(bean); '_v~+  
fileFetch.start(); V%-hP~nyBx  
} fe\lSGmf  
catch(Exception e){e.printStackTrace ();} >a8iY|QY  
[8QK @5[  
# ~<]z  
} 1I%u)[;>  
\[9VeqMU  
)^:H{1'  
public static void main(String[] args) m]qw8BoU`F  
{ A-Ba%Fv  
new TestMethod(); :jTSO d[r  
} O84]J:b  
} hQ#e;1uD  
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