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http断点续传简单实现(java)

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/* T30fp  
**SiteFileFetch.java "= %"@"<)  
*/ 8rS;}Bt  
package NetFox; _eq$C=3Ta  
import java.io.*; #BcUE?K*N  
import java.net.*; 41d+z>a]  
<z2.A/L  
6'N_bNW  
public class SiteFileFetch extends Thread {  QtG6v<A  
ps:`rVQ7  
13Z,;YW  
SiteInfoBean siteInfoBean = null; //文件信息Bean HyWR&0J  
long[] nStartPos; //开始位置 '" %0UflJS  
long[] nEndPos; //结束位置 f42F@M(:  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ~7KH/%Z-  
long nFileLength; //文件长度 wG7>2*(  
boolean bFirst = true; //是否第一次取文件 @:PMb Ub  
boolean bStop = false; //停止标志 :x[()J~N  
File tmpFile; //文件下载的临时信息 Ri`6X_xU  
DataOutputStream output; //输出到文件的输出流 Mb[4_Dc  
@$^4Av-  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) $.$nv~f  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5EVypw?]x  
{ hZ>m:es  
siteInfoBean = bean; KWjhkRK4]  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); g9JZ#BgZ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); <EgJm`V  
if(tmpFile.exists ()) {_*G"A 9  
{ "&f|<g5  
bFirst = false; \xggIW.^0  
read_nPos(); |;~2y>E  
} LXxQI(RO  
else p&Qm[!  
{ `5h^!="  
nStartPos = new long[bean.getNSplitter()]; HH7WMYoKY  
nEndPos = new long[bean.getNSplitter()]; \db=]L=|  
} CC"a2Hu/  
sCY  
#o} /'  
_<mY|  
} ?t6wozib2  
{*hvzS{1d  
e~(e&4pb  
public void run() A'~mJO/   
{ [o(!/38"@=  
//获得文件长度 4XVwi<)  
//分割文件 9#hp]0S6  
//实例FileSplitterFetch |y0k}ed  
//启动FileSplitterFetch线程 65O 8?I  
//等待子线程返回 fUY05OMZ  
try{ /%,aX [  
if(bFirst) s:xJ }Ll  
{ ke;=Vg|  
nFileLength = getFileSize(); Z:AB (c  
if(nFileLength == -1) f'5 6IT  
{ <Fx%P:d  
System.err.println("File Length is not known!"); W<#!He  
} <XDnAv0t  
else if(nFileLength == -2) ~/JS_>e#6P  
{ gfIS  
System.err.println("File is not access!"); Z&iW1  
} $G)HU6hF*  
else 6la'\l#  
{ u8>aO>(bVg  
for(int i=0;i<nStartPos.length;i++) u ynudO  
{ 1QD49)  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6XZjZ*)W  
} H{N},B  
for(int i=0;i<nEndPos.length-1;i++) PknKzrEG:>  
{ 0L32sF y  
nEndPos = nStartPos[i+1]; #T>?g5I  
} t}Td$K7  
nEndPos[nEndPos.length-1] = nFileLength; z?Z"*z  
} d(^HO~p  
} `<v$+mG  
Z}vDP^rf  
Pvt!G  
//启动子线程 W*_c*  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <N~9=g3  
for(int i=0;i<nStartPos.length;i++) j[\:#/J  
{ 6qTMHRI  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T!9AEG  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B?^~1Ua9Zv  
nStartPos,nEndPos,i); J;wBS w%1  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q=DMfJ"  
fileSplitterFetch.start(); l"`VvW[  
} rf@47H  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jLM y27Cn  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pn9;&`t  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |1A0YjOD  
nEndPos = " + nFileLength); D{\o*\TN  
// fileSplitterFetch[nPos.length-1].start(); |X XO0  
}xBO;  
zd$?2y8  
//等待子线程结束 Hu6Qr  
//int count = 0; WH39=)D%u  
//是否结束while循环 i g7|kl  
boolean breakWhile = false; E`qX|n  
gSwHPm%zn  
d(RMD  
while(!bStop) f2o6GC_  
{ Y7q Q` |  
write_nPos(); 1c]{rO=taN  
Utility.sleep(500); u]O}Ub`  
breakWhile = true; GKF!GbGR@  
4 Cd5-I  
7_jt =sr  
for(int i=0;i<nStartPos.length;i++) n=~!x  
{ <{;'0> ToM  
if(!fileSplitterFetch.bDownOver) '4#NVXVQm  
{ >cmz JS  
breakWhile = false; &3"ODAp'  
break; *$R9'Yo}F  
} c1FSQ m81  
} _](y<O^9yO  
if(breakWhile) b5]<!~Fv:`  
break; T;{}bc&I  
C}3a  ^j  
l4taD!WD/  
//count++; |k]]dP|:'  
//if(count>4) WwWOic2  
// siteStop(); os;9 4yd )  
} (7! pc  
toD!RE  
9SA%'  
System.err.println("文件下载结束!"); %rrD+  
} OIw[sum2  
catch(Exception e){e.printStackTrace ();} bw/mF5AsW  
} qHyOaK Md  
a[j]fv*6  
gn.)_  
//获得文件长度 6+ptL-Zt<  
public long getFileSize() c'VCCXe  
{ F|!=]A<  
int nFileLength = -1; 9mXmghoCO  
try{ vyWx{ @  
URL url = new URL(siteInfoBean.getSSiteURL()); ALO/{:l(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _D{FQRU<YD  
httpConnection.setRequestProperty("User-Agent","NetFox"); t(PA+~sIp  
`.pd %\  
nwfu@h0G  
int responseCode=httpConnection.getResponseCode(); SCMvq?9  
if(responseCode>=400) %q;y74  
{ V(LfFO{^>?  
processErrorCode(responseCode); daSx^/$R  
return -2; //-2 represent access is error u^]Gc p  
} 0i8\Lu6  
#pW!(tfN^a  
~~"U[G1  
String sHeader; l'2vo=IQ  
FGc#_4SiL  
jG& 8`*|*  
for(int i=1;;i++) |cuKC \  
{ @~7au9.V=X  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D8E^[w!  
//Utility.log(in.readLine()); !U2<\!_  
sHeader=httpConnection.getHeaderFieldKey(i); * &#M`,#  
if(sHeader!=null) Si23w'T  
{ 9)=bBQyr:  
if(sHeader.equals("Content-Length")) _^RN$4.R>  
{ O#J7GbrHO  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %$)Sz[=  
break; LB$0'dZU  
} zZ51jA9x  
} qJl DQc-  
else J%q)6&  
break; In:V.'D/>t  
} 0%HAa|L,,  
} &jg>X+;  
catch(IOException e){e.printStackTrace ();} n++ak\  
catch(Exception e){e.printStackTrace ();} Unt]=S3u  
fo>_*6i74  
@J^ Oy 3z  
Utility.log(nFileLength); &IDT[J  
9|@5eN:N  
/&@q*L  
return nFileLength; y9@j-m&  
} 5=9Eb  
>OjK0jiPf  
]JmE(Y1(1  
//保存下载信息(文件指针位置) I`g&>  
private void write_nPos() Q=[ IO,f  
{ HKOSS-`5  
try{ AhjCRYk+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); g.8^ )u  
output.writeInt(nStartPos.length);  =mcQe^M  
for(int i=0;i<nStartPos.length;i++) n >E1\($  
{ *N{k#d/  
// output.writeLong(nPos); u!It' ;j  
output.writeLong(fileSplitterFetch.nStartPos); { Ngut  
output.writeLong(fileSplitterFetch.nEndPos); pxyFM@Z](  
} Ho&f[T(  
output.close(); S @!z'$&  
} "_BWUY  
catch(IOException e){e.printStackTrace ();} !VudZ]Sg  
catch(Exception e){e.printStackTrace ();} O\]{6+$fm!  
} ZN'B @E=p  
# M3d=  
_|MK0'+f  
//读取保存的下载信息(文件指针位置) E2.!|u2  
private void read_nPos() $kR%G{j 4  
{ hQ L@q7tUr  
try{ y6G6wk;  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O_ $zK  
int nCount = input.readInt(); [z;}^3b  
nStartPos = new long[nCount]; m*7RC4"J  
nEndPos = new long[nCount]; ]D2 d=\  
for(int i=0;i<nStartPos.length;i++) DmB?.l-  
{ hS%oQ)zvE  
nStartPos = input.readLong(); lPA}06hU  
nEndPos = input.readLong(); _IxYnm`pc  
} Ib/e\+H\  
input.close(); z<yqQ[  
} 7o*~zDh@fH  
catch(IOException e){e.printStackTrace ();} /6 x[C  
catch(Exception e){e.printStackTrace ();} PCc{0Rp\vk  
} D7B g!*  
iM8l,Os]<f  
}^n"t>Z8  
private void processErrorCode(int nErrorCode) fP( n3Q  
{ =gd~rk9  
System.err.println("Error Code : " + nErrorCode); k%N$eO$  
} Vm I Afe  
?4W6TSW-'  
3Dj>U*fP  
//停止文件下载 mv/ Nz?  
public void siteStop() 3|URlz  
{ @lh]? |*[  
bStop = true; i~4$V  
for(int i=0;i<nStartPos.length;i++) (ze9-!%  
fileSplitterFetch.splitterStop(); K)n058PO  
k&u5`F  
k$7Kz"  
} Mt~2&$>  
} pYUQSsqC  
//负责部分文件的抓取 @zt"Y~9i  
**FileSplitterFetch.java <hgfgk7<  
*/ }tH_YF}u  
package NetFox; cy2K#  
bK!uR&i^l  
hb)83mH}  
import java.io.*;  [cfXcl  
import java.net.*; ,x[~|J!  
ob[G3rfd@Z  
5'wFZ=>vMt  
public class FileSplitterFetch extends Thread { ZNDjk  
QbWeQ[V{  
)fke;Y0  
String sURL; //File URL j4#S/:Q<7  
long nStartPos; //File Snippet Start Position 9m%+6#|  
long nEndPos; //File Snippet End Position "1Y DT-I"  
int nThreadID; //Thread's ID og*ti!Z  
boolean bDownOver = false; //Downing is over >T\^dHtz  
boolean bStop = false; //Stop identical 2aUE<@RU[  
FileAccessI fileAccessI = null; //File Access interface dA(+02U/.  
,LU|WXRB  
k/Ao?R=@gI  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y5mk*Q#q  
{ WBD"d<>'  
this.sURL = sURL; >IZ$ .-  
this.nStartPos = nStart; `n`HwDo;i  
this.nEndPos = nEnd; ,!^;<UR:  
nThreadID = id; -e+im(2D=  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {]7lh#M  
} P@Pe5H"o  
'H1k  
`4qtmbj  
public void run() A_.}- dzF  
{ e~6>8YO+7j  
while(nStartPos < nEndPos && !bStop) S<w? ,Z  
{ Z,, qmwd  
u6*0% Km  
~(.&nysZ-  
try{ GM0pHmC  
URL url = new URL(sURL); tRTJQ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0\o5+  
httpConnection.setRequestProperty("User-Agent","NetFox"); _J_QB]t  
String sProperty = "bytes="+nStartPos+"-"; L^ U.h  
httpConnection.setRequestProperty("RANGE",sProperty); W)odaab7  
Utility.log(sProperty); u&o<>d;)  
bI)%g  
{>X2\.Rl  
InputStream input = httpConnection.getInputStream(); v 5&8C  
//logResponseHead(httpConnection); ,e*WJh8k[  
AIM<mU  
^`9O$.'@  
byte[] b = new byte[1024]; .H86f !=  
int nRead; A] f^9F@  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H+N6VVnO  
{ wJWofFz  
nStartPos += fileAccessI.write(b,0,nRead); Gnie|[3  
//if(nThreadID == 1) 9Om3<der  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6[a;83  
} 90a!_8o  
9H cxL  
ZBc8 ^QZ  
Utility.log("Thread " + nThreadID + " is over!"); +,4u1`c|$  
bDownOver = true; ^ `[T0X  
//nPos = fileAccessI.write (b,0,nRead); 42PA?^xPw  
} '#612iZo  
catch(Exception e){e.printStackTrace ();} A+"'8%o9}  
} Es1T{<G|w  
} *HQ>tvUh  
D [K!xq  
edfb7prfTl  
//打印回应的头信息 mf gUf  
public void logResponseHead(HttpURLConnection con) lnrs4s Km  
{ Y\9zjewc  
for(int i=1;;i++) Rw`64L_  
{ wG&rkg";#  
String header=con.getHeaderFieldKey(i); <im<0;i&e  
if(header!=null) 3'tq`t:SQ  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e,@5`aYHM@  
Utility.log(header+" : "+con.getHeaderField(header)); bxAHzOB(\  
else @`rC2-V  
break; uVZX53 ,g  
} jG/@kh*m  
} zIc_'Z,b  
8qv>C)~~`  
|I=GI]I  
public void splitterStop() 7n'Ww=ttI  
{ %u*HNo  
bStop = true; G~zP&9N|  
} )1Z @}o 9  
Vx=tP.BO]  
qfgw^2aUa  
} wF{M"$am  
j k/-7/r  
3\a VZx!  
/* Qs8Rb]%|  
**FileAccess.java b'(Hwc\ t  
*//文件访问(定位,写) ,o6,(jJU  
package NetFox; HurF4IsHk  
import java.io.*; nM H:7[x3  
q.d qr<  
OCWyp  
public class FileAccessI implements Serializable{ d'e\tO  
oSkvTK$ &i  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G8Zl[8  
RandomAccessFile oSavedFile; _16r8r$V  
long nPos; D#d \1g  
'TDp%s*;  
L=kETJ:g  
public FileAccessI() throws IOException $`"$ZI6[  
{ 8:"s3xaO3  
this("",0); md /NMC \  
} Z" dU$ ,n  
'F Cmbry  
l +# FoN  
public FileAccessI(String sName,long nPos) throws IOException E5t /-4  
{ 7Q # A  
oSavedFile = new RandomAccessFile(sName,"rw"); k, jcLX.  
this.nPos = nPos; ePiZHqIsv/  
oSavedFile.seek(nPos); c^}DBvG,  
} 4siq  
23P7%\  
3u1\zse  
public synchronized int write(byte[] b,int nStart,int nLen) \&^U9=uq  
{ p)*x7~3e  
int n = -1; OT}P0 ~4s  
try{ J?qikE&  
oSavedFile.write(b,nStart,nLen); !'kr:r}gg  
n = nLen; ;^  YpQP  
} }n?D#Pk,  
catch(IOException e) ]oyWJ#8  
{ >$;,1N $bd  
e.printStackTrace (); PS`F  
} J''lOj(@  
\NQ[w7  
kQO5sX$;  
return n; QzV%m0  
} ZEG~ek=jM  
hGU 3DKHT  
Z>ztFU  
} SBamgc  
:hDv^D?3  
$qM&iI-l0  
/* 8l>YpS*S^  
**SiteInfoBean.java 9K=K,6 b  
*/ /Ca M(^W   
package NetFox; 4'H)h'#C  
F2dwT  
D1Q]Z63,  
public class SiteInfoBean { \N)!]jq  
]N6UY  
fq !CB]C  
private String sSiteURL; //Site's URL P B{7u  
private String sFilePath; //Saved File's Path XPMvAZL  
private String sFileName; //Saved File's Name *I`Eb7 ^  
private int nSplitter; //Count of Splited Downloading File FQ]5W |e  
@4P_Yfn  
+D M,+{}  
public SiteInfoBean() !1`f84d  
{//nSplitter的缺省值为5 P&AaD!Qn  
//default value of nSplitter is 5 j`_tb   
this("","","",5); <E7y:%L[Go  
} ~!'T!g%C  
jN!sL W  
``Rg0o  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^2"w5F  
{ %WtF\p  
sSiteURL= sURL; x=V3_HI/}  
sFilePath = sPath; >* ]B4Q  
sFileName = sName; P$"s*otr  
this.nSplitter = nSpiltter; &IkHP/  
.Iv`B:4  
$QaEU="Z  
} r z5@E  
JgcMk]|'  
z"V`8D  
public String getSSiteURL() [m9=e-KS$Q  
{ fILD~  
return sSiteURL; %TzdpQp"  
} K#dG'/M|Pb  
@mEB=X(-l=  
{hx=6"@  
public void setSSiteURL(String value) j]6YLM@5$  
{ gflO0$i  
sSiteURL = value; p I@!2c:}  
} j +Ro?  
QMwV6cA  
|S3wCG  
public String getSFilePath() [V41 Gk  
{ l/56;f\IA  
return sFilePath; a-9sc6@  
} W7.QK/@  
l:sfM`Z^[  
x^y&<tA  
public void setSFilePath(String value) (^^}Ke{J  
{ oC(.u?  
sFilePath = value; `&SBp }W}  
} <Mf(2`T  
^P owL:  
}*vO&J@z  
public String getSFileName() _sF Ad`  
{ 0#/Pc`z C  
return sFileName; cfPQcB>A  
} C.+:FY.H  
mWH;-F*%  
*NQsD C.J^  
public void setSFileName(String value) g3\1 3<  
{ -@/!u9l  
sFileName = value; r1.OLn?C  
} O @{<?[  
S|T*-?|  
&;$- &;  
public int getNSplitter() >!#or- C  
{ Ej'N !d.  
return nSplitter; 6KKQ)DNu_  
} ]?~[!&h  
$H1igYc  
A "~Oi  
public void setNSplitter(int nCount) BV]$= e'  
{ wQ\bGBks  
nSplitter = nCount; =[`gfw  
} -_BjzA|  
} .$ 5*v  
<Sp>uhet1  
Z8WBOf*~e  
/* y(jd$GM|  
**Utility.java Klqte*!  
*/ wK  Je^7  
package NetFox; [)nU?l  
64f6D"."  
rqhRrG{L|&  
public class Utility { 2yA+zJ 46B  
8<Ex`  
N-}|!pqb  
public Utility() Q=#!wWVP  
{ jQpG7H  
cDh\$7'b  
J24H}^~na  
} wyv%c/WlS  
]}nX$xy  
//线程睡眠 /UiB1-*b  
public static void sleep(int nSecond) iI!g1  
{ YG>6;g)Zm  
try{ 0<]]q[pr  
Thread.sleep(nSecond); -d6PXf5  
} ]0 ;,M  
catch(Exception e) wO"ezQ  
{ =+VI{~.|}  
e.printStackTrace (); &_$xMM,X  
} D?r% Y  
} $TavvO%#  
'o-J)+oa  
//日志 UUxP4  
public static void log(String sMsg) ,~7+r#q7  
{ .KF(_ 92  
System.err.println(sMsg); 'z">4{5  
} XC\'8hL:  
~JohcU}d  
]H=P(Z -  
public static void log(int sMsg) \-I)dMm[  
{ 'd9cCQ}  
System.err.println(sMsg); M[KYt"v  
} txy'7t  
} T$s)aM  
/{nZ I_v#  
n]bxG8~t  
/* q%wF=<W  
**TestMethod.java *AA78G|  
*/ <W88;d33r=  
package NetFox; |p":s3K"Hy  
u 9%AK g}~  
^uIKwql  
public class TestMethod { 30L/-+r1  
d(6&kXK  
"gq _^&  
public TestMethod() k1M?6TW&  
{ ///xx/weblogic60b2_win.exe 5C"A*Fg?;  
try{ vmT6^G  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); szD BfGd%j  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UJGmaE  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Dlo4Wy  
fileFetch.start(); rYk   
} f`_6X~ p  
catch(Exception e){e.printStackTrace ();} $ iU~p  
LX iis)1  
?1lx8+  
} @!s(Zkpev  
\|Ya*8V  
UQ)7uYQ5  
public static void main(String[] args) z;[Z'_B  
{ DqlspT  
new TestMethod(); -vBk,;^>  
} %~YQl N  
} LQ=Fck~[r  
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