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http断点续传简单实现(java)

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/* RjR+'<7E^  
**SiteFileFetch.java (!?%"e  
*/ 4hYK$!"r  
package NetFox; Pb1.X9*8c  
import java.io.*; CtUAbR  
import java.net.*; *^XMf  
9ph>4u(R  
bM }zGFt  
public class SiteFileFetch extends Thread { ^E)8Sb9t  
jkAru_C  
-=n!k^?lK  
SiteInfoBean siteInfoBean = null; //文件信息Bean !| q19$  
long[] nStartPos; //开始位置 j3S!uA?  
long[] nEndPos; //结束位置 H_ NoW  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 fhha-J  
long nFileLength; //文件长度 o=PW)37>  
boolean bFirst = true; //是否第一次取文件 b?<@  
boolean bStop = false; //停止标志 4QYStDFe  
File tmpFile; //文件下载的临时信息 |QQ(1#d  
DataOutputStream output; //输出到文件的输出流 sQ&<cBs2  
XsSDz}dg  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) '}OAl  
public SiteFileFetch(SiteInfoBean bean) throws IOException E 0OHl  
{ m:k;?p:x  
siteInfoBean = bean; QyrB"_dm  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ')iyD5/4  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); l\2"u M#7  
if(tmpFile.exists ()) l[<o t9P[  
{ ,Ww.W'#P  
bFirst = false; fP- =wd  
read_nPos(); y'<5P~W!a  
} F3 g$b,RMH  
else LG{50sP`  
{ |o ^mg9  
nStartPos = new long[bean.getNSplitter()];  .4Mc4'  
nEndPos = new long[bean.getNSplitter()]; {$7vd  
} "|N0oEG&  
! GtF%V  
=AF;3  
dsK*YY jH  
} =tX"aCW~  
'$4&q629d  
vq\L9$WJ  
public void run() IK8" 3+(  
{ 0Ca/[_  
//获得文件长度 g>a% gVly  
//分割文件 =(bTS n  
//实例FileSplitterFetch ?\<Kb|Q  
//启动FileSplitterFetch线程 Z4{N|h?  
//等待子线程返回 Z}IuR|=  
try{ <2LUq@Pg  
if(bFirst) $dKo}  
{ &x@N5j5Q  
nFileLength = getFileSize(); 82 1 6_Qm  
if(nFileLength == -1) L9l]0C37e  
{ }_Y\6fcd  
System.err.println("File Length is not known!"); dO9bxHMnM  
} (m')dSZ  
else if(nFileLength == -2) PpSQf14,  
{ b8 6c[2  
System.err.println("File is not access!"); yATXN>]l  
} >QBDxm  
else d1NKVMeWr  
{ )X6I #q8  
for(int i=0;i<nStartPos.length;i++) >/.Ae8I)  
{ T+:GYab/  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); jz I,B  
} d:h X3  
for(int i=0;i<nEndPos.length-1;i++) )$O'L7In&  
{ g{hbq[>X]  
nEndPos = nStartPos[i+1]; &hWYw+yH\  
} kcP&''  
nEndPos[nEndPos.length-1] = nFileLength; Slp_o\s$@  
} NRs%q}lX  
} iP?lP= M  
~-A"M_n ?  
,!98V Jmr  
//启动子线程 xz}=C:s  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h 3p~\%^  
for(int i=0;i<nStartPos.length;i++) A*W/Q<~I  
{ :ZXaJ!  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4@@gC&:Y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &qm:36Y7Xg  
nStartPos,nEndPos,i); F&OcI.OTXF  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k[1w] l8  
fileSplitterFetch.start(); %kk~qvW  
} X- SR0x  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _!o0bYD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Gx(%AB~9$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?1H>k<Jp  
nEndPos = " + nFileLength); ro^T L  
// fileSplitterFetch[nPos.length-1].start(); -B:O0;f  
{InW%qSn_  
k-$J #  
//等待子线程结束 /$UWTq/C7  
//int count = 0; lH>6;sE  
//是否结束while循环 6/|"y  
boolean breakWhile = false; T{Yk/Z/}?  
`^DP<&{  
D!bi>]Yd  
while(!bStop) '>% c@C[  
{ h6e,w$IL  
write_nPos(); p5bM/{DP;K  
Utility.sleep(500); V`LW~P;  
breakWhile = true; V V Aw y6  
SXmh@a"*\  
OJ}aN>k  
for(int i=0;i<nStartPos.length;i++) ^I!gteU;  
{ L$}'6y/@  
if(!fileSplitterFetch.bDownOver)  w1t0X{  
{ &- ZRS/_d>  
breakWhile = false; Q8bn|#`  
break; 2spK#0n.HV  
} )h;zH,DA[3  
} [.4D<}e  
if(breakWhile) fq0[7Yb  
break; Y1 6pT  
3$kElq[  
Ijs=4f  
//count++; *q(HW  
//if(count>4) $I90KQB\_  
// siteStop(); |( R[5q  
} #pX+~ {  
zuBfkW95+  
.t{?doOT  
System.err.println("文件下载结束!"); '8fh(`  
} Q9 RCN<!  
catch(Exception e){e.printStackTrace ();} 2pAshw1G  
} "C [uz&  
:,=Z)e  
Re'Ek  
//获得文件长度 8R.`*  
public long getFileSize() O}"fhMk  
{ OGU#%5"<  
int nFileLength = -1; *wJ'Z4_5F  
try{ O; <YLS^|6  
URL url = new URL(siteInfoBean.getSSiteURL()); R)qK{wq(1E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =v/x&,Uj@6  
httpConnection.setRequestProperty("User-Agent","NetFox");  tD}HL_  
74*iF'f?c  
.@]M'S^1  
int responseCode=httpConnection.getResponseCode(); vghn+P8  
if(responseCode>=400) IctLhYZ  
{ Q@#Gm9m  
processErrorCode(responseCode); &SK=ZOKg^  
return -2; //-2 represent access is error \{`*`WQF  
} ` G.:G/b%H  
*gXm&/2*  
+l_$}UN  
String sHeader; -<B{?D  
eE;")t,  
9 !qVYU42(  
for(int i=1;;i++) dCM*4B<  
{ _7w2E   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5Ai$1'*p  
//Utility.log(in.readLine()); q CB9z  
sHeader=httpConnection.getHeaderFieldKey(i); E.~~.2   
if(sHeader!=null) %epK-q9[  
{ W4(O2RU  
if(sHeader.equals("Content-Length"))  !#8=tO  
{ Nm/Fc   
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n;Etn!4M  
break; Y^f12%  
} H=k*;'  
} r#[YBaCZJ  
else yLlAK,5P0o  
break; E={W^k!Vz:  
} rfNt  
} /1q] D8  
catch(IOException e){e.printStackTrace ();} "A?_)=zZ  
catch(Exception e){e.printStackTrace ();} q<cpU'-#  
>h m<$3  
*oX~z>aE  
Utility.log(nFileLength); XL7jUi_4:L  
;"/ "  
L"6@3  
return nFileLength; I"=XM   
} \;A\ vQ[  
=`]yq;(C7j  
(8(z42  
//保存下载信息(文件指针位置) [2,u:0"  
private void write_nPos() RFu]vFff  
{ V-w[\u  
try{ o*u A+7n  
output = new DataOutputStream(new FileOutputStream(tmpFile)); %R{clbbbn  
output.writeInt(nStartPos.length); G#4cWn'  
for(int i=0;i<nStartPos.length;i++) BE }qwP^  
{ 9bT,=b;  
// output.writeLong(nPos); :8aIj_qds  
output.writeLong(fileSplitterFetch.nStartPos); rkl/5z??  
output.writeLong(fileSplitterFetch.nEndPos); y|X\f!  
} |JL47FR  
output.close(); wWflZ"%  
} 6X:- Z 3  
catch(IOException e){e.printStackTrace ();} O!uB|*  
catch(Exception e){e.printStackTrace ();} dR_hPBn/@  
} @]HV:7<q  
k>Qr 14F  
kc8T@5+I0  
//读取保存的下载信息(文件指针位置) <_H0Q_/(  
private void read_nPos() !`='K +  
{ bct&ge7YX  
try{ )[)-.{q  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0p$?-81BJ  
int nCount = input.readInt(); ^ :Q |,oy  
nStartPos = new long[nCount]; ap9eQsC  
nEndPos = new long[nCount]; 4#=!VK8ZH  
for(int i=0;i<nStartPos.length;i++) v.v3HB8p  
{ # dxlU/*  
nStartPos = input.readLong(); M)EUR0>8  
nEndPos = input.readLong(); jt2 m-*aP  
} Ye!=  
input.close(); $Y aL3n  
} lLtC9:  
catch(IOException e){e.printStackTrace ();} EGGy0ly  
catch(Exception e){e.printStackTrace ();} sS(^7GARa  
} ?-\KVha  
ZLKS4  
L +.K}w  
private void processErrorCode(int nErrorCode) +I\ bs.84  
{ AD?^.<  
System.err.println("Error Code : " + nErrorCode); w6Tb<ja  
} r?/>t1Z  
.FHOOw1r=  
>cM U<'&  
//停止文件下载  V|?  
public void siteStop() 05pCgI}F>  
{ "TjR]jnV(  
bStop = true; 9R;s;2$.  
for(int i=0;i<nStartPos.length;i++) YBS]JCO  
fileSplitterFetch.splitterStop(); S8,+6+_7  
/e{Oqhf[n  
N{p2@_fnB  
} @1Zf&'/6  
} [V jd )%  
//负责部分文件的抓取 KI>7h.t  
**FileSplitterFetch.java ;-]f4O8  
*/ `(o1&  
package NetFox; B4|% E$1+  
U;V. +onv  
H#Og0gEE}5  
import java.io.*; zLh ~x  
import java.net.*; eIqj7UY_  
^*{ xTB57  
(J^ Tss  
public class FileSplitterFetch extends Thread { acGmRP9g  
b0t];Gc%b  
:Dr& {3>  
String sURL; //File URL Yaa M-o  
long nStartPos; //File Snippet Start Position dNJK[1e6  
long nEndPos; //File Snippet End Position i*U\~CZjT  
int nThreadID; //Thread's ID +.lO8  
boolean bDownOver = false; //Downing is over WVN Q}KY  
boolean bStop = false; //Stop identical Aoo'i  
FileAccessI fileAccessI = null; //File Access interface C,I N+@  
n3|~X/I  
{YGz=5^  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s*8hN*A/,  
{ /d{L]*v)]  
this.sURL = sURL; QOF;j#H^  
this.nStartPos = nStart; 'Vrev8D  
this.nEndPos = nEnd; =AKW(v  
nThreadID = id; BO9Z "|"  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %cm5Z^B1"  
} Bw#ubQJ8}  
M5x!84  
l.34h  
public void run() [{{?e6J  
{ H_AV3 ;  
while(nStartPos < nEndPos && !bStop) #/tdZ0  
{ <7jb4n<  
T*{zL  
)Xh_q3=  
try{ "w'YZO]>  
URL url = new URL(sURL); `?D_=Gw  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fN4p G*D  
httpConnection.setRequestProperty("User-Agent","NetFox"); HJ'93,  
String sProperty = "bytes="+nStartPos+"-"; n5JB'F)  
httpConnection.setRequestProperty("RANGE",sProperty); qIqk@u  
Utility.log(sProperty); ILO+=xU  
FSQ&J|O  
V?O%kd  
InputStream input = httpConnection.getInputStream(); a:| 4q  
//logResponseHead(httpConnection); L$Leo6<3a  
GY",AL8f  
fhY[I0;}$  
byte[] b = new byte[1024]; dI 5sqM:  
int nRead; k,@J&   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nM; G; T  
{ &S3W/lQs  
nStartPos += fileAccessI.write(b,0,nRead); *M|\B|A.  
//if(nThreadID == 1) :HE]P)wz-  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #pe{:f?  
} #w*pWD^  
8@fDn(]w  
YT5>pM-%  
Utility.log("Thread " + nThreadID + " is over!"); 38m%ifh)  
bDownOver = true; PD}R7[".>  
//nPos = fileAccessI.write (b,0,nRead); &CL|q+-  
} v2n0[b0  
catch(Exception e){e.printStackTrace ();} )a^Yor)o"  
} p\{+l;`  
} 3opLLf_g  
8Wj=|Ow-q  
sv;zvEn;-L  
//打印回应的头信息 bNROXiX  
public void logResponseHead(HttpURLConnection con) `oMeR]~  
{ @"I#b99  
for(int i=1;;i++) 2Z O'X9  
{ <nvWC/LU  
String header=con.getHeaderFieldKey(i); f^)uK+:.  
if(header!=null) eCp|QSXE  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nF'xV44"  
Utility.log(header+" : "+con.getHeaderField(header)); ~& 5&s  
else &Bn; Vi  
break; A(n=kx  
} &{ {DS  
} IMGqJc,7  
>'6GcnEb4.  
5b#6 Y  
public void splitterStop() j#e.rNG  
{ {% _j~  
bStop = true; M_1Tx  
} gOyY#]g  
@LKG\zYBu  
y<`?@(0$  
} AD@PNM  
Tj=dL  
{TncqA  
/* &^IcL!t[  
**FileAccess.java ^ 6.lb\  
*//文件访问(定位,写) }[z<iij4  
package NetFox; A$~xG(  
import java.io.*; )E:,V~< 8  
^QAiySR`0  
;:Z=%R$wJ  
public class FileAccessI implements Serializable{ bW9"0=j[{  
lV<Tsk'  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #jZ@l3  
RandomAccessFile oSavedFile; `<J#l;y  
long nPos; HRV*x!|I  
/u)Rppu  
v'@b.R,  
public FileAccessI() throws IOException kwHqvO!G  
{ N\q)LM !M  
this("",0); i~)N QmH<  
} h.V]fS  
f>r3$WKj  
VD24X  
public FileAccessI(String sName,long nPos) throws IOException *AH^%!kVP  
{ 7%9)C[6NSs  
oSavedFile = new RandomAccessFile(sName,"rw"); "#twY|wW  
this.nPos = nPos; |qlS6Aln  
oSavedFile.seek(nPos); 85D^@{  
} "#pzZ)Zh  
HK0::6n{  
1n'$Ji7  
public synchronized int write(byte[] b,int nStart,int nLen) j u*fyt  
{ H#L#2M%  
int n = -1; S<nP80C  
try{ EqnpMHF  
oSavedFile.write(b,nStart,nLen); )C {h1 `  
n = nLen; dk_,YU'z  
} \Mb(6~nC  
catch(IOException e) qO-C%p [5  
{ hr$Sa  
e.printStackTrace (); '@TI48 J+  
} Hz?!BV0  
/vjGjb=3U  
f.oP   
return n; $Z;BQJVH  
} 2{ o0@  
(*,8KLV_i  
p9-0?(]  
} Di*]ab  
$!G`D=  
bj@xqAGl  
/* HG2GZ}~^1  
**SiteInfoBean.java BeK2;[5C  
*/ 2sKG(^=Z  
package NetFox; \M5P+Wk '  
=<{h^-j;a  
EeCFII  
public class SiteInfoBean { P##Z[$IJ3  
W`$[j0  
D?e"U_  
private String sSiteURL; //Site's URL JO2xT#V  
private String sFilePath; //Saved File's Path TPHYz>D]  
private String sFileName; //Saved File's Name !!FR[NK  
private int nSplitter; //Count of Splited Downloading File 9\ v.qo.  
~m=$VDWm  
S'o ]=&  
public SiteInfoBean() .Y1bY: =  
{//nSplitter的缺省值为5 2FGx _ Y  
//default value of nSplitter is 5 $uCiXDKCq  
this("","","",5); XaW4C-D&  
} tBseqS3<  
a/~29gW8E\  
 ="\*h(  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W;q+,Io  
{ CtM'L   
sSiteURL= sURL; w NH9WG  
sFilePath = sPath; gN?0m4[$i  
sFileName = sName; lEHwZ<je  
this.nSplitter = nSpiltter; /xySwSmh3  
[Tb\woU  
3jF|Ic  
} -#aZF2z   
&]< 3 ~6n  
O)uOUB  
public String getSSiteURL() EJLQ&oH[  
{ vU!8`x)  
return sSiteURL; Z:@6Lv?CN  
} _gW{gLYyJ  
)lh8 k {  
tMFsA`ng  
public void setSSiteURL(String value) h4(JUio  
{ *69c-` o  
sSiteURL = value; XJSa]P^B1  
} R}r~p?(M  
/b#q*x-b  
HzvlF0f  
public String getSFilePath() d&jjWlHgEN  
{ BwxnDeG)  
return sFilePath; rjUBLY1(  
} V^n0GJNo  
JrDHRIkgm  
QU/fT_ORw  
public void setSFilePath(String value) Uk,g> LG  
{ LkBZlh_  
sFilePath = value; z(me@P!D~  
} >)Gd:636+  
+`.,| |Mq  
F;u_7OM  
public String getSFileName() x=]S.XI  
{ -U -P}6^  
return sFileName; IU#x[P!  
} 5ZK&fKeCF  
d~@q%-`lA  
/r^[a,Q#x  
public void setSFileName(String value) s+,&|;Q  
{ m'x;,xfY&F  
sFileName = value; b,@aqu  
} %d;<2b0  
tnb$sulc+  
VFj(M j`}G  
public int getNSplitter() /0lC KU!=  
{ =e BmBn  
return nSplitter; z/7$NxJH  
} gnLn7?  
>A}0Ho  
LA4<#KP  
public void setNSplitter(int nCount) ;`(R7X *3  
{ [2 zt ^  
nSplitter = nCount; 8IGt4UF&?  
} _1|$P|$P.  
} JA^v  
7I}P*%(f  
#BY`h~&T  
/* ``|AgIg  
**Utility.java 6/tI8H3E  
*/ SfB8!V|;  
package NetFox; m"d/b~q  
uzBz}<M=  
?j{C*|yHO  
public class Utility { OBOwz4<  
T_;]fPajjD  
DlTR|(AL  
public Utility() A:# k  
{ DBsDk kB{  
Z4hLdHo_  
B4g8 ~f  
} >t  <pFh  
(\,BxvhG=  
//线程睡眠 #E$X ,[ZFo  
public static void sleep(int nSecond) }Hcx=}j  
{ ^6;V}2>v}  
try{ 3l4NC03I&  
Thread.sleep(nSecond); @T:fa J5\'  
} B_^]C9C|  
catch(Exception e) bw4oLu?  
{ #=,imsW)  
e.printStackTrace (); SO{p;g  
} nFM@@oA  
} 2oVV'9;B  
DN8}gl VxV  
//日志 ~i0R^qfr  
public static void log(String sMsg) / T c=  
{ #VGjCEeU  
System.err.println(sMsg); b]Z@^<_E  
} aFj.i8+  
@;Opx."  
?j O 5 9n  
public static void log(int sMsg) <l,o&p,>|c  
{ u0o'K9.r  
System.err.println(sMsg); NwlU%{7W6  
} xJwG=$o  
} },@^0UH4c  
Ykqyk')wm  
bzZ>lyH  
/* b-^p1{A0zW  
**TestMethod.java kkCZNQ~I  
*/ Y&.UIosWb  
package NetFox; {b)~V3rsY  
)2e#HBnH  
Vb|#MNf)  
public class TestMethod { ZC0-wr \  
JXqr3 Np1  
c64v,Hj9  
public TestMethod() ,'fxIO  
{ ///xx/weblogic60b2_win.exe TQ@d~GR  
try{ w#y0atsg'  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]j<Bo4~Il  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ZWUP^V  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^jE8+h  
fileFetch.start(); W"q@Qa`Bm  
} *OjKc s  
catch(Exception e){e.printStackTrace ();} An`3Ex[  
IE2"rQT  
Orn0Zpp<z  
} ]T:;Vo  
f9u^R=Ff[  
hT g<*  
public static void main(String[] args) `# P$ ]:  
{ S>Yj@L  
new TestMethod(); :[l\@>H1tX  
} .Ajzr8P  
} R`8@@ }  
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