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http断点续传简单实现(java)

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/* Os?~U/  
**SiteFileFetch.java (AXS QI~y  
*/ I&R4.;LW  
package NetFox; m:Z=: -x  
import java.io.*; \f@PEiARG7  
import java.net.*; -i?!em'J  
HtmJIH:  
[<f\+g2ct  
public class SiteFileFetch extends Thread { a.wRJ  
H.wp{m{  
2x3&o|J  
SiteInfoBean siteInfoBean = null; //文件信息Bean p# O%<S@?  
long[] nStartPos; //开始位置 j"J2&Y2  
long[] nEndPos; //结束位置 Wx;9N  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 0gfa7+Y  
long nFileLength; //文件长度 +a"A svw2  
boolean bFirst = true; //是否第一次取文件 >!`T=(u!  
boolean bStop = false; //停止标志 /g@.1z1w  
File tmpFile; //文件下载的临时信息 ,C(")?4aJ  
DataOutputStream output; //输出到文件的输出流 tC-(GDGy5  
u -CY-  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) . (Q;EF`_U  
public SiteFileFetch(SiteInfoBean bean) throws IOException R;'Pe>  
{ {$O.@#'  
siteInfoBean = bean; q=UKL`;C}U  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [g_f`ZJ=  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ]rC6fNhQ  
if(tmpFile.exists ()) q9icj  
{ l)=Rj`M  
bFirst = false; C!RxMccTh  
read_nPos(); A&F@+X6@  
} +a nNpy  
else I)Lg=n$  
{ e!G I<  
nStartPos = new long[bean.getNSplitter()]; r$R(4q:  
nEndPos = new long[bean.getNSplitter()]; (Dq3e9fX  
} \W}?4kz  
L;E9"7Jo  
QZt/Rm>W0  
ZDcv-6C)B  
} 4TC !P}  
2+ >.Z.pX  
4N*Fq!k~  
public void run() l|U=(aA]h  
{ Gzc{2"p  
//获得文件长度 KzI$GU3  
//分割文件 '1^\^)&q  
//实例FileSplitterFetch Q5{i#F7nJm  
//启动FileSplitterFetch线程 4+'yJ9~,B  
//等待子线程返回 9IC"p<D  
try{ )uZ<?bkQ  
if(bFirst) >vt#,8VAN  
{ ?Z*LTsPr  
nFileLength = getFileSize(); 2syKYHV  
if(nFileLength == -1) ,? <jue/bd  
{ qmtVk  
System.err.println("File Length is not known!"); C&Ow*~  
} [1 w  
else if(nFileLength == -2) K (Z d-U  
{ 1MX:^L!f8  
System.err.println("File is not access!"); (9fqUbG  
} u+z$+[lm!G  
else +%$!sp?  
{ 9V[|_  
for(int i=0;i<nStartPos.length;i++) ^xu`NE8;  
{ < yE(p  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 0[);v/@Ho  
} WI](a8bm  
for(int i=0;i<nEndPos.length-1;i++) E3_EXz9 h  
{ 1LT)%_d@  
nEndPos = nStartPos[i+1]; n]6xrsE  
} -Ufd+(   
nEndPos[nEndPos.length-1] = nFileLength; t 0nGZ%`  
} R%8nR6iG"  
} IAhyGD{b  
2 os&d|  
ZTM zL%i  
//启动子线程 EX=+TOkAf  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6=MejT  
for(int i=0;i<nStartPos.length;i++) dB^J}_wp  
{ *N[.']#n  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O&E1(M|*>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y>wpla[kUq  
nStartPos,nEndPos,i); o5i?|HJ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ShF ][v1L  
fileSplitterFetch.start(); vA;ml$  
}  ZRsDn  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $9M>B<]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P\*-n"  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S2;{)"mS  
nEndPos = " + nFileLength); ,BOB &u  
// fileSplitterFetch[nPos.length-1].start(); ~}$:iyJV(>  
J0C<Qb[  
V-O49  
//等待子线程结束 'nBJ[$2^  
//int count = 0; IP-CN  
//是否结束while循环 D0us<9q  
boolean breakWhile = false; =@G#c5H*  
M!;H3*  
2RT9Q!BX{  
while(!bStop)  Pb+oV  
{ "7l p|0I  
write_nPos(); * j:  
Utility.sleep(500); ubj ~ULA  
breakWhile = true; Czid"Ih-  
*x)WF;(]g  
M5: f^  
for(int i=0;i<nStartPos.length;i++) WK:~2m&y  
{ lWd)(9K j  
if(!fileSplitterFetch.bDownOver) =}Bq"m  
{ DTl M}  
breakWhile = false; L7wl3zG  
break; =LZj6'  
} $_@~t$  
} --Dw8FR9  
if(breakWhile) 0A9x9l9Wd  
break; }sd-X`lZ  
<@A/`3_O)  
L!3{ASIN0  
//count++; cx1U6A+  
//if(count>4) mhnD1}9,Ih  
// siteStop(); J,4]d u$  
} |.*),t3 (w  
pvDr&n9  
HJ !)D~M{  
System.err.println("文件下载结束!"); [qIi_(%o  
} ;]i&AAbj  
catch(Exception e){e.printStackTrace ();} RR75ke[Hs  
} [WRs1$5  
ryW1OV6?_0  
*;,=x<  
//获得文件长度 !})/x~~e  
public long getFileSize() i>7f9D7  
{ gTH1FR8$y  
int nFileLength = -1; T9*\I TA  
try{ l:z :tJ#(  
URL url = new URL(siteInfoBean.getSSiteURL()); UH%oGp$ykX  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e ! 6SJ7xC  
httpConnection.setRequestProperty("User-Agent","NetFox"); F,11 \j  
`[jQn;  
$io-<Z#Q  
int responseCode=httpConnection.getResponseCode(); TEh]-x`  
if(responseCode>=400) n AoGG0$5  
{ \&&kUpI  
processErrorCode(responseCode); {YcVeCq+N  
return -2; //-2 represent access is error x98LOO  
} ]^3_eHa^d  
\Y Cj/tG8  
zb?wl fT  
String sHeader; F$ZWQ9&5U0  
f"k?Ix\ e  
lqF{Y<l  
for(int i=1;;i++) $P866F  
{ awHfd5nRS  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /A9Mv%zjk  
//Utility.log(in.readLine()); fB3O zff  
sHeader=httpConnection.getHeaderFieldKey(i); X']>b   
if(sHeader!=null) l^u P?l"  
{ PJAE~|a  
if(sHeader.equals("Content-Length")) j<szQ%tJlI  
{ prlB9,3|C  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QTz{ZNi!  
break; U4 m[@wF  
} ;}A#ws_CD_  
} .sbU-_ij@U  
else 9(|[okB  
break; +y6|Nq  
} tmRD$O%:  
} ojs&W]r0Z  
catch(IOException e){e.printStackTrace ();} q&<#)#+  
catch(Exception e){e.printStackTrace ();} /q uf'CV}  
dsR{ P,!  
H'q&1^w)  
Utility.log(nFileLength); $a15 8  
6x]|IWvW  
?uU0NKZA  
return nFileLength; \S=!la_T@m  
} Pl}}!<!<z  
mIFS/C  
7v?tSob:b  
//保存下载信息(文件指针位置) S82NU2L  
private void write_nPos() ]WWre},  
{ !Ya +  
try{ }h +a8@  
output = new DataOutputStream(new FileOutputStream(tmpFile)); D4 {gt\V  
output.writeInt(nStartPos.length); :54|Z5h|  
for(int i=0;i<nStartPos.length;i++) #7lkj:j4  
{ 3a!/EP  
// output.writeLong(nPos); rHT8a^MO  
output.writeLong(fileSplitterFetch.nStartPos); 66p_d'U  
output.writeLong(fileSplitterFetch.nEndPos); D'fP2?3FK  
} o4w+)hh  
output.close(); Qc[[@=S%  
} Yo| H`m,  
catch(IOException e){e.printStackTrace ();} IH\k_Yf#u  
catch(Exception e){e.printStackTrace ();} iBp 71x65  
} )P|%=laE8  
{)4Vv`n  
F#X\}MvEU  
//读取保存的下载信息(文件指针位置) K ANE"M   
private void read_nPos() .Z%7+[  
{ e&; c^Z  
try{ +FY-r[_~  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Pk8L- [&v  
int nCount = input.readInt(); 2*K0~ b`  
nStartPos = new long[nCount]; @]3(l  
nEndPos = new long[nCount]; nXi6Q+YI  
for(int i=0;i<nStartPos.length;i++) <e/O"6='Z  
{ AU87cqq  
nStartPos = input.readLong(); II>X6  
nEndPos = input.readLong(); Y0s^9?*  
} y^;qT_)#  
input.close(); Qi=rhN`  
} M?[lpH3  
catch(IOException e){e.printStackTrace ();} R&ou4Y:DG  
catch(Exception e){e.printStackTrace ();} lmH!I )5  
} 7c %@2  
&sS k~:  
OUI}jJw+  
private void processErrorCode(int nErrorCode) ry~3YYEMI0  
{ <RGRvv  
System.err.println("Error Code : " + nErrorCode); DOhXb  
} 9?,n+  
F<V zVEx  
}{K)5k@  
//停止文件下载 @'C)ss=kj  
public void siteStop() Z]w_2- -  
{ cb'8Li8,j  
bStop = true; wTIf#y1=9  
for(int i=0;i<nStartPos.length;i++) ZmmuP/~2K  
fileSplitterFetch.splitterStop(); 6b<t|zb  
?ZDx9*f  
?a}eRA7  
} xZ;';}&pj  
} X\1D[n:  
//负责部分文件的抓取 ngm7Vs  
**FileSplitterFetch.java {F@;45)o  
*/ zh/+1  
package NetFox; Bj@&c>  
 }Ecm  
ARQ1H0_B  
import java.io.*; 8$G$Rdn  
import java.net.*; i3e|j(Gs4  
*,'"\n  
t8?+yG;  
public class FileSplitterFetch extends Thread { []dRDe;#  
ioa 1n=j  
i w m7M  
String sURL; //File URL A% Bz52yg  
long nStartPos; //File Snippet Start Position 'kx{0J?  
long nEndPos; //File Snippet End Position !%Z1" FDm/  
int nThreadID; //Thread's ID /f# rN_4  
boolean bDownOver = false; //Downing is over U]R7=  
boolean bStop = false; //Stop identical \2NiI]t]  
FileAccessI fileAccessI = null; //File Access interface E"L'm0i[[  
:-6_X<  
@F3d9t-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .S?,%4v%%  
{ |?g2k:fzB7  
this.sURL = sURL; BwEL\*$g  
this.nStartPos = nStart; 8\I(a]kM`  
this.nEndPos = nEnd; N#[/h96F  
nThreadID = id; JBoo7a1  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <n6/np!  
} U{ahA  
}:jXl!:V  
7kJ,;30)  
public void run() UI8M<  
{ uk\GAm@O  
while(nStartPos < nEndPos && !bStop) 4tu2%Og)?  
{ G 8NSBaZe  
l;|1C[V  
eGguq~s`  
try{ JT_#>',  
URL url = new URL(sURL); @l;f';+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O]~p)E  
httpConnection.setRequestProperty("User-Agent","NetFox"); x`o_&09;CG  
String sProperty = "bytes="+nStartPos+"-"; ~z< ? Wh  
httpConnection.setRequestProperty("RANGE",sProperty); SnXYq 7`t  
Utility.log(sProperty); .0a$E`V=D  
DH 9?~|  
#vDe/o+=  
InputStream input = httpConnection.getInputStream(); Q7Dkh KT  
//logResponseHead(httpConnection); CX1'B0=\r  
'E7|L@X"r  
\7/xb{z|  
byte[] b = new byte[1024]; +:Y6O'h.  
int nRead; .d8~]@U!<  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }RyYzm2  
{ 5,mb]v0k  
nStartPos += fileAccessI.write(b,0,nRead); sF<4uy  
//if(nThreadID == 1) zF{ z_c#3@  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yXEC@#?|  
} nKHyq\  
?VzST }  
 z!F?#L5  
Utility.log("Thread " + nThreadID + " is over!"); t;4{l`dk  
bDownOver = true; |bBYJ  
//nPos = fileAccessI.write (b,0,nRead); ZAiQofQ:2  
} leyX: +  
catch(Exception e){e.printStackTrace ();} &j>`H:  
} P"xP%zqo  
} =)T5Y,+rJ  
rsc8lSjH  
c3Mql+@  
//打印回应的头信息 e{?~ m6  
public void logResponseHead(HttpURLConnection con) 5q8bM.k\7N  
{ BGA.8qWR4  
for(int i=1;;i++) \?GMtM,  
{ 3-Ti'xM  
String header=con.getHeaderFieldKey(i); .IYE"0)wJ  
if(header!=null) '7E?|B0],  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^ 5UIbA(  
Utility.log(header+" : "+con.getHeaderField(header)); Qb SX'mx<  
else c5t?S@b  
break; "0]i4d1l  
} V= .'Db2D  
} Uq[NO JC  
H>W A?4  
p oNQ<ijK  
public void splitterStop() zx\?cF  
{ YxsW Y7J  
bStop = true; g@S"!9[;U  
} G_X'd  
hx:x5L>  
^c-1w V` /  
} K\;b3  
~A6QX8a  
M~wJe@bc  
/* Dpof~o,f  
**FileAccess.java T"dEa-O  
*//文件访问(定位,写) paiF ah  
package NetFox; ,c7 8O8|  
import java.io.*; rt."P20T  
Z!ub`coV[  
;up89a-,9  
public class FileAccessI implements Serializable{ Z,Q)\W<'-  
h"q`gj  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q,+d\-+  
RandomAccessFile oSavedFile; _STN^   
long nPos; P/0n) Q  
j4Lf6aUOX  
mF#{"  
public FileAccessI() throws IOException ~xzRx$vU  
{ 6{1c S  
this("",0); \f%jN1z  
} ~I!7]i]"*?  
nKV1F0-  
N|8TE7- F|  
public FileAccessI(String sName,long nPos) throws IOException O[q {y  
{ dx:],VB  
oSavedFile = new RandomAccessFile(sName,"rw"); 6R#f 8  
this.nPos = nPos; -x7b6o>$  
oSavedFile.seek(nPos); [['un\~r~  
} s_VP(Fe@K  
;JDxl-~  
Au:Q4x.  
public synchronized int write(byte[] b,int nStart,int nLen) N0/DPZX7  
{ Joe k4t&0<  
int n = -1; 5H>[@_u+:  
try{ l*/I ; a$  
oSavedFile.write(b,nStart,nLen); n Hy|  
n = nLen; {3!v<CY'  
} `|Tr"xavf  
catch(IOException e) k%Jw S_F  
{ q]<cn2  
e.printStackTrace (); rT5dv3^MW!  
} >* dqFZF  
t|d9EC]c(  
ZOfyy E  
return n; nIKh<ws4z  
} ^P\(IDJCo  
?r#e  
jsc1B  
} .J'}qkz~  
X >C*(/a  
fY$M**/,  
/* yp_:] RE  
**SiteInfoBean.java (B]rINY|  
*/ k)dLJ<EM  
package NetFox; OZs^c2 W  
t-i;  
Pf-k"7y  
public class SiteInfoBean { X.bNU  
fD]}&xc  
)<t5' +d%  
private String sSiteURL; //Site's URL GR Rv0M  
private String sFilePath; //Saved File's Path -T`rk~A9A  
private String sFileName; //Saved File's Name vG69z&  
private int nSplitter; //Count of Splited Downloading File pjWqI 6,  
{Jwh .bJ  
( {5LB4  
public SiteInfoBean() 9 }jF]P*Q  
{//nSplitter的缺省值为5 [C9->`(`  
//default value of nSplitter is 5 ON\_9\kv  
this("","","",5); 'eZ UNX  
} AWc7TW  
% sbDH  
@|idlIey  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "i(k8+i K  
{ ab: yH ')  
sSiteURL= sURL; 2 D>WIOX  
sFilePath = sPath; 5iwJdm  
sFileName = sName; L "P$LEk  
this.nSplitter = nSpiltter; g%Sl+gWdJ  
V*2uW2\}  
D:/^TEib  
} VkZrb2]v  
>/Gz*.  
db'Jl^  
public String getSSiteURL() Zchs/C 9{  
{ 2X!O '  
return sSiteURL; {'NdN+_C  
} K}L-$B*i  
bb`GV  
{.K >9#^m  
public void setSSiteURL(String value) 'C)`j{CS  
{ Om,+59ua*  
sSiteURL = value; !MOVv\@O  
} hjtkq .@  
d dkh*[  
67wY_\m9I  
public String getSFilePath() ,|<2wn#q  
{ -1 ;BwlL  
return sFilePath; !X[b 4p  
} 6*J`2U9Q  
3pl/k T.\  
P4-`<i]!S  
public void setSFilePath(String value) q;3.pRw(  
{ N0,wT6.  
sFilePath = value; */;[ -9  
} F#*vJb)  
*$1M= $  
u^8:/~8K  
public String getSFileName() Y!N *J  
{ M{<cqxY  
return sFileName; (sHqzWh  
} y0k*iS e  
)7l+\t  
e)]9u$x  
public void setSFileName(String value) k7z;^:  
{ *NHBwXg+  
sFileName = value; ;P3sDN  
} jCa%(2~iQ7  
rXPq'k'h#-  
d!mtSOh  
public int getNSplitter() ms@*JCL!t  
{ ^V#9{)B  
return nSplitter; "7mY s)=  
} UE3(L ^  
#  -e  
WvQK$}Ax4N  
public void setNSplitter(int nCount) *$~H=4t  
{ N}HQvlLkF9  
nSplitter = nCount; BQu_)@  
} kclClB:PS  
} W ZdEfY{  
#; CC"  
>>oR@  
/* #9M6 q  
**Utility.java ^x-vOG lR  
*/ MB06=N  
package NetFox; ?f<JwF<  
nk|j(D  
/n;Ll](ri  
public class Utility { (L}  
rH Et]Xa  
FKRO0%M4}Z  
public Utility() #}*w &y  
{ ,#:*dl  
6;6a.iZ  
qk VGa%^  
} \n$s5i-  
G- wQ weJ9  
//线程睡眠 +aR.t@D+"Y  
public static void sleep(int nSecond) HI)MBrj;r  
{ 4+2XPaI m  
try{ {\3k(NdEX  
Thread.sleep(nSecond); (7/fsfsF  
} `B'*ln'r5  
catch(Exception e) $8zsqd 4?  
{ K =T]@ix$  
e.printStackTrace (); ^K*uP^B=  
} BB@I|)9O(  
} WJ":BK{NM  
golr,+LSo  
//日志 Ww-%s9N<  
public static void log(String sMsg) #2l6'gWE0  
{ Fb#.Gg9b>  
System.err.println(sMsg); _yk} [x0>  
} M0VC-\W7f  
xEdCGwgp#  
hp=TWt~  
public static void log(int sMsg) =.NZ {G  
{ Au3> =x`  
System.err.println(sMsg); x}o]R  
} l}odW  
}  t9T3e  
k.=67L  
a Mp*Ap  
/* B^g+_;  
**TestMethod.java banie{ e  
*/ G%0G$3W"  
package NetFox; H^_]' ~.  
rw_T&>!  
dayp1%d  
public class TestMethod { JA0$Fz  
m| 8%%E}d  
$Gt1T[:QUX  
public TestMethod() N5 ITb0Tv  
{ ///xx/weblogic60b2_win.exe }%LwaRT  
try{ `~|8eKFq!  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pgT XyAP{  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U7O]g'BP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6&V4W"k  
fileFetch.start(); \;AW/& Ea  
} B198_T!  
catch(Exception e){e.printStackTrace ();} +bK[3KG4F5  
f5D.wSY  
[)UF@Sq4+Q  
} 18JhC*in  
0_b7*\xc  
;4. D%  
public static void main(String[] args) <K4`GT"n  
{ 09?n5x!6  
new TestMethod(); Yas!w'  
} Q|eRek  
} $tvGS6p>  
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