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http断点续传简单实现(java)

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/* SP?U@w%}  
**SiteFileFetch.java V;hwAQbF  
*/ QT= ,En  
package NetFox; .0fh>kQ  
import java.io.*; 9}jq`xSL  
import java.net.*; !+DJhw&c,  
i|]Va44  
=Pb5b6Y@6  
public class SiteFileFetch extends Thread { 5 -WRv;  
[aM'  
Li-(p"  
SiteInfoBean siteInfoBean = null; //文件信息Bean C| L^Ds0  
long[] nStartPos; //开始位置 $7DcQ b9  
long[] nEndPos; //结束位置 $n#Bi.A j  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 %::deV7  
long nFileLength; //文件长度 dbuJ~?D,  
boolean bFirst = true; //是否第一次取文件 6+B{4OY  
boolean bStop = false; //停止标志 " $IXZ  
File tmpFile; //文件下载的临时信息 =i^<a7M~  
DataOutputStream output; //输出到文件的输出流 4,F3@m:<  
Cq*}b4^;  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9kX=99kf[  
public SiteFileFetch(SiteInfoBean bean) throws IOException =e!l=d|/  
{ )dIfr  
siteInfoBean = bean; g?[& 0r1  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 71.\`'  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); oAZF3h]po  
if(tmpFile.exists ()) lHKf#|  
{ -?YTQ@ W  
bFirst = false; 5%Oyvt]}2  
read_nPos(); b~r{J5x@  
} W\qLZuQ  
else ig2 +XR#%  
{ ImV]}M~_  
nStartPos = new long[bean.getNSplitter()]; h#m:Y~GoF  
nEndPos = new long[bean.getNSplitter()]; $# !UGY  
} .Y(lB=pV  
RE>ks[  
%t~SOkx  
b WbXh$  
} E<<p_hX8R  
U7B/t3,=U  
QSF"8Uk  
public void run() :K^gu%,&$  
{ v"~Do+*+  
//获得文件长度 K4k~r!&OU  
//分割文件 M6jp1:ZH2q  
//实例FileSplitterFetch ![@T iM  
//启动FileSplitterFetch线程 )v52y8G-p  
//等待子线程返回 4j@i%  
try{ \/*Nf?;  
if(bFirst) Wyq~:vU.S  
{ 3xzkZ8]/  
nFileLength = getFileSize(); 6 tc:A5mK  
if(nFileLength == -1) rXY;m-  
{ R>d@tr  
System.err.println("File Length is not known!"); hr[B^?6  
} )XP#W|;  
else if(nFileLength == -2) -.{oqs$  
{ 4N~+G `  
System.err.println("File is not access!"); ,'C30A*p  
} v. Xoq  
else {4: -0itG  
{ WgA`kT  
for(int i=0;i<nStartPos.length;i++) ^Ue0mC7m  
{ H\fcY p6  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); LZM,QQ  
} \T`["<  
for(int i=0;i<nEndPos.length-1;i++) .73zik   
{ aUW/1nQHa  
nEndPos = nStartPos[i+1]; G[3k  
} 6x_ T@  
nEndPos[nEndPos.length-1] = nFileLength; 8M^wuRn  
} L6:W'u^  
} F&QTL-pQW  
3ar=1_Ar  
aqs%m (  
//启动子线程 J]}FC{CD!  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >*dQqJI  
for(int i=0;i<nStartPos.length;i++) kDzj%sm!  
{ *me,(C  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xMD rE?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *O@sh  
nStartPos,nEndPos,i); 4E=0qbt8  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Z)#lF|^  
fileSplitterFetch.start(); a`H\-G  
} FUaI2  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +7Yu^&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hCzjC|EO~  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #(%t*"IY;  
nEndPos = " + nFileLength); )n7|?@5U  
// fileSplitterFetch[nPos.length-1].start(); l80bHp=  
8p (!]^z  
fokwW}>B[f  
//等待子线程结束 fyI_  
//int count = 0; D@8jGcz62  
//是否结束while循环 b'velj3A  
boolean breakWhile = false; RT% x&j  
V: ^JC>6  
aje^Z=]  
while(!bStop) ;rd6ko  
{ \bhOPK>w  
write_nPos(); 9~@<-6jE3b  
Utility.sleep(500); J &!B|TS  
breakWhile = true; S|"Fgoj r  
+}Xr1fr{jw  
(/"thv5vT{  
for(int i=0;i<nStartPos.length;i++) Bvz62?  
{ Wk@ eV\H71  
if(!fileSplitterFetch.bDownOver) BlXX:aZv  
{ /7bw: h;  
breakWhile = false; NQ? x8h3  
break; n0_B(997*  
} 4d!S#zx  
} Nd`HB=ShJ  
if(breakWhile) R0%?:! F  
break; xE%O:a?S  
OI+E (nA  
n`]l^qE  
//count++; 3&es]1b  
//if(count>4) }wG,BB%N  
// siteStop(); wGPotPdE2  
} EMLx?JnP  
osl=[pm  
mA& =q_gS  
System.err.println("文件下载结束!"); W. ^Ei\w/t  
} Cz_AJ-WR  
catch(Exception e){e.printStackTrace ();} /Zc#j^_  
} 2s 7mI'  
e1Ob!N-  
MRQZIi  
//获得文件长度 !g8*r"[UJ  
public long getFileSize() \M9 h&I\7  
{ [*Q-nZ/L  
int nFileLength = -1; ! ,@ZQS  
try{ Zvxp%dES  
URL url = new URL(siteInfoBean.getSSiteURL()); pA<eTlH  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t\8&*(&3F  
httpConnection.setRequestProperty("User-Agent","NetFox"); C1d 04Q  
@r F/]UJ  
MEEAQd<*  
int responseCode=httpConnection.getResponseCode(); RcQ>eZHl  
if(responseCode>=400) G+U3wF],  
{ ~;[&K%n  
processErrorCode(responseCode); R2l[Q){!  
return -2; //-2 represent access is error rJ DnuR  
} [[w2p  
eK'wVg#  
(^LS']ybc  
String sHeader; \^LWCp,C"  
+semfZ)  
rj3YTu`  
for(int i=1;;i++) 4.8nY\_WF  
{ {7qA&c=  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >8|+%pK8<  
//Utility.log(in.readLine()); `fz,Lh*v  
sHeader=httpConnection.getHeaderFieldKey(i); =`-|&  
if(sHeader!=null) =+<d1W`>0  
{ u, eZ6  
if(sHeader.equals("Content-Length")) #4><r.v3  
{ V5AW&kfd  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \^&   
break; ;UrK {>B  
} ;|<(9u`  
} ~Q?!W0ZBE  
else Lj8)' [K"  
break; n+HsQ]z.  
} 3y ryeS  
} X8b|]Nr  
catch(IOException e){e.printStackTrace ();} [SkKz>rC  
catch(Exception e){e.printStackTrace ();} qgx?"$ Z  
:6Pnie  
>Q=Ukn;k  
Utility.log(nFileLength); d8E,o7$m  
|g<*Rk0  
i ?;R}%~  
return nFileLength; Cp^g'&  
} wz#A1F  
z1vw'VT>  
Ql &0O27  
//保存下载信息(文件指针位置) 'z5h3J  
private void write_nPos() \vCGU>UY  
{ DI,K(_@G  
try{ XX2h(-  
output = new DataOutputStream(new FileOutputStream(tmpFile)); h0Ee?=  
output.writeInt(nStartPos.length); EY=FDlV  
for(int i=0;i<nStartPos.length;i++) 7)^:8I(  
{ i)8N(HN  
// output.writeLong(nPos); #f*g]p{   
output.writeLong(fileSplitterFetch.nStartPos); >&WhQhZ3kg  
output.writeLong(fileSplitterFetch.nEndPos); ,."b3wR[w  
} ZYcd.?:6  
output.close(); C#;@y|Rw  
} R{?vQsLk  
catch(IOException e){e.printStackTrace ();} jJBnDxsA  
catch(Exception e){e.printStackTrace ();} ?gSSli[  
} R^%e1 KO]  
+}a C-&  
[ ]^X`R  
//读取保存的下载信息(文件指针位置) FRZs[\I|iT  
private void read_nPos() g$FEEDF  
{ 5wT>N46UX  
try{ Qf xH9_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d"ZU y!a  
int nCount = input.readInt();  )\ZzTS  
nStartPos = new long[nCount]; 7?nJ4x1  
nEndPos = new long[nCount]; dlDki.  
for(int i=0;i<nStartPos.length;i++) ufrqsv]=  
{ Bu3T/m  
nStartPos = input.readLong(); KKEN'-3  
nEndPos = input.readLong(); >o~Z>lr  
} =P`~t<ajB  
input.close(); \:v$ZEDJ>  
} c*;7yh&%  
catch(IOException e){e.printStackTrace ();} %}&(h/= e  
catch(Exception e){e.printStackTrace ();} S&(^<gwl  
}  ^$-Ye]<  
r?A|d.Tl  
\.#p_U5In  
private void processErrorCode(int nErrorCode) A&,,9G<  
{ ]|U-y6 45  
System.err.println("Error Code : " + nErrorCode); ECcZz.  
} l&W;b6L  
bk<FL6z z  
KrcgIB8X  
//停止文件下载 A6{b?aQ  
public void siteStop() B=X,7  
{ #yW\5)  
bStop = true; o>?*X(+le  
for(int i=0;i<nStartPos.length;i++) ~@4'HMQ  
fileSplitterFetch.splitterStop(); syPWs57pH  
.lNs4e  
jb[!E^'&>  
} `/nM[  
} Y<f_`h^r  
//负责部分文件的抓取 iqwkARG"  
**FileSplitterFetch.java %gd(wzco  
*/ mC[UXN/  
package NetFox; -*a?<ES`  
MCc$TttaVz  
u~1o(Zn =  
import java.io.*; T$+-IAE  
import java.net.*; _&#S@aGw  
|Au]1}  
L}sx<=8.m  
public class FileSplitterFetch extends Thread { g{:<2xI5P  
RJ4. kt  
PRB{VC<k  
String sURL; //File URL l=}~v  
long nStartPos; //File Snippet Start Position IQH[Q9%  
long nEndPos; //File Snippet End Position bb-qO#E  
int nThreadID; //Thread's ID g(ogXA1  
boolean bDownOver = false; //Downing is over v [njdP  
boolean bStop = false; //Stop identical e]Fp=*#  
FileAccessI fileAccessI = null; //File Access interface Sr_VL:Gg  
 dy>!KO  
bh p5<N  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IMGP'g  
{ A,gEM4  
this.sURL = sURL; beXNrf=bG  
this.nStartPos = nStart; sJG5/w  
this.nEndPos = nEnd; hk>;pU(  
nThreadID = id; MJ{%4S{K,p  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )C hqATKg  
} Ts$@s^S]  
E=]4ctK  
[KJ q  
public void run() q,>?QBct*  
{ YDC&u8  
while(nStartPos < nEndPos && !bStop) ZD>a>]  
{ TX [%(ft  
ciQZHH2  
^|MjJsn  
try{ Q{g;J`Z)p  
URL url = new URL(sURL); @>Mxwpl?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2aN<w'pA  
httpConnection.setRequestProperty("User-Agent","NetFox"); U/l?>lOD\  
String sProperty = "bytes="+nStartPos+"-"; BX+.0M  
httpConnection.setRequestProperty("RANGE",sProperty); _-TA{21)  
Utility.log(sProperty); BB$oq'  
?sz)J 3  
l fZ04M{2  
InputStream input = httpConnection.getInputStream(); gB'fFkd  
//logResponseHead(httpConnection); M]]pTU((  
#/2$+x  
t2HJsMX  
byte[] b = new byte[1024]; [K/m  
int nRead; tWeFEVg  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >slm$~rv  
{ 5Por "&%  
nStartPos += fileAccessI.write(b,0,nRead); }J:+{4Yn  
//if(nThreadID == 1) 5N[9 vW  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z;l`YK^-  
} Ev"|FTI/  
_ *f  
``VW;l{  
Utility.log("Thread " + nThreadID + " is over!"); k^"bLf(4  
bDownOver = true; \!]hU%Un  
//nPos = fileAccessI.write (b,0,nRead); kX`[Y@nUN  
} j=?'4sF  
catch(Exception e){e.printStackTrace ();} K14^JAdY/  
} M=qb^~ l  
} 1 rs&74-  
DV)3  
pCh2SQ(Q>  
//打印回应的头信息 -s|8<A||"  
public void logResponseHead(HttpURLConnection con) J (4"S o_  
{ d?AlI  
for(int i=1;;i++) Sq\(pfv o  
{ ^~`?>}MJ  
String header=con.getHeaderFieldKey(i); 2 dp>Z",  
if(header!=null) wr(*?p]R  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U6E\AvbRn  
Utility.log(header+" : "+con.getHeaderField(header)); 0|&\'{  
else 8lF\v/vN  
break; 1NQbl+w#I  
} lKWPTCU  
} FTc.]laO  
mrIh0B:`  
7\]E~/g  
public void splitterStop() 7/7Z`  
{ sg'pO*_&  
bStop = true; /S5| wNu  
} <@wj7\pQ  
W&(k!6<x  
!-`Cp3gqHr  
} *]hBGr#6  
7 >iU1zy  
g V5zSudW  
/* D8&`R  
**FileAccess.java ,Ys"W x  
*//文件访问(定位,写) 3pf[M{dG  
package NetFox; y[B>~m8$  
import java.io.*; n Ox4<Wk&  
nJ4pTOc  
F  
public class FileAccessI implements Serializable{ \^I>Q _LU  
q9w~A-Oh`1  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RrU BpqA  
RandomAccessFile oSavedFile; bVP"(H]  
long nPos; rc&%m  
_@S`5;4x  
 |@NiW\O  
public FileAccessI() throws IOException T91moRv  
{ niB `2 J  
this("",0); gs!(;N\j|  
}  w 4[{2  
!*- >;:9B  
4DZ-bt'  
public FileAccessI(String sName,long nPos) throws IOException *5w{8  
{ 4_Dp+^JF  
oSavedFile = new RandomAccessFile(sName,"rw"); ()&~@1U  
this.nPos = nPos; wtje(z5IL  
oSavedFile.seek(nPos); Eu"_MgD  
} 'y8]_K*  
U9b?i$  
.bBdQpF-  
public synchronized int write(byte[] b,int nStart,int nLen) Y0eE-5F,  
{ 4pw6bK,s2\  
int n = -1; q6YXM  
try{ )K &(  
oSavedFile.write(b,nStart,nLen); MSf;ZB  
n = nLen; ;M"9$M'  
} N F)~W#  
catch(IOException e) dOa%9[  
{ jKt7M>P  
e.printStackTrace (); Eke5Nb  
} 6Gf?m;  
2eMTxwt*S  
jLg9H/w{  
return n; A}eOFu`  
} *_>Lmm.yh  
B)d(TP,>  
pz"0J_xDM  
} bygx]RC[  
<&C]s b  
iY21Ql%  
/* J2:y6kGj>  
**SiteInfoBean.java &b:1I 7Cp*  
*/ \rv<$d@L  
package NetFox; t!RiUZAo  
!47n[Zs  
<[w=TdCPs  
public class SiteInfoBean { #%DE;  
):iA\A5q[  
-GxaV #{  
private String sSiteURL; //Site's URL m*JaXa  
private String sFilePath; //Saved File's Path Hh+ 2mkg  
private String sFileName; //Saved File's Name eM8}X[  
private int nSplitter; //Count of Splited Downloading File '- zD  
dAuJXGo  
82l~G;.n3  
public SiteInfoBean() &jmRA';sK  
{//nSplitter的缺省值为5 K6R.@BMN  
//default value of nSplitter is 5 TYW&!sm  
this("","","",5); wmTb97o  
} .9wk@C(Eh_  
=?!wXOg_  
;+"+3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \ Yx/(e  
{ %7|9sQ:  
sSiteURL= sURL; rW$[DdFA5{  
sFilePath = sPath; s0vDHkf8  
sFileName = sName; \-g)T}g,I  
this.nSplitter = nSpiltter; |ZmUNiAa  
VVlr*`  
q<M2,YrbAI  
} jyCXJa-!-  
q@{Bt{$x  
lnjXD oVb<  
public String getSSiteURL() 5 sX+~Q  
{ vam;4vyu  
return sSiteURL; 5aCgjA11  
} ?` ?)QE8  
 094o'k  
*WuID2cOI  
public void setSSiteURL(String value) zolt$p  
{ PpzP7  
sSiteURL = value; 'tH_p  
} s%W C/ZK  
m^zUmrj[  
?{[ v+t#  
public String getSFilePath() J\b^)  
{ y gz6C  
return sFilePath; A*\.NTM  
} z:wutqru  
:;9F>?VN>0  
r8RoE`/T  
public void setSFilePath(String value) ,>%}B3O:Y=  
{ F'21jy&  
sFilePath = value; K|[*t~59  
} 2GDD!w#!j  
.:F%_dS D  
%xI p5h]  
public String getSFileName() p;>ec:z3M  
{ @J/K-.r  
return sFileName; XwJ7|cB  
} "]} bFO7C  
dl.p\t(1  
3ca (i/c  
public void setSFileName(String value) %WjXg:R  
{ [D I+~F  
sFileName = value; ?82xdp g  
} 7fZDs j:  
Wi)_H$KII  
9dx/hFA  
public int getNSplitter() |Y ,b?*UF  
{ Hquc o  
return nSplitter; bKMy|_  
} Hx?;fl'G%  
X aMJDa|M  
W_"sM0 w  
public void setNSplitter(int nCount) g,!L$,/F  
{ ?Lk)gO^C  
nSplitter = nCount; \"P%`  C  
} V2wb%;q  
} sBT2j~jhJ  
[M=7M}f;  
ig/xv  
/* !$gR{XH$]  
**Utility.java GjvOM y  
*/ N 5lDS  
package NetFox; Pd_U7&w,5  
8}O lL,fP  
at,XB.}Z]  
public class Utility { 4O^xY 6m  
8;JWK3Gv  
'-Vt|O_Q  
public Utility() . 1Dg s=|  
{ )vE~'W  
t.i 8 2Q  
D2Kp|F;  
} tEvut=k'  
*0Skd  
//线程睡眠 vApIHI?-  
public static void sleep(int nSecond) G[uK-U  
{ (x;@%:3j$  
try{ nFHUy9q  
Thread.sleep(nSecond); "R;U/+  
} 8;RUf~q?  
catch(Exception e) K0|FY=#2y  
{ W}@c|d $`  
e.printStackTrace (); aC8} d  
} 3u+T~g0^  
} U:0mp"  
V^bwXr4f  
//日志 6 ob@[ @  
public static void log(String sMsg) p>v$FiV2N  
{ ^@s1Z7  
System.err.println(sMsg); Ot_]3:`J~  
} 6]WAUK%h  
|\pj;XU  
h+g_rvIG*  
public static void log(int sMsg) t%/&c::(6  
{ JcsHt;  
System.err.println(sMsg); Z&+ g;(g  
} /[ 5gX^A  
} On9A U:\  
6*78cg Io  
FXG]LoP  
/* "c%0P"u  
**TestMethod.java FrfM3x6UM  
*/ gwuI-d^  
package NetFox; d;Ym=YHJtn  
823Y\x~>  
Q4#m\KK;i9  
public class TestMethod { _{YWXRC#  
/K@XzwM  
M=@:ZQ^!  
public TestMethod() K7_UP&`=J  
{ ///xx/weblogic60b2_win.exe c<B/V0]  
try{ uP)'FI  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6_GhO@lOG  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); itt3.:y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); S6Q  
fileFetch.start(); -">;-3,K  
} u5`u>.!  
catch(Exception e){e.printStackTrace ();} Q%`@0#"]Sv  
t6 "%3#s  
r= `Jn6@  
} ^1I19q  
|.: q  
RB7tmJ c  
public static void main(String[] args) ^,TO#%$iE  
{ MS~(D.@ZS  
new TestMethod(); Y8~"vuIE5  
} 'x#~'v*  
} f643#1  
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