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http断点续传简单实现(java)

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/* 37bMe@W  
**SiteFileFetch.java 6iFlz9XiI  
*/ c '|*{%<e2  
package NetFox; |jsI-?%8J  
import java.io.*; ktu?-?#0,  
import java.net.*; UhB +c  
m l`xLZN>L  
E4#{&sRT  
public class SiteFileFetch extends Thread { \0@DOW22C  
OM'iJB6=  
8jK=A2pTa  
SiteInfoBean siteInfoBean = null; //文件信息Bean b[%@3}E  
long[] nStartPos; //开始位置 e8,_"_1 :F  
long[] nEndPos; //结束位置 +]l?JKV  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 '2,~'Zk  
long nFileLength; //文件长度 opX07~1  
boolean bFirst = true; //是否第一次取文件 FlO?E3d  
boolean bStop = false; //停止标志 O[X*F2LC4  
File tmpFile; //文件下载的临时信息 :@w~*eK~  
DataOutputStream output; //输出到文件的输出流 :J;U~emq  
~Nh6po{  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) F`}'^>  
public SiteFileFetch(SiteInfoBean bean) throws IOException !&)X5oJ  
{ " <bjS  
siteInfoBean = bean; {uDW<u_!  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 8lQ/cGAc  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); hzD)yf  
if(tmpFile.exists ()) pj'gTQ),0  
{ }gSoBu  
bFirst = false; *oO%+6nL  
read_nPos(); Q0*E&;|  
} iGW(2.Z  
else g pciv  
{ g$(Y\`zw  
nStartPos = new long[bean.getNSplitter()]; L F?/60  
nEndPos = new long[bean.getNSplitter()]; zD_5TG M=  
} 3}L3n*Ft#.  
j/V_h'}  
a )O"PA}2  
as07~Xvp-  
} (lsG4&\0F  
b+s'B4@rb  
-]EL|_;  
public void run() q/U-WQ<+  
{ F6{g{ B  
//获得文件长度 6v@Prw@.b  
//分割文件 R P{pEd  
//实例FileSplitterFetch Owp]>e  
//启动FileSplitterFetch线程 f,YORJ  
//等待子线程返回 v]JET9hY  
try{ 1$Up7=Dr=  
if(bFirst) A-x^JC=  
{ 81RuNs]  
nFileLength = getFileSize(); mF gqM:  
if(nFileLength == -1) dJ"44Wu+J  
{ r*HSi.'21  
System.err.println("File Length is not known!"); cT(nKHL  
} Gm+D1l i  
else if(nFileLength == -2) +m_ .?V6  
{ Y XhZWo{B  
System.err.println("File is not access!"); 'O%*:'5k  
} HoBx0N9\2  
else .M6. ]H  
{ GTs,?t16/  
for(int i=0;i<nStartPos.length;i++) tmGhJZ2j  
{ GEPWb[Oa  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `n+uA ~  
} !&%KJS6p4  
for(int i=0;i<nEndPos.length-1;i++) pI@71~|R  
{ l6zAMyau5  
nEndPos = nStartPos[i+1]; 9WHE4'Sa  
} l4gH]!/@  
nEndPos[nEndPos.length-1] = nFileLength; q\tr&@4iC  
} /OKp(u;)z  
} +kI}O*s  
lU 9o"2  
c coi  
//启动子线程 5a |R  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4lo7yx  
for(int i=0;i<nStartPos.length;i++) 51:5rN(_  
{ #jbC@A9Pe  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l@4pZkdq  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;apLMMsWC  
nStartPos,nEndPos,i); 5?3v;B6  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E2Sj IR}  
fileSplitterFetch.start(); [w](x  
} 2<7pe@c98  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W{Qb*{9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {UH45#Ua  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", THl:>s  
nEndPos = " + nFileLength); _9oKW;7f7  
// fileSplitterFetch[nPos.length-1].start(); 4#t'1tzu#  
&"u(0q  
`&I6=,YLp  
//等待子线程结束 _Q:ot'(~0-  
//int count = 0; {9J|\Zz3  
//是否结束while循环 W3l[a^1d  
boolean breakWhile = false; s=$xnc}mf  
$%U}k=-  
$d1ow#ROgy  
while(!bStop) xpZ@DK;  
{ I N@ ~~  
write_nPos(); UXZ3~/L5 O  
Utility.sleep(500); qX&+  
breakWhile = true; .0nT*LF  
52^3N>X4X  
hzbvR~rn  
for(int i=0;i<nStartPos.length;i++) '3XOU.  
{ :qS~"@?<  
if(!fileSplitterFetch.bDownOver) Qc33C A  
{ yO-2.2h  
breakWhile = false; r E1ouz!D  
break; '"Cqq{*  
} W}F~vx.  
} wz+mFf  
if(breakWhile) t<`wK8)  
break; E.yFCaL  
6oKlr,.  
2U%t  
//count++; !:d\A  
//if(count>4) #WA7}tHb  
// siteStop(); W)`>'X`  
} EQnU:a  
[YQtX_;w  
oCwep^P(v  
System.err.println("文件下载结束!"); ;E}&{w/My  
} x ~l"'qsK  
catch(Exception e){e.printStackTrace ();} 0"-H34M <D  
} uUl ;}W  
dyqk[$(  
?n<sN"  
//获得文件长度 w8>lWgN  
public long getFileSize() 7d{xXJ-  
{ Yy!G?>hC  
int nFileLength = -1; n n[idw  
try{ 0o6r3xc;  
URL url = new URL(siteInfoBean.getSSiteURL()); .K940& Ui  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qoan<z7  
httpConnection.setRequestProperty("User-Agent","NetFox"); wQ-BY"cK\  
KW0KXO06a  
c5CxR#O  
int responseCode=httpConnection.getResponseCode(); 7F~Jz*,B*W  
if(responseCode>=400) vr>J$(F  
{ GNG.N)q#C  
processErrorCode(responseCode); : Q,O:  
return -2; //-2 represent access is error q9zeN:><  
} j%vxCs>  
)W@  
L7II>^"B  
String sHeader; ),<h6$  
"{{@N4^  
PzjIM!>  
for(int i=1;;i++) /|Gz<nSc  
{ &=8ZGjR< }  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $ z+ =lF  
//Utility.log(in.readLine()); yYC\a7Al4  
sHeader=httpConnection.getHeaderFieldKey(i); DL_M#c`<  
if(sHeader!=null) hHt.N o  
{ ;r;>4+zn\  
if(sHeader.equals("Content-Length")) I tn?''~;  
{ ]~WIGl"g  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +SRM?av  
break; rI:]''PR  
} F7p`zf@O]  
} X bV?=  
else -r_Pp}s  
break; XF4NRs  
} RvW>kATb_F  
} I7ySm12}  
catch(IOException e){e.printStackTrace ();} Erl@] P4  
catch(Exception e){e.printStackTrace ();} or` "{wop  
@[(%b{TE;  
:Ea ]baM"  
Utility.log(nFileLength); {-IRX)m*  
YkV-]%c  
k/xNqN(  
return nFileLength; (w'k\y  
} [s!cc:JR  
KrECAc  
@0:mP  
//保存下载信息(文件指针位置) }>Lz\.Z/+[  
private void write_nPos() ku5g`ho  
{ "%t !+E>nr  
try{ P[cGCmM  
output = new DataOutputStream(new FileOutputStream(tmpFile)); YAF0I%PYU  
output.writeInt(nStartPos.length); V> eJ  
for(int i=0;i<nStartPos.length;i++) E<_+Tc  
{ !I8( Y  
// output.writeLong(nPos); $r)nvf`\  
output.writeLong(fileSplitterFetch.nStartPos); Y0OVzp9 b  
output.writeLong(fileSplitterFetch.nEndPos); !91<K{#A{  
} In4T`c?kQ  
output.close(); 20uR?/|@  
} *r3u=oWb  
catch(IOException e){e.printStackTrace ();} -aMwC5iR@  
catch(Exception e){e.printStackTrace ();} K[|d7e  
} jr5x!@rb  
W/R-~C e  
fm% Y*<Y"  
//读取保存的下载信息(文件指针位置) Y)4D$9:  
private void read_nPos() ~oBSf+N  
{ KWV{wW=-  
try{ [[u&=.Au  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~Urj:l  
int nCount = input.readInt(); yYTiAvN  
nStartPos = new long[nCount]; ">RDa<H]  
nEndPos = new long[nCount]; :!EOg4%i  
for(int i=0;i<nStartPos.length;i++) >7V&pH'  
{ M*c`@\  
nStartPos = input.readLong(); sXSZ#@u,WN  
nEndPos = input.readLong(); pKSVT  
} Ec]cCLB  
input.close(); <tTn$<b  
} g'b)]Q  
catch(IOException e){e.printStackTrace ();} eVWnD,'  
catch(Exception e){e.printStackTrace ();} ]HP  
} e{9(9qE"  
T%F8=kb-9  
[ !:.9  
private void processErrorCode(int nErrorCode) Hv>Hz*s_I  
{ BO ^T :  
System.err.println("Error Code : " + nErrorCode); "|"bo5M:   
} @le23+q  
R=M${u<t  
yz2NB?)  
//停止文件下载 g<{W\VOPm  
public void siteStop() |3g:q  
{ C31SXQ  
bStop = true; 1<qq69x  
for(int i=0;i<nStartPos.length;i++) ^Q_0Zq^H  
fileSplitterFetch.splitterStop(); *%cI,}%   
P z+8u&~p  
A|@d4+  
} [H)p#x  
} \9BIRY`  
//负责部分文件的抓取 _hLM\L  
**FileSplitterFetch.java @ B3@M  
*/ |xaA3UA  
package NetFox;  o*QhoDjc  
Da8qR+*x  
,k@fX oW  
import java.io.*; BiHBu8<  
import java.net.*; sM~|}|p  
+B'9!t4 2  
A\.M/)Qo  
public class FileSplitterFetch extends Thread { *Qg/W? "m  
:/Nz' n  
4Kt?; y ;  
String sURL; //File URL 37!}8  
long nStartPos; //File Snippet Start Position eA_1?j]E3  
long nEndPos; //File Snippet End Position KFCzf_P!  
int nThreadID; //Thread's ID Q_1EAxt  
boolean bDownOver = false; //Downing is over M>_S%V4a  
boolean bStop = false; //Stop identical s6).?oE  
FileAccessI fileAccessI = null; //File Access interface T.W/S0#j3  
^ tm,gh  
F{f "xM  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'J<KL#og  
{ JCaT^KLz  
this.sURL = sURL; Z)7 {e"5d  
this.nStartPos = nStart; +V7*vlx-  
this.nEndPos = nEnd; ZT_EpT=1  
nThreadID = id; F+Lq  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *Xl&N- 04  
} 0/(YH  
C `knFGb  
FQ(=Fnqn  
public void run() ]b<k%  
{ \&AmX8" [  
while(nStartPos < nEndPos && !bStop) ^O[q C X  
{ )Hlr 09t=]  
w},k~5U^s  
8u;l<^<  
try{ ycCEXu2F  
URL url = new URL(sURL); >48zRi\N  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I#S6k%-'  
httpConnection.setRequestProperty("User-Agent","NetFox"); 0Km{fZYq7;  
String sProperty = "bytes="+nStartPos+"-"; {?BxVDD07  
httpConnection.setRequestProperty("RANGE",sProperty); |'=R`@w~0  
Utility.log(sProperty); 2lHJ&fck<  
='OPU5(;O  
a*S4rq@  
InputStream input = httpConnection.getInputStream(); R[Kyq|UyVr  
//logResponseHead(httpConnection); KH2a 2  
^i#q{@g  
cD2}EqZ 9  
byte[] b = new byte[1024]; o $p*C  
int nRead; ](- :l6  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tX Z5oG7  
{ $N5}N\C:a  
nStartPos += fileAccessI.write(b,0,nRead); V!3O 1  
//if(nThreadID == 1) /o![%&-l  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 81H04L9K 7  
} 1c+[S]7rY  
-Vt*(L  
eSywWSdf0  
Utility.log("Thread " + nThreadID + " is over!"); =1yU& PJ  
bDownOver = true; +&-/$\"  
//nPos = fileAccessI.write (b,0,nRead); nvsuF)%9hZ  
} Kv!CL9^LX7  
catch(Exception e){e.printStackTrace ();} )UZ 's>O  
} NBE)DL  
} kUn55 l  
SH5GW3\h  
xC!,v 0&  
//打印回应的头信息 07# ~cVI  
public void logResponseHead(HttpURLConnection con) m[Px|A5{  
{ t#}/VnSQ  
for(int i=1;;i++) &FIPEe#n  
{ KS1Z&~4  
String header=con.getHeaderFieldKey(i); }O5c.3  
if(header!=null) *#+XfOtF  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q9yY%  
Utility.log(header+" : "+con.getHeaderField(header)); 7oh6G  
else =?0o5|u]  
break; QpAK]  
} eB<R@a|?S  
} J/M1#sE  
Mfuw y  
\O^b|0zc  
public void splitterStop() rH$0h2  
{ mz3!HksZ "  
bStop = true; = %\;7  
} ,X)0+DNsq  
j#9p 0[  
a(NN%'fDD  
} /^ hB6_'D  
$j)Er.!9|R  
/4<eI 3Z  
/* _}EGk4E  
**FileAccess.java G5Y 8]N  
*//文件访问(定位,写) KaZ*HPe(  
package NetFox; lnEc5J@c>i  
import java.io.*; M4XnuFGB[w  
gk"S`1>  
Y<#WC#3=  
public class FileAccessI implements Serializable{ , pq<.?&E  
LL7a 20  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '{@hBB+ D  
RandomAccessFile oSavedFile; MP-A^QT  
long nPos; 5^t68 WOl  
z%Op_Ddp  
P)XkqOGpT9  
public FileAccessI() throws IOException 3o%JJIn&  
{ fJtJ2xi  
this("",0); P>z k  
} [#fXmW>N/  
f"~+mO  
JR<#el  
public FileAccessI(String sName,long nPos) throws IOException f\!*%xS;  
{ C eNpJ  
oSavedFile = new RandomAccessFile(sName,"rw"); NDm@\<MIzB  
this.nPos = nPos; IpXg2QbN  
oSavedFile.seek(nPos); if9I7@  
} @] 1E~  
VjS %!P  
JUok@6  
public synchronized int write(byte[] b,int nStart,int nLen) ^)m]j`}IGb  
{ @#c(4}^ <w  
int n = -1; f#pT6  
try{ sZ{Kl\1@  
oSavedFile.write(b,nStart,nLen); )NGBA."t  
n = nLen; VHsuC$3W  
} c2Ua!p(c  
catch(IOException e) I1=YSi;A  
{ >G92k76G  
e.printStackTrace (); m0t 5oO  
} WW2VW-Hk  
4f ~CG r  
46o3F"  
return n; [-f0s;F1%  
} MeW8aL r  
DZ?>9W{  
N+rLbK*  
} ^2[0cne  
U5jY/e_  
6*Qn9Q%p-  
/* 1b+ B  
**SiteInfoBean.java HNxJ`x~Z~  
*/ "ZE JL.Wy  
package NetFox; 0I* ^VGZ  
Z`v6DfK}  
O66\s q  
public class SiteInfoBean { &ME[H  
%4Ylq|d  
@Ytsb!!  
private String sSiteURL; //Site's URL k ~lj:7g~  
private String sFilePath; //Saved File's Path oJVpNE[3]  
private String sFileName; //Saved File's Name d}3<nz,  
private int nSplitter; //Count of Splited Downloading File I&3L1rl3{*  
F IDNhu  
l]Jk  }.  
public SiteInfoBean() m1a0uEA G  
{//nSplitter的缺省值为5 >Y?B(I2e  
//default value of nSplitter is 5 R!lNm,i  
this("","","",5); aD8cqVhM3&  
} |jJC~/WR  
)I9AF,K  
Y=sRVypJ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Mii-Q`.:  
{ Na=9 ju  
sSiteURL= sURL; VG*BAFs  
sFilePath = sPath; -v8Jn# f  
sFileName = sName; Qf0$Z.-  
this.nSplitter = nSpiltter; w~afQA>  
k{Vc5F  
`0 uKJF g  
} z{bMW^F  
]|<PV5SY3.  
V:9|9$G  
public String getSSiteURL() J4 .C"v0a  
{ [Tby+pC  
return sSiteURL; h`Vb#5 ik  
} 73P=<3  
IhwJYPLF  
9~I\WjB "  
public void setSSiteURL(String value) {J%Na&D  
{ P5* :r3>  
sSiteURL = value; ZZ A!Y9ia2  
}  4%LG9hS  
L7_(KCh  
ZD/>L/  
public String getSFilePath() 9xP{#Qa  
{ K20n355uE  
return sFilePath; TDBWYppM  
} x=Qy{eIe  
\)eHf 7H  
KGxF3xS*7  
public void setSFilePath(String value) Gg|'T}0X  
{ 4*&x% ~*  
sFilePath = value; yZ~<! 5.P  
} EXH{3E54)`  
SJoQaR,)>  
yc|C}oQF  
public String getSFileName() "5 PP<A,F(  
{ n{d}]V@  
return sFileName; QG?7L_I  
} sqi~j(&\1  
vD D !.i  
m8n!<_NFt(  
public void setSFileName(String value) Y;6<AIx>  
{ #QXv[%k  
sFileName = value; Wg[?i C*~  
} g9}u6q  
Y'i0=w6G  
V2g,JFp&  
public int getNSplitter() .3?'+KZ,  
{ +L;[-]E8  
return nSplitter; D%(9ot{!e  
} ^c83_93)R  
"h_]it};C  
Wv_5sPqLW  
public void setNSplitter(int nCount) fKOm\R47  
{ V]L$`7G  
nSplitter = nCount; }oYR.UH  
} VH4P|w[YF  
} &JAQ:([:  
fU@}]&  
7U:,:=  
/* *h1Zqb  
**Utility.java kMKI=>s+  
*/ B/q/sC  
package NetFox; r/HKxXT  
0t}=F 4@&a  
<Xm5re.  
public class Utility { Oh6;o1UI  
"8ILV`[  
B3O^(M5W  
public Utility() 5IW^^<kiu  
{ |}^[f]  
@pQv}%  
-?e~dLu  
} |(}uagfrd  
G\Hck=P[$3  
//线程睡眠 q?[{fcNh$  
public static void sleep(int nSecond) z~4L=tA(  
{ {-^>) iJqt  
try{ .2Q`. o)  
Thread.sleep(nSecond); nuw90=qj!]  
} (Ew o   
catch(Exception e) {5.,gb@6  
{ LoOyqJ,  
e.printStackTrace (); l6xC'c,jg  
} =ADAMP  
} I m_yY  
c1wgb8  
//日志 dS0G+3J&+E  
public static void log(String sMsg) \>cZ=  
{ 9XT6Gf56  
System.err.println(sMsg); `>?\MWyu  
} .}ohnnJB0  
fTY@{t  
KK(x)(  
public static void log(int sMsg) on*?O O'  
{ V?Lf& X?  
System.err.println(sMsg); o80pmy7@  
} x?:WR*5w  
} g0rdF  
eQcy'GA06  
A&$!s)8z  
/* H b]    
**TestMethod.java o4Fh`?d}  
*/ 1dfA 8=L,s  
package NetFox; '0H +2  
5ez"B]&T  
5zpk6FR$  
public class TestMethod { mt fDl;/D  
H\8i9RI  
+SPC@E_v  
public TestMethod() -5p=gO  
{ ///xx/weblogic60b2_win.exe G8QJM0VpS  
try{ xVfJ ]Y  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QlJCdCSy  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t1Hd-]28V  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;TmwIZ  
fileFetch.start(); D: JGd$`  
} *X%`MN  
catch(Exception e){e.printStackTrace ();} BTjF^&`  
x9Gm)~  
Ip8 Ap$  
} lxbbyy25  
PwF}yx kI  
N g'f u|  
public static void main(String[] args) -jC. dz  
{ WRVKh  
new TestMethod(); Fj1/B0acS  
} '(2G qX!  
} |+!Jr_ By  
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