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http断点续传简单实现(java)

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/* 6%Ap/zvCZ>  
**SiteFileFetch.java [uP_F,Y/  
*/ yCZV:R;  
package NetFox; *(@(9]B~  
import java.io.*; hM^#X,7  
import java.net.*; `2\vDy1,j  
kxt@t#  
9,=3D2x&  
public class SiteFileFetch extends Thread { p_S8m|%  
MVU5+wX  
Jr m<u t  
SiteInfoBean siteInfoBean = null; //文件信息Bean AVyO5>w  
long[] nStartPos; //开始位置 v;" [1w}  
long[] nEndPos; //结束位置 I`kaAOe  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Bsi HVr  
long nFileLength; //文件长度 p ASNiH698  
boolean bFirst = true; //是否第一次取文件 VH7VJ [  
boolean bStop = false; //停止标志 #y13(u,dN  
File tmpFile; //文件下载的临时信息 #4"(M9kf  
DataOutputStream output; //输出到文件的输出流  $6w[h7  
~TwjcI*/  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) tjc3;9  
public SiteFileFetch(SiteInfoBean bean) throws IOException ;rWgt!l  
{ A\Rkt;:  
siteInfoBean = bean; CrC1&F\dq  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 8#NtZ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); YKq,`7"%  
if(tmpFile.exists ()) S'qEBz  
{ )p'ZSXb  
bFirst = false; z><=F,W  
read_nPos(); =zBcfFii`w  
} 6}"P m  
else !a?$  
{ o@j]yA.5)  
nStartPos = new long[bean.getNSplitter()]; &1Dq3%$c  
nEndPos = new long[bean.getNSplitter()]; so}(*E&(a  
} 6j{9\ R  
tr0P ;}=  
{vh}f+2  
FOiwB^$ >  
} ScU?T<u:i  
W|J8QNL?jm  
?{l}35Q.@  
public void run()  {h/[!I `  
{ U8L%=/N>B  
//获得文件长度 DJ;il)^  
//分割文件 (&R /ns~  
//实例FileSplitterFetch J'9hzag  
//启动FileSplitterFetch线程 g*69TqO^  
//等待子线程返回 DdDO.@-Z  
try{ ve[` 0  
if(bFirst) xrDHXqH  
{ s^+h>  
nFileLength = getFileSize(); P F#+G;q;  
if(nFileLength == -1) 4E]w4BG)  
{ _MQ)  
System.err.println("File Length is not known!"); Zyxr#:Qm  
} W1S7%6y_1  
else if(nFileLength == -2) 8P5yaS_  
{ Rhh5r0 \5  
System.err.println("File is not access!"); ||3%REliC  
} '<_nL8A^  
else `%}SK~<R  
{ i356m9j  
for(int i=0;i<nStartPos.length;i++) ;Z|X` <6g  
{ 7Y T%.ID  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]w z`j1  
} h`n,:Y^++P  
for(int i=0;i<nEndPos.length-1;i++) >+y[HTf-  
{ rZ`ob x\S  
nEndPos = nStartPos[i+1]; 9r.Os  
} *TQXE:vZ[  
nEndPos[nEndPos.length-1] = nFileLength; umZy=KHj  
} ZGgKCCt  
} Rd~-.&   
9TRS#iVL+*  
%suSZw`  
//启动子线程 6L[Yn?;  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; u;p.:{'  
for(int i=0;i<nStartPos.length;i++) o))z8n?b  
{  734)s  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d_s=5+Yj  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L+,p#w  
nStartPos,nEndPos,i); %+gYZv-  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =Hplg>h)  
fileSplitterFetch.start(); AsJN~<0h  
} I3`WY-uv  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5%,5Xe4p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E~vM$$O$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3V ~871:-~  
nEndPos = " + nFileLength); wSoIU,I  
// fileSplitterFetch[nPos.length-1].start(); o1C1F}gxU  
QND{3Q  
Cw7 07  
//等待子线程结束 h[~JCYA  
//int count = 0; +(n&>7 5  
//是否结束while循环 ?O3E.!Q|  
boolean breakWhile = false; V45A>#?U  
87WIDr  
..BIoSrj  
while(!bStop)  uYVlF@]  
{ CT5\8C  
write_nPos(); l~P%mVC3m  
Utility.sleep(500); T-e'r  
breakWhile = true; 7\x7ySM  
ZlQ@k{Es~  
;f,`T  
for(int i=0;i<nStartPos.length;i++) Tbf't^Ot$  
{ 3!E*h0$}  
if(!fileSplitterFetch.bDownOver) ZL/iX~}a'  
{ {8+FxmH  
breakWhile = false; -]yM<dP  
break; 8R?X$=$]!.  
} "Bl ]_YPv  
} ;e,_F/@`  
if(breakWhile) q.sErr[zc  
break; to9~l"n.s  
!p$HS0c  
P^9y0Q  
//count++; }-YM>q  
//if(count>4) JSz;>  
// siteStop(); pG"pvfEl9f  
} yOR]r+8  
b(^/WCykH  
W^j;"qj  
System.err.println("文件下载结束!"); ED0\k $  
} 2ZTz{|y  
catch(Exception e){e.printStackTrace ();} Bgb~Tz'  
} KnL-qc  
MLD1%* &0  
@bs YJ4-V  
//获得文件长度 @yc/1u $r  
public long getFileSize() qe. Qjq  
{ 2to~=/.  
int nFileLength = -1; |2RoDW  
try{ [+ ,%T;d;  
URL url = new URL(siteInfoBean.getSSiteURL()); : :;YS9e  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aumWU{j=  
httpConnection.setRequestProperty("User-Agent","NetFox"); *}fs@"S   
E"i<fr T  
%L;z~C  
int responseCode=httpConnection.getResponseCode(); ',Y`XP"Q  
if(responseCode>=400) 'T=$Q%Qv  
{ VF#2I %R*  
processErrorCode(responseCode); ])`+ 78  
return -2; //-2 represent access is error x=-dv8N?  
} =NJ:%kvF  
=VA5!-6<Uq  
rl:6N*kK  
String sHeader; X}jWNN  
]QM{aSvXA  
i'XW)n  
for(int i=1;;i++) N RB>X  
{ _8zZ.~)  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T}fH  
//Utility.log(in.readLine()); [l~Gwaul>  
sHeader=httpConnection.getHeaderFieldKey(i); ;MSdTHN"  
if(sHeader!=null) 7 2Zp%a=  
{ VtM:~|v  
if(sHeader.equals("Content-Length")) )|52B;yZx  
{ 87&BF)]  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y dgDMd-1  
break; W=QT-4  
} S  ^5EG;[  
} {T;A50  
else [\i0@  
break; S"-q*!AhK  
} 6f=,$:S$  
} ~HW8mly'  
catch(IOException e){e.printStackTrace ();} .kbo]P  
catch(Exception e){e.printStackTrace ();} Z\1*g k  
,[gu7z^|  
%IAZU c  
Utility.log(nFileLength); k[_)5@2  
vI84= n  
o<1a]M|  
return nFileLength; 7E0L-E=.  
} A(Tqf.,G  
i^<P@ |q  
K;ncviGu  
//保存下载信息(文件指针位置) ?WVp,vP  
private void write_nPos() LUPh!)8  
{ v3zd>fDnRp  
try{ Z~X\Z.  
output = new DataOutputStream(new FileOutputStream(tmpFile)); fRcs@yZnS  
output.writeInt(nStartPos.length); f&=WgITa  
for(int i=0;i<nStartPos.length;i++) FCr^D$_w  
{ -_%8Q#"  
// output.writeLong(nPos); v@xbur\L  
output.writeLong(fileSplitterFetch.nStartPos); `Zdeq.R]  
output.writeLong(fileSplitterFetch.nEndPos); 2YW| /o4  
} Re[x$rw  
output.close(); 3bWYRW  
} B|fh 4FNy  
catch(IOException e){e.printStackTrace ();} /5**2Kgv1  
catch(Exception e){e.printStackTrace ();} J&hzr t  
} yW =I*f  
Q4;%[7LU  
T O]wD^`  
//读取保存的下载信息(文件指针位置) OV~]-5gau  
private void read_nPos() tVUC@M>'  
{ 0c-.h  
try{ \`kH2`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h)NZG6R  
int nCount = input.readInt(); BB$(0mM^  
nStartPos = new long[nCount]; 7O.?I# 76  
nEndPos = new long[nCount]; t[r<&1[&  
for(int i=0;i<nStartPos.length;i++) ^X?D4a|;#g  
{ uT Z#85L `  
nStartPos = input.readLong();  c6f=r  
nEndPos = input.readLong(); ^i"~6QYE  
} tfAO#htq  
input.close(); LMGo8%2I  
} R>C^duos.  
catch(IOException e){e.printStackTrace ();} <2.87:  
catch(Exception e){e.printStackTrace ();} sxK|0i}6  
} tyI !y~-z  
KfPYH\ 0  
`F(ghC  
private void processErrorCode(int nErrorCode) tz^2?wO  
{ Rfx}[!<{N  
System.err.println("Error Code : " + nErrorCode); Y^Y1re+}  
} w'r?)WW$  
av8\?xmo.$  
^ ,cwm:B@  
//停止文件下载 RV=Z$  
public void siteStop() .="/n8B  
{ V7gv@<1<y  
bStop = true; &s{" Vc9]  
for(int i=0;i<nStartPos.length;i++) |T; ]%<O3E  
fileSplitterFetch.splitterStop(); Au\j6mB  
Lu][0+-  
swTur  
} RV_(T+  
} %U uVD  
//负责部分文件的抓取 _\ &N<  
**FileSplitterFetch.java .%"s| D  
*/ ahUc ;S:v#  
package NetFox; }x~1w:z Hd  
 Lw1aG;5  
/cXVJ(#j  
import java.io.*; {CaTu5\  
import java.net.*; au;ZAXM|  
(DnrJ.QU}t  
VpO+52&  
public class FileSplitterFetch extends Thread { \RF{ITV$kD  
xb (Cd  
sX c|++  
String sURL; //File URL h>:eu#  
long nStartPos; //File Snippet Start Position +7V4mF!u  
long nEndPos; //File Snippet End Position }o:sU^Pwa  
int nThreadID; //Thread's ID >qL-a*w:a  
boolean bDownOver = false; //Downing is over |y%M";MI  
boolean bStop = false; //Stop identical [-p?gyl  
FileAccessI fileAccessI = null; //File Access interface Z(|'zAb^  
3 q^^Os  
X+%5q =N  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s[n*fV']A  
{ K\VL[HP-  
this.sURL = sURL; wfMtWXd;KB  
this.nStartPos = nStart; ]n 'FD|  
this.nEndPos = nEnd; L5RBe  
nThreadID = id; #wS/QrRE  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uLq%Nu  
} +?%L X4Y  
[h0.k"&[  
YVW`|'7)|  
public void run() &a9Y4~e::  
{ 3*C|"|lJ  
while(nStartPos < nEndPos && !bStop) 5faY{;8  
{ Tya[6b!8  
XIRvIwO  
^V?W'~  
try{ 0K:3?Ik  
URL url = new URL(sURL); "/g\?Nce  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DlF6tcoI  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5<77o|  
String sProperty = "bytes="+nStartPos+"-"; KM9)  
httpConnection.setRequestProperty("RANGE",sProperty); $gPR3*0  
Utility.log(sProperty); 9NEL[J|  
40m>~I^q}  
2_C&p6VGj  
InputStream input = httpConnection.getInputStream(); A>B_~=  
//logResponseHead(httpConnection); Ap)pOD7  
=}1m.  
lBZhg~{  
byte[] b = new byte[1024]; %4I13|<A`  
int nRead; u}(K3H3  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +6;1.5Tc  
{ 3q)y;T\yW  
nStartPos += fileAccessI.write(b,0,nRead); SLjSNuOP  
//if(nThreadID == 1) py%_XL=w,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5tUN'KEbN  
} ,xOOR   
2od 9Q=v~  
caD|*.b  
Utility.log("Thread " + nThreadID + " is over!"); ~ \3j{pr  
bDownOver = true; +2 x|j>  
//nPos = fileAccessI.write (b,0,nRead); 5~H}%W,P  
} ;-"'sEu}  
catch(Exception e){e.printStackTrace ();} %^LwLyoVM  
} w(cl,W/w  
} cz.,QIt_  
=g^k$ Rc  
\Pt_5.bTs[  
//打印回应的头信息 $/|2d4O:{  
public void logResponseHead(HttpURLConnection con) >`)IdX  
{ Xo/0lT  
for(int i=1;;i++) 'FC#O%l  
{ }~+_|  
String header=con.getHeaderFieldKey(i); 7T/hmVi_  
if(header!=null) +2Wijrn  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H^J waF  
Utility.log(header+" : "+con.getHeaderField(header)); -;RW)n^n  
else z$b'y;k  
break; )Q)H!yin  
} yN:U"]glC  
} *$*V#,V-  
.3:s4=(f  
"3e1 7dsY  
public void splitterStop() Sc,a jT  
{  .H7xG'$  
bStop = true; Y8@TY?  
} $e/[!3CASP  
%WO4uOi:@  
5$<Ozkj(  
} a8v9j3.  
 Jknit  
vI5'npM  
/* OqlP_^Zz7p  
**FileAccess.java !v?WyGbUg  
*//文件访问(定位,写) r~Vb*~U"  
package NetFox; +xojnv  
import java.io.*; /~}<[6ZGCY  
tJ9-8ZT*  
3.@ I\p}  
public class FileAccessI implements Serializable{ Z O\x|E!b  
@*"H{xo.U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ! ~3zp L  
RandomAccessFile oSavedFile; &p83X  
long nPos; %Z!3[.%F  
XyrQJ}WR|  
6< @F  
public FileAccessI() throws IOException MwO`DrV  
{ zwJK|Sk  
this("",0); NsUP0B}.  
} Uk<2XGj  
fiZq C?(  
_6Qb 3tl  
public FileAccessI(String sName,long nPos) throws IOException (\*+HZ`(Uu  
{ hVf;{p &  
oSavedFile = new RandomAccessFile(sName,"rw"); P`]p&:  
this.nPos = nPos; q-R'5p\C?|  
oSavedFile.seek(nPos); (^9dp[2  
} 2x<4&^  
0o_wy1O1,  
-_+,HyJP  
public synchronized int write(byte[] b,int nStart,int nLen) O]%Vh l  
{ j5~nLo2  
int n = -1; apw/nhQ.[  
try{ |]+PDc%  
oSavedFile.write(b,nStart,nLen); ^J?y mo$>0  
n = nLen; D'Y=}I)8Dn  
} xG~7kj3  
catch(IOException e) &p_V<\(%  
{ Ew>lk9La(  
e.printStackTrace (); $4u8"ne)  
} }&Kl)2:O  
rJUXIV>z  
vD3j(d  
return n; SU>cJ*  
} _8ubo\M~  
/& wA$h  
/@feY?glc  
} D+('1E?  
c!Wj^  
rLx'.:  
/* KGNBzy~9  
**SiteInfoBean.java T%[!m5   
*/ Z<W`5sop^  
package NetFox; o*Kl`3=]  
XO,gEn&6V  
tA{?-5  
public class SiteInfoBean { xXfFi5Eom  
zot_ jSV  
$Fik]TbQp  
private String sSiteURL; //Site's URL ,Uu#41ZOKL  
private String sFilePath; //Saved File's Path 6):iu=/i/  
private String sFileName; //Saved File's Name k\A[p\  
private int nSplitter; //Count of Splited Downloading File M$MFUGS'  
SnFAv7_  
6y   
public SiteInfoBean() 8G?OZ47k#  
{//nSplitter的缺省值为5 xn,I<dL39  
//default value of nSplitter is 5 jrZH1dvE  
this("","","",5); +hUz/G+3  
} 2'5u}G9  
/Q\|u:oO,  
#5=!ew  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) H:!pFj  
{ 4$MV]ldUI  
sSiteURL= sURL; ,@r 0-gL  
sFilePath = sPath; 'q, L*  
sFileName = sName; !B:wzb_  
this.nSplitter = nSpiltter; SeIL   
^_!2-QY.~  
H-5h-p k  
} xF])NZy|  
}e0>Uk`[  
6 6Bx,]"6  
public String getSSiteURL() 8;Eg>_cL:  
{ b2G1@f.U  
return sSiteURL; y.+!+4Mg|  
} Tv /?-`Y  
Xn* >qm  
8Y&_X0T|  
public void setSSiteURL(String value) se`^g ,]P  
{ ve@E.`  
sSiteURL = value; Pe)SugCs  
} t)^18 z  
]D&\|,,(  
Fd1jElt  
public String getSFilePath() L]#b =Y  
{ <z R CT  
return sFilePath;  #[yZP9  
} =L&dV]'4P  
;$/]6@bqB  
mWX{I2  
public void setSFilePath(String value) qz&?zzz;  
{ #55_hY#  
sFilePath = value; hL}AgY@  
} z\+Ug9Of  
iNv"!'|  
*TC#|5  
public String getSFileName() 84f^==Y  
{ R&FO-{S  
return sFileName; `<IaQY  
} -mqL[ h,  
W~d^ *LZt  
l }WvO]  
public void setSFileName(String value) !]2`dp\!  
{ 9Z lfY1=  
sFileName = value; $3yn-'o'A  
} eh}I?:(a?  
cs7K^D;.V  
G}#p4 \/  
public int getNSplitter() /[,0,B9!3  
{ pv@w 8*  
return nSplitter; k4`(7Z  
} @ *n oma  
a&%v^r[  
:@K~>^+U  
public void setNSplitter(int nCount) 'QQa :3<x  
{ WWN2  
nSplitter = nCount; $64sf?aZ>#  
} ?d`j}  
} 8<PQ31  
2g$;ZBHO|8  
xy+hrbD)j  
/* Uj twOv|pF  
**Utility.java mG.H=iw  
*/ 2*TPW  
package NetFox; nZ8jBCh  
]7J*(,sp  
/A1qTG=Br  
public class Utility { cd]def[d  
A&L2&ofV&q  
Wh^wKF~%  
public Utility() X{tfF!+iy  
{ rL|9Xru  
.9@y*_ 9  
g![?P"i^t  
} Hl=M{)q@   
p61F@=EL  
//线程睡眠 ~ As_O6JI  
public static void sleep(int nSecond) iG+=whvL  
{ ChRCsu~  
try{ O ~D]C  
Thread.sleep(nSecond); *s$:"g-  
} 37 d-!  
catch(Exception e) + ;_0:+//  
{ }E#1Z\)  
e.printStackTrace (); xew s~74L  
} i9v|*ZM"  
} npMPjknl  
U~O*9  
//日志 A O3MlK9t  
public static void log(String sMsg) 36\_Y?zx%  
{ }T&~DVM  
System.err.println(sMsg); z@U5  
} UNyk, #4  
8]&\FA8  
_ pO1XM  
public static void log(int sMsg) CSlPrx2\  
{ |Pq z0n=v  
System.err.println(sMsg); ]:svR@E  
} O7z5,-  
} z, c=."<z  
G!E1N(%o  
,$bK)|pGV  
/* u+qj_Ej  
**TestMethod.java A9o"L.o)  
*/ %OJq(}  
package NetFox; MQq!<?/  
2 sK\.yS  
<8BNqbX  
public class TestMethod { %:yVjb,Yf  
Vu;z|L  
 J7p?9  
public TestMethod() Vw+RRi(  
{ ///xx/weblogic60b2_win.exe +k\cmDcb  
try{ fF.sT7Az+  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +l;AL5h  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?<U">8cP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); /-&2>4I  
fileFetch.start(); ="P&!lu  
} 5 #Et.P'  
catch(Exception e){e.printStackTrace ();} {~EPP .  
8SoTABHV  
q+W* ?a)  
} U(5Yg  
4q*mEV  
5U6b\jxX  
public static void main(String[] args) Zqj EVVB  
{ /7igPNhx  
new TestMethod(); :I8HRkp  
} G3j'A{  
} VvTi>2(.  
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