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http断点续传简单实现(java)

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/* ^Aq0<  
**SiteFileFetch.java k(l2`I4V  
*/ [/UchU]DT  
package NetFox; *q*3SP/  
import java.io.*; $Sgf jm  
import java.net.*; +t+<?M B  
:q]9F4im  
r8Mx +r  
public class SiteFileFetch extends Thread { fq]PKLW'  
RhH 1nf2UR  
|zYOCDFf  
SiteInfoBean siteInfoBean = null; //文件信息Bean o)/Pr7Qn  
long[] nStartPos; //开始位置 4=xi)qF/@  
long[] nEndPos; //结束位置 kkF)Tro\  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ]:59c{O  
long nFileLength; //文件长度 La;G S  
boolean bFirst = true; //是否第一次取文件 Aw |;C  
boolean bStop = false; //停止标志 }OL"38P  
File tmpFile; //文件下载的临时信息 l9Ir@.m  
DataOutputStream output; //输出到文件的输出流 @#)` -]g  
Dj&~x  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) kg[%Q]]  
public SiteFileFetch(SiteInfoBean bean) throws IOException /Hyz]46  
{ &0Yg:{k$  
siteInfoBean = bean; .p&@;fZ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); *h!fqT%9  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); _U<fS  
if(tmpFile.exists ()) /|1p7{km  
{ QEhn  
bFirst = false; VThr]$2Y  
read_nPos(); Nr4:Gih  
} 4^tSg#!V{  
else lmvp,BzC  
{ h'):/}JPl  
nStartPos = new long[bean.getNSplitter()]; )U?_&LY)[M  
nEndPos = new long[bean.getNSplitter()]; '4[=*!hs!  
} * x/!i^  
wZiUzS ;v  
:$MOdLr  
I6W`yh`I)  
} zTF{ g+  
O?JJE8~']  
NXU:b"G S  
public void run() V&M*,#(?  
{ }}JMwT  
//获得文件长度 =?<WCR C*  
//分割文件  `Vb  
//实例FileSplitterFetch 3@> F-N  
//启动FileSplitterFetch线程 `6D?te  
//等待子线程返回 vk& gR  
try{ {LO Pm1K8Y  
if(bFirst) r9i? H  
{ ;]>kp^C#  
nFileLength = getFileSize(); E-bswUVaEE  
if(nFileLength == -1) QJGGce  
{ tS'lJu  
System.err.println("File Length is not known!"); / (&E  
} 7A)\:k  
else if(nFileLength == -2) Fb5U@X/vE  
{ jT{T#_  
System.err.println("File is not access!"); sgX!4wG&Z  
} 2bp@m;g$  
else I0Pw~Jj{  
{ lkn|>U[  
for(int i=0;i<nStartPos.length;i++) 0bg"Q4  
{ 2$JGhgDI  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 4Gc M  
} #z*,CU#S9d  
for(int i=0;i<nEndPos.length-1;i++) H_DCdUgC'  
{ 1 em,/> "  
nEndPos = nStartPos[i+1]; za>UE,?h  
} t]yxLl\  
nEndPos[nEndPos.length-1] = nFileLength; tE7jTe  
} m&UP@hUV-  
} zM9#1^X  
H U|.5tP  
,fkvvM{mq  
//启动子线程 5)k8(kH  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; uN|A}/hr]  
for(int i=0;i<nStartPos.length;i++) _pvB$&  
{ rbw$=bX}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )g0lI  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `fu_){  
nStartPos,nEndPos,i); @I _cwUO  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I{Zb/}k-  
fileSplitterFetch.start(); RLmOg{L  
} WE<?y_0y&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N9e'jM>Oos  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !#tVQ2O  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &`"DG$N(  
nEndPos = " + nFileLength); $*yYmF  
// fileSplitterFetch[nPos.length-1].start(); diq}\'f  
D'"  T'@  
BuJo W@)  
//等待子线程结束 $ V^gFes  
//int count = 0; p@m0 Oi,=  
//是否结束while循环 z:Ml;y  
boolean breakWhile = false; qpjY &3SI  
1Ms[$$b$  
/k#-OXP~  
while(!bStop) g9_zkGc7  
{ dGIdSQ~ _  
write_nPos(); Rn1oD3w  
Utility.sleep(500); OxlA)$.hpu  
breakWhile = true; '%N?r,x C  
Pf*6/7S:  
b/SBQ" B%  
for(int i=0;i<nStartPos.length;i++) jkAjYR.  
{ m5\T,  
if(!fileSplitterFetch.bDownOver) hnnB4]c  
{ 0Y.z  
breakWhile = false; U&!TA(Yr  
break; j#NyNv(jE1  
} =$>=EBH,cm  
} `+7F H  
if(breakWhile) 615Ya<3f8  
break; ,6)N.  
k s40 5  
xEb>6+-F@  
//count++; #8$?# dT  
//if(count>4) Y"Cf84E  
// siteStop(); ZlT }cA/n  
} pu-HEv}]a|  
eV;r /4  
_:x]' w%  
System.err.println("文件下载结束!"); 9^gYy&+>6]  
} E C?}iP  
catch(Exception e){e.printStackTrace ();} Ss3p6%V/  
} ^QK`z@B  
=7Ln&tZ  
}0'=}BE  
//获得文件长度 xQoZ[  
public long getFileSize() u?osX;'w  
{ L\:|95Yq  
int nFileLength = -1; H4$qM_N  
try{ 'o AmA=  
URL url = new URL(siteInfoBean.getSSiteURL()); !8{ VLg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?Oyo /?/  
httpConnection.setRequestProperty("User-Agent","NetFox"); sS D8Sx/  
AjzTszByu  
@Jt$92i5PS  
int responseCode=httpConnection.getResponseCode(); -JW~_Q[  
if(responseCode>=400) ]\E"oZ  
{ lZFu|(  
processErrorCode(responseCode); Q@D7 \<t  
return -2; //-2 represent access is error VtBC~?2U)B  
} &D, Iwq  
d?,'$$aB  
{ 3G  
String sHeader; v 6~9)\!j  
agIqca;  
DUp`zW;B  
for(int i=1;;i++) p{f R$-d  
{ HJL! ;i  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y:^hd809  
//Utility.log(in.readLine()); Hon2;-:]{]  
sHeader=httpConnection.getHeaderFieldKey(i); -Q WvB  
if(sHeader!=null) !09)WtsEfx  
{ 144Y.  
if(sHeader.equals("Content-Length")) AdX))xgl  
{ OO:S2-]Y>e  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uLhGp@Dx  
break; Od1\$\4Z  
} q_MN  
} \PrJy6&  
else iw@rW5%'~  
break; Q(|@&83].  
} A8{jEJ=)P  
} rRTKF0+  
catch(IOException e){e.printStackTrace ();} |IgR1kp+.  
catch(Exception e){e.printStackTrace ();} Xp<q`w0I,  
"1O_h6 C  
n,N->t$i  
Utility.log(nFileLength); i3-5~@M  
2)}n"ibbT  
Q*DT" W/0  
return nFileLength; m\:^9A4HCg  
} V!}I$JiJ  
]RVu[k8  
r,5e/X  
//保存下载信息(文件指针位置) -@v^. @[Z&  
private void write_nPos() iZGbNN  
{ Lg:1zC  
try{ Wu>]R'C  
output = new DataOutputStream(new FileOutputStream(tmpFile)); eG=d)`.JaV  
output.writeInt(nStartPos.length); P1#g{f  
for(int i=0;i<nStartPos.length;i++) 5Xq+lLW>  
{ 2/-m-5A  
// output.writeLong(nPos); B=SA +{o  
output.writeLong(fileSplitterFetch.nStartPos); corm'AJ/  
output.writeLong(fileSplitterFetch.nEndPos); Ly= .  
} A95f!a  
output.close(); Xdvd\H=  
} :;$MUOps  
catch(IOException e){e.printStackTrace ();} E-A9lJWr  
catch(Exception e){e.printStackTrace ();} inu.U[.  
} HQ-[k$d W4  
wL;OQhI  
lrrTeE*  
//读取保存的下载信息(文件指针位置) *G"hjc$L  
private void read_nPos() X3:1KDVsV  
{ }7PJr/IuF  
try{ ;,y_^-h;  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1+%UZK= K  
int nCount = input.readInt(); .k#PrT1C  
nStartPos = new long[nCount]; y?s z&*:  
nEndPos = new long[nCount]; ZCCCuB  
for(int i=0;i<nStartPos.length;i++)  \XDiw~0  
{ \f,<\mJ#  
nStartPos = input.readLong(); ?1Nz ,Lc$  
nEndPos = input.readLong(); kQ\GVI11?  
} ]TvMT  
input.close(); x[ A|@\Z  
} 757&bH|a  
catch(IOException e){e.printStackTrace ();} +17!v_4^  
catch(Exception e){e.printStackTrace ();} .Xlo-gHk  
} |nMjv]#  
D+T/ Z)  
G|cjI*  
private void processErrorCode(int nErrorCode) ,Yag! i>;  
{ RDps{),E;d  
System.err.println("Error Code : " + nErrorCode); k>i88^kPV  
} Fe8X@63  
3M#x)cW  
bTs2$81[  
//停止文件下载 HT7,B(.}  
public void siteStop() 1wgL^Qz@  
{ ydWr&E5  
bStop = true; GRc)3 2,  
for(int i=0;i<nStartPos.length;i++) GMU!GSY  
fileSplitterFetch.splitterStop(); \`.v8C>vG  
l;M,=ctB(  
Zma;An6  
} tP_.-//  
} r] /Ej!|  
//负责部分文件的抓取 f2.=1)u.  
**FileSplitterFetch.java 7mtx^  
*/ "P7OD^(x/  
package NetFox; >s<Bu'r  
N8]DzE0%  
9KK^1<46c  
import java.io.*; RHsVG &<j  
import java.net.*; D#nHg  
@(R=4LL  
g0f4>m  
public class FileSplitterFetch extends Thread {  l!1_~!{y  
6AIqoX*p  
uh\G6s!4/  
String sURL; //File URL 5K Ij}VN  
long nStartPos; //File Snippet Start Position ^"Bhp:o2  
long nEndPos; //File Snippet End Position BOpZ8p'eH1  
int nThreadID; //Thread's ID :ok.[q  
boolean bDownOver = false; //Downing is over Y`g O:d8  
boolean bStop = false; //Stop identical Q8m~L1//S  
FileAccessI fileAccessI = null; //File Access interface Mg >%EH/'  
P`rfDQoZ  
&D<6Go/)_*  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >p&"X 2 @  
{ VjM/'V5  
this.sURL = sURL; JCH9~n.  
this.nStartPos = nStart; rDl/R^w"  
this.nEndPos = nEnd; #x 6/"Y2  
nThreadID = id; Up Z 9g"  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hUpour |b  
} (~Z&U  
[kJ;Uxncz~  
iKq_s5|sW  
public void run() (ot,CpI(I  
{ "%K'~"S#Q,  
while(nStartPos < nEndPos && !bStop) H~*N:$C  
{ F=5+JjrX  
)]n>.ZmLCB  
gpq ,rOIK  
try{ o^@#pU <  
URL url = new URL(sURL); KXZ G42w  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LYAGpcG  
httpConnection.setRequestProperty("User-Agent","NetFox"); <hzHrx'o{  
String sProperty = "bytes="+nStartPos+"-"; Cuylozj$&  
httpConnection.setRequestProperty("RANGE",sProperty); Dx\~#$S!=  
Utility.log(sProperty); f0eQq;D$K  
PE.UNo>o  
S))B^).0-  
InputStream input = httpConnection.getInputStream(); *vQ 6LF;y  
//logResponseHead(httpConnection); rvx2{1}I  
`;Ui6{|  
'!$ QI@@  
byte[] b = new byte[1024]; =nHkFi@D=t  
int nRead; p$F` 9_bZ  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :@p]~{m:G  
{ F=&,=r' Q8  
nStartPos += fileAccessI.write(b,0,nRead); v1u~[c=|^  
//if(nThreadID == 1) H-t$A, [  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0~<?*{~  
} h0-.9ym  
G%Lt>5*!nE  
TFldYKd/l  
Utility.log("Thread " + nThreadID + " is over!"); ~M7X]  
bDownOver = true; EFiVwH  
//nPos = fileAccessI.write (b,0,nRead); $Ptl&0MN%  
} {pQ8/Af!  
catch(Exception e){e.printStackTrace ();} C{U*{0}  
} '`tFZfT  
} ty[%:eG#  
Ud"_[JtGM  
<|'ETqP<+  
//打印回应的头信息 mR2"dq;U  
public void logResponseHead(HttpURLConnection con) #Br`;hL<T  
{ ZYB5s~;eB"  
for(int i=1;;i++) Gy+c/gK  
{ f2tCB1[D+  
String header=con.getHeaderFieldKey(i); +%<kcc3  
if(header!=null) ZK ?V{X{";  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |5(CzXR]  
Utility.log(header+" : "+con.getHeaderField(header)); Lww&[|k.  
else ,aWI&ve6  
break; %-YWn`yEm  
} t .&JPTK-H  
} ZT"vVX- )G  
Ag3+z+uS  
LD{~6RP  
public void splitterStop() `4ga~Ch  
{ [6\O <-?  
bStop = true; Li8/GoJW-T  
} f x:vhEX  
U4Zx1ieCKH  
HI1|~hOb'  
} MF$Dx| Tcj  
'oGMr=gp<&  
a^G>|+8  
/* ">B&dNrt  
**FileAccess.java s o: o b}  
*//文件访问(定位,写) }.u[';q ]S  
package NetFox; gdAd7 T  
import java.io.*; .R)Ho4CE  
jn]l!nm  
xn=mS!"1Zo  
public class FileAccessI implements Serializable{ @Nm{H  
gjiS+N[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EGRIhnED#  
RandomAccessFile oSavedFile; @<OsTF L  
long nPos; -0'< 7FSQ  
od@!WjcM[8  
R0w~ Z   
public FileAccessI() throws IOException *?Oh%.HgF  
{ Mu.tq~b >  
this("",0); 8u*Q^-fpo0  
} 'mv|6Y  
_x-2tnIxXv  
)+)qFGVz  
public FileAccessI(String sName,long nPos) throws IOException ~urk Uz  
{ #p{8  
oSavedFile = new RandomAccessFile(sName,"rw"); 1@-l@ P  
this.nPos = nPos; nbw8YO(=  
oSavedFile.seek(nPos); wd,6/5=lh  
} 2#R0Bd  
/ H GPy  
Qm[ )[M  
public synchronized int write(byte[] b,int nStart,int nLen) p-oEoA  
{ %h_N%B$7c1  
int n = -1; D1]?f`  
try{ .i7"qq.M  
oSavedFile.write(b,nStart,nLen); ;M+~ e~  
n = nLen; Q>z (!'dw  
} -hK^*vJ  
catch(IOException e) ) [)1  
{ SQ/}K8uZ  
e.printStackTrace (); R{B5{~m>W@  
} U~|)=+%O  
W9GjUswv!  
3;//o<  
return n; P=ubCS'  
} j;_E0j#  
`y"a>gHC  
3!KyO)8  
} Ngrj@_J  
S>[&]  
W Emh  
/* JFRbW Q0  
**SiteInfoBean.java U d+6=Us{  
*/ U,< ?]h  
package NetFox; DI :  
`'rvDaP  
Fe2iG-ec  
public class SiteInfoBean { 8P%Jky&(  
EBmkKiI;  
 L$]Y$yv  
private String sSiteURL; //Site's URL w~AO;X*Ke"  
private String sFilePath; //Saved File's Path JWQd6JQ_~V  
private String sFileName; //Saved File's Name yTWicW7i  
private int nSplitter; //Count of Splited Downloading File j3o?B  
_bCIVf`  
4?`*# DPl  
public SiteInfoBean() @Y%i`}T%(  
{//nSplitter的缺省值为5 ;A?86o'?  
//default value of nSplitter is 5 :9|CpC`.  
this("","","",5); L3S29-T  
} C61E=$  
|kHzp^S  
X-yS9E  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fHF*#  
{ C9%A?'`  
sSiteURL= sURL; G Mg|#DV  
sFilePath = sPath; 5N#Sic M  
sFileName = sName; (]"`>, ray  
this.nSplitter = nSpiltter; vf!lhV-UG+  
YQ-V^e6  
ocj^mxh =O  
} tY`%vI [  
ZjgfkZAS  
r#mH[|@W~  
public String getSSiteURL() G'iE`4`2  
{ #!j wn^yq  
return sSiteURL; a/~1CrYr  
} _o6Zj1p  
ib(4Y%U6~  
aslb^  
public void setSSiteURL(String value) ~kZ? e1H  
{ a^)@ }4  
sSiteURL = value; ZGS4P0$  
} c*V/2" 5  
Q/l388'  
239g pf]}  
public String getSFilePath() d?[8VfAnh  
{ )%I62<N,z  
return sFilePath; 1[(/{CClB  
} \2 [  
_WBWFGj  
0w".o!2\U{  
public void setSFilePath(String value) {G-y7y+E  
{ Z"9D1Uk  
sFilePath = value; Oz5Ze/HBN  
} YZc{\~d  
1{CVd m<9  
nhB.>ReAi  
public String getSFileName() P\2x9T  
{ N}\3UHtO  
return sFileName; X> V`)  
} 5eX+9niY  
M^y5 Dep  
1v9 #Fr Y  
public void setSFileName(String value) <)$JA  
{ 4#D>]AX  
sFileName = value; Z7=k$e  
} |EP=<-|  
QqB9I-_  
!@f!4n.e|I  
public int getNSplitter() M~*o =t  
{ Y#oY'S .;y  
return nSplitter; L@~0`z:>iP  
} #D Oui]  
M~djX} #\  
jGKI|v4U(  
public void setNSplitter(int nCount) ;<s0~B#9}  
{ joJQ?lG  
nSplitter = nCount; Ft 2u&Rtx  
} C <q@C!A  
} (x8D ]a  
$&FeR*$|g  
MMyJAGh ^G  
/* \r&9PkHWo  
**Utility.java Ehg(xK  
*/ i/q1>  
package NetFox; R?J=5tO  
`>\>'V<&  
@HP7$U"  
public class Utility { $McbVn)~f  
@<=<?T> 1  
0`kaT ?>  
public Utility() .Za)S5U  
{ +r 8/\'u-  
?&$BQK  
hdy N   
} -e_L2<7  
Mzj|57:gx  
//线程睡眠 "S0WFP\P+  
public static void sleep(int nSecond) Tf.DFfV#y  
{ K`twbTU  
try{ FSkz[D_}  
Thread.sleep(nSecond); McRfEF \  
} ~|=goHmm[  
catch(Exception e) @x/D8HK2  
{ L%0G >2x  
e.printStackTrace (); Hge0$6l  
} hH=}<@z   
} qku!Mg  
{Nny .@P)H  
//日志 7\ kixfEg  
public static void log(String sMsg) gwv s  
{ Y #6G&)M  
System.err.println(sMsg); vC%8-;8{H  
} N&-J,p~  
hBNA,e:  
}:4b_-&Q5  
public static void log(int sMsg) ^n<o,K4\}  
{ T8-,t];i  
System.err.println(sMsg); TCetd#;R  
} K_CE.8G&{  
} iCh,7I,m  
6@geakq  
K_ [B@( Xl  
/* 5!iBKOl#D  
**TestMethod.java J(=io_\bO  
*/ <%:,{u6  
package NetFox; h4k.1yH;  
rnS&^  
\"?5CHz*  
public class TestMethod { Z-rHYfa4  
TAKv E=a;  
hScC< =W  
public TestMethod() .{ r %C4q9  
{ ///xx/weblogic60b2_win.exe @_C?M5v  
try{ *MZa|Xy  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pn-`QB:{h  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8;1,saA_9  
SiteFileFetch fileFetch = new SiteFileFetch(bean); !t!\b9=  
fileFetch.start(); b[`fQv$G  
} /zZ";4  
catch(Exception e){e.printStackTrace ();} O}mz@- Z  
7':qx}c#!1  
db5@+_  
} )|`|Usn#[  
HMPb%'U~  
DNy 6Kw  
public static void main(String[] args) 8AuOe7D9A  
{ Q,< V)  
new TestMethod(); VVDd39q  
} e)A-.SRiO$  
} 0`%Ask  
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