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http断点续传简单实现(java)

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/* ]]y[t|6  
**SiteFileFetch.java ^ZVO ql&  
*/ QgZJ`G--  
package NetFox; vJThU$s-  
import java.io.*; vZk9gGjk  
import java.net.*; 7@a\*|K6  
Wr#~GFg  
vHc#m@4o  
public class SiteFileFetch extends Thread { 3+zzi  
`^%@b SE(  
Tk](eQsy.v  
SiteInfoBean siteInfoBean = null; //文件信息Bean w%2ziwgh  
long[] nStartPos; //开始位置 d?}hCo=/Xq  
long[] nEndPos; //结束位置 ^U{P3 %uZ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ;@4sd%L8V  
long nFileLength; //文件长度 vX.]hp5~  
boolean bFirst = true; //是否第一次取文件 )Ga8`t"  
boolean bStop = false; //停止标志 PW)8aLU  
File tmpFile; //文件下载的临时信息 6sy,A~e  
DataOutputStream output; //输出到文件的输出流 .hne)K%={y  
xT=ySa$|>  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) TrQm]9@  
public SiteFileFetch(SiteInfoBean bean) throws IOException c(&AnIlS  
{ rkIMM,   
siteInfoBean = bean; |0]YA  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); dk:xnX%  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); rXDJ:NP  
if(tmpFile.exists ()) ;-Ado8  
{ `u=oeM :  
bFirst = false; 5"uNj<.V  
read_nPos(); y($EK(cb  
} OPLl*bnf  
else f}blB?e  
{ s9 &)Fv-#V  
nStartPos = new long[bean.getNSplitter()]; y9ip[Xn-$:  
nEndPos = new long[bean.getNSplitter()]; C[0MA ,^  
} ogp{rY  
/+29.1#|  
 ]CIe~q  
fFHK:n`  
} Iu%^*K%  
f-&ATTx`J  
t)!V +Qcb  
public void run() SctJxY(}!  
{ 1 yJ75/  
//获得文件长度 SdSgn|S  
//分割文件 &t_A0z  
//实例FileSplitterFetch ,zoB0([  
//启动FileSplitterFetch线程 yZ|+VXO  
//等待子线程返回 R` 44'y|  
try{ ?(>k,[n  
if(bFirst) ;Rs.rl>;t/  
{ z2v<a{e  
nFileLength = getFileSize(); Nuo^+z E   
if(nFileLength == -1) WV@X@]U  
{ ;/R kMS  
System.err.println("File Length is not known!"); _hWuAJ9Qy  
} 0W_mCV  
else if(nFileLength == -2) BPh".RJ  
{ $8Ig&k|~8  
System.err.println("File is not access!"); ~;!BDLMC6  
} V07VwVD  
else Yfe'#MKfL  
{ #)FDl70S8  
for(int i=0;i<nStartPos.length;i++) 73VQ@J n  
{ Ej{+U  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !. p  
} R qn WtE  
for(int i=0;i<nEndPos.length-1;i++) @]E]W#xAn  
{ pbPz$Y  
nEndPos = nStartPos[i+1]; G~S))p  
} dD o6fP2  
nEndPos[nEndPos.length-1] = nFileLength; i`R(7Z  
} m^'~&!ba  
} o:H'r7N  
5 >'66gZ  
WqR7uiCi  
//启动子线程 \FVNXU MU  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tg3zXJ4k_  
for(int i=0;i<nStartPos.length;i++) [z^Od  
{ !ZX&r{pJp  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o>.AdZby  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2G ZF/9}  
nStartPos,nEndPos,i); K[e`t%2_  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jb7iBQ2%  
fileSplitterFetch.start(); `t%|.=R  
} e~3]/BL  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iQu^|,tHEM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |^ ?`Q.|c$  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gji*Wq  
nEndPos = " + nFileLength); Qg[heND  
// fileSplitterFetch[nPos.length-1].start(); c5<kbe  
7&h\l6}Yh  
>B`Cch/ 'U  
//等待子线程结束 *B %y`cj|  
//int count = 0; zf`5>h|  
//是否结束while循环 (v]P<3%  
boolean breakWhile = false; U&`6&$]  
5[nmP95YK  
!;TR2Zcn  
while(!bStop) zaH 5 Km_j  
{ J9NsHr:A[  
write_nPos(); ' J2ewW5  
Utility.sleep(500); JR] )xPI`  
breakWhile = true; ,tau9>!  
cD5w| rm?i  
ES^NBI j5P  
for(int i=0;i<nStartPos.length;i++) hK Fk$A  
{ bAN10U  
if(!fileSplitterFetch.bDownOver) mlD%d!.  
{ 15o9CaQw4"  
breakWhile = false;  c^rC8E  
break; *U :VM'a  
} DE5d]3B  
} z'?SRK5+  
if(breakWhile) I; ^xAd3G  
break; 3T"2S[gT  
VIb;96$Or  
I+*osk  
//count++; B^H4Q 4-  
//if(count>4) j'\>Nn+  
// siteStop(); >y]?MGk  
} (qJIu  
;& RUE  
pi|\0lH6W  
System.err.println("文件下载结束!"); iKohuZr  
} ]U_5\$  
catch(Exception e){e.printStackTrace ();} p 7 , f6kG  
} 3gC\{y!8  
]gH wfqx  
TViBCed40  
//获得文件长度 {F<)z% ^  
public long getFileSize() kZJt ~}  
{ eH ;Wfs2f  
int nFileLength = -1; f#*h^91x  
try{ f;e_04K  
URL url = new URL(siteInfoBean.getSSiteURL()); 2j2mW>Z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ga]47pQ"F  
httpConnection.setRequestProperty("User-Agent","NetFox"); u9esdOv  
`Q:de~+AM{  
~ &t!$  
int responseCode=httpConnection.getResponseCode(); {k kAqJ  
if(responseCode>=400) i:C.8hmAE  
{ ;+TMx(  
processErrorCode(responseCode); h1n*WQ-  
return -2; //-2 represent access is error &\JK%X.Jlt  
} d,zp `S  
Q1aHIc  
FX{ ~"  
String sHeader; " ]aQ Hh]f  
=n> iQS  
=AWX +znP  
for(int i=1;;i++) H0: iYHu  
{ f1)HHUB  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W/#KX}4  
//Utility.log(in.readLine()); @~JB\j9  
sHeader=httpConnection.getHeaderFieldKey(i); P]|J?$1K  
if(sHeader!=null) R1I I k  
{ !y.ei1diw  
if(sHeader.equals("Content-Length")) CW.&Y?>Tv  
{ ,Y`'myL8W  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hfJrQhmE  
break; b\kN_  
} &mX5&e  
} Is4%}J!8  
else /p[|DJo M  
break; b{Z^)u2X  
} z8 hTZU  
} |Dl*w/n  
catch(IOException e){e.printStackTrace ();} sjkWz2]S  
catch(Exception e){e.printStackTrace ();} C4&U:y<ju  
b7?U8/#'  
KC&H*  
Utility.log(nFileLength); SNQz8(O  
mgmWDtxN  
Ah6wU|_-g  
return nFileLength; pWWL{@J  
} %4?SY82  
qFvg}}^y  
~5lKL5w  
//保存下载信息(文件指针位置) _<u8%\  
private void write_nPos() vpZu.#5c  
{ 1"8Z y6t  
try{ N BV}4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); *ah>-}-  
output.writeInt(nStartPos.length); v_y!Oh?EG  
for(int i=0;i<nStartPos.length;i++) 6a "VCE]  
{ z7O Z4R:  
// output.writeLong(nPos); *ge].E  
output.writeLong(fileSplitterFetch.nStartPos); ^+(A&PyP?  
output.writeLong(fileSplitterFetch.nEndPos); *>H M$.?Q  
} "6NFe!/Y$*  
output.close(); Dj-\))L  
} <dju6k7uz  
catch(IOException e){e.printStackTrace ();} ;cM8EU^.  
catch(Exception e){e.printStackTrace ();} 1x~%Ydy  
} 7P3 <o!YA  
KzEuPJ?  
Qv9*p('~A  
//读取保存的下载信息(文件指针位置) 2rK-X_}  
private void read_nPos() h Jfa_  
{ .8u$z`j  
try{ "Y"t2l_n  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FK4nz2&4  
int nCount = input.readInt(); A)b)ff ,  
nStartPos = new long[nCount]; CL)1Q  
nEndPos = new long[nCount]; vjexx_fq  
for(int i=0;i<nStartPos.length;i++) 8>C; >v  
{ .b =M5JsyV  
nStartPos = input.readLong(); b*I&k":  
nEndPos = input.readLong(); YQN]x}:E+4  
}  l 'AK  
input.close(); ( z8]FT  
} @-)<|orU4  
catch(IOException e){e.printStackTrace ();} P<j4\zJ  
catch(Exception e){e.printStackTrace ();} &{-oA_@  
} M/::`yJQu  
,!o\),N  
XM$5S+e  
private void processErrorCode(int nErrorCode) fe& t-  
{ %NF<bEV  
System.err.println("Error Code : " + nErrorCode); w Mlf3Uz  
} !Z<mrr;T@  
`jD8(}_  
/|4Q9=  
//停止文件下载 OqfhCNAY  
public void siteStop() Bo\a  
{ ^l]]qdNr  
bStop = true; =:xV(GK}  
for(int i=0;i<nStartPos.length;i++) ]FY?_DGOA  
fileSplitterFetch.splitterStop(); jI*}y[o  
&&(4n?   
%Y)PH-z  
} )@8'k]Glw.  
} }<( "0jC  
//负责部分文件的抓取 ?D*Hl+iu  
**FileSplitterFetch.java KKeb ioW  
*/ SY!`a:It  
package NetFox; !SLP8|Cd  
C:'WX*W  
]p4`7@@)*  
import java.io.*; <GL}1W"Ay  
import java.net.*; ql#{=oGDnA  
Q{J"`d2  
?6gDbE%  
public class FileSplitterFetch extends Thread { dXA{+<!!  
Q%,o8E2~  
_ 6+,R  
String sURL; //File URL "?2  
long nStartPos; //File Snippet Start Position F]K$u <U  
long nEndPos; //File Snippet End Position \N# HPrv}  
int nThreadID; //Thread's ID ]t. WJC %  
boolean bDownOver = false; //Downing is over i# pjv'C  
boolean bStop = false; //Stop identical Mr5('9%  
FileAccessI fileAccessI = null; //File Access interface ^]#Ptoz^(l  
[OFTP#}c  
LW83Y/7  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rQd1Ch  
{ )V[w:=*  
this.sURL = sURL; yiv RpSL  
this.nStartPos = nStart; Gx(KN57D  
this.nEndPos = nEnd; wf~5lpI[  
nThreadID = id; :,h=2a_ 8  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {<- ouD  
} Ak\D6eHcB  
< '>d0:>N  
+BtLyQ  
public void run() ND9 n1WZ&x  
{ u):%5F/  
while(nStartPos < nEndPos && !bStop) mC{!8WC@k  
{ wS F!Xx0  
#K<=xP  
K]H"qG.K  
try{ z. _C*c  
URL url = new URL(sURL); d+YVyw.z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q8}TNJsU  
httpConnection.setRequestProperty("User-Agent","NetFox"); K%[}[.cW  
String sProperty = "bytes="+nStartPos+"-"; 1}n)J6m  
httpConnection.setRequestProperty("RANGE",sProperty); )M&Azbu  
Utility.log(sProperty); }2iKi(io*  
WL)_8!  
#"=yQZ6Y  
InputStream input = httpConnection.getInputStream(); #GDh/t2@  
//logResponseHead(httpConnection); V:,3OLL*  
;*>QG6Fh  
=\ Tud-1Z  
byte[] b = new byte[1024]; M@!]U:5~V  
int nRead; YWcui+4p}  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h|c:!VN@  
{ @mQ/W Ys  
nStartPos += fileAccessI.write(b,0,nRead); Zi<Sw  
//if(nThreadID == 1) y0&V$uv/  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  |(J ?#?  
} Sg_-OX@f  
X_0{*!v8  
oSu|Yn  
Utility.log("Thread " + nThreadID + " is over!"); ${TB2q}%  
bDownOver = true; Gpxb_}P  
//nPos = fileAccessI.write (b,0,nRead); 2kp|zX(  
} :uT fhr  
catch(Exception e){e.printStackTrace ();} T_(e(5  
} =XRgT1>e  
} .^9/ 0.g8t  
XDrlJvrPL  
)'K!)?&d  
//打印回应的头信息 d 40'3]/{  
public void logResponseHead(HttpURLConnection con) vZ_DG}n11  
{ HAI1%F236  
for(int i=1;;i++) Q8gdI  
{ cOZajC<G  
String header=con.getHeaderFieldKey(i); 9|G=KN)P:  
if(header!=null) "b1R5(Ar  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fUL{c,7xda  
Utility.log(header+" : "+con.getHeaderField(header)); U"%8"G0)  
else -pU\"$nuxH  
break; 0-t4+T  
} GH; F3s  
} O'&X aaZV  
fdCxMKlu;  
<Hr@~<@~  
public void splitterStop() 3*2&Fw!B  
{ {Gb)Et]<  
bStop = true; gk_Xu  
} zM8/ s96h  
A\PV@w%A i  
. f.j >  
} ZAnO$pA  
4Ow Vt&  
o{-USUGj7  
/* [r/Seg"  
**FileAccess.java `aX}.{.!  
*//文件访问(定位,写) UQji7K }  
package NetFox; zOu$H[  
import java.io.*; i*cE  
0|DG\&?  
QLpTz"H  
public class FileAccessI implements Serializable{ {7pE9R5  
9^Vx*KVrU  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d@>k\6%j  
RandomAccessFile oSavedFile; bbPd&7  
long nPos; i_ODgc`H  
1 Z$99  
<1'X)n&Kw$  
public FileAccessI() throws IOException o7 -h'b-  
{ Nh7!Ah  
this("",0); -) v p&-  
} B,VSFpPx  
{;z L[AgCg  
ae(]9VW  
public FileAccessI(String sName,long nPos) throws IOException f@. Q%+!4  
{ 6'sFmC  
oSavedFile = new RandomAccessFile(sName,"rw"); Vp-OGX[  
this.nPos = nPos; cwW~ *90#  
oSavedFile.seek(nPos); -m x3^  
} n5,Pq+[  
&<#BsFz  
Kn9=a-b?,  
public synchronized int write(byte[] b,int nStart,int nLen) :#&U95EC0  
{ T=p}By3a  
int n = -1; ~E6+2t*  
try{ @Qsg.9N3K  
oSavedFile.write(b,nStart,nLen); &40JN}  
n = nLen; G'}_ZUy#  
} &LxzAL,3!  
catch(IOException e) / jL{JF>I  
{ RVKaqJ0e<  
e.printStackTrace (); ^%OH}Z`ly  
} K/.hJ  
7rDRu]  
PA-0FlV|  
return n; 4oa P"T@6  
} T[!q&kFB  
HOQ _T4  
:~A1Ud4c  
} Y"\T*lKa  
3<' Q`H>  
3L!&~'.Ro  
/* nTtt$I@hW  
**SiteInfoBean.java yI|?iBc7nC  
*/ vhe Ah`u^&  
package NetFox; OFAqP1o{$  
{j=hQL3  
R^O)fL0_  
public class SiteInfoBean { LAVt/TcZS|  
;eEtdoy  
N4]6LA6x6  
private String sSiteURL; //Site's URL [N$_@[  
private String sFilePath; //Saved File's Path jvKaxB;e  
private String sFileName; //Saved File's Name .j<B5/+  
private int nSplitter; //Count of Splited Downloading File Hr,lA(  
0v)mgrl=,  
?bYQZJ>&  
public SiteInfoBean() gl\{QcI8<  
{//nSplitter的缺省值为5 Qs[EA_  
//default value of nSplitter is 5 om39;nk!}  
this("","","",5); N*oJ$:#  
} p YvF}8  
Y&Vbf>Hi+  
mE@o27  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /g- X=|?F  
{ GDQg:MgX  
sSiteURL= sURL; 2uR4~XjF  
sFilePath = sPath; sL`D}_:  
sFileName = sName; 9l^  
this.nSplitter = nSpiltter; M,U=zNPnk  
NeZYchR  
F4{. 7BT  
} 7ofH@U  
\^W?   
z)y(31K<1  
public String getSSiteURL() ph'SS=!.  
{ a|{<#<6n(  
return sSiteURL; k.R/X  
} ZZJ"Ny.2  
YZtA:>;p  
ZTz(NS EK  
public void setSSiteURL(String value) x3F L/^S  
{ #K*q(ei,7h  
sSiteURL = value; ]x{H  
} mb6?$1j  
[goPmVe+  
#"YWz)8  
public String getSFilePath() H9m2Whq  
{ ?-v?SN#  
return sFilePath; I:)#U[tn0  
}  1`JN  
soK_l|z:J  
\J g#X:d  
public void setSFilePath(String value) L#MxB|fcr  
{ n8D;6#P^  
sFilePath = value; @%85k/(  
} 3'uES4+r  
) G&3V  
UdgI<a~`k6  
public String getSFileName() Uy'ZL(2  
{ WSccR  
return sFileName; 1,D ^,  
} aL6 5t\2  
@9 tv N}  
I{UB!0H  
public void setSFileName(String value) qGUe0(  
{ <.XoC?j  
sFileName = value; ,(?4T~  
} RwHXn]1  
& b2(Y4  
5fv6RQD  
public int getNSplitter() %Ne>'252y  
{ XE%6c3s  
return nSplitter; *njB fH'  
} bv"({:x  
Bm>(m{sX>  
iEO2Bil]  
public void setNSplitter(int nCount) Nxk'!:  
{ .y/?~+N^  
nSplitter = nCount; j-\u_#kx%  
} 2_ DtzY:=  
} Q*o4zW  
8j +;Xlh  
Rzj!~`&N  
/* J=bOw//  
**Utility.java WuXRL}!\,  
*/ mw.aavB  
package NetFox; @D{[Hj`<  
!-Q!/?  
.b)(_*  
public class Utility { pMrf i}esx  
< VsZ$  
~/[N)RFD  
public Utility() ds[~Cp   
{ A|nU _*  
-<.NEV  
#>NZN1  
} 1S@k=EKM  
(G'ddZAJV  
//线程睡眠 ,urkd~  
public static void sleep(int nSecond) :Dm@3S$4<  
{ 8)ol6Mi{  
try{ CBHWMetJ*  
Thread.sleep(nSecond); @isqFKjph  
} ew~FN  
catch(Exception e) 1 SZa\ ][@  
{ 5n#&Hjb*F0  
e.printStackTrace (); D4T+Gk"n  
} |,f6c Om f  
} D]_\i[x  
Ps-d#~4U;  
//日志 _CT|5wQF<  
public static void log(String sMsg) wpmtv325  
{ qA[}\8}h  
System.err.println(sMsg); `buTP?]4.  
} aa!c>"g6  
N.rB-  
pp_ddk  
public static void log(int sMsg) l)bUHh5[  
{ 0$ EJ4  
System.err.println(sMsg); w| # 79,&  
} 9 f+7vCA  
} %QkvBg*  
?os0JQVB  
EaL+}/q&  
/* 1Qkuxw  
**TestMethod.java 3g?T,| 2K  
*/ 8ttw!x69)_  
package NetFox; Ric$Xmu  
_en8hi@Z  
3EdPKM j&  
public class TestMethod { :eO0{JN4T  
nQC[[G*x  
s=+G%B'  
public TestMethod() {[dqXG$v `  
{ ///xx/weblogic60b2_win.exe o)DKP>IM#  
try{ JJa?"82FXZ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i[ lH@fJm_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O%{>Zo_<  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ],m-,K  
fileFetch.start(); eSf:[^  
} (~4AG \  
catch(Exception e){e.printStackTrace ();} =cY]cPO  
n9ih^H  
?,[w6O*  
} ujBADDwOg)  
lnUy ? 0(  
Bf'(JJ7&N  
public static void main(String[] args) &bNj/n/  
{ #/6X44 *u  
new TestMethod(); <Do89  
} >~ :]+q  
} "tIx$?I  
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