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http断点续传简单实现(java)

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/* V8(-  
**SiteFileFetch.java kVL.PY\K  
*/ }WV:erg`  
package NetFox; pk~WrqK}  
import java.io.*; M=Wz  
import java.net.*; T C"<g  
QW"! (`K  
MQ4KdqgP  
public class SiteFileFetch extends Thread { $!DpjN  
Hv, LS ;W  
g&.=2uP  
SiteInfoBean siteInfoBean = null; //文件信息Bean e(yh[7p=  
long[] nStartPos; //开始位置 n`KY9[0U=  
long[] nEndPos; //结束位置 @pxcpXCy  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 G&dKY h\  
long nFileLength; //文件长度 KSL`W2}  
boolean bFirst = true; //是否第一次取文件 g .\[o@H  
boolean bStop = false; //停止标志 8ipez/  
File tmpFile; //文件下载的临时信息 Debv4Gr;^  
DataOutputStream output; //输出到文件的输出流 $8FUfJ1@  
snJ129}A  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 7o4\oRGV  
public SiteFileFetch(SiteInfoBean bean) throws IOException '<M{)?  
{ uq{ beC  
siteInfoBean = bean;  3CJwj  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); cNH7C"@GVu  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -YE^zzh  
if(tmpFile.exists ()) ;Qq\DFe.w  
{ ~5g~;f[4  
bFirst = false; `{Ul!  
read_nPos(); 1Z;iV<d  
} qWw=8Bq  
else o(HbGHIP  
{ j<x_&1  
nStartPos = new long[bean.getNSplitter()]; W%J\qA  
nEndPos = new long[bean.getNSplitter()]; (#'>(t(4  
} NO3/rJ6-  
j#6.Gq  
16 $B>  
;nGa.= "L  
} o}!PQ#`M  
cu6Opq9  
4m)n+ll  
public void run() [gB+C84%%  
{ F\! `/4  
//获得文件长度 fZ. ONq  
//分割文件 *] (iS  
//实例FileSplitterFetch l^qI, M  
//启动FileSplitterFetch线程 ~m |BC*)  
//等待子线程返回 nrb Ok4Dz  
try{ D]}G.v1  
if(bFirst) {8OCXus3m  
{ "]dI1 g_  
nFileLength = getFileSize(); AR=]=8  
if(nFileLength == -1) kP"9&R`E  
{ ceV}WN19l  
System.err.println("File Length is not known!"); HP =+<]?{G  
} 8_8l.!~  
else if(nFileLength == -2) =Uh$&m  
{ xA/D'  
System.err.println("File is not access!"); RpF&\x>  
} Ned."e  
else KSvE~h[#+  
{ ys~x $  
for(int i=0;i<nStartPos.length;i++) o@Oqm>]SS  
{ nlYNN/@"  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); OCUr{Nh  
} kl`W\tF  
for(int i=0;i<nEndPos.length-1;i++) HhpDR  
{ G?ZXWu.  
nEndPos = nStartPos[i+1]; ;fJ.8C  
} 8RX&k  
nEndPos[nEndPos.length-1] = nFileLength; uS-|wYE  
} 2?5>o!C  
} Qd-A.{[h  
$k?>DP 4  
dscgj5b1~  
//启动子线程 P%6~&woF  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [~^0gAlQC  
for(int i=0;i<nStartPos.length;i++) <!+Az,-  
{ T |p"0b A  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .h[:xYm  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~`/V(r;o  
nStartPos,nEndPos,i); s>en  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H.c7Nle  
fileSplitterFetch.start(); /mMV{[  
} K;(mC<  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^"g~-  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OPi0~s  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $Y;RKe9  
nEndPos = " + nFileLength); +%&yJ4-  
// fileSplitterFetch[nPos.length-1].start(); G3 m Z($y  
\8 ":]EU  
Kgv T"s.  
//等待子线程结束 @oNXZRg6  
//int count = 0; 0erNc'e  
//是否结束while循环 U(Zq= M  
boolean breakWhile = false; 9z0p5)]n>  
Z.WW(C.  
>Q/Dk7#  
while(!bStop) VQs5"K"  
{ [e q&C_|D  
write_nPos(); :U\tv[  
Utility.sleep(500); qLCR] _*  
breakWhile = true; N;d] 14|  
u y+pP!<  
#ABCDi={zA  
for(int i=0;i<nStartPos.length;i++) TseGXYH  
{ ~@!bsLSMU  
if(!fileSplitterFetch.bDownOver) I|OoRq  
{ 92c HwWZ!  
breakWhile = false; %C0Dw\A*:  
break; B[}6-2<>?C  
} D@KlOU{<  
} B1gR5p0  
if(breakWhile) =v\.h=~~  
break; LscGTs,  
*R"/|Ka  
O< I-  
//count++; lFk R=!?=  
//if(count>4) 7,MR*TO,  
// siteStop(); G5!^*jf  
} \^LFkp  
<$YlH@;)`a  
Lr+$_ t}r  
System.err.println("文件下载结束!"); u ?"Vm  
} #z(]xI)"  
catch(Exception e){e.printStackTrace ();} 6LZCgdS{  
} +mPx8P&%  
-/4P3SG/  
Kq!3wb;  
//获得文件长度 }b}m3i1  
public long getFileSize() df=f62  
{ ~~.}ah/_d  
int nFileLength = -1; ta0|^KAA  
try{ xG 1n GO  
URL url = new URL(siteInfoBean.getSSiteURL()); @ZJS&23E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YR70BOxK  
httpConnection.setRequestProperty("User-Agent","NetFox"); >_TZ'FT  
Om<a<q  
[;N'=]`  
int responseCode=httpConnection.getResponseCode(); "7 yD0T)2  
if(responseCode>=400) >~f]_puT  
{ d5b%  W3  
processErrorCode(responseCode); N mG#   
return -2; //-2 represent access is error QP x^_jA  
} t-AmX) $  
N+|d3X!  
m~|40)   
String sHeader; 0J|3kY-n>  
h1RSVp+?n  
"4Nt\WQ  
for(int i=1;;i++) +_!QSU,@  
{ \wZe] G%S  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bD^owa  
//Utility.log(in.readLine()); YUb_y^B^  
sHeader=httpConnection.getHeaderFieldKey(i); RCrCs  
if(sHeader!=null) *a)n62  
{ mv><HqDL1  
if(sHeader.equals("Content-Length")) TC('H[ ]  
{ #mT"gs  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5-V pJ  
break; R_KH"`q  
} $qiya[&G4  
} 9sP0D  
else #tHK"20  
break; :s,Z<^5a)g  
} ~u{uZ(~  
} SM '|+ d  
catch(IOException e){e.printStackTrace ();} zA 3_Lx!  
catch(Exception e){e.printStackTrace ();} kM 6 Qp  
NbobliC=  
e.>P8C<&  
Utility.log(nFileLength); hgmCRC  
W^Yxny  
D9df=lv mD  
return nFileLength; ~[ jQ!tz  
} K9[UB  
H}!r|nG  
EnR}IY&sI  
//保存下载信息(文件指针位置) _t$sgz&  
private void write_nPos() ! if   
{ pmM9,6P4@  
try{ b}f~il  
output = new DataOutputStream(new FileOutputStream(tmpFile)); SBpL6~NW  
output.writeInt(nStartPos.length); \zY!qpX<  
for(int i=0;i<nStartPos.length;i++) O^.#d  
{ > I?IPQB  
// output.writeLong(nPos); 8}[).d160  
output.writeLong(fileSplitterFetch.nStartPos); XX@ZQcN  
output.writeLong(fileSplitterFetch.nEndPos); T%Lx%Qn  
} .>S!ji  
output.close(); do%&m]#;  
} eRYK3W  
catch(IOException e){e.printStackTrace ();} .H|-_~Yx|  
catch(Exception e){e.printStackTrace ();} *|0 -~u%q  
} j.Hf/vi`z  
+0&/g&a\R  
` A>@]d  
//读取保存的下载信息(文件指针位置) +TJCLZ..  
private void read_nPos() M{@(G5  
{ =(Mch~  
try{  g(052]  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f 2.HF@  
int nCount = input.readInt(); q'DW~!>qX  
nStartPos = new long[nCount]; BLttb  
nEndPos = new long[nCount]; Wri<h:1  
for(int i=0;i<nStartPos.length;i++) b sX[UF  
{ pkzaNY/q  
nStartPos = input.readLong(); .]u /O`c]  
nEndPos = input.readLong(); ZH8,K Y"  
} ?}0,o.  
input.close(); |N2#ItBbW  
} Za9qjBH   
catch(IOException e){e.printStackTrace ();} t!XwW$@  
catch(Exception e){e.printStackTrace ();} vt8By@]:  
} n[z+<VGwC  
Z~CjA%l  
+2{Lh7Ks  
private void processErrorCode(int nErrorCode) JI}'dU>*U:  
{ khe}*y  
System.err.println("Error Code : " + nErrorCode); u[YGm:}  
} L_T5nD^D  
 )2.Si#  
M-71 1|eGI  
//停止文件下载 e= AKD#  
public void siteStop() wj,=$RX  
{ +whDU2 "  
bStop = true; q 1,~  
for(int i=0;i<nStartPos.length;i++) py4 h(04u  
fileSplitterFetch.splitterStop(); A&VG~r$  
KPF1cJ2N  
w>gYx(8b  
} xp t:BBo  
} v+XJ*N[W  
//负责部分文件的抓取 (HVGlw'`  
**FileSplitterFetch.java vzM ^$V  
*/ .]^?<bG  
package NetFox; ueudRb  
G[=c Ss,  
pP_LR ks}  
import java.io.*; b=vkiO`2  
import java.net.*; t_^4`dW`  
)pa]ui\t  
~ }P,.QQ  
public class FileSplitterFetch extends Thread { &ncvGDGi  
]G\}k  
AH^/V}9H  
String sURL; //File URL s AkdMo  
long nStartPos; //File Snippet Start Position r@V!,k#S  
long nEndPos; //File Snippet End Position rp$'L7lrX  
int nThreadID; //Thread's ID V`- 9m$  
boolean bDownOver = false; //Downing is over :X=hQ:>P  
boolean bStop = false; //Stop identical >7|VR:U?B  
FileAccessI fileAccessI = null; //File Access interface Ac@VGT:9  
s[jTP(d)8  
jp,4h4C^)  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K0~rN.C!0  
{ ?4,T}@P  
this.sURL = sURL; 1?}T=)3+$  
this.nStartPos = nStart; A^g(k5M*  
this.nEndPos = nEnd; dN q$}  
nThreadID = id; &~CI<\o P  
fileAccessI = new FileAccessI(sName,nStartPos);//定位  ];m_4  
} LVGe]lD  
Xvu(vA  
]M=&+c>H~  
public void run() aN?zmkPpov  
{ /: "1Z]@  
while(nStartPos < nEndPos && !bStop) <)9y{J}s:  
{ )`:UP~)H  
]Ze1s02(  
)7F/O3Tq  
try{ 0kh6@y3  
URL url = new URL(sURL); M%HU4pTW#o  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I9Xuok!0>=  
httpConnection.setRequestProperty("User-Agent","NetFox"); ye&;(30Oq  
String sProperty = "bytes="+nStartPos+"-"; nlP;nlW  
httpConnection.setRequestProperty("RANGE",sProperty); ~ljXzD93Z  
Utility.log(sProperty); 0J9x9j`&j  
lA]8&+,ZM  
jcOcWB|  
InputStream input = httpConnection.getInputStream(); 1}x%%RD_  
//logResponseHead(httpConnection); K?;DMUSY\  
afVT~Sf{  
(QEG4&9  
byte[] b = new byte[1024]; +7Gwg  
int nRead; @ Y+oiB~Y  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -w2/w@&  
{ 01]f2.5  
nStartPos += fileAccessI.write(b,0,nRead); K- v#.e4  
//if(nThreadID == 1) us-L]S+lm  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q9"96({\@  
} .v K-LHs  
pK*TE5]  
E GU2fA7x  
Utility.log("Thread " + nThreadID + " is over!"); ytImB`'\  
bDownOver = true; (PL UFT  
//nPos = fileAccessI.write (b,0,nRead); ?<!|  
} cuX)8+  
catch(Exception e){e.printStackTrace ();} !$ JT e  
} #a#F,ZT  
} KlEpzJ98  
7CysfBF0g  
-7ep{p-  
//打印回应的头信息 sJZ iI}Xc  
public void logResponseHead(HttpURLConnection con) >4TO=i  
{ i-1op> Y  
for(int i=1;;i++) t@(HF-4~=  
{ %{W6PrY{  
String header=con.getHeaderFieldKey(i); 1 MFbQs^  
if(header!=null) - ).C  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )0`C@um  
Utility.log(header+" : "+con.getHeaderField(header)); hN_]6,<\  
else X|dlt{Gf   
break; yi[x}ffdE  
} Rq-ZL{LR7  
} -"x$ZnHU  
]Wup/o  
W/N7vAx X  
public void splitterStop() 5xiEPh  
{ ).O)p9  
bStop = true; UMi~14& ;  
} W?& %x(6M  
tQVVhXQ7  
=pNY eR_[  
} UKGPtKE<  
*~`(RV  
h[ ZN+M  
/* CpN>p.kM  
**FileAccess.java Wwo0%<2y  
*//文件访问(定位,写) e-;}366}  
package NetFox; JF]JOI6.e  
import java.io.*; WH\d| 1)  
A/(a`"mK|'  
t20K!}D_  
public class FileAccessI implements Serializable{ TeQV?ZQ#}  
7zMr:JmV  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %T[]zJ(  
RandomAccessFile oSavedFile; BtZyn7a  
long nPos; sW$XH1Uf#  
0RfZEG)  
[g,}gyeS(  
public FileAccessI() throws IOException \V:^h [ad  
{ z:O8Ls^\T  
this("",0); >_} I.\ X  
} }H2 R3icE  
qs6aB0ln  
iZ%yd-  
public FileAccessI(String sName,long nPos) throws IOException %<5'=t'|-U  
{ |Tw~@kT@  
oSavedFile = new RandomAccessFile(sName,"rw"); AA_%<zK  
this.nPos = nPos; 7)m9"InDI  
oSavedFile.seek(nPos); 1C.VnzRnJ  
} :UdF  
}Z>)DN=+  
Bvj0^fSm  
public synchronized int write(byte[] b,int nStart,int nLen) 2%1hdA<  
{ rqq1TRg  
int n = -1; )u">it+  
try{ *hrd5na  
oSavedFile.write(b,nStart,nLen); +\'t E~V  
n = nLen; L];b< *d  
} rQXzR  
catch(IOException e) X&zis1A<  
{ E`q_bn  
e.printStackTrace (); YIE<pX4Q7)  
} 9uY'E'm*  
Tw% 3p=  
6~{C.No}  
return n; zDp2g)  
} Z)!C'cb  
J4utIGF  
:N@^?q{b  
} B!yr!DWv  
3T 9j@N77  
-&f$GUTJ  
/* |{;G2G1[  
**SiteInfoBean.java q4q6c")zp  
*/ ijcm2FJcG  
package NetFox; fM}#ON>Z  
+p^u^a  
neh(<>  
public class SiteInfoBean { -di o5a  
mmsPLv6  
wBzC5T%,  
private String sSiteURL; //Site's URL ]9L oZ)  
private String sFilePath; //Saved File's Path fVwU e _Y  
private String sFileName; //Saved File's Name f::Dx1VcX  
private int nSplitter; //Count of Splited Downloading File 'yth'[  
B *vM0  
H]!"Zq k  
public SiteInfoBean() >p/`;Kq@  
{//nSplitter的缺省值为5 51u0]Qx;fm  
//default value of nSplitter is 5 Bt#N4m[X*|  
this("","","",5); ^{{q V  
} \9d$@V  
u>$t'  
X 8|EHb<  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bcR_E5x$  
{ % nIf)/2g  
sSiteURL= sURL; OB7hlW  
sFilePath = sPath; r>\bW)e  
sFileName = sName; 2tLJU  Z1  
this.nSplitter = nSpiltter; eQ"E   
hcc/=_hA  
-&;TA0~;  
} {!`4iiF  
M;NX:mX9  
6RM/GM  
public String getSSiteURL() C?Ucu]cW  
{ X.V~SeS  
return sSiteURL; __@BUK{q  
} YP9^Bp{0  
ccnK#fn v  
[Yyk0Qv|4  
public void setSSiteURL(String value) l@\FWWQ  
{ Tr|JYLwF  
sSiteURL = value; FqifriLN  
} i?gSC<a  
&R siVBA  
q =Il|Nb>  
public String getSFilePath() ':}\4j&{E  
{ w*!aZ,P  
return sFilePath; fLVAKn  
} ^GX)Z~  
`kr?j:g  
]{kPrey  
public void setSFilePath(String value) HqTjl4ai  
{ Q^I\cAIB  
sFilePath = value; nd(S3rct&  
} ,P Z ge  
BC]?0 U  
x:7IIvP  
public String getSFileName() 8D].MI^  
{ <1 pEwI~  
return sFileName; + )?J#g  
} E e]-qN*8  
B;WCTMy}  
KU;9}!#  
public void setSFileName(String value) d1kJRJ   
{ xCKRxF  
sFileName = value; 0g\(+Qg^  
} WKU=.sY  
SB7c.H,  
d\Zng!Z'  
public int getNSplitter() &0f,~ /%Z  
{ dTtSUA|V7"  
return nSplitter; 2JFpZU"1  
} I0a<%;JJW  
&OBkevg  
MW{8VH6+  
public void setNSplitter(int nCount) vFsLY  
{ ETLD$=iS  
nSplitter = nCount; o Rzi>rr  
} c|1&lYal;  
} Ev P{p  
i?~3*#IpD  
!Uc T RI  
/* VD:/PL  
**Utility.java qCO/?kW  
*/ 0;ji65  
package NetFox; C-[1iW'  
tl].r|yl  
d| {r5[&  
public class Utility { %IRi1EmN8  
o]:9')5^  
4&f3%eTi  
public Utility() Rh |nP&6  
{ Z<phcqEi8  
bTu9;(  
C $JmzrE  
} "nWw;-V}}  
ERt{H3eCcJ  
//线程睡眠 #,.Hr#3nI  
public static void sleep(int nSecond) N?>vd*  
{ `@ FYkH  
try{ jSAjcLR  
Thread.sleep(nSecond); AK#1]i~  
} '=6\v!  
catch(Exception e) ;\l,5EG  
{ {_Gs*<.  
e.printStackTrace (); ZW}_Q s  
} mQ=#nk$~g  
} L:8q8i  
IMfqiH)  
//日志 )/EO&F  
public static void log(String sMsg) 'ah[(F<*@e  
{ \G3rX9xG  
System.err.println(sMsg); X|8c>_}  
} m9A!D  
Bw{I;rW{2  
-GgA&dh  
public static void log(int sMsg) Y DFyX){  
{ (khL-F  
System.err.println(sMsg); ~= -RK$=  
} F3N6{ysK#  
} d:{O\   
e!r-+.i(  
AvHCO8h|  
/* @gtQQxf"  
**TestMethod.java pBPl6%C.X-  
*/ !3v1bGk  
package NetFox; 2"S}bfrX  
xjUtl  
N&V`K0FU  
public class TestMethod { O<e{  
d'I"jZ  
'Qo*y%{@5  
public TestMethod() L~>i,  
{ ///xx/weblogic60b2_win.exe Y5d\d\e/  
try{ f4Rf?w*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2T TdH)  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BRYHX.}h\A  
SiteFileFetch fileFetch = new SiteFileFetch(bean); TBrPf-Xr  
fileFetch.start(); Fr$5RAyg  
} 2wgg7[tGi  
catch(Exception e){e.printStackTrace ();} pU7lnS[  
 v<:R#  
I)W`sBL  
} ~3S~\0&|  
-B\HI*u  
zkdetrR  
public static void main(String[] args)  :#~j:C|  
{ + +#5  
new TestMethod(); {GcO3G#FZ  
} ,i@:5X/t  
} Z87|Zl  
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