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http断点续传简单实现(java)

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/* "< c,I=A  
**SiteFileFetch.java AWXBk+  
*/ 9/@7NNKJ  
package NetFox; 3Dm`8Xt  
import java.io.*; 3fb"1z#  
import java.net.*; .o&Vu,/H  
N N1(f  
2<  "-  
public class SiteFileFetch extends Thread { 7a0kat '\  
$4&%<'l3I  
V"r2 t9A  
SiteInfoBean siteInfoBean = null; //文件信息Bean   OH*  
long[] nStartPos; //开始位置 (PM!{u=  
long[] nEndPos; //结束位置  MoFAQe  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 -/7[\S  
long nFileLength; //文件长度 XITh_S4fs=  
boolean bFirst = true; //是否第一次取文件 JxV 0y  
boolean bStop = false; //停止标志 0+vt LDq@P  
File tmpFile; //文件下载的临时信息 qrK\f  
DataOutputStream output; //输出到文件的输出流 XEB1%. p  
j\uh]8N3<  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) l?UFe$9(  
public SiteFileFetch(SiteInfoBean bean) throws IOException `F^~*FnR,B  
{ uE}A-\G  
siteInfoBean = bean; {tN?)~ZQ  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); f\{ynC2m  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 3T|xUY)G4  
if(tmpFile.exists ()) $YNWT\FE  
{ k^Gf2%k  
bFirst = false; RTJ\|#w  
read_nPos(); ):c)$$dn  
} !=Hu?F p  
else e[:i`J2  
{ z+k[HE^S  
nStartPos = new long[bean.getNSplitter()]; J'=iEI  
nEndPos = new long[bean.getNSplitter()]; SdJGhU  
} SFiK_;  
Y]33:c_;Mo  
j -R9=vB2  
=u.jZ*u]WT  
} \a .^5g  
K4{1}bU{>  
zIeJ[J@  
public void run() (9phRo)>  
{ u@{z xYn  
//获得文件长度 8q5 `A Gl  
//分割文件 7@6B\':  
//实例FileSplitterFetch [2 yxTK  
//启动FileSplitterFetch线程 g9XAUZe  
//等待子线程返回 /ta5d;@  
try{ /|HVp  
if(bFirst) t 5{Y'  
{ a#k=! W  
nFileLength = getFileSize(); `/4 R$E{  
if(nFileLength == -1) DA(ur'D  
{ /p PSo  
System.err.println("File Length is not known!"); TJhzyJ"t  
} X;vfbF   
else if(nFileLength == -2) ~:ldGfb|  
{ *>#mI/#}  
System.err.println("File is not access!"); 'Wv`^{y <^  
} ;L{#TC(]J]  
else EW:tb-%`  
{ Wj}PtQ%lp/  
for(int i=0;i<nStartPos.length;i++) V(5=-8k  
{ |RA|nu   
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &-h z&/A,  
} >B~vE2^tQ~  
for(int i=0;i<nEndPos.length-1;i++) D J:N  
{ R'Uw17I  
nEndPos = nStartPos[i+1]; w~n7l97Pw  
} Ny6 daf3f  
nEndPos[nEndPos.length-1] = nFileLength; 6iZ:0y0t+6  
} ^hN.FIzM  
} }R\9y bv  
9td[^EB#(h  
c'XvZNf .C  
//启动子线程 p[&6hXTd  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %_>+K;<  
for(int i=0;i<nStartPos.length;i++) \(.])I>)eh  
{ M#U#I :z%  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J:  T  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /ad]pdF  
nStartPos,nEndPos,i); hHoc>S6^M  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +,H6)'#Z  
fileSplitterFetch.start(); OfAh? ^R  
} d ~`_;.z  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]JUb;B;Z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); nG+L'SmI  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wRATe 0'  
nEndPos = " + nFileLength); $zR[2{bg  
// fileSplitterFetch[nPos.length-1].start(); &AS<2hB  
KXS{@/"-B  
Naqz":%.  
//等待子线程结束 IdzrQP  
//int count = 0; <.N33 7!  
//是否结束while循环 Y2B ",v"  
boolean breakWhile = false; M }H7`,@I  
2!y%nkO*  
}p <p(  
while(!bStop) +I9+L6>UR  
{ i,h)  
write_nPos(); eLd7|*|  
Utility.sleep(500); 4YmN3i  
breakWhile = true; R DAihq  
{TWgR2?{C  
fK'qc L  
for(int i=0;i<nStartPos.length;i++) ^&|$&7  
{ 8r 4 L4  
if(!fileSplitterFetch.bDownOver) +EnJyli  
{ ,XZ[L? >  
breakWhile = false; BUozpqN}  
break; YnCWmlC  
} DW,fh8w  
} z3lMD'uU3  
if(breakWhile) .-0;:>  
break; wU|Y`wJmF  
" * Qwaq_  
0tzMu#  
//count++; NyJ=^=F#  
//if(count>4) e+ZC<Bdh  
// siteStop(); 6-'Y*  
} XP$1CWI  
-i}@o1o\  
b,7@)sZ*  
System.err.println("文件下载结束!"); 9=-!~ _'1-  
} u}[Z=V  
catch(Exception e){e.printStackTrace ();} zg3q\ ~  
} f17pwJ~=  
Q>FuNdUk  
4eOQP  
//获得文件长度 9bpY>ze  
public long getFileSize() 7;_./c_@  
{ ` _+j+  
int nFileLength = -1; lIN`1vX(  
try{ zqq$PaH*  
URL url = new URL(siteInfoBean.getSSiteURL()); xV h-Mx+M  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [}/\W`C  
httpConnection.setRequestProperty("User-Agent","NetFox"); S"Q$ Ol"  
oXR%A7  
o,fBOPIN  
int responseCode=httpConnection.getResponseCode(); ^c9~~m16+  
if(responseCode>=400) *d,u)l :S  
{ 9tnW:Nw~  
processErrorCode(responseCode); 8^H <dR  
return -2; //-2 represent access is error 8#Q=CTjF  
} iCouGd}  
=;1MpD  
8: KlU(J  
String sHeader; V0]6F  
xl(];&A3  
P2nb&lVdu  
for(int i=1;;i++) !2('Cq_^  
{ *lN>RWbM%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &k5 Z|d|  
//Utility.log(in.readLine()); T/V 5pYl  
sHeader=httpConnection.getHeaderFieldKey(i); >Ic)RPO9  
if(sHeader!=null) az(u=}  
{ <%(nF+rQA"  
if(sHeader.equals("Content-Length")) F:8cd^d~u  
{ &}1PH% 6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m|O7@N  
break; 6 ]@H.8+  
} .[-d( #l{l  
} C^po*(W6  
else Q<y&*o3YF|  
break; <B;l).[6  
} %2<G3]6^U  
} ]F@XGJN  
catch(IOException e){e.printStackTrace ();} ^n|u$gIF8  
catch(Exception e){e.printStackTrace ();} _RFTm.9&  
> dJvl|  
T(<C8  
Utility.log(nFileLength); (R*K)(Nw[  
3wEVjT-  
#:v e3gWl  
return nFileLength; -*sDa6L  
} k,xY\r$  
R}Ih~zw  
|wKC9O@%  
//保存下载信息(文件指针位置) ;a/Gs^W  
private void write_nPos() Tn+6:<OFdO  
{ 9L}=xX`>?  
try{ i#t)tM"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); -E4e8'P;5  
output.writeInt(nStartPos.length); 1/Pou)D  
for(int i=0;i<nStartPos.length;i++) \c&%F=1+*  
{ |0?h6  
// output.writeLong(nPos); ).TQYrs  
output.writeLong(fileSplitterFetch.nStartPos); ~+{OSx<S  
output.writeLong(fileSplitterFetch.nEndPos); (u81p  
} ^D(N_va<  
output.close(); ,C88%k  
} 3,8>\yf`  
catch(IOException e){e.printStackTrace ();} 5MH\Gq e7  
catch(Exception e){e.printStackTrace ();} ^+zF;Q'  
} swvn*xr  
I3QK~ V*j)  
T`f6`1x  
//读取保存的下载信息(文件指针位置) nV-A0"z_&  
private void read_nPos() W6t"n_%?"  
{ >!|Hns  
try{ wRL=9/5(8  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0/d+26lR  
int nCount = input.readInt(); 33lD`4i+  
nStartPos = new long[nCount]; <wge_3W#  
nEndPos = new long[nCount]; ~3 Y)o|D3  
for(int i=0;i<nStartPos.length;i++) UdmYS3zs  
{ YFD'&N,sx  
nStartPos = input.readLong(); 7z'l}*FRD  
nEndPos = input.readLong(); K.?~@5%  
} ve2GRTO^aC  
input.close(); n$Z@7r  
} #pbPaRJL(  
catch(IOException e){e.printStackTrace ();} ,[}5@cS  
catch(Exception e){e.printStackTrace ();} Gxu&o%x [  
} dUOvv/,FZT  
kAbRXID  
[ Y_6PR  
private void processErrorCode(int nErrorCode) "q(#,,_  
{ W$7db%qFx  
System.err.println("Error Code : " + nErrorCode); ID" '`DKxe  
} wSHE~Xx  
)A9K9pZj  
D.H$4[u;j  
//停止文件下载 wt4uzg8  
public void siteStop() |;o#-YosP  
{ nS0K&MH6B  
bStop = true; .7TQae%  
for(int i=0;i<nStartPos.length;i++) > $0eRVL  
fileSplitterFetch.splitterStop(); "ZDc$v:Qa  
N.OC _H&  
wkK61a h6  
} 0[@ 9f1Nk4  
} RKsr}-1 8  
//负责部分文件的抓取 $:kG>R@\t  
**FileSplitterFetch.java \TS t  
*/ 3!M;Z7qF]  
package NetFox; beFVjVVHq  
rr fL [  
U7d%*g  
import java.io.*; nj99!"_   
import java.net.*; @O#4duM4Qz  
CZ*c["x2  
:1"{0 gm  
public class FileSplitterFetch extends Thread { h% BA,C  
;hi+.ng_  
#/zPAcV:  
String sURL; //File URL  &o$E1;og  
long nStartPos; //File Snippet Start Position euO!+9p  
long nEndPos; //File Snippet End Position Hzs]\%"  
int nThreadID; //Thread's ID |><hdBQXX<  
boolean bDownOver = false; //Downing is over = R|?LOEK+  
boolean bStop = false; //Stop identical )=TD}Xb  
FileAccessI fileAccessI = null; //File Access interface /NCEZ@2BN,  
j?D=Ij"o  
[$)C(1zY  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [@Y<:6  
{ deSrs:.  
this.sURL = sURL; m`!C|?hu  
this.nStartPos = nStart; bj4cW\b(  
this.nEndPos = nEnd; _y&m4Vuu  
nThreadID = id; !4cR&@[  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 E\Hhi.-  
} z5-vx`  
R,CFU l7Q  
L6yRN>5aE  
public void run() ucQ2/B#'4l  
{ Mw2?U>h1  
while(nStartPos < nEndPos && !bStop) es@_6ol.@  
{ ;u!qu$O  
0Qvbc}KP8  
4*W ??(=j  
try{ Uj&2'>MJ$  
URL url = new URL(sURL); B Jp\a7`;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?1JVzZ4H  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;Pik},  
String sProperty = "bytes="+nStartPos+"-"; l-4T Tg  
httpConnection.setRequestProperty("RANGE",sProperty); PV vNu5k  
Utility.log(sProperty); '"LrGvkZ  
bFk >IifN  
+h^>?U,  
InputStream input = httpConnection.getInputStream(); | Zx  
//logResponseHead(httpConnection); X=)Ue  
"M5P-l$p}  
MkZm =Sf  
byte[] b = new byte[1024]; w!o[pvyR$  
int nRead; ;rWgt!l  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) A\Rkt;:  
{ @.ebQR-:H  
nStartPos += fileAccessI.write(b,0,nRead); v'0A$`w`  
//if(nThreadID == 1) Ovh  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z?`&HU Nf  
} >oi`%V  
\G}EI|Wo  
V.5gxr3QqW  
Utility.log("Thread " + nThreadID + " is over!"); d{2+> >d  
bDownOver = true; 1P(rgn:8e  
//nPos = fileAccessI.write (b,0,nRead); rLO1Sv  
} wjW>#DE  
catch(Exception e){e.printStackTrace ();} so}(*E&(a  
} 6j{9\ R  
} pMM,ox"  
f$$l,wo  
$}&Y$w>S  
//打印回应的头信息 ?#"rI6  
public void logResponseHead(HttpURLConnection con) L A-H  
{ |f1 S&b.  
for(int i=1;;i++) WGFp<R  
{ {pMbkA Q@  
String header=con.getHeaderFieldKey(i); "mc/fp  
if(header!=null) ($EA/|z  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t98t&YUpm  
Utility.log(header+" : "+con.getHeaderField(header)); s*{l}~fPkW  
else Pn|A>.)z  
break; i-[ic!RnKj  
} xrDHXqH  
} yi*)g0M  
c jfYE]  
n{JBC%^g  
public void splitterStop() M72.  
{ .g71?^?(  
bStop = true; dC8 $Ql^<  
} "!()yjy  
=Tv|kJ| j  
?t++IEoP  
} 8o43J;mA  
AE!DftI  
-(9>{!",J  
/* KM$L u2  
**FileAccess.java /NfuR$oMd  
*//文件访问(定位,写) }SYR)eE\  
package NetFox; /.r|ron:e  
import java.io.*; |kJ'FZZd  
=W'a6)WE  
!gA<9h  
public class FileAccessI implements Serializable{ 1'DD9d{ qN  
DXu915  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FrBoE#  
RandomAccessFile oSavedFile; 6lw)L  
long nPos; Q qGf*  
.%;`: dtj  
- ;1'{v  
public FileAccessI() throws IOException P34UD:  
{ 7(cRm$)L  
this("",0); 1!_$HA  
} [.Vy  
Z5 iP1/&D  
|O3wAxc3W  
public FileAccessI(String sName,long nPos) throws IOException 9jq}`$S{  
{ xl [3*K   
oSavedFile = new RandomAccessFile(sName,"rw"); C3q}Dh+]  
this.nPos = nPos; Qgx9JJ>  
oSavedFile.seek(nPos); 9IJBK  
} A+P9M \u.  
\6o%gpUkD  
pw|f4c7AH  
public synchronized int write(byte[] b,int nStart,int nLen) B1)gudP`  
{ {3n|=  
int n = -1; JDPn   
try{ V45A>#?U  
oSavedFile.write(b,nStart,nLen); 87WIDr  
n = nLen; ..BIoSrj  
} FOJ-?s(  
catch(IOException e) ybLl[K(D=  
{ 2F* spu  
e.printStackTrace (); 278:5yC  
} kN(*.Q|VZ  
o2M+=O@  
~ 8L]!OQ9=  
return n; T DOOq;+  
} k4:$LFw@  
iUDNm|e  
~D# -i >Z  
} 2;h4$^`dt  
q"){P RTm/  
O[%"zO"S  
/* &V/n!|q<H  
**SiteInfoBean.java vbEAd)*S  
*/ )!SA]>-  
package NetFox; 'fpm] *ig  
|f5WN&c  
32h}+fd  
public class SiteInfoBean { 1 ; _tu  
7<FI[  
[7x,&  
private String sSiteURL; //Site's URL #dy z  
private String sFilePath; //Saved File's Path ED0\k $  
private String sFileName; //Saved File's Name 7A:k  
private int nSplitter; //Count of Splited Downloading File Do1 Ip&X  
.\Gl)W  
g7\MFertR^  
public SiteInfoBean() |v,%!p s  
{//nSplitter的缺省值为5 9N1Uv,OtB  
//default value of nSplitter is 5 {A!1s;  
this("","","",5); -u)f@e  
} =' %r"_`}  
\j C[|LM&  
- Q3jK)1  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ogD 8qrZ6J  
{ dH]0 (aJ  
sSiteURL= sURL; Z;M}.'BE  
sFilePath = sPath; Fuq MT`  
sFileName = sName; {qxFRi#\k  
this.nSplitter = nSpiltter; WX.6|  
sVXIR  
])`+ 78  
} x=-dv8N?  
=NJ:%kvF  
B%y?+4;zA  
public String getSSiteURL() pXn(#n<  
{ %[3?vX  
return sSiteURL; HC1jN8WDY  
} Ot,_=PP  
R=Qa54  
nsf.wHGZ"J  
public void setSSiteURL(String value) 4pU|BL\j  
{ :+?eF^ 5  
sSiteURL = value; KWuc*!  
} Eo h4#fZ\N  
,_SE!iL  
#B_Em$  
public String getSFilePath() 8 ckcTNPu  
{ _6U=7<f  
return sFilePath; vP k\b 3E  
} Ug}dw a  
Sr$&]R]^  
-@*[   
public void setSFilePath(String value) >.sdLA Si  
{ *=yUs'brB  
sFilePath = value; F7o#KN*.]  
} M:[rH  
\/qo2'V j`  
s,z$Vt"h*K  
public String getSFileName() ^)i5.o\  
{ :eHD{=  
return sFileName; A(Tqf.,G  
} i^<P@ |q  
K;ncviGu  
whH_<@!  
public void setSFileName(String value) JXT%@w>I  
{ RC[mpR ;2  
sFileName = value; <[*%d~92z  
} ,Z3 (`ftC  
B7'rbc'  
f{i~hVF  
public int getNSplitter() 2Ra}&ie  
{ R=7,F6.  
return nSplitter; nky%Eb[\  
} Re[x$rw  
 !' }  
Fa"/p_1  
public void setNSplitter(int nCount)  _%r+?I  
{ 62-,!N 1-  
nSplitter = nCount; *|Bu7nwg  
} to2#PXf]y  
} ejF GeR  
NE~R&ym9  
HQ187IwpTm  
/* n0\k(@+k  
**Utility.java r%:Q(|v?  
*/ X=1Po|  
package NetFox; s%cfJe_k  
/ 5\gP//9K  
7O.?I# 76  
public class Utility { t[r<&1[&  
9~rrN60Q  
;nSOe AF)Q  
public Utility() . X:  
{ ]J '#KT{  
%pJRu-D  
q.}M^iDe  
} +VSq[P  
jV|j]m&t  
//线程睡眠 |>'.(  
public static void sleep(int nSecond) 13JZ\`ceb  
{ *ku}.n  
try{ _L^(CFE  
Thread.sleep(nSecond); 8*bEsc|  
} /W|=Or2oR  
catch(Exception e) T A9Kg=_  
{ 1WP(=7$.  
e.printStackTrace (); av8\?xmo.$  
} ^ ,cwm:B@  
} RV=Z$  
uY_vX\;67z  
//日志 nt:d,H<p  
public static void log(String sMsg) @H83Ad  
{ bb4 `s0  
System.err.println(sMsg); 0[ BPmO6  
} t@#l0lu$  
gs:V4$(p4  
mVs<XnA47  
public static void log(int sMsg) @CB&*VoB  
{ i"_@iN0N  
System.err.println(sMsg); K*/X{3J;  
} c/'Cju W  
} Iq?#kV9)  
qlU"v)Mx  
Sb|9U8h  
/* >WZ_) `R  
**TestMethod.java 6OPYq*|  
*/ ,_iR  
package NetFox; >^Z==1  
F,.dC&B  
AZ7m=Q97  
public class TestMethod { ~u.( (GM  
+7V4mF!u  
i]{-KZC  
public TestMethod() >qL-a*w:a  
{ ///xx/weblogic60b2_win.exe 2R`dyg  
try{ ?= R C?K  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2mt S\bAF  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >D5WAQ>b  
SiteFileFetch fileFetch = new SiteFileFetch(bean); + e3{J_  
fileFetch.start(); 3;'RF#VL  
} DGJt$o=&@  
catch(Exception e){e.printStackTrace ();} |Bhj L,  
<tn6=IV  
n7p,{KSQ  
} pIhy3@bY  
?l/+*/AR;  
45(n!"u65  
public static void main(String[] args) 4Q?3gA1  
{ @s % !R  
new TestMethod(); 9`FPV`/  
} 5faY{;8  
} v*lj>)L  
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