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http断点续传简单实现(java)

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/* r3NdE~OAi  
**SiteFileFetch.java h e[2,  
*/ /o^/ J~/3  
package NetFox; _+9o'<#u(  
import java.io.*; >} E  
import java.net.*; G3o`\4p  
}60/5HNr  
3UX6Y]E3  
public class SiteFileFetch extends Thread { \ZtKaEXnx  
74=zLDDS  
c2u*<x  
SiteInfoBean siteInfoBean = null; //文件信息Bean {G+iobQdd  
long[] nStartPos; //开始位置 /5Sd?pW;  
long[] nEndPos; //结束位置 [(2XL"4D  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 jN AS'JV  
long nFileLength; //文件长度 6~-,.{Y  
boolean bFirst = true; //是否第一次取文件 5.LfN{gE)  
boolean bStop = false; //停止标志 +1]A$|qyW  
File tmpFile; //文件下载的临时信息 f28bBuv1?  
DataOutputStream output; //输出到文件的输出流 f~R+Q/Gtz`  
w! PguP  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) '!F'B:  
public SiteFileFetch(SiteInfoBean bean) throws IOException !;UoZ~  
{ nT%ko7~-  
siteInfoBean = bean; >qVSepK3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); (<}BlL   
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); L6"V=^Bq  
if(tmpFile.exists ()) kEp{L  
{ j[A:So  
bFirst = false; [:zP]l.|  
read_nPos(); ^'n;W<\p)  
} c,:nWf  
else p^1~o/  
{ @ qS Z=  
nStartPos = new long[bean.getNSplitter()]; / E!N:g<  
nEndPos = new long[bean.getNSplitter()]; 7h.fT`  
} J@OK"%12  
D\| U_>  
YkbuyUui  
*c>B-Fo/D  
} 0YC|;`J  
Sf*gAwnW  
Q ZC\%X8j  
public void run() (^"2"[?a  
{ lPD&Doa  
//获得文件长度 y'!"GrbZ  
//分割文件 uvAJJIae'  
//实例FileSplitterFetch DkSs^ym  
//启动FileSplitterFetch线程 uu.}<VM.1  
//等待子线程返回 ?r{hrAx  
try{ fB 0X9iV6j  
if(bFirst) 4Y{;%;-i  
{ [C\B2iU7_M  
nFileLength = getFileSize(); g;Zy3   
if(nFileLength == -1) kA> e*6  
{ lD{*Z spz  
System.err.println("File Length is not known!"); f40OVT@g  
} 9o4h~Imu  
else if(nFileLength == -2) 1xr2x;  
{ (I#mo2  
System.err.println("File is not access!"); BT`g'#O  
} G)q;)n;*=  
else ia (&$a8X  
{ ROXa/  
for(int i=0;i<nStartPos.length;i++) r@}8TE*|P  
{ FU(2,Vl  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); gLRDd~H  
} Omi/sKFMi  
for(int i=0;i<nEndPos.length-1;i++) gZiwXb  
{ X:lStO#5  
nEndPos = nStartPos[i+1]; Y^nm{;G+  
} GKKDO+A=!  
nEndPos[nEndPos.length-1] = nFileLength; tyWDa$u,u  
}  d0i|^  
} &KY!a0s  
rP}[>  
i5=~tS  
//启动子线程 @t;726  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M~n./wyC  
for(int i=0;i<nStartPos.length;i++) 1rS8+!9C  
{ $ U7#3-'  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nEPTTp+B  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *U}ztH-+/  
nStartPos,nEndPos,i); zkiwFEHA=  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !??g:2  
fileSplitterFetch.start(); K9]zUe&#w  
}  fZ&' _  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "LSzF_mK  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $ai;8)C6  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5^R?+<rd  
nEndPos = " + nFileLength); X7[gfKGL)N  
// fileSplitterFetch[nPos.length-1].start(); $$uMu{?0i  
M%Ksyr9  
vt n T   
//等待子线程结束 CZ'm|^S  
//int count = 0; I~6 o<HO  
//是否结束while循环 $4}G  
boolean breakWhile = false; 0qIg:+l+  
B,&QI&k`~  
yn"4qC#Z  
while(!bStop) tj*/%G{Y  
{ +KD7Di91<K  
write_nPos(); ;4(}e{  
Utility.sleep(500); Pjn{3/*wi  
breakWhile = true; j@w1S[vt  
:`E p#[Wvo  
d S'J@e=#  
for(int i=0;i<nStartPos.length;i++) l^$'6q"  
{ $:\`E 56\  
if(!fileSplitterFetch.bDownOver) 5KDCmw  
{ oH!O{pQK}  
breakWhile = false; + ~5P7dh6  
break; N'-[>w7vK2  
} ,tcUJ}l  
} 89;@#9  
if(breakWhile) 6Ol9P56j  
break; H9PnJr8 \  
1q@R04i  
4P"bOt5izR  
//count++; kN78j  
//if(count>4) I{r*Y9  
// siteStop(); l^OflZC~  
} ZHa>8x;Mjl  
Yb4ku7}  
qTN%9!0@9  
System.err.println("文件下载结束!"); 9(nq 4 HvI  
} cs ?WE9N  
catch(Exception e){e.printStackTrace ();} 1_#;+S  
} E1tCY.N{  
T1*.3_wtP  
k].swvIi  
//获得文件长度 D7T|K :F)  
public long getFileSize() E>f{j:M  
{ l)dE7$H  
int nFileLength = -1; $B_%MfI  
try{ gua7<z6=eh  
URL url = new URL(siteInfoBean.getSSiteURL()); (ie%zrhS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -*MY7t3  
httpConnection.setRequestProperty("User-Agent","NetFox"); jU7[z$GX  
""XAUxo  
,a,2I  
int responseCode=httpConnection.getResponseCode(); xY#J((-iH  
if(responseCode>=400) (3lA0e`Y  
{ HKJBR)T  
processErrorCode(responseCode); o5 fV,BJZO  
return -2; //-2 represent access is error [U8/nT  
} -egnMc67  
DyCzRkH  
R y#C#0  
String sHeader; Hz."4nhv  
~59lkr8  
:i4(cap&}F  
for(int i=1;;i++) -{ 1P`&G  
{ <Q/)SN6_E  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GCq4{_B\Q  
//Utility.log(in.readLine()); L!zdrCM  
sHeader=httpConnection.getHeaderFieldKey(i); Q}OloA(+  
if(sHeader!=null) op5 `#{  
{ 8cG`We8l&  
if(sHeader.equals("Content-Length")) q(:L8nKT]  
{ \U]K!K=  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1(dKb  
break; aEvbGo  
} [}ja \!P  
}  +:-xV  
else )J> dGIb  
break; 1=C12  
} NytTyk)  
} T|wz%P<J  
catch(IOException e){e.printStackTrace ();} h !K" ;qw  
catch(Exception e){e.printStackTrace ();} L;u5  
|[Fb&x  
]6[+tpx  
Utility.log(nFileLength); 3CjixXaA$  
QfAmGDaYQ  
BK+P  
return nFileLength; 05T?c{ ;  
} i79$D:PcLa  
&C+2p  
XLCqB|8`V  
//保存下载信息(文件指针位置) Z>bNU  
private void write_nPos() _!qD/ [/  
{ | U"fhG=g  
try{ EI6kBRMo  
output = new DataOutputStream(new FileOutputStream(tmpFile)); su%-b\8K  
output.writeInt(nStartPos.length); GI/NouaNfm  
for(int i=0;i<nStartPos.length;i++) 8]^|&"i.\d  
{ T`fT[BaY  
// output.writeLong(nPos); #jg-q|nd  
output.writeLong(fileSplitterFetch.nStartPos); bUm%#a  
output.writeLong(fileSplitterFetch.nEndPos); jaodcT0  
} IRx% L?  
output.close(); 7$Z_'GJ]1C  
} 5(J?C-Pk  
catch(IOException e){e.printStackTrace ();} D^6iQW+.P  
catch(Exception e){e.printStackTrace ();} g/!MEOVx  
} UIyLtoxu  
OxGfLeP.R!  
>fI\f <ez  
//读取保存的下载信息(文件指针位置) UWC4PWL,>C  
private void read_nPos() YR-G:-(#b  
{ h`\ $8 oV  
try{ UHvA43  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lWj*tnnn[  
int nCount = input.readInt(); 7)jN:+4N  
nStartPos = new long[nCount]; 6[k<&;  
nEndPos = new long[nCount]; TS9<uRO0  
for(int i=0;i<nStartPos.length;i++) (LmU\Pe%  
{ cYK:Y!|`F  
nStartPos = input.readLong(); F&R*njJcc  
nEndPos = input.readLong(); M-i3_H)  
} 9X 4[Zk  
input.close(); SR?mSpq5  
} 2e%\aP`D2  
catch(IOException e){e.printStackTrace ();} *cXq=/s  
catch(Exception e){e.printStackTrace ();} ZBpcC0 z  
} 5H XF3  
vRC >=y*=  
&lSNI5l  
private void processErrorCode(int nErrorCode) ,4t6Cq!  
{ s0;a j<J  
System.err.println("Error Code : " + nErrorCode); InbB2l4G  
} `i cs2po  
GJcxqgk$  
4z( B`t~7  
//停止文件下载 xRacgny:I  
public void siteStop() \XV8t|*  
{ FqA4 O U  
bStop = true; %AA&n*m  
for(int i=0;i<nStartPos.length;i++) ]b%U9hmL^f  
fileSplitterFetch.splitterStop(); ZN $%\,<  
b`D]L/}pr  
(Q=o 9o:b  
} SkmTW@v  
} -`XS2  
//负责部分文件的抓取 O)vGIp?f't  
**FileSplitterFetch.java &Jj|+P-lY  
*/ Jk>vn+q8P^  
package NetFox; T.;{f{  
["Ts7;q9[  
{Z8GG  
import java.io.*; UMRFTwY  
import java.net.*; lL:!d.{  
4E5;wH  
Rk g8  
public class FileSplitterFetch extends Thread { NJsaTBT  
U&BCd$  
KLW5Ad:/rI  
String sURL; //File URL T(x@ gwc  
long nStartPos; //File Snippet Start Position L5x;# \#p  
long nEndPos; //File Snippet End Position WyatHC   
int nThreadID; //Thread's ID ?K7uy5Y  
boolean bDownOver = false; //Downing is over r6uN6XCM  
boolean bStop = false; //Stop identical u:|^L]{  
FileAccessI fileAccessI = null; //File Access interface qH4|k 2Lm  
$+GDPYm'  
u*2?Gky  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zO"De~[9  
{ v(yJGEf0  
this.sURL = sURL; "JSIn"/  
this.nStartPos = nStart; ,M{G X  
this.nEndPos = nEnd; g@!U^mr*3  
nThreadID = id; v; i4ZSV^A  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lM4Z7mT /  
} )1#/@cU  
Xrb7.Y0d  
 ?{"r(  
public void run() ^PNDxtd|v  
{ k5aB|xo  
while(nStartPos < nEndPos && !bStop) @z ",1^I  
{ # tu>h  
hQj@D\}  
} uS0N$4  
try{ N!~]D[D  
URL url = new URL(sURL); b_nE4>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M;y*`<x  
httpConnection.setRequestProperty("User-Agent","NetFox"); aBReIK o  
String sProperty = "bytes="+nStartPos+"-"; tWy.Gz\  
httpConnection.setRequestProperty("RANGE",sProperty); pt.V^a  
Utility.log(sProperty); [nig^8  
?} 8r h%  
Jg=!GU/::  
InputStream input = httpConnection.getInputStream(); "!zJQl@  
//logResponseHead(httpConnection); [yN+(^ i  
./XX  
SZe55mK`  
byte[] b = new byte[1024]; wl]3g  
int nRead; _"Bj`5S  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M#o.O?.`  
{ nQOdM#dP  
nStartPos += fileAccessI.write(b,0,nRead); I?g}q,!]  
//if(nThreadID == 1) IXtG 36O  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8Y`g$2SZ^8  
} .kU^)H" l  
~|S0E:*.  
(CIcM3|9C  
Utility.log("Thread " + nThreadID + " is over!"); Wrb[\ ?-  
bDownOver = true; y*^UGJC:  
//nPos = fileAccessI.write (b,0,nRead); }#D=Rf?2\P  
} ;dUKFdKH}  
catch(Exception e){e.printStackTrace ();} nktGO  
} ZAfuW^r  
} FulFEnSV  
A{q%sp:3~  
,o n]Fts  
//打印回应的头信息 W{'hn&vU  
public void logResponseHead(HttpURLConnection con) R]%"YQ V  
{ fdK E1,;  
for(int i=1;;i++) FhY#3-jH  
{ KX9IC 5pR  
String header=con.getHeaderFieldKey(i); yC1OeO8{  
if(header!=null) {p1`[R&n#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %dPk,Ylz  
Utility.log(header+" : "+con.getHeaderField(header)); &J2 UAmB  
else s9sl*1n1m`  
break; FtyT:=Kpc  
} |#o' =whTl  
} VB*c1i  
 4 Pc-A  
wJ2cAX;"  
public void splitterStop() nE8z1hBUq  
{ "|Q.{(|kO1  
bStop = true; 1ygEyC[1  
} G(wK(P0j  
BH {z]a  
 :'F,l:  
} ,zx{RDI  
c6vJ;iz  
}nPt[77U_7  
/* *$%~/Q@]  
**FileAccess.java *d=}HO/  
*//文件访问(定位,写) <J+Oh\8tad  
package NetFox; rd0Fd+t/  
import java.io.*; vVo'f|fW  
3?V'O6  
`{{6vb^g  
public class FileAccessI implements Serializable{ J8S$YRZ_  
ho{%7\  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 neM)(` gp  
RandomAccessFile oSavedFile; G 0pq'7B  
long nPos; :Y/aT[  
3>VL>;75[  
GYQ:G=  
public FileAccessI() throws IOException A@< !'  
{ HcIJ&".~  
this("",0); A)9]^@,  
} ]pe7I P  
wnd #J `  
Yf9E0po  
public FileAccessI(String sName,long nPos) throws IOException R4;1LZ8XzS  
{ wp1O*)/q  
oSavedFile = new RandomAccessFile(sName,"rw"); qc,EazmU  
this.nPos = nPos; xwsl$Rj  
oSavedFile.seek(nPos); ]>)shH=Yx  
} l[[`-f8j  
_Kaqx"D  
BN]o!Y  
public synchronized int write(byte[] b,int nStart,int nLen) j7&#R+f  
{ M**Sus87Q  
int n = -1; gD)M7`4  
try{ s3A(`heoq  
oSavedFile.write(b,nStart,nLen); 9U<WR*H  
n = nLen; [VXQ&  
} @ xo8"kl  
catch(IOException e) }bw^p.ci  
{ &cyB}Gv  
e.printStackTrace (); d>F7i~W  
} ;/+<N  
[/hoNCH!  
zu?112-v2  
return n; -x6_HibbD  
} [x 7Rq_^  
gnN>Rl 5_  
'Y2$9qy-L  
} X HJdynt/  
gKTCfD~  
e}2?)B`[  
/* A7Y CSjB  
**SiteInfoBean.java {91Y;p C  
*/ <#BK(W~$  
package NetFox; y]{b4e  
?yAb=zI1b  
e:-pqZT`  
public class SiteInfoBean { xS@jV6E~  
(^B1Kt!<  
prS%lg>  
private String sSiteURL; //Site's URL /Hk})o_  
private String sFilePath; //Saved File's Path Y{j~;G@Wl  
private String sFileName; //Saved File's Name `/m] K ~~  
private int nSplitter; //Count of Splited Downloading File hb8oq3*x  
/[Fk>Vhp  
^3sv2wh^|8  
public SiteInfoBean() ?pJ2"/K   
{//nSplitter的缺省值为5 Ma?uB8o+~  
//default value of nSplitter is 5 Z*3RI5)dx  
this("","","",5); W!ug^2"  
} 4IZAJqw(*  
_s#J\!F  
WVQHb3Pe0  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7n .A QII  
{ C\"C12n{  
sSiteURL= sURL;  Hvz;[!  
sFilePath = sPath; Nz{qu}dt  
sFileName = sName; _gK}Gi?|  
this.nSplitter = nSpiltter; v,Kum<oi?  
kPy7e~  
!Usmm8!K  
} 8?L-3/  
,~$sJ2 g7  
g,YF$:e  
public String getSSiteURL() BPW.&2?<  
{ V+sZ;$  
return sSiteURL; nO6UlY  
} 2va[= >_  
p?Ux1S  
]{i0?c  
public void setSSiteURL(String value) =zAFsRoD_B  
{ ?8grK  
sSiteURL = value; ecl6>PS$'  
} M1P;x._n  
cyd_xB5K  
)ty>{t  
public String getSFilePath() h{HpI 0q4  
{ k:/Z6TLk3  
return sFilePath; ^`xS| Sq1D  
} ]D@aMC$#  
' $yy  
r4FSQ$[9w  
public void setSFilePath(String value) FDiDHOR  
{ ,^ -%<  
sFilePath = value; \s8h.xjU  
} C-49u<; ,  
gYh o$E  
yAGQD[ih  
public String getSFileName() =?Co<972Z  
{ Q!-"5P X  
return sFileName; yWc%z6dXC  
} Pt-mLINvG  
:k_)Bh?+  
#Z]Cq0=  
public void setSFileName(String value) h3>u[cX%  
{ b't6ekkN  
sFileName = value; :L:] 3L  
} \A!I ln  
NmpNme  
WB (?6"  
public int getNSplitter() "<^ Vp-7r  
{ Y._ACQG3  
return nSplitter; Qe7 SH{  
} o^uh3,.  
Ia9!ucN7DA  
?o]NV  
public void setNSplitter(int nCount) PCDvEbpG  
{ "E5=AW d  
nSplitter = nCount; "_dJ4<8  
} 4u2_xbT  
} #EKnjh=Uq  
e=jtF"&  
qoph#\  
/* fk2Uxg=[  
**Utility.java A&KY7[<AC{  
*/ 9l&G2 o   
package NetFox; |tY6+T}  
S:2 xm8 i  
H`3w=T+I  
public class Utility { <VN< ~sz  
DB jUHirK  
Q[`2? j?  
public Utility() .Xxxz Wyk  
{ "AWk jdj  
K;`*n7=IA  
1-4[w *u>  
} w3fD6$  
JqN$B\J,  
//线程睡眠 NXOvC!<  
public static void sleep(int nSecond) #N=_-  
{ 2gvS`+<TP  
try{ Mns=X)/hc  
Thread.sleep(nSecond); E[CvxVCx  
} Vhm^<I-d  
catch(Exception e) sdewz(xskj  
{ v<0S@9~  
e.printStackTrace (); +tlbO?  
} nu|?F\o!  
} >NpW$P{'  
Y8mv[+Z  
//日志 u7p:6W  
public static void log(String sMsg) ZkMHy1  
{ (Zy=e?E,  
System.err.println(sMsg); hL;??h,!_  
} 1mEW]z  
O1]XoUH<  
9 771D  
public static void log(int sMsg) aO<H!hK  
{ cwUor}<|  
System.err.println(sMsg); !VfVpi+-  
} )pey7-P7g5  
} FQJFq6l  
2NL|_W/  
;ov}%t>UD  
/* pAEJ=Te  
**TestMethod.java ~3Z(0 gujD  
*/ Xn<|6u  
package NetFox; D{t0OvQag  
h!hv{c  
+hT9V1'-D  
public class TestMethod { 5'0kf7  
>R/^[([;]  
r^\Wo7q  
public TestMethod() NXE1v~9V  
{ ///xx/weblogic60b2_win.exe "yXqf%CGE  
try{ Y}x_ud,  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); zWdz9;=_  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I|mxyyf  
SiteFileFetch fileFetch = new SiteFileFetch(bean); k"FY &;G(G  
fileFetch.start(); Lr>4~1:`  
} { lZ<'p  
catch(Exception e){e.printStackTrace ();} {\= NZ\  
r2Q) Q  
Lhgs|*M  
} g{7?#.7  
><@& &u.  
69C ss'  
public static void main(String[] args) qkyYt#4E  
{ u-dF ~.x  
new TestMethod(); E~Y%x/oX  
} 9l7 youZ]  
} Q[Tbdc%1EG  
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