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http断点续传简单实现(java)

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/* ]a8eDy  
**SiteFileFetch.java 4DvdE t  
*/ ymHKcQ  
package NetFox; %wOOzp`  
import java.io.*; N0]z/}hd@  
import java.net.*; t9ER;.e  
"K 8nxnq  
'T%IvJ#Xu  
public class SiteFileFetch extends Thread { wtlB  
'zE: fLo  
X z8$Xz,O  
SiteInfoBean siteInfoBean = null; //文件信息Bean L%f-L.9`u  
long[] nStartPos; //开始位置 JAN|aCzD  
long[] nEndPos; //结束位置 QI.t&sCh5  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 fQxSMPWB  
long nFileLength; //文件长度 cnbo +U  
boolean bFirst = true; //是否第一次取文件 &/HoSj>HS  
boolean bStop = false; //停止标志 0"hiCGm'  
File tmpFile; //文件下载的临时信息 S45'j(S=  
DataOutputStream output; //输出到文件的输出流 T)`gm{T  
-H4PRCDH  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) .a {QA  
public SiteFileFetch(SiteInfoBean bean) throws IOException "=FIFf  
{ eVTO#R*'|  
siteInfoBean = bean; *JwFD^<j  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); AYt*'Zeg!s  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); wtq,`'B  
if(tmpFile.exists ()) Vfb<o"BQk  
{ (s&ORoVGn  
bFirst = false; Dp^95V@  
read_nPos(); Q Qi@>v|d  
} "8FSA`>=  
else %,XI]+d  
{ f KHse$?_  
nStartPos = new long[bean.getNSplitter()]; m.!wsw  
nEndPos = new long[bean.getNSplitter()]; kw3 +>{\  
} r-*l1([eW  
Trpgx  
k2pT1QZnt  
3<+z46`?  
} f7ZA837Un  
<W?WUF  
'bl%Y).9w  
public void run() /Ad6+cY  
{ Zct!/u9 Q  
//获得文件长度 NfOp=X?Y  
//分割文件 (N7O+3+G  
//实例FileSplitterFetch .3(;9};  
//启动FileSplitterFetch线程 $ND90my  
//等待子线程返回 (NPxab8e*  
try{ }Iip+URG  
if(bFirst) #sS9vv7i  
{ f'i6QMk\&  
nFileLength = getFileSize(); :4U0I:J#  
if(nFileLength == -1) ]b> pI;  
{ 4? v,wq  
System.err.println("File Length is not known!"); ~+=E"9Oo  
} p+vh[+yp  
else if(nFileLength == -2) ]r!QmWw~V  
{ Et.j1M|g  
System.err.println("File is not access!"); v"/TmiZ  
} %/Bvy*X&  
else M.S s: ttj  
{ }DbE4"^K7  
for(int i=0;i<nStartPos.length;i++) *<UGgnmLE  
{ I.-v?1>,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); FZH-q!"^cK  
} Qne0kB5m  
for(int i=0;i<nEndPos.length-1;i++) fy`+Efuj  
{ h mds(lv7  
nEndPos = nStartPos[i+1]; z|Ap\[GS  
} 7pP+5&*  
nEndPos[nEndPos.length-1] = nFileLength; f0u56I9  
} z(rK^RT  
} "9%q bM B  
>gnF]<  
KXq_K:r?  
//启动子线程 P2t_T'R}  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~GA8_B  
for(int i=0;i<nStartPos.length;i++) aLYLd/ KV  
{ e62y  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _0.pvQ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6< >SHw  
nStartPos,nEndPos,i); 6{8/P'@/Zz  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C 0>=x{,v  
fileSplitterFetch.start(); /'\;8A$J`  
} W_%W%i|  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r ^ Y~mq  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M7vj^mt?  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C38%H  
nEndPos = " + nFileLength); Mc:b U  
// fileSplitterFetch[nPos.length-1].start(); xHe^"LL  
06jMj26!  
~{P:sjsU  
//等待子线程结束 I-bF{  
//int count = 0; !LiQ 1`V{  
//是否结束while循环 rH.gF43O:  
boolean breakWhile = false; k2.G%]j  
Mi?}S6bp  
'#<> "|  
while(!bStop) jq[x DwPG  
{ Oy%Im8.-A#  
write_nPos(); 7`dY1.rq  
Utility.sleep(500); 'in@9XO  
breakWhile = true; e3g_At\  
#%8 w  
nj  
for(int i=0;i<nStartPos.length;i++) Cg3ODfe  
{ $_FZn'Db6  
if(!fileSplitterFetch.bDownOver) jtCZfFD?  
{ HCazwX  
breakWhile = false; ;ctU&`  
break; ;'^, ,{  
} b2s~%}T  
} "H?QqrKx  
if(breakWhile) ]u0Jd#@  
break; {*$9,  
GS4_jvD-  
'evv,Q{87  
//count++; UJn/s;$.e  
//if(count>4) nvH|Ngg Q  
// siteStop(); /WYh[XKe  
} "Yb y  
KuXkI;63J>  
{(Fe7,.S3  
System.err.println("文件下载结束!"); eO[c lB  
} ;RHNRVP  
catch(Exception e){e.printStackTrace ();} !DcX8~~@  
} RHI&j~  
V.2[ F|P;3  
_Ex|f5+  
//获得文件长度 hy!6g n  
public long getFileSize() R&Ci/  
{ 6pm~sD  
int nFileLength = -1; q% E C  
try{ aS/`A  
URL url = new URL(siteInfoBean.getSSiteURL()); ]EN&SWh  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uA%Ts*aN  
httpConnection.setRequestProperty("User-Agent","NetFox"); t 7^D-l  
P7r4ePtLk{  
sUc iFAb  
int responseCode=httpConnection.getResponseCode(); iaRR5D-  
if(responseCode>=400) 9|3o<  
{ =:/>6 H1x  
processErrorCode(responseCode); |X3">U +-  
return -2; //-2 represent access is error rJV?) =Z  
} ls @5^g  
]]/lC  
(OqHfv  
String sHeader; ! Rvn'|!  
choL %g}  
M=[th  
for(int i=1;;i++) [%~^kq=|  
{ h. ^o)T  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OL9]*G?F  
//Utility.log(in.readLine()); TvM24Orct  
sHeader=httpConnection.getHeaderFieldKey(i); 9U'[88  
if(sHeader!=null) pl\b-  
{ xlw 2g<s  
if(sHeader.equals("Content-Length")) r=$gT@  
{ J7n5Ps\M  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =G>.-Qfs  
break; )!a$#"'  
} fYn{QS?  
} WW6yFriuW  
else 9P0yv3  
break; V{GXc:=  
} l5HWZs^  
} lY,/ W  
catch(IOException e){e.printStackTrace ();} >h%\HMKk  
catch(Exception e){e.printStackTrace ();} !.X _/$c  
\xeVDKJH+n  
7}o6_i  
Utility.log(nFileLength); !-RwB@\  
h!Y?SO.b  
`j:M)2:*y  
return nFileLength; tN}c0'H  
} QT;Va#a  
gVA; `<  
xE1rxPuq)d  
//保存下载信息(文件指针位置) XNlhu^jh  
private void write_nPos() 6F-JK1i  
{ DB~MYOX~  
try{ pn s+y  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6Hn)pD#U  
output.writeInt(nStartPos.length); (H1lqlVWV#  
for(int i=0;i<nStartPos.length;i++) B52H(sm  
{ HL8(lPgS  
// output.writeLong(nPos); *:j-zrwu&  
output.writeLong(fileSplitterFetch.nStartPos); r w\D>} \  
output.writeLong(fileSplitterFetch.nEndPos); 5& *zY)UL  
} xx0k$Dqt2I  
output.close(); ~v\hIm3=m  
} 3&9zGy{V+  
catch(IOException e){e.printStackTrace ();} 3G.r-  
catch(Exception e){e.printStackTrace ();} ^Xa*lR 3  
} 1ys(v   
h"8QeX:((  
Wxs>osq  
//读取保存的下载信息(文件指针位置) ctK65h{Eo  
private void read_nPos() x5PPu/  
{ ZYDW v/u  
try{ &N9IcNP  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D2)i3vFB  
int nCount = input.readInt(); 117c,yM0  
nStartPos = new long[nCount]; /sV?JV[t  
nEndPos = new long[nCount]; &M= 3{[  
for(int i=0;i<nStartPos.length;i++) #!L%J<MX  
{ w49{-Pp[  
nStartPos = input.readLong(); )^";BVY  
nEndPos = input.readLong(); x,f>X;04  
} Br&^09S  
input.close(); "8?TSm8  
} uR^.  
catch(IOException e){e.printStackTrace ();} -~} tq]  
catch(Exception e){e.printStackTrace ();} wsI5F&R,  
} o"\{OX  
L&'l3|  
b@!:=_Mr  
private void processErrorCode(int nErrorCode) DU`v J2  
{ NFV_+{X\  
System.err.println("Error Code : " + nErrorCode); Y!it!9  
} *V-ds8AQ  
5v+L';wx[T  
([tG y  
//停止文件下载 D$mf5G &  
public void siteStop() q^%5HeV 2  
{ 4a?r` '  
bStop = true; ozuIwzi7N  
for(int i=0;i<nStartPos.length;i++) hRLKb}  
fileSplitterFetch.splitterStop(); "\<P$&`HA  
d9|T=R  
HGb.656r  
} /0l-mfRr  
} 0NrTJ R`  
//负责部分文件的抓取 ]Cr]Pvab{  
**FileSplitterFetch.java ^7<[}u;qF  
*/ > R#9\/s  
package NetFox; LjCykk  
IX?@~'  
j 37:  
import java.io.*; 9[Y*k^.!  
import java.net.*; @E YK(QS-  
&jFKc0\i@  
Z<I[vp6{  
public class FileSplitterFetch extends Thread {  J(^ >?d'  
[C2kK *JZ  
l=,.iv=W  
String sURL; //File URL c9|I4=_K  
long nStartPos; //File Snippet Start Position D?%e"*>  
long nEndPos; //File Snippet End Position tfsh!)u?  
int nThreadID; //Thread's ID K/~Y!?:J r  
boolean bDownOver = false; //Downing is over ti+pUlVrM  
boolean bStop = false; //Stop identical C5cFw/',  
FileAccessI fileAccessI = null; //File Access interface ;*_I,|A:Xr  
NPP3 (3C  
SK}HXG{?  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1ZKz3)K  
{ I51M}b,[d  
this.sURL = sURL; ]yw_n^@  
this.nStartPos = nStart; ^fG`DjA)  
this.nEndPos = nEnd;  KzIt  
nThreadID = id; EmF]W+!z%  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BSjbnnW}"  
} [GOX0}$?  
y{:]sHyG  
j\nE8WH  
public void run() E*h0#m|)  
{  on6<l  
while(nStartPos < nEndPos && !bStop) zV6AuUIt  
{ ]<Z&=0i#9  
ZWov_  
G3oxa/mO  
try{ )H.ubM1  
URL url = new URL(sURL); vI4%d,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3KDu!w@  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4S^  
String sProperty = "bytes="+nStartPos+"-"; u!m,ilAnd  
httpConnection.setRequestProperty("RANGE",sProperty); =%:JjgKc*t  
Utility.log(sProperty); 0c%@e2(N  
Qfwwh`;  
;GiI'M  
InputStream input = httpConnection.getInputStream(); fma tc#G  
//logResponseHead(httpConnection); {hlT` K  
cw*(L5b u  
rE!G,^_{  
byte[] b = new byte[1024]; V]+o)A$  
int nRead; h9,wiT  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [_B+DD=}  
{ ,?P8m"  
nStartPos += fileAccessI.write(b,0,nRead); Sn_z  
//if(nThreadID == 1) mrhsKmH  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C}t+t  
} #L|JkBia  
& y#y>([~  
aNuZ/9O  
Utility.log("Thread " + nThreadID + " is over!"); D}=/w+  
bDownOver = true; U[K0{PbY  
//nPos = fileAccessI.write (b,0,nRead); N]3-L`t  
} '8]|E  
catch(Exception e){e.printStackTrace ();} AH"g^ gw~T  
} BH.:_Qrbh[  
} O>)n*OsS  
6Cop#kW#  
awj}K  
//打印回应的头信息 hfl%r9o  
public void logResponseHead(HttpURLConnection con) * K0j5dx  
{ S,d ngb{  
for(int i=1;;i++) I@y2HxM  
{ 4OqE.LFu  
String header=con.getHeaderFieldKey(i); F&nMI:h7  
if(header!=null) ]4LT#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LaEX kb*s  
Utility.log(header+" : "+con.getHeaderField(header)); mGM inzf  
else te!]9rR  
break; dQWA"6 ?i  
} _oMs `"4K  
} 6T} CPDRq  
/ y":/" h  
b3CspBgC  
public void splitterStop() )cv0$  
{ #J<`p  
bStop = true; Os]!B2j14  
} 2>_brz|7:|  
p;c_<>ws-Y  
],fwZd[t  
} Wf+Cc?/4  
V5(tf'  
3^iQe"P%a@  
/* 2yCd:wg  
**FileAccess.java "p6:ekw  
*//文件访问(定位,写) /v|68x6  
package NetFox; 8KGv?^M 6W  
import java.io.*; Ztpm_P6  
9$4/frd  
anKb  
public class FileAccessI implements Serializable{ *Wuctu^9  
L(!!7B_,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .9[8H:Fe  
RandomAccessFile oSavedFile; oE|u;o  
long nPos; 3ZJagJ\O  
q!9v}R3(  
tl,x@['p`  
public FileAccessI() throws IOException J!TK*\a2  
{ M#8Ao4 T  
this("",0); J:TI>*tn  
} '#An+;x{  
,N@Icl  
"DcueU#!  
public FileAccessI(String sName,long nPos) throws IOException r{6B+3J  
{ l]58P  
oSavedFile = new RandomAccessFile(sName,"rw"); ym,Ot1  
this.nPos = nPos; A86lyBDQ*  
oSavedFile.seek(nPos); [&O:qaD^  
} l_q>(FoqA  
]rX?n  
$=QGua V  
public synchronized int write(byte[] b,int nStart,int nLen) *l'$pJ X  
{ JXy667_  
int n = -1; I?B,rT3 h  
try{ C$re$9U  
oSavedFile.write(b,nStart,nLen); 3 Q%k (,  
n = nLen; 3PR7g  
} m 'H  
catch(IOException e) PuoJw~^h  
{ X#NeB>~  
e.printStackTrace (); (!&O4C5  
} Sy0s `\[  
l<MCmKuYp  
"a`0w9Mm}  
return n; 6x3Ew2  
} vJj j+:  
Vx4pP$S  
<~8f0+"  
} \#oV<MR  
1eR{~ ,  
Y;5^w=V  
/* nF[eb{GR`  
**SiteInfoBean.java YU\t+/b  
*/ uKAHJ$%  
package NetFox; HE<%d  
& I'F-F;  
XxU}|jTO#  
public class SiteInfoBean { q\pc2Lh?^  
h|>n3-k|p  
D '_#?%3^  
private String sSiteURL; //Site's URL 1bAp{u&  
private String sFilePath; //Saved File's Path 7a.#F]`  
private String sFileName; //Saved File's Name {]m e?I  
private int nSplitter; //Count of Splited Downloading File P>,D$-3  
xu pdjT%4  
=&G|} M  
public SiteInfoBean() #7:9XID /  
{//nSplitter的缺省值为5 c+M@{EbuN  
//default value of nSplitter is 5 g wjv&.T6^  
this("","","",5); "'dC>7*<  
} #^ [N4uV  
rTiuQdvo  
Q-%=ZW Z  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x,*t/nzR  
{ b,V=B{(~  
sSiteURL= sURL; &T.P7nJ=  
sFilePath = sPath; T`DlOi]Z_  
sFileName = sName; -Z& {$J  
this.nSplitter = nSpiltter; Xg#([}b  
8[p6C Jl)  
)8>f  
} b#'a4j-u  
XD>@EYN<X  
13@| {H CB  
public String getSSiteURL() oRF"[G8BV  
{ R20GjWy=  
return sSiteURL; i-W2!;G  
} +FK<j;}C7  
}Q(I&uz  
a8U2c;  
public void setSSiteURL(String value) JKbB,  
{ t$5]1dY$X  
sSiteURL = value; B{KD  ]  
} xeh|u"5  
dgD%I  
hiM!htc;M  
public String getSFilePath() xf SvvCy  
{ WSwmX3rn  
return sFilePath; a'~y'6  
} mMWNUkDq  
GlZDuU  
kniMXeiu  
public void setSFilePath(String value) #8|NZ6x,  
{ l.)!jWY  
sFilePath = value; E6)mBAE  
} #| Po&yu4R  
5q >u }J  
bV,R*C  
public String getSFileName() /_(Dq8^g@  
{ Ut=y`]F  
return sFileName; K; lC#  
} R6Lr]H  
1 j8,Zrg1  
B!anY}/U  
public void setSFileName(String value) V [>5  
{ vX%gcs/@  
sFileName = value; ']D( ({%g  
} 9tQk/niMM5  
i[n 1}E.@  
aQ. \!&U  
public int getNSplitter() p04w 83 jX  
{ jnY4(B   
return nSplitter; F6/bq/s  
} `r V,<  
VPbNLi  
'r CR8>k  
public void setNSplitter(int nCount) x.RZ!V-  
{ +`FY  
nSplitter = nCount; M}u2aW2]X  
} v/dcb%  
} [u:_J qf-  
d8po`J#nb  
$Izk]o;X~  
/* ]&>)=b!,  
**Utility.java 5KzU&!Zh9  
*/ %LyB~X  
package NetFox; XJ+sm^`vOf  
l ki(_ @3  
,D1QJPM  
public class Utility { b3H;Ea?^^<  
<U*d   
:&MiO3#+  
public Utility() A6VkVJZx  
{ rxA<\h,A  
.:}\Z27-c  
.755-S  
} ~7v^7;tT  
R.@GLx_zpQ  
//线程睡眠 E_P]f%  
public static void sleep(int nSecond) <Bwu N,}  
{ O{PRK5^h  
try{ )? xg=o/?  
Thread.sleep(nSecond); cQjJ9o7  
} %?seX+ne  
catch(Exception e) &IPT$=u  
{ & CgLF]  
e.printStackTrace (); ^*W3{eyi(L  
} w}iflAnjq  
} PNq#o%q  
U4g ZW]F  
//日志 kI]1J  
public static void log(String sMsg) m(Oup=\%b}  
{ %2.T1X%!  
System.err.println(sMsg); 1D$k:|pP~  
} n(L {2r  
Y:wds=lA  
8^T' a^Wt  
public static void log(int sMsg) F]&9Lp} "  
{ shD$,! k  
System.err.println(sMsg); *UTk. :G5  
} V}("8L  
} A /MOY@%G  
aaBBI S  
ny}?+&K  
/* x?k6ek  
**TestMethod.java Rj8l]m6U9  
*/ >U17BGJ.  
package NetFox; eu~;G H  
w v1R ]3}  
ixp%aRRP  
public class TestMethod { .]" o-(gB  
*]rV,\z:  
E^  rN)  
public TestMethod() wL{Qni3A  
{ ///xx/weblogic60b2_win.exe OSBE5  
try{ h0GXN\xI  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S +He  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E yNCky  
SiteFileFetch fileFetch = new SiteFileFetch(bean); U_:/>8})d  
fileFetch.start(); _C##U;e!  
} ]$7|1-&Y  
catch(Exception e){e.printStackTrace ();} Aam2Y,B  
yVW)DQ 4?  
<fP|<>s$@1  
} Ft07>E$/Q^  
F:n7yey  
D;Z\GnD  
public static void main(String[] args) 5!wa\)wY  
{ 1(-)$m8}  
new TestMethod(); :/u EPki  
} Ts.6 1Rx  
} TG!sck4/-Q  
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