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http断点续传简单实现(java)

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/* [0 7N<<  
**SiteFileFetch.java |Ia3bV W  
*/ PezUG{q(  
package NetFox; jqHg'Fq  
import java.io.*; +r)'?zU  
import java.net.*; .?b2Bd!MC  
c@:L7#8  
 "m3:HS  
public class SiteFileFetch extends Thread { {H eIY2  
5,!,mor$]  
m3]|I(]`Xe  
SiteInfoBean siteInfoBean = null; //文件信息Bean )5P*O5kQ -  
long[] nStartPos; //开始位置  =%AFn9q  
long[] nEndPos; //结束位置 0 1[LPN  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 _xign 3  
long nFileLength; //文件长度 #ej^K |Qx  
boolean bFirst = true; //是否第一次取文件 FKflN  
boolean bStop = false; //停止标志 07-S%L7Z  
File tmpFile; //文件下载的临时信息 42LlR 0  
DataOutputStream output; //输出到文件的输出流 l)E \mo 8  
XJnDx 09h  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) T{u!4Yu  
public SiteFileFetch(SiteInfoBean bean) throws IOException <Ft6d  
{ 5,>1rd<B  
siteInfoBean = bean; \s Fdp!M}2  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); MjC;)z  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); V%&t'H{  
if(tmpFile.exists ()) P%>? O :a  
{ k;:v~7VF  
bFirst = false; S4kGy}{+i  
read_nPos(); ByeyUw  
} J=6 7As  
else Okca6=2"  
{ u4B,|_MK  
nStartPos = new long[bean.getNSplitter()]; 6\4n y0  
nEndPos = new long[bean.getNSplitter()]; DHGv< F@  
} 70&v`"  
9Qp39(l:  
9"2.2li5$  
R3F>"(P@tS  
} mnL \c'  
=nOV!!  
`(1em%}  
public void run() X"b4U\A  
{ *Id$%O  
//获得文件长度 wo7.y["$  
//分割文件 ~6@zXHAS  
//实例FileSplitterFetch jD3,z*  
//启动FileSplitterFetch线程 'nI2RX  
//等待子线程返回 !*u5HVn  
try{ @lAOi1m,,  
if(bFirst) ?HVsIAU  
{ ]CH@ T9d5V  
nFileLength = getFileSize(); v vlfL*f  
if(nFileLength == -1) {6)fZpd)@  
{ ?ECmPS1  
System.err.println("File Length is not known!"); T^N Y|Y/  
} ,5'LbO-  
else if(nFileLength == -2) oM-{)rvQd  
{ &/R@cS6}'  
System.err.println("File is not access!"); C.s{ &  
} @/yRE^c  
else lDV8<  
{ g^8dDY[%  
for(int i=0;i<nStartPos.length;i++) /dhx+K~  
{ *wP8)yv7  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); %f\{ ]  
} rwFR5  
for(int i=0;i<nEndPos.length-1;i++) sF]v$ kq  
{ %0INtq  
nEndPos = nStartPos[i+1]; &d`Umm]  
} |8&AsQd  
nEndPos[nEndPos.length-1] = nFileLength; ~w Dmt  
} ?+GbPG~  
} M ! gX4  
J"|)?$d]z  
yk#yrxM  
//启动子线程 n=r}jRH1  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s8}:8  
for(int i=0;i<nStartPos.length;i++) "*laY<E  
{ < .$<d  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v6oPAqj,r  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D[ 7K2G+  
nStartPos,nEndPos,i); BQSA;;n]  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qh0)~JL4   
fileSplitterFetch.start(); ,.]e~O4R  
} BArsj  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nen6!bw4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E{T\51V]%  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GWjKZ1p  
nEndPos = " + nFileLength); XZcsx  
// fileSplitterFetch[nPos.length-1].start(); #i ?@S$  
N$pwTyk  
|C'w] QYm  
//等待子线程结束 /2>-h-zBjw  
//int count = 0; 7zr\AgV9  
//是否结束while循环 rRcfZZ~` M  
boolean breakWhile = false; y;0.P?Il"  
D\(,:_ge  
78+H|bH8  
while(!bStop) MP[v 9m@  
{ Qu!\Cx@  
write_nPos(); eN/s W!:P|  
Utility.sleep(500); {9;~xxTo  
breakWhile = true; au"HIyi?k  
"c!s\iuBU  
dtA- 4Ndm  
for(int i=0;i<nStartPos.length;i++) ^Q!:0D*  
{ dwrc"GK!o  
if(!fileSplitterFetch.bDownOver) .~v~~VL1NS  
{ ;zs*Zd7h M  
breakWhile = false; >]:R{1h  
break; zIF &ZYP  
} [w=x0J&  
} bQXxb(^  
if(breakWhile) 6 $ IXER  
break; C$*`c6R  
[7<X&Q  
zmr=iK  
//count++; ^+`vh0TPQ  
//if(count>4) t)cG_+rJ  
// siteStop(); G]P4[#5  
} :U)e 8  
Lom%eoH)  
32~Tf,  
System.err.println("文件下载结束!"); e"r}I!.  
} /lr RbZ  
catch(Exception e){e.printStackTrace ();} KG>.7xVWV7  
} !Q.c8GRUQ  
V.y+u7<3}  
W3<O+S&  
//获得文件长度 KNY<"b  
public long getFileSize() 0p2 0Rt  
{ QMtt:f]?i  
int nFileLength = -1; yqejd_cd  
try{ 'Dat.@j  
URL url = new URL(siteInfoBean.getSSiteURL()); LWVO%@)w  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wW%I < M  
httpConnection.setRequestProperty("User-Agent","NetFox"); `W]a @\EYA  
T{uktIO/  
30DpIkf  
int responseCode=httpConnection.getResponseCode(); /;OJ=x3i  
if(responseCode>=400) L+I[yJY:!  
{ m9L+|r  
processErrorCode(responseCode); 7y[B[$P  
return -2; //-2 represent access is error _Fz )2h,3  
} l$zNsf.  
,1~Zqprn  
//J:p,AF  
String sHeader; ]G1j\wnF  
A:D\!5=  
6,@M0CX  
for(int i=1;;i++) G!rcY5!J  
{ 3\4Cg()  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J&3;6I &  
//Utility.log(in.readLine()); mceSUKI;L  
sHeader=httpConnection.getHeaderFieldKey(i); Ce:R p?  
if(sHeader!=null) aLsGden|  
{ Ev^Xs6 }"  
if(sHeader.equals("Content-Length")) ^k_!+8"q{  
{ k&~vVx  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ey6K@@%  
break; [")0{LSA=  
} y:,{U*49  
}  R(zsn;  
else wz, \zh  
break; 'R'>`?Nh  
} PH7L#H^  
} M}nalr+#  
catch(IOException e){e.printStackTrace ();} 26Yg?:kP  
catch(Exception e){e.printStackTrace ();} JQtH },T r  
<5X@r#Lz  
WEsH@ [  
Utility.log(nFileLength); :EO}uP2  
hCDI;'ls  
YLCwo]\+>  
return nFileLength; a6]!4  
} sW]n~kTt'  
nuCK7X  
\O0fo^+U,,  
//保存下载信息(文件指针位置) r[,KE.^6~#  
private void write_nPos() @"~\[z5  
{ G` 8j ^H,  
try{ r]E$uq bR  
output = new DataOutputStream(new FileOutputStream(tmpFile)); h)<R#xw  
output.writeInt(nStartPos.length); xv*mK1e  
for(int i=0;i<nStartPos.length;i++) i]YQq!B  
{ }UO,R~q~  
// output.writeLong(nPos); gO/(/e>P  
output.writeLong(fileSplitterFetch.nStartPos); x$Dv&4  
output.writeLong(fileSplitterFetch.nEndPos); <G&v  
} _ 4W#6!  
output.close(); srSTQ\l4  
} T9$U./69-L  
catch(IOException e){e.printStackTrace ();} <VBw1|)$@  
catch(Exception e){e.printStackTrace ();} UP`q6] P  
} "/ "qg  
;CvGIp&y  
~H$XSNPi  
//读取保存的下载信息(文件指针位置) p']AXJ`Z  
private void read_nPos() ]S:@=9JB'  
{ H|!s.  
try{ v]J# SlF  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7 dzE"m  
int nCount = input.readInt(); \%C[l  
nStartPos = new long[nCount]; yjr@v!o  
nEndPos = new long[nCount]; m3WV<Cbz  
for(int i=0;i<nStartPos.length;i++) w\mF2h  
{ P~ykC{nD  
nStartPos = input.readLong(); };j&)M  
nEndPos = input.readLong(); esHiWHAC  
} xL BG}C  
input.close(); q)~qd$yMS  
} 6+FON$8  
catch(IOException e){e.printStackTrace ();} b1#=q0Zl  
catch(Exception e){e.printStackTrace ();} t#q> U%!  
} J#kdyBmuO  
w* I+~o-  
c]]F`B  
private void processErrorCode(int nErrorCode) '-vy Q^  
{ n~ql]Ln  
System.err.println("Error Code : " + nErrorCode); [v`4OQF/  
} gfYB|VyWo  
3/AUV%+  
. $k"+E  
//停止文件下载 ZFON]$Zk  
public void siteStop() IBqY$K+l  
{ n1t(ns|  
bStop = true; }"-r;i  
for(int i=0;i<nStartPos.length;i++) F[u%t34'  
fileSplitterFetch.splitterStop(); `#f=&S?k  
^55?VQB  
Kzb@JBIF  
} 9X%Klm 5w  
} *I67SBt  
//负责部分文件的抓取 Ig<p(G.;}  
**FileSplitterFetch.java E8i:ER $$7  
*/ p[)<d_  
package NetFox;  eqR#`  
uI2'jEjO  
f*],j  
import java.io.*; (HI%C@e9  
import java.net.*; _Pkh`}W:  
9qDGxW '1  
Dkb&/k:)  
public class FileSplitterFetch extends Thread { bw\=F_>L  
(Pd>*G\  
zl\#n:|  
String sURL; //File URL P1wRt5  
long nStartPos; //File Snippet Start Position H1nQ.P]_  
long nEndPos; //File Snippet End Position 0vp I#q  
int nThreadID; //Thread's ID F4Uk+|]Bu  
boolean bDownOver = false; //Downing is over 3\+p1f4  
boolean bStop = false; //Stop identical ~N9-an  
FileAccessI fileAccessI = null; //File Access interface {9".o,  
F 29AjW86  
}L!`K"^O&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^rwSbM$  
{ lc-|Q#$3$  
this.sURL = sURL; Xt =bc  
this.nStartPos = nStart; E<uOk  
this.nEndPos = nEnd; QZr<=}   
nThreadID = id; 9C;Y5E~'L  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h*UUtLi%WU  
} P;%QA+%7  
Hz8`)cv`  
(OB8vTRXP  
public void run() r6JkoP Mh  
{ pXv[]v  
while(nStartPos < nEndPos && !bStop) %KF:- w  
{ h<;[P?z  
v{n}%akc  
=-LX)|x}  
try{ >8fH5  
URL url = new URL(sURL); 1omvE9 %zM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >UY_:cW4%m  
httpConnection.setRequestProperty("User-Agent","NetFox"); 9M]"%E!s  
String sProperty = "bytes="+nStartPos+"-"; W_\L_)^X  
httpConnection.setRequestProperty("RANGE",sProperty); J~3T8e#  
Utility.log(sProperty); (Fzh1#  
lzG;F]  
NCnId}BT  
InputStream input = httpConnection.getInputStream(); hxVM]e[  
//logResponseHead(httpConnection); WN +Jf  
_|3TC1N$n  
ACO4u<M)  
byte[] b = new byte[1024]; VtiqAh}4  
int nRead;  IB{ZE/   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WV1 Z  
{ |HG b.^f?  
nStartPos += fileAccessI.write(b,0,nRead); qLi9ym, ]  
//if(nThreadID == 1)  |7zP 8  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _F@p53WE  
} "jO3Y/>S  
@O}j:b  
sLdUrD%  
Utility.log("Thread " + nThreadID + " is over!"); o?K|[gNi  
bDownOver = true; 6bKO;^0  
//nPos = fileAccessI.write (b,0,nRead); DhNo +"!z  
} Sn2Ds)Pfx3  
catch(Exception e){e.printStackTrace ();} qMES<UL>  
} gH^$Y~Lx  
} xeM':hD.o  
IXvz&4VD  
|4. o$*0Y  
//打印回应的头信息 gkML .u  
public void logResponseHead(HttpURLConnection con) ](>7h _2B  
{ iWM7, =1+  
for(int i=1;;i++) ?lDcaI>+n  
{ S~Iw?SK3  
String header=con.getHeaderFieldKey(i); ^[}0&_L w  
if(header!=null) I"32[?0 (;  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $Cd;0gdv  
Utility.log(header+" : "+con.getHeaderField(header)); nP\V1pgA  
else DJYXC,r  
break; QeeC2  
} 7Sz'vyiz  
} {L4>2rF  
t9n   
j22#Bw  
public void splitterStop() OZ!$%.?l  
{ L\Fu']l  
bStop = true; >9<8G]vcH  
} O%K?l}e  
@=NVOJy}c  
e*2&s5 #RT  
} (Ef2 w[ '  
B_"OA3d_  
)n}]]^Sc  
/* 4ZJT[zi  
**FileAccess.java )yNw2+ ~5  
*//文件访问(定位,写) r` `i C5Ii  
package NetFox; AqbT{,3yW  
import java.io.*; 37 O#aJ,K  
u1) TG "+0  
52MCUl  
public class FileAccessI implements Serializable{ _Hd1sx  
[pW1=tI  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cl8_rt  
RandomAccessFile oSavedFile; -S,ir  
long nPos; !/4 V^H  
Lk`k>Nn)  
qXB03}] G  
public FileAccessI() throws IOException 2JA&{ch  
{ k>:/D  
this("",0); W7*_T]  
} (I7&8$Zl  
JMirz~%ib  
s-GleX<  
public FileAccessI(String sName,long nPos) throws IOException )&Kn (l)  
{ I(^jOgYU  
oSavedFile = new RandomAccessFile(sName,"rw"); 7~kpRa@\P  
this.nPos = nPos; V#zhG AMy.  
oSavedFile.seek(nPos); Nxbd~^j  
} f/0v' Jt  
piYws<Q  
kMl@v`  
public synchronized int write(byte[] b,int nStart,int nLen) "#-Nqq  
{ R0Ax$Cv{  
int n = -1; nE]~E xr  
try{ }\`(m\2xo  
oSavedFile.write(b,nStart,nLen); 2fkIdy#n@  
n = nLen; 7 >PF~=  
} W(uP`M%][0  
catch(IOException e) Z:_m}Ya|  
{ y wW-p.  
e.printStackTrace (); %aj7-K6:t  
} r@*=|0(OrK  
' "ZRD_"  
&YT_#M  
return n; `e'G.@  
} Sni&?tcY  
a. h?4+^bN  
$ZQl IJZ  
} T&9`?QD  
Cz'xGW{  
E$]a?uA:  
/* {PN:bb  
**SiteInfoBean.java u^`eKak"l  
*/ &mh Ln4^  
package NetFox; *'Z-OY<V  
zc6H o  
tO?21?AD D  
public class SiteInfoBean { !2GHJHxv]c  
wn &$C0  
CnabD{uTf  
private String sSiteURL; //Site's URL e{,!|LhpQ  
private String sFilePath; //Saved File's Path 0Vf)Rw1%I  
private String sFileName; //Saved File's Name _FL<egK  
private int nSplitter; //Count of Splited Downloading File LWD.  
C= >B_EO  
E;9Z\?P  
public SiteInfoBean() t Y{; U#9  
{//nSplitter的缺省值为5 Q 2*/`L}m\  
//default value of nSplitter is 5 pPoH5CzcK  
this("","","",5); |}Q( F+cL  
} ows^W8-w  
h]qT1( I  
>OT \~C  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &kb\,mQ  
{ mRCHrw?WG  
sSiteURL= sURL; F#6cF=};@  
sFilePath = sPath; ?p(kh^z  
sFileName = sName; /4yOs@#  
this.nSplitter = nSpiltter; }qG#N  
pP3U,n   
(/'h4KS@  
} p:B ]Ft  
F@9Y\. ,  
LaDY`u0G%  
public String getSSiteURL() 9x(}F<L  
{ pL~=Z?(B  
return sSiteURL; G[#.mD{k  
} 3)y{n%3L  
uMHRUi  
d4J<,  
public void setSSiteURL(String value) L%f;J/  
{ 9<v}LeX  
sSiteURL = value; E[UO5X  
} ~ Yl<S(/4  
$Buf#8)F*  
AQe!Sqg'  
public String getSFilePath()  [@<G+j  
{ Ae6("Oid  
return sFilePath; ~6kJ~R4  
} %]#VdS|N  
l&3ki!  
a!D*)z Y  
public void setSFilePath(String value) O4E(R?wd  
{ *2=W5LaK.  
sFilePath = value; n26>>N  
} D M}s0O$ 0  
0Z,{s158L  
S*g`d;8gV  
public String getSFileName() UQ~4c,  
{ AFm,CINa  
return sFileName; XIRR Al(,  
} H*rx{F?  
pqeL%="p;  
"XhOsMJ  
public void setSFileName(String value) *> KHRR<N  
{ gQ>2!Qc a-  
sFileName = value; <BPRV> 0X  
} ]n5"Z,K  
q & b5g !  
88g47>{X  
public int getNSplitter() H|`R4hAk  
{ $/paEn"  
return nSplitter; b=1%pX_  
} [O_^MA,z  
&6/%k kv  
W' ep6O  
public void setNSplitter(int nCount) SX+4 HJB  
{ q{E"pyt36R  
nSplitter = nCount; %b =p< h'(  
} qo_]ZKL44  
} QrC/ssf}  
{6O0.}q]&  
C(o.Cy6  
/* 9tk" :ld  
**Utility.java Pz@/|&]  
*/ ]*;F. pZ  
package NetFox; 8bOT*^b$H  
8a>SC$8"  
a4&:@`=  
public class Utility { FZXyfZw!|  
OJ/SYZ.r  
%LQ/q 3?_  
public Utility() n+;vjVS%  
{ P+Z\3re  
"- eZZEl(  
w!`Umll2  
} iYKU[UP?  
`*yAiv>  
//线程睡眠 g1 9S  
public static void sleep(int nSecond) #3 bv3m  
{ %>y;zqZIU  
try{ 1b3(  
Thread.sleep(nSecond); iF9_b  
} 1h=D4yN  
catch(Exception e) z(H?VfJo  
{ _ 08];M|  
e.printStackTrace (); 2a `J%A  
} l>&sIX  
} .Xd0 Q=1h  
8!zb F<W9  
//日志 IgM v =^U  
public static void log(String sMsg) yC !/PQ"  
{ -$YJfQE6G  
System.err.println(sMsg); XmWlv{T+  
} S|K}k:v8  
A#DR9Eq  
%0XvJF)s  
public static void log(int sMsg) S LGW:  
{ ?`AGF%zp  
System.err.println(sMsg); ."mlSW"Wm  
} ai;\@$ cq  
} vM4<d>  
.Yx_:h=u  
ZL_[4 Y  
/* 6y  Wc1  
**TestMethod.java (oaYF+T  
*/ {TAw)!R~  
package NetFox; \%5MAQS  
r]LCvsVa  
%8FN0  
public class TestMethod { ut &/\k=N  
6 h'&6  
;7rv  
public TestMethod() 6G_<2bO  
{ ///xx/weblogic60b2_win.exe u7=T(4a  
try{ YaL]>.;Z:"  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H+l,)Se  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kuKa8c  
SiteFileFetch fileFetch = new SiteFileFetch(bean); -BhTkoN)  
fileFetch.start(); s@!$='|  
} <KQ(c`KW7  
catch(Exception e){e.printStackTrace ();} U7H9/<&o  
};S0 G!  
n%$ &=-Fk  
} mX\ ;oV!  
T PYDs+U  
Q_O*oT(0  
public static void main(String[] args) DDw''  
{ YBjdp=als  
new TestMethod(); QUOKThY?  
} tcL2J.  
} Zdn!qyR`  
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