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http断点续传简单实现(java)

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/* Rj])c^ZA'*  
**SiteFileFetch.java L9,O,f  
*/ PsyXt5Dk  
package NetFox; ^:^8M4:  
import java.io.*; :<R"Kk@  
import java.net.*; ]+@I] \S4  
$/$ 5{<  
^<+V[ =X  
public class SiteFileFetch extends Thread { hta y-  
{3|h^h_R  
T9-2"M=|<  
SiteInfoBean siteInfoBean = null; //文件信息Bean WXJ%hA  
long[] nStartPos; //开始位置 GvT ~zNd  
long[] nEndPos; //结束位置 oNIt<T  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 IF <<6.tz  
long nFileLength; //文件长度 nb #)$l  
boolean bFirst = true; //是否第一次取文件 KDJ-IXoU  
boolean bStop = false; //停止标志 fH ?s~X]  
File tmpFile; //文件下载的临时信息 u=PYm+q{  
DataOutputStream output; //输出到文件的输出流 2D ' $  
3 UG UZ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) e c4vX  
public SiteFileFetch(SiteInfoBean bean) throws IOException t}f,j^`e  
{ 9=p/'d8  
siteInfoBean = bean; .%x%(olf  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); V-w{~  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Y]: Ch (Q  
if(tmpFile.exists ()) |&AZ95v   
{ Tu_4kUCR!f  
bFirst = false; ^y<8 &ZFH  
read_nPos(); 6"u"B-cz  
} ,?`Zrxe[  
else k/2TvEV3=  
{ -=a,FDeR  
nStartPos = new long[bean.getNSplitter()]; 0E/,l``p  
nEndPos = new long[bean.getNSplitter()]; ^?-wov$  
} %p8#pt\$7  
w)xfP^M#  
i 3i  
d9.~W5^fC  
} m-MfFEZ  
q?bKh*48  
tIL ]JB  
public void run() }MW+K&sIh  
{ xw~3x*{  
//获得文件长度 D> EN:_v  
//分割文件 .[C@p`DZ  
//实例FileSplitterFetch ,]_<8@R  
//启动FileSplitterFetch线程 -~WDv[ [  
//等待子线程返回 o ^Ro 54i  
try{ ,^uQw/  
if(bFirst) Q> J9M` a  
{ }C<$q  
nFileLength = getFileSize(); yp"h$  
if(nFileLength == -1) _j}jh[M  
{ rqz`F\A;%  
System.err.println("File Length is not known!"); n1;zml:7_  
} ) S,f I  
else if(nFileLength == -2) ,V.Bzf%=O  
{ =RjseTS  
System.err.println("File is not access!"); 2dJP|T9H  
} 7L$\S[E  
else \,-e>  
{ pMLTXqL  
for(int i=0;i<nStartPos.length;i++) L(t!C~3  
{ NM0s*s42  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Fu[<zA^  
} y4j\y ? T8  
for(int i=0;i<nEndPos.length-1;i++) H_d^Xk QZ  
{ VhLS*YiSY  
nEndPos = nStartPos[i+1]; >h{)7Hv  
} b;I zK'  
nEndPos[nEndPos.length-1] = nFileLength; J)._&O$  
} 0Q!/A5z  
} !YENJJ  
cN%@ nW0i  
1}ws@hU  
//启动子线程 -xL^UcG0  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >Q[3t79^  
for(int i=0;i<nStartPos.length;i++) ^:Fj+d  
{ ,j e  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f:KZP;/[c  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \t?rHB3"  
nStartPos,nEndPos,i); QyD(@MFxb  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *1g3,NMA  
fileSplitterFetch.start(); k]9+/ $  
} tx,q=.(  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @!p0<&R@x  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W}'l8z]   
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Mew,g:m:  
nEndPos = " + nFileLength); %Z+FX,AK  
// fileSplitterFetch[nPos.length-1].start(); H_FT%`iM  
;C,t`(  
JiFB<Q\  
//等待子线程结束 &.[I}KH|B  
//int count = 0; 4n6t(/]b<  
//是否结束while循环 ,C0D|q4/!.  
boolean breakWhile = false; 7[ZoUWx  
vE&K!k`  
9NeHN@D)  
while(!bStop) Y@ X>ejk"  
{ bkFO4OZd  
write_nPos(); N^f_hL|:9  
Utility.sleep(500); .,<w_=  
breakWhile = true; q0L\{  
]]XXcQ,A  
W:JR\KKU  
for(int i=0;i<nStartPos.length;i++) o'K= X E  
{ N^4CA@'{  
if(!fileSplitterFetch.bDownOver) xiOAj"}~  
{ sQBKzvFO3  
breakWhile = false; Q PrP3DK  
break; & X#6jTh+  
} r7-H`%.  
} }h1y^fuGi  
if(breakWhile) -8:/My  
break; C2H2*"  
W#kd[Wi  
<RuLIu  
//count++; {'sp8:$a  
//if(count>4) %\T#Ik~3  
// siteStop(); 5O[\gd-  
} #@L5yy2  
\1<8'at  
~(\ .j=x  
System.err.println("文件下载结束!"); ;e6L@)dp9  
} >!bw8lVV  
catch(Exception e){e.printStackTrace ();} 3v ~[kVhoG  
} 7ygz52  
^~^=$fz  
sGG q~7  
//获得文件长度 Cs2kbG_  
public long getFileSize() KzQuLD(e  
{ @]etW>F_  
int nFileLength = -1; ^ddC a  
try{ eh}|Wd7J  
URL url = new URL(siteInfoBean.getSSiteURL()); X3'd~!a)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j937tn!Q  
httpConnection.setRequestProperty("User-Agent","NetFox"); .f&Z+MQ  
Hi nJ}MF  
VUC_|=?dL  
int responseCode=httpConnection.getResponseCode(); y+h/jEbM</  
if(responseCode>=400) Yf_/c*t\5  
{ m-]F]c=)w<  
processErrorCode(responseCode); Cd|rDa  
return -2; //-2 represent access is error >4bWXb'S}C  
} o:`^1  
`=%G&_3_<  
8ib e#jlg  
String sHeader; SB,#y>Zv?  
f`YHZ O  
49= K]X  
for(int i=1;;i++) kn+@)3W:*  
{ +2>, -V  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .EZ8yJj1Q  
//Utility.log(in.readLine()); .>1vN+  
sHeader=httpConnection.getHeaderFieldKey(i); ? (M$r\\  
if(sHeader!=null) E: Ul_m8  
{ V/tl-;W  
if(sHeader.equals("Content-Length")) mc4|@p*  
{ 39A|6>-?  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); is=x6G*r  
break; 5Gm8U"UR  
} NIHcX6Nw  
} ZEs^b  
else m -0}Pe9L  
break; : -$TD('F  
} a:KL{e[   
} x>+sqFd\  
catch(IOException e){e.printStackTrace ();} 2M)E1q|a  
catch(Exception e){e.printStackTrace ();} f9t+x+ Z  
ZB]234`0  
LI>Bl  
Utility.log(nFileLength); <?%49  
r,q.RWuII  
Y$_^f*sFn  
return nFileLength; vAjog])9s  
} h+w1 D}*  
mR~S$6cc  
yji>vJHu  
//保存下载信息(文件指针位置) =3PZGdWD  
private void write_nPos() lo-VfKvy  
{ }(oWXwFb&W  
try{ xeKm} MN]S  
output = new DataOutputStream(new FileOutputStream(tmpFile)); \H 5t-w=  
output.writeInt(nStartPos.length); 8%p+:6kP5  
for(int i=0;i<nStartPos.length;i++) pZ]&M@Ijp  
{ <) -]'@*c  
// output.writeLong(nPos); 5=  V29  
output.writeLong(fileSplitterFetch.nStartPos); t ?05  
output.writeLong(fileSplitterFetch.nEndPos); 5"bg 8hL  
} [AYJ(H/  
output.close(); zb s7G  
} VVfTFi<  
catch(IOException e){e.printStackTrace ();} O^8=Xj#}  
catch(Exception e){e.printStackTrace ();} (yoF  
} ZCA= n  
V P(JV  
7Kpv fyL{  
//读取保存的下载信息(文件指针位置) G?!8T91;  
private void read_nPos() *+(eH#_2/  
{ .g94|P  
try{ nI] zRduC  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); js!C`]1  
int nCount = input.readInt(); *VUJ);7k  
nStartPos = new long[nCount]; HY;kV6g{P  
nEndPos = new long[nCount]; /J9Or{#r  
for(int i=0;i<nStartPos.length;i++) 0IZF%`  
{ X{:3UTBR  
nStartPos = input.readLong(); ,; Uf>8~  
nEndPos = input.readLong(); rr>6;  
} K5z<n0X ~  
input.close(); OTNI@jQ)  
} _Ud!tK*H  
catch(IOException e){e.printStackTrace ();} +pQ3bX  
catch(Exception e){e.printStackTrace ();} u95D0S  
} qpzyl~g:C  
M!X^2  
|io)?`pj  
private void processErrorCode(int nErrorCode) - Rx;"J.H  
{ PEaZ3{-  
System.err.println("Error Code : " + nErrorCode); :ciD!Ly  
} 7Hj7b:3K&!  
 bDD29  
mQ9shdvt-  
//停止文件下载 'T7Y5X80$j  
public void siteStop() <9c{Kt.5(  
{ wk'&n^_br  
bStop = true; >CwI(vXn  
for(int i=0;i<nStartPos.length;i++) Eo6qC?5<  
fileSplitterFetch.splitterStop(); $LcMG,8%_  
}}bMq.Q'  
= J]M#6N0  
} 9W-1P}e,  
} i 1Kq (7  
//负责部分文件的抓取 \GKR(~f  
**FileSplitterFetch.java h8-uI.RZ  
*/ }a#=c*+_  
package NetFox; (Ffa{Tt!  
wc\`2(  
mHa~c(x  
import java.io.*; sHPj_d#  
import java.net.*; "<f?.l\+  
[+="I &  
~Q5]?ZNX  
public class FileSplitterFetch extends Thread { [)il_3t  
J*m7 d4^  
igEqty!.  
String sURL; //File URL 0uIBaW3s  
long nStartPos; //File Snippet Start Position M#Q"h5l  
long nEndPos; //File Snippet End Position wWSE[S$V  
int nThreadID; //Thread's ID K3h"oVn  
boolean bDownOver = false; //Downing is over y\[q2M<  
boolean bStop = false; //Stop identical ?b93! Q1  
FileAccessI fileAccessI = null; //File Access interface O}j@+p%M  
87m`K Str7  
f1?%p)C  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wA6E7vi'  
{ -B(p8YH  
this.sURL = sURL; [k&7h,  
this.nStartPos = nStart; w,_LC)9  
this.nEndPos = nEnd; I3}]MAE  
nThreadID = id; B\qy:nr j  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =kCiJ8q|  
} }^P"R[+4u  
2|U6dLZ!  
E,cQ9}/  
public void run() yU"#2 *C  
{  j8]M}Q$  
while(nStartPos < nEndPos && !bStop) P>$+XrTE  
{ ;jO+<~YP!  
|;^$IZSsz  
"KSdC8MS  
try{ U??OiKVZ+  
URL url = new URL(sURL); }SyK)W5Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); THB[(3q  
httpConnection.setRequestProperty("User-Agent","NetFox"); zU!d(ge.E  
String sProperty = "bytes="+nStartPos+"-"; q8,,[R_  
httpConnection.setRequestProperty("RANGE",sProperty); k ~F ,n  
Utility.log(sProperty);  *I}_g4  
hS>=p O+y  
oel?we6  
InputStream input = httpConnection.getInputStream(); wD W/?lT&  
//logResponseHead(httpConnection); <q Q@OUI   
E>O@Bv  
de[NIDA;`  
byte[] b = new byte[1024]; `LKf$cx(A  
int nRead; ;%cW[*Dw  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *P&lAyt6  
{ g>`D!n::n  
nStartPos += fileAccessI.write(b,0,nRead); B__e*d:)!m  
//if(nThreadID == 1) GiXs`Yt|  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5@ Hg 4.  
} Ekh)l0 l  
G({VK  
/gex0 w  
Utility.log("Thread " + nThreadID + " is over!"); JSaF7(a =  
bDownOver = true; tV4wkS=R|  
//nPos = fileAccessI.write (b,0,nRead); =h+-1zp{M^  
} cIK4sOTJ&  
catch(Exception e){e.printStackTrace ();} _1WA:7$C  
} %b~ND?nn-  
} /zr)9LQY0  
$vn)(zn+  
Bgp%hK  
//打印回应的头信息 fZ^ad1o  
public void logResponseHead(HttpURLConnection con) ~y whl'"k  
{ ] ;HCt=I~  
for(int i=1;;i++) ^t$uDQ[hA  
{ ;Cjj_9e,:  
String header=con.getHeaderFieldKey(i); dxH.  
if(header!=null) y(E<MRd8V  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z|)1ftcC  
Utility.log(header+" : "+con.getHeaderField(header)); {~G~=sC$  
else 8Z)wot  
break; ?crK613 t  
} l-x-  
} |CQ0{1R1  
]86*k %A  
9E4^hkD&  
public void splitterStop() +At0V(  
{ '+'h^  
bStop = true; ULs'oT)K;  
} 2OqEyXh  
|$+/IxDP  
@=Dc(5`[  
} `DM)tm3&m  
Y##lFEt  
h`(VMf'#  
/* s0 Z)BR #  
**FileAccess.java }r;=<mc,O  
*//文件访问(定位,写) YN7`18u  
package NetFox; g`tV^b")  
import java.io.*; "D KrQ,L  
Md8<IFi9]Q  
Y]5MM:mI  
public class FileAccessI implements Serializable{ `)MKCw$e  
q!~DCv df  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [$:L| V!{  
RandomAccessFile oSavedFile; 8U7d d[  
long nPos; Lr= ^0  
,}9 tJY@ E  
h-SKw=n  
public FileAccessI() throws IOException 6Tc! =lk  
{ E}<i?;  
this("",0); ~&+a.@T  
} eZ0-O /_i  
>p" U|  
oq|`;k   
public FileAccessI(String sName,long nPos) throws IOException _A0X[}^K  
{ nE2?3S>  
oSavedFile = new RandomAccessFile(sName,"rw"); BN&}g}N  
this.nPos = nPos; c6y>]8_  
oSavedFile.seek(nPos); "=JE12=u  
} /FC(d5I  
8HHR  
vo2GFo  
public synchronized int write(byte[] b,int nStart,int nLen) ={;+0Wjb8  
{ m}S}fH(  
int n = -1; W5~!)Ec  
try{ :_=YH+bZ  
oSavedFile.write(b,nStart,nLen); 6s ~!B{Q  
n = nLen; WT3g31  
} :VLYF$|  
catch(IOException e) Q/*|ADoq  
{ 1+Ik\  
e.printStackTrace (); VUz+ _)  
} FN (O  
Sq:J'%/z  
wb h=v;  
return n; GaL UZviJ_  
} 9\=SG"e(  
cqW(9A|8  
ZPz=\^  
} NzeiGj  
[;ZC_fD  
vF>]9sMv  
/* (A=Z,ed  
**SiteInfoBean.java $H]NC-\+>  
*/ n.R"n9v`  
package NetFox; cRNVqMpg  
GdrVH,j  
S 2W@;XvV  
public class SiteInfoBean { ^\Q%VTM  
r6:e 423  
Y> ~jho  
private String sSiteURL; //Site's URL {Ve`VV5E  
private String sFilePath; //Saved File's Path _={mKKoHs  
private String sFileName; //Saved File's Name '* /$66|  
private int nSplitter; //Count of Splited Downloading File y7GgTC/H  
B ?y[ %i  
?8U]UM6Tu4  
public SiteInfoBean() OjqT5<U  
{//nSplitter的缺省值为5 EQ|Wke  
//default value of nSplitter is 5 m&be55M;  
this("","","",5); 3"k n5)x  
}  3SPXJa\i  
6K=}n] n  
D]|{xKC}  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kc}|L9  
{ AR&l9R[{N  
sSiteURL= sURL; >B*zzj  
sFilePath = sPath; ~,xso0  
sFileName = sName; @U1t~f^  
this.nSplitter = nSpiltter; P97i<pB Y_  
gkKNOus  
BW`;QF<  
} v$5D&Tv  
{ 9\/aXPS  
2t45/:,  
public String getSSiteURL() ^uVPN1}b^@  
{ b.kV>K"X3  
return sSiteURL; P_75-0G  
} 036QV M$  
bqx2lQf,_  
HEhBOER?  
public void setSSiteURL(String value) )p:+!sX(  
{ &n0Ag]$P  
sSiteURL = value; I9`ZK2S  
} \g)?7>M|  
:m/qR74+"  
eIN0 T;1T  
public String getSFilePath() ,Z! I^  
{ C',uY7}<  
return sFilePath; pr,1pqiAf  
} AI9922}*  
TgJ6O,0  
\$F#bIjC  
public void setSFilePath(String value) z3>4 xn{  
{ ap"pQ[t;  
sFilePath = value; EVA&By6_k  
} u),.q7(m  
5l%g3F  
bUSa#pNO>  
public String getSFileName() W{j(=<|<  
{ N%e^2O)  
return sFileName; ]&P 4QT)f  
} *Ue#Sade  
2:e7'}\D.  
b' ~WS4xlD  
public void setSFileName(String value) .0;\cv4}  
{ :QXKG8^  
sFileName = value; 7+hc?H[&'  
} ua_,c\iL  
W%o! m,zFM  
A0v@L6m-O  
public int getNSplitter() *Gj`1# Z$  
{ Ag8lI+ h  
return nSplitter; 1Y~'U =9  
} 4-$kc wA  
6Lg#co}9  
3 +`,'Q9  
public void setNSplitter(int nCount) fRkx ^u P  
{ 6k<3,`VV|  
nSplitter = nCount; x;LO{S4Z  
} b5f+q:?{  
} Wc;N;K52   
roe_H>  
<yvo<R^30  
/* B[+b%a3  
**Utility.java c+8 Y|GB  
*/ _x,(576~  
package NetFox; /ZH*t\  
NJOV!\k  
8E9k7  
public class Utility { CoWT  
&SPr#OkW  
ilZ5a&X;  
public Utility() T eu.i   
{ iQLP~Z>,T  
X\*H7;k,  
"1%k"+&  
} Kq+vAp).  
lE8_Q*ev  
//线程睡眠 Vf=,@7  
public static void sleep(int nSecond) Rd5pLrr[0)  
{ |W&K@g$  
try{ g9d/nR X&  
Thread.sleep(nSecond); q~*|Wd'&  
} o? K>ji!  
catch(Exception e) ]"j%:fr  
{ */$]kE  
e.printStackTrace (); (Fq]y5  
} oU*e=uehj  
} Y ._O m}H  
-B-HZ_  
//日志 .f!:@fX>=  
public static void log(String sMsg) G%h+KTw  
{ 7;?7q  
System.err.println(sMsg); f3:dn7  
} RK)ikLgp  
|I|,6*)xg  
%+UTs'I  
public static void log(int sMsg) ft iAty0n  
{ ]I;owk,  
System.err.println(sMsg); o_ [I#PT  
} yBv4 xKMH  
} NL!xk cXO  
.v9i|E=<~  
 BrZ17  
/* Q^?$2ck=  
**TestMethod.java {?X +Yw  
*/  ;CV'  
package NetFox; Z 8GIZ  
g|4>S<uC  
^?0?*  
public class TestMethod { %(s2{$3  
ma"M?aM  
A v;NQt8ut  
public TestMethod() dKw[#(m5v  
{ ///xx/weblogic60b2_win.exe %uo#<Ny/ I  
try{ c^5fhmlt  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); th0>u.hJ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >km$zfM2-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); pNu?DF{ 3  
fileFetch.start(); ,I,Zl.5  
} [g+WL\1  
catch(Exception e){e.printStackTrace ();} =OKUSHu@V  
L%pAEoSG  
(+u&b< <6N  
} U-{3HHA  
+]hc!s8  
jDj=a->e^  
public static void main(String[] args) >: J1Gc  
{ EFu>  
new TestMethod(); 4r7a ZDVA\  
} OXX D}-t  
} =2} bQW  
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