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http断点续传简单实现(java)

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/* kSjvY&n%  
**SiteFileFetch.java 7$JE+gL/7  
*/ {$_Gjv  
package NetFox; .oe\wJS6  
import java.io.*; 2<uBC  
import java.net.*; 8qv>C)~~`  
|I=GI]I  
7n'Ww=ttI  
public class SiteFileFetch extends Thread { h&EF)~G  
h"ATRr^  
v}uzUY  
SiteInfoBean siteInfoBean = null; //文件信息Bean cnU()pd  
long[] nStartPos; //开始位置 !/E N  
long[] nEndPos; //结束位置 &v/R-pz  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 A7GWU{i  
long nFileLength; //文件长度 E*#5OT  
boolean bFirst = true; //是否第一次取文件 :gx]zxK  
boolean bStop = false; //停止标志 i [2bz+Z?  
File tmpFile; //文件下载的临时信息 >d^DN;p  
DataOutputStream output; //输出到文件的输出流 d PF*G$  
.2*h!d)E  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 6'1Lu1w  
public SiteFileFetch(SiteInfoBean bean) throws IOException '6f)^DYA'?  
{ Zy^ wS1io  
siteInfoBean = bean; m/aA q8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); )C0 y<:</  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); bMN ]co  
if(tmpFile.exists ()) :}Z Y*ind  
{ ~Z$Ro/;l  
bFirst = false; E.^F:$2  
read_nPos(); *XluVochrb  
} NV;T*I8O  
else L=kETJ:g  
{ $`"$ZI6[  
nStartPos = new long[bean.getNSplitter()]; 8:"s3xaO3  
nEndPos = new long[bean.getNSplitter()]; md /NMC \  
} '],G!U(  
;b0;66C8|  
)bK3%>H#  
}ykc AK3U  
} Y?JB%%WWI  
X "Q\MLy  
$&. rS.*  
public void run() c- "#  
{ (6X{ &  
//获得文件长度 j.SE'a_  
//分割文件 ~.J{yrJ&  
//实例FileSplitterFetch aoU5pftC  
//启动FileSplitterFetch线程 LTnbBh*mc  
//等待子线程返回 G5!!^p~  
try{ }ZfdjF8N!  
if(bFirst) FtybF  
{ -}"nb-RR\  
nFileLength = getFileSize(); x{$/|_  
if(nFileLength == -1) ffem7eQ  
{ PS`F  
System.err.println("File Length is not known!"); \kC'y9k  
} d(9C7GLC,  
else if(nFileLength == -2) 7$Pf  
{ -n6e;p]  
System.err.println("File is not access!"); DWk2=cO  
} h%Uq  
else (T =u_oe  
{ MQl GEJ  
for(int i=0;i<nStartPos.length;i++) >xIb|Yp)&  
{ *:Y9&s^6j  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 256V xn  
} QTjnXg?Ri  
for(int i=0;i<nEndPos.length-1;i++) U ]O>DM^'  
{ eY3<LVAX  
nEndPos = nStartPos[i+1]; X6n8Bi9Ik  
} L#`X;:   
nEndPos[nEndPos.length-1] = nFileLength; C@@PLsMg  
} D1Q]Z63,  
} ]|B_3* A  
p}|<EL}Z9  
H.)J?3  
//启动子线程 G PL^!_  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^6PKSEba  
for(int i=0;i<nStartPos.length;i++) ->J5|c#  
{ *!`bC@E  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y+$a}=cb0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ba9"IXKH  
nStartPos,nEndPos,i); }C5Fvy6uz  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /_tN&[  
fileSplitterFetch.start(); <(BIWm*  
} ])vqXjN6"  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8hZc#b;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,A>cL#Oe  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r ['zp=9  
nEndPos = " + nFileLength); /F}dC/W  
// fileSplitterFetch[nPos.length-1].start(); 'F7UnkKO|  
s"X0Jx}  
X92I==-w  
//等待子线程结束 nC#SnyUO  
//int count = 0; {"\pMY'7  
//是否结束while循环 X^d}eWP`I  
boolean breakWhile = false; \d QRQL{LL  
s~g]`/h$r  
U DHMNubB  
while(!bStop) #kAk d-QY6  
{ ?)e6:T(  
write_nPos(); 'o1lJ?~kH  
Utility.sleep(500); 4YCuO%  
breakWhile = true; j/hm)*\io  
68nPz".X  
X'usd$[ .  
for(int i=0;i<nStartPos.length;i++) uo7[T*<Q  
{ "2`/mt Mon  
if(!fileSplitterFetch.bDownOver) L+0O=zJF  
{ z#+Sf.  
breakWhile = false; W ZW:q  
break; EP6@5PNZ  
} KZ|p_{0&  
} ^- s`$lTp  
if(breakWhile) ,/UuXX  
break; ab*O7v  
W(PNw2  
u\=yY.   
//count++; -9$.&D|  
//if(count>4) \|$GBU  
// siteStop(); Qe]aI7Ei  
} 2z9N/SyN  
%wIb@km  
gA&`vnNP  
System.err.println("文件下载结束!"); sh}eKwh  
} cd)}a_9  
catch(Exception e){e.printStackTrace ();} 3q`Uq`t4mR  
} 57:27d0y  
T$tO[QR/  
4JGU`L:~  
//获得文件长度 /(Ryh6M  
public long getFileSize() FyRr/0C>  
{ J%8hf%! ud  
int nFileLength = -1; S|T*-?|  
try{ I3dUI~}u  
URL url = new URL(siteInfoBean.getSSiteURL()); je=XZ's,i~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); me@EKspX  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]wV_xZ)l^A  
]?~[!&h  
"qw.{{:tf  
int responseCode=httpConnection.getResponseCode(); [ejl #'*5  
if(responseCode>=400) BV]$= e'  
{ wQ\bGBks  
processErrorCode(responseCode); &u~%5;  
return -2; //-2 represent access is error -_BjzA|  
} .$ 5*v  
<Sp>uhet1  
:bz;_DZP  
String sHeader; BzI(  
Klqte*!  
%(g!,!l)  
for(int i=1;;i++) zCSLV>.F  
{ @;>Xy!G  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5>~q4t)6z}  
//Utility.log(in.readLine()); >;k~B  
sHeader=httpConnection.getHeaderFieldKey(i);  q #X[oVq  
if(sHeader!=null) |}<!O@<|  
{ n)R[T.E)+  
if(sHeader.equals("Content-Length")) HkyN$1s  
{ ;f2<vp;U  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CV *  
break; 2yndna-  
} %QX"oRMn0  
} ?^{Ey[)'(  
else | @p  
break; > `+lEob  
} qEnmms1  
} NucLf6  
catch(IOException e){e.printStackTrace ();} . "`f~s\G  
catch(Exception e){e.printStackTrace ();} OZE.T-{  
}62Q{>`  
$"`e^J9!!  
Utility.log(nFileLength); c.h_&~0qf  
<"!'>ZUt  
P;p;o]  
return nFileLength; B{lL}"++0  
} (t"rzH  
wy?Hp*E  
@gihIysf  
//保存下载信息(文件指针位置) qim|=  
private void write_nPos() 5S&^mj-9  
{ uN(N2m  
try{ a>Xq   
output = new DataOutputStream(new FileOutputStream(tmpFile)); *|)O  
output.writeInt(nStartPos.length); ^tl&FWF  
for(int i=0;i<nStartPos.length;i++) 1:Xg&4s  
{ !4mAZF b  
// output.writeLong(nPos); bE2{^5iG  
output.writeLong(fileSplitterFetch.nStartPos); A9M/n^61  
output.writeLong(fileSplitterFetch.nEndPos); RJLhR_t7n  
} jN2Xoh9  
output.close(); (eO_]<wmky  
} q4ej7T8  
catch(IOException e){e.printStackTrace ();} @{x+ln1r  
catch(Exception e){e.printStackTrace ();} e[t1V/ah  
} EtA,ow  
<`*v/D7\02  
U<U?&hB\@  
//读取保存的下载信息(文件指针位置) M,bcTa8  
private void read_nPos() ^%Fn|U\u  
{ 7dXh,sD  
try{ zM<yd#`yt8  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n_-k <3  
int nCount = input.readInt(); Y~I6ee,\  
nStartPos = new long[nCount]; =8x-+u5}rK  
nEndPos = new long[nCount]; 3vF-SgCV  
for(int i=0;i<nStartPos.length;i++) " {Nw K  
{ S{ qn^\0  
nStartPos = input.readLong(); "gq _^&  
nEndPos = input.readLong(); *uMtl'  
} rcG-V f@  
input.close(); 2%t!3F:  
} 9XW[NY#)#  
catch(IOException e){e.printStackTrace ();} fFd"21 >  
catch(Exception e){e.printStackTrace ();} a|@1RH>7H  
} LrnE6 U9  
D}EH9d  
\t]aBT,  
private void processErrorCode(int nErrorCode) "'mr0G9X  
{ _tVrLb7`s  
System.err.println("Error Code : " + nErrorCode); f`_6X~ p  
} ]\oE}7K%r  
f{f|frs  
'2c4 4F)i  
//停止文件下载 \DRYqLT`  
public void siteStop() F` ]s  
{ Xc7Qu?}  
bStop = true; p|R]/C0f  
for(int i=0;i<nStartPos.length;i++) Rj {D#5  
fileSplitterFetch.splitterStop(); QD*(wj  
-vBk,;^>  
({p @Ay  
} Op:7EdT#  
} ($:JI3e[;  
//负责部分文件的抓取 =/F\_/Xw  
**FileSplitterFetch.java S[o R q  
*/ xm}`6B^f  
package NetFox; QzA/HP a  
qAR}D~t  
J`{HMv  
import java.io.*; )z2hyGX  
import java.net.*; [bJAh ` I  
{t&+abY  
p&,2@(Q  
public class FileSplitterFetch extends Thread { 3W}xYYs] ^  
#ui7YUR=2  
] e]l08  
String sURL; //File URL fIcra  
long nStartPos; //File Snippet Start Position >,%7bq=T!  
long nEndPos; //File Snippet End Position NuKx{y}P  
int nThreadID; //Thread's ID OX/}j_8E^(  
boolean bDownOver = false; //Downing is over OPwO`pN  
boolean bStop = false; //Stop identical Oz_|pu  
FileAccessI fileAccessI = null; //File Access interface 3ZU<u;  
&y=~:1&f  
pM'AhzS  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oFUP`p%[  
{ a]|k w4  
this.sURL = sURL;  <IL$8a  
this.nStartPos = nStart; )9JuQ_ R  
this.nEndPos = nEnd; +{S^A)  
nThreadID = id; ce P1mO  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *ocbV`  
} >VWH bo  
nH]F$'rtA  
)x*pkE**c  
public void run() Gm1vVHAxv  
{ )0NE_AZ?  
while(nStartPos < nEndPos && !bStop) w/m ~#`a  
{ SgocHpyg  
obhq2sK  
d6hso  
try{ h *-j  
URL url = new URL(sURL); =1Mh %/y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $I-i=:}g  
httpConnection.setRequestProperty("User-Agent","NetFox"); zSFqy'b.M-  
String sProperty = "bytes="+nStartPos+"-"; xlWTHn!j  
httpConnection.setRequestProperty("RANGE",sProperty); xkzC+ _A  
Utility.log(sProperty); O;*.dR  
 p%6j2;D  
t'0dyQ%u  
InputStream input = httpConnection.getInputStream(); `[5QouPV  
//logResponseHead(httpConnection); sj?7}(s  
&Kgl\;}  
Qv@Z#  
byte[] b = new byte[1024]; |%~sU,Y\(  
int nRead; .5x+FHu7  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g+98G8 R  
{ *"D8E^9  
nStartPos += fileAccessI.write(b,0,nRead); enGjom  
//if(nThreadID == 1) -dn\*n5  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h .Iscr^~  
} Q0j$u[x6s  
Q+\?gU]  
D,rs)  
Utility.log("Thread " + nThreadID + " is over!"); &L S&O  
bDownOver = true; C%csQ m  
//nPos = fileAccessI.write (b,0,nRead); -a[] #v9  
} v*7lJNN.  
catch(Exception e){e.printStackTrace ();} ?Q)z5i'g#  
} eY1$s mh t  
} HwH Wi  
n8eR?'4  
uI I:Y{G  
//打印回应的头信息 0#rv.rJ{  
public void logResponseHead(HttpURLConnection con) !be6}  
{ iPxhDn<B  
for(int i=1;;i++) 3S'juHT e  
{ ]jz%])SzH  
String header=con.getHeaderFieldKey(i); +0Rr5^8u  
if(header!=null) '}{J;moB  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #D$vH  
Utility.log(header+" : "+con.getHeaderField(header)); YpT x1c-  
else YEWHr>&Z  
break; 7lvUIc?krW  
} av(d0E}}b  
} {g2cm'hD  
IPU'M*|Q  
.-;K$'YG  
public void splitterStop() 6}.B2f9  
{ Ds$8$1=L=k  
bStop = true; \]U@=w  
} \*H/YByTb  
dF{3 ~0+,  
j[XA"DZR<  
} 8z^?PZ/  
K2TO,J3 E  
!<!sB)  
/* kSH3)CC P  
**FileAccess.java b'^OW  
*//文件访问(定位,写) ${#5$U+kI  
package NetFox; ^j?\_r'j  
import java.io.*; L!3AiAnr  
W>Y8 u8  
6u3DxFiTm  
public class FileAccessI implements Serializable{ :z%vNKy1  
&+-ZXN  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S<f&?\wK=v  
RandomAccessFile oSavedFile; J_s?e#s  
long nPos; =z]&E 78Y  
K,[g<7X5  
2*Uwp; 0  
public FileAccessI() throws IOException O`O{n_o^u  
{ aC>r5b#:  
this("",0); #D3e\(  
} Hw5\~!FX  
0}qij  
/>XfK,c-  
public FileAccessI(String sName,long nPos) throws IOException Z&=K+P  
{ BBw`8!  
oSavedFile = new RandomAccessFile(sName,"rw"); L`YnrDZK  
this.nPos = nPos; ^Ois]#py  
oSavedFile.seek(nPos); ^>uzMR!q5  
} +15j^ Az  
h:(Jes2  
-gh',)R   
public synchronized int write(byte[] b,int nStart,int nLen) l!\C"f1o,  
{ +~=>72/r  
int n = -1; p 8BAan3  
try{ FyYQ4ov0&o  
oSavedFile.write(b,nStart,nLen); )1O *~%  
n = nLen; __c:$7B/4U  
} |v8>22y  
catch(IOException e) 9u1)Kr=e  
{ )_b #c+  
e.printStackTrace (); yw5MlZ4P=  
} 4hztYOhJ{  
EuqmA7s8A  
~)D2U:"^xm  
return n; C81+nR  
} ;)[RG\  
bvn?wK   
E$/`7p8)  
} 3=) /-l  
z-uJ+SA  
zzuDI_,/  
/* B4R!V!Z*  
**SiteInfoBean.java 'g#Ml`cm  
*/ fyx-VXu  
package NetFox; <"/Y`/  
E8=.TM]L  
%p"x|e  
public class SiteInfoBean { '/SMqmi  
SxC$EQ gL  
$I-$X?  
private String sSiteURL; //Site's URL q^Lj)zmnK  
private String sFilePath; //Saved File's Path ^o"9f1s5  
private String sFileName; //Saved File's Name P6S^wjk  
private int nSplitter; //Count of Splited Downloading File <(?ahO5  
y<k-dbr  
Gu~y/CE'  
public SiteInfoBean() N2;T\xx,  
{//nSplitter的缺省值为5 |A 7Yv  
//default value of nSplitter is 5 :D-d`OyjG>  
this("","","",5); }f^r@3Cb3  
} jfl7L"2  
b ^ ly  
J @"wJEF  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d7^:z%Eb|  
{ W+a>*#*  
sSiteURL= sURL; Pf6rr9  
sFilePath = sPath; W$N_GR'4  
sFileName = sName; s>~!r.GC  
this.nSplitter = nSpiltter; (G} *ho  
ag14omM-  
G?e,Q$  
} 6,uW{l8L  
CBs0>M/  
}k duN0  
public String getSSiteURL() C>N)~Ut  
{ 1]fqt[*)  
return sSiteURL; DkA cT[  
} Q0,]Q ]_  
-a]oN:ERb  
O\XN/R3  
public void setSSiteURL(String value) ,y,NVF  
{ i+Px &9o<9  
sSiteURL = value; ]0xbvJ8oK  
} [xk1}D  
@8|-  C  
9Z6] ];8E  
public String getSFilePath() U{h5uezD  
{ c%Yvj  
return sFilePath; g {8>2OK$c  
} <N=p_m 2T  
0^]E-Zf  
 ,L\OhT  
public void setSFilePath(String value) %D\TLY  
{ /Y:_qsO1  
sFilePath = value; B y6:  
} 9HRYk13ae  
J@H9nw+Q  
D._q'v<  
public String getSFileName() Sq UoXNw  
{ '_g8fz 3  
return sFileName; W&}R7a@:<~  
} MT$OjH'Q`  
7}%3Aw6]S  
Bg"b,&/^u  
public void setSFileName(String value) 4B<D.i ;}  
{ g*b%  
sFileName = value; %$Wt"~WE"O  
} '-4);:(^  
IJs*zzR  
PsEm(.z  
public int getNSplitter() ! 0fpD'f!n  
{ cA`R~o"  
return nSplitter; WA8Qt\Q  
} 6WgGewn  
jkFS=eonK  
>wdR4!x!?  
public void setNSplitter(int nCount) `{N0+n  
{ #|GP]`YT  
nSplitter = nCount; z~A||@4'  
} <!Nj2>  
} &rorBD 5aj  
E3_e~yu&  
6*S|$lo9B  
/* ^uMy|d  
**Utility.java Dvo.yn|kB  
*/ W~POS'1  
package NetFox; 1V+a;-?  
v~?d7p {  
IW Lv$bPZ/  
public class Utility { tcwE.>5O  
)2g\GRg6  
9|D!&=8   
public Utility() xQ* U9Wt;T  
{ )T(xQ2&r4  
R4_4FEo  
YCj"^RC^  
} ?2 u_E "  
0J7[n*~  
//线程睡眠 4G;+ETp  
public static void sleep(int nSecond) Fm`hFBKW  
{ >E#| H6gx  
try{ pOyM/L   
Thread.sleep(nSecond); zM|d9TS  
} =mn)].Wg  
catch(Exception e) 6U @3 xU`  
{ 7;5?2)+=6  
e.printStackTrace (); r'7;:  
} X<x"\Yk  
} ipQJn_:2  
* Od_Cl  
//日志 Agl5[{]E  
public static void log(String sMsg) !qV{OXdrB  
{ gLsl/G  
System.err.println(sMsg); zg.'  
} Kg VLXI6  
(Vf&,b@U_  
T8GxoNm  
public static void log(int sMsg) 0<>I\UN0b  
{ T@U_;v|rf  
System.err.println(sMsg); x4CrWm  
} L oe!@c  
} o*_[3{FU  
^ W eE%"  
al F*L  
/* GLB7h 9>  
**TestMethod.java 6Hi3h{  
*/ jJQ6]ucwa  
package NetFox; "6[' !rq0  
_'ltz!~  
pZ/x,b#.  
public class TestMethod { 7 }4T)k(a  
C;0H _  
4rO07)~l  
public TestMethod() >DBaKLu\  
{ ///xx/weblogic60b2_win.exe xlp^XT6#  
try{ @N7X(@O  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >~){KV1~  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -;a}'1HOE  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $ii/Q:w T"  
fileFetch.start(); y1p^ &9 U  
} "diF$Lj  
catch(Exception e){e.printStackTrace ();} `J|bGf#  
jX-v9eaA  
M`-#6,m3  
} J/>Y mi,  
jmxjiJKP  
EoD;'+d  
public static void main(String[] args) #~^#%G  
{ BD&JbH!(  
new TestMethod(); /csj(8^w  
} iBVV5 f  
} T6=,A }t-  
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