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http断点续传简单实现(java)

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/* 8# IEE|1  
**SiteFileFetch.java Yu:($//w  
*/ w:2yFC  
package NetFox; @%!Gj{   
import java.io.*; Mo\nY5  
import java.net.*; vH@$?b3VP  
5uU{!JuSa  
E//*bmww  
public class SiteFileFetch extends Thread { USH>`3  
+1Pu29B0  
G$s=P  
SiteInfoBean siteInfoBean = null; //文件信息Bean g_?bWm4br  
long[] nStartPos; //开始位置 ,irc=0M(  
long[] nEndPos; //结束位置 lM.k *`$  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Kir|in)r0  
long nFileLength; //文件长度 :@S=0|:j  
boolean bFirst = true; //是否第一次取文件 02C;  
boolean bStop = false; //停止标志 OT#foP   
File tmpFile; //文件下载的临时信息 Pt7C/ qM/  
DataOutputStream output; //输出到文件的输出流 'grb@+w(  
@'"7[k!y;  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) lr$,=P`  
public SiteFileFetch(SiteInfoBean bean) throws IOException )6 K)UA  
{ Hnf?`j>  
siteInfoBean = bean; Z|j\_VKhl  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); p7[&H/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); a KIS%M#Y  
if(tmpFile.exists ()) 4|NcWpaV7  
{ l#a*w  
bFirst = false; Pz-=Eq  
read_nPos(); #!4`t]E<  
} Mm%b8#Fe!  
else xI8v'[3  
{ hroRDD   
nStartPos = new long[bean.getNSplitter()]; F8B:P7I  
nEndPos = new long[bean.getNSplitter()]; 8},fu3Z  
} uKo4nXVtp  
mWuhXY^Q  
;(IAhWE?7  
 =h}PL22  
} '>>@I~<\  
n;k B_i*l  
I bE Nq  
public void run() w^/"j_p@  
{ vr$z6m ^  
//获得文件长度 $'bb)@_  
//分割文件 M B,Z4 ^  
//实例FileSplitterFetch 94.M 8  
//启动FileSplitterFetch线程 z_a7HCG2  
//等待子线程返回 i>;6Z s>S  
try{ C12y_E8Un  
if(bFirst) D66!C{  
{ rm,h\  
nFileLength = getFileSize(); `(8RK  
if(nFileLength == -1) uQkQ#'e|  
{ ,J'@e+jV  
System.err.println("File Length is not known!"); ||.Ve,<:  
} ;o.,vQF*  
else if(nFileLength == -2) >u=nGeO  
{ k_1o j[O  
System.err.println("File is not access!"); #DcK{|ty  
} cQh=Mri]  
else s$VLVT*6  
{ op|x~Thf  
for(int i=0;i<nStartPos.length;i++) qGie~S ##  
{ y |Tv;v1L  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); s4>xh=PoJ  
} [q!)Y:|u_>  
for(int i=0;i<nEndPos.length-1;i++) IF3V5Q  
{ _x?S0R1  
nEndPos = nStartPos[i+1]; VM"*@T  
} 7s1LK/R|u  
nEndPos[nEndPos.length-1] = nFileLength; NjSjE_S2B8  
} Fprhu;h  
} cS"PIelR  
{1W,-%  
 U66oe3W  
//启动子线程 K|.!)L  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .,SWa;[iB  
for(int i=0;i<nStartPos.length;i++) \K(# r=  
{ dH0wVI<z  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RTTEAh:.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'w}/ o+x@  
nStartPos,nEndPos,i); &qZ:"k  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @fSqGsSk  
fileSplitterFetch.start(); ,YmTx  
} )X-TJ+d  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mOx>p"n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~ *P9_<  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U6oab9C?k  
nEndPos = " + nFileLength); }ABHGr5[  
// fileSplitterFetch[nPos.length-1].start(); ZAMS;e+e  
,U'E!?=:VS  
Y--Uo|H  
//等待子线程结束 xsXf_gGu  
//int count = 0; )"<:Md$7  
//是否结束while循环 p\M\mK  
boolean breakWhile = false; y?{YQ)fj  
PWs=0.Wj  
R~(_m#6`:  
while(!bStop) uJ/ &!q<3  
{ Cg&cz]*q|  
write_nPos(); -44''w?z  
Utility.sleep(500); !u|s| 6{\  
breakWhile = true; Sc&p*G  
R8R,!3 N  
<4P"1#nHQ+  
for(int i=0;i<nStartPos.length;i++) u\|Ys  
{ Fv9n>%W&  
if(!fileSplitterFetch.bDownOver) xGymQ|y84  
{ 9$P*fx&m  
breakWhile = false; MM4Eq>F/  
break; CEp @-R  
} > v ]-B"Y  
} O PVc T  
if(breakWhile) XRR`GBI  
break; X7& ^"|:  
p*(]8pDC  
V .VV:`S  
//count++; Fs)m;C  
//if(count>4) qct:xviH<|  
// siteStop(); a,*~wmg  
} 1]Gp \P}  
UI.>BZ6}  
uSK<{UT~3  
System.err.println("文件下载结束!"); $WK~|+"{>  
} 3L(vZ2&  
catch(Exception e){e.printStackTrace ();} z8hAZ?r1`  
} :HG5{zP  
rui]_Fn]I  
>vY5%%}  
//获得文件长度 j /=4f�  
public long getFileSize() .[4Dv t|>6  
{ F^|4nBd*ub  
int nFileLength = -1; 6)~J5Fb  
try{ 2s:$4]K D  
URL url = new URL(siteInfoBean.getSSiteURL()); }N<> z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G8_|w6  
httpConnection.setRequestProperty("User-Agent","NetFox"); xu7Q^F#u  
S?Z"){  
vS'5Lm  
int responseCode=httpConnection.getResponseCode(); p-o!K\o-1  
if(responseCode>=400) L5yv}:.U  
{ iSxuor ^;  
processErrorCode(responseCode); VVyms7 VN  
return -2; //-2 represent access is error ~!{y3thZ  
}  MUd 9R  
_ -/<bO  
AjA.="3  
String sHeader; Kwa$5qZI  
-Lbi eS%  
B7!dp`rPp  
for(int i=1;;i++) w>ap8><4  
{  @Iy&Qo  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1ti4 ZM  
//Utility.log(in.readLine()); B)4>:j:{?W  
sHeader=httpConnection.getHeaderFieldKey(i); D#G(&<Q  
if(sHeader!=null) {Jj vF  
{ B#U:6Ty  
if(sHeader.equals("Content-Length")) =Wj{J.7mf]  
{ IDpW5Dc  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2E":6:Wsw  
break; +sc--e?  
} eDPmUlC+-  
} !Yan}{A,  
else 5<y pK`Kq  
break; x:O;Z~ |.  
} .;xt{kK  
} oj1,DU  
catch(IOException e){e.printStackTrace ();} ;<=B I!  
catch(Exception e){e.printStackTrace ();} n@Ar%%\  
rpu{YC1C%  
u`2[V4=L  
Utility.log(nFileLength); 3'zm)SXJ  
fudIUG.  
*To 5\|  
return nFileLength; `Mxi2Y{vp  
} Y([YDn  
h^}r$k_n  
TE.O@:7Z  
//保存下载信息(文件指针位置) i!JVGs  
private void write_nPos() Z/S7ei@56  
{ c)tG1|Og]  
try{ +$F_7Hx  
output = new DataOutputStream(new FileOutputStream(tmpFile)); hvS4"% \  
output.writeInt(nStartPos.length); *uq}jlD`!  
for(int i=0;i<nStartPos.length;i++) d;$<K  
{ nd[{DF?)/  
// output.writeLong(nPos); TEK]$%2  
output.writeLong(fileSplitterFetch.nStartPos); c= }#8d.  
output.writeLong(fileSplitterFetch.nEndPos); *"pf3x6  
} u#l@:p  
output.close(); yLI)bn!"  
} :6*FnKD  
catch(IOException e){e.printStackTrace ();} /b)V=mcR  
catch(Exception e){e.printStackTrace ();} `;9Z?]}`  
} w<ol$2&B  
[Ie;Jd>gG  
}op0`-Xb  
//读取保存的下载信息(文件指针位置) A80r@)i  
private void read_nPos() 5Cp6$V|/kv  
{ {iI" Lt  
try{ QD}'2{M!  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !4(X9}a  
int nCount = input.readInt(); uq>\pO&P  
nStartPos = new long[nCount]; VR@V3 ~  
nEndPos = new long[nCount]; GYX/G>-r  
for(int i=0;i<nStartPos.length;i++) SGd[cA Ko  
{ O{^ET:K@  
nStartPos = input.readLong(); e7(iMe  
nEndPos = input.readLong(); .<<RI8A  
} t@`w}o[#  
input.close(); S<f]Y4A&  
} LB1AjNJ  
catch(IOException e){e.printStackTrace ();} =q%Q^  
catch(Exception e){e.printStackTrace ();} KZ"&c~[  
} R<J1bH1n3  
}W:Rg}v  
<@DF0x!  
private void processErrorCode(int nErrorCode) 1gA9h-'w  
{ ne=?'e4  
System.err.println("Error Code : " + nErrorCode); ZB)`*z>*  
} O M]d}}=Y  
xH\#:DLY  
Rd?8LLz  
//停止文件下载 ']N1OVw^vf  
public void siteStop() 4@b~)av)  
{ oTtJ]`T  
bStop = true; M x/G^yO9  
for(int i=0;i<nStartPos.length;i++)  T\(w}  
fileSplitterFetch.splitterStop(); jvI!BZ  
qHZ!~Kq,"'  
ju jhK'\  
} lo1<t<w`  
} 4jOq.j  
//负责部分文件的抓取 i#&iT P`  
**FileSplitterFetch.java K@JGGgrE`!  
*/ *{t]fds  
package NetFox; Ihd{ @6m  
Hwz.5hV"  
tJ"8"T#6Vr  
import java.io.*;  iI!MF1  
import java.net.*; `b11,lg  
?06+"Z  
BHNcE*U}@?  
public class FileSplitterFetch extends Thread { _~l*p"PL<  
X j>?P/=Z  
%4=r .9  
String sURL; //File URL XF6ed  
long nStartPos; //File Snippet Start Position AHo4% 5  
long nEndPos; //File Snippet End Position 'ie+/O@G  
int nThreadID; //Thread's ID F*}.0SQ  
boolean bDownOver = false; //Downing is over TFQX}kr]  
boolean bStop = false; //Stop identical ;JD/4:  
FileAccessI fileAccessI = null; //File Access interface m]7oTmS  
!OCb^y  
Y"n$d0%  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException > [%ITqA$  
{ |7pi9  
this.sURL = sURL; P^)J^{r  
this.nStartPos = nStart; 0b)q,]l]  
this.nEndPos = nEnd; QY^v*+lr\  
nThreadID = id; `y^tCJ2u*  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2C@ui728  
} ;Y^.SR"  
yUyx&Y/  
JZUf-0q  
public void run() oEuV&m|yX  
{ -4=\uvYh  
while(nStartPos < nEndPos && !bStop) J"$Y`;  
{ MYlPG1X=?  
=o+js;3  
G@N-+  
try{ q83!PI  
URL url = new URL(sURL); A*a:#'"*N  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z8vR/  
httpConnection.setRequestProperty("User-Agent","NetFox"); A7hWAq  
String sProperty = "bytes="+nStartPos+"-";  ds#om2)  
httpConnection.setRequestProperty("RANGE",sProperty); FQgc\-8tm  
Utility.log(sProperty); skeXsls  
mC,:.d  
1UwpLd  
InputStream input = httpConnection.getInputStream(); K]Rb~+a<  
//logResponseHead(httpConnection); ~\QN.a   
'ZXd |WI  
v6#i>n~x,  
byte[] b = new byte[1024]; 3m]8>1e1"  
int nRead; .zQ'}H1.C  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3yXSv1  
{ <W2 YG6^i  
nStartPos += fileAccessI.write(b,0,nRead); Tg;1;XM%  
//if(nThreadID == 1) xfFsW^w  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \5q0nB@i5y  
} FhAYk  
Y *?hA'  
}%lk$g';  
Utility.log("Thread " + nThreadID + " is over!"); *`WD/fG  
bDownOver = true; Ce.*yO<-  
//nPos = fileAccessI.write (b,0,nRead); 8_h:_7e  
} Y2&hf6BE  
catch(Exception e){e.printStackTrace ();} #BOLq`9 f  
} F./$nwb  
} tg#d.(  
^a #  
@Z[XV"w|  
//打印回应的头信息 & Do|Hw  
public void logResponseHead(HttpURLConnection con) %&\DCAFk  
{ dxk~  
for(int i=1;;i++) r(i!".Z  
{ rpn&.#KS  
String header=con.getHeaderFieldKey(i); 7Pp~)Kq=  
if(header!=null) 9zac[t no  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =Dc9|WuHN  
Utility.log(header+" : "+con.getHeaderField(header)); mJFFst,  
else ^oH!FN`;{  
break; lDF26<<\`  
} 5 cz6\A&  
} Ew$-,KC[  
=CGB}qU l0  
?<h|Q~JH  
public void splitterStop() F2WMts  
{ gVU&Yl~/^  
bStop = true; oV,lEXz  
} :j[a X7Sq2  
Y1s3 >`  
y1*z," dx  
} qytH<UB  
y_A7CG"^  
)uxXG `,h  
/* n.tJ-l5[  
**FileAccess.java 5l,Q=V^@l  
*//文件访问(定位,写) YdiXj |k+  
package NetFox; ~h@<14c{X  
import java.io.*; K.I  \E  
` 8OA:4).  
=[x @BzH  
public class FileAccessI implements Serializable{ BzyzOtBp3L  
," ~4l&  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /Q*cyLv  
RandomAccessFile oSavedFile; l! 9G  
long nPos; I15g G.)  
vddh 2G  
x"xtILrI  
public FileAccessI() throws IOException o^b4l'&o  
{ qw mZOR#  
this("",0); =h/0k y  
} tW7*(D  
q[T='!Z\  
Xh*p\ $  
public FileAccessI(String sName,long nPos) throws IOException PN @[k:5(  
{ FdVWj 5 $a  
oSavedFile = new RandomAccessFile(sName,"rw"); {8a s _  
this.nPos = nPos; ' *x?8-KP  
oSavedFile.seek(nPos); 6:o?@%  
} EPMdR66  
]&kzIxh  
a}]zwV&  
public synchronized int write(byte[] b,int nStart,int nLen) JkMf+ !  
{ 7<?~A6  
int n = -1; )s';m$  
try{ .Lc<1s  
oSavedFile.write(b,nStart,nLen); I];Hx'/<~  
n = nLen; 5 LZ+~!2+  
} ?[K \X  
catch(IOException e) beM}({:`  
{ Gj}P6V _  
e.printStackTrace (); |( =`l  
} jSyF]$"  
1*!`G5c,}  
5$ra4+k0  
return n; MxXu&.| _  
} i C nWb  
T;u>]"S  
L*VO2YI  
} I}aiy.l  
k^IC"p Uc  
XNU[\I  
/* oKJj?%dHK9  
**SiteInfoBean.java k8;  
*/ }"'^.FG^_  
package NetFox; B0KZdBRx}  
HZ1e~IIw  
_"PT O&E  
public class SiteInfoBean { ZMHb  
Bk~lE]Q3c7  
~8-Z=-  
private String sSiteURL; //Site's URL )bqfj>%#c  
private String sFilePath; //Saved File's Path pOCLyM9c  
private String sFileName; //Saved File's Name  wv2  
private int nSplitter; //Count of Splited Downloading File rmW,#  
62&(+'$n  
R18jju>Zr  
public SiteInfoBean() ov=[g l  
{//nSplitter的缺省值为5 L//Z\xr|  
//default value of nSplitter is 5 Wh:SZa|  
this("","","",5); ['MG/FKuv  
} }' mBqn  
A3p@hQl  
-$E_L :M  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8} \Lt  
{ m"~^-mJ-  
sSiteURL= sURL; 9ZL3p!  
sFilePath = sPath; @LS*WJ< w-  
sFileName = sName; );wSay>%(  
this.nSplitter = nSpiltter; ^1vh5D  
1@ )8E`u  
M%dXy^e  
} JRkC~fv  
4ey m$UWw  
;[]{O5TB  
public String getSSiteURL() :!M/9D*}0  
{ #ra~Yb-F  
return sSiteURL; V fJYYR  
} vs/.'yD/C  
%pNK ?M+  
-v4kW0G  
public void setSSiteURL(String value) a W`q  
{ _-&\~w  
sSiteURL = value; ~Cx07I_lf  
} [lpzUB}<Yp  
.$/Su3]K/  
C:/O]slH  
public String getSFilePath() U5]{`C0H?  
{ CBA MAr  
return sFilePath; P {x`eD0  
} bsw0+UY=9  
0*MY4r|-  
V]cD^Fqp  
public void setSFilePath(String value) wuCiO;w  
{ <FIc!  
sFilePath = value; ZR<T\w  
} QCFLi n+r  
 `Nn=6[]  
Z5re Fok  
public String getSFileName() gnW `|-:\  
{ <=A1d\   
return sFileName; kh /n|2  
} 8<C u S  
RU3:[ (7  
WG8}}`F|  
public void setSFileName(String value) LfEeFF=#n  
{ 7q<2k_3<  
sFileName = value; &13qlc6  
} k{<]J5{7  
f"zXiUV  
}>I|\Z0I  
public int getNSplitter() )<bgZ, v  
{ 5o 4\Jwt  
return nSplitter; D<5;4Mb  
} v /{LC4BF  
luYkC@I@a  
XBE+O7  
public void setNSplitter(int nCount) A*jU&3#  
{ M=$ qus  
nSplitter = nCount; :DTKZ9>2D  
} 095:"GvO  
} ;LRY h?  
S"ZH5O(  
JsohhkJNGi  
/* C?jk#T  
**Utility.java >58N P1[k  
*/ pj:s+7"t  
package NetFox; 9P;}P! W  
xT7JGQ[|  
P` Hxj> {  
public class Utility { InnjZ>$  
Gf'qPLK0  
G+2!+N\P  
public Utility() u`I&&  
{ ;i*<HNQ  
| +osEHC  
"]\sw"zO?  
} D#}t)$"  
n qSjP5  
//线程睡眠 ME"B1 Se\  
public static void sleep(int nSecond) n1+1/  
{ #zflU99d  
try{ F !DDlYUz.  
Thread.sleep(nSecond); LT7C>b  
} -FRMal4Pg0  
catch(Exception e) |[apLQ6  
{ h"Qp e'D}  
e.printStackTrace (); &[u%ZL  
} U$+EUDFi3_  
} ~d]X@(G&  
b&[bfM<  
//日志 \ng!qN  
public static void log(String sMsg) `}t<5_  
{ qxKW% {6o  
System.err.println(sMsg); {j$:9  H  
} 2P3,\L  
[B<htD&  
0c6b_%Rd  
public static void log(int sMsg) KE>|,U r  
{ I`k%/ei38  
System.err.println(sMsg); xQLVFgd  
} 1iNq|~  
} Vwxb6,}Z  
P2la/jN  
bMe/jQuL.$  
/* &QHZ]2%U  
**TestMethod.java gR7in!8  
*/ D%[yAr;r  
package NetFox; mX8k4$z  
.[mI9dc  
Hw"Lo Vh  
public class TestMethod { r<< ]41  
t&5N{C:  
O5X@'.#rU  
public TestMethod() in}d(%3h  
{ ///xx/weblogic60b2_win.exe z~8`xn,  
try{ JZ=ahSi  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gY!+x=cx0  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [;6,lI}  
SiteFileFetch fileFetch = new SiteFileFetch(bean); C_CUk d[  
fileFetch.start(); (*qMs)~]B  
} >\f'QQ  
catch(Exception e){e.printStackTrace ();} 4FwtC"G3  
7]\_7L|>]  
h 8Shf"  
} g$X4ZRSel  
b&wyp@k  
KZeaM  
public static void main(String[] args) ^w|D^F=o  
{ SZ$~zT;c  
new TestMethod(); K=Q<G:+&V  
} Bs?B\k=  
} eKpWFP 0  
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