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http断点续传简单实现(java)

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/* zOR  
**SiteFileFetch.java ^L&hwXAO:  
*/ $u"t/_%  
package NetFox; =sG9]a<I  
import java.io.*; ]M|Iy~ X   
import java.net.*; +jcg[|-' /  
,+0>p  
9JHu{r"M  
public class SiteFileFetch extends Thread { 6?U2Et  
gA e*kf1  
Xa._  
SiteInfoBean siteInfoBean = null; //文件信息Bean RlU=  
long[] nStartPos; //开始位置 \JBJ$lBL  
long[] nEndPos; //结束位置 h9)QQPP  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 /J8'mCuC.  
long nFileLength; //文件长度 '-F }(9M  
boolean bFirst = true; //是否第一次取文件 Te`Z Qqb  
boolean bStop = false; //停止标志 rC>')`uk  
File tmpFile; //文件下载的临时信息 {1^9*  
DataOutputStream output; //输出到文件的输出流 u$c)B<.UR  
p]*BeiT#n%  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) <~BheGmmy  
public SiteFileFetch(SiteInfoBean bean) throws IOException jiPV ]aVN  
{ z.f~wAT@<  
siteInfoBean = bean; 2}P<}-?6  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 'l$<DcBj  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Ak!l}d  
if(tmpFile.exists ()) A &i  
{ 7Zl- |  
bFirst = false; hB#z8D  
read_nPos(); .!kqIx*3  
} |okS7.|IX  
else ,c:Fa)-  
{ ~Tv %6iaeE  
nStartPos = new long[bean.getNSplitter()]; Aj06"ep  
nEndPos = new long[bean.getNSplitter()]; v4}kmH1  
} 4  |$|]E  
gIR{!'  
9,|&+G$  
L3 M]06y  
} iP1u u  
Ws[[Me, =  
U!sv6=(y@  
public void run() 1]r+$L3  
{ irNGURLm  
//获得文件长度 !m"(SJn"  
//分割文件 Za{sT&(|  
//实例FileSplitterFetch ,4 ftQJ  
//启动FileSplitterFetch线程 L 6){wQ%c  
//等待子线程返回 hS4Ljyeg  
try{ "1rZwFI0l  
if(bFirst) JHN3 5a+  
{ Pm]6E[zC  
nFileLength = getFileSize(); z<~gv"  
if(nFileLength == -1) Xidt\08s  
{ ~y{(&7sM  
System.err.println("File Length is not known!"); CUOxx,V  
} 7kM_Ijd$  
else if(nFileLength == -2) zV {[0s  
{ )B@veso{  
System.err.println("File is not access!"); rvRtR/*?j  
} IAbK]kA  
else #`5 M( o  
{ \[&~.B  
for(int i=0;i<nStartPos.length;i++) ,[IN9W  
{ SE+K"faKQ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); e.eQZ5n~q`  
} iulM8"P  
for(int i=0;i<nEndPos.length-1;i++) TL(L[  
{ KYY~ YP  
nEndPos = nStartPos[i+1]; v2 [ l$  
} /ve8);cH\  
nEndPos[nEndPos.length-1] = nFileLength; H"8+[.xBh  
} kStWsc$;+T  
} B[F,D  
x,"'\=|s*  
vB, X)  
//启动子线程  hM2^[8  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'j];tO6GfC  
for(int i=0;i<nStartPos.length;i++) uQ#3;sFO  
{ !8]W"@qb  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GYot5iLg  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %&9tn0B  
nStartPos,nEndPos,i); v4sc  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D,+I)-k<  
fileSplitterFetch.start(); F7^d@hSV  
} :Vq gmn  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M:h~;+s  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ow=`tv$l  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )K\w0sjR  
nEndPos = " + nFileLength); = wNul"  
// fileSplitterFetch[nPos.length-1].start(); Y[x9c0  
['m@RJm+  
W&y%fd\&3  
//等待子线程结束 1tG,V%iCp  
//int count = 0; %(b`i C9  
//是否结束while循环 G8"L #[~  
boolean breakWhile = false; )Rla VAtM  
,WbO8#z+  
mfLS< /A  
while(!bStop) .EGZv (rz&  
{ EKf"e*|(L  
write_nPos(); ^<xpp.eY  
Utility.sleep(500); \}t(g}7T  
breakWhile = true; `bO+3Y'5  
Ps0'WRJnx  
^lB'7#7  
for(int i=0;i<nStartPos.length;i++) AEm?g$a  
{ S|Wv1H>  
if(!fileSplitterFetch.bDownOver) j2 "j Cv  
{ nm 66U4.@  
breakWhile = false; <pRb#G"  
break; J\XYUs  
} )DuOo83n["  
} ws4a(1  
if(breakWhile) hRSRz5 J}  
break; t#oJr2  
eu ~WFI  
3]0ETcT  
//count++; IZeWswz  
//if(count>4) GEy^*, d  
// siteStop(); 9>d$a2 nc  
} g+p?J.+  
dkJ+*L5  
)El#Ks5u  
System.err.println("文件下载结束!"); axnkuP(  
} 71nXROB  
catch(Exception e){e.printStackTrace ();} $+zev$f  
} %1a\"F![  
hf>JW[>Xo  
n_sCZ6uXEQ  
//获得文件长度 o6  
public long getFileSize() N54U [sy  
{ 2@Jw?+}vr  
int nFileLength = -1; |#$Wh+,*  
try{ FVsVY1  
URL url = new URL(siteInfoBean.getSSiteURL()); RvvK`}/6  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q&^ti)vB  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]H) x  
K[PIw}V$?:  
\MQ|(  
int responseCode=httpConnection.getResponseCode(); He. gl  
if(responseCode>=400) "CBe$b4  
{ Z.<OtsQN  
processErrorCode(responseCode); t.c XrX`k  
return -2; //-2 represent access is error zS18Kl  
} j*<H18^G  
v7T05  
#rqLuqw  
String sHeader; E"&fT!yi  
z '3  
2Q,e1' =  
for(int i=1;;i++) M?x/C2|  
{ |2AK~t|t  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); j%Y`2Ra  
//Utility.log(in.readLine()); V9NE kS  
sHeader=httpConnection.getHeaderFieldKey(i); & ,2XrXiFu  
if(sHeader!=null) 6<.Ma7)lA  
{ i[H`u,%+(  
if(sHeader.equals("Content-Length")) { :'#Ts<  
{ `$SX%AZA  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )FGm5-K@  
break; 4]u53`  
} NMM0'tY~  
} w0x, ~  
else ?V"X=B2  
break; >`Gys8T  
} 3iJ4VL7  
} Q3u P7j  
catch(IOException e){e.printStackTrace ();} m^@,0\F  
catch(Exception e){e.printStackTrace ();} c?"#x-<1s  
5;oWFl  
IM|VGT0  
Utility.log(nFileLength); i-~HT4iw  
z{Z'2,#  
4*d$o=wa  
return nFileLength; '@i/?rNi%N  
} rR&;2  
03L+[F&"?  
.Ebg>j:\  
//保存下载信息(文件指针位置) s6%%/|  
private void write_nPos() ?<bByxa  
{ SwpS6  
try{ k?3NF:Yy7  
output = new DataOutputStream(new FileOutputStream(tmpFile)); vdAaqM6D  
output.writeInt(nStartPos.length); }p$>V,u  
for(int i=0;i<nStartPos.length;i++) q asbK:}  
{ xDG8C39qrs  
// output.writeLong(nPos); gUwg\>UC  
output.writeLong(fileSplitterFetch.nStartPos); b/HhGA0  
output.writeLong(fileSplitterFetch.nEndPos); D/^yAfI  
} ZH;VEX  
output.close(); kL\ FY  
} S*VG;m #  
catch(IOException e){e.printStackTrace ();} ?%dsY\  
catch(Exception e){e.printStackTrace ();} *,q ?mO  
} C;];4[XR  
d5T M_ C  
~CCRs7V/L  
//读取保存的下载信息(文件指针位置) 1p=^I'#  
private void read_nPos() Md mS  
{ {.qeVE{  
try{ 5P-7"g ca  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n*{aN}auJ  
int nCount = input.readInt(); ?j9J6=2  
nStartPos = new long[nCount]; 0+%{1JkJq  
nEndPos = new long[nCount]; q">lP (t  
for(int i=0;i<nStartPos.length;i++) *UhYX)J  
{ uOUgU$%zqH  
nStartPos = input.readLong(); 4<[,"<G~3  
nEndPos = input.readLong(); ?-%Q[W  
} =+;l>mn?O  
input.close(); 8Y?zxmwn]  
} N^z4I,GV(  
catch(IOException e){e.printStackTrace ();} E j`  
catch(Exception e){e.printStackTrace ();} o|O730"2F  
} z)p( l!  
ui%B|b&&  
c u*8,*FU  
private void processErrorCode(int nErrorCode) 6RV42r^pf  
{ lHQ:LI  
System.err.println("Error Code : " + nErrorCode); `,a6su (?  
} 67/JsL  
no_;^Ou?  
&0cfTb)dG  
//停止文件下载 .P(k |D&  
public void siteStop() p^QZGu-.W  
{ BBuI|lr  
bStop = true; /}A"F[5  
for(int i=0;i<nStartPos.length;i++) n]:Xmi8p  
fileSplitterFetch.splitterStop(); |`vwykhezO  
7niZ`doBA  
>L[n4x\  
} kT)[<`p  
} V&)Jvx}^  
//负责部分文件的抓取 v6=pV4k9  
**FileSplitterFetch.java -E{D' X  
*/ 1oU/gm$7\q  
package NetFox; PJ}d-   
8 p D$/  
`t[b0; 'OH  
import java.io.*; m#6RJbEz  
import java.net.*; *g7BR`Bt]z  
Y\s ge  
4P(muOS  
public class FileSplitterFetch extends Thread { X.}i9a 6  
'kU5  
w]L^)_'Th  
String sURL; //File URL Xb#!1hA  
long nStartPos; //File Snippet Start Position E,IeW {6s  
long nEndPos; //File Snippet End Position h;" 9.  
int nThreadID; //Thread's ID C\ 2rSyo  
boolean bDownOver = false; //Downing is over x6yYx_  
boolean bStop = false; //Stop identical MX Qua:&HW  
FileAccessI fileAccessI = null; //File Access interface wNc.z*+O"H  
xs#g  
>,%or cN  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #<h//<  
{ c_"=G#^9@i  
this.sURL = sURL; {BV0Y.O  
this.nStartPos = nStart; E;v#'  
this.nEndPos = nEnd; m8[XA!,  
nThreadID = id; xf2|9Tqt  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7m.#No>^  
} yuP1*QJ%  
zm>^!j !  
rfo7\'yk  
public void run() m&S *S_c  
{ suKr//_  
while(nStartPos < nEndPos && !bStop) EKu%I~eM  
{ [G!#y  
hp|.hN(kS]  
pW&K=,7|  
try{ tzIcR #Z  
URL url = new URL(sURL);  iYaS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *Wj]e%  
httpConnection.setRequestProperty("User-Agent","NetFox"); N!~O~ Eo3  
String sProperty = "bytes="+nStartPos+"-";  'ug:ic  
httpConnection.setRequestProperty("RANGE",sProperty); deLLqdZa  
Utility.log(sProperty); w'uB&z4'  
6W\G i>  
LX'z7fh  
InputStream input = httpConnection.getInputStream(); {,NF'x4$  
//logResponseHead(httpConnection); [?>\]  
r>ziQq8C&  
X!xmto  
byte[] b = new byte[1024]; gN@|lHbU  
int nRead; k~%j"%OB  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wK]p`:3  
{ B,S~Idr}  
nStartPos += fileAccessI.write(b,0,nRead); bZ 0{wpeK=  
//if(nThreadID == 1) C))x#P36  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;_X2E~i[  
} ;cEoc(<?  
;F_pF+&q  
=\`iC6xP}  
Utility.log("Thread " + nThreadID + " is over!"); /@w w"dmqU  
bDownOver = true; rdH3!  
//nPos = fileAccessI.write (b,0,nRead); m?O~(6k@C  
} J?C#'2 /   
catch(Exception e){e.printStackTrace ();} n58yR -"  
} 3N[Rrxe2  
} Ce/l[v  
8bJj3vr  
% * k`z#b  
//打印回应的头信息 zq(4@S-TU  
public void logResponseHead(HttpURLConnection con) *^oL$_Y  
{ Z% DJ{!Hnh  
for(int i=1;;i++) @{>0v"@  
{ pC~ M5(F_  
String header=con.getHeaderFieldKey(i); 5>6:#.f%!e  
if(header!=null) : X}n[K  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9Iu"DOxX%  
Utility.log(header+" : "+con.getHeaderField(header)); .H@b zm  
else Cs4ks`Z18  
break; ~^TH5n  
} R53^3"q~  
} Xp+lpVcJ  
1/f{1k  
lqTc6@:D  
public void splitterStop() r2*8.j51  
{ NkV81?  
bStop = true; A?bqDy  
} uH&B=w  
t6uYFxE  
ds2%i  
} ZkJLq[:cM  
VqUCcT  
B*(BsXQLY  
/* M5a&eO  
**FileAccess.java xa'^:H $X  
*//文件访问(定位,写) *Z$W"JP  
package NetFox; yJ/YK  
import java.io.*; |}?H$d  
 + \]-"  
7gcR/HNeF  
public class FileAccessI implements Serializable{ _N {4Rs0  
%8H$62w]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uPq@6,+  
RandomAccessFile oSavedFile; z/]]u.UP  
long nPos; $1$0M  
M1]}yTCd  
R< L =&I  
public FileAccessI() throws IOException fK6[ p&  
{ "}"/d(  
this("",0); C :An  
} mW$Oi++'d  
:R`e<g~4  
5 JlgnxRq  
public FileAccessI(String sName,long nPos) throws IOException m lxtey6H3  
{ Y&1N*@YP  
oSavedFile = new RandomAccessFile(sName,"rw"); '?jsH+j+  
this.nPos = nPos; tI@aRF=p]2  
oSavedFile.seek(nPos); XzPOqZ`Nv  
} F$-fj "jC  
t.+)g-X  
J'ZC5Xr  
public synchronized int write(byte[] b,int nStart,int nLen) #UE}JR3g  
{ 'ieTt_1.G  
int n = -1; !?>QN'p.b  
try{ {cUGksz]}  
oSavedFile.write(b,nStart,nLen); oI!"F=?&6  
n = nLen; otdRz<C  
} z4 <_>)p  
catch(IOException e) Oi'y0S~ g  
{ R7"7 Rx   
e.printStackTrace (); Ab]tLz|Z  
} 2i0;b|-=  
!u'xdV+bf  
"F}dZ  
return n; z#Fel/L`O  
} q 'd]  
]ag{sU@#  
Q5}XD  
} x|yJCs>  
EjFn\|VK  
",&QO 7_  
/* F b?^+V]9  
**SiteInfoBean.java (3K3)0fy  
*/ ">G*hS  
package NetFox; t=X=",)f  
HE35QH@/`  
.^M#BAt2  
public class SiteInfoBean { R:+'"dBge  
Ge/K.]>i  
D+v?zQw  
private String sSiteURL; //Site's URL 8 R%<~fq r  
private String sFilePath; //Saved File's Path SswcO9JCX3  
private String sFileName; //Saved File's Name &TY74 w*  
private int nSplitter; //Count of Splited Downloading File Xy%||\P{)  
{Ef.wlZ  
ii_kgqT^  
public SiteInfoBean() }LCm_av  
{//nSplitter的缺省值为5 <T?-A}0uO  
//default value of nSplitter is 5 8^^ 1h  
this("","","",5); !(7m/R  
} kc0MQ TJU  
Pn^`_  
nShXY6bA  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pbEWnx_  
{ g<(!>:h  
sSiteURL= sURL; 0VcHz$ 6  
sFilePath = sPath; "b~C/-W I  
sFileName = sName; } A+ncabm  
this.nSplitter = nSpiltter; "T_9_6tH  
a7c`[   
/='0W3+o*L  
} U+*l!"O,  
ZT@=d$Z&t  
|,@D <  
public String getSSiteURL() v@|<.  
{ ~h_ _Y>  
return sSiteURL; }3A~ek#*~  
} y~\ujp_5w  
U+qyS|i  
 {ibu 0  
public void setSSiteURL(String value) vRH^en  
{ 'KIT^k0"Ih  
sSiteURL = value; C{}PO u  
} bJetqF6 n  
X5YOxMq  
eM_;rMCr}  
public String getSFilePath() [:.wCG5  
{ |,p"<a!+{w  
return sFilePath; u{_,S3Aa  
} gy%.+!4>v`  
Fy"M 4;7  
Et!J*{s  
public void setSFilePath(String value) &n;*'M  
{ {QM rgyQ E  
sFilePath = value; EP#2it]0]  
} )I[f(f%W7  
`v!. ,Yr  
% Y%r2  
public String getSFileName() p~@,zetS  
{ h\UKm|BZ  
return sFileName; lwq:0Rj@Q  
}  s[{[pIH  
I{OizBom  
beBG40  
public void setSFileName(String value) aaig1#a@1b  
{ u0Wt"d-=  
sFileName = value; <HoCt8>U  
} zI4rAsysL  
o[cOL^Xd1  
KR#,6  
public int getNSplitter() !nSa4U,$w<  
{ V.&F%(L  
return nSplitter; /Ne#{*z)hO  
} 3T8d?%.l  
f-enF)z  
84QOW|1  
public void setNSplitter(int nCount) a$|U4Eqo  
{ k}v`UiGM  
nSplitter = nCount; v1 8<~  
} %jzTQ+.%]^  
} VIz(@  
$U*eq [  
llP V{  
/* KE3`5Y!  
**Utility.java /IWA U)A0  
*/ YK6LJv}  
package NetFox; <4; nq~  
04-_ K  
FL' }~il  
public class Utility { 9$\s v5  
g8N"-j&@  
ksC_F8Q+  
public Utility() aO(PVS|P  
{ 2.aCo, Kb;  
QcL@3QC  
U0_)J1Yp  
} %PYO9:n  
(U.Go/A#wE  
//线程睡眠 ;|WUbc6&g  
public static void sleep(int nSecond) OM[MRZEh G  
{ D{N8q^Cs9  
try{ GK}52,NM  
Thread.sleep(nSecond); M!J7Vj?Ps  
} + f67y  
catch(Exception e) ri{*\LV*@  
{ P:'wSE91  
e.printStackTrace (); D!~ Y"4<  
} btuG%D{a^  
} Bib<ySCre  
)$:1e)d  
//日志 eL SzGbKf  
public static void log(String sMsg) Ma|4nLC}  
{ t,7%| {  
System.err.println(sMsg); ekhv.;N~  
} 3:x(2 A  
A0Mjk  
X(ph$,[  
public static void log(int sMsg) t Ly:F*1i  
{ V O:4wC"7  
System.err.println(sMsg); R'v~:wNTNs  
} &IQ=M.!r  
} uI-T]N:W8x  
P+j=]Yg  
>}V?GK36  
/* tVRN3fJH  
**TestMethod.java `3F#k[IR  
*/ /Sj~lHh  
package NetFox; +]%S}<R  
T'5{p  
j9NF|  
public class TestMethod { b)I-do+  
5*$yY-A  
O=2|'L'h!  
public TestMethod() I_<VGU k  
{ ///xx/weblogic60b2_win.exe 6j(/uF4!#  
try{ vUpAW[[  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g0grfGo2p  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0)WAQt\/  
SiteFileFetch fileFetch = new SiteFileFetch(bean); P4[kW}R  
fileFetch.start(); `NW/Z/_  
} V.*TOU{{xh  
catch(Exception e){e.printStackTrace ();} BD C DQ  
E@SFK=`  
=K`.$R  
} \1<'XVS  
L0wT:x*  
^o3,YH  
public static void main(String[] args) |q w0:c=7!  
{ L0g+RohW  
new TestMethod(); GY]P(NU  
} RM|J |R  
} tY)L^.*7  
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