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http断点续传简单实现(java)

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/* 00pHnNoxW  
**SiteFileFetch.java 6!Isz1.re  
*/ 1xtbhk]D  
package NetFox; Vxgc|E^J  
import java.io.*; ^U_jeAuk8[  
import java.net.*; 6ldDt?iSg  
fQx 4/4j  
SwP h-6  
public class SiteFileFetch extends Thread { b'-gy0  
5 ?vIkf  
M(3E b;`   
SiteInfoBean siteInfoBean = null; //文件信息Bean 6 *8Ge  
long[] nStartPos; //开始位置 gieX`}  
long[] nEndPos; //结束位置 U |4% ydG  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 *gT TI;:  
long nFileLength; //文件长度 hcaH   
boolean bFirst = true; //是否第一次取文件 %)aDh }  
boolean bStop = false; //停止标志 E 0oJ|My  
File tmpFile; //文件下载的临时信息 ^$#Q_Y|  
DataOutputStream output; //输出到文件的输出流 ac&tpvij  
o!H"~5Trv!  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) E>V8|Hz;  
public SiteFileFetch(SiteInfoBean bean) throws IOException 3]VTQl{P  
{ t1~*q)!Mo  
siteInfoBean = bean; P7Y[?='v  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); \|&5eeE@  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); )O&$-4gL'  
if(tmpFile.exists ()) $K G?d>wx  
{ zR<jZwo]#  
bFirst = false; :e9E#o  
read_nPos(); oL6_Ya  
} 3> fuH'=  
else )US) -\^  
{ nEn2!)$  
nStartPos = new long[bean.getNSplitter()]; be@MQ}6>  
nEndPos = new long[bean.getNSplitter()];  z`_N|iEd  
} n+i}>3'A  
FP\[7?ZLn  
?QMs<  
-zTeIvcy5  
} )t.q[O`  
igQyn|  
=Tj0dfO|"  
public void run() FVpe*]  
{  3sw1y  
//获得文件长度 kB:R- St  
//分割文件 eeX>SL5'i  
//实例FileSplitterFetch 0!zWXKX  
//启动FileSplitterFetch线程 DuFlN1Z  
//等待子线程返回 JL$RBr  
try{ l:[=M:#p  
if(bFirst) N!va12  
{ j"dbl?og  
nFileLength = getFileSize(); < <xJ-N  
if(nFileLength == -1) e'?(`yW>  
{ U--ER r8  
System.err.println("File Length is not known!"); [zfGDMG&  
} KVntBe]I  
else if(nFileLength == -2) ~lL($rE  
{ %$}iM<  
System.err.println("File is not access!"); qy]-YJZ  
} a&<<X:$Hy  
else s6 ^JgdW  
{ O|/tRkDMP{  
for(int i=0;i<nStartPos.length;i++) lDA%M3(p  
{ ~& l`"  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 3A9|{Vaz+6  
} qjFgy)qV  
for(int i=0;i<nEndPos.length-1;i++) aD:+,MZ  
{ bd9c/>&  
nEndPos = nStartPos[i+1]; 5Tu.2.)N  
} n#R!`*[  
nEndPos[nEndPos.length-1] = nFileLength; Ea !j-Lbo  
} St3~Y{aI|  
} G@;aqe[dB  
p[$I{F*a  
{J]|mxo  
//启动子线程 8 , =$>@u  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~E\CAZ  
for(int i=0;i<nStartPos.length;i++) ^q6~xC,/  
{ x{- caOH  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +1y#=iM{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *SW,pHYnLb  
nStartPos,nEndPos,i); @PI\.y_w  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (/Mc$V  
fileSplitterFetch.start(); t>[r88v  
} h Na<LZ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wVVe L$28  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); AjS5  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oMVwId f  
nEndPos = " + nFileLength); j{PX ~/  
// fileSplitterFetch[nPos.length-1].start(); )<|TEp4r-  
Q&J,"Vxw  
^/+sl-6/F  
//等待子线程结束 ?-f>zx8O  
//int count = 0; Cr` 0C  
//是否结束while循环 `#]\Wnp~y  
boolean breakWhile = false; fS ~.K9  
`4=b|N+b"  
$1v5*E  
while(!bStop) ymzm x$o=  
{ S;NXOsSu  
write_nPos(); ![ QQF|  
Utility.sleep(500); zxh"@j$?  
breakWhile = true; = `^jz}  
gr;M  
NR*SEbUU*  
for(int i=0;i<nStartPos.length;i++) 7I|%GA_  
{ gU?)  
if(!fileSplitterFetch.bDownOver) *t_&im%E  
{ 0D'Wr(U(  
breakWhile = false; TU/J]'))C  
break; eZ!k'bS=  
} Vo%d;>!G\;  
} $o/>wgQY-  
if(breakWhile) @2mP  
break; &0g,Xkr  
]VvJ1Xn0  
1@WGbORc*  
//count++; c;^J!e  
//if(count>4) ^Toi_  
// siteStop(); ff#-USK^R  
} cabN<a l  
BUb(BzC  
6"GpE5'*  
System.err.println("文件下载结束!"); <-F"&LI{<  
} `T70FsSJ  
catch(Exception e){e.printStackTrace ();} F MVmH!E  
} G DV-wPX  
"" U_|JH-  
:~(im_r  
//获得文件长度 ju#6 3  
public long getFileSize() RVfe}4Stm#  
{ W%1S:2+Kl  
int nFileLength = -1; }>0 Kc=  
try{ Db=gS=Qm  
URL url = new URL(siteInfoBean.getSSiteURL()); gnXjd}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +a/o)C{  
httpConnection.setRequestProperty("User-Agent","NetFox"); W(aRO  
))`Zv=y"  
9^u?v`!  
int responseCode=httpConnection.getResponseCode(); R~~rqvLm  
if(responseCode>=400) =@2V#X]M*  
{ #E9['JnZ  
processErrorCode(responseCode); ' l|_$3  
return -2; //-2 represent access is error [Ni4[\  
} Y9;Mey*oW  
"|%9xGX|D  
WM"^#=+$  
String sHeader; `dP+5u!  
*K|aK p}  
A ? M]5d  
for(int i=1;;i++) tWn m{mF  
{ 8-:k@W  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zc+;VtP|8  
//Utility.log(in.readLine()); %K"%Qm=Tl  
sHeader=httpConnection.getHeaderFieldKey(i); u7?juI#Cl  
if(sHeader!=null) 1c#'5~nB  
{ g5Rm!T+@I<  
if(sHeader.equals("Content-Length")) s{e(- 7'  
{ %z~U@Mka  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^d80\PXz  
break; #ja`+w}  
} ]%|WE  
} #-T.@a1X  
else /BM1AV{s6  
break; +ZKhmb!  
} iwQ-(GjM[A  
} cO,V8#H  
catch(IOException e){e.printStackTrace ();} xV#a(>-4  
catch(Exception e){e.printStackTrace ();} Hc]1mM  
AxlFU~E4  
GYC&P]  
Utility.log(nFileLength); wkD:i2E7  
(0W}e(D8  
Eap/7U1Q  
return nFileLength; y.p6%E_`  
} -vHr1I<  
SFk#bh  
A Vm{#^p[(  
//保存下载信息(文件指针位置) N?;o_^C  
private void write_nPos() U@MP&sdL  
{ k-V I9H!,  
try{ ulf/C%t,R  
output = new DataOutputStream(new FileOutputStream(tmpFile)); iIaT1i4t.  
output.writeInt(nStartPos.length); 9T2A)a]0  
for(int i=0;i<nStartPos.length;i++) _-]!;0E IV  
{ *W12Rb2  
// output.writeLong(nPos); o^Ysp&#p  
output.writeLong(fileSplitterFetch.nStartPos); v Q"s  
output.writeLong(fileSplitterFetch.nEndPos); -fJ@R1]  
} ~AanU1U<  
output.close(); i ,pN1_-  
} O[)]dD&'  
catch(IOException e){e.printStackTrace ();} tvT8UW'  
catch(Exception e){e.printStackTrace ();} c%@~%IGF  
} i1I>RK  
&_d/ciq1f  
QaWHz   
//读取保存的下载信息(文件指针位置) k0_$M{@Y  
private void read_nPos() qQOD  
{ <m,yFk  
try{ K;p<f{PE  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xexe{h4t_>  
int nCount = input.readInt(); Pzp+I}  
nStartPos = new long[nCount]; f&}A!uLe4x  
nEndPos = new long[nCount]; &3Z. #*  
for(int i=0;i<nStartPos.length;i++) d-;9L56{P  
{ fu<2t$Cn>  
nStartPos = input.readLong(); `E5"Pmg  
nEndPos = input.readLong(); P5>5ps"iU  
} u=;nU(]M '  
input.close(); !?o$-+a|  
} g'ZMV6b?K  
catch(IOException e){e.printStackTrace ();} Zknewv*sS4  
catch(Exception e){e.printStackTrace ();} !I5~))E  
} RP,:[}mPl  
knOn UU  
,p!B"# ot  
private void processErrorCode(int nErrorCode) - SS r  
{ ~ sIGI?5f  
System.err.println("Error Code : " + nErrorCode); B>Cs&}Y!  
} xs'kO=  
$tCcjBK\  
{^2W>^  
//停止文件下载 #)0Tt>d6  
public void siteStop() y168K[p  
{ -, Q$  
bStop = true; w,Zx5bBg%  
for(int i=0;i<nStartPos.length;i++) 0<@KDlF  
fileSplitterFetch.splitterStop(); dA1 C)gLi  
dHG  Io  
8b:clvh  
} 6 W;?8Z_1  
} bugFl>  
//负责部分文件的抓取 %,,`N I{  
**FileSplitterFetch.java ;wXY3|@  
*/ p x|>v8  
package NetFox; 1Vf78n  
+K;Y+ K&;2  
X#DL/#z k  
import java.io.*; ')5L_$  
import java.net.*; wfDp,T3w7  
lMwk.#  
+Cf0Y2*@hM  
public class FileSplitterFetch extends Thread { YxEbg(Y  
qsihQ d  
x(9; !4O>  
String sURL; //File URL TTZ['HP oI  
long nStartPos; //File Snippet Start Position 1a&/Zlr  
long nEndPos; //File Snippet End Position t0e{| du  
int nThreadID; //Thread's ID M_h8#7{G  
boolean bDownOver = false; //Downing is over hB?,7-  
boolean bStop = false; //Stop identical VJN/#   
FileAccessI fileAccessI = null; //File Access interface x^)g'16`  
^p 2.UW  
`u#;MUg  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2"leUur~rO  
{ 1Sg|3T8bGT  
this.sURL = sURL; G; C8Kde  
this.nStartPos = nStart; {jOzap|  
this.nEndPos = nEnd; goDV2 alC^  
nThreadID = id; )C>}"#J>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dc.n-ipv$  
} u3Usq=Ij{  
+_ *eu  
QSHJmk 6L  
public void run() N^ h |h  
{ '7Mep ]  
while(nStartPos < nEndPos && !bStop) 0{?: FQ#  
{ <E>7>ZL  
q]"2hLq  
F1gt3 ae  
try{ ZT) !8  
URL url = new URL(sURL); Cf0|Z  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;Y'8:ncDn  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6| *(dE2x(  
String sProperty = "bytes="+nStartPos+"-"; d"B@c;dD  
httpConnection.setRequestProperty("RANGE",sProperty); J}Qs"+x  
Utility.log(sProperty); ]8$#qDS@  
rH$eB/#F  
|*^8~u3J"  
InputStream input = httpConnection.getInputStream(); uW}Hvj;0a*  
//logResponseHead(httpConnection); URYZV8=B~  
=U4f}W;  
&|Lh38s@$#  
byte[] b = new byte[1024]; ^W Y8-6  
int nRead; `FA) om  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >vWEUE[  
{ nnt8 sf@\  
nStartPos += fileAccessI.write(b,0,nRead); i`[#W(m  
//if(nThreadID == 1) 5vD3K! \u  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v:r D3=M-  
} 6exI_3A4jh  
lSH ZV Fd  
XkPv*%Er8  
Utility.log("Thread " + nThreadID + " is over!"); EKZA5J7kn  
bDownOver = true; |',M_ e]  
//nPos = fileAccessI.write (b,0,nRead); z,pNb%*O  
} 6xH;: B)d  
catch(Exception e){e.printStackTrace ();} X=v~^8M7%  
} 5>k>L*5J  
} )@}A r  
}m6f^fs}  
?gLR<d_  
//打印回应的头信息 [IiwNqZ[~  
public void logResponseHead(HttpURLConnection con) ,YjxC p3  
{ ]SFWt/<  
for(int i=1;;i++) a9[mZVMgUK  
{ i=oTg  
String header=con.getHeaderFieldKey(i); _ XE;-weE  
if(header!=null) ,H>W:O  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XZ.7c{B<  
Utility.log(header+" : "+con.getHeaderField(header)); wJ6_I$>  
else :qxm !P  
break; oJ^C]E  
} 1p8:.1)q  
} kMM'[w  
jcE Msc  
'KH lrmnr  
public void splitterStop() .iFViVZC  
{ '%R<"  
bStop = true; ~gP7s_ qr{  
} qQ^d9EK'?~  
tcZa~3.  
& =G)NeT_  
} H#OYw#L"u  
%/51o6a  
>-!r9"8@  
/* +A@m9  
**FileAccess.java <mL%P`Jj  
*//文件访问(定位,写) C 8N%X2R  
package NetFox; @B?FE\  
import java.io.*; _ w/_(k  
Ua %UbAt  
>w9sE8i  
public class FileAccessI implements Serializable{ kP@H G<~  
IXnb]q.  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 TN5>"? ?"  
RandomAccessFile oSavedFile; /iplU  
long nPos; +jUgx;u,  
RO.U(T  
vQ1 v# Z  
public FileAccessI() throws IOException )"| ||\Iv  
{ 2 o4^  
this("",0); 2}vNSQvG  
} !X]8dyW  
'1Y\[T*  
-_em%o3XC  
public FileAccessI(String sName,long nPos) throws IOException }gv8au<  
{ vcv CD7MD  
oSavedFile = new RandomAccessFile(sName,"rw"); BhkoSkr  
this.nPos = nPos; q9]IIv  
oSavedFile.seek(nPos); /&^W#U$4  
} V kjuyK  
9AQxNbs  
T.ML$"f  
public synchronized int write(byte[] b,int nStart,int nLen) .X'pq5  
{ A%X X5*  
int n = -1; rS7)6h7(7  
try{ v-Qmx-N  
oSavedFile.write(b,nStart,nLen); wNYg$d0M  
n = nLen; X!>eiYK)  
} S\*`lJzPM  
catch(IOException e) E=$p^s  
{ 2YlH}fnH  
e.printStackTrace (); j.%K_h?V5  
} H C0w;MG)  
?6"{!s{v  
.4-,_`T?  
return n; >/=> B7  
} ]rN#B-aAr  
= a}b+(R  
"N5!mpD"  
} mbxbEqz  
}D;WN@],  
(V?:]  
/* _zMgoc7  
**SiteInfoBean.java =Vw 5q},3  
*/ 69G`2_eKCp  
package NetFox; Ba'LRz  
Bd~1P/  
T.m mmT  
public class SiteInfoBean { k[kju%i4  
._PzYE|m2  
u0Nm.--;_3  
private String sSiteURL; //Site's URL Wl- <HR!n  
private String sFilePath; //Saved File's Path !EIjN  
private String sFileName; //Saved File's Name 1P(&J  
private int nSplitter; //Count of Splited Downloading File U;q];e:,=}  
~xLJe`"JUx  
t#i,1aHA  
public SiteInfoBean() n6<V+G)T  
{//nSplitter的缺省值为5 SUM4Di7  
//default value of nSplitter is 5 #oni:]E!m  
this("","","",5); {Ui =b+  
} T~:|!`  
4\M.6])_   
EYX$pz(x;  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $O)3 q $|  
{ p-SJ6Gg 9  
sSiteURL= sURL; ]#2Y e7+  
sFilePath = sPath; alq%H}FF  
sFileName = sName; vVl; |  
this.nSplitter = nSpiltter; tmUFT  
kwpK1R4zs  
BV#78,8(  
} hC <O`|lF  
v <Kmq-b  
U}k9 Py  
public String getSSiteURL() E&$yuW^z  
{ Yz$3;  
return sSiteURL; $%R$ G`.KM  
} jPZaD>!  
67SV~L#%O  
26vp1  
public void setSSiteURL(String value) {gbn/{  
{ j _L@U2i  
sSiteURL = value; wV\gj~U;P  
} d5 7i)=  
$(e#aHB  
X;v$5UKU  
public String getSFilePath() '6y}ZE[  
{ MY#   
return sFilePath; G  uQ=gN  
} UFAL1c<V  
Xce0~\_ A  
*jIqAhs0{  
public void setSFilePath(String value) mE%$HZ}  
{ RPd}Wf  
sFilePath = value; 1K,1X(0rL8  
} 91>fqe  
U-/{0zB  
K"j_>63)  
public String getSFileName() VA *y|Q6  
{ kVK/9dy-F  
return sFileName; OCZaQ33  
} Suk  
8{`?= &%6  
1$qh`<\  
public void setSFileName(String value) ,1OyN]f3  
{ c:Wze*vI ;  
sFileName = value; om?-WJI  
} |sRipWh  
)q7UxzE+  
m<FOu<y  
public int getNSplitter() 8#!i[UF dj  
{ 5%sE] Y#  
return nSplitter; 2MZCw^s>  
} {:@tQdM:i8  
w2_bd7Wp<  
b)(?qfXWP  
public void setNSplitter(int nCount) ?v>ET2wD  
{ M9zfT !-  
nSplitter = nCount; {pM?5"M MJ  
} hW!)w  
} Z R/#V7Pj  
b& 1`NO  
y6]vl=^L  
/* z~`b\A,$  
**Utility.java zg-2C>(6a  
*/ jck}" N  
package NetFox; ys 5&PZg*  
Vz6Qxd{m3  
a5a($D  
public class Utility { Reatd h  
S[WG$  
&gzCteS  
public Utility() e[hcJz!D  
{ `{qG1  
[JF150zr  
t%F0:SH  
} )iFJz/n>  
/cU<hApK  
//线程睡眠 Um&(&?Xf  
public static void sleep(int nSecond) =s<( P1|"  
{ HRB<Y mP@  
try{ " Hd|7F'u=  
Thread.sleep(nSecond); Y nLErJ  
} \hCH>*x<  
catch(Exception e) {%_L=2n6  
{ "etPT@gF  
e.printStackTrace (); M)SEn/T-  
} 8#vc(04(  
} / X1 x  
_a1x\,R|DB  
//日志 N<~ku<nAU  
public static void log(String sMsg) O{ #=d  
{ F_CYYGZ  
System.err.println(sMsg); 72'5%*1  
} KEWTBBg  
>,td(= :  
hdrm!aBd  
public static void log(int sMsg) z[Xd%mhjO  
{ P#AW\d^"B  
System.err.println(sMsg); TqnT S0fx  
} >y,-v:Vy  
} H)n9O/u  
aA,!<^&}  
K.0:C`C  
/* Hw4%uS==V  
**TestMethod.java 1YH+d0UGn  
*/ MG.` r{5  
package NetFox; w!D|]LoE  
55z]&5N  
9Q"'" b*?z  
public class TestMethod { >3Eo@J,?d  
I"GB <oB  
( SvWv m  
public TestMethod() {E@Lft-  
{ ///xx/weblogic60b2_win.exe A,a.8!*}vd  
try{ S_Wrw z  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8SGo9[U2  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &G-!qxe  
SiteFileFetch fileFetch = new SiteFileFetch(bean); .X;3,D[w  
fileFetch.start(); /{&tY: ;m  
} bD?VU<)3  
catch(Exception e){e.printStackTrace ();} R~PA 1wDZ  
.hifsB~  
Om5Y|v"*  
} s=;uc] 9g  
u?}(P_9  
n^g|Ja  
public static void main(String[] args) ynQ: > tw  
{ P09;ng67  
new TestMethod(); Hg=";,J  
} xU4 +|d  
} z*!%g[3I  
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