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http断点续传简单实现(java)

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/* +Z(VWu6  
**SiteFileFetch.java TmAb! Y|F  
*/ 19`0)pzZ*P  
package NetFox; JN-8\ L  
import java.io.*; ' *C)S  
import java.net.*; (\Zo"x;(  
cU[pneY  
?S:_J!vX{  
public class SiteFileFetch extends Thread { Q</HFpE  
+%$V?y (  
"jMnYEG  
SiteInfoBean siteInfoBean = null; //文件信息Bean x)mC^  
long[] nStartPos; //开始位置 9Bw5 t@  
long[] nEndPos; //结束位置 1/J*ki+?  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 <bppu>&  
long nFileLength; //文件长度 r:Cid*~m  
boolean bFirst = true; //是否第一次取文件 \1_&?( pU  
boolean bStop = false; //停止标志 [M>_(u6  
File tmpFile; //文件下载的临时信息 [+7X&B  
DataOutputStream output; //输出到文件的输出流 [kkcV5I-  
n}kz&,  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) D|#(zjl@  
public SiteFileFetch(SiteInfoBean bean) throws IOException &g>+tkC  
{ hG3Lj7)UH  
siteInfoBean = bean; F4gc_>{|  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); !qve1H4d2  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); t4f\0`jN  
if(tmpFile.exists ()) {0 {$.L  
{ rrRC5h  
bFirst = false; "evV/Fg (  
read_nPos(); &" n9,$  
} SVz.d/3Y  
else }CqIKoX.  
{ pz=Wq4 l  
nStartPos = new long[bean.getNSplitter()]; xWV7#Z7  
nEndPos = new long[bean.getNSplitter()]; "!?Ya{  
} Nuq/_x  
W)O'( D  
6E4L4Vb  
L]")TQ  
} 4`]1W,t  
1_]l|`Po  
AOUO',v  
public void run() "ET"dMxU  
{ #JM*QVzv  
//获得文件长度 .JjuY'-Q  
//分割文件 biK.HL\V  
//实例FileSplitterFetch cXH?'q 'vZ  
//启动FileSplitterFetch线程 wyM3|%RZ  
//等待子线程返回 -3 Hq1  
try{ /RJSkF+!  
if(bFirst) \ziF(xTvqG  
{  }"tYb6*  
nFileLength = getFileSize(); Vd~k4  
if(nFileLength == -1) +N:%`9}2V  
{ 0[Aa2H*  
System.err.println("File Length is not known!"); h 42?^mV4?  
} _;W|iUreb  
else if(nFileLength == -2) }qPo%T  
{ 8^T$6A[b  
System.err.println("File is not access!"); {eV_+@dT  
} ;oE4,  
else Lq^/Z4L  
{ 1]~}0;,  
for(int i=0;i<nStartPos.length;i++) f#mpd]e+6  
{ -XB>&dNl)T  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); mQJGKh&Pk  
} dGjvSK<1@  
for(int i=0;i<nEndPos.length-1;i++) b L~<~gA  
{ eyV904<F  
nEndPos = nStartPos[i+1]; qsx1:Ny 1  
} ktRdf6:~  
nEndPos[nEndPos.length-1] = nFileLength;  VVY\W!  
} \ 3N#%  
} 3iTjM>+>  
4F?1,-X  
oY:>pxSz<@  
//启动子线程 [ Ma9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]W,g>91m  
for(int i=0;i<nStartPos.length;i++) ) |a5Qxz  
{ Vy $\.2=  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u:$x,Q  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `R^VK-=C  
nStartPos,nEndPos,i); uv!/DX#  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0:EiCKb)ol  
fileSplitterFetch.start(); K9=_}lS@'  
} )9O{4PbU!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), % e(,PL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7 &Aakl  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EzaOg|  
nEndPos = " + nFileLength); uPPe"$  
// fileSplitterFetch[nPos.length-1].start(); gu!A:Q  
^y,ip=<5\3  
- _(!  
//等待子线程结束 zO,sq%vQn'  
//int count = 0; /^"TMm   
//是否结束while循环 hAdEq$  
boolean breakWhile = false; *RO ~%g  
[A47OR  
sh 1fz 6g  
while(!bStop) j06DP _9M  
{ ?}.(k/  
write_nPos(); {U9jA_XX  
Utility.sleep(500); Df9}YI ;?  
breakWhile = true; -~g3?!+Hb  
;DTNw=  
<Jx{Uv  
for(int i=0;i<nStartPos.length;i++) "O`;zC  
{ ?W(f%/B#  
if(!fileSplitterFetch.bDownOver) yLP0w^Q  
{ M<729M  
breakWhile = false; IP3-lru  
break; yY+2;`CH  
} 6-~  
} "?!IPX2\S  
if(breakWhile) b8Qm4b?:4  
break; t j0vB]c  
6yU~^))bx  
#LZ`kSlv4  
//count++; = N#WwNC  
//if(count>4) j.K yPWO  
// siteStop(); !Zrvko  
} @fw U%S[v  
, F[mh  
y-U(`{[nM  
System.err.println("文件下载结束!"); #3S/TBy,  
} yRtFUlm`  
catch(Exception e){e.printStackTrace ();} ]8#{rQ(  
} }y1M0^M-$  
'coqm8V[%  
yQ}~ aA#h  
//获得文件长度 @l8?\^N  
public long getFileSize() 1#V0g Q  
{ [|YMnV<B  
int nFileLength = -1; z(ajR*\#  
try{ B@4#y9`5  
URL url = new URL(siteInfoBean.getSSiteURL()); E_OLf%um  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x[X.// :  
httpConnection.setRequestProperty("User-Agent","NetFox"); xfzR>NU  
u0,~pJvX  
`'>>[*06:a  
int responseCode=httpConnection.getResponseCode(); WXM_H0K  
if(responseCode>=400) #df43_u  
{ YW5E |z  
processErrorCode(responseCode); /X?Nv^Hy  
return -2; //-2 represent access is error Wi[Y@  
} ru&RL HFV  
;KhYh S(q  
-nW{$&5AF  
String sHeader; lbPxZ'YO#  
m H?hzxa+  
xU&rUk/L  
for(int i=1;;i++) @ZVc!5J_,  
{ 17GyE=Uu  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xk3Ufz]QN  
//Utility.log(in.readLine()); 1Nz\3]-  
sHeader=httpConnection.getHeaderFieldKey(i); ka hv1s-  
if(sHeader!=null) ?z6C8T~+  
{ ]8^2(^3ct  
if(sHeader.equals("Content-Length")) fkYQ3d,`  
{ OV[-m;h|  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zwc b5\Q  
break; ovl@[>OB  
} yP-Dj ,  
} I}:/v$btM  
else *n47.(a2i  
break; 9. R _=  
} `>*P(yIN  
} M_e! s}F  
catch(IOException e){e.printStackTrace ();} ck}y-,>,[O  
catch(Exception e){e.printStackTrace ();} b9U2afd  
ql4T@r3l}3  
8177x7UG2[  
Utility.log(nFileLength); ?1d_E meG2  
T:-Uy&pBEN  
R[Rs2eS_  
return nFileLength; ,To ED  
} Mk?9`?g.  
suVS!} C  
~UnfS};U  
//保存下载信息(文件指针位置) RsbrD8*AD  
private void write_nPos() vw3W:TL  
{ 2|cIu 'U  
try{ GP[$&8\M  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZGrV? @o,6  
output.writeInt(nStartPos.length); [`&cA#C9Yp  
for(int i=0;i<nStartPos.length;i++) #<JrSl62(K  
{ G{J9Fb8  
// output.writeLong(nPos); %H@fVWe2wT  
output.writeLong(fileSplitterFetch.nStartPos); }X$>84s>[P  
output.writeLong(fileSplitterFetch.nEndPos); AkF1Hj  
} %8ul}}d9  
output.close(); $&4Zw6"=  
} U!Lws#\X  
catch(IOException e){e.printStackTrace ();} j04Q3d \f  
catch(Exception e){e.printStackTrace ();} ed{9UJWh  
} XH. _Z  
HqbTJ!a  
ED6H  
//读取保存的下载信息(文件指针位置) i"b*U5k  
private void read_nPos() Y8d%L;b[D  
{ < ;g0?M\  
try{ { sZrI5   
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kN_LD-  
int nCount = input.readInt(); r8 xH A  
nStartPos = new long[nCount]; !b 7H  
nEndPos = new long[nCount]; ^a(q7ZfY  
for(int i=0;i<nStartPos.length;i++) Kq1sGk  
{ OS!47Z /q  
nStartPos = input.readLong(); )y K!EK\  
nEndPos = input.readLong(); l"- D@]"  
} C>;}CH|X  
input.close(); iU3co|q7  
} NO<myN+N  
catch(IOException e){e.printStackTrace ();} J@$>d  
catch(Exception e){e.printStackTrace ();} uIR_p \)  
} X@cV']#V  
)TWf/L cp  
c>^_4QQ  
private void processErrorCode(int nErrorCode) c{E-4PYbah  
{ t512]eqhb(  
System.err.println("Error Code : " + nErrorCode); |[qI2-el?  
} aw,8'N)  
B1GSZUd^?0  
$Fo ,$  
//停止文件下载 iX,Qh2(ig  
public void siteStop() vEb~QX0~  
{ isaT0__8  
bStop = true;  $% jV%k  
for(int i=0;i<nStartPos.length;i++) ~E)I+$,  
fileSplitterFetch.splitterStop(); Mn=_lhW K  
JRG7<s $  
_[<I&^%  
} }3+(A`9h f  
} M- -6oR7  
//负责部分文件的抓取 3~ qgvAr  
**FileSplitterFetch.java 'Hq}h)`  
*/ gK PV*  
package NetFox; xNx!2MrR;  
*BF1 Sso  
2^juLXc|R  
import java.io.*; 3U}z?gP[  
import java.net.*; CfVz'  
lUp 7#q  
:gR`rc!  
public class FileSplitterFetch extends Thread { #de]b  
zRKg>GG`  
OtC/)sX  
String sURL; //File URL F|"NJ*o}  
long nStartPos; //File Snippet Start Position m1frN#3  
long nEndPos; //File Snippet End Position . E.OBn  
int nThreadID; //Thread's ID k<St:X%.O  
boolean bDownOver = false; //Downing is over 5$y<nMP  
boolean bStop = false; //Stop identical ! |}>Y  
FileAccessI fileAccessI = null; //File Access interface `W-:@?PmQx  
HezCRtxRcc  
|~>8]3. Y  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Hj5b.fB  
{ 5Po.&eS  
this.sURL = sURL; wp@c;gK7  
this.nStartPos = nStart; t!K|3>w  
this.nEndPos = nEnd; tV<A u  
nThreadID = id; t!PFosFp  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Wy|=F~N  
} rm2TWM|  
KLoHjBq  
BtjsN22  
public void run() pE=wP/#  
{ 8*|@A6ig  
while(nStartPos < nEndPos && !bStop) fc M~4yP?  
{ 3GaM>w}>W  
7%0PsF _  
N!P* B $d  
try{ #$A6s~`B  
URL url = new URL(sURL); wi&m(f(~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }g`A*y;t  
httpConnection.setRequestProperty("User-Agent","NetFox"); JiRW|+`pe  
String sProperty = "bytes="+nStartPos+"-"; {Xl 5F.q  
httpConnection.setRequestProperty("RANGE",sProperty); lD{9o2  
Utility.log(sProperty); )`L!eN  
 Z3I<  
&3AGj,  
InputStream input = httpConnection.getInputStream(); k6dSj>F>  
//logResponseHead(httpConnection); 8I@_X~R  
Lrz>00(*4  
DTJ~.  
byte[] b = new byte[1024]; wD*_S}]  
int nRead; %T 88K}?=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VD1*br^,  
{ KC  
nStartPos += fileAccessI.write(b,0,nRead); ??k^Rw+0R  
//if(nThreadID == 1) oW-luC+  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "--rz;+K  
} Ar>-xCT D  
(0Y6tcV]R  
~DCw [y  
Utility.log("Thread " + nThreadID + " is over!"); hmks\eb~  
bDownOver = true; \l#=p+x5  
//nPos = fileAccessI.write (b,0,nRead); Fn 6>n04v  
} bZ0r/f,n$  
catch(Exception e){e.printStackTrace ();} aLP 2p]  
} rJR"[TTJ  
} ; zs4>>^>  
> Y LwWU<X  
+]B^*99  
//打印回应的头信息 u YJ6 "j  
public void logResponseHead(HttpURLConnection con) QHA<7Wg  
{ _sw,Y!x%dF  
for(int i=1;;i++) c~p4M64  
{ ]2tX'=X  
String header=con.getHeaderFieldKey(i); [<bfwTFsl  
if(header!=null) 8_W<BXW  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ib]{rmaP  
Utility.log(header+" : "+con.getHeaderField(header)); qA&N6`  
else ]W]Vkkg]  
break; FJ~Dg3F1  
} ij%\ld9kd  
} U JY`P4(  
`y m^0x8  
:h?Zg(l  
public void splitterStop() _G[5S-0 [  
{ #j'O rD  
bStop = true; (5VP*67  
} O[Nc$dc  
NaLec|6<t  
~^:/t<N  
} G^oBu^bq~  
>H[&Wa+_  
= R; 0Ed&b  
/* 8!E$0^)c|  
**FileAccess.java 8%2*RKj  
*//文件访问(定位,写) /1t(e._  
package NetFox; v?5Xx{ym  
import java.io.*; qH$G_R#)8B  
7w YSP&$  
^uC1\!Q1  
public class FileAccessI implements Serializable{ ZA+$ZU^  
J?u",a]|H"  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <#LH L  
RandomAccessFile oSavedFile; 5"k _Ms7R,  
long nPos; sl>4O]N  
;?bRRW  
pn>zuH e  
public FileAccessI() throws IOException pT:CvJ  
{ &A]*"lt|w  
this("",0); J3g>#N]='(  
} }G_ i+  
-N~*h  
PUF"^9v  
public FileAccessI(String sName,long nPos) throws IOException [K x_%Le  
{ KhYGiVA  
oSavedFile = new RandomAccessFile(sName,"rw"); cBiv=!n  
this.nPos = nPos; On d"Eq=r  
oSavedFile.seek(nPos); R2Lq,(@-  
} 6D6=5!l  
>J|I  
{b8!YbG  
public synchronized int write(byte[] b,int nStart,int nLen) _ i.CvYe  
{ JaiYVx(  
int n = -1; XLI'f$w&  
try{ i%D/@$\D6  
oSavedFile.write(b,nStart,nLen); vUY?Eb[  
n = nLen; A<QYW,:|  
} )k- 7mwkZ  
catch(IOException e) i=]IUjx<  
{ CSR 6  
e.printStackTrace (); /%=p-By<V  
} `N;u#z  
L*11hyyk  
{>pB  
return n; O=G2bdY{,  
} ^7vh ize  
Yk6fr~b  
's(0>i  
} WOz dYeeG  
m%'9zL c  
HkGzyDt  
/* g=:%j5?.e  
**SiteInfoBean.java jrvhTej  
*/ av&dGsFP  
package NetFox; 9Or3X/:o  
!s9<%bp3  
`9kjYSd#E  
public class SiteInfoBean { 7a-> "W  
fZ 17  
e}-uU7O  
private String sSiteURL; //Site's URL Wi'BX#xCB  
private String sFilePath; //Saved File's Path W9ZT=#>)[  
private String sFileName; //Saved File's Name qL,QsRwN  
private int nSplitter; //Count of Splited Downloading File VABrw t  
ig7)VKr  
[`yiD>  
public SiteInfoBean() b'St14_  
{//nSplitter的缺省值为5 Z[slN5]([  
//default value of nSplitter is 5 1Hy  
this("","","",5); tt6ElP|D  
} 2sk^A ly  
Cx} Yp-  
_Oh;._PS  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _|g(BK2}  
{ Xa Yx avq  
sSiteURL= sURL; >OBuHqC  
sFilePath = sPath; U3&*,xeU@H  
sFileName = sName; I^qk`5w  
this.nSplitter = nSpiltter; /1gKc}rB2  
 7=6p  
VQ$=F8ivG  
} mdoy1a  
3Yp_k  
OHR9u  
public String getSSiteURL() V89!C?.[]1  
{ 7Q/v#_e(  
return sSiteURL; LGgEq -  
} |&o1i~Y  
BB1'B-O  
K/, B  
public void setSSiteURL(String value) J3}^\k=p"  
{ +pnT6kU|  
sSiteURL = value; nv2Y6e}dG  
} mO?G[?*\  
wGBQ.Ve[  
'.#KkvE##  
public String getSFilePath()  ?MPM@9  
{ }^pnwo9vV  
return sFilePath; _( 0!bUs>  
} |U8;25Y  
w-HgC  
{MO`0n; rt  
public void setSFilePath(String value) [f:>tRdH  
{ qF%wl  
sFilePath = value; &bRmr/D  
} ^8 AV#a  
'i%Azzv  
13}=;4O  
public String getSFileName() ~g;(` g  
{ t/u$Ts  
return sFileName; Bb}JyT  
} @:oMlIw;  
49 fs$wr@  
6K[s),rdv  
public void setSFileName(String value) Yc"G="XP;  
{ __-rP  
sFileName = value; R0gjx"U  
} R =mawmQ2  
^r(2 r  
LZX-am`%  
public int getNSplitter() o//N"S.)  
{ kVe^g]F  
return nSplitter; s><RL]+{G+  
} +7sdQCO(Co  
 &j2L- )  
V<\:iNXX{  
public void setNSplitter(int nCount) b0rC\^x  
{ A:cc @ku  
nSplitter = nCount; z }R-J/xr2  
} q ^n6"&;*  
} {>5z~OV  
V. 1sb pI  
bO9F rEz5  
/* %UV_ 3  
**Utility.java 5u~Ik c~  
*/ deda=%w0  
package NetFox; Nr|.]=K)5n  
<Zl0$~B:5  
]\+bx=  
public class Utility { Gvtd )9^<  
C3G?dZKv2  
8ftLYMX@  
public Utility() rQ30)5^V|  
{ :* /<eT_  
TJ?}5h5  
85w D<bN27  
} |uj1T=ZY  
yJ/m21f  
//线程睡眠 Mff_j0D  
public static void sleep(int nSecond) E@0w t^  
{ E{wVf_K  
try{ U1 1rj,7  
Thread.sleep(nSecond); fR_)e:  
} 0 m";=:(w  
catch(Exception e) j<"0ym)A  
{ FGy7KVR  
e.printStackTrace (); AWh{dM  
} m&Ms[X  
} qWw@6VvoQ  
"h2;65@  
//日志 6Ck?O/^  
public static void log(String sMsg) U87VaUr  
{ *h@nAB\3  
System.err.println(sMsg); <saS2.4  
} )#xd]~ <  
dm8veKW'l  
:*0k:h6g  
public static void log(int sMsg) `vL R;D  
{ #y-OkGS ^  
System.err.println(sMsg); bsP:tFw>  
} Y^2Ma878  
} :M1+[FT  
y{!`4CxF  
UF,T  
/* hy W4=  
**TestMethod.java 4JU#3  
*/ A>R ^iu  
package NetFox; 43,- t_jV  
K*7*`6iU  
5\:#-IYJ  
public class TestMethod { rouD"cy  
nFw&vR/q  
03$Ay_2  
public TestMethod() G U0zlG] C  
{ ///xx/weblogic60b2_win.exe 3|P P+<o  
try{ v@Otp  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _q3SR[k+`  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )Qw|)='-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ln3x1^!  
fileFetch.start(); (0Hhn2JA  
} _L%/NXu,  
catch(Exception e){e.printStackTrace ();} 0:v7X)St  
P:ys--$"  
*v8Cj(69  
} Fe"0Hp+  
|+suGqo  
IW6;ZDP  
public static void main(String[] args) *`|.:'  
{ cMC1|3  
new TestMethod(); @<>](4D  
} lJ}G"RTm  
} sBwkHsDD  
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