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http断点续传简单实现(java)

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/* aGws?<1$  
**SiteFileFetch.java ,^<39ng  
*/ {ot6ssT=D  
package NetFox; =<zlg~i  
import java.io.*; "(kiMo g-  
import java.net.*; L|1~'Fz#w  
tL1\q Qg  
[Ls%nz|  
public class SiteFileFetch extends Thread { /TIt-c  
t("koA=.  
)7Qp9Fxo  
SiteInfoBean siteInfoBean = null; //文件信息Bean /11CC \  
long[] nStartPos; //开始位置 "{3|(Qs  
long[] nEndPos; //结束位置 PI,2b(`h_  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Ml{4)%~Y7f  
long nFileLength; //文件长度 z(2G"}  
boolean bFirst = true; //是否第一次取文件 ~Ga{=OM??  
boolean bStop = false; //停止标志 A`>^A]%  
File tmpFile; //文件下载的临时信息 5~(nHCf>  
DataOutputStream output; //输出到文件的输出流 hhI*2|i"L  
Gl6:2  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ]"YXa~b  
public SiteFileFetch(SiteInfoBean bean) throws IOException 0tPwhJ  
{ }#Iqq9[  
siteInfoBean = bean; (Kg)cc[B`  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $BB^xJ\O  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); wyAh%'V  
if(tmpFile.exists ()) p6)6Gcx  
{ npbf>n^R  
bFirst = false; ~DB:/VSmu  
read_nPos(); J~ +p7S  
} fD8GAav  
else g2rH"3sC  
{ :O?3lj)  
nStartPos = new long[bean.getNSplitter()]; Y$j !-l5z  
nEndPos = new long[bean.getNSplitter()]; hewc5vrL  
} P=9UK`n  
r?^L/HGc  
}jFRuT;35  
m6 Y0,9  
} A2\3.3  
/'_Yct=  
hw)z]  
public void run() /rK/ l  
{ g0s4ZI+T  
//获得文件长度 /Bk`3~]E>  
//分割文件 EQM[!g^a  
//实例FileSplitterFetch 98 uMD  
//启动FileSplitterFetch线程 w_LkS/  
//等待子线程返回 #G?",,&dM  
try{ =KD[#au6a  
if(bFirst) t#-4edB,  
{ i1]}Q$  
nFileLength = getFileSize(); 62G %.'7  
if(nFileLength == -1) RQ#9[6w!v  
{ /#L4ec-'  
System.err.println("File Length is not known!"); - ku8n%u  
} yZNg[KH  
else if(nFileLength == -2) o"A?Aq  
{ 3RcnoXX_  
System.err.println("File is not access!"); Wg8*;dvtM  
} %N\8!aXnf  
else ) :Px`] 5  
{ ?nE9@G5Gc  
for(int i=0;i<nStartPos.length;i++) _(8N*q*w  
{ ?#nk}=;g8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ~*~aFf5  
} [i> D|X  
for(int i=0;i<nEndPos.length-1;i++) Eq8:[o  
{ R?}%rP+^e  
nEndPos = nStartPos[i+1]; }?O>.W,/  
} B2WPbox  
nEndPos[nEndPos.length-1] = nFileLength; 5a2;@ }%V  
} .R@XstQ  
} }wJH@'0+  
0wF)bQv1  
%/!f^PIwX  
//启动子线程 !RjC0,  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,Hp7`I>/  
for(int i=0;i<nStartPos.length;i++) ?/~Q9My  
{ 8k.#4}fP  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "tDB[?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #&z'?x^a  
nStartPos,nEndPos,i); $`lGPi(Jc  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R[m+s=+  
fileSplitterFetch.start(); a\B?J  
} (S6>^:;=~  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %.fwNS  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5*Dh#FRp  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5CH8;sMK  
nEndPos = " + nFileLength); bZj5qjl`x  
// fileSplitterFetch[nPos.length-1].start(); !QME!c>*$  
GNW.n(a  
[8 23w.{]#  
//等待子线程结束 6J cXhlB`  
//int count = 0; wX!0KxR/Z  
//是否结束while循环 5 (q4o`  
boolean breakWhile = false; "=$uv  
zW[HGI6w  
azRp4~2?  
while(!bStop) S]4!uv^y  
{ N,F[x0&?  
write_nPos(); 5UG"i_TC  
Utility.sleep(500); 4]xD-sc  
breakWhile = true; lcfs 1].  
uE.. 1N&*  
NZ+TTMv  
for(int i=0;i<nStartPos.length;i++) v9#F\F/  
{ RS2uk 7MB  
if(!fileSplitterFetch.bDownOver) bY~V?yNgKM  
{ I y5)SZ'  
breakWhile = false; I-Am9\   
break; w.+G+ r=  
} ~{{7y]3M-  
} S&Hgr_/}c  
if(breakWhile) gTd r  
break; h66mzV:`  
_d>{Hz2  
\#C]|\  
//count++; i7&ay\+@  
//if(count>4) DJ1!Xuu  
// siteStop(); /7ykmW  
} $9W,1wg  
iRV=I,  
QQ %W3D @  
System.err.println("文件下载结束!"); crgVedx~}  
} UH((d*HX4  
catch(Exception e){e.printStackTrace ();} {GGP8  
} Q4g69IE  
Y+0GJuBf  
hANe$10=H  
//获得文件长度 vVjk9_Ul  
public long getFileSize() :8]y*j  
{ I(z16wQ  
int nFileLength = -1; *-E'$  
try{ =yPV9#(I/  
URL url = new URL(siteInfoBean.getSSiteURL()); I`x[1%y2 F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s+h}O}RV  
httpConnection.setRequestProperty("User-Agent","NetFox"); L}K8cB  
Kv ajk~  
\Y6r !D9  
int responseCode=httpConnection.getResponseCode(); 6yC4rX!a  
if(responseCode>=400) RQ8;_)%  
{ Lx| 0G $  
processErrorCode(responseCode); .F/s (  
return -2; //-2 represent access is error %kP=VUXj  
} F><ficT  
CbOCL~ "  
x X.{(er  
String sHeader; h" f_T [  
7s Gf_`Z  
l4U  
for(int i=1;;i++) 5!Ovd O}g  
{ YU\k D  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $KS!vS7  
//Utility.log(in.readLine()); qTG i9OP6/  
sHeader=httpConnection.getHeaderFieldKey(i); [* |+ it+!  
if(sHeader!=null) }-T,cA_H|  
{ O-3aU!L  
if(sHeader.equals("Content-Length")) @]Ac >&  
{ drbim8 !q~  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); eAjsMED  
break; /E:BEm!  
} T`GiM%R;g  
} .X:,]of  
else hUEA)c  
break; Mt@Ma ]!  
} WYIv&h<h"  
} +fQJ#?N2n  
catch(IOException e){e.printStackTrace ();} dZ4c!3'F  
catch(Exception e){e.printStackTrace ();} I ^[[*Bh*C  
$<3^( y  
,}NTV ~  
Utility.log(nFileLength); -wh  
gJ^taUE  
4zZ.v"laVM  
return nFileLength; x~](d8*=  
} s&XL{FE  
o.s(=iG  
b Rr3:"=sE  
//保存下载信息(文件指针位置) F45-M[z  
private void write_nPos() /<Z3x _c  
{ M C y~~DL  
try{ PZI6{KOis  
output = new DataOutputStream(new FileOutputStream(tmpFile)); m>*~ tP  
output.writeInt(nStartPos.length); cM]ZYi  
for(int i=0;i<nStartPos.length;i++) m|v$F,Lv  
{ ZKM@U?PK  
// output.writeLong(nPos); #$}A$sm  
output.writeLong(fileSplitterFetch.nStartPos); 5=8t<v1Bn  
output.writeLong(fileSplitterFetch.nEndPos); !lBK!'0  
} as@? Kv  
output.close(); %AmyT  
} DVDzYR**4  
catch(IOException e){e.printStackTrace ();} $)d34JM  
catch(Exception e){e.printStackTrace ();} Mh {>#Gs  
} Eqh*"hE7  
T wzpq1  
;d FJqo82  
//读取保存的下载信息(文件指针位置) LjIkZ'HuF  
private void read_nPos() nYe:$t3F=  
{ 9Q'[>P=1  
try{ p1W6s0L  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )KGz -!1c  
int nCount = input.readInt(); #w:nj1{_  
nStartPos = new long[nCount]; gEw9<Y  
nEndPos = new long[nCount]; 0E)M6 jJ  
for(int i=0;i<nStartPos.length;i++) "8~PfLJ+  
{ ,H1K sN  
nStartPos = input.readLong(); }F|B'[wn  
nEndPos = input.readLong(); hE<Sm*HU  
} }daU/  
input.close(); Wfy+9"-;s  
} ^x_$%8  
catch(IOException e){e.printStackTrace ();} KLG29G  
catch(Exception e){e.printStackTrace ();} YOUB%N9+  
} = |2F?  
X#zp,7j?  
U+C ^"[B  
private void processErrorCode(int nErrorCode) :}-?X\|\  
{ {WQ6=wGpS  
System.err.println("Error Code : " + nErrorCode); vKfjP_0$  
} lS#^v#uS  
-!K&\hEjj  
k|{ 4"4r  
//停止文件下载 /_YTOSZjm  
public void siteStop() y|zIu I-p  
{ wuW{ 2+)B  
bStop = true; 8H`L8: CM  
for(int i=0;i<nStartPos.length;i++) [B+:)i  
fileSplitterFetch.splitterStop(); c2?VjuB0  
y~su1wUp  
G6+6u Wvl  
} )PW|RW  
} EY:H\4)  
//负责部分文件的抓取 ?[P>2oz  
**FileSplitterFetch.java oB~V~c}8x  
*/ @;N(3| n7  
package NetFox; i% , 't  
j(k}NWPH  
b*/Mco 9O  
import java.io.*; #=;vg  
import java.net.*; B2|0.G|[j  
DIJmISk  
)dh`aQ%N "  
public class FileSplitterFetch extends Thread { B< HN$/  
L&~'SC  
upX@8WxR  
String sURL; //File URL H6Bw3I[  
long nStartPos; //File Snippet Start Position lJdYR'/Wd  
long nEndPos; //File Snippet End Position j; R20xf0  
int nThreadID; //Thread's ID B|,d  
boolean bDownOver = false; //Downing is over 3s67)n  
boolean bStop = false; //Stop identical <]X 6%LX  
FileAccessI fileAccessI = null; //File Access interface 9X +dp  
xGOVMo +  
L ./c#b!{  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g-1j#V`5  
{ X$6QQnyR  
this.sURL = sURL; Xo&\~b#-  
this.nStartPos = nStart; cbs ;  
this.nEndPos = nEnd; adAdX;@e`  
nThreadID = id; $R NHRA.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F ^aD#  
} Tku6X/LF  
g"(@+\XZH"  
=\oL'>q  
public void run() gVI`&W__,  
{ %QEyvl4  
while(nStartPos < nEndPos && !bStop) uG +ZR: _  
{ M&<qGV$A  
Px9 K  
 ; (A-  
try{ _zi| GD  
URL url = new URL(sURL); 8R:Glif  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O0s!3hKu  
httpConnection.setRequestProperty("User-Agent","NetFox"); y n_.  
String sProperty = "bytes="+nStartPos+"-"; j>uu3ADd2  
httpConnection.setRequestProperty("RANGE",sProperty); O:GAS [O`  
Utility.log(sProperty); os&FrtDg  
*'-t_F';  
>,h{`  
InputStream input = httpConnection.getInputStream(); ^E:-Uy  
//logResponseHead(httpConnection); ByO?qft>u  
m7C!}l]9  
3,X8 5`v^  
byte[] b = new byte[1024]; k7;i^$@c  
int nRead; /wl]kGF  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U_ j[<.aN)  
{ !pkIaCxs  
nStartPos += fileAccessI.write(b,0,nRead); S^|U"  
//if(nThreadID == 1) z Tz_"N I  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }/,Rp/+7]  
} R!lug;u#  
RA;/ ?l  
-sZb+2tDa  
Utility.log("Thread " + nThreadID + " is over!"); Li"+`  
bDownOver = true; W&&|T;P<J  
//nPos = fileAccessI.write (b,0,nRead); 8lGM>(:o  
} E*wG5] at  
catch(Exception e){e.printStackTrace ();} #z<# oC5  
} EtaKo}!A}  
} ! K_<hNG&  
E_DQ.!U!o  
odC"#Rb  
//打印回应的头信息 Xo] 2iQy  
public void logResponseHead(HttpURLConnection con) <lWj-+m  
{ &1?6Q_p6c  
for(int i=1;;i++) s=F[.X9lp  
{ G6}&k[d5%  
String header=con.getHeaderFieldKey(i); DwZRx@  
if(header!=null) URg;e M#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :#35mBe}k  
Utility.log(header+" : "+con.getHeaderField(header)); w0lgB%97p  
else (Y8 LyY  
break; =QbOvIq  
} vt^7:! r  
} R=&-nC5e  
EP>Lh7E9n  
4,Oa(b  
public void splitterStop() <\O8D0.d  
{ $eG_LY 1v  
bStop = true; _X mxBtk9f  
} 6M_:D  
_aF8Us  
D,[Nn_N  
} ]'M B3@T  
G &NK  
ZfH>UHft  
/* 8ih_S2Cd  
**FileAccess.java D7JrGaF{  
*//文件访问(定位,写) $u'"C|>8  
package NetFox; ;UM(y@  
import java.io.*; S50}]5K  
VltM{-k^  
cs.t#C  
public class FileAccessI implements Serializable{ xW*Lceb  
g,!.`[e'ex  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H.E=m0 np  
RandomAccessFile oSavedFile; OFyy!r@?  
long nPos; *PV"&cx  
7aKI=;60.  
4%w<Ekd  
public FileAccessI() throws IOException bv'>4a  
{ law$LL  
this("",0); kp*!  
} JGTsVa2  
SA&(%f1d  
naH(lz|v  
public FileAccessI(String sName,long nPos) throws IOException %.r \P@7/Q  
{ p9u*l  
oSavedFile = new RandomAccessFile(sName,"rw"); A%HIfSzQBS  
this.nPos = nPos; $p4e8j[EJ  
oSavedFile.seek(nPos); G9LWnyQt  
} 6kLy!QS  
/j}Tv.'d  
+Ln^<!P  
public synchronized int write(byte[] b,int nStart,int nLen) GD]epr%V  
{ b @0= &4  
int n = -1; 3di;lzGq  
try{ T 4p}5ew'  
oSavedFile.write(b,nStart,nLen); ?%qaoxG37  
n = nLen; e98QT9  
} Y6H?ZOq  
catch(IOException e) D"$Y, d  
{ &*ocr&  
e.printStackTrace (); CJ%'VijhD  
} K8MET&  
,f>9oOqqA  
^>Z_3 {s:$  
return n; 1/w8'Kf'u  
} h]t v+\0  
%<a3[TQd`\  
B ;E"VS0  
} 9X=<uS  
`y^\c#k  
amC)t8L?  
/* Ao}<a1f  
**SiteInfoBean.java dVj2x-R)  
*/ :i?6#_2IC  
package NetFox; h8 N|m0W  
5R~M@   
5$'[R ;r  
public class SiteInfoBean { tzGQo5\  
`4'=&c9  
R2a99#J  
private String sSiteURL; //Site's URL iz^uj  
private String sFilePath; //Saved File's Path -V}xvSVg  
private String sFileName; //Saved File's Name Kc2y  
private int nSplitter; //Count of Splited Downloading File gDLS)4^w  
EJTM >Rpor  
O!f37n-TB  
public SiteInfoBean() 4c 8{AZ  
{//nSplitter的缺省值为5 l1'v`!  
//default value of nSplitter is 5 k)*apc\W  
this("","","",5); =Q<7[  
} + c3pe4  
*->*p35  
mHW%:a\L  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Gt*K:KT=L  
{ vr4r,[B6y  
sSiteURL= sURL; h+j^VsP zB  
sFilePath = sPath; z{\tn.67  
sFileName = sName; `14@dk  
this.nSplitter = nSpiltter; |e2s\?nB0S  
m!w|~ Rk  
3lZl  
} ;#9?3O s  
=LV-n  
U!r8}@  
public String getSSiteURL() XK3O,XM  
{ ^O@eyP  
return sSiteURL; B!x#|vGXL  
} l+P!I{n  
b)KEB9w  
`MPR-"Z6  
public void setSSiteURL(String value) k &J;,)V  
{ JfWkg`LqL  
sSiteURL = value; axvZA:l  
} ph6'(,  
tyW}=xs  
uuwJ-  
public String getSFilePath() c( U,FUS  
{ !"qT2<A  
return sFilePath; [niFJI sc  
} R3_OCM_*  
[.xY>\e  
qm><}N7f  
public void setSFilePath(String value) t :YZua  
{ P8By~f32_  
sFilePath = value; ;xz_H$g  
} 1-? i*C  
"J+L]IC?AD  
"0jwCX Cu  
public String getSFileName() Z8bg5%  
{ I]W7FZ=o  
return sFileName; 7afG4 (<k  
} U?f-/@fc  
83Rs1}*  
f|w;u!U(  
public void setSFileName(String value) AP,ZMpw  
{ E!1\9wzM{  
sFileName = value; ri8=u$!  
} 9MZ)-  
hDB(y4/  
K 'l-6JY-  
public int getNSplitter() Sxc)~y  
{ %\48hSe  
return nSplitter; TCRTC0_}k  
} V;MmPNP|  
;a1DIUm'  
qCcLd7`$  
public void setNSplitter(int nCount) B <r0y  
{ |X:`o;Uma  
nSplitter = nCount; uXFI7vV6P  
} K |=o-  
} z*jaA;#  
) u{ ]rb[  
|=YK2};  
/* vi^YtA  
**Utility.java _";w*lg}  
*/ rrRv 7J&Q  
package NetFox; 5?`4qSUz  
V? tH/P  
LJ@(jO{z  
public class Utility { +`Q]p" G  
vFdI?(c-  
V':A!  
public Utility() 3GE;:;8B  
{ eEVB   
'9WTz(0?  
Yl&[_ l  
} d"?"(Q_8n  
m85ZcyW1T  
//线程睡眠 O-V] I0  
public static void sleep(int nSecond) Yh1nXkA!V  
{ Q<AOc\oO  
try{ ~HGSA(  
Thread.sleep(nSecond); SF; \*]["f  
} l VD{Y`)  
catch(Exception e) P-2DBNB7  
{ EoPvF`T  
e.printStackTrace (); AA^K /y  
} 9;6)b 0=$  
} 0M;El2 P$  
\\:%++}J  
//日志 5`fUR/|[  
public static void log(String sMsg) zo@vuB.  
{ vv,<#4d  
System.err.println(sMsg); QAxy?m,'  
} %XukiA+  
e< @$(w  
KPz0;2}  
public static void log(int sMsg) $Xt""mlQ  
{ eC<RM Q4  
System.err.println(sMsg); sjLMM_'  
} OW};i|  
} meV Z_f/  
<B|b'XVH2  
$Q#n'#c  
/* rucw{) _  
**TestMethod.java >e/>@ J*  
*/ vd#)+  
package NetFox; 0/ 33Z Oc  
8Pd9&/Y  
p%*s3E1.D  
public class TestMethod { Sw E7U~  
X);'[/]E*  
>>J$`0kM*  
public TestMethod() ,}W|cm>  
{ ///xx/weblogic60b2_win.exe (kO(R#M  
try{ R- >~MLeK]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 08jk~$%  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u `xQC /  
SiteFileFetch fileFetch = new SiteFileFetch(bean); g$e|y#Ic$  
fileFetch.start(); Cx~;oWZ  
} Mn&_R{{=  
catch(Exception e){e.printStackTrace ();} \Db`RvEmR  
3S_H&>K  
;\A_-a_(#  
} 8%;Wyqdf]  
30WOH 'n  
9teP4H}m  
public static void main(String[] args) 0/] h"5H3  
{ D`G;C  
new TestMethod(); :I&y@@UG  
} _XP}f x7$C  
} mYo~RXKGF  
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