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http断点续传简单实现(java)

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/* WKN\* N<  
**SiteFileFetch.java ,ujoGSx}  
*/ pBHr{/\5  
package NetFox; u|+O%s TQ  
import java.io.*; uoF9&j5E@Z  
import java.net.*; .uhP (  
n#4Ra+dD  
+~7@K{6 q-  
public class SiteFileFetch extends Thread { _KKG^ u<  
*dGW=aM#C  
,9=a(j"  
SiteInfoBean siteInfoBean = null; //文件信息Bean R#oXQaBJ  
long[] nStartPos; //开始位置 8NpQ"0X  
long[] nEndPos; //结束位置 :=-h'<D  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 }v`5  
long nFileLength; //文件长度 BwbvZfV|  
boolean bFirst = true; //是否第一次取文件 n]|[|Rf1  
boolean bStop = false; //停止标志 q K]Wk+  
File tmpFile; //文件下载的临时信息 daaurT  
DataOutputStream output; //输出到文件的输出流 p 5P<3(  
Z(Xu>ap  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 5=l Ava#  
public SiteFileFetch(SiteInfoBean bean) throws IOException [&e}@!8O`  
{ oM J5;  
siteInfoBean = bean; g,\<fY+ 4  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); m,'u_yK  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Z x3m$.8  
if(tmpFile.exists ()) kFeuKSa^d  
{ &ceZu=*  
bFirst = false; Qd$d*mwg:  
read_nPos(); PX+$Us  
} 1SQ&m H/  
else z[l17+v  
{ f.Jz]WXw,  
nStartPos = new long[bean.getNSplitter()]; ]@Q14   
nEndPos = new long[bean.getNSplitter()]; y;uk|#qnPS  
} w_6h $"^x  
!YCYmxw#  
L[D}pL=  
ZVViu4]?y  
} ^ *RmT  
q_JES4ofx  
evq *&.6\  
public void run() j`(o\Fd )  
{ {~VgXkjsC  
//获得文件长度 >!?u8^C  
//分割文件 iYR8sg[' #  
//实例FileSplitterFetch PbCXcs  
//启动FileSplitterFetch线程 AfyEFnY  
//等待子线程返回 )0YMi!&j`  
try{ 8MV=?  
if(bFirst) 'xhX\?mD  
{ a>6!?:Rj  
nFileLength = getFileSize(); *SL v$A  
if(nFileLength == -1) 5s`NR<|2L  
{ s@Y0"   
System.err.println("File Length is not known!"); a,!c6'QE  
} d-lC|5U%  
else if(nFileLength == -2) Za5*HCo  
{ 7\<#z|  
System.err.println("File is not access!"); c)+IX;q-C  
} Vf,t=$.[Q  
else ~#N^@a  
{ $yBU ,lu}  
for(int i=0;i<nStartPos.length;i++) Mvu!  
{ c[f  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ^|(F|Z  
} u9_ Fjm}&  
for(int i=0;i<nEndPos.length-1;i++) UJ2Tj+  
{ Ub%5# <k|-  
nEndPos = nStartPos[i+1]; yS %J$o&  
} ohOze\T)=  
nEndPos[nEndPos.length-1] = nFileLength; Kb#py6  
} Syo1Dq6z.  
} Bzw~OB{!=J  
5l}v  
PohG y  
//启动子线程 d?.ewsC  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8W9kd"=U  
for(int i=0;i<nStartPos.length;i++) "xi)GH]H_  
{ )L<NW{  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n'K,*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NN>,dd3T  
nStartPos,nEndPos,i); twq!@C  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \IQf|  
fileSplitterFetch.start(); %[l5){:05  
} T32C=7  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +' QX`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iG!tRNQ{y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Dqs{ n?@n  
nEndPos = " + nFileLength); %@Bl,!BJ,  
// fileSplitterFetch[nPos.length-1].start(); 4 bw8^  
!"Jne'f  
RQ;pAO  
//等待子线程结束 lQ {k  
//int count = 0; oYG9i=lZ  
//是否结束while循环 <j+DY@*  
boolean breakWhile = false; bx#GOK-  
/PafIq  
ZBUEg7c  
while(!bStop) x* ?-KS|  
{ Rt}H.D #  
write_nPos(); |@`F !bnLr  
Utility.sleep(500); `A_CLVE  
breakWhile = true; KmG*`Es  
W1dpKv  
8M <q-sn4B  
for(int i=0;i<nStartPos.length;i++) d="Oge8  
{ Dp3&@M"^yY  
if(!fileSplitterFetch.bDownOver) 0z1m!tr  
{ ~oWCTj-  
breakWhile = false; 1RgtZp%  
break; D2z" Z@  
} 7o_1PwKS6  
} G:7HL5u  
if(breakWhile) ry)g<OA  
break; ?Z 9C}t]  
_bRd2k,  
Uus%1hC%a  
//count++; ?%-VSL>$w=  
//if(count>4) XHKiz2Pc1  
// siteStop(); ND $m|V-C  
} I|8'#QX  
^yL6A1  
2.)xWCG  
System.err.println("文件下载结束!"); c5C 2xE}T  
} 3M\~#>  
catch(Exception e){e.printStackTrace ();} @TBcVHy  
} a~ sU  
iI\ bD  
7)SG#|v[$  
//获得文件长度 ]/g&y5RG  
public long getFileSize() W}{RJWr  
{ JcV'O)&  
int nFileLength = -1; HqC 1Dkw  
try{ s\O4D*8  
URL url = new URL(siteInfoBean.getSSiteURL()); -!V+>.Oh  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R-QSv$  
httpConnection.setRequestProperty("User-Agent","NetFox"); V{4=, Ax  
<cS"oBh&u0  
cetHpU ,  
int responseCode=httpConnection.getResponseCode(); E}6q;"[  
if(responseCode>=400) v8 rK\  
{ Kcf1$`F24  
processErrorCode(responseCode); J< Ljg<t+  
return -2; //-2 represent access is error *9T a0e*  
} `s1>7XWf  
@pq2Z^SQH  
cBcfGNTJ~  
String sHeader; 9n9Z  
 t~_vzG  
ggn C #$  
for(int i=1;;i++) wzX(]BG  
{ [.:SV|AF#  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XK#~w:/fB  
//Utility.log(in.readLine()); E/+H~YzO  
sHeader=httpConnection.getHeaderFieldKey(i); T1$=0VSEa+  
if(sHeader!=null) B}S!l>.z  
{ K!~j}z*  
if(sHeader.equals("Content-Length")) }\ kLh(  
{ r:N =?X`N  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LL% Aw)Q`  
break; $mgamWNE8w  
} 5\!t!FL_  
} J34/rL/s  
else WX~: Y,l+u  
break; ]]Bq te  
} l$_q#Kd  
} c+S<U*  
catch(IOException e){e.printStackTrace ();} J)o.@+Q}  
catch(Exception e){e.printStackTrace ();} 2-G6I92d  
?OjZb'+=K  
hSkI]%  
Utility.log(nFileLength); lQ&"p+n  
G42J  
A$ 2AYQ  
return nFileLength; 0nOkQVMk>  
} Z2P DT  
;@ <E  
??5y0I6+  
//保存下载信息(文件指针位置) Dfhu  
private void write_nPos() =:fN  
{ 0+3_CS++r  
try{  >;qAj!'  
output = new DataOutputStream(new FileOutputStream(tmpFile)); = 1ltX+   
output.writeInt(nStartPos.length); }^Ymg7wA  
for(int i=0;i<nStartPos.length;i++) G.{)#cR  
{ qe/dWJBa  
// output.writeLong(nPos); 1Jm'9iy3  
output.writeLong(fileSplitterFetch.nStartPos); E^s<5BC;  
output.writeLong(fileSplitterFetch.nEndPos); o,NTI h  
} ccR#<Pb6q  
output.close(); kz!CxI (  
} S"=y >.#  
catch(IOException e){e.printStackTrace ();} L/Tsq=  
catch(Exception e){e.printStackTrace ();} WNnB s  
} b;;mhu  
vQH 6CB"  
 C\`*_t  
//读取保存的下载信息(文件指针位置) ]`+J!G,  
private void read_nPos() U3 t$h  
{ Ty&Ok*  
try{ ob. Br:x  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y,/Arl}yc  
int nCount = input.readInt(); W^e"()d/Z  
nStartPos = new long[nCount]; JX)%iJq#  
nEndPos = new long[nCount]; wjzR 8g0bQ  
for(int i=0;i<nStartPos.length;i++) fvE:'( #?  
{ <Jc :a?ICe  
nStartPos = input.readLong(); %VH{bpS|i:  
nEndPos = input.readLong(); ?z pN09e  
} 0 k (su  
input.close(); 8el\M/u{  
} uD=FTx  
catch(IOException e){e.printStackTrace ();} *`]#ntz9  
catch(Exception e){e.printStackTrace ();} D[H #W[  
} eo [eN.  
U0m 5Rc  
\8^c"%v,:  
private void processErrorCode(int nErrorCode) zk++#rB  
{ Hd_W5R  
System.err.println("Error Code : " + nErrorCode);  j1~'[  
} 0rrNVaM  
)JsmzGC0  
"/k TEp  
//停止文件下载 w}rsboU  
public void siteStop() E+"m@63  
{ c0U=Hj@@  
bStop = true; 1F,>siuh ,  
for(int i=0;i<nStartPos.length;i++) FW@(MIH  
fileSplitterFetch.splitterStop(); zn)Kl%N^  
"?HDv WP=w  
"3;b,<0  
} 'eYM;\%('  
} bXNM.K  
//负责部分文件的抓取 #S|DoeFs  
**FileSplitterFetch.java }7HR<%< 7  
*/ qdNt2SO  
package NetFox; ISDeLUihY  
+1pY^#A  
5H^"  
import java.io.*; ExxD w_VGT  
import java.net.*; Ri<'apl  
eEmuE H@X  
'DdR2  
public class FileSplitterFetch extends Thread { "6t#   
pNNvg,hS8  
))xP]Muv  
String sURL; //File URL 7x''V5*j  
long nStartPos; //File Snippet Start Position FzzV%  
long nEndPos; //File Snippet End Position gp(: o$  
int nThreadID; //Thread's ID b?]Lx.l-  
boolean bDownOver = false; //Downing is over D.ERt)l>  
boolean bStop = false; //Stop identical )|N_Q}  
FileAccessI fileAccessI = null; //File Access interface X3zpU7`Av+  
0`Hr(J`F  
T$IwrTF@?  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M "\j7(  
{ f=--$o0U~  
this.sURL = sURL; +t7n6  
this.nStartPos = nStart; ?,z/+/:  
this.nEndPos = nEnd; _O;2.M%@  
nThreadID = id; hd N[wC]  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p*C|kEqk  
} vp4NH]fJ  
^~DDl$NH  
De`p@`+<#~  
public void run() 5H79-QLd  
{ z@Uf@~+U  
while(nStartPos < nEndPos && !bStop) 5Z_7Sc  
{ `Kb"`}`_vm  
6d{&1-@>  
(iJ9ekB  
try{ 3aUWQP2  
URL url = new URL(sURL); Vo`,|3^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8Cef ]@x  
httpConnection.setRequestProperty("User-Agent","NetFox"); rE?Fp  
String sProperty = "bytes="+nStartPos+"-"; "n%0L4J  
httpConnection.setRequestProperty("RANGE",sProperty); kNk$[Yfs  
Utility.log(sProperty); Hw 1:zro  
8nE}RD7bx  
0K'^g0G  
InputStream input = httpConnection.getInputStream(); ]AB'POa  
//logResponseHead(httpConnection); r7Zx<c  
PD $' ~2  
z,K;GZuP  
byte[] b = new byte[1024]; =berCV  
int nRead; f >$V:e([  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )8&;Q9'o  
{ jBMGm"NE  
nStartPos += fileAccessI.write(b,0,nRead); hCpcX"wND  
//if(nThreadID == 1) 05 o vz   
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I[w;soI  
} ZwOX ,D  
bnZ~jOHl  
py }`thx  
Utility.log("Thread " + nThreadID + " is over!"); >_|$7m.?n[  
bDownOver = true; 4GqwY"ja  
//nPos = fileAccessI.write (b,0,nRead); L0X/  
} %4,v2K  
catch(Exception e){e.printStackTrace ();} #5X535'ze  
} gZ@z}CIw'  
} N%Uk/ c'  
n^iq?u  
ZG$PW< 73~  
//打印回应的头信息 u:w   
public void logResponseHead(HttpURLConnection con) Ohn?>qQ  
{ d;hv_h  
for(int i=1;;i++) ~-f"&@){,  
{ -*[:3%  
String header=con.getHeaderFieldKey(i); _lMSW6  
if(header!=null) D~b_nFD  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !hjA   
Utility.log(header+" : "+con.getHeaderField(header)); Ox%p"xuP,  
else (sqI:a  
break; e#odr{2#4u  
} :^rt8>~  
} 0b(x@>  
h.jO3q  
mlix^P  
public void splitterStop() iHKX#*  
{ y$y!{R@   
bStop = true; sc&u NfJ  
} X'J!.Jj  
6~^ M<E  
n?:%>Os$  
} * zt?y  
H b?0?^#  
bbs'>D3  
/* :Z&<5  
**FileAccess.java ^v5<*uf%m  
*//文件访问(定位,写) <Uc?#;% Y}  
package NetFox; Q!y%N&  
import java.io.*; `8/D$  
J%FF@.)k  
s("\]K  
public class FileAccessI implements Serializable{  7 T  
vYg>^!Q  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n7/>+V+  
RandomAccessFile oSavedFile; Hu$y8_Udw  
long nPos; <DZ$"t  
+Z e;BKZ3  
mtmTlGp6Lc  
public FileAccessI() throws IOException M(?0c}z  
{ 4'5|YGQj  
this("",0); $.x,[R aN  
} B  
w:+&i|H>  
2ElZ&(RZJF  
public FileAccessI(String sName,long nPos) throws IOException 5x"eM=  
{ \}71p zw(  
oSavedFile = new RandomAccessFile(sName,"rw"); L;-V Yo#  
this.nPos = nPos; an2Yluc;  
oSavedFile.seek(nPos); <q&4Y+b  
} 8d7 NESYl  
^[6el_mj  
8j)*T9  
public synchronized int write(byte[] b,int nStart,int nLen) m5v IS  
{ :-Ml?:0_X  
int n = -1; [@_W-rA  
try{ %-woaj   
oSavedFile.write(b,nStart,nLen); /2'l=R5#  
n = nLen; A(*c |Aj9  
} E>iN>  
catch(IOException e) xqb*;TBh*  
{ 3EHB~rL/C  
e.printStackTrace (); :(iBLO<x  
} C55Av%-=  
tl; b~k  
20# V?hX3  
return n; l5#SOo\  
} =!\Y;rk  
p\R&vof*  
!Df>Q5~g  
} .C` YO2,  
zpjE_|  
]$=#:uf  
/* x4K A8  
**SiteInfoBean.java @N ]]Cf>x  
*/ Lg~ll$ U  
package NetFox; G6dUm_iB  
m}7Nu  
cn Oh j  
public class SiteInfoBean { A*g-pJ h  
msY6zJc`  
"W~vSbn7  
private String sSiteURL; //Site's URL R.cR:fA  
private String sFilePath; //Saved File's Path >p'{!k  
private String sFileName; //Saved File's Name K^ ALE  
private int nSplitter; //Count of Splited Downloading File S=j pn  
O7p=N8V  
3m| C8:  
public SiteInfoBean() THARr#1b};  
{//nSplitter的缺省值为5 O?O=]s u  
//default value of nSplitter is 5 ?:h*=0>  
this("","","",5); N=\weuED  
} ^GlzKl   
bjo} 95  
9s1^hW2%Q  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7Ie=(x8):  
{ LmytO$?2(  
sSiteURL= sURL; fm L8n<1  
sFilePath = sPath; d8iq9AP\o  
sFileName = sName; 6bPl(.(3  
this.nSplitter = nSpiltter; 0U~*uDU  
Mi;Pv*  
o{hX?,4i  
} B$n1 k 45  
OJd/#KFm  
U(LLIyZv  
public String getSSiteURL() +~~2OUL  
{ 0HUylnXf0  
return sSiteURL; 2$ &B@\WY  
} QIg'js$W  
C T\@>!'f  
7WwE] ^M  
public void setSSiteURL(String value) b;%t*?t  
{ lh[?`+A  
sSiteURL = value; Z #T  
} Y2;2Exp^  
T];dFv-GT  
uuxVVgWp{  
public String getSFilePath() qXhdU/ =  
{ e,&#,O  
return sFilePath; ^,,}2dsb>  
} [Ky3WppR  
x FWhr#5,  
> lfuo  
public void setSFilePath(String value) lj UdsUw  
{ l&}}Io$?@  
sFilePath = value; NSBcYObX  
} b]fx  
TDUY&1[  
#qh ,  
public String getSFileName() \ H~zN]3^  
{  vP=68muD  
return sFileName; O=;jDWE  
} IrMB=pWo  
i")0 3b  
8XG';K_  
public void setSFileName(String value) .r2*tB).  
{ 9Msy=qvYG  
sFileName = value; z~ywFk}KGd  
} R|v'+bv  
H]pI$t3~  
yIrJaS-  
public int getNSplitter() Zk`yd8C  
{ 'E+"N'M|  
return nSplitter; AYgXqmH~+  
} u*TC8!n  
B\v+C!/f |  
Xl$, f`f~  
public void setNSplitter(int nCount) 76wNZv) 9  
{ '3Lu_]I-  
nSplitter = nCount; ICvV}%d  
} pF4Z4?W  
} __2<v?\  
P RWb6  
Qr9;CVW  
/* ?oFd%|I  
**Utility.java 6,a H[ >W  
*/ * <\K-NSL  
package NetFox; Xv|=RNz  
@phVfP"M  
\ l#eW x  
public class Utility { mL=d E Q  
ocFk#FW  
z -!w/Bv@  
public Utility() Aeb(b+=  
{ XzHR^^;u"*  
b:D92pH  
qD4]7"9  
} S0)JIrrHC  
&CQO+Yr$l  
//线程睡眠 Y.\x.Hg  
public static void sleep(int nSecond) $[A\i<#  
{ tqZ+2c<W3  
try{ PDuc;RG  
Thread.sleep(nSecond); @kqxN\DE  
}  @Fb1D"!  
catch(Exception e) +yp:douERi  
{ Z*i p=FYR  
e.printStackTrace (); P"8Ix  
} N+=|WeZ  
} 80Dn!9j*  
RqtBz3v  
//日志 eHyUY&N/  
public static void log(String sMsg) U}RBgPX!  
{ &ASR2J  
System.err.println(sMsg); ujZ`T0  
} bI55G#1G  
h 6Z:+  
`8ac;b  
public static void log(int sMsg) f9W:-00QD  
{ kFv*>>X`  
System.err.println(sMsg); t$18h2yOL  
} yQiY:SH  
} -GA F>  
c]PTU2BB8  
G}fB d  
/* @kWL "yy,  
**TestMethod.java <X:JMj+  
*/ }l|S]m!  
package NetFox; 6O As%QZ  
#$I@V4O;#  
D\AVZ76F1  
public class TestMethod { Uj):}xgi'  
`m7<_#Y  
 X0VS a{  
public TestMethod() >u?.gJm~  
{ ///xx/weblogic60b2_win.exe OG/b5U  
try{ At'CT5=  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DB5J3r81  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iT>u&0B-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); R}ki%i5|  
fileFetch.start(); x b"z%.j  
} :A8}x=K  
catch(Exception e){e.printStackTrace ();} H~a ~ 'tm  
fQJ`&9m*BF  
qq/>E*~  
} d:@+dS  
<+_XGOt0<  
jk9f{Iu  
public static void main(String[] args) D\acA?d`  
{ {^WK#$]  
new TestMethod(); RdYmh>c  
} EtKq.<SJ  
} +/~]fI  
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