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http断点续传简单实现(java)

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/* CP{cAzHO  
**SiteFileFetch.java n(|^SH4$b  
*/ frQ{iUx  
package NetFox; wf $s*|z  
import java.io.*; Dxxm="FQZ  
import java.net.*; m6djeOl  
bTu9;(  
C $JmzrE  
public class SiteFileFetch extends Thread { "nWw;-V}}  
ERt{H3eCcJ  
=ruao'A  
SiteInfoBean siteInfoBean = null; //文件信息Bean 9C \Fq-  
long[] nStartPos; //开始位置 iIogx8[  
long[] nEndPos; //结束位置 _y3Xb`0a  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 {GO#.P"  
long nFileLength; //文件长度 U?=Dg1  
boolean bFirst = true; //是否第一次取文件 9E tz[`|  
boolean bStop = false; //停止标志 -]=@s  
File tmpFile; //文件下载的临时信息 e]tDy0@  
DataOutputStream output; //输出到文件的输出流 N!|wo:  
YF:L)0H'O  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) @v B!u[{  
public SiteFileFetch(SiteInfoBean bean) throws IOException 39|MX21k  
{ &I406Z f7y  
siteInfoBean = bean; ;'Nd~:-]  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); QwJyY{O`  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); d M-%{  
if(tmpFile.exists ()) z~Q>V]a>;  
{ 4{l,  
bFirst = false; 3t6 LT  
read_nPos(); 9I/N4sou  
} w\brVnt  
else t_suF$  
{ Ki~1qu:  
nStartPos = new long[bean.getNSplitter()]; j w9b )  
nEndPos = new long[bean.getNSplitter()]; \j)E 5b+  
} I9Fr5p-%O  
9k~8  
n}77##+R&C  
2dzrRH  
} A={UL  
p6WX9\qS(  
6i*sm.SDw  
public void run() D)'bH5  
{ TW>WHCAm  
//获得文件长度 *|E[L^  
//分割文件 XS BA$y  
//实例FileSplitterFetch uOGw9O-d9  
//启动FileSplitterFetch线程 ilva,WFa^  
//等待子线程返回 fg{n(TE"8  
try{ X~i<g?]  
if(bFirst) hiw|2Y&`  
{ pO.2<  
nFileLength = getFileSize(); 8h4'(yGQQW  
if(nFileLength == -1) Yir [!{  
{  0{ [,E.  
System.err.println("File Length is not known!"); C{b gkzr  
} BV+ Bk+  
else if(nFileLength == -2) S/I/-Bp~  
{ (2 a`XwR  
System.err.println("File is not access!"); .-X8J t  
} :U(A;U1,  
else ;]jNk'oa  
{ /[>sf[X\I9  
for(int i=0;i<nStartPos.length;i++) T${Q.zHY[!  
{ N{~Y J$!8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); BI}Cg{^km  
} 3 SGDy]  
for(int i=0;i<nEndPos.length-1;i++) HOh!Xcu  
{ CWP2{  
nEndPos = nStartPos[i+1]; I15{)o(8$  
} c\V7i#u[d;  
nEndPos[nEndPos.length-1] = nFileLength; )@'}\_a3[]  
} C=4Qlt[`  
} P}G+4Sk  
D{~fDRR  
y<bDTeoo  
//启动子线程 Iy3GE[  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7 ^mL_SMj  
for(int i=0;i<nStartPos.length;i++) FtC^5{V+V  
{ r{%qf;  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >u8gD6X  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *C=>X193U  
nStartPos,nEndPos,i); *U\`CXn;  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;l-!)0 U  
fileSplitterFetch.start(); w(TJ*::T  
} QW~1%`  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V}NbuvDB@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1|6%evPu(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nL.<[]r  
nEndPos = " + nFileLength); J{&H+rd  
// fileSplitterFetch[nPos.length-1].start(); r_;N t  
=6|&Jt  
g^ i&gNDx  
//等待子线程结束 ; p{[1  
//int count = 0; _W'-+,  
//是否结束while循环 \A6B,|@  
boolean breakWhile = false; :'&brp3ii=  
Zdo'{ $  
HuKc9U'7A  
while(!bStop) k/gZ,  
{ Q7COQ2~K   
write_nPos();  H =^`!  
Utility.sleep(500); Sw^u3  
breakWhile = true; x*&|0n.D  
Ziu]'#  
nSAdCJ;4  
for(int i=0;i<nStartPos.length;i++) wtV#l4  
{ X<; f  
if(!fileSplitterFetch.bDownOver) Jl9k``r*  
{ fku<,SV$O4  
breakWhile = false; 4^OY C  
break; %lGfAYEM=  
} p >t#@Eu|  
} cX OK)g#  
if(breakWhile) &7wd?)s  
break; @\P;W(m.i  
6ez<g Uf  
M$8^91%4B  
//count++; t=O8f5Pf{  
//if(count>4) KC#q@InK  
// siteStop(); 8rS:5:Hi  
} X~,aNRy  
_v=SH$O+  
Q=20IQp  
System.err.println("文件下载结束!"); z4]api(xZ  
} jc f #6   
catch(Exception e){e.printStackTrace ();} EeRX+BM,  
} c[1oww  
V0XvJ  
!*. -`$x  
//获得文件长度 V2|aN<Sx<  
public long getFileSize() :| 8M`18lZ  
{ {"QNJq#:  
int nFileLength = -1; Um-[~-  
try{ FfPar:PHj  
URL url = new URL(siteInfoBean.getSSiteURL()); k<{{*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); spPNr  
httpConnection.setRequestProperty("User-Agent","NetFox"); oVfLnI ;  
&,CiM0  
P8)=Kbd  
int responseCode=httpConnection.getResponseCode(); j*jo@N |  
if(responseCode>=400) }\:Nu Tf  
{ &_|#.  
processErrorCode(responseCode); )vb*Ef  
return -2; //-2 represent access is error > eIP.,9  
} zSja/yq  
1gy.8i  
+sUFv)!4  
String sHeader; #"\gLr_:m  
,+{LYF  
Pjjewy1}^  
for(int i=1;;i++) i,4>0o?  
{ CZI66pDy  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W_8wed:b  
//Utility.log(in.readLine()); {|:;]T"y  
sHeader=httpConnection.getHeaderFieldKey(i); jesGV<`?l  
if(sHeader!=null) Rt!FPoN,y  
{ m6CI{Sa](l  
if(sHeader.equals("Content-Length")) @A89eZbW  
{ <\ :Yk  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ix=}+K/  
break; YccH+[X;  
} >X4u]>X  
} f;gw"onx8F  
else T<p !5`B1  
break; EYEnN  
} h+&OQ%e=8  
} ,\n&I(  
catch(IOException e){e.printStackTrace ();} DBD%6o>]K  
catch(Exception e){e.printStackTrace ();} &NoS=(s,  
D9 |n)f  
MET' (m  
Utility.log(nFileLength); $79=lEn,  
[8,yF D_U  
^ ALly2  
return nFileLength; 8'nVwb8I  
} giIWGa.a+  
@u]rWVy;\[  
\$e)*9)  
//保存下载信息(文件指针位置) *b/` Ya4  
private void write_nPos() E5xzy/ZQ  
{ ZR]25Yy  
try{ )~] (&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); NzOo0tz:  
output.writeInt(nStartPos.length); IS 2^g>T#1  
for(int i=0;i<nStartPos.length;i++) <_tT<5'[$u  
{ D (m j7oB  
// output.writeLong(nPos); ;y\IqiA{o  
output.writeLong(fileSplitterFetch.nStartPos); (Dl$kGn  
output.writeLong(fileSplitterFetch.nEndPos); W$OG( m!W>  
} s1NKLt  
output.close(); FUjl8b-|  
} sOJQ,"sB  
catch(IOException e){e.printStackTrace ();} !&/{E [  
catch(Exception e){e.printStackTrace ();} *HO}~A%Lx  
} CcFn.omA  
3.W@ }   
3#&7-o  
//读取保存的下载信息(文件指针位置) | >htvDL  
private void read_nPos() LBsluT  
{ >>o dZL  
try{ OJ$]V,Z00x  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J/GSceHF  
int nCount = input.readInt(); $[&*Bj11Yg  
nStartPos = new long[nCount]; G <f@#[$'  
nEndPos = new long[nCount]; af+IP_6 .  
for(int i=0;i<nStartPos.length;i++) 80/F7q'tn  
{ .#Z%1U%P.  
nStartPos = input.readLong(); e5B Qr$j  
nEndPos = input.readLong(); ~ga`\% J  
} TXk?#G\o  
input.close(); % !>I*H  
} g,95T Bc  
catch(IOException e){e.printStackTrace ();} MLWM&cFG  
catch(Exception e){e.printStackTrace ();} ;\Y& ce  
} T}P".kpbS  
!Kj,9NX{U  
@I/]D6 ~"  
private void processErrorCode(int nErrorCode) "4H +!r}  
{ ^Z# W_R\l  
System.err.println("Error Code : " + nErrorCode); V<@ o<R  
} k"]dK,,  
_/!y)&4"  
;z:UN}  
//停止文件下载 \":m!K;Z  
public void siteStop() ^8Q62  
{ G *;a^]-  
bStop = true; 1ilBz9x*!  
for(int i=0;i<nStartPos.length;i++) ;Q[mL(1:  
fileSplitterFetch.splitterStop(); Upd3-2kr&J  
#KXa&C  
;b(p=\i  
} ,%Up0Rr,  
} MP 2~;T}~  
//负责部分文件的抓取 "7V2lu  
**FileSplitterFetch.java :8+Nid)  
*/ 1/-43B  
package NetFox; )ZqJh  
#w-xBM @  
tAte)/0C  
import java.io.*; p)3U7"q  
import java.net.*; @u%_1  
y2vUthRwo  
glXZZ=j  
public class FileSplitterFetch extends Thread { #x3ujJ  
F[[TWf/  
yH*6@P4:0=  
String sURL; //File URL sWblFvHqrU  
long nStartPos; //File Snippet Start Position $3uKw!z  
long nEndPos; //File Snippet End Position GJp85B!PlO  
int nThreadID; //Thread's ID 16i "Yg!*  
boolean bDownOver = false; //Downing is over Bw64  
boolean bStop = false; //Stop identical HcV"X,7S  
FileAccessI fileAccessI = null; //File Access interface (BfgwC)  
'@CR\5 @  
>Ll$p 0W  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *`Yv.=cd  
{ R@#G>4  
this.sURL = sURL; %ck]S!}6  
this.nStartPos = nStart; (S`2[.j  
this.nEndPos = nEnd; njnDW~Snb  
nThreadID = id; %T9  sz4V  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X2i}vjkY  
} L%c0Z@[~  
e$uiJNS2  
,qrQ"r9  
public void run() 4bJZmUb  
{ 0 Ir<y  
while(nStartPos < nEndPos && !bStop) Z)xaJGbw  
{ z.VyRBi0  
yxq}QSb \3  
mA@Me7m}  
try{ [j:[  
URL url = new URL(sURL); &0BdUU+:<  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D.6,VY H  
httpConnection.setRequestProperty("User-Agent","NetFox"); T,OwM\`.X{  
String sProperty = "bytes="+nStartPos+"-"; TbF4/T1b  
httpConnection.setRequestProperty("RANGE",sProperty); i^!ez5z  
Utility.log(sProperty); j]m|7]  
e=QK}gzX  
~E^,=4  
InputStream input = httpConnection.getInputStream(); c9nH}/I_  
//logResponseHead(httpConnection); T}=>C+3r  
\Ro^*4B  
KyO8A2'U  
byte[] b = new byte[1024]; 5+jf/}t A  
int nRead; fn/7wO$!  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3u\;j; Td!  
{ oejfU;+$  
nStartPos += fileAccessI.write(b,0,nRead); e~T@~(fft  
//if(nThreadID == 1) K!mOr  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cbu@*NzY,  
} LR,7,DH$9'  
2.X"f  
0G2g4DSKD  
Utility.log("Thread " + nThreadID + " is over!"); a3 >zoN  
bDownOver = true; m3g2b _;  
//nPos = fileAccessI.write (b,0,nRead); TV}}dw  
} M-uMZQ e  
catch(Exception e){e.printStackTrace ();} *$M'`vj:  
} ,[nm_^R*\  
} Jj^GWZRu  
=)OC|?9 C\  
fXQiNm[P  
//打印回应的头信息 V=:_d,  
public void logResponseHead(HttpURLConnection con) Ih[+K#t+E  
{ +"g~"<  
for(int i=1;;i++) ^5t  
{ l48k<  
String header=con.getHeaderFieldKey(i); 5ZAb]F90  
if(header!=null) @oG)LT  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v1.q$ f^(  
Utility.log(header+" : "+con.getHeaderField(header)); SgE/!+{  
else ?Jtg3AY  
break; jec:i-,  
} [W,-1.$!dM  
} C+MSVc  
Y+/l X6'  
&VWlt2-R0h  
public void splitterStop() m^{ xd2  
{ | H ;+1  
bStop = true; n`;R pr&  
} aP>37s  
K.SeK3(  
ZZ)G5ji  
} (5uJZ!m  
pyW u9  
YbMssd2Yg  
/* s([Wn)I  
**FileAccess.java R.1Xst &i  
*//文件访问(定位,写) Z]-WFU_ N  
package NetFox; i.rU&yT%  
import java.io.*; 8kW/DcLE  
?|t/mo|K?  
GF--riyfB  
public class FileAccessI implements Serializable{ :LV.G0)#  
->yeJTsE9  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hr U :Wr  
RandomAccessFile oSavedFile; Xi~9&ed#$i  
long nPos; BQjam+u6  
$+:(f{Va*  
?TuI:dC  
public FileAccessI() throws IOException }#b %"I0  
{ mTEVFm  
this("",0); / = ^L iP  
} 7>x;B  
w4:<fnOM  
NdQ%:OKC  
public FileAccessI(String sName,long nPos) throws IOException v'nHFC+p  
{ Jqg3.2q  
oSavedFile = new RandomAccessFile(sName,"rw"); z`'P>.x   
this.nPos = nPos; `45d"B I  
oSavedFile.seek(nPos); O: u%7V/  
} `$9L^Yg,4  
YZ[%uArm  
"3t\em!  
public synchronized int write(byte[] b,int nStart,int nLen) xzK>Xi?  
{ l @A"U)A(  
int n = -1; U,3d) ]Zy&  
try{ @9_)On9hZ  
oSavedFile.write(b,nStart,nLen); [s %\.y(q  
n = nLen; EVSK8T,  
} >q&L/N5  
catch(IOException e) 0Uaem  
{ ype"7p\  
e.printStackTrace (); dP3VJ3+ %  
} ?zE<  
AJWLEc4XK  
36i_D6  
return n; !pS~'E&q  
} WH;xq^  
D JJZJ}7  
n8?KSQy$  
} WFpl1O73  
q @*UUj@   
'Ix5,^M}B  
/* Q^q=!/qQ  
**SiteInfoBean.java Rh yegD  
*/ DoTs9w|5  
package NetFox; ujNt(7Cz  
67,3i~  
g` kZ T} h  
public class SiteInfoBean { &{hc   
>VypE8H]x  
u-1@~Z  
private String sSiteURL; //Site's URL )PHl>0i!  
private String sFilePath; //Saved File's Path 1 S^'C2/b  
private String sFileName; //Saved File's Name NB3/A"}"02  
private int nSplitter; //Count of Splited Downloading File `-5cQ2>"  
l4DeX\ly7f  
|M]sk?"^  
public SiteInfoBean() 7:ckq(89  
{//nSplitter的缺省值为5 H.)fO ctbO  
//default value of nSplitter is 5 U=M#41J  
this("","","",5); UVnrDhd!0  
} Sq.9-h%5  
0U9+  
"C?:T'dW  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G) jG!`I  
{ A"`L~|&  
sSiteURL= sURL; il=?of\,i  
sFilePath = sPath; 2c!h2$w  
sFileName = sName; T27:"LVw  
this.nSplitter = nSpiltter; XlE$.  
5ZZd.9ZgM  
xAFek;GY?  
} cvn-*Sj  
Cl%V^xTb  
[))gn  
public String getSSiteURL() &f$a1#O}dx  
{ p<<6}3~  
return sSiteURL; UeFtzty,a  
} YmdsI+DbIu  
i%#th'C!P  
;:-}z.7Y  
public void setSSiteURL(String value)  ]v/t8`  
{ ~oEXM ?M  
sSiteURL = value; Vj?*= UL  
} /W7&U =d9  
|p'_k(z}  
x(exx )w  
public String getSFilePath() l#mqV@?A~  
{ _SU,f>  
return sFilePath; yz54:q?  
} X20<r?^,,  
/&y,vkZTT  
9aW8wYL~b  
public void setSFilePath(String value) >b[4  
{ J@=!w[v+  
sFilePath = value; g)2m$#T&s  
} T\<M?`Y  
#c8"  
;,[EJR^CI  
public String getSFileName() Pl`Bd0  
{ W$x K^}  
return sFileName; WV9[DFU  
} t!+%g) @  
7$E2/@f  
%3#b6m~  
public void setSFileName(String value) CNpCe-%&  
{ A5(kOtgiT  
sFileName = value; SLbavP#G  
} ^hGZVGSv  
RXCygPT   
K6 PC&+x  
public int getNSplitter() ^MF=,U'8  
{ >?:i6&4o  
return nSplitter; +'{:zN5m  
} 3R Y|l?n>  
J:M<9W  
FQv02V+&<  
public void setNSplitter(int nCount) C5W-B8>  
{ OV0cr  
nSplitter = nCount; dNS9<8JX  
} R[2[[M  
} O~c+$(  
Rqv+N]  
T`0`]z!~  
/* Mz% d_  
**Utility.java ]xVL11p  
*/ c qU$gKT  
package NetFox; 1bFEx_  
H f`&&  
l.Lc]ZpB  
public class Utility { J}93u(T5  
~h~r]tV*+  
ZFd{q)qe   
public Utility() `rRg(fCN!M  
{ _YD<Q@  
+eH=;8  
(\AszLW  
} iIC9rso"Q1  
U iPVZ@?  
//线程睡眠 ir1RAmt%  
public static void sleep(int nSecond) Jq=>H@il  
{ Qcy+ {j]  
try{ ;_;H(%uY  
Thread.sleep(nSecond); NEjB jLJZ  
} QRn:=J%W W  
catch(Exception e) 0[3tW[j  
{ Hr_x~n=w  
e.printStackTrace (); d&3I>E$UP  
} hKH Q!`&v  
} A`mf 8'nTG  
L2Qp6A6S  
//日志 b~N|DKj  
public static void log(String sMsg) 55)ep  
{ xDAA`G  
System.err.println(sMsg); {U2| ):  
} N'q/7jOy  
u6CM RZ$  
22H=!.DJ  
public static void log(int sMsg) S7\jR%p b  
{ M4$4D?  
System.err.println(sMsg); Kk"B501  
} ,YuWz$aF{  
} +HVG5l  
wNlV_  
'e8d["N  
/* w2mlqy2L  
**TestMethod.java 1QdB`8in  
*/ .bl/At3A  
package NetFox; ,_7tRkn  
r+WPQ`Ar  
[zO(V`S2  
public class TestMethod { <\#  
:8/M6-EK  
OW5|oG  
public TestMethod() \c`r9H^v{  
{ ///xx/weblogic60b2_win.exe Z6HkQ=A64  
try{ zz''FmedF  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aABE= 9Y  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q(eQZx{  
SiteFileFetch fileFetch = new SiteFileFetch(bean); \6PIw-)  
fileFetch.start(); g\mrRZ/?  
} SGT-B.  
catch(Exception e){e.printStackTrace ();} "}Sid+)<  
*/@bNT9BgO  
XVK[p=cIL  
} c`[uQXv  
;Z<*.f'^fc  
{b8Y-  
public static void main(String[] args) QRc=-Wu_(  
{ b J5z??  
new TestMethod(); >w2WyYJYH  
} p9bxhnn|  
} X2mm'J DwK  
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