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http断点续传简单实现(java)

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/* {q+gm1iC  
**SiteFileFetch.java #O,w{S  
*/ !};Ll=dz  
package NetFox; Z%LS{o~LK.  
import java.io.*; hR:i!  
import java.net.*; _A& [rBm|  
l+@k:IK  
+t1+1 Zv  
public class SiteFileFetch extends Thread { QmGK! H>3  
\o3s&{+ y,  
l-20X{$m:  
SiteInfoBean siteInfoBean = null; //文件信息Bean uPN^o.,/.  
long[] nStartPos; //开始位置 I![/bwObG  
long[] nEndPos; //结束位置 } _];yw  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Wd(|w8J{a  
long nFileLength; //文件长度 ZAeJTCCk  
boolean bFirst = true; //是否第一次取文件 ]9'F<T= $_  
boolean bStop = false; //停止标志 v0(}"0  
File tmpFile; //文件下载的临时信息 3D5adI<aq"  
DataOutputStream output; //输出到文件的输出流 !>!jLZ0  
ubsv\[:C  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) g`C"t3~%S  
public SiteFileFetch(SiteInfoBean bean) throws IOException =B'Yx  
{ i$}G[v<4  
siteInfoBean = bean; )+hJi/g  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); _8-1wx  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $7xfLS8Vo  
if(tmpFile.exists ()) uh#E^~5S  
{ {|j-e{*  
bFirst = false; $AvaOI.l  
read_nPos(); p`Tl)[*  
} Y#-c<o}f  
else OVgak>$  
{ EG &me  
nStartPos = new long[bean.getNSplitter()]; <nV3`L&]  
nEndPos = new long[bean.getNSplitter()]; mr_NArF  
} "Wk K1u  
8'fF{C  
RtxAIMzh?  
 ]SL+ZT  
} /:BC<]s  
Uvi@HB HJ  
*Sbc 8Y  
public void run() SX =^C  
{ #Q_<eo%lI*  
//获得文件长度 X MF? y  
//分割文件 @n9iOf~<  
//实例FileSplitterFetch ]d%Ou]609  
//启动FileSplitterFetch线程 ts@ e ,  
//等待子线程返回 W$l4@A  
try{ DIvxut  
if(bFirst) ?v F8 y;Jh  
{ (r'NB  
nFileLength = getFileSize(); )PkGT~3I  
if(nFileLength == -1) )[&j&AI  
{ [Q6$$z92Q  
System.err.println("File Length is not known!"); 7~P!Z=m^^f  
} $gk=~p|  
else if(nFileLength == -2) Aq(,  
{ w)YTHY (k;  
System.err.println("File is not access!"); &?y|Pn  
} |\"%Dy[m  
else i*09m^r  
{ \Km+>G  
for(int i=0;i<nStartPos.length;i++) 7<2?NLE8*  
{ eCg|@d%D  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); lD _iIe~c  
} l#w0-n%S  
for(int i=0;i<nEndPos.length-1;i++) bZQ_j#{$  
{ #a8i($k{e  
nEndPos = nStartPos[i+1]; 1OqVNp%K  
} f_hG2Sk  
nEndPos[nEndPos.length-1] = nFileLength; $m+Pl[s  
} *_Pkb.3R  
} jlUT9Zp  
8jLO-^X<<  
s>>lf&7  
//启动子线程 ,d=Dicaz  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b+CvA(*  
for(int i=0;i<nStartPos.length;i++) gKPqU@$*  
{ Zyz)`>cB  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iq 8Hq)I]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *s2 C+@ef  
nStartPos,nEndPos,i); 1'k,P;s  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =)Goip  
fileSplitterFetch.start(); : :/vDUDc  
} dGR #l)  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IY(;:#l  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SQuW`EHBgs  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t +CU  
nEndPos = " + nFileLength); IueI7A  
// fileSplitterFetch[nPos.length-1].start(); x_4{MD^%  
)$2h:dw_  
g%4=T~  
//等待子线程结束 n0^3F1Z  
//int count = 0; [ID#P Ule  
//是否结束while循环 -#AO4xpI  
boolean breakWhile = false; 3[m~6 Ys  
4'`*Sce}  
|qq29dS?  
while(!bStop) cavzXz  
{ 4&`d$K  
write_nPos(); {?IUf~<  
Utility.sleep(500); bGB5]%v,  
breakWhile = true; zn\$6'"  
).$kp2IN  
2QIo|$  
for(int i=0;i<nStartPos.length;i++) VZA>ErB  
{ FvBnmYn W  
if(!fileSplitterFetch.bDownOver) 7{f{SIB  
{ GIUyW  
breakWhile = false; tZD^<Q7}\  
break; v #Q(g/^  
} TiI3<.a!  
} 42DB0+_wz  
if(breakWhile) 0Jm)2@  
break; "LVN:|!  
]5eZLXM  
yf e4}0}  
//count++; 0:>C v<N  
//if(count>4) Yp9%u9tNq  
// siteStop(); _qS4Ns/4s  
} .OF2O}  
uF-Rl## >  
8uetv  
System.err.println("文件下载结束!"); ,aSK L1  
} sRGIHT#  
catch(Exception e){e.printStackTrace ();} V"sm+0J  
} 5U JMiwP{  
k=5v J72U  
t$U eks  
//获得文件长度 +r__>V,  
public long getFileSize() 5cC)&}I  
{ %0eVm   
int nFileLength = -1; p{rzP,Pb&  
try{ _,|N`BBqd  
URL url = new URL(siteInfoBean.getSSiteURL()); a[V4EX1E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i}ti  
httpConnection.setRequestProperty("User-Agent","NetFox"); s#)tiCSVW  
6C*4' P9>  
jR,3 -JQ  
int responseCode=httpConnection.getResponseCode(); dv \aP  
if(responseCode>=400) f<2<8xS  
{ G%fNGQwT  
processErrorCode(responseCode); K db:Q0B  
return -2; //-2 represent access is error ^g N?Io  
} s!K9-qZl<  
0Y ld!L  
(k5d.E]CK  
String sHeader; 3VmF1w 2  
1?ST*b  
DUu~s,A  
for(int i=1;;i++) 1BA5|  
{ P;l D ri  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >]l7AZ:,  
//Utility.log(in.readLine()); e{IwFX  
sHeader=httpConnection.getHeaderFieldKey(i); :.NCS`z_  
if(sHeader!=null) hc5iIJ]  
{ AU H_~SY  
if(sHeader.equals("Content-Length")) ln=:E$jX  
{ YU%U  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L)/^%/!  
break; ]Saw}agE[%  
} [%BWCd8Q~P  
} P}bwEj  
else FKu^{'Y6E0  
break; /hbdQm  
} Ng<oz*>U  
} H}&4#CQ'!  
catch(IOException e){e.printStackTrace ();} TY *q[AWG  
catch(Exception e){e.printStackTrace ();} &+F}$8,  
W!WeYV}kb  
1jQlwT(:  
Utility.log(nFileLength); eWAgYe2  
BZWGXzOFh  
:jioF{,  
return nFileLength; ZuQ\Pyx  
} +^@6{1  
"+KAYsVtU  
/s~&$(d59o  
//保存下载信息(文件指针位置) \I`g[nT|  
private void write_nPos() e't1.%w  
{ .2:S0=xt<  
try{ Z?tw#n[T  
output = new DataOutputStream(new FileOutputStream(tmpFile)); F6 c1YI[  
output.writeInt(nStartPos.length);  8&KqrA86  
for(int i=0;i<nStartPos.length;i++) ]u@`XVEJ  
{ pj9s=}1 '  
// output.writeLong(nPos); ,O ]AB  
output.writeLong(fileSplitterFetch.nStartPos); 2*@.hBi  
output.writeLong(fileSplitterFetch.nEndPos); ?o6\>[O  
} CaqMLi%  
output.close(); 1q;r4$n  
} l>:\% ol  
catch(IOException e){e.printStackTrace ();} wZ =*ejo  
catch(Exception e){e.printStackTrace ();} K+J fU J  
} ~ 'L`RJR  
E'4 dI:  
:\8&Th}Se  
//读取保存的下载信息(文件指针位置) 66shr  
private void read_nPos() ,2 _!hm /  
{ @jevY81)  
try{ %oEvp{I  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x$\w^h\F  
int nCount = input.readInt(); /0I=?+QSo  
nStartPos = new long[nCount]; ~`Xu 6+1o  
nEndPos = new long[nCount]; xKC{P{:  
for(int i=0;i<nStartPos.length;i++) @Tg +Kt  
{ eMV@er|  
nStartPos = input.readLong(); 8 |iMD1  
nEndPos = input.readLong(); tM;S )S(=  
} P_3U4J  
input.close(); G`r*)pdm  
} QHuh=7u)  
catch(IOException e){e.printStackTrace ();} E?Ofkc$q  
catch(Exception e){e.printStackTrace ();} JqmKD4p  
} /Jci1o  
9 ]W4o"  
w_eUU)z  
private void processErrorCode(int nErrorCode) "sU  ~|  
{ [ O"8Tzr  
System.err.println("Error Code : " + nErrorCode); `OmYz{*r  
} L=WB'*N  
0al8%z9e@  
GcYT<pwN6  
//停止文件下载 :Y;\1J<b1  
public void siteStop() LQrm/)4bF5  
{ Ghpk0ia%d  
bStop = true; ,HM~Zs  
for(int i=0;i<nStartPos.length;i++) [r5k8TB1  
fileSplitterFetch.splitterStop(); Jz6,2,LN  
'}q1 F<&  
%/x%hs;d  
} FI$#x%A  
} Tx'ctd#Y  
//负责部分文件的抓取 N$SJK  
**FileSplitterFetch.java h8lI# Gs  
*/ pe1_E KU  
package NetFox; B 8ycr~  
I!1nB\l  
Y2,\WKa  
import java.io.*; $"&U%3  
import java.net.*; aY7.<p*a  
H;O PA8\n  
b_JW3l  
public class FileSplitterFetch extends Thread { )c$)am\I{  
>av.pJ(>  
';z5]O~  
String sURL; //File URL -'OO6mU  
long nStartPos; //File Snippet Start Position NJglONO  
long nEndPos; //File Snippet End Position h8MkfHH7{  
int nThreadID; //Thread's ID ]XH}G9X^  
boolean bDownOver = false; //Downing is over JrdH6Zg  
boolean bStop = false; //Stop identical ].eY]o}=  
FileAccessI fileAccessI = null; //File Access interface )tV^)n[w  
Z|kMoB  
>O{/%(9  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uF=xo`=|  
{ yNb :zoT  
this.sURL = sURL; sC .R.  
this.nStartPos = nStart; {PCf'n  
this.nEndPos = nEnd; nBVknyMFNF  
nThreadID = id; !7K-Kqn  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xf.2Ig  
} >xt*(j&}  
MXxE)"G*a  
P00pSRQHD  
public void run() K{&b "Ba1  
{ Xkv+"F=-  
while(nStartPos < nEndPos && !bStop) Q b|.;_  
{ CXs i  
h8yv:}XU*  
.ZxH#l _  
try{ 9$xEktfV  
URL url = new URL(sURL); plY`lqm  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *0^t;A+  
httpConnection.setRequestProperty("User-Agent","NetFox"); '*KP{"3\  
String sProperty = "bytes="+nStartPos+"-"; DjT ekn  
httpConnection.setRequestProperty("RANGE",sProperty); M\s^>7es  
Utility.log(sProperty); -0) So  
~"*;lT5KX  
-e{H8ro  
InputStream input = httpConnection.getInputStream(); pw7_j;}l  
//logResponseHead(httpConnection); UI4Xv  
Vo%UiVHy  
diLjUC`69  
byte[] b = new byte[1024]; ,QpDz{8  
int nRead; A_t<SG5  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O;A/(lPW+  
{ ]rh)AE!Y(  
nStartPos += fileAccessI.write(b,0,nRead); "iof -b=ys  
//if(nThreadID == 1) 8bX\^&N  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \?} {wh8  
} &\C{,:[  
[^gSWU  
bz~-uHC  
Utility.log("Thread " + nThreadID + " is over!"); _l?5GLl_F$  
bDownOver = true; f-\l<o(  
//nPos = fileAccessI.write (b,0,nRead); Z v=p0xH  
} ]'aG oR  
catch(Exception e){e.printStackTrace ();} -BV&u(  
} g(:y_EpmLH  
} B%Yb+M&K  
a<V=C  
S)"5X)mq  
//打印回应的头信息 |7zm!^t$  
public void logResponseHead(HttpURLConnection con) >NwrJSx  
{ u%O^hcfb  
for(int i=1;;i++) fxLhVJ"b  
{ `,(1'  
String header=con.getHeaderFieldKey(i); %;9e h'  
if(header!=null) ZUyM:$  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zYOPE 6E  
Utility.log(header+" : "+con.getHeaderField(header)); n20H{TA  
else IBVP4&}x$  
break; -}UC daQ3  
} 0zpP$q$  
} ,Z%!38gGsu  
[,5clR=F  
-X4`,0y%{O  
public void splitterStop() GX_Lxc_<f  
{ {\t:{.F A  
bStop = true; q9Y0Lk  
} U hCd,  
E"Xi  
=]E1T8|  
} YA^9, q6u?  
N13 <!QQ  
&TbnZnv  
/* !wrl.A/P  
**FileAccess.java Dz)bP{iq"  
*//文件访问(定位,写) oRu S_X  
package NetFox; A|>a Gy  
import java.io.*; ]-.Q9cjc$q  
73xI8  
Zt` ,DM  
public class FileAccessI implements Serializable{ xs &vgel>  
,75,~  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l!iB -?'u  
RandomAccessFile oSavedFile; kd\yHI9A  
long nPos; Mdwh-Cis/  
!s)2H/KM8  
"E2 g7n&  
public FileAccessI() throws IOException . ~|^du<X  
{ 0t4i'??  
this("",0); F"23>3  
} v!`M=0k  
YgWnPp  
"Pys3=h  
public FileAccessI(String sName,long nPos) throws IOException "Ln\ZYB]  
{ C1G Wi4)  
oSavedFile = new RandomAccessFile(sName,"rw"); SwP h-6  
this.nPos = nPos; b'-gy0  
oSavedFile.seek(nPos); M(3E b;`   
} 6 *8Ge  
gieX`}  
U |4% ydG  
public synchronized int write(byte[] b,int nStart,int nLen) *gT TI;:  
{ i&LbSxUh9  
int n = -1; 98O z  
try{ U3U eTa_  
oSavedFile.write(b,nStart,nLen); x@k9]6/zs  
n = nLen; b`:Eo+p   
} f CVSVn"o  
catch(IOException e) jN {ED_  
{  b'{D4/  
e.printStackTrace (); YT:5J%"  
} .HtDcGp  
uPp(l4(+  
*@Qt*f  
return n; v^E5'M[A  
} oL6_Ya  
3> fuH'=  
ja>Tnfu  
} [D?E\Nkk  
er<~dqZ}]  
(Pu*[STTT  
/* G/`_$ c  
**SiteInfoBean.java iCEX|Tj;  
*/ i/Hi  
package NetFox; ?QMs<  
-zTeIvcy5  
E|fPI u  
public class SiteInfoBean { (p2a{v}fEz  
w\QpQ~OX  
[,e_2<   
private String sSiteURL; //Site's URL 4i19HD_  
private String sFilePath; //Saved File's Path @O(\ TIg  
private String sFileName; //Saved File's Name ``\H'^{B  
private int nSplitter; //Count of Splited Downloading File 7:;V[/  
~p 1y+  
r:o!w7C:a  
public SiteInfoBean() \4&g5vE  
{//nSplitter的缺省值为5 oyd{}$71d  
//default value of nSplitter is 5 m8f_w  
this("","","",5); U--ER r8  
} [zfGDMG&  
KVntBe]I  
NSkI2>+P  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P6?Q;-\q0  
{ w7W-=\Hvh  
sSiteURL= sURL; #nd,cn  
sFilePath = sPath; &, )tD62s  
sFileName = sName; :H87x?e[  
this.nSplitter = nSpiltter; :=8vy  
RU'J!-w{  
1hN! 2Y:  
} _1Eyqh`oh  
ls5S9R 5  
MWuVV=rd8a  
public String getSSiteURL() "N;|~S)w!  
{ S,v`rmI  
return sSiteURL; BZBsE :(F  
} WV% KoM,%  
g?`J,*y  
I F@M  
public void setSSiteURL(String value) *Zvw&y*  
{ x{- caOH  
sSiteURL = value; *SW,pHYnLb  
} @PI\.y_w  
(/Mc$V  
6 qq7:  
public String getSFilePath() Em 7q@  
{ 8?$2;uGL  
return sFilePath; jL8zH  
} /IC' R"V a  
Zry>s0  
7MfT~v  
public void setSFilePath(String value) Y `{U45  
{ q}!4b'z^  
sFilePath = value; c'6H@m#=  
} x<l1s  
}B5I#Af7  
PX'LN  
public String getSFileName() 2Ar<(v$  
{ zaZnL7ZJX  
return sFileName; RD4)NN6y5}  
} 40<&0nn  
u%pief  
8%4`Yj=  
public void setSFileName(String value) EI;\of2,  
{ %L/=heBBd  
sFileName = value; (pmo[2kg  
} q2Kn3{  
EDo (  
|h7v}Y  
public int getNSplitter() H07j&  
{ |}`5< a!6U  
return nSplitter; 5c"kLq6r  
} E;qwoTmul  
1bBK1Uw  
qEAF!iB]L  
public void setNSplitter(int nCount) 5-OvPTY`M  
{ HZ}*o%O  
nSplitter = nCount; I?>#neHc6  
} <%z/6I Af|  
} B4}XK =)  
Y[!a82MTzn  
]Q3Gj@6  
/* 8VZ-`?p  
**Utility.java zCHr  
*/ p{rS -`I  
package NetFox; xeI{i{8  
2]+.8G7D%  
-)oBh  
public class Utility { a5-\=0L~  
my1kF%?  
T?Y\~.+99  
public Utility() ng*%1;P  
{ IfcFlXmt2  
,<1*  
6"7qZq  
} z'lNO| nU  
Ro<kp8  
//线程睡眠 aW"!bAdx`,  
public static void sleep(int nSecond)  zjA/Z(  
{ c #kV+n<  
try{ *3$,f>W^  
Thread.sleep(nSecond); HhvG#Sam!  
} {<kG{i/  
catch(Exception e) z(3"\ ^T  
{ 8|({ _Z  
e.printStackTrace (); MxRU6+a  
} D@^ZpN8r  
} uNbA>*c4M  
/<0D E22  
//日志 $T6Qg(p  
public static void log(String sMsg)  qR qy  
{ WM"^#=+$  
System.err.println(sMsg); I*}#nY0+  
} Ct)MvZ  
sh ;uKzQ  
3ZlI$r(  
public static void log(int sMsg) &r%*_pX  
{ oui!fTy  
System.err.println(sMsg); L2'd sOn  
} :2E1aVo4b  
} j&A3s{S4A  
opMUt,4  
KIo}Gd&  
/* >Mw &Tw}o  
**TestMethod.java #ja`+w}  
*/ P0xLx  
package NetFox; !dY:S';~  
bZ.N7X PH  
+ZKhmb!  
public class TestMethod { * Xoscc  
d|]O<]CG_  
K;[%S  
public TestMethod() AxlFU~E4  
{ ///xx/weblogic60b2_win.exe GYC&P]  
try{ #OWs3$9  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A[kH_{to;  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v9U(sEDq  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6;cY!  
fileFetch.start(); Da [C'm=  
} wy {>gvqK  
catch(Exception e){e.printStackTrace ();} ,g_onfY  
u!o]Co>  
NRisr  
} X5Y `(/V  
e({fY.)SGo  
S2E HmE&  
public static void main(String[] args) PuCDsojclh  
{ 4|N\Q=,  
new TestMethod(); o^Ysp&#p  
} 61W/BU7O  
} hG7S]\N_  
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