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http断点续传简单实现(java)

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/* qde.;Yv9  
**SiteFileFetch.java DGTSk9iK(  
*/ m#mM2Guxe  
package NetFox; Q9Wa@gi|  
import java.io.*;  tQB+_q z  
import java.net.*; { D1.  
'@9h@,tc  
E/9 U0  
public class SiteFileFetch extends Thread { `ej  
*Y6BPFE*4  
rE-Xv. |  
SiteInfoBean siteInfoBean = null; //文件信息Bean 6e$(-ai  
long[] nStartPos; //开始位置 =u(. Y  
long[] nEndPos; //结束位置 o-B9r+N  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 E@aR5S>  
long nFileLength; //文件长度 O2?ye4uq  
boolean bFirst = true; //是否第一次取文件 vAi kd#C)  
boolean bStop = false; //停止标志 V4}9f5FR  
File tmpFile; //文件下载的临时信息 (t1:2WY@  
DataOutputStream output; //输出到文件的输出流 v&%GK5j7O  
I3D8xl>P\  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Sve~-aG  
public SiteFileFetch(SiteInfoBean bean) throws IOException Y(ly0U}  
{ dy;Ue5  
siteInfoBean = bean; l=[<gPE  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ?&ThMWl  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 0ejx; Mum  
if(tmpFile.exists ()) I|,^a|\  
{ +Cl(:kfYB  
bFirst = false; PmO utYV  
read_nPos(); 9 W> <m[O  
} i2A>T/?{  
else as- Z)h[B  
{ a;D{P`%n  
nStartPos = new long[bean.getNSplitter()]; xWD=",0+  
nEndPos = new long[bean.getNSplitter()]; :f?\ mVS+  
} v{^_3 ]  
7^#f<m;Ar!  
/Ou`$2H87  
I4ZL +a  
} #.UooFk+Y  
_ro^<V$%  
;(fDR8  
public void run() UP}Y s*  
{ lwaxj7  
//获得文件长度 aErms-~  
//分割文件 *+re2O)Eh'  
//实例FileSplitterFetch iXK.QktHw  
//启动FileSplitterFetch线程 c_<m8b{AEF  
//等待子线程返回 )uiYu3 I  
try{ -$J\BkI  
if(bFirst) uA7~`78  
{ EFu2&P  
nFileLength = getFileSize(); S)of.Nq.;  
if(nFileLength == -1) A&rk5y;  
{ Uc%(#I]Mi  
System.err.println("File Length is not known!"); XYhN;U}Z  
} b[<r+e8  
else if(nFileLength == -2) ^A dHP!I  
{ Ikql  
System.err.println("File is not access!"); xQ9P'ru  
} a,tzt ]>  
else @&t ';"AE  
{ #'fh'$5"  
for(int i=0;i<nStartPos.length;i++) G?CaCleG  
{ R)MWO5  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); b}< T<  
} ma[%,u`  
for(int i=0;i<nEndPos.length-1;i++) c[J(H,mt/  
{ A(G%9'T  
nEndPos = nStartPos[i+1]; v=e`e68U~  
} kIhP 73M  
nEndPos[nEndPos.length-1] = nFileLength; $#4Qv5}  
} EjW3_ %  
} VI7f}  
$mOVo'2  
nXPl\|pXt  
//启动子线程 '8\7(0$c  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Uyf<:8U\  
for(int i=0;i<nStartPos.length;i++) P,U$ X+  
{ yW5/Y02  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C4wJSQl_I  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2u9O+]EP  
nStartPos,nEndPos,i); G<n(\85X  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )@+lfIE(l  
fileSplitterFetch.start(); $BHbnsaQ  
} ]5| o8.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "zFv? ay  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u"eO&Vc  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =OY&;d!C  
nEndPos = " + nFileLength); X,-QxV=lc)  
// fileSplitterFetch[nPos.length-1].start(); ZI.;7G@|  
I3sH8/*  
x?s5vxAKf  
//等待子线程结束 CR8a)X4j#  
//int count = 0; n.9k<  
//是否结束while循环 ]gHxvT\E  
boolean breakWhile = false; M]9oSi  
GjTj..G/  
/I Ql  
while(!bStop) mBW E^  
{ ,K4*0!TXP  
write_nPos(); '2)c;/-E  
Utility.sleep(500); 1K(a=o[Ce  
breakWhile = true; ~{69&T}9  
P(iZGOKUs=  
Ce&nMgd~  
for(int i=0;i<nStartPos.length;i++) 0u0<)gdX  
{ % 1f, 8BM  
if(!fileSplitterFetch.bDownOver) ?naPti1GX  
{ QG{).|pm  
breakWhile = false; n =SY66  
break; <eWGvIEP[  
} 6AS'MD%&  
} 8R !3}kx  
if(breakWhile) @q=l H *=  
break; %cIF()  
7\.Ax  
00DWXGt20o  
//count++; ,$;g'z!N  
//if(count>4) t<`h(RczHI  
// siteStop(); %y@iA91K  
} / D9FjOP  
iQ[0d.(A  
eFO+@  
System.err.println("文件下载结束!"); F[aow$",+}  
} iz|mJUx  
catch(Exception e){e.printStackTrace ();} re.%$D@  
} ~&E|;\G  
>v4k_JX  
|=OO$z;q|  
//获得文件长度 9&'I?D&8  
public long getFileSize() [\9WqHs  
{ vBUl6EmWu  
int nFileLength = -1; A<6V$e$:2  
try{ )9,*s !)9  
URL url = new URL(siteInfoBean.getSSiteURL()); eYL7G-3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ru%: z>Y  
httpConnection.setRequestProperty("User-Agent","NetFox"); `[+9n2j  
7f4R5c  
d6lhA7  
int responseCode=httpConnection.getResponseCode(); !'14mN#A  
if(responseCode>=400) r#{r]q_E*  
{ &77]h%B >  
processErrorCode(responseCode); v}6YbY Tq  
return -2; //-2 represent access is error uo1G   
} _/[n/"gn  
 1fbd/-h  
Rl4r 9  
String sHeader; i '!M<>7  
;F&wGe  
$,k SR}  
for(int i=1;;i++) ?o0#h  
{ hp(n;(OR  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ` n{rzenPX  
//Utility.log(in.readLine()); A>L(#lz#ek  
sHeader=httpConnection.getHeaderFieldKey(i); @C=, >+D  
if(sHeader!=null) $"{V],:T |  
{ 4Uz:zB  
if(sHeader.equals("Content-Length")) f}4c#x  
{ ^F*)Jq  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *f8,R"]-g  
break; @];#4O  
} Fga9  
} NrvS/ cI!t  
else ~QdwoeaD  
break; Pi?*rr5WZ  
} +!POKr  
} 9\)NFZ3Mz  
catch(IOException e){e.printStackTrace ();} kyJv,!};  
catch(Exception e){e.printStackTrace ();} n#3y2,Ml  
We#*.nr{3Z  
#py7emu  
Utility.log(nFileLength); p!'wOThO`  
_| 8"&*T^  
_0F6mg n  
return nFileLength; }sy3M rb  
} va8:QHdU  
 1 ,PFz  
tBBN62^ X  
//保存下载信息(文件指针位置) NtTLvO6  
private void write_nPos() Op3 IL/  
{ v,>F0ofJ  
try{ %o4d4 3uZ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2|}p&~G(  
output.writeInt(nStartPos.length); Wr)% C  
for(int i=0;i<nStartPos.length;i++) >\DXA)nc  
{ ]^ O<WD  
// output.writeLong(nPos); N83RsL "}_  
output.writeLong(fileSplitterFetch.nStartPos); lYw A5|+  
output.writeLong(fileSplitterFetch.nEndPos); 6%S>~L66  
} }T c)M_  
output.close(); /LSiDys  
} |P?8<8p  
catch(IOException e){e.printStackTrace ();} ,A6*EJ\w   
catch(Exception e){e.printStackTrace ();} r~s03g0  
} n; rOH[P  
0jq&i#yNB  
l3g6y 9;  
//读取保存的下载信息(文件指针位置) hChM hc  
private void read_nPos() %oor7 -l  
{ r LfS9H  
try{ *fd` .}  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %Vt@7SwRJ  
int nCount = input.readInt(); /asyj="N7  
nStartPos = new long[nCount]; Gj)Qw 6  
nEndPos = new long[nCount]; }p- %~ Y  
for(int i=0;i<nStartPos.length;i++) v>R.M"f  
{ rz7yAm  
nStartPos = input.readLong(); PPq*_Cf  
nEndPos = input.readLong(); ))KsQJ"V  
} 2!6Kzq  
input.close(); O3BU.X1'%  
} 1$Hf`h2  
catch(IOException e){e.printStackTrace ();} v<c Hx/  
catch(Exception e){e.printStackTrace ();} lmc-ofEv  
} }E1Eq  
\U-5&,fP  
1b!l+ 8!  
private void processErrorCode(int nErrorCode) 11-uJVO~*  
{ $OhL 95}7  
System.err.println("Error Code : " + nErrorCode); 9=}/t9k  
} B+B v(p  
5g5pzww  
k m|wB4  
//停止文件下载 kt:%]ZZL  
public void siteStop() T a[74;VO  
{ !*ucVv;  
bStop = true; uA,{C%?  
for(int i=0;i<nStartPos.length;i++)  Uh8ieb  
fileSplitterFetch.splitterStop(); a $|u!_)!h  
a|53E<5X  
2M1mdkP3  
} YOoP]0'L  
} $.cGRz  
//负责部分文件的抓取 1lQ1 0J  
**FileSplitterFetch.java W P&zF$  
*/ t8+93,*B  
package NetFox; _t[%@G>P  
$3Ia+O   
'ng/A4  
import java.io.*; !{XO#e  
import java.net.*; y$"L`*W  
OE"Bb   
gA|j\T{c  
public class FileSplitterFetch extends Thread { ?C{N0?[P-  
<>oW f  
K7Vr$,p  
String sURL; //File URL ;v'Y' !-J  
long nStartPos; //File Snippet Start Position <coCu0  
long nEndPos; //File Snippet End Position el%Qxak`"  
int nThreadID; //Thread's ID y_&XF>k91  
boolean bDownOver = false; //Downing is over 7EXmmB~>,  
boolean bStop = false; //Stop identical $gTPW,~s[  
FileAccessI fileAccessI = null; //File Access interface eH8.O  
yB1>83!q  
AVWrD[ wD2  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3"n8B6  
{ A&'%ou  
this.sURL = sURL; SAJ=)h~  
this.nStartPos = nStart; :JIPF=]fc  
this.nEndPos = nEnd; ( -@>  
nThreadID = id; 1aG}-:$t'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 aB)DX  
} v],DBw9  
nE;gM1I  
1 %`:8  
public void run() 0Kk*~gR?  
{ MvmP["%J4_  
while(nStartPos < nEndPos && !bStop) oUSG`g^P(M  
{ S/;Y4o  
m5X=P5U  
7p$*/5fk  
try{ tV9C33  
URL url = new URL(sURL); )M 0O=Cl1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^nF$<#a  
httpConnection.setRequestProperty("User-Agent","NetFox"); `qz5rPyZ  
String sProperty = "bytes="+nStartPos+"-"; :nUsC+oBS  
httpConnection.setRequestProperty("RANGE",sProperty); 9A(K_d-!H  
Utility.log(sProperty); dCTpO  
>}*jsqaVU  
M3 u8NRd5|  
InputStream input = httpConnection.getInputStream(); E 5{)d~q  
//logResponseHead(httpConnection); @&##c6\$  
A5ID I<a  
hp4(f W  
byte[] b = new byte[1024]; P;L Z!I  
int nRead; nn:pf1  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;@ X   
{ vh8Kd' y  
nStartPos += fileAccessI.write(b,0,nRead); q"<-  
//if(nThreadID == 1) !\O,dq  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b.*4RL  
} ~HRWKPb  
'LLx$y.Ei[  
3uG5b8?  
Utility.log("Thread " + nThreadID + " is over!"); 2(/ /slP  
bDownOver = true; "]Dzc[Vp  
//nPos = fileAccessI.write (b,0,nRead); .@-]A   
} [F[<2{FQF  
catch(Exception e){e.printStackTrace ();} k.[) R@0%  
} NOp=/  
} 4(GgaQFO?  
@zF:{=+]+  
g*r;( H>e  
//打印回应的头信息 =w$"wzc  
public void logResponseHead(HttpURLConnection con) -L?% o_  
{  m+{: ^  
for(int i=1;;i++) }QW~.>`  
{ bk9~63tN+>  
String header=con.getHeaderFieldKey(i); -0WCwv  
if(header!=null) T8TsKjqOZ  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^GaPpm  
Utility.log(header+" : "+con.getHeaderField(header)); WTv\HI2X !  
else Y6? mY!  
break; <L ( =  
} SH$cn,3F8  
} ":^ NLBm>5  
Xb:BIp!e  
h]DE Cd{  
public void splitterStop() Bp{`%86S E  
{ J K]tcP  
bStop = true; xp8f  
} aa%&&  
@:QdCG+  
jP.b oj_u*  
} z/&a\`DsU  
J}_Dpb[L  
/A))"D  
/* |-Esc|J(  
**FileAccess.java S}Y|s]6  
*//文件访问(定位,写) Sc$8tLDLj  
package NetFox; ?&<o_/`-H5  
import java.io.*; <eFAI}=s  
DcR}pQ(e  
$#ju?B~  
public class FileAccessI implements Serializable{ l8AEEG8>  
eGSp(o56  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dGD^op,6g  
RandomAccessFile oSavedFile; /b:t;0G  
long nPos; CndgfOF  
K _+;"G  
5H :~6z  
public FileAccessI() throws IOException mV*/zWh_  
{ 71/m.w  
this("",0); } B9~X  
} MjXE|3&  
hKZ`DB4  
L}jF#*Q%  
public FileAccessI(String sName,long nPos) throws IOException y-\A@jJC5  
{ _:Jp*z  
oSavedFile = new RandomAccessFile(sName,"rw"); %X"m/4c8}  
this.nPos = nPos; #;"D)C  
oSavedFile.seek(nPos); 5%Oyvt]}2  
} 4`U0">gY  
pba8=Z  
h#m:Y~GoF  
public synchronized int write(byte[] b,int nStart,int nLen) I' ! r  
{ VwOG?5W/  
int n = -1; 4d e]?#=  
try{ %`?;V;{=  
oSavedFile.write(b,nStart,nLen); bKuj po6  
n = nLen; 8L -4}!~C  
} 6vgBqn[  
catch(IOException e) *|k;a]HT  
{ $' (QTEM  
e.printStackTrace (); IObx^N_K  
} 6 tc:A5mK  
GjeUUmr  
C1T=O  
return n; ',JrY)  
} &v$,pg%-:  
?jri!]ux#  
\+iu@C  
} Gg9VS&VI  
os1?6 z~  
Pknc[h},  
/* % Cu.u)/+  
**SiteInfoBean.java T0`"kjE  
*/ iUIy,Y  
package NetFox; a#+>w5  
wqlcLIJPR  
20UqJM8 Ot  
public class SiteInfoBean { q]6_ rY.  
Y5ogi )  
4l&"]9D  
private String sSiteURL; //Site's URL IS[Vap:  
private String sFilePath; //Saved File's Path Q !9HA[Ly  
private String sFileName; //Saved File's Name %5JW< 9  
private int nSplitter; //Count of Splited Downloading File v@8S5KJ  
e(yQKwVD  
q*6q}s3n  
public SiteInfoBean() tu\mFHvlg  
{//nSplitter的缺省值为5 A7k'K4  
//default value of nSplitter is 5 ^ <qrM  
this("","","",5); vd}*_d  
} Tu]&^[B('  
NJ ZXs_%>$  
-uWKY6 :5  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R? O-x9  
{ M h`CP  
sSiteURL= sURL; NSw<t9Yi  
sFilePath = sPath; [2Iau1<@  
sFileName = sName; _6;<ow  
this.nSplitter = nSpiltter; ht?CH Uu  
/b.$jnqL  
o2DtCU-A  
} ezp<@'0ZT  
n`]l^qE  
_=ugxL #eB  
public String getSSiteURL() Bn\l'T  
{ tG/a H%4S  
return sSiteURL; QwBXlO?  
} n ]w7Zj  
|U#DUqw  
;4 ,'y  
public void setSSiteURL(String value) b\?3--q  
{ @7-=zt+f  
sSiteURL = value; W9dYljnZ8i  
} t\8&*(&3F  
5.w iTy  
RcQ>eZHl  
public String getSFilePath() ?0{yq>fTu  
{ G*B$%?n  
return sFilePath; V] rhVMA  
} ?w*yW;V`  
vv &BhIf3  
iNQ0p:<k  
public void setSFilePath(String value) &pM'$}T*  
{ `)$`-Pw*  
sFilePath = value; NvQ%J+  
} H'EY)s Hi  
~AQ>g#|%  
Nsn~@.UuSW  
public String getSFileName() e2c1pgs&+  
{ >B_n/v3P(M  
return sFileName; CZY7S*fL  
} ZHCr2^w6  
qK?$= h.  
K#!X><B'  
public void setSFileName(String value) >Q=Ukn;k  
{ zI^Da!r.  
sFileName = value; dCeX}Z  
} ]dG\j^e|  
'a#mViPTQ)  
03([@d6<E  
public int getNSplitter() h*3{6X#(/  
{ _ij$f<  
return nSplitter;  F~6#LT  
} <'+ %\  
%v{1# ~u  
ZB[k{Y  
public void setNSplitter(int nCount) 6):Xzx,  
{ a }'->H  
nSplitter = nCount; G 4qy*.  
} (?3[3 w~  
} ka/XK[/'  
5wT>N46UX  
26L~X[F  
/* Dx-KMiQ,"(  
**Utility.java C!&y   
*/ >$H|:{D  
package NetFox; ;:mu}  
O'$K],=BS  
L9FHgl?  
public class Utility { lw[e *q{s.  
Kesy2mE  
?WpenUWk  
public Utility() _M t Qi  
{ Bs8[+Ft5  
(qBvoLkF9N  
347eis'  
} 4woO;Gm  
AIRr{Y  
//线程睡眠 yGj.)$1},@  
public static void sleep(int nSecond) Xsuwa-G!5~  
{ nfdq y)  
try{ 'dJ/RJ~  
Thread.sleep(nSecond); *7$P]  
} u~1o(Zn =  
catch(Exception e) feX^~gM  
{ iv&v8;B  
e.printStackTrace (); E9}{1A  
} MYLsHIPC  
} e3(/qMl  
p$E8Bn%[  
//日志 g(ogXA1  
public static void log(String sMsg) atF?OP|{,w  
{ d s:->+o  
System.err.println(sMsg); TDtAmk  
} T=Z.TG|lIx  
`ln1$  
58V[mlW)O0  
public static void log(int sMsg) )C hqATKg  
{ 'gso'&Uaj  
System.err.println(sMsg); ^aZAw%K  
} "xJ0 vlw  
} TX [%(ft  
%A/_5;PZ/  
 vZj`|  
/* I5m][~6.?  
**TestMethod.java I=DxRgt  
*/ V5f9]D  
package NetFox; .L6Zm U  
Zw1U@5}A  
O$u"/cwe*  
public class TestMethod { (la[KqqCO  
_~u2: yl (  
5Por "&%  
public TestMethod() ~]C%/gEh  
{ ///xx/weblogic60b2_win.exe aGZi9O7G}  
try{ 8;14Q7,S  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k^"bLf(4  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cTTW06^  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4QOEw-~w&s  
fileFetch.start(); PxS4,`#~  
} BQH}6ueZ  
catch(Exception e){e.printStackTrace ();} $Fkaa<9;P  
#|GSQJ$F)`  
|*/[`|*G  
} ) rW&c- '  
r}#\BbCv;7  
5irwz4.4  
public static void main(String[] args) Q6gt+FKU9  
{ FTc.]laO  
new TestMethod(); YOr:sb   
} x<Vm5j  
} X$%4$  
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