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http断点续传简单实现(java)

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/* sq `f?tA?  
**SiteFileFetch.java JGQlx-qv  
*/ &)`xlIw}  
package NetFox; i#Tm] ++  
import java.io.*; A&EVzmj-+X  
import java.net.*; z}I=:  
$:IOoS|e  
9))E\U  
public class SiteFileFetch extends Thread { _BGw)Z 6  
7)&}riQ  
_'pow&w~  
SiteInfoBean siteInfoBean = null; //文件信息Bean $n_'# m2LE  
long[] nStartPos; //开始位置 O.61-rp  
long[] nEndPos; //结束位置 $HVus=D"  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ~uqpF-.  
long nFileLength; //文件长度 lS"g[O+  
boolean bFirst = true; //是否第一次取文件 69#mj*p@+  
boolean bStop = false; //停止标志 >YP6/w,e  
File tmpFile; //文件下载的临时信息 I(LBc  
DataOutputStream output; //输出到文件的输出流 V1 y"  
lAjP'(  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ffMh2   
public SiteFileFetch(SiteInfoBean bean) throws IOException _}MO.&Y  
{ =eG?O7z&  
siteInfoBean = bean; ?,G CR1|4  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); HJ4T! `'d  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ^s*j<fH  
if(tmpFile.exists ()) anDwv }  
{ 7{<:g!  
bFirst = false; #E35%7*  
read_nPos(); .m--# r  
} \@G 7Kk*l  
else X!=E1TL  
{ _dQVundH  
nStartPos = new long[bean.getNSplitter()]; mocR_3=Q?  
nEndPos = new long[bean.getNSplitter()]; CjtBQ5  
} <1")JDW  
SN w3xO!;&  
BET3tiHV  
B~S"1EE[  
} _X ?W)]:  
LxD >eA  
wHneVqI/U  
public void run() \HR<^xY  
{ FR%9Qb7  
//获得文件长度 zadn`B#2  
//分割文件 Md!L@gX6<  
//实例FileSplitterFetch IE/F =Wr  
//启动FileSplitterFetch线程 <ezv  
//等待子线程返回 $|J16tW  
try{ 5/U|oZM"  
if(bFirst) {NmpTb  
{ <'s_3AC  
nFileLength = getFileSize(); 8?p40x$m%  
if(nFileLength == -1) " S8JHHx  
{ :|j,x7&/{  
System.err.println("File Length is not known!"); T-" zK r!  
} hC1CISm.U  
else if(nFileLength == -2) zJ-_{GiM*L  
{ |Z\?nZ~  
System.err.println("File is not access!"); y"N7r1Pf  
} <*D{uMw  
else -P I$SA,  
{ ]IX6>p,  
for(int i=0;i<nStartPos.length;i++) kR+xInDM*  
{ CKC%|xke  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ii0{$}eoh  
} Xx.4K>j+j  
for(int i=0;i<nEndPos.length-1;i++) 3O{*~D&n  
{ c?@WNv  
nEndPos = nStartPos[i+1]; +rT%C&ze  
} RM^3Snd=V  
nEndPos[nEndPos.length-1] = nFileLength; H{XbKLU  
} E0F8FR'  
} P''5A6#5  
2oY.MQD7iW  
4J#F;#iA  
//启动子线程 PwF 1Pr`r  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <d2?A}<  
for(int i=0;i<nStartPos.length;i++) (~C_zG  
{ c!,&]*h"k  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '. Ww*N  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aQ@9(j> F  
nStartPos,nEndPos,i); l/=2P_8+Z  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x2-i1#j`;  
fileSplitterFetch.start(); WCa>~dF>  
} /g|H?F0  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }>)e~\Tdzb  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j=r aS  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o+9b%I^1V  
nEndPos = " + nFileLength); %[1\d)  
// fileSplitterFetch[nPos.length-1].start(); Y}db<Cz X  
5|T[:m  
C!]R0L*  
//等待子线程结束 KyQO>g{R  
//int count = 0; 1 _A B; ^  
//是否结束while循环 Ino$N|G[  
boolean breakWhile = false; [73 \jT  
i=m5M]Ef  
,r$k79TI  
while(!bStop) M%*D}s-QE  
{ HR.^ y$IE  
write_nPos(); X@ zw;Se  
Utility.sleep(500); yH\3*#+  
breakWhile = true; 'VgdQp$L$  
M @|n"(P  
IJWUNKqo=  
for(int i=0;i<nStartPos.length;i++) H2f!c{t$p  
{ = [N= mC  
if(!fileSplitterFetch.bDownOver) 2 kP0//  
{ y. xt7 F1  
breakWhile = false; }6Ut7J]a|  
break; 1z .  
} O9+Dd%_KS#  
} h8nJt>h  
if(breakWhile) -?jI{].:8  
break; A* 1-2  
.G ^-. p  
#hp 7@ Tu  
//count++; {}sF ?wZf  
//if(count>4) gD13(G98  
// siteStop(); uX.^zg]}%  
} 2)iwAu   
+ ESEAi91  
iy<|<*s2D  
System.err.println("文件下载结束!"); nC:>1 kt  
} UN FQ`L  
catch(Exception e){e.printStackTrace ();} Q9i&]V[`  
} S]}hh,A  
w^ AY= Fc  
 X.q,  
//获得文件长度 TFfV?rBI  
public long getFileSize() &dH[lB  
{ 5Kadh2nz  
int nFileLength = -1; Aof)WKo  
try{ R6(sWN-  
URL url = new URL(siteInfoBean.getSSiteURL()); nrhzNW>]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |S0w>VH>  
httpConnection.setRequestProperty("User-Agent","NetFox"); QLs9W& PG  
@r.w+E=  
n7|8`? R^  
int responseCode=httpConnection.getResponseCode(); Az+k8=?  
if(responseCode>=400) [~aRA'qJ{V  
{ r<%ua6@  
processErrorCode(responseCode); H^VNw1.   
return -2; //-2 represent access is error lQ8h-Tz  
} h_( #U)z_3  
/?ZO-]q  
BR*'SF\T  
String sHeader; K@f@vyw]  
d@0p<at>~  
L:.z FW,  
for(int i=1;;i++) Bf21u 9  
{ xJ$/#UdP  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ; ,vGw <|o  
//Utility.log(in.readLine()); 7J[DD5  
sHeader=httpConnection.getHeaderFieldKey(i); .83{NF  
if(sHeader!=null) Cr7T=&L  
{ wV604eO(  
if(sHeader.equals("Content-Length")) N4[`pXM6  
{ gNWTzz<[f>  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [%0{7pz}  
break; rN3qTp  
} g3Xa b  
} l.@v@T(/  
else hf JeVT-/v  
break; +HXR ))X  
} 8opd0'SNaB  
} @TQzF-%#7  
catch(IOException e){e.printStackTrace ();} o]@Mg5(8Q  
catch(Exception e){e.printStackTrace ();} 5LX%S.CW  
!y$:}W?_  
r6b;v2!8  
Utility.log(nFileLength); cXd?48O  
FxFRrRRH@  
up@I,9C/  
return nFileLength; j;MQ_?"iN  
} L0Ycf|[s,  
iwXMe(k  
*el~sor;S  
//保存下载信息(文件指针位置) 1_jd1 UT  
private void write_nPos() NimW=X;c  
{ N^TE ;BM  
try{ @ Y&UP  
output = new DataOutputStream(new FileOutputStream(tmpFile)); XkEJ_;:  
output.writeInt(nStartPos.length); m|M'vzu1  
for(int i=0;i<nStartPos.length;i++) H{BP7!t[V  
{ Wik8V0(  
// output.writeLong(nPos); W>o>Y$H  
output.writeLong(fileSplitterFetch.nStartPos); W{i s2s  
output.writeLong(fileSplitterFetch.nEndPos); O a%ZlEUF  
} 8Y,imj\(v  
output.close(); xU!eT'Y  
} \C}_l+nY  
catch(IOException e){e.printStackTrace ();} mm:g9j  
catch(Exception e){e.printStackTrace ();} ;ztt*py  
} W^k|*Y|  
*}P=7TuS  
3FgTM(  
//读取保存的下载信息(文件指针位置) CX}==0od  
private void read_nPos() fP KFU  
{ bzWWW^kNL  
try{ k9_c<TSzu  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ncr*F^J4  
int nCount = input.readInt(); k0v&U@+-J  
nStartPos = new long[nCount]; fe4Ki  
nEndPos = new long[nCount]; TF %MO\!  
for(int i=0;i<nStartPos.length;i++) a;h.I}*]  
{ V#,jUH|  
nStartPos = input.readLong(); wj{[g^y%  
nEndPos = input.readLong(); >+FaPym  
} di4>Ir~]  
input.close(); M(Tlkr  
} 'JRYf;9c  
catch(IOException e){e.printStackTrace ();} >X_5o^s2s  
catch(Exception e){e.printStackTrace ();} m#,AD,s  
} \|YIuzlO4  
:V!F~  
=v{Vl5&>?  
private void processErrorCode(int nErrorCode) ,<t)aZL,A;  
{ O%)Wo?)HM  
System.err.println("Error Code : " + nErrorCode); ["1Iz{  
} };;k5z I%  
ms{iQ:'9  
_]t^F9l  
//停止文件下载 L}\ oFjVju  
public void siteStop() EM7Z g 65  
{ f 0r?cZ  
bStop = true; AF\gB2^  
for(int i=0;i<nStartPos.length;i++) w(oi6kg  
fileSplitterFetch.splitterStop(); })y B2Q0  
gLK_b;:  
V0G"Z6  
} ( u^`3=%n  
} +A-z>T(  
//负责部分文件的抓取 #GuN.`__n,  
**FileSplitterFetch.java 6qd?&.=r  
*/ =mYwO=:D  
package NetFox; Y=ksrs>w  
=$-+~  
a797'{j#PI  
import java.io.*; ,92wW&2  
import java.net.*; ]ne  
isU4D  
*6aIDFNl  
public class FileSplitterFetch extends Thread { \P;2s<6i\  
jdX *  
85_Qb2<'r  
String sURL; //File URL (3?W) i  
long nStartPos; //File Snippet Start Position BMO&(g  
long nEndPos; //File Snippet End Position >zo_}A!  
int nThreadID; //Thread's ID rlQ=rNrG&E  
boolean bDownOver = false; //Downing is over wE3fKG.  
boolean bStop = false; //Stop identical LUzn7FZk  
FileAccessI fileAccessI = null; //File Access interface hjq@ .5  
*t300`x  
R.Kz nJ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6E{(_i  
{ 2&zklXuo:  
this.sURL = sURL; 9/JB n  
this.nStartPos = nStart; V~sfR^FQ'  
this.nEndPos = nEnd; ] @uuB\u  
nThreadID = id; C@3UsD\s(  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mRIBE9K+&  
} ;;K ~  
97k}{tG  
7hhv/9L1  
public void run() 8?LHYdJ  
{ x c|1?AFj  
while(nStartPos < nEndPos && !bStop) E5yn,-GyE0  
{ J^-a@' `+  
8`z  
DJb9] ,=a  
try{ snYyxi  
URL url = new URL(sURL); [nf 5<  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L:\>)6]Ls  
httpConnection.setRequestProperty("User-Agent","NetFox"); oFKTBH:I  
String sProperty = "bytes="+nStartPos+"-"; xEg@Y"NQ  
httpConnection.setRequestProperty("RANGE",sProperty); NwN3T]W  
Utility.log(sProperty); .q<5OE(f  
SQJ +C%   
7U!-_)n{  
InputStream input = httpConnection.getInputStream(); U%n>(!d  
//logResponseHead(httpConnection); H.< F6  
@RHG@{x{K  
~3)d?{5  
byte[] b = new byte[1024]; `R*SHy! _  
int nRead; "fC>]iA8I  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I2WWhsNC  
{ &Qmb?{S0  
nStartPos += fileAccessI.write(b,0,nRead); $IqubC>O  
//if(nThreadID == 1) :{9HsF"h0  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]Pe8G(E!  
} )jjL'  
*|ef#-|D  
1&RB=7.h  
Utility.log("Thread " + nThreadID + " is over!");  Vqr]Ui  
bDownOver = true; P4:Zy;$v!  
//nPos = fileAccessI.write (b,0,nRead); 0),fY(D2T  
} Fl!D2jnN  
catch(Exception e){e.printStackTrace ();} &88c@Ksn  
} 2U3e!V  
} eV"s5X[$  
(}rBnD  
Sd/7#  
//打印回应的头信息 vxS4YRb  
public void logResponseHead(HttpURLConnection con) V  n+a-v  
{ ( 7ujJ}#,  
for(int i=1;;i++) qJE_4/<^!  
{ Sx1|Oq]  
String header=con.getHeaderFieldKey(i); [ldBI3  
if(header!=null) "m`}J*s"  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X\kWJQ:  
Utility.log(header+" : "+con.getHeaderField(header)); ??f,(om  
else ZiPz~G0[^  
break; \Vpv78QF;  
}  $Gcjm~  
} r>gf&/Pl  
]c M8TT  
juI)Do2_  
public void splitterStop() 5Z:T9F4  
{ N'CW Sf.e  
bStop = true; ' e %>Ip  
} ~x^Ra8A  
{Ve3EYYm  
qP-_xpu]R  
} sL,|+>7T^M  
#pyFIUr=w  
RL[F 9g  
/* xo4lM  
**FileAccess.java [+L!c}#  
*//文件访问(定位,写) RKZBI?@4  
package NetFox; i-9W8A  
import java.io.*; jX0^1d@  
+BDW1%  
I+( b!(H  
public class FileAccessI implements Serializable{ G#ELQ/Q  
_St ":9'uU  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;p7R~17  
RandomAccessFile oSavedFile; JXHf$k  
long nPos; P/xE n_*v  
BF 0#G2`h>  
`KZu/r-M9  
public FileAccessI() throws IOException UC j:]!P  
{ _GM?`  
this("",0);  > H&v  
} P 5.@LN  
MS:,I?  
Dp4x\97O  
public FileAccessI(String sName,long nPos) throws IOException uzT+,  
{ /N#=Tol  
oSavedFile = new RandomAccessFile(sName,"rw"); 6&QOC9JW+7  
this.nPos = nPos; Lq2jXy5#n  
oSavedFile.seek(nPos); `q`ah_  
} zG{jRth  
i'.D=o  
XMz*}B6GQ  
public synchronized int write(byte[] b,int nStart,int nLen) {Us^ 4Xe  
{ B@S~v+Gr  
int n = -1; |bhv7(_  
try{ *>2e4j]  
oSavedFile.write(b,nStart,nLen); {jv+ J L"5  
n = nLen; ohs`[U=%~  
} B`||4*  
catch(IOException e) `+0dz,  
{ e tL?UF$  
e.printStackTrace (); |UB)q5I  
} zeq")A  
@n=&muC}  
vvs2:87zvJ  
return n; 6=qC/1,l  
} =M}tet }  
/r2S1"(q  
 ZpMv16  
} V(:wYk?ZR  
%YbL%i|U  
a5aHv/W#P  
/* 3t9CN )*  
**SiteInfoBean.java cucmn*o?  
*/ -ssmj8:Q\|  
package NetFox; L8H:, } 2  
1wH6 hN,  
^>>9?  
public class SiteInfoBean { ,F*HZBNFZ  
~]].i~EV(  
_CTg")0o  
private String sSiteURL; //Site's URL ng~LCffpY  
private String sFilePath; //Saved File's Path cNN0-<#c  
private String sFileName; //Saved File's Name on"ENT  
private int nSplitter; //Count of Splited Downloading File C<(qk_  
zbr^ulr  
<6s@eare8  
public SiteInfoBean() `'*4B_.  
{//nSplitter的缺省值为5 :_]0 8  
//default value of nSplitter is 5 MppT"t  
this("","","",5); z}B8&*>  
} {'[VL;k  
V;^N:I\js  
FFcIOn  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P;K LN9/4  
{ CrSBN~  
sSiteURL= sURL; N-t"CBTO  
sFilePath = sPath; N=7iQ@{1   
sFileName = sName; s diWQv  
this.nSplitter = nSpiltter; _sZ&=-FR  
w\UAKN60  
=,C]d~  
} ~kj96w4eAR  
?m+];SJk  
wjZ Q.T!  
public String getSSiteURL() Gy;Fe=  
{ zGNW5S9G  
return sSiteURL; mlLqQ<  
} 'n1$Y%t  
[b&V^41W  
4mKH |\g  
public void setSSiteURL(String value) SSTn |  
{ *M*WjEOA  
sSiteURL = value; xWqV~NnE  
} :475FPy]  
<}h <By)  
$tI<MZ&Z  
public String getSFilePath() J] w3iYK  
{ )siW c_Z4  
return sFilePath; Xit@.:a;  
} Nd_A8H,&B  
e M5-v-  
n%G[Y^^,  
public void setSFilePath(String value) /OB)\{-  
{ )db:jPkwd  
sFilePath = value; V~ MsGj  
} -3 ANNj  
k3e6y  
6V ncr}  
public String getSFileName() G<k.d"<  
{ mPqK k  
return sFileName; :-<30LS $  
} n qx0#_K-E  
63_#*6Pv28  
Ayv:Pv@  
public void setSFileName(String value) 7=yjd)Iy9m  
{ w ^^l,  
sFileName = value; nd,\<}uP9  
} Y<kz+d,C  
W(Md0*   
K'e,9P{  
public int getNSplitter() u"%D;  
{ It/hXND `  
return nSplitter; ~3%\8,0  
} 4}t&yu<P>  
1Y;.fZE  
isy[RAP<  
public void setNSplitter(int nCount) =R 4]Kf  
{ Y:#B0FD,gC  
nSplitter = nCount; [u=yl0f  
} gdoaXw;Sy  
} 3Nwix_&S  
yB/F6/B~  
;($xAAR  
/* <gGO  
**Utility.java L[<Y6u>m!1  
*/ BNA1"@9q  
package NetFox; xdDe@G;"  
lq]8zm<\)]  
rZ5xQ#IA  
public class Utility { =8TBkxG  
;I80<SZ  
=./PY10'  
public Utility() :f%kk atO  
{ JUj.:n2e  
(CH6Q]Wi_!  
K>LS8,8V  
} .iP>?9$f"  
BB9eQ: xO  
//线程睡眠 $cuBd  
public static void sleep(int nSecond) Vr"'O6  
{ ^+-]V9?+  
try{ 5-k gGOt  
Thread.sleep(nSecond); _ W#Km  
} d0|{/4IWw;  
catch(Exception e) 3djw  
{ .@EzHe ^W  
e.printStackTrace (); :?= 1aiS  
} ( xzruI5P  
} oOLA&N-A~  
Zn40NKYc  
//日志 t2.jg?`k  
public static void log(String sMsg) E BoC,{R#  
{ 4 #KC\C  
System.err.println(sMsg); w S?Kc^2O  
} .I]v D#o  
Mae2L2vc  
d(d3@b4Ta  
public static void log(int sMsg) z.\\m;s  
{ y!:vX6l  
System.err.println(sMsg); zFipuG02  
} TOgH~R=  
} vN@04a\h  
N+5f.c+S-  
VKu_ l  
/* <0hVDk~  
**TestMethod.java ubsv\[:C  
*/ 7bE`P[  
package NetFox; =B'Yx  
$G}k'[4C  
)+hJi/g  
public class TestMethod { aO?KRn  
 5T9[a  
$7xfLS8Vo  
public TestMethod() uh#E^~5S  
{ ///xx/weblogic60b2_win.exe j jv'"K2  
try{ F3$8l[O_  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [; $:Lr  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Mh3L(z]/E  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |HJ`uGN<b  
fileFetch.start(); `*yOc6i]  
} _Gb 7n5p  
catch(Exception e){e.printStackTrace ();} -iW>T5f  
S;iD~>KP  
WLh!L='{BK  
} mI:D  
E5|GP  
t1oTZ  
public static void main(String[] args) FEopNDy@y  
{ NU{eoqaT  
new TestMethod(); 0pB'^Q{  
} P@n rcgM.  
} 3BLH d<  
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