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http断点续传简单实现(java)

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/* V7+/|P_  
**SiteFileFetch.java YKx+z[A/p  
*/ \;"S>dg  
package NetFox; F<)f&<5E-  
import java.io.*; @Z96902<t  
import java.net.*; 6$fwpW  
gX* &RsF  
4@-Wp]  
public class SiteFileFetch extends Thread { "7?xaGh8  
1+tPd7U  
5)w;0{X!P  
SiteInfoBean siteInfoBean = null; //文件信息Bean @*$"6!3s5  
long[] nStartPos; //开始位置 7 S%`]M4;  
long[] nEndPos; //结束位置 0s.4]Zg>5  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 m# ^).+  
long nFileLength; //文件长度 ldG$hk'  
boolean bFirst = true; //是否第一次取文件 w *o _s  
boolean bStop = false; //停止标志 t"6u  
File tmpFile; //文件下载的临时信息 AP?m,nd6  
DataOutputStream output; //输出到文件的输出流 ;uuBX0B  
\i)@"}  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) <(us(zbk]  
public SiteFileFetch(SiteInfoBean bean) throws IOException  GU xhn  
{ I#zL-RXT  
siteInfoBean = bean; E7]a#  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); (. ,{x)H  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [bN_0T.YI  
if(tmpFile.exists ()) v\XO?UEJ2  
{ Xd&oERJj  
bFirst = false; L-e6^%eU  
read_nPos(); vNU[K%U  
} fqol-{F.V  
else D6EqJ,~  
{ AgdU@&^  
nStartPos = new long[bean.getNSplitter()]; ulk yP  
nEndPos = new long[bean.getNSplitter()]; zG&yu0;D6  
} u 0 K1n_  
QW%xwV?8  
 <XnxAA  
QwI HEmdM  
} "3?:,$*  
C,{ Ekbg  
)/{~&L U  
public void run() 8sL+ik"  
{ j*_#{niy:  
//获得文件长度 5)M#hx%]#  
//分割文件 4o@^._-R  
//实例FileSplitterFetch yLt>OA<X  
//启动FileSplitterFetch线程 z'EphL7r   
//等待子线程返回 V>Nw2u!!  
try{ AE%zqvp>  
if(bFirst) ' PmBNT  
{ (HeIO  
nFileLength = getFileSize(); :NWrbfz  
if(nFileLength == -1) {d,^tG}  
{ Km0P)Z  
System.err.println("File Length is not known!"); ;{g>Z|  
} rrZ'Dz  
else if(nFileLength == -2) 8p~|i97W]!  
{ By0Zz  
System.err.println("File is not access!"); 8noo^QO  
} xllmF)]*Y  
else 7L!q{%}  
{ ;B"S*wYMN  
for(int i=0;i<nStartPos.length;i++) &F +hh{  
{ {^K&9sz  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 0a)LZp|  
} et6@);F  
for(int i=0;i<nEndPos.length-1;i++) it=ir9  
{ Qexv_:C  
nEndPos = nStartPos[i+1]; `I5So-^&z  
} }4xz,oN  
nEndPos[nEndPos.length-1] = nFileLength; $ 2k9gO  
} ~"vRH  
} p,#**g:  
e&=T`  
g0RfvR  
//启动子线程 Il<ezD{  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [2zS@p  
for(int i=0;i<nStartPos.length;i++) yrR,7v J  
{ +RD{<~i  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w Yr M2X@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P Z+Rz1x  
nStartPos,nEndPos,i); G~Fjla\?Q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @X#e  
fileSplitterFetch.start(); OlYCw.Zu  
} 0S>U_#-  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X!0m,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {hKf 'd9E  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1$ {Cwb/F  
nEndPos = " + nFileLength); .^uYr^( |[  
// fileSplitterFetch[nPos.length-1].start(); xA"7a  
^g n7DiIPH  
K]Q1VfeL=  
//等待子线程结束 eHI7= [h  
//int count = 0; Jgf= yri  
//是否结束while循环 gz"I=9  
boolean breakWhile = false; )Ft>X9$  
d##'0yg   
UmA'aq  
while(!bStop) C)0JcM  
{ /;r k-I  
write_nPos(); J(x42Q}*S  
Utility.sleep(500); ;S^7Q5-  
breakWhile = true; pkEqd"G  
OYNPZRu  
/9 soUt  
for(int i=0;i<nStartPos.length;i++) _cXLQ)-  
{ w]Vd IS  
if(!fileSplitterFetch.bDownOver) `n~bDG>  
{ ngQ]  
breakWhile = false; n$(_(&  
break; O8WLulo  
} nHmi%R7k  
} m=%WA5c?  
if(breakWhile) npdpKd+*K"  
break; {!7 ^ w  
+"2IQme5  
5oE!^bF?  
//count++; (8OaXif  
//if(count>4) EU-=\Y  
// siteStop(); M }tr*L  
} hKYA5]  
JGKiVBN  
IH0qx_;P&  
System.err.println("文件下载结束!"); )]C7+{ImC  
} I:%O`F  
catch(Exception e){e.printStackTrace ();} Z,m;eCLG]  
} M `bEnu  
l*C(FPw4  
^ G(GjW8  
//获得文件长度 H0\5a|X-  
public long getFileSize() YDr/Cw>J  
{ gsp|?) ]x  
int nFileLength = -1; !<xeAo%8  
try{ `l8^n0-  
URL url = new URL(siteInfoBean.getSSiteURL()); _ Tj`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jB!Q8#&Q  
httpConnection.setRequestProperty("User-Agent","NetFox"); .ahYj n  
;.P9t`*  
]za1=~[  
int responseCode=httpConnection.getResponseCode(); +gQoYlso  
if(responseCode>=400) mOvwdRKn  
{ l~V^  
processErrorCode(responseCode); F2$Z4%x#  
return -2; //-2 represent access is error }^ j"@{~  
} L z'05j3!  
-I#1xJU  
Lg[_9 `\  
String sHeader; h tn?iLq  
Dk XB  
RwC1C(ZP  
for(int i=1;;i++) 5w+X   
{ F7zBm53  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4^mpQ.]lO  
//Utility.log(in.readLine()); Cp 2$I<T  
sHeader=httpConnection.getHeaderFieldKey(i); @< @\CiM  
if(sHeader!=null) OJ:iQ  
{ P9aGDma  
if(sHeader.equals("Content-Length")) "##Ylq("  
{ J9 iQW  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  #{8n<sE  
break; EJrn4QOs  
} JtrLTo  
} ,U#$Qb 12  
else w1+xlM,,9  
break; r-$SF5uv  
} |?Z;tAF!  
} `|i[*+WC  
catch(IOException e){e.printStackTrace ();} tOK lCc  
catch(Exception e){e.printStackTrace ();} {$ghf"  
C 4 &1M  
7VdG6`TDR  
Utility.log(nFileLength); P+Ta|-  
(Wu_RXfCw_  
Q!<b"8V]  
return nFileLength; qUY QN2wG  
} ]#N~r&hmQ  
_f8<t=R  
v]tbs)x;h  
//保存下载信息(文件指针位置) QDg\GA8|  
private void write_nPos() "&ElKy 7j  
{ vq~btc.p{&  
try{ ?6gC;B  
output = new DataOutputStream(new FileOutputStream(tmpFile)); N!}r(Dd*  
output.writeInt(nStartPos.length); 9?M><bBX  
for(int i=0;i<nStartPos.length;i++) \i-HECc"U  
{ (@H'7,  
// output.writeLong(nPos); )h0F'MzW  
output.writeLong(fileSplitterFetch.nStartPos); jMvWS71  
output.writeLong(fileSplitterFetch.nEndPos); B|-E3v:f 4  
} h<50jnH!  
output.close(); .OHjn|  
} }l/ !thzC  
catch(IOException e){e.printStackTrace ();} h4 s!VK1X  
catch(Exception e){e.printStackTrace ();} ZCZYgf@  
} mRT`'fxK  
R30{/KK  
m 4Vh R_  
//读取保存的下载信息(文件指针位置) (q!tI* }  
private void read_nPos() |7V:~MTkk&  
{ Xx~XW ^lsh  
try{ RSLMO8  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Jp<Y2-  
int nCount = input.readInt(); TixXA:Mf  
nStartPos = new long[nCount]; BK>uJv-qU  
nEndPos = new long[nCount]; .r/6BDE"  
for(int i=0;i<nStartPos.length;i++) zice0({iJ  
{ fD#VI   
nStartPos = input.readLong(); piE9qXn  
nEndPos = input.readLong(); I |?zSFa  
} X#$mBRK7  
input.close(); ,nJYYM   
} !biq7f%6#  
catch(IOException e){e.printStackTrace ();} <j93   
catch(Exception e){e.printStackTrace ();} uX-]z3+  
} U[1Ir92:  
oW*e6"<R7  
jjgjeY  
private void processErrorCode(int nErrorCode) w1-/U+0o  
{ -,t2D/xK  
System.err.println("Error Code : " + nErrorCode); Q Fv"!Ql  
} oGi;S="I  
8m0GxgS  
F)mlCGv:R  
//停止文件下载 X0Q};,  
public void siteStop() _ 13M  
{ URbu=U  
bStop = true; cNzn2-qv  
for(int i=0;i<nStartPos.length;i++) R&13P&:g  
fileSplitterFetch.splitterStop(); v*+.;60_  
_e<3 g9bj  
p.9VyM  
} beyC't  
} Farcd!}  
//负责部分文件的抓取 /`YHPeXu  
**FileSplitterFetch.java #\kYGr-G)  
*/ %Y"@VcN  
package NetFox; [:geDk9O#'  
Tti]H9g_  
N'nI ^=  
import java.io.*; =FkU: q$  
import java.net.*; $*ujX,}xG  
zT[[WY4  
] 8sVXZ  
public class FileSplitterFetch extends Thread { Ij_Y+Mnl4:  
Suixk'-  
k\UDZ)TQV  
String sURL; //File URL U$j*{`$4  
long nStartPos; //File Snippet Start Position x j6-~<  
long nEndPos; //File Snippet End Position >1[Hk0 <x  
int nThreadID; //Thread's ID Fa`/i v  
boolean bDownOver = false; //Downing is over ;Ub;AqY  
boolean bStop = false; //Stop identical u%FG% j?C  
FileAccessI fileAccessI = null; //File Access interface &h.E B  
PT7L65  
E\2|  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )J&1uMp{  
{ FI1R7A  
this.sURL = sURL; q(0V#kKC  
this.nStartPos = nStart; hX\z93an  
this.nEndPos = nEnd; eqK6`gHa6  
nThreadID = id; B[:-SWd  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9ZjSM,+  
}  GU99!.$  
6@`Y6>}$_  
xy>~ 15  
public void run() Zvd^<SP<?  
{ ;0Yeo"-  
while(nStartPos < nEndPos && !bStop) gbOd(ugH  
{ bKsl'3~ k  
.l$'%AG:~  
Wpo:'?!(M^  
try{ P!q U8AJkt  
URL url = new URL(sURL); <^?64  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rWKc,A[  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8<}f:9/  
String sProperty = "bytes="+nStartPos+"-"; |7Z7_YWs  
httpConnection.setRequestProperty("RANGE",sProperty); (J(JB}[X,  
Utility.log(sProperty); 'ojI_%9<  
KD9Y  
~C6Qp`VF  
InputStream input = httpConnection.getInputStream(); ]K'iCYY  
//logResponseHead(httpConnection); 6 <JiHVP7  
*i#m5f}  
\M>}-j`v  
byte[] b = new byte[1024]; n5i#GvO^  
int nRead; MsMNP[-l  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^v. ~FFK  
{ iJ HOLz"!  
nStartPos += fileAccessI.write(b,0,nRead); H~1&hF"d  
//if(nThreadID == 1) -g'[1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p!<Y 'G  
} wjGD[~mB  
1A;>@4iC0  
^ sxcBG  
Utility.log("Thread " + nThreadID + " is over!"); |,c\R"8xS  
bDownOver = true; :d7Ju.*J  
//nPos = fileAccessI.write (b,0,nRead); Ie(vTP1Cj  
} VmM?KlC  
catch(Exception e){e.printStackTrace ();} w8M,35b  
} F;l*@y Tq  
} xh[De}@  
5 3=zHYQ  
b]s.h8+v;  
//打印回应的头信息 :4]^PB@dl  
public void logResponseHead(HttpURLConnection con) 8 ;oU{  
{ zmk#gk2H  
for(int i=1;;i++) sFaboI  
{ <%fcs"Mb  
String header=con.getHeaderFieldKey(i); 4J3cQ;z  
if(header!=null) Op^r}7  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $OK}jSH*v)  
Utility.log(header+" : "+con.getHeaderField(header)); %lsk> V  
else a=3?hVpB  
break; B.nq3;Y  
} [ UN`~  
} AZ~= ]1  
=H&@9=D*  
?k)(~Y&@p  
public void splitterStop() {R b|";  
{ 2aiZ  
bStop = true; yD6lzuk{X  
} S<"T:Y &  
_h1n]@ d5  
KTX;x2r  
} NLZTIZCK  
uXPvl5(Y?  
kWs"v6B  
/* ;2X/)sxWz  
**FileAccess.java h^#K4/  
*//文件访问(定位,写) |` gSkv  
package NetFox; ni$7)YcF  
import java.io.*; 3#7D g't  
w@U`@})r.  
NsYeg&>`  
public class FileAccessI implements Serializable{ H6Q1r[(B  
%,Fx qw  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @&!HMl  
RandomAccessFile oSavedFile; ,<]X0;~oB  
long nPos; z>HeM Mei  
N- E)b  
Dg]( ?^  
public FileAccessI() throws IOException C]{:>= K  
{ r9@4-U7v&  
this("",0); xB=~3  
} V4Yw"J  
h\GlyH~  
h?H:r <  
public FileAccessI(String sName,long nPos) throws IOException G  @ib  
{ >W%tEc  
oSavedFile = new RandomAccessFile(sName,"rw"); #SiOx/  
this.nPos = nPos; B=K& +  
oSavedFile.seek(nPos); FbRq h|  
} cY1d6P0  
*3_@#Uu7  
+/,J$(  
public synchronized int write(byte[] b,int nStart,int nLen) "_Wv,CYmNr  
{  =lIG#{`Q  
int n = -1; r@;n \  
try{ x5/O.5>f  
oSavedFile.write(b,nStart,nLen);  )L}6to  
n = nLen; 9Tbi_6[  
} F)x^AJi e  
catch(IOException e) <0!/7*;#ZT  
{ Ic_>[E?k  
e.printStackTrace (); (h;4irfX  
} /$v0Rq9  
Ik_u34U  
8RC7 Ei  
return n; /DPD,bA  
} +[$d9  
5e^t;  
0zR4Kj7EE  
} Z["[^=EP  
JY4sB8  
H4#|f n  
/* f>d aK9$(  
**SiteInfoBean.java V> K sbPqR  
*/ [0v`E5  
package NetFox; 7Ddo ^Gtx  
9z)p*+r UK  
R{zAs?j  
public class SiteInfoBean { ,[6N64fy  
+m Plid\  
md8r"  
private String sSiteURL; //Site's URL %hcn|-" F  
private String sFilePath; //Saved File's Path oZ% rzLH  
private String sFileName; //Saved File's Name  XI+m  
private int nSplitter; //Count of Splited Downloading File WJ)( *1  
E3X6-J|  
NbPv>/r  
public SiteInfoBean() ZuV/!9qU  
{//nSplitter的缺省值为5 e RiPC  
//default value of nSplitter is 5 ,A`.u\f(:  
this("","","",5); 0"q^`@sZ  
} $ekJs/I&  
qi!Nv$e  
 [o]^\a y  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) *m_B#~4  
{ nqX)+{wAXe  
sSiteURL= sURL; nSWW^ ;  
sFilePath = sPath; 3\J-=U  
sFileName = sName; @k_xA-a  
this.nSplitter = nSpiltter; 1_}* aQ  
ZMs$C3  
$2l<X KT-  
} iQryX(z  
aYIAy]*1e  
SM3Q29XIw  
public String getSSiteURL() YcJZG|[  
{ # fvt:iE  
return sSiteURL; 7]}n 0*fe  
} \nQV{J  
l(;~9u0sa  
q'u^v PO  
public void setSSiteURL(String value) VFUuG3p)  
{ N 2|?I(\B  
sSiteURL = value; *_Y{wNF *  
} *Mu X]JK  
>>}4b2U  
".Lwq_  
public String getSFilePath() [kfLT::mT  
{ }Yd7<"kp  
return sFilePath; 7GN>o@t  
} O>P792)  
7A!E~/nSC  
JO\F-xO  
public void setSFilePath(String value) 9b KK  
{ obYXDj2  
sFilePath = value; 2)O-EAn  
} pwq a/Yi  
&PJ&XTR  
Hggp*(AQK  
public String getSFileName() yht|0mZV  
{ ')ZM# :G  
return sFileName; D[d+lq#p  
} *;(wtMg  
r`? bYoz  
 U/v }4b  
public void setSFileName(String value) N_AAhD  
{ SJ/($3GkBd  
sFileName = value; v;=F $3  
} 6y;R1z b  
bUR; d78  
O3Jp:.ps  
public int getNSplitter() yXg #<H6V  
{ Jzqv6A3G  
return nSplitter; *AEN  
} CxyL'k  
4~;x(e@S  
@m*^v\q<u  
public void setNSplitter(int nCount) rnB-e?>  
{ DEmU},<S  
nSplitter = nCount; <B,z)c  
} p[kEFE,%  
} nP9zTa  
$w,&h:.p  
]xO`c  
/* +Usy  
**Utility.java nJEm&"AI  
*/ Qfx:}zk{  
package NetFox; >Q159qZ  
~N2<-~=si  
_0Mt*]L }  
public class Utility { ^SdorPOq&  
==$>M d  
-ti nL(?3  
public Utility() Aqi9@BH  
{ ~_XJ v  
;xp^F KP  
xp+Z%0D  
} (`z`ni  
. 4$SNzv3V  
//线程睡眠 5u(B]_r.  
public static void sleep(int nSecond) 8Ja't8  
{ D;~c`G "f  
try{ 4d\1W?i-  
Thread.sleep(nSecond); :%&~/@B  
} 'IR2H{Q  
catch(Exception e) :i;iSrKy  
{ e -sZ_<GH  
e.printStackTrace (); gpo+-NnG  
} Ebmd[A&&  
} (QARle(i  
$j ZU(<4,  
//日志 7od6`k   
public static void log(String sMsg) %hEhZW{:  
{ Oy> V/  
System.err.println(sMsg); $Tc"7nYu  
} W{z7h[?5,  
A^ :/*  
Sb9O#$89  
public static void log(int sMsg) bf9LR1  
{ "mBX$t'gb  
System.err.println(sMsg); "YUh4uZ~P  
} Us5P?}  
} eiiI Wr_7  
]yvHb)X  
`%PU_;Y5Q  
/* zOV.cI6fZz  
**TestMethod.java  >^<%9{  
*/ DOk(5gR  
package NetFox; _]g?3Gw7!  
]KsL(4PY  
}]i re2j8  
public class TestMethod { Sdk:-Zuv  
rD7L==Ld  
]z^*1^u^ig  
public TestMethod() g;|3n&  
{ ///xx/weblogic60b2_win.exe U{^~X_?  
try{ Iuh1tcc  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9ZKB,  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yXuc< m  
SiteFileFetch fileFetch = new SiteFileFetch(bean); KF'DOXBw>  
fileFetch.start(); dZS v=UY)  
} 3,Dc}$t  
catch(Exception e){e.printStackTrace ();} o.)8  A8  
#&L[?jEn  
xEX"pd  
} {6V;$KqH6  
aGUKpYF  
`i'72\(  
public static void main(String[] args) -d|Q|zF^x  
{ G;^},%<  
new TestMethod(); {$dq7m(  
} tEj-c@`"x-  
} H%}ro.u  
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