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http断点续传简单实现(java)

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/* sm"s2Ci=}  
**SiteFileFetch.java L Q0e@5  
*/ L Iz<fB  
package NetFox; 7>lM^ :A  
import java.io.*; .F},Z[a&  
import java.net.*; T/]f5/  
Z7XFG&@6  
F.),|t$\  
public class SiteFileFetch extends Thread { s@IgaF {  
}`.d4mm  
&EmG\vfE  
SiteInfoBean siteInfoBean = null; //文件信息Bean {B-*w%}HU  
long[] nStartPos; //开始位置 Qk72ra)  
long[] nEndPos; //结束位置 >#VNA^+t  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 C),i#v  
long nFileLength; //文件长度 Z+=M_{`{  
boolean bFirst = true; //是否第一次取文件 lg +>.^7k  
boolean bStop = false; //停止标志 R*/s#*gmL  
File tmpFile; //文件下载的临时信息 \@[,UZ  
DataOutputStream output; //输出到文件的输出流 6n^@Ps  
u4j"U6"]M  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9l(T>B2a  
public SiteFileFetch(SiteInfoBean bean) throws IOException vUCmm<y  
{ 0X3yfrim  
siteInfoBean = bean; UmR4zGM}  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 2Qt!JXC  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ~7an j.  
if(tmpFile.exists ()) 4Cv*zn  
{ (x fN=Te,-  
bFirst = false; ``%yVVg}  
read_nPos(); T'{9!By,P  
} k/(]1QnW  
else w2db=9  
{ j#0JD!Vr  
nStartPos = new long[bean.getNSplitter()]; F1A40h7R$Y  
nEndPos = new long[bean.getNSplitter()]; 1ktxG1"1  
} $<yhEvv  
.5uqc.i"f  
=*1NVi $n  
H@1}_d  
} |nE4tN#J<  
/3&MUB*z&y  
SA7(EJ95  
public void run() Re&"Q8I.8  
{ M*f]d`B  
//获得文件长度 P?S]Q19Q4  
//分割文件 s VHk;:e>x  
//实例FileSplitterFetch sn"z'=ch  
//启动FileSplitterFetch线程 3~VV2O  
//等待子线程返回 bF6J>&]!  
try{ }wkY`"  
if(bFirst) <v'&Pk<  
{ $1g1Bn  
nFileLength = getFileSize(); C!|LGzs0  
if(nFileLength == -1) YZ`SF"Bd(  
{ tj$[szo  
System.err.println("File Length is not known!"); :AS`1\ C  
} K8R>O *~  
else if(nFileLength == -2) vd)zvI  
{ ,yA[XAz~U  
System.err.println("File is not access!"); S*$?~4{R  
} zCuB+r=C  
else `CI_zc=jx  
{ T;?k]4.X  
for(int i=0;i<nStartPos.length;i++) aL%E#  
{ |R1T;J<[  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); SiUu**zC  
} yOt#6Vw  
for(int i=0;i<nEndPos.length-1;i++) Fn7OmxfD  
{ Qn,6s%n  
nEndPos = nStartPos[i+1]; ZP5 !O[Ut  
} IzJq:G.  
nEndPos[nEndPos.length-1] = nFileLength; 2 rr=FJ  
} [orL.D]  
} =MMd&  
}z x ~  
!1fZ7a  
//启动子线程 ),-gy~  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QeG9CS)E}j  
for(int i=0;i<nStartPos.length;i++) N@L{9ak1  
{ -sfv"?  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;}j(x;l>t  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X.#)CB0c1Q  
nStartPos,nEndPos,i); P6R_W  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RFy MRE!?  
fileSplitterFetch.start(); y;uR@{  
} z V\+za,  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t2s/zxt  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wV"`Du7E;  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "J`&"_CyZ  
nEndPos = " + nFileLength);  +l/v`=C  
// fileSplitterFetch[nPos.length-1].start(); CF2Bd:mfZ  
:Ys~Lt54  
VOLj#H  
//等待子线程结束 l6&\~Z(  
//int count = 0; EgU#r@7I  
//是否结束while循环 &8z<~q  
boolean breakWhile = false; d.^g#&h  
+)iMJ]>  
(rd [tc  
while(!bStop) M{Z ;7n'  
{ m$kQbPlatN  
write_nPos(); %KXiB6<4  
Utility.sleep(500); {VL@U$'oI  
breakWhile = true; =I'3C']Z W  
o[T+/Ej&  
{@^;Nw%J  
for(int i=0;i<nStartPos.length;i++) B+j]C$8}  
{ <ZF|2  
if(!fileSplitterFetch.bDownOver) r~lZ8$KC  
{ . \"k49M`  
breakWhile = false; 0{|HRiQH9+  
break; R<Lf>p>_  
} `daqzn  
} iU;e!\A  
if(breakWhile) WXl+w7jr  
break; )&Oc7\J,  
6JDHwV  
>w@+cUto  
//count++; `x#Ud)g  
//if(count>4) @)?]u U"L  
// siteStop(); K"H\gmV_ g  
} `X6JZxGyd  
&$F<]]&  
Jpj=d@Of70  
System.err.println("文件下载结束!"); #_@cI(P  
} 3KkfQ{  
catch(Exception e){e.printStackTrace ();} XiE`_%NW  
} pn gto  
TZAd{EZa  
~,b^f{7`!  
//获得文件长度 CwA_jOp  
public long getFileSize() ViPC Yt`of  
{ \=A A,Il  
int nFileLength = -1; 'J|)4OG:  
try{ $(aq;DR  
URL url = new URL(siteInfoBean.getSSiteURL()); _1p8(n  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HYmC3  
httpConnection.setRequestProperty("User-Agent","NetFox"); l%0bF9\  
U]iI8c  
QO/0VB42  
int responseCode=httpConnection.getResponseCode(); f'^uuO#x  
if(responseCode>=400) d,b4q&^X8  
{ a/sjW  
processErrorCode(responseCode); `hi=y BO  
return -2; //-2 represent access is error //q(v,D%Q  
} vxOqo)yO  
&12K pEyf  
_\ToA9m  
String sHeader; b-&iJ &>'  
(+> 2&@@<  
[1VA`:?W  
for(int i=1;;i++) QPJ \Iu@D$  
{ d(T4Kd$r  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {r,U ik-nL  
//Utility.log(in.readLine()); .$qa?$@  
sHeader=httpConnection.getHeaderFieldKey(i); G<;~nAo?f0  
if(sHeader!=null) T{k P9 4  
{ <v:VA!]  
if(sHeader.equals("Content-Length")) 5ilGWkb`'X  
{ tnRf!A;m  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oJz2-P mX  
break; 5i!Q55Yv=,  
} "is(  
} )/H;5 cn  
else 7A)\:k  
break; Km` SR^&\  
} jT{T#_  
} sgX!4wG&Z  
catch(IOException e){e.printStackTrace ();} EKwQ$?I  
catch(Exception e){e.printStackTrace ();} I0Pw~Jj{  
M&Ka ^h;N  
LVj 1NP  
Utility.log(nFileLength); 8M,*w6P  
eqo0{e  
Ps!MpdcL3  
return nFileLength; { mi}3/  
} SB_Tzp  
]pax,| +$C  
ef5)z}B   
//保存下载信息(文件指针位置) iC gZ3M]  
private void write_nPos() :Ha/^cC/3  
{ LKIMT  
try{ xM*_1+<dT$  
output = new DataOutputStream(new FileOutputStream(tmpFile)); B$4*U"tk  
output.writeInt(nStartPos.length); >XD?zF)6  
for(int i=0;i<nStartPos.length;i++) {3~VLdy  
{ 5)k8(kH  
// output.writeLong(nPos); uN|A}/hr]  
output.writeLong(fileSplitterFetch.nStartPos); pP. _%5  
output.writeLong(fileSplitterFetch.nEndPos); 8Bf >  
} 3Vb4zZsl  
output.close(); _4ag-'5  
} 6>>; fy2  
catch(IOException e){e.printStackTrace ();} Kc/1LeAik  
catch(Exception e){e.printStackTrace ();} rhJ&* 0M  
} 8+zW:0"[  
3db{Tcn\@]  
w?Te%/s.  
//读取保存的下载信息(文件指针位置) V]=22Cxi'~  
private void read_nPos() LW %AZkAx  
{ :QE5 7 .  
try{  +\/Q  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |VBt:dd<  
int nCount = input.readInt(); Yh":>~k?SY  
nStartPos = new long[nCount]; {ZJO5*  
nEndPos = new long[nCount]; m|a9T#B(  
for(int i=0;i<nStartPos.length;i++) :RaQ =C  
{ C"{^wy{sL  
nStartPos = input.readLong(); (o^tmH*  
nEndPos = input.readLong(); "HMEoZ  
} {keZ_2  
input.close(); 1|bXIY.J*  
} +#}GmUwPG$  
catch(IOException e){e.printStackTrace ();} d>NGCe  
catch(Exception e){e.printStackTrace ();} 7FB?t<x  
} B VBn.ut  
]P4WfV d  
Kb.qv)6i*  
private void processErrorCode(int nErrorCode) D!<F^mtl  
{ wu41Mz7  
System.err.println("Error Code : " + nErrorCode); vwCQvt  
} rPV Q#iB  
8Sbz)X  
[);oj<  
//停止文件下载 DiCz%'N  
public void siteStop() H?$dnwR  
{ uZqL'l+/y  
bStop = true; B=_w9iVN  
for(int i=0;i<nStartPos.length;i++) o`U}u qrO  
fileSplitterFetch.splitterStop(); ,+=9Rp`md  
}V?m =y [  
%b6$N_M{H1  
} 6x+ujUBkK  
} i_Kwxn$  
//负责部分文件的抓取 iSW2I~PD  
**FileSplitterFetch.java d t/AAk6  
*/ 0YH5B5b  
package NetFox; =7Ln&tZ  
O[@!1SKT0  
xQoZ[  
import java.io.*; u?osX;'w  
import java.net.*; <Xf6?nyZ(  
rTPgHK]?l  
J2mHPV A3  
public class FileSplitterFetch extends Thread { ^7gGtz2  
zj 6I:Q r  
&i#$ia r  
String sURL; //File URL _y@ 28t  
long nStartPos; //File Snippet Start Position -IPo/?}  
long nEndPos; //File Snippet End Position <r%K i`u(p  
int nThreadID; //Thread's ID +;N]34>S7  
boolean bDownOver = false; //Downing is over LGP"S5V  
boolean bStop = false; //Stop identical EX8JlA\-W  
FileAccessI fileAccessI = null; //File Access interface %I1@{>OxG  
PmR].Ohzi  
> p`,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mH o#"tc  
{ .<x6U*)\O  
this.sURL = sURL; C{exvLQ  
this.nStartPos = nStart; S?J!.(  
this.nEndPos = nEnd; KX) n+{   
nThreadID = id; 2d)Dhxzxk  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /6x&%G:m#  
} 8 Rx@_   
]\, ?u /  
["-rD y P  
public void run() {)YbksrJ{  
{ @rl5k(  
while(nStartPos < nEndPos && !bStop) J_Lmy7~xbD  
{ 7! O"k#  
IH|zNg{\Y  
TI>5g(:3\  
try{ mF4W4~"  
URL url = new URL(sURL); 0PzSp ]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qu=~\t1[6  
httpConnection.setRequestProperty("User-Agent","NetFox"); $?= $F  
String sProperty = "bytes="+nStartPos+"-"; ^q7V%{54  
httpConnection.setRequestProperty("RANGE",sProperty); 727#7Bo  
Utility.log(sProperty); S%SYvA  
&@~K8*tmK  
-amo8V;2H  
InputStream input = httpConnection.getInputStream(); UXm_-/&b9  
//logResponseHead(httpConnection); ,d"T2Hy  
&<&tdShI  
m+QS -woHn  
byte[] b = new byte[1024]; MZgaQUg  
int nRead; Cbbdq%ySI  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'gwh:  
{ T:^.; ZY  
nStartPos += fileAccessI.write(b,0,nRead); 5 jrR]X  
//if(nThreadID == 1) HqGI.  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ysaRH3M  
} +a,SP   
QiCia#_  
pdu1 kL  
Utility.log("Thread " + nThreadID + " is over!"); .K C* (}-  
bDownOver = true; O=K lc+Oo  
//nPos = fileAccessI.write (b,0,nRead); TWP@\ BQ  
} >A Ep\ *  
catch(Exception e){e.printStackTrace ();} WQ|Ufl;  
} $^x=i;>aK.  
} Fh~9(Y#  
/b+~BvTh  
"4b{YWv  
//打印回应的头信息 o&JoeKXor  
public void logResponseHead(HttpURLConnection con) `bP`.Wm  
{ <ZC .9  
for(int i=1;;i++) Kz'GAm\  
{ oj8r*  
String header=con.getHeaderFieldKey(i); YwVA].p@TI  
if(header!=null) Xo PJ?6 3  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vo/x`F'ib  
Utility.log(header+" : "+con.getHeaderField(header)); pY&6p~\p  
else 3u@,OE  
break; #2=l\y-#  
} ~WrpJjI[  
} ZflB<cI  
s_^`t+5  
|d0X1(  
public void splitterStop() F|%PiC,,qO  
{ }Qo]~/  
bStop = true; '5}hm1,  
} ;~3;CijJ8  
2/SUEnaLy_  
"8QRYV~Z  
} =!Ik5LiD  
{i>AQ+z61f  
_L,~WYRo  
/* MN: {,#d0  
**FileAccess.java &A:&2sP8  
*//文件访问(定位,写) Dj/Hz\  
package NetFox; Df"PNUwA"  
import java.io.*;  ?K-4T  
PKlR_#EB?  
Zma;An6  
public class FileAccessI implements Serializable{ C(>!?-.  
r] /Ej!|  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f2.=1)u.  
RandomAccessFile oSavedFile; 2Z; !N37U  
long nPos; XX=OyDLqP  
2)EqqX[D  
:7{GOx  
public FileAccessI() throws IOException |5>Tf6 $(  
{ g? vz\_  
this("",0); 2j f!o  
} ;CO qu#(  
F=\ REq  
8UB2 du@?  
public FileAccessI(String sName,long nPos) throws IOException 'IU3Xu[-.  
{ G}U <^]c  
oSavedFile = new RandomAccessFile(sName,"rw"); `8ob Xb  
this.nPos = nPos; lhM5a \  
oSavedFile.seek(nPos); S @[]znH  
} % J\G[dl  
S{llpp{E  
1 -Z&/3T]  
public synchronized int write(byte[] b,int nStart,int nLen) O 0}uY:B  
{ 7\@c1e*e  
int n = -1; UDHOcb  
try{ NXD-  
oSavedFile.write(b,nStart,nLen); y,?=,x}o#  
n = nLen; >4g!ic~O  
} C\{A|'l!x  
catch(IOException e) m9h<)D'>  
{ =2q#- ,t  
e.printStackTrace (); S6bW r0XR  
} dr)*.<_+a(  
%=z>kU1|  
auI`'O`/  
return n; s<*+=aIfu  
} e;v7!X  
7,)E1dx -V  
I(UK9H{0$  
} cO:lpsKYQ  
IAA_Ft  
F]RPM(!5O)  
/* ,wf_o%'eW  
**SiteInfoBean.java  x,: k/]  
*/ Ztk%uc8_lM  
package NetFox; c ,#=In2  
eNfH9l2k  
5H'Iul<Os  
public class SiteInfoBean { ,b^Y8_ltoT  
5]mH.{$x$?  
e@c8Ce|0  
private String sSiteURL; //Site's URL $c*fbBM(&n  
private String sFilePath; //Saved File's Path ^5Y<evjm  
private String sFileName; //Saved File's Name 7(5d$W  
private int nSplitter; //Count of Splited Downloading File ]prw=rD  
E2l" e?AN~  
h~QQ-  
public SiteInfoBean() y%|Ez  
{//nSplitter的缺省值为5 aP(~l_  
//default value of nSplitter is 5 aGW O3Nk  
this("","","",5); N?3p,2  
} .|"E:qTD  
Ud"_[JtGM  
<IU   
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CUB;0J(  
{ 5> dA7j^v  
sSiteURL= sURL; [cFD\"gJAr  
sFilePath = sPath; f2tCB1[D+  
sFileName = sName; +%<kcc3  
this.nSplitter = nSpiltter; ZK ?V{X{";  
nls$ wE  
*QNX?8Fm_  
} l`75BR  
}2Ge??!  
wBlE!Pm  
public String getSSiteURL() t .&JPTK-H  
{ l_((3e[)  
return sSiteURL; t<+>E_Xw  
} Z$i?p;HnW  
j*?E~M.'1K  
|0^IX   
public void setSSiteURL(String value) V6>{k_0{V  
{ `?^<r%*F.  
sSiteURL = value; zgS)j9q}  
} ys)  
8/B8yY-O  
qi^kf  
public String getSFilePath() 3f>9tUWhTy  
{ 8bw, dBN  
return sFilePath; Ur[ai6LNG  
} c.Izm+9k  
{OQ)Np!  
uR=*q a  
public void setSFilePath(String value) AN,3[Sh  
{ s!W{ru  
sFilePath = value; {y|.y~vW  
} f% 8n?f3;u  
.$f0!` t  
8\)4waz$  
public String getSFileName() 3Zz_wr6  
{ dr8Q>(ZY  
return sFileName; %U<lS.i  
} a@_n>$LZL  
bTx4}>=5l  
Yjy%MR  
public void setSFileName(String value) | Eu#mN  
{ Q(WfWifu-|  
sFileName = value; 8z-wdO\  
} ]Gj%-5G  
D41.$t[  
}WR@%)7ay  
public int getNSplitter() NUBzc'qb  
{ zzC{I@b  
return nSplitter; e*<pO@Uy  
} nbw8YO(=  
wd,6/5=lh  
0p,_?3nX  
public void setNSplitter(int nCount) ?+c-m+;wj  
{ %h_N%B$7c1  
nSplitter = nCount; D1]?f`  
} 8XfOM f~d`  
} svC m }`  
EAs^i+/  
RR`\q>|  
/* zYis~ +  
**Utility.java pm}_\_  
*/ 5:~ zlg  
package NetFox; n>o=RQ2  
_Fkb$NJ"]Q  
us#ji i.<  
public class Utility { %@I= $8j  
ip|l3m$Mi  
=m;cy0))  
public Utility() ;F2"gTQS  
{ r"7 !J[u  
.L)j ql%  
x` 4|^ u  
} 4{$ L]toP  
}y|_v^  
//线程睡眠 1LmbXH]%  
public static void sleep(int nSecond) Z'wGZ(  
{ gE23C*!'&:  
try{ H'@@%nO (  
Thread.sleep(nSecond); "NV~lJS%  
} f1\mE~#}  
catch(Exception e) P?=}}DI  
{ |l~#qeZ%  
e.printStackTrace (); pSx}:u^am  
} ?R@u'4yK  
} V4*/t#L/  
_k)EqPYu@  
//日志 tac_MtW?  
public static void log(String sMsg) `:gXQmt  
{ UE/iq\a>  
System.err.println(sMsg); oJc v D  
} m.yt?`  
,_'Z Jlx  
@ &GA0;q0t  
public static void log(int sMsg) RHI?_gf&  
{ y<ZT~e  
System.err.println(sMsg); 4g+o/+6!4  
} 1mv8[^pF  
} /p{$HkVw  
\NL*$SnxP  
q] '2'"k  
/* !imjfkG  
**TestMethod.java |x ir93|  
*/ 9+'*  
package NetFox; ATD4 %|a9h  
opReAU'I  
x c?=fv  
public class TestMethod { `! )^g/>0i  
NE?tfj  
JPe<qf-  
public TestMethod() ,/-DAo~O  
{ ///xx/weblogic60b2_win.exe Zu ![v0  
try{ RPTIDA))  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E`q)vk   
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &*qAB)* *  
SiteFileFetch fileFetch = new SiteFileFetch(bean); _lw:lZM?  
fileFetch.start(); n?NUnFA  
}  )jH|j  
catch(Exception e){e.printStackTrace ();} %bB:I1V\  
~T\:".C  
J'yiVneMw  
} 4='/]z  
<xD6}h/  
j2%M-y4E  
public static void main(String[] args) E(an5x/r  
{ V}/AQe2m&  
new TestMethod(); R@[1a+}5  
} UmP\;  
} ^%RIz!}  
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