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http断点续传简单实现(java)

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/* o^6jyb!j  
**SiteFileFetch.java K|`+C1!  
*/ `2>XH:+7F  
package NetFox; ksTzXG8  
import java.io.*; %,33gZzf  
import java.net.*; 3}08RU7[!  
:_>\DJ'>  
|a%B|CX  
public class SiteFileFetch extends Thread { "]v uD  
4S'[\ZJO  
`tX@8|  
SiteInfoBean siteInfoBean = null; //文件信息Bean ;?0_Q3IML  
long[] nStartPos; //开始位置 Tj Mb>w9  
long[] nEndPos; //结束位置 D)y{{g*Lnm  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 g8KY`MBnC&  
long nFileLength; //文件长度 3 sl=>;-  
boolean bFirst = true; //是否第一次取文件 {W-5:~?"  
boolean bStop = false; //停止标志 6*sw,sU[y  
File tmpFile; //文件下载的临时信息 Ah*wQow  
DataOutputStream output; //输出到文件的输出流 B#1:Y;Z  
i[PvDv"n  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) zkd3Z$Ce  
public SiteFileFetch(SiteInfoBean bean) throws IOException ooY\t +  
{ JwjI{,jY  
siteInfoBean = bean; \WcB9  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); n|6?J_{<b>  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); }X.>4\B5  
if(tmpFile.exists ()) sA3UeTf  
{ .x EJaID\N  
bFirst = false; AfN&n= d K  
read_nPos(); &2Q*1YXj  
} 8[oYZrg  
else `v~!H\q  
{ n3'dLJH|  
nStartPos = new long[bean.getNSplitter()]; W,DZ ;). %  
nEndPos = new long[bean.getNSplitter()]; NIaF5z  
} 8-ZUS|7B  
'[Xl>Z[  
A?DB#-z.r  
kff ZElV  
} <~N%W#z/  
+ZclGchw  
a&C.=  
public void run() zFywC-my@  
{ ocwE_dR{  
//获得文件长度 7lR<@$q  
//分割文件 7-X/>v  
//实例FileSplitterFetch {c@G$  
//启动FileSplitterFetch线程 ;T>+,  
//等待子线程返回 v77fQ0w3  
try{ 1M+oTIN  
if(bFirst) 'y.JcS!|  
{ W^k,Pmopy  
nFileLength = getFileSize(); lufeieW  
if(nFileLength == -1) ] IS;\~  
{ [zQ WyDu  
System.err.println("File Length is not known!"); ?Wa<AFXQ  
} m6i%DE  
else if(nFileLength == -2) pv&^D,H,  
{ M&f#wQ  
System.err.println("File is not access!"); *T1~)z}j<  
} 3cixQzb}u  
else \(fq8AL?  
{ 4H-j .|e  
for(int i=0;i<nStartPos.length;i++) /c#l9&,  
{ MwAJ(  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); iP#=:HZu;  
} a+Ab]m8`  
for(int i=0;i<nEndPos.length-1;i++) A=X-;N#  
{ QPs:RhV7  
nEndPos = nStartPos[i+1]; =EpJZt  
} p411 `]Zf  
nEndPos[nEndPos.length-1] = nFileLength; qfr Ni1\9-  
} NR3`M?Hjf  
} .6m_>Y6  
x8\<qh*:  
"SR5wr   
//启动子线程 "!KpXBc,>  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pl78fs"L@  
for(int i=0;i<nStartPos.length;i++) 6P*O&1hv  
{ r~>,$[|n})  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n8u*JeN  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !ni>\lZ  
nStartPos,nEndPos,i); ]JMl|e  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qn|+eLY  
fileSplitterFetch.start(); Js{= i>D  
} HnU Et/  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,@.EpbB  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VLdB_r3lQ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IzUo0D*@  
nEndPos = " + nFileLength); &{z<kmc$6  
// fileSplitterFetch[nPos.length-1].start(); P^i.La,  
E\$C/}T  
S_\ F  
//等待子线程结束 Cj^{9'0  
//int count = 0; x8"#!Pw:`"  
//是否结束while循环 N wtg%;  
boolean breakWhile = false; `@XehSQ  
Wi$dZOcSJ  
cj g.lzY H  
while(!bStop) .Dw,"VHP  
{ ~xDw*AC-  
write_nPos(); x_!ZycEa  
Utility.sleep(500); CS@&^SEj  
breakWhile = true; Lh ap4:  
/!T> b:0  
R#eg^7HfX  
for(int i=0;i<nStartPos.length;i++) F,T~\gO5,  
{ -^SA8y  
if(!fileSplitterFetch.bDownOver) |/T43ADW  
{ ?KP}#>Ba@  
breakWhile = false; >|*yh~  
break; 'jjb[{g^}}  
}  CdZ BG  
} v\%G|8+]  
if(breakWhile) 33a uho  
break; L`[z[p {?  
>EP(~G3u  
YI@Fhr &NU  
//count++; JhX=l-?  
//if(count>4) fn}UBzED\  
// siteStop(); vAi$ [p*im  
} "A[ b rG  
FWY2s(5p  
S$[k Q|Am  
System.err.println("文件下载结束!"); 2Z/K(J"&J  
} 50~K,Jx6B  
catch(Exception e){e.printStackTrace ();} J4aB Pq`  
} ll<NIdf\r  
g/Wh,f3  
0KvVw rWJ  
//获得文件长度 k6**u  
public long getFileSize() lMifpK  
{ jbmTmh1q  
int nFileLength = -1; jirbUl  
try{ ;*cLG#&'M  
URL url = new URL(siteInfoBean.getSSiteURL()); %2l7Hmp4H  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B'weok  
httpConnection.setRequestProperty("User-Agent","NetFox"); <J{'o`{  
MI#mAg<  
>e&:`2%.  
int responseCode=httpConnection.getResponseCode(); QIU,!w-3X  
if(responseCode>=400) Es'Um,ku  
{ Re= WfG  
processErrorCode(responseCode); 0ejdKdYN  
return -2; //-2 represent access is error vO@s$qi  
} uCP>y6I  
=o=1"o[  
F%/ h*  
String sHeader; TprtE.mP  
A( d5G^  
s0W2?!>)  
for(int i=1;;i++) @QEqB_W  
{ slW3qRT\k  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8E^@yZo{  
//Utility.log(in.readLine()); 6][1 <}8  
sHeader=httpConnection.getHeaderFieldKey(i); !|G(Yg7C  
if(sHeader!=null) \5><3*\  
{ >cR)?P/o  
if(sHeader.equals("Content-Length")) +M\8>/0oA  
{ V5rp.~   
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IB5BO7J  
break; } :?.>#  
} z;}6f  
} /Z%>ArAx  
else +a+`Z>  
break; m <k!^jp  
} 'cdN3i(  
} _YHu96H;  
catch(IOException e){e.printStackTrace ();} EeQ5vqU  
catch(Exception e){e.printStackTrace ();} kODK@w V-  
c6AWn>H  
Ca>&  
Utility.log(nFileLength); ~,gXaw  
Qvoqx>2p5  
nKh&-E   
return nFileLength; lC?Icn|o  
} 9s$U%F6}  
~Pf5ORoe  
/ !xF?OmVd  
//保存下载信息(文件指针位置) '/%zi,0  
private void write_nPos() NeOxpn[  
{ "5|Lz)=  
try{ #Z!b G?="  
output = new DataOutputStream(new FileOutputStream(tmpFile)); uQ Co6"e  
output.writeInt(nStartPos.length); WMuD}s  
for(int i=0;i<nStartPos.length;i++) Mtm OUI&'  
{ ^CT&0  
// output.writeLong(nPos); yX/";Oe  
output.writeLong(fileSplitterFetch.nStartPos); NY B[Zyp  
output.writeLong(fileSplitterFetch.nEndPos); 12`_;[37  
} v> z@  
output.close(); P&A|PY,P  
} pxINw>\Qv  
catch(IOException e){e.printStackTrace ();} 30cd| S?  
catch(Exception e){e.printStackTrace ();} &XLD S=j  
} 9uB(Mx(-:`  
wsfd8T4  
\}]iS C.2  
//读取保存的下载信息(文件指针位置) |QZ 58)>  
private void read_nPos() ' P"g\;Ij  
{ [IBQvL  
try{ yubSj*  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =!MY4&YX  
int nCount = input.readInt(); P>Qpv Sd_#  
nStartPos = new long[nCount]; %"$@%"8;3  
nEndPos = new long[nCount]; WOytxE  
for(int i=0;i<nStartPos.length;i++) O9h+Q\0\W  
{ gPC@Yy  
nStartPos = input.readLong(); W0`Gc {  
nEndPos = input.readLong(); H:{7X1bV  
} {{yt*7k{  
input.close(); Owv +1+B  
} YoODR  
catch(IOException e){e.printStackTrace ();} QL7>;t;  
catch(Exception e){e.printStackTrace ();} Hgc=M  
} Oxx^[ju~  
,w)p"[^b  
,d,\-x-+/  
private void processErrorCode(int nErrorCode) $a;]_Y  
{ 'Pltn{iq[  
System.err.println("Error Code : " + nErrorCode); f<jb=\}x  
} hq>Csj==@  
!$qKb_#nC  
6)gd^{  
//停止文件下载 }OShT+xeX  
public void siteStop() k)(Biz398E  
{ ?:rx1}:F  
bStop = true; /'DwfX  
for(int i=0;i<nStartPos.length;i++) XAOak$(j  
fileSplitterFetch.splitterStop(); p#d+>7  
*gsAn<  
5MxL*DB=b  
} N]/!mo?  
} F_;tT%ywfx  
//负责部分文件的抓取 fp>.Owt%.  
**FileSplitterFetch.java 8Z#j7)G  
*/ Zy"=y+e!E;  
package NetFox; USML~]G z  
S4NL "m  
Mio>{%/  
import java.io.*; @)YY\l#  
import java.net.*; XFZ~ #DT&  
. 5HQ   
HaNboYW_K  
public class FileSplitterFetch extends Thread { M++0zhS  
MLVB^<qkeH  
5rxA<G s  
String sURL; //File URL Y#V8(DTyH  
long nStartPos; //File Snippet Start Position +54aO  
long nEndPos; //File Snippet End Position Tt# bg1  
int nThreadID; //Thread's ID ;I6s-moq_  
boolean bDownOver = false; //Downing is over A/*%J74v  
boolean bStop = false; //Stop identical %"3 )TN4  
FileAccessI fileAccessI = null; //File Access interface ~.tvrx g  
`d]Z)*9  
\y Hen|%  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException  ^y.UbI  
{ cL7g}$W $  
this.sURL = sURL; aC=['a>)  
this.nStartPos = nStart; ~Vh=5J~  
this.nEndPos = nEnd; my\&hCE  
nThreadID = id; Iq5pAHm>M6  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b}z`BRCc  
} ?2J?XS>  
T`YwJ6N  
]Tp U"JD  
public void run() U\<-mXv  
{ :>3=gex@^0  
while(nStartPos < nEndPos && !bStop) @|-OJ4[5  
{ Qc-(*}  
;6;H*Y0,|E  
s'I)A^i+  
try{ V-W'RunnW  
URL url = new URL(sURL); L^Wz vv]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w_-+o^  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3x*z\VJ  
String sProperty = "bytes="+nStartPos+"-"; `x8B n"  
httpConnection.setRequestProperty("RANGE",sProperty); mX# "+X|  
Utility.log(sProperty); Y>6.t"?Q^  
<lwuTow  
F3E[wdT  
InputStream input = httpConnection.getInputStream(); nS.G~c|  
//logResponseHead(httpConnection); w<wV]F*  
D@54QJ<  
1 i|.h  
byte[] b = new byte[1024];  $g8}^1  
int nRead; HxwlYx,4  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $xW **&  
{ V^fV7hw<  
nStartPos += fileAccessI.write(b,0,nRead); :- +4:S  
//if(nThreadID == 1) S'i;xL>  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kToOIx  
} bY8GA  
M?&zY "c  
L ubrn"128  
Utility.log("Thread " + nThreadID + " is over!"); o+?@5zw -&  
bDownOver = true; [ = M%  
//nPos = fileAccessI.write (b,0,nRead); |7F*MP  
} K'b*A$5o  
catch(Exception e){e.printStackTrace ();} L4' [XcY  
} `iixq9xi  
} 02b6s&L  
a+z2Zd!u\x  
tai Vk4  
//打印回应的头信息 2: ^njqX  
public void logResponseHead(HttpURLConnection con) HCnf2td  
{ F9o6V|v  
for(int i=1;;i++) |m>}%{  
{ ~1 ZD[@  
String header=con.getHeaderFieldKey(i); b5`KB75sbo  
if(header!=null) v548ysE)  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o#hI5  
Utility.log(header+" : "+con.getHeaderField(header)); ?[1SiJT  
else __N.#c/l{  
break; .KA V)So"  
} |ng%PQq)  
} s@@1 *VQ  
[?KIN_e#  
'CV^M(o'9  
public void splitterStop() vgG}d8MW37  
{ ;)/@Xx  
bStop = true; J\`^:tcG  
} kn  Hv?#  
#uvJH8)D  
 W'/>et  
} L]bVN)JU  
<0j{ $.  
Ol+Kp!ocY  
/* pM$ @m]  
**FileAccess.java @p!Q1-]=  
*//文件访问(定位,写) x mo&![P  
package NetFox; ZwJciT!_~  
import java.io.*; sBW3{uK  
;;#nV$  
McP.9v}H0_  
public class FileAccessI implements Serializable{ "sbBe73 m  
Lo`F  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4M`Xrfwm'[  
RandomAccessFile oSavedFile; `iYc<N`  
long nPos; :t$A8+A+0  
{8CWWfHCD  
&=w|vB)(p  
public FileAccessI() throws IOException VTw/_Hf2p  
{ 2P}I'4C-  
this("",0); Mtp%co)f  
} 4XG]z_+I  
:JV\){P  
L3c*LL  
public FileAccessI(String sName,long nPos) throws IOException $WaZ_kt  
{ +VOb  
oSavedFile = new RandomAccessFile(sName,"rw"); Yn<)k_kp  
this.nPos = nPos; qei$<j'b  
oSavedFile.seek(nPos); }98-5'u.X  
} SMO*({/  
.ZX2^)`XD  
xZ ;bMxZ  
public synchronized int write(byte[] b,int nStart,int nLen) j#igu#MB*  
{ "$@,n7 k  
int n = -1; \y~)jq:d"  
try{ 'p)QyL`d  
oSavedFile.write(b,nStart,nLen); {nRUH*(d9  
n = nLen; I'A:J  
} l>Av5g)  
catch(IOException e) K-@bwB7~s  
{ M,..Kw/ }~  
e.printStackTrace (); l%PnB )F  
} %$9:e J?  
wZ>Y<0,  
=J3`@9;  
return n; chLeq  
} w%u5<  
n-OWwev)  
.<w)Bmh  
} !sK#zAR2  
DQ_ 2fX~)  
<!!nI%NC  
/* )%#?3X^sI  
**SiteInfoBean.java aL)$b  
*/ O5MDGg   
package NetFox; Q \WXi  
u}CG>^0C  
@_O3&ZK  
public class SiteInfoBean { PP4d?+;V  
LUul7y'"  
M,G8*HI"  
private String sSiteURL; //Site's URL g RU-g  
private String sFilePath; //Saved File's Path *1,=qRjL  
private String sFileName; //Saved File's Name 88YC0!Ni  
private int nSplitter; //Count of Splited Downloading File _LsYMUe  
L9J;8+ge  
gvr]]}h:O  
public SiteInfoBean() .+uVgSN  
{//nSplitter的缺省值为5 j4vB`Gr]  
//default value of nSplitter is 5 J/[7d?hI/  
this("","","",5); Zh? V,39  
} .h6Y< E  
k(9s+0qe  
lb95!.av+I  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VO|u8Z"  
{ P2QRvn6v  
sSiteURL= sURL; ir+8:./6  
sFilePath = sPath; "i(U  
sFileName = sName; _Q^y_f  
this.nSplitter = nSpiltter; E6Q91Wz9f  
QRiF!D)Nk  
>vxWx[fRu  
} c}'Xoc  
2{gwY85:  
8E=vR 8  
public String getSSiteURL() C#T)@UxBZ  
{ PbQE{&D#  
return sSiteURL; ]3 j[3'  
} qw)Key  
%0 qc@4  
x' ?.~  
public void setSSiteURL(String value) 8z0Hx  
{ /t5g"n3  
sSiteURL = value; 9?!u2 o  
} F*. /D~K  
\CDAFu#  
P 4H*jy@?  
public String getSFilePath() `43vxcMg  
{ uzO {{S-  
return sFilePath; % dYI5U89  
} k|fh\F+$  
Q>V?w gZ  
\Qp}|n1JY  
public void setSFilePath(String value) 4t*<+H%  
{ sq48#5Tc^r  
sFilePath = value; ~{9x6<g!  
} '%:5axg?]  
z(jU|va{_1  
9M;I$_U`vj  
public String getSFileName() %qONJP  
{ )v};C<  
return sFileName; Jfe~ ,cI  
} C\J@fpH(t`  
#'#4hJ*YC  
Vj29L?3  
public void setSFileName(String value) [KD}U-(Wg  
{ M Ey1~h/  
sFileName = value; @H3|u`6V  
} Re7{[*Q4  
rx{#+ iw  
+$'e4EwqV  
public int getNSplitter() e1oFnu2R  
{ _pJX1_vD  
return nSplitter; fO0- N>W'P  
} +Z )`inw  
y B1W>s8&  
Cx$9#3\  
public void setNSplitter(int nCount) BzN/6VEw  
{ rffVfw  
nSplitter = nCount; <.: 5Vx(Aw  
} }1l}-w`F  
} #3YdjU3w  
w"yK\OE  
NT'Ie]|  
/* Dy98[cL  
**Utility.java {E3;r7  
*/ HE9. k.sS  
package NetFox; -v;iMEZ)  
//VG1@vaVX  
#@IQlqJfY7  
public class Utility { "pR $cS  
o@Dk%LxP  
(q055y  
public Utility() 7&#'c8]/qh  
{ B[C7G7<B  
 GE{8I<7c  
rD_Ss.\^g  
} C,V|TF.i2  
r7zf+a]  
//线程睡眠 cKaL K#~  
public static void sleep(int nSecond) ER0TY,  
{ <t% Ao,"  
try{ E>o&GYc  
Thread.sleep(nSecond); #Lu4OSM+  
} 8Ng) )7g!  
catch(Exception e) 1t!&xvhG  
{ |j\eBCnH3  
e.printStackTrace (); OFJJ-4[_3  
} c }g$1of87  
} z1z =P%WK  
\UV T_=Y  
//日志 F0DPS:c  
public static void log(String sMsg) DK2c]i^|=  
{ TiwHLb9  
System.err.println(sMsg); :FEd:0TS  
} Lqy|DJ%  
1',+&2)oj  
k i~Raa/e  
public static void log(int sMsg) ":5~L9&G  
{ VKl~oFKXJ  
System.err.println(sMsg); H J2O@e  
} g;| n8]  
} N9~'P-V  
{FrHm  
D_L'x"  
/* B' <O)"1w  
**TestMethod.java c~Q`{2%+  
*/ #l8K8GLuf  
package NetFox; ;tZ}i4Ud  
F 5b]/;|  
 p1[WGeV  
public class TestMethod { f)!{y> Q  
 uhPIV\  
l%vhV&  
public TestMethod() >B|ofwm*  
{ ///xx/weblogic60b2_win.exe ulJ+:zwq$  
try{ zwF7DnW<<  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZVCv(J  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #CBo  
SiteFileFetch fileFetch = new SiteFileFetch(bean); #RsIxpc  
fileFetch.start(); PDa06(t7  
} ~XN]?5GQf  
catch(Exception e){e.printStackTrace ();} |wl")|b%  
* S+7BdP  
^+.e5roBKj  
} JJ= ~o@|c  
^$^Vd@t>a  
Av\ 0GqF  
public static void main(String[] args) WoN]eO  
{ c"jhbH!u4  
new TestMethod(); ?j ;,q  
} s`dkEaS  
} $txWVjR?\  
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