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http断点续传简单实现(java)

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/* CzDJbvv ]  
**SiteFileFetch.java i E p{  
*/ WX<),u2@  
package NetFox; uflRW+-2  
import java.io.*; hDBVL"  
import java.net.*; Zpc R   
7bJAOJ'_  
?=$=c8xw  
public class SiteFileFetch extends Thread { <4UF/G)  
Q #!|h:K  
L *",4!  
SiteInfoBean siteInfoBean = null; //文件信息Bean  {}x{OP  
long[] nStartPos; //开始位置 kD1[6cJ!=.  
long[] nEndPos; //结束位置 Z ,4G'[d  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 %z1y3I|`[t  
long nFileLength; //文件长度 /A$mP)}tz  
boolean bFirst = true; //是否第一次取文件 l@C39VP  
boolean bStop = false; //停止标志 ROH 2KSt  
File tmpFile; //文件下载的临时信息 BhFyEY(  
DataOutputStream output; //输出到文件的输出流 fbv%&z  
Sy\ec{$+V]  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Ib V 7}  
public SiteFileFetch(SiteInfoBean bean) throws IOException SA3!a.*c  
{ !.\-l2f  
siteInfoBean = bean; .zDm{_'  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Vm6 0aXm_  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %#gHa  
if(tmpFile.exists ()) ]&;M 78^6  
{ 8":O\^i  
bFirst = false; AE?G+:B  
read_nPos(); V'n4iM  
} 7l+>WB_]  
else 1uz7E  
{ UB5X2uBv  
nStartPos = new long[bean.getNSplitter()]; Dq$co1eT  
nEndPos = new long[bean.getNSplitter()]; JY6&CL`C  
} $<c;xDO&t  
dJ/(u&N  
svT1b'=\$I  
HzuB.B<  
} 6xfG`7Az  
T~Z7kc'  
I{rW+<)QGC  
public void run() fQ.{s Q$@h  
{ . PAR  
//获得文件长度 m`3Mev  
//分割文件 ICbT{Mla  
//实例FileSplitterFetch ZA;VA=)\8  
//启动FileSplitterFetch线程 zG%ZDH^82_  
//等待子线程返回 ;8VvpO^G/  
try{ P. V #  
if(bFirst) Gd= l{~  
{ ;R#:? r;t  
nFileLength = getFileSize(); +|SvJ  
if(nFileLength == -1) hp:8e@  
{ VlLc[eVV  
System.err.println("File Length is not known!"); O7KR~d  
} ?M02|8-  
else if(nFileLength == -2) ^Ko{#qbl/  
{ *CnrzrKtQ  
System.err.println("File is not access!"); _jhdqON6E  
} ku`bwS  
else MZ/PXY  
{ XyM?Dc5,  
for(int i=0;i<nStartPos.length;i++) L.]mC !  
{ x>E**a?!L  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6Eu&%`  
} TAXl73j_CY  
for(int i=0;i<nEndPos.length-1;i++) =z]8;<=pL  
{ l}Fa-9_'  
nEndPos = nStartPos[i+1]; Q<e`0cu|p  
} WecJ^{g>r{  
nEndPos[nEndPos.length-1] = nFileLength; TYs#v/)I  
} SdI/  
} 2k^dxk~$V;  
wG&+*,}  
ilyQ gEjC  
//启动子线程 o`@B*, @  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0 CJ4]mYl  
for(int i=0;i<nStartPos.length;i++) .QhH!#Y2D  
{ #=MQE  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T21SuM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rCmxv7" a}  
nStartPos,nEndPos,i); BBg&ZIYEh  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >QusXD"L>  
fileSplitterFetch.start(); ? }k~>. \  
} 7 %P?3  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x%;Q /7&$  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cZ" Ut  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GC3:ZpV`  
nEndPos = " + nFileLength); zn |=Q$81  
// fileSplitterFetch[nPos.length-1].start(); j=^b'dyL  
`P`n qn  
GM/3*S$c  
//等待子线程结束 '(/ZJ88JP  
//int count = 0; S*H :/Ip  
//是否结束while循环 !n`ogzOh  
boolean breakWhile = false; 6g ,U+~  
}G8RJxy  
V.IgEE]  
while(!bStop) !d1}IU-h  
{ {C%/>e2-%  
write_nPos(); lA4Bq  
Utility.sleep(500); |wf:|%  
breakWhile = true; /HNZwbh]uJ  
t9&z|?Vz  
?80@+y]  
for(int i=0;i<nStartPos.length;i++) ]|q\^k)JU  
{ ];P^q`n=.  
if(!fileSplitterFetch.bDownOver) tUmI#.v   
{ b'$j* N  
breakWhile = false; JlsRP  
break; A a2*f[  
} %J `;  
} 4/{Io &|  
if(breakWhile) j$*]'s&_hZ  
break; 'JEZ;9}  
+q]  
VI%879Z\e  
//count++; D PnKr/  
//if(count>4) p[e|N;W8A  
// siteStop(); !MB%  
} RB_7S!qC5  
0k5Z l?  
I~S`'()J  
System.err.println("文件下载结束!"); Z*kGWL  
} wLD/#Hfi7  
catch(Exception e){e.printStackTrace ();} 1h\:Lj  
} RR:m <9l  
}H{{@RU  
=&,zWNz)  
//获得文件长度 yXNE2K  
public long getFileSize() GI$t8{M  
{ hQBeM7$F_  
int nFileLength = -1; v,RLN`CID  
try{ i^uC4S~  
URL url = new URL(siteInfoBean.getSSiteURL()); +[r%y,k  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wC BL1[~C  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8N(bLGUG  
dv%gmUUf}k  
Fm-W@  
int responseCode=httpConnection.getResponseCode(); 'oTcx Jx  
if(responseCode>=400) m7kDxs(KO  
{ P58U8MEG  
processErrorCode(responseCode); )?pin|_x  
return -2; //-2 represent access is error 1l\O9D +$  
} scqG$~O)  
a-Cp"pKlVY  
P1 (8foZA  
String sHeader; K4n1#]8i  
$t 1]w]}d  
GU'5`Yzd9  
for(int i=1;;i++) 9;Wz;p  
{ /^uvY  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $2>tfKhtA  
//Utility.log(in.readLine()); FTCp3g  
sHeader=httpConnection.getHeaderFieldKey(i); j Xi<ZJ  
if(sHeader!=null) :c)<B@NqNo  
{ 35RH|ci&  
if(sHeader.equals("Content-Length")) tb/u@}")  
{ 'xStA  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Jkm\{;  
break; ]vQo^nOo  
} +@%9pbM"z  
} rxa"ji!)  
else YhLtf(r  
break; J-?\,N1R7  
} ~8pf.^,fi  
} !kASEjFz|f  
catch(IOException e){e.printStackTrace ();} e,~c~Db* Q  
catch(Exception e){e.printStackTrace ();} dN |w;|M  
  |J(]  
308w0eP  
Utility.log(nFileLength); A$XjzTR  
Q=PaTh   
`Q(ac| 0  
return nFileLength; 7=QV^G  
} }lpcbm  
crgYr$@s?  
~BS*x+M  
//保存下载信息(文件指针位置) i $I|JJJ  
private void write_nPos() M8cLh!!  
{ x ;Gyo  
try{ t_]UseP$RF  
output = new DataOutputStream(new FileOutputStream(tmpFile)); [PX'Jer  
output.writeInt(nStartPos.length); 6{7O  
for(int i=0;i<nStartPos.length;i++) p Hg8(ru|  
{ ^G2vA8%  
// output.writeLong(nPos); M\v4{\2l0  
output.writeLong(fileSplitterFetch.nStartPos); "BFW&<1  
output.writeLong(fileSplitterFetch.nEndPos); qsk71L  
} 5\4>H6  
output.close(); Z,4=<;PF  
} +:'Po.{"  
catch(IOException e){e.printStackTrace ();} _ZS<zQ'  
catch(Exception e){e.printStackTrace ();} B:mlBSH  
} $s]@%6 f  
_r8AO>  
SD.ze(P  
//读取保存的下载信息(文件指针位置) #[[p/nAy}A  
private void read_nPos() "V^jAPDXb  
{ _b5iR<f  
try{ -+PPz?0  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bs`/k&'  
int nCount = input.readInt(); \!^o<$s.G  
nStartPos = new long[nCount]; ]yIy~V  
nEndPos = new long[nCount]; xK y<o  
for(int i=0;i<nStartPos.length;i++) &&y@/<t  
{ X_YD[  
nStartPos = input.readLong(); =f|>7m.p  
nEndPos = input.readLong(); |1<Z3\+_/  
} ~%}g"|o  
input.close(); b,`\"'1  
} eS.]@ E-T  
catch(IOException e){e.printStackTrace ();} (i?^g &  
catch(Exception e){e.printStackTrace ();} _0f[.vN  
} Z*QRdB%,  
Y$Ke{6 4  
/<2_K4(-{4  
private void processErrorCode(int nErrorCode) d{trO;%#f  
{ h/k`+  
System.err.println("Error Code : " + nErrorCode); lz*2wGI9  
} n$?oZ *;  
Lf:Z (Z>  
;8v5 qz  
//停止文件下载 avz 4 &  
public void siteStop() > @%!r  
{ W6iIL:sp  
bStop = true; 8(I"C$D!k  
for(int i=0;i<nStartPos.length;i++) lt4UNJ3w  
fileSplitterFetch.splitterStop(); ( BGipX4  
MDq@:t  
Sce9R?II  
} 1_QO>T'  
} t(yv   
//负责部分文件的抓取 CMr`n8M  
**FileSplitterFetch.java ')aYkO{%sb  
*/ dWUu3  
package NetFox; Ll`apKr  
6{~I7!m"  
5 9vGLN!L  
import java.io.*; 4jW{IGW  
import java.net.*; IviWS84  
k?#6j1pn  
IW#(ICeb  
public class FileSplitterFetch extends Thread { <*+ MBF  
88K*d8m  
0>`69&;g|  
String sURL; //File URL 0{yx*}.  
long nStartPos; //File Snippet Start Position 'n no)kQ"  
long nEndPos; //File Snippet End Position 1}pR')YL[  
int nThreadID; //Thread's ID -*A'6%`  
boolean bDownOver = false; //Downing is over ]*|K8&jxl  
boolean bStop = false; //Stop identical #o RUH8  
FileAccessI fileAccessI = null; //File Access interface ZS+2.)A  
vn<S"  
(G VGoh&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UQ)}i7v  
{ Kf4z*5Veqr  
this.sURL = sURL; ?zEF?LJoK  
this.nStartPos = nStart; f+V':qz  
this.nEndPos = nEnd; E'G>'cW;x  
nThreadID = id; qo;\dp1  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?MH4<7?"  
} TRZ^$<AG  
l_ c?q"X  
|@BN+o;`Om  
public void run() q1y4B`  
{ 4_<Uk  
while(nStartPos < nEndPos && !bStop) (=j!P*  
{ K^H t$04  
Ie"R,,c   
Z3dd9m#.]  
try{ ^ne8~ ;Q  
URL url = new URL(sURL);  B]7jg9/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %j@FZ )a[  
httpConnection.setRequestProperty("User-Agent","NetFox"); 7o. 'F  
String sProperty = "bytes="+nStartPos+"-"; 8GldVn.u  
httpConnection.setRequestProperty("RANGE",sProperty); \0h/~3  
Utility.log(sProperty); TXcKuo=  
VaxO L61xE  
 iC]lO  
InputStream input = httpConnection.getInputStream(); lG9ARRy(=  
//logResponseHead(httpConnection); L])w-  
_GqE'VX  
}=a4uCE  
byte[] b = new byte[1024]; "N]o5d   
int nRead; mx~sxYa  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .h,xBT`}Ji  
{ sE6J:m(  
nStartPos += fileAccessI.write(b,0,nRead); 9eiBj  
//if(nThreadID == 1) c'";3 6y  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2(Uz9!<V  
} =joXP$n^  
Bq@wS\W>b}  
\F~Cbj+'Nu  
Utility.log("Thread " + nThreadID + " is over!");  2p>SB/  
bDownOver = true; ^z^e*<{WEl  
//nPos = fileAccessI.write (b,0,nRead); 5Q`n6x|  
} 9^ p{/Io  
catch(Exception e){e.printStackTrace ();} /T)n5X  
} 4Z9wzQ>  
} Z4ioXl  
mndl~/  
JWHt|zB g  
//打印回应的头信息 R Sz[6  
public void logResponseHead(HttpURLConnection con) JyC&L6[]Z  
{ xc.D!Iav  
for(int i=1;;i++) 8? Wxd65)  
{ [P=[hj;  
String header=con.getHeaderFieldKey(i); ^!o}>ls['  
if(header!=null) {@__%=`CCS  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2 pa3}6P+  
Utility.log(header+" : "+con.getHeaderField(header)); Uy5!H1u  
else +\GZ(!~  
break; ,,%:vK+V  
} 2 BX GVo  
} +'KE T,  
'QojSq   
heZy 66  
public void splitterStop() <3=qLm  
{ kN |5 J  
bStop = true; 5}bZs` C  
} nVn|$ "r  
=yX&p:-&  
E8_Le  
} )9L pX  
_T|H69 J  
a,*p_:~i  
/* Yz-JI=  
**FileAccess.java uO@3vY',n  
*//文件访问(定位,写) Ocwp]Mut&  
package NetFox; U5CPkH1  
import java.io.*; ^qGA!_  
=lC;^&D-0/  
}"?nU4q;S  
public class FileAccessI implements Serializable{ )w2K&Zr0  
\!JS7!+  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N^ s!!Sbpq  
RandomAccessFile oSavedFile; Zfy~mv$  
long nPos; -}X?2Q  
H >:4MY  
7e c0Xh1  
public FileAccessI() throws IOException /ggkb8<3  
{ Fu4EEi  
this("",0); uR:=V9O  
} yw.~trF&%  
:Wg-@d  
w;c#drY7S  
public FileAccessI(String sName,long nPos) throws IOException o"#TZB+k  
{ y=9Dxst"V  
oSavedFile = new RandomAccessFile(sName,"rw"); _jTwiuMS-  
this.nPos = nPos; f(6UL31  
oSavedFile.seek(nPos); Xqg.kX  
} Ln=>@  
$89ea*k  
xaWGa1V'z  
public synchronized int write(byte[] b,int nStart,int nLen) VX;zZ`BJ  
{ *5y W  
int n = -1; 6h2x~@  
try{ T)(e!Xz  
oSavedFile.write(b,nStart,nLen); F)/~p&H  
n = nLen; X a"XB  
} 4|6&59?pnc  
catch(IOException e) X'FEOF  
{ ,@Fgr(?'`>  
e.printStackTrace (); &[5n0e[  
} $N;"}G z  
[,<\RviI  
[`.3f'")j  
return n; ,u}<Ws8N  
} .pM &jni Y  
s(AJkO'`  
k,,!P""  
} Fn86E dFM  
Dac ^*k=D  
j:3EpD@GS  
/* vpm ]9>1[  
**SiteInfoBean.java 0)d?Y  
*/ T?X^0UdJj  
package NetFox; +/y{^}b/  
T8$%9&j!UE  
rI0)F  
public class SiteInfoBean { 3sZ,|,ueD  
ybZ}  
h/I@_?k+  
private String sSiteURL; //Site's URL cMDRWh  
private String sFilePath; //Saved File's Path s$DGd T)  
private String sFileName; //Saved File's Name ~J0,)_b%*  
private int nSplitter; //Count of Splited Downloading File \F 3C=M@:  
Gn]d;5P=  
dgS4w@)@V;  
public SiteInfoBean() S8O)/Sg=  
{//nSplitter的缺省值为5 7p)N_cJD  
//default value of nSplitter is 5 |d $1wr  
this("","","",5); *(k%MTG  
} X[V?T>jsM  
_yj1:TtCNT  
}>V/H]B  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~xS@]3n=  
{ 42fprt  
sSiteURL= sURL; ^8:VWJM  
sFilePath = sPath; }6).|^]\'  
sFileName = sName; 8N% z9b  
this.nSplitter = nSpiltter; nO~b=qO  
%yiD~&  
<EtUnj:qK8  
} B &?fM~J  
}2l O _i}L  
25d\!3#E  
public String getSSiteURL() `gt:gx>a  
{ %`#G92Z_  
return sSiteURL; a mqOxb  
} 4otl_l(`yv  
%y>+1hakkX  
lW p~t  
public void setSSiteURL(String value) T|ZF/&XP  
{ a:A n=NA  
sSiteURL = value; t05_Px!mW  
} Uo2+:p  
:r&iM b:Ra  
jyi FM5&  
public String getSFilePath() `mzb(b E  
{ q +R*Hi  
return sFilePath; 'w(y J  
} -/>9c-F  
OUzR@$  
o~#f1$|Xn  
public void setSFilePath(String value) }X]\VSF{  
{ !EOQhh  
sFilePath = value; QdDObqVdy  
}  `?|Rc  
}B0sC%cm  
%x2 uP9  
public String getSFileName() ~.Cv DJy  
{ k#C f})  
return sFileName; ~-_i  
} i5"5&r7r  
edijfhn  
CvK3H\.&;k  
public void setSFileName(String value) _({@B`N}  
{ =A@>I0(7  
sFileName = value; 6YmP[%  
} l4vTU=  
nO{ x^b <  
@vRwzc\   
public int getNSplitter() 8[zb{PRu  
{ bO3GVc+S  
return nSplitter; *}cSE|S%  
} >{5 p0  
T#EFXHPr  
&gn-Wb?  
public void setNSplitter(int nCount) 2q PhLCe Z  
{ I[0!S IqY  
nSplitter = nCount; >2b`\Q*<  
} khx.yRx  
} gCuAF$o  
V.6)0fKZW  
gEwd &J  
/* sw;|'N$:<  
**Utility.java 5\ hd4  
*/ .[:VSM7T  
package NetFox; HYCuK48F[_  
tfYB_N  
h3!$r~T!a:  
public class Utility { +G*JrwJ&=  
'<dgT&8C  
8'#/LA[uPe  
public Utility() w1 `QIv  
{ ,LhCFw{8?~  
< zOi4v0  
65TfFcQ<S  
} 7 oQ[FdRn*  
DM{ 4@*]  
//线程睡眠 ;H'gT+t<c  
public static void sleep(int nSecond) ,q#0hy%5/  
{ ZnW@YC#9  
try{ !H@0MQ7  
Thread.sleep(nSecond); #Sh <Ih  
} J00VTb`  
catch(Exception e) #8XL :I  
{ 9'[ N1Un.=  
e.printStackTrace (); +4))/` DA  
}  _; Y`  
} U_B(( Z(g  
%NHkDa!  
//日志 wkUlrL/~  
public static void log(String sMsg) p-GAe,2q  
{ ZcJ\ZbE|  
System.err.println(sMsg); m ci/'b Xt  
} 72W s K"  
&;&ho+qD  
)2IH 5  
public static void log(int sMsg) d5`3wd]]'v  
{ v'!a\b`9  
System.err.println(sMsg); v\tEVhm  
} iB[~U3  
} **3 z;58i  
s$D ^>0  
;r[@v347  
/* 9h4({EE2t  
**TestMethod.java (xHf4[[u  
*/ o1cErI&q"  
package NetFox; G+UMBn  
4%nE*H%  
a`[uNgDO  
public class TestMethod { Qv,"($n\  
/1mW|O>0  
}G4 z tiuG  
public TestMethod() t3(]YgF  
{ ///xx/weblogic60b2_win.exe eIRLNxt+v  
try{ E;JsBH  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); - K9c@?  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g L_Y,A~Q{  
SiteFileFetch fileFetch = new SiteFileFetch(bean); l&iq5}[n&  
fileFetch.start(); 7(5xL T$  
} pn.wud}R  
catch(Exception e){e.printStackTrace ();} P9g en6  
=6"2UC&  
'Vyt4^$%  
} ?7<JQh)"e  
91 =OF*w  
At7>V-f}  
public static void main(String[] args) vnWWneeNr  
{ Tb3J9q+ya  
new TestMethod(); d ,4]VE  
} Ut2y;2)a  
} ?c[*:N(  
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