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http断点续传简单实现(java)

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/* JJtx `@Bc  
**SiteFileFetch.java ]'(D*4  
*/ KB](W  
package NetFox; _,T 4DS6  
import java.io.*; -GCo`PR?b  
import java.net.*; / 'qoKof  
9)'f)60^  
lh"*$.j-  
public class SiteFileFetch extends Thread { c'eZ-\d{  
_;;Zz&c  
m:?"|.]  
SiteInfoBean siteInfoBean = null; //文件信息Bean 9ET1Er{4  
long[] nStartPos; //开始位置 rjK`t_(=  
long[] nEndPos; //结束位置 PZusYeV8b  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Wvr{l  
long nFileLength; //文件长度 s b;q)Rh  
boolean bFirst = true; //是否第一次取文件 ?![[la+f  
boolean bStop = false; //停止标志 0Z8"f_GK  
File tmpFile; //文件下载的临时信息 E(PBV  
DataOutputStream output; //输出到文件的输出流 8\lh'8  
ciS,  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) =zyA~}M2  
public SiteFileFetch(SiteInfoBean bean) throws IOException BtC*]WB"_'  
{ 'q)g, 2B%  
siteInfoBean = bean; G7nhUg  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); '&![h7B  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); =,(TP  
if(tmpFile.exists ()) MY@&^71i4  
{ 3J+2#ML  
bFirst = false; VWE>w|'  
read_nPos(); 9dhEQ=K{3  
} ccHf+=  
else PVo7Sy!'H  
{ $mn0I69  
nStartPos = new long[bean.getNSplitter()]; 06S R74  
nEndPos = new long[bean.getNSplitter()]; :D)(3U5  
}  ;v:(  
3x0t[{l  
q#W|fkfx+  
{6zNCO  
} g F*AS(9  
hGz_F/  
Kp`{-dUf  
public void run() 5.9<g>C  
{ XVN`J]XHk  
//获得文件长度 U-I,Q+[C[^  
//分割文件 ?Afe }  
//实例FileSplitterFetch "0An'7'm  
//启动FileSplitterFetch线程 VLez<Id9(  
//等待子线程返回 !#c'| *k  
try{ by/H:5}7  
if(bFirst) GXtK3YAr  
{ RRIh;HhX  
nFileLength = getFileSize(); cKt=?  
if(nFileLength == -1) P]43FPb  
{ gc.Lh~  
System.err.println("File Length is not known!"); #J"xByQKK  
} c1yRy|  
else if(nFileLength == -2) I,{YxY[$7  
{ SO$Af!S:bB  
System.err.println("File is not access!"); !bE-&c  
} 6Wu*zY_+  
else .:$(o&  
{ 8W\yM;'  
for(int i=0;i<nStartPos.length;i++) _}R[mr/  
{ zt(lV  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6:ettdj  
} _=Gj J~2n  
for(int i=0;i<nEndPos.length-1;i++) $4nAb^/  
{ : {p'U2  
nEndPos = nStartPos[i+1]; d y HC8  
} ,vR?iNd:q[  
nEndPos[nEndPos.length-1] = nFileLength; v'W{+>.  
} uuC ["Z  
} X-c|jn7  
XQ#K1Z  
D.K""*ula  
//启动子线程 v675C#l(  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Eomfa:WL  
for(int i=0;i<nStartPos.length;i++) XX8HSw!w  
{ +>Wo:kp3  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K-0=#6?y4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Xz_WFLq4  
nStartPos,nEndPos,i); ZL( j5E  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \}Jznzx;  
fileSplitterFetch.start(); !dLu($P  
} 2J7|y\N,  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U#jz5<r  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @/ z\p7e  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h?mDtMCw2  
nEndPos = " + nFileLength); :o s8"  
// fileSplitterFetch[nPos.length-1].start(); \P<aK$g  
5Gz!Bf@!!  
2S?7j[@%i`  
//等待子线程结束 >,e^}K}C  
//int count = 0; bA^uzE  
//是否结束while循环 n{tc{LII/  
boolean breakWhile = false; ,md_eGF  
8q^}AT<C  
dli(ckr  
while(!bStop) (` *BZ_  
{ 1'~Xn 4 f  
write_nPos(); n1sYD6u<&  
Utility.sleep(500); pbH!u+DF  
breakWhile = true; jI ol`WX  
?qgQ)#6  
a(gXvgrf[  
for(int i=0;i<nStartPos.length;i++) 3s6obw$ki  
{ TSB2]uH  
if(!fileSplitterFetch.bDownOver) |Y7SP]/`gB  
{ +:S `]  
breakWhile = false; cOVj @z  
break; yHeL&H  
} J p'^!  
} scg&"s  
if(breakWhile) i2=- su  
break; h^Wb<O`S  
G+zhL6]F  
Q:A#4Z  
//count++; 2bt>t[0ad  
//if(count>4) rzf Lp  
// siteStop(); L'+bVP{L  
} Z-iU7 O  
4MgN  
%_(vSpk  
System.err.println("文件下载结束!"); 6,>$Jzs)5E  
} uNyU]@R<W  
catch(Exception e){e.printStackTrace ();} _{[6hf4p  
} 3#7V1  
\Zj%eW!m  
jPWONz(#  
//获得文件长度 hb`9Vn\-E  
public long getFileSize() \|PiQy*_?  
{ Z@bgJL8 3  
int nFileLength = -1; -CvmZ:n  
try{ dbf<k%i6  
URL url = new URL(siteInfoBean.getSSiteURL()); c8uaZvfW  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]LvP)0=  
httpConnection.setRequestProperty("User-Agent","NetFox"); jSI1tW8  
V:\:[KcL^  
4 &bmt  
int responseCode=httpConnection.getResponseCode(); , $7-SN  
if(responseCode>=400) NI?O  
{ f_~T  
processErrorCode(responseCode); dxeiN#(XT  
return -2; //-2 represent access is error )D8op;Fn  
} 8zK#./0\  
_Ewh:IM-  
1eI*.pt  
String sHeader; ufXWK3~\  
T`# nn|  
v "l).G?  
for(int i=1;;i++) GfONm6A  
{ a\P:jgF  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +XWTu!  
//Utility.log(in.readLine()); ?_eLrz4>L^  
sHeader=httpConnection.getHeaderFieldKey(i); FB6Lz5:Vf  
if(sHeader!=null) <*5S7)]BP  
{ w B)y@w4k  
if(sHeader.equals("Content-Length")) ;[y( 14g  
{ gj^)T_E_  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F_@B ` ,  
break; e{x>u(  
} b|i4me@  
} ~XR ('}5D  
else |lNp0b  
break; 72l:[5ccR  
} }a"=K%b<\  
} A$2 ;Bf  
catch(IOException e){e.printStackTrace ();} [UwQi!^-O  
catch(Exception e){e.printStackTrace ();} $0V+<  
d+DO}=]  
@X/ 1`Mp  
Utility.log(nFileLength); @b(@`yz.a  
klKUX/ g  
@Ou H=<YN  
return nFileLength; ]xRR/S4  
} i!YfR]"}  
?`+VWa[,e  
\GEz.Vb  
//保存下载信息(文件指针位置) :!Ci#[g  
private void write_nPos() OU{c| O  
{ uH\EV`@'  
try{ `+w= p7ET  
output = new DataOutputStream(new FileOutputStream(tmpFile)); lWRl  
output.writeInt(nStartPos.length); U$2Em0HO}  
for(int i=0;i<nStartPos.length;i++) ,7V?K j  
{ Do4hg $:40  
// output.writeLong(nPos); kn:hxdZ  
output.writeLong(fileSplitterFetch.nStartPos); NfDS6i.Fqp  
output.writeLong(fileSplitterFetch.nEndPos); Zj[m  
} .>W [  
output.close(); 1uw1(iL+  
} #M!u';bZ  
catch(IOException e){e.printStackTrace ();} gdIk%m4  
catch(Exception e){e.printStackTrace ();} q 4Pv\YO  
} .]E(P   
2S7 BzZ/  
JWHsTnB  
//读取保存的下载信息(文件指针位置) w10~IP  
private void read_nPos() syu/"KY^!  
{ N[eL Qe]q  
try{ WWSycH ?[  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H!Gw@u]E  
int nCount = input.readInt(); $6m@gW]N  
nStartPos = new long[nCount]; D2VYw<tEA  
nEndPos = new long[nCount]; cn}15JHdR  
for(int i=0;i<nStartPos.length;i++) }"+"nf5h  
{ )VQ[}iT  
nStartPos = input.readLong(); 'A|c\sy  
nEndPos = input.readLong(); ou0TKE9 _  
} +788aK,{#  
input.close(); NK|U:p2H  
} mh4 VQ9  
catch(IOException e){e.printStackTrace ();} o|>=< l  
catch(Exception e){e.printStackTrace ();} -`8@  
} ?5't1219  
!RJ@;S  
9]N{8  
private void processErrorCode(int nErrorCode) XR",.3LD  
{ t{UVX%b  
System.err.println("Error Code : " + nErrorCode); 4U\>TFO  
} $cn8]*Z =  
d7BpmM  
O-[YU%K3?  
//停止文件下载 Ak3^en  
public void siteStop() F4~ OsgZ'N  
{ 3B;Gm<fJ9N  
bStop = true; .WSn Y71  
for(int i=0;i<nStartPos.length;i++)  MMk9rBf  
fileSplitterFetch.splitterStop(); @F8NN\  
Pg.JI:>2Ku  
(,sz.  
} V}TPt6C2  
} cFie;k  
//负责部分文件的抓取 j)G%I y[`  
**FileSplitterFetch.java m\*ca3$  
*/ bv <^zuV  
package NetFox; H,<CR9@(5d  
Zz (qc5o,F  
_*=4xmB.=  
import java.io.*; ommW  
import java.net.*; c1kV}-v  
oeKl\cgFx  
Q~"Lyy8  
public class FileSplitterFetch extends Thread { /Q W^v;^  
+)h# !/  
zEQQ4)mA  
String sURL; //File URL rhzI*nwOT  
long nStartPos; //File Snippet Start Position N6kMl  
long nEndPos; //File Snippet End Position O<wH+k[  
int nThreadID; //Thread's ID xK0;saG#  
boolean bDownOver = false; //Downing is over [Cd#<Te3  
boolean bStop = false; //Stop identical o1 27? ^  
FileAccessI fileAccessI = null; //File Access interface 8yYag[m8  
qPi $kecx  
&:C[ nq  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Nq9pory^  
{ u`B/9-K)y  
this.sURL = sURL; c='W{47  
this.nStartPos = nStart; Ib2&L  
this.nEndPos = nEnd; Dd0yQgCu  
nThreadID = id; b"@-9ke5I  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nzxHd7NIZ  
} %1cxZxGT  
o9ys$vXt*  
#2\M(5d  
public void run()  })!-  
{ n9 bp0#K  
while(nStartPos < nEndPos && !bStop) V@LBy1z  
{ .rg "(I  
L4+R8ojG  
rv)Eg53Q  
try{ r_ m|?U %  
URL url = new URL(sURL); W@GU;Nr  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ku57<kb  
httpConnection.setRequestProperty("User-Agent","NetFox"); H[g i`{c  
String sProperty = "bytes="+nStartPos+"-"; EQ"_kJ>81Y  
httpConnection.setRequestProperty("RANGE",sProperty); rY &lx}  
Utility.log(sProperty); ;E{@)X..|  
qc'KQ5w7!  
U4a8z<l$  
InputStream input = httpConnection.getInputStream(); FME,W&_d  
//logResponseHead(httpConnection); L#D)[v"  
=.J>'9Q  
~y Dl & S  
byte[] b = new byte[1024]; |VE.khq#  
int nRead; `{yD\qDyX  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +|oLS_  
{ .2P3 !KCL  
nStartPos += fileAccessI.write(b,0,nRead); 7"eIZ  
//if(nThreadID == 1) U1yspHiZ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -hF!_);{  
} rWJRoGk/  
(.z0.0W  
bQ?Vh@j(M  
Utility.log("Thread " + nThreadID + " is over!"); @d5t%V\  
bDownOver = true; b*Hk} !qH  
//nPos = fileAccessI.write (b,0,nRead); b!QRD'31'j  
} 7 mA3&<&q  
catch(Exception e){e.printStackTrace ();} ~s?y[yy6i  
} DjZTr}%q  
} blG?("0!  
KKg\n^  
:[PA.Upi  
//打印回应的头信息 hOqNZ66{  
public void logResponseHead(HttpURLConnection con) -e51 /lhpd  
{ >_\]c-~<  
for(int i=1;;i++) DDT]A<WUV  
{ lS2 `#l>  
String header=con.getHeaderFieldKey(i); `Lw Z(M-hI  
if(header!=null) %0u5d$bq  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); CJ3/8*;w  
Utility.log(header+" : "+con.getHeaderField(header)); 8;UkZN"hy5  
else X)TZ  S  
break; 8BY`~TZO$q  
} /K,@{__JP  
} |e+r~).4B  
T/%k1Hsa4H  
kDiR2K&  
public void splitterStop() sBxCi~  
{  )DW".c  
bStop = true; *xeJ4h  
} 0!c/4^  
kmJ<AnK  
tsB}'+!v#  
} g]b%<DJ  
21?>rezJ  
rd(-2,$4  
/* $0M7P5]N*G  
**FileAccess.java |f}`uF  
*//文件访问(定位,写) +miL naO~L  
package NetFox; '7]9q#{su  
import java.io.*; 5"x1Pln  
obX2/   
>^f]Lgp  
public class FileAccessI implements Serializable{ wC<FF2T  
85H*Xm?d#  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zs-,Y@ZL  
RandomAccessFile oSavedFile; cnDBT3$~Z  
long nPos; naY#`xig  
nrTCq~LO(  
2Y}A9Veb  
public FileAccessI() throws IOException esv<b>`R  
{ `1 Tg8  
this("",0); }V+&o\4  
} M7gqoJM'Q  
m}m|(;T  
@<S'f<>g  
public FileAccessI(String sName,long nPos) throws IOException %CrpUx  
{ 61b<6 r0o  
oSavedFile = new RandomAccessFile(sName,"rw"); 'Te'wh=Y  
this.nPos = nPos; |L)qH"Eo  
oSavedFile.seek(nPos); ?`SB GN;  
} 8?o{{ay  
:y!{=[>M(  
%A@U7gqc  
public synchronized int write(byte[] b,int nStart,int nLen) %8"Aq  
{ y$|OE%S  
int n = -1; y=1(o3(  
try{ ,ce$y4%(  
oSavedFile.write(b,nStart,nLen); 7ws[Rp8  
n = nLen; ;p( Doy)i  
} BLo=@C%w5  
catch(IOException e) "L)?dlb6T  
{ W$R@Klz  
e.printStackTrace (); {f>e~o  
} ]"vpCL  
nlx~yUXL4  
d:n .Vp  
return n; n*qn8Dq  
} lHgmljn5u  
_4t  
k'd=|U;(FV  
} T!H }^v  
4V5h1/JPm  
Nu%MXu+  
/* sTYA  
**SiteInfoBean.java 4p(\2?B%f  
*/ u,Cf4H*xS  
package NetFox; *2I@_b6&  
/3 ;t &]  
SDW!9jm>R  
public class SiteInfoBean { @(e/Y/  
iC<qWq|S_m  
+r]2.  
private String sSiteURL; //Site's URL vj<JjGP  
private String sFilePath; //Saved File's Path ?7aeY5p  
private String sFileName; //Saved File's Name WNV}@  
private int nSplitter; //Count of Splited Downloading File AhSN'gWpbF  
&;%LTF@I,  
E"Y[k8-:2/  
public SiteInfoBean() Ivc/g,  
{//nSplitter的缺省值为5 sMWNzt  
//default value of nSplitter is 5 y)+l U  
this("","","",5); #6Fc-ysk:  
} 140_WV?7  
ygTc Y  
]AB4w+6!  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @avG*Mr^  
{ n]WVT@  
sSiteURL= sURL; Q2xzux~T  
sFilePath = sPath; <8 25?W|  
sFileName = sName; "?{=|%mf  
this.nSplitter = nSpiltter; q!8aYw+c  
Fpy-? U  
*Ag,/Cm]  
} |`ZW(} ~  
-Y/c]g  
4Y}{?]>pu  
public String getSSiteURL() Z[zRZ2'i5  
{ MJI`1*(  
return sSiteURL; xEqr3(  
} HO9w"){d$  
c`_[q{(^m  
\zyvu7YA  
public void setSSiteURL(String value) 45tQ$jr`1  
{ j.7BoV  
sSiteURL = value; QNgfvy  
} nK9?|@S*'  
o",J{  
Ex$i8fO(  
public String getSFilePath() 6Y&`mgMF'  
{ J`d;I#R%c  
return sFilePath; ._US8  
} +I r  
C7 T}:V](q  
m e&'BQ  
public void setSFilePath(String value) v<t r1cUT  
{ 'o]8UD(  
sFilePath = value; zP|^) h5  
} Y4I;-&d's  
58o'Q  
jLv8K  
public String getSFileName() *t,1(Gw|7q  
{ ,\=,,1_  
return sFileName; n]fMl:77  
} w j<fi  
w>h\643  
cCbZ*  
public void setSFileName(String value) BXB ZX@jVk  
{ 7Nt6}${=z  
sFileName = value; [e;c)XS[  
} zM2 _z  
Q?]-/v  
E8] kd  
public int getNSplitter() k?;B1D8-n  
{ j NkobJ1  
return nSplitter; fKOC-%w  
} :SvgXMY@  
z6;6 o!ej  
b,uu dtlH  
public void setNSplitter(int nCount) ![9um sx  
{ #l#8-m8g)  
nSplitter = nCount; K:(E"d;  
} $bsD'Io  
} F;sZc,Y,^  
1j?+rs+o-  
_|I`A6`=  
/*  jWqjGX`  
**Utility.java \x;`8H  
*/ = 4 wf  
package NetFox; ?Es(pwJB  
SZ(]su:  
(]N- HN]v  
public class Utility { qPF`=#  
cogIkB&Ju  
,u_ Z0S M  
public Utility() 7B{LRm6;Vu  
{ d=d*:<Zx  
7oV$TAAf  
P+bA>lJd  
} !!?TkVyEyM  
}WDzzjDR+  
//线程睡眠 k{ ~0BK  
public static void sleep(int nSecond) TP{2q51yM  
{ B"?ivxM:U  
try{ #.j}:  
Thread.sleep(nSecond); T:I34E[  
} 7m:ZG  
catch(Exception e) (NC]S  
{ E.eUd4XG  
e.printStackTrace (); _9:r4|S  
} 2mEvoWnJ  
} dJ>~  
cp$GP*{@  
//日志 "Tz'j}< 9C  
public static void log(String sMsg) Fj4>)!^kM  
{ .bY R  
System.err.println(sMsg); `IV7\}I|  
} R9\ )a2  
Yhte&,D"  
n#^ii/H  
public static void log(int sMsg) 0TWd.+  
{ g5:?O,?  
System.err.println(sMsg); 'S%H"W\  
} {hFH6]TA  
} $Da?)Hz'F  
y #zO1Nig`  
76cLf~|d~  
/* 50""n7I<%  
**TestMethod.java H)+QkQb}  
*/ w)C5XX30;  
package NetFox; S#:l17e3  
N@0cn q:"  
ny1;]_X_  
public class TestMethod { +\]Gu(z<  
)M><09  
DS=$* Trk  
public TestMethod() `vZX"+BAh  
{ ///xx/weblogic60b2_win.exe Y'C1L4d  
try{ =M=v; ,I-  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EKus0"|  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2Gh&h(  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $C{,`{=  
fileFetch.start(); =;Dj[<mJ45  
} ly:2XvV3~  
catch(Exception e){e.printStackTrace ();} T~L&c  
3$wK*xK  
CEW1T_1U<\  
} LXqPNVp#  
EF6h>"']/  
Cxeam"-HTt  
public static void main(String[] args) ?4^ 0xGyE  
{ V503  
new TestMethod(); Y (p Ud3y  
} tI)|y?q  
} _n1[(I  
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