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http断点续传简单实现(java)

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/* I`$"6 Xy  
**SiteFileFetch.java ~HFqAOr  
*/ ;;^OKrzWW  
package NetFox; X]Aobtz  
import java.io.*; N)kZ2|oD  
import java.net.*; kB2]Z}   
P}2i[m.*,  
3 #8bG(  
public class SiteFileFetch extends Thread { f: j9ze  
G^G= .9O  
)p$a1\ ~m  
SiteInfoBean siteInfoBean = null; //文件信息Bean I@$cw3  
long[] nStartPos; //开始位置 '7oWN,-  
long[] nEndPos; //结束位置 yHXQCWY{8;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 n=z=%T6  
long nFileLength; //文件长度 Ft<6`C  
boolean bFirst = true; //是否第一次取文件 %4=r .9  
boolean bStop = false; //停止标志 U<YP@?w  
File tmpFile; //文件下载的临时信息 \aEarIX#*  
DataOutputStream output; //输出到文件的输出流 AHo4% 5  
oMb&a0-7u  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) M$jU-;hRH  
public SiteFileFetch(SiteInfoBean bean) throws IOException _d[4EY  
{ _Q**4  
siteInfoBean = bean; q =\3jd  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); &>@  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); hT=6XO od4  
if(tmpFile.exists ()) :t7M'BSm2z  
{ pie,^-_.g  
bFirst = false; ?tA<:.<vtY  
read_nPos(); ;R_H8vp  
} U_&v|2o#3  
else !`A]YcQ  
{ T{USzMj  
nStartPos = new long[bean.getNSplitter()]; R_vF$X'Ow  
nEndPos = new long[bean.getNSplitter()]; \y7kb  
} ;kX:k~,]}>  
%Kk MWl&:  
m,Fug1+N  
F[ '<;}  
} 8l50@c4UF~  
`y^tCJ2u*  
.|VWYN  
public void run() $:RP tG  
{ 3axbW f3[  
//获得文件长度 *_ U=KpZF  
//分割文件 R7 WGc[  
//实例FileSplitterFetch z#( `H6n:  
//启动FileSplitterFetch线程 J)o =0i>*  
//等待子线程返回 <`f~Z|/-_(  
try{ oEuV&m|yX  
if(bFirst) :L6,=#  
{ j><8V Qx  
nFileLength = getFileSize(); b9%G"?~Zz  
if(nFileLength == -1) X!AD]sK  
{ GyVRe]<>B  
System.err.println("File Length is not known!"); Edp%z"J;C  
} >jBa  
else if(nFileLength == -2) M>yt\qbkA  
{ 'QP~uK  
System.err.println("File is not access!"); q83!PI  
} (2l?~CaK  
else NbyXi3@v  
{ ;bMmJ>[l-  
for(int i=0;i<nStartPos.length;i++) t0"2Si  
{ b~u53   
nStartPos = (long)(i*(nFileLength/nStartPos.length)); x\R%hGt  
} \Wn0,%x2  
for(int i=0;i<nEndPos.length-1;i++) (QFu``ae+  
{ "Yy)&zKr  
nEndPos = nStartPos[i+1]; 4#fgUlV  
} :&'[#%h8  
nEndPos[nEndPos.length-1] = nFileLength; w vQ.9  
} Rnd.<jz+Y  
} ?O|CY  
UWPzRk#s"  
1UwpLd  
//启动子线程 =iFI@2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )Bb:?!EuEH  
for(int i=0;i<nStartPos.length;i++) /hC'-6:]^  
{ Z{ AF8r  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "Xz[|Xl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A4mnm6Tf  
nStartPos,nEndPos,i); Ltrw)H}  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PX$_."WA  
fileSplitterFetch.start(); AB0>|.  
} +*')0I  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I&s!}$cD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d>YX18'<Q  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", px~:'U  
nEndPos = " + nFileLength); .}4^b\   
// fileSplitterFetch[nPos.length-1].start(); 4r- CF#o  
.1@8rVp7  
Q\qI+F2?  
//等待子线程结束 {*NM~yQ  
//int count = 0; Z< 4Du  
//是否结束while循环 +W}dO#  
boolean breakWhile = false; b&_u+g  
-nL!#R{e  
Dx*tolF  
while(!bStop) _C&XwC Im  
{ r1R\cor  
write_nPos(); Frd`u .I  
Utility.sleep(500); [izP1A$r#Q  
breakWhile = true; rJ^*8C!  
*_,: &Ur  
'X(Sn3  
for(int i=0;i<nStartPos.length;i++) )N}.n2Y8W  
{ 0/~20KD{s  
if(!fileSplitterFetch.bDownOver) a*3h|b<  
{ DFvj  
breakWhile = false; D:DtP6  
break; &f_ua)cyY  
} ` & {  
} 11Y4oS  
if(breakWhile) s<b(@L 1  
break; 4Mr)~f rc  
0\tdxi  
xC^|S0B  
//count++; e{k)]]J  
//if(count>4) BqG7E t  
// siteStop(); C?-_8OA  
} D@iE2-n&V  
(V:)`A_-  
ll#_v^  
System.err.println("文件下载结束!"); h#?)H7ft  
} {Hr P;)  
catch(Exception e){e.printStackTrace ();} 5y8ajae:  
} {K ,-fbE  
*T:gx:Sg/  
*m.4)2u=  
//获得文件长度 = t!$72g\  
public long getFileSize() ZD`p$:pT  
{ m1{OaHxKh  
int nFileLength = -1; y-R:-K XH=  
try{ U!D\Vd  
URL url = new URL(siteInfoBean.getSSiteURL()); !`qw" i  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (|t)MnPfY  
httpConnection.setRequestProperty("User-Agent","NetFox"); <HMmsw  
/`H{ n$  
G}N T[  
int responseCode=httpConnection.getResponseCode(); bQBYzvd  
if(responseCode>=400) a$2 WL g,  
{ VcpN PU6  
processErrorCode(responseCode); _a&Mk  
return -2; //-2 represent access is error ^^ +vt8|  
} Q|&Wcxq2!  
cjyb:gAO  
geJO#;  
String sHeader; > a"4aYj  
"Wz74ble  
.N~YVul[a*  
for(int i=1;;i++) 6SVh6o@]  
{ snti*e4"V  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Rf0F`D k  
//Utility.log(in.readLine()); yIG*  
sHeader=httpConnection.getHeaderFieldKey(i); 0OF]|hH  
if(sHeader!=null) nA 5-P}  
{ l~j{i/>  
if(sHeader.equals("Content-Length")) OdHl)"#  
{ `bMwt?[*  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S/H!a:_5r  
break; 3lo.YLP^  
} }v$T1Cw  
} 8B"my\  
else |p"4cG?)  
break; M F_VMAq  
} O9jpt>:kZ  
} GJ P\vsaQ  
catch(IOException e){e.printStackTrace ();} b]XDfe  
catch(Exception e){e.printStackTrace ();} D! $4  
l.AG^b  
i48Tb7Rx~n  
Utility.log(nFileLength); ~ s# !\Ye  
hJasnY7  
` 8OA:4).  
return nFileLength; QCVwslj,K  
} ppXt8G3% x  
@ 9q/jv`  
a]nyZdt`  
//保存下载信息(文件指针位置) Yt#e[CYnu  
private void write_nPos() 81&5g'  
{ !Q" 3B6 86  
try{ +t`QHvxv  
output = new DataOutputStream(new FileOutputStream(tmpFile)); wML5T+  
output.writeInt(nStartPos.length); XJ9l, :c,  
for(int i=0;i<nStartPos.length;i++) u[yUUYe  
{ ?KF.v1w7  
// output.writeLong(nPos); ]id5jVY  
output.writeLong(fileSplitterFetch.nStartPos); GFmVR2z_+  
output.writeLong(fileSplitterFetch.nEndPos); w 7Y>B`wm?  
} \[F4ooe  
output.close(); Ey**j  
} L7 f'  
catch(IOException e){e.printStackTrace ();} `z]MQdE_w  
catch(Exception e){e.printStackTrace ();} 50J"cGs~  
} Q?"-[6[v  
@o6^"  
53jtwklA  
//读取保存的下载信息(文件指针位置) *3r{s'm  
private void read_nPos() 8jxs%N,aI  
{ PN @[k:5(  
try{ gt= _;KZ  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fsVQZ$h73  
int nCount = input.readInt(); ^7O,Vk"Z  
nStartPos = new long[nCount]; G: p!PB>=  
nEndPos = new long[nCount]; ' *x?8-KP  
for(int i=0;i<nStartPos.length;i++) 6:o?@%  
{ >xa k  
nStartPos = input.readLong(); JJe?Zu\  
nEndPos = input.readLong(); %U$PcHOo  
} J;S@Q/s  
input.close(); is,r:  
} $Y Cy,Ew   
catch(IOException e){e.printStackTrace ();} |=CV.Su  
catch(Exception e){e.printStackTrace ();} 3[E)/~-  
} //\UthOT  
a|\ZC\(xI  
3kl\W[`?  
private void processErrorCode(int nErrorCode) .Lc<1s  
{ i'}Z>g5D  
System.err.println("Error Code : " + nErrorCode); ?a]u yw,  
} !`-/E']/  
F 6 xQ`T|  
!Qd4Y=  
//停止文件下载 gbJz5EEq  
public void siteStop() }\oy?_8~  
{ {V)Z!D  
bStop = true; ctg[C$<q|  
for(int i=0;i<nStartPos.length;i++) pdQ6/vh  
fileSplitterFetch.splitterStop(); jSyF]$"  
5I(gP  
TXlxnB  
} Uhz<B #tj  
} P{!r<N  
//负责部分文件的抓取 c>*RQ4vE  
**FileSplitterFetch.java @'yD(ZMAz  
*/ Y=#g_(4*  
package NetFox; 4LBMhLy  
'[h|f  
/o19/Pvwm  
import java.io.*; I}aiy.l  
import java.net.*; ~+GMn[h  
LOkNDmj  
6k=ink-/  
public class FileSplitterFetch extends Thread { ]zza/O;31(  
oKJj?%dHK9  
PB :Lj  
String sURL; //File URL [foZO&+!  
long nStartPos; //File Snippet Start Position =O)dHY}  
long nEndPos; //File Snippet End Position ttwfWfX  
int nThreadID; //Thread's ID IaU  
boolean bDownOver = false; //Downing is over uW8LG\Z>D5  
boolean bStop = false; //Stop identical W]UGo,  
FileAccessI fileAccessI = null; //File Access interface 6J|Y+Y$  
@ qfVt  
v_gQCS  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1o;+.]B  
{ [8VB"{{&  
this.sURL = sURL; GCUzKf&  
this.nStartPos = nStart; <E(#;F^y  
this.nEndPos = nEnd; x"Hi!h)v  
nThreadID = id; ^/3R/;?  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0r?}LWjf  
} *\Y \$w  
I]]3=?Y  
SY` U]-h  
public void run() A(mU,^  
{ "(hhb>V1Wl  
while(nStartPos < nEndPos && !bStop) R^.oM1qu|  
{ =-`}(b2N  
*:q3<\y{  
E0<9NF Qr7  
try{ aMSX"N"ot  
URL url = new URL(sURL); A3p@hQl  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -$E_L :M  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8} \Lt  
String sProperty = "bytes="+nStartPos+"-"; t]~L o3  
httpConnection.setRequestProperty("RANGE",sProperty); `5[d9z/6  
Utility.log(sProperty); >5&'_  
(I d]'w4  
=8r%zLDw  
InputStream input = httpConnection.getInputStream(); 3hOiHO ;  
//logResponseHead(httpConnection); h7NS9CgO  
jB*%nB*x  
ZkW,  
byte[] b = new byte[1024]; ThX%Uzd"[;  
int nRead; ,c@^u6a  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *v[WJ"8@  
{ y#:_K(A" k  
nStartPos += fileAccessI.write(b,0,nRead); krPwFp2[*  
//if(nThreadID == 1) )QGj\2I  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4|uh&4"*@W  
} 6uCa iPV  
k[]B P4  
%X Jv;|  
Utility.log("Thread " + nThreadID + " is over!"); zo-hH8J:  
bDownOver = true; !F*7Mif_E  
//nPos = fileAccessI.write (b,0,nRead); O+Fu zCWj  
} gRS}Y8  
catch(Exception e){e.printStackTrace ();} i2SR.{&  
} ,F7W_f# @3  
} 1MH[-=[Q  
.v36xXK(  
_uuxTNN0x*  
//打印回应的头信息 \ %Er%yv)  
public void logResponseHead(HttpURLConnection con) (c ?OcwTH  
{ \f6SA{vR|  
for(int i=1;;i++) %vvA'WG  
{ I @TR|  
String header=con.getHeaderFieldKey(i); H3Y FbR  
if(header!=null) ~F^(O{EG  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QAigbSn]  
Utility.log(header+" : "+con.getHeaderField(header)); G[1:<Vg8  
else sr+* q6W  
break; Q# w`ZQX3  
} \WG6\Zg0A  
} |*5Kfxq  
?(el6J}  
%|$h<~  
public void splitterStop() B] dvX  
{ GndU}[0J  
bStop = true; 6 eqxwj{S[  
} <(dHh9$~  
}>I|\Z0I  
_5(lp} s  
} w yP|#Z\  
x2 *l5t  
I@a y&NNh  
/* .5*h']iFr1  
**FileAccess.java ld8E!t[  
*//文件访问(定位,写) S>isWte  
package NetFox; iB;EV8E  
import java.io.*; ES[H^}|Gi  
K,{P b?  
+G';no\h  
public class FileAccessI implements Serializable{ `iYiAc  
W 86`R  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Tf/jd 3>  
RandomAccessFile oSavedFile; &<}vs`W  
long nPos; u}ULb F  
BbEWa  
"c8 -xG  
public FileAccessI() throws IOException T 22tZp  
{ 8yEN)RqI  
this("",0); 64Gd^.Z  
} qRkY-0vBP  
'NyIy:  
x%Ph``XI  
public FileAccessI(String sName,long nPos) throws IOException 7\>P@s  
{ 2Fk4jHj  
oSavedFile = new RandomAccessFile(sName,"rw"); od=%8z  
this.nPos = nPos; [IT*>;b+?  
oSavedFile.seek(nPos); u;f${Wn'3  
} hK F*{,'  
.?T,>#R  
6)i4&  
public synchronized int write(byte[] b,int nStart,int nLen) c++GnQc.  
{ u~WBu|  
int n = -1; npC:SrI%  
try{ "mlVs/nsyG  
oSavedFile.write(b,nStart,nLen); E9e|+$  
n = nLen; '4-J0S<<_  
} `|maf=SnY5  
catch(IOException e) {;uOc{~+  
{ 5}S~8  
e.printStackTrace (); nBw4YDR!  
} {~J'J$hn8  
coa+@g,w7#  
t5: 1' N9P  
return n; d:C|laZHn  
} 1t&LNIc|^  
a6\0XVU  
~6YTm6o  
} cu{c:z~  
m'{gO9V  
jeb ]3i=pw  
/* e ]-fb{oVH  
**SiteInfoBean.java |q0F*\z3  
*/ X{cFq W7  
package NetFox; D6X0(pU0  
D%[yAr;r  
mX8k4$z  
public class SiteInfoBean { .[mI9dc  
Hw"Lo Vh  
r<< ]41  
private String sSiteURL; //Site's URL t&5N{C:  
private String sFilePath; //Saved File's Path @ sLb=vb  
private String sFileName; //Saved File's Name ?'>pfU  
private int nSplitter; //Count of Splited Downloading File 'cp1I&>  
N_jpCCG~  
+H"[WZ5  
public SiteInfoBean() #aHPB#  
{//nSplitter的缺省值为5 EWz,K] _'  
//default value of nSplitter is 5 '" MT$MrT  
this("","","",5); 1ym^G0"s  
} &+0WZ#VI  
{`RCh]W  
py \KY R  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]#$l"ss,  
{ bhk:Szqz  
sSiteURL= sURL; d\eTyN'rA  
sFilePath = sPath; PB[ Y^q  
sFileName = sName; a-[:RJW  
this.nSplitter = nSpiltter; !*I0}I ~  
)gNS%t c*K  
tW$Di*h  
} d WKjVf  
wE*o1.  
9NXL8QmC8  
public String getSSiteURL() 2TQyQ%  
{ :8( "n1^  
return sSiteURL; `^d[$IbDW  
} 6KH&-ffd  
W20qn>{z  
9Rf})$o+  
public void setSSiteURL(String value) _P].Z8  
{ 3lh^maQ]  
sSiteURL = value; L0^rw|Z%'  
} Nw3K@ Ge  
[hhPkJf|f  
ve3-GWT{C  
public String getSFilePath() PiL[&_8g  
{ Hl|EySno  
return sFilePath; -F->l5  
} cc0e(\  
{tKi8O^Rb  
%[l#S*)~  
public void setSFilePath(String value) :,8eM{.Q  
{ E]MyP=g$  
sFilePath = value; K^6fg,&  
} r &.gOC  
]K<mkUpY  
Xi  8rD"v  
public String getSFileName() n0 q$/Y.  
{ Jxo#sV-  
return sFileName; U"T>L  
} s[dq-pc "  
i3dV2^O  
cXDG(.!n7B  
public void setSFileName(String value) K?J?]VCw  
{ =w,cdU*  
sFileName = value; KtMD?  
} V#Pz `D  
(_ TKDx_  
RCC~#bb  
public int getNSplitter() bnZ`Wc*5b  
{ b<E0|VW  
return nSplitter; C@F3iwTtp  
} EJByYk   
M[:},?ah0  
[&MhAzF  
public void setNSplitter(int nCount) hLo'q^mGr  
{ .9uw@ Eq  
nSplitter = nCount; x2M{=MExE.  
} o0 &pSCK  
} .E/NlGm[  
SbYs a  
zNh$d;(O$^  
/* .dw;b~p  
**Utility.java :k&5Z`>)  
*/ _mG>^QI.  
package NetFox; 1)N~0)dO  
p=jIDM'  
$ T2 n^yz  
public class Utility { -. J@  
2;`F` }BA  
\L]T|]}(  
public Utility() y%Wbm&h  
{ gI5Fzk@:  
<8sy*A?0z  
Su>UXuNdE#  
} O_^X:0}  
" ra C?H  
//线程睡眠 au?5^u\  
public static void sleep(int nSecond) U/j+\Kc~  
{ dk@j!-q^  
try{ .!2Ac  
Thread.sleep(nSecond); \0bZ1"  
} JQO%-=t  
catch(Exception e) ) mG  
{ Xxmvg.Nl  
e.printStackTrace (); OE8H |?%  
} nNP{>\x;"  
} k<.VR"I p  
@'lO~i  
//日志 no UXRQ  
public static void log(String sMsg) 8 aC]" C  
{ qJ5gdID1_  
System.err.println(sMsg); ptCAtEO72  
} ;Y@"!\t}  
Ynx.$$`$=  
s]@k,%  
public static void log(int sMsg) <uL0 M`u3  
{ R)u ${  
System.err.println(sMsg); >=!$(JgX  
} bA*T1Db,t>  
} O ]Stf7]%;  
O~u@J'4  
'boAv%1_sa  
/* nv-_\M   
**TestMethod.java *p>1s!i  
*/ vkg."G:=  
package NetFox; L\/YS;Y  
@;T?R  
1Zi(5S)  
public class TestMethod { z<Y >phc  
nq3B(  
+f]\>{o4  
public TestMethod() 7nOn^f D  
{ ///xx/weblogic60b2_win.exe AOVoOd+6  
try{ A_}%YHb  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Jz Z9ua  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?:1)=I<A4  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]Yd7  
fileFetch.start(); d*(wU>J '  
} %n<.)R  
catch(Exception e){e.printStackTrace ();} ,Y_[+  
[-*8 S1  
J6m(\o  
} )9mUE*[  
%. -nZC  
Z+J;nl  
public static void main(String[] args) ?&>H^}gDZ  
{ }y P98N5o  
new TestMethod(); /{7we$+,p  
} S&w(H'4N  
} ].,T Snb  
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