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http断点续传简单实现(java)

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/* n7t}G'*Y!^  
**SiteFileFetch.java \Zj%eW!m  
*/ H*=cw<  
package NetFox; }z` x-(V  
import java.io.*; hb`9Vn\-E  
import java.net.*; \|PiQy*_?  
C QkY6  
V(';2[)  
public class SiteFileFetch extends Thread { m Q2i$ 0u  
& NYaKu,}  
JW>k8QjyN  
SiteInfoBean siteInfoBean = null; //文件信息Bean B/a gW  
long[] nStartPos; //开始位置 cY?|RXNmZ  
long[] nEndPos; //结束位置 p6DI7<C<H  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 (?z?/4>7<  
long nFileLength; //文件长度 @%4'2b  
boolean bFirst = true; //是否第一次取文件 cYSn   
boolean bStop = false; //停止标志 7:4c\C0  
File tmpFile; //文件下载的临时信息 m$vq %[/#  
DataOutputStream output; //输出到文件的输出流 x-%O1frc  
G5}_NS/  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) b}! cEJY  
public SiteFileFetch(SiteInfoBean bean) throws IOException "wcaJ;Os  
{ UmR)L!QT8  
siteInfoBean = bean; 8eXe b|?J  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 0D5Z#iW>1  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); q5f QTV  
if(tmpFile.exists ()) %' DO FiU  
{ R"cQyG4  
bFirst = false; iOiF kka  
read_nPos(); *AH `ob}  
} 4|x _C-@  
else yYz{*hq  
{ |` T7}U  
nStartPos = new long[bean.getNSplitter()]; lNX*s E .  
nEndPos = new long[bean.getNSplitter()]; MJ}{Q1|*  
} a 0SZw  
v5[gFY(?  
q{w|`vIb  
|"*P`C=  
} <*5S7)]BP  
w B)y@w4k  
LUQ.=:mBR  
public void run() od `;XVG  
{ um9&f~M  
//获得文件长度 ]it. R-  
//分割文件 Cy-p1s  
//实例FileSplitterFetch ZF>:m>  
//启动FileSplitterFetch线程 a6 Vfd&  
//等待子线程返回  a*p|Ij  
try{ 9vRLM*9|  
if(bFirst) t0 e6iof^o  
{ >Na.C(DZ  
nFileLength = getFileSize(); &M|rRd~*  
if(nFileLength == -1) ^G!cv  
{ mV}bQ^*?Z  
System.err.println("File Length is not known!"); Uu7]`Ul  
} RP~nLh3=\  
else if(nFileLength == -2) utck{]P  
{ tA1?8`bQ  
System.err.println("File is not access!"); bB<S4@jF8z  
} wDvu2iC=  
else u!X~!h-6~  
{  q0ktABB  
for(int i=0;i<nStartPos.length;i++) gS FZ>v*6  
{ )@! fLA T  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !oH{=.w  
} }83 8F&  
for(int i=0;i<nEndPos.length-1;i++) .$\-{)  
{ ip?]&5s  
nEndPos = nStartPos[i+1]; qJG;`Ugl:  
} Zh8\B)0unn  
nEndPos[nEndPos.length-1] = nFileLength; H9WYt#  
} lWRl  
} U$2Em0HO}  
;1&"]N%  
! $JX3mP  
//启动子线程 L&6^(Bn   
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ULK] ' Rn  
for(int i=0;i<nStartPos.length;i++) i*$+>3Q-  
{ &4OOW;,?<  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L } R"1O  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >/-H!jUF]  
nStartPos,nEndPos,i); $}vk+.!*1  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4q .;\n  
fileSplitterFetch.start(); 3I 0pHP5  
} ) f3A\^  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >vD}gGBe  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2S7 BzZ/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x<I[?GT=  
nEndPos = " + nFileLength); 3$"V,_TBZ  
// fileSplitterFetch[nPos.length-1].start(); G$,s.MSf  
ZV{C9S&  
C]b:#S${  
//等待子线程结束 k (AE%eA  
//int count = 0; N[eL Qe]q  
//是否结束while循环 w6Gez~ 8  
boolean breakWhile = false; /T6bc^nOW  
KTYjC\\G  
X>$Wf3  
while(!bStop) y],op G6  
{ "6C a{n1hk  
write_nPos(); {N]WVp*R  
Utility.sleep(500); :?~)P!/xl5  
breakWhile = true; &en2t=a  
|kZ!-?9Z  
gq?O}gVD  
for(int i=0;i<nStartPos.length;i++) )VQ[}iT  
{ g7323m1=  
if(!fileSplitterFetch.bDownOver) 0j8fU7~6S  
{ GyL9}  
breakWhile = false; qG,h 1  
break; z uNm !$  
} E^J &?-  
} 4Pr^>m  
if(breakWhile) #_^ p~:  
break; }Bv1fbD4U  
xD*Zcw(vj~  
6n/=n%US  
//count++; %3dc_YPS  
//if(count>4) $-/-%=  
// siteStop(); 2<*"@Vj  
} od#Lad@p  
Q>Ct]JW&  
9]N{8  
System.err.println("文件下载结束!"); qJF'KHyU{l  
} wdj?T`4  
catch(Exception e){e.printStackTrace ();} X.{xH D&_  
} 2XL^A[?   
^0"^  
W'"hjQ_  
//获得文件长度 uPl7u 1c  
public long getFileSize() ^6# yL6E,~  
{ R@grY:h  
int nFileLength = -1; r1F5'?NZ(0  
try{ G\tN(%.f  
URL url = new URL(siteInfoBean.getSSiteURL()); mNC?kp  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @5&57R3>  
httpConnection.setRequestProperty("User-Agent","NetFox"); gK~Z Ch  
n3?P8m$  
2Bi]t%<{  
int responseCode=httpConnection.getResponseCode(); Pg.JI:>2Ku  
if(responseCode>=400) lZ5-lf4  
{ V}TPt6C2  
processErrorCode(responseCode); Ur 1k3  
return -2; //-2 represent access is error j)G%I y[`  
} m\*ca3$  
ax5n}  
H,<CR9@(5d  
String sHeader; w}6~t\9D  
\>4>sCC  
'`k  
for(int i=1;;i++) M &-p  
{ K?M~x&Q  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !^Ay !  
//Utility.log(in.readLine()); oeKl\cgFx  
sHeader=httpConnection.getHeaderFieldKey(i); u gRyUny  
if(sHeader!=null) Q~"Lyy8  
{ /Q W^v;^  
if(sHeader.equals("Content-Length")) DNj<:Pdd)  
{ $'}|/D  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q65M(x+oy  
break; xBc$qjV  
} 2.JrLBhN  
} O<wH+k[  
else xK0;saG#  
break; ~tTa[_a!  
} o1 27? ^  
} 8yYag[m8  
catch(IOException e){e.printStackTrace ();} mx1Bk9h%Xe  
catch(Exception e){e.printStackTrace ();} &:C[ nq  
L$a{%]I  
u`B/9-K)y  
Utility.log(nFileLength); E_ 30)"]  
A##Q>|>)  
j/O9LygB  
return nFileLength; ^{J^oZ'%~  
} <NDV 5P  
us5Zi#}  
K HNU=k  
//保存下载信息(文件指针位置) sMAH;'`!Eu  
private void write_nPos() StR)O))I  
{ T__@hfT  
try{ {|%^'lS  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y: C qQ  
output.writeInt(nStartPos.length); o;9H~E  
for(int i=0;i<nStartPos.length;i++) dC4`xUv  
{ UCmJQJc  
// output.writeLong(nPos); B4*,]lS?  
output.writeLong(fileSplitterFetch.nStartPos); Ts, U T L  
output.writeLong(fileSplitterFetch.nEndPos); )y!gApNs"  
} 3bLOT#t  
output.close(); s(5(zcBK  
} ?N+pWdi  
catch(IOException e){e.printStackTrace ();} b+RU <qR  
catch(Exception e){e.printStackTrace ();}  eJ[+3Wh  
} X`Lv}6}xT  
?st}rJ_  
%/U'Wu{*  
//读取保存的下载信息(文件指针位置) |]:6IuslJ  
private void read_nPos() Pvv7|AV   
{ mGwJ>'+d  
try{ ^eoW+OxH  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); R/B/|x  
int nCount = input.readInt(); }#g &l*P  
nStartPos = new long[nCount]; V/\`:  
nEndPos = new long[nCount]; l YdATM(h  
for(int i=0;i<nStartPos.length;i++) \2f?)id~  
{ d hg($m  
nStartPos = input.readLong(); zb~;<:<  
nEndPos = input.readLong(); T z:,l$  
} .1h\r, #  
input.close(); ELG{xN=o  
} MjBI1|*  
catch(IOException e){e.printStackTrace ();} Vl(id_~_  
catch(Exception e){e.printStackTrace ();} 6 P9#6mZ  
} [$>@f{:  
),o=~,v:  
\/wk!mWV@  
private void processErrorCode(int nErrorCode) S=L#8CID  
{ BB/c5?V  
System.err.println("Error Code : " + nErrorCode); o{2B^@+Vb  
} x `%x f  
/ml+b8@  
K)Ya%%6[U#  
//停止文件下载 55y}t%5  
public void siteStop() RU.MJ kYQ5  
{ 2 =>3B  
bStop = true; 0ikA@SAq  
for(int i=0;i<nStartPos.length;i++) : @gW3'  
fileSplitterFetch.splitterStop(); e=tM=i"  
Z0~,cO8~  
e v7A;;  
} H11@ DQ6  
} fA V.Mj-  
//负责部分文件的抓取 VK%ExMSqEh  
**FileSplitterFetch.java Zic:d-Q47  
*/ {poTA+i  
package NetFox; j9%vw.3b  
H?=[9?1wI5  
mCI5^%*0jQ  
import java.io.*; 'w;J) _Yc2  
import java.net.*; {j[*:l0Ui  
C-Y7n5  
z`J-J*R>d  
public class FileSplitterFetch extends Thread { g]b%<DJ  
21?>rezJ  
rd(-2,$4  
String sURL; //File URL $0M7P5]N*G  
long nStartPos; //File Snippet Start Position |f}`uF  
long nEndPos; //File Snippet End Position H!y-o'Z  
int nThreadID; //Thread's ID }6__E;h#J  
boolean bDownOver = false; //Downing is over 6il+hz2&lH  
boolean bStop = false; //Stop identical !cO<N~0*5x  
FileAccessI fileAccessI = null; //File Access interface )Ps<u-V  
grd fR`3  
.D=#HEshk  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b3=XWzK5  
{ Pl|*+g  
this.sURL = sURL; e 7Sg-NWV  
this.nStartPos = nStart; naY#`xig  
this.nEndPos = nEnd; nrTCq~LO(  
nThreadID = id; WK SWOSJ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mL@7,GD  
} 4%>tk 8 [  
!?B2OE  
@nj`T{*.  
public void run() r_V^sX  
{ Ys5I qj=mp  
while(nStartPos < nEndPos && !bStop) 1 x0)mt3  
{ {mHxlG)  
57N<OQWf  
gi/W3q3c6  
try{ -,"eN}P^  
URL url = new URL(sURL); 8?o{{ay  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8L))@SA+uJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); w (,x{Bg\  
String sProperty = "bytes="+nStartPos+"-"; NC x)zJ\S  
httpConnection.setRequestProperty("RANGE",sProperty); ^X*l&R_=R  
Utility.log(sProperty); p!(]`N   
K!G/iz9SB  
Kku@!lv  
InputStream input = httpConnection.getInputStream(); xAf?E%_pi  
//logResponseHead(httpConnection); %(1y  
Z3 na.>Z  
erV&N,cI  
byte[] b = new byte[1024]; $O9#4A;  
int nRead; M[Jy?b)  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i:^ 8zW  
{ *pGbcBQ  
nStartPos += fileAccessI.write(b,0,nRead); J s,.$t  
//if(nThreadID == 1) `b5pa`\4  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {'zs4)vw  
} pmDFmES  
o PA m*  
s.!gsCQme  
Utility.log("Thread " + nThreadID + " is over!"); VC NQ}h[D  
bDownOver = true; 3_Re>i  
//nPos = fileAccessI.write (b,0,nRead); 'p,54<e  
} `9VRT`e  
catch(Exception e){e.printStackTrace ();} wIQt f|ZI>  
} M0MvOO*ad  
} DB+.<  
yu'@gg(  
5lm>~J!/^  
//打印回应的头信息 qP[jtRIN  
public void logResponseHead(HttpURLConnection con) L8KMMYh[  
{ ){i 9,u")  
for(int i=1;;i++)  u+]8Sq  
{ s !HOrhV  
String header=con.getHeaderFieldKey(i); L q;=UE  
if(header!=null) kAk+ Sq^n  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cfW;gFf  
Utility.log(header+" : "+con.getHeaderField(header)); k`,>52  
else flU?6\_UC  
break; wb-_CQ  
} Cy\! H&0wg  
} &o)eRcwH`  
WS ^%< h#  
ohB@ijC!  
public void splitterStop() ncij)7c)u  
{ p w`YMk  
bStop = true; 3gba~}c)  
} +C[%^G-:  
O>2i)M-h9x  
<SNu`,/I  
} ,S=ur%  
Md1ePp]  
a"X9cU[  
/* B P0*`TY  
**FileAccess.java /:aY)0F0<&  
*//文件访问(定位,写) YZ^;xV  
package NetFox; HY7#z2L  
import java.io.*; b(:U]>J  
WQYw@M~4Q!  
agPTY{;  
public class FileAccessI implements Serializable{ !&vPG>V  
(%iCP/E3  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Wr\A ->+  
RandomAccessFile oSavedFile;  i(n BXV{  
long nPos; &\M<>>IB  
Zm/I&  
Gmh6|Dsg  
public FileAccessI() throws IOException 2lRE+_qz  
{ IX 2 dic'  
this("",0); =$Sd2UD  
} Q)\4  .d  
p6W|4_a?  
`-82u :"  
public FileAccessI(String sName,long nPos) throws IOException J0 x)NnWJ  
{ Meo. V|1  
oSavedFile = new RandomAccessFile(sName,"rw"); /~;om\7r  
this.nPos = nPos; pK@8= +  
oSavedFile.seek(nPos); i}r|Zo  
} ORo,.#<  
(<xl _L:*.  
xr1,D5  
public synchronized int write(byte[] b,int nStart,int nLen) TKZ[H$Z  
{ 5}"9)LT@@w  
int n = -1; NuC+iC$_/  
try{ 4,qhWe`/  
oSavedFile.write(b,nStart,nLen); m e&'BQ  
n = nLen; {Z(kzJwN  
} :c`Gh< u  
catch(IOException e) vAjvW&'g  
{ (E]q>'X  
e.printStackTrace (); ~~X-$rtU  
} i5jsM\1j  
2N[/Cc2Tg/  
0hM!#BU5K  
return n; R>n=_C  
} ($r-&]y  
$irF  
m>ApN@n  
} gX!-s*{E  
\d}>@@U&  
`0Bk@B[>  
/* Vo8gLX]a  
**SiteInfoBean.java NNP ut$.  
*/ /K\]zPq  
package NetFox; EK$3T5e  
.*Ylj2nM  
)@[##F2  
public class SiteInfoBean { ?_nbaFQK3  
:SvgXMY@  
z6;6 o!ej  
private String sSiteURL; //Site's URL ^n&_JQIXb  
private String sFilePath; //Saved File's Path B'8/`0^n5  
private String sFileName; //Saved File's Name 5l4YYwd>v  
private int nSplitter; //Count of Splited Downloading File jPa"|9A  
mL]a_S{H  
&Na,D7A:3I  
public SiteInfoBean() r: M>/Z/  
{//nSplitter的缺省值为5 2nkymEPu  
//default value of nSplitter is 5 $u P'>  
this("","","",5); db`L0JB  
} XsbYWJdds  
`A ^  
:.aMhyh#*  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \2!1fN  
{ ;Bwg'ThT  
sSiteURL= sURL; 6tF_u D  
sFilePath = sPath; (rm*KD"]  
sFileName = sName; M2lvD&  
this.nSplitter = nSpiltter; FE,BvNBZ  
kmT5g gy  
]-"G:r  
} f O,5 u;  
2rPmu  
P+bA>lJd  
public String getSSiteURL() !!?TkVyEyM  
{ ~EtwX YkRZ  
return sSiteURL; a|eHo%Qt  
} VMIX=gTZ  
7-#   
#Ic)]0L  
public void setSSiteURL(String value) +o-jMvK9  
{ o&ETs)n|  
sSiteURL = value; +^|_vq^XR  
} Lv UQ&NmY  
T7~H|%  
@L?KcGD  
public String getSFilePath() 7BkY0_KK  
{ RG_.0'5=hc  
return sFilePath; I>JBGR`j  
} F<TIZ^gFP  
#ADm^UT^  
ohna1a^  
public void setSFilePath(String value) qsWy <yL+  
{ 75^AO>gt   
sFilePath = value; 5D eo}(3  
} ez<V  
0TWd.+  
g5:?O,?  
public String getSFileName() U*4r<y9R  
{ sm"s2Ci=}  
return sFileName; ,0a\Ka {^  
} ( 4(,"  
7!Qu+R  
Z0%:j\W4c  
public void setSFileName(String value) 4i7+'F  
{ 49.B!DqQW&  
sFileName = value; 5Mz:$5Tm  
} 1]69S(  
Kf1NMin7  
+\]Gu(z<  
public int getNSplitter() )M><09  
{ /mXxj93UA  
return nSplitter; Qk72ra)  
} >#VNA^+t  
2Gh&h(  
lg +>.^7k  
public void setNSplitter(int nCount) R*/s#*gmL  
{ < 1[K1'7h  
nSplitter = nCount; sGa}Cf;H@g  
} Ad&VOh+0  
} $[UUf}7L   
CEW1T_1U<\  
LXqPNVp#  
/* EF6h>"']/  
**Utility.java Cxeam"-HTt  
*/ H*e+ 2  
package NetFox; ALj~e#{;z  
BP}@E$  
F3hG8YX  
public class Utility { E!_3?:[S_  
#a9O3C/MP  
5;+KMM:zb  
public Utility() ,x$^^  
{ M|NQoQ8q  
.$@+ / @4  
dIfy!B"  
} )k;;O7C k  
m*jTvn  
//线程睡眠 Ol~M BQs  
public static void sleep(int nSecond) c?N,Cd~q  
{ #_{Q&QUk  
try{ }R11G9N.  
Thread.sleep(nSecond); Z&O6<=bg!  
} tzthc*-<  
catch(Exception e) K)U[xS;<  
{ inip/&P?V  
e.printStackTrace (); `/^ _W <  
} M*f]d`B  
} P?S]Q19Q4  
s VHk;:e>x  
//日志 sn"z'=ch  
public static void log(String sMsg) xv&h>GOg  
{ oC-v>&bW  
System.err.println(sMsg); |c^?tR<  
} 1je j7p>K  
`nKN|6o#x  
^=5x1<a9$  
public static void log(int sMsg)  +IO>%  
{ Ek1c>s,t  
System.err.println(sMsg); AgZ?Ry  
} GC:q6}  
} @$~IPg[J  
em'ADRxG+  
-]+pwZ4g  
/* "F%JZO51  
**TestMethod.java [q U v|l1  
*/ SnR2o3r-Of  
package NetFox; U (#JC(E-#  
iGkysU<wcp  
le]~Cy0  
public class TestMethod { x x4GP2  
uKXNzz  
nwh@F1|  
public TestMethod() ^sB0$|DU  
{ ///xx/weblogic60b2_win.exe 3H`{ A/r  
try{ /-,\$@J5)  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mf)+ 5On  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pQKSPr  
SiteFileFetch fileFetch = new SiteFileFetch(bean); QW$p{ zo  
fileFetch.start(); l<BV{Gl  
} !1fZ7a  
catch(Exception e){e.printStackTrace ();} ),-gy~  
)Qd x  
ddyX+.LMk  
} HC/z3b;  
!3Pbu=(cte  
!Av9 ?Q:  
public static void main(String[] args) r4fHD~#l{  
{ c(e>Rmh  
new TestMethod(); p |1u,N  
} a5GLbanF  
} # )y/aA  
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