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http断点续传简单实现(java)

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/* ;7P '>j1?U  
**SiteFileFetch.java IEhD5?  
*/ /}m)FaAi  
package NetFox; sF {,n0<8  
import java.io.*; u"HGT=Nl  
import java.net.*; b(0<,r8  
.$&^yp  
-!PJHCLd  
public class SiteFileFetch extends Thread { %y RGN  
3(WijtH  
+HS]kFH  
SiteInfoBean siteInfoBean = null; //文件信息Bean eN=jWUoCh  
long[] nStartPos; //开始位置 3YvKHn|V"  
long[] nEndPos; //结束位置 i1B!oZ3q  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 t1?aw<  
long nFileLength; //文件长度 Z mJ<h&  
boolean bFirst = true; //是否第一次取文件 n~ *|JJ*`  
boolean bStop = false; //停止标志 7 9t E  
File tmpFile; //文件下载的临时信息 ?8-Am[xH  
DataOutputStream output; //输出到文件的输出流 ;M3%t=KV  
WWunS|B!  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) `dZ|Ko%k  
public SiteFileFetch(SiteInfoBean bean) throws IOException .TGw+E1k  
{ h$02#(RHJ  
siteInfoBean = bean; )=5 &Q  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [~9UsHfH  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); O52 /fGt  
if(tmpFile.exists ()) x"b'Pmw  
{ DG;7+2U  
bFirst = false; C8-7XQ=B:b  
read_nPos(); <w9~T TS  
} cXb*d|-|N  
else o !tC{"g  
{ w)EY j+L  
nStartPos = new long[bean.getNSplitter()]; +u$l]~St\  
nEndPos = new long[bean.getNSplitter()]; #LasTN9  
} ok\-IU?  
K0.aU  
9nG^_.}|  
2o SM|  
} /7UvV60  
iXMJ1\!q\|  
L I<S  
public void run() 9+@h2"|N4*  
{ aZmN(AJ8v  
//获得文件长度 ,Wlt[T(.;  
//分割文件 /JR+WmO  
//实例FileSplitterFetch 5NhFjPETr  
//启动FileSplitterFetch线程 j*.;6}\o  
//等待子线程返回 a}UmD HS-  
try{  cyl%p$  
if(bFirst) ,';|CGI cP  
{ {+J{t\`  
nFileLength = getFileSize(); PJ5}c!o[  
if(nFileLength == -1) 3]*Kz*i  
{ ^FLs_=E  
System.err.println("File Length is not known!"); :{%[6lE^G  
} 2^o7 ^S  
else if(nFileLength == -2) g{'f%bkG  
{  L8`v  
System.err.println("File is not access!");  >. K  
} QEr<(wM-y  
else :H]d1  
{ 4#IT" i  
for(int i=0;i<nStartPos.length;i++) 2VN].t:  
{ hZJ~zx~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ray3gM%JLj  
} -#ZLu.  
for(int i=0;i<nEndPos.length-1;i++) *`H*@2  
{ pAy4%|(  
nEndPos = nStartPos[i+1]; @ VWED  
} c""&He4zp  
nEndPos[nEndPos.length-1] = nFileLength; mh3S?Uc  
} \bARp z?a  
} jrQ0-D%M d  
aC,adNub  
p":u]Xgb  
//启动子线程 #^T`vTD-  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,U\ s89  
for(int i=0;i<nStartPos.length;i++) 91]|4k93  
{ n4{%M  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +9Tc.3vQ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EVPQe-  
nStartPos,nEndPos,i); ;\pVc)\4"  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aj5HtP-  
fileSplitterFetch.start(); 'gf[Wjb,%  
} z8X7Y >+SA  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .y s_'F-]0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [.}qi[=n  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t.( `$  
nEndPos = " + nFileLength); n#">k%bD  
// fileSplitterFetch[nPos.length-1].start(); E;a,].  
*Ypn@YpSp  
" aG6u^%  
//等待子线程结束 (  cs  
//int count = 0; >?@5>wF  
//是否结束while循环 !8G)` '  
boolean breakWhile = false; &Gt{9#  
5&n:i,  
Q5ASN"_  
while(!bStop)  R0Vt_7  
{ (l99a&] t  
write_nPos(); DzpWU8j  
Utility.sleep(500); H\>{<`sD;f  
breakWhile = true; @AZNF+ \W$  
yI^Yh{  
!,`'VQw$  
for(int i=0;i<nStartPos.length;i++) I/(U0`%  
{ :M"+  
if(!fileSplitterFetch.bDownOver) ({E,}x  
{ u !BU^@P  
breakWhile = false; }k }=e  
break;  nYx /q  
} @\g}I`_M  
} x {NBhq(4  
if(breakWhile) G J%^hr`P  
break; 0Q{lyu  
B=cA$620  
Ic0Sb7c  
//count++; /GgID!8  
//if(count>4) D)-LZbPa  
// siteStop(); Jt[ug26  
} "&={E{pQ  
4;YP\{u  
8!2)=8|f  
System.err.println("文件下载结束!"); sOLh'x f.  
} |Y!^E % *  
catch(Exception e){e.printStackTrace ();} )Eozo4~  
} +Csb8  
JQKXbsXS  
F7<mm7BGZ  
//获得文件长度 -9dZT  
public long getFileSize() RW&o3_Ua  
{ 6y^ zC?  
int nFileLength = -1; \Eh5g/,[  
try{ Zv %>m  
URL url = new URL(siteInfoBean.getSSiteURL()); ~<_#%R!  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J&aN6l?  
httpConnection.setRequestProperty("User-Agent","NetFox"); $]|3^(y``  
gCg hWg{S  
U,U=udsi  
int responseCode=httpConnection.getResponseCode(); pb97S^K[  
if(responseCode>=400) A"7YkOfwH  
{ WR #XPbk  
processErrorCode(responseCode); D|5mNX %e  
return -2; //-2 represent access is error A$wC !P|;  
} Y!M0JSaM  
% G!!0V!  
*P' X[z  
String sHeader; \ aJ>?   
Osqk#Oh  
lj]M 1zEz&  
for(int i=1;;i++) "e-Y?_S7R8  
{ .JKH=?~\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fn<dr(Dx  
//Utility.log(in.readLine()); JzEg`Sn^  
sHeader=httpConnection.getHeaderFieldKey(i); 4pL'c@'  
if(sHeader!=null) :P-H8*n""  
{ }[eUAGhDU  
if(sHeader.equals("Content-Length")) 3V]dl)en%  
{ PY.HZ/#d  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uf?;;wg  
break; G `|7NL   
} __}SHU0R  
} $ #!oejLD  
else ;}Jv4Z  
break; {gzQ/|}#z-  
} ' wl})  
} a~yiLq  
catch(IOException e){e.printStackTrace ();} Kz;Ar&^`N  
catch(Exception e){e.printStackTrace ();} bVcJ/+Yx|  
h?TIxo:6/  
N #v[YO`.  
Utility.log(nFileLength); HW[&q  
'_?Z{|  
Kii@Z5R_?  
return nFileLength; T}!9T!(HdF  
} H {=]94  
q&:7R .Ci  
fExFpR,`  
//保存下载信息(文件指针位置) 76T7<.S  
private void write_nPos() ~;oXLCL0})  
{ SXsszb:_  
try{ B}04E^  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ILCh1=?{9r  
output.writeInt(nStartPos.length); al#(<4sJ  
for(int i=0;i<nStartPos.length;i++) ?J$k 5;  
{ 2Ug_3ZuU  
// output.writeLong(nPos); fOMaTnm'  
output.writeLong(fileSplitterFetch.nStartPos); h_ t`)]-  
output.writeLong(fileSplitterFetch.nEndPos); 3fLdceT  
} % (h6m${j  
output.close(); ;^:8F  
} k:n{AoUc  
catch(IOException e){e.printStackTrace ();} L/fXP@u  
catch(Exception e){e.printStackTrace ();} ;*rGZ?%*  
} 5%D`y|  
yPmo1|'X>d  
3F, M{'q  
//读取保存的下载信息(文件指针位置) ;jxX/c  
private void read_nPos() 9(fh+  
{ \r aP  
try{ 8T"L'{ggWB  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G>pedE\  
int nCount = input.readInt(); 5!ngM  
nStartPos = new long[nCount]; ;r2DQg"#@  
nEndPos = new long[nCount]; f IV"U  
for(int i=0;i<nStartPos.length;i++) C1A  X  
{ uNy-r`vg  
nStartPos = input.readLong(); ->qRGUW  
nEndPos = input.readLong(); JRBz/ j  
} + _ehzo97  
input.close(); 12i`82>;  
} r7VBz_Q  
catch(IOException e){e.printStackTrace ();} Jb{g{a/  
catch(Exception e){e.printStackTrace ();} * 0K]/tn<  
}  @mw1__?  
)*%uG{h  
|j"C52Q  
private void processErrorCode(int nErrorCode) hcU^!mp  
{ "u^2!d  
System.err.println("Error Code : " + nErrorCode); 8]&Fu3M^  
} TS#1+f]9J<  
=_&,^h@'3e  
Z3o HOy  
//停止文件下载 n jd2  
public void siteStop() 1f3g5y'z5  
{ k4&adX@Y  
bStop = true; 3B[tbU(  
for(int i=0;i<nStartPos.length;i++) dDiy_Q6  
fileSplitterFetch.splitterStop(); g&RhPrtl  
`Zp*?  
(M;d*gN r  
} E_& ;.hw  
} ?p6@uM\Q7  
//负责部分文件的抓取 8Ud.t =2  
**FileSplitterFetch.java h_X'O3r  
*/ ,6y.wNb:F  
package NetFox; FXk*zXn6  
v+E J $  
y=8KNseW|  
import java.io.*; gs}&a3d7k  
import java.net.*; ?b d&Av  
/slCK4vFc  
H^*[TX=#[  
public class FileSplitterFetch extends Thread { CWZv/>,%  
j}lne^ h  
!]"M]tyv\  
String sURL; //File URL ZLaht(`+  
long nStartPos; //File Snippet Start Position 6k')12~'  
long nEndPos; //File Snippet End Position hJFxT8B/  
int nThreadID; //Thread's ID "pX|?ap  
boolean bDownOver = false; //Downing is over 0dx%b677d  
boolean bStop = false; //Stop identical @ #J2t#  
FileAccessI fileAccessI = null; //File Access interface V#599-  
z__{6"^  
O 8l`1  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9XUYy2{G  
{ Fbotn(\h@  
this.sURL = sURL; %N\45nYU:  
this.nStartPos = nStart; _ y'g11 \  
this.nEndPos = nEnd; ;|=5)KE  
nThreadID = id; 5:+x7Ed  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "kt7m  
} =H-BsX?P  
Yk{4 3yw  
mr>E'd.'  
public void run() r"L:Mu  
{ 1"A"AMZf  
while(nStartPos < nEndPos && !bStop) T*k{^=6"!  
{ B*`[8kb,  
DbI)tDi5D  
"@+Z1k-8U  
try{ m{*_%tjN0  
URL url = new URL(sURL); "V:RKH`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d|tNn@jN  
httpConnection.setRequestProperty("User-Agent","NetFox"); L$Xkx03lz>  
String sProperty = "bytes="+nStartPos+"-"; 4d`f?8vS  
httpConnection.setRequestProperty("RANGE",sProperty); ktY  
Utility.log(sProperty); /xg1i1Et  
*Ta {  
u<\Sf"fs  
InputStream input = httpConnection.getInputStream(); tR=1.M96Y  
//logResponseHead(httpConnection); =?M{B1;H  
?YFSK  
W'zI~'K  
byte[] b = new byte[1024]; AGlFbc(L  
int nRead; YFcMU5_F  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]7,0}q.  
{ !':y8(Ou  
nStartPos += fileAccessI.write(b,0,nRead); Q >h7H{c  
//if(nThreadID == 1) ]<iD'=a  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wVv@   
} R-Tf9?)  
fn//j7 j  
F{&0(6^p!  
Utility.log("Thread " + nThreadID + " is over!"); x;&iLQZh  
bDownOver = true; 2Zq_zvKUt  
//nPos = fileAccessI.write (b,0,nRead); ;k1VY Ie}  
} #%CB`l  
catch(Exception e){e.printStackTrace ();} <7%#RJwe  
} Zh:@A Fz:R  
} RLh%Y>w  
#FGj)pu  
MR":a T  
//打印回应的头信息 [r1\FF@v,  
public void logResponseHead(HttpURLConnection con) 30cb+)h(  
{ "f!H[F1~  
for(int i=1;;i++) zM%2h:*+{  
{ E zU=q E  
String header=con.getHeaderFieldKey(i); ]D>\Z(b  
if(header!=null) x50ZwV&j  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +o 6"Z)  
Utility.log(header+" : "+con.getHeaderField(header));  N,ihQB5  
else Xj6?,J  
break; s=&x%0f%  
} ! M7727  
} TwZmZE ?!  
G{'`L)~3N  
NW*$+u%/R  
public void splitterStop() R5cpmCs@R  
{ ];{CNDAL2  
bStop = true; l5Q-M{w0x  
} d?GB#N|+g  
covK6SH  
y $>U[^G[  
} 5F5)Bh  
DvBRK}'  
[@/x  
/* =eeZtj.  
**FileAccess.java 4^w`] m  
*//文件访问(定位,写) /kFw(l_.  
package NetFox; T;Ra/H  
import java.io.*; enQev?8%  
?Hf8<C}3  
ftqeiZ 2  
public class FileAccessI implements Serializable{ ]%6XE)  
<`=(Ui$fD  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O&PrO+&  
RandomAccessFile oSavedFile; jW.IkG[|  
long nPos; WD'[|s\  
m@c\<-P  
qJJ~#W)  
public FileAccessI() throws IOException &Ht5!zuW,  
{ vy5SBiK  
this("",0); VL@eR9}9K  
} \yo)oIi[p  
7,D6RP(b  
>KCnmi  
public FileAccessI(String sName,long nPos) throws IOException R`>z>!)  
{ }woNI  
oSavedFile = new RandomAccessFile(sName,"rw"); .5YW >PV  
this.nPos = nPos; {# TZFB  
oSavedFile.seek(nPos); cY%6+uJ1  
} IaYy5Rw  
2u^/yl  
;fKFmY41  
public synchronized int write(byte[] b,int nStart,int nLen) /: }"Zb  
{ ~`CWpc:  
int n = -1; 4wx _@8  
try{ V%'+ ob6  
oSavedFile.write(b,nStart,nLen); A:Kit_A  
n = nLen; r=^?  
} i{nFk',xX  
catch(IOException e) p V`)  
{ N:e5=;6s  
e.printStackTrace (); ^yVKW5x  
} *gL-v]V  
`RL n)a  
Ab)X/g-I @  
return n; Hyz:i)2  
} + Awo\;@,  
U=\!`_f':  
kmF@u@5M  
} (GDW9:  
H6%%n X  
0%GQXiy  
/* f-l(H="e  
**SiteInfoBean.java o" e]9{+<  
*/ x`gsD3C  
package NetFox;  Y.v. EZ  
xa|/P#q  
%Ig3udcY?  
public class SiteInfoBean { IO]%AL(.;  
` @Tl7I\  
 ,7w[r<7  
private String sSiteURL; //Site's URL m?pm)w  
private String sFilePath; //Saved File's Path Ny)N  
private String sFileName; //Saved File's Name Ga#5xAI{a  
private int nSplitter; //Count of Splited Downloading File &! MV!9$  
dhmZ3~cW>  
5AO' IhpL  
public SiteInfoBean() 72{Ce7J4  
{//nSplitter的缺省值为5 DmpG35Jk  
//default value of nSplitter is 5 N3QDPQ  
this("","","",5); *Bm _  
} t7qY!S (  
|$a!Zx94^  
H m Z*  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QcG-/_,'}  
{ We*&\e+"T  
sSiteURL= sURL; *B1%-  
sFilePath = sPath; l5esx#([*R  
sFileName = sName; zY&/^^y  
this.nSplitter = nSpiltter; !1cVg ls|  
"kg;fF|  
`78)|a*R.  
} U%E364;F  
SK G!DKQ  
 ]pP:  
public String getSSiteURL() UKBaGX:v  
{ QO(P_az3mg  
return sSiteURL; !f!HVna  
} >7I"_#x1:  
A/w7 (  
55#s/`gd)^  
public void setSSiteURL(String value) B~t[Gy  
{ ?0k4l8R  
sSiteURL = value; lzup! `g  
} &'d3Yt  
Rt2<F-gY  
af<wUxM0  
public String getSFilePath() -Ay=*c.4  
{ <maY S2  
return sFilePath; @fO[{V  
} N9=1<{Z  
kcN#g- 0  
z*B-`i.  
public void setSFilePath(String value) F>/"If#  
{ b'$fr6"O1  
sFilePath = value; p`2w\P3;)  
} oVYW '~OID  
, UiA?7k  
=9y&j-F  
public String getSFileName() 5x/LHsr=m  
{ rf]'V Jg#3  
return sFileName; ?A`8c R=)I  
} yITL;dBy  
U9eb&nd  
sxFkpf_h  
public void setSFileName(String value) `37$YdX  
{ U+wfq%Fz  
sFileName = value; $F/Uk;*d!  
} yTwtGo&  
%RX}sS  
\GEf,%U<K  
public int getNSplitter() bfl%yGkd/|  
{ IMtfi(Y%F  
return nSplitter; "D1u2>(  
} ?3|jB?:k  
0;  BX  
qGrUS_~q*  
public void setNSplitter(int nCount) .T|1l$Jn  
{ 5`H.{4@  
nSplitter = nCount; !H/5Ud9  
} moT*r?l  
} ipdGAG  
)$oboAv#  
C6ry]R@  
/* aq-R#q  
**Utility.java B(B77SOb  
*/ .qGfLvx%  
package NetFox; # )]L3H<  
YR/%0^M'0  
T>qI,BEY  
public class Utility { 8^>qzaf 8  
C^8n;i9  
 "yA=Tw  
public Utility() I@jXW>$  
{ ,wPvv(b]a  
xR`M#d5"  
yHIZpU|(j  
} |h(05Kbk  
tVFydN~  
//线程睡眠 M'-Z"  
public static void sleep(int nSecond) V4>qR{5  
{ Hu-Y[~9^L:  
try{ Lk>o`<*  
Thread.sleep(nSecond); ~"8D]  
} |';oIYs|$  
catch(Exception e) (dgBI}Za  
{ S?K x:]  
e.printStackTrace (); %.[jz,;)  
} `<x((@#  
} O\&-3#e  
' zz ^ !@  
//日志 S&Szc0-|k  
public static void log(String sMsg) u-%|ZSg  
{ !Un &OAy.!  
System.err.println(sMsg); rS&"UH?c7  
} `m7w%J.>n  
|(77ao3  
Iq["(!7E5  
public static void log(int sMsg) SL ) ope  
{ [B+]F~}@  
System.err.println(sMsg); Q$lgC v^M  
} ]**h`9MF  
} yh:Wg$qx  
q\]"}M 8  
vn(ji=  
/* g;mX{p_@  
**TestMethod.java A8oTcX_  
*/ f<;w1sM\  
package NetFox; -lqsFaW  
c[<>e#s+;  
8o%g2 P9.  
public class TestMethod { rGIf/=G^r  
&V77Wn OY  
X4I+  
public TestMethod() _CImf1  
{ ///xx/weblogic60b2_win.exe vzH"O=  
try{ /*kc|V  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i2&I<:  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J@lQzRqRb  
SiteFileFetch fileFetch = new SiteFileFetch(bean); "eG@F  
fileFetch.start(); (N[R`LN  
} /{71JqFis  
catch(Exception e){e.printStackTrace ();} }8&?  
#_?m.~`g[  
tQ7:4._  
} %|AXVv7IN>  
VV$4NV&`Q  
\qZ>WCp>r  
public static void main(String[] args) J{qsCJiB  
{ pr?k~Bn  
new TestMethod(); >_'0 s  
} I3,0vnE@  
} LTlbrB  
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