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http断点续传简单实现(java)

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/* &\X;t|  
**SiteFileFetch.java %|,<\~P  
*/ >(*jbL]p  
package NetFox; Nz}Q"6L  
import java.io.*; kx=AX*I  
import java.net.*; .FXQ,7mZ-  
f.P( {PN  
w%_BX3GTO  
public class SiteFileFetch extends Thread { kTk?[BK  
H);'\]_'x  
_uu:)%  
SiteInfoBean siteInfoBean = null; //文件信息Bean wwAT@=X*}  
long[] nStartPos; //开始位置 Y>#c2@^i<  
long[] nEndPos; //结束位置 j d8 1E  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W_ 6Jl5]  
long nFileLength; //文件长度 *(scSC>  
boolean bFirst = true; //是否第一次取文件 qJ/C*Wqic  
boolean bStop = false; //停止标志 8Cqs@<r4Od  
File tmpFile; //文件下载的临时信息 "|G,P-5G"  
DataOutputStream output; //输出到文件的输出流 ^]DWrmy  
lhI;K4#  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) IcoL/7k3  
public SiteFileFetch(SiteInfoBean bean) throws IOException Td  F<  
{ %xfy\of+Nk  
siteInfoBean = bean; j&Aq^aI  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Na6z,TW  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); \Cs<'(=  
if(tmpFile.exists ()) S }n;..{  
{ J9 =gv0  
bFirst = false; |d3agfS[n  
read_nPos(); * Z:PB%d5  
} (>K$gAQH  
else L&N"&\K2U  
{ 0/ Ht;(  
nStartPos = new long[bean.getNSplitter()]; 'oHR4O*  
nEndPos = new long[bean.getNSplitter()]; (Lo2fY5  
} 709eLhXrH  
,![=_d  
7asq]Y}<  
XJzXxhk2  
} dc>y7$2  
Vw*x3>`  
Ax0,7,8y  
public void run() h0 Sf=[>z  
{ W =zG  
//获得文件长度 ??m7xH5u1  
//分割文件 ifs*-f  
//实例FileSplitterFetch -"zu"H~t4  
//启动FileSplitterFetch线程 8[C6LG  
//等待子线程返回 6b/b} vl  
try{ `g1Oon_  
if(bFirst) ]1&9~TL  
{ QB[s8"S  
nFileLength = getFileSize(); I5L7BTe  
if(nFileLength == -1) ja;5:=8A5  
{ -"e}YN/  
System.err.println("File Length is not known!"); &XsLp&Do2  
} x3s^u~C)(w  
else if(nFileLength == -2) Wn^^Q5U#  
{ faq K D:  
System.err.println("File is not access!"); %jxuH+L   
} [!&k?.*;<  
else A,{D9-%  
{ FZnH G;af  
for(int i=0;i<nStartPos.length;i++) ^JtHTLHL=  
{ Y*k<NeDyn  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); lAk1ncx  
} ^eW.hNg  
for(int i=0;i<nEndPos.length-1;i++) ]uvbQ.l_t  
{ >t2b?(h/x  
nEndPos = nStartPos[i+1]; 4c=kT@=jX  
} (@ E#O$'  
nEndPos[nEndPos.length-1] = nFileLength; GX)QIe~;qJ  
} g8+,wSE  
} zb/Xfu.)?6  
@(c<av?  
@S7=6RKa[  
//启动子线程 H040-Q;S'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; : xZC7"  
for(int i=0;i<nStartPos.length;i++) aELT"b,x  
{ udGGDH  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zt2-w/[Q  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }qv-lO  
nStartPos,nEndPos,i); XyphQ}\u  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E ZKz-}  
fileSplitterFetch.start(); ? SP7vQ/  
} 9Nu#&_2R  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~{YgM/c|dt  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xD# I&.  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", WWcm(q =  
nEndPos = " + nFileLength); AtlR!I EUb  
// fileSplitterFetch[nPos.length-1].start(); &t/<yq}{  
9yo[T(8  
%"Q!5qH&  
//等待子线程结束 iwJ-<v_:h  
//int count = 0; hZWK5KwT  
//是否结束while循环 iFG5%>5F  
boolean breakWhile = false; / JeqoM"x  
W<91m*  
`_U0>Bfg;  
while(!bStop) s|r7DdI  
{ Zk#i9[g9*  
write_nPos(); y]]Vp~R:[  
Utility.sleep(500); ^Cn]+0G#C8  
breakWhile = true; ff1B)e  
0~b6wuFl  
!7`=rT&  
for(int i=0;i<nStartPos.length;i++) pE/3-0;}N  
{ d4>-a^)V  
if(!fileSplitterFetch.bDownOver) 1IQOl  
{ rg^\BUa-W,  
breakWhile = false; z %3"d0  
break; Jf<yTAm  
} {2k< k(,  
} 0nz@O^*g(  
if(breakWhile) pZ~> l=-  
break; V 1nZ M  
qV8\/7'A0a  
Ym{%"EB  
//count++; qm8n7Z/  
//if(count>4) C.)&FW2F_  
// siteStop(); m2uML*&O5K  
} 8N* -2/P&  
5rA!VES T  
+'j*WVE%5  
System.err.println("文件下载结束!"); OO\biYh o  
} /Np"J  
catch(Exception e){e.printStackTrace ();} b/,!J] W  
} 8^/Ek<Q b|  
ENXW#{N.v  
6a]f&={E  
//获得文件长度 c w]>a&d  
public long getFileSize() K'5sn|)  
{ #X@<U <R  
int nFileLength = -1; v#%>uLl  
try{ {9.~]dI|L  
URL url = new URL(siteInfoBean.getSSiteURL()); <fsn2[V:B%  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iC|6roO!jk  
httpConnection.setRequestProperty("User-Agent","NetFox"); QjjJtKz  
Na 9l#  
$ l sRg:J  
int responseCode=httpConnection.getResponseCode(); HvgK_'  
if(responseCode>=400) zHoO?tGf  
{ hW !@$Ph  
processErrorCode(responseCode); }Q r0T  
return -2; //-2 represent access is error 2}`Vc{\  
} )-?uX.E{  
J%f=A1Q  
&PBWJ?@O)r  
String sHeader; a.}:d30  
wdcryejCkr  
h/0-Mrk;e  
for(int i=1;;i++) OZB}aow  
{ &>zy_)  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?fa,[r|G  
//Utility.log(in.readLine()); U~#^ ^  
sHeader=httpConnection.getHeaderFieldKey(i); >RL6Jbo|  
if(sHeader!=null) Z_V&IQo-7  
{ o(X90X  
if(sHeader.equals("Content-Length")) 3w^J"O/T  
{ ^,Y~M_=  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j&[3Be'pQ  
break; J'&B:PZObB  
} ??zABV  
} IJ_ 'w[k  
else Pvg  
break; xL39>PB  
} OZC/+"\,  
} RZ)vU'@kx  
catch(IOException e){e.printStackTrace ();} 1f@U :<:  
catch(Exception e){e.printStackTrace ();} @[>+Dzn[6  
uU[[[LQq  
ttbQergS  
Utility.log(nFileLength); M~z (a3@[V  
3<)@ll  
$E`i qRB  
return nFileLength; Y6f+__O  
} 7<QYT+6xV  
HzG~I8o(d  
ndKvJH4  
//保存下载信息(文件指针位置) @u"kX2>Eq  
private void write_nPos() C?/r}ly<\  
{ C;)Xwm>e  
try{ 8!&ds~?  
output = new DataOutputStream(new FileOutputStream(tmpFile)); }W@#S_-e8  
output.writeInt(nStartPos.length); ,Og[[0g  
for(int i=0;i<nStartPos.length;i++) VO @ 4A6  
{ zy5s$f1IA  
// output.writeLong(nPos); EN-8uY.  
output.writeLong(fileSplitterFetch.nStartPos); /HjI=263  
output.writeLong(fileSplitterFetch.nEndPos); ek(kY6x:  
} :@QK}qFP  
output.close(); 4iYKW2a  
} fbHWBb  
catch(IOException e){e.printStackTrace ();} ]U#[\ Z  
catch(Exception e){e.printStackTrace ();} "S B%02  
} *fQ ?A|l!x  
*2"bG1`  
&3 XFg Ho  
//读取保存的下载信息(文件指针位置) ^T}}4I_Y  
private void read_nPos() N'eQ>2>O@  
{ 2sd ) w  
try{ s.p1L  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \sHy.{  
int nCount = input.readInt(); OXIu>jF  
nStartPos = new long[nCount]; yd0=h7s  
nEndPos = new long[nCount]; >ggk>s|  
for(int i=0;i<nStartPos.length;i++) a9? v\hG  
{ =q"w2b&  
nStartPos = input.readLong(); [$1: &!(!  
nEndPos = input.readLong(); {m_A1D/_  
} RWh9&O:6'  
input.close(); J3lG"Ww  
} iL7-4Lv#  
catch(IOException e){e.printStackTrace ();} F= _uNq  
catch(Exception e){e.printStackTrace ();} Cz=A{< ^g  
} |c 06ix;).  
<4l.s  
Qr|N)  
private void processErrorCode(int nErrorCode) I8<Il ^  
{ Giy3eva2  
System.err.println("Error Code : " + nErrorCode); y"|K |QT  
} ( E"&UC[  
uKR\Xo}  
so?pA@O  
//停止文件下载 cotxo?)Zv  
public void siteStop() o;M.Rt\A  
{ XI@6a9Uk  
bStop = true; ` x%U  
for(int i=0;i<nStartPos.length;i++) 5T$9'5V7  
fileSplitterFetch.splitterStop(); 0\\ueMj  
{2}tPT[a(  
zqHpT^B?  
} pIID= 8RJ.  
} Wz6]*P`qv  
//负责部分文件的抓取 ~8H&m,{j  
**FileSplitterFetch.java ||{T5E-.F  
*/ 5YTb7M  
package NetFox; *} *!+C3  
2y9:'c|  
T@K7DkP@  
import java.io.*; w|!YoMk+o  
import java.net.*; ^f^-.X  
KAj"p9hq+k  
_Hz~HoNU  
public class FileSplitterFetch extends Thread { ? -v  
3iu!6lC  
L\/u}]dPQ  
String sURL; //File URL [n!$D(|"!V  
long nStartPos; //File Snippet Start Position EpRXjz  
long nEndPos; //File Snippet End Position /~H[= Pf  
int nThreadID; //Thread's ID /[\6oa  
boolean bDownOver = false; //Downing is over BKa A=Bl  
boolean bStop = false; //Stop identical -vyIOH,  
FileAccessI fileAccessI = null; //File Access interface G*kE~s9R  
07.nq;/R  
3c01uObTL  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -rE eKt  
{ Zij"/gx\  
this.sURL = sURL; 7!O^;]+,  
this.nStartPos = nStart; R<0Fy=z  
this.nEndPos = nEnd; R^jlEt\&P  
nThreadID = id; GwgFi@itN  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ak xH  
} #=X)Jx~  
ShC_hi  
J y]FrSm^  
public void run() 8!Wfd)4=,F  
{ =jJ H^Y2  
while(nStartPos < nEndPos && !bStop) >}-~rZ  
{ `)rg|~#k  
L_tjcfVo  
%)zk..K{l  
try{ 9k+N3vA  
URL url = new URL(sURL); mZ`1JO9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \\Y,?x_0T  
httpConnection.setRequestProperty("User-Agent","NetFox"); gb.f%rlZ`  
String sProperty = "bytes="+nStartPos+"-"; Q{H17]W  
httpConnection.setRequestProperty("RANGE",sProperty); wY' "ab  
Utility.log(sProperty); M%7`8KQ  
@''&nRC1  
w@87]/4Rq  
InputStream input = httpConnection.getInputStream(); _aVJ$N.  
//logResponseHead(httpConnection); /)sDnJ1r  
* eA{[  
Gh2#-~|cB  
byte[] b = new byte[1024]; %GM>u2baw  
int nRead; ^$e0t;W=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~RcNZ\2y  
{ VT'0DQ!NIq  
nStartPos += fileAccessI.write(b,0,nRead); o^6jyb!j  
//if(nThreadID == 1) 4uFIpS|rq  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3Z_t%J5QZ$  
} [_j6cj]  
:9(3h"  
`2>XH:+7F  
Utility.log("Thread " + nThreadID + " is over!");  `>%-  
bDownOver = true; 7;^((.]ln  
//nPos = fileAccessI.write (b,0,nRead); {?w"hjy  
} MKomq  
catch(Exception e){e.printStackTrace ();} BqQ] x'AF  
} ||R0U@F,  
} /rqqC(1  
_~juv&  
Nfr:`$k  
//打印回应的头信息 P=c?QYF  
public void logResponseHead(HttpURLConnection con) L {!ihJr  
{ :lNg:r$4  
for(int i=1;;i++) 9H>BWjS  
{ A_@I_V$  
String header=con.getHeaderFieldKey(i); p=2zS.  
if(header!=null) R|-6o)$  
//responseHeaders.put(header,httpConnection.getHeaderField(header));  wjL|Z8  
Utility.log(header+" : "+con.getHeaderField(header)); P= e4lF.  
else B#1:Y;Z  
break; "<qEXX  
} b9`iZ  
} Jth=.9mrM  
;{Xy`{Cg!  
F{;; :  
public void splitterStop() Ky *DfQA  
{ 4ffU;6~l'  
bStop = true; ~xw5\Y^  
} ,`y yR:F  
4b]_ #7Qm  
Yhe+u\vGs\  
} "2%>M  
6eM6[  
#^Ys{  
/* ^/k ,  
**FileAccess.java z9 O~W5-U  
*//文件访问(定位,写)  O)OUy  
package NetFox; 21 ViHV  
import java.io.*; _$8{;1$T?  
8qN"3 Et  
!I~C0u  
public class FileAccessI implements Serializable{ n3'dLJH|  
lw s(/a*c  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {$0&R$v3  
RandomAccessFile oSavedFile; !Qcir&]C>  
long nPos; ]Dh1~k.Kp  
te)n{K",  
8`*`nQhWa  
public FileAccessI() throws IOException \2j|=S6  
{ wra byRjK  
this("",0); ka#K [qI  
} t}VwVf<K  
6%E~p0)i%  
nx B32  
public FileAccessI(String sName,long nPos) throws IOException c8<xFvYG  
{ *!Y- !  
oSavedFile = new RandomAccessFile(sName,"rw"); b_|u<  
this.nPos = nPos; F;pQ\Y  
oSavedFile.seek(nPos); .A(i=!{q  
} .9OFryo  
IfMpY;ow=  
9qr UM`z$g  
public synchronized int write(byte[] b,int nStart,int nLen) Z^*NnL.'  
{ )yrAov\z*  
int n = -1; ./7v",#*.'  
try{ Ssf+b!e]  
oSavedFile.write(b,nStart,nLen); MQJ%He"  
n = nLen; 3"Yif  
} 0yz~W(tsm  
catch(IOException e) S7CV w,2  
{ ' l|R5   
e.printStackTrace (); FN!1| 'VK  
} '#W_boN  
~r&D6Y  
TY~Vi OC  
return n; +;dXDZ2  
} q? 9GrwL8F  
] IS;\~  
1[s0Lz  
} iX%n0i  
> ws!5q  
@cIgxp  
/* LWD#a~  
**SiteInfoBean.java m6i%DE  
*/ w.uK?A>W,  
package NetFox; hg8Be6G <  
&\^rQi/tf  
U-g9C.  
public class SiteInfoBean { yUe+":7k.  
=Dk7RKoHF  
(sCAR=5v\  
private String sSiteURL; //Site's URL I+" lrU  
private String sFilePath; //Saved File's Path Xk,>l6 vc  
private String sFileName; //Saved File's Name Vo M6  
private int nSplitter; //Count of Splited Downloading File "r..  
OJpj}R  
'E-FO_N  
public SiteInfoBean() #ib^Kg  
{//nSplitter的缺省值为5 c+2sT3).D  
//default value of nSplitter is 5 a+Ab]m8`  
this("","","",5); 63M=,0-Qt  
} DsGI/c  
%i"}x/CD[  
EnJ!mr  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =EpJZt  
{ 0hwj\{"  
sSiteURL= sURL; |dk[cX>  
sFilePath = sPath; Ri @`a  
sFileName = sName; J633uH}}  
this.nSplitter = nSpiltter; 7W|Zq6p i  
:gf;}  
k.GA8=]>  
} XYAmJ   
.S7:;%qL6  
"SR5wr   
public String getSSiteURL() [PWL<t::c  
{ <lj\#'G3  
return sSiteURL; R ]P;sk5  
} >1ZJ{se  
6P*O&1hv  
sS9%3i/>  
public void setSSiteURL(String value) TzKK;(GX  
{ wkBL=a  
sSiteURL = value; 3?`"  
} p/*"4-S  
_a5(s2wq+  
,2,5Odrz  
public String getSFilePath() x=*L-  
{ aWGon]2p  
return sFilePath; EB,4PEe:  
} 1'O0`Me>#  
Im)EDTm$  
Uc&iZFid2K  
public void setSFilePath(String value) C-w5KW  
{ mQr0sI,o]  
sFilePath = value; 8\# ^k#X  
} 2d`c!  
@;Y~frT  
_u5dC   
public String getSFileName() /S~m)$vu  
{ A,#2^dR  
return sFileName; SaO3 zz@L  
} {rXs:N@  
61@EDIYPc  
yZ3nRiuRT  
public void setSFileName(String value) RH[+1z8  
{ %e_"CS  
sFileName = value; dR+1aY;  
} :2y"3azxk  
"HlgRp]u  
zwr\:Hu4  
public int getNSplitter() ZnfNQl[  
{ v>m n/a  
return nSplitter; XUmR{A  
} v(O=IUa  
`hrQw)5?r  
XvKFPr0~  
public void setNSplitter(int nCount) GwLFL.Ke  
{ o#D.9K(  
nSplitter = nCount; GoE 'L  
} ^Z}Ob= .G  
} s>%Pd7:  
T ):SGW  
Uyx&E?SlEq  
/* ,t,wy37*D  
**Utility.java *b)Q5dw@1  
*/ x0Z5zV9  
package NetFox; &.N $  
r;m`9,RW  
|vILp/"9=W  
public class Utility { O#_b7i  
<Kt3PyF  
>M;u*Go`QO  
public Utility() g^~Kze  
{ tju|UhP3  
&`!^Zq vG  
aGoE,5  
} 7r 0,> 3"  
0KvVw rWJ  
//线程睡眠 ,1 UZv>}S  
public static void sleep(int nSecond) Qa`hR  
{ 11UB4CA  
try{ tIuoD+AW  
Thread.sleep(nSecond); nII^mg~  
} sl|_=oXT  
catch(Exception e) B0Xl+JIR#  
{ glUo7^ay7  
e.printStackTrace (); nH[+n `{o  
}  ux-CpI  
} ~<9{#uM  
c&'JmKV>&  
//日志 %f ju G  
public static void log(String sMsg) z#Nl@NO&  
{ F n|gVR  
System.err.println(sMsg); .EP6oKA  
} `-UJ /{  
'Kbl3fUF  
QIU,!w-3X  
public static void log(int sMsg) Is.WZY a  
{ 0l\y.   
System.err.println(sMsg); %NARyz  
} Qt+:4{He  
} S h4wqf  
vO@s$qi  
-kj< 1~YW  
/* :k,Q,B.I  
**TestMethod.java KMK`F{  
*/ 7^:4A'  
package NetFox; ;LwqTlJ*[L  
.dmi#%W  
l!~ mxUb  
public class TestMethod { $2#7D* Rx  
SpSnoVI  
b=[?b+  
public TestMethod() 0$vj!-Mb^j  
{ ///xx/weblogic60b2_win.exe E~hzh /,34  
try{ 6oL1_)  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T-" I9kM  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "ZMkL)'7-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]MTbW=*}ED  
fileFetch.start(); Qx`~g,wk8  
} !|G(Yg7C  
catch(Exception e){e.printStackTrace ();} (lH,JX`$a  
k(s;,B\  
O8u3y  
} ~H6;I$e[  
UlovXb  
G*}F5.>8(  
public static void main(String[] args) saZ>?Owz  
{ >_ \<E!j  
new TestMethod(); v."Dnl  
} 9.+/~$Ht  
} ,LYFEq_  
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