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http断点续传简单实现(java)

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/* 13@| {H CB  
**SiteFileFetch.java QlXF:Gx"=  
*/ ]b$,.t5  
package NetFox; .B n2;nO  
import java.io.*; EqU[mqeF  
import java.net.*; g2_df3Q  
P9!]<so  
J4^cd  
public class SiteFileFetch extends Thread { !@ '2  
[uV/ Ra*g  
JKbB,  
SiteInfoBean siteInfoBean = null; //文件信息Bean *zht(~%  
long[] nStartPos; //开始位置 %NoZf^ ?  
long[] nEndPos; //结束位置 cO+`8`kv  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 74OM tLL$  
long nFileLength; //文件长度 |hyr(7  
boolean bFirst = true; //是否第一次取文件 v0J1%{/xs  
boolean bStop = false; //停止标志 _$lQK{@rY  
File tmpFile; //文件下载的临时信息 @Ec9Do>  
DataOutputStream output; //输出到文件的输出流 P &._ -[  
wd0ACF  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) WSwmX3rn  
public SiteFileFetch(SiteInfoBean bean) throws IOException Vjd =F.V+  
{ c?Qg :yU  
siteInfoBean = bean; KO"iauW  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ~q>ilnL"h  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 73`UTXvWU  
if(tmpFile.exists ()) n-.k&B{a  
{ d)sl)qt}0  
bFirst = false; ;VBfzFH  
read_nPos(); ,DZLEsFM  
} bGa":|}F  
else E6)mBAE  
{ 9R3=h5Y  
nStartPos = new long[bean.getNSplitter()]; Sw)ftC~d  
nEndPos = new long[bean.getNSplitter()]; 03;(v%  
} %;J`dM  
DF =. G1  
W=w@SO_?wp  
Zt=X %M|aw  
} 9q{dRS[A  
|7fBiVo  
XITQB|C??$  
public void run() *?'T8yf^  
{ 1 j8,Zrg1  
//获得文件长度 ,:,|A/U  
//分割文件 9] \vw  
//实例FileSplitterFetch 5+Ut]AL5  
//启动FileSplitterFetch线程 \ed(<e>  
//等待子线程返回 NQD b;5:  
try{ `9gx-')]\  
if(bFirst) jm"xf7  
{ pn|{P<b\  
nFileLength = getFileSize(); "de:plMofy  
if(nFileLength == -1) HOG7||&y  
{ O}V2> W$  
System.err.println("File Length is not known!"); \O~P !`  
} B~rK3BS  
else if(nFileLength == -2) =;T[2:JUu  
{ J-c7ZcTt  
System.err.println("File is not access!"); 2S/7f:  
} ZC-N4ESr  
else F6/bq/s  
{ z{x -Vfd  
for(int i=0;i<nStartPos.length;i++) EK^2 2vi$  
{ NKrk*I"G  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &aOOG8l  
} Y$^QH.h  
for(int i=0;i<nEndPos.length-1;i++) q?\D9aT9  
{ HC+R :Dz  
nEndPos = nStartPos[i+1]; 10 ^=1@U  
} /-lmfpT  
nEndPos[nEndPos.length-1] = nFileLength; 2F(j=uV+  
} v/dcb%  
} *<1m 2t>.  
UHWun I S  
d8po`J#nb  
//启动子线程 =t2epIr 5  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NKws;/u  
for(int i=0;i<nStartPos.length;i++) ImVe 71mh  
{ ^;d;b<  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /_8V+@im  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G39t'^ZK*#  
nStartPos,nEndPos,i); v\vn}/>*d  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I%Z &i-33y  
fileSplitterFetch.start(); b`mEnI VIz  
} Tj:F Qnx  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vvCGzOv  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JAK*HA  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zZ63 P  
nEndPos = " + nFileLength); T5)?6i -N  
// fileSplitterFetch[nPos.length-1].start(); dWA7U6c<  
AXFVsZH"zi  
m" Gr pE3  
//等待子线程结束 :&MiO3#+  
//int count = 0; 04:Dbt~=?p  
//是否结束while循环 4Ki'r&L\  
boolean breakWhile = false; L<n_}ucA  
Cpl)byb  
qI}Zg)q]  
while(!bStop) -_+0[Nb.  
{ 6822xk  
write_nPos(); y-YYDEl  
Utility.sleep(500); sQw-#f7t  
breakWhile = true;  Sk-Ti\  
E_P]f%  
( _2eiE71  
for(int i=0;i<nStartPos.length;i++) l:+1j{ d7  
{ Up:#Zs2  
if(!fileSplitterFetch.bDownOver) = j -  
{ "q8wEu,z[  
breakWhile = false; [}D)73h`  
break; eYFCf;  
} &oBJY'1  
} N ~Gh>{N  
if(breakWhile) EifYK  
break; jp|wc,]!  
^H'#*b0u  
K^+B"  
//count++; {ib`mC^  
//if(count>4) _B2t|uQ  
// siteStop(); Wo&i)S<i0F  
} %zGPF  
h!MT5B)r.  
ETtR*5Y 5  
System.err.println("文件下载结束!"); =S,^"D\Z:  
} | zf||ju  
catch(Exception e){e.printStackTrace ();} b\?`721BG  
} :}lE@Y,R   
q:( K^  
lWR  
//获得文件长度 S}<(9@]z  
public long getFileSize() Q]\x O/  
{ 'EQAG' YV  
int nFileLength = -1; =vWnqF:  
try{ =~)n,5  
URL url = new URL(siteInfoBean.getSSiteURL()); 2 Ug jH  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |Z<adOg  
httpConnection.setRequestProperty("User-Agent","NetFox"); *+G K ?Ga  
V}("8L  
S9.jc@#.`  
int responseCode=httpConnection.getResponseCode(); 7W*OyH^  
if(responseCode>=400) (L\tp> E-  
{ D4G{= Y}G  
processErrorCode(responseCode); C9fJLCufC  
return -2; //-2 represent access is error -`( :L[  
} nv={.H  
JO$0Z  
X@ss d  
String sHeader; *m;L.r`5[  
eu~;G H  
wZ\0<skU  
for(int i=1;;i++) 0Bll6Rd  
{ $]_=B Jyu  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @`T6\ 1  
//Utility.log(in.readLine()); 4#o` -vcW  
sHeader=httpConnection.getHeaderFieldKey(i); ji1A>jepF  
if(sHeader!=null) 7M4iBk4I  
{ P++gR@  
if(sHeader.equals("Content-Length")) :F_U^pyG  
{ te`4*t  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); It4F;Ah  
break; hk~ s1"  
} {*: C$"L  
} )TxhJB5|  
else KS%,N _F<  
break; V/03m3!q  
} >uVG]  
} F$caKWzny5  
catch(IOException e){e.printStackTrace ();} __a9}m4i7x  
catch(Exception e){e.printStackTrace ();} zUOYH4+  
4:K9FqU  
-+z^{*\; N  
Utility.log(nFileLength); Q5Wb)  
]UNmhF!W>u  
2Bx\nLf/ K  
return nFileLength; Q<M>+U;t  
} u}pLO9V"`  
4|~o<t8  
(|WqOwmoUt  
//保存下载信息(文件指针位置) 8.vD]hO  
private void write_nPos() ^*ZO@GNL  
{ uQ{M<%K  
try{ J^u{7K,  
output = new DataOutputStream(new FileOutputStream(tmpFile)); H.YntFtD'  
output.writeInt(nStartPos.length); #e=[W))  
for(int i=0;i<nStartPos.length;i++) $+Xohtt  
{ 9Gy1T3y5"  
// output.writeLong(nPos); 7,:QFV  
output.writeLong(fileSplitterFetch.nStartPos); a^,Xm(Wb}  
output.writeLong(fileSplitterFetch.nEndPos); gG#M-2P  
} I!{5*~ 3  
output.close(); f\ Qi()  
} Er{yQIi0L  
catch(IOException e){e.printStackTrace ();} \KTX{qI"f  
catch(Exception e){e.printStackTrace ();} oR5'g7?  
} (*#S%4(YX  
# TvY*D,  
0Rj_l:d=  
//读取保存的下载信息(文件指针位置) V-VR+Ndz  
private void read_nPos() QqRL>.)W  
{ W&* 0F~  
try{ ZM\Z2L]n  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w'}b 8m(L  
int nCount = input.readInt(); fi1tF/ `  
nStartPos = new long[nCount]; $[H3O(B0*  
nEndPos = new long[nCount]; +"Ka #Z  
for(int i=0;i<nStartPos.length;i++) |TkO'QN  
{ |A"zxNeS"  
nStartPos = input.readLong(); xw`Pq6  
nEndPos = input.readLong(); gx3arVa  
} <_h  
input.close(); "zv?qS  
} *S7<QyVh  
catch(IOException e){e.printStackTrace ();} p2\@E} z  
catch(Exception e){e.printStackTrace ();} aCQAh[T  
} "I u3&mc  
V4_ZBeWA  
E-CZk_K9  
private void processErrorCode(int nErrorCode) wPyfne?~,  
{ Y\s@'UoVN  
System.err.println("Error Code : " + nErrorCode); <&B)i\j8=b  
} !ouJ3Jn   
ht)J#Di  
[8[g_  
//停止文件下载 n{aD4&  
public void siteStop() OLTgBXh  
{ 'V/+v#V+>  
bStop = true; bDK72cQ  
for(int i=0;i<nStartPos.length;i++) Rjt]^gb!*  
fileSplitterFetch.splitterStop(); TF2'-"2Y  
h<JV6h:8  
C`Zz\DNG@  
} &Yb!j  
} O(#DaFJv  
//负责部分文件的抓取 icH\(   
**FileSplitterFetch.java CKCot  
*/ 4"7/+6Z  
package NetFox; w6aq/m"'  
G?*)0`~W  
FbhF45H  
import java.io.*; <<4U:  
import java.net.*; yJNQO'wcv  
=)!sWY:  
p%[/ _ -7  
public class FileSplitterFetch extends Thread { Y'H|Tk^`  
r1ao=N  
G*^4+^Vz?  
String sURL; //File URL GUSEbIz):  
long nStartPos; //File Snippet Start Position H85J MPZ7  
long nEndPos; //File Snippet End Position NH~\kV  
int nThreadID; //Thread's ID DxoW,G W  
boolean bDownOver = false; //Downing is over GKIO@!@[  
boolean bStop = false; //Stop identical U4M}E h8  
FileAccessI fileAccessI = null; //File Access interface >cJfD9-<h  
aYW 9 C<5  
vnc- W3N  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b1\.hi  
{ c&X2k\  
this.sURL = sURL; mQUI9  
this.nStartPos = nStart; 2!QQypQ  
this.nEndPos = nEnd; /-s-W<S[  
nThreadID = id; Lh\ 1L  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m9M#)<@*  
} (ZSd7qH"  
d;@"Naw  
-?nr q <3  
public void run() O/ybqU\7  
{ t\S=u y  
while(nStartPos < nEndPos && !bStop) xl>8B/Zmf#  
{ 9?]69O  
Y].,}}9k  
$\Oc]%  
try{ #83`T&Xw*  
URL url = new URL(sURL); A{|^_1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 17la/7l<  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]-g9dV_[>j  
String sProperty = "bytes="+nStartPos+"-"; 4 '"C8vw.  
httpConnection.setRequestProperty("RANGE",sProperty); (P'{A>aHl0  
Utility.log(sProperty); Ui|z#{8&  
}ff+RGxLIG  
*be"$ Q  
InputStream input = httpConnection.getInputStream(); \w#)uYK{i_  
//logResponseHead(httpConnection); G{CKb{  
FNlS)Bs  
'-X[T}  
byte[] b = new byte[1024]; ?*LVn~y  
int nRead; .7BJq?K.  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q<[m(]:  
{ _59f.FsVR  
nStartPos += fileAccessI.write(b,0,nRead); x/NjdK  
//if(nThreadID == 1) x4bmV@b  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [|&#A;{F#  
} G9_7jX*  
/Ixv{H)H  
f*o+g:]3  
Utility.log("Thread " + nThreadID + " is over!"); L _D#  
bDownOver = true; z=/&tRe W  
//nPos = fileAccessI.write (b,0,nRead); &$yxAqdab  
} +9exap27  
catch(Exception e){e.printStackTrace ();} }i$ER,hXh  
} 45Hbg  
} q\Q'9Rl0(  
7K5 tBUNQ  
`NySTd)\  
//打印回应的头信息 V!\'7-[R  
public void logResponseHead(HttpURLConnection con) InA=ty]"_U  
{ |W*#N8I P  
for(int i=1;;i++) zt;aB>jz#  
{ mR O@ZY;5  
String header=con.getHeaderFieldKey(i); "*< )pnJ  
if(header!=null) G,!{Q''w  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P](/5KrK  
Utility.log(header+" : "+con.getHeaderField(header)); .no<#l  
else ULH<FDot  
break; @)XR  
} Tm\a%Z`U>  
} >=1Aa,_tc  
QpCTHpZ  
(}m2}  
public void splitterStop() U0=: `G2l  
{ qr4.s$VGs*  
bStop = true; 1 R,SA:L$  
} # Rhtaq9  
x7GYWK 9  
]w0_!Z&  
} s}qtM.^W  
p~WX\;   
"^Vnnb:Z*o  
/* ~jJF&*)  
**FileAccess.java / %1-tGh  
*//文件访问(定位,写) zJ)`snN|  
package NetFox; % oJH 6F  
import java.io.*; ]TVc 'G;  
_1G;!eO  
} `Cc-X7  
public class FileAccessI implements Serializable{ }Q a  
H1c>3c  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;Wgkf_3  
RandomAccessFile oSavedFile; MzMVs3w|  
long nPos; & LhQr-g  
U1Y0G[i)  
`m}G{jfk  
public FileAccessI() throws IOException Y0yu,   
{ ~p?D[]h  
this("",0); 3S .2  
} L8J] X7  
Ax6zx  
.=N?;i  
public FileAccessI(String sName,long nPos) throws IOException .Zc:$"gDu  
{ D@%!|:  
oSavedFile = new RandomAccessFile(sName,"rw"); 5(t hDZ!  
this.nPos = nPos; QtA@p  
oSavedFile.seek(nPos); MxOIe|=&  
} F9k}zAY\J  
4C[kj  
2 ?F?C  
public synchronized int write(byte[] b,int nStart,int nLen) Z.`0  
{ 4-BrE&2f  
int n = -1; rgo!t028^  
try{ j-d542"  
oSavedFile.write(b,nStart,nLen); P~84#5R1  
n = nLen; z))rk vL%  
} N)/7j7c~;  
catch(IOException e) tzY?LX[3  
{ 9a#Y D;-p  
e.printStackTrace (); LJA uTg  
} 1 F&}e&}c  
9"?;H%.  
~l('ly  
return n; ~7gFddi=i  
} X4L@|"ZI  
\0K&2'  
M< H+$}[  
} .pG`/[*a  
558!?kx$  
sf O{.#5<  
/* ]E.\ |I(  
**SiteInfoBean.java FE1'MUT_  
*/ Y.q$"lm7k  
package NetFox; cqaq~  
OepQ Z|2  
<sn,X0W  
public class SiteInfoBean {  PZY6 I  
X/bu z  
tkmzOc H  
private String sSiteURL; //Site's URL 3e>U(ES  
private String sFilePath; //Saved File's Path e~SRGyIww  
private String sFileName; //Saved File's Name r)B55;*Fh  
private int nSplitter; //Count of Splited Downloading File *TrpW?]Y&  
dkW7k^g  
..x 2  
public SiteInfoBean() P'<j<h6  
{//nSplitter的缺省值为5 nt@uVwfQ  
//default value of nSplitter is 5 N;DE,[:<  
this("","","",5); G^Y^)pc]   
} )LsUO#%DO  
*to#ZMR;!  
i*8j|  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ] f5vk  
{ K+d{R=s^  
sSiteURL= sURL; (:^YfG~e  
sFilePath = sPath; {P3gMv;  
sFileName = sName; (Q.tH  
this.nSplitter = nSpiltter; sX ]gL  
K"!U&`T  
t qUBl?i  
} 8g=];@z  
cG(%P$  
XtE O)  
public String getSSiteURL() {b-SK5%]L  
{ nkz<t   
return sSiteURL; xVrLoAw  
} |WNI[49  
F$'po#  
KO/#t~  
public void setSSiteURL(String value) ^)o]hE|  
{ @V&HE:P  
sSiteURL = value; _Ea1;dJmq  
} $h}w: AV:  
gB>AYL%o=  
iVo-z#  
public String getSFilePath() eep/96G ?  
{ )`S5>[6  
return sFilePath; L8oqlq( 9  
} fl4 0jo]  
8@){\.M  
a p(PI?]X  
public void setSFilePath(String value) '*EKi  
{ >;#rK@*&  
sFilePath = value; Y5P9z{X=  
} ERIF#EY  
WqS$C;]%  
rCb$^(w{7  
public String getSFileName() (!?%"e  
{ 3HNm`b8G4m  
return sFileName; i~3\dp  
} brK7|&R<  
b&]z^_m)  
@1qdnU  
public void setSFileName(String value) Nfv` )n@  
{ OB++5Wd  
sFileName = value; i>C%[dk9  
}  z@~mu  
99%R/m  
C' WX$!$d  
public int getNSplitter() =$T[  
{ TH55@1W,[  
return nSplitter; ?m9=Me  
} ,|]k4F  
I,"q:QS+  
] VEc9?  
public void setNSplitter(int nCount) 9!0-~,o  
{ vP_mS 4X  
nSplitter = nCount; ^W`RBrJay  
} x_<,GE@  
} 3JD"* <zs  
9yu#G7  
5g;mc.Cvt  
/* I0;gTpt9  
**Utility.java muDOY~.  
*/ o)Px d  
package NetFox; R?dMM  
fJ=(oF=  
R%\<al$O  
public class Utility { ^f 0-w`D  
s=1k9   
s7\Ee-x)s  
public Utility() uz:r'+v  
{ x7i,jMR  
|h&okR+_,  
JUJrtK S  
} di ]CYLf  
b(adM3MP  
//线程睡眠 K.Cx 9  
public static void sleep(int nSecond) [#AI!-  
{ 7\H_9o0$  
try{ 1c*:" k  
Thread.sleep(nSecond); twt's,dO  
} FTzc,6  
catch(Exception e) 7f*b5$+r  
{ :OqEkh"$#  
e.printStackTrace (); + (`.pa z@  
} ^* CKx  
} i3) 7Qa[  
|Qpd<L  
//日志 g6$\i m  
public static void log(String sMsg) hVCxwTg^X  
{ LaL{ ^wP  
System.err.println(sMsg); rKTc 6h:)  
} y>cT{)E$  
-vh\XO  
mR#"ng  
public static void log(int sMsg) ]<9o>#3  
{ kLXa1^Lq  
System.err.println(sMsg); J:IAs:e`  
} A6xN6{R!  
} 61sEeM  
/N")uuv  
?\<Kb|Q  
/* MRHRa  
**TestMethod.java n<eK\ w  
*/ Z}IuR|=  
package NetFox; +O8}twt@  
Y$fF"p G?  
 {+gK\Nz  
public class TestMethod { )/z+W[t  
%wGQu;re  
:>jzL8  
public TestMethod() ;0Ih:YY6  
{ ///xx/weblogic60b2_win.exe L9l]0C37e  
try{ 6kONuG7Yv  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZfS"  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y+EwBg)co  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~F;>4q   
fileFetch.start(); Smd83W&  
} R0nUS<b0  
catch(Exception e){e.printStackTrace ();} ,0?3k  
qg*xdefQ%  
Q.V+s   
} l\u5RMS('  
3'7X[{uBr  
n0uL^{B  
public static void main(String[] args) VT;cz6"6b4  
{ !F2JT@6  
new TestMethod(); kPSi6ci  
} >^v,,R8j  
} bV*q~ @xh  
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