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http断点续传简单实现(java)

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/* G#1GXFDO{  
**SiteFileFetch.java ]:\dPw`A  
*/ } d }lR  
package NetFox; 8.~kK<)!  
import java.io.*; E~:x(5'%d  
import java.net.*; jA/w|\d!  
D,ln)["xm  
Q3SS/eNP  
public class SiteFileFetch extends Thread { TOAAQ  
K4);HJ|=  
8x{'@WCG%  
SiteInfoBean siteInfoBean = null; //文件信息Bean bYPKh  
long[] nStartPos; //开始位置 'Z|mQZN  
long[] nEndPos; //结束位置 ctJE+1#PH  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 <^uBoKB/f  
long nFileLength; //文件长度 bs'n+:X `  
boolean bFirst = true; //是否第一次取文件 ]0\MmAJRn  
boolean bStop = false; //停止标志 VD\=`r)nT  
File tmpFile; //文件下载的临时信息 e0 T\tc  
DataOutputStream output; //输出到文件的输出流 A+)`ZTuO  
2Wb]4-  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) F}q c0  
public SiteFileFetch(SiteInfoBean bean) throws IOException a@*\o+Su  
{ K_-MYs.  
siteInfoBean = bean; \^%}M!tan  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); )F2OT<]m,  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -PQv ?5  
if(tmpFile.exists ()) $tS}LN_!  
{ 9&ids!W~yx  
bFirst = false; I!?}jo3  
read_nPos(); 40<mrVl  
} +d;bjo 2  
else PiYxk+N  
{ Wxe0IXq3Nn  
nStartPos = new long[bean.getNSplitter()]; e 3TI|e_  
nEndPos = new long[bean.getNSplitter()]; &8 x-o,  
} yvYad  
vZoaT|3 G]  
eGHaY4|  
}>X~  
} 0K2`-mL  
L,@lp  
3%ZOKb"D*  
public void run() *=c1d o%F  
{ mdg i5v  
//获得文件长度 ;d9QAN&0}  
//分割文件 D5HZ2cz|a  
//实例FileSplitterFetch I 2|Bg,e  
//启动FileSplitterFetch线程 ^v`\x5"Vp  
//等待子线程返回 r$~HfskeI  
try{ 6i~WcAs  
if(bFirst) &9)\wnOS  
{ Ez=Olbk  
nFileLength = getFileSize(); # 4PVVu<  
if(nFileLength == -1) &pp|U}  
{ :[!j?)%>  
System.err.println("File Length is not known!"); \K!VNB>h  
} xK\d4 "  
else if(nFileLength == -2) e@OX_t_  
{ 9 |vLwQ  
System.err.println("File is not access!"); w*JGUk  
} $ DSZO!pB  
else Q)[C?obd v  
{ > "=>3  
for(int i=0;i<nStartPos.length;i++) 6f*CvW  
{ %-0t?/>  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); t1y4 7fX6  
} )TH@# 1  
for(int i=0;i<nEndPos.length-1;i++) 0=E]cQwh  
{ $H>W|9Kg,  
nEndPos = nStartPos[i+1]; *w&Y$8c(  
} EJNU761  
nEndPos[nEndPos.length-1] = nFileLength; fsWTF<Y  
}  'CkIz"Wd  
} 'y3!fN =h  
ITT@,  
OH(waKq2I  
//启动子线程 +&2%+[nBZ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =$Nq   
for(int i=0;i<nStartPos.length;i++) Ak"m 85B  
{ KNIn:K^/  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5,6"&vU,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u^qT2Ss0  
nStartPos,nEndPos,i); ah+iZ}E%  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wx0j(:B]  
fileSplitterFetch.start(); X*@dj_,  
} xx%j.zDI]  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r #cGop]  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ge-vWf-RbB  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ? '{SX9  
nEndPos = " + nFileLength); @7j AL-  
// fileSplitterFetch[nPos.length-1].start(); C={Y;C1  
VZmLS 4E  
ByNn  
//等待子线程结束 D\NKC@(M  
//int count = 0; JB[~;nLlC  
//是否结束while循环 )C]g ld;8  
boolean breakWhile = false; hp-<2i^"!  
Y^EcQzLw  
dvJ M6W>^=  
while(!bStop) >_"an~Ss  
{ $6iX   
write_nPos(); S2VA{9:m  
Utility.sleep(500); Q:k}Jl  
breakWhile = true; j yUCH*@  
 DwE[D]7o  
8i#2d1O  
for(int i=0;i<nStartPos.length;i++) !58@pLJw  
{ !\.pq  2  
if(!fileSplitterFetch.bDownOver) ]*[ 2$  
{ XG{zlOD+  
breakWhile = false; &H/'rd0M  
break; %.-4!vj  
} GM f `A,>  
} T&u5ki4NE  
if(breakWhile) Doyx[zZ  
break; qm8B8&-  
JNXq.;:`Q  
2?ez,*-[  
//count++; UIN<2F_  
//if(count>4) hAnPXiD  
// siteStop(); !/i{l  
} } .m<  
=QiI :|eRA  
mQ 26K~  
System.err.println("文件下载结束!"); =Qj{T  
} V_}"+&W9  
catch(Exception e){e.printStackTrace ();} ;dZZ;#k%  
} T{ XS")Vw  
9u}Hmb  
lbl?k5  
//获得文件长度 a>I+]`g  
public long getFileSize() W^LY'ypT  
{ ex (.=X 1  
int nFileLength = -1; :Cs4NF   
try{ BdblLUGK#  
URL url = new URL(siteInfoBean.getSSiteURL()); cZU=o\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k(7&N0V%zz  
httpConnection.setRequestProperty("User-Agent","NetFox"); " h~Z u  
CiLg]va   
`1{ZqRFQ  
int responseCode=httpConnection.getResponseCode(); MSqVlj  
if(responseCode>=400) q"sed]  
{ ]e>w }L(gV  
processErrorCode(responseCode); !_D0vI;  
return -2; //-2 represent access is error 9YQb &  
} ^{;oM^Q'  
Z|j>gq  
[KaAXv .X  
String sHeader; <?}-$  
V0.vQ/  
/saIs%(fU  
for(int i=1;;i++) ?5|>@>  
{ Pz|>"'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q{I%Q)t)gU  
//Utility.log(in.readLine()); j2.|ln"!  
sHeader=httpConnection.getHeaderFieldKey(i); hl(hJfp  
if(sHeader!=null) 1&evG-#<:  
{ Gm.T;fc:  
if(sHeader.equals("Content-Length")) u jq=F  
{ 9gEwh<  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?; +1)>{  
break; )E@.!Ut4o  
} JNYFD8J~  
} z] P SpUd  
else }mq6]ZrK  
break; wyj{zWRJp  
} BsqP?/  
} #crQ1p) \  
catch(IOException e){e.printStackTrace ();} #9}D4i.`}  
catch(Exception e){e.printStackTrace ();} D] jz A x  
(%e .:W${  
T?soJ]A  
Utility.log(nFileLength); ukfQe }I  
ag#S6E^%S  
*,8^@(th  
return nFileLength; fg!__Rdi  
} zrL$]Oy}x  
w/S%YW3*  
[OV"}<V  
//保存下载信息(文件指针位置) ," Wr"  
private void write_nPos() aa?b`[Xa  
{ >WQMqQ^t@  
try{ NI}yVV  
output = new DataOutputStream(new FileOutputStream(tmpFile)); st3l2Q  
output.writeInt(nStartPos.length); wh\}d4gN  
for(int i=0;i<nStartPos.length;i++) Ng>5?F^v  
{ l7259Ro~  
// output.writeLong(nPos); 7BjJhs  
output.writeLong(fileSplitterFetch.nStartPos); >:S?Mnv6  
output.writeLong(fileSplitterFetch.nEndPos); ZaDyg"Tw+  
} RO VW s/  
output.close(); C]eSizS.  
} 4Lh!8g=/  
catch(IOException e){e.printStackTrace ();} [.8BTj1%  
catch(Exception e){e.printStackTrace ();} %C'?@,7C  
} &Gn 2tr  
6]_pIf  
]kG"ubHV?h  
//读取保存的下载信息(文件指针位置) V2?=4mb  
private void read_nPos() #ASz;$P  
{ U;V7 u/{  
try{ 9T}pT{~V  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uK#4(eY=W  
int nCount = input.readInt(); gA5/,wDO  
nStartPos = new long[nCount]; ~xfP:[u  
nEndPos = new long[nCount]; 7he,?T)vD  
for(int i=0;i<nStartPos.length;i++) a 3b/e8c  
{ Lh"<XYY  
nStartPos = input.readLong(); f/NH:1)y  
nEndPos = input.readLong(); |`Ntv }  
}  |`f$tj  
input.close(); Z!#!Gu*V  
} 7 60Y$/Wz  
catch(IOException e){e.printStackTrace ();} ?m=N]!n  
catch(Exception e){e.printStackTrace ();} 1k5Who@  
} k\YG^I  
UcDS9f_87  
axRV:w;E<  
private void processErrorCode(int nErrorCode) MS>Ge0P("~  
{ P[#e/qnXu|  
System.err.println("Error Code : " + nErrorCode); RtP2]O(F  
} V>%rv'G8  
V _/%b)*  
dvx#q5f_S  
//停止文件下载 }DE g-j,F  
public void siteStop() WZejp}x  
{ e7r -R3_  
bStop = true; 9ni1f{k  
for(int i=0;i<nStartPos.length;i++)  $s c  
fileSplitterFetch.splitterStop(); dA`IEQJL  
#$+*;  
3cyHfpx-W  
} p8H'{f\G  
} i2A81>68<  
//负责部分文件的抓取 A*R^n}sh  
**FileSplitterFetch.java | y# Jx  
*/ S8w _ii3zd  
package NetFox; v ~?qz5:K~  
>,Ci?[pf  
x{8xW0  
import java.io.*; ' !cCMTj  
import java.net.*; TnOggpQ6X  
qIE9$7*X  
6V:U (g  
public class FileSplitterFetch extends Thread { HT cb_a  
2K6qY)/_  
<X^@*79m  
String sURL; //File URL mh{d8<Q2  
long nStartPos; //File Snippet Start Position |`,2ri*5A  
long nEndPos; //File Snippet End Position \fr~  
int nThreadID; //Thread's ID IH&|Tcf\  
boolean bDownOver = false; //Downing is over V`d,qn)i  
boolean bStop = false; //Stop identical +wU@ynw  
FileAccessI fileAccessI = null; //File Access interface S_4?K)n #  
=^f<v_L  
Y>T-af49  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $}q23  
{ GPv1fearl  
this.sURL = sURL; LTCb@L{^i  
this.nStartPos = nStart; YnS#H"  
this.nEndPos = nEnd; d-ZJL6-  
nThreadID = id; =sU<S,a*  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D~iz+{Q4  
} -1_)LO&H  
!bx;Ta.  
e8!5 I,I  
public void run() .x.]`b(  
{ ")5":V~fN  
while(nStartPos < nEndPos && !bStop) rgv?gaQ>  
{ l -mfFN  
w"|L:8  
1..+F0U  
try{ a=1@*ID  
URL url = new URL(sURL); NC`aP0S  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nFe<w  
httpConnection.setRequestProperty("User-Agent","NetFox"); q=m'^ ,gPS  
String sProperty = "bytes="+nStartPos+"-"; aQcleTb  
httpConnection.setRequestProperty("RANGE",sProperty); $am$ EU?s  
Utility.log(sProperty); Xp% v.M  
"5!oi]@>(  
uc\Kg1{  
InputStream input = httpConnection.getInputStream(); \<>ih)J@tt  
//logResponseHead(httpConnection); 7wqK>Y1a  
CL;}IBd a  
OU.6bmWy|  
byte[] b = new byte[1024]; JPUW6e07o  
int nRead; _pG-qK  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qLG&WB  
{ RFcv^Xf  
nStartPos += fileAccessI.write(b,0,nRead); fk>aqm7D!  
//if(nThreadID == 1) IGQFtO/x  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RnE4<Cy  
} v^NIx q}U  
>J?fl8  
o4,6.1}  
Utility.log("Thread " + nThreadID + " is over!"); 6]N;r5n  
bDownOver = true; /NFj(+&g+  
//nPos = fileAccessI.write (b,0,nRead); QXFo1m  
} 1{. |+S Z!  
catch(Exception e){e.printStackTrace ();} L,`LN>  
} X-Kh(Z  
} T!kN)#S  
q`a'gJx#y  
1#2 I  
//打印回应的头信息 MUc$ j&  
public void logResponseHead(HttpURLConnection con) @ioJ] $o7  
{ [5b--O  
for(int i=1;;i++) a0E)2vt4  
{ j0aXyLNX  
String header=con.getHeaderFieldKey(i); KqJs?Won  
if(header!=null) 50wulGJud  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9>/4W.  
Utility.log(header+" : "+con.getHeaderField(header)); iC~^)-~H=w  
else 9T9!kb  
break; 5 PJhEB  
} }C?'BRX  
} 4f@rv^f(X  
WDD%Q8ejV&  
itP,\k7>d  
public void splitterStop() =BAr .m+"  
{ _8J.fT$${  
bStop = true; p38-l'{#  
} JR21>;l#2  
HM1Fz\Sf  
aFm_;\  
} &`r-.&Y  
-3 *]G^y2  
m dg8,n  
/* k%#EEMh  
**FileAccess.java 4.aZ# c91_  
*//文件访问(定位,写) FVbb2Y?R  
package NetFox; Lg.gfny[(t  
import java.io.*; s^9Voi.y  
Y\P8 v  
7Q9 w?y~c  
public class FileAccessI implements Serializable{ [ l??A3G  
H$t_Xw==  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &PHTpkaam  
RandomAccessFile oSavedFile; Bm<`n;m  
long nPos; ltSU fI  
,w4(kcg%iQ  
: *#-%0  
public FileAccessI() throws IOException o5PO =AN  
{ rXP,\ ]r+  
this("",0); AV]2 euyn  
} my1@41 H  
J yK3{wYS  
3;9^  
public FileAccessI(String sName,long nPos) throws IOException Mfuv0P~  
{ 4F:\-O  
oSavedFile = new RandomAccessFile(sName,"rw"); f'RX6$}\1X  
this.nPos = nPos; eM6<%?b  
oSavedFile.seek(nPos); Dml;#'IF3  
} v;{#Q&(  
_;y9$"A  
Dx?,=~W9  
public synchronized int write(byte[] b,int nStart,int nLen) LonxT&"!D  
{ Bk c4TO  
int n = -1; i&fuSk EP  
try{ &6!)jIWJ  
oSavedFile.write(b,nStart,nLen);  8dA~\a  
n = nLen; #zs~," dRv  
} T?0eVvM  
catch(IOException e) (5YM?QAd  
{ vA{-{Q  
e.printStackTrace (); F/{!tx  
} T'9'G M  
Sz`,X0a  
RtS+<^2a;  
return n; ? OM!+O  
} 1CZgb   
<'oQ \eB  
PC8Q"O  
} (ZZ8L-s  
tDcT%D {:  
"(O>=F&  
/* #trK^(  
**SiteInfoBean.java (?c"$|^J  
*/ Rhs/3O8k  
package NetFox; dZ@63a>>@  
{JT&w6Jz  
f8dB-FlMm  
public class SiteInfoBean { &p@O _0nF  
6nvz8f3*r]  
Yj49t_$b  
private String sSiteURL; //Site's URL v\ )W?i*l  
private String sFilePath; //Saved File's Path M%m4i9~!?  
private String sFileName; //Saved File's Name (L&d!$,Dv  
private int nSplitter; //Count of Splited Downloading File [z{1*Xc  
g! |kp?  
=dKtV.L  
public SiteInfoBean() _B<X`L =  
{//nSplitter的缺省值为5 rb.N~  
//default value of nSplitter is 5 $U WZDD  
this("","","",5); 6bC3O4Rw  
} n7[V&`e_  
1Pu~X \sO  
S,UDezxg  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b4kgFA  
{ Jnov<+  
sSiteURL= sURL; d$!RZHo10V  
sFilePath = sPath; {EQOP]  
sFileName = sName; g) jYFfGfH  
this.nSplitter = nSpiltter; ~$^XP.a.  
}Sv:`9=  
T0)@pt7>  
} DTL.Bsc-.  
~f98#43  
kl:Bfs)b  
public String getSSiteURL() /U9"wvg  
{ f]CXu3w(J  
return sSiteURL; VTE .^EK!  
} ;e*!S}C,  
7!E,V:bt'  
} q8ASYNc  
public void setSSiteURL(String value) zrb}_  
{ Q![@c   
sSiteURL = value; 8d'0N  
} (jE9XxQY  
6i/(5 nQ  
26h21Z16q  
public String getSFilePath() b ]KBgZ  
{ R\[e!g*I  
return sFilePath; 9yP;@y*d  
} iH@UTE;  
L!xi  
Gd85kY@w7  
public void setSFilePath(String value) i XjM.G  
{ ?Ir:g=RP*  
sFilePath = value; #ABZ&Z  
} tR$NRMZ.  
i/Zd8+.n$  
-iZ`Y?  
public String getSFileName() 3Y$GsN4ln  
{ Q$"D]!G  
return sFileName; ~t~|"u"P  
} ;2QP7PrSY  
T>W,'H  
]Y&VT7+Z  
public void setSFileName(String value) ;$g?T~v7  
{ @r1_U,0e  
sFileName = value; 5{,<j\#L  
} 9pfIzs su3  
ECmW`#Otb)  
Z% UP6%  
public int getNSplitter() 'I;zJ`Trd  
{ $XH^~i;  
return nSplitter; Eu3E-K@y  
} Q~9^{sHZjP  
`R^gU]Z,  
@6-jgw>W2  
public void setNSplitter(int nCount) VIf.q)_k  
{ ;O,jUiQ  
nSplitter = nCount; qHsA1<wg  
} N;%6:I./  
} %?/X=}sE  
dWBA1p  
m1AJ{cs  
/* {)<v&'*c~  
**Utility.java Ow,b^|  
*/ 8z\xrY  
package NetFox; ]Hv[IodJ  
#/37V2E  
8u]2xB=K  
public class Utility { F!K>Kz  
lyhiFkO iH  
A=0'Ks  
public Utility()  Vxt+]5X  
{ BZ^}J!Q'*  
oXgcc*j  
veECfR;  
} (/] J3  
tZo} ;|~'  
//线程睡眠 '|=;^Z7.K  
public static void sleep(int nSecond) zm;C\s rF  
{ GC'O[q+  
try{ j'K/22  
Thread.sleep(nSecond); TA~{1_l  
} `Q,H|hp;k;  
catch(Exception e) X}0cCdW  
{ k9F=8q  
e.printStackTrace (); aw>#P   
} _o~ nr]zx  
} 8q7b_Pq1U  
3G4-^hY<  
//日志 c:.eGH_f  
public static void log(String sMsg) ?Mfw]z"\C)  
{ ,R|BG  
System.err.println(sMsg); 93hxSRw  
} 0{SL&<&  
ddR>7d}N  
Z3!`J&  
public static void log(int sMsg) Ek}A]zC  
{ u]@['7  
System.err.println(sMsg); tq?!-x+>  
} TL#3;l^  
} +"VP-s0  
+"@ .8m  
(7*}-Uy[C  
/* 6W Ur QFK  
**TestMethod.java Gs[XJ 5%`~  
*/ @KAI4LP  
package NetFox; jz0T_\8D`  
3;Fhg!Z O  
vvOV2n .WD  
public class TestMethod { 9nbLg5P  
zx7{U8*`<  
&kw@,];4Z  
public TestMethod() &+R?_Ooibk  
{ ///xx/weblogic60b2_win.exe ehY5!D1Q  
try{ Rlirs-WQ  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :U x_qB  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ct}9i"H#1  
SiteFileFetch fileFetch = new SiteFileFetch(bean); e(G |;a  
fileFetch.start(); gZ1?G-Q  
} sx<%2  
catch(Exception e){e.printStackTrace ();} `P ,d$H "  
PFK  '$  
n(]-y@X0_  
} ;*&-C9b  
Wv/=O}  
ete.!*=  
public static void main(String[] args) RpYERAgT  
{ Sa5G.^ XI  
new TestMethod(); )\^-2[;  
} pD]OT-8  
} ~u+9J}  
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