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http断点续传简单实现(java)

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/* i`nw"8  
**SiteFileFetch.java '-]BSU  
*/ qddT9U|8~  
package NetFox; %V1T !<  
import java.io.*; j% USu+&  
import java.net.*; 8(/f!~  
P~ pbx  
07"Oj9NlA  
public class SiteFileFetch extends Thread { W]}V<S$  
jKV?!~/F  
`L*;58MA  
SiteInfoBean siteInfoBean = null; //文件信息Bean !@Vp Bl  
long[] nStartPos; //开始位置 -zLI!F 0  
long[] nEndPos; //结束位置 {i}Q}OgYq  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ftU5 A@(T  
long nFileLength; //文件长度 Hr*Pi3dSI  
boolean bFirst = true; //是否第一次取文件 YB3=ij!K  
boolean bStop = false; //停止标志 <d&)|W  
File tmpFile; //文件下载的临时信息 W>wi;Gf#  
DataOutputStream output; //输出到文件的输出流 2-c0/?_4  
d~Ry>   
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) H'\EA(v+  
public SiteFileFetch(SiteInfoBean bean) throws IOException bl>b/u7/6  
{ g?AqC  
siteInfoBean = bean; {5IG3'  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Y4qyy\}  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); JIKxY$GS  
if(tmpFile.exists ()) ZpctsCz]  
{ J'c9577$  
bFirst = false; 5"~^;O  
read_nPos(); HgATH  
} sfPN\^k2  
else 71&+dC  
{ 49fq6ZhO  
nStartPos = new long[bean.getNSplitter()]; <m:wuNEM  
nEndPos = new long[bean.getNSplitter()]; M*6@1.n  
} LbbQ3$@ WD  
{bW3%iU  
~tuFjj^  
Z:$b)+2:\  
} xy3%z  
b{>dOI*.}  
`srZ#F5  
public void run() .) ;:K  
{ O:p649A  
//获得文件长度 AX RNV  
//分割文件 }/r%~cZ  
//实例FileSplitterFetch _:p_#3s$  
//启动FileSplitterFetch线程 }Y ];ccT  
//等待子线程返回 tRBK1h  
try{ l'%R^  
if(bFirst) ^|;4/=bbs  
{ R./6Q1  
nFileLength = getFileSize(); {1DYXKe  
if(nFileLength == -1) jF_I4H  
{ c+/C7C o  
System.err.println("File Length is not known!"); iQ"F`C  
} ~WXxVm*@  
else if(nFileLength == -2) F/>Pv q]  
{ ^tcBxDC"]  
System.err.println("File is not access!"); azc:C  
} Hbc&.W;g7[  
else +##I4vP  
{ Bic { H  
for(int i=0;i<nStartPos.length;i++) X hX'*{3k  
{ 0%NI- Zyo  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); VDY1F_Fk  
} :Rj,'uH+h)  
for(int i=0;i<nEndPos.length-1;i++) {leG~[d  
{ &)jZ|Q~  
nEndPos = nStartPos[i+1]; .{Oq)^!ot  
} 4H)" d  
nEndPos[nEndPos.length-1] = nFileLength; r['C.S6  
} 6|cl`}g_j  
} DJ0T5VE W3  
\%Q rN+WQ  
fr2w k}/b  
//启动子线程 E2kRt'~N  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G@!9)v]9  
for(int i=0;i<nStartPos.length;i++) 1^^D :tt  
{ S Tk#hhx  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >D62l*VC)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1tz .e\  
nStartPos,nEndPos,i); 1u+ (rVQN  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (r\h dLX  
fileSplitterFetch.start(); MXV4bgltT  
} P[8N58#  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nn%xN\~<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D~&e.y/gHN  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &~f_1<  
nEndPos = " + nFileLength); bR,Iq}p  
// fileSplitterFetch[nPos.length-1].start(); JhIK$Ti  
p;=(-4\V}  
(k&aD2PH  
//等待子线程结束 0*@S-Lj^c  
//int count = 0; gj X1b2  
//是否结束while循环 5K~6`  
boolean breakWhile = false; Ib2pV2`h(  
|R/50axI  
*G41%uz  
while(!bStop) *=@pdQkR  
{ 0|;=mYa4M  
write_nPos(); 8:fiO|~%  
Utility.sleep(500); K.m[S[cy  
breakWhile = true; mDf WR  
]t;5kj/  
zAUfd[g  
for(int i=0;i<nStartPos.length;i++) TeqsP1{?  
{ j~q`xv+R  
if(!fileSplitterFetch.bDownOver) Mwc3@  
{ {2@96o2}  
breakWhile = false; _I4sy=tYXK  
break; q:.BY}X9  
} dxWw%_Q  
} = g}yA=.  
if(breakWhile) G].KJ5,y  
break; oD\+ 5[x  
O_^h 7   
>O~5s.1u  
//count++; nVzo=+Yp  
//if(count>4) '7s!N F2  
// siteStop(); 54w-yY  
} Lai"D[N  
Shz;)0To  
P7-3Vf_L  
System.err.println("文件下载结束!"); IhLfuyFWu  
} 0aWb s$FyU  
catch(Exception e){e.printStackTrace ();} C<>.*wlp=  
} `f]O  
CI{x/ e^(  
y>8?RX8  
//获得文件长度 q3`t0eLZ  
public long getFileSize() o:<3n,T  
{ ^dv>n]?  
int nFileLength = -1; 7<D_ h/WV  
try{ y{JkY\g  
URL url = new URL(siteInfoBean.getSSiteURL()); F}>`3//u  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BYU.ptiJJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); Xk'.t|  
:f;|^(]"  
8t%1x|!  
int responseCode=httpConnection.getResponseCode(); a0.XJR{T"  
if(responseCode>=400) mN02T@R-  
{ za7wNe(s  
processErrorCode(responseCode); K<GCP2  
return -2; //-2 represent access is error W6Pg:Il7  
} C.<4D1}P  
Di*>PE@  
6-"&jbvm  
String sHeader; :xCobMs_/  
;rgsPVbVf  
*en{pR'  
for(int i=1;;i++) fF%r$`2  
{ jQ*Qh  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~55>uw<  
//Utility.log(in.readLine()); 'oG'`ED"  
sHeader=httpConnection.getHeaderFieldKey(i); Bx F  
if(sHeader!=null) dp_q:P4; B  
{ soF^G21N  
if(sHeader.equals("Content-Length")) g 7X>i:  
{ ,dBI=D'  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m='OnTeOE  
break; 4<|u~n*JF  
} { SV$fl;  
} G<'S  
else -eTGRr  
break; JK4  @  
} 7(H/|2;-d8  
} zYgLGwi{  
catch(IOException e){e.printStackTrace ();} zeX?]@]Y  
catch(Exception e){e.printStackTrace ();} GCHssw~P'v  
yFG&Ir  
? t-2oLE  
Utility.log(nFileLength); P6Ei!t,>  
x% 1Rp[  
_qV_(TpS+  
return nFileLength; V QI7lJV"  
} Dg`W{oj  
Cb.Aw!  
Lst5  
//保存下载信息(文件指针位置) ( C&f~U  
private void write_nPos() lV8Mr6m  
{  UWI5 /R  
try{ I8y\D,  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8CCA/6  
output.writeInt(nStartPos.length); 1Q<a+ l  
for(int i=0;i<nStartPos.length;i++) i&Ea@b  
{ eo!z>9#.  
// output.writeLong(nPos);  BeQJ/`  
output.writeLong(fileSplitterFetch.nStartPos); zx27aZ[  
output.writeLong(fileSplitterFetch.nEndPos); 3?:}lY<,  
} A Ho<E"R\  
output.close(); <$E8T>U  
} M5]w U   
catch(IOException e){e.printStackTrace ();} R-ci?7dt3  
catch(Exception e){e.printStackTrace ();} /-T%yuU  
} R##O9BSI8Z  
y03l_E,  
F>OYZOC]  
//读取保存的下载信息(文件指针位置) 7DD ot_qb  
private void read_nPos() $\H>dm  
{ 3I]5DW %-  
try{ ]#`bYh^y  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H X8q+  
int nCount = input.readInt(); VrpY BU  
nStartPos = new long[nCount]; BtspnVB ez  
nEndPos = new long[nCount]; q6q= ,<T%S  
for(int i=0;i<nStartPos.length;i++) 7 UR)4dYA  
{ `g7' )MSy  
nStartPos = input.readLong(); q07>FW R  
nEndPos = input.readLong(); ;RXv%ML  
} [yz;OoA:;  
input.close(); m9/a!|fBE  
} Mvux=Ws  
catch(IOException e){e.printStackTrace ();} H_9~gi  
catch(Exception e){e.printStackTrace ();} E)Dik`Ccl  
} 1*Z}M%  
YV+e];s  
B6BOy~B0  
private void processErrorCode(int nErrorCode) @I%m}>4Jm  
{ b+kb7  
System.err.println("Error Code : " + nErrorCode); X:YxsZQ 5Y  
} E>&dG:3no  
q;rU}hAzG0  
kns[b [!H  
//停止文件下载 I)clGMS,  
public void siteStop() NFQ0/iuW  
{ l 1@:&j3h  
bStop = true; FkH4|}1  
for(int i=0;i<nStartPos.length;i++) xaPTTa  
fileSplitterFetch.splitterStop(); 1*XqwBV  
D`u{U]  
Ou/{PK}  
} mWZV O,t$  
}  A/9 wr  
//负责部分文件的抓取 H=0Y4 T@)T  
**FileSplitterFetch.java [.2>=3T  
*/ fSj^/>  
package NetFox; f.!cR3XgV  
~`y6YIJ3  
W_?S^>?l/  
import java.io.*; 0'gJSrgNI  
import java.net.*; JWLQ9U X  
;(z0r_p<q  
uJi|@{V  
public class FileSplitterFetch extends Thread { iKu5K0x{>I  
{L#Pdj{  
L;Nm"[ `  
String sURL; //File URL C3|M\[*fp  
long nStartPos; //File Snippet Start Position x k#/J]j  
long nEndPos; //File Snippet End Position kc}e},k  
int nThreadID; //Thread's ID VP[ J#TPU  
boolean bDownOver = false; //Downing is over 4]Krx m`8  
boolean bStop = false; //Stop identical C@xh$(y  
FileAccessI fileAccessI = null; //File Access interface 86[T BX5'  
TtHqdKL  
o_?YYw-:  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1g *4e  
{ J 9z\ qTI  
this.sURL = sURL; 0 ~VniF^  
this.nStartPos = nStart; ^*Sb)tu\ W  
this.nEndPos = nEnd; 0 j6/H?OT  
nThreadID = id; ^X^4R1V)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zT.qNtU%  
} U`xjau+  
w9vqFtj  
[-Dx)N  
public void run() $cc]pJy"}  
{ QHK$2xtq|  
while(nStartPos < nEndPos && !bStop) )8yNqnD  
{ B&cC;Hw  
r.[9/'>  
jfk`%C Ek=  
try{ `C,479~J  
URL url = new URL(sURL); #5F\zeo@F?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $cnIsyKWY  
httpConnection.setRequestProperty("User-Agent","NetFox"); 60Y&)UR  
String sProperty = "bytes="+nStartPos+"-"; O.}{s;  
httpConnection.setRequestProperty("RANGE",sProperty); ;'*"(F=D6  
Utility.log(sProperty); @Kp2l<P  
~qs 97'  
4\>Cnc{  
InputStream input = httpConnection.getInputStream(); Q 1g@FsW&U  
//logResponseHead(httpConnection); M*|x,K=U  
WJ8i,7  
'RXh E  
byte[] b = new byte[1024]; 9|fg\C  
int nRead; .^ soX}  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =}F &jl  
{ s~,Ypo?  
nStartPos += fileAccessI.write(b,0,nRead); K%.\@l2Cp  
//if(nThreadID == 1) =j6f/8   
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Eb[*nWF=  
} }!x\qpA  
`|[Q]+Mx  
u`3J2 ,.  
Utility.log("Thread " + nThreadID + " is over!"); 4Z,MqG>  
bDownOver = true; M#UW#+*g!  
//nPos = fileAccessI.write (b,0,nRead); lo Oh }y+  
} NZ7g}+GTG  
catch(Exception e){e.printStackTrace ();} ,!Gw40t  
} abp]qvCV  
} CtfI&rb[  
#3leMZ6  
Z+x,Awq  
//打印回应的头信息 <`}Oi 5nW  
public void logResponseHead(HttpURLConnection con) 1Jjay#  
{ E)7vuWO O  
for(int i=1;;i++) 9t9x&.A  
{ /^SIJS@^`>  
String header=con.getHeaderFieldKey(i); CNwIM6t  
if(header!=null) ;N#d'E\  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qS:hv&~  
Utility.log(header+" : "+con.getHeaderField(header)); -W<x|ph U  
else Yxp.`  
break; QX-%<@  
} ?#da4W  
} {1Z8cV   
Dyyf%'\M  
hOG9  
public void splitterStop() [@(M%  
{ Bvb.N$G  
bStop = true; E<y0;l?H<  
} u_shC"X:  
B&3oo   
G(" S6u  
} xEb+sE6Z  
MOi.bHCQJP  
%ukFn &-2@  
/* n]S DpptM  
**FileAccess.java 5[suwaJQ  
*//文件访问(定位,写) L|A}A[P  
package NetFox; M{w[hV  
import java.io.*; `lygJI?H+{  
*:L-/Q)i  
"^Y)&<J&  
public class FileAccessI implements Serializable{ {}RE;5n\['  
PT4Wox9U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6aRPm%  
RandomAccessFile oSavedFile; bis}zv^%v  
long nPos; {xJq F4  
z><u YO$  
M$iDaEu-  
public FileAccessI() throws IOException Z\c^CN  
{ _$g6Mj]1z  
this("",0); iZm# "}VG  
} 4LO4SYW7  
HtY0=r  
)lh48Ag0t;  
public FileAccessI(String sName,long nPos) throws IOException iYJ:P  
{ <?yf<G'$  
oSavedFile = new RandomAccessFile(sName,"rw"); dp;;20z  
this.nPos = nPos; IsP-[0it  
oSavedFile.seek(nPos); trlZ^K  
} #y;TSHx/  
DD5 S R  
X)6}<A  
public synchronized int write(byte[] b,int nStart,int nLen) '9d<vW g  
{ [Ume^  
int n = -1; tjLp;%6e  
try{ \A "_|Yg  
oSavedFile.write(b,nStart,nLen); "  ,k(*  
n = nLen; WRIOjQ:  
} #x|xL7  
catch(IOException e) yR}PC/>  
{ Y%$@ZYW  
e.printStackTrace (); GY% ^!r  
} v|~&I%S7  
[&H$Su}$0  
^hL?.xj  
return n; F3 uR:)4<M  
} Fs+ CY  
pAK7V;sJ  
*S _[8L"  
} }MU}-6  
B:5NIa  
QEtf-xNn^  
/* 5~8FZ-x  
**SiteInfoBean.java <=O/_Iu(  
*/ sVzU>  
package NetFox; MX*T.TG8  
0'm$hU}  
o}^/K m+t  
public class SiteInfoBean { "!w$7|% T  
R{6~7<m.  
Ei$?]~ &  
private String sSiteURL; //Site's URL $4YyZ!_.@  
private String sFilePath; //Saved File's Path _T\/kJ)Q\  
private String sFileName; //Saved File's Name Q5K<ECoPk  
private int nSplitter; //Count of Splited Downloading File AlPk o($E*  
MZPXI{G  
?so=k&I-M  
public SiteInfoBean() l  rRRRR  
{//nSplitter的缺省值为5 q!fdiv`  
//default value of nSplitter is 5 /i !3Fr"  
this("","","",5); Uw`YlUT\  
} J)kH$!csi  
yLFZo"r  
$RAS pM  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $nf5bo/;  
{ g#W/WKvM  
sSiteURL= sURL;  s*XE  
sFilePath = sPath; UYw_k\  
sFileName = sName; *HC[LM  
this.nSplitter = nSpiltter; 3P}^Wu  
N*mm[F2+F  
P }BU7`8  
} fC4#b?Q  
.@5Ro D[o  
\+9~\eeXb  
public String getSSiteURL() Ire+r "am  
{ 6x]x>:8  
return sSiteURL; mK Ta.  
} PQ0l<]Y  
,V`zW<8  
k'6Poz+<  
public void setSSiteURL(String value) %jBI*WzR  
{ '!V5 #J  
sSiteURL = value; (7zdbJX  
} K-<kp!v  
^Fop/\E  
GS*Mv{JJ  
public String getSFilePath() ,)svSzR  
{ jIvSjlmI  
return sFilePath; dRhsnT+KX  
} j]6c_r3  
-O~ V4004  
9y$"[d27;+  
public void setSFilePath(String value) L!>EW0  
{ HxE`"/~.7k  
sFilePath = value; i!nPiac  
} Le?yzf  
SWq5=h  
s.uw,x  
public String getSFileName() bdxmJ9a:R  
{ L/+KY_b:*  
return sFileName; s7 K](T4  
} q8=hUD%5C  
>}I BPC  
Ho^rYz  
public void setSFileName(String value) `i"7; _HoV  
{ ^q@6((O  
sFileName = value; )@hG#KMK  
} _T^+BUw  
12olVTuw  
s*3p*zf  
public int getNSplitter() rn8#nQ>QZ%  
{ sI,S(VWor  
return nSplitter; _v\L'`bif  
} (\qO~)[0  
wOg?.6<Kxa  
vR*TW   
public void setNSplitter(int nCount) sM  _m  
{ CS\ E]f  
nSplitter = nCount; =Z~nzyaN  
} _Pe,84Ro  
} }i\U,mH0_&  
ajJ+Jn\  
5h!ZoB)n  
/* WF&?OHf2  
**Utility.java n7$2 1*,  
*/ ^{l^Z +b.  
package NetFox; p]^?4  
]!mC5Ea  
+<TnE+>j  
public class Utility { cy%S5Rz  
}b$W+/M\  
F,)\\$=,  
public Utility() U%qE=u-  
{ 3B^`xnV  
kCVO!@yZz  
^DaP^<V  
} I<}<!.Bc!  
?E2$  
//线程睡眠 F?jFFw im  
public static void sleep(int nSecond) QVq+';cG  
{ /t $J<bU  
try{ ch-.+p3  
Thread.sleep(nSecond); qVe&nXo  
} MEled:i  
catch(Exception e) >I&'Rj&Mc  
{ 3{/Y&/\"'^  
e.printStackTrace (); 6 h%%?  
} \[CPI`yQe  
} C\RJ){dk  
2 g`<*u*  
//日志 Kc,=J?Ob  
public static void log(String sMsg) i p"LoCE  
{ yr"BeTrS.  
System.err.println(sMsg); wusj;v4C4M  
} QGkMT +A  
65g"$:0  
7#G8qh<  
public static void log(int sMsg) 8 mFy9{M  
{ <,\Op=$l3I  
System.err.println(sMsg); tpQ?E<O  
} 9`8D Ga  
} R32A2Ml  
KN\*|)  
#J_+ SL[  
/* !\(j[d#  
**TestMethod.java %7vjYvo>  
*/ Jp#Onl+d6  
package NetFox; @ 5tW*:s  
s/cclFji]  
$eQf5)5  
public class TestMethod { ynQ+yW74Z  
83[gV@LW0m  
:@=;WB*0  
public TestMethod() a|5^4 J \%  
{ ///xx/weblogic60b2_win.exe >anq1Kf  
try{ u.~`/O  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); O S%  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {!]7=K)W9  
SiteFileFetch fileFetch = new SiteFileFetch(bean); R8(Bt73  
fileFetch.start(); +"8-)'  
} OMM5p=2Q  
catch(Exception e){e.printStackTrace ();} >$ok3-tuU  
a*GiLq  
EH2a  
} ~;ZT<eCIA  
QswbIP/>:'  
Lo-\;%y  
public static void main(String[] args) iFBH;O_~  
{ _O w]kP='  
new TestMethod(); (t%+Z"j  
} 3~5 %6`  
} 7LZ A!3  
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