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http断点续传简单实现(java)

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/* h= Mmd  
**SiteFileFetch.java m[8?d~  
*/ _y5J]Yu`j  
package NetFox; K$kI%eGZA  
import java.io.*; PDNbhUAV  
import java.net.*; _oAWj]~rO  
=s/UF_JN  
:&`,T.N.vK  
public class SiteFileFetch extends Thread { bBg=X}9  
B6J <  
bSgdVP-  
SiteInfoBean siteInfoBean = null; //文件信息Bean ![Ll$L r  
long[] nStartPos; //开始位置 ;%B:1Z  
long[] nEndPos; //结束位置 Z%$ tV3a?  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 wzf%~ats  
long nFileLength; //文件长度 ffI z>Of:  
boolean bFirst = true; //是否第一次取文件 HVH<S  
boolean bStop = false; //停止标志 `PS^o#  
File tmpFile; //文件下载的临时信息 Hkzx(yTi  
DataOutputStream output; //输出到文件的输出流 !cNw 8"SIU  
B:rzM:BQ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 1 WUlBr/k  
public SiteFileFetch(SiteInfoBean bean) throws IOException hmp!|Q[)  
{ -F`uz,wZ  
siteInfoBean = bean; P TMJ.;  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); _>RTef L5  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); (,^jgv|I  
if(tmpFile.exists ()) O 4C}]E  
{ Mem1X rBH  
bFirst = false; kO/]mNLG  
read_nPos(); B2T=O%  
} S'}pUGDO  
else JyDg=%-$2  
{ {n 4W3  
nStartPos = new long[bean.getNSplitter()]; y134m  
nEndPos = new long[bean.getNSplitter()]; 4zhg#  
} O)%s_/UX  
*_@t$W  
A Qm!7,  
1w}D fI  
} BFvRU5&Sz  
JIU8~D  
s6(bTO.  
public void run() A; Av0@w  
{ TxP8&!d  
//获得文件长度 3A!Qu$r9  
//分割文件 (-%1z_@Y  
//实例FileSplitterFetch Dks"(0g  
//启动FileSplitterFetch线程 Ef\&3TcQ  
//等待子线程返回 Rj!9pwvT  
try{ EYSBC",  
if(bFirst) kK_9I (7c  
{ UH`cWVLpr  
nFileLength = getFileSize(); 71G\b|5  
if(nFileLength == -1) w=kW~gg  
{ !EOYqD  
System.err.println("File Length is not known!"); M$Ow*!DfP  
} Jxsch\  
else if(nFileLength == -2) BPd *@l  
{ bBY7^k  
System.err.println("File is not access!"); b^R_8x  
} e'T|5I0K  
else 9s&dN  
{ 1 Sz v4  
for(int i=0;i<nStartPos.length;i++) )7  M  
{ X86r`}  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 9w.ZXd  
} u[6aSqwC |  
for(int i=0;i<nEndPos.length-1;i++) l#&\,T  
{ dmPAPCm%y  
nEndPos = nStartPos[i+1]; z 8<"  
} \pVNJ y$`<  
nEndPos[nEndPos.length-1] = nFileLength; 4u E|$  
} j7yUya&  
} WSqo\]  
6kHuKxY,  
b8&z~'ieR  
//启动子线程 >D_!d@Z  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6vf<lmN  
for(int i=0;i<nStartPos.length;i++) ODKHI\U  
{ ]ASTw(4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q .g44>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ntlbn&lc;D  
nStartPos,nEndPos,i); O #5`mo  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d@ef+-  
fileSplitterFetch.start(); uJU;C.LX  
} o[aIQ|G  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U*\ 1d  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g 9AA)Ykp  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d,E2l~s  
nEndPos = " + nFileLength); 9a]JQ  
// fileSplitterFetch[nPos.length-1].start(); ]SUW"5L-  
/ >O.U?  
=8A L>:_  
//等待子线程结束 Z b:S IJ  
//int count = 0; 5`)[FCQ  
//是否结束while循环 ld7B{ ?]  
boolean breakWhile = false; HXgf=R/$  
A'suZpL  
VEx )  
while(!bStop) ne# %Gr  
{ j`QXl  
write_nPos(); { {+:Vy  
Utility.sleep(500); %<\tN^rP  
breakWhile = true; !RwMUnp  
#YK=e&da  
 h 3V; J  
for(int i=0;i<nStartPos.length;i++) I @ D<rjR  
{ ]u47]L#  
if(!fileSplitterFetch.bDownOver) dG)}H _  
{ )JOo|pr-K  
breakWhile = false; B3Ws)nF"  
break; 4o kZ  
} <*z9:jz Q  
} t:%u4\nZ;  
if(breakWhile) TE-(Zil\  
break; Q #p gl  
n!L}4Nmp  
bq z*90  
//count++; UQq Qim  
//if(count>4) y-_IMu.J`  
// siteStop(); &"=<w  
} +@MG$*}Oz  
K QCF "  
xpWY4Q  
System.err.println("文件下载结束!"); JPq' C$  
} @!B% ynrG  
catch(Exception e){e.printStackTrace ();} vlPViHF.  
} te+r.(p  
m'U>=<!D  
K%YR; )5A  
//获得文件长度 ese?;1r  
public long getFileSize() ?-=<7 ~$  
{ j=Z;M1  
int nFileLength = -1; 89ab?H}/  
try{ +m1*ou'K  
URL url = new URL(siteInfoBean.getSSiteURL()); jR"ACup(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]QKKt vN  
httpConnection.setRequestProperty("User-Agent","NetFox"); u(g9-O  
' [%?j?2r  
|t_SN,)dd  
int responseCode=httpConnection.getResponseCode(); !DXK\,;>  
if(responseCode>=400) ap[Q'=A`  
{ bE b+oRI  
processErrorCode(responseCode);  dQI6.$?  
return -2; //-2 represent access is error s[}cj+0  
} y~<_ux,  
lGX8kAv?  
S{UEV7d:n0  
String sHeader; <,Fj}T-  
dyt.( 2  
Xd'B0kQaT  
for(int i=1;;i++) +[Q`I*C  
{ 2Jqr"|sw  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *u!l"0'\  
//Utility.log(in.readLine()); gCM(h[7A  
sHeader=httpConnection.getHeaderFieldKey(i); Q;=3vUN  
if(sHeader!=null) a4eE/1  
{ -o YJ&r  
if(sHeader.equals("Content-Length")) rXVR X#Lh  
{ ] jycg@=B  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }XfRKGQw  
break; v+ "9&  
} PGA `R  
} }PzHtA,V  
else nOK1Wc%/'  
break; >H,PST  
} #z9@x}p5g  
} /\5u-o)  
catch(IOException e){e.printStackTrace ();} c6LPqPcN  
catch(Exception e){e.printStackTrace ();} VX e7b  
:@J.!dokF  
3.@ir"vy  
Utility.log(nFileLength); 5>&C.+A 9  
L%I8no-Q  
^Kn:T`vB  
return nFileLength; w s7LDY&(  
} X,`e1nsR  
_OJ19Ry  
HQV#8G#B  
//保存下载信息(文件指针位置) W" 1=K] B  
private void write_nPos() >{=~''d,w  
{ :6W * ;<o  
try{ k9iB-=X?4s  
output = new DataOutputStream(new FileOutputStream(tmpFile)); E 7"`D\*  
output.writeInt(nStartPos.length); FyA0"  
for(int i=0;i<nStartPos.length;i++) d? 4-"9Y  
{ =7 -@&S=?s  
// output.writeLong(nPos); gU@BEn}  
output.writeLong(fileSplitterFetch.nStartPos); _+. )8   
output.writeLong(fileSplitterFetch.nEndPos); ;a`I8Fj  
} w'<"5F`  
output.close(); -qJO6OM  
} hmJa1fw=  
catch(IOException e){e.printStackTrace ();} AHn Yfxv_  
catch(Exception e){e.printStackTrace ();} *w6(nG'M{  
} +P;&/z8i*g  
)%~<EJ*&Z  
y\<\P8X  
//读取保存的下载信息(文件指针位置) ~P!%i9e_  
private void read_nPos() 1IWP~G  
{ $ cYKVhf  
try{ n!%'%%o2v  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %Su,  
int nCount = input.readInt(); ,\D* =5  
nStartPos = new long[nCount]; i>z {QE  
nEndPos = new long[nCount]; fnn /akGKI  
for(int i=0;i<nStartPos.length;i++) NSQ#\:3:S  
{ a VIh|v  
nStartPos = input.readLong(); "[\),7&03  
nEndPos = input.readLong(); EGK7)O'W  
} zC_@wMWB  
input.close(); VU \{<j{  
} BVv{:m{w  
catch(IOException e){e.printStackTrace ();} 7kh(WtUz  
catch(Exception e){e.printStackTrace ();} >d$Sh`a6  
} n{xL1A=9  
YY 8vhnw  
nBGcf(BE.$  
private void processErrorCode(int nErrorCode) a,KqTQB  
{ {[[/*1r|  
System.err.println("Error Code : " + nErrorCode); GJn ~x  
} .X{U\{c|a  
D@o8Gerq~  
?a'P;&@7  
//停止文件下载 9Vtn62+  
public void siteStop()  4,?ZNyl  
{ CL<m+dW%*  
bStop = true; *&~wl(+O=  
for(int i=0;i<nStartPos.length;i++) oE'Flc.  
fileSplitterFetch.splitterStop(); "i~~Q'=7  
e6uVUzP4  
8 J;\Z  
} qt4^e7o  
} ;@V1*7y  
//负责部分文件的抓取 `E-cf7%  
**FileSplitterFetch.java Qs;MEt1  
*/ 3Tz~DdB  
package NetFox; E  *{_=pX  
L3y`*&e>  
i=X B0-  
import java.io.*; A!^gF~5  
import java.net.*; #wfb-`,5&9  
F]6$4o[  
}+i~JK  
public class FileSplitterFetch extends Thread { MNd[Xzm  
wv&#lM(  
(v1~p3H  
String sURL; //File URL l[M?"<Ot;  
long nStartPos; //File Snippet Start Position >PoVK{&y  
long nEndPos; //File Snippet End Position %mMPALN]{  
int nThreadID; //Thread's ID Kld#C51X f  
boolean bDownOver = false; //Downing is over fm&pxQjg  
boolean bStop = false; //Stop identical l|5;&(Y+s  
FileAccessI fileAccessI = null; //File Access interface \I #}R4z  
*1CZRfWI  
gkL{]*9&%  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W^N|+$g>H  
{ ^=7XA894  
this.sURL = sURL; !7jVKI80  
this.nStartPos = nStart; QV9 z81[  
this.nEndPos = nEnd; CCU<t Q  
nThreadID = id; tLo_lLn*~%  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J0,;F9<C#X  
} .lyK ,p  
q o tWWe#  
jC_m0Iwc  
public void run() l&oc/$&|[  
{ J3,m{%EtNM  
while(nStartPos < nEndPos && !bStop) 2^4OaHY88  
{ 9jW"83*5  
i4H,Ggb  
;cp,d~mrf  
try{ [LDY;k~5+  
URL url = new URL(sURL); 5:|=/X%#qp  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "]ZDs^7  
httpConnection.setRequestProperty("User-Agent","NetFox"); )Rr0f 8  
String sProperty = "bytes="+nStartPos+"-"; tl+ 9SBl  
httpConnection.setRequestProperty("RANGE",sProperty); ] 8dzTEjk  
Utility.log(sProperty); sX,S]:X  
"ot# g"  
 95l)w  
InputStream input = httpConnection.getInputStream(); OS sYmF  
//logResponseHead(httpConnection); O8)N`#1>+  
N Nw0 G&  
#8@o%%F d  
byte[] b = new byte[1024]; y{Vh?Z<E  
int nRead; 5dkXDta[G  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B\Uocn  
{ LZ<^b6Dxk  
nStartPos += fileAccessI.write(b,0,nRead); }0~X)Vgm(  
//if(nThreadID == 1) YuFR*W;$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SaSj9\o  
} dq^vK  
tZan1C%p>  
)SyU  
Utility.log("Thread " + nThreadID + " is over!"); njckPpyb@  
bDownOver = true; {.o@XP,.  
//nPos = fileAccessI.write (b,0,nRead); z#^;'nnw  
} _(F8}s  
catch(Exception e){e.printStackTrace ();}  4}F~h  
} =Hx]K8N)  
} HMmB90P`  
6|Xe ],u  
.X34[AXd  
//打印回应的头信息 JsHD3  
public void logResponseHead(HttpURLConnection con) )W*A[c 2  
{ h&2l0 |8k  
for(int i=1;;i++) Cf>(,rt};  
{ +F+M[ef<ws  
String header=con.getHeaderFieldKey(i); odWK\e  
if(header!=null) _BZ6Ws$C2  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f"SK3hI$p  
Utility.log(header+" : "+con.getHeaderField(header)); uYC1}Y5N  
else pT/z`o$#V  
break; AK(x;4  
} N5.B"l  
} CD[}|N  
%S/?Ci  
gUY~ l= c  
public void splitterStop() a'(B}B=h  
{ '^M.;Giz  
bStop = true; mM.YZUX  
} ^09-SUl^  
U1O8u-X  
`T{'ufI4B  
} 0ZJj5<U  
;Vpp1mk|  
=Y Y 7V!  
/* %~L"TK`?  
**FileAccess.java >:HmIW0PLe  
*//文件访问(定位,写) b8E7/~<z3  
package NetFox; )+|Y;zC9  
import java.io.*; ih-J{1  
}$i/4?dYsQ  
+QNsI2t;r  
public class FileAccessI implements Serializable{ )]kxLf#  
rn/~W[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l=ZD&uK  
RandomAccessFile oSavedFile; ]kd:p*U6P  
long nPos; ;8a9S0eS  
<~P!yLr  
R3%%;`c=  
public FileAccessI() throws IOException N'i)s{'  
{ Bj<s!}i{[  
this("",0); %SuELm  
} _ s*p$/V\  
sNM ]bei  
Ft38)T"2R\  
public FileAccessI(String sName,long nPos) throws IOException Tl2(%qB  
{ <Zvvx  
oSavedFile = new RandomAccessFile(sName,"rw"); QiK-|hFj  
this.nPos = nPos; X9ZHYlr+Q  
oSavedFile.seek(nPos); '$),i>6gJ  
} 7ug"SV6Hb  
vn!5@""T  
3?&v:H  
public synchronized int write(byte[] b,int nStart,int nLen) `][vaLd`Q  
{ 7Mk>`4D'c  
int n = -1; &>&6OV]P'  
try{ `mA;1S  
oSavedFile.write(b,nStart,nLen); *<X1M~p$  
n = nLen; (cyvE}g  
} QO^V@"N  
catch(IOException e) g9fYt&  
{ [$;cjys  
e.printStackTrace (); =fJU+N+<  
} >]8(3&zd  
b.v +5=)B  
e^oGiL ~  
return n; k%X $@NP  
} V:>r6  
>I/@GX/  
.$7RF!p  
} ptrwZ8'  
_VVq&t}  
qS9<_if2  
/* 1DcX$b  
**SiteInfoBean.java OTE,OCB[  
*/ '%wSs,HD  
package NetFox; 0|.jIix;  
q ajZ~oB{  
c BZ,"kp-  
public class SiteInfoBean { 9cHo~F|ur  
l5.k2{'  
3UaW+@  
private String sSiteURL; //Site's URL 1ANFhl(l  
private String sFilePath; //Saved File's Path wN58uV '  
private String sFileName; //Saved File's Name ^C1LQ Z  
private int nSplitter; //Count of Splited Downloading File 1Y*k"[?dW  
!#:5^":;  
:L@n(bu RN  
public SiteInfoBean() +<.o,3  
{//nSplitter的缺省值为5 r7oFG!.?  
//default value of nSplitter is 5 ?'Hd0)yZ  
this("","","",5); yvj/u c  
} ]XbMqHGS  
,h*N9}xYTi  
iiQ q112`  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7P<f(@0h$E  
{ q)L4*O  
sSiteURL= sURL; '~Cn+xf4]  
sFilePath = sPath; }oA>0Nw$K  
sFileName = sName; Jw8?o/1D@  
this.nSplitter = nSpiltter; J@2wPKh?Yp  
@fYVlHT%E  
'/NpmNY:L  
} [K$5 Rm5  
2H}y1bkW  
Vx2/^MiXy  
public String getSSiteURL() ;b*qunJ3L  
{ &>C+5`bg  
return sSiteURL; 5{k,/Z[L  
} xi(1H1KN5B  
Fz';H  
vReX7  
public void setSSiteURL(String value) bf0,3~G,P  
{ 't}\U&L.{  
sSiteURL = value; Y&j`HO8f  
} R%RxF=@  
Ao8ua|:  
)f|`mM4DW!  
public String getSFilePath() '"E!av>  
{ I51]+gEN  
return sFilePath; I2WP/  
} tRJ5IX##L  
=DJ:LmK  
fMg9h9U  
public void setSFilePath(String value) H^*AaA9-   
{ (O4oI U  
sFilePath = value; Hs'~) T  
} BP@tI|  
` = O  
BYXc 'K  
public String getSFileName() FHQ`T\fC$@  
{ 88v8lt;R  
return sFileName; 9GH5  
} a%B&F|u  
5m 0\ls\  
m6mGcbpn  
public void setSFileName(String value) +FqD.=8  
{ f(w>(1&/B  
sFileName = value; qisvGHo  
} (l^7EpNs  
"ktuq\a@  
[w'Q9\,p  
public int getNSplitter() iVn4eLK^v  
{ W+!UVUpW  
return nSplitter; +Pb:<WT}%  
} ,~naKd.ZY  
bPxL+ +  
BA: x*(%~  
public void setNSplitter(int nCount) H_ $?b  
{ #j~FlY5  
nSplitter = nCount; =WT$\KYGv  
} c EYHB1*cT  
} \uOM,98xS  
*uyP+f2O  
!6'N-b1  
/* S{;Pga*Px  
**Utility.java ZX:rqc  
*/ d#0:U Y%~  
package NetFox; 4tZ*%!I'  
?"9h-g3`x}  
am]M2+,2Ip  
public class Utility { "5V;~}=S  
P0.cF]<m  
^<OYW|q?\r  
public Utility() xc#t8`  
{ JLE&nbKS  
{oqbV#/&  
SUUNC06V  
} :Ph>\aG  
}(t`s  
//线程睡眠 mF;mJq<d  
public static void sleep(int nSecond) JI-i7P  
{ cuQ!"iH  
try{ Z&n[6aV'F  
Thread.sleep(nSecond); d.vNiq,`  
} }d?;kt  
catch(Exception e) :0l+x 0l}  
{ juOStTq<  
e.printStackTrace (); @-)?uYw:r  
} >)ekb7  
}  B(;MI`  
py'vD3Q  
//日志 3@V?L:J  
public static void log(String sMsg) f#!+l1GV  
{ l/G +Xj4M  
System.err.println(sMsg); x 7by|G(  
} H[~ D]RG}'  
&THtQ1D  
C(XV YND3  
public static void log(int sMsg) uB  I/3aQ  
{ _X4Y1zh  
System.err.println(sMsg); 'v]0;~\mp>  
} {6ZSf[Y6B  
} 1VgGF^cYR  
WoZU} T-  
E#KZZ lbx  
/* 7\ _MA!:<  
**TestMethod.java oK\zyNK  
*/ G+<XYkz*  
package NetFox; NuQ!huh  
+LRKS  
dun`/QKV  
public class TestMethod { ;mU;+~YE  
sG u.G  
C1D:Xi-  
public TestMethod() Lm4`O %  
{ ///xx/weblogic60b2_win.exe f`hZb  
try{ 3*h"B$g!  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); TTVmm{6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sjyr9AF  
SiteFileFetch fileFetch = new SiteFileFetch(bean); EQ$k^Y8 "  
fileFetch.start(); R 0RxcB tG  
} 8 MO-QO  
catch(Exception e){e.printStackTrace ();} x &R9m,  
OE@[a  
>Q/;0>V  
} Ur])*#  
'OA*aQ=K  
ZHNL ~=r}  
public static void main(String[] args) gQPw+0w  
{ `D77CC]vU  
new TestMethod(); ef`_ n+`  
} ,\6Vb*G|E>  
} J#$U<`j*G  
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