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http断点续传简单实现(java)

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/* H$>D_WeJ  
**SiteFileFetch.java wj!p6D;;S  
*/ j0B, \A  
package NetFox; odMjxWY  
import java.io.*; p%EU,:I6  
import java.net.*; ^n!{ vHz  
Q.7Rv XNw8  
:WIbjI=  
public class SiteFileFetch extends Thread { C '4u+raq  
[X ]\^   
nud,ag  
SiteInfoBean siteInfoBean = null; //文件信息Bean BQ{Gp 2N  
long[] nStartPos; //开始位置 i;;CU9`E2q  
long[] nEndPos; //结束位置 AR\>P  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 7Te`#"  
long nFileLength; //文件长度 v%n'_2J =^  
boolean bFirst = true; //是否第一次取文件 QDYS}{A:V  
boolean bStop = false; //停止标志 $6}siU7s4  
File tmpFile; //文件下载的临时信息 IzF7W?k  
DataOutputStream output; //输出到文件的输出流 [X0Wfb}{  
E]WammX c  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) zDeh#  
public SiteFileFetch(SiteInfoBean bean) throws IOException BoYWx^VHx^  
{ jv>l6)  
siteInfoBean = bean; .%_scNP  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); wUHuykF  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); yS p]+  
if(tmpFile.exists ()) 7D\#1h  
{ X[_w#Hwp-  
bFirst = false; o[q Kf  
read_nPos(); ,uqSq  
} /1:`?% ,2  
else ]^$&Ejpe#  
{ $J"}7+  
nStartPos = new long[bean.getNSplitter()]; mV^+`GWvo  
nEndPos = new long[bean.getNSplitter()]; c) Zid1  
} *X8<hYKZq  
YqX/7b+  
B;9X{"  
34_:.QK-  
} zRN_` U  
pqFgi_2m  
Qc#<RbLL  
public void run() w^e<p~i!^E  
{ ]n1@!qa48  
//获得文件长度 NF&R}7L  
//分割文件 tNg}: a|J  
//实例FileSplitterFetch 'hfQ4EN  
//启动FileSplitterFetch线程 hd1(q33  
//等待子线程返回 +168!Jw;  
try{ uoR_/vol8  
if(bFirst) 5xX*68]%  
{ &Q 7Q1`S  
nFileLength = getFileSize(); LPX@oha  
if(nFileLength == -1) n,}\;Bp  
{ wR +C>  
System.err.println("File Length is not known!"); *>,8+S33r{  
} QxG:NN;jW  
else if(nFileLength == -2) Pd9qY 8CP  
{ z}&w7 O#   
System.err.println("File is not access!"); $ ,Y\  
} rdZk2\<  
else BC0SSR@e  
{ Rl90uF]8  
for(int i=0;i<nStartPos.length;i++) .E}fk,hLB  
{ D_er(  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); }bIbMEMn  
} s"*ZQ0OaD  
for(int i=0;i<nEndPos.length-1;i++) xD+n2:I{  
{ 5<h7+ %?t9  
nEndPos = nStartPos[i+1]; HLm6BtE  
} 7qj<|US  
nEndPos[nEndPos.length-1] = nFileLength; $?RxmWsP  
} I?c "\Fe  
} OhMnG@@  
0Snl_@s  
TpXbJ]o9  
//启动子线程 + |(-7 "  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q${0(#Nu  
for(int i=0;i<nStartPos.length;i++) {`~uBz+dJq  
{ xQ4 5B` $  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9>,$q"M}?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), B^Y AKbY  
nStartPos,nEndPos,i); ^1y (N>W  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a{*r^m'N  
fileSplitterFetch.start(); b.HfxYt(  
} }4G/x;D  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  /6)6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NKyaR_q`  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o"h* @.  
nEndPos = " + nFileLength); nGb%mlb  
// fileSplitterFetch[nPos.length-1].start(); cb|cYCo5  
M.B0)  
]6JI((  
//等待子线程结束 'Pk1 4`/  
//int count = 0; `-Yo$b;:  
//是否结束while循环 ,au-g)IFZ  
boolean breakWhile = false; P]V/<8o.53  
^|Bpo(  
~J #^L*  
while(!bStop) 66RqjP '2  
{ ;&="aD  
write_nPos(); B#Sg:L9Tr'  
Utility.sleep(500); WGy3SV )  
breakWhile = true; xnz(hz6  
g+CTF67  
kC : pal  
for(int i=0;i<nStartPos.length;i++) p\xi5z  
{ .4I "[$?Q  
if(!fileSplitterFetch.bDownOver) i qLNX)  
{ f~bZTf  
breakWhile = false; >b^|SL  
break; ?r< F/$/  
} . Y@)3  
} fMg3  
if(breakWhile) /m>%=_nz  
break; R 2.y=P8N  
y]9PLch]vZ  
<qGVOAnz+  
//count++; >LqW;/&S<  
//if(count>4) i,k.#Vx[m  
// siteStop(); Ojea~Y]Sr  
} V s/Z8t  
l;u_4`1H  
/Q|guJx  
System.err.println("文件下载结束!"); FPg5!O%  
} CqF= 5z:A  
catch(Exception e){e.printStackTrace ();} u+U '|6)E  
} Kr;7~`$[  
R9dC$Y]\M  
Q#wl1P  
//获得文件长度 ^;KL`  
public long getFileSize() K9-?7X  
{ 6Vq]AQx  
int nFileLength = -1; T*m;G(  
try{ 47(/K2  
URL url = new URL(siteInfoBean.getSSiteURL()); M@R_t(&=   
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;'\#+GZ9p  
httpConnection.setRequestProperty("User-Agent","NetFox"); x{Gdr51%  
^+v6?%m  
jsXj9:X I  
int responseCode=httpConnection.getResponseCode(); QvPG 6A]T  
if(responseCode>=400) hqPpRSv'  
{ KINKq`Sx  
processErrorCode(responseCode); s :4<wmu4=  
return -2; //-2 represent access is error i/Nd  
} ^5"2s:vP  
/M Hml0u  
=f4v: j}'|  
String sHeader; Oyfc!  
xe4F4FC'  
> x$eKN  
for(int i=1;;i++) |C MKY  
{ EPY64 {  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n'dxa<F2|  
//Utility.log(in.readLine()); EQ;,b4k?&g  
sHeader=httpConnection.getHeaderFieldKey(i); \P3[_kbf1  
if(sHeader!=null) "F,d}3}  
{ `L-GI{EJ  
if(sHeader.equals("Content-Length")) 4bT21J37  
{ #U46Au  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T'n~Qf U  
break; `ViFY   
} yNw YP%"y  
} 0K0[mC}ZwM  
else 4h|48</  
break; $m.e}`7SF!  
} '+!@c&d#%o  
} "R"7'sJMI  
catch(IOException e){e.printStackTrace ();} 8z?q4  
catch(Exception e){e.printStackTrace ();} m{U+aqAQK  
~AD%aHR  
]5!}S-uJq  
Utility.log(nFileLength); AWp{n  
sj)$o94=  
ERql^Yr  
return nFileLength; R\L0   
} *AO^oBeY  
CC(At.dd  
;8Z\bHQ>  
//保存下载信息(文件指针位置) a<Ru)Q?=  
private void write_nPos() H#/}FoBiS  
{ !y8/El  
try{ a0vg%Z@!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); p8%/T>hK  
output.writeInt(nStartPos.length); O23dtH  
for(int i=0;i<nStartPos.length;i++) 0>uMR{ #  
{ ?a8 o.&`l  
// output.writeLong(nPos); RHV& m()Q  
output.writeLong(fileSplitterFetch.nStartPos); A4}6hG#  
output.writeLong(fileSplitterFetch.nEndPos); MroJ!.9  
} T.1*32cX  
output.close(); QEl:>HG  
} x Z 3b)j2D  
catch(IOException e){e.printStackTrace ();} Et\z^y  
catch(Exception e){e.printStackTrace ();} I8|7~jRB  
} O-rHfIxY  
VA9" Au  
N :#"4e  
//读取保存的下载信息(文件指针位置) )qGw!^8  
private void read_nPos() vT*z3  
{ [B}$U|V0  
try{ gZ!vRO <%  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -Y#YwBy;M  
int nCount = input.readInt(); f'hrS}e  
nStartPos = new long[nCount]; ;a]2hd"6  
nEndPos = new long[nCount]; @M[t|  
for(int i=0;i<nStartPos.length;i++) Fdgu=qMm  
{ %3L4&W _T  
nStartPos = input.readLong(); _f9XY  
nEndPos = input.readLong(); C;#-2^h  
} )aW;w|#n  
input.close(); \2q!2XWgK  
} c/fU0cA@  
catch(IOException e){e.printStackTrace ();} Lh0qB)>  
catch(Exception e){e.printStackTrace ();} L&[uE;ro  
} `|Aj3a3sND  
MP5 vc5[  
]a4rA+NFLB  
private void processErrorCode(int nErrorCode) -YF]k}|  
{ p^QEk~qw  
System.err.println("Error Code : " + nErrorCode); SE%B&8ZD  
} ZPrL)']  
8lG@8tbW^  
B d#D*"gx  
//停止文件下载 ~b.C[s  
public void siteStop() 11%<bmJ]Q3  
{ 2g>4fZ  
bStop = true; dso6ZRx  
for(int i=0;i<nStartPos.length;i++) qmNgEz%  
fileSplitterFetch.splitterStop(); J$' Q3k  
q)Qd+:a7{  
5F#Q1gP-  
} [1 pWg^  
} 6Fp}U  
//负责部分文件的抓取 -4  ~(*  
**FileSplitterFetch.java y~,mIM$[@  
*/ mmE!!J`B  
package NetFox; @FC|1=+  
S;pKL,d>r  
Nqf6CPXE  
import java.io.*; R07 7eX  
import java.net.*; AoL2Wrk]\B  
{51<EvyE*  
;ps 0wswX  
public class FileSplitterFetch extends Thread { r&$r=f<  
7x 6q:4Ep\  
BU3VXnqT[  
String sURL; //File URL qfRsp rRI"  
long nStartPos; //File Snippet Start Position *@2+$fgz  
long nEndPos; //File Snippet End Position 4z {jWNM)N  
int nThreadID; //Thread's ID yeI((2L@E2  
boolean bDownOver = false; //Downing is over jv8diQ.  
boolean bStop = false; //Stop identical @-^jbmu^ P  
FileAccessI fileAccessI = null; //File Access interface bl/tl_.p00  
rn$LZE %  
w;e42.\  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?^y!}(  
{ R 4= ~  
this.sURL = sURL; EbG`q!C  
this.nStartPos = nStart; >gj%q$@  
this.nEndPos = nEnd; etcpto=Mo  
nThreadID = id; V_1'` F  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g}uVuK;<  
} z8MKGM  
/'yi!:FZFC  
>~+'V.CNW  
public void run() {pzu1*  
{ ^@"H(1Hxu/  
while(nStartPos < nEndPos && !bStop) k&<cFZU  
{ ap 5D6y+  
4hymQ3 g  
58vq5j<V  
try{ Or({|S9d2  
URL url = new URL(sURL); 0=WZ 8|R  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?3=D-Xrb  
httpConnection.setRequestProperty("User-Agent","NetFox"); gwm}19JC  
String sProperty = "bytes="+nStartPos+"-"; Kuj*U'ed7t  
httpConnection.setRequestProperty("RANGE",sProperty); |I0O|Zdv  
Utility.log(sProperty); X+R?>xq{=h  
yf lt2 R  
?zS t  
InputStream input = httpConnection.getInputStream(); (toN? ?r  
//logResponseHead(httpConnection); (Lp$EC&%6  
QH) uh"  
Z'u:Em  
byte[] b = new byte[1024]; z~Ec*  
int nRead; @u4q\G\  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y*f 5_  
{ ! u4'1jd[d  
nStartPos += fileAccessI.write(b,0,nRead); {j0c)SETN  
//if(nThreadID == 1) );m7;}gE  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sz7|2OV"  
} i&%/]Nq  
Gtyy^tz[  
*irYSTA$  
Utility.log("Thread " + nThreadID + " is over!"); _ +"V5z  
bDownOver = true; 8/tvS8I#y  
//nPos = fileAccessI.write (b,0,nRead); fw[Z7`\Q5  
} 4a]$4LQV  
catch(Exception e){e.printStackTrace ();} 0\Q/$#3  
} @~Uu]1  
} CP%?,\  
xDJs0P4  
0Ud.u  
//打印回应的头信息 t+2!"Jr  
public void logResponseHead(HttpURLConnection con) 3T<aGW1  
{ &4m\``//9  
for(int i=1;;i++) `Dn"<-9:  
{ _a?(JzLw5  
String header=con.getHeaderFieldKey(i); gbl`_t/  
if(header!=null) I Ceb2R  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `Tt;)D  
Utility.log(header+" : "+con.getHeaderField(header)); j$he5^GC  
else &' 0|U{|  
break; *[QFIDn:  
} 6oQSXB@  
} 3Dm`8Xt  
sK&[sN33  
]:6M!+?(  
public void splitterStop() 2brxV'tk  
{ @u.%z# h"1  
bStop = true; y1FE +EX[  
} E&wz0d;gf  
;:Yz7<>Y,  
tr<iFT}C  
} `E4+#_ v  
'0\v[f{K3G  
_tJm0z!  
/* q0>@!1Wb  
**FileAccess.java x9U(,x6r  
*//文件访问(定位,写) saj%[Gsy  
package NetFox; Vzs_g]V  
import java.io.*; lo!.%PP|  
3T|xUY)G4  
gZ^'hW-{  
public class FileAccessI implements Serializable{ !qQ B}sAf  
vpoYb  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J'=iEI  
RandomAccessFile oSavedFile; n;F/}:c_a  
long nPos; GjfPba4>  
Sp2<rI  
T|L_ +(M{  
public FileAccessI() throws IOException +'@j~\>^yJ  
{ &6#>a"?"  
this("",0); C;EC4n+s  
} JSAbh\Mq6  
Vp.&X 8  
,?k~>,{3  
public FileAccessI(String sName,long nPos) throws IOException t 5{Y'  
{ ,ezC}V0M  
oSavedFile = new RandomAccessFile(sName,"rw"); /M3UK  
this.nPos = nPos; ~hk;OB;  
oSavedFile.seek(nPos); n$03##pf  
} _Z>I"m  
; { MK  
!go$J]T  
public synchronized int write(byte[] b,int nStart,int nLen) \uUd *  
{ #j?SdQ  
int n = -1; I/HcIBJ  
try{ A@o:mZ+XN(  
oSavedFile.write(b,nStart,nLen); Jj :Bi&C  
n = nLen; w~n7l97Pw  
} wyVQV8+&>  
catch(IOException e) !VXs yH3r5  
{ 9eh9@~mU"l  
e.printStackTrace (); A$a>=U|Z8  
} ^G*zFqa+`  
2`ED?F68gH  
97]$*&fH  
return n; M;$LB@h  
} ?vd_8C2B  
@8jc|X<A  
iL](w3EM  
} r@.3.Q  
dPtQ Sa  
@S>$y5if  
/* %dN',  
**SiteInfoBean.java CL%+`c0  
*/ |rhCQ"H  
package NetFox; F\H^=P  
Z`9yGaTO  
,]\:]Y&?  
public class SiteInfoBean { /;K?Y#mf~j  
v)VhR2d3  
"92Z"I~1  
private String sSiteURL; //Site's URL Og8'K=O#  
private String sFilePath; //Saved File's Path \kQ@G  
private String sFileName; //Saved File's Name  mDJg-BQ  
private int nSplitter; //Count of Splited Downloading File bB#6Xx  
L 2Z9g`>  
eT4+O5t  
public SiteInfoBean() t622b?w  
{//nSplitter的缺省值为5 Y >N`(  
//default value of nSplitter is 5 Q~L"Mr8>V  
this("","","",5); u>cU*E4/  
} ?d? cD  
R\+O.vX  
5ZPe=SQ{  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u{/!BCKE  
{ @uWPo2  
sSiteURL= sURL; sHr!GF  
sFilePath = sPath; |RdiM&C7  
sFileName = sName; s)e'}y  
this.nSplitter = nSpiltter; @Qa)@'u  
h>l  
z3lMD'uU3  
} Mv O!p  
ua'dm6",:  
0tzMu#  
public String getSSiteURL() BU|bo")  
{ c20'{kH  
return sSiteURL; g@ ZZcBx  
} A^a9,T  
4/rd r80  
e?&4;  
public void setSSiteURL(String value) 9bDxml1  
{ 6 s+ Z  
sSiteURL = value; @Lj28&4:<  
} |c]Y1WwDx  
ON$^_l/c  
lIN`1vX(  
public String getSFilePath() h.\9a3B:r  
{ 05<MsxB"w  
return sFilePath; #\&jM -.-  
} ye9-%~sjX  
p^LUyLG`  
6^L4wd7)  
public void setSFilePath(String value) U 9?!|h;7  
{ tXocGM {6C  
sFilePath = value; <3!jra,h  
} h4xRRyK  
YdI|xu>0A^  
((U-JeFW   
public String getSFileName() kpkN GQ2  
{ hr8v O"tZN  
return sFileName; pvJsSX  
} crJyk#_  
BO b#9r  
a9ab>2G?FR  
public void setSFileName(String value) `]^JOw5o  
{ .1yp}&e#  
sFileName = value; =NH p%|  
} Og`6>?>97  
> dJvl|  
e+z_Rj%Y;I  
public int getNSplitter() bP`.teO\  
{ CL*i,9:NR  
return nSplitter; 7P`|wNq  
} 1{oq8LB  
:[iWl8  
|pv:'']J  
public void setNSplitter(int nCount) /?%zNkcxu  
{ `e t0i.  
nSplitter = nCount; g4WN+y`  
} s%nx8"   
} M@rknq@  
:XK.A   
5FJ<y"<6  
/* ) 5r*2I  
**Utility.java R 2uo ZA,  
*/ SU.T0>w  
package NetFox; I3QK~ V*j)  
#Sj:U1x  
9-Bp=M  
public class Utility { dnVl;L8L3  
@Y'BqDFlZ  
$UMxO`F  
public Utility() 9 ve q  
{ gG0P &9xz  
LB_y lfg  
+(iM]L$Fw%  
} s+>VqyHgf  
d]0.6T1[K  
//线程睡眠 %EYh5 W  
public static void sleep(int nSecond) k:nR'TI  
{ "q(#,,_  
try{ Yxye?R-:  
Thread.sleep(nSecond); wSHE~Xx  
} zhbp"yju7  
catch(Exception e) $\l7aA5~  
{ s5T$>+ a  
e.printStackTrace (); tuuc9H4B  
} F gM<2$h  
} je1f\N45  
& IVwm"  
//日志 RKsr}-1 8  
public static void log(String sMsg) 76a+|TzR  
{ +2!J3{[J  
System.err.println(sMsg); U`_(Lq%5W  
} +U9Gj#  
J&w%lYiu5  
!uLW-[F,  
public static void log(int sMsg) ZcgSVMqEX  
{ jA R@?X  
System.err.println(sMsg); 5;5;bBo~  
} Hzs]\%"  
} Q6Z%T.1  
$e#p -z  
n<6p0w  
/* Mp*")N,  
**TestMethod.java n.]K"$230  
*/ 6]^; s1!  
package NetFox; 1UX"iO x(  
Cdl#LVqs  
Ql sMMIax  
public class TestMethod { )tGeQXVhbJ  
Um 9Gjd  
Uj&2'>MJ$  
public TestMethod() !_rAAY  
{ ///xx/weblogic60b2_win.exe WUx}+3eWv  
try{ I`kaAOe  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p ASNiH698  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `#B|l+baq  
SiteFileFetch fileFetch = new SiteFileFetch(bean); "M5P-l$p}  
fileFetch.start(); GFasGHAw  
} .VN"j  
catch(Exception e){e.printStackTrace ();} ko\VDyt,  
p@]\ N  
62K7afH  
} {Y-<#U~iH  
d{2+> >d  
$6.CN#  
public static void main(String[] args) |SC^H56+  
{ bI.LE/yk  
new TestMethod(); ,R/HT@  
} ?#"rI6  
} ?{l}35Q.@  
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