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http断点续传简单实现(java)

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/* _:-ha?W$;y  
**SiteFileFetch.java b D[!/'4eJ  
*/ ?}RSwl  
package NetFox; 2;^y4ssg  
import java.io.*; ,^x4sA[/  
import java.net.*; z6?)3'  
& M~`:R  
_%B^9Yl3(  
public class SiteFileFetch extends Thread { |/2y-[;:  
KTn}w:+B\  
|kvC H<F'  
SiteInfoBean siteInfoBean = null; //文件信息Bean tvu!< dxZ  
long[] nStartPos; //开始位置 niqN{  
long[] nEndPos; //结束位置 u)V#S:9]  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 nD)K}4  
long nFileLength; //文件长度 T.We: ,{  
boolean bFirst = true; //是否第一次取文件 $`wMX{  
boolean bStop = false; //停止标志 n< ud> JIb  
File tmpFile; //文件下载的临时信息 %_(H{y_!  
DataOutputStream output; //输出到文件的输出流 )EL!D%<A  
d8m6B6 CW  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) CMCO}#  
public SiteFileFetch(SiteInfoBean bean) throws IOException j~+>o[c  
{ EC\yz H*X  
siteInfoBean = bean; 59!Fkd3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); lK4M.QV ?\  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); rDQ!zlg>l  
if(tmpFile.exists ()) h-m \%|D  
{ B?)@u|0  
bFirst = false; ']>Mp#j  
read_nPos(); {qmdm`V[  
} BWM YpZom  
else >9f%@uSM$3  
{ sL@U  
nStartPos = new long[bean.getNSplitter()]; Ma\Gb+>  
nEndPos = new long[bean.getNSplitter()]; `"@g8PWe  
} _^ 'I  
:OkT? (i  
ph_4q@  
h?f>X"*|(  
} T<L^N+<,{N  
VB?O hk]<  
y8 KX<2s1  
public void run() !Yw3 d   
{ ~O]]N;>72"  
//获得文件长度 1|?05<8  
//分割文件 3 HIz9F(  
//实例FileSplitterFetch #."Hh<C  
//启动FileSplitterFetch线程 v\,N5  
//等待子线程返回 u@.>Z{h  
try{ g(Io/hyj  
if(bFirst) t(+) #  
{ J8"[6vId~  
nFileLength = getFileSize(); XgxX.`H7  
if(nFileLength == -1) NO0"*c;  
{ e+]6OV&+  
System.err.println("File Length is not known!"); `$~Rxz Z g  
} Sje wuIi1  
else if(nFileLength == -2) 1t Jg#/?  
{ p[@5&_u(z  
System.err.println("File is not access!"); %\kOLE2`  
} xxm%u9@s  
else )' hH^(Yu  
{ -\y-qHgb/  
for(int i=0;i<nStartPos.length;i++) LT~YFS  
{ +,&O1ykY  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); "ywh9cp  
} C'!;J  
for(int i=0;i<nEndPos.length-1;i++) Y(+^;Y3U  
{ -wv6s#"u  
nEndPos = nStartPos[i+1]; K 9kUS  
} >z%Q>(F  
nEndPos[nEndPos.length-1] = nFileLength; M^7MU}5w  
} HJC(\\~  
} z*a8sr  
WA$>pG5s  
DS2)@  
//启动子线程 S/`%Q2za4  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6ATtW+sN]  
for(int i=0;i<nStartPos.length;i++) #"ftI7=42  
{ +xXH2b$wWC  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Nk;iiz+_p  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <X_!x_x  
nStartPos,nEndPos,i); BT_tOEL#  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IhiGP {  
fileSplitterFetch.start(); 1 Vy,&[c~"  
} '>k{tPi.  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g2R@`./S  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kL90&nP   
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", QJW`}`R  
nEndPos = " + nFileLength); >m'x8xB=  
// fileSplitterFetch[nPos.length-1].start(); 8CC/BOe  
tQ~WEC  
W0zbxJKjd  
//等待子线程结束 hKlZi!4J  
//int count = 0; e.o;eD}"  
//是否结束while循环 )B!d,HKt;  
boolean breakWhile = false; ir:d'g1k  
%>WbmpIyc  
zTD@  
while(!bStop) *8ExRQZ$  
{ 8z<r.joxC  
write_nPos(); eV6o3u:9  
Utility.sleep(500); '+*-s7o{  
breakWhile = true; n^hocGH*  
#)`A7 $/,  
(shK  
for(int i=0;i<nStartPos.length;i++) &kQ!KA28  
{ ArI]`h'W  
if(!fileSplitterFetch.bDownOver) ]$M<]w,IJ2  
{ cgj.e  
breakWhile = false; fA^7^0![  
break; 4Z)DDz-}V  
} cX At :m  
} \h3e-)  
if(breakWhile) Y'Z+, CNf  
break; mEQ!-p   
mYNEz @  
d `j?7Z  
//count++; ,vG<*|pn  
//if(count>4) @ERu>nSP  
// siteStop(); 3AlqBXE"Z<  
} EX?h0Uy  
~4)Y#IxL  
PM4>ThQ  
System.err.println("文件下载结束!"); "A]Y~iQ  
} 9b6!CNe!  
catch(Exception e){e.printStackTrace ();} 2W3W/> 2 h  
} P 4;{jG  
o&^NwgRCF  
>$ F:*lO  
//获得文件长度 wk 02[  
public long getFileSize() #@Ujx_F  
{ MB* u-N0v  
int nFileLength = -1; w{'2q^>6*  
try{ 4&N$:j<  
URL url = new URL(siteInfoBean.getSSiteURL()); aed+C:N  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q[s 2}Z!N;  
httpConnection.setRequestProperty("User-Agent","NetFox"); 9NWloK6bT  
\8"QvC]  
V_;9TC  
int responseCode=httpConnection.getResponseCode(); 8Z:Ezg3^  
if(responseCode>=400) 7Qh_8M  
{ H4skvIl  
processErrorCode(responseCode); <lOaor c  
return -2; //-2 represent access is error S!7g)  
} f[qPG&  
{Bvm'lq`  
e d;"bb  
String sHeader; :l~EE!  
`{G?>z Fp  
/{DaPqRa  
for(int i=1;;i++) ,U%=rfB~  
{ M5Wl3tZL  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b5Q8pWZg,  
//Utility.log(in.readLine()); Z}[xQ5  
sHeader=httpConnection.getHeaderFieldKey(i); [EGx  
if(sHeader!=null) wsfysat$  
{ gPUo25@pn*  
if(sHeader.equals("Content-Length")) _[1^s$  
{ gUGOHd(A  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XTj73 MWY  
break; ;\s~%~ \  
} }Z-I2 =]  
} @,YlmX}  
else cno;>[$  
break; O!] ;_q/  
} L *{QjH  
} c `ud;lI  
catch(IOException e){e.printStackTrace ();} y.fs,!|%@  
catch(Exception e){e.printStackTrace ();} A^cU$V%?W  
3"vRK5Bf  
&GU@8  
Utility.log(nFileLength); 8;8YA1@w  
`A"Q3sf%  
:p&IX"Hh  
return nFileLength; UnjNR[=  
} p6[#f96^u  
qM*S*,s  
lJ'trYaq7  
//保存下载信息(文件指针位置) t]r7cA  
private void write_nPos() .}~$1QKS  
{ |f3U%2@  
try{ W[GQ[h  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 77^ "xsa  
output.writeInt(nStartPos.length); wH#-mu#Yl<  
for(int i=0;i<nStartPos.length;i++) -HN%B?}. x  
{ k%^<}s@  
// output.writeLong(nPos); & L3UlL  
output.writeLong(fileSplitterFetch.nStartPos); )ZN(2z  
output.writeLong(fileSplitterFetch.nEndPos); %awVVt{aG  
} [='p!7 z  
output.close(); .`mtA`N  
} /4^G34  
catch(IOException e){e.printStackTrace ();} o|+E+l9\  
catch(Exception e){e.printStackTrace ();} rWqkdi1  
} 6QW<RXom  
||`qIElAW,  
q`cEA<~S  
//读取保存的下载信息(文件指针位置) [h^f%  
private void read_nPos() (GnVwJ<v9V  
{ 90?,-6  
try{ m,=)qex  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *$JB`=Q  
int nCount = input.readInt(); |GuKU!  
nStartPos = new long[nCount]; )&XnM69~b  
nEndPos = new long[nCount]; U%h7h`=F?  
for(int i=0;i<nStartPos.length;i++) 0n\^$WY  
{ >H)^6sJ;%b  
nStartPos = input.readLong(); m';#R9\Fz  
nEndPos = input.readLong(); .r7D )xNa@  
} 9^(HXH_f  
input.close(); #>@<n3rq  
} m**0rpA  
catch(IOException e){e.printStackTrace ();} &3WkH W   
catch(Exception e){e.printStackTrace ();} DL %S(l  
} uXjoGcW  
n}=rj7  
g'KzdG`O0  
private void processErrorCode(int nErrorCode) Ft)t`E'%j  
{ {ms,q_Zr  
System.err.println("Error Code : " + nErrorCode); nt drXg  
} Qk+=znJ  
n?zbUA#  
t8t}7XD   
//停止文件下载 aB=vu=hF  
public void siteStop() ;R/k2^uF  
{ N 9c8c  
bStop = true; S&5Q~}{,  
for(int i=0;i<nStartPos.length;i++) UaH26fWs  
fileSplitterFetch.splitterStop(); /&*m1EN#o  
P{"  WlJ  
ub[""M?  
} .=>\Qq%  
} m5X3{[a :  
//负责部分文件的抓取 o G (0i  
**FileSplitterFetch.java aUKh}) B  
*/ ?H y%ULk  
package NetFox; o9_(DJ<{  
M4zX*&w.T  
F9Ifw><XM  
import java.io.*; xN e_qO  
import java.net.*; #S@UTJa  
=$^Wkau  
{z.[tvE8h  
public class FileSplitterFetch extends Thread { >r;ABz/  
>(IITt  
l5{(z;xM  
String sURL; //File URL /d{glOk  
long nStartPos; //File Snippet Start Position tn"Y9 k|  
long nEndPos; //File Snippet End Position 4$0jz'  
int nThreadID; //Thread's ID "}S9`-Wd|  
boolean bDownOver = false; //Downing is over @`w'   
boolean bStop = false; //Stop identical A6{t%k~F  
FileAccessI fileAccessI = null; //File Access interface >&$$(Bp  
Rf)'HT  
RY\{=f  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e*Uz# w:  
{ P]!LN\[  
this.sURL = sURL; GCcwEl!K^  
this.nStartPos = nStart; S 23S.]r  
this.nEndPos = nEnd; >Sc$R0  
nThreadID = id; wm); aWP  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (Wm/$P;  
} 2"pE&QNd  
t` }20=I+  
:NwMb^>  
public void run() X% Spv/8{  
{ hKk\Y{wv'  
while(nStartPos < nEndPos && !bStop) n.2E8m/  
{ i1b4 J  
qT4I Y$h  
8CHb~m@^$  
try{ #JJp:S~`   
URL url = new URL(sURL); pRQ fx^ On  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); * kX3sG$8  
httpConnection.setRequestProperty("User-Agent","NetFox"); *=-__|t  
String sProperty = "bytes="+nStartPos+"-"; OYqYI!N/  
httpConnection.setRequestProperty("RANGE",sProperty); v$gMLu=  
Utility.log(sProperty); R$!;J?SS  
,cGwtt(  
Hj5WJ{p.  
InputStream input = httpConnection.getInputStream(); jSeA %Te  
//logResponseHead(httpConnection); -V;0_Nx7p  
4b3F9  
Pe+ 8~0o=R  
byte[] b = new byte[1024]; ]MqH13`)A  
int nRead; Q|j@#@O1  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jV,(P$ 5;  
{ <FUqD0sQ  
nStartPos += fileAccessI.write(b,0,nRead); D,}'E0  
//if(nThreadID == 1) f>\bUmk(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f_re"d 3u  
} @yU!sE:  
e' /  
t6<sNz F&  
Utility.log("Thread " + nThreadID + " is over!"); :f?,]|]+-  
bDownOver = true; 4pfix1F g  
//nPos = fileAccessI.write (b,0,nRead); +!L_E6pyXE  
} 0p:ClM 2O  
catch(Exception e){e.printStackTrace ();} 66^1&D"  
} |"Xi%CQ2  
} =M/ UHOY  
RS||KA])J  
!_XU^A>  
//打印回应的头信息 r?5@Etpg  
public void logResponseHead(HttpURLConnection con) I9:G9  
{ 0TuOY%+  
for(int i=1;;i++) XvA0nEi  
{ g9([3pV,  
String header=con.getHeaderFieldKey(i); ga{25q}"  
if(header!=null) ;G4HMtL  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); d}wa[WRv   
Utility.log(header+" : "+con.getHeaderField(header)); 2vh!pez_  
else s_ GK;;  
break; ~*' 8=D?)  
} 9h3~;Q  
} 5|6z1{g8  
_pH6uuB  
8H 3!; ]  
public void splitterStop() *&hXJJ[+  
{ +]S;U&vQ  
bStop = true; shDt&_n  
} ^7~SS2t!  
8JtI&aH-L  
Wy^[4|6  
} < o'7{  
8)-t91hkL  
"#\bQf}  
/* 2W"cTm  
**FileAccess.java O&?CoA?  
*//文件访问(定位,写) St3(1mApl  
package NetFox; M[ ~2,M&H  
import java.io.*; 0IPhVG~#  
k9_VhR|!  
tZNad  
public class FileAccessI implements Serializable{ >Rki[SNb-b  
o. V0iS]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hyvV%z Z  
RandomAccessFile oSavedFile; g]iy-,e  
long nPos; qh(-shZ4Du  
[BZ(p  
L yA(.  
public FileAccessI() throws IOException SbPjU5 0  
{ vU$O{|J  
this("",0); X,!OWz:[  
} L1Cn  
@Pb 1QLiz  
0ZID @^  
public FileAccessI(String sName,long nPos) throws IOException Ji}IV  
{ U70@}5!  
oSavedFile = new RandomAccessFile(sName,"rw"); $NGtxZp  
this.nPos = nPos; *Xt c`XH  
oSavedFile.seek(nPos); ^cmP  
} cdtzf:#q  
GaK_9Eg-2  
FUqhSW  
public synchronized int write(byte[] b,int nStart,int nLen) PcSoG\- G<  
{ v/TlXxfil  
int n = -1; ^`>Ysc(@&  
try{ G4exk5  
oSavedFile.write(b,nStart,nLen); a@=36gx)  
n = nLen; xZ'` _x9l  
} jVFRqT%  
catch(IOException e) _F|_C5A  
{ w6In{uO-Z  
e.printStackTrace (); u FYQ^  
} W Pp\sIP  
zc,9Qfn  
Z=t#*"J  
return n; FiU;>t<)  
} uuK]<h*  
;pNbKf:  
8.%a"sxr  
} g d}TTe  
K"6+X|yxE  
i!}nGJGg  
/* y[@j0xlO  
**SiteInfoBean.java `~+a=Q  
*/ `J ,~hK  
package NetFox; w4MMo  
L"du"-  
&{4Mo,x  
public class SiteInfoBean { {6y.%ysU  
sd@gEp)L  
:8|3V~%m  
private String sSiteURL; //Site's URL RJs G]`  
private String sFilePath; //Saved File's Path GxBPEIim  
private String sFileName; //Saved File's Name qH$rvD!]  
private int nSplitter; //Count of Splited Downloading File U W)&Eky  
|e; z"-3  
M^Ay,jK!  
public SiteInfoBean() jc~*#\N  
{//nSplitter的缺省值为5 2c`=S5  
//default value of nSplitter is 5 VJtTbt;>  
this("","","",5); )I-?zyL  
} 5b4V/d* '  
@C [|'[xQ  
=?*"V-l  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) eh7r'DmAR  
{ +P)[|y +e  
sSiteURL= sURL; `1}?{ud  
sFilePath = sPath; ;OCI.S8  
sFileName = sName; l=?y=2+  
this.nSplitter = nSpiltter; ;Owu:}   
{s'_zS z  
Y^m=_*1g5  
} ! E#.WX  
U\ E{-7  
Ollv _o3  
public String getSSiteURL() 8=o5;]Cg  
{ 3$yL+%i  
return sSiteURL; f4y;K>u7p  
} T9<nD"=:  
QuRg(K%:  
v.v%k2;  
public void setSSiteURL(String value) jz7ltoP  
{ i[^lJ)[>N  
sSiteURL = value; v oS"X  
} >!F,y3"5S  
zXU{p\;)\  
ZBq*<VtV  
public String getSFilePath() +5|nCp6||j  
{ v/+}FS=  
return sFilePath; "?&bh@P&  
} :k/U7 2  
]3u'Qv}o  
Y4!q 1]TGX  
public void setSFilePath(String value) UKQ&TV}0  
{ CWsv#XOg]  
sFilePath = value;  n(xlad  
} SWd[iD  
LVl0:!>~  
&B0&183  
public String getSFileName() Y]Vc}-a(h  
{ Cwf$`?|W  
return sFileName; mg/kyua^  
} <+,0 G`  
fQ4$@  
+p6\R;_E  
public void setSFileName(String value) nJH%pBc  
{ Jxw:Jk ~  
sFileName = value; Cbvl( (  
} 8%f! X51  
Qnx92   
F+S#m3X  
public int getNSplitter() 3Dvk oV  
{ EZRZ)h  
return nSplitter; 1)Bi>X  
} E9-'!I!  
(k.7q~:  
=8_TOvSJ4p  
public void setNSplitter(int nCount) Vn;] ''_  
{ 7Q}@L1A9F,  
nSplitter = nCount; CoXL;\  
} j&GKpt  
} 1A.\Ao  
.cog9H'  
e91d~  
/* ~kT{O!x}4  
**Utility.java cs;Gk:  
*/ Vs"Q-?  
package NetFox; \>7-<7+I6  
#eyx  
|JQKxvjT  
public class Utility { FuBRb(I  
{z_pL^S'52  
Te#[+B?  
public Utility() JdEb_c3S  
{ ! NE q|Y  
{v 0(0  
"ZW*O{  
} t[,\TM^h}0  
<sOB j'  
//线程睡眠 -;z\BW5 y  
public static void sleep(int nSecond) f |5|n>*  
{ <qx-%6  
try{ WfZ#:G9  
Thread.sleep(nSecond); ^o:5B%}#[  
} 8!Kfe  
catch(Exception e) bNgcZ V.  
{ TA7w:<  
e.printStackTrace (); &pl;U\dc*a  
} WU_Q 7%+QS  
} A???s,F_  
$hh=-#J8  
//日志 &LYZQ?|  
public static void log(String sMsg) VE m[F/'  
{ `#F>?g$2  
System.err.println(sMsg); "&F/'';0}E  
} r$zXb9a|<  
s]OXB {M  
m%puD 9  
public static void log(int sMsg) '"a8<7  
{ 7\lc aC@  
System.err.println(sMsg); 8nM]G4H.f  
} T^t`H p  
} X3vrD{uNU  
qm@hD>W+  
mi?Fy0\  
/* d1N&J`R\1  
**TestMethod.java ;$]R#1i44  
*/ Emo]I[<&q  
package NetFox; B}.ia_&DLR  
^m\n[<x^  
hQO~9mQ+!  
public class TestMethod { x($1pAE  
@VFg XN  
IU/*YI%W  
public TestMethod() 0vEa]ljS  
{ ///xx/weblogic60b2_win.exe 89l}6p/L  
try{ 8dfx _kY`/  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yL1\V7GI{[  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @M-bE=  
SiteFileFetch fileFetch = new SiteFileFetch(bean); MwZ`NH|n3"  
fileFetch.start(); BDA\9m^3  
} +%^D)   
catch(Exception e){e.printStackTrace ();} .u)YZN0\  
~2H)#`\ac8  
y g7z?AZ  
} 4Y'qo M;  
3ul  
rB\UNXy  
public static void main(String[] args) {k>m5L  
{ Wo%&,>]<H  
new TestMethod(); : f Wh7X3  
} ^,50]uX_  
} J_tJj8  
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