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http断点续传简单实现(java)

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/* +1nzyD_E  
**SiteFileFetch.java s)G?5Gz  
*/ IL{tm0$r  
package NetFox; 6z2%/P-'  
import java.io.*; (bAw>  
import java.net.*; ;r} yeI Sf  
]OV}yD2p  
IXpn(vX  
public class SiteFileFetch extends Thread { HcM/  
l4ru0V8s7  
rgF4 W8  
SiteInfoBean siteInfoBean = null; //文件信息Bean {uurLEe?  
long[] nStartPos; //开始位置 `_SV1|=="8  
long[] nEndPos; //结束位置 oSLm?Lu  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 _R}yZ=di  
long nFileLength; //文件长度 dOVu D(  
boolean bFirst = true; //是否第一次取文件 :,V&P_  
boolean bStop = false; //停止标志 EMzJyGt7  
File tmpFile; //文件下载的临时信息 06e dVIRr  
DataOutputStream output; //输出到文件的输出流 t==\D?Rt  
! ~tf0aY  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) m qwJya  
public SiteFileFetch(SiteInfoBean bean) throws IOException W3jwc{lj  
{ TE6]4E*  
siteInfoBean = bean; <R?S  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); NAOCQDk{  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Qna*K7kv  
if(tmpFile.exists ()) CA5T3J@vAQ  
{ 9"zp>VR  
bFirst = false; }Fsr"RER@{  
read_nPos(); Ygc|9}  
} 5+UNLvsZ  
else 0Oa&vx  
{ qWJHb Dd  
nStartPos = new long[bean.getNSplitter()]; 2"c5<  
nEndPos = new long[bean.getNSplitter()]; u4$R ZTC  
} Bj GfUQ  
^6J*:(eM  
5?[hr5E.E  
HPg%v |  
} \/b[V3<"  
L1f=90  
FY`t7_Y?GV  
public void run()  DTa!vg  
{ 8Ltl32JSB[  
//获得文件长度 =~5N/!  
//分割文件 q[ 9N4nj$<  
//实例FileSplitterFetch C DoD9Hq,  
//启动FileSplitterFetch线程 f8ZuG !U  
//等待子线程返回 _Tm]tlV  
try{ ,U)&ny  
if(bFirst) R x(yn  
{ '$rCV,3q  
nFileLength = getFileSize(); !2>@:CKX  
if(nFileLength == -1) jFip-=T{4  
{ ||ugb6q[6B  
System.err.println("File Length is not known!"); .FV^hrJxI;  
} R+_!FnOJ  
else if(nFileLength == -2) }Q@~_3,UJ  
{ 78r0K 5=  
System.err.println("File is not access!"); XE&h&v=>  
} IZ\fvYp  
else j dz IU  
{ "Q:h[)a  
for(int i=0;i<nStartPos.length;i++) W;l0GxOxQ  
{ oz]&=>$1I  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Gs,e8ri!  
} ,p /{!BX  
for(int i=0;i<nEndPos.length-1;i++) :H&G}T(#  
{ &,=FPlTC=  
nEndPos = nStartPos[i+1]; KV8<'g+2?  
} \q3ui}-9  
nEndPos[nEndPos.length-1] = nFileLength; t\ a|Gp W  
} m OE!`fd  
} q VI0?B x  
r ;MFVj{  
5pC}ZgEa<  
//启动子线程 Z[ &d2'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^\kH^   
for(int i=0;i<nStartPos.length;i++) WUo\jm[yr  
{ T ,jb%uPcE  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U]w"T{;@.)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iK+Vla`}  
nStartPos,nEndPos,i);  I8`$a  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); + d3  
fileSplitterFetch.start(); u`.)O2)xU  
} ;ISe@ yR;  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eG8 l^[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iRlpNsN  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Jj\lF*B  
nEndPos = " + nFileLength); %?aq1 =B  
// fileSplitterFetch[nPos.length-1].start(); UV0[S8A  
;,e16^\' &  
FpU8$o~r{  
//等待子线程结束 b GI){0A  
//int count = 0; #.[eZ[  
//是否结束while循环  y1T(R#  
boolean breakWhile = false; Hk@Gkx_  
|FM*1Q[1  
OG$v"Yf~  
while(!bStop) 'P" i9j  
{ +xU({/  
write_nPos(); 3+s$K(%I  
Utility.sleep(500); QIevps*  
breakWhile = true; :$,MAQ'9  
 X(X[v]  
;RX u}pd  
for(int i=0;i<nStartPos.length;i++) #v xq|$e  
{ Uc'}y!R  
if(!fileSplitterFetch.bDownOver) R3l{.{3p2  
{ Bf;_~1+vLG  
breakWhile = false; 1' v!~*af  
break; ^.\O)K {h  
} jBOl:l,+  
} -f mJkI  
if(breakWhile) 9A} *  
break; G$MEVfd"  
i!e8-gVMP&  
{&mH fN  
//count++; 1O NkmVtL  
//if(count>4) ) y;7\-K0  
// siteStop(); ^Y%_{   
} u;-fG9xs  
$*iovam>^]  
,NS*`F[O  
System.err.println("文件下载结束!"); ^N|8 B?Vg  
} HOFxOBV  
catch(Exception e){e.printStackTrace ();} W_JO~P  
} ?SElJ? Z  
(BeJ,K7  
[i ~qVn2vT  
//获得文件长度 =(D"(OsQ/  
public long getFileSize() U|%}B(  
{ l[ $bn!_ e  
int nFileLength = -1; E KV[cq  
try{ 9tPRQ M7  
URL url = new URL(siteInfoBean.getSSiteURL()); /}m*|cG/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^zQI_ydG  
httpConnection.setRequestProperty("User-Agent","NetFox"); s{yw1:  
*1<kYrB  
5HV+7zU5  
int responseCode=httpConnection.getResponseCode(); cS9jGD92  
if(responseCode>=400) diY7<u#  
{ 9"]#.A^Q*  
processErrorCode(responseCode); ud$-A  
return -2; //-2 represent access is error  Q}L?o  
} O.(2  
5P-t{<]tx  
oIj=ba(n1  
String sHeader; 7<] EH:9  
A,cXN1V  
}ARA K^%  
for(int i=1;;i++) N8dxgh!,  
{ lt&(S)  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {}$7Bp  
//Utility.log(in.readLine()); w>&*-}XX  
sHeader=httpConnection.getHeaderFieldKey(i); 5FoZ$I  
if(sHeader!=null) Z,.Hz\y1D  
{ LZRg%3.E  
if(sHeader.equals("Content-Length")) Y"GNJtsL"  
{ 0 Uropam  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tbd=A]B-  
break; (?na|yd  
} |h\7Q1,1~2  
} AAevN3a#nI  
else V*uE83x 1  
break; E[]5Od5#  
} MYWkEv7  
} ,_Z(!| rW  
catch(IOException e){e.printStackTrace ();} H4w\e#|  
catch(Exception e){e.printStackTrace ();} 20;9XJmjl  
,yYcjs!=o  
FPDTw8" B;  
Utility.log(nFileLength); I+8n;I)]X  
YA4D?'  
j<B9$8x&  
return nFileLength; 7MKX`S  
} 69g{oo  
hy5[ L`B  
]%' AZ`8  
//保存下载信息(文件指针位置) AI-*5[w#A  
private void write_nPos() ~zqb{o^pT  
{ $ F2Uv\7=  
try{ _v,0"_"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); +xFn~b/  
output.writeInt(nStartPos.length); r7m~.M+W"  
for(int i=0;i<nStartPos.length;i++) *; Jb=  
{ 9zu;OK%  
// output.writeLong(nPos); P!eo#b^S  
output.writeLong(fileSplitterFetch.nStartPos); BzzC|  
output.writeLong(fileSplitterFetch.nEndPos); m\L`$=eO8  
} =RQF::[h  
output.close(); }aZuCe_  
} WAa45G  
catch(IOException e){e.printStackTrace ();} 95l)s],  
catch(Exception e){e.printStackTrace ();} B>,e HXW  
} )6OD@<r{  
T6U/}&{O  
i9;  
//读取保存的下载信息(文件指针位置) D}_.D=)  
private void read_nPos() `q^#u  
{ C= ~c`V5>r  
try{ `JySuP2~/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :<QknU}dwy  
int nCount = input.readInt(); "rv~I_zl  
nStartPos = new long[nCount]; |N.2iN:  
nEndPos = new long[nCount]; 8 #_pkVQw:  
for(int i=0;i<nStartPos.length;i++) A3jxjQ  
{ hyI7X7Hy  
nStartPos = input.readLong(); Bn}woyJdx  
nEndPos = input.readLong(); d54iZ`  
} "tJ+v*E  
input.close(); k# [!; <  
} Nu5|tf9%A  
catch(IOException e){e.printStackTrace ();} oz) [ -  
catch(Exception e){e.printStackTrace ();} ;J%:DD  
} $R9D L^iD  
NXW*{b  
50,'z?-_  
private void processErrorCode(int nErrorCode) K"#$",}=  
{ GEc6;uz<  
System.err.println("Error Code : " + nErrorCode); _D '(R  
} YvR bM  
AZj&;!}  
eV9U+]C`  
//停止文件下载 UcRP/LR%C  
public void siteStop() "#Rh\DQ  
{ ;tOs A #  
bStop = true; I2Xd"RHN  
for(int i=0;i<nStartPos.length;i++) g'"~'  
fileSplitterFetch.splitterStop(); }w0pi  
5ZCu6 A  
q+ax]=w  
} LEb$Fd  
} <kh.fu@.Q  
//负责部分文件的抓取 p~D}Iyww1_  
**FileSplitterFetch.java +|A`~\@N  
*/ Rh>B# \  
package NetFox; amBg<P`'_  
#:K=zV\  
T{{:p\<]_  
import java.io.*; +VIA@`4  
import java.net.*; o) )` "^  
XT7m3M  
K~W(ZmB  
public class FileSplitterFetch extends Thread { 9YzV48su#  
K-RmB4WI  
*2AD#yIKC  
String sURL; //File URL JEUU~L;  
long nStartPos; //File Snippet Start Position "{q#)N  
long nEndPos; //File Snippet End Position  a"Qf  
int nThreadID; //Thread's ID I)HO/i 6>3  
boolean bDownOver = false; //Downing is over "Q?+T:D8|  
boolean bStop = false; //Stop identical ' zyw-1  
FileAccessI fileAccessI = null; //File Access interface /%@;t@BK4  
Qqm?%7A1  
9+ 'i(q z  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %rwvY`\  
{  N' hT  
this.sURL = sURL; XKp&GE@Y  
this.nStartPos = nStart; JT+ c7W7  
this.nEndPos = nEnd; 7KC>?F  
nThreadID = id; AuNUW0/ 7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H0l1=y  
} EPm~@8@"j?  
l\<.*6r  
*22Vc2[i;  
public void run() (r|m&/  
{ nrac )W  
while(nStartPos < nEndPos && !bStop) <PLAAh8  
{ B[b>T=  
Wjb_H (D  
YT(N][V  
try{ $1f2'_`8~  
URL url = new URL(sURL); R%UTYRLUn  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection ();  -WC0W  
httpConnection.setRequestProperty("User-Agent","NetFox"); nFnM9 pdMK  
String sProperty = "bytes="+nStartPos+"-"; 4@9Pd &I  
httpConnection.setRequestProperty("RANGE",sProperty); $/wm k7T  
Utility.log(sProperty); *,\v|]fc  
I&-r^6Yx  
*HoRYCL  
InputStream input = httpConnection.getInputStream(); )/RG-L  
//logResponseHead(httpConnection); CG1MT(V7?  
1wFu3fh@  
C;W@OS-;  
byte[] b = new byte[1024]; M(X _I`\E  
int nRead; B;k'J:-"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) __=53]jGE  
{ ibkB>n{(  
nStartPos += fileAccessI.write(b,0,nRead); eiMP:  
//if(nThreadID == 1) Oeh A3$|#  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A`7(i'i5]  
} JK$3qUDnI  
:nx+(xgw  
>@vu;j\*E5  
Utility.log("Thread " + nThreadID + " is over!"); 4=Th<,<  
bDownOver = true; c p"K?)  
//nPos = fileAccessI.write (b,0,nRead); u)@:V)z  
} [)"\Aq  
catch(Exception e){e.printStackTrace ();} ~F"S]  
} Xm#W}Y'  
} \U:OQ.e  
+ktv : d  
:\^b6"}8  
//打印回应的头信息 DNGyEC  
public void logResponseHead(HttpURLConnection con) ?%,LZw^[  
{ T]th3*  
for(int i=1;;i++) Spn[:u@  
{ ]IV{;{E)  
String header=con.getHeaderFieldKey(i); JSL&` `  
if(header!=null) $;^|]/-  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FX!KX/OE)  
Utility.log(header+" : "+con.getHeaderField(header)); MG?,,8sO  
else #)'Iqaq7  
break; 505c(+  
} }O\IF}X  
} +La2-I  
}m+Q(2  
~Dt$}l-9  
public void splitterStop() (OiV IH  
{ riW9l6s'  
bStop = true; 3t-STk?  
} 4X^$"lM  
k A3K   
iq' PeVo  
} x,C8):\t`B  
a3 }V/MY  
]N 9N][n  
/* /?;'y,(Q  
**FileAccess.java |R.yuSL)(  
*//文件访问(定位,写) )K[\j?   
package NetFox; b-ss^UL  
import java.io.*; rd7p$e=i  
r;{$x  
BL&AZv/T  
public class FileAccessI implements Serializable{ ,lH }Ba02F  
5Npxs&Ea  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0`"oR3JY  
RandomAccessFile oSavedFile; \Y!#Y#c  
long nPos; @ujwN([I  
-J3~j kf  
\-yI dKj  
public FileAccessI() throws IOException *Z#OfB4}  
{ ,ayEZ#4.m  
this("",0); QF/ULW0G!  
} [mzed{p]]  
Rq|6d M6H  
# >k|^*\  
public FileAccessI(String sName,long nPos) throws IOException eA7 Iv{M  
{ !JXiTI!  
oSavedFile = new RandomAccessFile(sName,"rw"); ulxlh8=  
this.nPos = nPos; 1_t+lJI9j  
oSavedFile.seek(nPos); n~UI 47  
} X$5  
WO.u{vW]'  
q;,lv3I  
public synchronized int write(byte[] b,int nStart,int nLen) fHd[8{;P:  
{ ktrIi5B  
int n = -1; # ][i!9$  
try{ :EOai%i  
oSavedFile.write(b,nStart,nLen); \96\!7$@O  
n = nLen; xnMcxys~  
} ?JZ$M  
catch(IOException e) 1dLc/, |  
{ wPM&N@Pf  
e.printStackTrace (); Y'iI_cg  
} I(^0/]'  
cCZp6^/<x  
%g@?.YxjT  
return n; ~)f^y!PMQ  
} d#E&,^@M  
V<UChD)N`  
Kkp dcc  
} |^l_F1+w  
zhw*Bed<  
D<J'\mo  
/* SxY z)aF~  
**SiteInfoBean.java !}!KT(% %  
*/ R0=f`;  
package NetFox; G^Gs/- f  
.~o{i_JH  
@l CG)Ix<  
public class SiteInfoBean { Q("m*eMRt  
st) is4  
b23A&1X  
private String sSiteURL; //Site's URL P7-k!p"  
private String sFilePath; //Saved File's Path ATkd#k%S  
private String sFileName; //Saved File's Name I#MPJ@*WT  
private int nSplitter; //Count of Splited Downloading File %!\=$s}g  
:i!fPNn  
Ln# o:"E  
public SiteInfoBean() []A9j ?_w  
{//nSplitter的缺省值为5  [^ }$u[  
//default value of nSplitter is 5 xq;>||B  
this("","","",5); o:#jvi84F  
} E.*hY+kGZ  
zn>lF  
|X=p`iz1&  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {O>Td9  
{ }K)A jZ  
sSiteURL= sURL; N 8[r WJ#  
sFilePath = sPath; c= t4 gf  
sFileName = sName; us.[wp'Sh  
this.nSplitter = nSpiltter; |>(Vo@  
) ' xyK  
2-'_Nwkl*  
} ) r.Wge  
;:=j{,&dl[  
K ar!  
public String getSSiteURL() U1:m=!S;x  
{ q%G[tXw  
return sSiteURL; |y7TYjg6  
} 7D<Aa?cv_l  
m u9,vH  
P1OYS\  
public void setSSiteURL(String value) f1:>H.m`  
{ oL~1M=r  
sSiteURL = value; \Yj_U'2"i  
} $@6q5Iz!&  
#Tc`W_-  
R>"pJbS;L  
public String getSFilePath() J ?{sTj"KB  
{ ulALGzPh  
return sFilePath; F7<M{h5s  
} R7IFlQH%  
<&[`  +  
qf K gNZ  
public void setSFilePath(String value) cWnEp';.  
{ Pm P&Qje7  
sFilePath = value; NdJ]\>5oN,  
} |m\7/&@<  
#.u &2eyqQ  
)r"R  
public String getSFileName() F$i50s  
{ vV"YgN:  
return sFileName; .Od@i$E>&  
} R}(Rv3>Xx  
v"2A?  
Y|mtQ E?c  
public void setSFileName(String value) GF@` ~im  
{ ih("`//nP  
sFileName = value; lrPIXIM  
} nd\$Y  
s-6$C  
}cUO+)!Y  
public int getNSplitter()  uWMSn   
{ _$A?  
return nSplitter; BV<_1 WT}  
} w?_'sP{pd  
 ~9YEb  
= <A0;  
public void setNSplitter(int nCount) DQ$m@_/4w  
{ >8>s K(S]  
nSplitter = nCount; bOYM-\ {y  
} ]/p>p3@1C  
} +bso4 }rS  
c;KMox/  
tw 3zw`o:  
/* 2ETv H~23  
**Utility.java "KCG']DF  
*/ 3 q8S  
package NetFox; eF0FQlMe[  
D @wIbU  
v! DU ewz  
public class Utility { Nj?Q{ztS  
V~8]ag4  
HOPl0fY$L  
public Utility() lV./K;\T  
{ Rm_+kp@\  
@G>e Cj  
Dm?:j9o]g  
} N3Q .4? z9  
Ii3F|Vb G  
//线程睡眠 ]T40VGJ:h  
public static void sleep(int nSecond) B$OV^iwxK  
{ h0x'QiCc  
try{ i6FJG\d  
Thread.sleep(nSecond); $WRRCB/A6  
} x'G_z_<V  
catch(Exception e) r0OP !u  
{ r|z B?9Q  
e.printStackTrace (); S%?%06$  
} @5 ??`n  
} #l*w=D?  
aU.!+e%_  
//日志 k8+U0J_{'  
public static void log(String sMsg) benqm ~{\  
{ b'4}=Xpn  
System.err.println(sMsg); Y~r)WV!G  
} 9[ &q C  
V<}chLd,  
,l,q;]C%  
public static void log(int sMsg) iTT7<x  
{ =|fB":vk  
System.err.println(sMsg); fG8^|:  
} 7 > _vH]  
} t3v_o4`&  
Gy6x.GX  
|~v2~   
/* szqR1A  
**TestMethod.java %n,_^voE  
*/  zDxJK  
package NetFox;  e?o/H  
XQOM6$~,  
E2=vLI]  
public class TestMethod { #Hl?R5  
>C5u>@%9O  
V HLNJnA  
public TestMethod() kf95)iLo  
{ ///xx/weblogic60b2_win.exe JPZH%#E(  
try{ SoFl]^l  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !@arPN$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oykb8~u}}  
SiteFileFetch fileFetch = new SiteFileFetch(bean); JZ> (h  
fileFetch.start(); (*T$:/zI S  
} #oR@!?  
catch(Exception e){e.printStackTrace ();} l?xd3Z@7[  
rzvKvGd#N  
MlbcJo3  
} n7/&NiHxv/  
?O]RQXsZ2  
}YM[aq?6  
public static void main(String[] args) =<K6gC27  
{ [e{W:7uFV  
new TestMethod(); ;R@D  
} rz%^l1@-  
} >4+KEK  
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