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http断点续传简单实现(java)

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/* M(1cf(<+  
**SiteFileFetch.java :_|Xr'n`A  
*/ ojyP.R  
package NetFox; d&lT/S  
import java.io.*; S$=caZ?  
import java.net.*; J1w,;T\55  
seVT| z  
}.1}yz^y  
public class SiteFileFetch extends Thread { Ept=&mJPu  
%\L{Ud%7  
5+2qx)FZ  
SiteInfoBean siteInfoBean = null; //文件信息Bean :F_>`{  
long[] nStartPos; //开始位置 '~VF*i^4  
long[] nEndPos; //结束位置 rZ&li/Z  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 WRrg5&._q  
long nFileLength; //文件长度 hC4 M}(XM  
boolean bFirst = true; //是否第一次取文件 nRyx2\Py+  
boolean bStop = false; //停止标志 yeam-8  
File tmpFile; //文件下载的临时信息 ,Jx.Kj.,  
DataOutputStream output; //输出到文件的输出流 Pk;1q?tGw  
w"O{@2B3:H  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ^{YK'60  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1vYa&!  
{ N cp   
siteInfoBean = bean; Yx&d\/9  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); a ?\:,5=  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); H43d[@h  
if(tmpFile.exists ()) Z<*"sFpAO  
{ /9,y+"0SQz  
bFirst = false; gnYo/q=K  
read_nPos(); MEu{'[C  
} ~iPXn1  
else T7|=`~  
{ E#Ol{6  
nStartPos = new long[bean.getNSplitter()]; Y$#6%`*#>n  
nEndPos = new long[bean.getNSplitter()]; p,tkVedR  
} \E'z+0  
9 e|[9  
] &SmeTe  
}:Y)DH% u  
} yMD3h$w3a  
CM6! 1 7  
[{>3"XJ'  
public void run() ;U3K@_  
{ 1p$*N  
//获得文件长度 /l+"aKW 2  
//分割文件 :2V|(:^ '  
//实例FileSplitterFetch 1,7 }ah_  
//启动FileSplitterFetch线程 <rvM)EJv|  
//等待子线程返回 I%b5a`7  
try{ MdFFt:y:  
if(bFirst) b`JS&E  
{ v4K! BW  
nFileLength = getFileSize(); WM%w_,Z  
if(nFileLength == -1) Dk&(QajL  
{ ~pHuh#>  
System.err.println("File Length is not known!"); h/2@4XKj  
} eFotV.T!#  
else if(nFileLength == -2)  F&lH5  
{ @NL37C  
System.err.println("File is not access!"); 1!yd(p=cL  
} xLms|jS  
else Xpv<v[a  
{ -zWNQp$  
for(int i=0;i<nStartPos.length;i++) $$SJLV  
{ J*_^~t  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 4l>U13~#  
} Z|fi$2k0!  
for(int i=0;i<nEndPos.length-1;i++) 4TyzD%pOw  
{ {?q`9[Z  
nEndPos = nStartPos[i+1]; ^/cqE[V~,  
} .V\~#Ro$G  
nEndPos[nEndPos.length-1] = nFileLength; hi4-Z=pl  
} &M tF  
} [mj=m?j  
cB_9@0r[S  
J@QOF+&  
//启动子线程 DliDBArxZ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WYP\J1sy  
for(int i=0;i<nStartPos.length;i++) s>1\bio*I  
{ `GlOl-  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !? H:?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !1K.HdK  
nStartPos,nEndPos,i); 5j\Kej  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  E(wS6  
fileSplitterFetch.start(); H=w6  
} LK!sk5/  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Efoy]6P\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TU;AO%5  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _yF@k~ h  
nEndPos = " + nFileLength); 9I`0`o"A  
// fileSplitterFetch[nPos.length-1].start(); `gF`Sgz  
<f=<r*6  
O3)B]!xL  
//等待子线程结束 hsJ^Au=})w  
//int count = 0; rP,|  
//是否结束while循环 [P0c,97_ H  
boolean breakWhile = false; 0l/7JH_@V  
? * r  
EQk omjv  
while(!bStop) -0BxZ AW=  
{ wWSw0 H/  
write_nPos(); a8v\H8@X  
Utility.sleep(500); xA<-'8ST  
breakWhile = true; kM@e_YtpY  
h~qv_)F_  
[w-Tf&  
for(int i=0;i<nStartPos.length;i++) \}%_FnP0ZU  
{ I2pE}6q  
if(!fileSplitterFetch.bDownOver) >o%X;U 3  
{ vbX.0f "n  
breakWhile = false; p!)PbSw#  
break; P)XR9&o':  
} S4c-i2Rq  
} :4x6dYNU  
if(breakWhile) u\/TR#b  
break; L@jpid95  
mM2I  
ZoYllk   
//count++; w~+\Mfz  
//if(count>4) MmU`i ,z  
// siteStop(); WnU2.:  
} ,Z :2ba  
eD3\>Y.z  
mkPqxzxbrL  
System.err.println("文件下载结束!"); MiKq|  
} M= |is*t  
catch(Exception e){e.printStackTrace ();} ]Nw ]po+  
} m5a'Vs  
O/$41mK+!  
 >|gXE>  
//获得文件长度 O2yD{i#l*#  
public long getFileSize() IP-M)_I  
{ NPFI^Uj#A  
int nFileLength = -1; U3-MvI,Q  
try{ 9i lJ  
URL url = new URL(siteInfoBean.getSSiteURL()); N})vrB;1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I 9?X  
httpConnection.setRequestProperty("User-Agent","NetFox"); $ %|b6Gr/&  
[Jjo H1E@  
T00sYoK  
int responseCode=httpConnection.getResponseCode(); ~IPATG  
if(responseCode>=400) {X<_Y<  
{ ;Jb% 2?+=!  
processErrorCode(responseCode); MtgY `p  
return -2; //-2 represent access is error 2P${5WT  
} .wTb/x  
1}SON4U  
k_Sm ep  
String sHeader; :oYSvK7>  
3q@H8%jcw  
Xr4k]'Mg  
for(int i=1;;i++) s jaaZx1  
{ <lU(9) L;&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R#?atL$(  
//Utility.log(in.readLine()); LaZ @4/z!  
sHeader=httpConnection.getHeaderFieldKey(i); DHyQ:0q  
if(sHeader!=null) T-lP=KF=  
{ ;9-J=@KY4  
if(sHeader.equals("Content-Length")) BZKg:;9  
{ jq_4x[  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jeO`45O  
break; n=0^8QQ  
} u-bgk(u  
} ,J<+Wxz  
else w@YPG{"j  
break; 3h%Nd &_9  
} /QCg E ~  
} YguW2R=6]  
catch(IOException e){e.printStackTrace ();} FPZ@6  
catch(Exception e){e.printStackTrace ();} cRCji^,KJ  
"(~fl<;  
OwgPgrV  
Utility.log(nFileLength); D vN0h(?  
m]'+Eye ]r  
ep`8LQf  
return nFileLength; _5p]Arg?}&  
} _ 5b~3K/V  
$]W*;MTI}  
&uV|Ie8@q  
//保存下载信息(文件指针位置) J-G)mvkv  
private void write_nPos() cg_tJ^vrY  
{ Qw_> l}k/  
try{ ;NAKU  
output = new DataOutputStream(new FileOutputStream(tmpFile)); o/vD]Fs  
output.writeInt(nStartPos.length); P]2 /}\f  
for(int i=0;i<nStartPos.length;i++) aW;)-0+  
{ )(1tDQ`L>  
// output.writeLong(nPos);  n$>_2v  
output.writeLong(fileSplitterFetch.nStartPos); "]=XB0)  
output.writeLong(fileSplitterFetch.nEndPos); R!\._m?\h  
} kFT*So`'  
output.close(); zxd<Cq>d  
} unnuSW#v=  
catch(IOException e){e.printStackTrace ();} vDR> Q&/K  
catch(Exception e){e.printStackTrace ();} p]toDy-}  
} B{S^t\T$  
|TJu|zv^  
nDLiER;U  
//读取保存的下载信息(文件指针位置) %x}Unk  
private void read_nPos() jH;L7  
{ 8u"C7} N_  
try{ x #|t#N%  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5g'aNkF6>  
int nCount = input.readInt();  (tT%rj!  
nStartPos = new long[nCount]; w*(1qUF#%  
nEndPos = new long[nCount]; ,wHlU-%  
for(int i=0;i<nStartPos.length;i++) Ly1t'{"7  
{ bIk4?S  
nStartPos = input.readLong(); M?n}{0E4  
nEndPos = input.readLong(); mM+^v[=  
} .\)ek[?  
input.close(); S3QX{5t\  
} BHNJH  
catch(IOException e){e.printStackTrace ();} {n<1uh9~$8  
catch(Exception e){e.printStackTrace ();} U D5hk  
} |h((SreO  
*Ct ^jU7  
P`_Q-vu  
private void processErrorCode(int nErrorCode) a +9_sUq  
{ \!0~$?_)P  
System.err.println("Error Code : " + nErrorCode); wLg@BSC.  
} Y]B9*^d<  
q'Y)Y(d  
u=#_8e(9Z  
//停止文件下载 Cs,t:ajP  
public void siteStop()  z}*L*Sk  
{ mhs%8OTN  
bStop = true; u2U+uD@yA  
for(int i=0;i<nStartPos.length;i++) wNh\pWA  
fileSplitterFetch.splitterStop(); ? fM_Y  
 .g=D70  
=;?Maexp3$  
} x51xY$M  
} H4M`^r@)'  
//负责部分文件的抓取 <#T #+uO  
**FileSplitterFetch.java #,!/Cnqis  
*/ !Pd)  
package NetFox; u 1Wixjd|  
H~0B5Hl!F  
t-]~^s  
import java.io.*; gA2]kZg  
import java.net.*; )Oj{x0{\Q  
sX`by\s,  
|~Vq"6`  
public class FileSplitterFetch extends Thread { &iJvkt  
!4$o*{9Lx:  
"T>;wyGW  
String sURL; //File URL }\W^$e-  
long nStartPos; //File Snippet Start Position 0F &(}`V  
long nEndPos; //File Snippet End Position `2HNQiK'@  
int nThreadID; //Thread's ID <*ME&c gh4  
boolean bDownOver = false; //Downing is over DM(c :+K-  
boolean bStop = false; //Stop identical ^X:g C9  
FileAccessI fileAccessI = null; //File Access interface sHSg _/|  
bHz H0v]:  
cNl$ vP83z  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -e*(+  
{ - KaU@t  
this.sURL = sURL; cA!o xti  
this.nStartPos = nStart; ovvg"/>L  
this.nEndPos = nEnd; 7X.B  
nThreadID = id; V?jot<|$  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o& ?:pE  
} l<s6Uu"  
<VT|R~  
]Lm?3$u$  
public void run() ( D@ U%  
{ Qf}}/k|)k  
while(nStartPos < nEndPos && !bStop) TM,Fab &  
{ g6.Tx]?b$  
(.g?|c  
GVM)-Dp]  
try{ FyllVrK  
URL url = new URL(sURL); }eLth0d`'o  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 73+)> "x>  
httpConnection.setRequestProperty("User-Agent","NetFox"); r}#,@<  
String sProperty = "bytes="+nStartPos+"-"; $~1~+s0$  
httpConnection.setRequestProperty("RANGE",sProperty); e:n3@T,R  
Utility.log(sProperty);  U%tpNWB  
N8m3 Wy  
&2pa9i  
InputStream input = httpConnection.getInputStream(); cN]g^  
//logResponseHead(httpConnection); kfkcaj4l]  
z'k@$@:0XD  
{6;S= 9E\  
byte[] b = new byte[1024]; oJ0ZZu?{D  
int nRead; mX@!O[f%9e  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bN>|4hS  
{ hoZM;wC  
nStartPos += fileAccessI.write(b,0,nRead); 5?Rzyfwk|  
//if(nThreadID == 1) V<t!gT#&o!  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SD1M`PI  
} jg(cpo d  
+J2;6t  
T<u QhPMw  
Utility.log("Thread " + nThreadID + " is over!"); 1u_< 1X3  
bDownOver = true; "pQ) 5/e  
//nPos = fileAccessI.write (b,0,nRead); F{ sPQf'  
} dpB\=  
catch(Exception e){e.printStackTrace ();} `& ]H`KNa  
} OUtMel_  
} ~s) `y2Y  
<USr$  
z_t%n<OvK  
//打印回应的头信息 <io;d$=}  
public void logResponseHead(HttpURLConnection con) e]3b0`E  
{ c+G%o8  
for(int i=1;;i++) sN@=Ri?\  
{ ko`KAU<T_  
String header=con.getHeaderFieldKey(i); SfGl*2  
if(header!=null) ?w>-ya  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /jd.<r=_I  
Utility.log(header+" : "+con.getHeaderField(header)); 4cJka~  
else 'a=QCO 0  
break; e!1am%aE  
} !sh>`AF  
} ,h* 'Cs04h  
70T{tB  
Q>l5:2lq  
public void splitterStop() G"F:68  
{ N/r8joi#  
bStop = true; aQL$?,  
} ^7V{nT@H3  
M1e79p<  
ZKoISuM  
} 5>S)+p  
Jm]P,jaLc  
ECLQqjB  
/* JnXVI!+JDL  
**FileAccess.java "Rr650w[  
*//文件访问(定位,写) 'E kuCL  
package NetFox; >1NE6T  
import java.io.*; 1p COLC%1  
}\ hz@G<  
fwz-)?   
public class FileAccessI implements Serializable{ A%% Vyz  
ZRj&k9D^U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Pfl8x  
RandomAccessFile oSavedFile; ,g{Ob{qT  
long nPos; 75*q^ui  
G q2@37U  
i'uSu8$'*  
public FileAccessI() throws IOException 0z`-fQfK  
{ ^(T_rEp  
this("",0); ;;7: l,vy  
} d\j[O9W>  
Tu_4kUCR!f  
^y<8 &ZFH  
public FileAccessI(String sName,long nPos) throws IOException 6"u"B-cz  
{ ,?`Zrxe[  
oSavedFile = new RandomAccessFile(sName,"rw"); 3s$vaV~(a  
this.nPos = nPos; 9<-7AN}Z  
oSavedFile.seek(nPos); L3'$"L.|u  
} +`'>   
3 cF4xUIZ  
!A&>Eeai  
public synchronized int write(byte[] b,int nStart,int nLen) T6I$7F  
{ raB', Vp  
int n = -1; +`l)W`zX  
try{ V D.T=(  
oSavedFile.write(b,nStart,nLen); aW;DfH  
n = nLen; N 2$uw@s  
} %O\zYtQR  
catch(IOException e) \??20iz  
{ ^/DP%^D  
e.printStackTrace (); $Lt'xW`8  
} p{oc}dWin  
LV`tnt's  
4s7&*dJ  
return n; u/(~ew I  
} &^(4yw(~  
X@H/"B%u2  
`tEW.s%Y(6  
} ?[c{pb ,|  
F$te5 ` a  
2dJP|T9H  
/* 7L$\S[E  
**SiteInfoBean.java \,-e>  
*/ v&8s>~i`K  
package NetFox; n+SHkrW  
 -wQ@z6R  
nIf~ds&TT  
public class SiteInfoBean { ANq3r(  
GtpBd40"  
-X_dY>>s  
private String sSiteURL; //Site's URL 9|qzFmE#  
private String sFilePath; //Saved File's Path rIQ%X`Y  
private String sFileName; //Saved File's Name *dPG[ }  
private int nSplitter; //Count of Splited Downloading File QHgkfo  
(e _l1O?  
^!*nhs%  
public SiteInfoBean() 8\Kpc;zb  
{//nSplitter的缺省值为5 n'qWS/0U=  
//default value of nSplitter is 5 BKk+<#Ti  
this("","","",5); vX<^x2~9(  
} G?<uw RV  
,j e  
f:KZP;/[c  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aXh~w<5F  
{ )8*}-z  
sSiteURL= sURL; \"1%>O*  
sFilePath = sPath; @cu#rWiG  
sFileName = sName; \/F*JPhy  
this.nSplitter = nSpiltter; XWag+K  
L*(`c cU  
G|.6%-  
} #&K?N  
Ox9M![fC  
UOn:@Qn  
public String getSSiteURL() e3,@prr  
{ n<e1=L  
return sSiteURL; mKuY=#RP  
} <ZjT4><  
Hd57Iw  
@Io@1[kj  
public void setSSiteURL(String value) '9@AhiNV  
{ /Csk"IfuO  
sSiteURL = value; S9%ZeM +  
} @K1'Q!S *  
/B)`pF.n  
YT}ZLx  
public String getSFilePath() ToM1#]4  
{ g9@H4y6fe=  
return sFilePath; pch8A0JAl)  
} <kKuis6h  
pMd!Jl#(N  
X"g`hT"i  
public void setSFilePath(String value) r7-H`%.  
{ }h1y^fuGi  
sFilePath = value; -8:/My  
} C2H2*"  
W#kd[Wi  
@]7s`?  
public String getSFileName() $g_|U:,  
{ %\T#Ik~3  
return sFileName; m\G45%m  
} *R3^:Y&  
1|:'jK#gE  
/<1zzeHRSD  
public void setSFileName(String value) +h@ZnFp3  
{ oc;4;A-;`c  
sFileName = value; DdqE6qE  
} lQ&J2H<w  
&Gs/#2XQ  
~rlPS#]o  
public int getNSplitter() !GnwE  
{ g[ N3jt@  
return nSplitter; TjicltQi4  
} X}g"_wN,g>  
z&yVU<;  
Mh]4K" cs  
public void setNSplitter(int nCount) j937tn!Q  
{ .f&Z+MQ  
nSplitter = nCount; Hi nJ}MF  
} T&'LQZM8  
} CbFO9q  
jHk.]4&0  
sKC(xO@L;`  
/* i,,mt_/,  
**Utility.java P"+R:O\!g  
*/ XZT|ID_u"  
package NetFox; O Ke 9/._  
JqV}$E"M2  
<[vsGUbc  
public class Utility { f`YHZ O  
49= K]X  
(t5vBUj  
public Utility() E Q]>^VE2B  
{ j\iNag(   
ySHpN>U  
^O<@I  
} Y>x3`f]  
a]!u go}  
//线程睡眠 JA% y{Wb  
public static void sleep(int nSecond) 08/Tk+  
{ B.L_EIw  
try{ poy_?7G  
Thread.sleep(nSecond); ZEs^b  
} m -0}Pe9L  
catch(Exception e) mQ3gp&d3W  
{ 5w5"rcV  
e.printStackTrace (); 0E9 lv"3o  
} ,/Q`gRBh"  
} hqa6aYY x  
<5zr|BTF]F  
//日志 Zt}b}Bz  
public static void log(String sMsg) -$I$zo  
{ EAHdt=8W{  
System.err.println(sMsg); OZ/"W)  
} H(kxRPH4@]  
=.l>Uw!  
mR~S$6cc  
public static void log(int sMsg) JFq<sY!  
{ >7z(?nQYT^  
System.err.println(sMsg); *ZIX76y<!A  
} iD/+#UTY  
} |h6, .#n  
vhzz(UPUt  
h+}{FB 29  
/*  Q.Y6  
**TestMethod.java w$j6!z  
*/ _&[-< cu  
package NetFox; !Ej?9LHo  
[LrO"9q(  
zb s7G  
public class TestMethod { VVfTFi<  
y5XFJj  
^4xl4nbx  
public TestMethod() U+aiH U9  
{ ///xx/weblogic60b2_win.exe &{q<  
try{ t"OP*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _+Z5qUmQ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !wC( ]Y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); /T 2 v`Li  
fileFetch.start(); ExF6y#Y G<  
} >8&fFq  
catch(Exception e){e.printStackTrace ();} N*\r i0  
l;@bs  
kx;7/fH  
} Q_dMuoI  
HkY#i;%N  
i-. AD4  
public static void main(String[] args) 2b Fr8FUt-  
{ VxE;tJ>1  
new TestMethod(); [fY7|  
} k1SD{BL  
} ?)Je%H  
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