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http断点续传简单实现(java)

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/* }uR[H2D`L  
**SiteFileFetch.java c!0u,6  
*/ +}VaQ8ti4  
package NetFox; OCW0$V6;D-  
import java.io.*; Ah 2*7@U  
import java.net.*; tq$L* ++O  
S4 j5-  
DplS\}='s  
public class SiteFileFetch extends Thread { [x%[N)U3  
f`<elWgc"  
2x5^kN7  
SiteInfoBean siteInfoBean = null; //文件信息Bean ,Iv eKk5W  
long[] nStartPos; //开始位置 ~ k"r  
long[] nEndPos; //结束位置 ^yLhL^Y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ^/~ZP?%]  
long nFileLength; //文件长度 dvAG}<  
boolean bFirst = true; //是否第一次取文件 0 i'bo*  
boolean bStop = false; //停止标志 @vZeye  
File tmpFile; //文件下载的临时信息 q\pI&B  
DataOutputStream output; //输出到文件的输出流 6b2Z}B  
vmzc0J+3p  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) YjCHKI"e  
public SiteFileFetch(SiteInfoBean bean) throws IOException q@Aw]Kh  
{ o;TS69|D  
siteInfoBean = bean; VQ"Z3L3-4  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); !n7'TM '  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?kIyo  
if(tmpFile.exists ()) "hmLe(jo}  
{ Wu~cy}\  
bFirst = false; K<rv|bJ  
read_nPos(); ;A6%YY  
} $-)T  
else @ D,]v:  
{ f@@7?5fW  
nStartPos = new long[bean.getNSplitter()]; % }IrZrh  
nEndPos = new long[bean.getNSplitter()]; <Hf3AB;#4  
} G{.[o6>  
c>Tf@A og>  
UY6aD~tD0  
2U|"]tpM&  
} f\;w(_  
Z=9<esx  
nR]*RIp5  
public void run() wrQ0 2?  
{ 1oc@]0n  
//获得文件长度 J@o_-\@  
//分割文件 \ 5.nr*5  
//实例FileSplitterFetch )n6,uTlOw  
//启动FileSplitterFetch线程 h2-v.Tjf  
//等待子线程返回 }_Ci3|G>%D  
try{ 7qSnP 30}  
if(bFirst) Sse%~:FL  
{ 7@&mGUALO  
nFileLength = getFileSize(); g`z;:ao  
if(nFileLength == -1) E~@&&d U8  
{ 2qdc$I&$  
System.err.println("File Length is not known!"); `?{6L#  
} &MZ{B/;;H  
else if(nFileLength == -2) 4bCA"QM[[  
{ CcTdLq  
System.err.println("File is not access!"); %+htA0aX  
} ]=o1to-  
else `Ez8!d{MD8  
{ Hu9nJ  
for(int i=0;i<nStartPos.length;i++) <0VC`+p<)  
{ xw}rFY $  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ch2m Ei(  
} +DG-MM%\  
for(int i=0;i<nEndPos.length-1;i++) `_f&T}]  
{ mGDy3R90  
nEndPos = nStartPos[i+1]; 8.G<+.  
} `$Um  
nEndPos[nEndPos.length-1] = nFileLength; [+d~He  
} 4{Q$^wD+.  
} ;m7~!m)  
?0'e_s  
*LMzq9n3o  
//启动子线程 \2!.  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k`#E#1niN  
for(int i=0;i<nStartPos.length;i++) |$;4/cKfy  
{ _&(L{cFx6  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T6b~uE  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F Uz1P  
nStartPos,nEndPos,i); 6 .9C 4  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d~MY z6"  
fileSplitterFetch.start(); |"PS e~ u  
} GSs?!BIC  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q:nUn?zB  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3ZC@q #R A  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,Ne9x\F  
nEndPos = " + nFileLength); (t){o> l  
// fileSplitterFetch[nPos.length-1].start(); !rs }83w!  
_M&n~ r  
M,W-,l ]  
//等待子线程结束 rizjH+  
//int count = 0; ]#[4eaCg  
//是否结束while循环 |)xWQ KzA  
boolean breakWhile = false; E2 FnC}#W  
o~9sO=-O  
7IFZK\V  
while(!bStop) Y}xM&%  
{ 7NT0]j(w-  
write_nPos(); MLlvsa0  
Utility.sleep(500); V FM!K$_  
breakWhile = true; |Eh2#K0x4G  
~Ad2L*5S  
!4`:(G59  
for(int i=0;i<nStartPos.length;i++) }z#M!~  
{ @-L\c>rqT  
if(!fileSplitterFetch.bDownOver) q sUBvq  
{ w#hg_RK(Jr  
breakWhile = false; Niu |M@  
break; N p*T[J  
} vz#-uw,O:  
} .%dGSDru  
if(breakWhile) pacD7'1{  
break; Pr>05lg  
5Ok3y|cEx  
x4PzP  
//count++; ]%I\FefT  
//if(count>4) #?+[|RS|  
// siteStop(); FZ}^)u}o  
} N34-z|"q  
4DDBf j  
u  Fw1%  
System.err.println("文件下载结束!"); XZ{rKf2  
} ev0>j4Q  
catch(Exception e){e.printStackTrace ();} 8ki3>"!A  
} mR|5$1[b  
 0Gc:+c7{  
YM#MfL#  
//获得文件长度 qou\4YZ  
public long getFileSize() ]'?Ue7  
{ #AP;GoIf"j  
int nFileLength = -1; Z m%,L$F*L  
try{ OiXO<1'$  
URL url = new URL(siteInfoBean.getSSiteURL()); .gGO+8[N*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7QnWw0  
httpConnection.setRequestProperty("User-Agent","NetFox"); oH&@F@r:+  
eub}+~_?[  
[mQ1r*[j  
int responseCode=httpConnection.getResponseCode(); aeI0;u  
if(responseCode>=400) \2=I//YF  
{ 0:71Xm  
processErrorCode(responseCode); 0:n"A,-p  
return -2; //-2 represent access is error &;pM<h  
} ?% 8%1d  
 *U6+b  
;du},>T$n  
String sHeader; {$Uj&/IC  
F-b]>3r  
&o7PB` (l  
for(int i=1;;i++) Q\}-MiI/  
{ SrB>_0**  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s3m \  
//Utility.log(in.readLine()); |c8\alw  
sHeader=httpConnection.getHeaderFieldKey(i); us~cIGm  
if(sHeader!=null) rM,f7hm[S*  
{ '(C+qwdRv  
if(sHeader.equals("Content-Length")) AX%}ip[PC  
{ Y>/_A%vQU  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x7<NaMK\  
break; AG}j'   
}  oJ*,a  
} ` L 1+j  
else ! [1aP,  
break; R&6@*Nn  
} /O.Ql ,6[  
} )+'=Zvgej=  
catch(IOException e){e.printStackTrace ();} [<{r~YFjWW  
catch(Exception e){e.printStackTrace ();} JFO,Q -y\  
1fsNQ!vQP  
#]5KWXC'~  
Utility.log(nFileLength); q2J |koT  
N>YSXh`W`y  
/n(0w`   
return nFileLength; `p9N| V  
} #:N#i  
[;7zg@Sa  
C|Y[T{g?t  
//保存下载信息(文件指针位置) nA_'j l  
private void write_nPos() X<.l(9$  
{ %XeN_ V  
try{ .)+c01  
output = new DataOutputStream(new FileOutputStream(tmpFile)); {4A,&pR  
output.writeInt(nStartPos.length); gED|2%BXb  
for(int i=0;i<nStartPos.length;i++) G/FDD{y  
{ uq-`1m }  
// output.writeLong(nPos); CJCxL\  
output.writeLong(fileSplitterFetch.nStartPos); `JDZR:bMaT  
output.writeLong(fileSplitterFetch.nEndPos); ZiQ<SSo:  
} ?!jJxhK<h  
output.close(); Yq51+\d  
} IO9|o!&>  
catch(IOException e){e.printStackTrace ();} :L+ xEL  
catch(Exception e){e.printStackTrace ();} Rc{R^5B  
} D iOd!8Y  
GVA%iE.  
z9OpMA  
//读取保存的下载信息(文件指针位置) w' J`$=  
private void read_nPos() &n_f.oUc  
{ p&V64L:V  
try{ 4G' E< ab  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \b $pH  
int nCount = input.readInt(); Ssz;d&93  
nStartPos = new long[nCount]; "P@ SR`v#  
nEndPos = new long[nCount]; YaSBIq{z  
for(int i=0;i<nStartPos.length;i++) bo90;7EK8  
{ xR%NiYNQz  
nStartPos = input.readLong(); 2[3t7C  
nEndPos = input.readLong(); ps:`rVQ7  
} 13Z,;YW  
input.close(); d7G@Z|R3p  
} #k)z5vZ$h  
catch(IOException e){e.printStackTrace ();} P2f^]z  
catch(Exception e){e.printStackTrace ();} hp/pm6  
} pO7OP"q1  
Z}0xK6  
gsEcvkj*  
private void processErrorCode(int nErrorCode) LFxk.-{=  
{ \+sa[jK  
System.err.println("Error Code : " + nErrorCode); ;A@DE@^5w  
} F.aG7  
M_UmnqN1C  
bri8o"  
//停止文件下载 *A8*FX>\F  
public void siteStop() &}Wi@;G]2  
{ 9M7P|Q  
bStop = true; 7- LjBlH  
for(int i=0;i<nStartPos.length;i++) MG.c`t/w  
fileSplitterFetch.splitterStop(); R!"|~OO  
,9jk<)m]L  
fV Y I  
} 6pS}\aD  
} Q <D_QJ  
//负责部分文件的抓取 wGT>Xh!  
**FileSplitterFetch.java gt.F[q3  
*/ ;>6~}lMgJ  
package NetFox; O.QR1  
`W@jo~ y<  
L-}Uj^yF  
import java.io.*; pGR3  
import java.net.*; 3b0|7@_E  
ohx$;j  
|4pl}:g/Z  
public class FileSplitterFetch extends Thread { ?qSwV.l]d  
2bw) , W  
xSM1b5=Pu  
String sURL; //File URL nj;3U^  
long nStartPos; //File Snippet Start Position 'a JE+  
long nEndPos; //File Snippet End Position c;"e&tW  
int nThreadID; //Thread's ID KFO K%vbM  
boolean bDownOver = false; //Downing is over <Fx%P:d  
boolean bStop = false; //Stop identical W<#!He  
FileAccessI fileAccessI = null; //File Access interface <XDnAv0t  
:NWIUN  
/*BU5  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GT] >  
{ oxeu%wj_  
this.sURL = sURL; AhA&=l i;  
this.nStartPos = nStart; +HUy,@^ Pa  
this.nEndPos = nEnd; B/@LE{qUn  
nThreadID = id; KGc.YUoE  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u1UCe  
} >jmHe^rH  
-R]~kGa6m<  
H? z~V-8  
public void run() 1twpOZ>  
{ ']\SX*z?  
while(nStartPos < nEndPos && !bStop) 0',buJncV  
{ "?aI  
4\|Q;@f  
d(V4;8a0  
try{ Bnk<e  
URL url = new URL(sURL); <Rn-B).3bs  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V0 Z8VqV  
httpConnection.setRequestProperty("User-Agent","NetFox"); (j@c946z""  
String sProperty = "bytes="+nStartPos+"-"; Z+6WG  
httpConnection.setRequestProperty("RANGE",sProperty); 5HHf3E [  
Utility.log(sProperty); (=WYi~2v  
F|m &n&  
YCb|eS^u  
InputStream input = httpConnection.getInputStream(); =Gzs+6A8  
//logResponseHead(httpConnection); S~fP$L5  
[tt{wl"E  
??.aLeF&  
byte[] b = new byte[1024]; 8`)* ?Q9~  
int nRead; k+"7hf=C|  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w nQy   
{ W,yLGz\  
nStartPos += fileAccessI.write(b,0,nRead); C<T6l'S{?  
//if(nThreadID == 1) LdOme [C1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *! :j$n;  
} jwLZC  
zx]r.V  
9a]o?>`E  
Utility.log("Thread " + nThreadID + " is over!"); ,aS+RJNM  
bDownOver = true; 1c]{rO=taN  
//nPos = fileAccessI.write (b,0,nRead); u]O}Ub`  
} GKF!GbGR@  
catch(Exception e){e.printStackTrace ();} 8O{V#aop  
} 9__Q-J  
} p8-$MF]] 6  
K$}K2w  
$?z} yx$  
//打印回应的头信息 +'93%/:  
public void logResponseHead(HttpURLConnection con) YG= :lf  
{ ZWS:-]P.  
for(int i=1;;i++) - uO(qUa#  
{ *6AqRE  
String header=con.getHeaderFieldKey(i); L ..  
if(header!=null) ~J~R.r/  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?F$#t6Q  
Utility.log(header+" : "+con.getHeaderField(header)); Ho*B<#&(A|  
else -Q<OSa='  
break; -!5l4  
} MxX)&327  
} kiyKL:6D|  
#Q["[}flVv  
"O$WfpKX  
public void splitterStop() OIw[sum2  
{ bw/mF5AsW  
bStop = true; a[j]fv*6  
} gn.)_  
9$9a BW  
c'VCCXe  
} $>_`.*I/  
BT0;I  
Uj 4HVd  
/* 1uKIO{d @  
**FileAccess.java FwB xag:u  
*//文件访问(定位,写) <v_Wh@m  
package NetFox; CXz9bhn<4  
import java.io.*; FcZ)^RQ4G  
reYIF*  
@C[p?ak  
public class FileAccessI implements Serializable{ OKau3T]  
d^tY?*n  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ' i5}`\  
RandomAccessFile oSavedFile; bcu Uej:  
long nPos; VFnxj52<  
C{t}q*fG 5  
Oi~Dio_?  
public FileAccessI() throws IOException G[>CBh5  
{ (yuOY/~k/  
this("",0); |cuKC \  
} @~7au9.V=X  
L_:~{jV  
$ Fc}K+  
public FileAccessI(String sName,long nPos) throws IOException G#NbLj`h  
{ Q (gA:aQ  
oSavedFile = new RandomAccessFile(sName,"rw"); 7iv g3*  
this.nPos = nPos; ER&\2,fZ  
oSavedFile.seek(nPos); Ji=`XsV  
} mrKIiaU<J  
${ DSH  
k'e1ZAn  
public synchronized int write(byte[] b,int nStart,int nLen) #^|2PFh5  
{ 8~.8"gQ  
int n = -1; |7Z}#eP//  
try{ IvQuxs&a  
oSavedFile.write(b,nStart,nLen); qyy .&+  
n = nLen; {A ,w%  
} -cn`D2RP  
catch(IOException e) {H9g&pfv  
{ '?NMQ  
e.printStackTrace (); , .=7{y~  
} 2p 7;v7)y  
f` -vnh^+  
e iH&<AH  
return n; ' < >Q20  
} I'n}6D.M  
U_Mag(^-  
vGJw/ij'X  
} E"/k"1@  
ZtGk Md$  
B 'd@ms  
/* bng/v  
**SiteInfoBean.java &:g1*+  
*/ l;aO"_E1m  
package NetFox; )N3/;U;  
r t)[}+ox  
sUxEm}z  
public class SiteInfoBean { 0oi.k;  
QJx<1#  
#!yX2lR  
private String sSiteURL; //Site's URL .p'McCV=  
private String sFilePath; //Saved File's Path [;D1O;c'W.  
private String sFileName; //Saved File's Name W_/$H_04+  
private int nSplitter; //Count of Splited Downloading File hQ L@q7tUr  
+zo\#8*0MF  
4@ny%_/  
public SiteInfoBean() J=O_nup6C  
{//nSplitter的缺省值为5 `tKs|GQf  
//default value of nSplitter is 5 ^foCcO  
this("","","",5); DI-CC[  
} I>-1kFma;  
.ubZ  
pf yJL?_%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 81I9xqvSd~  
{ Ib/e\+H\  
sSiteURL= sURL; *'{9(Oj  
sFilePath = sPath;  aqi]5,  
sFileName = sName; 3_i29ghv  
this.nSplitter = nSpiltter; &wkb r2P  
(Nf!E[ }Z  
wYv++< z  
} %(\et%[]  
K}whqe]j  
Rp_}_hL0  
public String getSSiteURL() 0Uk;&a0s  
{ l u{6  
return sSiteURL; M4d4b  
} :V)=/mR  
):L0{W{  
(J(SwL|  
public void setSSiteURL(String value) K[9P{0hA  
{ }^odUIj  
sSiteURL = value; ^ Vc(oa&;  
} /kO%aN  
RW Jyd=  
1dy"  
public String getSFilePath() l?^}n(_.  
{ )g U#[}6H  
return sFilePath; g+4x  
} ~qA\u5sB9@  
o6 :]Hvqjr  
~ sWXd~\  
public void setSFilePath(String value) zrC1/%T  
{ $TAsb>W!(  
sFilePath = value; /}d)g4\j  
} a72L%oJ   
m'ZxmsFo  
`w "ooK  
public String getSFileName() {~Q}{ha  
{ QbWeQ[V{  
return sFileName; j4#S/:Q<7  
} 9m%+6#|  
]qk`Yi  
a5`9mR)Y$'  
public void setSFileName(String value) p%\&M bA  
{ X#MC|Fzy@  
sFileName = value; uxW<Eh4H*  
} )@ .0ai  
OeQ~g-n  
j#H&~f  
public int getNSplitter()  O&dh<  
{ W#x~x|(c  
return nSplitter; HJe6h. P  
} Fa X3@Sd!  
0v3 8LBH)  
v/Xz.?a\jF  
public void setNSplitter(int nCount) }ol<DV  
{ G98fBw  
nSplitter = nCount; IfCa6g<&(  
} 0A75)T=lQ  
}  I$fm"N  
=u5( zaBe  
5J6~]J  
/* fQ2U |  
**Utility.java  S^5Qhv  
*/ M(Yt9}Z%Y  
package NetFox; vH"^a/95|  
x^YsXzu  
M&rbXi.  
public class Utility { lBG"COu  
CG!9{&F  
@@6c{r^P  
public Utility() |q\Rvt$d  
{ yV) 9KGV+:  
1#vi]CX  
!~}@Eoii4  
} r{Z4ifSl(  
mr XmM<  
//线程睡眠 i%r+/D)KvG  
public static void sleep(int nSecond) p,mKgL63  
{ L5]uT`Twa  
try{ qI2&a$Zb$  
Thread.sleep(nSecond); WG5)-;>q|  
} .DhB4v&  
catch(Exception e) Xc G   
{ R)]+>M-.  
e.printStackTrace (); e1R<+`]  
} {"*gX&;~  
} (S63:q&g  
:CXm@yF~4=  
//日志 f(c#1AJE53  
public static void log(String sMsg) mqQC`Aqx:  
{ @dhnpR :L  
System.err.println(sMsg); N >];xb>  
} qoC<qn{.a  
,mE}#cyY  
6dqI{T-i?  
public static void log(int sMsg) *XG.?%x*|  
{ K'U=);W  
System.err.println(sMsg); L\t?^u  
} AK$i0Rn;pm  
} }Y3*X: i7  
JuR x>F4  
di~ [Ivw  
/* AZbFj-^4  
**TestMethod.java %07vH&<C.  
*/ E qt\It9  
package NetFox; 3s,a%GOk  
Q\*zF,ek  
" 8g\UR"[  
public class TestMethod { ] N7(<EV/  
eeOG(@@o(  
%VO>6iVn  
public TestMethod() 9G{#a#Z.  
{ ///xx/weblogic60b2_win.exe '.t{\  
try{ FN D+Ok&  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tr%VYc|}  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "0?" E\  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 207h$a,  
fileFetch.start(); 6oq/\D$6~  
} >u?a#5R:m  
catch(Exception e){e.printStackTrace ();} b}m@2DR'|m  
L&Pj0K-HT3  
)bB Va^  
} H:`H4 S}  
?H21Ru>:*  
0@}:`OynX  
public static void main(String[] args) F Xp_`9.zH  
{ i dY Xv)R  
new TestMethod(); J!5&Nc  
} cwI3ANV  
} bMN ]co  
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