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http断点续传简单实现(java)

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/* %,>> <8  
**SiteFileFetch.java 9k2HP]8=[{  
*/ j'CRm5O  
package NetFox; 'J]V"Z)  
import java.io.*; >l 'QX(  
import java.net.*; _Z5l Nu  
uVOOw&q_  
fl+ [(x<  
public class SiteFileFetch extends Thread { sDWX} NV  
_vvnxG!x&  
(zye Ch  
SiteInfoBean siteInfoBean = null; //文件信息Bean Y.jg }oV  
long[] nStartPos; //开始位置 jw#'f%*  
long[] nEndPos; //结束位置 ToDN^qE+  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 b)'Ew27  
long nFileLength; //文件长度 bIe>j*VPh@  
boolean bFirst = true; //是否第一次取文件 Lj({ T'f(  
boolean bStop = false; //停止标志 H6rWb6i  
File tmpFile; //文件下载的临时信息 ?$F:S%eH  
DataOutputStream output; //输出到文件的输出流 0XL x@FYn  
PS(9?rX#+  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) :uhvDYp(-  
public SiteFileFetch(SiteInfoBean bean) throws IOException In=3#u ,M  
{ ZXHG2@E)  
siteInfoBean = bean; j:$2 ,?|5  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); fd*=`+P  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); -Qqb/y  
if(tmpFile.exists ()) op&,&  
{ yIqsZJj  
bFirst = false; LK/gG6n5M0  
read_nPos(); tSE6m-  
} ]#))#-&1  
else $U"/.Mh\  
{ mMu3B2nke=  
nStartPos = new long[bean.getNSplitter()]; E{ Y0TZ+  
nEndPos = new long[bean.getNSplitter()]; KdYT5VUM/  
} y|iZuHS}  
;z)$wH0xc  
k/!Vv#8  
M ~.w:~Jm  
} LDr!d1A  
Ri aO`|1  
EmG`ga)s  
public void run() C[? itk!  
{ @+B .<@V  
//获得文件长度 [,|KVc=&H  
//分割文件 `=b*g24z[N  
//实例FileSplitterFetch NZ9`8&93  
//启动FileSplitterFetch线程 J'^BxN&  
//等待子线程返回 SM! [ yC  
try{ F)5QpDmqb  
if(bFirst) 1H-R-NNJ:  
{ RYS]b[-xZz  
nFileLength = getFileSize(); JB''Ujyi  
if(nFileLength == -1) 9v 0.]  
{ c*MjBAq  
System.err.println("File Length is not known!"); FbW kT4t|  
} |PDuvv!.f  
else if(nFileLength == -2) hFj.d]S  
{ j$&k;S  
System.err.println("File is not access!"); VH+^G)^)W  
} *Rr,ii  
else 0!_D M^3  
{ U|-4*l9Ed  
for(int i=0;i<nStartPos.length;i++) {eqUEdC  
{ =?vk n  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); f1hi\p0q  
} VH,k EbJ  
for(int i=0;i<nEndPos.length-1;i++) DU]MMR  
{ G\Toi98d*  
nEndPos = nStartPos[i+1]; B58H7NH ;G  
} /Eh\07p  
nEndPos[nEndPos.length-1] = nFileLength; )0fQ(3oOg  
} peR=J7  
} .Eh~$wm  
k;;?3)!  
zUIh8cAoE  
//启动子线程 Z UAWSJ,s  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sB-c'`,w`  
for(int i=0;i<nStartPos.length;i++) 0ydAdgD  
{ eey <:n/Z  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yTkYPx  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bN<c5  
nStartPos,nEndPos,i); d7$H})[^  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T* -*U /  
fileSplitterFetch.start(); @\u)k  
} %jKR\f G  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3,3{wGvHHW  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /=,^fCCN  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", roj/GZAy"  
nEndPos = " + nFileLength); <MA!?7Z|  
// fileSplitterFetch[nPos.length-1].start(); (RWZ [-;)  
V*U"OJ%  
 6:ZqS~-  
//等待子线程结束 w v9s{I{P  
//int count = 0; e%(zjCA  
//是否结束while循环 ~9h6"0K!  
boolean breakWhile = false; sjWhtd[fgG  
2"yzrwZ:  
D#W{:_f  
while(!bStop) n_.2B$JD  
{ 8[(c'rl|)|  
write_nPos(); s2b!Nib  
Utility.sleep(500); ?n\~&n'C  
breakWhile = true; @<W"$_ r-  
K]N^6ome  
6\OSIxJZF  
for(int i=0;i<nStartPos.length;i++) &"Ua"H)  
{ s3/->1#i  
if(!fileSplitterFetch.bDownOver) P]]9Sqo7  
{ Qn[4&nUD  
breakWhile = false; qECc[)B  
break; onG,N1`+  
} (}gF{@sn  
} dm)V \?b  
if(breakWhile) a%Mbq;  
break; ,Xo9gn  
zRsT6u  
FspI[g UN,  
//count++; J);1Tpm  
//if(count>4) Rk2ZdNc\  
// siteStop(); \EUc17  
} A9p$5jt7  
c c ,]  
:==kC672  
System.err.println("文件下载结束!"); ] bhzB  
} 5 (2g*I  
catch(Exception e){e.printStackTrace ();} I;uZ/cZ|/  
} e>uV8!u  
&tLg}7?iB  
s:jr/ j!  
//获得文件长度 !i.`m-J*  
public long getFileSize() 7bQ#M )}  
{ #9#N+  
int nFileLength = -1; PrDvRWM  
try{ ZKAIG=l&!  
URL url = new URL(siteInfoBean.getSSiteURL()); q fadsVp  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); at6f(+  
httpConnection.setRequestProperty("User-Agent","NetFox"); }1N)3~  
`@")R-  
s-*8=  
int responseCode=httpConnection.getResponseCode(); YPf&y"E&H  
if(responseCode>=400) %DgU  
{ 8 6?D  
processErrorCode(responseCode); eZI&d;i  
return -2; //-2 represent access is error }P-9\*hlm  
} ,Y &Q,  
JQQD~J1)E  
1 (P >TH  
String sHeader; vb5tyY0c  
`r+e! o  
v|t^th,  
for(int i=1;;i++) rZ w&[ G  
{ |Wi$@sWO  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S%mN6b~{  
//Utility.log(in.readLine()); +]`MdOu  
sHeader=httpConnection.getHeaderFieldKey(i); _BHb0zeot  
if(sHeader!=null) 9.#\GI ;  
{ ; =F^G?p^  
if(sHeader.equals("Content-Length")) Pt";f  
{ n#,AZ&  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zhz.8W  
break; 7!<cU  
} Z-Bw?_e_K  
} e,`+6qP{  
else r}D`15IHJ  
break; 1i2jYDB"  
} jW?.>(  
} t#6gjfIi  
catch(IOException e){e.printStackTrace ();} N''9Bt+:  
catch(Exception e){e.printStackTrace ();} -;Cl0O%  
e|"`W`"-  
Y]B2-wt-  
Utility.log(nFileLength); l: 1Zq_?v;  
,)S|%tDW  
~?[%uGI0h  
return nFileLength; y5|`B(  
} WvUe44&^$  
NrNbNFfo  
%$!}MxUM  
//保存下载信息(文件指针位置) ?G0=\U< o,  
private void write_nPos() 1UyI.U]  
{ A;Xn#t ,(K  
try{  p&:R SO  
output = new DataOutputStream(new FileOutputStream(tmpFile)); + :iNoDz  
output.writeInt(nStartPos.length); :HMnU37m W  
for(int i=0;i<nStartPos.length;i++) A5!f#  
{ /3'-+bp^=  
// output.writeLong(nPos); uDQ d48>  
output.writeLong(fileSplitterFetch.nStartPos); uJF,:}qA  
output.writeLong(fileSplitterFetch.nEndPos); HMrS::  
} _4xX}Z;  
output.close(); Tx`;y|  
} "eZNci  
catch(IOException e){e.printStackTrace ();} 0&2TeqsLh)  
catch(Exception e){e.printStackTrace ();} MFiX8zwhx+  
} |v[{k>7f  
M:Xswwq  
iN<&  
//读取保存的下载信息(文件指针位置) pRPz1J$58  
private void read_nPos() \96?OC dr  
{ D0lgKQ  
try{ `:-{8Vo7  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L*D-RYW  
int nCount = input.readInt(); z"=#<C  
nStartPos = new long[nCount]; C;G~_if4PR  
nEndPos = new long[nCount]; WnvuB.(@3  
for(int i=0;i<nStartPos.length;i++) efl6U/'Ij  
{ pWO,yxr:  
nStartPos = input.readLong(); o*'J8El\y^  
nEndPos = input.readLong(); l?pZdAE  
} ,DXNq`24  
input.close(); &>*f J  
} wu/]M~XwI  
catch(IOException e){e.printStackTrace ();} |9~{&<^X  
catch(Exception e){e.printStackTrace ();} F1w~f <  
} jiC;*]n  
daGGgSbh  
C8-4 m68"  
private void processErrorCode(int nErrorCode) kNd[M =%  
{ \m*?5]m ;  
System.err.println("Error Code : " + nErrorCode); m9wV#Ldu  
} mI@E>VCV[  
st+X~;PX*  
) $#ov-]  
//停止文件下载 ;jo,&C  
public void siteStop() `:}GE@]  
{ |A 8xy#  
bStop = true; 4F??9o8}  
for(int i=0;i<nStartPos.length;i++) )l\BZndf  
fileSplitterFetch.splitterStop(); H}dsd=yO  
do+HPnfDzU  
tceQn ^|<  
} 5m=3{lBi  
} *&% kkbA  
//负责部分文件的抓取 8ooj)  
**FileSplitterFetch.java qyP@[8eH  
*/ TStu)6%`  
package NetFox; TsfOod   
P%ev8]2  
#J\ 2/~  
import java.io.*; b U-Cd  
import java.net.*; \3O#H  
[JO'ta  
4%KNHeaN  
public class FileSplitterFetch extends Thread { 600-e;p  
BN|+2D+S  
#T99p+O  
String sURL; //File URL I}kx;!*b  
long nStartPos; //File Snippet Start Position oz(<e  
long nEndPos; //File Snippet End Position Y"K7$+5#\  
int nThreadID; //Thread's ID dSS_^E[{  
boolean bDownOver = false; //Downing is over `Ft.Rwj2:m  
boolean bStop = false; //Stop identical BYqDC<Fq  
FileAccessI fileAccessI = null; //File Access interface qCc'w8A  
4IG'T m  
/H:'(W_b;  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,}=x8Xxr  
{ @Vr?)_ 0  
this.sURL = sURL; Hh(_sewo  
this.nStartPos = nStart; /IxMRi=  
this.nEndPos = nEnd; 4["$}O5  
nThreadID = id; qg 4:Vq  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l$}h1&V7  
} CD +,&id  
I8Y[d$z  
2(\~z@g  
public void run() CGbW] D$@  
{ `-hFk88  
while(nStartPos < nEndPos && !bStop) VWI|`O.w  
{ "o*F$7D!  
>wNE!Oa*B  
L @_IGH  
try{ q-KN{y/  
URL url = new URL(sURL); P2_JS]>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lo,?mj%M  
httpConnection.setRequestProperty("User-Agent","NetFox"); Q6`oo/  
String sProperty = "bytes="+nStartPos+"-"; ^; Nu\c  
httpConnection.setRequestProperty("RANGE",sProperty); QNLkj`PL/  
Utility.log(sProperty); vh"zYl`  
>Yl?i&3n  
'%. lY9D  
InputStream input = httpConnection.getInputStream(); !}9k @=[  
//logResponseHead(httpConnection); I%h9V([  
HH&`f3  
W=M]1hy  
byte[] b = new byte[1024]; KA0Ui,q3  
int nRead; w[^s) 1  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1,p7Sl^h  
{ |>gya&  
nStartPos += fileAccessI.write(b,0,nRead); ^+Ie   
//if(nThreadID == 1) #VgPg5k.<  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Dr^#e  
} +#"CgZ]  
[;7&E{,C  
$A`D p{e"  
Utility.log("Thread " + nThreadID + " is over!"); Xjt/ G):L  
bDownOver = true; =nh/w#  
//nPos = fileAccessI.write (b,0,nRead); &y[Od{=  
} j="{^b  
catch(Exception e){e.printStackTrace ();} *T$`5|  
} +?),BRCce  
} DB We>Ef(  
m*6C *M  
+t({:>E  
//打印回应的头信息 Ko]A}v\]  
public void logResponseHead(HttpURLConnection con) jqPQ= X  
{ ]E .+)>  
for(int i=1;;i++) 8`EzvEm  
{ $VvL  
String header=con.getHeaderFieldKey(i); JQP7>W  
if(header!=null) ?\L@Pr|=Dr  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~c%H3e>Jcq  
Utility.log(header+" : "+con.getHeaderField(header)); -fI-d1@  
else L~%@pf>  
break; zqh.U @  
} (|(#~o]40t  
} _Jn-#du  
T\eOrWt/  
>V2Tr$m j  
public void splitterStop() +/'3=!oyd  
{ U iqHUrx  
bStop = true; oyZ}JTl( Q  
} OGw =e{  
IP~*_R"bM  
]x8 ^s  
} AifnC4  
I'{-T=R-q  
l~kxt2&  
/* (, Il>cR4  
**FileAccess.java p&/}0eL y  
*//文件访问(定位,写) I,OEor6%R(  
package NetFox; L=nyloz,0  
import java.io.*; LE%3.. !  
4:GVZR|-  
|_@ '_  
public class FileAccessI implements Serializable{ 5(R ./  
1K.i>]}>  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q%o:*(x[O  
RandomAccessFile oSavedFile; *~~ >?  
long nPos; u )cc  
o(Yj[:+m  
T$RVz   
public FileAccessI() throws IOException -$WU -7`  
{ 59A@~;.F  
this("",0); -\O%f)R  
} H3"90^|,@  
B~K@o.%  
1|_jV7`Mz  
public FileAccessI(String sName,long nPos) throws IOException jHBzZ!<  
{ r8x<- u4  
oSavedFile = new RandomAccessFile(sName,"rw"); x?v/|  
this.nPos = nPos; Z+! ._uA  
oSavedFile.seek(nPos); %;$zR}  
} 8R<2I1xn2  
;L (dmx?  
MwMv[];I  
public synchronized int write(byte[] b,int nStart,int nLen) ^}vLZA  
{ Q^}6GS$  
int n = -1; 9aky+  
try{ [+<lm 5t  
oSavedFile.write(b,nStart,nLen); f mu `o-  
n = nLen; FMMQO,BU  
} .G8+D%%.  
catch(IOException e) ANh7`AUuO  
{ wPdp!h7B~N  
e.printStackTrace (); [9dW9[Z+!  
} ,$BbJQ5  
O}5mDx  
{}!`v%z  
return n; &Jw]3U5J  
} -8H0f- 1  
(`<X9w,  
f'._{"  
} w ryjs!  
M|IR7OtLV  
VX#4Gh,~N  
/* faH113nc  
**SiteInfoBean.java fR[kjwX)<1  
*/  n aE;f)  
package NetFox; sTeW4Hnp  
SKO*x^"eU  
,?s3%<\2   
public class SiteInfoBean { $*a'[Qot#  
80=6B  
(ns> z7  
private String sSiteURL; //Site's URL do0;"O0 (  
private String sFilePath; //Saved File's Path |]FJfMX  
private String sFileName; //Saved File's Name pV`?=[h9  
private int nSplitter; //Count of Splited Downloading File MD`1KC_m  
Ovu!G q  
[AgS@^"sf5  
public SiteInfoBean() 6bj.z  
{//nSplitter的缺省值为5 GddP)l{uCF  
//default value of nSplitter is 5 gYb}<[O!  
this("","","",5); kex4U6&OQB  
} ?VVtEmIN  
7S+_eL^  
_4H 9rPhf  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Reci:T(_  
{ a?&{eMEe}  
sSiteURL= sURL; }s i{  
sFilePath = sPath; &,~0*&r0  
sFileName = sName; <*I%U]  
this.nSplitter = nSpiltter; ^=kUNyY  
HjG!pO{  
l!U F`C0g  
} \Nd8,hE  
hbfTv;=z  
+JQ/DNv  
public String getSSiteURL() 24;F~y8H  
{ ]!l]^/ .  
return sSiteURL; Y*oT (  
} H$GJpXIb  
-U'3kaX5<  
:f1Q0klwP  
public void setSSiteURL(String value) v8=7  
{ ,D#ssxV  
sSiteURL = value; ="X2AuK%1$  
} Z*,Nt6;e  
mWhQds6  
'L$%)`;e  
public String getSFilePath() w=]id'`?q  
{ yffg_^fR  
return sFilePath; @0js=3!2  
} 19V  
H\W/;Nn  
9UF^h{X  
public void setSFilePath(String value) wLX:~]<xl  
{ ^Yu<fFn  
sFilePath = value; _G9 vsi  
} oUXi 4lsSc  
ZY N HVR  
p%MH**A  
public String getSFileName() /"$A?}V  
{ ?"23XKe  
return sFileName; + Xc s<+b  
} VG,O+I'^z  
|Dz$OZP  
u7L!&/6On  
public void setSFileName(String value) >\J({/ #O  
{ O+ ].'  
sFileName = value; Pr|:nJs  
} $_bhZnYp7  
/da5 "  
?f}lYQzM  
public int getNSplitter() POZ5W)F(  
{ W ='c+3O6  
return nSplitter; *Cs RO  
} bU3e*Er  
8v eG^o  
7t8[M(  
public void setNSplitter(int nCount) k(<:  
{ Sxn#  
nSplitter = nCount; 7bC1!x*qw  
} ?<_yW#x6  
} K chp%  
?ykQ]r6a<  
tXlo27J  
/* 1Z. D3@  
**Utility.java 4$HU=]b6Tf  
*/ ~3 ,>TV  
package NetFox; .TI =3*`G  
8oAr<:.=  
$>Y2N5  
public class Utility { l'Oz-p.@  
2.xA' \M  
nu'r `  
public Utility() 1=R6||8ws  
{ CJn{tP  
LYYz =gvZl  
=IbDGw(  
} `>.^/SGu>?  
U^AywE]  
//线程睡眠 q\0CS>.  
public static void sleep(int nSecond) 4V2}'/|[  
{ 2h_XfY'3pX  
try{ g>L4N.ZH_v  
Thread.sleep(nSecond); Z>9uVBE02  
} huPAWlxT  
catch(Exception e) aicvu(%EE  
{ gL)l)}#  
e.printStackTrace (); MM+x}g.?  
} 8mrB_B5  
} ]g/:lS4  
ef !@|2  
//日志 {>x6SVF  
public static void log(String sMsg) he/WqCZg  
{ !xqy6%p  
System.err.println(sMsg); NVt612/'7y  
} EISgc {s  
z' oK 0"  
! 06 !`LT  
public static void log(int sMsg) %A]?5J)Bi  
{ E.ugr])  
System.err.println(sMsg); bSG}I|  
} %3Ba9Nmid  
} [9hslk  
g?TPRr~$9  
MXVQ90  
/* pZVT:qFF  
**TestMethod.java ][gr(-68  
*/ D7X8yv1  
package NetFox; &3@ {?K  
IdHyd Y1  
?.A~O-w  
public class TestMethod { HITw{RPrW  
){D6E9  
V:YN!  
public TestMethod() *6C ]CS  
{ ///xx/weblogic60b2_win.exe l0 Eh?  
try{ ZqONK^  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PU& v{gn  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %oee x1`=  
SiteFileFetch fileFetch = new SiteFileFetch(bean); -2D/RE7|  
fileFetch.start(); GBh$nVn$  
} nfj8z@!  
catch(Exception e){e.printStackTrace ();} ls;!Og9  
5 ]c\{G  
80'!XKSP  
} =yR$^VSY  
.=kXO{>  
|.ZYY(}  
public static void main(String[] args) cs-wqxTX[$  
{ ?W27 h  
new TestMethod(); /s/\5-U7q  
} zUQn*Cio e  
} iNlY\67sW  
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