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http断点续传简单实现(java)

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/* <L-L}\-I"  
**SiteFileFetch.java rT#QA=YB  
*/ iT%UfN/q=I  
package NetFox; \rJk[Kec  
import java.io.*; Rz)#VVYC=  
import java.net.*; uO6_lOT9n  
&jJgAZ!  
vV|egmw01  
public class SiteFileFetch extends Thread { x .q%O1  
roKiSE`  
$W09nz9?  
SiteInfoBean siteInfoBean = null; //文件信息Bean 8_lD*bEt   
long[] nStartPos; //开始位置 !cpBX>{w  
long[] nEndPos; //结束位置 Np<Aak  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 FKQnz/  
long nFileLength; //文件长度 ei5S<n  
boolean bFirst = true; //是否第一次取文件 ofSOy1  
boolean bStop = false; //停止标志 -K0tK~%q  
File tmpFile; //文件下载的临时信息 `{/=i|6  
DataOutputStream output; //输出到文件的输出流 Xy{b(b;9  
'>6-ie^0  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) *<hpq)  
public SiteFileFetch(SiteInfoBean bean) throws IOException  v/.2Z(sZ  
{ S `[8TZ  
siteInfoBean = bean; *w _j;  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); X;1q1X)K  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); *0U(nCT&m  
if(tmpFile.exists ()) ;V;4#  
{ qgDBu\  
bFirst = false; BZj[C=#x  
read_nPos(); uODsXi{z  
} z TK  
else f 6q@  
{ \yxr@z1_b  
nStartPos = new long[bean.getNSplitter()]; %~h'#S2X(  
nEndPos = new long[bean.getNSplitter()]; zx!1jS  
} T/3UF  
&F:7U!  
@iaN@`5I6s  
BoXCc"q[  
} NlDM/  
}$o%^ "[  
VTHDGBU  
public void run() V_~wWuZ-  
{ B|Omz:c  
//获得文件长度 e7;]+pN]J  
//分割文件 `A'*x]l  
//实例FileSplitterFetch " JRlj  
//启动FileSplitterFetch线程 ;A C] *  
//等待子线程返回 x:2_FoQ  
try{ }O>IPRZ  
if(bFirst) bw4b'9cK  
{ ?G{fF H  
nFileLength = getFileSize(); D|S)/o6  
if(nFileLength == -1) :eO]65N  
{ H5 -I}z  
System.err.println("File Length is not known!"); & dS+!<3  
} k X-AC5]  
else if(nFileLength == -2) 5 9X|l&/  
{ R|vF*0)>W  
System.err.println("File is not access!"); ux }DWrR  
} V *] !N  
else %>bwpN  
{ Y~CS2%j  
for(int i=0;i<nStartPos.length;i++) ir m8z|N-  
{ GwvxX&P  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ufo?ZFq@$L  
} LgaJp_d>9*  
for(int i=0;i<nEndPos.length-1;i++) N>z8\y  
{ @s/ qOq?  
nEndPos = nStartPos[i+1]; +VeLd+Q}  
} *dTw$T#  
nEndPos[nEndPos.length-1] = nFileLength; {tMD*?C[6  
} ~\^8 ^  
}  2O  
Uag1vW,c  
?=vwr,ir  
//启动子线程 -(2-zznZ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ANNL7Z3C  
for(int i=0;i<nStartPos.length;i++) "6}+|!"$  
{ {kzM*!g  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), spI{d!c  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /t/q$X  
nStartPos,nEndPos,i); T;%SB&  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Du*Re6g  
fileSplitterFetch.start(); Gnw>%f1@u  
} ;~K($_#H  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [brrziZ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); J0oR]eT}  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5|b/G  
nEndPos = " + nFileLength); 1@ina`!1O  
// fileSplitterFetch[nPos.length-1].start(); wVvU]UT  
cnsGP*w  
w"e2}iE7  
//等待子线程结束 ?R+$4;iy  
//int count = 0; pr?/rXw  
//是否结束while循环 Ju\"l8[f  
boolean breakWhile = false; -7`J(f.rYC  
Mc8^{br61  
k (R4-"@  
while(!bStop) C+k>Ajr  
{ v!uLd.(  
write_nPos(); <(^pHv7Q  
Utility.sleep(500); vuAjAeKm  
breakWhile = true; ]]7T5'.  
B8&@Qc@~  
ovohl<o\  
for(int i=0;i<nStartPos.length;i++) P TP2QAt  
{ I,[EL{fz  
if(!fileSplitterFetch.bDownOver) YU`{  
{ WIghP5%W  
breakWhile = false; usA!MMH4  
break; U}7[8&k1  
} u|ZO"t  
} 3:gk:j#  
if(breakWhile) lD pi1]2  
break; kel {9b=i  
H1]\B:  
`zL9d lZ  
//count++; $CmTsnR1#y  
//if(count>4) ?,NAihN]  
// siteStop(); kr?| >6?  
} *+AP}\p0F  
*}J_STM  
?Y9?x,x  
System.err.println("文件下载结束!"); D8ly8]H  
}  #59zv=  
catch(Exception e){e.printStackTrace ();} )N/KQ[W  
} YV msWuF  
X]!@xlwF\  
[=Z{y8#:J  
//获得文件长度 8n)Q^z+ K  
public long getFileSize() [h1{{Nb#ez  
{ *.RVH<W=8  
int nFileLength = -1; 0#JBz\  
try{ lySaJ d  
URL url = new URL(siteInfoBean.getSSiteURL()); UQFuEI<1-  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^wlep1D  
httpConnection.setRequestProperty("User-Agent","NetFox"); Ir'f((8:  
{ SfU!  
F\I^d]#,[  
int responseCode=httpConnection.getResponseCode(); k-U/x"Pl  
if(responseCode>=400) &u8c!;y$b  
{ 55,-1tWs  
processErrorCode(responseCode); [xPE?OD  
return -2; //-2 represent access is error {>Px.%[<  
} 2?j1~]DvZ  
 AMdS+(J  
K="+2]{I  
String sHeader; UwU]l17~  
@jHio\/_  
6,PL zZ5  
for(int i=1;;i++) i`qh|w/b_  
{ .p`'^$X^  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U4gwxK  
//Utility.log(in.readLine()); H<;j&\$q  
sHeader=httpConnection.getHeaderFieldKey(i); MeX1y]<It  
if(sHeader!=null) WQx;tX  
{ 9x!y.gx  
if(sHeader.equals("Content-Length")) sYpogFfV  
{ ;Y\,2b, xh  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \4k*Zk  
break; #pfosC[  
} LnGSYrx1  
} OT i3T1&  
else }b`*%141  
break; AHGcWS\,X  
} ;^]A@WN6_  
} j`B{w   
catch(IOException e){e.printStackTrace ();} S41>VbtEp  
catch(Exception e){e.printStackTrace ();} 1tdCzbEn+  
/5Loj&!=  
R`q!~8u  
Utility.log(nFileLength); 1tW:(~ =a;  
G.8b\E~  
@_3$(*n$~  
return nFileLength; [3Rj?z"S  
} L:-lqag!  
V-jL`(JF%  
}c%y0)fL  
//保存下载信息(文件指针位置) !`lqWO_/ :  
private void write_nPos() `'WLGQG  
{ [<QWTMjR  
try{ Umg81!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); |T*qAJ8c  
output.writeInt(nStartPos.length); m{c#cR  
for(int i=0;i<nStartPos.length;i++) QEa=!O  
{ K8Zk{on  
// output.writeLong(nPos); /&7Yi_]r  
output.writeLong(fileSplitterFetch.nStartPos); (_ah~VnO  
output.writeLong(fileSplitterFetch.nEndPos); avu,o   
} %<yM=1~>  
output.close(); J-F_XKqH  
} uszSFe]E  
catch(IOException e){e.printStackTrace ();} mC92J@m/L!  
catch(Exception e){e.printStackTrace ();} :g#it@  
} NCt sx /C  
6a?p?I K^  
KTt$Pt/.  
//读取保存的下载信息(文件指针位置) R"`{E,yj  
private void read_nPos() `g N68:B  
{ ^~ $&  
try{ nX%'o`f  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g/p9"eBpq  
int nCount = input.readInt(); .N&}<T[  
nStartPos = new long[nCount]; 7"ps#)O  
nEndPos = new long[nCount]; bK9~C" k  
for(int i=0;i<nStartPos.length;i++) ^1=|(Z/  
{ vp-7>Wj  
nStartPos = input.readLong(); J5_Y\@  
nEndPos = input.readLong(); mX@* 2I  
} s$x] fO  
input.close(); yMl'1W  
} Ba|}C(Ws?  
catch(IOException e){e.printStackTrace ();} K"j=_%{  
catch(Exception e){e.printStackTrace ();} 5KE%@,k k  
} +|)1_NK  
2EwWV 0BS  
NqE7[wH  
private void processErrorCode(int nErrorCode) LoE(W|nj  
{ &xroms"S=  
System.err.println("Error Code : " + nErrorCode); k<zGrq=8J  
} i03}f%JnuO  
)=nPM`Jn.  
UQ])QTrZFi  
//停止文件下载 N('DIi*or  
public void siteStop() O>M*mTM  
{ Pl& `&N;  
bStop = true; l~TIFmHkh%  
for(int i=0;i<nStartPos.length;i++) &iy(oM  
fileSplitterFetch.splitterStop(); N3p 7 0  
3H#/u! W  
p6*a1^lU6  
} cN}A rv  
} I S8nvx\  
//负责部分文件的抓取 p[F=LP  
**FileSplitterFetch.java -u9yR"n\}  
*/ \}QuNwc   
package NetFox; H9Q7({v  
}9udo,RWu  
w <>6>w@GZ  
import java.io.*; ivz9R'  
import java.net.*; &9w%n  
G4%M$LJ h  
1 lCikS^c  
public class FileSplitterFetch extends Thread { bL],KW;Q  
WfT)CIKs  
R|J>8AL}BY  
String sURL; //File URL 3r:)\E+Q_  
long nStartPos; //File Snippet Start Position Nwl RPyt  
long nEndPos; //File Snippet End Position *R\/#Y|  
int nThreadID; //Thread's ID dN\P&"`  
boolean bDownOver = false; //Downing is over qvU$9cTY  
boolean bStop = false; //Stop identical =>}.W:=  
FileAccessI fileAccessI = null; //File Access interface Z F yX@#B9  
}42qMOi#w1  
uj9tr`Zh  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p/WH#4Xdr  
{ 4:eq{n  
this.sURL = sURL; Y:!/4GF  
this.nStartPos = nStart; hf+/kc!>i  
this.nEndPos = nEnd;  ]RX tC*  
nThreadID = id; K*U=;*p)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gLSG:7m@  
} Z++Z@J"  
Prb_/B Dd  
{_toh/8)r  
public void run() -8Jl4F ,  
{ *- IlF]  
while(nStartPos < nEndPos && !bStop) R-A'v&=  
{ ?+,*YVT  
PMN2VzE4{  
7hF,gl5  
try{ ~r>EF!U`h  
URL url = new URL(sURL); s 9|a2/{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xngeV_xc2  
httpConnection.setRequestProperty("User-Agent","NetFox"); ELrZ8&5G  
String sProperty = "bytes="+nStartPos+"-"; jQxPOl$-  
httpConnection.setRequestProperty("RANGE",sProperty); (O_t5<A*X  
Utility.log(sProperty); o(d_uJOB  
*0&4mi8  
2 ]DCF  
InputStream input = httpConnection.getInputStream(); FJd8s*  
//logResponseHead(httpConnection); k99gjL`  
Q3Z%a|3W  
3$$5Mk(&  
byte[] b = new byte[1024]; tFvgvx\:  
int nRead;  [ }p  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TvWU[=4Yk  
{ =|gJb|?w  
nStartPos += fileAccessI.write(b,0,nRead); 3Zaq#uA  
//if(nThreadID == 1) vTMP&a'5L  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); i{|lsd(+  
} YHO;IQ5  
o%Uu.P  
9QC"Od9H  
Utility.log("Thread " + nThreadID + " is over!"); |6sT,/6  
bDownOver = true; Z{a{HX[Jx  
//nPos = fileAccessI.write (b,0,nRead); tKG;k"wk  
} 5?3Isw`v2  
catch(Exception e){e.printStackTrace ();} ^sT +5M^  
} u>,lf\Fgz  
} P1 7>6)a  
` $.X[\*U  
a9D gy_!Y  
//打印回应的头信息 /FP~jV!z  
public void logResponseHead(HttpURLConnection con) (XbMrPKG  
{ aQ!9#d_D  
for(int i=1;;i++) X"hOHx5P  
{ `d}W;&c  
String header=con.getHeaderFieldKey(i); C 'B4 mmC  
if(header!=null) 1-6gB@cvQ  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hi;WFyJTu  
Utility.log(header+" : "+con.getHeaderField(header)); 4NpHX+=P  
else i(M(OR/4  
break; [<D+p qh  
} tk`: CT *  
} }iPo8Ra  
2j8Cv:{Nn%  
S}zC3  
public void splitterStop() f![xn2T  
{ ZhGh {D[,  
bStop = true; 9"WRIHt'c  
} *oEv,I_  
/J1S@-  
s~'9Hv9  
} f*{M3"$E  
<)_:NRjBF&  
{[Uti^)m%  
/* %:" RzHN  
**FileAccess.java CCuxC9i7  
*//文件访问(定位,写) Rz`@N`U  
package NetFox; v\fzO#vj  
import java.io.*; vx04h~  
q$MHCq;  
>lA7*nn  
public class FileAccessI implements Serializable{ l*QIoRYFW  
>:.w7LQy/  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rU; g0'4e  
RandomAccessFile oSavedFile; P7}t lHX  
long nPos; 5+y@ ]5&g  
*w=z~Jq^R"  
nURvy}<r  
public FileAccessI() throws IOException 2#'rk'X,K  
{ | d~B]65t  
this("",0); jZa25Z00  
} OF-E6bc  
B1y<.1k  
&@=u+)^-{  
public FileAccessI(String sName,long nPos) throws IOException `ajx hp  
{ btUq  
oSavedFile = new RandomAccessFile(sName,"rw"); jVX._bEGX  
this.nPos = nPos; j'k8^*M6  
oSavedFile.seek(nPos); / pO{2[  
} _mw13jcN]  
53bM+  
CI IY|DI`l  
public synchronized int write(byte[] b,int nStart,int nLen) UV?[d:\>'  
{ =ZG<BG_  
int n = -1; "=9-i-K9B  
try{ d0'7efC+  
oSavedFile.write(b,nStart,nLen); zs4>/9O  
n = nLen; P`}$-#DF  
} Mg#`t$ u  
catch(IOException e) U%Dit  
{ j -#E?&2  
e.printStackTrace (); \^yXc*C  
} =nLO?qoe  
'^hsH1  
sjSi;S4  
return n; "P MO  
} T&]Na  
vxb@9 eb!H  
bk.*k~_  
} %WZ$]M?q  
iA]DE`S  
:*=Ns[Y  
/* (m6EQoW^s+  
**SiteInfoBean.java Ys-^7 y_  
*/ '[%jjUU  
package NetFox; B<Ol+)@,}  
kPWBDpzN  
V)=Z6ti  
public class SiteInfoBean { >Dxe>Q'df  
*E.LP1xP  
)5U !>,fT  
private String sSiteURL; //Site's URL XWJ SLN(O  
private String sFilePath; //Saved File's Path 5~QhX22  
private String sFileName; //Saved File's Name k<!<<,Z  
private int nSplitter; //Count of Splited Downloading File Ha?G=X  
KVg[#~3  
JT}.F!q6E  
public SiteInfoBean() uN8/Q2   
{//nSplitter的缺省值为5 ti}f&w ICJ  
//default value of nSplitter is 5 3+ e4e  
this("","","",5); aFyh,  
} 7q!?1 -?8R  
pKq]X}[^c  
7"#f!.E  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ><cU7 ja[^  
{ eap8*ONl  
sSiteURL= sURL; .wP/ai>}  
sFilePath = sPath; V n^)  
sFileName = sName; w;~>k%}j  
this.nSplitter = nSpiltter; z4bN)W )p  
\Y+")  
)Z("O[  
} nX)f'[ 7  
~JLYhA^'+<  
-A}zJBcR  
public String getSSiteURL() a#$N%=j  
{ G?R_aPP  
return sSiteURL; X{`1:c'x  
} zz&vfO31J  
L1:nfH&:'  
MF^_Z3GS'  
public void setSSiteURL(String value) ##v`(#fu  
{ |U EC  
sSiteURL = value; !3@{U@*Z]  
} Ia#"/`||  
h D.)M  
^zg acn  
public String getSFilePath() ?,>5[Ha^?  
{ Ch t%uzb,  
return sFilePath; #~S>K3(  
} 6Kp}_^|z  
"b`7[;a  
hXc}r6<B  
public void setSFilePath(String value) O>%$q8x@i  
{ 0yaMe@&,  
sFilePath = value; Kr]z]4.d@  
} J0sGvj{  
-x{&an=  
JCD?qeTg  
public String getSFileName() Z%OW5]q  
{ rI>LjHP  
return sFileName; *7Xzht&f  
} _4v"")Xe  
I|T7+{5z  
uFo/s&6K  
public void setSFileName(String value) \E77SO,$  
{ Mb.4J2F?  
sFileName = value; ?!y"OrHg  
} Zw#<E =\  
7h`^N5H.q  
^KbL ,T  
public int getNSplitter() xCq'[9oU  
{ 'g hys1H  
return nSplitter; b]i>Bv  
} 7]Rk+q2:  
3ev -Iqz  
Kp&3=e;vn{  
public void setNSplitter(int nCount) )NIv  "Q  
{ 5gshKmt_  
nSplitter = nCount; qnXTNs ?b  
} |IN[uQ  
} kC`Rd:5  
3+V#[JBJv  
>pdnCv_c  
/* RX>2~^  
**Utility.java 9`Vc  
*/ vBoO'l9'M  
package NetFox; y\,f6=%k  
q:]Q% IC^  
;7j,MbU  
public class Utility { `tVy_/3(9  
Z0\Iyc G  
J@Yj\9U  
public Utility() n[CoS  
{ EEwWucQ  
CA*~2|  
328L)BmW  
} (w$'o*z;(  
U\bC0q   
//线程睡眠 vQHpf>o  
public static void sleep(int nSecond) ="(>>C1-  
{ _ZyT3P&  
try{ K*+6`z#fMF  
Thread.sleep(nSecond); [.&[<!,.  
} GTAf   
catch(Exception e) %/pc=i|+  
{ NwpS)6<-  
e.printStackTrace (); &,MFB  
} V.VJcx  
} >lLo4M 3  
&<0ZUI |S3  
//日志 ?cK]C2Ak  
public static void log(String sMsg) B9#;-QO  
{ P }Te"Y  
System.err.println(sMsg); JA6";fl;  
} ri=+(NKo-  
iLtc HpN  
(p,}'I#i*  
public static void log(int sMsg) Pm?B 9S  
{ e=>% ^F  
System.err.println(sMsg); D^?_"wjW  
} l$M +.GB<  
} 8xTix1u0  
28UVDG1?  
A*i_|]Q  
/* mH\@QdF  
**TestMethod.java 1;&T^Gdj  
*/ nk/vGa4  
package NetFox; 0>@[o8  
M-Sv1ZLh  
RxG^  
public class TestMethod { P {H{UKs#  
38Efp$)  
Ue7 6py9  
public TestMethod() ; k}H(QI  
{ ///xx/weblogic60b2_win.exe hQ';{5IKvC  
try{ Zi{0-m6+  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +)gB9DoK  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F1c&0*_A  
SiteFileFetch fileFetch = new SiteFileFetch(bean); !G+u j(  
fileFetch.start(); 28oJFi]  
} MZ~.(&  
catch(Exception e){e.printStackTrace ();} o^GC=Aca`  
o;QZe&  
&HL{LnLP@/  
} w~N-W8xNR  
K\^&+7&zVg  
rBfg*r`)  
public static void main(String[] args) w+_Wc~f  
{ TSQh X~RN  
new TestMethod(); *h:kmT  
} VGZ6  
} 2 ~-( A  
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