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http断点续传简单实现(java)

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/* Eh *u6K)Z  
**SiteFileFetch.java 5IRUG)Icr  
*/ DnCIfda2g  
package NetFox; ;|,*zD  
import java.io.*; !W b Q9o  
import java.net.*; 6anH#=(  
"JgwL_2  
_Q*,~ z~  
public class SiteFileFetch extends Thread { @><8YN^)%  
7Xh ;dJAF3  
+~xzgaL  
SiteInfoBean siteInfoBean = null; //文件信息Bean ,y)V5 c1  
long[] nStartPos; //开始位置 L7yEgYB  
long[] nEndPos; //结束位置 F~GIfJU  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 OFZo"XtF  
long nFileLength; //文件长度 *b`1+~p_2  
boolean bFirst = true; //是否第一次取文件 &<(&u`S  
boolean bStop = false; //停止标志 5hDm[*83  
File tmpFile; //文件下载的临时信息 <Ug1g0.  
DataOutputStream output; //输出到文件的输出流 =>e> r~cW  
+[V.yY/t|>  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) pWeD,!f  
public SiteFileFetch(SiteInfoBean bean) throws IOException Wm!cjGK  
{ \ 5#eBJ  
siteInfoBean = bean; A4)TJY 3g  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5_rx$avm  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); g T0@pxl  
if(tmpFile.exists ()) b~!Q3o'W  
{ @ n$/2y_.  
bFirst = false; LoO"d'{  
read_nPos();  {T5u"U4  
} }gQnr;lv  
else $F@ ,,*  
{ 5"L.C32  
nStartPos = new long[bean.getNSplitter()]; QOv@rP/  
nEndPos = new long[bean.getNSplitter()]; w*7wSP  
} Dd:48sN:Jq  
i@ehD@.dH  
 ^5R2~  
nYTPcT4x|  
} 3g3Znb  
Ee{Y1W  
we33GMxHl`  
public void run() u"U7aYGkY  
{ cE*d(g  
//获得文件长度 'Z6x\p  
//分割文件 2GRv%:rZ  
//实例FileSplitterFetch v+DXs!O{  
//启动FileSplitterFetch线程 NqN}] nu6  
//等待子线程返回 gq.l=xS  
try{ WS\Ir-B  
if(bFirst) S3y(' PeF  
{ o}Q3mCB  
nFileLength = getFileSize(); *dx E (dP  
if(nFileLength == -1) 6&"GTK  
{ pE{Ecrc3|  
System.err.println("File Length is not known!"); B# o6UO\  
} $g }aH(vf  
else if(nFileLength == -2) V17!~  
{ =DXN`]uN  
System.err.println("File is not access!"); 4 udW 6U  
}  qy/t<2'  
else Wfsd$kN6{  
{ |u#7@&N1  
for(int i=0;i<nStartPos.length;i++) Z)<lPg!YAR  
{ &[5pR60  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); O&@CT])8  
} HDj260a  
for(int i=0;i<nEndPos.length-1;i++) a-NicjV#  
{ V=H:`n3k  
nEndPos = nStartPos[i+1]; Bm +Ca:p%  
} ,Y7QmbX^  
nEndPos[nEndPos.length-1] = nFileLength; 5jsZJpk$  
} Fzy5k?R  
} q!YAA\'31  
Fm[3Btn  
wT+\:y  
//启动子线程 M AL;XcRR  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `ix&j8E22w  
for(int i=0;i<nStartPos.length;i++) n]jw!;  
{ z2 mjm  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `r&]Ydu:  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vywpX^KPv  
nStartPos,nEndPos,i); 1/J6<FVq  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @jKB[S;JSn  
fileSplitterFetch.start(); &W*^&0AV  
} nNh5f]]  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @ el  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pz]! T'  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EvF[h:C2  
nEndPos = " + nFileLength); v4, Dt  
// fileSplitterFetch[nPos.length-1].start(); *$@u`nM  
No*[@D]g  
H`rd bE  
//等待子线程结束 (btm g<WT"  
//int count = 0; H4<Q}([w  
//是否结束while循环 V+t's*9o3  
boolean breakWhile = false; l\ Vr D2j8  
$t0JfDd6Ky  
_7'5IA  
while(!bStop)  upGLZ#  
{ _IWLC{%V  
write_nPos(); xcH&B %;f  
Utility.sleep(500); 9A *gW j  
breakWhile = true; ]D,\(|  
-L!lJ  
x kdC -S  
for(int i=0;i<nStartPos.length;i++) d-T pY*v  
{ o_03Io ~Bf  
if(!fileSplitterFetch.bDownOver) \susLD  
{ w YQEm  
breakWhile = false; R$;TX^r'o&  
break; )T^xDx  
} i:1 @ vo  
} ?@;#|^k9  
if(breakWhile) PJ^qE| X  
break; J|`.d46  
w8a49Fv  
\J;_%-Z  
//count++; ;RYIc0%  
//if(count>4) DKF '*  
// siteStop(); 5<YL^m{/L  
} tTWEhHQ`  
'UM *7  
d{Owz&PL  
System.err.println("文件下载结束!"); -F MonM  
} .h(iyCxP  
catch(Exception e){e.printStackTrace ();} <LN7+7}  
} %*#+(A"V  
`@#rAW D  
b7B|$T,  
//获得文件长度 nlA:C>=  
public long getFileSize() (p<pF].  
{ Y(R.<LtY  
int nFileLength = -1; $=) Pky-~  
try{ {(I":rt#  
URL url = new URL(siteInfoBean.getSSiteURL()); (%mV,2|:20  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z58{YCY  
httpConnection.setRequestProperty("User-Agent","NetFox"); Pb sxjP  
n]i#&[*A(  
I5 qrHBJ >  
int responseCode=httpConnection.getResponseCode(); l]OzE-*$b  
if(responseCode>=400) c=X+uO-  
{ mhB2l/  
processErrorCode(responseCode); ij;P5OA  
return -2; //-2 represent access is error 8|zOgn{  
} c3r`T{Kf  
2f62 0   
bF5"ab0  
String sHeader; <_#2+7Qs  
f+8 QAvh  
'gHg&E9E&  
for(int i=1;;i++) Xj~%kPe  
{ ~S\> F\v6'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~H1<8py\J  
//Utility.log(in.readLine()); _W^;a  
sHeader=httpConnection.getHeaderFieldKey(i); X0REC%  
if(sHeader!=null) e5 }amrz  
{ {`,)<R>}  
if(sHeader.equals("Content-Length")) dqs~K7O^E  
{ eze%RjO}  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2=/-,kOL_  
break; zTc*1(^  
} T5z]=Pd"^  
} Q<gUu^rq  
else `.J17mQe"  
break; >H ?k0M`L  
} >##Z}auY  
} 1GK>&;  
catch(IOException e){e.printStackTrace ();} 3&nN;4~Zx6  
catch(Exception e){e.printStackTrace ();} niKfat?  
0[e!/*_V  
6?;z\ AP&  
Utility.log(nFileLength); Ih>s2nL  
)Yv=:+f  
|0Xf":  
return nFileLength; FSn3p}FVa  
} 6)7cw8^  
B(ktIy  
imeE&  
//保存下载信息(文件指针位置) 4QTHBT+2`  
private void write_nPos() 0^sY>N"  
{ f 9Kt>2IN  
try{ %S'+x[ 4W  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Fj]06~u  
output.writeInt(nStartPos.length); U7 ?v4O]D[  
for(int i=0;i<nStartPos.length;i++) 0Qq<h;8xEc  
{ =*"8N-FU  
// output.writeLong(nPos); >0W P:-\*  
output.writeLong(fileSplitterFetch.nStartPos); %qiVbm0  
output.writeLong(fileSplitterFetch.nEndPos); +vaA P=  
} Ikw@B)0}  
output.close(); t%%()!|)j  
} Q;g7<w17  
catch(IOException e){e.printStackTrace ();} IWq#W(yM  
catch(Exception e){e.printStackTrace ();} X-(4/T+v  
} JO+tY[q  
&T~X`{V]`  
DA.k8M  
//读取保存的下载信息(文件指针位置) W\NC3]  
private void read_nPos() =$fz</S=J  
{ KmTFJ,iM  
try{ w"wW0uE^  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qz{9ND| )  
int nCount = input.readInt(); M/dgW` c  
nStartPos = new long[nCount]; >36,lNt  
nEndPos = new long[nCount]; X;N?L%Pp  
for(int i=0;i<nStartPos.length;i++) 6-fv<Pn  
{ R$8{f:Pj  
nStartPos = input.readLong(); yDwh]t  
nEndPos = input.readLong(); 3 h d30o  
} 6#!CBY^{  
input.close(); -(]C FnD_N  
} f!`? _  
catch(IOException e){e.printStackTrace ();} ^9:`D@Z+  
catch(Exception e){e.printStackTrace ();} V5z2.} 'o-  
} eqsmv [  
j~G(7t  
}#7rg_O]>  
private void processErrorCode(int nErrorCode) O ~6%Iz`  
{ .Zv~a&GE  
System.err.println("Error Code : " + nErrorCode); uVCH<6Cp  
} Z|%h-~  
o3/o2[s  
#-<Go'yF  
//停止文件下载 4&sf{tI  
public void siteStop() hHU=lnO  
{ ^2nrA pF  
bStop = true; 9`*Eeb>  
for(int i=0;i<nStartPos.length;i++) H8FvI"J  
fileSplitterFetch.splitterStop(); $_E.D>5^%7  
k#Sr;"  
/HpM17   
} +tT"  
} ~x \uZ^:  
//负责部分文件的抓取 >&KH!:OX|  
**FileSplitterFetch.java Q(nTL WW  
*/ q.`< q  
package NetFox; G rp{ .  
>kK@tJn  
ZBK0`7#&EH  
import java.io.*; |HD>m'e  
import java.net.*; i7XY3yhC  
{pIh/0  
$t.oGd@N  
public class FileSplitterFetch extends Thread { LhbdvJAk@  
jez0 A  
H.ksI;,  
String sURL; //File URL ,3Q~X$f  
long nStartPos; //File Snippet Start Position w;`Jj -  
long nEndPos; //File Snippet End Position 6dR+qJa6i  
int nThreadID; //Thread's ID >5Yn`Fc5  
boolean bDownOver = false; //Downing is over k`8O/J  
boolean bStop = false; //Stop identical t4_yp_  
FileAccessI fileAccessI = null; //File Access interface ?J2A1iuq3  
<&l$xn  
MmN{f~Kq9  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XNWtX-[ ^@  
{ gZ$ 8Y7  
this.sURL = sURL; ~3?-l/$  
this.nStartPos = nStart; 5 ix*wu`,  
this.nEndPos = nEnd; !q\=e@j-i  
nThreadID = id; f?Zjd&|Ch  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p{^:b6  
} .i RKuBM/  
+ig%_QED[\  
$qQYxx@  
public void run() ]O"f%   
{ dDpAS#'s\  
while(nStartPos < nEndPos && !bStop) (4cdkL  
{ .Rk8qRB  
.cHgYHa  
k i<X^^  
try{ l5{60$g  
URL url = new URL(sURL); UrizZ 5a  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w5HIR/kP  
httpConnection.setRequestProperty("User-Agent","NetFox"); m7'<k1#"Y  
String sProperty = "bytes="+nStartPos+"-"; UJI2L-;Ul  
httpConnection.setRequestProperty("RANGE",sProperty); FfJ;r'eGs  
Utility.log(sProperty); MF4 (  
B@&sG 5ES  
W/!P1M n  
InputStream input = httpConnection.getInputStream(); dj Ojd,  
//logResponseHead(httpConnection); 5;/n`Bd  
CW &z?Bra  
uGMzU&+  
byte[] b = new byte[1024]; +M0pmK!  
int nRead; '6dVe 2V  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Snf_{A<  
{ gM3:J:N  
nStartPos += fileAccessI.write(b,0,nRead); e.n(NW  
//if(nThreadID == 1) "=Br&FN{|  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e c&Y2  
} kL*P 3 0  
+twoUn{#  
?7aZU  
Utility.log("Thread " + nThreadID + " is over!"); U"k$qZ[  
bDownOver = true; -+rzc&h  
//nPos = fileAccessI.write (b,0,nRead); E{|B&6$[}  
} H`CID*Ji  
catch(Exception e){e.printStackTrace ();} V%oZT>T3  
} (SBhU:^h  
} 90<g=B  
{-\U)&6#v  
MNd\)nX  
//打印回应的头信息 ."$t&[;s  
public void logResponseHead(HttpURLConnection con) ~(^P(  
{ 2IJK0w@  
for(int i=1;;i++) H{*D c_  
{ :25LQf^nz  
String header=con.getHeaderFieldKey(i); +lx& $mr?  
if(header!=null) 2 |je{  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A `Z/B[)  
Utility.log(header+" : "+con.getHeaderField(header)); M/?,Qii  
else uAn}qrqE9  
break; 5daq}hsQs  
} ]c/E7|0Q  
} 2FIL@f|\7z  
y/Xs+ {x  
' k,2*.A  
public void splitterStop() l a3B`p  
{ )\akIA  
bStop = true; R@o&c%K"  
}  'o-4'  
,QcS[9$  
.G O0xnm  
} tqGrhOt  
JXB)'d0  
w>%@Ug["  
/* wh8';LZ>R  
**FileAccess.java Y %"Ji[  
*//文件访问(定位,写) j7~FR{: j  
package NetFox; h:?^0b!@  
import java.io.*; U] LDi8  
5'} V`?S  
xLW$>;kI  
public class FileAccessI implements Serializable{ ``-N2U5  
L'= \|r  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vF27+/2+R  
RandomAccessFile oSavedFile; XnyN*}8  
long nPos; QKG3>lU  
3Qy@^"  
q)k:pQ   
public FileAccessI() throws IOException 3z8i0  
{ ue_wuZi  
this("",0); '$9o(m#  
} YWFE*wQ!  
^jL '*&l  
R BYhU55B  
public FileAccessI(String sName,long nPos) throws IOException |6E_N5~  
{ o`bc/3!  
oSavedFile = new RandomAccessFile(sName,"rw"); 2d&F<J<sU  
this.nPos = nPos; ;k<dp7^  
oSavedFile.seek(nPos); 80=0S^gEZ  
} j6m;03<|  
K zWo}tT  
&`r/+B_W  
public synchronized int write(byte[] b,int nStart,int nLen) uz8LF47@:-  
{ n#(pT3&  
int n = -1; k#].nQG  
try{ [l23b{  
oSavedFile.write(b,nStart,nLen); q(KjhM  
n = nLen; g>lZs  
} ]S6Gz/4aV+  
catch(IOException e) [X(4( 1i  
{ aFnel8  
e.printStackTrace (); pXk^EV0  
} or]v]*:~l  
7UfNz60+~  
ZVjB$-do  
return n; W XQ@kQD  
} X6HaC+P  
02-ql F@i  
MEDh  
} / F0q8j0  
^""edCs  
I|@+O#  
/* /DQYlNa  
**SiteInfoBean.java gEh/m.L7  
*/ da$FY7  
package NetFox; zxyl+tU &  
Tgdy;?  
-k'<6op  
public class SiteInfoBean { G@8)3 @  
H [=\_X1o(  
(80m'.X  
private String sSiteURL; //Site's URL s0SzO,Vi  
private String sFilePath; //Saved File's Path 4#$#x=:  
private String sFileName; //Saved File's Name ? #K|l*  
private int nSplitter; //Count of Splited Downloading File ATs_d_Sz  
K`4lL5oH  
{r^_g(.q  
public SiteInfoBean() :Jd7q.  
{//nSplitter的缺省值为5 4V+bE$Wu  
//default value of nSplitter is 5 1h,iWHC  
this("","","",5); /5@YZ?|#2  
} &.)=>2  
|2(q9j  
;ArwEzo(  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CFtQPTw  
{ }%wd1`l7  
sSiteURL= sURL; 3lP;=* m.  
sFilePath = sPath; 'a~@q~!  
sFileName = sName; ~ ld.I4  
this.nSplitter = nSpiltter; t>j_C{X1(  
f}:C~L!  
a'J0}j!  
} +-izC%G  
LF dvz0  
L:i&OCU2k  
public String getSSiteURL() >*-%:ub  
{ GP} ;~  
return sSiteURL; #AD_EN9  
} VvhfD2*T  
d ^bSV4  
ho\1[xS  
public void setSSiteURL(String value) fM= o?w6v  
{ \6b~$\~B  
sSiteURL = value; u$nzpw0=H  
} 6!<I'M'[e  
"Y&I#&$b\  
[&lK.?V)  
public String getSFilePath() il0K ^i  
{ O. * 0;5  
return sFilePath; (v]%kXy/G  
} 3?93Pj3oPt  
3[m~-8  
@r"\bBi  
public void setSFilePath(String value) mqSVd^  
{ }lZEdF9GhG  
sFilePath = value; GBJL B  
} cO?*(e1m=  
74%vNKzc~  
~1G^IZ6  
public String getSFileName() ptCF))Zm'  
{ \:vF FK4a  
return sFileName; WogUILB  
} c{q+h V=  
}Fe~XO`  
BQu |qr q  
public void setSFileName(String value) o[C^z7WG0  
{ r%,?uim#  
sFileName = value; N ,~O+  
} {cK<iQJ  
u0C:q`;z  
EC+t-:a]  
public int getNSplitter() CK_dEh2c  
{ j7I=2xnTWu  
return nSplitter; E7uIur=g!  
} V?mP7  
bWFa{W5!  
?ANW I8'_j  
public void setNSplitter(int nCount) ~f<'] zXv  
{ ~k*]Z8Z  
nSplitter = nCount; [ 8Ohg  
} $>rt0LOF  
} mGT('iTM4  
U:7h>Z0W  
+){^HC\7h  
/* l+ }=D@l  
**Utility.java f:;-ZkIU ?  
*/ *D]:{#C*  
package NetFox; DV5hTw0  
Q'<AV1<  
.S` q2C\  
public class Utility { :V/".K-:J  
6H#: rM  
wE .H:q4&  
public Utility() Ev fvU:z  
{ x ;DoQx  
*>m[ZJd%=  
~Ztn(1N  
} +k`L8@a3&  
KzHN|8 $o  
//线程睡眠 [LVXXjkFI  
public static void sleep(int nSecond) |$WHw*F^  
{ 9*"  
try{ -]3K#M)s  
Thread.sleep(nSecond); TmgC {_  
} r)<A YX]J  
catch(Exception e) OUv)`K  
{ P\"kr?jZP  
e.printStackTrace (); T?3Q<[SmI  
} J=A)]YE  
} [S6u:;7  
fUw:jE xz  
//日志 "Q:Gd6?h;  
public static void log(String sMsg) x^ s,<G  
{ Q 3WD!Z8y  
System.err.println(sMsg); cU;Bm}U  
} w2B)$u  
wNa5qp 0  
=!TUf/O-  
public static void log(int sMsg) L>Y+}]~  
{ C[FHqo9M?H  
System.err.println(sMsg); Ym'h vK  
} 8h] TI_  
} f&-`+V}U  
v :pT(0N  
1}VaBsEV  
/* yP"2.9\erH  
**TestMethod.java 5/.W-Q\pl}  
*/ yi$CkG}  
package NetFox; &xGdKH  
{B$CqsvJ  
80nEQT y  
public class TestMethod { 7L~ *%j  
:WB uU  
'#Wx@  
public TestMethod() V]zZb-m=  
{ ///xx/weblogic60b2_win.exe XYU5.  
try{ V.B@@ ;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,_V V;P  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BJ UG<k  
SiteFileFetch fileFetch = new SiteFileFetch(bean); y##h(y  
fileFetch.start(); .}__XWK5  
} CW1l;uwtU  
catch(Exception e){e.printStackTrace ();} 9p_?t'&>q  
@a8lF$<  
Tm" H9  
} oidZWy  
Jm_)}dj3o  
'_v~+  
public static void main(String[] args) V%-hP~nyBx  
{ V60L\?a  
new TestMethod(); Q[OwP  
} {!Qu(%  
} ^4sfVpD2!  
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