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http断点续传简单实现(java)

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/* Tn7Mt7h  
**SiteFileFetch.java 8<VDp Y  
*/ 7{#p'.nc5  
package NetFox; $--8%gh dG  
import java.io.*; q8{Bx03m6  
import java.net.*; j1_>>xB  
,} t%7I  
ug9Ja)1|  
public class SiteFileFetch extends Thread { ;jzJ6~<  
K *@?BE  
56Wh<i3  
SiteInfoBean siteInfoBean = null; //文件信息Bean $u<;X^  
long[] nStartPos; //开始位置 K)'[^V Xh  
long[] nEndPos; //结束位置 n {?Du  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 V%R]jbHZ#  
long nFileLength; //文件长度 #Pd9i5~N  
boolean bFirst = true; //是否第一次取文件 ([8*Py|  
boolean bStop = false; //停止标志 `oxBIn*BD  
File tmpFile; //文件下载的临时信息 mI&3y9; (  
DataOutputStream output; //输出到文件的输出流 )z7CT|h7S  
`wi+/^);  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 1uo- ?k  
public SiteFileFetch(SiteInfoBean bean) throws IOException VzT*^PFBg  
{ (Y~/9a4X  
siteInfoBean = bean; zZ[kU1Fyv  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); lMgguu~qg  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); CEj_{uf|  
if(tmpFile.exists ()) Te+#  
{ K3zY-yIco  
bFirst = false; 3~sV-  
read_nPos(); }9ulHiR  
} EZj rX>"#  
else }hn?4ny  
{ /[/L%;a'p  
nStartPos = new long[bean.getNSplitter()]; #'/rFT4{v  
nEndPos = new long[bean.getNSplitter()]; =ls+vH40&  
} JrBPx/?(,;  
Yup#aeXY/  
|E6Thvl$  
5YrzOqg=  
} ~=yU%5 s@  
}oD^tU IK  
61_PSScSY  
public void run() 6GuTd  
{ MgiW9@_(  
//获得文件长度 CV[9i  
//分割文件 J{4=:feIC?  
//实例FileSplitterFetch ZKI8x1>Iq  
//启动FileSplitterFetch线程 Q%6zr9  
//等待子线程返回 D&fOZVuqZ  
try{ >FeCa h Fn  
if(bFirst) 56Lxr{+X  
{ !~zn*Hm  
nFileLength = getFileSize(); O C;~ H{  
if(nFileLength == -1) 92j[b_P  
{ (%6fZ  
System.err.println("File Length is not known!"); O}C*weU  
} 6EY\  
else if(nFileLength == -2) 5xc e1[  
{ whN<{AG  
System.err.println("File is not access!"); >JNdtP8s/1  
} CL7_3^2qI  
else \6AM?}v  
{ rX^uHq8  
for(int i=0;i<nStartPos.length;i++) K7s[Fa6J  
{ W /v &V#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 0<V/[$}\D  
} $JOtUB{  
for(int i=0;i<nEndPos.length-1;i++) y:E$n!  
{ Q0-gU+ig  
nEndPos = nStartPos[i+1]; U^}7DJ  
} ?* +>T@MH  
nEndPos[nEndPos.length-1] = nFileLength; I`+,I`~u  
} "uplk8iCJ  
} ?0 cv  
y /vc\e  
xsU%?"r  
//启动子线程 (e;/Smol  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -V2f.QE%  
for(int i=0;i<nStartPos.length;i++) bRggt6$z  
{  `\##M=  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `)$G}7cRUH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P*[wB_^&UP  
nStartPos,nEndPos,i); n+ H2cl }  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n3? msY(*  
fileSplitterFetch.start(); uju'Bs7   
} |J@ &lBlq  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P\@kqf~pC  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); uNEl]Q]<e]  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mY=sh{ir  
nEndPos = " + nFileLength); *|q{(KX  
// fileSplitterFetch[nPos.length-1].start(); B3yTN6-  
GsO(\hR6^  
Z6b]EcP)#  
//等待子线程结束 D\;5{,:d  
//int count = 0; g'!"klS93  
//是否结束while循环 N*[b 26  
boolean breakWhile = false; XlXt,  
Pc?"H!Hkn  
t!xdKX& }  
while(!bStop) W$7H "tg  
{ oumbJ7X=L  
write_nPos(); du0o4~-  
Utility.sleep(500); ld"rL6  
breakWhile = true; Ne;0fk O  
7'At_oG  
EajJv>X7  
for(int i=0;i<nStartPos.length;i++) d %FLk=]  
{ W9} ,f  
if(!fileSplitterFetch.bDownOver) r=37Q14v  
{ s-IM  
breakWhile = false; tYgHJ~1L*  
break; DBGU:V,85  
} o; 6^:  
} 4C?4M;  
if(breakWhile) )Ft+eMYti[  
break; ?c8( <_I+  
Wm{ebx  
\FX"A#  
//count++; \ C$t  
//if(count>4) Ttl m&d+C  
// siteStop(); |bQF.n_  
} a~R.">>$  
Q(Yn8t  
cDYO Ju.  
System.err.println("文件下载结束!"); ]Ar,HaX-  
} RnC+]J+?4  
catch(Exception e){e.printStackTrace ();} E 6MeM'sx  
} J8@.qC'!  
I5QtPqB>  
sZ7,7E|_  
//获得文件长度 pyX:$j2R+%  
public long getFileSize() B[h^]k  
{ unqUs08  
int nFileLength = -1; -ON-0L  
try{ i`<L#6RBT  
URL url = new URL(siteInfoBean.getSSiteURL()); *:+ZEFMq  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3mopTzs)  
httpConnection.setRequestProperty("User-Agent","NetFox"); R'vNJDFY  
!?).4yr  
[+l6x1Am  
int responseCode=httpConnection.getResponseCode(); j(k%w  
if(responseCode>=400) Jqgm>\y  
{ 0;)Q  
processErrorCode(responseCode); - q(a~Ge  
return -2; //-2 represent access is error k;JDVRL  
} -{C Gn5]_#  
ShlTMTgS  
,B_tAg4~  
String sHeader; o~CEja &(  
T.')XKP)1N  
!Ea9 fe  
for(int i=1;;i++) ~z]VDEJ{q  
{ `'5vkO>  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z5F#r>>`  
//Utility.log(in.readLine()); a[z$ae7  
sHeader=httpConnection.getHeaderFieldKey(i); LXJ;8uW2y  
if(sHeader!=null) \Wg_ gA  
{ qQ3pe:n?  
if(sHeader.equals("Content-Length")) 2"shB(:z>  
{ QBi]gT@&g  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q}l~n)=  
break; lup2> "?*  
} bZAL~z+ V  
} IsJx5GO  
else PJ?C[+&  
break; (C uM*-  
} XHdhSFpm  
} f[R~oc5P0  
catch(IOException e){e.printStackTrace ();} Bxw(pACf  
catch(Exception e){e.printStackTrace ();} Y-st2r[,  
4{vEW(  
|N)),/R_  
Utility.log(nFileLength); |*b-m k  
Q@PDhISa  
]xoG{%vgb  
return nFileLength; C4gES"T  
} 34"PtWbV>  
 .9r85  
%{3q=9ii  
//保存下载信息(文件指针位置) 7{w}0PMx  
private void write_nPos() %\|{_]h}y  
{ QY<5o;m`  
try{ '+vmC*-I(  
output = new DataOutputStream(new FileOutputStream(tmpFile)); r_,;[+!  
output.writeInt(nStartPos.length); `jr?I {m;  
for(int i=0;i<nStartPos.length;i++) ;PMh>ZE`  
{ D*PEIsV  
// output.writeLong(nPos); m__pQu:  
output.writeLong(fileSplitterFetch.nStartPos); l1O"hd'~s  
output.writeLong(fileSplitterFetch.nEndPos); uM,Ps}  
} E,K>V:P*  
output.close(); gX-hYQrC  
} 0b n%L~KU  
catch(IOException e){e.printStackTrace ();} GP %hf{  
catch(Exception e){e.printStackTrace ();} |#SZd Xg  
} v@M^ukk'}  
uPYH3<  
< FO=PM  
//读取保存的下载信息(文件指针位置) 1kUlQ*[<|  
private void read_nPos() liLhvcd  
{ %m[ZU<v  
try{ Z_S{$D  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f^"pZS  
int nCount = input.readInt(); nu~]9~)I  
nStartPos = new long[nCount]; :-Py0{s  
nEndPos = new long[nCount]; dVHbIx  
for(int i=0;i<nStartPos.length;i++) cL03V?} ~  
{ rMZuiRz*  
nStartPos = input.readLong(); B@6L<oZ  
nEndPos = input.readLong(); mK"s*tD  
} t#t[cgI  
input.close(); gJrWewEe  
} Q@NFfJJ  
catch(IOException e){e.printStackTrace ();} W-&V:S{<  
catch(Exception e){e.printStackTrace ();} U-m MKRV  
} ,5ZQPICF  
=8<~pr-NO  
3b]M\ F9  
private void processErrorCode(int nErrorCode) Av5:/c.B  
{ C&*1H`n  
System.err.println("Error Code : " + nErrorCode); 'x"(OdM:[  
} 2=0HQXXrq  
8=joVbs  
w=rD8 @  
//停止文件下载 u-4@[*^T$  
public void siteStop() vW vu&3tx  
{ CAs:>s '8  
bStop = true; qdv O>k3  
for(int i=0;i<nStartPos.length;i++) H, :]S-T  
fileSplitterFetch.splitterStop(); $8HiX6r  
R(VOHFvW6  
'/@wk#,  
} k>.8lc\  
} 9:VUtx#}2  
//负责部分文件的抓取 6X m'^T  
**FileSplitterFetch.java T :m" eD;  
*/ CPRVSN0b{4  
package NetFox; h"0)spF"d  
P}A!C9Frh  
m}=E$zPbO  
import java.io.*; GbL1<P$V  
import java.net.*; 9jEH"`qqk  
h3 XS t  
0*rD'?)K+  
public class FileSplitterFetch extends Thread { b"N!#&O]  
]SRpMZ  
A0k?$ko  
String sURL; //File URL <EN9s  
long nStartPos; //File Snippet Start Position ^ W?cuJ8  
long nEndPos; //File Snippet End Position 3)\fZYu)  
int nThreadID; //Thread's ID X|eZpIA45  
boolean bDownOver = false; //Downing is over |llJ%JhF  
boolean bStop = false; //Stop identical _(kaaWJ  
FileAccessI fileAccessI = null; //File Access interface 0.n[_?<(  
lNa+NtQu  
1nskf*Z  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ihf :k_;  
{ y*vSt^  
this.sURL = sURL; PMB4]p%o  
this.nStartPos = nStart; Uza '%R  
this.nEndPos = nEnd; :Z6j5V;s  
nThreadID = id; TSsZzsdr2  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~qGW9 4  
} e}d(.H%l0  
FC, =g`Q!  
Im/tU6ybV  
public void run() A&~fw^HM  
{ TxP +?1t  
while(nStartPos < nEndPos && !bStop) ^sLx3a  
{ "W(Ae="60  
+W*~=*h|  
RK|*yt"f"  
try{ lYQ|NL():  
URL url = new URL(sURL); ~:bdS 4w  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'Uf?-t*LT@  
httpConnection.setRequestProperty("User-Agent","NetFox"); KBN% TqH|  
String sProperty = "bytes="+nStartPos+"-"; 9T24dofkJ  
httpConnection.setRequestProperty("RANGE",sProperty); sEdz`F  
Utility.log(sProperty); #H>{>0q  
PKSfu++Z  
@3O)#r}\  
InputStream input = httpConnection.getInputStream(); `!HD. E[2c  
//logResponseHead(httpConnection); "Nj/{BU  
PLc5m5  
D @*<O=_D(  
byte[] b = new byte[1024]; f;zNNx< ;  
int nRead; >{IPt]PCn  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r%ES#\L6+|  
{ ~&73f7  
nStartPos += fileAccessI.write(b,0,nRead); "/i$_vl  
//if(nThreadID == 1) ?s^3 o{!<W  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TD}<U8I8_  
} 'YNdrvz  
0^-1d2Z~  
Wx GD*%  
Utility.log("Thread " + nThreadID + " is over!"); 3Hom0g,V4  
bDownOver = true; w#9Kt W,tt  
//nPos = fileAccessI.write (b,0,nRead); =L" 0]4K  
} :V)jm`)#+  
catch(Exception e){e.printStackTrace ();} cu0IFNF}[  
} ^}d]O(  
} P6 OnE18n  
JF4A  
-Qn7+?P  
//打印回应的头信息 FRrp@hE  
public void logResponseHead(HttpURLConnection con) YNU}R/u6^  
{ kk3^m1  
for(int i=1;;i++) <'I["Um  
{ :;7I_tb  
String header=con.getHeaderFieldKey(i); fo@^=-4A-  
if(header!=null) [s {!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); St-uE |8  
Utility.log(header+" : "+con.getHeaderField(header)); y!77gx?-  
else A]/o-S_  
break; { :tO RF  
} J/?Nf2L4  
} pFd8p@m_2  
"n!yK  
;"wCBuXcu  
public void splitterStop() tF0jH+7J-  
{ B;1qy[  
bStop = true; ~.m<`~u  
} 85GIEUvH/  
&[.`xZ(|  
H,!xTy"Wh  
} )#}>,,S  
jV3PTU  
=^nb+}Nz(  
/* \c}(rqT  
**FileAccess.java dw bR,K  
*//文件访问(定位,写) Q6@<7E]y  
package NetFox; ^"/^)Lb!@M  
import java.io.*; zN4OrG 0  
Ic#xz;elM  
R2~Tr$:  
public class FileAccessI implements Serializable{ iEr,ly  
[]>'Dw_r  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kz"uTJK  
RandomAccessFile oSavedFile; #&&T1;z"#  
long nPos; _>;Wz7  
!Lf<hS^  
V)`2 Kw  
public FileAccessI() throws IOException _IDZ.\'>$  
{ pN%&`]Wev  
this("",0); N4!`iS Y  
} Z4j6z>qE  
,BU;i%G&s  
7~/cz_  
public FileAccessI(String sName,long nPos) throws IOException 'YNaLZ20  
{ I &t~o  
oSavedFile = new RandomAccessFile(sName,"rw"); Eah6"j!B8n  
this.nPos = nPos; OU[<\d  
oSavedFile.seek(nPos); *U?O4E9  
} NB"S ,\M0  
HGDrH   
l90mM'[  
public synchronized int write(byte[] b,int nStart,int nLen) (jgk! 6  
{ Ej(J j\  
int n = -1; 'ZfgCu)St  
try{ Ey46JO"  
oSavedFile.write(b,nStart,nLen); c3A\~tHW  
n = nLen; }htjT/Nm  
} 0lfK} a  
catch(IOException e) >H2`4]4]  
{ vT'Bs;QR  
e.printStackTrace (); !>8~R2  
} (yOkf-e2y  
1o_kY"D<  
BM%wZ: s  
return n; h+f>#O+:  
} 0B NLTRv  
> VG  
H",B[ YK  
} _'u]{X\k{J  
a|aVc'j  
bLgH3[{  
/* /:&!o2&1H  
**SiteInfoBean.java l>?c AB[  
*/ ^PksXfk  
package NetFox; J3K=z  
7|P kc(O  
U@lc 1#  
public class SiteInfoBean { NR{wq|"  
l\HdB"nT  
aER|5!7(2\  
private String sSiteURL; //Site's URL 9(CvGzco <  
private String sFilePath; //Saved File's Path |y\Km  
private String sFileName; //Saved File's Name OZ,kz2SF#  
private int nSplitter; //Count of Splited Downloading File /HC:H,"i  
[m t.2.  
pm&TH d  
public SiteInfoBean() Ac7^JXh%  
{//nSplitter的缺省值为5 1^p/#jt  
//default value of nSplitter is 5 iTVe8eI  
this("","","",5); S2~cAhR|M  
} )xGAe#E~j  
[M_{~1xX  
:QCL9QZ'  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^E !v D  
{ #x%'U}sF  
sSiteURL= sURL; bf3!|Um  
sFilePath = sPath; L"L3n,%F  
sFileName = sName; &J[a.:..  
this.nSplitter = nSpiltter; 8s%/5v"  
^S9y7b^;r  
R`?l .0  
} 4JSPD#%f  
mYBEjZ B  
5sD,gZ7  
public String getSSiteURL() g;IlS*Ld  
{ T) C@6/  
return sSiteURL; BxY t*b%  
} $EMOz=)I#  
s:`i~hjq  
85{m+1O~  
public void setSSiteURL(String value) o9?@jjqH  
{ G4&s_ M$  
sSiteURL = value; DA =U=F  
} W+nu=iQ!  
J3Mb]X)_}  
e5 =d Ev  
public String getSFilePath() 9N ]Xa  
{ 7*'/E#M  
return sFilePath; (z?HyxRT  
} ]' mbHkn68  
\ /-c)  
'nJF:+30ZH  
public void setSFilePath(String value) *p l6 V|  
{ LzygupxY!  
sFilePath = value; ^\)a[OWp  
} WKf<% E$  
k#*-<1  
`S&a.k  
public String getSFileName() 'X~tt#T  
{ mgxIxusR  
return sFileName; T?9D?u?]  
} *P()&}JK  
~m%[d. }e  
,N/@=As9$  
public void setSFileName(String value) D{|qP nE4  
{ E3L?6Qfx>  
sFileName = value; I8F+Z  
} T}~TW26v  
BT{;^Hp  
J=V  
public int getNSplitter() gmTBT#{6yH  
{ \}-4(Xdaq  
return nSplitter; y)f.ON36I  
} !`ol&QQ#  
\?bV\/GBR  
D+8d^-:  
public void setNSplitter(int nCount) w$gvgz  
{ R^Rc!G}  
nSplitter = nCount; p< R:[rz  
} fBO/0uW  
} r4.6W[| d  
[ X*p [  
Re%[t9 F&  
/* -luQbGcT3  
**Utility.java ia6 jiW x  
*/ ,,3lH-C  
package NetFox; PN}+LOD<t  
#mH@ /6,#[  
6K2e]r  
public class Utility {  *7Dba5B  
B6XO&I1c  
E}^V@ :j>  
public Utility() k(Yz2  
{ xh6(~'$  
|9@,ri\'Rg  
0SpB 2>_  
} :\T Mm>%q  
>T$0*7wF  
//线程睡眠 W? 7l-k=S  
public static void sleep(int nSecond) LS@TTiN   
{ s"(RdJ-,  
try{ *k$[/{S1-  
Thread.sleep(nSecond); ~cz}C("Z  
} O5dS$[`j\p  
catch(Exception e) <H[w0Z$  
{ \u=d`}E  
e.printStackTrace (); `At.$3B  
} 2Gyq40  
} u ExLj6  
Q G) s  
//日志 'Kelq$dn#  
public static void log(String sMsg) F?L]Dff  
{ jKSj);  
System.err.println(sMsg); , c.^"5  
} _h%Jf{nu  
+sNS  
+/OSg.  
public static void log(int sMsg) whI{?NP  
{ .j6udiv5  
System.err.println(sMsg); $C16}^  
} OT#@\/>  
} +)jUA]hJ/  
F)P:lvp<r  
QE]@xLz   
/* =g% L$b<i  
**TestMethod.java b3N IFKw  
*/ x/QqG1q  
package NetFox; s|YH_1r  
h y rPu_  
+]l?JKV  
public class TestMethod { uJ`N'`Z  
M-WSdG[AJ  
ulR yt^bx|  
public TestMethod() .EYL  
{ ///xx/weblogic60b2_win.exe ^Z (cV g  
try{ /E>;O47a  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f5}afPk  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gz`Jzh j  
SiteFileFetch fileFetch = new SiteFileFetch(bean); X)g X9DA  
fileFetch.start(); cIug~ x>  
} --HDEc|  
catch(Exception e){e.printStackTrace ();} h'ik3mLH  
=D zrM%  
WC_.j^sW  
} #1YMpL  
Km2~nkQ  
P0N/bp2Uy  
public static void main(String[] args) /Qgb t  
{ Z;+,hR((  
new TestMethod(); tpI/I bq  
} hvt]VC]]  
} cGot0' mB  
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