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http断点续传简单实现(java)

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/* l:bbc!3  
**SiteFileFetch.java \ykA7Y%  
*/ 6d6Dk>(V  
package NetFox; K7.ayM 0  
import java.io.*; 3-6MGL9  
import java.net.*; "L`BuAB  
{O).!  
2L[!~h2  
public class SiteFileFetch extends Thread { r..f$FF)\  
c`hENPhW  
PhV/WjCZ  
SiteInfoBean siteInfoBean = null; //文件信息Bean ZR%$f-  
long[] nStartPos; //开始位置 f*88k='\W  
long[] nEndPos; //结束位置 %.wR@9?  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Q9h=1G\K  
long nFileLength; //文件长度 5} <OB-9  
boolean bFirst = true; //是否第一次取文件 E(_k#X  
boolean bStop = false; //停止标志 Rq e|7/As  
File tmpFile; //文件下载的临时信息 ZZwIB3sNhf  
DataOutputStream output; //输出到文件的输出流 zBwqIJfM  
u|.|dv'mbp  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ,)!%^ ~v  
public SiteFileFetch(SiteInfoBean bean) throws IOException ntB#2S  
{ ;@Z1y  
siteInfoBean = bean; lj8ficANo  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); W"pHR sf  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");  W/u(9  
if(tmpFile.exists ()) R >SZE"  
{ y1~ QKz  
bFirst = false; f%1\1_^g  
read_nPos(); Anpp`>}N  
} 6I=xjgwvf  
else {06ClI  
{ fF>hca>  
nStartPos = new long[bean.getNSplitter()]; hR:i!  
nEndPos = new long[bean.getNSplitter()]; C+ Y;D:  
} Z+EZ</'(a  
.I]v D#o  
Mae2L2vc  
U(x$&um(l  
} y!:vX6l  
zFipuG02  
TOgH~R=  
public void run() 8tf>G(I{  
{ N+5f.c+S-  
//获得文件长度 {R[V  
//分割文件 RhT:]  
//实例FileSplitterFetch =h=-&DSA  
//启动FileSplitterFetch线程 #lSGH 5Fp?  
//等待子线程返回 >ifys)wg>  
try{ 8'zfq ]g  
if(bFirst) 7<(U`9W/q  
{ hH-!3S2'  
nFileLength = getFileSize(); 59:kL<;S-  
if(nFileLength == -1) "R-j  
{ oRcP4k;d=  
System.err.println("File Length is not known!"); n ~&ssFC  
} wv\"(e7(  
else if(nFileLength == -2) r4gLoHD)  
{ y?3u6q++  
System.err.println("File is not access!"); `('Up?  
} Au/'|%2#(  
else W>?aZv  
{ g2}aEfp!H  
for(int i=0;i<nStartPos.length;i++) v;g,qO!LJ  
{ 8'fF{C  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); RtxAIMzh?  
}  ]SL+ZT  
for(int i=0;i<nEndPos.length-1;i++) /:BC<]s  
{ Uvi@HB HJ  
nEndPos = nStartPos[i+1]; n>:e8KVM;  
} qPUACuF'  
nEndPos[nEndPos.length-1] = nFileLength; : 4lR`%  
} cFJZ|Ld  
} rW~G'  
,If"4C!w  
,,IK}  
//启动子线程 'cIFbjJ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _U*1D*kLI[  
for(int i=0;i<nStartPos.length;i++) 6 !fq658  
{ N>P" $  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f4dHOH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), prIJjy-F  
nStartPos,nEndPos,i); Oq3t-omXS  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !^1oH**  
fileSplitterFetch.start(); @^-f +o  
} }095U(@  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ov\%*z2=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q'ib7R;V,  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Zw/??Tq b  
nEndPos = " + nFileLength); {+kWK;1  
// fileSplitterFetch[nPos.length-1].start(); L+lye Ir'  
AGVipI #  
aK,\e/Oo  
//等待子线程结束 $SniQ  
//int count = 0; >%_i#|dE>  
//是否结束while循环 ]i `~J  
boolean breakWhile = false; rXe+#`m2  
eB,@oo%  
Tn38]UL  
while(!bStop) Nii5},  
{ Ur""&@  
write_nPos(); z!~{3M  
Utility.sleep(500); }y*rO(cu7G  
breakWhile = true; ?ia O6HD  
N a.e1A&?j  
[f$pq5f='  
for(int i=0;i<nStartPos.length;i++) &mA{_|>  
{ z^%`sUgP  
if(!fileSplitterFetch.bDownOver) RcI0n"Gi_  
{ %V!!S#W  
breakWhile = false; :O;uP_r9  
break; IY(;:#l  
} SQuW`EHBgs  
} RT9%E/m  
if(breakWhile) j2n 4; m  
break; 3}.OSt'=  
!#WJ(zSq  
X%B2xQM 5  
//count++; @XKVdtG  
//if(count>4) 3);W gh6  
// siteStop(); Ftu d6  
} 'sI @e s  
f_QZ ql  
HNfd[#gV  
System.err.println("文件下载结束!"); GMob&0l8_  
} )f%Q7  
catch(Exception e){e.printStackTrace ();} l~*d0E-$  
} Y3'dV)  
Vt4,?"  
2-"`%rE  
//获得文件长度 w /CD-  
public long getFileSize() 9v}vCg  
{ %BRll  
int nFileLength = -1; 6b4]dvl_  
try{ L7.LFWq$S  
URL url = new URL(siteInfoBean.getSSiteURL());  <>=abgg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); twPD'X!r  
httpConnection.setRequestProperty("User-Agent","NetFox"); TiI3<.a!  
.ldBl  
piPV&ytI  
int responseCode=httpConnection.getResponseCode(); Jqt|' G3  
if(responseCode>=400) 8.' THLI  
{ `SYq/6$VEH  
processErrorCode(responseCode); 7)Bizlf  
return -2; //-2 represent access is error I{u+=0^Y  
} o7:"Sl2AD  
^c>ROpic  
AiV1 vD`  
String sHeader; X,+N/ nku  
Otm7j>w  
"I[u D)$  
for(int i=1;;i++) {_J1m&/  
{ NUX2{8gs  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [\pp KC  
//Utility.log(in.readLine()); JB!KOzw  
sHeader=httpConnection.getHeaderFieldKey(i); 'jU;.vZex  
if(sHeader!=null) \YF'qWB  
{ fu`|@S  
if(sHeader.equals("Content-Length")) brt` oR  
{ Cqw`K P  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J`A )WsKkb  
break; xgB-m[Xi  
} ' C1yqkIa`  
} xO'xZ%cUI  
else j|(bdTZY:  
break; `[.4SIah  
} o}lA\A  
} Ns`:=  
catch(IOException e){e.printStackTrace ();} ^g N?Io  
catch(Exception e){e.printStackTrace ();} s!K9-qZl<  
)%(H'omvl  
@)Sd3xw[  
Utility.log(nFileLength); @>hXh +!2h  
>U[YSsFt6  
je~gk6}Y  
return nFileLength; JztSP?  
} T#R*]  
<o&\/uO~H  
qu0dWgK  
//保存下载信息(文件指针位置) q8f nUK?i  
private void write_nPos() G!m;J8#m(  
{ `v1~nNoY  
try{ ndB*^nT  
output = new DataOutputStream(new FileOutputStream(tmpFile)); >U'gQS?\]  
output.writeInt(nStartPos.length); ~px)Jd  
for(int i=0;i<nStartPos.length;i++) WzO[-csy  
{ V]A*' ke/  
// output.writeLong(nPos); 1ba* U~OEg  
output.writeLong(fileSplitterFetch.nStartPos); ?O#,|\v?]  
output.writeLong(fileSplitterFetch.nEndPos); V']1j  
} u-#J!Z<T8  
output.close(); -Mufo.Jz1o  
} a6.0 $'  
catch(IOException e){e.printStackTrace ();} PsoW:t  
catch(Exception e){e.printStackTrace ();} Z <vTr6?  
} 3gU*,K7  
23[XmBf  
C*,PH!$k  
//读取保存的下载信息(文件指针位置) _8nT$!\\  
private void read_nPos() +h? z7ZY^  
{ _f~m&="T!  
try{ e.pq6D5  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i?pC[Ao-_  
int nCount = input.readInt(); Z%O>|ozpq  
nStartPos = new long[nCount]; wDS(zG   
nEndPos = new long[nCount]; ( G#W6  
for(int i=0;i<nStartPos.length;i++) ^6I8a"  
{ Q?TXM1Bp  
nStartPos = input.readLong(); ^B7C8YP  
nEndPos = input.readLong(); P0^7hSo  
} \KPwh]0  
input.close(); )Aa  h  
} qx\P(dOUf  
catch(IOException e){e.printStackTrace ();} *%`jcF  
catch(Exception e){e.printStackTrace ();} Hs6}~d  
} B#;0{  
[}bPkD  
7F D.3/  
private void processErrorCode(int nErrorCode) p*S;4+>#  
{ Z:s:NvFX  
System.err.println("Error Code : " + nErrorCode); Pi:=0,"XOp  
} xSoXf0zq:  
`tZ`a  
/QCyA%y  
//停止文件下载 H@hHEzO  
public void siteStop() Qp]-4%^Vz  
{ 1brKs-z  
bStop = true; ZRo-=/1  
for(int i=0;i<nStartPos.length;i++) 2k3yf_N  
fileSplitterFetch.splitterStop(); meNz0ve  
+zn207 .`  
@&M$oI$4*  
} O/2Jz  
} i7(\i2_P  
//负责部分文件的抓取 vAp?Zl?g  
**FileSplitterFetch.java uA2-&smw  
*/ f$^+;j  
package NetFox; [?Ub =sp  
j>t*k!db  
-S%)2(f^  
import java.io.*; *<nfA}  
import java.net.*; v\?J$Hdd  
Ffp<|2T2_  
z ''-AH,  
public class FileSplitterFetch extends Thread { SR\F2@u  
P",E/beV  
{Lm%zdk*k  
String sURL; //File URL ;NzS;C'  
long nStartPos; //File Snippet Start Position trC+Etc   
long nEndPos; //File Snippet End Position y()Si\9v  
int nThreadID; //Thread's ID E)7ODRVbl  
boolean bDownOver = false; //Downing is over Co#_Cyxg=9  
boolean bStop = false; //Stop identical #yVMC;J?W  
FileAccessI fileAccessI = null; //File Access interface &BDdJwE  
2r|!:^'?W  
qEbzF#a-:  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k_<8SG+`  
{ #XlE_XD  
this.sURL = sURL; `2Oh0{x0*O  
this.nStartPos = nStart; @Ui dQX"b  
this.nEndPos = nEnd; {<3>^ o|"  
nThreadID = id; ;Jrk#7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Yi+~}YP.E(  
} ep3iI77/  
]\t+zF>&Y  
{Q la4U  
public void run() #Qp.O@e  
{ pD>^Dfd  
while(nStartPos < nEndPos && !bStop) d@72z r  
{ ^BFD -p  
0fTEb%z8  
 !bi}9w  
try{ 9k@`{+wmZ  
URL url = new URL(sURL); on q~wEr  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cOr@dUSL  
httpConnection.setRequestProperty("User-Agent","NetFox"); SAEV "  
String sProperty = "bytes="+nStartPos+"-"; 32sb$|eQq  
httpConnection.setRequestProperty("RANGE",sProperty); KVrK:W--p  
Utility.log(sProperty); mTW@E#)n  
`1[GY){?)  
bu2'JIDR  
InputStream input = httpConnection.getInputStream(); t[ZumQ@HC  
//logResponseHead(httpConnection); !F|iL  
k5@_8Rc  
dIR6dI   
byte[] b = new byte[1024]; #`0iN+qh  
int nRead; 7o4 vf~  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rGe^$!QB  
{ ^{W#ut>IN  
nStartPos += fileAccessI.write(b,0,nRead); :tA|g  
//if(nThreadID == 1) Um$a9S8b&  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ymsqJ   
} Mwdw7MZ"S  
69v[* InSd  
] cv|A^  
Utility.log("Thread " + nThreadID + " is over!"); E+&]96*Lby  
bDownOver = true; ew n/@;E  
//nPos = fileAccessI.write (b,0,nRead); |UO1vA@  
} 2.K"+%  
catch(Exception e){e.printStackTrace ();} {mp;^/O`er  
} H5N(MihT  
} JqdNO:8  
n>dM OQb  
"p\XaClpz  
//打印回应的头信息 >)N}V'9  
public void logResponseHead(HttpURLConnection con) Lz VvUVk  
{ RhJL`>W`  
for(int i=1;;i++) 2,>q(M6,EA  
{ qKL_1 ~  
String header=con.getHeaderFieldKey(i); Hf/2KYZ  
if(header!=null) lE54RX}e4  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?ExfxR!~  
Utility.log(header+" : "+con.getHeaderField(header)); \\D~Yg\#  
else A*h)p@3t<  
break; [^gSWU  
} bz~-uHC  
} _l?5GLl_F$  
f-\l<o(  
Z v=p0xH  
public void splitterStop() ]'aG oR  
{ -BV&u(  
bStop = true; 7#,+Q(2  
} (WW,]#^  
"gCSbMq(Vq  
B(MO!GNg=  
} nDvny0^a  
>NwrJSx  
u%O^hcfb  
/* fxLhVJ"b  
**FileAccess.java `,(1'  
*//文件访问(定位,写) %;9e h'  
package NetFox; ZUyM:$  
import java.io.*; zYOPE 6E  
n20H{TA  
e<^tY0rR&  
public class FileAccessI implements Serializable{ 0nAeeVz|  
Iw"?%k\U  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }}qR~.[  
RandomAccessFile oSavedFile; 8IC((  
long nPos; >t8eVMMa  
r/Pg,si  
+V |]:{3W  
public FileAccessI() throws IOException /$rS0@p  
{ nWZrB s _  
this("",0); YKh%`Y1<  
} O)5-6lm  
%!rsu-W:Y  
Yb =8\<;  
public FileAccessI(String sName,long nPos) throws IOException Pr<?E[  
{ $zCUQthL@  
oSavedFile = new RandomAccessFile(sName,"rw"); $)@zlnU  
this.nPos = nPos; HIh oYSwB  
oSavedFile.seek(nPos); >[xQUf,p  
} I{cn ,,8  
ecf7g)+C  
rI]:| k  
public synchronized int write(byte[] b,int nStart,int nLen) )KRO=~Y  
{ q#\eL~k  
int n = -1; 3F}d,aB A  
try{ F{T|lTl  
oSavedFile.write(b,nStart,nLen); 9/s-|jD  
n = nLen; /gFyow1W  
} 6}ax~wYct  
catch(IOException e) uR"]w7=  
{ +[2lS54"W4  
e.printStackTrace (); 00pHnNoxW  
} &U 'Ds!  
g1J]z<&  
f\(Kou$  
return n; jv0e&rt  
} >8NQ8i=]V1  
5. l&nt'  
q>omCk%h  
} |J}~a8o  
3\@6i'  
[1vrv(u>  
/* NM]6  o  
**SiteInfoBean.java I3s}t$`y(  
*/ 8'cDK[L  
package NetFox; 3YT _GW{  
'ZDa*9nkF  
eB]ZnJ2^=  
public class SiteInfoBean { E 0oJ|My  
^$#Q_Y|  
ac&tpvij  
private String sSiteURL; //Site's URL f CVSVn"o  
private String sFilePath; //Saved File's Path 2dI:],7  
private String sFileName; //Saved File's Name rz.`$b  
private int nSplitter; //Count of Splited Downloading File \R#XSW,  
q5RLIstQ\  
4*dT|NU  
public SiteInfoBean()  03#_ (  
{//nSplitter的缺省值为5 pI^n("|  
//default value of nSplitter is 5 WD)[Ac[  
this("","","",5); Ql V:8:H$  
} ]CL70+[^9  
oD}I{&=wa  
L|H{;r'  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter)  z`_N|iEd  
{ da<1,hF  
sSiteURL= sURL; FP\[7?ZLn  
sFilePath = sPath; g{a0,B/j  
sFileName = sName; &`%C'KZ  
this.nSplitter = nSpiltter; 1IsR}uLh  
)i>KYg w  
eX$Biv1N  
} "{:*fI;!  
_6[NYv$"  
L`p[Dq.  
public String getSSiteURL() 5s|gKM  
{ Cv=0&S.  
return sSiteURL; lubS{3<  
} @rdC/=Y[  
fAm2ls7c  
lk'RWy"pw  
public void setSSiteURL(String value) =Vv{td  
{ ~>EVI=?  
sSiteURL = value; SVHtv0Nx  
} b13>>'BMB  
#*`|}_6L  
8_ LDS  
public String getSFilePath() r#j*vO '  
{ ?:2Xh/8-  
return sFilePath; u J$"2<O  
} SW=p5@Hy{  
z(=:J_N  
=wQ=`  
public void setSFilePath(String value) %SE g(<  
{ 04"hQt{[  
sFilePath = value; GQQ!3LwP\O  
} npF[J x[  
f0uiNy(r$  
^m7PXY  
public String getSFileName() ,s)H%  
{ ~E\CAZ  
return sFileName; ^q6~xC,/  
} +1y#=iM{  
ZA P+jX;  
~Mx fud  
public void setSFileName(String value) p)ONw"sb  
{ 8?$2;uGL  
sFileName = value; nGt8u4gcP  
} Zry>s0  
7MfT~v  
tX_eN  
public int getNSplitter() (!b: gG  
{ c'6H@m#=  
return nSplitter; 8+ u8piG  
} gM*s/,;O"  
Vh<`MS0X  
7~16letQ  
public void setNSplitter(int nCount) a !IH-XJ2  
{ ZUu^==a  
nSplitter = nCount; W< n`[  
} |); >wV"  
} x EBjfn  
Q^k# ?j#  
(g Z!o_  
/* !2Orklzd1  
**Utility.java  /F_ :@#H  
*/ JVkawkeX  
package NetFox; sa`Yan  
S|[UEU3FpB  
GXfVjC31z  
public class Utility {  g{%';  
 UyQn onS  
o;[oy#aWl_  
public Utility() &0g,Xkr  
{ g|P hNo  
1@WGbORc*  
82X.  
} Y8PT`7gd`  
R+K[/AA  
//线程睡眠 #RF=a7&F  
public static void sleep(int nSecond) Trrh`@R  
{ gy{a+Wbc*  
try{ @I&"P:E0F;  
Thread.sleep(nSecond); =Wf@'~K0k"  
} `T70FsSJ  
catch(Exception e) QP#Wfk(C  
{ #-;BU{3*  
e.printStackTrace (); G DV-wPX  
} L9T u>4  
} {9Y'v  
$<v_Vm?6d  
//日志 z m'jk D|  
public static void log(String sMsg) ! Cl/=0$[L  
{ +2SX4Kxu  
System.err.println(sMsg); Iqsk\2W]a3  
} qC )VT3  
L?0l1P  
f[I c hCwX  
public static void log(int sMsg) +]-KzDsr"V  
{ lIz_0rE  
System.err.println(sMsg); 2An`{')  
} Bt,Xe~$z-  
} R~~rqvLm  
=@2V#X]M*  
#E9['JnZ  
/* ' l|_$3  
**TestMethod.java yr>bL"!CA  
*/ ;X(n3F  
package NetFox; ?_aR-[XRg  
spJ(1F{|V  
4*x!B![]y  
public class TestMethod { Ct)MvZ  
sh ;uKzQ  
3ZlI$r(  
public TestMethod() >K :"[?  
{ ///xx/weblogic60b2_win.exe iI*7WO[W  
try{ 8(>.^667  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QCR-lxO1  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +,Az\aT/%  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |xVCl<{F%  
fileFetch.start(); 86#mmm)  
}  2JP?6N  
catch(Exception e){e.printStackTrace ();} KeB4Pae|V  
_m],(J=,z  
)\-";?sYky  
} (L$~ zw5gr  
|8 bO5l:  
Wq(l :W'  
public static void main(String[] args) C8EC?fSQ  
{ /\rq$W_  
new TestMethod(); <(4#4=ivP  
} ,SF.@^o@a  
} Eap/7U1Q  
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