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http断点续传简单实现(java)

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/* A+UU~?3y  
**SiteFileFetch.java <fs2fTUeqF  
*/ %bdjBa}  
package NetFox; zdp/|"D!  
import java.io.*; M_%B|S {  
import java.net.*; >(snII  
5A4&+rdU  
mSo_} je(  
public class SiteFileFetch extends Thread { m-jHze`D3  
:Pv*, qHE  
cDI [PJ9  
SiteInfoBean siteInfoBean = null; //文件信息Bean .YZgOJi  
long[] nStartPos; //开始位置 qBT.x,$  
long[] nEndPos; //结束位置 5j-]EJb  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 WsD M{1c  
long nFileLength; //文件长度 p^pOuy8  
boolean bFirst = true; //是否第一次取文件 IO/4.m-aN#  
boolean bStop = false; //停止标志 }`NU@O#  
File tmpFile; //文件下载的临时信息 EFc-foN  
DataOutputStream output; //输出到文件的输出流 i:l<C  
kMsnW}Nu  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Tc+gdo>G  
public SiteFileFetch(SiteInfoBean bean) throws IOException dqX;#H}h  
{ -!\fpl{  
siteInfoBean = bean; sQ 8s7l0D  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Rtjqx6-B;  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); E{2Eoj;gq  
if(tmpFile.exists ()) EutP\K_Y  
{ 9Mgq1Z  
bFirst = false; /o2P+Xr8"  
read_nPos(); $8crN$ye  
} 1lpwZ"  
else Ia'ZV7'  
{ 1HPx|nmE]  
nStartPos = new long[bean.getNSplitter()]; F]I=+T   
nEndPos = new long[bean.getNSplitter()]; ZY56\qcY  
} K2<~(78C  
Ea( ,aVlj  
wI5Yn h  
p)~lL  
} S{K0.<,E  
 P5gN#G  
@WKzX41'  
public void run() &''WRgZ}  
{ 9*:gr#(5  
//获得文件长度 |0z;K:5s  
//分割文件 <A.W 8b7D  
//实例FileSplitterFetch wdvLx  
//启动FileSplitterFetch线程 dz[ bm< T7  
//等待子线程返回 DKm Z  
try{ NS C/@._  
if(bFirst) bOI3^T  
{ F6hmku>\1  
nFileLength = getFileSize(); 3u33a"nL8  
if(nFileLength == -1) |7@O( $b  
{ z 5]bia,  
System.err.println("File Length is not known!"); -]:G L>b  
} B[9 (FRX  
else if(nFileLength == -2) 7P7b8 ]  
{ _e!F~V.  
System.err.println("File is not access!"); \b*X:3g*  
} N:"C+ a(  
else ^ZTGJ(j7~  
{ CCDDK L]N:  
for(int i=0;i<nStartPos.length;i++) jKIc09H|  
{ )$Z(|M4  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); _KD5T4FZR  
} ;PyZ?Z;  
for(int i=0;i<nEndPos.length-1;i++) q|)Q9+6$+  
{ #2xSyOrmf  
nEndPos = nStartPos[i+1]; <a le$[  
} W0cgI9=9  
nEndPos[nEndPos.length-1] = nFileLength; insY(.N  
} }vt%R.u  
} tK%c@gGU9  
B ?%L  
]|:uU  
//启动子线程 jQj,q{eA  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z"I/ NGiU  
for(int i=0;i<nStartPos.length;i++) `xKFqx:e  
{ 34|a:5c  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8Og3yFx[rt  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), sNU}n<J-  
nStartPos,nEndPos,i); V7t!?xOL  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g\M5:Qm  
fileSplitterFetch.start(); qS8B##x+=  
} *9gD*AnM,  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u2sR.%2U<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #^mqQRpgq  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KhM.Tc  
nEndPos = " + nFileLength); XY+y}D %  
// fileSplitterFetch[nPos.length-1].start(); *i<\iMoW  
^i_Iqph=  
Jfg7\&|  
//等待子线程结束 s'_,:R\VM>  
//int count = 0; @C.GKeM*  
//是否结束while循环 aU<s<2 O)  
boolean breakWhile = false; /r.6XZs6  
r[HT9  
>#N[GrJAE  
while(!bStop) XizPMN5a  
{ R,Ml&4pZ}  
write_nPos(); vD=%`G[m  
Utility.sleep(500); ; Zq/eiB  
breakWhile = true; d bO#  
MD'>jO;n  
e.X@] PQJQ  
for(int i=0;i<nStartPos.length;i++) kX8=cL9G  
{ Fh`-(,e?5  
if(!fileSplitterFetch.bDownOver) \f"?Tv-C'  
{ Q\#UWsN(T/  
breakWhile = false; elbG\qXBp  
break; vR]mSX3)?  
} /4C`k=>  
} .[f;(WR  
if(breakWhile) R [9w  
break; g@E&uyM  
oBw}hH,hp  
]P*!'iYN(  
//count++; 0>Fqx{!heq  
//if(count>4) R$xY8+}V  
// siteStop(); K/Jk[29"\  
} 2X_>vIlEm  
;c)! @GoA  
T}2:.Hk:N  
System.err.println("文件下载结束!"); ~V$ f #X  
} eU~?p|Np  
catch(Exception e){e.printStackTrace ();} t F/nah  
} 46dc.Yi  
2v\W1VF  
h[H%:743  
//获得文件长度 yqBa_XPV8  
public long getFileSize() "%kG RHq  
{ ITn;m  
int nFileLength = -1; 1"$R 3@s;  
try{ qvTKfIl{  
URL url = new URL(siteInfoBean.getSSiteURL()); oeGS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FF@`+T  
httpConnection.setRequestProperty("User-Agent","NetFox"); xA9V$#d|  
x3;jWg~'  
 V IYV92[  
int responseCode=httpConnection.getResponseCode(); %1Jd ^[W  
if(responseCode>=400) eE,;K1  
{ gA:[3J,[;  
processErrorCode(responseCode); /h-6CR Ka  
return -2; //-2 represent access is error !5E9sk{)  
} .xnQd^qoac  
z'e1"Y.  
9,KVBO  
String sHeader; {]@Qu"M  
Fd}<Uote3  
X}?ESjZJ  
for(int i=1;;i++) fOJj(0=y  
{ L"9 Gc  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s+N^PX3  
//Utility.log(in.readLine()); @LHtt/&  
sHeader=httpConnection.getHeaderFieldKey(i); taixBNv  
if(sHeader!=null) sM0c#YK?  
{ < %/:w/  
if(sHeader.equals("Content-Length")) !4L#$VG  
{ ,0FwBK  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tNYJQ  
break; &R0OeRToUb  
} +&?'KZ+Z_v  
} j]#wrm  
else pB[%:w/@l:  
break; at=D&oy4"+  
} G+fd.~aGE  
} 8 `o{b"l+  
catch(IOException e){e.printStackTrace ();}  .?70=8{  
catch(Exception e){e.printStackTrace ();} q?1yE@th  
4 ;^g MI9  
m^5s >hUl  
Utility.log(nFileLength); XEa~)i{O  
bD  d_}  
BZ2nDW*%  
return nFileLength; /!:L7@BZ  
} |z]aa  
xa' nJ"f;  
Euqjxz  
//保存下载信息(文件指针位置) 8IpxOA#jQ  
private void write_nPos() l#p }{  
{ ofVEao  
try{ P_v0))n{  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $R8>u#K!  
output.writeInt(nStartPos.length); C0P*D,  
for(int i=0;i<nStartPos.length;i++) ^zKt{a  
{ #"|"cYi,  
// output.writeLong(nPos); ?VUgwP_=  
output.writeLong(fileSplitterFetch.nStartPos); ~v^%ze  
output.writeLong(fileSplitterFetch.nEndPos); E`Q;DlXv>  
} Ii,~HH  
output.close(); ;5-R =e(KA  
} 9e0C3+)CY  
catch(IOException e){e.printStackTrace ();} Wk7L:uK  
catch(Exception e){e.printStackTrace ();} U.HoFf+HN  
} F\zkyk 4  
z|Hy>|+  
"[#@;{@Gt  
//读取保存的下载信息(文件指针位置) B{[f}h.n  
private void read_nPos() ^).WW  
{ vYYS .ve  
try{  Y>xi|TWN  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); MV% :ES?  
int nCount = input.readInt(); f37ji  
nStartPos = new long[nCount]; X\o/i\ C}  
nEndPos = new long[nCount]; dMey/A/VYt  
for(int i=0;i<nStartPos.length;i++) 0m]~J_   
{ tniPEmeS  
nStartPos = input.readLong(); Y')O>C0~  
nEndPos = input.readLong(); [`y:M&@  
} A4~D#V  
input.close(); Vf"O/o}hq,  
} IOSuaLH^  
catch(IOException e){e.printStackTrace ();} UOn!Y@  
catch(Exception e){e.printStackTrace ();} BM|-GErE  
} 6U;Jg_zS  
Cf.pTYSl  
"Czz,;0  
private void processErrorCode(int nErrorCode) pe\Txg6  
{ 9(QU2QY  
System.err.println("Error Code : " + nErrorCode); "bHtf_  
} &>&dhdTQ  
ipx@pNW;"  
h5LJij J  
//停止文件下载 ,:0Q1~8  
public void siteStop() /Ki0+(4  
{ XR{5]lKt_  
bStop = true; dH ^b)G4  
for(int i=0;i<nStartPos.length;i++) se<i5JsSV  
fileSplitterFetch.splitterStop(); Paae-EmC  
2(+RIu0d  
)![f\!'PI  
} 5W?yj>JR  
} Y|hzF:ll  
//负责部分文件的抓取 <7vIh0  
**FileSplitterFetch.java kGB#2J  
*/ }V1DyLg :  
package NetFox; 4@/q_*3o  
0C7thl{Dms  
1Qp1Es<)  
import java.io.*; xHM&csL  
import java.net.*; <Z\MZ&{k{*  
. 1{vpX  
9pVf2|5hj  
public class FileSplitterFetch extends Thread { {u(}ED#p  
"ay,Lr  
zxk??0] /  
String sURL; //File URL +XU$GSw3(  
long nStartPos; //File Snippet Start Position t7U,AQ=;P5  
long nEndPos; //File Snippet End Position `@u+u0  
int nThreadID; //Thread's ID z/eU^2V  
boolean bDownOver = false; //Downing is over 9G`FY:(K  
boolean bStop = false; //Stop identical wu&|~@_s@  
FileAccessI fileAccessI = null; //File Access interface 6nY )D6$JG  
!Zk%P  
^'C,WZt  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +LQs.*  
{ V'HlAQr  
this.sURL = sURL; }\PE {  
this.nStartPos = nStart; -7Aw s)  
this.nEndPos = nEnd; )|{1&F1  
nThreadID = id; =u:6b} =  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /JK-}E  
} NE=#5?6%g7  
O5G<O(,\  
K=!ZI/+ju  
public void run() v)C:E9!|  
{ j &0fC!k  
while(nStartPos < nEndPos && !bStop) V:0uy>  
{ lt2Nwt0bv  
LAK-!!0X  
NU)`js  
try{ ,#'o)O#  
URL url = new URL(sURL); 'n>3`1E,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =7J|KoKK  
httpConnection.setRequestProperty("User-Agent","NetFox"); 764}yV>  
String sProperty = "bytes="+nStartPos+"-"; `:bvuc(  
httpConnection.setRequestProperty("RANGE",sProperty); Vlp*'2VO  
Utility.log(sProperty); (Qh7bfd  
$3]E8t  
 [A%e6  
InputStream input = httpConnection.getInputStream(); vS J<  
//logResponseHead(httpConnection); x^='pEt{  
G0 nH Z6  
_#^A:a^e8  
byte[] b = new byte[1024]; Z_^Kl76D  
int nRead; ax{-Qi7z-+  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =-Q  
{ TgQ|T57  
nStartPos += fileAccessI.write(b,0,nRead); \HP,LH[P:  
//if(nThreadID == 1) 'Qs 3  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -MHX1`P:Sn  
} wsb=[$C  
'+q'H  
(;Q <@PZg  
Utility.log("Thread " + nThreadID + " is over!"); U+RCQTo  
bDownOver = true; 6ImV5^l  
//nPos = fileAccessI.write (b,0,nRead); &h4Z|h[01  
} K3r>nGLBo  
catch(Exception e){e.printStackTrace ();} ;5oH6{7_Z  
} C1P t3  
} H'= i  
T`'3Cp$q  
Alk* "p  
//打印回应的头信息 >gi{x|/  
public void logResponseHead(HttpURLConnection con) Uhx2 _  
{ CO%O<_C  
for(int i=1;;i++) 0.Ol@fO  
{ xX4^nem\G  
String header=con.getHeaderFieldKey(i); Ff#N|L'9_  
if(header!=null) -_4jJxh=OB  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); rW%'M#! =  
Utility.log(header+" : "+con.getHeaderField(header)); E?q'|f  
else ;'18  
break; J>|:T  
} eUw;!Du  
} OB  i!fLa  
g`8 mh&u%  
@Kb|  
public void splitterStop() Zn 5m.=z  
{ U/&qV"Ih  
bStop = true; q}A3"$-F  
} -qCJwz30  
$XU$?_O  
UUEDCtF)  
} Pymh^i  
a5~C:EU0  
uy-Ncy  
/* Sl<-)a:  
**FileAccess.java Umwg iw  
*//文件访问(定位,写) xY'YbHFz  
package NetFox; v*]Xur6e}  
import java.io.*; A`/7>'k/q[  
+#db_k  
4aGpKvW  
public class FileAccessI implements Serializable{ 7<Js'\Z  
(X7yNIPfA  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IlL   
RandomAccessFile oSavedFile; ZXDMbMD  
long nPos; qlT:9*&g  
gV44PI6h  
+~{nU'  
public FileAccessI() throws IOException -Izg&u &  
{ VM|)\?Q  
this("",0); U"kK]Stk<  
} W2(=m!:U  
)3\rp$]1  
zw9ULQ$#  
public FileAccessI(String sName,long nPos) throws IOException *ik)>c_  
{ G8-d%O p  
oSavedFile = new RandomAccessFile(sName,"rw"); uOUw8  
this.nPos = nPos; (qONeLf%  
oSavedFile.seek(nPos); jtpNo~O  
} g^^m a}i  
L`@&0Zk  
2m}]z.w#  
public synchronized int write(byte[] b,int nStart,int nLen) Yy~Dg  
{ .z7f_KX^  
int n = -1; vjWgR9 4/{  
try{ GuDD7~qxY  
oSavedFile.write(b,nStart,nLen); 'N/%SRk  
n = nLen; ^o<Nz8  
} BeCr){,3  
catch(IOException e) m,fr?d/;  
{ V0B4<TTAo~  
e.printStackTrace (); yf>,oNIAg  
} zMg^2{0L  
r 24]2A  
Y(mwJud|  
return n; TU6EE  
} B|w}z1.  
3CL:VwoW  
TK1M mL  
} X,Q(W0-6$u  
#f@53Pxb  
!LESRh?  
/* +eat,3Ji  
**SiteInfoBean.java duTSU9  
*/ ^U1 +D^AJ  
package NetFox;  KX@Fgs  
@72G*u\Wz  
Jx,s.Z0@7,  
public class SiteInfoBean { &$ 9bC 't6  
hD=D5LYAZ  
%|||M=akk  
private String sSiteURL; //Site's URL ;0WlvKF  
private String sFilePath; //Saved File's Path oOw"k*,h:S  
private String sFileName; //Saved File's Name Z.:A26  
private int nSplitter; //Count of Splited Downloading File TR;-xst@  
V!4E(sX  
wjs7K|PK  
public SiteInfoBean() $xwF;:)  
{//nSplitter的缺省值为5 gNBI?xs`p  
//default value of nSplitter is 5 oWT0WS  
this("","","",5); d DTt_B  
} : DP{YL|x  
3x$#L!VuU  
n+w>Qz'  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \^D`Hvg  
{ pwQ."2x  
sSiteURL= sURL; *0tNun 5=3  
sFilePath = sPath; (["u"m%  
sFileName = sName; ekXHfA!i%  
this.nSplitter = nSpiltter; nfU}ECun4  
GQQ6 t  
Si(?+bda0c  
} -8: @xG2  
\(s ";@  
>U]. k8a)  
public String getSSiteURL() ]y/:#^M+  
{ ^  +G> N  
return sSiteURL; UKdzJEhG  
} KA7nncg;,  
mD:!"h/  
2TO1i0  
public void setSSiteURL(String value) N[%IrN3  
{ %\u>%s <9  
sSiteURL = value; -b<+Ra  
} y+_U6rv[  
01b0;|  
 lwlR"Z  
public String getSFilePath() {1 mD(+pJ{  
{ CEiG jo^  
return sFilePath; NoT oLt\  
} qp8;=Nfa  
#=2~MXa@z7  
Qoc-ZC"<6  
public void setSFilePath(String value) YZd4% zF  
{ .#SWfAb2h  
sFilePath = value; u=5^xpI<D  
} pE#0949  
!|]%^G  
O-RiDYej  
public String getSFileName() xK f+.6 wz  
{ R[6&{&E:  
return sFileName; q0o6%c:gW  
} 3i<*,@CY  
W/+0gh7`,(  
!^%b|=[  
public void setSFileName(String value) i=+ "[h^  
{ M~v{\!S  
sFileName = value; A-kI_&g\Og  
} N gr7E  
3Dy.mtP  
Xv6s,<#\  
public int getNSplitter() 1*s Lj#  
{ BX?Si1c  
return nSplitter; }Q*8QV  
} !GO4cbdQ  
/PO5z7n0J  
!,]_tw>R  
public void setNSplitter(int nCount) p AD@oPC  
{ y37@4p^@9  
nSplitter = nCount; k;]&`c^5  
} a`}HFHm\2,  
} u(P D+Gz  
XWk^$"  
|zSkQ_?54  
/* NVQ IRQ.  
**Utility.java PR6{Y]e%  
*/ 6HyQm?c>a  
package NetFox; ,+f'%)s_x  
=6ojkTk  
.Sm7na K  
public class Utility { s i C/k*  
V7.EDE2A3  
cu |{cy-  
public Utility() dx|j,1e  
{ 8{'L:yzMY  
~%'M[3Rb  
Vg0Rc t  
} rTQrlQ:@  
!-[e$?-  
//线程睡眠 XvWUJ6M  
public static void sleep(int nSecond) hl8[A-d(R  
{ =MA$xz3  
try{ ! fY'^Ya?  
Thread.sleep(nSecond); ka655O/)&  
} PKk_9Xd  
catch(Exception e) {qK>A?9  
{ y<MXd,eE  
e.printStackTrace (); =*fOej>G  
} n"* A.  
} Y'wQ(6ok  
&G:#7HX@-  
//日志 B\`4TU}kE  
public static void log(String sMsg) w\!aKeP'  
{ _3.=| @L  
System.err.println(sMsg); M"W-|t)~  
} It&$R`k  
C0J/FFBQ^  
M, f6UYo=  
public static void log(int sMsg) rxJmK$qd  
{  Q#i[Y?$L  
System.err.println(sMsg); *>I4X=  
} p@0Va  
} )cxLpTr  
f5'Cq)Vw_  
8tJB/P w`S  
/* 0e-M 24,C  
**TestMethod.java EVX*YGxx6  
*/  *Yj!f68  
package NetFox; yy8h8{=g  
k  <SFl  
8iQ8s;@S&>  
public class TestMethod { /x\{cHAt8J  
#l2KJ7AMK  
YBF|0A{[Y  
public TestMethod() AUBZ7*VO  
{ ///xx/weblogic60b2_win.exe dz_~_|  
try{ hhRUC&Y%V  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v"-@'qN'  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vuN!7*d+  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ls51U7  
fileFetch.start(); ?o$ hlX  
} ,%Sf,h?"^  
catch(Exception e){e.printStackTrace ();} _=$:<wIE[  
Ts)ox}rYVm  
L{&5Ets  
} o>~xrV`E  
x:dI:G  
@~g][O#Fu  
public static void main(String[] args) T3H\KRe6  
{ P~xP@? I%  
new TestMethod(); 3Q;XvrGA  
} 7UnB]-:.  
} %OT} r  
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