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http断点续传简单实现(java)

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/* \:UIc*S  
**SiteFileFetch.java ;4pYK@9w_  
*/ q0zr E5  
package NetFox; sjV!5Z  
import java.io.*; \vO,E e~#W  
import java.net.*; uu>Pkfo  
@8I4[TE  
:Cj OPl  
public class SiteFileFetch extends Thread { (R("H/6xs  
v p/yG   
U3dwI:cG  
SiteInfoBean siteInfoBean = null; //文件信息Bean )z28=%g  
long[] nStartPos; //开始位置 Ptdpj)oi&Q  
long[] nEndPos; //结束位置 L}pt)w*V1j  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W@I|Q -  
long nFileLength; //文件长度 Zo~  
boolean bFirst = true; //是否第一次取文件 @P?~KW6<|  
boolean bStop = false; //停止标志 XY3v_5~/1F  
File tmpFile; //文件下载的临时信息 ZNvEW  
DataOutputStream output; //输出到文件的输出流 fd.^h*'mU  
]%u@TK7  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ,]d /Q<  
public SiteFileFetch(SiteInfoBean bean) throws IOException @W"KVPd  
{ z+n,uHs  
siteInfoBean = bean; ybKWOp:O  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); lE(a%'36  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /x p|  
if(tmpFile.exists ()) }xh$T'M8  
{ :BV6y|J9O^  
bFirst = false; m3/O.DY%0  
read_nPos(); [UWd W  
} M]2]\km  
else !*B'?|a<\  
{ x5-}h*  
nStartPos = new long[bean.getNSplitter()]; @X;!92i  
nEndPos = new long[bean.getNSplitter()]; z?*w8kU&>  
} >]vlkA(  
IHv[v*4:  
)x=1]T>v"'  
E vg_q>  
} 2KYw}j|5  
S(*sw 0O@+  
+Z !)^j  
public void run() ;"~ fZ2$U  
{ x#xFh0CA  
//获得文件长度 :Ra,Eu  
//分割文件 =*c7i]@}  
//实例FileSplitterFetch .7avpOfz  
//启动FileSplitterFetch线程 A#J`;5!Sc  
//等待子线程返回 lHPd"3HDK  
try{ SPY|K  
if(bFirst) ORJIo  
{ mQ|v26R  
nFileLength = getFileSize(); g'n7T|h ~  
if(nFileLength == -1) 9\mLW"  
{ Vg>dI&O  
System.err.println("File Length is not known!"); ]rH\`0  
} MS 81sN\d  
else if(nFileLength == -2) 9Hb6nm  
{ tne ST.  
System.err.println("File is not access!"); !C3MFm{B  
} |es?;s'  
else #(N+(():  
{ O @j} K4  
for(int i=0;i<nStartPos.length;i++) ':3 pq2{  
{ R5 - @  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); P"IPcT%Ob%  
} iW%I|&  
for(int i=0;i<nEndPos.length-1;i++) H2jgO?l;!  
{ AicBSqUke  
nEndPos = nStartPos[i+1]; 3yU.& k  
} bU2Z[sn.  
nEndPos[nEndPos.length-1] = nFileLength; ] [+#;avU  
} IID-k  
} v,-HU&/*B  
CR"|^{G  
d\|?-hY`[  
//启动子线程 $!-c-0ub  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R6kD=JY/!  
for(int i=0;i<nStartPos.length;i++) 4gz H8sF  
{ %\dz m-d(C  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <66X Xh.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7e|s wJ>4  
nStartPos,nEndPos,i); O7-mT8o  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q1"$<# t  
fileSplitterFetch.start(); F@'Jbd`   
} 1Z+8r  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W14 J],{L  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !Sh&3uy_qN  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", p6#g;$V$  
nEndPos = " + nFileLength); i1NY9br  
// fileSplitterFetch[nPos.length-1].start(); t\~P:"  
|y!=J$ $_H  
(a.z9nqGA  
//等待子线程结束 i@)i$i4  
//int count = 0; 75f"'nJ)  
//是否结束while循环 Q  Nh|Wz  
boolean breakWhile = false; -pf}  
N~goI#4  
(_mnB W  
while(!bStop) bnq; )>&  
{ 2Mc3|T4)U  
write_nPos(); ODNM+#}`  
Utility.sleep(500); nYR#  
breakWhile = true; K1"*.\?F  
Z<1FSk,[  
"U>JM@0DNm  
for(int i=0;i<nStartPos.length;i++) 4:$4u@   
{ Ai=s e2  
if(!fileSplitterFetch.bDownOver) N kb|Fd/s  
{ G'Q-An%z  
breakWhile = false; iNtaDX| %/  
break; JQ8fdP A  
} O`x;,6Vr  
} 1PVtxL?1P  
if(breakWhile) Z_};|B}  
break; v7BA[jQr  
D[aCsaR  
dx5#\"KX=,  
//count++; A&.WH?p  
//if(count>4) Vd,jlt.t  
// siteStop(); ([\  
} J%v=yBC2  
V:In>u$QJ!  
); !eow  
System.err.println("文件下载结束!"); W=^#v  
} n$x c];j  
catch(Exception e){e.printStackTrace ();} [842&5Pd?  
} WejY y|  
`<`` 8  
:|V$\!o'U  
//获得文件长度 Q('r<v96  
public long getFileSize() `5cKA;j>b  
{ &S{RGXj_  
int nFileLength = -1; >kj`7GA  
try{ qON|4+~u%  
URL url = new URL(siteInfoBean.getSSiteURL()); @Owb?(6?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cs,N <|  
httpConnection.setRequestProperty("User-Agent","NetFox"); +%zAQeb  
V)Z}En["1  
zT =Ho   
int responseCode=httpConnection.getResponseCode(); j"ThEx0  
if(responseCode>=400) lGPUIoUo  
{ Bn=by{i  
processErrorCode(responseCode); .0S~872  
return -2; //-2 represent access is error Uol|9F  
} 1n >X[! 8x  
AF;)#T<  
~P*6ozSYpY  
String sHeader; 3m]4=  
9_L[w\P|4  
|{BIHgMh  
for(int i=1;;i++) ?{P"O!I{  
{ @TLS<~  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); iEVb"w0 59  
//Utility.log(in.readLine()); +X#vVD3"  
sHeader=httpConnection.getHeaderFieldKey(i); w k(VR  
if(sHeader!=null) q M fT>rH  
{ J`peX0Stl  
if(sHeader.equals("Content-Length")) 3 R=,1<  
{ ypbe!Y<i]  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m!|kW{B#A  
break; nW PF6V>  
} /7a BDc-v  
} =e/9&993  
else s>B5l2Q4  
break; j`JMeCG=Ee  
} )IP,;<  
} iZ#!O* >  
catch(IOException e){e.printStackTrace ();} F3N?Nk/  
catch(Exception e){e.printStackTrace ();} "Q}#^h]F  
^ZvWR%  
j@W.&- _  
Utility.log(nFileLength); '-r).Xk  
(yu/l 6[  
' KWyx  
return nFileLength; d?s<2RkPT  
} ~ZmN44?R  
;X8yFq  
EY^1Y3D w0  
//保存下载信息(文件指针位置) bx#>BK!  
private void write_nPos() F|d\k Q  
{ o1-m1<ft  
try{ 3B1XZm  
output = new DataOutputStream(new FileOutputStream(tmpFile)); |jQ:~2U|   
output.writeInt(nStartPos.length); =}lh_  
for(int i=0;i<nStartPos.length;i++) 8ZM?)# `@{  
{ lW+\j3?Z$  
// output.writeLong(nPos); :}Xll#.,m  
output.writeLong(fileSplitterFetch.nStartPos); O!m vJD  
output.writeLong(fileSplitterFetch.nEndPos); 5QW=&zI`=  
} 8>trS=;n  
output.close(); (n*^4@"2  
} > A Khf  
catch(IOException e){e.printStackTrace ();} )_+rU|We  
catch(Exception e){e.printStackTrace ();} <>dT64R|  
} Y'c>:;JEe  
 |XT)QK1  
M`. tf_x  
//读取保存的下载信息(文件指针位置) !S^AgZ~  
private void read_nPos() G<At_YS  
{ 0C =3dnp6  
try{ H35S#+KX  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile));  J}htu  
int nCount = input.readInt(); j5K]CTz#  
nStartPos = new long[nCount]; UR%/MV  
nEndPos = new long[nCount]; ?+_Gs;DGVE  
for(int i=0;i<nStartPos.length;i++) FK:;e lZ  
{ dU6ou'p f  
nStartPos = input.readLong(); xAqb\|$^  
nEndPos = input.readLong(); YNLV9.P6  
} un)4eo!7  
input.close(); NE"@Bk cm  
} cQ/5qg  
catch(IOException e){e.printStackTrace ();} R{WE\T'  
catch(Exception e){e.printStackTrace ();} 9*2[B"5  
} C\3y {s  
~8~aJ^[  
1_o],? Q  
private void processErrorCode(int nErrorCode) $&y%=-]|  
{ yyoqX"v[  
System.err.println("Error Code : " + nErrorCode); $LKIT0  
} (*Z)(O*z  
hLI`If/+K  
{\S+#W\  
//停止文件下载 m`v2: S}  
public void siteStop() JI?rL  
{ I, -hf=-  
bStop = true; ]Uw<$!$-]s  
for(int i=0;i<nStartPos.length;i++) V `b2TS  
fileSplitterFetch.splitterStop(); M3J#'%$  
NV)!7~r}:  
:?k>HQe  
} )hd@S9Z.Y  
} _p# CwExuy  
//负责部分文件的抓取 CKtB-a  
**FileSplitterFetch.java &+a9+y  
*/ Fw/6?:C}O6  
package NetFox; C+?Hm1  
N96jJk  
~Fe${2   
import java.io.*; )i~cr2Hk  
import java.net.*; +1Vjw'P  
CAWA3fcQp  
*meZ8DV2DH  
public class FileSplitterFetch extends Thread { c;%_EN%  
`sUZuWL_  
wHsYF`  
String sURL; //File URL 3Vsc 9B"w  
long nStartPos; //File Snippet Start Position dA-2%uJ  
long nEndPos; //File Snippet End Position nIAx2dh?  
int nThreadID; //Thread's ID iDN;m`a  
boolean bDownOver = false; //Downing is over m$`RcwO  
boolean bStop = false; //Stop identical 6Se?sHC>  
FileAccessI fileAccessI = null; //File Access interface V_>\ 9m  
ji1viv  
_]04lGx27  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Scp7X7{N  
{ M^MdRu  
this.sURL = sURL; l*ayd>`~x  
this.nStartPos = nStart; ;6gDV`Twy  
this.nEndPos = nEnd; j Yx38_5e  
nThreadID = id; 4,..kSA3iw  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h "Xg;(K  
} g+DzscIT  
9!f/aI  
uG?_< mun  
public void run() Q Btnx[  
{ #%`|~%`{:  
while(nStartPos < nEndPos && !bStop) 9)0D~oUi  
{ FjK3 .>'  
0T@Zb={  
[r3!\HI7x  
try{ D5$wTI  
URL url = new URL(sURL); Q<z_/ j9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5 elw~u  
httpConnection.setRequestProperty("User-Agent","NetFox"); E_Im^a  
String sProperty = "bytes="+nStartPos+"-"; 6^%UU o%  
httpConnection.setRequestProperty("RANGE",sProperty); LL]zT H0  
Utility.log(sProperty); @WJg WJm  
 '/`= R  
eKgisY4#  
InputStream input = httpConnection.getInputStream(); 7bqBk,`9  
//logResponseHead(httpConnection); ykv94i?Q  
;E@G`=0St  
pM x  
byte[] b = new byte[1024]; | B. 0TdF  
int nRead; &?VQ,+[ <  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tDSJpW'd  
{ kV?y0J.  
nStartPos += fileAccessI.write(b,0,nRead); 9w"h  
//if(nThreadID == 1) M>DaQ`b  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kz{/(t  
} 6726ac{xz  
cS>e?  
zEs>b(5u  
Utility.log("Thread " + nThreadID + " is over!"); 3l)hyVf&  
bDownOver = true; aT_&x@x  
//nPos = fileAccessI.write (b,0,nRead); 8S>&WR%jH]  
} umD!2 w  
catch(Exception e){e.printStackTrace ();} AP[|Ta  
} 6^uq?  
} T^:UBjK6t{  
eyefWn&  
NZ ;{t\  
//打印回应的头信息 fYp'&Btb]x  
public void logResponseHead(HttpURLConnection con) D|@/yDQ  
{ JmPHAUd  
for(int i=1;;i++) OTMJ6)n7  
{ 1v,Us5s<"6  
String header=con.getHeaderFieldKey(i); aD=a,  
if(header!=null) S M!Txe#  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f-}[_Y%;  
Utility.log(header+" : "+con.getHeaderField(header)); N*%@  
else !xP8# |1  
break; 5Ycco,x  
} a-l; vDs  
} $"0MU  
HOw -]JSP2  
m0LTx\w!  
public void splitterStop() 8d?g]DEN)6  
{ "5;;)\o ~  
bStop = true; ?z}=B  
} hZh9uI7.  
^[]}R:  
f~Fm4 >\(  
} x\F,SEj  
-`<kCW"  
20vXSYa~  
/* g) p,5BADm  
**FileAccess.java lrnyk(M}Q.  
*//文件访问(定位,写) C K:y?  
package NetFox; KC(xb5x Y  
import java.io.*; NLS%Sq  
/3e KN  
CLeG<Hi ~  
public class FileAccessI implements Serializable{ mocI&=EF2X  
D@.tkzU@E  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _u{c4U0,  
RandomAccessFile oSavedFile; \cC%!4  
long nPos; Jj,U RD&0R  
AgV G`q  
T32+3wb"I  
public FileAccessI() throws IOException gN24M3{C  
{ D|rFu  
this("",0); dY@WI[yog  
} uwa~-xX6  
vJ\pR~?  
N` aF{3[  
public FileAccessI(String sName,long nPos) throws IOException 43={Xy   
{ rA2 g&  
oSavedFile = new RandomAccessFile(sName,"rw"); Y|8:;u'  
this.nPos = nPos; BhM '@g*  
oSavedFile.seek(nPos); T%6&PrQ7  
} rF aF Bd  
BYs-V:  
c7tfRq n+  
public synchronized int write(byte[] b,int nStart,int nLen) zunV<2~(2}  
{ B*4}GPQ  
int n = -1; Ggl~nxz  
try{ ,Y|^^?'j Q  
oSavedFile.write(b,nStart,nLen); bx]N>k J  
n = nLen; IX*idcxR  
} XK|R8rhg8`  
catch(IOException e) %CS@g.H=_  
{ f 1w~!O9  
e.printStackTrace ();  emK$`9  
} Kl2lbe7  
356>QW'm  
Cl ^\OZN\=  
return n; 0{dz5gUde  
} Lb;zBmwB  
N@O8\oQG  
p"l3e9&'j  
} 3l3+A+ n  
%=?cZfFqO  
e =4+$d  
/* oI}kH=<,  
**SiteInfoBean.java DA2}{  
*/ -8r  
package NetFox; ~><^'j[  
T:/,2.l  
3 n'V\H vz  
public class SiteInfoBean { A,%C,*)Cg  
Hir Fl  
D8>enum  
private String sSiteURL; //Site's URL  EI_  
private String sFilePath; //Saved File's Path F>]m3(  
private String sFileName; //Saved File's Name 1Ab>4UhD  
private int nSplitter; //Count of Splited Downloading File Q$:![}[(  
p/U+0f  
bYi`R)  
public SiteInfoBean() 2RN)<\P  
{//nSplitter的缺省值为5 oS7(s  
//default value of nSplitter is 5 \3'9Uz,OC  
this("","","",5); aX~%5 mF  
} AX= 1b,s  
abJ" [  
AJSx%?h:6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qTAc[Ko  
{ br0++}vwL  
sSiteURL= sURL; ?Y:8eD"*  
sFilePath = sPath; zN{K5<7o  
sFileName = sName; TQ`Rk;0R  
this.nSplitter = nSpiltter; LJOr!rWi  
UTf9S>HS  
#]#sGmW/L  
} "TUe%o  
Kx=4~  
:$_6SQ<?  
public String getSSiteURL() H}H7lO  
{ N nk@h  
return sSiteURL; mcn 2Wt  
}  ~BDu$  
nPs7c %  
`5~ +,/Ys  
public void setSSiteURL(String value) $Bj;D=d@V  
{ ^2$ lJ  
sSiteURL = value;  qNm$Fx  
} -jn WZ5.  
x5QaM.+=J  
'0\@McU]  
public String getSFilePath() t=u  Qb=  
{ ?gPKcjgoH!  
return sFilePath; 5Q 'i2*j  
} >[ Ye  
&BtK($  
N.4q.  
public void setSFilePath(String value) 549jWG  
{ #fJ] o_  
sFilePath = value; rQEyD  
} 5w\fSY  
52b*[tZ  
K{ \;2M  
public String getSFileName() `E!N9qI?t$  
{ "Vr[4&`  
return sFileName; ]D@0|  
} l#lF +Q;  
9 _QP!,  
A8q;q2  
public void setSFileName(String value) 2MATpV#BT  
{ 0vVV%,v  
sFileName = value; {0;3W7  
} P ~#>H{  
LY[~Os W  
xGU(n _Y  
public int getNSplitter() Qc[3Fq,f  
{ 8E8N6  
return nSplitter; kN%MP 6?J  
} &AlJ "N|  
?7 M.o  
*loOiM\5a  
public void setNSplitter(int nCount) eeHP&1= 7  
{ 6<'rG''  
nSplitter = nCount; "Tm[t?FMbe  
} ,^gyH \  
} R|f~>JUF  
PG8^.)]M  
M\Gdn92pd  
/* k{VE1@  
**Utility.java ?6nF~9Z'  
*/ kPQtQh]y%  
package NetFox; }U SC1J  
aA'|Rg,  
Oky**B[D'  
public class Utility { FSRm|  
$ ''9K  
+rIL|c}J  
public Utility() >(y<0   
{ 9}c8Xt^&  
wHIj<"2  
%?aS#4jI  
} pGSai &  
[w\9as/ E  
//线程睡眠 mKT>,M  
public static void sleep(int nSecond) p-%|P ]&  
{ }gkM^*$:%  
try{ 11|Rdd+}  
Thread.sleep(nSecond); h(qQsxIOhS  
} pDQ}*   
catch(Exception e) l c_E!"1  
{ EwS!]h?  
e.printStackTrace (); lpRR&  
} f30Pi1/h=c  
} /XudV2P-CA  
y7S4d~&  
//日志 /m( =`aRt  
public static void log(String sMsg) rCS#{x  
{ ^m/14MN|  
System.err.println(sMsg); NxVw!TsR  
} a=XW[TY1  
hk/! 'd  
Sa"9^_.2#  
public static void log(int sMsg) Dfd-^N!  
{ SlSM+F  
System.err.println(sMsg); k|BHnj  
} vA)O {W\o  
} c8Q]!p+Yp  
cEe? *\G  
*cTO7$\[  
/* 8 4i_k  
**TestMethod.java #wc \T  
*/ ^ FZ^6*  
package NetFox; w'X]M#Q><  
oo=#XZkk  
l{VSb92f  
public class TestMethod { 'xv8Gwf"  
=&!HwOnp  
tA$)cg+.  
public TestMethod() <`!PCuR  
{ ///xx/weblogic60b2_win.exe Qm8) 4?FZ  
try{ `VQb-V  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |0{u->+ )  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jKZt~I  
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y F:2>w<  
fileFetch.start(); h;V,n  
} w[_x(Ojq;  
catch(Exception e){e.printStackTrace ();} DFO7uw1  
]APvp.Tw:  
dr{y0`CCN  
} -[OXSaf6  
Omi^>c4G  
?EU\}N J  
public static void main(String[] args) |wox1Wt|E  
{ 8h<ehNX ^I  
new TestMethod(); $6F)R|  
} xsjO)))f  
} pPVRsXy  
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