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http断点续传简单实现(java)

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/* `Al5(0Q  
**SiteFileFetch.java z$d/Vz,a  
*/ 6J|Y+Y$  
package NetFox; yBPaGZ{f  
import java.io.*; L##lXUl  
import java.net.*; Jz!8Xg%a  
[Pu~kiN  
@Ee'nP   
public class SiteFileFetch extends Thread { mGXjSWsd  
*\Y \$w  
XZv(B^  
SiteInfoBean siteInfoBean = null; //文件信息Bean \wxS~T<&L  
long[] nStartPos; //开始位置 }/yhwijg  
long[] nEndPos; //结束位置 0wLu*K5$4E  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 8gv \`  
long nFileLength; //文件长度 O6^>L0'  
boolean bFirst = true; //是否第一次取文件 -|MeC  
boolean bStop = false; //停止标志 3+<}Hm+  
File tmpFile; //文件下载的临时信息 &cSTem 0  
DataOutputStream output; //输出到文件的输出流 >5&'_  
cp0@wC#d  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) u6A ReL 'f  
public SiteFileFetch(SiteInfoBean bean) throws IOException ;~$_A4;  
{ SsDe\"?Q  
siteInfoBean = bean; Uj)~>V'  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); -bo5/`x  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); coHzbD~#H  
if(tmpFile.exists ())  iK$)Iy0  
{ `/:ZB6  
bFirst = false; ,%#FK|  
read_nPos(); M1^?_;B  
} 6 s{~9  
else nk,X6o9%  
{ ,F7W_f# @3  
nStartPos = new long[bean.getNSplitter()]; (PjC]`FK  
nEndPos = new long[bean.getNSplitter()]; I @TR|  
} ~F^(O{EG  
5-M E Oy(  
kh /n|2  
3%Z:B8:<y  
} 37DyDzW)'  
5A,@$yp+  
W3s>+yU  
public void run() V?Y;.n&y  
{ "d60IM#N?  
//获得文件长度 hA.?19<Z  
//分割文件 Vu '3%~  
//实例FileSplitterFetch -y70-K3  
//启动FileSplitterFetch线程 Z,%^BAJ  
//等待子线程返回 6]yYiz2Xn  
try{ l2"{uCcA  
if(bFirst) +jePp_3$O  
{ v1Tla]d  
nFileLength = getFileSize(); )$XW~oA'  
if(nFileLength == -1) ^s/HbCA  
{ !%{/eQFT4  
System.err.println("File Length is not known!"); B#Cb`b"  
} o(GXv3L  
else if(nFileLength == -2) K,{P b?  
{ 'M>QA"*48E  
System.err.println("File is not access!"); LeDty_  
} ezn%*X y,  
else MaDdiyeC  
{ 68 % = V>V  
for(int i=0;i<nStartPos.length;i++) 8"L#5MO t  
{ 4}@J]_]Z  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); w Q /IT}-  
} &~ of]A  
for(int i=0;i<nEndPos.length-1;i++) @sUYjB  
{ +eSNwR=  
nEndPos = nStartPos[i+1]; % UDz4?zx  
} o2  
nEndPos[nEndPos.length-1] = nFileLength; XKD0n^L[  
} h.PVRAwk  
} `)Z"||8K  
 J jRz<T;  
f%fD>a  
//启动子线程 2Wwzcvs@  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @v^;,cu'8  
for(int i=0;i<nStartPos.length;i++) -`nQa$N-  
{  xE.K  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NUBf>~_}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |[apLQ6  
nStartPos,nEndPos,i); *->2$uWP  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $+CKy>  
fileSplitterFetch.start(); hTZ&  
} %M8 m 8 )  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7kX;|NA1  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UnSi=uj  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q`1"]gy.  
nEndPos = " + nFileLength); \1Tu P}P  
// fileSplitterFetch[nPos.length-1].start(); KY5it9e  
`@%hz%8Y  
B:Y"X:Y  
//等待子线程结束 iNj*G j  
//int count = 0; g\_J  
//是否结束while循环 DFDlp  
boolean breakWhile = false; a;a^- n|D  
T1,Nb>gBq^  
m)"gj**|y  
while(!bStop) Jbv66)0M  
{ cAFYEx/(  
write_nPos(); SU>2MT^  
Utility.sleep(500); /4Ud6gscf  
breakWhile = true; *AK{GfP_  
]fxYS m  
!1G6ZC:z  
for(int i=0;i<nStartPos.length;i++) L@9@3?  
{ @JB9qT  
if(!fileSplitterFetch.bDownOver) HRQ3v`P.  
{ G8bc\]  
breakWhile = false; Ruy qB>[o  
break; 'W'['TV  
} 9)P-<  
} "[A]tklP  
if(breakWhile) `"@Pr,L   
break; @8\7H'K"\  
X#v6v)c  
}eKY%WU>O  
//count++; TS2zzYE6Z  
//if(count>4) ;iA6[uz  
// siteStop(); )W,tL*9[  
} m9~cQ!m  
6:\0=k5  
PB[ Y^q  
System.err.println("文件下载结束!"); a-[:RJW  
} B\WIoz;'  
catch(Exception e){e.printStackTrace ();} \%],pZsA~  
} tW$Di*h  
d WKjVf  
wE*o1.  
//获得文件长度 9NXL8QmC8  
public long getFileSize() 2TQyQ%  
{ :8( "n1^  
int nFileLength = -1; `^d[$IbDW  
try{ hCpX# rg?  
URL url = new URL(siteInfoBean.getSSiteURL()); nDG41)|  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); { $ a $m  
httpConnection.setRequestProperty("User-Agent","NetFox"); -_`dA^  
X(r$OZ  
`1xJ1 z#  
int responseCode=httpConnection.getResponseCode(); vZ6_/ew8  
if(responseCode>=400) Al93x  
{ e-&0f);i  
processErrorCode(responseCode); |.]g&m)y^h  
return -2; //-2 represent access is error &];:uYmMU  
} T)CEcz  
5~ip N/)E  
}Bk>'  
String sHeader; @#u'z ~a)  
:`Sd5b>  
+HAd=DU  
for(int i=1;;i++)  []L yu  
{ QmiS/`AAv  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XEX-NE"]  
//Utility.log(in.readLine()); 7Be\^%  
sHeader=httpConnection.getHeaderFieldKey(i); I_.Jo `lK~  
if(sHeader!=null) qI= j>x  
{ Q[6<Y,}(pd  
if(sHeader.equals("Content-Length")) PR+L6DT_  
{ 7my7|s[  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); UngK9uB~  
break; ~;AJB  
} v)c[-:"z  
} ]y kMh  
else =w,cdU*  
break; ^X\{MW'>4  
} 1b` `y  
} d,V]j-  
catch(IOException e){e.printStackTrace ();} RCC~#bb  
catch(Exception e){e.printStackTrace ();} bnZ`Wc*5b  
Au"7w=G`f  
C@F3iwTtp  
Utility.log(nFileLength); (~U1 X4  
'Dx_n7&=  
#cCR\$-~  
return nFileLength; <jz\U7TBf  
} be+]kp  
yN/Uyhq  
i w(4!,4~  
//保存下载信息(文件指针位置)  b^dBX  
private void write_nPos() 9zKbzT]  
{ nW"ml$  
try{ sry`EkS  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Om,M8!E  
output.writeInt(nStartPos.length); 5^0K5R6GQf  
for(int i=0;i<nStartPos.length;i++) *.P3fVlZ  
{ (X|`|Y  
// output.writeLong(nPos); S(NUuu}S  
output.writeLong(fileSplitterFetch.nStartPos); VT:m!<^  
output.writeLong(fileSplitterFetch.nEndPos); b&g`AnYT  
} kN8?.V%Utw  
output.close(); x7!YA>  
} m&I5~kD  
catch(IOException e){e.printStackTrace ();} wK*b2r}0/  
catch(Exception e){e.printStackTrace ();} 0(h'ZV  
} egHvI&w"o  
n[c/L8j  
&{=`g+4n  
//读取保存的下载信息(文件指针位置) V|T3blG?D  
private void read_nPos()  ~=Q|EhF5  
{ p}K\rpvJpu  
try{ $ 0Up.  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -Izc-W  
int nCount = input.readInt(); W^T6^q5;H  
nStartPos = new long[nCount]; Hphfqdh0`  
nEndPos = new long[nCount]; Ks/Uyu. X  
for(int i=0;i<nStartPos.length;i++) G ]JWd  
{ IA(+}V  
nStartPos = input.readLong(); A1kqWhg\  
nEndPos = input.readLong(); l ]CnLqf&  
} 2nv-/ %]  
input.close(); #Py\'  
} y^tp^  
catch(IOException e){e.printStackTrace ();} \?K>~{)  
catch(Exception e){e.printStackTrace ();} 5Vu@gRk_  
} a"pejW`m  
15U[F0b  
>&DNxw  
private void processErrorCode(int nErrorCode) k_A 9gj1  
{ 0o*  
System.err.println("Error Code : " + nErrorCode); ;Y"*Z2U  
} f%ynod8  
<f/wWu}  
n%%u0a %  
//停止文件下载 FZJyqqA$_  
public void siteStop() 38HnW  
{ 6JZ$; x{j  
bStop = true; 6~y7A<[^  
for(int i=0;i<nStartPos.length;i++) w@Gk#  
fileSplitterFetch.splitterStop(); :d`8:gv?  
KGq4tlM6  
P6([[mmG  
} 3^%sz!jK+  
} h8-'I= ~  
//负责部分文件的抓取 )WR*8659e  
**FileSplitterFetch.java {WYmO1  
*/ c:f++||  
package NetFox; =F>nqklc  
GTBT0$9 g.  
x}*Y =Xh  
import java.io.*; vo3[)BDbT  
import java.net.*; -7\6j#;l  
;DN:AgXP  
OK1f Y`$z  
public class FileSplitterFetch extends Thread { /&Vgo ~.J  
a"|\n_  
u*C"d1v=  
String sURL; //File URL C~([aH@-I  
long nStartPos; //File Snippet Start Position ab-MEN`5  
long nEndPos; //File Snippet End Position *d/,Y-tl  
int nThreadID; //Thread's ID |= U(8t  
boolean bDownOver = false; //Downing is over /@~&zx&_  
boolean bStop = false; //Stop identical y+D"LeCAad  
FileAccessI fileAccessI = null; //File Access interface 3V2w1CERE  
j"Vb8}  
$v*0 \O  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YTo^Q&  
{ ; rJ  
this.sURL = sURL; 9X[}ik0  
this.nStartPos = nStart; y+ ZCuX  
this.nEndPos = nEnd; q=|0lZ$`V_  
nThreadID = id; R404\XGL  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sxBRg=  
} Hz] p]  
DJ#z0)3<p  
{Vj25Gt  
public void run() DZ9qIc}Y  
{ TV&4m5  
while(nStartPos < nEndPos && !bStop) {aRZBIv  
{ Vy:MK9U2  
$xsmF?Dsx5  
QW_QizR>|  
try{ *E-VS= #  
URL url = new URL(sURL); K`d3p{M  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :.,3Zw{l  
httpConnection.setRequestProperty("User-Agent","NetFox"); 3ZKaqwK  
String sProperty = "bytes="+nStartPos+"-"; xK8R![x  
httpConnection.setRequestProperty("RANGE",sProperty); S3(2.c~  
Utility.log(sProperty); >|e>=  
9v2(cpZ  
\p&a c&]  
InputStream input = httpConnection.getInputStream(); }:5>1FfX=  
//logResponseHead(httpConnection); ;*8nd-\  
!Ho=(6V  
D;l)&"|r?  
byte[] b = new byte[1024]; LN?b6s75U  
int nRead; ^M Zdht   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9+sOSz~ P  
{ k-M-=VvA  
nStartPos += fileAccessI.write(b,0,nRead); LpJ_HU7@lk  
//if(nThreadID == 1) $*u{i4b  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <Gr775"  
} ,UD,)ZPf[  
J&IFn/JK$  
G3G"SJ np  
Utility.log("Thread " + nThreadID + " is over!"); }813.U  
bDownOver = true;  8/|~E  
//nPos = fileAccessI.write (b,0,nRead); oQvG3(.  
} #(`@D7S"  
catch(Exception e){e.printStackTrace ();} h""a#n)q}`  
} @e/40l|X  
} G)E#wh_S^  
Y}C~&Ph  
x_3Zd  
//打印回应的头信息 $]05?JY#  
public void logResponseHead(HttpURLConnection con) Wo^r#iRko  
{ q&-A}]  
for(int i=1;;i++) $ZPiM  
{ Yjr6/&ML  
String header=con.getHeaderFieldKey(i); `[+nz rLkO  
if(header!=null) y/}>)o4Q  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]o(&J7Z6-  
Utility.log(header+" : "+con.getHeaderField(header)); AwKxt'()^  
else t*? CD.S  
break;  t : =  
} "lp),  
} fi[c^e+IX  
O_p:`h:;M  
oR=^NEJv  
public void splitterStop() Q1Jkt  
{ :q2tda  
bStop = true; cJ%u&2J_  
} .+H8c.  
V^t5 Y+7  
s1!_zf_  
} @ P=eu3  
ezt_ct/Z  
#@m*yJg<  
/* d`| W6Do  
**FileAccess.java %KeQp W  
*//文件访问(定位,写) G~{xTpL  
package NetFox; \Mv8pU  
import java.io.*; ;n*N9-|.  
O/IW.t  
V;Zp3Qo!  
public class FileAccessI implements Serializable{ fNi&1J-/  
Hy<4q^3$G  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ] =jnt  
RandomAccessFile oSavedFile; 3:rH1vG.m  
long nPos; j/bebR}X  
sBuVm<H  
g#V3u=I8~  
public FileAccessI() throws IOException d0b--v/  
{ 2O|o%`?  
this("",0); FxKb  
} (WK $ )f  
[UI4YZu}  
=*q:R9V  
public FileAccessI(String sName,long nPos) throws IOException eB:obz  
{ -K`0`n}  
oSavedFile = new RandomAccessFile(sName,"rw"); .~ a)  
this.nPos = nPos; % 8kbX  
oSavedFile.seek(nPos); Y"mD)\Bw?  
} ,>%AEN6N2  
3:a}<^DuCS  
 ]D7z&h  
public synchronized int write(byte[] b,int nStart,int nLen) B{W2D  
{ j=)%~@  
int n = -1; P Z-|W  
try{ %Hu Qc^  
oSavedFile.write(b,nStart,nLen); g S;p::  
n = nLen; 4];Qpln  
} b9(d@2MtK  
catch(IOException e) HLAYmXX"w  
{ #UC4l]Ru A  
e.printStackTrace (); &_&])V)<\S  
} dCcV$BX,K  
Yuze9b\[  
"2CiW6X[M  
return n; <W vuW6  
} :*1Gs,  
pM\)f  
1uv"5`%s  
} =[`wyQe`_  
#JZf]rtp  
+=MO6}5T  
/* 6.~(oepu  
**SiteInfoBean.java oC U8;z  
*/ ~sAINV>A  
package NetFox; M!=v"C#  
P-No;/!B#  
AY0o0\6cw  
public class SiteInfoBean { 5Zn3s()  
F& H~JJ  
RgQ\Cs24Q  
private String sSiteURL; //Site's URL W1y,.6  
private String sFilePath; //Saved File's Path 5cyl:1Ln  
private String sFileName; //Saved File's Name U*k$pp6\b~  
private int nSplitter; //Count of Splited Downloading File I_#)>%H  
7 m&M(ct  
WLNkO^zb  
public SiteInfoBean() ^gkyi/z  
{//nSplitter的缺省值为5 b]RnCu"  
//default value of nSplitter is 5 u|8`=  
this("","","",5); pa+^5N  
} h+.^8fPR   
/R k5n  
3Luv$6  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Um15@p;  
{ :!tQqy2  
sSiteURL= sURL; gNs@Q !  
sFilePath = sPath; 1 EC0wX  
sFileName = sName; I U 4[}x  
this.nSplitter = nSpiltter; ":"M/v%F  
sNX$ =<E  
=q5A@!D  
}  G!O D7:  
)KBv[|  
FNmIXpAn*@  
public String getSSiteURL() <`| }bt  
{ K~,,xsy,G&  
return sSiteURL; o?p) V^7  
}  }tv-  
gMI%z2]'-  
B7 }-g"p$/  
public void setSSiteURL(String value) ,{8~TVO  
{ 9KXp0Q?-$  
sSiteURL = value; w=#&(xm0  
} {Fb)Z"8]  
,*S?L qv^  
#wM0p:<  
public String getSFilePath() |.(o4<nx.  
{ {,s:vPoiA  
return sFilePath; W11_MTIU  
} >454Yir0Mk  
Jz%&-e3  
~`-9i{L  
public void setSFilePath(String value) p2&KGt X'  
{ 4f"be  
sFilePath = value; 3\mFK$#sr  
} >%[(C*Cks  
V!},a@>p  
rKJ%/7m  
public String getSFileName() -Qn:6M>w^  
{ sU bZVPDr  
return sFileName; $AsM 9D<BE  
} )2^OBfl7  
=C#,aoa!  
qM1$?U  
public void setSFileName(String value) ]E=JUYf0  
{ })!n1kt  
sFileName = value; ]"CA P%  
} jsez$m%vs  
M $e~Rlw  
bQ .y,+  
public int getNSplitter() {5%<@<? )  
{ 3 !}'A  
return nSplitter; jH:*x$@ =  
} ) Fm  
1km=9[;w'  
YKM(qh2  
public void setNSplitter(int nCount) B:x4H}`vh  
{ HPpnw] _  
nSplitter = nCount;  dc5B#  
} n$=n:$`q  
} w[|!$J?  
<M\Z}2d  
=lDmP |^  
/* ,bH  
**Utility.java *i$+i  
*/ 3(PU=  
package NetFox; ,5L &$Q6  
<XLATS8Y  
GzR;`,_O/  
public class Utility { O:Z|fDQ`  
f%|g7[  
@wa/p`gj5w  
public Utility() hQet?*diU  
{ nwkhGQ  
UHCx}LGe  
_@RW7iP>  
} A!^,QRkRN  
'Uc|[l]  
//线程睡眠 'Klz`)F  
public static void sleep(int nSecond) };KmMpBn  
{ (PB|.`_<H  
try{ f'.yM*  
Thread.sleep(nSecond); 4Fz^[L}[  
} dm 2_Fj  
catch(Exception e) >i ~zG6H  
{ /3c1{%B\  
e.printStackTrace (); }=L >u>cP  
} HL!-4kN <$  
} #/1Bam6  
ca`=dwe>  
//日志 woR)E0'qx  
public static void log(String sMsg) &#)3v8  
{ x*)Wl!  
System.err.println(sMsg); r8> q*0~s  
} "vJADQ4F  
8uu:e<PLv  
Uex b>|  
public static void log(int sMsg) v>e4a/  
{ JBg>E3*N  
System.err.println(sMsg); {:dE_tqo  
} >/n/n{{  
} LTCjw_<7  
lWdE^-  
A} "*`y  
/* F 4h EfO3  
**TestMethod.java D\TL6"wo  
*/ :V"}"{ (6  
package NetFox; $C>EnNx  
9Z*vp^3  
!XicX9n  
public class TestMethod { !hc7i=V ?  
f[v??^  
jc?Hip'  
public TestMethod() 4 I~,B[|  
{ ///xx/weblogic60b2_win.exe f9 rToH  
try{ uu/M XID  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B\mdOTLQ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PNG'"7O  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8[Qw8z5-  
fileFetch.start(); xv ja  
} w_ Ls.K5"  
catch(Exception e){e.printStackTrace ();} 0$ (}\hMLt  
J'7Oxjlg  
m$ JQ[vgh  
} jC@^/rMh  
TwkzX|  
5_O.p3$tV  
public static void main(String[] args) eu4x{NmQ  
{ ewLr+8  
new TestMethod(); V?gQ`( ,  
} [ wROIvV  
} $M8'm1R9  
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