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http断点续传简单实现(java)

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/* "# BI"  
**SiteFileFetch.java OO+QH 2j  
*/ Az>gaJ/_  
package NetFox; 8_F5c@7  
import java.io.*; =`6_{<&  
import java.net.*; #Y9~ Xp^.  
u@-x3%W  
7q[a8rUdh  
public class SiteFileFetch extends Thread { m339Y2%=  
`>cBR,)r  
weky 5(:  
SiteInfoBean siteInfoBean = null; //文件信息Bean P ||:?3IH  
long[] nStartPos; //开始位置 2hI|] p  
long[] nEndPos; //结束位置 *_7%n-k  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 V0x;*)\PYm  
long nFileLength; //文件长度 rSvQarT  
boolean bFirst = true; //是否第一次取文件 &?#G)suP  
boolean bStop = false; //停止标志 vmZyvJSE  
File tmpFile; //文件下载的临时信息 0? QTi(  
DataOutputStream output; //输出到文件的输出流 nB1[OB{  
,P9q[  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) \P|PAU@,  
public SiteFileFetch(SiteInfoBean bean) throws IOException u4a(AB>S  
{ 8/dx)*JCq  
siteInfoBean = bean; u:f.g?!`"  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 7U\GX  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); G>);8T%l  
if(tmpFile.exists ()) nuip  
{ X]OVc<F  
bFirst = false; xMu[#\Vc  
read_nPos(); 5J4'\M  
} 69$[yt>KYz  
else hln.EAW'Yc  
{ i#Y[I"'  
nStartPos = new long[bean.getNSplitter()]; mew,S)dq!  
nEndPos = new long[bean.getNSplitter()]; 9c@."O`  
} +bw>9VmG  
AsW!GdIN  
hc;8Vsa  
RrGFGn{  
} MIJ^ n(-G  
&6`h%;a/&  
58@YWv Ak  
public void run() Z4 +6'  
{ ZYy?JDAO  
//获得文件长度 |aovZ/b4  
//分割文件 :Ej#qYi  
//实例FileSplitterFetch W5^m[,GU'  
//启动FileSplitterFetch线程 w+NdEE4H9z  
//等待子线程返回 MM*B.y~TxZ  
try{ .A. VOf_  
if(bFirst) "[rChso  
{ Hq*\,`b&  
nFileLength = getFileSize(); uwcm%N;I"  
if(nFileLength == -1) Gb\Nqx(  
{ 8AK=FX&@&  
System.err.println("File Length is not known!"); 0Y81B;/F  
} }9GD'N?4  
else if(nFileLength == -2) |ZAR!u&0  
{ 5DEK`#*  
System.err.println("File is not access!"); WDC+Jmlgp  
} `EUufTYi  
else ([r4N#lx  
{ 8tR(i[L   
for(int i=0;i<nStartPos.length;i++) T5g}z5~"  
{ x9s 7:F  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =skw@c ^  
} ur,!-t(~t  
for(int i=0;i<nEndPos.length-1;i++) {WE1^&Vk-}  
{ s^{hdCCl67  
nEndPos = nStartPos[i+1]; 9BJP|L%q  
} PE~umY]  
nEndPos[nEndPos.length-1] = nFileLength; _qq> 43  
} CHeU?NtFps  
} 0GtL6M@pP  
^}+qd1r  
iz&$q]P8  
//启动子线程 avmuI^LLs  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S4m??B  
for(int i=0;i<nStartPos.length;i++) ,F,\bp}  
{ ' DZYN {}  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6 K+DgNK  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =r3%jWH6  
nStartPos,nEndPos,i); O]\6Pv@N  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GESEj%R/b  
fileSplitterFetch.start(); F~`Yh6v  
} p5C:MA~*  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TzC'x WO  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :ub 4p4h*  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OD*\<Sc  
nEndPos = " + nFileLength); csceu+ IA  
// fileSplitterFetch[nPos.length-1].start(); ;#F/2UgHB  
Q M#1XbT  
L9|55z  
//等待子线程结束 ^usZ&9"@P  
//int count = 0; J4yL"iMt  
//是否结束while循环 ZPktZ  
boolean breakWhile = false; 6`>WO_<z  
</UUvMf"  
;"}yVV/4  
while(!bStop) yJCqP=  
{ F3-<F_4.w  
write_nPos(); \(ygdZ{R  
Utility.sleep(500); S_E-H.d"  
breakWhile = true; 0Jz5i4B  
*Kpk1  
KW* 2'C&  
for(int i=0;i<nStartPos.length;i++) {`FkiB` i  
{ SXYH#p  
if(!fileSplitterFetch.bDownOver) {t.5cX"[  
{ k`l={f8C  
breakWhile = false; emhI1 *}  
break;  xJphG  
} k$u\\`i]oC  
} {:D8@jb[  
if(breakWhile) `&\jOve   
break; 1 ZL91'U  
0rt@4"~~w  
UlG8c~p  
//count++; =cwQG&as  
//if(count>4) qO;.{f  
// siteStop(); aC\O'KcH  
} y /$Q5P+o  
f<14-R=  
g*]hmkYe9  
System.err.println("文件下载结束!"); B3+9G,or  
} [y(DtOR  
catch(Exception e){e.printStackTrace ();} Q]JWWKt6rV  
} aG"j9A~ &  
(i1 JDe  
1JRM@!x  
//获得文件长度 1V\tKDM  
public long getFileSize() )\S3Q  
{ U$*AV<{%   
int nFileLength = -1; Jy#c 6  
try{ dRdI('  
URL url = new URL(siteInfoBean.getSSiteURL()); wzXIEWJ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?QDHEC62  
httpConnection.setRequestProperty("User-Agent","NetFox"); y*F !k{P  
F@8G,$  
N('=qp9  
int responseCode=httpConnection.getResponseCode(); JPH! .@  
if(responseCode>=400) <r9L-4  
{ 9J3@8h p  
processErrorCode(responseCode); 4YuJ-  
return -2; //-2 represent access is error %^ bHQB%  
} 'YKzs;y$  
)x!b{5'"7  
;u+k! wn  
String sHeader; 86*9GS?U(  
.wU0F  
.tdaj6x  
for(int i=1;;i++) |r U?  
{ CPW^pGT+i  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $U_M|Xa  
//Utility.log(in.readLine()); y% Q0* _  
sHeader=httpConnection.getHeaderFieldKey(i); AiP#wK;  
if(sHeader!=null) ]u]BxMs  
{ t5| }0ID-  
if(sHeader.equals("Content-Length")) S/itK3  
{ - w{`/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bj=lUn`T:  
break; = 9Ow!(!@  
} i,H(6NL.  
} i/C`]1R/  
else V< Ib#rd'  
break; *:5S*E&}V  
} GM~Ek] 9C%  
} z#[PTqD-_  
catch(IOException e){e.printStackTrace ();} |rgp(;iO  
catch(Exception e){e.printStackTrace ();} 3s]aXz:  
=bBV A0y  
"t.Jv%0=  
Utility.log(nFileLength); !K8Kw W|X  
9{GEq@`7  
%(uYYr 6  
return nFileLength; r|_@S[hZg  
} ]\C wa9  
e9=UTn{!  
6e;POW  
//保存下载信息(文件指针位置) `f[  
private void write_nPos() 0!Vza?9  
{ `j1b5&N;7  
try{ UkTq0-N;2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); YYN'LF#j  
output.writeInt(nStartPos.length); ,M.phRJ-`  
for(int i=0;i<nStartPos.length;i++) 4,P(w+  
{ )ZW[$:wA  
// output.writeLong(nPos); /fSsh;F  
output.writeLong(fileSplitterFetch.nStartPos); [;Y,nSw  
output.writeLong(fileSplitterFetch.nEndPos); `0_,>Z  
} h6Q~Di  
output.close(); AI^!?nJ%'  
} -O^R~Q_`w  
catch(IOException e){e.printStackTrace ();} 'ti~TG  
catch(Exception e){e.printStackTrace ();} q^DQ9B  
} ]#\De73K   
'5m4kDs  
FN w0x6,~R  
//读取保存的下载信息(文件指针位置) dC<2%y  
private void read_nPos() #z1/VZ  
{ 5SMV3~*P  
try{ k\TP3*fD  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yW)r`xpY  
int nCount = input.readInt(); [ [#R ry  
nStartPos = new long[nCount]; B1V+CP3t  
nEndPos = new long[nCount]; Eq?U$eE  
for(int i=0;i<nStartPos.length;i++) I/*^s  
{ SHYbQF2  
nStartPos = input.readLong(); ~>#?.f  
nEndPos = input.readLong(); {pc  (b  
} a&Z,~Vp  
input.close(); ]6 HR  
} p9E/#U8A_  
catch(IOException e){e.printStackTrace ();} wVq9t|V  
catch(Exception e){e.printStackTrace ();} {4$aA*  
} DDq?4  
%a?\y_a=b  
n) j0h-  
private void processErrorCode(int nErrorCode) _o T+x%i  
{ ? *v*fs0  
System.err.println("Error Code : " + nErrorCode); `6P2+wf1j~  
} Yr*!T= z  
S"t\LB*'Ls  
~dC.,"  
//停止文件下载 iR!]&Oh  
public void siteStop() c{IL"B6>  
{ Ou4 `#7FR  
bStop = true; (;;.[4,y  
for(int i=0;i<nStartPos.length;i++) zsLMROo3  
fileSplitterFetch.splitterStop(); 9X&=?+f  
>"+ ho  
Q;s {M{u  
} R,s}<N$  
} r1Hh @sxn  
//负责部分文件的抓取 lWn}afI  
**FileSplitterFetch.java +c8t~2tuN  
*/ P }^Y"zF2  
package NetFox; (5;nA'  
sPMICIv|  
2^=8~I!n&  
import java.io.*; ucJ}KMz  
import java.net.*; Ifokg~X~G  
njZJp|y6  
{<$tEj:  
public class FileSplitterFetch extends Thread { FUXJy{n6"2  
01&@8z'E  
MGf*+!y,  
String sURL; //File URL +w7U7" xQ  
long nStartPos; //File Snippet Start Position |2=@8_am  
long nEndPos; //File Snippet End Position #].q jOj  
int nThreadID; //Thread's ID tLU@&NY`  
boolean bDownOver = false; //Downing is over @^<&LG5^  
boolean bStop = false; //Stop identical U)M&AYb  
FileAccessI fileAccessI = null; //File Access interface *fs[]q'Q  
TNckyP75u  
BNF*1JO  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException | TG6-e_  
{ ,zuS)?  
this.sURL = sURL; 7n o6  
this.nStartPos = nStart; xkRS?Q g  
this.nEndPos = nEnd; +p`BoF9~  
nThreadID = id; q{_f"  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C4qK52'2s  
} &Nh zEl1  
k ~Q 5Cs  
'7}2}KD  
public void run() `zrg?  
{ aOw#]pB|  
while(nStartPos < nEndPos && !bStop) Cn{v\Q~.4  
{ lo1bj*Y2  
\#]C !JQ  
op/_ :#&'  
try{ ^eyVEN  
URL url = new URL(sURL); OSfT\8YA  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $f _C~O  
httpConnection.setRequestProperty("User-Agent","NetFox"); 9XYm8g'X  
String sProperty = "bytes="+nStartPos+"-"; ce#Iu#qT  
httpConnection.setRequestProperty("RANGE",sProperty); Zoc4@% n  
Utility.log(sProperty); 4x&Dz0[[S  
5Po:$(  
+$#<gp"  
InputStream input = httpConnection.getInputStream(); nW^h +   
//logResponseHead(httpConnection); "O-X*>?f  
EADN   
.p.( \5Fo  
byte[] b = new byte[1024]; )hl7)~S<  
int nRead; 10h; N[  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z5oJQPPi  
{ \NMqlxp2  
nStartPos += fileAccessI.write(b,0,nRead); 0%< hj  
//if(nThreadID == 1) G3`9'-2q@c  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .%)uCLZr$  
} x/CM)!U)  
hJ]Oa7r  
|/H?\]7  
Utility.log("Thread " + nThreadID + " is over!"); =4'V}p  
bDownOver = true; 3!\h'5{  
//nPos = fileAccessI.write (b,0,nRead); |OAM;@jH  
} qjhk#\y  
catch(Exception e){e.printStackTrace ();} -.y1]4  
} [|YvVA  
} SD:D8"8  
b9#(I~}  
kW2DKr-[  
//打印回应的头信息 RD"-(T  
public void logResponseHead(HttpURLConnection con) i}zz!dJTE  
{ Tg"? TZO~  
for(int i=1;;i++) @MVul_@6  
{ N&p0Emg  
String header=con.getHeaderFieldKey(i); (&Jo. <  
if(header!=null) Hi=</ Wy;  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j5Da53c#^  
Utility.log(header+" : "+con.getHeaderField(header)); 4_iA<}>|  
else 1<1+nGO  
break; GS=E6  
} x>B\2;  
} ^\Z+Xq1~/  
4ryG_p52l  
MJqWc6{ n  
public void splitterStop() 2C}Yvfm4  
{ n[gE[kw  
bStop = true; d{Jk:@.1  
} gSw4\R  
Ex zB{ "  
"^6Fh"]  
} jd-ccnR l  
.MG83Si  
KUYwc@si\  
/* =f y|Dm74  
**FileAccess.java &PRoT#,  
*//文件访问(定位,写) J,)ytw]  
package NetFox; h2T\%V_j  
import java.io.*; aQ $sn<-l  
2aCf?l(  
te2vv]W1  
public class FileAccessI implements Serializable{ KcpYHWCa.  
\u{4=-C.  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u>.a;BO  
RandomAccessFile oSavedFile; G 3,v'D5  
long nPos; bY.VNA  
!CX WoM  
*!$Z5Im  
public FileAccessI() throws IOException a-E}3a  
{ -$o0P'Vx  
this("",0); 7`;f<QNo  
} iLZY6?_^  
Ms,MXJtH  
dt:$:,"   
public FileAccessI(String sName,long nPos) throws IOException KS93v9|  
{  {Ba&  
oSavedFile = new RandomAccessFile(sName,"rw"); y)&K9 I  
this.nPos = nPos; X.;VZwT+  
oSavedFile.seek(nPos); C 5gdvJN  
} c/tB_]  
hBpa"0F  
O# ZZ PJ"  
public synchronized int write(byte[] b,int nStart,int nLen) PBb&.<   
{ 9/29>K_  
int n = -1; PjEJ C@n  
try{ 1J"9Y81   
oSavedFile.write(b,nStart,nLen); g ass Od  
n = nLen; 5[SwF& zZ  
} S Dil\x  
catch(IOException e) ebI2gEu;a  
{ >*h+ N? m  
e.printStackTrace (); `8W HVC$  
} O1\Hx8^  
9D1WUUa  
E3O^Tg?j  
return n; }|=/v( D  
} ]5S`y{j1  
4\&Y;upy+  
F!EiF&[\J  
} QcQ%A%VIV  
|A 'I!Jm  
kJ FWk  
/* \(P?=] -  
**SiteInfoBean.java E|f[ #+:+  
*/ Ha-]U:Vcx  
package NetFox; U[f00m5{HV  
{:uv}4Z  
BNNM$.ZIQ  
public class SiteInfoBean { rnj$u-8  
u3+B/ 5x  
tj@(0}pi4  
private String sSiteURL; //Site's URL 1B2#uhT]r  
private String sFilePath; //Saved File's Path v>} +->f  
private String sFileName; //Saved File's Name rl%,9JD!  
private int nSplitter; //Count of Splited Downloading File PmE)FthdP(  
G$i)ELs  
950N\Y @u  
public SiteInfoBean() %|(c?`2|  
{//nSplitter的缺省值为5   < v]  
//default value of nSplitter is 5 p 4> ThpX  
this("","","",5); 70c]|5  
} lJu^Bcrv  
( 4L/I  
Y\-xX:n.\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UrvUt$WO  
{ dz9U.:C  
sSiteURL= sURL; Z{0BH{23  
sFilePath = sPath; 1}DA| !~  
sFileName = sName; m g'q-G`\<  
this.nSplitter = nSpiltter; c("|xe  
oM~y8O  
jn V=giBu  
} |g3:+&  
b/z-W`gw  
ja_8n["z  
public String getSSiteURL() ]WDmx$"&e  
{ %Gh5!e:$SI  
return sSiteURL; 6*9 wGLE  
} \QK@wgu  
S"Cz. bv  
Kt_oo[ey{  
public void setSSiteURL(String value) +r8bGS]ki  
{ &*<27-x  
sSiteURL = value; A ]A{HEX  
} ^r\ rpSN  
JkAM:,^(  
vAUt~ X"  
public String getSFilePath() 13!@L bC  
{ }~I!'J#)  
return sFilePath; yQ[;y~W  
} z5fE<=<X_W  
njy2pDC@  
:jl*Y-mM  
public void setSFilePath(String value) C:J;'[,S  
{ fkzSX8a9}  
sFilePath = value; NZq-%bE  
} ccuGM WG*  
.c"nDCFVR  
^}=)jLS  
public String getSFileName() y d 97ys  
{ ]^~}/@  
return sFileName; 2nB99L{6  
} e,p"=/!aY  
PdcIHN  
o{s2T)2  
public void setSFileName(String value) ,5n!a.T  
{ } GB~3 J  
sFileName = value; tUv>1) [  
} 6ZQ |L=Ytp  
Q Q3<)i  
>j5\J_( ;D  
public int getNSplitter() m+Ye`]  
{ 7=6:ZSI  
return nSplitter; q9/v\~m  
} AFz:%m  
s:U:Dv  
_ >OP  
public void setNSplitter(int nCount) ANhtz1Fl  
{ K|P0nJT  
nSplitter = nCount; Yr9'2.%Q  
} y *i&p4Y*  
} 2zBk#c+  
J6Z[c*W  
\]tBwa  
/* @k?vbq  
**Utility.java QHk\Z  
*/ Dl;hOHvKk  
package NetFox; ?,vLRq.  
JmI%7bH@  
7Q .Su  
public class Utility { \zO.#H  
*d 1Bp R%  
kt6x"'"1  
public Utility() rQjk   
{ ]at$ohS  
(g##wa)L  
.<hHK|HF  
} O*xx63%jR  
7>Z|K  
//线程睡眠 ')uYI;h9  
public static void sleep(int nSecond) o PSPb(.  
{ H%wB8Y ]  
try{ Mg2+H+C~:  
Thread.sleep(nSecond); ]&*POri&  
} FZe/3sY  
catch(Exception e)  =z.j{%  
{ G]K1X"W?  
e.printStackTrace (); )pWgt5:7~  
} oB:7R^a  
} 1V%tev9a  
jRK}H*uem  
//日志 Y <6|z3  
public static void log(String sMsg) R|st<P  
{ 0@ `]m  
System.err.println(sMsg); k%.v`H!  
} }. &nEi`  
clE9I<1v  
VeA@HC`?"  
public static void log(int sMsg) ^)AECn  
{ V*p[6{U0  
System.err.println(sMsg); ?JrUZXY  
} HsCL%$k  
} voa)V 1A/]  
O=0p}{3l  
5GsmBf$RUb  
/* TDh)}Ms  
**TestMethod.java +IdM|4$\1  
*/ {?qfH>oFA  
package NetFox; }a]`"_i;[  
|Xso}Y{  
NQdwj>_a  
public class TestMethod { x93@[B*%  
o0H^J,6gV  
<y6`8J7:  
public TestMethod() PQHztS"  
{ ///xx/weblogic60b2_win.exe -)V0D,r$[  
try{ BZeEZ2"  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pzF_g- B  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T\6Qr$t  
SiteFileFetch fileFetch = new SiteFileFetch(bean); X`8<;l  
fileFetch.start(); A(y6]E!  
} 1-kuK<KR  
catch(Exception e){e.printStackTrace ();} V3,C5KKk&z  
9jal D X  
Ia2WBs =  
} e{)giJY9  
z|g2Q#$-\S  
49qa  
public static void main(String[] args) e@'x7Zzh  
{ \8{SQ%  
new TestMethod(); lu#a.41  
} mF6-f#t>H+  
} x;mw?B[  
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