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http断点续传简单实现(java)

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/* CzwnmSv{.  
**SiteFileFetch.java RSp=If+4  
*/ cc@y  
package NetFox; ,i'>+Ix<  
import java.io.*; \=w|Zeu{l  
import java.net.*; Eg ;r]?|6  
>8PGyc*9  
EZypqe):/C  
public class SiteFileFetch extends Thread { GKIO@!@[  
$bOiP  
6fY-D qF!  
SiteInfoBean siteInfoBean = null; //文件信息Bean b1\.hi  
long[] nStartPos; //开始位置 Cl&YN}t5  
long[] nEndPos; //结束位置 wl7G6Y2  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 m9M#)<@*  
long nFileLength; //文件长度 qjDt6B^RO  
boolean bFirst = true; //是否第一次取文件 9X/]O<i,Es  
boolean bStop = false; //停止标志 y rH@:D/  
File tmpFile; //文件下载的临时信息 FLUvFD  
DataOutputStream output; //输出到文件的输出流 S\io5|P  
/0CS2mLC  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 9lqH  
public SiteFileFetch(SiteInfoBean bean) throws IOException 4 '"C8vw.  
{ ur\<NApT;  
siteInfoBean = bean; n37P$0  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [3D*DyQt  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 4M*Z1  
if(tmpFile.exists ()) s k_TKN`+  
{ AdD,94/  
bFirst = false; aGBUFCCa  
read_nPos(); '9u(9S  
} G9_7jX*  
else ghU~H4[xD  
{ :_k5[KT.]9  
nStartPos = new long[bean.getNSplitter()]; &$yxAqdab  
nEndPos = new long[bean.getNSplitter()]; Ahk q  
} {:] u 6l  
0uL*-/|  
+R"Y~ m{F  
Dr K@y8  
} { k>T*/  
L.2!Q3&  
L8,/  
public void run() ;W{2\ Es  
{ >npTUOGL=n  
//获得文件长度 "O~7s}  
//分割文件 O\F$~YQ  
//实例FileSplitterFetch 8'qq!WR~  
//启动FileSplitterFetch线程 uN&UYJ' B  
//等待子线程返回 [nA1WFfM  
try{ \AeM=K6q+D  
if(bFirst) mor[AJ  
{ XM f>B|  
nFileLength = getFileSize(); Gv&%cq1  
if(nFileLength == -1) ZiW&*nN?M  
{ lk*w M?Z  
System.err.println("File Length is not known!"); `*WzHDv5p  
} RiG]-K:  
else if(nFileLength == -2) G5hf m-  
{ &$bcB]C\3  
System.err.println("File is not access!"); LNcoTdv}k  
} wEZieHw  
else "m > BE  
{ cHC1l  
for(int i=0;i<nStartPos.length;i++) CHyT'RT  
{ .On3ZN  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); NvvD~B b  
} 4k!>JQor  
for(int i=0;i<nEndPos.length-1;i++) G/ H>M%M  
{ 40aD\S>  
nEndPos = nStartPos[i+1]; lWDSF]ZYV  
} *4/KK  
nEndPos[nEndPos.length-1] = nFileLength; [9d\WPLC  
} =)}Yw)  
} P~84#5R1  
!?" pnKb}  
d ATAH}r&  
//启动子线程 XVF!l>nE  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p7W9?b9  
for(int i=0;i<nStartPos.length;i++) 1,Jy+1G0w  
{ jX .' G   
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1:RK~_E  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GL _hRu  
nStartPos,nEndPos,i); ^fV-m&F)K*  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  ;{Yr|  
fileSplitterFetch.start(); >`^;h]Q  
} Gzp*Vr  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XP[~ :+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O;$}j:;KF  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Fr-Vq =j&  
nEndPos = " + nFileLength); 7[0<,O6Q  
// fileSplitterFetch[nPos.length-1].start(); IH`7ou{  
pd|l&xvka  
J\FLIw4  
//等待子线程结束 ]x66/O\0u  
//int count = 0; MwX8FYF D  
//是否结束while循环 C)~%(< D  
boolean breakWhile = false; 3sgo5D-rMI  
qC-4X"y+  
l GJN;G7  
while(!bStop) ~i.rk#{?D  
{ 2V~uPZ  
write_nPos(); E B! ,t  
Utility.sleep(500); {b-SK5%]L  
breakWhile = true; `<#O8,7`  
W)^%/lAh  
%q.5; L  
for(int i=0;i<nStartPos.length;i++) I+`>e*:@W  
{ &XW ~l>!+  
if(!fileSplitterFetch.bDownOver) )NTpb  
{ BjHp3-A'  
breakWhile = false; ti3S'K0t  
break; qiq=v)  
} a p(PI?]X  
} "Xl"H/3r  
if(breakWhile) UR(i_T&w  
break; It VVI"-  
n'?]_z<  
S_^;#=_c  
//count++; O]?\<&y  
//if(count>4) >jnx2$  
// siteStop(); +:Nz_l  
} I}|E_U1Qj  
sLzZ}u?(  
2IP<6l8N  
System.err.println("文件下载结束!"); ?X\uzu  
} /7ShE-.5#  
catch(Exception e){e.printStackTrace ();} l\!`ZhM,  
} \?|^w.  
?T,a(m<i {  
P)~olrf  
//获得文件长度 9yu#G7  
public long getFileSize() 1;!dTh  
{ =L;g:hc<  
int nFileLength = -1; NCYOY  
try{ &x4*YM h  
URL url = new URL(siteInfoBean.getSSiteURL()); 9j}Q~v\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9JeT1\VvHY  
httpConnection.setRequestProperty("User-Agent","NetFox"); *g9VI;X  
a/rQ@c>  
xCyD0^KY  
int responseCode=httpConnection.getResponseCode(); IR&b2FTcU  
if(responseCode>=400) 1c*:" k  
{ jF(R;?,  
processErrorCode(responseCode); QtcYFf g  
return -2; //-2 represent access is error sp_19u  
} yNG|YB;  
0LTsWCUQ6e  
{cjp8W8hS  
String sHeader; J<9}) m  
K.}jyhKIKi  
^rGuyW#  
for(int i=1;;i++) e?\hz\^  
{ .eCUvX`$  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dIA1\;@  
//Utility.log(in.readLine()); Wd7qpWItjQ  
sHeader=httpConnection.getHeaderFieldKey(i); L"uidd0(g  
if(sHeader!=null) H2+V1J=  
{ DweF8c  
if(sHeader.equals("Content-Length")) 76u\# {5  
{ <W^>:!?w  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cet|k!   
break; 0}e&ONDQ  
} yb\!4ml  
} 7{VN27Fa_  
else ']H*f2y  
break; 6kONuG7Yv  
} oJc7a z  
} &$h#9  
catch(IOException e){e.printStackTrace ();} Bi0&F1ZC!  
catch(Exception e){e.printStackTrace ();} LRdV_O1e6M  
yATXN>]l  
kZcGe*  
Utility.log(nFileLength); @[5]?8\o  
"msPH<D  
}To-c'  
return nFileLength; &}0#(Fa`  
} J$(79gH{  
2W/*1K}  
o%h[o9i  
//保存下载信息(文件指针位置) Zj)A%WTD,  
private void write_nPos() 99[v/L>F  
{ ZCDXy  
try{ .]; `  
output = new DataOutputStream(new FileOutputStream(tmpFile)); b\xse2#  
output.writeInt(nStartPos.length); WmblY2  
for(int i=0;i<nStartPos.length;i++) 1Nz#,IdQ  
{ F[X;A\  
// output.writeLong(nPos); yq`  ,)  
output.writeLong(fileSplitterFetch.nStartPos); u}jC$T>2%6  
output.writeLong(fileSplitterFetch.nEndPos); |W SvAM3  
} TezwcFqH  
output.close(); %,udZyO3uR  
} De49!{\a  
catch(IOException e){e.printStackTrace ();} ?cD_\~  
catch(Exception e){e.printStackTrace ();} ,(kaC.Em  
} UFj/Y;  
KwxJ{$|xH  
ro^T L  
//读取保存的下载信息(文件指针位置) *C(q{|f  
private void read_nPos() #o(@S{(NZ  
{ NOtwgZ-  
try{ Bs<LJzS{V  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9}11>X  
int nCount = input.readInt(); ^ ;cJjl'=  
nStartPos = new long[nCount]; *35o$P46  
nEndPos = new long[nCount]; !6*4^$i#o  
for(int i=0;i<nStartPos.length;i++) '>% c@C[  
{ }ct*<zj[~u  
nStartPos = input.readLong(); 0Pg@%>yb~  
nEndPos = input.readLong(); L$; gf_L  
} o q cu<]  
input.close(); K(}<L-cv  
} %&4\'lE  
catch(IOException e){e.printStackTrace ();} L$}'6y/@  
catch(Exception e){e.printStackTrace ();} KI5099_/  
} D o!]t7Y$  
l4q7,%G  
,jMV # H[  
private void processErrorCode(int nErrorCode) 21\?FQrz  
{ x_x|D|@wM  
System.err.println("Error Code : " + nErrorCode); `wNJ*`  
} Y\{lQMCy  
"C9.pdP\8  
|r53>,oR<:  
//停止文件下载 A|P `\_  
public void siteStop() "QV1G'  
{ t($z+ C<  
bStop = true; $ dHD  
for(int i=0;i<nStartPos.length;i++) '8fh(`  
fileSplitterFetch.splitterStop(); B4;P)\ 2  
IV$2`)[A&X  
r7N% onx  
} yykyvy  
} 8R.`*  
//负责部分文件的抓取 3S1`av(tD  
**FileSplitterFetch.java Uc|MfxsL  
*/ 2N_9S?a3sK  
package NetFox; Px"K5c*  
x8* @<]!  
y1hJVYE2  
import java.io.*; 2v\-xg%1  
import java.net.*; Jl,\^)DSw  
&8 4Izs/[  
6c&OR2HGqO  
public class FileSplitterFetch extends Thread { cOEzS  
Q*AgFF%wn  
JZrUl^8E  
String sURL; //File URL U*em)/9  
long nStartPos; //File Snippet Start Position &0S/]E`_M  
long nEndPos; //File Snippet End Position J*O$)K%Hx  
int nThreadID; //Thread's ID 8rsv8OO  
boolean bDownOver = false; //Downing is over &b&o];a  
boolean bStop = false; //Stop identical 9 8eS f  
FileAccessI fileAccessI = null; //File Access interface VR0#"  
esQRg~aCGy  
uDi#a~m@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wH[}@w  
{ pvJPMx  
this.sURL = sURL; W'9=st'  
this.nStartPos = nStart; k|T0Bly3P  
this.nEndPos = nEnd; j>OB<4?.+  
nThreadID = id; bwAL:  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4\yKd8I  
} I3V>VLv  
>#\&%0OZw  
mD p|EXN  
public void run() .U !;fJ9  
{ D`^9 u K  
while(nStartPos < nEndPos && !bStop) lCyp&b#(L  
{ n`hes_{,g  
5K*-)F ]  
QP e}rQnm  
try{ %lU$;cY  
URL url = new URL(sURL); ai ,Mez  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jP";ll|c  
httpConnection.setRequestProperty("User-Agent","NetFox"); qlg~W/  
String sProperty = "bytes="+nStartPos+"-"; G{ $Zg  
httpConnection.setRequestProperty("RANGE",sProperty); O({-lI  
Utility.log(sProperty); /vB%gqJvX  
9bT,=b;  
VRoeq {  
InputStream input = httpConnection.getInputStream(); $*H>n!&  
//logResponseHead(httpConnection); u[oYVpe)IG  
wWflZ"%  
Sk$ XC  
byte[] b = new byte[1024]; 2g^Kf,m  
int nRead; k>Qr 14F  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7j& l2Z  
{ qD4e] 5  
nStartPos += fileAccessI.write(b,0,nRead); [M2,bc8SJV  
//if(nThreadID == 1) ]IJ.}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @11voD  
} MnsnW{VGX  
>|7&hj$  
6SsZK)X  
Utility.log("Thread " + nThreadID + " is over!"); %2oLND}?z  
bDownOver = true; tO?*x/XC{  
//nPos = fileAccessI.write (b,0,nRead); Q ;5'I3w  
} L i=l/  
catch(Exception e){e.printStackTrace ();} Dl/UZ@8pl  
} ,lA J{5\#  
} OG 5n9sx  
>e-XZ2>Sj  
+U%lWE%  
//打印回应的头信息 /IV:JVT  
public void logResponseHead(HttpURLConnection con) [dU/;Sk5  
{ K{>O. 5  
for(int i=1;;i++) p|Rxy"}  
{ &[\rnJ?D  
String header=con.getHeaderFieldKey(i); Punbw\9!d,  
if(header!=null) 2 >xV&  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )vGRfFjw_  
Utility.log(header+" : "+con.getHeaderField(header)); ^#^u90I  
else Z*]n]eS  
break; R?|_` @@A  
} a/)TJv  
} (%+DE4?  
<J H0 &  
nI_Zk.R  
public void splitterStop() *%)L?*  
{ l]v *h0!  
bStop = true; ^ <|If:|  
} Y @.JW  
& bw1  
l1W5pmhK]'  
} 6gR=e+  
=h_4TpDQ  
{8B\-LUR  
/* ":-)mfgGU  
**FileAccess.java p-(Z[G*  
*//文件访问(定位,写) Fsq S)  
package NetFox; Bxa],inuZ  
import java.io.*; .PAkW2\#  
2Vu|uZd  
fnmZJJ,Q  
public class FileAccessI implements Serializable{ )Y *?VqZn  
ZXU e4@qfl  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -I_lCZ{Nbi  
RandomAccessFile oSavedFile; 5W{>5.Arx)  
long nPos; 9lD,aOb  
I8Zp#'|U  
!<YRocQY  
public FileAccessI() throws IOException BO9Z "|"  
{ %cm5Z^B1"  
this("",0); .y\HQ^j  
} 3tm z2JIb  
.e"jnP~  
 q?^0 o\  
public FileAccessI(String sName,long nPos) throws IOException :,ym)|YV  
{ ?\O+#U%W  
oSavedFile = new RandomAccessFile(sName,"rw"); ]Z84w!z  
this.nPos = nPos; H]!y |p  
oSavedFile.seek(nPos); 7GIv3Dc  
} 4KM$QHS5{  
4vX]c  
8uGPyH  
public synchronized int write(byte[] b,int nStart,int nLen) LNN:GD)>  
{ @LE?XlhD  
int n = -1; n47=eKd70  
try{ !:n),sFv45  
oSavedFile.write(b,nStart,nLen); aEk*-v#{  
n = nLen; 6>L.)V  
} ^ 2AF:(E  
catch(IOException e) >=`c [=:Z_  
{ rgYuF,BT.  
e.printStackTrace (); x ?V/3zW  
} 3'"M31iA  
j^ _I{  
!Q(xOc9>Ug  
return n; ^i8I 1@ =  
} `HM3YC  
5j{@2]i  
Me}TW!GC  
} B@;)$1-UT  
NI1HUUZz  
*3/7wSV:  
/* gZjOlp  
**SiteInfoBean.java S[a5k;8GL  
*/ 3opLLf_g  
package NetFox; Z8&C-yCC  
E~>6*_?  
^c\IZ5  
public class SiteInfoBean { K7hf m%`N  
L, {rMLM%  
bJ|?5  
private String sSiteURL; //Site's URL p0rwiBC=q  
private String sFilePath; //Saved File's Path O8r"M8  
private String sFileName; //Saved File's Name 2\w=U,;(  
private int nSplitter; //Count of Splited Downloading File h6h1.lZ  
|nEV Oy>'  
PEBFN  
public SiteInfoBean() >fye^Tx  
{//nSplitter的缺省值为5 &#@>(u: .  
//default value of nSplitter is 5 qP"JNswI_  
this("","","",5); f%{Tu`  
} 'Y[A'.*}4  
4VNb`!e  
T'M66kg  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Fd[h9 G  
{ rh`.$/^  
sSiteURL= sURL; + |qfgi  
sFilePath = sPath; (b%y$D  
sFileName = sName; d_C4B  
this.nSplitter = nSpiltter; sdf%  
b;L>%;  
F:J7|<J^F  
} <s8? Z1  
g?~Tguv  
m`$>:B  
public String getSSiteURL() tQ~<i %;  
{ nnE_OK!}T  
return sSiteURL; |:9Ir^  
} _E6} XNS  
_IL2-c8  
7"q+"0G  
public void setSSiteURL(String value) ck+b/.gw`  
{ iS"8X#[]N  
sSiteURL = value; D;zWksq  
} HmExfW  
fYhR#FVI  
G*\abL  
public String getSFilePath() xHB/]Vd-  
{ h}|6VJ@.  
return sFilePath; xP/OsaxN  
} 0)AM-/"  
YZGS-+  
mF'-Is  
public void setSFilePath(String value) uuSR%KK]|  
{ !7*(!as  
sFilePath = value; $J"%I$%X=  
} yW\XNX  
pp~3@_)b  
yGvDn' m  
public String getSFileName() fw' r.  
{ mz\NFC<  
return sFileName; _BV`,`8}  
} ,?g=U8y|  
r<*O  
f.oP   
public void setSFileName(String value) 3ai (x1%  
{ \=!H2M  
sFileName = value; yo'9x s  
} lC#RNjDp/~  
3J%V%}mD  
ImIqD&a-h  
public int getNSplitter() HG2GZ}~^1  
{ upypxC  
return nSplitter; k-"<{V  
} pW\z\o/2  
QDS0ejhp  
vwKw?Z0%J  
public void setNSplitter(int nCount) 3AURzU  
{ rA,CQypo  
nSplitter = nCount; G0}Dq M Ti  
} (ZV;$N-t  
} 3bH~';<  
{Eu'v$c!  
9x=3W?K:,  
/* @\)fzubu  
**Utility.java p*|ah%F6N  
*/ td >,TW=A*  
package NetFox; OX+hZ<y  
Gn59 yG!4  
ic-IN~J-  
public class Utility { {I{3(M#"  
nq' M?c#E  
-Q$b7*"z(  
public Utility() &]< 3 ~6n  
{ 1Bg_FPu  
lkA^\ +Ct  
3_W{T@T  
} ?E<c[*F05  
.+yW%~0  
//线程睡眠 3B{[%#vO  
public static void sleep(int nSecond) HzvlF0f  
{ R \5Vq$Q  
try{ 3OP.12^  
Thread.sleep(nSecond); B'}"AC"  
} _ h9o@  
catch(Exception e) +TN^NE  
{ =&7@<vBpy  
e.printStackTrace (); Ox qguT,  
} (a.1M8v+Sg  
} 9tK>gwb  
/p)F>WR  
//日志 ?x3Jv<G0*  
public static void log(String sMsg) m'x;,xfY&F  
{ Es.nHN^]%K  
System.err.println(sMsg); c@R; /m:R  
} *Qkc[XHqy  
{)@D`{$  
y-B=W]E  
public static void log(int sMsg) |~K(F <;j  
{ MBw-*K'?zB  
System.err.println(sMsg); %NajFjBI  
} K2rzhHfb  
} &yIGr` ;  
?6P.b6m}0  
S1b Au <  
/* ZFvyL8o  
**TestMethod.java E0l _--  
*/ -5b A $  
package NetFox; gfy19c 9  
 8=;k"  
\9:wfLF8!  
public class TestMethod { 5`-UMz<]  
{f DTSr?/  
U BZ9A  
public TestMethod() qpp/8M  
{ ///xx/weblogic60b2_win.exe edvFQ#,d  
try{  jz'<  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5[gh|I;D  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2/7_;_#vJ%  
SiteFileFetch fileFetch = new SiteFileFetch(bean); _yH`t[  
fileFetch.start(); : c.JhE3D  
} /)>S<X  
catch(Exception e){e.printStackTrace ();} K#mOSY;}  
-YGbfd<wq  
},@^0UH4c  
} oPQtGl p  
BR5BJX  
X~9j$3lUBR  
public static void main(String[] args) !mJo'K  
{ Vb|#MNf)  
new TestMethod(); /JJw 6[ N  
} h9s >LY  
} '0RwO[A#1  
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