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http断点续传简单实现(java)

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/* "|%9xGX|D  
**SiteFileFetch.java (5~C _Y  
*/ B$l`9!,  
package NetFox; D.(G9H  
import java.io.*; yUO|3ONT  
import java.net.*; ~-5@- V  
CeTr%j  
<+gl"lG  
public class SiteFileFetch extends Thread { Ug21d42Z4  
ozC!q)j  
M N#C2 qz  
SiteInfoBean siteInfoBean = null; //文件信息Bean %v[ Kk-d  
long[] nStartPos; //开始位置 "ILWIzf.]  
long[] nEndPos; //结束位置 @@IA35'tc  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 {yR)}r  
long nFileLength; //文件长度 Wq(l :W'  
boolean bFirst = true; //是否第一次取文件 U$)Hhn|X  
boolean bStop = false; //停止标志 <im<(=m9  
File tmpFile; //文件下载的临时信息 M"^Vf{X^  
DataOutputStream output; //输出到文件的输出流 5vf t}f  
@@83PJFid  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) _wNPA1q0J  
public SiteFileFetch(SiteInfoBean bean) throws IOException b`W*vduf  
{ |*KS<iHr%  
siteInfoBean = bean; "<x~{BN?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); lGUV(D  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); oDP((I2-  
if(tmpFile.exists ()) </gp3WQ.  
{ AwU c{h l<  
bFirst = false; \oX8/-0f  
read_nPos(); R:<@+z^A[  
} _-]!;0E IV  
else *W12Rb2  
{ #}dVaXY)  
nStartPos = new long[bean.getNSplitter()]; 61W/BU7O  
nEndPos = new long[bean.getNSplitter()]; hG7S]\N_  
}  YX`=M  
vt@Us\fI  
eJw="  
*frJ^ Ws{  
} [!@oRK=~  
U}w+`ZLN  
K;p<f{PE  
public void run() K3:|Tc(  
{ t-i6FS-  
//获得文件长度 hNnX-^J<o  
//分割文件 aGB0-;.t7  
//实例FileSplitterFetch =Y &9 qt  
//启动FileSplitterFetch线程 mPs%ZC  
//等待子线程返回 '7Mep ]  
try{ (@)2PO /  
if(bFirst) "H>r-cyh  
{ X-kXg)!Bg  
nFileLength = getFileSize(); *$i;o3  
if(nFileLength == -1) #%? FM>  
{ 5zNSEI"PY  
System.err.println("File Length is not known!"); R2}kz.  
} L#`2.nU  
else if(nFileLength == -2) ]?0{(\  
{ tYs8)\{  
System.err.println("File is not access!"); h@*lWi2K7  
} +"cRhVR  
else x37/cu  
{ bz{^h'  
for(int i=0;i<nStartPos.length;i++) >u=%Lz"J  
{ XkPv*%Er8  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); U^%9 )4bj  
} K;oV"KRK  
for(int i=0;i<nEndPos.length-1;i++) CifA,[l34  
{ )@}A r  
nEndPos = nStartPos[i+1]; (VgNb&Yo9  
} }@Xh xZu  
nEndPos[nEndPos.length-1] = nFileLength; tNK^z7Dm  
} .#*D!;f  
} t]s94 R q  
Y!SE;N&  
`-VG ?J  
//启动子线程  fO K|:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h`=r )D  
for(int i=0;i<nStartPos.length;i++) A9 U5,mOz  
{ \B_i$<Sz  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N83!C=X'  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), l+%Fl=Q2em  
nStartPos,nEndPos,i); 4~!Eje!  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LU%#mY  
fileSplitterFetch.start(); c$9sF@K?  
} R7lYu\mA  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WFouoXlG0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :-z&Y492  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rfYP*QQY  
nEndPos = " + nFileLength); G.E[6G3  
// fileSplitterFetch[nPos.length-1].start(); 7 0_}S*T  
Y?<)Dg.[  
Gb;99mE  
//等待子线程结束 z&O#v9.NE|  
//int count = 0; \.o=icOx  
//是否结束while循环 # Mu<8`T-  
boolean breakWhile = false; ^w.]Hd 2  
7%e1cI  
/iplU  
while(!bStop) u t$c)_  
{ u$C\E<G^  
write_nPos(); 42&v % ;R  
Utility.sleep(500); a"x}b  
breakWhile = true; 8) HBh7/  
F% `zs\  
_BbvhWN&+  
for(int i=0;i<nStartPos.length;i++) ?\ZL#)hr"p  
{ k@yh+v5  
if(!fileSplitterFetch.bDownOver) =~&VdPZ  
{ 6ZcXS  
breakWhile = false; * r;xw  
break; 3f"C!l]Xu  
} + ~ "5!  
} \/ErPi=g  
if(breakWhile) jXixVNw  
break; e?b)p5g  
5Q W}nRCZ  
ZWS2q4/S  
//count++; 802H$P^ps  
//if(count>4) V C-d0E0  
// siteStop(); =>qTNh*'  
} A{N\)  
eNbpwne  
+"dv7  
System.err.println("文件下载结束!"); -jB3L:  
} z8E1m"  
catch(Exception e){e.printStackTrace ();} ];1R&:t  
} &kzj?xK=(j  
A (okv  
c+g@Z"es  
//获得文件长度 `PgdJrE  
public long getFileSize() k[ %aCGo  
{ lNz]H iD  
int nFileLength = -1; E$A3|rjnoN  
try{ ;'0=T0\  
URL url = new URL(siteInfoBean.getSSiteURL()); xR?V,uV'$&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vQ1 v# Z  
httpConnection.setRequestProperty("User-Agent","NetFox"); zU&L.+   
2z\e\I  
MG{l~|\x)  
int responseCode=httpConnection.getResponseCode(); I-DXb M  
if(responseCode>=400) 8PBvV[  
{ Z+4D.bA  
processErrorCode(responseCode); T7[NcZ:I  
return -2; //-2 represent access is error WF[bO7:  
} F'FP0t!S  
T]9m:z X9s  
((bTwx  
String sHeader; O$D?A2eI  
;SY\U7B\  
aJzLrX  
for(int i=1;;i++) cE\>f8 I  
{ !Ms[eB  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yCP4r6X0  
//Utility.log(in.readLine()); /TV= $gB`  
sHeader=httpConnection.getHeaderFieldKey(i); Dvc&RG  
if(sHeader!=null) e2cP *J  
{ 6;iJ*2f5V  
if(sHeader.equals("Content-Length")) `XKVr  
{ x#*QfE/E(@  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iOCqE 5d3  
break; l63hLz  
} BUsV|e\  
} %\Wf^6Y^  
else \)/yC74r7(  
break; R[jEvyD>(  
} &%mXYj3y5  
} !RH.|}  
catch(IOException e){e.printStackTrace ();} /.1. MssQM  
catch(Exception e){e.printStackTrace ();} yK%ebq]  
@7 <uMasfp  
(Un_!)  
Utility.log(nFileLength); ,r8Tbk]m  
\r {W  
_S`o1^Ad  
return nFileLength; S1S;F9F  
} 'hqBo|  
Qk976  
eOI (6U!  
//保存下载信息(文件指针位置) qfoD  
private void write_nPos() Qk1xUE  
{ ~*W!mlg  
try{ <RNJ>>0  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Zd:Taieh@  
output.writeInt(nStartPos.length); ,Lr<)p  
for(int i=0;i<nStartPos.length;i++) UVQ7L9%?f  
{ / JkC+7H4  
// output.writeLong(nPos); [U/(<?F{(  
output.writeLong(fileSplitterFetch.nStartPos); .iD*>M:W  
output.writeLong(fileSplitterFetch.nEndPos); OEx^3z^  
} Iw<i@=V  
output.close(); Av'GB  
} }Gyqq6Aeb  
catch(IOException e){e.printStackTrace ();} JM- t<.  
catch(Exception e){e.printStackTrace ();} P [Uy  
} Y!J>U  
r.ZF_^y}+  
$(e#aHB  
//读取保存的下载信息(文件指针位置) a ^d8I  
private void read_nPos() :>Rv!x`  
{ GVHV =E  
try{ 6(d}W2GP  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9}a_:hAy/  
int nCount = input.readInt(); Z[__"^}  
nStartPos = new long[nCount]; jO*l3:!~\  
nEndPos = new long[nCount]; kHw_ S-  
for(int i=0;i<nStartPos.length;i++) R218(8S  
{ lKZB?Kk^w\  
nStartPos = input.readLong(); YQJ==C1  
nEndPos = input.readLong(); U8qtwA9t  
} LI2&&Mw  
input.close(); JM1R ;i6  
} D%6;^^WyUx  
catch(IOException e){e.printStackTrace ();} GaX[C<Wt  
catch(Exception e){e.printStackTrace ();} g<{xC_J  
} )q7UxzE+  
m<FOu<y  
8#!i[UF dj  
private void processErrorCode(int nErrorCode) ; bHV  
{ l2N]a9bq@  
System.err.println("Error Code : " + nErrorCode); iY"l}.7)  
} \%^%wXfp  
]BR,M4   
U!U$x74D5  
//停止文件下载 sBrI}[oyx  
public void siteStop() {ZY+L;eg1  
{ P) 3mX.(}  
bStop = true; U- )i+}Ng  
for(int i=0;i<nStartPos.length;i++) [q !T Iq  
fileSplitterFetch.splitterStop(); ^&y$Wd]6  
\]$IDt(s  
_uc hU=  
} V3 ~~  
} .{y uo{u  
//负责部分文件的抓取 Reatd h  
**FileSplitterFetch.java qOIW(D  
*/ da)NK!  
package NetFox; @E:,lA  
mZd , 9  
Kq i4hK  
import java.io.*; AU2i%Q!  
import java.net.*; kbM3  
5mb]Q)f9-  
EkziAON  
public class FileSplitterFetch extends Thread { jH_JmYd  
,}K<*t[I  
^o7;c[E`  
String sURL; //File URL V+O"j^Z_J  
long nStartPos; //File Snippet Start Position 6{txm+U  
long nEndPos; //File Snippet End Position eq U ME  
int nThreadID; //Thread's ID VkZ7#  
boolean bDownOver = false; //Downing is over 72'5%*1  
boolean bStop = false; //Stop identical 9-MUX^?u  
FileAccessI fileAccessI = null; //File Access interface 7hsGua  
jy'13G/b\  
z[Xd%mhjO  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException KZ/=IP=  
{ K'GBMnjD  
this.sURL = sURL; >y,-v:Vy  
this.nStartPos = nStart; ti#7(^j  
this.nEndPos = nEnd; 'q`^3&E  
nThreadID = id; Cg(Y&Gxf.  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .0es 3Rj  
} <_7*67{  
DY`kx2e!  
;3@cy|\:  
public void run() ( SvWv m  
{ {E@Lft-  
while(nStartPos < nEndPos && !bStop) A,a.8!*}vd  
{ S_Wrw z  
8SGo9[U2  
&G-!qxe  
try{ .X;3,D[w  
URL url = new URL(sURL); /{&tY: ;m  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bD?VU<)3  
httpConnection.setRequestProperty("User-Agent","NetFox"); ml+; Rmvb  
String sProperty = "bytes="+nStartPos+"-"; % yw?s0  
httpConnection.setRequestProperty("RANGE",sProperty); 76`8=!]R  
Utility.log(sProperty); qw^uPs7Uw  
ynQ: > tw  
7Ve1]) u  
InputStream input = httpConnection.getInputStream(); w9bbMx  
//logResponseHead(httpConnection); I"A_b}~*}  
Eq j_m|@  
2%_vXo=I  
byte[] b = new byte[1024]; ci?qT,&  
int nRead; 3R.W >U  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~=uWD&5B4  
{ _I:/ZF5  
nStartPos += fileAccessI.write(b,0,nRead); N/MUwx;P  
//if(nThreadID == 1) ]7Tkkw$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (KDD e}f  
} J1C3&t}  
gaZu;t2u  
-;^j:L{   
Utility.log("Thread " + nThreadID + " is over!"); OC BgR4I  
bDownOver = true; JzQ)jdvp  
//nPos = fileAccessI.write (b,0,nRead); +%ee8|\  
} |#]@Z)xa  
catch(Exception e){e.printStackTrace ();} X:vghOt?  
} w5Y04J  
} 7/I,HxXp!  
;V*l.gr'2  
v>Q #B  
//打印回应的头信息 \1D<!k\S  
public void logResponseHead(HttpURLConnection con) 2AT5  
{ H|3:6x  
for(int i=1;;i++) Mygf T[_  
{ Cv6'`",Yzm  
String header=con.getHeaderFieldKey(i); sn obT Q  
if(header!=null) X-K=!pET  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *Q ?tl\E  
Utility.log(header+" : "+con.getHeaderField(header)); VY |_d k  
else t*Sa@$p  
break; I ?gSG*m  
} A%KDiIA  
} CDQW !XHc  
=8AO:  
Lr$go6s  
public void splitterStop() dfKF%27  
{ gOSJM1Mr3  
bStop = true; Enum/O5  
} M2OIBH4!  
k_ & :24Lj  
1w@(5 ^V  
} K|zZS%?$  
WrQDX3  
I>]oS(GNT  
/* *>7>g"  
**FileAccess.java dCi?SIN  
*//文件访问(定位,写) [ 9 {*94M  
package NetFox; KL1/^1  
import java.io.*; Ql/cN%^j$  
TC!Yb_H}gN  
l?Udn0F  
public class FileAccessI implements Serializable{ {o_X`rgrL  
+ga k#M"n\  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l=S35og  
RandomAccessFile oSavedFile; {XR6>]  
long nPos; Uc7mOa}4  
dP# |$1  
UQ)W%Y;[0  
public FileAccessI() throws IOException OK[T3/v,  
{ "c3Grfoz  
this("",0); K28+]qy[  
} dgR g>)V  
Xe6w|  
wvO|UP H\  
public FileAccessI(String sName,long nPos) throws IOException /oR0+sH]  
{ hn5h\M?  
oSavedFile = new RandomAccessFile(sName,"rw"); ~ELNyI11  
this.nPos = nPos; sy:[T T!w  
oSavedFile.seek(nPos); %<k2#6K  
} qkt0**\  
K&POyOvT  
lD)%s!  
public synchronized int write(byte[] b,int nStart,int nLen) jF ^~p9z  
{ ~zHjMo2  
int n = -1; HJLu'KY }  
try{ ?I6fye7  
oSavedFile.write(b,nStart,nLen); C7rNV0.Fq  
n = nLen; 5b*M*e&=C  
} K{&mI/ ;  
catch(IOException e) @Z*W  
{ Dd'm U  
e.printStackTrace (); rM`X?>iT+  
} Ov 5"  
Huy5-[)15  
61SlVec*o8  
return n; C"6?bg5N  
} Ja,wfRq  
(\\eo  
sPr~=,F  
} &ib5* 4!  
fKeT,U`W  
d;zai]]  
/* 1,6}_MA  
**SiteInfoBean.java ^Y=\#-Dd  
*/ A0o-:n Fu  
package NetFox; N*"p|yhd]  
{9?JjA  
LgKaPg$  
public class SiteInfoBean { @OV|]u  
k jg~n9#T  
q;R],7Re  
private String sSiteURL; //Site's URL V}J)\VZ2#  
private String sFilePath; //Saved File's Path gbI^2=YT'  
private String sFileName; //Saved File's Name WlB  
private int nSplitter; //Count of Splited Downloading File iI\oz&!vH  
'?!zG{x  
Ir {OheJ  
public SiteInfoBean() ]^Qn  
{//nSplitter的缺省值为5 !j:9`XD|  
//default value of nSplitter is 5 $CY~5A`l9  
this("","","",5); I/a/)No  
} >hPQRd  
q|j2MV5#g  
V,mw[Hw  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IEXt:  
{ T;L>;E>B  
sSiteURL= sURL; ]ro*G"-_1#  
sFilePath = sPath; gG]Eeu+z   
sFileName = sName; >d,jKlh^.%  
this.nSplitter = nSpiltter; wCr(D>iM  
!D@ZYK;  
b:Wm8pp?  
} GO__$%~  
N"" BCh"  
%5eY'  
public String getSSiteURL() q?4p)@#   
{ ;LG#.~f  
return sSiteURL; nSW=LjrO~<  
} )\eI;8  
`V`lo,"\  
F @mQQ  
public void setSSiteURL(String value) X;i~ <Tq  
{ L\@I*QP  
sSiteURL = value; <~6h|F8  
} l5zS  
eO?p*"p"F  
4Uphfzv3D  
public String getSFilePath() znxnL,-  
{ x[$z({Yf  
return sFilePath; G&i!Hs  
} g]4(g<:O  
qAn!RkA  
;\]b T;#  
public void setSFilePath(String value)  f4Xk,1Is  
{ ?AJKBW^  
sFilePath = value; PcA2/!a  
} )TVFtI=,NN  
mS~o?q-n  
*v9 2  
public String getSFileName() Y~L2  
{ }s(N6a&(  
return sFileName; yzerOL  
} *M:B\ D  
n/SwP  
K_RjX>q%N  
public void setSFileName(String value) \6R,Nq  
{ 6LalW5I  
sFileName = value; \/: {)T~  
} 2w["aVr =  
$wo?!gt  
}T&iewk  
public int getNSplitter() NYrQ$N"  
{ v6>_ j L  
return nSplitter; *=(lyx_O  
} gDQ1?N'8{t  
f"%{%M$K  
U)E(`{p]  
public void setNSplitter(int nCount) M luVx'  
{ :cF[(i/k4  
nSplitter = nCount; ^Wt*  
} U<DZ:ds ?T  
} n ~shK<!C  
L&u$t}~)  
IIn"=g=9  
/* xlA$:M&  
**Utility.java Qa-K$dm%  
*/ sj HrPs e  
package NetFox; I'uSp-Sfy  
9s6U}a'c  
v^d]~ !h  
public class Utility { hRUhX[  
j$?{\iXZ  
Jl#%uU/sx  
public Utility() *Zt#U#  
{ \$*7 >`k  
Rm255z p  
y:~ZLTAv  
} Hn5|B 3vN  
Bq D'8zLD  
//线程睡眠 P<M?Qd 1.  
public static void sleep(int nSecond) B9NWW6S  
{ {>DE sO  
try{ )qo {c1X  
Thread.sleep(nSecond); A8uVK5  
} 2O.i\cH  
catch(Exception e) #xX5,r0  
{ }\\KYyjY  
e.printStackTrace (); \s=t|Wpu2  
} "4ri SxEyF  
} El.hu%#n*G  
_AAaC_q  
//日志 VF?<{F  
public static void log(String sMsg) vms|x wb  
{ xv(9IEjt0  
System.err.println(sMsg); Jk7|{W\OA  
} 5,_u/5Y4  
m1B+31'>^  
d1AioQ9  
public static void log(int sMsg) YwDbPX  
{ r'^Hg/Jzt  
System.err.println(sMsg); *AO,^R&e.  
} X*/ho  
}  gQ'zW  
$8 UUzk  
Cs9.&Y  
/* V@zg}C|e  
**TestMethod.java ^(vs.U^U<  
*/ ([SU:F!uW(  
package NetFox; n>ULRgiT:o  
t&H?\)!4  
r^FhTzA=1  
public class TestMethod { . $BUw  
+S>j0m<*  
}4 )H   
public TestMethod() F5P[dp-`1  
{ ///xx/weblogic60b2_win.exe _I@9HC 4  
try{ 0AZ")<^~7  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (s.0P O`  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5);  6:b! F  
SiteFileFetch fileFetch = new SiteFileFetch(bean); W>) M5t4i  
fileFetch.start(); &"yx<&c}  
} yv t.  
catch(Exception e){e.printStackTrace ();} $"+djI?E9  
} Yb[   
Zq+v6fk_Mn  
} ^q{9  
X <f8,n  
cG[l!Z  
public static void main(String[] args) 0)Uce=t`  
{ (SpX w,:  
new TestMethod(); - Ajo9H  
} ] eotc2?u  
} jyZ  (RB  
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