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http断点续传简单实现(java)

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/* IIN,Da;hD  
**SiteFileFetch.java 2HO2  
*/ I?RUVs  
package NetFox; I? ="Er[g}  
import java.io.*; iG#9 2e4  
import java.net.*; ,FwpHs $A  
fV2w &:^3  
Eh^gR`I  
public class SiteFileFetch extends Thread { Rl&nR$#  
tOX -vQ  
,xg-H6Xfa{  
SiteInfoBean siteInfoBean = null; //文件信息Bean T|,/C|L  
long[] nStartPos; //开始位置 .W\JvPTC  
long[] nEndPos; //结束位置 +%H=+fJ2}  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 OLo?=1&;;  
long nFileLength; //文件长度 >0_{80bdO  
boolean bFirst = true; //是否第一次取文件 Oyb0t|do+  
boolean bStop = false; //停止标志 =ld!=II  
File tmpFile; //文件下载的临时信息 $_3 )m  
DataOutputStream output; //输出到文件的输出流 6"?#E[ #[  
!jf!\Uu[U  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ep4?;Qmho  
public SiteFileFetch(SiteInfoBean bean) throws IOException W[R`],x`  
{ Vqcw2  
siteInfoBean = bean; * mH&Gn1  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ,Wtgj=1!.  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); pedyWA>  
if(tmpFile.exists ()) T"t.t%(8  
{ +:W/=C d(h  
bFirst = false; ht#,v5oG>f  
read_nPos(); k!bG![Ie|  
} \u04m}h]  
else %k<+#j6ZH  
{ 39MOqVc  
nStartPos = new long[bean.getNSplitter()]; 5g.w"0MkY  
nEndPos = new long[bean.getNSplitter()]; qHgzgS7a  
} m#ig.z|A  
Vju/+  
e,Z[Nox  
#l h' !  
} M N (o  
6VS_L@  
LcT;7yv  
public void run() F|cli <  
{ 1:Ff#Eq,s  
//获得文件长度 5{WvV%  
//分割文件 EI)2 c.A  
//实例FileSplitterFetch J\>/ J%  
//启动FileSplitterFetch线程 nBLb1T  
//等待子线程返回 Q~/=p>=uu  
try{ 7nB X@Uo  
if(bFirst) aK_k'4YTm  
{ }u1h6rd `  
nFileLength = getFileSize(); 'Fc$?$c\  
if(nFileLength == -1) byTH SRt  
{ gLY15v4?  
System.err.println("File Length is not known!"); r&ys?@+G  
} VoQhzp6&  
else if(nFileLength == -2) ty:{e]e  
{ scTt53v^  
System.err.println("File is not access!"); kGL3*x  
} <EdNF&S-  
else rxs:)# ?A  
{ f3 imkZ(  
for(int i=0;i<nStartPos.length;i++) _0ZU I^#  
{ k)[c!\a[i  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); R<vbhB/lU  
} GHo mk##0E  
for(int i=0;i<nEndPos.length-1;i++) u/NcX  
{ B~M6l7^?  
nEndPos = nStartPos[i+1]; =p7id5"  
} XL9-N?(@  
nEndPos[nEndPos.length-1] = nFileLength; fQwLx  
} \/C5L:|p_  
} wCV~9JTJ!  
u?rX:KkS  
fdHFSnQ g  
//启动子线程 ~]`U)Aw  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7F_N{avr  
for(int i=0;i<nStartPos.length;i++) m>3\1`ZF~<  
{ o?c NH  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jP0TyhM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lauq(aD_C  
nStartPos,nEndPos,i); u#`51Hr$  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <>Ha<4A =E  
fileSplitterFetch.start(); =(Y0wZP|  
} jW4>WDN:  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5y] %Cu1.u  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MttFB;Tp  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %mD{rG9  
nEndPos = " + nFileLength); Gd'_X D  
// fileSplitterFetch[nPos.length-1].start(); K r<UPr  
us8HXvvp{  
E$ &bl  
//等待子线程结束 +WKN&@  
//int count = 0; KfPgj  
//是否结束while循环 y&eU\>M  
boolean breakWhile = false; UR S=1+  
~;YkR'q0_  
kBnb9'.A1  
while(!bStop) Rlm28  
{ HuK Ob4g  
write_nPos(); g$vOWSI +  
Utility.sleep(500); Ct zW do.  
breakWhile = true; .JJ50p  
"zzb`T[8  
~=t9-AF-  
for(int i=0;i<nStartPos.length;i++) hs:iyr]@9  
{ ie>mOsz  
if(!fileSplitterFetch.bDownOver) sTep2W.9  
{ 1)qD)E5&cf  
breakWhile = false; }W(t> >  
break; .<xD'54  
} yq<W+b/  
} P_H_\KsH*(  
if(breakWhile) Y*O Bky  
break; B52dZb  
e\f\CMb  
&Vu-*?  
//count++; PfB9 .f{  
//if(count>4) QC&,C}t,  
// siteStop(); !4<A|$mQ  
} k*C[-5&#  
ts("(zI1E  
\PFjw9s  
System.err.println("文件下载结束!"); ,H<nNBv 3M  
} 9 g- 8u+&  
catch(Exception e){e.printStackTrace ();} .u=|h3&  
} g6S-vSX,  
}R YPr  
-}( o+!nl  
//获得文件长度 DRTT3;,N  
public long getFileSize() "3|OB, <;:  
{ -j:yEZ4Oy  
int nFileLength = -1; GU9p'E  
try{ .2_xTt   
URL url = new URL(siteInfoBean.getSSiteURL()); m(EV C}Y  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :S7[<SwL  
httpConnection.setRequestProperty("User-Agent","NetFox"); &p*rEs  
84i0h$ZZo  
& .#dZ}J  
int responseCode=httpConnection.getResponseCode(); h?} S|>9  
if(responseCode>=400) T &bB8tQk  
{ hd[t&?{=  
processErrorCode(responseCode); }odjaM}5Nc  
return -2; //-2 represent access is error TDWD8??e  
} t]iKU@3  
%K7;ePu  
Z!jJ93A"  
String sHeader; Ke]'RfO\  
qPJSVo  
%K06owV(S)  
for(int i=1;;i++) 0ia-D`^me  
{ v6E5#pse8  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g:U -kK!i  
//Utility.log(in.readLine()); rSm#/)4A  
sHeader=httpConnection.getHeaderFieldKey(i); gQ%mVJB{(  
if(sHeader!=null) 8DbP$Wwi  
{ Ge=\IAj  
if(sHeader.equals("Content-Length")) 'WBhW5@  
{ a1[J>  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PL!dkaD^y>  
break; =4U$9jo!;  
} ,JTyOBB<I  
} <1:I[b  
else {i3=N{5b  
break; Z@$'fX?~9  
} )nK+`{;@!  
} 1=!2|D:C)i  
catch(IOException e){e.printStackTrace ();} _F^NX%  
catch(Exception e){e.printStackTrace ();} +&J1D8  
bxBndxl  
7 n^1H[q  
Utility.log(nFileLength); n!lE|if  
~DB:/VSmu  
f.E{s*z>  
return nFileLength; :O?3lj)  
} 9;`hJ!r  
F&3:]1  
HzuG- V  
//保存下载信息(文件指针位置) 1|>bG#|  
private void write_nPos() v:>sS_^  
{ "d M-3o<  
try{ ~3-+~y=o~  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2 '$nz  
output.writeInt(nStartPos.length); w_LkS/  
for(int i=0;i<nStartPos.length;i++) 1:./f|m  
{ Ys?0hd<cn  
// output.writeLong(nPos); YG*}F|1  
output.writeLong(fileSplitterFetch.nStartPos); 300[2}Y]  
output.writeLong(fileSplitterFetch.nEndPos); :`<MlX  
} Ywcgt|  
output.close(); uaCI2I  
} at2)%V)  
catch(IOException e){e.printStackTrace ();} 04}c_XFFE  
catch(Exception e){e.printStackTrace ();} $?LegX  
} 1Vz3N/AP%?  
{W%XS E  
XB:E<I'q!3  
//读取保存的下载信息(文件指针位置) jxYze/I  
private void read_nPos() c`\qupnY  
{ }wJH@'0+  
try{ u%OLXb  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )]\-Uy$x  
int nCount = input.readInt(); fj9&J[  
nStartPos = new long[nCount]; kn`O3cW/  
nEndPos = new long[nCount]; w7\ \m9  
for(int i=0;i<nStartPos.length;i++) e. E$Ej]w  
{ , 0?_? GO  
nStartPos = input.readLong(); >rYMOC~  
nEndPos = input.readLong(); OL@$RTh  
} 'c >^Aai  
input.close(); @Yw42`> !s  
} \vpX6!T  
catch(IOException e){e.printStackTrace ();} Zl.,pcL  
catch(Exception e){e.printStackTrace ();} -f?,%6(1  
} Le,;)Nd  
k? ,/om1  
tU>7 jo[-p  
private void processErrorCode(int nErrorCode) F9r|EU#;  
{ )L_@l5l  
System.err.println("Error Code : " + nErrorCode); sn'E}.uhXH  
} vJX0c\e  
e Dpt1  
{ / ,?3  
//停止文件下载 v[jg|s&6"  
public void siteStop() Lg-!,Y   
{ wzY{ii  
bStop = true; ~;t/VsgGW  
for(int i=0;i<nStartPos.length;i++) [?XP[h gd  
fileSplitterFetch.splitterStop(); \GK]6VW  
F8\JL %  
\J-D@b;  
} fd&>p  
} g?u=n`k]\  
//负责部分文件的抓取 FU)=+m  
**FileSplitterFetch.java :8]y*j  
*/ I(z16wQ  
package NetFox; *-E'$  
F^?DnZs  
E7I$GD  
import java.io.*; IUD@Kf]S  
import java.net.*; [&lH[:Y#  
o;OEb  
p]7IoO -@  
public class FileSplitterFetch extends Thread { |!CAxE0d$B  
:xY9eq=  
0aJcX)  
String sURL; //File URL f7;<jj;w7  
long nStartPos; //File Snippet Start Position #W4 "^#2  
long nEndPos; //File Snippet End Position T5dnj&N ]  
int nThreadID; //Thread's ID 0u +_D8G  
boolean bDownOver = false; //Downing is over ` :Oje  
boolean bStop = false; //Stop identical jZiz 0[  
FileAccessI fileAccessI = null; //File Access interface L08lkq,  
%Vk77(  
WM ]eb, 8q  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8KsPAK_  
{ NC sem  
this.sURL = sURL; #1WCSLvtV  
this.nStartPos = nStart; E9' 2_e  
this.nEndPos = nEnd; z00,Vr^m  
nThreadID = id; ~{pds  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "kjSg7m*:  
} l]~IZTC  
:*YnH&  
n(sseQ|\  
public void run() \Qf2:[-V0  
{ W< $!H V$  
while(nStartPos < nEndPos && !bStop) |FSp`P  
{ F'T.-lEO_d  
X3?RwN:P  
!x")uYf  
try{ =VV><^uzdY  
URL url = new URL(sURL); $KP&#;9  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y~Mu~/s  
httpConnection.setRequestProperty("User-Agent","NetFox"); k:N/-P&+  
String sProperty = "bytes="+nStartPos+"-"; UtR wZ(09  
httpConnection.setRequestProperty("RANGE",sProperty); iV!V!0- @  
Utility.log(sProperty); B`)bo}h  
b,>>E^wd!  
Q(x/&]7=V  
InputStream input = httpConnection.getInputStream(); 0g#xQzE  
//logResponseHead(httpConnection); Y+5aT(6O  
bGxHzzU}  
`v)ZOw9&  
byte[] b = new byte[1024]; lAkg47i  
int nRead; aj<r=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FuG;$';H75  
{ ?P/73p  
nStartPos += fileAccessI.write(b,0,nRead); 7R5+Q\W  
//if(nThreadID == 1) 1\g r ;b  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `O`MW} c  
} )jh~jU?c@  
e\!Aoky  
:#D~j]pP  
Utility.log("Thread " + nThreadID + " is over!"); bCiyz+VyJn  
bDownOver = true; *;U<b  
//nPos = fileAccessI.write (b,0,nRead); 4[)tO-v:Y  
} 7`&6l+S|  
catch(Exception e){e.printStackTrace ();} JEF;Q  
} x~K79Mya  
} #7KR`H  
tYhcoV  
g{f7 } gTG  
//打印回应的头信息 !7p&n3dz  
public void logResponseHead(HttpURLConnection con) \ _?d?:#RD  
{ T1'\!6_5  
for(int i=1;;i++) 5=R]1YI~$  
{  GInw7  
String header=con.getHeaderFieldKey(i); ZZi|0dG4;  
if(header!=null) RE1M4UV.  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PKQ.gPu6*@  
Utility.log(header+" : "+con.getHeaderField(header)); "8~PfLJ+  
else 3eB)X2~   
break; ?]o(cz  
} L\V`ou  
} amQTPNI  
^]Z@H/]H  
KLG29G  
public void splitterStop() YOUB%N9+  
{ = |2F?  
bStop = true; X#zp,7j?  
} 0& ?L%Y  
M27H{} v  
u4bVp+  
} qh6rMqq  
}0iHf'~DH*  
Xz9[0;Q  
/* >?6HUUQ  
**FileAccess.java JpxQS~VX  
*//文件访问(定位,写) \xcf<y3_  
package NetFox; KP7 {  
import java.io.*; wuW{ 2+)B  
8H`L8: CM  
&gUa^5'#  
public class FileAccessI implements Serializable{ ;--D?Gs]Qr  
>(.Y%$9"E  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7 |GSs=  
RandomAccessFile oSavedFile; 1N<n)>X4  
long nPos; >0uj\5h)I]  
`6;$Z)=.  
]2 $T 6  
public FileAccessI() throws IOException X4Pm&ol  
{ lxr;AJ(  
this("",0); j(k}NWPH  
} b*/Mco 9O  
#=;vg  
/Gn0|]KI  
public FileAccessI(String sName,long nPos) throws IOException USS%T<Vk  
{ X *:,|  
oSavedFile = new RandomAccessFile(sName,"rw"); E0yx @Vx  
this.nPos = nPos; [rL 8L6,!  
oSavedFile.seek(nPos); D@:'*Z(  
} _pDfPLlY&  
dCo3VF"u  
yH>C7M7 t  
public synchronized int write(byte[] b,int nStart,int nLen) gXM+N(M-  
{ xA`j:zn'j  
int n = -1; FCWk8/  
try{ pjs4FZ`Pd;  
oSavedFile.write(b,nStart,nLen); 0s\ -iub=d  
n = nLen; X8-x$07)  
} ?~(#~3x  
catch(IOException e) @|bJMi  
{ mx UyD[|  
e.printStackTrace (); s`0IyQXVU  
} !l Egta[Ql  
 sFnR;  
Y*\N{6$2  
return n; h+A+>kC5  
} L]u^$=rI  
`w`F-ke]I  
 ; (A-  
} scYqU7$%T  
6:6A" A  
YDj5+'y  
/* Jb^{o+s53  
**SiteInfoBean.java 29VX-45  
*/ xplV6q`  
package NetFox; Wq"-T.i  
]f&f_"D  
e+D]9wM8  
public class SiteInfoBean { IV1Y+Z )  
Dln1 R[  
9%"`9j~H>  
private String sSiteURL; //Site's URL 1uCF9P ai  
private String sFilePath; //Saved File's Path >tx[UF@P@  
private String sFileName; //Saved File's Name SM2N3"\  
private int nSplitter; //Count of Splited Downloading File }p?67y/  
|lg jI!iK  
}L&LtW{X  
public SiteInfoBean() 3bR%#G%  
{//nSplitter的缺省值为5 ^SKHYo`,,N  
//default value of nSplitter is 5 )rt%.`  
this("","","",5); SMJRoK3  
} E`<ou_0N@q  
{K6Z.-.`  
R/*"N'nH-%  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &43c/T Sb  
{ #z<# oC5  
sSiteURL= sURL; EtaKo}!A}  
sFilePath = sPath; ! K_<hNG&  
sFileName = sName; E_DQ.!U!o  
this.nSplitter = nSpiltter; odC"#Rb  
Xo] 2iQy  
<lWj-+m  
} &1?6Q_p6c  
s=F[.X9lp  
G6}&k[d5%  
public String getSSiteURL() DwZRx@  
{ URg;e M#  
return sSiteURL; LME&qKe5  
} 'b z&m(!  
5]upfC6  
~zG)<S"q  
public void setSSiteURL(String value) hayJgkZ '  
{ }!R*Q`m  
sSiteURL = value; -2>s#/%  
} o 9/,@Ri\5  
c5b }q@nH  
,\cV,$  
public String getSFilePath() i$Kx@,O8t  
{ CCol>:8{P  
return sFilePath; W5= j&&|!  
} EhM=wfGKw  
bgKC^Q/F  
FI.F6d)E$  
public void setSFilePath(String value) Us!ZQ#pP  
{ G &NK  
sFilePath = value; ZfH>UHft  
} 8ih_S2Cd  
D7JrGaF{  
$u'"C|>8  
public String getSFileName() ;UM(y@  
{ S50}]5K  
return sFileName; VltM{-k^  
} 6)ln,{  
wet[f{c  
kGo2R]Dd[  
public void setSFileName(String value) _$5DK%M}  
{ w,vnpdT  
sFileName = value; .UQ|k,,t  
} doHE]gC2Uz  
qe&B$3D|  
_*%K!%}l=  
public int getNSplitter() X[1D$1Dvw  
{ -N wic|  
return nSplitter; OuEcoIK  
} ]@<VLP?  
KYJP`va6k  
*<y9.\z Y<  
public void setNSplitter(int nCount) DB-79U%W  
{ .5o~^  
nSplitter = nCount; /|P{t{^WM  
} G9LWnyQt  
} Sw,*#98  
58HA*w  
6Aq]I$  
/* !rAH@y.l  
**Utility.java adIrrK  
*/ X' 5R4j  
package NetFox; ;CF:cH*  
,>7dIJqzw  
Ky,upU  
public class Utility { uax0%~O\  
 Fpn*]x  
2|& S2uq  
public Utility() F0z7".)  
{ S`zu.8%5  
OUF%DMl4  
Ys}^ hy  
} z EtsMU  
'@hUmrl  
//线程睡眠 `x#S. b  
public static void sleep(int nSecond) K-#d1+P+  
{ _.V5-iN  
try{ YX-j|m|  
Thread.sleep(nSecond); U'(zKqC   
} EYj~Xj8_  
catch(Exception e) Uoe;=P@  
{ ]bh%pn  
e.printStackTrace (); JN+7o h]u  
} 5;" $X 1{  
} [>54?4{|.  
;5[ OS8  
//日志 |TM n  
public static void log(String sMsg) Z^%a 1>`  
{ 6P717[  
System.err.println(sMsg); U!r8}@  
} Sv/P:r _  
hN!;Tny  
T*%GeY [  
public static void log(int sMsg) 9]lI?j]o  
{ 'vVWUK956  
System.err.println(sMsg); T%6JVFD  
} \}=T4w-e  
} 7AT8QC`u  
WXmfh  
o [V8h @K)  
/* w ods   
**TestMethod.java :FS5BT$=  
*/ "0jwCX Cu  
package NetFox; ^-q{:lx  
o^X3YaS)  
EniV-Uj\D  
public class TestMethod { sGhw23  
}M%3  
"%D"h  
public TestMethod() $%DoLpE>  
{ ///xx/weblogic60b2_win.exe )GVTa4}p  
try{ ZwsQ}5  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i;C` .+  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \ .#Y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); K |=o-  
fileFetch.start(); H%Vf$1/TF  
} z;oia!9z  
catch(Exception e){e.printStackTrace ();} K\%\p$ZD  
tkHmH/'7  
DmuQE~DV  
} _xh)]R  
)r{Wj*u  
,}'8. f  
public static void main(String[] args) , p}:?uR  
{ "}xIt)n%;  
new TestMethod(); SJP3mq/^K  
} RN)XIf$@_  
} Q >[>{N&\  
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