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http断点续传简单实现(java)

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/* LNk 3=v2M  
**SiteFileFetch.java P,D >gxl  
*/ *w> /vu  
package NetFox; BjOrQAO  
import java.io.*; 83;1L:}`  
import java.net.*; J>XaQfzwU  
U5izOFc  
_.Uz!2  
public class SiteFileFetch extends Thread { n1buE1r?  
-^\k+4;  
Jg;Hg[  
SiteInfoBean siteInfoBean = null; //文件信息Bean i!YZF$|  
long[] nStartPos; //开始位置 +zz9u?2C`  
long[] nEndPos; //结束位置 >JCSOI  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 uTB; Bva  
long nFileLength; //文件长度 @RbAC*Y]g  
boolean bFirst = true; //是否第一次取文件 ~~ )&? \N  
boolean bStop = false; //停止标志 >,hJ5-9  
File tmpFile; //文件下载的临时信息 XD%?'uUQ_  
DataOutputStream output; //输出到文件的输出流 g<}EL[9  
;#fB=[vl";  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) nb0<.ICF%R  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5g/^wKhKG  
{ K2:r7f  
siteInfoBean = bean; ]DC]=F.  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); rv|k8  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); k_O"bsI)  
if(tmpFile.exists ()) j(Q$frI  
{ ?uQ|?rk  
bFirst = false; .$v]B xu  
read_nPos(); a,&Kvh  
} ~LYKt0/W&  
else |(XV '-~  
{ fa5($jJ&  
nStartPos = new long[bean.getNSplitter()]; hO{@!H$l  
nEndPos = new long[bean.getNSplitter()]; )@SIFE  
} ?_n.B=H`8  
JJ qX2B  
V! "^6)  
t'm]E2/  
} ]2b" oHg  
kFD-  
YF&SH)Y7  
public void run() fVR ~PG0  
{ hTVN`9h7  
//获得文件长度 >SfC '*1  
//分割文件 +u25>pX  
//实例FileSplitterFetch z13"S(5D~  
//启动FileSplitterFetch线程 s/P\w"/fN  
//等待子线程返回 rYm<U!k  
try{ !4.;Ftgjn  
if(bFirst) ?:n{GK  
{ tGM)"u-  
nFileLength = getFileSize(); Vy-S9=  
if(nFileLength == -1) Ie4*#N_  
{ uz'beE  
System.err.println("File Length is not known!"); |W:kzTT-T  
} '*-X 3p  
else if(nFileLength == -2) b;!ilBc  
{ S$muV9z2=  
System.err.println("File is not access!"); mpr["C"l  
} :*c@6;2@  
else \O7,CxD2  
{ 2(`2f  
for(int i=0;i<nStartPos.length;i++) @J" }~Y  
{ UxzwgVT  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); #Kn7 xn[  
} bmT  J  
for(int i=0;i<nEndPos.length-1;i++) mO> [kb"V'  
{ IwWo-WN7.  
nEndPos = nStartPos[i+1]; /_jApZz  
} 9h*$P:S;1v  
nEndPos[nEndPos.length-1] = nFileLength; z:< (b   
} ?]h+En5z8  
} 2$1rS}}  
Ej.D!@   
QW6k!ms$  
//启动子线程 jN5Sc0|b  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wJ IJPYTK  
for(int i=0;i<nStartPos.length;i++) WYaDN:kZf  
{ _}JygOew  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rR C3^X`u  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X]y3~|K  
nStartPos,nEndPos,i); rM>&! ?y+  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @X\nY</E#M  
fileSplitterFetch.start(); g`J? 2 _]  
} "OK(<x]3;>  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JZP2NB_xt  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); - *yj[?6  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Iun!r v  
nEndPos = " + nFileLength); ap;UxWqx  
// fileSplitterFetch[nPos.length-1].start(); +[~\\X  
8^< -;  
uc7Y8iO  
//等待子线程结束 6;(Slkv  
//int count = 0; B8a!"AQ~5  
//是否结束while循环 2M1yw "  
boolean breakWhile = false; !L3Bvb;Q  
Y|B/(  
|'KNR]: N  
while(!bStop) ?pQ, 5+8  
{ }T(|\ X  
write_nPos(); 70KXBu<6  
Utility.sleep(500); {v]>sn;P1  
breakWhile = true; >O\-\L  
( !Ml2  
P<2yCovn`  
for(int i=0;i<nStartPos.length;i++) xsAF<:S\  
{ r-Dcc;+=Q  
if(!fileSplitterFetch.bDownOver) !uHI5k,f  
{ ih~c(&n0  
breakWhile = false; -F5U.6~`!  
break;  ) mv}u~  
} lbv, jS  
} x!"!oJG^k  
if(breakWhile) *FG@Dts^&  
break; _B W$?:)9  
W:EXL@  
gB~SCl54  
//count++; ASu9c2s  
//if(count>4) Pv/P<i^  
// siteStop(); rx^pGVyg  
} jq =-Y  
AHZ6  
Q g"{F},4  
System.err.println("文件下载结束!"); W/?D}#e<4  
} L<Lu;KnY6  
catch(Exception e){e.printStackTrace ();} rxDule3m  
} 0U$6TDtmE  
X.UIFcK^  
d3n TJX  
//获得文件长度 gNZ^TeT  
public long getFileSize() IFv2S|  
{ }#yRa Ip  
int nFileLength = -1; ;W+.]_$6)T  
try{ N8nyTPw  
URL url = new URL(siteInfoBean.getSSiteURL()); #Q$4EQB  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {[Yv@CpN  
httpConnection.setRequestProperty("User-Agent","NetFox"); yY&(?6\{<<  
3q1O:b^eo  
H_*]Vg  
int responseCode=httpConnection.getResponseCode(); 7rhpIP2n  
if(responseCode>=400) I=3q#^}[  
{ 1 1p\ z  
processErrorCode(responseCode); `_v-Y`Z  
return -2; //-2 represent access is error S?8q.59  
} H!45w;,I  
,#"AWQ  
JBWiTUk  
String sHeader; ZFdQ Z=.'  
w=^*)jZ8  
VVe>}  
for(int i=1;;i++) F;~ #\ X  
{ k)4|%  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9r8{9h:  
//Utility.log(in.readLine()); }xdI{E1 q)  
sHeader=httpConnection.getHeaderFieldKey(i); X=.+XP]  
if(sHeader!=null) n*O/ X  
{ G&Cl:CtC  
if(sHeader.equals("Content-Length")) C ]r$   
{ j?&FK  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F^ Q  
break; xH' H! 8  
} +Oyt   
} Qy3e ,9nS  
else 4Y)3<=kDG  
break; k| jC c  
} :+R ||q i  
} :*oI"U*f  
catch(IOException e){e.printStackTrace ();} ,cm2uY  
catch(Exception e){e.printStackTrace ();} W)9KYI9u  
{) .=G  
@9c^{x\4  
Utility.log(nFileLength); Ok*:;G@  
L g%cVSz/C  
WV&BZ:H  
return nFileLength; H-rf?R2  
} }_gq vgI>p  
s]2k@3|e  
uvmNQg  
//保存下载信息(文件指针位置) +h9CcBd  
private void write_nPos() Ak9W8Z}  
{ 4ErDGYg}  
try{ )FHaJ*&d  
output = new DataOutputStream(new FileOutputStream(tmpFile)); _6(zG.Fg  
output.writeInt(nStartPos.length); {+r?g J  
for(int i=0;i<nStartPos.length;i++) \|T0@V  
{ -l,ib=ne  
// output.writeLong(nPos); ,-{j.  
output.writeLong(fileSplitterFetch.nStartPos); N.isvDk%  
output.writeLong(fileSplitterFetch.nEndPos); I;xT yhUd  
} [I^SKvM  
output.close(); 9(@bjL465  
} 5Y,e}+I>  
catch(IOException e){e.printStackTrace ();} F]ALZxwkz  
catch(Exception e){e.printStackTrace ();} gVI*`$  
} p@Qzg /X  
aFC3yMKXh  
rgP$\xn-  
//读取保存的下载信息(文件指针位置) h]zx7zt-  
private void read_nPos() \Xkx`C  
{ i3Ffk+ |b  
try{ l"cO@.T3  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i "-#1vy=  
int nCount = input.readInt(); V K NCK  
nStartPos = new long[nCount]; U2bb|6j  
nEndPos = new long[nCount]; ,3W a~\/Q  
for(int i=0;i<nStartPos.length;i++) h]D=v B  
{ :s$9#}hw,  
nStartPos = input.readLong(); d-?~O~qD|!  
nEndPos = input.readLong(); }U #S*  
} Y&j6;2-Z  
input.close(); |RpC0I  
} Ia(A&Za  
catch(IOException e){e.printStackTrace ();} v h%\ " h  
catch(Exception e){e.printStackTrace ();} Z4(2&t^  
} nrf%/L  
=LT({8  
/`'50C j  
private void processErrorCode(int nErrorCode) fO:*85 %}7  
{ FF/MTd}6qG  
System.err.println("Error Code : " + nErrorCode); 6?Ks H;L9  
} $[>wJXj3R  
CId`6W  
rVN|OLh  
//停止文件下载 rSZWmns  
public void siteStop() n@%'Nbc>b  
{ 8l}|.Q#--  
bStop = true; v)pdm\P  
for(int i=0;i<nStartPos.length;i++) ae^xuM?7  
fileSplitterFetch.splitterStop(); ,O-lDzcw  
AOfQqGf  
F`ihw[ Wn  
} dyx 4_!fO  
} -9Can4  
//负责部分文件的抓取 w6cPd'  
**FileSplitterFetch.java $>BP}V33  
*/ qt1# P  
package NetFox; - jyD!(  
Nh+$'6yT%  
s0`uSQ2X  
import java.io.*; IBuuZ.=j2h  
import java.net.*; oZ8SEC "]  
=9)ypI-2  
=* (d+[_  
public class FileSplitterFetch extends Thread { V3`*LU  
"Srp/g]a  
G!Uq#l>  
String sURL; //File URL s/T5aJR  
long nStartPos; //File Snippet Start Position =-:o?&64  
long nEndPos; //File Snippet End Position E@@quK  
int nThreadID; //Thread's ID R4v=i)A~Z  
boolean bDownOver = false; //Downing is over 5fLCmLM`  
boolean bStop = false; //Stop identical fe Q%L  
FileAccessI fileAccessI = null; //File Access interface ]>AW  
r`&ofk1K  
\{&55>  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i 9b^\&&  
{ '!Sj]+  
this.sURL = sURL;  t]vz+VQ  
this.nStartPos = nStart; +fwq9I>L  
this.nEndPos = nEnd; uj]GBo=  
nThreadID = id; u_[Zu8  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :J<S-d=  
} 7v?Ygtv  
2GD%=rP2]  
J[B8sa  
public void run() x x 'XR'zK  
{ gr2zt&Z4  
while(nStartPos < nEndPos && !bStop) ,sc>~B@Q  
{ iA< EJ  
eR}d"F4W  
SEuj=Vie#  
try{ O/<jt'  
URL url = new URL(sURL); V]<dh|x  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qv?jo(]  
httpConnection.setRequestProperty("User-Agent","NetFox"); =uvv|@Z  
String sProperty = "bytes="+nStartPos+"-"; u.arkp  
httpConnection.setRequestProperty("RANGE",sProperty); OC [a?#R1  
Utility.log(sProperty); HKh)T$IZM  
pkT a^I  
i@p?.%K{  
InputStream input = httpConnection.getInputStream(); tL3(( W"  
//logResponseHead(httpConnection); `hfwZ*s  
: i(h[0  
z;3}GxE-si  
byte[] b = new byte[1024]; ~f@;.  
int nRead; ']dTW#i  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )Q\;N C=4  
{ zJV4)  
nStartPos += fileAccessI.write(b,0,nRead); ~<$8i}7  
//if(nThreadID == 1) Im Tq`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B]hZ4.B1  
} 2T|L# #C  
Fdzd!r1 v  
&?9.Y,  
Utility.log("Thread " + nThreadID + " is over!"); @9L%`=]b^  
bDownOver = true; *$s)p>  
//nPos = fileAccessI.write (b,0,nRead); eHjR/MMr_  
} [&39Yv.k,7  
catch(Exception e){e.printStackTrace ();} `  ^6}Dn  
} p]>bN  
} d82IEhZ#  
nyDqR#t  
INkrG.=u  
//打印回应的头信息 l/1uP  
public void logResponseHead(HttpURLConnection con) v` B_xEl  
{ <oeHZD_ OR  
for(int i=1;;i++) T @z$g  
{ &d*9#?9  
String header=con.getHeaderFieldKey(i); k!%HcU%J  
if(header!=null) xWlB!r<}Gz  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]]]7"a  
Utility.log(header+" : "+con.getHeaderField(header)); A]n !d}?  
else #{]=>n)j  
break; Vxw?"mhP  
} *Lufz-[1  
} M 35}5+  
>DV0!'jW  
aTPpE9Pa&  
public void splitterStop() @ce4sSo  
{ 0W>O,%z&P#  
bStop = true; k"n#4o:  
} hQk mB|];5  
";zl6g"  
pGOS'.K%t8  
} %+'&$  
U M#]olh  
B(>_.x#kv  
/* AUN Tc3  
**FileAccess.java F:H76O`8  
*//文件访问(定位,写) p@^2 .O+  
package NetFox; Y /w vn8~C  
import java.io.*; X!"y>J  
:q= XE$%H  
6 HEl1FK{@  
public class FileAccessI implements Serializable{ ;or> Sh7  
f.u{;W  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,%:`Ll t]$  
RandomAccessFile oSavedFile; -Pvt+I>  
long nPos; {=(4  
A,iXiDb3pK  
w}E?FEe.  
public FileAccessI() throws IOException 1]kk  
{ a`{'u)@  
this("",0); ;1y\!f3#V~  
} z,NHH):~  
wbpxJtJB  
tC&y3!k2jR  
public FileAccessI(String sName,long nPos) throws IOException wUSWB{y  
{ } M1<a4~  
oSavedFile = new RandomAccessFile(sName,"rw"); 7>4t{aRf_8  
this.nPos = nPos; ](W #Tj5-  
oSavedFile.seek(nPos); Xau.4&\d  
} *]EcjK%  
A+dY~@*a  
)dvOg'it  
public synchronized int write(byte[] b,int nStart,int nLen) x~mXtqg  
{ %?cPqRHJ ~  
int n = -1; "JGaw_o  
try{ bhgh ]{  
oSavedFile.write(b,nStart,nLen); aRV!0?fS  
n = nLen; |g9^]bT  
} ]:f1r8<3p  
catch(IOException e) Z@*Z@]FC  
{ "q%)we  
e.printStackTrace (); SnXLjJe  
} :_^YEm+A  
9 V;m;sz  
,iHt*SZ,*  
return n; SHaZ-d  
} y_nh~&  
7X.1QSuE  
ar{e<&Bny  
} >Te{a*`"m:  
7eO8cPy  
I?:V EN:  
/* eFx*lYjA  
**SiteInfoBean.java k{;:KW|  
*/ 44]ae~@a  
package NetFox; zZy>XHR H  
M\]E;C'"U  
DnTM#i:  
public class SiteInfoBean { [C&c;YNp  
$X{& KLM[  
[R~HhM  
private String sSiteURL; //Site's URL ZWFH5#=  
private String sFilePath; //Saved File's Path h0gT/x  
private String sFileName; //Saved File's Name Z86[sQBg  
private int nSplitter; //Count of Splited Downloading File n1LS*-@  
%GIla *  
}%}eyLm(  
public SiteInfoBean() MRa>@Jn??A  
{//nSplitter的缺省值为5 x 1 _(j  
//default value of nSplitter is 5 E^qKkl  
this("","","",5); z4<h)hh"k6  
} A76=^ iw  
?,!qh  
O=mJ8W@  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i44`$ps  
{ >,y QG+  
sSiteURL= sURL; c[YC}@l%a  
sFilePath = sPath; X ak~He  
sFileName = sName; {Cd*y6lI  
this.nSplitter = nSpiltter; LO2sP"9  
< /}[x2w?]  
.h6h&[TEU  
} %AJdtJ@0H  
FkS{Z s  
i7p3GBXh[  
public String getSSiteURL() $;">/ "7m  
{ WT0U)x( m5  
return sSiteURL; b :+ X3  
} B>'\g O\2  
`aUA_"f  
i ^W\YLE  
public void setSSiteURL(String value) .d*vfE$  
{ g,1\Gj%y  
sSiteURL = value; _7;#0B  
} ru U|  
#8(@a Y  
ugL$W@   
public String getSFilePath() C{,nDa?|  
{ d9^h YS{  
return sFilePath; `Ffn:=Do  
} 8<o(z'&y  
mT9TSW}  
R{WG>c  
public void setSFilePath(String value) $`riB$v  
{ ^ yfT7050  
sFilePath = value; ](O!6_'d  
} 0 8U:{LL  
7<) .luV  
QM$?}>:  
public String getSFileName() @U9ov >E  
{ Rk'pymap  
return sFileName; Xh{EItk~oO  
} c-3? D;  
+yYz;, \  
Lkb?,j5  
public void setSFileName(String value) BEY}mR]  
{ AKHi$Bk  
sFileName = value; s*Fmu7o43  
} 2yN~[, L  
68D.Li  
/1^%32c  
public int getNSplitter() [k.<x'#  
{ v3[ 2!UXq  
return nSplitter; 7N:,F9V<  
} [bZXzV(  
UrtN3icph  
t#d~gBe?V  
public void setNSplitter(int nCount) hxv/285B  
{ u=4tW:W,  
nSplitter = nCount; 9SU;c l  
} .qHgQ_%  
} !]"T`^5,Y  
cLXMq"?C  
uYs+x X_  
/* }6o` in>M  
**Utility.java Mbi)mybM  
*/ BO1Mz=q  
package NetFox; /6f$%:q  
DQE.;0ld  
-m-~  
public class Utility { {5RM)J1  
-f'z _&KI  
1|Fukx<@J<  
public Utility() (llg!1  
{ H*!E*_  
3vMfms  
`?La  
} JWEqy+,Fjw  
9_&.G4%V  
//线程睡眠 QYg2'`(  
public static void sleep(int nSecond) :V >Z|?[*H  
{ Q.!D2RZc  
try{ f>Ij:b`Z2  
Thread.sleep(nSecond); = i `o+H  
} oo /#]a  
catch(Exception e) aiz_6@Qfz*  
{ r% qgLP{v  
e.printStackTrace (); []'BrG)!  
} Xo'_|-N+  
} O>}aK.H  
3Hr ZN+D  
//日志 tNq~M  
public static void log(String sMsg) \# #~Tq  
{ 3p")  
System.err.println(sMsg); 0dXWy`Mn  
} /5SBLp}Sy  
mgg/i@(  
0*+i~g,Kl@  
public static void log(int sMsg) @ UX'(W  
{ -MeGJX:^I  
System.err.println(sMsg); {Z$Aw4a"d  
} dMYDB  
} 2jaR_` `=:  
/SjA;c! .  
\]GBd~i<  
/* j]YS(Y@AY  
**TestMethod.java >+&524xc  
*/ eAPGy-  
package NetFox; JH5ckgdZ  
=r#of|`Q  
\y{C>! WX4  
public class TestMethod { @/7tN3O  
va| 1N/&  
LG@5Z-  
public TestMethod() L%Me wU0TZ  
{ ///xx/weblogic60b2_win.exe /wKL"M-%  
try{ lor jMS  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >DPC}@Wl  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {}~7Gi!  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {QI"WFdGx  
fileFetch.start(); K&\xbT  
} <-FAF:6$@@  
catch(Exception e){e.printStackTrace ();} r. :LZEr  
`!  
AYfW}V"  
} 7<=xc'*8t  
Il,2^54q  
Qv|A^%Ub!  
public static void main(String[] args) 7$Jb"s  
{ +CaPF  
new TestMethod(); 0M>+.}e+  
} Ic P]EgB  
} IyOb0WiEj  
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