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http断点续传简单实现(java)

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/* G\8ps ~3T  
**SiteFileFetch.java d/>owCwQ  
*/ LQVa,'  
package NetFox; v3 $+ l1  
import java.io.*; #*^vd{fl  
import java.net.*; p7 b`Z>}  
R/)cEvB-0  
'I|A*rO  
public class SiteFileFetch extends Thread { b2OVg +3  
}wmn v  
4_3O?IY  
SiteInfoBean siteInfoBean = null; //文件信息Bean /]=d Pb%  
long[] nStartPos; //开始位置 t7|uZHKK  
long[] nEndPos; //结束位置 odxsF(Q0p  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 M{Ss?G4H  
long nFileLength; //文件长度 J8|F8dcz  
boolean bFirst = true; //是否第一次取文件 >*ey 7g  
boolean bStop = false; //停止标志 #E`-b9Q  
File tmpFile; //文件下载的临时信息 Z5aU7  
DataOutputStream output; //输出到文件的输出流 %-? :'F!1  
(17%/80-J  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) / d S!  
public SiteFileFetch(SiteInfoBean bean) throws IOException QG\lXY,  
{ k%w5V>]1  
siteInfoBean = bean; G #.(% ,  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 4&r+K`C0  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 0T,Qn{  
if(tmpFile.exists ()) sW)C6 #  
{ j-2`yR  
bFirst = false; :O:Rfmr~  
read_nPos(); /s.O3x._'  
} 4^1B'>I  
else @fR^":.h  
{ uPk`9c52%  
nStartPos = new long[bean.getNSplitter()]; +5pK[%k  
nEndPos = new long[bean.getNSplitter()]; TK.a6HJG  
} (fON\)l  
[;M31b3  
[u[`!L=  
ne nYP0  
} 2`(-l{3  
q1j<p)(  
~@ZdO+n?  
public void run() jbQ2G|:Q  
{ fu|N{$h%X  
//获得文件长度 J%']t$ AR  
//分割文件 5p6Kq=jhb  
//实例FileSplitterFetch [KXxn>n  
//启动FileSplitterFetch线程 w[w{~`([",  
//等待子线程返回 #~um F%#  
try{ ND[u$N+5x"  
if(bFirst) *OU>s;"$  
{ 65bLkR{0  
nFileLength = getFileSize(); ?Dro)fH1  
if(nFileLength == -1) 5T,Doxo  
{ q;3,}emg  
System.err.println("File Length is not known!"); kYBTmz} z  
} }B2H)dG^K  
else if(nFileLength == -2) )@.bkzW  
{ Tyu]14L  
System.err.println("File is not access!"); 7kU:91zR  
} REnd# V2x  
else w)-@?jN  
{ 87%t=X  
for(int i=0;i<nStartPos.length;i++) P9Hv){z  
{ ^_b+o  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,j wU\xo`C  
} .#R\t 7m%  
for(int i=0;i<nEndPos.length-1;i++) Eq zS={Olj  
{ J{' u  
nEndPos = nStartPos[i+1]; 5VIpA  
} |D)NP N&  
nEndPos[nEndPos.length-1] = nFileLength; 9 v)p0  
} ul~>eZ  
} PT4Xr=z =  
lJ@2N$w  
L%`~`3%n-  
//启动子线程 jI@0jxF  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -e#YWMo(  
for(int i=0;i<nStartPos.length;i++) B e+'&+  
{ {\22C `9t  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B]dHMLzl  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \7Hzj0hSi  
nStartPos,nEndPos,i); ey<u  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v'*  
fileSplitterFetch.start(); "!<Kmh5  
} 6'W79  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~rE U83  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NGB%fJ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %Qc#v$;+J  
nEndPos = " + nFileLength); KquHc-fzqr  
// fileSplitterFetch[nPos.length-1].start(); ^7v}wpwX\  
Z"#ysC  
tr"iluwGc  
//等待子线程结束 >XP]NY}Po[  
//int count = 0; i'J.c4  
//是否结束while循环 kRNr`yfN  
boolean breakWhile = false; $wU.GM$t~  
c38RE,4U  
}Q_IqI[7  
while(!bStop) yrO'15TB  
{ FT73P0!8.  
write_nPos(); i_ws*7B<  
Utility.sleep(500); z<c^<hE:l  
breakWhile = true; %Rv&VFg  
BDZB;DPb  
eKn&`\j6  
for(int i=0;i<nStartPos.length;i++) %)*!(%\S*3  
{ W"4E0!r  
if(!fileSplitterFetch.bDownOver) {EbR =  
{ STu!v5XY}-  
breakWhile = false; g[Ah> 5  
break; {55{ YDqx  
} 6XUcJ0  
} r=4'6!  
if(breakWhile) ]]@jvU_?kS  
break; !>b>"\b  
u7G@VZ Ux5  
P{5p'g ,  
//count++; OQaM47"  
//if(count>4) c#nFm&}dm  
// siteStop(); .:Bjs*  
} wl2rw93  
/A\'_a|  
I<|)uK7  
System.err.println("文件下载结束!"); (: 2:_FL  
} VaQ>g*(I  
catch(Exception e){e.printStackTrace ();} ;%2/  
} m8$6FN  
7CYu"+Ea  
&0SGAJlec  
//获得文件长度 Je2o('MA  
public long getFileSize() 0z/tceW'F  
{ is?`tre\P  
int nFileLength = -1; 85Q2c   
try{ KL# F5\ E  
URL url = new URL(siteInfoBean.getSSiteURL()); 53P\OG^G`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q6Y1Jr">X  
httpConnection.setRequestProperty("User-Agent","NetFox"); ZgF-.(GV  
_1hc^j  
9>u2; 'Ls  
int responseCode=httpConnection.getResponseCode(); &#v^y 3r  
if(responseCode>=400) SSycQ4[{o  
{ } IFZ$Y  
processErrorCode(responseCode); xy46].x-  
return -2; //-2 represent access is error wx -NUTRim  
} z %{>d#rw  
Z"'rc.>a  
[VIdw 92  
String sHeader; </tiNc  
Gnp,~F"  
GjE/!6b  
for(int i=1;;i++) |M#b`g$JO,  
{ iN+Dmq5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Tk $rwTCl  
//Utility.log(in.readLine()); !I]fNTv<  
sHeader=httpConnection.getHeaderFieldKey(i); W=}l=o!G.  
if(sHeader!=null) p.TR1BHw  
{ \$ ^z.  
if(sHeader.equals("Content-Length")) \lCr~D5  
{ &}32X-~y  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^i_mGeu  
break; ?;> s<  
} rtv\Pf|  
} xb0hJ~e  
else ^tsIgK^9H  
break; *!%y.$\cE  
} K6~N{:.s  
} ??=CAU%\  
catch(IOException e){e.printStackTrace ();} /ivt8Uiw  
catch(Exception e){e.printStackTrace ();} ,,mkB6;  
GV6!`@<  
W*;~(hDz  
Utility.log(nFileLength); 'IP'g,o++  
NZ9=hI;iM  
;j=/2vU~@  
return nFileLength; '@2pOq  
} 5[`!\vCiZ  
\6)l(b;  
5fv eQI~!  
//保存下载信息(文件指针位置) g[*+R9'  
private void write_nPos() #tN)OZA  
{ (S0MqX*  
try{ 'Fo*h6=  
output = new DataOutputStream(new FileOutputStream(tmpFile)); #<0%_Ca  
output.writeInt(nStartPos.length); c.m ' %4  
for(int i=0;i<nStartPos.length;i++) +`kfcA#pi  
{ 5Ft bZ1L  
// output.writeLong(nPos); K8Gc5#OF  
output.writeLong(fileSplitterFetch.nStartPos); |@]J*Kh  
output.writeLong(fileSplitterFetch.nEndPos); yeKzI~  
} k6ER GQ9|I  
output.close(); Z/sB72K1  
} P[n` X  
catch(IOException e){e.printStackTrace ();} 3m#v|52oj  
catch(Exception e){e.printStackTrace ();} Z66akr  
} r1EccY  
w4:S>6X  
]p(+m_F  
//读取保存的下载信息(文件指针位置) ! 1C3{  
private void read_nPos() T=:O(R1*0  
{ b=:AFs{  
try{ N/DcaHFYo  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yJWgz`/L  
int nCount = input.readInt(); 15r,_Gp8  
nStartPos = new long[nCount]; hdW",Bf'  
nEndPos = new long[nCount]; }+#-\a2  
for(int i=0;i<nStartPos.length;i++) qg:R+`z  
{ *GbC`X)  
nStartPos = input.readLong(); # ,u7lAz  
nEndPos = input.readLong(); Y"D'|i  
} +8."z"i3lE  
input.close(); r|:|\"Yk  
} A`Z!=og=  
catch(IOException e){e.printStackTrace ();} ]7O)iq%  
catch(Exception e){e.printStackTrace ();} ^)rX27!G  
} <?&GBCe  
Tc,Bv7:  
l^:m!SA_  
private void processErrorCode(int nErrorCode) LVq3 R 8A  
{ :HYqm*v;W  
System.err.println("Error Code : " + nErrorCode); bWt>tEnf  
} vI{JBWE,S  
W tnZF]1:u  
*;Dd:D9  
//停止文件下载 1s-k=3)  
public void siteStop() x6* {@J&5*  
{ kCL)F\v"iT  
bStop = true; T_\HU*\  
for(int i=0;i<nStartPos.length;i++) N)lzX X  
fileSplitterFetch.splitterStop(); w}G2m)(  
m/| >4~  
(Z=ziopDE  
} M]!R}<]{  
} as)2ny!u  
//负责部分文件的抓取 {0q;:7Bt  
**FileSplitterFetch.java 49bzHEqZ  
*/ p H5IBIf'  
package NetFox; S+R<wv ,6  
vpFN{UfD  
j,80EhZ  
import java.io.*; jx!)N>  
import java.net.*; ? 1?^>M  
PYkcGtVa_  
] ^to r  
public class FileSplitterFetch extends Thread { AT<gV/1l  
00Tm0rY  
sD1L P  
String sURL; //File URL ;y%lOYm  
long nStartPos; //File Snippet Start Position F_/]9tz?;  
long nEndPos; //File Snippet End Position _K )B  
int nThreadID; //Thread's ID zawU  
boolean bDownOver = false; //Downing is over RU,f|hB 4  
boolean bStop = false; //Stop identical e,={!P"f  
FileAccessI fileAccessI = null; //File Access interface J|sX{/WT  
WiH%URFB  
m( C7Fa  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException S]KcAz(fX  
{ @BbZ(cZ*  
this.sURL = sURL; i@6MO'y  
this.nStartPos = nStart; xQ>c.}J/i  
this.nEndPos = nEnd; wp-5B= #:{  
nThreadID = id; )pjd*+V  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;o,t *  
} b3wE8Co  
 $Tfq9  
t LdBnf  
public void run() a^'1o9  
{ $yIcut7  
while(nStartPos < nEndPos && !bStop) VQZ3&]o  
{ k;3Bv 6  
GfUIF]X  
(sW:^0p  
try{ g.kpUs  
URL url = new URL(sURL); k~>9,=::d  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DifRpj I-0  
httpConnection.setRequestProperty("User-Agent","NetFox"); N;>>HN[bBP  
String sProperty = "bytes="+nStartPos+"-"; fGcAkEstT!  
httpConnection.setRequestProperty("RANGE",sProperty); d@b0z$<s  
Utility.log(sProperty); tE]g*]o  
,ZJI]Q=!  
COOazXtW  
InputStream input = httpConnection.getInputStream(); VCiJ]$`M  
//logResponseHead(httpConnection); zid?yuP  
#E2`KGCzW  
c,Zs. kC  
byte[] b = new byte[1024]; {p|OKf  
int nRead; ;Z-Cn.  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 79~,KFct  
{ ZFOYYht  
nStartPos += fileAccessI.write(b,0,nRead); qDqIy+WR  
//if(nThreadID == 1) kI<C\ *N  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O4@Ki4f3A%  
} qRJg/~_h{  
$G"PZ7  
iVd*62$@$  
Utility.log("Thread " + nThreadID + " is over!"); ?|%^'(U}  
bDownOver = true; U_ V0  
//nPos = fileAccessI.write (b,0,nRead); MfJk`-%~  
} 6.6~w\fR8  
catch(Exception e){e.printStackTrace ();}  &{7n  
} L4zSro:Si  
} 3Ym5SrKK  
 uw LT$  
$ e+@9LNK  
//打印回应的头信息 [])M2_  
public void logResponseHead(HttpURLConnection con) :)c >5  
{ Q0gO1 T  
for(int i=1;;i++) ,vrdtL  
{ "@gJ[BL#  
String header=con.getHeaderFieldKey(i); hAOXOj1  
if(header!=null) $.QnM  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kNI m90,g  
Utility.log(header+" : "+con.getHeaderField(header)); .Y&_k  
else enF.}fo]  
break; ?p. dc ~tZ  
} vPi\ v U{  
} Ufv{6"sH  
!}"npUgE  
Al3Hu-Hf;`  
public void splitterStop() Wv77ef  
{ D ,mFme  
bStop = true; X-3L4@T:?  
} 1|;WaO1Q  
u,PrEmy-  
' hO+b  
} cK(}B_D$  
kX'1.<[  
(dpBGt@  
/* Fy`VQ\%7t  
**FileAccess.java zO2<Igb  
*//文件访问(定位,写) ,<R/x[  
package NetFox; }C/}8<  
import java.io.*; GE Xz)4[  
e:AB!k^xp$  
 *X*D, VY  
public class FileAccessI implements Serializable{ O~">-'f  
t82Bp[t  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :7W5R  
RandomAccessFile oSavedFile; eP &K]#  
long nPos; `gfK#0x#  
5c{=/}Y  
E Q?4?  
public FileAccessI() throws IOException ^nkwT~Bya  
{ 66:|)  
this("",0); r\@"({q}_-  
} /W:}p(>4a  
@faf  
6@H& S  
public FileAccessI(String sName,long nPos) throws IOException |8`}yRsQ  
{ %04>R'mN  
oSavedFile = new RandomAccessFile(sName,"rw"); Y +HVn0~qz  
this.nPos = nPos; {EW}Wd  
oSavedFile.seek(nPos); }mu8fm'  
} dam.D.o"  
U!3nn#!yE  
6XFO@c}d  
public synchronized int write(byte[] b,int nStart,int nLen) dMRwQejY{7  
{ p"q-sMYl  
int n = -1; i;6\tK"!  
try{ fkRb;aIl  
oSavedFile.write(b,nStart,nLen); IdzF<>;W  
n = nLen; \Q^\z   
} q?} G?n 4  
catch(IOException e) A.35WGu&:  
{  gxU(&  
e.printStackTrace (); (>WV)  
} *eUL1m8Y  
Qksw+ZjY#{  
;1(OC-2>d  
return n; DgClN:Hw  
} HeSnj-mtr}  
7T4rx53  
_AVCh)Zb  
} 'v6Rd )E\z  
6TfXz2D'J  
>f`}CLsY  
/* KgAc0pz{7H  
**SiteInfoBean.java AuO%F YKY  
*/ 07/5RFmJ  
package NetFox; -BEPpwb<g  
F4bF&% R  
<=A&y5o  
public class SiteInfoBean { _QXo4z!a8  
QXXcJc~  
c^Wm~"r  
private String sSiteURL; //Site's URL HK2`.'D  
private String sFilePath; //Saved File's Path y)s/\l&  
private String sFileName; //Saved File's Name ;R 2(Gb  
private int nSplitter; //Count of Splited Downloading File C$,S#n@  
Xk7zXah  
zoUW}O  
public SiteInfoBean() )h+JX8K)l  
{//nSplitter的缺省值为5 "T~Ps$  
//default value of nSplitter is 5 K VQZ  
this("","","",5); I,  
} !Y\hF|[z  
HnOF_Twq  
/Zm@.%.  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /f0_mi,bD  
{ _fMooI)U1  
sSiteURL= sURL; |d{(&s}  
sFilePath = sPath; ~PoGuj2wA  
sFileName = sName; 0&5}[9?V'  
this.nSplitter = nSpiltter; Or_9KX2  
}$$b6G  
3FX` dZ  
} N>]u;HjH  
q!O~*   
V!ajD!00  
public String getSSiteURL() (MxLw:AV  
{ 9wtl|s%A %  
return sSiteURL; Y~Jq!  
} sjaG%f&h  
5R o5Cg~  
yM\ 1n  
public void setSSiteURL(String value) 8, B9y D  
{ Nc;7KMOIA  
sSiteURL = value; ](Sp0t  
} P!]DV$o  
F"0 tv$  
@|d|orMC  
public String getSFilePath() 9k$uo_i'  
{ { ET+V  
return sFilePath; :;7qup  
} /iukiWeW  
F,lQj7  
lzw r]J%|?  
public void setSFilePath(String value) 9ykmz (  
{ sq<y2j1oF  
sFilePath = value; }* BY!5  
} !PQ@"L)p  
nY~CAo/:  
<Ft.{aNq$c  
public String getSFileName() ,l@hhaLm?  
{ ^8fO3<Jg  
return sFileName; T.K$a\/{,  
} ,u\M7,a^  
@Z|cUHo  
A Ys<IMQ  
public void setSFileName(String value) e@I?ESZ5  
{ Y$,]~Qzq  
sFileName = value; QTP1u  
} <X;y 4lPZ  
o9Agx{'oV  
*/Y@:Sjf  
public int getNSplitter() ]INbRytvc  
{ v"bOv"!al  
return nSplitter; yWX:`*GV  
} ^M,Q<HL  
g4-HUc zk  
7v=Nh  
public void setNSplitter(int nCount) /yH:ur  
{ C\fc 4  
nSplitter = nCount; *[ A%tj%  
} [!DLT6Qk  
} F%< 0pi  
rV1JJ.I  
\hm=AGI0  
/* _A%z^&k(i  
**Utility.java %q:V  
*/ ob0clJX  
package NetFox; B04Br~hel*  
~j8x"  
ph3[}><6  
public class Utility { am@\$Sa4  
qwVpGNc45  
;O.U-s  
public Utility() ``zg |h  
{ ,.F,]m=  
uTn(fs) D  
'n.ATV,  
} pU}>}  
?hmj0i;XC  
//线程睡眠 A$%%;O   
public static void sleep(int nSecond) B_@>HZ\&  
{ 7gPkg63  
try{ zvD$N-#`p  
Thread.sleep(nSecond); c\-I+lMBi  
} N/^r9Nu  
catch(Exception e) -a/5   
{ D'A)H  
e.printStackTrace (); ("IRv>} 0  
} C2!POf;GdN  
} qzmY]N+w|  
8=<d2u'  
//日志 t7R;RF  
public static void log(String sMsg) y 37n~~%  
{ ]D(%Ku,O%  
System.err.println(sMsg); DBVe69/S  
} @(oz`|*  
8l)^#"ySA  
$ V}s3  
public static void log(int sMsg) 4qiG>^h9  
{ &Du!*V4A  
System.err.println(sMsg); t;ggc{  
} VNA VdP  
} o6oZk0  
Rl$NiY?2  
ud! iy  
/* N}zQ)]xz+r  
**TestMethod.java lq+FH&  
*/ -l$]>J~  
package NetFox; a i}8+L8-  
0*,r  
z <s]Z  
public class TestMethod { pbju;h)O!|  
y{5ZC~Z<!  
Wh 8fC(BE  
public TestMethod() ?hsOhUs(5  
{ ///xx/weblogic60b2_win.exe e7 5*84  
try{ "y>l2V,4j%  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -/KVZ  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2h u;N  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :DQHb"(  
fileFetch.start(); (x#4BI}L9)  
} mp !6MOQ  
catch(Exception e){e.printStackTrace ();} A1Rt  
ezy0m}@   
@[.%A;E4  
} l}Jf;C*j1z  
m9xO& @#vx  
O`~T:N|D  
public static void main(String[] args) 36.L1!d)pE  
{ =U3 !D;XP  
new TestMethod(); k`kmmb>  
} "-(yZigQ  
} ADlPdkmym  
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