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http断点续传简单实现(java)

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/* -F';1D!l%  
**SiteFileFetch.java T2MXwd&l  
*/ w O*x0$  
package NetFox; b:6e2|xf?  
import java.io.*; Ve|=<7%%S  
import java.net.*;  ~&Y%yN^  
JcI~8;Z@Z~  
Zl=IZ?F   
public class SiteFileFetch extends Thread { 'FmnlC1  
6kHb*L Je  
#s|/5[i  
SiteInfoBean siteInfoBean = null; //文件信息Bean >I *uo.OF  
long[] nStartPos; //开始位置 4[f>kY%[  
long[] nEndPos; //结束位置 }FT8 [m<  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 :pg]0X;  
long nFileLength; //文件长度 *d,Z ?S/  
boolean bFirst = true; //是否第一次取文件 {~~'  
boolean bStop = false; //停止标志 iea7*]vW  
File tmpFile; //文件下载的临时信息 (&-!l2  
DataOutputStream output; //输出到文件的输出流 ]s^Pw>/`  
t,R4q*  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Q`[J3-Q*{  
public SiteFileFetch(SiteInfoBean bean) throws IOException Iq: G9M  
{ iig@$ i#  
siteInfoBean = bean; kZHIzU  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Nmu=p~f}3`  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); vS+E`[  
if(tmpFile.exists ()) tJZ3P@ L  
{ g7<u eF  
bFirst = false; #(Ezt% ^  
read_nPos(); {&s.*5  
} [5s4Jp$+  
else }#QYZ nR  
{ jmh$6 N% F  
nStartPos = new long[bean.getNSplitter()]; }1pG0V4  
nEndPos = new long[bean.getNSplitter()]; Id 40yER  
} {,zn#hU.R  
PitDk 1T  
{qPu }?0  
#H/suQZN"g  
} w]Z:Y`  
IRB BLXv7\  
}C9P--  
public void run() Rkz[x  
{ Sv|jR r'  
//获得文件长度 '7/c7m/$X<  
//分割文件 W)m\q}]FYz  
//实例FileSplitterFetch -4nSiI  
//启动FileSplitterFetch线程 J:Ncy}AO  
//等待子线程返回 s2iL5N|"Q  
try{ KeE)9e   
if(bFirst) Y@R9+ 7!  
{ ,lr\XhO  
nFileLength = getFileSize(); EZg$mp1  
if(nFileLength == -1) b0!ZA/YC-  
{ Jx4"~ 4  
System.err.println("File Length is not known!"); %t J@)  
} <B3$ODGJp  
else if(nFileLength == -2) ?9m@ S#@  
{ Vrx3%_NkQ  
System.err.println("File is not access!"); $WHmG!)*  
} B0eKj=y;  
else qB44;!(  
{ 8:)itYE  
for(int i=0;i<nStartPos.length;i++) S|v")6  
{ (b>B6W\&  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); x#,nR]C  
} "qvJ-Y  
for(int i=0;i<nEndPos.length-1;i++) W<s5rMx  
{ <c$K3  
nEndPos = nStartPos[i+1]; Q=Y1kcTOn  
} UfAN)SE"  
nEndPos[nEndPos.length-1] = nFileLength; Mg76v<mv<  
} ?wYvBFRn7"  
} K1*]6x,  
h!h<!xaclW  
:~{x'`czJ  
//启动子线程 :ZP`Y%dt'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^TCgSi7k`L  
for(int i=0;i<nStartPos.length;i++) qJPEq%'Q  
{ w.6Gp;O  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %q)*8  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QpC,komLJ  
nStartPos,nEndPos,i); |>L|7>J{<d  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); leomm+f^  
fileSplitterFetch.start(); ~k[q:$T  
} =[T_`*s&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NM:\T1  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l&4+v.zr  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -P'KpX:]hd  
nEndPos = " + nFileLength); i#W0  
// fileSplitterFetch[nPos.length-1].start(); 'k(aZ"  
XDcA&cM}p  
EAi!"NJ  
//等待子线程结束 |#_`aT"  
//int count = 0; Eggdj+  
//是否结束while循环 wEJ) h1=)^  
boolean breakWhile = false; s`Z'5J;S  
v<c@bDZ>  
d0MF\yxh  
while(!bStop) .S =^)  
{ qe"t0w|U?  
write_nPos(); 7 G<v<&  
Utility.sleep(500); 3'D<'S}[  
breakWhile = true; $^;b 1bnO  
FSn&N2[D  
3A>Bnb  
for(int i=0;i<nStartPos.length;i++) <qpDAz4k  
{ ap[{`u  
if(!fileSplitterFetch.bDownOver) j9G1  _  
{ a2tRmil  
breakWhile = false; 38Bh9>c3  
break; mFdj+ &2\  
} eH9Ofhsry  
} /<WK2G  
if(breakWhile) b ?-VZA:  
break; i1E~F  
f R?Xq@c  
N 2\lBi  
//count++; 8kwe._&)  
//if(count>4) ohPCYt  
// siteStop(); ]~H\X":[>  
} oPPxja g\  
|0e7<[  
IxQ(g#sj_k  
System.err.println("文件下载结束!"); =A< Fcl\Rz  
} 1<ic 5kB  
catch(Exception e){e.printStackTrace ();} |JD"iP:  
} 4$^\s5K  
]gHi5]\NC  
sS5:5i  
//获得文件长度 h &R1"  
public long getFileSize() ,|r%tNh<8$  
{ D#I^;Xg0h  
int nFileLength = -1; u6#=<FD/}  
try{ 1!4-M$-  
URL url = new URL(siteInfoBean.getSSiteURL()); ?=\&O=_ln  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5i42o+'  
httpConnection.setRequestProperty("User-Agent","NetFox"); i G%h-  
#-*#? -  
0~:Eo89  
int responseCode=httpConnection.getResponseCode(); Z:2a_A tm  
if(responseCode>=400) HpX ;:/I  
{ ;I^+u0ga  
processErrorCode(responseCode); g* & |Eq/  
return -2; //-2 represent access is error |{a`,%mw  
} "7&DuF$s)  
9h$08l  
jLZ^EM-  
String sHeader; c{X:0man  
lPywr TG0  
" A}S92  
for(int i=1;;i++) X5hamkM*m  
{ f*IC ZM  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z&VH7gi  
//Utility.log(in.readLine()); th?w&;L  
sHeader=httpConnection.getHeaderFieldKey(i); { #,eD  
if(sHeader!=null) RrG5`2  
{ 7i$)iNW  
if(sHeader.equals("Content-Length")) sOY+ X  
{ $yA>j (k4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x&kM /z?/  
break; +"i|)yUYy}  
} K_" denzT+  
} &*4C{N  
else nbECEQ:|B  
break; dpPu&m+  
} ZHWxU  
} 5@kNvi  
catch(IOException e){e.printStackTrace ();} oXxY$x*R1  
catch(Exception e){e.printStackTrace ();} \[57Dmo  
,R~{$QUl  
|v6kZ0B<  
Utility.log(nFileLength); 3m#/1=@o  
^z%ShmM&LZ  
.a0]1IkatV  
return nFileLength; P,}cH;w6Ck  
} fUg<+|v*  
`v|w&ty*  
1ab_^P  
//保存下载信息(文件指针位置) ,_N+t:*#0  
private void write_nPos() pmIOV~K  
{ {|E'  
try{ 7^2  
output = new DataOutputStream(new FileOutputStream(tmpFile)); O_kBAC-|R(  
output.writeInt(nStartPos.length); fy6<KEea  
for(int i=0;i<nStartPos.length;i++) NZTG)<  
{ UCz\SZ{za  
// output.writeLong(nPos); }^@Q9<P^E  
output.writeLong(fileSplitterFetch.nStartPos); iaAj|:  
output.writeLong(fileSplitterFetch.nEndPos); IOjp'6Yr  
} 5x=aJl;G  
output.close(); @5rl;C  
} VPh0{(O^=  
catch(IOException e){e.printStackTrace ();} ;Eer  
catch(Exception e){e.printStackTrace ();} V8Fp1?E9S  
} {#_CzI.0f  
ye-EJDZN  
?DwI>< W  
//读取保存的下载信息(文件指针位置) 4Ucs9w3[  
private void read_nPos() aJ{-m@/ 5  
{ e}u68|\EC  
try{ Hrk]6*  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \|gE=5!Am=  
int nCount = input.readInt(); z[0+9=<Y  
nStartPos = new long[nCount]; <0w"$.K#3  
nEndPos = new long[nCount]; cR *5iqA  
for(int i=0;i<nStartPos.length;i++) @BfJb[A#  
{ :< d.  
nStartPos = input.readLong(); I0qS x{K  
nEndPos = input.readLong(); 0'QX*xfa>  
} J2BCaAwEP,  
input.close(); XsXO S8  
} <?>1eU%  
catch(IOException e){e.printStackTrace ();} nc2=S^Fqu  
catch(Exception e){e.printStackTrace ();} RXD*;B$v  
} X>la!}sV  
UD!-.I]  
:Rftn6!  
private void processErrorCode(int nErrorCode) e2><Y<  
{ GGQ%/i]:  
System.err.println("Error Code : " + nErrorCode); %6%~`((4  
} Pss$[ %  
V`WSZ  
3OlXi9>3  
//停止文件下载 z]%c6ty  
public void siteStop() I,lX;~xb  
{ u^4$<fd  
bStop = true; ..K@'*u  
for(int i=0;i<nStartPos.length;i++) -`8pahI  
fileSplitterFetch.splitterStop(); +v.<Fw2k#  
]<xzCPB  
B@ xjwBUk  
} VRs|";  
} [pRRBMho  
//负责部分文件的抓取 1`Ig A0V`"  
**FileSplitterFetch.java iCtDV5  
*/ 0R-J \  
package NetFox; Ym8 V)  
D^Gs_z$['  
l"rX'g?  
import java.io.*; :u9OD` D  
import java.net.*; gr^T L1(  
JE *d-  
`w_%HVw>"  
public class FileSplitterFetch extends Thread { f|'0FI  
i< b-$9  
Mp7X+o/  
String sURL; //File URL (k^o[HF  
long nStartPos; //File Snippet Start Position ,6 IKkyD  
long nEndPos; //File Snippet End Position @dyh: 2!  
int nThreadID; //Thread's ID cFZcBiw  
boolean bDownOver = false; //Downing is over *8I"7'xh  
boolean bStop = false; //Stop identical )vsX (/WU  
FileAccessI fileAccessI = null; //File Access interface <0!O'" "J  
jAcrXB*  
PrKH{nyJk  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W5Uw=!LdEY  
{ =o5|W'>`  
this.sURL = sURL; S0' ACt`  
this.nStartPos = nStart; S aH':UN  
this.nEndPos = nEnd; dJjkH6%}  
nThreadID = id; S?[@/35)  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _M) G  
} X5tx(}j  
,(A $WT@e  
YvG=P<_xw  
public void run() eev-";c  
{ B2,c_[UZ.  
while(nStartPos < nEndPos && !bStop) )kT.3 Q  
{ {ldt/dl~  
9vauCIfVC  
^m/7T wD  
try{ !+u K@z&G  
URL url = new URL(sURL); agkGUK/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +^DDWVp  
httpConnection.setRequestProperty("User-Agent","NetFox"); QnA~,z/ .w  
String sProperty = "bytes="+nStartPos+"-"; }n( ?|  
httpConnection.setRequestProperty("RANGE",sProperty); .>a [  
Utility.log(sProperty); {SkE`u4Sz  
= inp>L  
o/6VOX  
InputStream input = httpConnection.getInputStream(); #\8"d  
//logResponseHead(httpConnection); k2O3{xIjc  
#,9s\T  
2e9.U/9  
byte[] b = new byte[1024]; ifcp!l+8  
int nRead; GO)5R,  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $Jo4n>/  
{ ph$ vP;}  
nStartPos += fileAccessI.write(b,0,nRead); &/n*>%2  
//if(nThreadID == 1) 1Ror1%Q"?  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3yrb7Rn3  
} neQ~h4U"  
bd\%K`JQ{  
s1]m^,  
Utility.log("Thread " + nThreadID + " is over!"); yv|`A2@9  
bDownOver = true; f_2(`T#  
//nPos = fileAccessI.write (b,0,nRead); K3iQ/j~aq  
} ~1&WR`U  
catch(Exception e){e.printStackTrace ();} Ew JNpecX  
} 3rY\y+m  
} T& 4f} g/  
Z(XohWe2  
3 "iBcsLn  
//打印回应的头信息 "AP$)xM-:  
public void logResponseHead(HttpURLConnection con) )Dp0swJ  
{ B@U'7`v  
for(int i=1;;i++) q B IekQT  
{ \n`/?\r.z  
String header=con.getHeaderFieldKey(i); PthgxB^  
if(header!=null) B!  P/?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +e, c'.  
Utility.log(header+" : "+con.getHeaderField(header)); l,*5*1lM  
else Wu"1M^a  
break; as(/ >p  
} >=4('  
} J5(^VKj  
R@-x!*z  
/xSFW7d1  
public void splitterStop() @QMy!y_K~m  
{ '55G:r39  
bStop = true; I~;w Q  
} { V) `6  
2M*i'K;;)P  
58d[>0Xa[g  
} \wD L oR  
zW\s{  
fTso[r:F.  
/* 7 =D,D+f  
**FileAccess.java ,5x#o  
*//文件访问(定位,写) S@'%dN6e  
package NetFox; `{|w*)mD  
import java.io.*; L6ap |u  
SK#&%Yk  
\%7fm#z6  
public class FileAccessI implements Serializable{ Y]7503J  
qX*xQA|ak,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wTD}c1J(  
RandomAccessFile oSavedFile; RRXp9{x`  
long nPos; 51u\am'T  
L9<\vJ  
?;_*8Doq-a  
public FileAccessI() throws IOException 1BEs> Sm  
{ '$c9S[  
this("",0); r6nnRN/S=  
} :w -:B^VB  
+TyN;e   
P@keg*5@  
public FileAccessI(String sName,long nPos) throws IOException |;7mDhj=  
{ lWe cxD$  
oSavedFile = new RandomAccessFile(sName,"rw"); yVgC1-8i*  
this.nPos = nPos; T9I$6HAi  
oSavedFile.seek(nPos); ]BUirJ,2  
} <=V{tl  
@TQ/Z$y  
MI'"Xzp{s  
public synchronized int write(byte[] b,int nStart,int nLen)  4=ovm[  
{ ,zdGY]$  
int n = -1; i!RfUod  
try{ lm 96:S  
oSavedFile.write(b,nStart,nLen); S2e3d  
n = nLen; _3:%b6&Pz  
} ]'"Sa<->  
catch(IOException e) 641P)  
{ 71y{Dwya  
e.printStackTrace (); l -xc*lC  
} x1?mE)n]  
_U}vKm  
K2yu}F^}  
return n; hHhDs>tB  
} p#{y9s4h  
9=~ZA{0J  
?].MnwYo  
} p0WUF\"  
ccrWk*tr  
) $_1U!z  
/* [gpO?'~  
**SiteInfoBean.java D;NL*4zt  
*/ F3EAjO)ch  
package NetFox; Uns%6o  
Z[OX {_2]K  
PMpq>$6b7  
public class SiteInfoBean { 3i7EF.  
F_(~b  
s*[ I"iE  
private String sSiteURL; //Site's URL .whi0~i  
private String sFilePath; //Saved File's Path uE41"?GS  
private String sFileName; //Saved File's Name In^mE(8YO  
private int nSplitter; //Count of Splited Downloading File >7PQOQMW'  
MzX&|wimb  
=T,Q7Dh  
public SiteInfoBean() 9-/q-,  
{//nSplitter的缺省值为5 aTTkj\4  
//default value of nSplitter is 5 RARA_tii  
this("","","",5); 50QDqC-]XS  
} ,puoq {  
5, ,~k=  
BLy V~   
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NX,m6u  
{ v>#Njgo  
sSiteURL= sURL; `VKFA<T  
sFilePath = sPath; b9RHsr]V  
sFileName = sName; }q`9U!v  
this.nSplitter = nSpiltter; X'jyR:ut#  
<@"rI>=  
%*}rLn"?  
} Yr/$92(  
T2MC`s|`  
)b #5rQ  
public String getSSiteURL() o 2 Nu@^+  
{ [M[<'+^*  
return sSiteURL; 8Y.q P"s  
} v*?8:>:}  
JFVx&  
6[3Xe_  
public void setSSiteURL(String value) /iFn =pk1?  
{ AN Fes*8j  
sSiteURL = value; IQ @9S  
} q* p  
Q-'j131[  
!xfDWbvHV  
public String getSFilePath() #\w N2`" W  
{ .Qx5,)@9  
return sFilePath; M5ZH6X@5  
} x.*^dM@V  
Ks P2./N  
<E4(KE  
public void setSFilePath(String value) Tse#{  
{ GIM/T4!)  
sFilePath = value; q$:7j5E  
} a#=d{/ ab  
Y7.+ Ma#|  
`s}L3bR]  
public String getSFileName() iz#R)EB/g  
{ N!(mM;1X)  
return sFileName; o>r P\  
} &T,|?0>~=J  
ZOEe-XW  
E+lR&~mK=  
public void setSFileName(String value) EwzR4,r\M  
{ KVa{;zBwl  
sFileName = value; &))d],tJX  
} YCD |lL#  
%]_: \!  
7H Dc]&z  
public int getNSplitter() HLW_Y|QaFo  
{ 'z. GAR  
return nSplitter; $Y|OGZH8E  
} |reA`&<q  
!FL"L 9   
;#85 _/  
public void setNSplitter(int nCount) ojy^ A  
{ R'k `0  
nSplitter = nCount; >J7slDRo  
} FMVAXOO  
} lV$JCNe  
=HCEUB9Fs  
B-MS@ <2  
/* ,a{85HLr]  
**Utility.java rkjnw@x\  
*/ 5G`HJ6  
package NetFox; hI:.Qp`r  
']1n?K=A  
l;iU9<~  
public class Utility { mH$tG $  
<Q~N9W  
r @4A% ql<  
public Utility() t(#9.b`W)  
{ ?XHQdN3e  
e]RzvWq  
a<<4gXx  
} ]@#9B>v=  
|fgUW.  
//线程睡眠 \_`qon$9  
public static void sleep(int nSecond) )%K<pIk  
{ !zX() V  
try{ L+8ar9es  
Thread.sleep(nSecond); INN}xZ  
} L]kBY2c  
catch(Exception e) |Mb{0mKb  
{ lcdhOjz!N  
e.printStackTrace (); {$^'oRk  
} Vgm'&YT  
} IEhD5?  
|8k1Bap`z  
//日志 = wD#H@h  
public static void log(String sMsg) /Q;wz!V$  
{ q 6>eb  
System.err.println(sMsg); L BbST!  
} hTtn /j  
JY"jj}H]|  
#d@wjQ0DW  
public static void log(int sMsg) 2<@2_wSJ  
{ f;{Q ~  
System.err.println(sMsg); 1CB&z@  
} 3+6Ed;P  
} J#(AX6  
v&d1ACctJ  
5%I3eL%s  
/* $,}jz.R@  
**TestMethod.java R(wUu#n$  
*/ OXEEpoU?V  
package NetFox; ^lHy)!&A  
<o%T]  
t8*Jdd^3Z/  
public class TestMethod { %zcA|SefP  
e(t}$Q=  
8FuxN2  
public TestMethod() ).71gp@&  
{ ///xx/weblogic60b2_win.exe iww/s  
try{ tJ^p}yxO  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Hm2Y% 4i%  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1[!:|=  
SiteFileFetch fileFetch = new SiteFileFetch(bean); g6,DBkv2  
fileFetch.start(); |[.-pA^  
} sy"}25s  
catch(Exception e){e.printStackTrace ();} 3k1e  
dVbFMQ&  
1@|+l!rYF  
} j .q}OK  
3uuIISK  
m{Q #f\<  
public static void main(String[] args) ,Pa*; o\  
{ X!]v4ma`  
new TestMethod(); 9nG^_.}|  
} 2o SM|  
} /7UvV60  
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