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http断点续传简单实现(java)

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/* onmpMU7w  
**SiteFileFetch.java _<]0hC  
*/ +@uA  
package NetFox; j|8!gW  
import java.io.*; y =sae  
import java.net.*; Lios1|5  
..Dm@m}  
8D>5(Dg-  
public class SiteFileFetch extends Thread { ;07$G+['  
MtwlZg`c3  
_1RvK? ;.{  
SiteInfoBean siteInfoBean = null; //文件信息Bean =p5]r:9W  
long[] nStartPos; //开始位置 O`Qke Z}  
long[] nEndPos; //结束位置 iOIq2&sV  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 MB:[: nX  
long nFileLength; //文件长度 VMF?qT3Nd  
boolean bFirst = true; //是否第一次取文件 FO>!T@0G  
boolean bStop = false; //停止标志 ">!pos`<C  
File tmpFile; //文件下载的临时信息 R`$Y]@i&B  
DataOutputStream output; //输出到文件的输出流 ;o)'dK  
s)E8}-v  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) tq,^!RSbZ  
public SiteFileFetch(SiteInfoBean bean) throws IOException [>>_%T\I  
{ oQpGa>6U&  
siteInfoBean = bean; )?OdD7gd  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Kg~D~ +j  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); QuMv1)n  
if(tmpFile.exists ()) G>:v1lde  
{ uX!6: v]  
bFirst = false; iVnMn1h  
read_nPos(); {/)i}V#RE  
} vN v'%;L  
else H!0m8LCnb  
{ 0827z  
nStartPos = new long[bean.getNSplitter()]; T~$Eh6 D  
nEndPos = new long[bean.getNSplitter()]; [;aM8N  
} ~tTn7[!  
(e5Z^9X  
FZ%h7Oe  
\15'~ ]d  
} |5`ecjb.  
&?Erkc~#  
\VEnP=*:W  
public void run() JFc, f  
{ A@_>9;   
//获得文件长度 .3UJ*^(?  
//分割文件 <sm"3qs"_  
//实例FileSplitterFetch '_7rooU9  
//启动FileSplitterFetch线程 u4T$  
//等待子线程返回 _#v"sGmN  
try{ {[:C_Up)f  
if(bFirst) N LQ".mM+  
{ 9[X'9* ,  
nFileLength = getFileSize(); Fhllqh)  
if(nFileLength == -1) y@$E5sz  
{ ha;fxM]  
System.err.println("File Length is not known!"); +1yi{!j1  
} LKI\(%ba#  
else if(nFileLength == -2) ,<K+.7,)E  
{ ^Os }sJ*5S  
System.err.println("File is not access!"); Qp[ Jw?a  
} p),* 4@2<  
else &qPezyt  
{ A0@,^|]  
for(int i=0;i<nStartPos.length;i++) N2 3:+u<)E  
{ A{-S )Z3}  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); fnr8{sr.2Z  
} Q[#8ErUY  
for(int i=0;i<nEndPos.length-1;i++) 3f^jy(  
{ c\>I0HH;!  
nEndPos = nStartPos[i+1]; Z2g<"M  
} {Mb<on W  
nEndPos[nEndPos.length-1] = nFileLength; ng|^Zm%   
} &R.5t/x_  
} ORP<?SG55u  
G na%|tUz|  
tb oQn~&4  
//启动子线程 '{~[e**  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  WvF{`N  
for(int i=0;i<nStartPos.length;i++) Q\IViM  
{ ;*zLf 9i  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hc<@T_h+2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q3=5q w^  
nStartPos,nEndPos,i); y2?9pVLa\y  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PHT<]:"`<  
fileSplitterFetch.start(); 'l!\2Wv2  
} l,Y5VGiH#  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wk3-J&QbS  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *szs"mQ/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SX'NFdY  
nEndPos = " + nFileLength); Ebj0 {ZL  
// fileSplitterFetch[nPos.length-1].start(); 1 Vc_jYO@  
j3%Wrt  
ayn aV  
//等待子线程结束 3t.!5 L  
//int count = 0; 05HCr"k  
//是否结束while循环 Y R~e_cA:  
boolean breakWhile = false; xjnAK!sD  
EI?8/c  
eLh35tw  
while(!bStop) b@4UR<  
{ /@ g 8MUq7  
write_nPos(); d)biMI}<5  
Utility.sleep(500); r|ZB3L|7  
breakWhile = true; :epB:r  
NWiDNK[VE}  
mYJ8O$  
for(int i=0;i<nStartPos.length;i++) A0A|cJP  
{ Bx}"X?%S  
if(!fileSplitterFetch.bDownOver) oF+yh!~mM  
{ G6>sAOf  
breakWhile = false; K\B!tk  
break; dn])6Xl;i  
} Hr}"g@ <  
} <W3p!  
if(breakWhile) "38<14V  
break; 6ZI7V!k  
gU&+^e >  
MTl @#M  
//count++; ^)Y3V-@t  
//if(count>4) &Q"vXs6Gt  
// siteStop(); N GnE  
} bvZD@F`2  
3;}YW^oXq  
"#0P*3-c  
System.err.println("文件下载结束!"); yr>J^Et%_  
} G.XxlI}  
catch(Exception e){e.printStackTrace ();} k 75 p  
} 6 mLC{X[  
=&"pG` x  
O{byMV{Ou  
//获得文件长度 1#"wfiW  
public long getFileSize() B[8 RBTsA  
{ 7yg {0a  
int nFileLength = -1; &``nD  
try{ GFbn>dY  
URL url = new URL(siteInfoBean.getSSiteURL()); G] tT=X[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b9i_\  
httpConnection.setRequestProperty("User-Agent","NetFox"); jM6$R1HX  
F+R1}5-3cl  
B&59c*K  
int responseCode=httpConnection.getResponseCode(); Z \ @9*  
if(responseCode>=400) zSsBbu:  
{ s/~[/2[bnf  
processErrorCode(responseCode); ? B|i  
return -2; //-2 represent access is error im:[ViR {  
} t W   
s2N'Ip  
tQ'R(H`  
String sHeader; @pv:uON\  
Qz{Vl> "  
g9g ] X  
for(int i=1;;i++) .uX(-8n ~  
{ :u=y7[I  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z(4/;v <CT  
//Utility.log(in.readLine()); j&A9 &+w  
sHeader=httpConnection.getHeaderFieldKey(i); u}R|q  
if(sHeader!=null) MxGQM>  
{ PPpaH!(D  
if(sHeader.equals("Content-Length")) v\!Cq+lFML  
{ d1^5r 31  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c??m9=OX1  
break; fIx|0,D&7L  
} H)*%eG~  
} ^Vh^Z)gGi  
else +dq2}gM  
break; Y@ ;/Sf$Q  
} qB$QC  
} Te)%L*X  
catch(IOException e){e.printStackTrace ();} BgCEv"G5  
catch(Exception e){e.printStackTrace ();} ,T  3M  
'{JMWNY  
{~EsO1p  
Utility.log(nFileLength); sKiy 1Ww  
{}" <  
d--6<_q  
return nFileLength; w[QC  
} \:n<&<aVSr  
<Z~Nz>'r  
0_^3 |n  
//保存下载信息(文件指针位置) ~ U8#yo  
private void write_nPos() @frV:%  
{ Pa|*Jcr  
try{ M M @&QaK  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5V0#_!QAN  
output.writeInt(nStartPos.length); JGzEm>_ m  
for(int i=0;i<nStartPos.length;i++) rF?QI*`Y(  
{ mv*M2NuhT  
// output.writeLong(nPos); &;vMJ   
output.writeLong(fileSplitterFetch.nStartPos); Je'%EJ  
output.writeLong(fileSplitterFetch.nEndPos); G-o6~"J\  
} +H? XqSC  
output.close(); ~me/ve  
} PEKXPF N  
catch(IOException e){e.printStackTrace ();} BH$hd|KD<  
catch(Exception e){e.printStackTrace ();} URr{J}5  
} 2'ws@U}lR  
YZ->ep}  
gd]k3XN$f  
//读取保存的下载信息(文件指针位置) 7.yCs[Z  
private void read_nPos() >v/%R~BuX  
{ UD2 l!)rW  
try{ \/m-G:|  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3?&P^{  
int nCount = input.readInt(); ub4(g~E  
nStartPos = new long[nCount]; AY9#{c>X  
nEndPos = new long[nCount]; )o::~ eu  
for(int i=0;i<nStartPos.length;i++) fzjtaH?  
{ ?IiFFfs  
nStartPos = input.readLong(); ZzT"u1,&  
nEndPos = input.readLong(); 1HRcEzA  
} j  W -K  
input.close(); clT[ ?8*  
} 'L%)B-,n  
catch(IOException e){e.printStackTrace ();} [hiV #  
catch(Exception e){e.printStackTrace ();} - l0X]&Ex  
} <Um5w1  
cw~-%%/  
Ige*tOv2  
private void processErrorCode(int nErrorCode) RE;)#t?K  
{ G|UeR=/  
System.err.println("Error Code : " + nErrorCode); m]VOw)mBF  
} zwlz zqV  
*W4~.peoE  
V67<Ky>  
//停止文件下载 pvM`j86 _  
public void siteStop() +'9xTd  
{ xI5zP? _v  
bStop = true; V:8{MO(C\  
for(int i=0;i<nStartPos.length;i++) C^ ~[b o  
fileSplitterFetch.splitterStop(); `6*1mE1K&  
 1W>0  
R+=Xr<`%U|  
} l27J  
} %/K;!'7  
//负责部分文件的抓取 Mbxrj~ue  
**FileSplitterFetch.java }pT>dbZ  
*/ @.v{hkM`  
package NetFox; ].N%A07  
DV~g  
04!akPP<  
import java.io.*; -$f$z(h  
import java.net.*; G>+iisb%  
 11-?M  
YM +4:P2  
public class FileSplitterFetch extends Thread { wg KM6?  
,k6V?{ZA  
#Gu(h(Z s  
String sURL; //File URL vsbD>`I  
long nStartPos; //File Snippet Start Position -+ Mh( 'K  
long nEndPos; //File Snippet End Position ~"U^N:I"  
int nThreadID; //Thread's ID 'n "n;  
boolean bDownOver = false; //Downing is over o:RO(oA0?  
boolean bStop = false; //Stop identical ]Cc8[ZC  
FileAccessI fileAccessI = null; //File Access interface od]1:8OF  
x^!LA,`j  
udX!R^8jE  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O['5/:-  
{ 'X1/tB8*  
this.sURL = sURL; qyY]: (8  
this.nStartPos = nStart; Q|W~6  
this.nEndPos = nEnd; RjG=RfB'V  
nThreadID = id; /8s>JPXKH[  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :stA]JB# w  
} ne'Y{n(8%  
Jnq}SUev  
2~W8tv0^b2  
public void run() |F?/L>  
{ `&o>7a;  
while(nStartPos < nEndPos && !bStop) d2<+Pp  
{ h[j(@P  
Xwk_QFv3  
M[5fNK&nD  
try{ E>x,$w<?  
URL url = new URL(sURL); &v&e- |r8;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "I^pb.3  
httpConnection.setRequestProperty("User-Agent","NetFox"); "I&,':O+  
String sProperty = "bytes="+nStartPos+"-"; PQ4)kVT  
httpConnection.setRequestProperty("RANGE",sProperty); n~v*  
Utility.log(sProperty); Q`(h  
jR mo9Bb2  
\Qe`>nA  
InputStream input = httpConnection.getInputStream(); l=ZX9<3  
//logResponseHead(httpConnection); JReJlDu  
} !RBH(m%  
8H2A<&3i  
byte[] b = new byte[1024]; a3E.rr;b  
int nRead; MDOP2y`2i  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +>o} R?xj  
{ JI[9c,N  
nStartPos += fileAccessI.write(b,0,nRead); sGFC?1r?\  
//if(nThreadID == 1) OA8iTn  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fk?(mxx"  
} !1Z rS  
B-EDVMu  
Vi\kB%  
Utility.log("Thread " + nThreadID + " is over!"); ./E<v  
bDownOver = true; u75(\<{  
//nPos = fileAccessI.write (b,0,nRead); >iFi~)i_4y  
} `ouCQ]tKz  
catch(Exception e){e.printStackTrace ();} Nd61ns(N  
} 5vqh09-FB  
} >Gi* BB  
}1pG0V4  
#)EVi7UP  
//打印回应的头信息 K6@9=_A  
public void logResponseHead(HttpURLConnection con) P)&qy .+E0  
{ b0lZb'  
for(int i=1;;i++) 2W vf[2Xw  
{ 8YwSaBwO  
String header=con.getHeaderFieldKey(i); p& +w  
if(header!=null) j+Q E~L  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "2 J2za  
Utility.log(header+" : "+con.getHeaderField(header)); zT"W(3  
else "gGv>]3  
break; p+O,C{^f  
} #tQ__ V   
} `{W>Dy  
G}p* oz~  
Q a8;MxK`  
public void splitterStop() Dro2R_j{  
{ b;Uqyc  
bStop = true; +C ){&/=#  
} ":,J<|Oy  
ok<!/"RX$  
CWS&f g%o{  
} ca!DZ%y  
4Q n5Mr@<  
2g:V_%  
/* )6 [d'2  
**FileAccess.java ^%~ux0%^T  
*//文件访问(定位,写) n6s[q- td  
package NetFox; =s$UU15  
import java.io.*; xO2CgqEb  
"qvJ-Y  
a  C<  
public class FileAccessI implements Serializable{ =P\Tk)(`  
B_#U|10et  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c6f[^Q%#j  
RandomAccessFile oSavedFile; 'r_NA!R  
long nPos; ]9/{  
15tT%TC  
$g+q;Y~i0  
public FileAccessI() throws IOException ;Vh5nO  
{ 3X A8\Mg  
this("",0); ^=V b'g3P~  
} P gK> Z,  
(n3MbVi3LU  
RYem(%jq  
public FileAccessI(String sName,long nPos) throws IOException w*7BiZ{s<  
{ 0) T`&u3!  
oSavedFile = new RandomAccessFile(sName,"rw"); 25CO_  
this.nPos = nPos; |$aTJ9 Iq:  
oSavedFile.seek(nPos); >,s.!vpK  
} ;^Hg\a  
&$+nuUA  
f+iM_MI  
public synchronized int write(byte[] b,int nStart,int nLen) ^t#W?rxp&  
{ !%s&GD8&l  
int n = -1; {Wp5Ane  
try{ $MB /j6#j  
oSavedFile.write(b,nStart,nLen); Eggdj+  
n = nLen; wEJ) h1=)^  
} s`Z'5J;S  
catch(IOException e) v<c@bDZ>  
{ 5<?s86GHh'  
e.printStackTrace (); |'" 17c&  
} @ATJ|5.gr  
)`B n"=  
:^oF0,-qZ  
return n; KoL3CA"N  
} gV-x1s+  
x]%'^7#v)  
KaGG4?=V  
} \6z_ ;  
[[sfuJD  
}HC6m{vH(  
/* +{F2hEYP  
**SiteInfoBean.java ~KF>Jow?Y  
*/ BQTibd  
package NetFox; I"1H]@"=  
mcB8xE  
/9..hEq^  
public class SiteInfoBean { \uT y\KA  
4Cl41a  
O)E8'Oe"Q  
private String sSiteURL; //Site's URL  [ijK ~  
private String sFilePath; //Saved File's Path /degBL+  
private String sFileName; //Saved File's Name UZ` <D/  
private int nSplitter; //Count of Splited Downloading File v Ol<  
~p0M|  
'ixu+.ZL/  
public SiteInfoBean() VkChRzhC  
{//nSplitter的缺省值为5 1>"[b8a/  
//default value of nSplitter is 5 jjLwHJ  
this("","","",5); [%`L sY  
} F}Kkhs {  
byW9]('e  
E0o?rgfdq  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9< $n'g  
{ {+V]saYP  
sSiteURL= sURL; eXdE?j  
sFilePath = sPath; _'"whZ)2  
sFileName = sName; zj9)vr`7  
this.nSplitter = nSpiltter; /\0 rRT  
WK<:(vu.  
6pCQP c*A  
} tin5.N)"z  
5RysN=czA  
<@puWm[p  
public String getSSiteURL() >m-VBo  
{ {hmC=j  
return sSiteURL; [_pw|BGp  
} MY]<^/Q  
6 ?C|pO  
?mCino  
public void setSSiteURL(String value) X?8EPCk  
{ >A RZ=x[  
sSiteURL = value; +Kz baBK  
} `,O#r0m  
c6@7>PM  
%gb4(~E+N  
public String getSFilePath() 1K`7  
{ C =6.~&(  
return sFilePath; X*^^W_LH.  
} $k|:V&6SV  
:p@.aD5  
&*4C{N  
public void setSFilePath(String value) nbECEQ:|B  
{ dpPu&m+  
sFilePath = value; kU {>hG4  
} 5@kNvi  
oXxY$x*R1  
d}Y\; '2,  
public String getSFileName() BsJ d*-:X  
{ abW[hp  
return sFileName; b-+~D9U <  
} ,_N+t:*#0  
pmIOV~K  
{|E'  
public void setSFileName(String value) wIbxnn  
{ \@}G'7{  
sFileName = value; fy6<KEea  
} NZTG)<  
UCz\SZ{za  
}^@Q9<P^E  
public int getNSplitter() iaAj|:  
{ IOjp'6Yr  
return nSplitter; 5x=aJl;G  
} E<~Fi .M;\  
+'ZJ]  
>OLKaghV.5  
public void setNSplitter(int nCount) ,DZoE~  
{ Biva{'[m  
nSplitter = nCount; RI[=N:C^  
} #aeKK7[  
} 3!H&bOF  
J dK' ~-L  
pXy'Ss@y  
/* U{JD\G 8m  
**Utility.java FoNkISzW  
*/ ~v$1@DQ}  
package NetFox; ,Hzz:ce  
2 lc  
w1&\heSQ  
public class Utility { ZR," w  
o _G,Ph!7  
aWCZ1F  
public Utility() M&v;#CV  
{ j TyR+#Wn  
?^Q8#Y^M  
%2;Nj; J$  
} @|2L>N  
4!</JZX~$  
//线程睡眠 bih%hqny  
public static void sleep(int nSecond) ms]r1x"  
{ Sf>#Zqj/  
try{ cEK<CV  
Thread.sleep(nSecond); `B A'a" $  
} F{*h~7D-|  
catch(Exception e) 'nMj<:0wlD  
{ 6L!/#d0  
e.printStackTrace (); \2c 3Nsra  
} a$AR  
} ++=f7y u  
3n!f'" T  
//日志 q?* z<)#  
public static void log(String sMsg) z8@[]6cW  
{ K7-z.WTUR  
System.err.println(sMsg); 8)o%0#;0B  
} hE;|VSdo  
cp)BPg  
*/6lyODf  
public static void log(int sMsg) +L,V_z  
{ +7KRoF|  
System.err.println(sMsg);  ;H4s[#K  
} !\}X?G f  
} B" 0a5-pkr  
N*`qsv 0  
H,3WdSL`K  
/* K0usBA  
**TestMethod.java rHa*WA;TE  
*/ z @21Z`,  
package NetFox; L+X:M/)  
)vsX (/WU  
QG=K^g  
public class TestMethod { II'"Nkxd  
9R m\@E [  
I !J'  
public TestMethod() jf^BEz5  
{ ///xx/weblogic60b2_win.exe EvKzpxCh  
try{ X=KC +1e  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FTQNS8  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KDS} "/  
SiteFileFetch fileFetch = new SiteFileFetch(bean); N`HiNb [  
fileFetch.start(); [0n[\& 0  
} jcbq#  
catch(Exception e){e.printStackTrace ();} /&  W&  
%xv*#.<Vj  
3`TD>6rs  
}  &<LBz|  
AnK~<9WQj  
9vauCIfVC  
public static void main(String[] args) ^m/7T wD  
{ ^~;"$=Wf  
new TestMethod(); 7|PB6h3  
} Ii&\LJ  
} RG.wu6Av  
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