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http断点续传简单实现(java)

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/* {^ 1s  
**SiteFileFetch.java  *e{d^  
*/ zk= 3L} C  
package NetFox; T<kyxbjR  
import java.io.*; JTB_-J-TU  
import java.net.*; )]~'zOE_  
OJe#s;oH  
WL(u'%5  
public class SiteFileFetch extends Thread { j*aN_UTr3  
>:%YAR`  
o\u31,  
SiteInfoBean siteInfoBean = null; //文件信息Bean 1"ko wp  
long[] nStartPos; //开始位置 &niROM,;K  
long[] nEndPos; //结束位置 7c$;-O  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 v[WbQ5AND  
long nFileLength; //文件长度 )$V}tr!  
boolean bFirst = true; //是否第一次取文件 \ a18Hp|%  
boolean bStop = false; //停止标志 Ag QR"Nu6  
File tmpFile; //文件下载的临时信息 sI4Ql0[  
DataOutputStream output; //输出到文件的输出流 8"l9W=  
g &~T X  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }3 NGMGu$  
public SiteFileFetch(SiteInfoBean bean) throws IOException ]X/1u"  
{ (NrH)+)J!a  
siteInfoBean = bean; IBm&a^  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :c%vl$  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); //*>p  
if(tmpFile.exists ()) _D7MJT  
{ ~jMdM~}  
bFirst = false; wZN<Og+;  
read_nPos(); J'B6l#N  
} j4RM'_*G  
else rf1Us2vp  
{ K~8;wDN`b  
nStartPos = new long[bean.getNSplitter()]; ]Ija,C!#  
nEndPos = new long[bean.getNSplitter()]; r#LoBfM;^A  
} o mstJ9  
Ga0= G&/  
#"% ]1={b  
\Ku6 gEy  
} C=2"*>lTn  
4Sv&iQ=vh  
,p6X3zY  
public void run() s8iJl+Jm  
{  L>Bf}^  
//获得文件长度 r2H_)Oi  
//分割文件 ~$ } `R=  
//实例FileSplitterFetch :{<( )gfk  
//启动FileSplitterFetch线程 W _(  
//等待子线程返回 -~T?xs0_  
try{ fbp6lE  
if(bFirst) y)_T!&ze  
{ Pda(O;aNU  
nFileLength = getFileSize(); &A>Hq/Y  
if(nFileLength == -1) Y0iL+=[k`m  
{ UV8,SSDTV  
System.err.println("File Length is not known!"); l9 RjxO.~U  
} Z=`\U?,  
else if(nFileLength == -2) }wzU<(Rx  
{ Z{nJ\`  
System.err.println("File is not access!"); RkP g&R;i  
} v WKUV|  
else FRpTYLA2  
{ hp?hb-4l  
for(int i=0;i<nStartPos.length;i++) H^P uC (  
{ +FiM?,G  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); /N(L52mz  
} diN5*CF'~  
for(int i=0;i<nEndPos.length-1;i++) _ h\wH;  
{ Xao 0cb.R  
nEndPos = nStartPos[i+1]; s>Xx:h6m  
} {'P7D4w  
nEndPos[nEndPos.length-1] = nFileLength; H: q(T >/w  
} dE9xan  
} N9IBw',  
_ Js & _d  
FaO=<jYi  
//启动子线程 HVG9 C$  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2@WF]*Z  
for(int i=0;i<nStartPos.length;i++) `h+ia/  
{ wlr/zquAE9  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R:HF~}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cd,)GF  
nStartPos,nEndPos,i); s\g"~2+  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gd3~R+Kd  
fileSplitterFetch.start(); `ro~l_U;A  
} rxtp?|v9  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r<4FF=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +BcJHNIB  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v#i,pBj  
nEndPos = " + nFileLength); dX|(n.}  
// fileSplitterFetch[nPos.length-1].start(); d7Lna^  
iW\cLp "  
h;105$E1  
//等待子线程结束 q]+'{Ci@  
//int count = 0; ;~Y0H9`  
//是否结束while循环 tM3eB= .*  
boolean breakWhile = false; 3}{od$3G  
Ig*68M<  
3>%oGbo  
while(!bStop) 4kZX$ct}  
{ Z^w11}  
write_nPos(); U6V+jD}L]  
Utility.sleep(500); ``bIqY  
breakWhile = true; 9 A0wiKp  
)=6 |G^  
$OMTk  
for(int i=0;i<nStartPos.length;i++) P+00wbx0  
{ #=r:;,,  
if(!fileSplitterFetch.bDownOver) "bZ {W(h  
{ qzq_3^ 66  
breakWhile = false; # T_m|LN 7  
break; B ^>}M  
} '?Fw]z1$  
} K4938 v  
if(breakWhile) -Bymt[  
break; 2uw1R;zw  
9&e=s<6dO  
{,z$*nf  
//count++; 3dm lP2  
//if(count>4) ;`<uo$R  
// siteStop(); ir^%9amh  
} Dj!v+<b  
CjRI!}S  
[]R`h*#  
System.err.println("文件下载结束!"); Yg_;Eu0'?  
} tNf?pV77  
catch(Exception e){e.printStackTrace ();} f S-(Kmh  
} >D20f<w(H  
c\.Hs9T >  
T;/Y/Fd  
//获得文件长度 ?`R;ZT)U-  
public long getFileSize() LJ7Qwh_",  
{ 3 D<s #  
int nFileLength = -1; dd4g?):  
try{ #P[d?pY  
URL url = new URL(siteInfoBean.getSSiteURL()); oJ}!qrrH  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qu4Bd|`(k  
httpConnection.setRequestProperty("User-Agent","NetFox"); et[n;nl>V  
6`(x)Q9  
w6ZyMR,T  
int responseCode=httpConnection.getResponseCode(); := OdjfhY  
if(responseCode>=400) &~`Ay4hq  
{ [|{2&830  
processErrorCode(responseCode); nk8jXZ"w  
return -2; //-2 represent access is error ,CACQhrng  
} r9:Cq  
Y"J' 'K  
q)S70M_1  
String sHeader; x;d*?69f]  
UuDs  
[k)xn3[  
for(int i=1;;i++) $-4OveS~B  
{ v5J% p4  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C>\0 "}iD  
//Utility.log(in.readLine()); h>>KH*dQ  
sHeader=httpConnection.getHeaderFieldKey(i); ]:Y@pZ  
if(sHeader!=null) (.6~t<DRv  
{ a "*DJ&  
if(sHeader.equals("Content-Length")) |8,|>EyqK  
{ J,@SSmJ`  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "[W${q+0x  
break; s^:8bFn9$  
} vU5a`0mH  
} vFuf{ @P  
else Z)=S. )  
break; ')!+>b(P  
} F$[1KjS  
} 2flgfB}2k  
catch(IOException e){e.printStackTrace ();} pO^goo V\  
catch(Exception e){e.printStackTrace ();} b|7c]l  
~loJYq'y  
{Dv^j#  
Utility.log(nFileLength); 5LJUD>f9 Z  
'9O4$s1  
u~kfz*hz  
return nFileLength; (sX=#<B%  
} & w%%{lM  
RY8Ot2DWi  
46U?aHKW@|  
//保存下载信息(文件指针位置) "M e)'  
private void write_nPos() k 4|*t}o7  
{ Snm m (.  
try{ R.KqTEs<k  
output = new DataOutputStream(new FileOutputStream(tmpFile)); <zmtVE*>g  
output.writeInt(nStartPos.length); 0#K?SuY.eN  
for(int i=0;i<nStartPos.length;i++) ;%u'w;sgq  
{ +C`h*%BW  
// output.writeLong(nPos); Grot3a  
output.writeLong(fileSplitterFetch.nStartPos); :-Gf GL>]  
output.writeLong(fileSplitterFetch.nEndPos); a;},y|'E  
} 879x(JII  
output.close(); O0|**Km\+  
} :Bk!YK  
catch(IOException e){e.printStackTrace ();} )C \ %R  
catch(Exception e){e.printStackTrace ();} %Pl 7FHfB  
} l5?fF6#j  
;=.i+  
J$Huzs#  
//读取保存的下载信息(文件指针位置) pVuJ4+`  
private void read_nPos() #9HQW:On  
{ s06tCwPp  
try{ 3_%lN4sz  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z^P]-CB|6A  
int nCount = input.readInt(); :wlX`YW+e  
nStartPos = new long[nCount]; v4X\LsOP  
nEndPos = new long[nCount]; ZHA6BVVT  
for(int i=0;i<nStartPos.length;i++) .QwwGm  
{ "rnZ<A}  
nStartPos = input.readLong(); y,I?3 p|S  
nEndPos = input.readLong(); D%PrwfR  
} r&^LSTU0!  
input.close(); &c;@u?:@S  
} +o{]0~ y  
catch(IOException e){e.printStackTrace ();} CYIp 3D'k  
catch(Exception e){e.printStackTrace ();} bf~gWzA  
} m(~5X0  
x6=Yt{  
;QMRm<CLV  
private void processErrorCode(int nErrorCode) Gp}:U>V)  
{ [A@K)A$f  
System.err.println("Error Code : " + nErrorCode); 8|:bis~wm  
} )(&Z&2~A  
/qf2LO'+  
f>g< :.k*  
//停止文件下载 4Ji6B)B  
public void siteStop() ym>>5(bni  
{ XaFu(Xu7  
bStop = true; cP >MsUZWl  
for(int i=0;i<nStartPos.length;i++) )s @ }|`  
fileSplitterFetch.splitterStop(); ~g&FeMo  
-!X,M DO  
T6 K?Xr{_  
} os=Pr{  
} -,;r %7T  
//负责部分文件的抓取 Oa[G #  
**FileSplitterFetch.java U g 'y  
*/ wi{qN___  
package NetFox; [^iQE  
6\8 lx|w  
E=Z;T   
import java.io.*; P!;%DI!<b  
import java.net.*; SV-M8Im73z  
ROWb:tX}  
_RzwE$+9  
public class FileSplitterFetch extends Thread { $UgQ1Qc  
2(_+PQ6C=  
RR*eq.;  
String sURL; //File URL @-uV6X8|  
long nStartPos; //File Snippet Start Position sbWen?  
long nEndPos; //File Snippet End Position BvXA9YQ3  
int nThreadID; //Thread's ID |AY`OVgcKD  
boolean bDownOver = false; //Downing is over C26vH#C  
boolean bStop = false; //Stop identical NGA8JV/U  
FileAccessI fileAccessI = null; //File Access interface }sbh|#  
V$D+Joj  
K^H{B& b8  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =Gka;,n  
{ _;o)MTw|'  
this.sURL = sURL; cc LTA  
this.nStartPos = nStart; QKj8~l(  
this.nEndPos = nEnd; dNQR<v\IL  
nThreadID = id; D..dGh.MY  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '\v mm>  
} fjc8@S5x9j  
\KBE+yj  
HnDz4eD  
public void run() i_ha^mq3  
{  ,\HZIl[8  
while(nStartPos < nEndPos && !bStop) J$9`[^pV  
{ ^A4bsoW  
Ro&s\T+d  
4$j7DJ8dj  
try{ v[3QI7E3  
URL url = new URL(sURL); zz4TJ('  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z *9Qeu-N:  
httpConnection.setRequestProperty("User-Agent","NetFox"); H9@24NFb  
String sProperty = "bytes="+nStartPos+"-"; m :6.  
httpConnection.setRequestProperty("RANGE",sProperty); J(k\Pz*  
Utility.log(sProperty); ?`m#Y&Oi  
<ptskbu  
l%$~X0%DM  
InputStream input = httpConnection.getInputStream(); xq U@87[_  
//logResponseHead(httpConnection); {FIr|R&  
cqP)1V]  
~OuKewr\  
byte[] b = new byte[1024]; 0^5*@vt  
int nRead; 75u5zD   
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4Nz@s^9  
{ -?m"+mUP  
nStartPos += fileAccessI.write(b,0,nRead); : h"Bf@3  
//if(nThreadID == 1) {8!\aYI  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R2]2#3`  
} jH 4,-  
Hr?_`:  
/< OoZf+[  
Utility.log("Thread " + nThreadID + " is over!"); aP#nK  
bDownOver = true; k9V#=,K0  
//nPos = fileAccessI.write (b,0,nRead); K,ccM[hu|  
} 8'niew 5d  
catch(Exception e){e.printStackTrace ();} +3;`4bW  
} cip"9|"  
} {LwV&u(  
K *<+K<Tp  
*%[L @WF  
//打印回应的头信息 2X:OS/  
public void logResponseHead(HttpURLConnection con) -y@# ^SrJ  
{ 4pYscB  
for(int i=1;;i++) %K9 9_Cl3  
{ ;9WS#>o  
String header=con.getHeaderFieldKey(i); _TGv"c@V  
if(header!=null) _LVi}mM  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Tz PG(f  
Utility.log(header+" : "+con.getHeaderField(header)); 8ZnHp~  
else nfL-E:n=  
break; *OX;ZQg0  
} "@P)  
} m1d*Lt>F@  
Kd<c'!  
" [Z'n9C  
public void splitterStop() )<<}8Fs  
{ i4Ps#R_wx  
bStop = true; /Dmuvb|A  
} lk<}`#(g  
W7\s=t\  
ji8)/  
} ~8A !..Z  
^ UB*Q  
Ct8}jg"  
/* I%8>nMTJ  
**FileAccess.java ;,OZ8g)LH  
*//文件访问(定位,写) w=|"{-ijo  
package NetFox; aMLtZ7i>  
import java.io.*; Vr|sRvz  
li4"|T&  
2^V/>|W>w  
public class FileAccessI implements Serializable{ Cyn_UE  
@4ccZ&`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B1u.aa$  
RandomAccessFile oSavedFile; "DpgX8lG_  
long nPos; D^\gU-8M  
<w9<G  
ZQ MK1  
public FileAccessI() throws IOException p+ki1! Ed  
{ .huk>  
this("",0); F\)?Ntj)>@  
} -45xa$vv  
5[qCH(6  
(^U 8wit/  
public FileAccessI(String sName,long nPos) throws IOException OG!+p}yD]  
{ W%&[gDp  
oSavedFile = new RandomAccessFile(sName,"rw"); t,v=~LE  
this.nPos = nPos;  x%$as;  
oSavedFile.seek(nPos); 4ayZ.`aK  
} )<>1Q{j@  
EN\ uX!  
(mR ;MC  
public synchronized int write(byte[] b,int nStart,int nLen) DJ]GM|?  
{ 5N5Deb#V  
int n = -1; #rps2nf.j  
try{ v}>5!*  
oSavedFile.write(b,nStart,nLen); I<&(Dg|XQ  
n = nLen; [VL+X^  
} ]"T1clZKd(  
catch(IOException e) u A=x~-I  
{ V 5  
e.printStackTrace (); K+F]a]kld  
} :JI&ngWK  
fRow@DI\  
i& phko}  
return n; 1dE |q{  
} asLvJ{d8s  
Iu=n$H  
HOPi2nf{  
} @`D`u16]i  
7hq$vI%0  
xDtJ& 6uFw  
/* T`Jj$Lue{  
**SiteInfoBean.java $z":E(oy  
*/ #]MV  
package NetFox; Y!0ZwwW  
k04CSzE"%  
eGEeWJ}[$  
public class SiteInfoBean { M{   
1P '_EJ]M  
UbDRE[^P  
private String sSiteURL; //Site's URL $HE ?B{  
private String sFilePath; //Saved File's Path %1jlXa  
private String sFileName; //Saved File's Name gA/8Df\G:l  
private int nSplitter; //Count of Splited Downloading File xUw)mUn@N  
-Y:^<C^^&8  
Mu>WS)1lS  
public SiteInfoBean() 2 yY.rs  
{//nSplitter的缺省值为5 0;6 ^fiSY;  
//default value of nSplitter is 5 uY"Bgz:=d  
this("","","",5); aEJds}eE6)  
} nUy2)CL[L  
 0+P[0  
4!,`|W1  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c c^I9g~  
{ U5f<4I  
sSiteURL= sURL; ^~65M/  
sFilePath = sPath; S(Ej: H  
sFileName = sName; ,!{/Y7PmJ  
this.nSplitter = nSpiltter; $Lf-Gi  
rT}k[  
@x4IxGlUs  
} D?Y j5eOa  
A]WR-0Z7  
;H%T5$:trP  
public String getSSiteURL() z~R:!O-  
{ -sqoE*K[8  
return sSiteURL; UwQyAD]Ht  
} jy kY8;4  
8t$w/#'@  
qEW3k),  
public void setSSiteURL(String value) :~gG]|F  
{ _=s{,t &u  
sSiteURL = value; ^|+;~3<J  
} 12bt\ h9  
hZ;[}5T\<S  
B+w< 0No  
public String getSFilePath() x*}*0).  
{ omEnIfQSO  
return sFilePath; 5kju{2`GF  
} 99]&Xj  
CKau\N7T  
k5X& |L/  
public void setSFilePath(String value) Jd0I!L  
{ MRn;D|Q  
sFilePath = value; D3MRRv#  
} }0(.HMiGj  
h,u?3}Knnb  
zwEZ?m!  
public String getSFileName() +_E\Omcw  
{ }-8ZSWog6f  
return sFileName; WXgGB[x  
} 9}_ccq  
Bf-KCqC".  
4a6WQVS  
public void setSFileName(String value) G&?,L:^t  
{ NZh\{!  
sFileName = value; $^XCI%DH  
} ?~_[/  
b+rn:R  
c|,6(4j>$  
public int getNSplitter() x6BO%1  
{ X u+^41  
return nSplitter; JJ=%\j  
} Z91GM1lrf8  
p+pBk$4  
`ywI+^b  
public void setNSplitter(int nCount) / ~\ I  
{ =8!FY"c*  
nSplitter = nCount; },W<1*|  
} 0zC mU)ng  
} 8qi6>}A  
%0<-5&GE  
$afE= qC*  
/* 8M DX()Bm  
**Utility.java *sPG,6>  
*/ c%bGVRhE  
package NetFox; ;vDjd2@  
w '<8l w  
mTsl"A>  
public class Utility { EG|fGkv"  
8FmRD  
BnL[C:|  
public Utility() cp&- 6 w+  
{ hj_%'kk-A  
|~y>R#u8pm  
"iC*Eoz#.  
} Zc<fopih  
S=R}#  
//线程睡眠 F.%g_Xvk:  
public static void sleep(int nSecond) c2aW4 TX2  
{ .-[d6Pnw  
try{ ha%3%O8Z  
Thread.sleep(nSecond); mK>c+ u)  
} +F9)+wT~;q  
catch(Exception e) V:wx@9m)  
{ Bn5O;I13  
e.printStackTrace (); \en}8r9cy  
} dg?[gD8!4&  
} N!u(G  
iLyJ7zby  
//日志 A{3?G -]*  
public static void log(String sMsg) ju AUeGT  
{ _W3>Km-A=/  
System.err.println(sMsg); -ST[!W V  
} Y5Ub[o  
c~0hu*&  
r/32pY  
public static void log(int sMsg) J!5>8I(_wX  
{ 8)1 k>=  
System.err.println(sMsg); (1|_Nr  
} xD#r5  
} ;ZSJ-r  
9MmAoLm  
*&m{)cTs  
/* '|9fDzW"]  
**TestMethod.java rerl-T<3  
*/ S\F;b{S1  
package NetFox; e{~3&  
n&`=.[+A  
C_RxJWka  
public class TestMethod { **%/Ke[  
k6p Xc<]8  
vwlPFr Ll  
public TestMethod() dC F!.  
{ ///xx/weblogic60b2_win.exe x P3v65Q1  
try{ _I&];WM\  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y7s:Buyc  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p7\}X.L  
SiteFileFetch fileFetch = new SiteFileFetch(bean); W 6d[v/+K+  
fileFetch.start(); {5$.:Y  
} U1Z.#ETnM  
catch(Exception e){e.printStackTrace ();} RO]Vn]qb  
\R6D'Yt  
8w:A""  
} 4^KeA".  
K_fQFuj+  
[|XMR=\>  
public static void main(String[] args) ?_!} lg  
{ ;Tn$c70  
new TestMethod(); +;H-0Q5  
} G<S(P@ss  
} RoG `U  
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