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http断点续传简单实现(java)

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/* #W$6[#7=I  
**SiteFileFetch.java #~}4< 18  
*/ y^0 mf|  
package NetFox; gQQve{'  
import java.io.*; xig4H7V  
import java.net.*; q$7w?(Lk  
V36u%zdX5n  
o[I s$j  
public class SiteFileFetch extends Thread { i/{dD"HwM  
xs 1V?0  
B_DyH C\<  
SiteInfoBean siteInfoBean = null; //文件信息Bean E]w2 {%  
long[] nStartPos; //开始位置 ?_-5W9  
long[] nEndPos; //结束位置 sA~Ijg"6  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 rS>@>8k2,  
long nFileLength; //文件长度 w`GjQIA  
boolean bFirst = true; //是否第一次取文件 -M6#,Ji  
boolean bStop = false; //停止标志 /+wCx#!  
File tmpFile; //文件下载的临时信息 73j\!x  
DataOutputStream output; //输出到文件的输出流 n  +v(t  
|zbM$37 ?k  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) a#D \8;  
public SiteFileFetch(SiteInfoBean bean) throws IOException + L [a  
{ ?`= <*{_o  
siteInfoBean = bean; 'QSj-  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); =Q,D3F -+f  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); bV$g]->4e  
if(tmpFile.exists ()) Ddh  
{ \J(kevX  
bFirst = false; _TwE ym.V  
read_nPos(); &8;Fi2}(L  
} / z m+  
else g-pEt#  
{ h e=A%s  
nStartPos = new long[bean.getNSplitter()]; [jz@d\k$_  
nEndPos = new long[bean.getNSplitter()]; &E]<KbVx  
} }0[<xo>K  
P^aNAa  
`*o ko[\3  
(fYYcpd,k  
} sF Ph?  
v}5||s!=  
E]Q d5l  
public void run() %H[~V f?d  
{ wwNkJ+  
//获得文件长度 c!kzwc(  
//分割文件 %x./>-[t  
//实例FileSplitterFetch 00LL&ot  
//启动FileSplitterFetch线程 @.,Mn#  
//等待子线程返回 ba tXj]:  
try{ 2Akh/pb  
if(bFirst) ,Yn$X  
{ >Qqxn*O  
nFileLength = getFileSize(); ' %&-`/x  
if(nFileLength == -1) SB|Cr:wM  
{ >]HvXEdNZ|  
System.err.println("File Length is not known!"); ta@fNS4  
} >guX,hx^  
else if(nFileLength == -2) 8Ow#W5_3|  
{ [F!h&M0z  
System.err.println("File is not access!"); #nQboTB@  
} } rX)A\ g6  
else 4~AY: ib|  
{ >uo=0=9=  
for(int i=0;i<nStartPos.length;i++) ?AVnv(_  
{ bN&DotG  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); :*vSC:q  
} Z6zLL   
for(int i=0;i<nEndPos.length-1;i++) [x%8l,O #l  
{ ]|N"jr?7H  
nEndPos = nStartPos[i+1]; RA!8AS?  
} 610u!_-  
nEndPos[nEndPos.length-1] = nFileLength; )8taMC:H^  
} hltUf5m'b  
} BI<(]`FP;s  
J vl-=~  
BM9:|}\J65  
//启动子线程 .] 0:`Y,;  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RWB]uHzE  
for(int i=0;i<nStartPos.length;i++) 5s%FHa  
{ 2J Wp5  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /!_FE+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), J|@O4 g   
nStartPos,nEndPos,i); )h]tKYx  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f[*g8p  
fileSplitterFetch.start(); #3O$B*gV6  
} &gP1=P,!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YkQ=rurE  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9 ge'Mo  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lmIphOUoIw  
nEndPos = " + nFileLength); *&5./WEOH  
// fileSplitterFetch[nPos.length-1].start(); uG+eF  
k!T-X2L=  
[,Y;#;   
//等待子线程结束 mC$ te  
//int count = 0; ?es9j]  
//是否结束while循环 /VFQbJ+`  
boolean breakWhile = false; rcf#8  
*o6QBb  
MH]?:]K9V  
while(!bStop) "HLh3L~  
{ 5>:p'zI  
write_nPos(); uG/b Cb+V  
Utility.sleep(500); KkJE-k*D+w  
breakWhile = true; Oiw!d6"Ovq  
Ko!a`I2M}  
]E*xn  
for(int i=0;i<nStartPos.length;i++) ;[7#h8  
{ cef:>>6_  
if(!fileSplitterFetch.bDownOver) 'N&s$XB,  
{ F)50 6  
breakWhile = false; SbobXTbG  
break; ?i\$U'2*z3  
} }5d|y*  
} "/x/]Qx2  
if(breakWhile) Of  nN  
break; Kww+lgzS  
m[w~h\FS  
:U faMe5  
//count++; V.!z9AQ  
//if(count>4) ^fU,9  
// siteStop(); }]pOR&o  
} 0Rn`63#  
t&C0V|s79$  
m xy=3cUi  
System.err.println("文件下载结束!"); G[ q<P  
} '<wZe.Q!  
catch(Exception e){e.printStackTrace ();} (OG>=h8?  
} CelM~W$=u  
$cGV)[KWp@  
O_D;_v6Ii+  
//获得文件长度 InG<B,/W?  
public long getFileSize() ^Uldyv/  
{ 6a6N$v"  
int nFileLength = -1; ?YM0VB,y  
try{ UFE~6"t(  
URL url = new URL(siteInfoBean.getSSiteURL()); %"3tGi:/  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AVp"<Uv  
httpConnection.setRequestProperty("User-Agent","NetFox"); b~+\\,q}  
2!a~YT  
([hd  
int responseCode=httpConnection.getResponseCode(); |H8UT S X+  
if(responseCode>=400) qjRp5  
{ =V^8RlBi  
processErrorCode(responseCode); 0[s<!k9=  
return -2; //-2 represent access is error ibgF,N  
} z.:IUm{z  
"'c =(P  
sv*xO7D.  
String sHeader; g1q%b%8T  
rgu7g  
n{E + r  
for(int i=1;;i++) 1gH>B5`  
{ >&|/4`HSB  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oX-h7;SD  
//Utility.log(in.readLine()); (P nrY~9  
sHeader=httpConnection.getHeaderFieldKey(i); IUy5=Sl   
if(sHeader!=null) 5{#ya 2  
{ ~ [=2d a  
if(sHeader.equals("Content-Length")) T) cbpkH4  
{ .7H* F9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `"|u NVn  
break; G]I^zd&P  
} ?tYc2R9x6"  
} d\rs/ee  
else ;hPo5uZQ  
break; GnW_^$Fs  
} -KCQ!0\F  
} V7>{,  
catch(IOException e){e.printStackTrace ();} <V*M%YWs  
catch(Exception e){e.printStackTrace ();} ;<v9i#K5  
{q BbzBG  
o(5 ( ]bJ  
Utility.log(nFileLength); wEIAU  
7A>glZ/x  
!'%`g,,r  
return nFileLength; UyOoyyd.  
} v:Z.8m8D  
FuO'%3;c  
9Dx9alJR  
//保存下载信息(文件指针位置) }!Xj{Eoc  
private void write_nPos() aEqDxr6  
{ -cWxS{vO  
try{ J OH=)+xj  
output = new DataOutputStream(new FileOutputStream(tmpFile)); LwIX&\Ub  
output.writeInt(nStartPos.length); e@L7p,  
for(int i=0;i<nStartPos.length;i++) +DP{_x)t  
{ ,9ZN k@q  
// output.writeLong(nPos); w77"?kJ9X  
output.writeLong(fileSplitterFetch.nStartPos); i9y&<^<W  
output.writeLong(fileSplitterFetch.nEndPos); xr 4kBC t  
} 31}kNc}n  
output.close(); zI3Bb?4.  
} (yi{<$ U*  
catch(IOException e){e.printStackTrace ();} nYO4JlNP  
catch(Exception e){e.printStackTrace ();} (B;rjpK  
} V|bN<BYJ  
J9/}ZD^  
u:&Lf  
//读取保存的下载信息(文件指针位置) G |vG5$Nf  
private void read_nPos() $Z^HI  
{ . vQCX1V(  
try{ T>s3s5Y  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JIU=^6^2'  
int nCount = input.readInt(); c*x5t"{  
nStartPos = new long[nCount]; )~[hf,R5S  
nEndPos = new long[nCount]; (SYSw%v$A  
for(int i=0;i<nStartPos.length;i++) <f`G@  
{ - AxO1 qO  
nStartPos = input.readLong(); [O(8iz v  
nEndPos = input.readLong(); <lwkjt=RV  
} khtSZ"8X  
input.close(); ~uz4  
} 2:l8RH!Y  
catch(IOException e){e.printStackTrace ();} K ZSvT{  
catch(Exception e){e.printStackTrace ();} )]5}d$83  
} }W k!):=y  
uVw|fT  
yPza  
private void processErrorCode(int nErrorCode) o@KK/f  
{ .`K<Iug1  
System.err.println("Error Code : " + nErrorCode); |Ptv)D  
} o Kfm=TbY  
[Dq!t1  
k),.  
//停止文件下载 J-g<-!>RM  
public void siteStop() myeez+@ m  
{ W{(q7>g  
bStop = true; pT`oC&  
for(int i=0;i<nStartPos.length;i++) `aW>h8$I)  
fileSplitterFetch.splitterStop(); ^5 sO;vf  
rt[w yz8  
%Cz&7qf"  
} %0!!998  
} td#B$$[  
//负责部分文件的抓取 9vZD?6D,n  
**FileSplitterFetch.java N8^ AH8l  
*/ -r5JP[0kP  
package NetFox; Xn 1V1sr  
%nfaU~IqK  
kq kj.#u  
import java.io.*; V>&WZY  
import java.net.*; {FU,om9  
[_h/Dh C:+  
TZk.?@s5  
public class FileSplitterFetch extends Thread { 6eh\-+=  
2=PX1kI  
tmJ-2  
String sURL; //File URL 54%@q[-  
long nStartPos; //File Snippet Start Position 'dstAlt?  
long nEndPos; //File Snippet End Position 0qj:v"~Q  
int nThreadID; //Thread's ID #r}O =izi  
boolean bDownOver = false; //Downing is over _3YuPMaN  
boolean bStop = false; //Stop identical  bK|I  
FileAccessI fileAccessI = null; //File Access interface hY@rt,! 8  
Io81zA  
:"9P {xe^  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $R2iSu{kO  
{ yIL6Sb  
this.sURL = sURL; w+NdEE4H9z  
this.nStartPos = nStart; Pn*+g!`  
this.nEndPos = nEnd; ROyG+dUy  
nThreadID = id; As;@T$G  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 n@)Kf A)&  
} zMf .  
,33[/j  
n5~7x   
public void run() N%k6*FBp~  
{ {T^"`%[   
while(nStartPos < nEndPos && !bStop) YnzhvE  
{ 1sqBBd"=PY  
[%alnY  
'518S"T @  
try{ c05kHB$O  
URL url = new URL(sURL); .BR2pf|R  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ([r4N#lx  
httpConnection.setRequestProperty("User-Agent","NetFox"); 8tR(i[L   
String sProperty = "bytes="+nStartPos+"-"; <:mV^tK  
httpConnection.setRequestProperty("RANGE",sProperty); x9s 7:F  
Utility.log(sProperty); =skw@c ^  
:QGd/JX$n`  
2|KgRk|!  
InputStream input = httpConnection.getInputStream(); N<|_tC+ct  
//logResponseHead(httpConnection); G98P<cyD  
\CP)$0j-&o  
ok"v`76~f5  
byte[] b = new byte[1024]; [zO:[i 7  
int nRead; -.>b7ui  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Nm.H  
{ E*!  
nStartPos += fileAccessI.write(b,0,nRead); p=7{  
//if(nThreadID == 1) QU]& q`GE  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fZqqU|tq  
} 6fozc2h@x%  
&p)]Cl/`  
xpWx6  
Utility.log("Thread " + nThreadID + " is over!"); X2? ^t]-N  
bDownOver = true; 7<<-\7`  
//nPos = fileAccessI.write (b,0,nRead); 5,I|beM  
} i: 6`Rmz1.  
catch(Exception e){e.printStackTrace ();} $?.0>0 ,<  
} `u z R!^X  
} vU:FDkx*nn  
H\Y5Fd9)  
0UJ% tPS  
//打印回应的头信息 WU wH W  
public void logResponseHead(HttpURLConnection con) []'gIF  
{ 8!~8:?6n  
for(int i=1;;i++) g[]UM;D*  
{ H]6i1j  
String header=con.getHeaderFieldKey(i); 2qw-:  
if(header!=null) Tq\S-K}4!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Fgf5OHX  
Utility.log(header+" : "+con.getHeaderField(header)); 9w^lRbn  
else bjQp6!TsZ  
break; u?(@hUV.  
} TY(B]Q_o  
} raWs6b4Q  
^PnXnH?  
WF)(Q~op0U  
public void splitterStop() G E=J Y  
{  I~'%  
bStop = true; $2p=vi 3  
} otA59 ;Z  
S'Hb5C2u  
Gb=pQ (n4  
} KT3W>/#E  
gRnn}LL^  
,g.*Mx`-  
/* \~sc6ho  
**FileAccess.java |[/<[@\''  
*//文件访问(定位,写) DChqcdx~~  
package NetFox; {XHAQ9'  
import java.io.*; PTU_<\  
V`/ E$a1&  
WrA!'I  
public class FileAccessI implements Serializable{ uwQ~4   
PQl^jS  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lO (MF  
RandomAccessFile oSavedFile; [~3[Tu( C  
long nPos; b`%3>  
!cLdoX  
Vs[A  
public FileAccessI() throws IOException ',7LVT7  
{ E,~|-\b}h  
this("",0); `-R-O@X|  
} ?IKSSe#,  
eb6Ux  
-6Y@_N  
public FileAccessI(String sName,long nPos) throws IOException m\4V;F  
{  ;Y6XX_  
oSavedFile = new RandomAccessFile(sName,"rw"); nx   
this.nPos = nPos; GI+x,p  
oSavedFile.seek(nPos); 6:fHPlqW  
} v r=va5  
ans(^Up$  
04K[U9W3  
public synchronized int write(byte[] b,int nStart,int nLen) _d|CO  
{ iS p +~  
int n = -1; R[C+?qux  
try{ Kyf,<z F  
oSavedFile.write(b,nStart,nLen); q7}rD$  
n = nLen; Y X`BX$  
} / [s TN.MG  
catch(IOException e) Y FJw<5&  
{ oZD+AF$R  
e.printStackTrace (); VjI=5)+~  
} 4YV 0v,z  
>>cb0fH5  
#r=Jc8J_  
return n; i\zVP.c])*  
} x0KW\<k  
</hv{<  
`D%U5Jb  
} (#&-ld6  
$ Jz(Lb{  
]C;X/8'Jf5  
/* LD=eMk: ~  
**SiteInfoBean.java 5NR@<FE  
*/ 4. =jKj9j  
package NetFox; ~'9\y"N1  
 uc<JF=  
kxanzsSr9  
public class SiteInfoBean { g<E[IR  
HUA{ P%  
bu?4$O  
private String sSiteURL; //Site's URL L">\c5ca  
private String sFilePath; //Saved File's Path rD\)ndPv  
private String sFileName; //Saved File's Name fT2F$U  
private int nSplitter; //Count of Splited Downloading File x>cl$41!W  
YE*%Y["  
r|_@S[hZg  
public SiteInfoBean() AMw#_8Y  
{//nSplitter的缺省值为5 K7 J RCLA  
//default value of nSplitter is 5 Q$yMU [l)  
this("","","",5); 5%_aN_1?ef  
} 22T\ -g{  
~n"?*I`  
:`>$B?x+  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k-Z :z?M  
{ f7SMO-3a  
sSiteURL= sURL; e7Sp?>-d  
sFilePath = sPath; "5!T-Z+F  
sFileName = sName; \{a!Z&df  
this.nSplitter = nSpiltter; KB"N',kG  
9Q.@RO$%C  
;*G';VuT  
} ;/h&40&  
&RHZ7T  
'8yCwk  
public String getSSiteURL() _UA|0a!-  
{ 4 Aj<k  
return sSiteURL; i91 =h   
} ~m'8<B5+  
O**~ Tj  
}G)2HTaZ  
public void setSSiteURL(String value) U*:ju+)k  
{ oj(st{,  
sSiteURL = value; 4;bc!> sfC  
}  SDc8\ms  
LPeVr^  
-N'wKT5  
public String getSFilePath() F%:74.]Y  
{ l*$~Y0  
return sFilePath; .(&w/jR  
} FVxORQI  
-q]5@s/  
<t&Qa~mA  
public void setSFilePath(String value) b/w5K2  
{ zIA)se Js  
sFilePath = value; 3L CT-rp  
} *iN5/w{VG  
&qzy?/i8  
``-pjD(t  
public String getSFileName() \ iA'^69  
{ jL7r1pu5  
return sFileName; D#D55X^6*  
} mKqXB\<  
^;9<7 h[l  
%L|xmx!c  
public void setSFileName(String value) 6)PnzeYW  
{ R/xT.EQ(N  
sFileName = value; js9^~:Tw  
} PfsUe,*  
@6 a'p  
>WA'/Sl<A<  
public int getNSplitter() y=aWSb2y'  
{ )<f4F!?,A  
return nSplitter; gN2oUbf8  
} @uz(h'~  
s f.z(o  
va:<W H  
public void setNSplitter(int nCount)  )$GCur~  
{ T/.UMw  
nSplitter = nCount; !rF1Remw  
} (hBph+  
} !9{hbmF#  
)MF 4b ][  
:-WNw n  
/* 2q(gWhcj  
**Utility.java 44s 9\  
*/ 8`wKq6  
package NetFox; D59q/@  
UpPl-jeT  
ZWni5uF-c  
public class Utility { f62rm[  
h;#046-7  
5UJ ?1"J  
public Utility() zBK"k]rz  
{ }Q*J!OH  
$)  M2  
ff7#LeB9  
} !Eg2#a?  
&8pGq./lr=  
//线程睡眠 !C|Z+w9Y  
public static void sleep(int nSecond) 3 l}9'j  
{ %gQUog  
try{ V'gJtF  
Thread.sleep(nSecond); lQiw8qD  
} &Z3%UOY  
catch(Exception e) 8f1M6GK?  
{ Bd 0oA )i  
e.printStackTrace (); 5 1N/XEk  
} &Nh zEl1  
} +'Y?K]zbt  
'7}2}KD  
//日志 q7r b3d  
public static void log(String sMsg) Td|u-9OM  
{ Rc3!u^?u  
System.err.println(sMsg); 4x}U+1B  
} cIQbu#[@  
8AuE:=?,,  
9Zj3"v+b  
public static void log(int sMsg) }& W=  
{ >tPf.xI|l  
System.err.println(sMsg); v%c/eAF  
} 7M _ mR Vh  
} zRd.!Rv  
mr/?w0(C  
k6J&4?xZ  
/* " dGN0i  
**TestMethod.java cWG%>.`5r  
*/ J<0d"'  
package NetFox; )HC/J-  
ll1N`ke  
b !y  
public class TestMethod { z5oJQPPi  
\NMqlxp2  
C7G,M  
public TestMethod() G3`9'-2q@c  
{ ///xx/weblogic60b2_win.exe .%)uCLZr$  
try{ x/CM)!U)  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P 4t@BwU$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6Q\|8a  
SiteFileFetch fileFetch = new SiteFileFetch(bean); F\&{>&  
fileFetch.start(); \+nV~Pi"A  
} &tvtL  
catch(Exception e){e.printStackTrace ();} a] 7g\rg)  
NtM ? Jh  
Zj-U^6^L  
} 1x=x,lcL  
7V8k =  
ZgG~xl\My  
public static void main(String[] args) *l 4[`7|  
{ -)^vO*b 0  
new TestMethod(); #R:&Irh  
} m< )`@6a/  
} cfilH"EK  
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