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http断点续传简单实现(java)

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/*  N>Pufr  
**SiteFileFetch.java /m;w~ -N  
*/ NOa.K)^k  
package NetFox; oLn| UWe_  
import java.io.*; Te#wU e-|  
import java.net.*; V6d*O`  
*X;g Y  
m`c(J1Et  
public class SiteFileFetch extends Thread { ~QsQ7SAs  
::vw 1Es  
4[!&L:tR  
SiteInfoBean siteInfoBean = null; //文件信息Bean x./jTebeO  
long[] nStartPos; //开始位置 ma }Y\(38  
long[] nEndPos; //结束位置 #1zWzt|DW  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Ac.z6]p  
long nFileLength; //文件长度 EVj48  
boolean bFirst = true; //是否第一次取文件 uBks#Y*3$  
boolean bStop = false; //停止标志 ^tuJM:  
File tmpFile; //文件下载的临时信息 ANCgch\  
DataOutputStream output; //输出到文件的输出流 {Pg7IYjH  
V]PTAhc  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) $XI5fa4Tt  
public SiteFileFetch(SiteInfoBean bean) throws IOException pKMf#)qm  
{ 7@vc Qv kC  
siteInfoBean = bean; *k'9 %'<  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); j86s[Dty  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); I01On>"@7  
if(tmpFile.exists ()) i*Y/q-N|  
{ 't{=n[  
bFirst = false; 5Tp n`2F  
read_nPos(); |U^ ff^]  
} 2uWzcy ?F  
else 5Kv=;o=U  
{ wrn[q{dX  
nStartPos = new long[bean.getNSplitter()]; ?k_=?m  
nEndPos = new long[bean.getNSplitter()]; "eQ96^'J  
} !*|CIxk(  
y::;e#.  
ORx,n7-  
igz:ek`  
} Sjr(e}*  
`bT{E.(T  
HXdPKS4q  
public void run() O|j5ulO}&"  
{ VUF7-C*  
//获得文件长度 ^[%~cG  
//分割文件 J7QlGm,=  
//实例FileSplitterFetch Y=3Y~  
//启动FileSplitterFetch线程 1}8e@`G0.]  
//等待子线程返回 NE9e br K  
try{ I/WnF"yP  
if(bFirst) r 'jVF'w  
{ _n}!1(xYa`  
nFileLength = getFileSize();  b9y E  
if(nFileLength == -1) K?T)9  
{ V7401@F  
System.err.println("File Length is not known!"); v,|;uc+  
} FcW ?([l  
else if(nFileLength == -2) Vn/6D[}Tu  
{ &7DE$ S  
System.err.println("File is not access!"); ;5Sr<W\:;  
} 5Ij_$a  
else *=/XlSWF  
{ 7FDraEr#f  
for(int i=0;i<nStartPos.length;i++) T>uLqd{hH  
{ F'j:\F6C;  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); )edM@beY_  
} }(tGjx]  
for(int i=0;i<nEndPos.length-1;i++) yJp& A  
{ W: ?-d{  
nEndPos = nStartPos[i+1]; WejY b;KS  
} W&!Yprr  
nEndPos[nEndPos.length-1] = nFileLength; >uuX<\cW  
} C#-x 3d-{  
} cE*|8'rSf  
~!A,I 9  
i2j)%Gc}  
//启动子线程 %?wuKZLnc  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N{ 9<Tf*  
for(int i=0;i<nStartPos.length;i++) `z=MI66Nl  
{ <![T~<.  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZY/at/v  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,OasT!Sr  
nStartPos,nEndPos,i); sG VC+!E  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MJg^ QVM  
fileSplitterFetch.start(); E>g'!  
} zWY6D4   
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @W @L%<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g{J3Ba  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9M7P]$^  
nEndPos = " + nFileLength); ev?>Nq+Z  
// fileSplitterFetch[nPos.length-1].start(); '[-/X a['  
K0E ;4r  
hsE!3[[  
//等待子线程结束 }]s~L9_z['  
//int count = 0; *TXq/ 3g  
//是否结束while循环 R*[ACpxr  
boolean breakWhile = false; gR(c;  
KcU,RTE  
=;{S>P!I(t  
while(!bStop) Z9sg6M@s  
{ 8@qahEgQ  
write_nPos(); MoX* e  
Utility.sleep(500); MYx*W7X  
breakWhile = true; F@I_sGCcb  
c"z%AzUV'  
9/%|#b-z  
for(int i=0;i<nStartPos.length;i++) N4Lk3]  
{ iK#{#ebAoW  
if(!fileSplitterFetch.bDownOver) T5Fah#-4  
{ w}1)am &pD  
breakWhile = false; Sph+kiy|  
break; /d=$,q1  
} 3|?fGT;P  
} *m"mt  
if(breakWhile) O:x=yj%^  
break; 8zGzn%^  
82=][9d #  
1Jd:%+T  
//count++; RTU:J67E  
//if(count>4) S; c=6@"  
// siteStop(); {l6]O  
} W[?B@sdSZ  
)5t_tPv  
Qpc{7#bp  
System.err.println("文件下载结束!"); xl9l>k6,  
} lxd<^R3i#^  
catch(Exception e){e.printStackTrace ();} dg!sRm1iZ:  
} UEeqk"t^  
uJO*aA{K  
/Yh([P>  
//获得文件长度 kp$ILZ  
public long getFileSize() #X8[g_d/  
{ TXaXJIp  
int nFileLength = -1; 4|e#b(!  
try{ Ov|j{}=L=9  
URL url = new URL(siteInfoBean.getSSiteURL()); b?^n'0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w#1dO~  
httpConnection.setRequestProperty("User-Agent","NetFox"); t}tKm  
4Klfnki  
QXz!1o+"  
int responseCode=httpConnection.getResponseCode(); S&Sf}uK  
if(responseCode>=400) zXD@M{  
{ 4[ra  
processErrorCode(responseCode); S'O0'5U@  
return -2; //-2 represent access is error JU@$(  
} + ND9###  
.3&m:P8zV  
;H=6u  
String sHeader; [Ok8l='  
e&5K]W0{  
hJ<2bgQo  
for(int i=1;;i++) 7S`H?},sR  
{ EyeLC6u  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T82_`u  
//Utility.log(in.readLine()); YZ>cE#  
sHeader=httpConnection.getHeaderFieldKey(i); g)9/z  
if(sHeader!=null) -0`hJ_(  
{ n`,Q:  
if(sHeader.equals("Content-Length")) kUt9'|9!  
{ m&q;.|W  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hF~B&^dd.  
break; ]| y H8m  
} twtDyo(\  
} ,fw[J  
else H1[aNwLr  
break; zi ,Rk.  
} h[]N=X  
} *LRGfk+h  
catch(IOException e){e.printStackTrace ();} ^sKXn:)  
catch(Exception e){e.printStackTrace ();} MUrY>FYgx  
nf4 P2<L!  
IMZKlU3  
Utility.log(nFileLength); 'dzp@-\  
L@Z &v'A  
4.'EEuRw\}  
return nFileLength; + LwoBn>6  
} D$cMPFa2Nt  
*ls6#j@  
bwJi[xF  
//保存下载信息(文件指针位置) n@Ag`}  
private void write_nPos() eFQi K6`i  
{ 4L e5Ms/  
try{ Z|c9%.,  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Lvq]SzOw  
output.writeInt(nStartPos.length); FQFENq''B  
for(int i=0;i<nStartPos.length;i++) ej;ta Kzj  
{ pJz8e&wyLM  
// output.writeLong(nPos); {yHfE,  
output.writeLong(fileSplitterFetch.nStartPos); L\ %_<2  
output.writeLong(fileSplitterFetch.nEndPos); O[y`'z;C  
} ?/( K7>`  
output.close(); b-?o?}*  
} Z?.*.<"Sj  
catch(IOException e){e.printStackTrace ();} v+#j>   
catch(Exception e){e.printStackTrace ();} dYd~9  
} X6,9D[Nw  
^wa9zs2s;/  
<k](s  
//读取保存的下载信息(文件指针位置) 0EOX@;}  
private void read_nPos() s%oAsQ_y  
{ #P#R~b]  
try{ [bG>qe1}&  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $O'2oeM  
int nCount = input.readInt(); *fSM'q;  
nStartPos = new long[nCount]; %j">&U.[  
nEndPos = new long[nCount]; p2vBj.*J  
for(int i=0;i<nStartPos.length;i++) jtv Q<4  
{ ogqV]36Idh  
nStartPos = input.readLong(); wsrx|n[]  
nEndPos = input.readLong(); V|\A?   
} $>=Nb~t!/  
input.close(); 0 '7s  
} +^? -}v  
catch(IOException e){e.printStackTrace ();} {*;]I?9Al  
catch(Exception e){e.printStackTrace ();} 2^6TrZA7M6  
} ?d<:V.1U@  
]B3FTqR{i  
uV_)JZ W,L  
private void processErrorCode(int nErrorCode) q7&yb.<KD.  
{ $|(|Qzi%  
System.err.println("Error Code : " + nErrorCode); 'c0'P%[5A  
} =t$mbI   
:{:?D\%6  
s2?,'es  
//停止文件下载 \'+{X(]  
public void siteStop() o U}t'WU  
{ v^W?o}W  
bStop = true; Cw[Od"B\?U  
for(int i=0;i<nStartPos.length;i++) qM>OE8c#/  
fileSplitterFetch.splitterStop(); n,jE#Z.D  
s.;KVy,=Bu  
h:jI  
} e4q k>Cw  
} EO/cW<uV'  
//负责部分文件的抓取 aC yb-P  
**FileSplitterFetch.java ;Nf hKu%K  
*/ Ag#5.,B-  
package NetFox; O\?5#.   
>9tkx/J  
m0A@jWgd  
import java.io.*; 2x`xyR_Q.R  
import java.net.*; O3C)N I\i  
x|v[Dxf]  
DAMpR3  
public class FileSplitterFetch extends Thread { ;/";d]j  
t66f 7AR  
W_BAb+$aF  
String sURL; //File URL DtF![0w/  
long nStartPos; //File Snippet Start Position R!/,E  
long nEndPos; //File Snippet End Position dVVvG]  
int nThreadID; //Thread's ID -wtTq ph'  
boolean bDownOver = false; //Downing is over krr-ZiK  
boolean bStop = false; //Stop identical hDB`t $  
FileAccessI fileAccessI = null; //File Access interface v;bM.OL  
vN0L( B  
U-~*5Dd  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^C:{z)"h  
{ b#Fk>j  
this.sURL = sURL; p9&gEW  
this.nStartPos = nStart; o}mhy`}  
this.nEndPos = nEnd; Pa +AF  
nThreadID = id; t7*G91Hoq&  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0i`v:Lq%  
} k5fH ;  
AF*ni~  
]xJ'oBhy  
public void run() ^Kw&=u  
{ a8bX"#OR&N  
while(nStartPos < nEndPos && !bStop) u,Q_WR-wJ  
{ JO& ;bT<  
pu2wEQ  
,);= (r9  
try{ u-%r~ }  
URL url = new URL(sURL); f\x@ C)E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _o&,  
httpConnection.setRequestProperty("User-Agent","NetFox"); P;L)1 g  
String sProperty = "bytes="+nStartPos+"-"; uHUvntr  
httpConnection.setRequestProperty("RANGE",sProperty); fw:7Q7 qo  
Utility.log(sProperty); 2rR@2Vsw2  
?b*/ddIs  
EaM"=g  
InputStream input = httpConnection.getInputStream();  r21?c|IP  
//logResponseHead(httpConnection); zH=/.31Q  
%S >xSqX  
_ bXVg3oDt  
byte[] b = new byte[1024]; k\mXo-:V6  
int nRead; xP{HjONu  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {*M>X}voS  
{ `eMrP`  
nStartPos += fileAccessI.write(b,0,nRead); 1BMV=_  
//if(nThreadID == 1) 0^<Skm27"  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 12:h49AP  
} Y91 e1PsV  
NSMjr_  
@b ::6n/u  
Utility.log("Thread " + nThreadID + " is over!"); OQytgXED  
bDownOver = true; Edf=?K+\!i  
//nPos = fileAccessI.write (b,0,nRead); g33<qYxP  
} XI%RneuDr:  
catch(Exception e){e.printStackTrace ();} +X* F<6mZ  
} ' D)1ka.  
} K)Df}fVOc  
CU#L *kz  
eHVdZ'%x  
//打印回应的头信息 r!=]Q}`F  
public void logResponseHead(HttpURLConnection con) sW]yuu!/  
{ vF.?] u  
for(int i=1;;i++) Vr&el  
{ .KT 7le<Zm  
String header=con.getHeaderFieldKey(i); dAYI DE  
if(header!=null) Dh\S`nfFq  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b[J-ja.  
Utility.log(header+" : "+con.getHeaderField(header)); Eonq'Re$  
else %K&+~CJE  
break; %mK3N2N$  
} 8~&F/C*  
} 6pM"h5hA  
W\I$`gyC/  
4)z3X\u|Z2  
public void splitterStop() T8,k7 7  
{ ALE808;|  
bStop = true; D:YN_J"kV  
} l1-4n*fU  
 uD.  
>Jm-2W5J  
} \ &eY)^vw  
=gMaaGg p,  
'+)6#/*  
/* DHh+%|e  
**FileAccess.java K?h[.`}  
*//文件访问(定位,写) (,- 5(fW  
package NetFox; g2[K<  
import java.io.*; L0X&03e=e:  
]uBT &  
g>6:CG"  
public class FileAccessI implements Serializable{ iyA*J CD  
4/*]`  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KW&nDu t  
RandomAccessFile oSavedFile; M,b<B_$  
long nPos; YYTO,4  
&GXtdO>;Zv  
pj!k|F9  
public FileAccessI() throws IOException W@:^aH  
{ ]h #WkcXQ  
this("",0); GIl:3iB49  
} |RHO+J  
H/cs_i  
H "Q(2I  
public FileAccessI(String sName,long nPos) throws IOException 3mpP| b"  
{ { M`  
oSavedFile = new RandomAccessFile(sName,"rw"); L\QQjI{  
this.nPos = nPos; 3M}AxE u  
oSavedFile.seek(nPos); '4J&Gpx  
} ,DE(5iDS  
'b LP ~  
er(8}]X8Q  
public synchronized int write(byte[] b,int nStart,int nLen) CMC?R,d  
{ P/FrE~  
int n = -1; MB}:GY?  
try{ i0ILb/LS  
oSavedFile.write(b,nStart,nLen); 3cmbK  
n = nLen; 5|yZEwq  
} !Bag}|#  
catch(IOException e) =L:[cIRrT;  
{ <2n'}&F  
e.printStackTrace (); Wl,%&H2S<  
} I 'x$,s  
G i$  
+ckMT3  
return n; slu$2-H  
} 08`f7[JQo]  
?+3R^%`V  
\U==f &G?J  
} {]+ jL1  
TAXd,z N  
F?!FD>L{`  
/* BfX%|CWh  
**SiteInfoBean.java 0Wa#lkn$I  
*/ g;$E1U=R-E  
package NetFox; HkW/G[7x&  
lTn;3'  
5fU!'ajaN7  
public class SiteInfoBean { )URwIe{  
g+:$X- r  
#N; $  
private String sSiteURL; //Site's URL cB{%u '  
private String sFilePath; //Saved File's Path %rFP#L  
private String sFileName; //Saved File's Name }%_qx|(P|t  
private int nSplitter; //Count of Splited Downloading File H!p!sn  
%(fL?  
|d5ggf .w  
public SiteInfoBean() Q%rVo4M#2  
{//nSplitter的缺省值为5 #1MKEfv(~  
//default value of nSplitter is 5 2q12y Y f  
this("","","",5); N0]z/}hd@  
} pMOD\J:l,  
N[>:@h  
"_t4F4z  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X8 8F>1}  
{ 8a7YHUL<3i  
sSiteURL= sURL; QT_Srw@  
sFilePath = sPath; L+_8QK<  
sFileName = sName; Xu6jHJ@x  
this.nSplitter = nSpiltter; JFe4/ V  
g .3f2w  
$,!hD\a  
} p#)e:/Qy  
,bxz]S1W  
VcP:}a< B\  
public String getSSiteURL() 7Ez}k}aR<  
{ GM:, CJ?  
return sSiteURL; 4>l0V<  
} 6{L F-`S%  
V!mWn|lf  
6ezcS}:+  
public void setSSiteURL(String value) r8sdzz%  
{ q5!0\o:  
sSiteURL = value; /\~l1.6`  
} R;%^j=Q  
NOV.Bs{ yL  
!!9{U%s  
public String getSFilePath() .-J`d=Krp  
{  j|ozGO  
return sFilePath; [;<<4k(nL  
} wI*Y{J  
4yhcK&  
O(odNQy~  
public void setSFilePath(String value) r;9z 5'  
{ f;R>Pr;rD  
sFilePath = value; fD0{ 5  
} .6LS+[  
$kv@tzO  
{Wh BoD  
public String getSFileName() 8*vFdoE_oO  
{ li@k Lh  
return sFileName; Ur n  
} :u AjV  
tO7I&LNE  
bZu$0IG  
public void setSFileName(String value) L,6MF,vx  
{ 6I"C~&dt  
sFileName = value; A^8x1ydZ  
} Mg+4huT  
- gB{:UYi3  
!1("(Eb  
public int getNSplitter() _$!`VA%  
{ pVY4q0@  
return nSplitter; D]jkR} t  
} _g65pxt =Z  
&u("|O)w$  
sLNNcj(Cy>  
public void setNSplitter(int nCount) Y4`QK+~fH  
{ V>AS%lXj  
nSplitter = nCount; f P+QxOz  
} I-TlrW=t  
} ,^HS`!s[ E  
(N7O+3+G  
ve6x/ PD  
/* SijS5irfk  
**Utility.java $ND90my  
*/ |g+!  
package NetFox; loLKm]yV  
}Iip+URG  
,2,W^HJ  
public class Utility { j|k @MfA  
f'i6QMk\&  
v O PMgEI  
public Utility() !n:uiwh  
{ ;|;iCaD a+  
(ZS/@He  
Jb9F=s+  
} ~+=E"9Oo  
UUGe"]V^g:  
//线程睡眠 YlrB@mE0n$  
public static void sleep(int nSecond) ]r!QmWw~V  
{ 6A.P6DW  
try{ {79qtq%W{  
Thread.sleep(nSecond); * O5:  
} l!/!?^8|f  
catch(Exception e) >GmN~"iJ  
{ T30Zk*V  
e.printStackTrace (); ",T` \8&@e  
} h^Qh9G0dn  
} ETe-  
"U*5Z:8?9  
//日志 YroNpu]s  
public static void log(String sMsg) .x>HA^4  
{ %OEq,Tb  
System.err.println(sMsg); [1Uz_HY["3  
} i_NJ -K  
fQP,=  
H@Q`  
public static void log(int sMsg) puA |NT  
{ cFDxjX?~  
System.err.println(sMsg); 8!;$qVt  
} ]{Z8  
} V8tghw  
so*/OBte  
VjY<\WqbS  
/* `On3/gU|  
**TestMethod.java P,U$ %C!  
*/ d- h"JZ9  
package NetFox; z,avQR&  
}I]W'<jY  
ifvU"l  
public class TestMethod { GZ"&L?ti  
ydB$4ZB3[  
mbGcDG[HQ  
public TestMethod() *Wso3 6an  
{ ///xx/weblogic60b2_win.exe p&\K9hfi  
try{ XddHP;x  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d+Ds9(gV  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +2Z#M  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6< >SHw  
fileFetch.start(); *%I[ ke *  
} 4~Dax)  
catch(Exception e){e.printStackTrace ();} C 0>=x{,v  
,z G(u 1  
%<AS?Ry  
} _[F@1NJ  
Qm; BUG]  
e"~)Utk  
public static void main(String[] args) gJk[Ja  
{ q1w|'V  
new TestMethod(); ,z[(k"  
} t$5jx  
} ZtR&wk  
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