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http断点续传简单实现(java)

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/* .n 9.y8C  
**SiteFileFetch.java $S6(V}yh  
*/ bxXpw&  
package NetFox; GkAd"<B  
import java.io.*; -X.#Y6(  
import java.net.*; ~;"eNg{ T  
(}A$4?  
,1]UOQ>AP  
public class SiteFileFetch extends Thread { ` H'G"V  
TFSdb\g  
#7uH>\r  
SiteInfoBean siteInfoBean = null; //文件信息Bean +25}X{r$_  
long[] nStartPos; //开始位置 #VQZ"7nI@  
long[] nEndPos; //结束位置 VfnL-bDGV  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 aBA oSn  
long nFileLength; //文件长度 %'2P4(  
boolean bFirst = true; //是否第一次取文件 P;5)Net1X  
boolean bStop = false; //停止标志 t[|oSF#i  
File tmpFile; //文件下载的临时信息 NLsF6BX/-  
DataOutputStream output; //输出到文件的输出流 UF9={fN1  
M\1CDU+*Ns  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) g\aO::  
public SiteFileFetch(SiteInfoBean bean) throws IOException HhbBt'fH  
{ $(1t~u<17  
siteInfoBean = bean; {v"f){   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :5kDc" =Z|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); s< tG  
if(tmpFile.exists ()) 1g;2e##)  
{ }8O9WS  
bFirst = false; }&v}S6T  
read_nPos(); L$ T2 bul  
} ,EQ0""G!  
else #$WnMJ@  
{ u(9pRr L  
nStartPos = new long[bean.getNSplitter()]; v`h>5#_[  
nEndPos = new long[bean.getNSplitter()]; d?oXz|;H(  
} (B#FLoK  
"im5Fnu  
]OpGD5jZ  
c)EYX o  
} S^s-md>  
`I7s|9-=  
:!i=g+e]  
public void run() -jjB2xP  
{ 1d<?K7%^  
//获得文件长度 HNkOPz+d&8  
//分割文件 r\m{;Z#LJm  
//实例FileSplitterFetch AbNr]w&pXC  
//启动FileSplitterFetch线程 -^NW:L$|  
//等待子线程返回 rfDGS%!O%  
try{ A1zRzg4I  
if(bFirst) 0Gu77&  
{ `0upm%A  
nFileLength = getFileSize(); M^ * ~?9  
if(nFileLength == -1) ww|fqx?  
{ @3n!5XM{EE  
System.err.println("File Length is not known!"); aT^ $'_ G  
} LJrH_h8C  
else if(nFileLength == -2) +}jzge"  
{ jdG'sITv  
System.err.println("File is not access!"); qkfof{z  
} smCACQ$ (  
else gj;gl ="3  
{ f@sC~A. 9\  
for(int i=0;i<nStartPos.length;i++) mxqZj8VuH  
{ Gza= 0  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); R&1>\t  
} _;}$/  
for(int i=0;i<nEndPos.length-1;i++) } W]A`-Jv  
{ zFOtOz`9H  
nEndPos = nStartPos[i+1]; >s%Db<(P=  
} fBX@ MedC  
nEndPos[nEndPos.length-1] = nFileLength; %:C6\4  
} gLMb,buqC  
} WX Fm'5Vr  
W~H`{x%Av>  
1n8y4k)  
//启动子线程 Q`i@['?p  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A^lm0[3q  
for(int i=0;i<nStartPos.length;i++) 9>{ml&$  
{ wQW` Er3w  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #~Xj=M%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;)ay uS sQ  
nStartPos,nEndPos,i); H[w';u[%  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dpz@T>MS=  
fileSplitterFetch.start(); Z +/3rd  
} shB3[W{}!)  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jl59;.P  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S^R dj ]  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @ws&W=NQ  
nEndPos = " + nFileLength); JQb{?C  
// fileSplitterFetch[nPos.length-1].start(); Vu_oxL}  
HnPy";{  
KyIUz9$  
//等待子线程结束 |HAbZd7PG  
//int count = 0; U ]pE{ ^\w  
//是否结束while循环 gwNZ`_Q  
boolean breakWhile = false; >~d'i  
5[2kk5,  
*~U*:>hS  
while(!bStop) P}'B~ ~9W  
{ uznqq}  
write_nPos(); }#g]qK  
Utility.sleep(500); /y1+aTiJ  
breakWhile = true; L%[>z'Zp  
@n qM#  
[<r.M<3  
for(int i=0;i<nStartPos.length;i++) b4:{PD~Mh  
{ K1YxF  
if(!fileSplitterFetch.bDownOver) jNbVp{%/S}  
{ h5P ]`r  
breakWhile = false; vo E t\H  
break; yIiVhI?X  
} 62;xK-U  
} nK< v  
if(breakWhile) (e_<~+E  
break; =~s+<9c]  
3LyNi$`f  
BN&)5M?Xt6  
//count++; nh7_ jEX  
//if(count>4) UvMkL  
// siteStop(); U8aVI  
} /IcGJ&;  
Q~.t8g/  
~(*tcs]hY  
System.err.println("文件下载结束!"); x+~!M:fAc9  
} P,zQl;  
catch(Exception e){e.printStackTrace ();} /7#MJH5b6  
} T!?tyW  
XR VZU~ZV  
?(zCv9Pg  
//获得文件长度 AP z"k?D0  
public long getFileSize() tvn o3"  
{ v? 8i;[  
int nFileLength = -1; P cbhylKd  
try{ +*W lj8  
URL url = new URL(siteInfoBean.getSSiteURL()); lA4-ZQ2Zp[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .~ uKr^%  
httpConnection.setRequestProperty("User-Agent","NetFox"); (z;lNl(*C  
R68:=E4  
W3ms8=z  
int responseCode=httpConnection.getResponseCode(); s;Bh69  
if(responseCode>=400) 6? lAbW  
{ -vm1xp$  
processErrorCode(responseCode); E"[p_ALdC  
return -2; //-2 represent access is error 4cy,'B  
} AEM;ZQU  
DXj>u9*%  
b IxH0=f  
String sHeader; {o^tSEN!-  
H9'psv  
# B <%  
for(int i=1;;i++) -Sh&x  
{ 2\&3x} @  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s[eSPSFZ  
//Utility.log(in.readLine()); Q%~BD@Io  
sHeader=httpConnection.getHeaderFieldKey(i); 67/\0mV:~  
if(sHeader!=null) xC5Pv">  
{ / j "}e_Q  
if(sHeader.equals("Content-Length")) [< g9jX5  
{ *[i49X&rd  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5"G-r._  
break; Nk7=[y#z  
} u,:hT] ~+  
} GL>YJ%  
else #: [F=2@,A  
break; zC:Pg4=w]  
} =mX26l`B  
} o=!_.lDF:  
catch(IOException e){e.printStackTrace ();} %hmRh~/&  
catch(Exception e){e.printStackTrace ();} &=S:I!9;;  
`, ]ui*  
og8hc~:ro  
Utility.log(nFileLength); I*N v|HST  
&2.DZ),L  
y4@gw.pt  
return nFileLength; IP{$lC  
} >h:'Z*9  
<7)sS<I  
]Ue aXwaU  
//保存下载信息(文件指针位置) IDf\! QGx  
private void write_nPos() l-nH  
{ 9%SC#V'  
try{ 569p/?  
output = new DataOutputStream(new FileOutputStream(tmpFile)); }&L%c>  
output.writeInt(nStartPos.length); ~}{_/8'5  
for(int i=0;i<nStartPos.length;i++) PP\ bDEPy  
{ -Op^3WWyY  
// output.writeLong(nPos); jPo,mz&^  
output.writeLong(fileSplitterFetch.nStartPos); zp:QcL"  
output.writeLong(fileSplitterFetch.nEndPos); 7*M-?  
} tBJ4lb  
output.close(); RcJtVOrd  
} a {x3FQ  
catch(IOException e){e.printStackTrace ();} ?zC{T*a  
catch(Exception e){e.printStackTrace ();} SmDNN^GR  
} /zXOta G  
nC[aEZ7  
/9gn)q2f(  
//读取保存的下载信息(文件指针位置) 8PVjNS/  
private void read_nPos() \}4*}Lr  
{ \`z%5/@f;  
try{ 9MO=f^f-  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S,5>/'fy0  
int nCount = input.readInt(); 2[(~_VJ  
nStartPos = new long[nCount]; WK?5`|1l:x  
nEndPos = new long[nCount]; 3O-vO=D  
for(int i=0;i<nStartPos.length;i++) nql9SQ'\\  
{ oR~d<^z(  
nStartPos = input.readLong(); j[R.UB3J  
nEndPos = input.readLong(); L#'XN H"  
} Gt?l 2s  
input.close(); g5pFr=NV  
} :JX2GRL4  
catch(IOException e){e.printStackTrace ();} .vy@uT,  
catch(Exception e){e.printStackTrace ();} 8!.V`|@lt  
} !x ~s`z  
"P|n'Mx  
WvArppANo  
private void processErrorCode(int nErrorCode) 5oCg&aT  
{ cNwH Y Z'  
System.err.println("Error Code : " + nErrorCode); ~@6l7H6{  
} }[lP^Qs  
jDQ?b\^  
- G/qfd|s/  
//停止文件下载 Fx.Ly]L  
public void siteStop() Ye$j43b  
{ sCt)Yp+8}B  
bStop = true; <FU?^*~  
for(int i=0;i<nStartPos.length;i++) <)!,$]S  
fileSplitterFetch.splitterStop(); <"K*O9 nst  
z7sDaZL?_  
z k}AGw  
} >EFWevT{  
} p[xGL } +\  
//负责部分文件的抓取 |kvH`&s  
**FileSplitterFetch.java L~;(M6Jp  
*/ rOE: ap|KL  
package NetFox; zdU 46|!u  
AIn/v`JeX  
EZjtZMnj  
import java.io.*; h/{1(c}  
import java.net.*; w< Xwz`O  
JttDRNZAU  
[PUu9rz#  
public class FileSplitterFetch extends Thread { lqMr@ :t  
`#l3a  
(57!{[J  
String sURL; //File URL o<3$|`S&  
long nStartPos; //File Snippet Start Position $Z;/Sh  
long nEndPos; //File Snippet End Position pw4^E|X  
int nThreadID; //Thread's ID itirh"[  
boolean bDownOver = false; //Downing is over ,>b>I#{  
boolean bStop = false; //Stop identical 1d FuoX  
FileAccessI fileAccessI = null; //File Access interface 8 I_  
"|1iz2L  
7M7Ir\d0lp  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IKP GqoM  
{ S:}"gwFM  
this.sURL = sURL; &*7KQd  
this.nStartPos = nStart; $57b.+2n  
this.nEndPos = nEnd; p$|7T31 *  
nThreadID = id; eZU9L/w:  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -j]k^  
} jMTM:~0N  
]7K2S{/o{  
7`A]X,:  
public void run() R Qo a  
{ < ]1,L%  
while(nStartPos < nEndPos && !bStop) K6-M.I  
{ J=$\-  
TE+>|}]R  
rqmb<# Z  
try{ egG<"e*W}N  
URL url = new URL(sURL); :yD>Tn;1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HLwMo&*rA  
httpConnection.setRequestProperty("User-Agent","NetFox"); r#4/~a5i~  
String sProperty = "bytes="+nStartPos+"-"; lD3nz<p  
httpConnection.setRequestProperty("RANGE",sProperty); 37jxl+  
Utility.log(sProperty); :p: C  
{LF4_9 =  
`wtso  
InputStream input = httpConnection.getInputStream(); 77)WNL/ x  
//logResponseHead(httpConnection); RM `qC  
$+7uB-KsU  
L0!CHP/nRS  
byte[] b = new byte[1024]; W!? h2[  
int nRead; Qw'905;(  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nDC0^&  
{ Su2{nNC>  
nStartPos += fileAccessI.write(b,0,nRead); -%yrs6  
//if(nThreadID == 1) ;50&s .gZ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,n8\y9{G  
} sNo8o1Hby  
<R@,wzK  
kc^,V|Nbq6  
Utility.log("Thread " + nThreadID + " is over!"); @pYEzizP7  
bDownOver = true; iI IXv  
//nPos = fileAccessI.write (b,0,nRead); 'v V7@@  
} pCh v;  
catch(Exception e){e.printStackTrace ();} Wvr{l  
} *|dr-e_j  
} }Rw,4  
kzRJzJquP  
I8 :e `L  
//打印回应的头信息 s4"Os gP+  
public void logResponseHead(HttpURLConnection con) -<6?ISF2  
{ @ps(3~?7  
for(int i=1;;i++) |sReHt2)d  
{ ;cI*"-I:F  
String header=con.getHeaderFieldKey(i); \4>,L_O  
if(header!=null) =otO@22Np  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I} jgz  
Utility.log(header+" : "+con.getHeaderField(header)); 3@gsKtA&H4  
else V|_ h[hXE  
break; O[C4xq  
} ^E.L8  
} !o /=,ZIx  
Eu`|8# [ W  
r!2U#rz  
public void splitterStop() w]0@V}}u$o  
{ 2aM7zP[Z  
bStop = true; | ]*3En:  
} R2Fjv@Egk  
@m#OhERv  
=+!l8o&o,  
} Fye>H6MU  
K] (*l"'U5  
K"0IWA  
/*  ;v:(  
**FileAccess.java P"Al*{:J  
*//文件访问(定位,写) q#W|fkfx+  
package NetFox; {6zNCO  
import java.io.*; 5 aA* ~\  
hGz_F/  
I x%>aee  
public class FileAccessI implements Serializable{ (.ir"\k1(  
Db,"Gl  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -^xbd_'  
RandomAccessFile oSavedFile; }xk(aM_  
long nPos; 3#>W\_FY*D  
 oBkhb  
sE pI)9  
public FileAccessI() throws IOException !ajBZ>Q  
{ `5IrV&a  
this("",0); vQljxRtW  
} nF,F#V8l  
T- en|.  
^viabkf C  
public FileAccessI(String sName,long nPos) throws IOException _p-e)J$7  
{ &J>e; X  
oSavedFile = new RandomAccessFile(sName,"rw"); N*o{BboK;  
this.nPos = nPos; UZyg_G6  
oSavedFile.seek(nPos); @AEH?gOX  
} LjI`$r.B  
X8$i*#D  
e73=*~kfR  
public synchronized int write(byte[] b,int nStart,int nLen) ^m|@pp  
{ l-+=Yk!X  
int n = -1; m2j&0z  
try{ x}+zhRJ  
oSavedFile.write(b,nStart,nLen); fST.p|b7  
n = nLen; p0Jr{hM  
} %F;BL8d  
catch(IOException e) ^+_rv  
{ |C [!A  
e.printStackTrace (); q!$s<n  
} ]vvYPRV76  
("9bV8:@B  
yQK{ +w  
return n; tVAi0`DV  
} heVk CM :  
"v8p<JfB`  
V?uT5.B2  
} @+gr/Pul^  
J}#gTG( '  
?=? _32O  
/* $ DL}jH^S  
**SiteInfoBean.java q[&Kr+)j  
*/ _K^Q]V[nZ  
package NetFox; YB38K(  
TN(Vzs%  
$UR:j8C{p$  
public class SiteInfoBean { ^_WR) F'K  
 LR97FG  
e4S@ J/D  
private String sSiteURL; //Site's URL @Rr=uf G  
private String sFilePath; //Saved File's Path 0:$ }~T9T  
private String sFileName; //Saved File's Name uJw?5kEbv<  
private int nSplitter; //Count of Splited Downloading File v(1 [n]y  
\P<aK$g  
5Gz!Bf@!!  
public SiteInfoBean() 2S?7j[@%i`  
{//nSplitter的缺省值为5 >,e^}K}C  
//default value of nSplitter is 5 }[AaI #  
this("","","",5); u<-)C)z  
} n{tc{LII/  
0#*6:{/^  
OQ-) 4Uk}  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) , >LJpv  
{ +fP.Ewi  
sSiteURL= sURL; e^y9Kmd  
sFilePath = sPath; 'ygKP6M  
sFileName = sName; #Rw!a#CX.  
this.nSplitter = nSpiltter; 2u3Kyn  
K10G+'H^  
h `Lr5)B'  
} S!(3-{nC  
n' ~ ==2  
7he73  
public String getSSiteURL() 1m*)MZ)  
{ EA"hie7  
return sSiteURL; W$4$%r8  
} Coi[cfg0  
0<,{poMM  
mTZ/C#ir(  
public void setSSiteURL(String value) 6TP /0o)  
{ O$*lPA[  
sSiteURL = value; h^Wb<O`S  
} /2tA n  
[:8\F#KW  
EF0v!XW  
public String getSFilePath() giakEPl  
{ YYWD\Y`8  
return sFilePath; k@4N7}  
} }y(t')=9  
IW~R{ ]6  
TM)INo^  
public void setSFilePath(String value) 6/UOz V,[  
{ `Fd \dn  
sFilePath = value; gRLt0&Q~  
} qM\ 2f<)  
^^a6 (b  
.5|[gBK  
public String getSFileName() >?$2`I  
{ sscbf  
return sFileName; 5YY5t^T  
} :""HyjY!  
'RjEdLrI  
Lq(=0U\"P  
public void setSFileName(String value) wvv+~K9jq  
{ Z"`w>c.  
sFileName = value; )lG}B U.  
} UG2+Y']  
Z/Rp?Jz\j/  
DbMVbgz<e  
public int getNSplitter() V]H(;+^P  
{ .?Eb{W)^br  
return nSplitter; ynI e4b  
} ]A5F}wV4  
ha :l-<a  
=pL$*`]?  
public void setNSplitter(int nCount) Nq8ON!<<  
{ #(^<qr   
nSplitter = nCount; |AYii-g  
} 4 &bmt  
} 7:4c\C0  
WVP?Ie8  
MBWoPK  
/* .p[uIRd`  
**Utility.java (\6E.Z#  
*/ K9N31'  
package NetFox; _^iY;&  
*!QmYH5r0  
Ip t;NlR  
public class Utility { 1eI*.pt  
@Jd&[T27Lr  
)!8q JQD  
public Utility() T`# nn|  
{ yYz{*hq  
|` T7}U  
-.D?Z8e  
} v=k+MvX  
i}m'#b  
//线程睡眠 d{fd5jv;  
public static void sleep(int nSecond) lR?y tIY  
{ !tq]kKJ3:  
try{ &y? |$p\;/  
Thread.sleep(nSecond); "6U0 !.ro@  
} k4{!h?h  
catch(Exception e) dz^HN`AlzC  
{ ~XR ('}5D  
e.printStackTrace (); +`d92Tz  
} }a"=K%b<\  
} >Na.C(DZ  
O=%Ht-kOc  
//日志 8a6.77c  
public static void log(String sMsg) _7!ZnJrR  
{ gC$_yd6m L  
System.err.println(sMsg); GCl *x:  
} c7CYulm  
tddwnpnSw  
%R GZu\p  
public static void log(int sMsg) i!YfR]"}  
{ DuC#tDP  
System.err.println(sMsg); :!Ci#[g  
} `l45T~`]$  
} AZ.QQ*GZ#y  
-mO#HZIq  
a;[\nCK  
/* {IOc'W-C#2  
**TestMethod.java b ri[&=  
*/ > TYDkEs0  
package NetFox; L } R"1O  
HzM\<YD  
xd{.\!q.  
public class TestMethod { i$kB6B#==  
WN]k+0#  
`)cI^!  
public TestMethod() HS |Gz3~  
{ ///xx/weblogic60b2_win.exe $~5H-wJ  
try{ 1gK|n  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q{h,}[U=  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !SuflGx,q  
SiteFileFetch fileFetch = new SiteFileFetch(bean); h; q&B9  
fileFetch.start(); %ddH4Q/p  
} n[>hJ6  
catch(Exception e){e.printStackTrace ();} zU1D@  
> %KEMlKZ  
"E+;O,N-  
} k -G9'c~  
)2c]Z|  
/)[-5n{  
public static void main(String[] args) Z"c-Ly{vEj  
{ P[fy  
new TestMethod(); |mMsU,*gB  
} R+.4|1p  
} k2Cq9kQq  
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