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http断点续传简单实现(java)

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/* qj&)w9RLJE  
**SiteFileFetch.java V5B-S.i@  
*/ {Fi@|'  
package NetFox; :j ~5(K"  
import java.io.*; 7mM;Q  
import java.net.*; O[ !o1.  
%U GlAyj  
>v[(w1?rX  
public class SiteFileFetch extends Thread { 9HX+sB M  
Q7|13^ |C  
2?QJh2  
SiteInfoBean siteInfoBean = null; //文件信息Bean Q$1K{14I  
long[] nStartPos; //开始位置 sh ;uKzQ  
long[] nEndPos; //结束位置 3ZlI$r(  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 &>e DCs  
long nFileLength; //文件长度 iI*7WO[W  
boolean bFirst = true; //是否第一次取文件 B5:g{,C  
boolean bStop = false; //停止标志 er0D5f R  
File tmpFile; //文件下载的临时信息 `VtwKt*  
DataOutputStream output; //输出到文件的输出流 <+gl"lG  
Ug21d42Z4  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) $)Yog]}  
public SiteFileFetch(SiteInfoBean bean) throws IOException  3Mx@  
{ ]%|WE  
siteInfoBean = bean; #-T.@a1X  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); /BM1AV{s6  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Nz*sD^SJa  
if(tmpFile.exists ()) |Vi&f5p,@  
{ "Vq]|j,B/c  
bFirst = false; 4Umsc>yfK  
read_nPos(); aLi_Hrb9  
} Z~c'h  
else M"^Vf{X^  
{ 5vf t}f  
nStartPos = new long[bean.getNSplitter()]; hyiMOa  
nEndPos = new long[bean.getNSplitter()]; pm]DxJ@  
} .KucjRI  
LUck>l\l  
N@6OQ:,[F  
Z=@)  
} 6 ]Oxx{|}  
d&uTiH?0  
m > (h_j  
public void run() SDHc[66'  
{ xGfD z*t  
//获得文件长度 87KrSZ  
//分割文件 c^O#O  
//实例FileSplitterFetch Cc)P5\j h  
//启动FileSplitterFetch线程 *O> aqu  
//等待子线程返回 /;AZ/Ocy!  
try{ V<4+g/  
if(bFirst) i ,pN1_-  
{ O[)]dD&'  
nFileLength = getFileSize(); cmhN(==  
if(nFileLength == -1) c%@~%IGF  
{ {|Ki^8h/p  
System.err.println("File Length is not known!"); (YHvGGr  
} bz0P49%  
else if(nFileLength == -2) [Cj}nld   
{ -,VhSI  
System.err.println("File is not access!"); _sR9   
} 1/ pA/UVO  
else _]xt65TL  
{ RR!!hY3 K  
for(int i=0;i<nStartPos.length;i++) .3<IOtD=  
{ Jh4&Qh|t  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 3;MjO*-  
} 0^_lj9B!  
for(int i=0;i<nEndPos.length-1;i++) EB5_;  
{ Hpi%9SAM  
nEndPos = nStartPos[i+1]; `n`"g<K)Q  
} eQFb$C]R}y  
nEndPos[nEndPos.length-1] = nFileLength; 7TkxvSL X  
} vM7vf6  
} Y#&0x_Z  
{M r~%y4  
^2^|AXNES  
//启动子线程 5!F\h'E  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ZBmXaP[9  
for(int i=0;i<nStartPos.length;i++) #RM3^]h  
{ HNy/ -  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x8?x/xE  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5 n+ e  
nStartPos,nEndPos,i); {kPe#n>xT  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q{cp|#m#G  
fileSplitterFetch.start(); 3z)"U  
} r1oku0o  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $54=gRo^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <D!c ~*[  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /3Nb  
nEndPos = " + nFileLength); Pc)VK>.fc  
// fileSplitterFetch[nPos.length-1].start(); U2V^T'Y[  
g[s\~MF@s  
/^LH  
//等待子线程结束 *)bd1B#  
//int count = 0; B9e.-Xaf  
//是否结束while循环 |Vwc/9`t]>  
boolean breakWhile = false; 8.CKH4h  
f[Fgh@4cj  
)W]>\=@Y  
while(!bStop) 0^9:KZ.!  
{ }B"|z'u  
write_nPos(); _t|G@D{   
Utility.sleep(500); :,NFFN  
breakWhile = true; e" Eqi-  
qsihQ d  
x(9; !4O>  
for(int i=0;i<nStartPos.length;i++) Fkc x+d  
{ 1a&/Zlr  
if(!fileSplitterFetch.bDownOver) 5'X74`  
{ K)/!&{7n}a  
breakWhile = false; %e Sm&`  
break; y98JiNq  
} cXS;z.M\_  
} W""*hJ  
if(breakWhile)  O[IR|  
break; q*[!>\ Z8  
19F ;oFp  
RQ^m6)BTo  
//count++; CYtjY~  
//if(count>4) | "Jx  
// siteStop(); . QXG"R  
} > 'aG /(  
d $fvg8^  
X<~k =qwA  
System.err.println("文件下载结束!"); 7-".!M  
} 6[*;M  
catch(Exception e){e.printStackTrace ();} 4[TS4p  
} %'L].+$t  
djsz!$  
K/vxzHSl  
//获得文件长度 894r;UA7  
public long getFileSize() V(;55ycr  
{ m7r j>X Y  
int nFileLength = -1; W?qpnPW  
try{ x0\e<x9s  
URL url = new URL(siteInfoBean.getSSiteURL()); VY/|WD~"CW  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j-J(C[[9  
httpConnection.setRequestProperty("User-Agent","NetFox"); 48tcgFg[  
M*5,O   
`]`=]*d  
int responseCode=httpConnection.getResponseCode(); 17>5#JLP  
if(responseCode>=400) ]?0{(\  
{ Nfv="t9e  
processErrorCode(responseCode); K,f* SXM  
return -2; //-2 represent access is error \G$QNUU  
} 0 kf(g156  
+"cRhVR  
+ a-wv  
String sHeader; C-llq`(d  
c ]>DI&$;J  
.E+OmJwD  
for(int i=1;;i++) "jL1. 9%"  
{ tJ=3'?T_k  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (M ]XNn  
//Utility.log(in.readLine()); Dv<wge`  
sHeader=httpConnection.getHeaderFieldKey(i); AL>c:K)qO  
if(sHeader!=null) 2E$^_YT C  
{ 5>k>L*5J  
if(sHeader.equals("Content-Length")) wgY6D!Y   
{ 9p <:=T  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [34zh="o  
break; 1ZT^)/G  
} Wrmgu}q  
} 3A-*vaySV  
else >M?H79fF2s  
break; !|:RcH[  
} $hh+0hs  
} 8h2D+1,PZC  
catch(IOException e){e.printStackTrace ();} OmB TA=E<  
catch(Exception e){e.printStackTrace ();} ,H>W:O  
Z6 ;Wd_  
O\6vVM[  
Utility.log(nFileLength); B!eK!B  
oJ^C]E  
1p8:.1)q  
return nFileLength; ;0IvF#SJ(.  
} jcE Msc  
'KH lrmnr  
.iFViVZC  
//保存下载信息(文件指针位置) ^6Yd}  
private void write_nPos() 6\NvG,8  
{ -*?p F_*w  
try{ swt tp`  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]k[x9,IU\y  
output.writeInt(nStartPos.length); E W`W~h[  
for(int i=0;i<nStartPos.length;i++) jDR')ascn  
{ FJ{=2]x|  
// output.writeLong(nPos); jz*0`9&_  
output.writeLong(fileSplitterFetch.nStartPos); (~h7rAEc  
output.writeLong(fileSplitterFetch.nEndPos); BU`ckK\(  
} _ w/_(k  
output.close(); w4UD/zO  
} ^w.]Hd 2  
catch(IOException e){e.printStackTrace ();} ~p:?QB>1]  
catch(Exception e){e.printStackTrace ();} iC\%_5/ _  
} 4sTMgBzw  
j !`B'{cH  
ymYBm: "  
//读取保存的下载信息(文件指针位置) 'xIyGDe  
private void read_nPos() eH %Ja[  
{ u^t$ cLIZ  
try{ }MP>]8Aq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i0>]CJG  
int nCount = input.readInt(); tAERbiH  
nStartPos = new long[nCount]; OZf6/10O/  
nEndPos = new long[nCount]; =~&VdPZ  
for(int i=0;i<nStartPos.length;i++) :_v!#H)  
{ * r;xw  
nStartPos = input.readLong(); &=X.*H%  
nEndPos = input.readLong(); UbO4%YHt  
} e?b)p5g  
input.close(); $E\^v^LW  
} }Al YNEY  
catch(IOException e){e.printStackTrace ();} :|rPT)yT]  
catch(Exception e){e.printStackTrace ();} (-,>qMQs  
} TN\|fzj  
\w%@?Qik  
ziiwxx_  
private void processErrorCode(int nErrorCode) $#e1SS32  
{ c+g@Z"es  
System.err.println("Error Code : " + nErrorCode); ZIDbqQu  
} zyFUl%  
7CGyC[[T~  
.1#kD M  
//停止文件下载 [*Uu#9  
public void siteStop() Ab2Q \+,  
{ {e"dm5  
bStop = true;  lq>AGw  
for(int i=0;i<nStartPos.length;i++) \F{:5,Du)  
fileSplitterFetch.splitterStop(); "j^MB)YD  
 cG{L jt  
?IF)+]  
} q9]IIv  
} +.kfU)6@  
//负责部分文件的抓取 P6\6?am  
**FileSplitterFetch.java !Ms[eB  
*/ cj$d=k~  
package NetFox; ,eRQu.  
;j9\b9m  
ac8P\2{"  
import java.io.*; ok{!+VCB5  
import java.net.*; vUesV%9hq  
H,y4`p 0  
Gh\q^?}  
public class FileSplitterFetch extends Thread {  }ptq )p  
[0y$! f4  
Nd@~>&F  
String sURL; //File URL Uz dc  
long nStartPos; //File Snippet Start Position U*)m' ,  
long nEndPos; //File Snippet End Position Hy_;nN+e  
int nThreadID; //Thread's ID S1S;F9F  
boolean bDownOver = false; //Downing is over Ub amB+QT  
boolean bStop = false; //Stop identical 5Qh?>n>*  
FileAccessI fileAccessI = null; //File Access interface IzLQhDJ1  
g(|{')8?d  
\tN-(=T  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~*W!mlg  
{ {Ui =b+  
this.sURL = sURL; =] C]=  
this.nStartPos = nStart; 5jxQW ;  
this.nEndPos = nEnd; N<(.%<!  
nThreadID = id; nh>K`+>co  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m P'^%TE  
} w= P 9FxB  
6CbxuzYer  
C3NdE_E  
public void run() Yz$3;  
{ QPt Gdd  
while(nStartPos < nEndPos && !bStop) P [Uy  
{ Y!J>U  
XolZonJr  
<FI-zca  
try{ e [_m< e  
URL url = new URL(sURL); 6Htg5o|W  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4k-+?L!/G  
httpConnection.setRequestProperty("User-Agent","NetFox"); YuZ"s55zU{  
String sProperty = "bytes="+nStartPos+"-"; N- H^lqD  
httpConnection.setRequestProperty("RANGE",sProperty); l 'DsZ9y@2  
Utility.log(sProperty); @f]{>OS  
A+J*e  
w }^ I  
InputStream input = httpConnection.getInputStream(); ?`zXLY9q7  
//logResponseHead(httpConnection); } :=Tm]S  
n_ lo`  
&e-U5'(6v_  
byte[] b = new byte[1024]; r%:+$aIt  
int nRead; h\v'9  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,to+oSZE  
{ Tm_B^ W}  
nStartPos += fileAccessI.write(b,0,nRead); b2b?hA'k  
//if(nThreadID == 1) om?-WJI  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |sRipWh  
} Mi'8 ~J  
26T"XW'_  
8#!i[UF dj  
Utility.log("Thread " + nThreadID + " is over!"); ^uv<6  
bDownOver = true; mKo C.J  
//nPos = fileAccessI.write (b,0,nRead); [ i#zP  
} >SPh2[f  
catch(Exception e){e.printStackTrace ();} oF(Lji?m  
} ;qHOOT  
} `W/sP\3  
#Zrlp.M4  
=] *.ZH#h  
//打印回应的头信息 mU}F!J#6  
public void logResponseHead(HttpURLConnection con) 4jD2FFG- G  
{ {43>m)8+  
for(int i=1;;i++) Y%`xDI  
{ b[V^86X^  
String header=con.getHeaderFieldKey(i); A\8}|r(>9E  
if(header!=null) K2%w0ohC  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,^#yo6-  
Utility.log(header+" : "+con.getHeaderField(header)); KM^ufF2[  
else y~()|L[  
break; ")=X4]D  
} P#=`2a#G  
} 8 r_>t2$  
Aq3}Ng  
5^^XQ?"  
public void splitterStop() >jD[X5Y  
{ 4Y[1aQ(%  
bStop = true; (}}S9 K  
} W`c'=c  
M Y|w  
yX~v-N!X  
} s%<eD  
[l,Ei?  
3}e%[AKh  
/* ^o7;c[E`  
**FileAccess.java M)SEn/T-  
*//文件访问(定位,写) 8#vc(04(  
package NetFox; / X1 x  
import java.io.*; _a1x\,R|DB  
)"pF R4  
"~'b  
public class FileAccessI implements Serializable{ g)-bW+]q  
u*hSj)vr1  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >$4d7.^hb/  
RandomAccessFile oSavedFile; B ~OZ2-~  
long nPos; 720DV +o  
R?]02Q  
`]%|f  
public FileAccessI() throws IOException i>(e}<i  
{ wiiCd  
this("",0); ti#7(^j  
} -\C!I  
i-6 Z"b{  
~c\e'&sc;  
public FileAccessI(String sName,long nPos) throws IOException RsYU59_Y  
{ '3g[]M@M  
oSavedFile = new RandomAccessFile(sName,"rw"); "s{5O>  
this.nPos = nPos; <u2}i<#  
oSavedFile.seek(nPos); NU0g07"  
} F]<Xv"  
o_~eg8  
?nL.w  
public synchronized int write(byte[] b,int nStart,int nLen) t2)rUWg  
{ , N)/w1?I  
int n = -1; &G-!qxe  
try{ /HaHH.e  
oSavedFile.write(b,nStart,nLen); xoN3  
n = nLen; <*qnY7c&N;  
} #?S^kM-0  
catch(IOException e) 6ZP"p<xX  
{ Q637N|01  
e.printStackTrace (); `G}TG(  
} `7r@a  
maNl^i  
3eF -8Z(f  
return n; sc}~8T  
} Sn|BlXrey  
X<I+&Zi  
X"fb;sGT  
} 5;YMqUkw  
Ck) * &  
H*r)Z 90  
/* 4GX-ma,  
**SiteInfoBean.java  B\o Mn  
*/ C)`Fv=]R  
package NetFox; 85LAY aw  
MB~=f[cUnd  
 A|<jX}  
public class SiteInfoBean { C@'h<[v`1v  
N u<_}  
o%IA}e7PAa  
private String sSiteURL; //Site's URL {y_98N  
private String sFilePath; //Saved File's Path )!P)U(*v  
private String sFileName; //Saved File's Name : qd`zG3  
private int nSplitter; //Count of Splited Downloading File JPoN&BTCj  
~=uWD&5B4  
,Vt/(x-  
public SiteInfoBean() K/|Z$4S  
{//nSplitter的缺省值为5 x$6^R q>2  
//default value of nSplitter is 5 vzim<;i  
this("","","",5); E2Q[ZoVS  
} !1$])VQWI  
~Vr.J}]J  
)p<ExMIxd  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~?K~L~f5  
{ 0.8  2kl  
sSiteURL= sURL; }&w Ur>=  
sFilePath = sPath; &E.^jR~*  
sFileName = sName; ewctkI$,5  
this.nSplitter = nSpiltter; +JjW_Rl?=V  
n[lJLm^(_C  
^\4h<M  
} z=q3Zo  
iO|se:LY<  
i OW#>66d  
public String getSSiteURL() Ab{ K<:l  
{ 9_Be0xgJ3^  
return sSiteURL; 2AT5  
} H|3:6x  
Uq^#riq  
zh8nc%X{  
public void setSSiteURL(String value) [YlKR'_  
{ [XEkz#{  
sSiteURL = value; ;DFSzbF`  
} 21K>`d\  
`4=^cyt+  
1_PoqD!q  
public String getSFilePath() &,{fw@#)_  
{ <G|(|E1  
return sFilePath; fF7bBE)L/|  
} `d5%.N  
RI(DXWM|h  
9]f!'d!5  
public void setSFilePath(String value) tX_R_]v3  
{ a7r%X -  
sFilePath = value; D1zBsi94D  
} p@xf^[50k  
_m5uDF?[  
_Kl_61k  
public String getSFileName() Enum/O5  
{ %4et&zRC  
return sFileName; J^SdH&%Z  
} J;.wXS_U8  
4|riKo)  
E8$20Ue  
public void setSFileName(String value) /Z'L^ L%R  
{ "{@A5A  
sFileName = value; 9K{%vK  
} 47+&L   
JtYP E?  
IzikDc10  
public int getNSplitter() )dbB =OZ  
{ GpY"f c%  
return nSplitter; Pg,b-W?n*  
} 6Ypc`  
E ~Sb  
$q6BP'7  
public void setNSplitter(int nCount) /uPcXq:L~  
{ 8!O5quEc  
nSplitter = nCount; uwzvbgup?  
} }vxw*8d?  
} ~zCEpU|@N  
-JMdE_h  
{.?ZHy\Rk  
/* *H"B _3<n  
**Utility.java -]/I73!b  
*/ #lmB AL~3  
package NetFox; >`Y.+4 mE  
^Cu\VV  
?pr9f5  
public class Utility { IUE~_7  
j9eTCJqB  
-+(jq>t  
public Utility() [#-b8Cu  
{ @L<*9sLWh  
7Ri46Tkt  
Xe6w|  
} .k,1f*%  
RDW8]=uM  
//线程睡眠 )97SnCkal  
public static void sleep(int nSecond) `eE&5.   
{ Y-kt.X/Z-  
try{ Zn&, t &z  
Thread.sleep(nSecond); Sg&UagBj  
} ^o^H3m  
catch(Exception e) >80;8\  
{ HW3 }uP\c  
e.printStackTrace (); )j9SGLo  
} hL/)|N~  
} xSktg]u Se  
m+`fn;*  
//日志 w~(1%p/  
public static void log(String sMsg) .L9j>iP9 *  
{ 7mI:| G  
System.err.println(sMsg); D^yRaP*|7  
} QS%%^+E2  
nygbt<;?  
K&vF0*gN3  
public static void log(int sMsg) R<\F:9  
{ RN$1bxY  
System.err.println(sMsg); d/PiiiFf,  
} x'+T/zw  
} |jI#"LbF  
xf<at->  
mw_~*Nc'9  
/* 5's87Z;6  
**TestMethod.java a|%J=k>>  
*/ 9>l*lCA  
package NetFox; Ov 5"  
+ln9c  
^V?<K.F  
public class TestMethod { ^8 zR  
rf $QxJ  
o)Iff)m$  
public TestMethod() Li!Vx1p;u.  
{ ///xx/weblogic60b2_win.exe )m`<H>[Eb=  
try{ Rn}l6kbM  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gp5_Z-me  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C"6?bg5N  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^N7e76VwR  
fileFetch.start(); AP68V  
} x.7]/)  
catch(Exception e){e.printStackTrace ();} ;XF:\<+  
cJ{ Nh;"  
sx7eC  
} &ib5* 4!  
,5i`-OI  
W#^2#sjO  
public static void main(String[] args) 0 t Fkd  
{ dCE0$3'5  
new TestMethod(); < vL,*.zd  
} 1;C+$  
} =Q+;=-1  
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