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http断点续传简单实现(java)

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/* B=& [Z2  
**SiteFileFetch.java B?=R= p  
*/ 1bCE~,tD  
package NetFox; !6=;dX  
import java.io.*; &|GH@^)@  
import java.net.*; DX>LB$dy?  
S W%>8  
-@"3`uv"  
public class SiteFileFetch extends Thread { [+dCA  
=JzzrM|V*  
~Dq-q6-@t  
SiteInfoBean siteInfoBean = null; //文件信息Bean ?j.a>{  
long[] nStartPos; //开始位置 Q!@M/@-Ky  
long[] nEndPos; //结束位置 |ffHOef  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 K?' m#}]  
long nFileLength; //文件长度 =+MF@ 4  
boolean bFirst = true; //是否第一次取文件 -^CW}IM{ I  
boolean bStop = false; //停止标志 M1-tRF  
File tmpFile; //文件下载的临时信息 sPvs}}Z]P  
DataOutputStream output; //输出到文件的输出流 2[+.* Ef  
pxTtV g.  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ;QXg*GNAv$  
public SiteFileFetch(SiteInfoBean bean) throws IOException <$z[pw<  
{ #C&';HB;y  
siteInfoBean = bean; s_NY#MPz[  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); X1.-C@o  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); '2lzMc>wvP  
if(tmpFile.exists ()) 0<!9D):Bb  
{ q& -mbWBj  
bFirst = false; PljPhAce  
read_nPos(); ) Su>8f[?e  
} qP#LJPaS  
else ~Yk^(hl2  
{ x;u#ec4  
nStartPos = new long[bean.getNSplitter()]; r4SwvxhG  
nEndPos = new long[bean.getNSplitter()]; JHa1lj  
} L.'61ZU  
w gS'/  
z Fm`e:td  
V_J0I*Qa4  
} &!X<F,  
_F6<ba}o3  
1!MJ+?Jl  
public void run() f )T\  
{ -\f7qRW^U  
//获得文件长度 #17 &rizl  
//分割文件 :VlA2Ih&q  
//实例FileSplitterFetch iRsB|7v[,  
//启动FileSplitterFetch线程 -z`FKej   
//等待子线程返回 jSE)&K4nI  
try{ .J O3#  
if(bFirst) gdf0  
{ EO)JMV?6  
nFileLength = getFileSize(); (1D1;J4g  
if(nFileLength == -1) A)]&L`s  
{ MygAmV&  
System.err.println("File Length is not known!"); 9 fB|e|  
} ' 9f0UtT|[  
else if(nFileLength == -2) JyE-c}I  
{ xcW\U^1d  
System.err.println("File is not access!"); #G]IEO$M6  
} 5eff3qrH{  
else BC.3U.  
{ p"%D/-%Gu  
for(int i=0;i<nStartPos.length;i++) qBBCnT  
{ 0QZT<Zs  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); X|{Tljn  
} )]C]KB  
for(int i=0;i<nEndPos.length-1;i++)  aO<7a 6  
{ hc q&`Gun  
nEndPos = nStartPos[i+1]; 8C*@d_=q  
} WBWW7HK  
nEndPos[nEndPos.length-1] = nFileLength; ]?=87w  
} " 7^nRJy  
} p\ =T#lb  
*xNc^ &.  
wx3_?8z/O  
//启动子线程 1}\p:`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3Sfd|0^  
for(int i=0;i<nStartPos.length;i++) k^%=\c  
{ 8<Iq)A]'Z  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), % vUU Fub  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I9qZE=i  
nStartPos,nEndPos,i); gP QOv  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $}W T"K  
fileSplitterFetch.start(); sr;&/l#7h  
} >ZOlSLu  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5m~9Vl-&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gaz7u8$A=  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }2;P`s  
nEndPos = " + nFileLength); b69nj  
// fileSplitterFetch[nPos.length-1].start(); N0w?c 5>  
O+o)z6(  
nvrh7l9nX  
//等待子线程结束 ^.LB(GZ,  
//int count = 0; j<(E %KN3  
//是否结束while循环 fU|v[  
boolean breakWhile = false; .S|7$_9;b  
sn:VMHrOT  
M99ku'  
while(!bStop) 6m?<"y8]  
{ ,VVA^'+  
write_nPos(); hb; CpA  
Utility.sleep(500); D?_K5a&v,  
breakWhile = true; "G@K(bnHn  
l0,VN,$Yl  
y5eEEG6  
for(int i=0;i<nStartPos.length;i++) B%\&Q @X  
{ _\\Al v.  
if(!fileSplitterFetch.bDownOver) ]\^O(BzB  
{ Nt $4;  
breakWhile = false; ]Y I9  
break; u1X^#K$nu'  
} 9o>D Uc  
} CPy>sV3Ru0  
if(breakWhile) Z4/D38_  
break; &/U fXKr  
+45SKu=  
c~(61Sn]  
//count++; q{&c?l*2  
//if(count>4) D-{*3?x  
// siteStop(); lW| =rq-|  
} )$S=iL8(  
C1NU6iV^z  
Xsa8YP9  
System.err.println("文件下载结束!"); PyfWIU7O  
} =OF hM7  
catch(Exception e){e.printStackTrace ();} Q$5 t~*$`  
} 4\-11!'08  
=?C <@  
k( 0;>)<i  
//获得文件长度 nRBS&&V  
public long getFileSize() :^kAFLU  
{ )$TN%hV!  
int nFileLength = -1; \Vx^u}3O  
try{ FQO=}0Hl  
URL url = new URL(siteInfoBean.getSSiteURL()); nlB'@r  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v Z]j%c@  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4o}{3 ! m  
n}a`|Nbk  
A4f"v)vM  
int responseCode=httpConnection.getResponseCode(); =%~- M  
if(responseCode>=400) ftRFG  
{ dGk"`/@  
processErrorCode(responseCode); }T$BU>z33N  
return -2; //-2 represent access is error K/*R}X  
} Q*<KX2O  
7<WUj K|  
A2gFY}  
String sHeader; ;l!<A  
3H!]X M  
i_N8)Z;r  
for(int i=1;;i++) CsZm8oL$  
{ Mbxl{M >  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fCUx93,>z  
//Utility.log(in.readLine()); 15jQ87)  
sHeader=httpConnection.getHeaderFieldKey(i); )dfhy  
if(sHeader!=null) t[2b~peNI  
{ }Ecv6&G  
if(sHeader.equals("Content-Length")) K*5gb^Ul  
{ f@;pN=PS  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g "Du]_,  
break; uEb:uENk'(  
} VLm\PS   
} yJ!26  
else ~4+Y BN  
break; 'sI ne>  
} O W.CU=XU  
} w98M #GqV  
catch(IOException e){e.printStackTrace ();} VX8rM!3  
catch(Exception e){e.printStackTrace ();} 1_{e*=/y  
H4`>B>\  
.pPuBJL]<  
Utility.log(nFileLength); b|AjB:G  
wzy[sB274  
-KC@M  
return nFileLength; @}6<,;|DQ  
} 1P"7.{  
W)ug %@)  
2 )o2d^^  
//保存下载信息(文件指针位置) Ut2T:%m{  
private void write_nPos() qZ!kVrmg&  
{ ykbfK$j z  
try{ T&[6  
output = new DataOutputStream(new FileOutputStream(tmpFile)); bxYSZCo*  
output.writeInt(nStartPos.length); mQ1  
for(int i=0;i<nStartPos.length;i++) U<&=pv  
{ ]a/dvj}  
// output.writeLong(nPos); 5xr>B7MRM?  
output.writeLong(fileSplitterFetch.nStartPos); hkl0N%[  
output.writeLong(fileSplitterFetch.nEndPos); &Y1h=,KR9  
} f 4pIF"U9>  
output.close(); ZgEV-.>P  
} =LLpJ+  
catch(IOException e){e.printStackTrace ();} 5rLx b  
catch(Exception e){e.printStackTrace ();} fUf 1G{4  
} 6 9$R.  
ZhCd**  
1/mBp+D  
//读取保存的下载信息(文件指针位置) Sydl[c pH$  
private void read_nPos() W3[>IH"+  
{ {f/]K GGk  
try{ %1p-DX6  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <m\Y$Wv  
int nCount = input.readInt(); xkFa  
nStartPos = new long[nCount]; 3(K.:376  
nEndPos = new long[nCount]; 8!35 K  
for(int i=0;i<nStartPos.length;i++) Vp; `!+z"  
{ rF[-4t %  
nStartPos = input.readLong(); c*\i%I#f2  
nEndPos = input.readLong(); sHPAr}14  
} >x%HqP#_V  
input.close(); >y8>OJ?A7-  
} )6%*=-  
catch(IOException e){e.printStackTrace ();} }=f\WWJf0  
catch(Exception e){e.printStackTrace ();} L44|/~  
} ~6t<`&f  
#Ev}Gf+5Q  
fr`#s\JKw  
private void processErrorCode(int nErrorCode) [@/p 8I  
{ 0.+Eo.AX4M  
System.err.println("Error Code : " + nErrorCode); i?d545. u  
} 0;LF>+fJ  
XSof{:V  
xKBi".wA  
//停止文件下载 U*{0,Ue'  
public void siteStop() W2-l_{  
{ A?04,l]y  
bStop = true; G)YmaHeI;[  
for(int i=0;i<nStartPos.length;i++) - s'W^(  
fileSplitterFetch.splitterStop(); Q'jGNWep  
eXsp0!v  
~rI2 RJ  
} *MfH\X379  
} mEYfsO  
//负责部分文件的抓取 9[\do@  
**FileSplitterFetch.java :I"2 2EH  
*/ TT9 \m=7  
package NetFox; k;<@ 2C  
,V j&  
:55a9d1bL  
import java.io.*; RLex#j  
import java.net.*; 13 L&f\b  
2V;{@k  
z2Wblh"_  
public class FileSplitterFetch extends Thread {   +fM8  
G"3KYBN>  
AW \uE[kg  
String sURL; //File URL 2sgp$r  
long nStartPos; //File Snippet Start Position VDv.N@ ) 7  
long nEndPos; //File Snippet End Position zk3\v "  
int nThreadID; //Thread's ID 28M^ F~0  
boolean bDownOver = false; //Downing is over 45wqX h  
boolean bStop = false; //Stop identical _~tF2`,Y_p  
FileAccessI fileAccessI = null; //File Access interface Ha]vG@?+  
416}# Mk  
#k/T\PQ0s  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }LS.bQKqi,  
{ +68age;dM  
this.sURL = sURL; 6qmV/DL  
this.nStartPos = nStart; nF]E":  
this.nEndPos = nEnd; %OHWGac"i  
nThreadID = id; Tt{X(I} J  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GMZ6 dK  
} s^6,"C  
2N |iOog  
ODKh/u_  
public void run() V/DMkO#a  
{ };}N1[D   
while(nStartPos < nEndPos && !bStop) dm_Pz\ *  
{ qp*~  |  
%L)QTv/  
BE&8E\w  
try{ )mAD<y+  
URL url = new URL(sURL); JgHYuLB  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6)=;cc{Vr  
httpConnection.setRequestProperty("User-Agent","NetFox"); 6NyUGGRq  
String sProperty = "bytes="+nStartPos+"-"; O%bltNEx1  
httpConnection.setRequestProperty("RANGE",sProperty); NMg(tmh  
Utility.log(sProperty); ~ m vv :u  
n(LO`{  
[vuikJP>1k  
InputStream input = httpConnection.getInputStream(); _qOynW  
//logResponseHead(httpConnection); H/ ejO_{  
=Gj~:|;$  
OcpvY~"Pr  
byte[] b = new byte[1024]; 4_2oDcdf  
int nRead; {C?$osrr  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m@I}$  
{ je#LD  
nStartPos += fileAccessI.write(b,0,nRead); Omn $O>  
//if(nThreadID == 1) hxJKYU^%m  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +3AX1o%p,#  
} QTF1~A\  
HnFH|H<Uf  
QA~F  
Utility.log("Thread " + nThreadID + " is over!"); L{;Q6_m  
bDownOver = true; Z s| *+[  
//nPos = fileAccessI.write (b,0,nRead); (I;81h`1G  
} kuLur)^  
catch(Exception e){e.printStackTrace ();}   h)W#  
} IcqzMm b  
} zA|lbJz=GY  
=d~pr:.F  
3 %r*~#nz  
//打印回应的头信息 A? jaS9 &)  
public void logResponseHead(HttpURLConnection con) :.BjJ2[S  
{ ; %AgKgV  
for(int i=1;;i++) Rq",;,0ZJ  
{ MVQ6I/EA4  
String header=con.getHeaderFieldKey(i); =D?HL?  
if(header!=null) zmuR n4Nv  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MYxuQ|w  
Utility.log(header+" : "+con.getHeaderField(header)); DuAix)#FN9  
else pnuwj U-  
break; N5#j}tT  
} ,G?Kb#  
} P A*U\  
Q>\DM'{:4  
,0nrSJED  
public void splitterStop() d7&d FvG  
{ Ps 0<CUyI  
bStop = true; eLHhfu;k  
} x}` )'a[  
m,6u+Z ,  
E)p[^1WC  
} ^xgPL'  
BlT)hG(M>  
H8@z/  
/* *U\`HUW  
**FileAccess.java 7FaF]G  
*//文件访问(定位,写) })PU`?f  
package NetFox;  C !v%6[  
import java.io.*; BGH'&t_5  
KG(l=? N  
#IqRu:csp  
public class FileAccessI implements Serializable{ V!@6Nv  
FSkX95  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6"[,  
RandomAccessFile oSavedFile; ?caHS2%?ae  
long nPos; _x$Eq: i  
6I _4{  
Y2ON!Rno  
public FileAccessI() throws IOException v$;URF%^  
{ a 7b1c!  
this("",0); U: <  
} J*%IvRg  
3F6A.Ny  
&`]T# ">  
public FileAccessI(String sName,long nPos) throws IOException RA+M.  
{ X}QcXc.d  
oSavedFile = new RandomAccessFile(sName,"rw"); [oXr6M:  
this.nPos = nPos; @L607[!?  
oSavedFile.seek(nPos); 8{&.[S C7  
} %l%2 hvGZ  
?d3<GhzlR3  
w&hCt c  
public synchronized int write(byte[] b,int nStart,int nLen) [%Z{Mp'g  
{ @o<B>$tbu4  
int n = -1; VGCd)&s  
try{ &[PA?#I`  
oSavedFile.write(b,nStart,nLen); E3CwA8)k  
n = nLen; KNF{NFk  
} )C0I y.N-  
catch(IOException e) *xx)j:Sc2  
{ r0\C2g_X  
e.printStackTrace (); {8;}y[R  
} B1Z;  
-" r4  
]h`d>#Hw!  
return n; 1p-<F3;  
} qckRX+P`  
(II#9 n)  
OwDwa~  
} (enOj0  
%bG\  
']^]z".H  
/* \mt Y_O  
**SiteInfoBean.java `Xi)';p  
*/ bXM&VW?OP  
package NetFox; \4fuC6d2  
%_39Wa  
['6Sq@c)  
public class SiteInfoBean { NUuIhB+  
YQ1rS X3  
%r(qQM.Pl  
private String sSiteURL; //Site's URL SapVS*yx@  
private String sFilePath; //Saved File's Path Cs vwc%  
private String sFileName; //Saved File's Name X7?14W  
private int nSplitter; //Count of Splited Downloading File -2C^M> HZ  
f$?`50D"1  
pG v*{.  
public SiteInfoBean() |$GPJaNqa  
{//nSplitter的缺省值为5 Hr}\-$  
//default value of nSplitter is 5 GJF ,w{J  
this("","","",5); S[l z>I  
} 2c*}1 _  
Q} -YD.bx3  
Uw)B(;Hy?  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter)  T#Z#YMk  
{ O_DT7;g  
sSiteURL= sURL; m_;XhO  
sFilePath = sPath; 16~5;u  
sFileName = sName; W6u(+P]("  
this.nSplitter = nSpiltter; ?. L]QU  
TyR@3H  
&TN.6Hm3  
} 4dI`  
b>} )G7b}  
i\K88B&24  
public String getSSiteURL() ,nUovWN07  
{ Q[T)jo,j%  
return sSiteURL; Yic4|N?u  
} Gy'/)}}Z  
|B2>}Y/  
BG1hk!  
public void setSSiteURL(String value) MTbCL53!-  
{ y8v0>V0)  
sSiteURL = value; a\p`J9Z@  
} vhU#<59a1  
BGstf4v>A<  
gU@R   
public String getSFilePath() Iqj?wI 1)  
{ @k-GyV-v  
return sFilePath; <yw=+hz[u  
} ,GtN6?  
JUq7R%"h6  
+N|t:8qaf  
public void setSFilePath(String value) ndvt $*  
{ AFsYP/g]  
sFilePath = value; MJn=  
} NMN&mJsmh  
^>y|{;`  
\rH0=~F-P  
public String getSFileName() 0p*Oxsy  
{ w)>/fG|;  
return sFileName; :{-/b  
} FlbM(ofY  
e "Tr0k  
3_J({  
public void setSFileName(String value) }AS3]Lub@  
{ 8(!?y[  
sFileName = value; h~Z:YY)4  
} ^jk-GRD*  
rFW,x_*_vP  
kr44@!s+'  
public int getNSplitter() FJsM3|{2=d  
{ UQBc$`v  
return nSplitter; T4;gF6(0]  
}  ]C-a[  
]1q`N7  
#V@vz#bo=  
public void setNSplitter(int nCount) fDChq[LAn  
{ T>5N$i  
nSplitter = nCount; Ye/Y<Ij  
} %(r.`I$  
} h9&0"LHr  
A%EGu4  
}#Kl6x  
/* w!Ii   
**Utility.java `pd+as  
*/ J c:j7}OOV  
package NetFox; jZ<f-Ff0  
.6iJ:A6T  
P#,g5  
public class Utility { 80LN(0?x  
2KNs,4X@  
Et;Ubj"+  
public Utility() j__l'?s  
{ [-nPHmZV[  
G;J!3A;TE  
h- %RSei5  
} X $SXDb~G  
[qxDCuxq  
//线程睡眠 6D4 j];~X  
public static void sleep(int nSecond) 6PMu*-Nv!j  
{ ca:Vdrw`  
try{ M"ZeK4qh  
Thread.sleep(nSecond); F^!_!V B  
} ;4*mUD6  
catch(Exception e) W"D>>]$|u  
{ xHlO~:Lc  
e.printStackTrace (); p7,dl*'  
} +GNXV-S  
} [XD3}'Aa  
fLuOxYQbf  
//日志 )24 1-b V  
public static void log(String sMsg) + $Lc'G+:  
{ Rab7Y,AA  
System.err.println(sMsg); 6I\4Yv$N  
} t28 y=nv  
`Oe}OSxnT  
p$$0**p!`  
public static void log(int sMsg) t'HrI-x  
{ ,'@t .XP  
System.err.println(sMsg); Nkk+*(Z  
} jB\Knxm v  
} .:Zb~  
(l)r.Vj  
Jwbb>mB!  
/* 1sXVuto  
**TestMethod.java T{*!.+E  
*/ W"5VqN6v  
package NetFox; S8;5|ya  
T{lK$j  
^7Z.~A y  
public class TestMethod { Y-]Ne"+vf  
vgKdhN2kI  
>2#F5c67  
public TestMethod() +QEiY~i  
{ ///xx/weblogic60b2_win.exe YvFt*t  
try{ 69zMWuY  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w[/m:R?eX  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ynZfO2kf  
SiteFileFetch fileFetch = new SiteFileFetch(bean); dK7BjZTJo  
fileFetch.start(); !eD f}~  
} =gO4B-[  
catch(Exception e){e.printStackTrace ();} 1*OZu.NdK  
A7aW]  
]J.|XRp/  
} !InC8+be  
77%I%<#  
%"AB\lL.  
public static void main(String[] args) :Gf  
{ KOhIk*AC '  
new TestMethod(); ?rQIUP{D7  
} !Gh*Vtd8-  
} f+4j ^y}  
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