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http断点续传简单实现(java)

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/* y$6m|5  
**SiteFileFetch.java a.P7O!2Lp  
*/ _-^bAr`z  
package NetFox; 1J8okBhZ  
import java.io.*; 8?ig/HSt2  
import java.net.*; C@!C='b,  
z}I4m  
e[txJ*SuO  
public class SiteFileFetch extends Thread { SplEY!.k  
gFk~SJd  
`-)!4oJ]  
SiteInfoBean siteInfoBean = null; //文件信息Bean l=(4o4um  
long[] nStartPos; //开始位置 y+3< ] N  
long[] nEndPos; //结束位置 ~ Iin|  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 J;Y=o B  
long nFileLength; //文件长度 K-D{Z7J^l  
boolean bFirst = true; //是否第一次取文件 AvW2)+6G  
boolean bStop = false; //停止标志 G2#={g{  
File tmpFile; //文件下载的临时信息 /_Z--s> j  
DataOutputStream output; //输出到文件的输出流 HsA4NRF'7  
u\~dsD2)q  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) r;3{%S._  
public SiteFileFetch(SiteInfoBean bean) throws IOException @^g/`{j>J  
{ Jw%0t'0Zi  
siteInfoBean = bean; #BA=?7  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); bMT1(edm  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); Jt4&%b-T  
if(tmpFile.exists ()) 6"+/Imb-  
{ U`gQ7  
bFirst = false; S}=d74(/n  
read_nPos(); T &.ZeB1  
} \^<eJf D  
else eow6{CD8  
{ _D%aT6,G+(  
nStartPos = new long[bean.getNSplitter()]; KA)9&6  
nEndPos = new long[bean.getNSplitter()]; L_fu<W  
} yKJKQ9  
o K;.|ja  
>T*/[{L8;  
U68o"iE  
} lR5< G  
;XFo:?  
H,r>@Y  
public void run() w+ZeVZv!r  
{ N?!]^jI,  
//获得文件长度 q,k/@@Qd9  
//分割文件 qTM,'7Rwn  
//实例FileSplitterFetch KPGo*mY  
//启动FileSplitterFetch线程 SrMg=a  
//等待子线程返回 BMlnzi  
try{ Lf+M +^l  
if(bFirst) md`PRZzj@  
{ 0(A(Vb5J.T  
nFileLength = getFileSize(); y%.^| G  
if(nFileLength == -1) an+`>}]F  
{ lq2P10j@  
System.err.println("File Length is not known!"); b!W!Vvf^x  
} HCP' V  
else if(nFileLength == -2) ~Yrtz   
{ `<I+(8]Uz  
System.err.println("File is not access!"); ya7/&Z )0  
} 8BUPvaP<[  
else  m9My  
{ '~?\NeO=  
for(int i=0;i<nStartPos.length;i++) 32[lsU>1  
{ zyNg?_SM  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); N*.JQvbnr  
} zZ3Ko3L%g_  
for(int i=0;i<nEndPos.length-1;i++) V+7x_>!&)  
{ GC(:}e|  
nEndPos = nStartPos[i+1]; eil"1$k  
} 83,ATQg  
nEndPos[nEndPos.length-1] = nFileLength; &Q7vY  
} ?nOul}y/  
} 2/.E uf   
n6T@A;_g  
iU^KmM I  
//启动子线程 DgOO\  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h+o-h4X  
for(int i=0;i<nStartPos.length;i++) s53 Pw>f  
{ h WvQh  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `usX(snY  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1#H=<iJ  
nStartPos,nEndPos,i); *QAcp` ;*  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,v;P@RL|g  
fileSplitterFetch.start(); 6 /8?:  
} E? > ERO3  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W7 9wz\a  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7hPiPv  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", > %5<fK2  
nEndPos = " + nFileLength); +o]DT7W  
// fileSplitterFetch[nPos.length-1].start(); -3 .Sr|t  
b(8#*S!U  
Yj+p^@{S2P  
//等待子线程结束 OZ2gIK  
//int count = 0; n_[;2XQQ  
//是否结束while循环 @ToY,@]e  
boolean breakWhile = false; Kj| l]'  
OQt_nb#z`{  
Ogp Zwwk  
while(!bStop) ?Rlo<f:Mf  
{ @1_M's;  
write_nPos(); HyKvDJ 3_  
Utility.sleep(500); ay}} v7)GM  
breakWhile = true; };5d>#NK,Y  
v8Ga@*  
LadE4:oy  
for(int i=0;i<nStartPos.length;i++) eH.~c3o  
{ 2H7b2%  
if(!fileSplitterFetch.bDownOver) R pUq#Y:a  
{ 3 o=R_%r  
breakWhile = false; r(g:b ^S  
break; e nsou!l  
} 15NeC7GAh  
} @edx]H1~^  
if(breakWhile) p*F.WxB)4  
break; 49vKb(bz{  
neN #Mo'A  
QDO.&G2  
//count++; }=.:bwX5  
//if(count>4) Gt >*y.]  
// siteStop(); A.0eeX{  
} Bf {h\>q  
mUFg(;ya  
`;?`XC"m  
System.err.println("文件下载结束!"); HV_5 +  
} QahM)Gb  
catch(Exception e){e.printStackTrace ();} /l o;:)AiP  
} )YSS>V  
$9LI v  
9|y?jb5im  
//获得文件长度 -_<rmR[:]  
public long getFileSize() E?,O>bCJ5  
{ 6|h~pH  
int nFileLength = -1; Yz6+ x]  
try{ >"}z % #  
URL url = new URL(siteInfoBean.getSSiteURL()); J['pBlEb\  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (e,5 b  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1?6zsA%N  
pAZD>15l"  
t|/{oAj  
int responseCode=httpConnection.getResponseCode(); ~yrEB:w`_  
if(responseCode>=400) HN7C+e4U~  
{ s48 { R4  
processErrorCode(responseCode); 2h:*lV^  
return -2; //-2 represent access is error ak_&\'P  
} 0+H4sz%.  
wtm=  
)HaW# ,XB  
String sHeader; m+Um^:\jX  
3b9SyU2  
Tj[=E  
for(int i=1;;i++) P LHiQ:  
{ NG)Xk[q4  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qv v~nGq$  
//Utility.log(in.readLine()); Ms * `w5n  
sHeader=httpConnection.getHeaderFieldKey(i); fWutB5?P  
if(sHeader!=null) *=b# >//  
{ !Z0p94L  
if(sHeader.equals("Content-Length")) f_{O U E  
{ `XmT)C  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,)u7PMs  
break; ZSs)AB_Pe/  
} /E%r@Rui3$  
} f&ZFG>)6  
else 0P?\eoB@8  
break; aC2cyUuaN  
} rzk]{W  
} 8dBG ZwyET  
catch(IOException e){e.printStackTrace ();} ";>>{lYA.  
catch(Exception e){e.printStackTrace ();} &IZthJqV  
IegZ)&_n  
 ,xhB  
Utility.log(nFileLength); ue/GB+U  
^ y1P~4w?  
i!tF{'*%#  
return nFileLength; -_4ZT^.Lna  
} "&@v[O)!xu  
`3QAXDWE  
d^.@~  
//保存下载信息(文件指针位置) <}vult^  
private void write_nPos() Q r n^T  
{ VQMPs{tm  
try{ '9w.~@7  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~8htg8CZ`  
output.writeInt(nStartPos.length); Y*KHr`\C4  
for(int i=0;i<nStartPos.length;i++) F~C9,`#Wf@  
{ ~"t33U6  
// output.writeLong(nPos); L<` p;?   
output.writeLong(fileSplitterFetch.nStartPos); X (0`"rjg  
output.writeLong(fileSplitterFetch.nEndPos); Wu\szI"  
} mv0JD(  
output.close(); Kx@Papn|6  
} 7^3a296  
catch(IOException e){e.printStackTrace ();} A=+ |&+? t  
catch(Exception e){e.printStackTrace ();} i_KAD U&mP  
}  > h>  
hG8 !aJo  
R{X@@t9@  
//读取保存的下载信息(文件指针位置)  55<f  
private void read_nPos() $Qc`4x;N  
{ -9(9LU2  
try{ p^yuz (  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vnrP;T=^  
int nCount = input.readInt(); DNu^4#r  
nStartPos = new long[nCount]; #+ <"`}]N  
nEndPos = new long[nCount]; |oL}c!0vs  
for(int i=0;i<nStartPos.length;i++) iFi6,V*PRt  
{ 2/coa+Qkv]  
nStartPos = input.readLong(); M|l`2Hpe  
nEndPos = input.readLong(); B>!OW2q0D  
} ,Zs"r}G^  
input.close(); T`?{Is['(  
} ,o\-'   
catch(IOException e){e.printStackTrace ();} G5R"5d'  
catch(Exception e){e.printStackTrace ();} s>VpbJ3S  
} kg@Okz N%  
U11bQ4ak  
~53uUT|B  
private void processErrorCode(int nErrorCode) x_yQoae  
{ e=yQFzQT)  
System.err.println("Error Code : " + nErrorCode); K:osfd  
} w}`TJijl  
nB#m?hK  
?df*Y5I2  
//停止文件下载 n& j@7R  
public void siteStop() $}*bZ~  
{ , Ac gsC  
bStop = true; 2c Pd$j  
for(int i=0;i<nStartPos.length;i++) C(Bh<c0@  
fileSplitterFetch.splitterStop(); B]""%&! O  
Wvg+5Q  
-!~ T$}/F  
} I>(3\z4s  
} ^)|!nd  
//负责部分文件的抓取 ]V 4Fm{]  
**FileSplitterFetch.java p;P"mp\'  
*/ ,'KS:`m!  
package NetFox; ?c$z?QTMJ  
k /hD2tBLu  
de&*#O5  
import java.io.*; zOEdFU{x  
import java.net.*; R;6$lO8C&  
Tf|?j=f  
VN5UJ!$?J  
public class FileSplitterFetch extends Thread { 49gm=XPm  
Ui^~A  
^ |xSU_wa  
String sURL; //File URL a___SYl 'K  
long nStartPos; //File Snippet Start Position h}T+M BA%  
long nEndPos; //File Snippet End Position H;eGBVi  
int nThreadID; //Thread's ID e?V7<7$  
boolean bDownOver = false; //Downing is over 0pC}+ +  
boolean bStop = false; //Stop identical 9ozK}Cg4  
FileAccessI fileAccessI = null; //File Access interface ;$\?o  
y,.X5#rnX*  
CXe2G5  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YM:;mX5B  
{ W`qiPLk  
this.sURL = sURL; =}$YZuzmU  
this.nStartPos = nStart; p H5iv>H  
this.nEndPos = nEnd; |\ZsoA  
nThreadID = id; qId-v =L  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m,u5S=3A{!  
} l$1z%|I  
vLc7RL  
0c$0<2D%  
public void run() ?tf/#5t}  
{ em@bxyMm  
while(nStartPos < nEndPos && !bStop) _>6xU t  
{ sp/l-a  
V[w Y;wj  
':mw(`  
try{ lJ'. 1Z&  
URL url = new URL(sURL); Q?Y\WD  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1feZ`P ;  
httpConnection.setRequestProperty("User-Agent","NetFox"); {hXIP`  
String sProperty = "bytes="+nStartPos+"-"; 4)cQU.(*k  
httpConnection.setRequestProperty("RANGE",sProperty); XMR$I&;G8  
Utility.log(sProperty); w;=fi}<G|e  
A<1:vV  
[32]wgw+{1  
InputStream input = httpConnection.getInputStream(); |<Cz#| ,q  
//logResponseHead(httpConnection); 3k#?E]'  
ae&i]K;  
TIs~?wb$  
byte[] b = new byte[1024]; TpHvZ]c  
int nRead; d~G, *  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'V*ixK8R0  
{ ed=pRb  
nStartPos += fileAccessI.write(b,0,nRead); s!vvAD;\  
//if(nThreadID == 1) \NiW(!Z}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  ?^8CD.|  
} xb N)z  
 ]\qbe  
Eeumi#$Z   
Utility.log("Thread " + nThreadID + " is over!"); 2/T4.[`t  
bDownOver = true; k^JV37;bl  
//nPos = fileAccessI.write (b,0,nRead); c]eDTbXd  
} !4"!PrZDB  
catch(Exception e){e.printStackTrace ();} zq:+e5YT?T  
} 0ESxsba  
} e%Sw(=a  
a5)<roWQ  
up# R9 d|  
//打印回应的头信息 b`lLqV<[cB  
public void logResponseHead(HttpURLConnection con) ~x!"(  
{ y@T 0 jI  
for(int i=1;;i++) :RxWHh3O  
{ S .KZ)  
String header=con.getHeaderFieldKey(i); B7*^rbI:X  
if(header!=null) ?4[IIX-  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k\ 2.\Lwb  
Utility.log(header+" : "+con.getHeaderField(header)); $$,/F  
else C1x"q9| \`  
break; y7x&/2  
} BA5b;+o-  
} 8zOoVO  
Pl>BTo>p'  
A;06Zrf1  
public void splitterStop() b3zxiq x  
{ )P>}uK;  
bStop = true; &| d6  
} (=T%eJ61  
{mkD{2)KQ  
vFz#A/1  
} 4YT d  
oB$P6   
aw3 oG?3I  
/* [myIcLp^aP  
**FileAccess.java Xf"B\%,(`  
*//文件访问(定位,写) oZ /z{`  
package NetFox; snH9@!cG8  
import java.io.*; 0bcbH9) 1q  
(59u<F  
\qo}}I>e  
public class FileAccessI implements Serializable{ bW/^2B  
R)>F*GsR  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?}n\&|+  
RandomAccessFile oSavedFile; 19g-#H!  
long nPos; A~!v+W%vO1  
.!B>pp(9  
C{5bG=Sg~  
public FileAccessI() throws IOException R9!GDKts%  
{ ; xz}]@]Ar  
this("",0); O1 KT  
} Z ZMz0^V  
I?z*.yA*  
GY3g`M   
public FileAccessI(String sName,long nPos) throws IOException Hy*_4r  
{ W`d\A3v  
oSavedFile = new RandomAccessFile(sName,"rw"); T1([P!g*  
this.nPos = nPos; /Cl=;^)  
oSavedFile.seek(nPos); Gy3t   
} -Y{=bZS u  
pSPVY2qKX  
HgY>M`U  
public synchronized int write(byte[] b,int nStart,int nLen) )[Bl3+'  
{ CZ~%qPwDw  
int n = -1; $3BH82  
try{ p bT sn  
oSavedFile.write(b,nStart,nLen); ?kF_C,k/>N  
n = nLen; #cF ?a5  
} CkHifmc(u-  
catch(IOException e) Mqk[+n  
{ dB=aq34l  
e.printStackTrace (); qGYru1  
} pAm L  
U.kTdNSp  
gE}+`w/X  
return n; `nvm>u~[Hq  
} &y~~Z [.F,  
&l<~Xd#  
L+]|-L`S  
} 9?6]Z ag  
(9A`[TRwi  
jW!x!8=  
/* 5RUhrE   
**SiteInfoBean.java 5TB==Fj ?  
*/ i+Fk  
package NetFox; h%0FKi^  
,iy;L_N  
Z'V"nhL  
public class SiteInfoBean { y?}R,5k  
+Y9n@`  
#6'+e35^8  
private String sSiteURL; //Site's URL ;"1  
private String sFilePath; //Saved File's Path br[n5  
private String sFileName; //Saved File's Name H*H=a  
private int nSplitter; //Count of Splited Downloading File _-mJI+^/  
Ed^F_Gg#  
pn._u`xMV  
public SiteInfoBean() Fb^Ae6/i  
{//nSplitter的缺省值为5 X^% E"{!nU  
//default value of nSplitter is 5 $&@etsW0/  
this("","","",5); Bt?.8H6Y  
} JKMcdD?'  
`SN?4;N0  
yJMHm8OB7  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (e~vrSk+)~  
{ K;NaiRP#k  
sSiteURL= sURL; b~L8m4L  
sFilePath = sPath; mKh <M)Bz  
sFileName = sName; n?EL\B   
this.nSplitter = nSpiltter; Zi4Ektj2  
Kd%>:E*  
0D=7Mef  
} ZBf9Upg  
J nzI- y  
f|cF [&wo  
public String getSSiteURL() "?Mf%u1R  
{ ;<~lzfs  
return sSiteURL; xdV $dDCT  
} #2U4}#Mi  
rjJ-ZRs\  
1 xu2$x.b  
public void setSSiteURL(String value) w?db~"T  
{ uV'w0`$y  
sSiteURL = value; TXDb5ZCzM  
} HXg4 T  
]L?DV3N  
w*3DIVlxL  
public String getSFilePath() H5 'Le{  
{ w]Fi:kV  
return sFilePath; 4[$D3,A  
} 3~uWrZ.u  
 &9*MO  
R{hq1-  
public void setSFilePath(String value) d mj T$a|  
{ ?xgrr7  
sFilePath = value; N`Q[OFe  
} 0 3/ <A^  
)b_ GKA `  
::Nhs/B/  
public String getSFileName() 7Hm/ g  
{ `Y5{opG7-  
return sFileName; k"V@9q;*  
}  #VA8a=t  
*G,'V,?  
z#|#Cq`VG  
public void setSFileName(String value) ncy?w e  
{ ji~P?5(:  
sFileName = value; Z%uDz3I\Q"  
} C6neZng  
ly)b=ph&  
"~uo4n~H  
public int getNSplitter() G^ 2a<?Di  
{ wV,l }Xb-  
return nSplitter; ,7{}}l  
} df$VC  
nLfITr|5  
]rs7%$ZW  
public void setNSplitter(int nCount) \XUG-\$p  
{ ~_YU%y  
nSplitter = nCount; 5Tt%<#4  
} o3oAk10  
} ONkHHyT  
M\f1]L|8d  
4X prVB  
/* U'8ub(:&  
**Utility.java \1p_6U7  
*/ <X{hW^??)  
package NetFox; f/VrenZ_  
dLtn,qCX0^  
"Y7 ]t:8  
public class Utility { !83N. gN  
KC`~\sYRN]  
Q;3 v ]h_  
public Utility() 4GY:N6qe '  
{ tluyx  
L< gp "e  
iQI$Y]Y7  
} q|[P[7z  
yM8<)6=  
//线程睡眠 ^6Std x_  
public static void sleep(int nSecond) .$k2.-k  
{ mO UIGlv  
try{ O+o4E?}  
Thread.sleep(nSecond); jC)lWD  
} t[.wx.y&0  
catch(Exception e) njk1x  
{ y.LJ 5K$&a  
e.printStackTrace (); xGzp}   
} qhPvU( ,  
} V@(7K0  
ARZ5r48)  
//日志 l/JE}Eg(  
public static void log(String sMsg) zMXlLRC0  
{ :IZ(9=hs  
System.err.println(sMsg); ?rD`'B  
} Ifc}=:nr  
l{{wrU`  
,a$ ?KX  
public static void log(int sMsg) kUdl2["MZ  
{ nA\9UD<G.  
System.err.println(sMsg); 4l2xhx  
} es` A<  
} BE;J/  
JVORz-uBs  
#0hX'8];(  
/* nVTCbV  
**TestMethod.java _V9 O,"DDc  
*/ KXgC]IO~  
package NetFox; &tULSp@J  
}Ot I8;>  
G$5N8k[2  
public class TestMethod { + !I7(gL  
xz+Y1fYT  
$=c79Al(  
public TestMethod() NdS6j'%B@7  
{ ///xx/weblogic60b2_win.exe M=n_;3,o  
try{ 9\/T #EP  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J#0oL_xY#  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Kzs]+Cl  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,=9e]pQ  
fileFetch.start(); Dm=Em-ST6  
} G n_AXN  
catch(Exception e){e.printStackTrace ();} da[u@eNrnX  
uF!3a$4]  
yW$ja|^ E  
} pX:FXzYQ  
wXc"Car)  
ERW>G {+  
public static void main(String[] args) 93Yo }6>  
{ fwojFS.K  
new TestMethod(); [I;5V=bKW  
} 1GnT^u y/  
} &AMW?vO  
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