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http断点续传简单实现(java)

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/* &?(472<f**  
**SiteFileFetch.java 2 i:tPe&  
*/ geJO#;  
package NetFox; > a"4aYj  
import java.io.*; VU ,tCTXz  
import java.net.*; ("T8mt[w>  
6,j&u7  
Hr/3nq}.  
public class SiteFileFetch extends Thread { -h1FrDBt  
~9h/{$  
^h~oxZJw  
SiteInfoBean siteInfoBean = null; //文件信息Bean r3mQoTvnv  
long[] nStartPos; //开始位置 vI1UFD D  
long[] nEndPos; //结束位置 -$@4e|e%a  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 W;y ,Xs  
long nFileLength; //文件长度 g6l&;S40  
boolean bFirst = true; //是否第一次取文件 OaCp3No  
boolean bStop = false; //停止标志 eW.[M?,  
File tmpFile; //文件下载的临时信息 yr, Oq~e  
DataOutputStream output; //输出到文件的输出流 w W1>#F  
!dZpV~g0  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) <h[l)-86  
public SiteFileFetch(SiteInfoBean bean) throws IOException u(bPdf@kz  
{ 5l,Q=V^@l  
siteInfoBean = bean; Y&y5^nG  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 6fcn(&Qk  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [&H?--I  
if(tmpFile.exists ()) +E8}5pDt  
{  OYwH$5  
bFirst = false; ns;nle|m  
read_nPos(); 6S6E 1~  
} ^_o9%)RL(  
else ^iz2 =}Q8  
{ +~cW0z  
nStartPos = new long[bean.getNSplitter()]; $kCXp.#k@~  
nEndPos = new long[bean.getNSplitter()]; [2Rw)!N  
} xGVL|/?8  
I$vM )+v=  
9<Kc9Z  
lL]8~3b  
} &bw ``e&c  
XJ9bY\>)q1  
3GU JlFj  
public void run() o^b4l'&o  
{ 2 }HS`) /  
//获得文件长度 b{i7FRR>o4  
//分割文件 nd?R|._R  
//实例FileSplitterFetch -YfpfNt  
//启动FileSplitterFetch线程 jm$v0=W9#  
//等待子线程返回 3G9AS#-C  
try{ 7.DAwx.HYK  
if(bFirst) ~n $e  
{ Xh*p\ $  
nFileLength = getFileSize(); n]]!:jFC  
if(nFileLength == -1) ;zZGV4Qc~  
{ -f!oq7U  
System.err.println("File Length is not known!"); +ziQ]r2g  
} Tx!c }  
else if(nFileLength == -2) i[x;k;m2q  
{ i~04P  
System.err.println("File is not access!"); '.&z y#  
} .-W_m7&}  
else xs ^$fn\  
{ ecgGl,{  
for(int i=0;i<nStartPos.length;i++) n gC|BLT%h  
{ 2 - ?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); *q/oS8vavd  
} 5Zdxn>  
for(int i=0;i<nEndPos.length-1;i++) -+#g.1UL/  
{ 7<?~A6  
nEndPos = nStartPos[i+1]; Z-BPC|e  
} ;q6FdS  
nEndPos[nEndPos.length-1] = nFileLength; B\z4o\am%  
} #H1ng<QV  
} E%E3h1Ua  
g,seqh%  
5 LZ+~!2+  
//启动子线程 '5vgpmn  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; std4Nyp  
for(int i=0;i<nStartPos.length;i++) sG~5O\,E  
{ h0)Wy>B=,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Gj}P6V _  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), BHW8zY=F  
nStartPos,nEndPos,i); XCTee  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s]p3dB#  
fileSplitterFetch.start(); B{0m0-l  
} RO1xcCp  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (!0=~x|Z[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5$ra4+k0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e2 ?7>?  
nEndPos = " + nFileLength); !SFF 79$c  
// fileSplitterFetch[nPos.length-1].start(); <Hq|<^_K  
X(;,-7Jw  
T;u>]"S  
//等待子线程结束 BEv>?T 0  
//int count = 0; 8yDu(.Q  
//是否结束while循环 !Xbr7:UPN1  
boolean breakWhile = false; C$1}c[  
k^IC"p Uc  
XdDy0e4{%<  
while(!bStop) .CL\``  
{ fem>WPvG  
write_nPos(); ~Z'3(n*9  
Utility.sleep(500); |<n+6  
breakWhile = true; K8l|qe  
U_UX *  
. d;XLS~  
for(int i=0;i<nStartPos.length;i++) \HzI*|*A  
{ 'b* yYX<  
if(!fileSplitterFetch.bDownOver) <R.5 Ma  
{ N:y3tpG  
breakWhile = false; m-Uq6_e  
break; LI&+5`  
} 3PEv.hGx  
} ZMHb  
if(breakWhile) cI O7RD$8  
break; [7~ !M*o9  
JRm:hf'  
hK+Iow-  
//count++; P>dMET  
//if(count>4) 8W]6/st?]  
// siteStop(); pOCLyM9c  
} C#< :x!  
^fLePsmd  
]Xur/C2A  
System.err.println("文件下载结束!"); R18jju>Zr  
} ov=[g l  
catch(Exception e){e.printStackTrace ();} K>h=  
} 8gv \`  
aIv>X@U}  
T'cahkSw'O  
//获得文件长度 T #&9|  
public long getFileSize() L44/eyrp  
{ XF{ g~M  
int nFileLength = -1; Xz'pZ*Hr$v  
try{ 1Z +3=$P  
URL url = new URL(siteInfoBean.getSSiteURL()); [=Y@Ul  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1}C|Javkn  
httpConnection.setRequestProperty("User-Agent","NetFox"); k;w1y(  
`4RraJj>0~  
u6A ReL 'f  
int responseCode=httpConnection.getResponseCode(); IRemF@  
if(responseCode>=400) <|NP!eMsw8  
{ b<de)MG  
processErrorCode(responseCode); ?q(7avS9  
return -2; //-2 represent access is error Uj)~>V'  
} ,c@^u6a  
XHgwK @GU  
y#:_K(A" k  
String sHeader; :h tOz.  
P"J(O<(1-:  
4|uh&4"*@W  
for(int i=1;;i++) ysV0Ed  
{ k[]B P4  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (bxSN@hp2  
//Utility.log(in.readLine()); L\Uf+d:&}G  
sHeader=httpConnection.getHeaderFieldKey(i); =h?WT*  
if(sHeader!=null) y]B?{m``6  
{ [2UjY^\;T  
if(sHeader.equals("Content-Length")) )z/+!y  
{ ]A:n]mL  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C`z[25o  
break; ')w:`8Tl  
} !>g_9'n'  
} ty|E[Ez1  
else Ll%CeP  
break; 5Xu2MY=  
} %nQii? 1`i  
} c(. 2D  
catch(IOException e){e.printStackTrace ();} Kv'2^B  
catch(Exception e){e.printStackTrace ();} \0iF <0oy  
VLuhURI)  
gnW `|-:\  
Utility.log(nFileLength); <=A1d\   
D9M<>Xz)  
#5xK&qA  
return nFileLength; Y]aVa2!Wb  
} MzRws f  
D.zEE-cGyb  
Vv4 w?K  
//保存下载信息(文件指针位置) ~ztsR;iL  
private void write_nPos() =B g  
{ -t_t3aU|  
try{ bT<if@h-  
output = new DataOutputStream(new FileOutputStream(tmpFile)); n}MW# :eJe  
output.writeInt(nStartPos.length); *Ppb;   
for(int i=0;i<nStartPos.length;i++) eXY*l>B  
{ =m.Lw  
// output.writeLong(nPos); v /{LC4BF  
output.writeLong(fileSplitterFetch.nStartPos); luYkC@I@a  
output.writeLong(fileSplitterFetch.nEndPos); NGIbUH1[  
} 0Ym+10g  
output.close(); `0Y`]kSY+  
} }{Ab:+aNd  
catch(IOException e){e.printStackTrace ();} #Hl0>"k ,  
catch(Exception e){e.printStackTrace ();} =&RpW7]  
} DT`TA#O  
5qzFH,  
f 4CS  
//读取保存的下载信息(文件指针位置) 1'or[Os3=  
private void read_nPos() MaDdiyeC  
{ 68 % = V>V  
try{ XdX1GH*C  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fvn`$  
int nCount = input.readInt(); 0|kkwZVPn  
nStartPos = new long[nCount]; E|OB9BOS  
nEndPos = new long[nCount]; =e2|:Ba!  
for(int i=0;i<nStartPos.length;i++) sdF;H[  
{ @j*K|+X"  
nStartPos = input.readLong(); (3Hz=k_  
nEndPos = input.readLong(); u`I&&  
} ;i*<HNQ  
input.close(); | +osEHC  
} p|!5G&O,  
catch(IOException e){e.printStackTrace ();} U5N/'p%)<  
catch(Exception e){e.printStackTrace ();} oc+TsVt  
} ?.t naE  
ru#,pJ=O(  
p4QQ5O$;  
private void processErrorCode(int nErrorCode) qdkhfm2(K  
{ |[apLQ6  
System.err.println("Error Code : " + nErrorCode); h"Qp e'D}  
} eT33&:n4  
)Qe<XJH!  
77D>;90>?  
//停止文件下载 f]Jn\7j4  
public void siteStop() H9}z0VI  
{ G`H4#@]  
bStop = true; ] TY$  
for(int i=0;i<nStartPos.length;i++) dm8N;r/w  
fileSplitterFetch.splitterStop(); to-DXT.  
lrq u%:q  
"Sm'TZx  
} xN lxi  
} {nvF>  
//负责部分文件的抓取 4&b*|"Iw  
**FileSplitterFetch.java kr ,&aP<,  
*/ =-wF Brw  
package NetFox; qWz%sT?C3L  
E,u/^V9x  
H_w&_h&  
import java.io.*; 6Ih8~Hu  
import java.net.*; g{|F<2rd[m  
mX8k4$z  
.[mI9dc  
public class FileSplitterFetch extends Thread { ?8AV-rRX  
r<< ]41  
M_ *KA  
String sURL; //File URL S7i,oP7  
long nStartPos; //File Snippet Start Position @">^2  
long nEndPos; //File Snippet End Position UAleGR`,  
int nThreadID; //Thread's ID &CP]+ at  
boolean bDownOver = false; //Downing is over  zciL'9  
boolean bStop = false; //Stop identical :wWPEhK  
FileAccessI fileAccessI = null; //File Access interface lICpfcc(+  
\! `k:lusa  
=CBY_  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException MZJ@qIg[Y  
{ okwkMd-yW  
this.sURL = sURL; vndD#/lXq  
this.nStartPos = nStart; CMu/n]?c  
this.nEndPos = nEnd; ckDWY<@v  
nThreadID = id; b&wyp@k  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8v{0=9,Z  
} 'PO+P~|oa&  
M N-j$-y}  
iO$Z?Dyg9  
public void run() 9 5cIdF 6m  
{ V46=48K.  
while(nStartPos < nEndPos && !bStop) [f._w~  
{ 3[_zz;Y*d  
1u`{yl*+?  
9NXL8QmC8  
try{ oU|yBs1  
URL url = new URL(sURL); eMT}"u8$A  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JSp V2c5Q  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4Ny lc.2mi  
String sProperty = "bytes="+nStartPos+"-"; q>X30g  
httpConnection.setRequestProperty("RANGE",sProperty); JWB3;,S  
Utility.log(sProperty); Y8i'=Po%,  
n1Ic[cM}  
#_(t46  
InputStream input = httpConnection.getInputStream(); C!,|Wi2&  
//logResponseHead(httpConnection); le7!:4/8  
!+R_Z#gB  
T:<mme3v  
byte[] b = new byte[1024]; "UM*(&  
int nRead; Z'Uc}M'U  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %"yy8~|  
{ i!yu%>:M  
nStartPos += fileAccessI.write(b,0,nRead); :"Gx  
//if(nThreadID == 1) ta;q{3fe  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GkU]>8E'"  
} :o37 V!  
itU P%  
y [jck:  
Utility.log("Thread " + nThreadID + " is over!"); Aq]*$s2\G  
bDownOver = true; @Z+(J:Grm5  
//nPos = fileAccessI.write (b,0,nRead); [D$% LRX  
} $!LL  
catch(Exception e){e.printStackTrace ();} Uo]x6j<  
} F/ si =%  
} 5w9oMM {  
PI-o)U$Ehv  
T[(4z@d`5  
//打印回应的头信息 :qAF}|6  
public void logResponseHead(HttpURLConnection con) |'+ [ '  
{ sjW;Nsp  
for(int i=1;;i++) sUe<21:  
{ Jf</83RZ  
String header=con.getHeaderFieldKey(i); j&y>?Y&Sb  
if(header!=null) }L|cg2y  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7g%.:H =  
Utility.log(header+" : "+con.getHeaderField(header)); ^U;r>[T9h  
else f53WDI6  
break; eVvDis  
} h 0c&}kM  
} fU^6h`t  
a +lTAe  
@%[ dh@oY  
public void splitterStop() 0}4FwcCr\  
{ 8GKqPS+  
bStop = true; 2EAY`}Rl6.  
} K0 6 E:  
UmNh0nS  
z~0f[As.  
} <c!I\y  
u^X,ASkQ  
a? <Ar#)j  
/*  \X]  
**FileAccess.java yv+DM`0  
*//文件访问(定位,写) o|njgmF;\  
package NetFox; |+h8g@;Z  
import java.io.*; _ry7 [/)  
R64/m9  
O_^X:0}  
public class FileAccessI implements Serializable{ " ra C?H  
au?5^u\  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p6*|)}T_%  
RandomAccessFile oSavedFile; dk@j!-q^  
long nPos; .!2Ac  
\0bZ1"  
mA" 82"   
public FileAccessI() throws IOException ) mG  
{ Xxmvg.Nl  
this("",0); OE8H |?%  
} ^(.utO  
k<.VR"I p  
@'lO~i  
public FileAccessI(String sName,long nPos) throws IOException no UXRQ  
{ 8 aC]" C  
oSavedFile = new RandomAccessFile(sName,"rw"); qJ5gdID1_  
this.nPos = nPos; *<IQ+oat,a  
oSavedFile.seek(nPos); U66}nN9  
} Y)KO*40c  
D  Kng.P  
B`;DAsmT  
public synchronized int write(byte[] b,int nStart,int nLen) _ ATIV  
{ ?5Ub&{  
int n = -1; # fkOm Y7X  
try{ ~'3hK4  
oSavedFile.write(b,nStart,nLen); !1{kG%B=  
n = nLen; ZNjqH[  
} f<K7m  
catch(IOException e) j87IxB?o  
{ 1v"r8=Wt  
e.printStackTrace (); M\w%c5  
} R3!3TJ  
&-B&s.,kj  
Q!(qL[o  
return n; (.J8Q  
} m=e#1Hs   
z<Y >phc  
>^V3Z{;  
} +f]\>{o4  
lBcRt)_O7  
qcdENIy0b  
/* ]>'yt #]  
**SiteInfoBean.java 3!<} -sW4  
*/ B_uAa5'  
package NetFox; EC0M0qQ  
u4,b%h.  
@"$rR+r'  
public class SiteInfoBean { ^{(i;IVG  
5^GFN*poig  
VQ]MJjvb  
private String sSiteURL; //Site's URL $ix*xm. 4m  
private String sFilePath; //Saved File's Path DUOSL  
private String sFileName; //Saved File's Name ,`nl";Zc  
private int nSplitter; //Count of Splited Downloading File qW(_0<E  
$KGpcl  
mzoNXf:x  
public SiteInfoBean() }N}\<RG  
{//nSplitter的缺省值为5 8QaF(?  
//default value of nSplitter is 5 J"W+9sI0  
this("","","",5); J`@#yHL  
} Vo-]&u&cr  
eH y.<VX  
i<]Y0_?s  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #&jr9RB  
{ 4t;m^Iv  
sSiteURL= sURL; d;c<" +  
sFilePath = sPath; kn1+lF@  
sFileName = sName; x[i Et%_  
this.nSplitter = nSpiltter; g bc])`aJ>  
4 fxD$%9  
?=lnYD j  
} ;N/=)m  
}^/;8cfLY  
-a(\(^NW  
public String getSSiteURL() Z<t(h=?  
{ fqgm`4>  
return sSiteURL; 6opu bI<  
} <0hJo=6a8  
-$J%.fdPs  
;n-IpR#|  
public void setSSiteURL(String value) /^>yDG T,0  
{ N;BS;W5I  
sSiteURL = value; J@I-tS  
} mK2M1r  
w}jH,Ew  
H%\\-Z$#  
public String getSFilePath() I$7TnMug  
{ 6qgII~F'  
return sFilePath; ^-'t`mRl]d  
} ->S6S_H/+&  
EjYCOb-  
9+sOSz~ P  
public void setSFilePath(String value) k-M-=VvA  
{ b[I;6HW  
sFilePath = value; $*u{i4b  
} <Gr775"  
}nW)+  
,UD,)ZPf[  
public String getSFileName() ecI[lB  
{ E*t0ia8  
return sFileName; =>7\s}QZ  
} bC mhlSNi  
aF'9&A;q  
@$(/6]4p  
public void setSFileName(String value) +yYv"J  
{ 8'kA",P  
sFileName = value; B?xu!B,  
} ZoiCdXvTN  
 9g*MBe:  
"w\Iz]  
public int getNSplitter() W]v[Xm$q  
{ Je6=N3)  
return nSplitter; pSq3\#Twr  
} )n[ oP%  
GAlAFsB  
bh8IF,@a  
public void setNSplitter(int nCount) 32f lOi:  
{ Odo"S;)  
nSplitter = nCount; -;?5<>zZ  
} w]{NaNIeq1  
} FB0y  
B0:[3@P7  
2Q,8@2w;  
/* <p'~$vK  
**Utility.java wghz[qe  
*/ 3psCV=/z  
package NetFox; &!3=eVg  
FH'jP`  
N>fC"  
public class Utility { xwH+Q7O&l  
SRN:!-  
35;)O -  
public Utility() BHwQB2t gc  
{ cs?@Ri=g  
jG3}V3|.  
S"iQQV{)Z  
} vYD>m~Qc^  
I54O9Aoy  
//线程睡眠 I [J0r  
public static void sleep(int nSecond)  ,T{(t@  
{  pPm9v_G  
try{ "Q~6cH[#  
Thread.sleep(nSecond); |f^/((:D  
} 27vLI~  
catch(Exception e) 3mIX9&/  
{ {.N" 6P  
e.printStackTrace (); #lax0IYY=  
} #zcp!WE.OI  
} <%JRZYZ  
,~Y5vnaOQ  
//日志 #EpDIL  
public static void log(String sMsg) N b(f  
{ &/J[PdSb$  
System.err.println(sMsg); mmXLGLMd  
} |n;gGR\  
YZCPS6PuE  
-K`0`n}  
public static void log(int sMsg) .~ a)  
{ % 8kbX  
System.err.println(sMsg); qFV=P k  
} =L$};ko  
} J ,fXXi)J  
y @AKb  
C"/]X  
/* N1I1!!$K;%  
**TestMethod.java [Bp[=\  
*/ 5FHpJlFK,  
package NetFox; $2F*p#l(<Z  
:&dY1.<N+  
j>M 'nQ,;d  
public class TestMethod { &b}!KD1  
/n7F]Ok'*  
*?gn@4Ly  
public TestMethod() "w`f>]YLA  
{ ///xx/weblogic60b2_win.exe >]=1~ sF  
try{ I0O)MR<  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Zg7~&vs$  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xZS  
SiteFileFetch fileFetch = new SiteFileFetch(bean); : H<u@%  
fileFetch.start(); ?T5^hQT   
} _f,q8ZkSr  
catch(Exception e){e.printStackTrace ();} >ofS'mp  
:Qu!0tY  
1+o>#8D  
}  "t8mQ;n  
{!B0&x  
TUZ-4{kV"  
public static void main(String[] args) -(>x@];r0  
{ B|%=<1?  
new TestMethod(); amGQ!$] %#  
} d {moU\W  
} C4Q ^WU+$j  
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