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http断点续传简单实现(java)

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/* j8PK\j[  
**SiteFileFetch.java ' ft  |  
*/ a+X X?uN{  
package NetFox; a\zbi$S  
import java.io.*; r1[0#5kJ;J  
import java.net.*; 2]7nw1&  
KT8Fn+  
N=wB1gJ  
public class SiteFileFetch extends Thread { &W ~,q(  
y.>r>o"0  
{U4%aoBd8  
SiteInfoBean siteInfoBean = null; //文件信息Bean h7*m+/O  
long[] nStartPos; //开始位置 ,0~'#x>  
long[] nEndPos; //结束位置 |OC6yN *P)  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 wk3yz6V2  
long nFileLength; //文件长度 67#;.}4a  
boolean bFirst = true; //是否第一次取文件 6L2.88 i  
boolean bStop = false; //停止标志 / og'W j  
File tmpFile; //文件下载的临时信息 X<1# )xC  
DataOutputStream output; //输出到文件的输出流 ~h1'_0t   
{C<ch@sR  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) L.8-nTg"y  
public SiteFileFetch(SiteInfoBean bean) throws IOException s)-=l _4T  
{ m\Dbb.vBvW  
siteInfoBean = bean; # wG}T .*  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); E)`+1j  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); FuD$jsEw  
if(tmpFile.exists ()) 1|zo -'y  
{ G6I>Ry[2?  
bFirst = false; SnVnC09y  
read_nPos(); kY*D s;  
} Pp}j=$&j\  
else LTi0,03l<  
{ {AB0 PM;-  
nStartPos = new long[bean.getNSplitter()]; l{;vD=D  
nEndPos = new long[bean.getNSplitter()]; 6@bO3K|  
} gHTo|2 Q{  
v67o>`<$  
FzNs >*  
%=GnGgu  
} \s,ZE6dQ  
#/YKA{  
E$RH+):|  
public void run() xY@V.  
{ ,3x3&c  
//获得文件长度 oJ5V^.  
//分割文件 %POoyH@D}  
//实例FileSplitterFetch t,&1~_9  
//启动FileSplitterFetch线程 x ;kW }U  
//等待子线程返回 O7E0{8  
try{ { c]y<q  
if(bFirst) S25&UwUw  
{ kMK-E<g  
nFileLength = getFileSize(); xFgY#F  
if(nFileLength == -1) h_H$+!Nzb  
{ CY9`ztO*  
System.err.println("File Length is not known!");  Qq>M}  
} )Wgh5C`  
else if(nFileLength == -2) 2jA-y!(e  
{ JEj.D=@[  
System.err.println("File is not access!");  d':c  
} <D=U=5  
else }O8$?7j(  
{ 6tj +  
for(int i=0;i<nStartPos.length;i++) rIy,gZr.U  
{ ^xFZ;Yf  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 8n NRn[oS  
} bz,C%HFA  
for(int i=0;i<nEndPos.length-1;i++) !}<Y^="  
{ `O*+%/(  
nEndPos = nStartPos[i+1]; D/{hLp{  
} G 9d@vu  
nEndPos[nEndPos.length-1] = nFileLength; E7ixl~  
} >/GVlXA'  
} { "=d7i  
!@5B:n*  
EE-jU<>|  
//启动子线程 fm Fh.m.+N  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6/ F]ncwG  
for(int i=0;i<nStartPos.length;i++) r;SA1n#  
{ d'q,:="c  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  qauk,t  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), # sm>;+J  
nStartPos,nEndPos,i); QF Vy2 q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >}Fe9Y.o  
fileSplitterFetch.start(); X)x$h{ OE  
} xV}-[W5sr'  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6o!+E@V b  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m&cVda/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "1yXOy^2  
nEndPos = " + nFileLength); Fn1|Wt*  
// fileSplitterFetch[nPos.length-1].start(); n}}$-xl  
rISg`-  
a}EO7tcg,  
//等待子线程结束 1UT&kD!si  
//int count = 0; : OQx;>'  
//是否结束while循环  1ti+ Q0~  
boolean breakWhile = false; ]+Ik/+Nz  
Z2!O)8  
wgp{P>oBX  
while(!bStop) %9C_p]P*  
{ .Xqe]cax%  
write_nPos(); z^'3f!:3  
Utility.sleep(500); :  *k   
breakWhile = true; ?@!dc6   
 ]Vuq)#  
ha&2V=  
for(int i=0;i<nStartPos.length;i++) @Ge\odfF:  
{ / p}^ Tpu  
if(!fileSplitterFetch.bDownOver) kzcl   
{ Z]jm.'@z@  
breakWhile = false; U8m/L^zh  
break; W^v3pH-y#  
} \("|X>00  
} C5"=%v[gQv  
if(breakWhile) HN?NY  
break; ^`?2g[AA  
!#xk?LyB  
)! +~q!A  
//count++; j]~;|V5Z  
//if(count>4) ]rY:C "#  
// siteStop(); \jH^OXxb  
} AXFQd@#  
.EpcMXT%  
^}8qPBz  
System.err.println("文件下载结束!"); \W:~;GMeD  
} _!2bZ:emG  
catch(Exception e){e.printStackTrace ();} XA PqRJ*Z  
} mhpaPin*JS  
Vz[tgb]-  
X+dLk(jI`u  
//获得文件长度 G6@XRib3  
public long getFileSize() )i|0Ubn[|  
{ J$"3w,O6+U  
int nFileLength = -1; l/ufu[x!a  
try{ 0&wbGbg(W  
URL url = new URL(siteInfoBean.getSSiteURL()); )"KKBil0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p(vmMWR!  
httpConnection.setRequestProperty("User-Agent","NetFox"); qJN!L))  
Ps<;DE\$f4  
^V,?n@c!  
int responseCode=httpConnection.getResponseCode(); JiH^N!  
if(responseCode>=400) p^J=*jm)x  
{ ~*NG~Kn"s  
processErrorCode(responseCode); #s% _ L  
return -2; //-2 represent access is error IqD;*  
} ePLpGT  
.0 }eg$d  
}Y9= 3X  
String sHeader; ' m^nKG$"  
9eR4?^(3!  
*,az`U  
for(int i=1;;i++) b5!D('w>]  
{ T%q@jv{c  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {/ef`MxV }  
//Utility.log(in.readLine()); we?# Dui  
sHeader=httpConnection.getHeaderFieldKey(i); ,v\^efc:%  
if(sHeader!=null) |f67aN  
{ 1xBgb/+  
if(sHeader.equals("Content-Length")) GoSdo  
{ 7H=V|Btnc  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9:9gam  
break; p#;I4d G  
} :}0>IPW-V  
} ; ,9:1.L  
else XSOSy2:  
break; \k 9EimT}  
} +V Oczl=  
} rvEX ;8TS  
catch(IOException e){e.printStackTrace ();} j{&*]QTN  
catch(Exception e){e.printStackTrace ();} [[FDt[ l4  
r&rip^40  
?cur}`  
Utility.log(nFileLength); !a9`]c  
kD*r@s]=  
.30eO_msK  
return nFileLength; @y1:=["b  
} N1!O8"Q|*3  
\Dlmrke  
X^o0t^  
//保存下载信息(文件指针位置) 1Y+g^Z;G  
private void write_nPos() z*,J0)<Q  
{ A  r,fmq  
try{ 'LX]/ D  
output = new DataOutputStream(new FileOutputStream(tmpFile)); b%wm-p  
output.writeInt(nStartPos.length); +Z7:(o<  
for(int i=0;i<nStartPos.length;i++) \0fS;Q^{j  
{ 15J t @{<r  
// output.writeLong(nPos); }ebu@)r  
output.writeLong(fileSplitterFetch.nStartPos); OrP i ("/  
output.writeLong(fileSplitterFetch.nEndPos); BWF>;*Xro  
} !FA[ ]d4  
output.close(); u; G-46  
} 2QIx~Er  
catch(IOException e){e.printStackTrace ();} Qo\+FkhYq  
catch(Exception e){e.printStackTrace ();} 1[:tiTG|C  
} rK~Obv  
 Q'~3Ik  
[6cF#_)*  
//读取保存的下载信息(文件指针位置) +?9. &<?  
private void read_nPos() 7 MZ(tOR  
{ as^!c!  
try{ IRG-H!FV  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A<p6]#t#X)  
int nCount = input.readInt(); qxbGUyH==  
nStartPos = new long[nCount]; 5}Z_A?gy  
nEndPos = new long[nCount]; 6<SX%Bc~  
for(int i=0;i<nStartPos.length;i++) Eg+ z(m$M  
{ sI<PYi={-6  
nStartPos = input.readLong(); q=x1:^rVH  
nEndPos = input.readLong(); ^~` t q+  
} RLNto5?  
input.close(); Vw";< <0HZ  
} p>h&SD?b  
catch(IOException e){e.printStackTrace ();} Lj2Au_5  
catch(Exception e){e.printStackTrace ();} ~5:-;ZbZ  
} HDHC9E6  
Ihy76_OZ  
~0V,B1a  
private void processErrorCode(int nErrorCode) ,Pj UlcO_  
{ I?OnEw  
System.err.println("Error Code : " + nErrorCode); 2fFGS.l  
} (@i2a  
Z Tzh[2u*  
VMl)_M:'  
//停止文件下载 6 ~+/cY-V  
public void siteStop() 0eFvcH:qG  
{ I><sK-3  
bStop = true; Qm@v}pD  
for(int i=0;i<nStartPos.length;i++) FA$1&Fu3Y  
fileSplitterFetch.splitterStop(); (5h+b_eB  
W.m2`] &  
(W'3Zv'f  
} l<-0@(x)  
} ov|/=bzro  
//负责部分文件的抓取 ~{$5JIpCm  
**FileSplitterFetch.java  2p;N|V  
*/ cyXnZs ?|  
package NetFox; OM (D@up  
snvixbN  
|PutTcjQ  
import java.io.*; ><w=  
import java.net.*; cz;gz4d8  
T:0#se  
F.$NYr/|y  
public class FileSplitterFetch extends Thread { cr>"LAi  
R4 AKp1Y  
&O\$=&, h  
String sURL; //File URL JW9U&Bj{  
long nStartPos; //File Snippet Start Position h e1=  
long nEndPos; //File Snippet End Position \(;X3h  
int nThreadID; //Thread's ID 8/T,.<5  
boolean bDownOver = false; //Downing is over l'FNp  
boolean bStop = false; //Stop identical ^"{txd?6  
FileAccessI fileAccessI = null; //File Access interface j-(k`w\  
:d} @Z}2sD  
;t5e]  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |m>{< :  
{ 0u=FlQ }h  
this.sURL = sURL; k|; [)gE  
this.nStartPos = nStart; uoMDf{d  
this.nEndPos = nEnd; [`U9  
nThreadID = id; ;S}_/'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f[+N=vr  
} Zd <8c^@  
IgNL1KRD  
@ $2xiE.[  
public void run() aP`V  
{ q%hxU.h  
while(nStartPos < nEndPos && !bStop) !_pryNcb  
{ IiB"F<&[j{  
+^<-;/FZue  
Av,E|C  
try{ UlH;0P?  
URL url = new URL(sURL); +&qj`hA-b  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o 4cqLM u  
httpConnection.setRequestProperty("User-Agent","NetFox"); >Ni<itze$i  
String sProperty = "bytes="+nStartPos+"-"; &vV_,$  
httpConnection.setRequestProperty("RANGE",sProperty); "2>_eZ#b  
Utility.log(sProperty); MB!$s_~o#L  
<,huajQs  
zOT(>1'  
InputStream input = httpConnection.getInputStream(); ,_!MI+o0  
//logResponseHead(httpConnection); 3-U@==:T  
.TKKjS%8  
`%Jq^uW  
byte[] b = new byte[1024]; +?y9EZB%  
int nRead; yGX"1Fb?;x  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =N<Z@'c  
{ rF)[ Sed:T  
nStartPos += fileAccessI.write(b,0,nRead); 'G8.)eTA'  
//if(nThreadID == 1) [.LbX`K:  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B^lm'/,@  
} (C60HbL  
eG\`SKx_  
9xM7X?  
Utility.log("Thread " + nThreadID + " is over!"); ctT6va  
bDownOver = true; pHv~^L%=  
//nPos = fileAccessI.write (b,0,nRead); N3?@CM^hHw  
} '/~j!H4q9  
catch(Exception e){e.printStackTrace ();} m\;@~o'k  
} vj4n=F,Z  
} Qv/Kbw N{  
,-.a! a  
';Ew-u  
//打印回应的头信息 \iM  
public void logResponseHead(HttpURLConnection con) A i5|N  
{ +9[s(E?SY  
for(int i=1;;i++) +"F9yb  
{ JVt(!%K}&  
String header=con.getHeaderFieldKey(i); n Wb0S  
if(header!=null) D/Hob  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |n q}#  
Utility.log(header+" : "+con.getHeaderField(header)); q}MPl2  
else ]}HuK#  
break; mrId`<L5l{  
} 6ujePi <U  
} #P5tTCM  
T Z_](%  
7FvtWE*  
public void splitterStop() ar[*!:!  
{ ]q<Zc>OC  
bStop = true; tZqy \_G  
} fLR\@f  
iz5WWn^  
f]37Xl%I  
} C">w3#M%  
a[A9(Ftn  
EH~XN9b  
/* -9> oB  
**FileAccess.java 8}<4f|?  
*//文件访问(定位,写) Y!nxHRE  
package NetFox; ! C|VX,w  
import java.io.*; |Y|gT*v  
Qz9*o  
<{k r5<  
public class FileAccessI implements Serializable{ &(t/4)IZox  
4Y:[YlfD.  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D0HLU ~o  
RandomAccessFile oSavedFile; P8=!/L2?  
long nPos; l4smAT  
M73d^z  
x9s1AzM{  
public FileAccessI() throws IOException YMfjTt@Q  
{ \g<=n&S?  
this("",0); W*/0[|n*  
} J8:f9a:|M  
xIb^x=|h  
zf}X%tp  
public FileAccessI(String sName,long nPos) throws IOException >YuiCf?c7  
{ ^oT!%"\  
oSavedFile = new RandomAccessFile(sName,"rw"); o:8*WCiqrN  
this.nPos = nPos; ZQ'bB5I  
oSavedFile.seek(nPos); r~U/t~V=D  
} Mz#<Vm4  
+8~C&K:  
4g}'/  
public synchronized int write(byte[] b,int nStart,int nLen) dyN Kok#  
{ ?O.1HEr  
int n = -1; k7\ ,N o}  
try{ @$ggPrs  
oSavedFile.write(b,nStart,nLen); *oca   
n = nLen; "Acc]CqH*  
} 7GVI={ b  
catch(IOException e) Z[pMlg6Z  
{ /Xo8 kC  
e.printStackTrace (); N6wCCXd  
} ]> 36{k]&  
ic]b"ItD  
0}d^UGD  
return n; >Qg 9KGk'  
} W]U}, g8Z  
@Wb_Sz4`  
{ i2QLS  
} L}x,>hbT  
Fy8$'oc  
#FQkwX'g  
/* !.}ZlA  
**SiteInfoBean.java S#wy+*  
*/ kvo V?<!  
package NetFox; F#^<t$5t  
H@%Y"iIUP  
{} gr\  
public class SiteInfoBean { fu]mxGPc  
t/`~(0F  
H:jx_  
private String sSiteURL; //Site's URL {ICW"R lcs  
private String sFilePath; //Saved File's Path a/v!W@Zz}  
private String sFileName; //Saved File's Name X:1&Pdi  
private int nSplitter; //Count of Splited Downloading File }aC@ov]2  
j68_3zpl  
7\xGMCctM  
public SiteInfoBean() ~vMdIZ.h  
{//nSplitter的缺省值为5 g!*5@k|C  
//default value of nSplitter is 5 7Fd`M To  
this("","","",5); p,'Z{7HG  
} n^P~]1i   
y +2  
.\6q\7Ej  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4`M7 3k0  
{ *(>,\8OVf  
sSiteURL= sURL; b)1v:X4Bv=  
sFilePath = sPath; F\G-. 1  
sFileName = sName; AZgeu$:7p<  
this.nSplitter = nSpiltter; THl={,Rw`  
1q7Y,whp  
jqeR{yo&0b  
} !i{9wI  
KqI<#hUl  
W3.(s~ )o  
public String getSSiteURL() VsJ4sb7  
{ pd Fa]  
return sSiteURL; k(bDj[0q^  
} psaPrE  
;)'@kzi  
:U!@  
public void setSSiteURL(String value) B2/d%B  
{ Q2(K+!Oe  
sSiteURL = value; ^/V>^9CZ  
} !`h^S)$  
E@(nKe&6T_  
Jdc{H/10  
public String getSFilePath() gFQ\zOlY8a  
{ .%x%b6EI  
return sFilePath; :Ou[LF.O  
} KyQd6 1  
4J9VdEKk  
)4tOTi[  
public void setSFilePath(String value)  Z,Z4Sp  
{ >=+: lD  
sFilePath = value; `k]2*$%  
} cKM#0dq  
nd4Z5=X  
}gR!]Cs)^  
public String getSFileName() 618k-  
{ #q mv(VB4  
return sFileName; rY,zZR+@  
} ;rqW?':(i  
9m+ejTK{U  
km,I75o.  
public void setSFileName(String value) !-cK@>.pE  
{ y:Ne}S*ncE  
sFileName = value;  n)t'?7  
} uK;&L?WB  
-2/&i  
]H$Trf:L  
public int getNSplitter() V7}]39m(s  
{ =73aME}  
return nSplitter; h; "pAE  
} Hq;*T3E  
UrRYK-g  
h7a/]~  
public void setNSplitter(int nCount) w =2; QJ<  
{ r >;(\_@  
nSplitter = nCount; XEe$Wh  
} # H)\ts  
} -%)S~ R  
ya'Ma<4  
B"Hz)-MW  
/* qvC2BQ  
**Utility.java #6F|}E  
*/ &y&pjo6v1  
package NetFox; h2P&<ggqX  
o5;|14O  
O/b1^ Y   
public class Utility { {TVQ]G%'b  
Memb`3  
\f-@L;8#  
public Utility() <Eu/f`8  
{ JH+uBZh6  
>v'@p  
j^)=<+Q;=  
} *bl|[(pP  
u/.# zn@9h  
//线程睡眠 +k{l]-)1  
public static void sleep(int nSecond) Q79WGW  
{ 8JojKH  
try{ +|6E~#zklY  
Thread.sleep(nSecond); }Dx5W9Ri"  
} fJK;[*&Y  
catch(Exception e) ;;}}uW=  
{ c yH=LjgJf  
e.printStackTrace (); "BA&  
} %zYTTPLZ  
} OIY  
5h [<!f=  
//日志 R q .2  
public static void log(String sMsg) ,X)/ T!ff  
{ E^C [G)7n  
System.err.println(sMsg); `1i\8s&O6@  
} ?`3G5at)9f  
_+ERX[i  
#}+_Hy  
public static void log(int sMsg) ?.g="{5X  
{ RV>n Op}R  
System.err.println(sMsg); l(Y\@@t1  
} ow4|GLU^;  
} lFV\Go  
Sd *7jW?  
1B`JvNtd  
/* ^%t{:\  
**TestMethod.java p?' F$Wz  
*/ Exz(t'  
package NetFox; "P!zu(h4  
xgJyG.?  
p?#xd!tc2N  
public class TestMethod { /xb37,   
gJg%3K~,  
I|tn7|*-A[  
public TestMethod() S #C;"se  
{ ///xx/weblogic60b2_win.exe 50^CILKo7  
try{ A"wso[{  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SN5Z@kK  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0Ci:w|J  
SiteFileFetch fileFetch = new SiteFileFetch(bean); =zRjb>  
fileFetch.start(); f!bGH-.r5  
} mMtva}=*  
catch(Exception e){e.printStackTrace ();} Q(BM0n)f  
$%z M Z  
DcsQ6  
} ',s{N9  
6)1xjE#  
.#_g.0<  
public static void main(String[] args) uz@lz +  
{ oR}'I  
new TestMethod(); vFK!LeF%  
} ]//D d/L6  
} oRHWb_$"  
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