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http断点续传简单实现(java)

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/* _I"<?sh 3  
**SiteFileFetch.java aZ0iwMK  
*/ ?U[nYp}"v  
package NetFox; )s[S.`S Tz  
import java.io.*; H4",r5qw:  
import java.net.*; 6#63D>OWp  
=@/^1.`  
[*E.G~IS`  
public class SiteFileFetch extends Thread { u\Q**m2XP  
PsT v\!  
DMpd(ws  
SiteInfoBean siteInfoBean = null; //文件信息Bean C^v -&*v  
long[] nStartPos; //开始位置 (j Q6~1  
long[] nEndPos; //结束位置 wq`Kyhk  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 s|`)'  
long nFileLength; //文件长度 1ORi]`  
boolean bFirst = true; //是否第一次取文件 Q"_T040B  
boolean bStop = false; //停止标志 tl#s:  
File tmpFile; //文件下载的临时信息 siZ_JJW  
DataOutputStream output; //输出到文件的输出流 L. ?dI82c  
5Jd {Ev  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) AS^$1i:  
public SiteFileFetch(SiteInfoBean bean) throws IOException /3%xQK>%  
{ mK/P4]9g  
siteInfoBean = bean; &jd<rs5}  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); nM}`H'0  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $6%;mep  
if(tmpFile.exists ()) #mxfU>vQ:  
{ n,LKkOG  
bFirst = false; JNCtsfd  
read_nPos(); w:(7fu=  
} -zkL)<7  
else ``CADiM:S  
{ -%$ dFq  
nStartPos = new long[bean.getNSplitter()]; OvG|=  
nEndPos = new long[bean.getNSplitter()]; Pt;Ahmi  
} RIx6& 7$  
!9OgA  
dR{ V,H7N  
6MQ:C'8T&=  
} LZ:\V)5+  
T<GD!j(  
7OHw/-j\  
public void run() V2skr_1  
{ [)c|oh%  
//获得文件长度 "$YLU}S9  
//分割文件 &h[}5  
//实例FileSplitterFetch p[:%Ck"$7  
//启动FileSplitterFetch线程 ^Pp FI  
//等待子线程返回 K0a 50@B]  
try{ Mc^7FWkw  
if(bFirst) ?LM'5  
{ mSeN M  
nFileLength = getFileSize(); 8 z7,W3b  
if(nFileLength == -1) P#oV ^  
{ $o H,:x?}  
System.err.println("File Length is not known!"); @b({QM|  
} z9w.=[Io  
else if(nFileLength == -2) xK'IsMo[  
{ 2a-hf|b1  
System.err.println("File is not access!"); 5aQg^f%\  
} yt,;^o^  
else fdHxrH >*  
{ y5h[^K3  
for(int i=0;i<nStartPos.length;i++) *&MkkI#  
{ LRs; >O  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); >*CK@"o  
} L@GD$F=<0  
for(int i=0;i<nEndPos.length-1;i++) ^2@~AD`&h  
{ (Ad! hyE(  
nEndPos = nStartPos[i+1]; l]&)an  
} 1k i"UF/  
nEndPos[nEndPos.length-1] = nFileLength; x*V<afLY[  
} @U5>w\  
} NDG Bvb  
)Cfrqe1^  
E+ 20->  
//启动子线程 rNp#5[e  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xpwom'  
for(int i=0;i<nStartPos.length;i++) Gjr2]t;E  
{ 2 wvDC@  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (P8oXb+%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &i RX-)^u  
nStartPos,nEndPos,i); r U5'hK  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t,nB`g?  
fileSplitterFetch.start(); D3ad2vH  
} gp2)35  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JnJz{(c  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KYN{iaj  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }FVX5/.'  
nEndPos = " + nFileLength); ObzlZP r@  
// fileSplitterFetch[nPos.length-1].start(); ry"zec B  
(7,Awf5D~  
wYG0*!Vj  
//等待子线程结束 ?Pc 3*.  
//int count = 0; p7er04/}\  
//是否结束while循环 BZ9iy~  
boolean breakWhile = false; Bs}>#I  
Q8i6kf!  
w.H+$=aK  
while(!bStop) ?C3cPt"  
{ lX3h'h  
write_nPos(); |e >-v  
Utility.sleep(500); pM3BBF%  
breakWhile = true; 6Tnzg`0I  
9v0|lS!-  
xkovoTzV  
for(int i=0;i<nStartPos.length;i++) jfamuu7  
{ B?Skw{&  
if(!fileSplitterFetch.bDownOver) ;0'v`ob'.?  
{ FO$Tn+\6  
breakWhile = false; UepBXt3)  
break; OFv} jT  
} Q2Rj0E`  
} w3D_ c~  
if(breakWhile) K-3 _4As  
break; $EF@x}h:A  
!4:,,!T  
d9"4m>ymS  
//count++; $}fA;BP  
//if(count>4) ev $eM  
// siteStop(); 4aC#Cv:0  
} u7d]%<~'$F  
{,=,0NQKn  
`>Cx!sYhV  
System.err.println("文件下载结束!"); E12k1gC`  
} KJ_R@,v\  
catch(Exception e){e.printStackTrace ();} 8n?.w:Y/  
} tw66XxE  
>.|gmo>b  
 ~A/_\-  
//获得文件长度 LNkyV*TI  
public long getFileSize() 3 6 ;hg #  
{ {W]jVh p  
int nFileLength = -1; xFZq6si?  
try{ Rd)QVEk>SD  
URL url = new URL(siteInfoBean.getSSiteURL()); wG O)!u 4  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c3##:"wr  
httpConnection.setRequestProperty("User-Agent","NetFox"); S J5kA`  
{Y Ymt!Ic  
+zsya4r  
int responseCode=httpConnection.getResponseCode(); 'Nh^SbD+_|  
if(responseCode>=400) bd4q/w4q  
{ `Nj|}^A  
processErrorCode(responseCode); )T?ryp3ev  
return -2; //-2 represent access is error lS^0*(Y  
} @zbXG_J  
s><co]  
00i9yC8@6  
String sHeader; N2>JG]G  
Xc!w y9m  
;/@R{G{+~;  
for(int i=1;;i++) W= !f  
{ rAKd f??  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4%TC2Laii  
//Utility.log(in.readLine()); (P?9Jct  
sHeader=httpConnection.getHeaderFieldKey(i); T (qu~}  
if(sHeader!=null) - g0>>{M'  
{ Z>l>@wNm  
if(sHeader.equals("Content-Length")) 4rm/+Zes  
{ cu-WY8n  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ty=}A MMyE  
break; E _K7.c4M  
} gA6C(##0  
} . fIodk  
else H|Ems}b  
break; a|.u;  
} )-(NL!?`  
} {Fj`'0Xu;  
catch(IOException e){e.printStackTrace ();} G;e}z&6<k  
catch(Exception e){e.printStackTrace ();} 5j]%@]M$Z  
_bX)fnUu  
KjadX&JD  
Utility.log(nFileLength); c\Dv3bF  
iaB5t<t1r  
t`  Sh!e  
return nFileLength; _3hEYeh  
} E O5Vg  
<\5{R@A*6  
tVOx  
//保存下载信息(文件指针位置) $[Fk>d  
private void write_nPos() 5M*p1^ >  
{ 4:.M*Dz  
try{ /SiQw7yp%  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^N]*Zf~N?  
output.writeInt(nStartPos.length); {'1,JwSmb  
for(int i=0;i<nStartPos.length;i++) <6@Db$-  
{ $Ix^Rm9c  
// output.writeLong(nPos); %^S1 fUwT  
output.writeLong(fileSplitterFetch.nStartPos); zSu2B6YU}  
output.writeLong(fileSplitterFetch.nEndPos); 'Gk|&^  
} D<MtLwH  
output.close(); &b_duWs  
} n3(HA  
catch(IOException e){e.printStackTrace ();} &\LbajP:+  
catch(Exception e){e.printStackTrace ();} tm$3ZzP4  
} B4hR3%  
0^+W"O  
 ZM"t.  
//读取保存的下载信息(文件指针位置) OHU(?TBo  
private void read_nPos() >a<;)K^1  
{ >(3 y(1;  
try{ -8]$a6`{_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .FeEK(  
int nCount = input.readInt(); W+QI D/  
nStartPos = new long[nCount]; R&?p^!`%  
nEndPos = new long[nCount]; fA8 ,wy|>  
for(int i=0;i<nStartPos.length;i++) ?g 3sv5\u  
{ COap*  
nStartPos = input.readLong(); R#0UwRjeF  
nEndPos = input.readLong(); % n^]1R#  
} #r\uh\Cy  
input.close(); di|l?l^l  
} Cd4G&(=  
catch(IOException e){e.printStackTrace ();} O_ ~\$b  
catch(Exception e){e.printStackTrace ();} v"`w'+  
} -{dw Ll_  
7*sB"_U2  
j9%=^ZoQj  
private void processErrorCode(int nErrorCode) {'/8{dS  
{ Hxjh P(  
System.err.println("Error Code : " + nErrorCode); +U[A.^t  
} `W5f'RU  
m 9r X  
(UCWSA7oc  
//停止文件下载 b<%6aRC\  
public void siteStop() #}.db?[Rv  
{ dP82bk/e  
bStop = true; y&UsSS  
for(int i=0;i<nStartPos.length;i++) 1'ZBtX~A  
fileSplitterFetch.splitterStop(); &a V`u?'e  
TV}H  
y@F{pr+dA  
} !^y'G0  
} 5( 3tPbm{  
//负责部分文件的抓取 GE|V^_|i  
**FileSplitterFetch.java vV%w#ULxE~  
*/ L~\Ir  
package NetFox; j sm{|'  
2gA6$s7  
_T1|_9b  
import java.io.*; &Mol8=V)  
import java.net.*; kxh $R>  
KcHW>IBxdv  
D ,nF0p  
public class FileSplitterFetch extends Thread { LVX.stN#p  
C&\#{m_1B  
$aEL>, X  
String sURL; //File URL \]zH M.E1  
long nStartPos; //File Snippet Start Position u-D%: lz85  
long nEndPos; //File Snippet End Position Zf ;U=]R  
int nThreadID; //Thread's ID GujmBb  
boolean bDownOver = false; //Downing is over iNcB6,++  
boolean bStop = false; //Stop identical 06ZyR@.@v  
FileAccessI fileAccessI = null; //File Access interface uT_bA0jK  
)Zox;}WK+  
H?PaN)_6-+  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kIyif7  
{ mk}8Cu4  
this.sURL = sURL; 1$4dzI()  
this.nStartPos = nStart; ->d 3FR  
this.nEndPos = nEnd; svN& ~@ l  
nThreadID = id; y6f YNB  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }5EvBEv-)  
} s~3"*,3@  
{>9vm!<[*\  
q>t#5Z81  
public void run() b}WU  
{ @u?m4v{  
while(nStartPos < nEndPos && !bStop) R,8;GS42  
{ +Y-Gp4"  
r3'0{Nn+  
>HyZ~M  
try{ V3 2F  
URL url = new URL(sURL); XsEDI?p2  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?g}G#j  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,VI2dNst\  
String sProperty = "bytes="+nStartPos+"-"; 6YNd;,it>p  
httpConnection.setRequestProperty("RANGE",sProperty); U&GSMjqg  
Utility.log(sProperty); voiWf?X  
5 y0 N }}  
f]Xh7m(Gh  
InputStream input = httpConnection.getInputStream(); UZz/v#y~  
//logResponseHead(httpConnection); 1 Qln|b8<  
zt6GJ z1q  
Kqm2TMO]>V  
byte[] b = new byte[1024]; m9 1Gc?c  
int nRead; @kd`9Yw  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :>f}rq  
{ jBb:)  
nStartPos += fileAccessI.write(b,0,nRead); A{MMY{K3  
//if(nThreadID == 1) z#m ~}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \(C6|-:GY  
} UyENzK<%u  
~ 6DaM!  
a[I :^S  
Utility.log("Thread " + nThreadID + " is over!"); mb,\wZ  
bDownOver = true; vhvFBx0  
//nPos = fileAccessI.write (b,0,nRead); }Y:V&4DW  
} T,r?% G{XE  
catch(Exception e){e.printStackTrace ();} shKTj5s?  
} $Y,y~4I  
} h/k00hD60  
xPCRT*Pd  
T\q:  
//打印回应的头信息 9eBD)tnw  
public void logResponseHead(HttpURLConnection con) >P@g].Q-  
{ a5cary Z"z  
for(int i=1;;i++) r'8qZJgm  
{ gamE^Ee  
String header=con.getHeaderFieldKey(i); a`I \19p]  
if(header!=null) X lLG/N  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0fu*}v"  
Utility.log(header+" : "+con.getHeaderField(header)); 8 kvF~d ;  
else z9Z4MXl  
break; \(_(pcl  
} 0Xb,ne 7  
} 2ci[L:U  
z.lIlp2:  
=U'!<w<-  
public void splitterStop() 9k /L m  
{ z;DNl#|!L  
bStop = true; C cPOK2  
} 9:R3+,ZN  
A*G ~#v^  
,<k%'a!B  
} 6%it`A8}  
:CLWmMC_  
M0yv= g  
/* w p\-LO~  
**FileAccess.java Q p7h|<  
*//文件访问(定位,写) 1J([*)  
package NetFox; =WT&unw}  
import java.io.*; o%7-<\qS  
fqjBor}  
;.'?(iEB  
public class FileAccessI implements Serializable{ ulE5lG0c  
X!_&%^L'  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e>6|# d  
RandomAccessFile oSavedFile; @Bds0t  
long nPos; {7jl) x3l  
X$e*s\4  
!0dQfj^_  
public FileAccessI() throws IOException i-PK59VZ8f  
{ p4V*%A&w  
this("",0); |sdG<+  
} tk]D)+{u&c  
i\<S ;  
k4a51[SYBK  
public FileAccessI(String sName,long nPos) throws IOException _3(rwD  
{ !wN2BCSY@  
oSavedFile = new RandomAccessFile(sName,"rw"); 3\2%i 6W6  
this.nPos = nPos; )r^vrCNy>  
oSavedFile.seek(nPos); BmKf%:l}  
} @^T~W^+  
p#).;\M   
rY 6x):sC  
public synchronized int write(byte[] b,int nStart,int nLen) KLvAe>#,  
{ p[w! SR%=  
int n = -1; LN~mKoW  
try{ ]DKRug5  
oSavedFile.write(b,nStart,nLen); Q 9fK)j1$  
n = nLen; EB| iW2'  
} dP?prT  
catch(IOException e) M!+J[q  
{ ?z`={oN  
e.printStackTrace (); oUwo!n}  
} 3CgID6[Sy  
<o/!M6^:  
b{qN7X~>  
return n; SV@*[r  
} ~P#mvQE)  
0N^+d,Xt.  
ltf KqY-  
} <3!Al,!ej@  
$2\ 8Rn6'  
yUj`vu 2  
/* o3V\   
**SiteInfoBean.java (P`=9+  
*/ :h5G|^  
package NetFox; $m;`O_-T  
y{/7z}d  
0KnL{Cj   
public class SiteInfoBean { ?HJh;96B  
j*@@H6G  
jB8Q% {%  
private String sSiteURL; //Site's URL ele@xl  
private String sFilePath; //Saved File's Path ;Ax-f04gG  
private String sFileName; //Saved File's Name \o}T0YX  
private int nSplitter; //Count of Splited Downloading File Asv]2> x  
XHekz6_  
s EFQ8S  
public SiteInfoBean() @QV0l]H0+  
{//nSplitter的缺省值为5 *#'j0;2F  
//default value of nSplitter is 5 H.\`(`6  
this("","","",5); T[ZmD{6l  
} \?; `_E`j  
ss[`*89  
wn.~Dx  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n74\{`8]o  
{ y92R}e\M  
sSiteURL= sURL; +9w[/n^,G  
sFilePath = sPath; Iz1x|EQ  
sFileName = sName; [a04( 2g  
this.nSplitter = nSpiltter; `p&[b]b  
>*RU:X  
< mQXS87  
} LP6 p  
l3sF/zkH  
|]4!WBK  
public String getSSiteURL() T[Zs{S  
{ HwHF8#D*l  
return sSiteURL; c`soVqT$?  
} '|DW#l\n  
-T,?'J0 2  
Up{[baWF  
public void setSSiteURL(String value) :D*U4< /u  
{ =..Bh8P71!  
sSiteURL = value; aOH|[  
} ^K;k4oK  
sFc\L94  
. :Skc  
public String getSFilePath() j:h}ka/!p  
{ sq!$+=1-X  
return sFilePath; mY.v:  
} 1Z) Et,  
8cG?p  
G IN|cv=  
public void setSFilePath(String value) #B;P4n3  
{ c,4~zN8Ou  
sFilePath = value; -g@!\{  
} m<h%BDSzr{  
/?eVWCR  
g}s$s}  
public String getSFileName() Y~AjcqS  
{ )O]6dd  
return sFileName; '{"Rjv7  
} QselW]  
j|t=%*  
3[ xdls  
public void setSFileName(String value) ECOJ .^  
{ ~Q&J\'GQH  
sFileName = value; HU'Mi8xxy  
} ob\-OMNs@  
hx9{?3#  
--WQr]U/  
public int getNSplitter() V`y^m@U!  
{ VHxBs  
return nSplitter; ( zWBrCX  
} <0})%V?-  
X:oOp=y]|  
`}EnY@*h  
public void setNSplitter(int nCount) krUtOVI  
{ Vh^y6U<  
nSplitter = nCount; ^ Oh  
} k7^hc th  
} \rS*\g:i  
4j#y?^s  
(xHmucmwp  
/* J].Oxch&y  
**Utility.java $-}&RW9  
*/ % T({;/  
package NetFox; Sc7 Ftb%  
 >Uw:cq  
)0VL$A  
public class Utility { 'z ?Hv  
x4WCAqi/2  
cUY-  
public Utility() geme_  
{ eFG/!b<17  
3`bQ0-D;  
;P91'B~t  
} {7o3wxsS  
6KMO*v  
//线程睡眠 |J-X3`^\H  
public static void sleep(int nSecond)  [E1qv;   
{ #EH=tJgO|J  
try{ "`>6M&`U  
Thread.sleep(nSecond); 0P$1=oK  
} 8A#,*@V[  
catch(Exception e) ~CNB3r5R  
{ MgXZN{  
e.printStackTrace (); Tn&_ >R  
} csy6_q(  
} MTu\T  
Sq5,}oT_{j  
//日志 \Y4(+t=4  
public static void log(String sMsg) B[N]=V  
{ TTXF r  
System.err.println(sMsg); w?ugZYwX*  
} NM{)liP ;8  
_4by3?<c  
J :O!4gI  
public static void log(int sMsg) cYA:k  
{ e$[O J<t  
System.err.println(sMsg); ZC?~RXL(  
} wW%b~JX  
} $|~ <6A{y  
uj8saNu  
287j,'vR  
/* ^B<-.(F  
**TestMethod.java 4fi4F1f  
*/ /HdXJL9B  
package NetFox; 1dN/H)]  
V'kBF2}   
dla_uXtM6  
public class TestMethod { 1CC0]pyHX  
 ?(9*@  
=t,oj6P~  
public TestMethod() hIV9.{J  
{ ///xx/weblogic60b2_win.exe LeCc`x,5  
try{ _}F& ^  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "S;4hO  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j9fBl:Fr  
SiteFileFetch fileFetch = new SiteFileFetch(bean); !]F`qS>  
fileFetch.start(); o@)Fy51DD  
} Ue}1(2.v  
catch(Exception e){e.printStackTrace ();} 1S?~ c25=h  
j,OA>{-$  
d]E=w6 +;Q  
}  .\oz  
Ic'D# m  
G#%Sokkb'  
public static void main(String[] args) & DP"RWT/  
{ Oe Q[-e  
new TestMethod(); wq?"NQ?O<  
} iHv+I~/  
} F@<cp ?dR  
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