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http断点续传简单实现(java)

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/* -s Iji)t  
**SiteFileFetch.java ki`7S  
*/ "Xq.b"N{*  
package NetFox; z Qtg]@S  
import java.io.*; yj!4L&A  
import java.net.*; W ~sP7&sp  
ooa>~!91P  
J6}J/  
public class SiteFileFetch extends Thread { 'Dl31w%:  
bbevy!m  
{1 fva^O  
SiteInfoBean siteInfoBean = null; //文件信息Bean RM2<%$  
long[] nStartPos; //开始位置 G5~ Jp#uA  
long[] nEndPos; //结束位置 :p^7XwX%w  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 X.V6v4  
long nFileLength; //文件长度 XBi}hT  
boolean bFirst = true; //是否第一次取文件 Gb]t%\  
boolean bStop = false; //停止标志 C FqteY"  
File tmpFile; //文件下载的临时信息 u Ey>7I  
DataOutputStream output; //输出到文件的输出流 }r`m(z$z  
F)x^AJi e  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) <0!/7*;#ZT  
public SiteFileFetch(SiteInfoBean bean) throws IOException ]<\Ft H  
{ 8:V:^`KaSs  
siteInfoBean = bean; "0al"?  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); $ K>.|\  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); y#-mj,e  
if(tmpFile.exists ()) % j4  
{ &HdzbKO=  
bFirst = false; I8=p_Ie  
read_nPos(); S i[:l  
} FF]xwptrx  
else -z"=d<@  
{ tY=sl_  
nStartPos = new long[bean.getNSplitter()]; U#3Y3EdF<  
nEndPos = new long[bean.getNSplitter()]; gp Aqz Y  
} O=c^Ak   
8P8@i+[]W  
0'ha!4h3Z  
wGfU@!m  
} Q9v OY8  
"p<B|  
u*#j;Xc  
public void run() s>8;At-  
{ =?Y%w%2  
//获得文件长度 +AVYypql8K  
//分割文件 A1{ 7g<k6  
//实例FileSplitterFetch \bJ,8J1C  
//启动FileSplitterFetch线程 4,D$% .  
//等待子线程返回 W10=SM}  
try{ 24u;'i-y5  
if(bFirst) v[efM8  
{ 0"q^`@sZ  
nFileLength = getFileSize(); $ekJs/I&  
if(nFileLength == -1) qi!Nv$e  
{ $ f`\TKlN  
System.err.println("File Length is not known!"); mx`C6G5  
} 4c"x&x|  
else if(nFileLength == -2) h`X>b/V  
{ ;{xk[f m=  
System.err.println("File is not access!"); N;4tvWI  
} C^sHj5\(  
else c#l W ?  
{ ")%)e;V3  
for(int i=0;i<nStartPos.length;i++) OV)J  
{ )%e`SGmp  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 2u0C ~s  
} _=ani9E]uF  
for(int i=0;i<nEndPos.length-1;i++) >^vyp!  
{ 7v9l+OX,6  
nEndPos = nStartPos[i+1]; QH:PClW![  
} u(W%snl  
nEndPos[nEndPos.length-1] = nFileLength; Q2wEt >0a  
} [se J'Io  
} VFUuG3p)  
N 2|?I(\B  
*`]LbS  
//启动子线程 EjZ_|Q  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bDh,r!I  
for(int i=0;i<nStartPos.length;i++) :q6j{C(  
{ :Osw4u]JXd  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E yJWi<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FbxrBM  
nStartPos,nEndPos,i); 3f;W+^NY  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jb. V4  
fileSplitterFetch.start(); .L;M-`^  
} y#%*aV}|B  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j<+Q Gd%  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &DnX6%2  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RLuA^ONI  
nEndPos = " + nFileLength); X%ii z  
// fileSplitterFetch[nPos.length-1].start(); ,Jqi J?,4C  
n)]]g3y2  
<PCa37  
//等待子线程结束 {FV_APL9_  
//int count = 0; Ja$Ple*XU8  
//是否结束while循环 &j4 1<A  
boolean breakWhile = false; crx8+  
5X2&hG*  
5[^pU$Y  
while(!bStop) AcF6p)@_  
{ P+tnXT>nE  
write_nPos(); 1A>>#M=A  
Utility.sleep(500); Y", :u@R  
breakWhile = true; E+>$@STv#  
;MD6iBD  
GEJEhwO;H  
for(int i=0;i<nStartPos.length;i++) 5i 56J1EC  
{ QFn .<@  
if(!fileSplitterFetch.bDownOver) R $vo  
{ @m*^v\q<u  
breakWhile = false; J!l/!Z>!cF  
break; DEmU},<S  
} <B,z)c  
} p[kEFE,%  
if(breakWhile) aZK%?c  
break; ko-:) z  
$w,&h:.p  
85$W\d  
//count++; wWaO"N]  
//if(count>4) (_2;}eg  
// siteStop(); $+#Lq.3,  
} ) `u)#@x  
u 3&9R)J1  
3vs;ZBM  
System.err.println("文件下载结束!"); zq(R!a6  
} 'q+CL&D  
catch(Exception e){e.printStackTrace ();} 9NX/OctFa'  
} | Vl Q0{  
nYfZ[Q>v  
i+`N0!8lY  
//获得文件长度 Knd2s~S  
public long getFileSize() La$*)qD,  
{ -Xm/sq(i)%  
int nFileLength = -1; Iu<RwB[#Q  
try{ 58T<~u7  
URL url = new URL(siteInfoBean.getSSiteURL()); MiB"CcU  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u$A*Vsmr  
httpConnection.setRequestProperty("User-Agent","NetFox"); |&O7F;/_  
z: x|;Ps!  
-Re4G78%  
int responseCode=httpConnection.getResponseCode(); s@Q, wa(  
if(responseCode>=400) _FG?zE  
{ !1g2'  
processErrorCode(responseCode); <,r(^Ntz  
return -2; //-2 represent access is error G}MJWf Hl  
} l$j/Ye]  
f$\gm+&hXE  
qXI>x6?*  
String sHeader; JqX+vRY;dd  
RtE2%d$JT  
=D1%-ym  
for(int i=1;;i++) Hchh2  
{ KW1 7CJ@  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U_1syaY!  
//Utility.log(in.readLine()); #q[k"x=c  
sHeader=httpConnection.getHeaderFieldKey(i); *^]lFuX\&E  
if(sHeader!=null) :fxG]uf-P  
{ U9uy (KOW  
if(sHeader.equals("Content-Length")) ups] k?4  
{ 2aROY2  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4T]n64Yid  
break; VeLuL:4I  
} 6jdNQC$#B  
} 6xFvu7L_c;  
else ?8{x/y:  
break; :E$<!q  
}  X`REhvT  
} F_Pv\?35z  
catch(IOException e){e.printStackTrace ();} 82mKI+9&"  
catch(Exception e){e.printStackTrace ();} //[zUn  
Iuh1tcc  
_trF/U<  
Utility.log(nFileLength); X>0$zE@0  
2swHJ.d\  
dZS v=UY)  
return nFileLength; Rn"Raq7Cn*  
} s]D&):  
-!p +^wC  
W,\LdQ  
//保存下载信息(文件指针位置) g~>g])  
private void write_nPos() DU@ZLk3  
{ %Ls5:Z=  
try{ L?W F[nF R  
output = new DataOutputStream(new FileOutputStream(tmpFile)); G;^},%<  
output.writeInt(nStartPos.length); {$dq7m(  
for(int i=0;i<nStartPos.length;i++) tEj-c@`"x-  
{ Oa8lrP`(  
// output.writeLong(nPos); >?pWbL  
output.writeLong(fileSplitterFetch.nStartPos); BqF%2{  
output.writeLong(fileSplitterFetch.nEndPos); 5x( [fG  
} F4Jc7k2  
output.close(); x4r=ENO)q  
} V3^=Mj2"  
catch(IOException e){e.printStackTrace ();} R]s\s[B  
catch(Exception e){e.printStackTrace ();} E{Gkq:  
} A,P_|  
dZMOgZ.!yr  
fR:BF47  
//读取保存的下载信息(文件指针位置) _ct18nh9  
private void read_nPos() oNk ASAd  
{ V>8)1)dF  
try{ "kYzgi  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1;e"3x"  
int nCount = input.readInt(); CG`s@5y>5  
nStartPos = new long[nCount]; __F?iRrCM  
nEndPos = new long[nCount]; eU[f6OGqC  
for(int i=0;i<nStartPos.length;i++) f{} zqCK  
{ @L p;p$G`  
nStartPos = input.readLong(); ?0ezr[`.  
nEndPos = input.readLong(); Aqc Cb[1r  
} |^uU&O;.  
input.close(); lur$?_gt  
} m'L7K K-Y)  
catch(IOException e){e.printStackTrace ();} 'aq9]D_k  
catch(Exception e){e.printStackTrace ();} Z~JX@s0v  
} 3)? v  
*{ =5AW}o  
2 /rDi  
private void processErrorCode(int nErrorCode) $p(,Qz(.8  
{ FuA8vTV{  
System.err.println("Error Code : " + nErrorCode); y([""z3<w  
} %Ydzzr3  
M[;N6EJH  
Qh 3V[br  
//停止文件下载 QG|KZ8uO  
public void siteStop() vf |lF9@U  
{ igoUKDNiQ-  
bStop = true; 0<,Q7onDD:  
for(int i=0;i<nStartPos.length;i++) +IRr&J*P  
fileSplitterFetch.splitterStop(); pPC_ub  
0:,8Ce  
X2 Z E9b  
} yq?7!X  
} R%(ww  
//负责部分文件的抓取 Hy?+p{{G  
**FileSplitterFetch.java tt|v opz  
*/ $. ;j4%%  
package NetFox; c`hj^t  
YTQom!O  
)Mtw9[  
import java.io.*; UL46%MFQ\  
import java.net.*; 0+i\j`O&  
&WqKsH$  
Q%seV<!/  
public class FileSplitterFetch extends Thread { nJdO~0}3  
gypE~@  
TAkM-iyH]  
String sURL; //File URL sRM3G]nUr  
long nStartPos; //File Snippet Start Position ?|&plf |  
long nEndPos; //File Snippet End Position \Y EV 5  
int nThreadID; //Thread's ID \z/_vzz4  
boolean bDownOver = false; //Downing is over 34@f(^d+^  
boolean bStop = false; //Stop identical bZ/4O*B  
FileAccessI fileAccessI = null; //File Access interface Cb{n4xKW6  
,>DaS(  
SM<kR1bo  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f9Vxtd  
{ af:wg]g  
this.sURL = sURL; 75O-%9lFF  
this.nStartPos = nStart; S.!0~KR: U  
this.nEndPos = nEnd; YivWvV  
nThreadID = id; K*ZH<@o4  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nDdF(|Qt  
} C:]&V*d.v4  
!A.Kb74  
QO'=O}e  
public void run() b),_rr  
{ F(-1m A&-  
while(nStartPos < nEndPos && !bStop) S`!MoIMsD  
{ 4z~%gt74O]  
&HPzm6.3  
33R_JM{  
try{ /,>@+^1  
URL url = new URL(sURL); ""j(wUp-W  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OMr&f8  
httpConnection.setRequestProperty("User-Agent","NetFox"); NwK(<dzG  
String sProperty = "bytes="+nStartPos+"-"; Qx_K)  
httpConnection.setRequestProperty("RANGE",sProperty); pB3dx#l  
Utility.log(sProperty); [n53 eC  
if S) < t  
JD\:bI  
InputStream input = httpConnection.getInputStream(); v{R:F  
//logResponseHead(httpConnection); jh3LD6|s}  
`7;I*|  
p'`SYEY@Z  
byte[] b = new byte[1024]; JG2)-x;9  
int nRead; C ?^si  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :&]THUw  
{ . PzlhTL7  
nStartPos += fileAccessI.write(b,0,nRead);  2Z ? N  
//if(nThreadID == 1) dM A"% R  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~}SOd<n)|  
} UUxDW3K  
..ig jc#UF  
N"i'[!H%  
Utility.log("Thread " + nThreadID + " is over!"); @ =RH_NB  
bDownOver = true; =5JTVF  
//nPos = fileAccessI.write (b,0,nRead); Jy,Dcl  
} G1Qc\mp  
catch(Exception e){e.printStackTrace ();} IZ2c<B5&  
} R+c  {Pl  
} 6j]pJ]F6  
ty8\@l  
'qosw:P  
//打印回应的头信息 G(alM=q  
public void logResponseHead(HttpURLConnection con) u -CCUMR  
{ a;Nj'M~U  
for(int i=1;;i++) HWr")%EhD  
{ DhQYjC[  
String header=con.getHeaderFieldKey(i); #+1*g4m~B  
if(header!=null) ]LvpYRU$P  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [*-DtbEk  
Utility.log(header+" : "+con.getHeaderField(header)); ODG OWw0  
else \#bk$R@  
break; 6 u3$ .Q  
} UTatcn  
} hM!D6: t  
:Fm{U0;"  
5"f')MKUV9  
public void splitterStop() htn"rY(  
{ sA3=x7j%c  
bStop = true; ^-CQ9r*  
} UMg*Yv%  
AZmABl  
[:HT=LX3  
} ]-o0HY2  
GEg8\  
ZMSP8(V  
/* 0]dL;~0y.  
**FileAccess.java Kvu0Av-7  
*//文件访问(定位,写) ''9FB5  
package NetFox; k1A64?p  
import java.io.*; a95QDz  
QR!8n  
U]!D=+  
public class FileAccessI implements Serializable{ t83n`LC  
8:j8>K*6  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u S$:J:Drx  
RandomAccessFile oSavedFile; e1e2Wk  
long nPos; wv 7j ES  
C<!%VHs  
V 0<>Xo%  
public FileAccessI() throws IOException WJG&`PP  
{ L< MIl[z7  
this("",0); EwSE;R -  
} ( }DCy23  
:*wnO;eN  
JW!SrM xF  
public FileAccessI(String sName,long nPos) throws IOException AiXxn'&i  
{ P^-tGo!  
oSavedFile = new RandomAccessFile(sName,"rw"); SwESDo)  
this.nPos = nPos; 0K -jF5i$`  
oSavedFile.seek(nPos); 3P1OyB  
} tHhA _  
,q yp2Y7  
?#F}mOVAa  
public synchronized int write(byte[] b,int nStart,int nLen) %N!2 _uk5  
{ wo;`D  
int n = -1; @u./VK  
try{ `I.Uw$,P  
oSavedFile.write(b,nStart,nLen); * i[^-  
n = nLen; Z 8??+d=  
} mlgw0   
catch(IOException e) ?]S!-6:  
{ pKrol]cth8  
e.printStackTrace (); o=`FGowF  
} W s!N%%g  
%J06]FG7  
a7#J af  
return n; ?)9mHo^  
} tA+ c  
mZVYgJQ[  
/cBQE=]6  
} L]o 5=K  
?XVJ$nzW  
gB!K{ Io'  
/* m: 77pE&o  
**SiteInfoBean.java /? n 9c;w  
*/ $=8?@My<  
package NetFox; ?`Oh]2n)6  
jI$}\*g  
(ilU<Ht  
public class SiteInfoBean { F`9;s@V*  
M2ig iR  
i"uAT$xe  
private String sSiteURL; //Site's URL !$'s?rnh  
private String sFilePath; //Saved File's Path pU`4bT(w%  
private String sFileName; //Saved File's Name yQ> *F  
private int nSplitter; //Count of Splited Downloading File O>^0}  
_zQ3sm  
9,|&+G$  
public SiteInfoBean() L3 M]06y  
{//nSplitter的缺省值为5 #NM .g  
//default value of nSplitter is 5 #`6A}/@.+  
this("","","",5); bdiyS.a-  
} NJb5HoYZ  
`jR;RczC  
N{@kgc  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YX+Da"\  
{ /8baJ+D"4\  
sSiteURL= sURL; S8+Xk= x  
sFilePath = sPath; CCJ!;d;&87  
sFileName = sName; /#?lG`'1  
this.nSplitter = nSpiltter; QKYGeT7&Y'  
9k_3=KS3N  
tk5Bb`a  
} h5 Y3 v  
FAAqdK0  
6Cut[*lj^  
public String getSSiteURL() I(r^q"  
{ [o)P  
return sSiteURL; J;Az0[qMR  
} #2c-@),  
5-|fp(Ww_W  
Qci<cVgP  
public void setSSiteURL(String value) FJ3Xeo s4|  
{ $l:?(&u  
sSiteURL = value; |y@TI  
} &$fe%1#  
F"9f6<ge  
)J+vmY~&  
public String getSFilePath() 7 \aLK#  
{ 9viQ<}K<  
return sFilePath; r=dFk?8XbC  
} S86%o,Saq\  
VIL #q  
Ml8'=KN_  
public void setSFilePath(String value) ANh5-8y  
{ >\b=bT@iM  
sFilePath = value; 2s,wC!',  
} >S5:zz\  
,L&Ka|N0  
)+[IR  
public String getSFileName() |MvCEp  
{ xz YvD{>  
return sFileName; JpDc3^B*  
} @*W,Jm3Y  
`zAo IQ  
j3F[C:-zY  
public void setSFileName(String value) ]* -9zo0  
{ -\yaP8V  
sFileName = value; [Dp6q~RM  
} eHG**@"X  
a  1bu  
J ?$4Yf  
public int getNSplitter() _T^ip.o  
{ LR D71*/  
return nSplitter; ( B$;'U<  
} XiI@Px?FL  
0q"&AxNsP  
uj_u j!  
public void setNSplitter(int nCount) r?d601(fa  
{ d; \x 'h2  
nSplitter = nCount; $(_Xt-6  
} BuI&kU,WY  
} rWF~a ec  
>L?)f3_a  
*""'v   
/* uY5&93R  
**Utility.java FLY#   
*/ .Vq-<c%  
package NetFox; XXacWdh \  
#X7fs5$&  
&ZFsK c#  
public class Utility { n@w$5y1@  
=kohQ d.n  
xtN%v0ZZ  
public Utility() 0Ep%&>@  
{ l"!.aIY"e  
?f[#O&#  
j&) +qTV  
} [-_u{j  
m6QlIdl  
//线程睡眠 yL&F!+(/Ix  
public static void sleep(int nSecond) ? e%Pvy<i  
{ qR!SwG44+  
try{ ]1rr$f9  
Thread.sleep(nSecond); RUm1;MWs  
} Fsv%=E{  
catch(Exception e) I(ds]E ;_E  
{ Z6SM7? d  
e.printStackTrace (); z^S=ji U++  
} ;id0|x  
} K=VYR Y  
VWd=7  
//日志 r8+{HknB;  
public static void log(String sMsg) om$)8'A,l  
{ I :%(nKBK  
System.err.println(sMsg); L~SM#?z:ue  
} HS]|s':  
"zR+}  
f$9V_j-K+  
public static void log(int sMsg) &H;0N"Fn  
{ G$:T!  
System.err.println(sMsg); ` :Am#"j]}  
} Dms 6"x2  
} W1M<6T.{7  
=:mD)oX*  
&%L1n?>Q}  
/* j*<H18^G  
**TestMethod.java v7T05  
*/ #rqLuqw  
package NetFox; E"&fT!yi  
z '3  
2Q,e1' =  
public class TestMethod { $S|bD$e  
B@G'6 ?  
bcC ;i~9  
public TestMethod() `gfh]7T  
{ ///xx/weblogic60b2_win.exe #, W7N_mt  
try{ mu04TPj  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]wWN~G)2lV  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0RN]_z$;H  
SiteFileFetch fileFetch = new SiteFileFetch(bean); z%(m:/N70  
fileFetch.start(); 1XU sr;Wz  
} 0sto9n3  
catch(Exception e){e.printStackTrace ();} su>GeJiPW  
5Q,#Co  
w_q{C>- cR  
} _n@#Lufx  
J7/"8S_#N  
c?"#x-<1s  
public static void main(String[] args) y|Tb&XPD  
{ :w:hqe|_  
new TestMethod(); w4<1*u@${  
} j8WnXp_  
} \I1+J9Gl  
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