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http断点续传简单实现(java)

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/* oore:`m;  
**SiteFileFetch.java k!T-X2L=  
*/ [,Y;#;   
package NetFox; 7CCSG{k  
import java.io.*; a *bc#!e  
import java.net.*; @7t*X-P.;-  
4<- E0  
*c( J4  
public class SiteFileFetch extends Thread { s]HJcgI  
x&N@R?AG1  
m;sYg  
SiteInfoBean siteInfoBean = null; //文件信息Bean UZL-mF:)&  
long[] nStartPos; //开始位置 .G}$jO}  
long[] nEndPos; //结束位置 vos-[$  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ZSB;4 ?:h  
long nFileLength; //文件长度 fc<,kRp  
boolean bFirst = true; //是否第一次取文件 #bb$Icmtk  
boolean bStop = false; //停止标志 rW)}$|-Z  
File tmpFile; //文件下载的临时信息 PKev)M;C+  
DataOutputStream output; //输出到文件的输出流 k#2b3}(,  
`uc`vkVZ  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) #UnGU,J  
public SiteFileFetch(SiteInfoBean bean) throws IOException QZ5%nJme_  
{ FC4hvO(/m  
siteInfoBean = bean; qvs[Gkaa@  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); >`n)-8  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); :U faMe5  
if(tmpFile.exists ()) V.!z9AQ  
{ ioslarw1J  
bFirst = false; xw*/8.Md6f  
read_nPos(); 0Rn`63#  
} "VeNc,-nfQ  
else B~3qEdoK5`  
{ aSeh?2n8  
nStartPos = new long[bean.getNSplitter()]; HmV JkkksJ  
nEndPos = new long[bean.getNSplitter()]; 1 y7$"N8Xo  
} _Ry  
@iVEnb.'  
ZO\bCrk  
(DM8PtZg  
} d 8z9_C-  
_2<k,Dl;RY  
 P!/:yWd  
public void run() UFE~6"t(  
{ ?osYs<k \  
//获得文件长度 'fIG$tr9X  
//分割文件 =/N0^  
//实例FileSplitterFetch =Q8$O 2TW  
//启动FileSplitterFetch线程 YY$O"!."  
//等待子线程返回 hw&~OJeo  
try{ tY?evsVgz  
if(bFirst) 6}_J;g\|  
{ } ejc  
nFileLength = getFileSize(); af/;Dr@  
if(nFileLength == -1) >;X^+JH!)  
{ 7v(<<>  
System.err.println("File Length is not known!"); wHErF #xo  
} z6OJT6<'  
else if(nFileLength == -2) !M k]%  
{ Z?'?+48xv4  
System.err.println("File is not access!"); Wp=:|J   
} 0urM@/j+  
else P' k`H  
{ +B OuU#  
for(int i=0;i<nStartPos.length;i++) .:;#[Z{-  
{ kJ0otr2P  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Rx4O?7;  
} L;' v,s  
for(int i=0;i<nEndPos.length-1;i++) \fC}l Ll  
{ D]Gt=2\NG9  
nEndPos = nStartPos[i+1]; MLn?t^v-  
} G]I^zd&P  
nEndPos[nEndPos.length-1] = nFileLength; j"<F?k@`Q  
} ;4(FS  
} ACH!Gw~  
y/ah<Y0(  
RTYhgq  
//启动子线程 x;/%`gKn8  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r)Iq47Uiw  
for(int i=0;i<nStartPos.length;i++) ?E7.x%n7X5  
{  av!~B,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wEIAU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7A>glZ/x  
nStartPos,nEndPos,i); _+nlm5  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o n?8l?iQ  
fileSplitterFetch.start(); b .v^:M  
} 9,Ug  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j*1O(p+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?;Ge/~QU5  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b%I2ig  
nEndPos = " + nFileLength); .sbV<ulbc  
// fileSplitterFetch[nPos.length-1].start(); M{~KT3c  
a.g:yWL\  
-\fn\n  
//等待子线程结束 AlT04H   
//int count = 0; rxAb]~MMp  
//是否结束while循环 n5 jzVv  
boolean breakWhile = false; y :8Oc?  
z,=k F I  
.JL?RH2@8  
while(!bStop) RLbxNn  
{ $.r:  
write_nPos(); .cm$*>LW:x  
Utility.sleep(500); #3Jn_Y%P.  
breakWhile = true; 4O3-PU>N  
V s1Z$HS`  
54, (;  
for(int i=0;i<nStartPos.length;i++) n>I NJ  
{ xn 4-^2  
if(!fileSplitterFetch.bDownOver) hlTM<E  
{ _cH 7lO[  
breakWhile = false; c*x5t"{  
break; )~[hf,R5S  
} p'IF2e&z  
} <f`G@  
if(breakWhile) - AxO1 qO  
break; [O(8iz v  
].<B:]:,  
@I|gA  
//count++; bT{iei]?  
//if(count>4) v}\Nx[}  
// siteStop(); ?)B\0` %*'  
} y2 ,M9  
{QTnVS't 0  
4&([<gyR<  
System.err.println("文件下载结束!"); !5K9L(gqb  
} 9;u&,R  
catch(Exception e){e.printStackTrace ();} }e*OprF  
} X,h"%S<c#H  
KPSHBv-#  
 ,L}  
//获得文件长度 pe$l'ur  
public long getFileSize() |\MgE.N  
{ m dTCe HX  
int nFileLength = -1; vMV}M%~  
try{ 2bk~6Osp  
URL url = new URL(siteInfoBean.getSSiteURL()); pT`oC&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [q{[Avqf  
httpConnection.setRequestProperty("User-Agent","NetFox"); S( r Fa  
L) ]|\|  
mxJ& IV  
int responseCode=httpConnection.getResponseCode(); qE&R.I!o  
if(responseCode>=400) 4R/cN' -  
{ "?UBW5nM#  
processErrorCode(responseCode); fSFb)+  
return -2; //-2 represent access is error g",htYoEnj  
} [~<X|_L G  
U6@Hgi>  
B#T4m]E/  
String sHeader; 8vLaSZ="[  
Yq?FiE0  
VgO:`bDF  
for(int i=1;;i++) zg2}R4h  
{ ?@i_\<A2  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]FNqNZ  
//Utility.log(in.readLine()); sox0:9Oqnf  
sHeader=httpConnection.getHeaderFieldKey(i); $Dm2>:Dmt  
if(sHeader!=null) j!:^+F/  
{ &6`h%;a/&  
if(sHeader.equals("Content-Length")) 58@YWv Ak  
{ R6A{u(  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =k\V~8XZ  
break; fGtUr _D  
} j:;[Y`2  
} #DI%l`B  
else B~RVFc +  
break; jLRh/pbz4  
} :d ts>  
} 8(Ab NQ  
catch(IOException e){e.printStackTrace ();} +I {ZW}rA  
catch(Exception e){e.printStackTrace ();} D 1Q@4  g  
TUQ+?[  
#Jo#[-r  
Utility.log(nFileLength); uoM;p'  
8i=c|k,GL.  
>vPDF+u  
return nFileLength; *?a rEYc8  
} b!7*bFTt  
69{BJ] q  
x"9e eB,  
//保存下载信息(文件指针位置) oK5"RW  
private void write_nPos() ([r4N#lx  
{ oWu2}#~z_  
try{ T5g}z5~"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); x9s 7:F  
output.writeInt(nStartPos.length); =skw@c ^  
for(int i=0;i<nStartPos.length;i++) ur,!-t(~t  
{ 2|KgRk|!  
// output.writeLong(nPos); V kA$T8  
output.writeLong(fileSplitterFetch.nStartPos); [!ghI%VK  
output.writeLong(fileSplitterFetch.nEndPos); LK}Ih@ f  
} &G)I|mv  
output.close(); h2SVDKj  
} Y%FQ]Q=+  
catch(IOException e){e.printStackTrace ();} 78}QaE  
catch(Exception e){e.printStackTrace ();} ZPieL&uV`  
} zF9SZ#{a  
4' ym vR  
L"|~,SVF  
//读取保存的下载信息(文件指针位置)  jIMT&5k  
private void read_nPos() K/,y"DUN&  
{ s\k4<d5  
try{ H6Mqy}4W  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); E,S[3+  
int nCount = input.readInt(); Li jisE  
nStartPos = new long[nCount]; QgZwU$`p0  
nEndPos = new long[nCount]; o"te7nBI  
for(int i=0;i<nStartPos.length;i++) "%o,P/<X  
{ :ub 4p4h*  
nStartPos = input.readLong(); OD*\<Sc  
nEndPos = input.readLong(); csceu+ IA  
} lTe7n'y^^  
input.close(); KxZO.>,  
} `K,{Y_  
catch(IOException e){e.printStackTrace ();} 8 z) K  
catch(Exception e){e.printStackTrace ();} ~$GRgOn  
} PJq;OM|  
b) k\?'j  
0h[p w   
private void processErrorCode(int nErrorCode) Z`UwXp_s  
{ |\?mX=a.y  
System.err.println("Error Code : " + nErrorCode); s#%$aQ|Fp  
} yJCqP=  
F3-<F_4.w  
\(ygdZ{R  
//停止文件下载 S_E-H.d"  
public void siteStop() 0Jz5i4B  
{ *Kpk1  
bStop = true; KW* 2'C&  
for(int i=0;i<nStartPos.length;i++) [g bYIwL.  
fileSplitterFetch.splitterStop(); 0zQ^ 6@  
ne]P-50  
c>_tV3TDA  
} >Mu I-^ 3  
} fgiOYvIS2m  
//负责部分文件的抓取 5`TbM  
**FileSplitterFetch.java RZ(*%b<C  
*/ \3M<_73  
package NetFox; ,buSU~c_Q  
S(B$[)(  
qXOWCYqs  
import java.io.*; ae1?8man  
import java.net.*; zn,y'},  
"!ZQ`yl  
HHT_}_?  
public class FileSplitterFetch extends Thread { R&>G6jZ?8  
Fgx{ s%&-  
uPVM>xf>w  
String sURL; //File URL #.<Uy."z2  
long nStartPos; //File Snippet Start Position ~  4v  
long nEndPos; //File Snippet End Position WpPm|h  
int nThreadID; //Thread's ID 4LEWOWF}  
boolean bDownOver = false; //Downing is over r8.`W\SKX  
boolean bStop = false; //Stop identical }ZQ)]Mr  
FileAccessI fileAccessI = null; //File Access interface 9H~2 iW,Q;  
dRdI('  
bW]7$?acv  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HE;}B!>  
{ iyA=d{S;V  
this.sURL = sURL; ~XzT~WxW  
this.nStartPos = nStart; ;PS V3Zh  
this.nEndPos = nEnd; v qt#JdPp9  
nThreadID = id; 'n:|D7t  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Vu0d\l^$  
} zBQV2.@  
wMW."gM|  
RP@U0o  
public void run() /C[Q?  
{ O$qxo &  
while(nStartPos < nEndPos && !bStop) C+0MzfLgf  
{ KKBrw+)AJ  
B(pxyv)  
f`$F^=  
try{ ,4Q1[K35B  
URL url = new URL(sURL); 3WVH8Sb  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fy; sVB  
httpConnection.setRequestProperty("User-Agent","NetFox"); ,Y:ET1:  
String sProperty = "bytes="+nStartPos+"-"; ty"|yA  
httpConnection.setRequestProperty("RANGE",sProperty); r}**^"mFy  
Utility.log(sProperty); Qe[ejj1o:  
&RJ*DAmL  
Fb!Ew`;QT  
InputStream input = httpConnection.getInputStream(); i,H(6NL.  
//logResponseHead(httpConnection); i/C`]1R/  
V< Ib#rd'  
*:5S*E&}V  
byte[] b = new byte[1024]; K2XRKoG  
int nRead; :17Pc\:DS  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~WjK'N4n5  
{ AV>_ bw.  
nStartPos += fileAccessI.write(b,0,nRead); bu?4$O  
//if(nThreadID == 1) L">\c5ca  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rD\)ndPv  
} fT2F$U  
\,AE5hnO  
3 T1,:r  
Utility.log("Thread " + nThreadID + " is over!"); V0l"tr@  
bDownOver = true; AMw#_8Y  
//nPos = fileAccessI.write (b,0,nRead); K7 J RCLA  
} 5K:'VX  
catch(Exception e){e.printStackTrace ();} .E:3I!dH7  
} gW5yLb_Vz$  
} u|mTF>L  
VLfc6:Yg  
t]CA!i`  
//打印回应的头信息  [HEljEv  
public void logResponseHead(HttpURLConnection con) /E39Z*  
{ y}F;~H~P  
for(int i=1;;i++) th1;Ym+Ze  
{ z/I\hC9i  
String header=con.getHeaderFieldKey(i); H|IG"JB  
if(header!=null) b9xvLR8  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l(y,lK=YP1  
Utility.log(header+" : "+con.getHeaderField(header)); 1K UM!DUD  
else V0<g$,W=  
break; ~.<QC<dN  
} `0_,>Z  
} g5C$#<28  
5|jsv)M+  
-U{CWn3G  
public void splitterStop() /V {1Zw=  
{ bess b>=  
bStop = true; -d.i4X3j  
} O**~ Tj  
}G)2HTaZ  
U*:ju+)k  
} oj(st{,  
;u-[%(00S  
2<T/N  
/* !(F?Np Am  
**FileAccess.java 9Tg k=  
*//文件访问(定位,写) l;SXR <EU  
package NetFox; I7#^'/  
import java.io.*; 3xz|d`A  
*E wDwS$$  
nWes,K6T  
public class FileAccessI implements Serializable{ iYf)FPET  
8og8;#mnyr  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `Frr?.3&-  
RandomAccessFile oSavedFile; +lXIv  
long nPos; TVM19)9  
%Z3B9  
n) j0h-  
public FileAccessI() throws IOException I 6'!b/  
{ p/qu4[Mm  
this("",0); P6I<M}p  
} 4?fpk9c{2  
O I0N(V  
'T|EwrS j  
public FileAccessI(String sName,long nPos) throws IOException !Ln 'Mi_B  
{ hD[r6c  
oSavedFile = new RandomAccessFile(sName,"rw"); y`i?Qo3  
this.nPos = nPos; D<`M<:nq  
oSavedFile.seek(nPos); m1e Sn |)7  
} )<f4F!?,A  
gN2oUbf8  
@uz(h'~  
public synchronized int write(byte[] b,int nStart,int nLen) s f.z(o  
{ #~m 8zG  
int n = -1; |)C #  
try{ H _JE)a:+  
oSavedFile.write(b,nStart,nLen); !' 0PM[  
n = nLen; [C/{ru&E  
} gt9(5p  
catch(IOException e) #+N_wIP4  
{ Ifokg~X~G  
e.printStackTrace (); ify48]  
} }[=)sb_  
ULhXyItL  
BIS.,  
return n; Fi'ZId  
} ilXKJJda  
D~bx'Wr+  
,c-*/{3  
} pss e^rFg  
J(K/z,4h  
\*&?o51 !e  
/* $)  M2  
**SiteInfoBean.java ff7#LeB9  
*/ !Eg2#a?  
package NetFox; &8pGq./lr=  
!C|Z+w9Y  
3 l}9'j  
public class SiteInfoBean { ~;z] _`_Va  
M~7Cb>%<  
-\USDi(  
private String sSiteURL; //Site's URL w?zy/+N~  
private String sFilePath; //Saved File's Path p>i8aN  
private String sFileName; //Saved File's Name $)nPj_h  
private int nSplitter; //Count of Splited Downloading File +V(^ "Z~  
vS"h`pL  
X-X`Z`o  
public SiteInfoBean() =1k%T{>  
{//nSplitter的缺省值为5 gKcBx6G Q  
//default value of nSplitter is 5 lXF7)H&T  
this("","","",5); rT=C/SKP  
} lo1bj*Y2  
\#]C !JQ  
pY[b[ezb  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YR? E z<p  
{ |h%HUau  
sSiteURL= sURL; eXD~L&s[  
sFilePath = sPath; 7W*a+^   
sFileName = sName; z]SEPYq:  
this.nSplitter = nSpiltter; *>"NUHq  
%6%mf>Guf  
nW*cqM%+  
} $)$ r  
^pH8'^n  
/qJCp![X  
public String getSSiteURL() oc]:Ty  
{ ul~6zBKO   
return sSiteURL; =|``d-  
} d=meh4Y  
%[5GGd5w  
ke!  
public void setSSiteURL(String value) S~ Z<-@S  
{ )/vom6y*   
sSiteURL = value; iqdU?&.;  
} hJ]Oa7r  
|/H?\]7  
=4'V}p  
public String getSFilePath() MU sF  
{ 9a=>gEF],@  
return sFilePath; f^*Yqa  
} NtM ? Jh  
Zj-U^6^L  
1x=x,lcL  
public void setSFilePath(String value) 7V8k =  
{ ZgG~xl\My  
sFilePath = value; 9) ,|h  
} ~c<8;,cjYR  
.)$MZyo  
z/+{QBen8  
public String getSFileName() EPH n"YK  
{ +or<(%o @  
return sFileName; OJ"./*H  
} e ><0crb  
J _dgP[  
{J izCUo_'  
public void setSFileName(String value) 3N-pND0>p  
{ $[Z~BfSQ  
sFileName = value; 2"?DaX  
} SepwMB4@  
bEj}J_#  
\?R#ZxP@  
public int getNSplitter() EnlAgL']|  
{ :H3/+/x  
return nSplitter; qzJ<9H  
} ZLxa|R7  
.MG83Si  
KUYwc@si\  
public void setNSplitter(int nCount) =f y|Dm74  
{ &PRoT#,  
nSplitter = nCount; J,)ytw]  
} [|1I.AZ{  
} aQ $sn<-l  
xSd&xwP  
BCe'J!  
/* ^Z#G_%\Y:  
**Utility.java \u{4=-C.  
*/ u>.a;BO  
package NetFox; G 3,v'D5  
#"KC29!Yj  
!hZ: \&V  
public class Utility { \Z3K ~  
d8vf kV B  
eK l; T  
public Utility() 3m!tb)  
{ 5v)bs\x6  
/ @"{u0  
pXl[I;  
} &l7E|.JE  
0y,w\'j  
//线程睡眠 5 | ,b  
public static void sleep(int nSecond) I/tMFg  
{ ap )B%9  
try{ Uzzm2OS`  
Thread.sleep(nSecond); s$>n U  
} M Zz21H  
catch(Exception e) YIg43Av  
{ z8ZQL.z%h  
e.printStackTrace (); PBb&.<   
} 9/29>K_  
} PjEJ C@n  
1J"9Y81   
//日志 g ass Od  
public static void log(String sMsg) b{ xlW }S  
{ clV^Xg8D  
System.err.println(sMsg); g?v(>#i  
} >":xnX#  
X2Z)> 10  
CUI+@|]%  
public static void log(int sMsg) wxo  
{ 2=Naq Ht(  
System.err.println(sMsg); ) yMrE T m  
} iO5g30l  
} aim\ 3y~  
8]&:'  
T8z?_ *k  
/* }Cu[x'J  
**TestMethod.java $xZ ~bE9  
*/ Cn3 _D  
package NetFox;  SW#/;|m  
f; |fS~  
zZCRej  
public class TestMethod { (?\+  
5\bGCf  
g) oOravV  
public TestMethod() Mz6(M,hkq  
{ ///xx/weblogic60b2_win.exe 6EyPZ{  
try{ ZK^cG'^2|  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rl%,9JD!  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PmE)FthdP(  
SiteFileFetch fileFetch = new SiteFileFetch(bean);  rvd $4l^  
fileFetch.start(); WqNXE)'  
} %/ y=_G  
catch(Exception e){e.printStackTrace ();} #mu L-V  
YkWHI (p  
h7"U1'b  
} W[O]Aal{  
$C\ETQ@  
qXW\/NT"p<  
public static void main(String[] args) dz9U.:C  
{ Z{0BH{23  
new TestMethod(); f+ceL'fr  
} 8-nf4=ll  
} ~%/Rc`  
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