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http断点续传简单实现(java)

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/* r2A(GUz  
**SiteFileFetch.java !br0s(|  
*/ i 7:R4G(/#  
package NetFox; i]{M G'tg  
import java.io.*; 41y}n{4n8  
import java.net.*; .aWEXJ  
:]%z8,6k  
,bRvj8"M  
public class SiteFileFetch extends Thread { _5I" %E;S  
} FcWzi  
| fAt[e_E  
SiteInfoBean siteInfoBean = null; //文件信息Bean 4e d+'-"m  
long[] nStartPos; //开始位置 Sr)rKc  
long[] nEndPos; //结束位置 q^],K'  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 j[ !'l,I  
long nFileLength; //文件长度 kN9pl^2  
boolean bFirst = true; //是否第一次取文件 K8y/U(@|D  
boolean bStop = false; //停止标志 t.m65  
File tmpFile; //文件下载的临时信息 hETTD%  
DataOutputStream output; //输出到文件的输出流 MR$Bl"d  
45l/)=@@B  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 4C2JyP3  
public SiteFileFetch(SiteInfoBean bean) throws IOException ^|DI9G(Bs  
{ [m7jZOEu  
siteInfoBean = bean; RG=!,#X  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); W/U&w.$  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); V.Pb AN  
if(tmpFile.exists ())  ?C   
{ GH2D5HVN  
bFirst = false; +OkR7bl  
read_nPos(); '`^<*;w  
} BBy"qkTe  
else 1bb~u/jU  
{ H"W%+{AR  
nStartPos = new long[bean.getNSplitter()]; -:(,<Jt<  
nEndPos = new long[bean.getNSplitter()]; :(EU\yCzK  
} ` INcZr"  
|V{'W-` |[  
2ul!f7#E  
7-81,ADv(  
} :70cOt~Z  
-fu=RR  
SesJg~8  
public void run() n0#HPI"  
{ c;l d  
//获得文件长度 ?#^(QR|/  
//分割文件 :`6E{yfM  
//实例FileSplitterFetch H XF5fs  
//启动FileSplitterFetch线程 "FI]l<G&  
//等待子线程返回 GkjTE2I3  
try{ /7X:=~m  
if(bFirst) RrSo`q-h+  
{ g9OO#C>  
nFileLength = getFileSize(); HgY"nrogt$  
if(nFileLength == -1) dE2(PQb*P  
{ eX$P k:  
System.err.println("File Length is not known!"); `-S6g^Y  
} 0%.l|~CE&  
else if(nFileLength == -2) ZK4/o  
{ jvn:W{'Q  
System.err.println("File is not access!"); %76N$`{u  
} n\ aG@X%oq  
else !=>pI/ECQ*  
{ 31-%IkX+k  
for(int i=0;i<nStartPos.length;i++)  lTsl=  
{ S!o!NSn@1  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); :WejY`}H%  
} b 8v?@s~  
for(int i=0;i<nEndPos.length-1;i++) jI0gQ [  
{ B@dA?w.x  
nEndPos = nStartPos[i+1]; p;Kw$fQ?  
} 1{R 1:`  
nEndPos[nEndPos.length-1] = nFileLength; X.V7od>  
} G&MI@Hq  
} E`.dU<8HE  
Hw[u Sv8  
L !:}  
//启动子线程 8)3g!3S  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g83]/s+  
for(int i=0;i<nStartPos.length;i++) x7 jE Ns )  
{ qazM@  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :a(er'A  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^yiRrcOo  
nStartPos,nEndPos,i); [_ESR/&N  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u$d T^c  
fileSplitterFetch.start(); "1_eZ`  
} XJTY91~R  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S{aK\>>H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MDa 4U@Q  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dN J2pfvv  
nEndPos = " + nFileLength); h{I)^8,M  
// fileSplitterFetch[nPos.length-1].start(); BKe~ y  
&^^zm9{  
*?%DdVrO@  
//等待子线程结束 #WlIH7J8Tc  
//int count = 0; k2muHKBlk  
//是否结束while循环 )xIk#>)  
boolean breakWhile = false; jD9 ^DzFx  
gy/z;fB  
yU3fM?a  
while(!bStop) hrPm$`  
{ Lh0Pvq0C  
write_nPos(); vFXih'=_  
Utility.sleep(500); @D&VOJV  
breakWhile = true; .p&4]6  
uG@Nubdwuy  
m[,! orq  
for(int i=0;i<nStartPos.length;i++) ,Hn{nVU1R=  
{ OF'y]W&  
if(!fileSplitterFetch.bDownOver) B/g.bh~)q  
{ wYK-YY:Q3  
breakWhile = false; !8M]n  
break; vx /NG$  
} jHq.W95+P  
} hb'S!N5m  
if(breakWhile) ~itrM3^"w  
break; .zO/8y(@  
\wqi_[A  
EE5I~k 5  
//count++; {Sm^F  
//if(count>4) Vr0-evwfo  
// siteStop(); f}b= FV{  
} 21x?TZa  
-Zd0[& ']  
E'zLgU)r`  
System.err.println("文件下载结束!"); {(#Dou  
} H'Q4IRT  
catch(Exception e){e.printStackTrace ();} 5%j !SVW  
} `)$'1,]u  
h-<2N)>!  
:786Z,')  
//获得文件长度 -t2bHhG  
public long getFileSize() ?]SSmZpk  
{ HM ;9%rtO  
int nFileLength = -1;  Svj%O(  
try{ @DG$  
URL url = new URL(siteInfoBean.getSSiteURL()); 6Pc3;X~  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \zCT""'i  
httpConnection.setRequestProperty("User-Agent","NetFox"); =n|n%N4Y  
$lmGMljF  
`b 6j7  
int responseCode=httpConnection.getResponseCode(); jC7`_;>=  
if(responseCode>=400) 9q;n@q:29  
{ "pGSz%i-  
processErrorCode(responseCode); }S|~^  
return -2; //-2 represent access is error 3(l^{YC+[7  
} daS l.:1  
6jT+kq)  
aj;OG^(!2_  
String sHeader; F @ lJk|*_  
R@Ch3l@  
X}C }  
for(int i=1;;i++) ^Rriu $\  
{ H7!j5^  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A]^RV{P  
//Utility.log(in.readLine()); L5 ~wX  
sHeader=httpConnection.getHeaderFieldKey(i); Kt5;GUV  
if(sHeader!=null) QyN<o{\FD!  
{ :^7/+|}9p  
if(sHeader.equals("Content-Length")) ]p C/6'  
{ W=j  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H.#<&5f  
break; R@_i$Df|  
} c+P.o.k;  
}  uaN0X"  
else (F9U`1~4  
break; -)_"7}|u5  
} seO7/h_a  
} KLi&T mIB  
catch(IOException e){e.printStackTrace ();} YJi C}.4Q  
catch(Exception e){e.printStackTrace ();} ]/>(C76  
H0tj Bnu   
~kM# lh7At  
Utility.log(nFileLength); J_) .Hd  
SJ4[n.tPI  
Q@zD'G >  
return nFileLength; ha_&U@w  
} #_)<~  
QEo i9@3  
?QuD:v ck  
//保存下载信息(文件指针位置) . AJ(nJ)  
private void write_nPos() uEqL Dg  
{ NVqJN$z  
try{ ;Gf,$dbWn  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3Q'Q %2  
output.writeInt(nStartPos.length); Te&F2`vo  
for(int i=0;i<nStartPos.length;i++) \D Oqx  
{ @T>\pP]o  
// output.writeLong(nPos); F2jZ3[P  
output.writeLong(fileSplitterFetch.nStartPos); LDilrG)  
output.writeLong(fileSplitterFetch.nEndPos); "tax  
} M'gw-^(  
output.close(); );X &J:-l+  
} );-?~   
catch(IOException e){e.printStackTrace ();} AG ?cI@',  
catch(Exception e){e.printStackTrace ();} S+aXlb  
} ;jC}.] _)w  
4O}ZnE1[  
t.0F  
//读取保存的下载信息(文件指针位置) ^lADq']  
private void read_nPos() x z5 V.  
{ :Y/>] tS4  
try{ VHwAO:+-  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _`'VOY`o  
int nCount = input.readInt(); Wx~N1+  
nStartPos = new long[nCount]; /{h@A~<96  
nEndPos = new long[nCount]; /1A3 Sw  
for(int i=0;i<nStartPos.length;i++) NrQGoAOw  
{ -2Bkun4Pt  
nStartPos = input.readLong(); #6w\r&R6  
nEndPos = input.readLong(); %NH#8#';2  
} O"%b@$p\L  
input.close(); 3QNu7oo  
} |"t)#BUtL  
catch(IOException e){e.printStackTrace ();} 1>5l(zK!9  
catch(Exception e){e.printStackTrace ();} 1< 22,  
} U tb"6_   
L;jzDng<  
:x85:pa  
private void processErrorCode(int nErrorCode) `[.b>ztqgJ  
{ %ae|4u#b  
System.err.println("Error Code : " + nErrorCode); ddR*&.Y!a  
} \q2:1X |  
@D$^- S6  
9@'^}c#  
//停止文件下载 D}.Pk>5  
public void siteStop() +hoZW R  
{ nd~cpHQR^  
bStop = true; zn!H&!8&  
for(int i=0;i<nStartPos.length;i++) w +pK=R  
fileSplitterFetch.splitterStop(); &d5n_:^  
K=S-p3\g  
J3 Y-d7=|  
} H] i.\2z  
} 2L\}  
//负责部分文件的抓取 Nu}x`Qkmr  
**FileSplitterFetch.java G3[X.%g`  
*/ v@_^h}h/,=  
package NetFox; |AgdD  
j%_{tB  
?%)G%2  
import java.io.*; ;^fGQ]`4  
import java.net.*; j.}@9  
|_fmbG  
O $ p  
public class FileSplitterFetch extends Thread { 'aj97b;lpG  
mI$<+S1!  
"#<P--E9  
String sURL; //File URL g4p-$WyT8>  
long nStartPos; //File Snippet Start Position }02#[vg  
long nEndPos; //File Snippet End Position nw.,`M,N  
int nThreadID; //Thread's ID I%4)%  
boolean bDownOver = false; //Downing is over g3fxf(iY(  
boolean bStop = false; //Stop identical no~Yet+<"  
FileAccessI fileAccessI = null; //File Access interface 6A$  Y]u  
jFE1k(2e  
{DP%=4  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c;RL<83:  
{ YTb/ LeuT  
this.sURL = sURL; O{P@fv%~(o  
this.nStartPos = nStart; 3c%dErch  
this.nEndPos = nEnd; `lI(SS]w  
nThreadID = id; 1]DPy+  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gfr y5e  
}  gAFu  
[.ya&E)x  
\my5E\  
public void run() _lK+/"-l  
{ aRt`IcZYz  
while(nStartPos < nEndPos && !bStop) !Eqp,"ts7  
{ VXfp=JE  
F'NX  
uD'GI  
try{ u*W6fg/"  
URL url = new URL(sURL); v|]1x2191  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7dg2-4  
httpConnection.setRequestProperty("User-Agent","NetFox"); [unK5l4_!  
String sProperty = "bytes="+nStartPos+"-"; QGC%, F"+  
httpConnection.setRequestProperty("RANGE",sProperty); Un~ }M/  
Utility.log(sProperty); {Yt@H  
\w6A-daD0  
Z30r|Ufh  
InputStream input = httpConnection.getInputStream(); G8sxg&bf{  
//logResponseHead(httpConnection); Xyz w.%4c  
1o Z!Up0  
#0:N$'SZ  
byte[] b = new byte[1024]; gG?sLgL:  
int nRead; _"4u?C#  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d_ [l{  
{ f+WN=-F\  
nStartPos += fileAccessI.write(b,0,nRead); jPDk~|  
//if(nThreadID == 1) L\GjG&Y5  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R&v V! d  
} YA?46[:  
$;k2b4u  
2#y-3y<G  
Utility.log("Thread " + nThreadID + " is over!"); 6=aXz2.f  
bDownOver = true; [B2g{8{!  
//nPos = fileAccessI.write (b,0,nRead); CO<P$al  
} MS>QU@z7c  
catch(Exception e){e.printStackTrace ();} n7>L&?N#y#  
} "t ^yM`$5[  
} {S$]I)tV  
mdNIC  
s MZ90Q$  
//打印回应的头信息 m-wK8]t9  
public void logResponseHead(HttpURLConnection con) 9 SBVp 6'  
{ _Hp[}sv4)  
for(int i=1;;i++) G\PFh&  
{ ]YF_c,Q  
String header=con.getHeaderFieldKey(i); y\C_HCU H  
if(header!=null) $sfDtnRy  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *vqr+jr9  
Utility.log(header+" : "+con.getHeaderField(header)); 0t^Tm0RzH  
else eBN!!Y:7  
break; P {0iEA|k  
} wf,B/[,d  
} T F[8r[93  
LBw$K0  
Q7{/ T0  
public void splitterStop() xG7/[ jG  
{ _U<r@  
bStop = true; 141G~@-  
} 1SwKd*aRR?  
GKg&lM!O$  
S=^kR [O"  
} ^C|N  
/=i+7^  
G.B~n>}JU,  
/* "C~Zl&3  
**FileAccess.java -ld1o+'`v!  
*//文件访问(定位,写) QI WfGVc-  
package NetFox; 6");NHE  
import java.io.*; d95 $w8>  
XD8Q2un  
cq0#~20  
public class FileAccessI implements Serializable{ vxt<}h5J/!  
+#LD@)G  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q|] 9  
RandomAccessFile oSavedFile; mh :eUFe  
long nPos; ^!j,d_)b!  
ui!MQk+D9  
n]< >$  
public FileAccessI() throws IOException Xf/qUao  
{ _Z0O]>KH  
this("",0); #[ TOe  
} ]7/6u.G7R  
8w\ZY>d   
*f*o ,~8V1  
public FileAccessI(String sName,long nPos) throws IOException \-nbV#{  
{ 1R"?X'w  
oSavedFile = new RandomAccessFile(sName,"rw"); H]<@\g*l@P  
this.nPos = nPos; T:|PSJc0  
oSavedFile.seek(nPos); RK\$>KFE  
} nN*:"F/^  
av:9kPKm  
`;v5o4.`  
public synchronized int write(byte[] b,int nStart,int nLen) T@?uA*J  
{ C#tY};t  
int n = -1; 277Am*2  
try{ H"vy[/UcR  
oSavedFile.write(b,nStart,nLen); 6_zyPh  
n = nLen; YkJnZ_k/P  
} %1UdG6&J_  
catch(IOException e) tGVC"a  
{ M\L^ Wf9  
e.printStackTrace (); c-" .VF  
} V")u y&Ob  
'p> *4}  
gu|cQ2xV  
return n; Qs #7<NQ  
} wxW\L!@  
(-bLP  
? f>pKe  
} I?~iEO\nh  
/xh/M@G3  
1 [D,Mu%E  
/* -8pQI  
**SiteInfoBean.java dOx0'q"Z  
*/ /^9KZj  
package NetFox; fb;y*-?#  
K)_DaTmi)  
j3_vh<U\  
public class SiteInfoBean { /{sFrEMP\  
WcZck{ehd  
o>?#$~XNv  
private String sSiteURL; //Site's URL k=``Avp?  
private String sFilePath; //Saved File's Path N799@:.  
private String sFileName; //Saved File's Name >[&Zs3>  
private int nSplitter; //Count of Splited Downloading File 0$1-5XY9  
WJs2d73Qp  
72akOx   
public SiteInfoBean() ])D39  
{//nSplitter的缺省值为5 79G& 0 P\  
//default value of nSplitter is 5 6ntduXeNVh  
this("","","",5); M.h8Kr!.  
} Pp ~:e}  
p)y'a+|7  
-V 'h>K  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (I0QwB  
{ am(jmf::  
sSiteURL= sURL; ]<g`rR7}  
sFilePath = sPath; t/Y)%N  
sFileName = sName; xa]e9u%  
this.nSplitter = nSpiltter; ['#3GJz-  
)a0%62  
;($"_h  
} /^^wHW:  
R8n/QCeY{  
JR^#NefJ  
public String getSSiteURL() N2/t  
{ `zjbyY  
return sSiteURL; -JwwD6D  
} Lq cHsUFj  
riz[AAB  
d%w#a3(  
public void setSSiteURL(String value) Lcow2 SbH  
{ A{,ZfX;SPO  
sSiteURL = value; ~3r}6,%  
} #24 eogo~  
~uRL+<.c  
9f7T.}HM  
public String getSFilePath() \$[; d:9j  
{ ]aqg{XdGt  
return sFilePath; = k7}[!T  
} TL*8h7.(  
oJ`cefcWo  
]^c]*O[8  
public void setSFilePath(String value) 'pQ\BH  
{ wD|I^y;  
sFilePath = value; =lG/A[66  
} ml\2%07  
p"k[ac{  
tShyG! b  
public String getSFileName() VY]L<4BfGL  
{ '%\FT-{  
return sFileName; 4 /Q4sE~<  
} ed:[^#Lj  
nQ}$jOU &  
rUOl+p_47  
public void setSFileName(String value)  *CS2ndp  
{ Y}UVC|Ef  
sFileName = value; M,(UCyT  
} V<W$ h`  
nr>Os@\BU  
@?YO_</  
public int getNSplitter() u>-pg u  
{ f\]splL  
return nSplitter; `%nj$-W:  
} hH])0C  
/@`kM'1:  
sBV})8]K M  
public void setNSplitter(int nCount) Z @d(0 z  
{ @24)*d^1  
nSplitter = nCount; 9zs!rlzQ  
} u/S{^2`b  
} &>$+O>c ,  
3qNLosm#M  
(//f"c]/  
/* Gr}lr gPS  
**Utility.java ~4'AnoD1w  
*/ 0oiz V;B5%  
package NetFox; 1p }:K`#{  
0kOl,%Ey  
=>en<#[\:  
public class Utility { Yp(F}<f?  
#cdrobJ  
~;uc@GGo  
public Utility() m2h@*  
{ *%;+3SV  
RwyRPc _  
l:$i}.C  
} MeMSF8zSQ  
NPY\ >pf  
//线程睡眠 f&ri=VJY\T  
public static void sleep(int nSecond) &w"1VOV<  
{ lw j,8  
try{ 0<'Q;'2* L  
Thread.sleep(nSecond); /ij)[WK@  
} ;.EW7`)Z  
catch(Exception e) 6X`i*T$.  
{ ).D+/D/"2  
e.printStackTrace (); \#O}K  
} guc[du  
} \Jy/ a-  
}?KfL$@$  
//日志 ]sL)[o  
public static void log(String sMsg) K#_x.: <J  
{ 5@&{%99  
System.err.println(sMsg); JT(6Uf  
} }X?M6;$)  
wcW8"J'AH  
(eEs0  
public static void log(int sMsg) T\3a T  
{ ]R?{9H|jwE  
System.err.println(sMsg); 6! .nj3$*  
} HJ^SqSm  
} yNU.<d 5  
|18h p  
9qcA+gz:|  
/* gR\-%<42  
**TestMethod.java nEgDwJ<wl  
*/ %TUvH>;0  
package NetFox; M|DVFC  
;FfDi*S7  
3 jR I@  
public class TestMethod { K0xka[x=(  
YggeKN  
&'KJh+jJ  
public TestMethod() 4M,Q{G|e  
{ ///xx/weblogic60b2_win.exe Z(c3GmY  
try{ -{O>'9'1A  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MFzJ 8^.1R  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b;k3B7<  
SiteFileFetch fileFetch = new SiteFileFetch(bean); OPe3p {]  
fileFetch.start(); )oAxt70  
} lNRGlTD%  
catch(Exception e){e.printStackTrace ();} SR8)4:aKW  
Q!*}^W  
-'%>Fon  
} F)n^pT  
g:rjt1w`D  
F :p9y_W  
public static void main(String[] args) =&~7Q"  
{ 9S_PZH  
new TestMethod(); vOQ 3A%/  
} 1=U NA :t<  
} 68 \73L=  
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