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http断点续传简单实现(java)

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/* naz:A  
**SiteFileFetch.java uBmxh%]C~  
*/ bV@7mmz:X+  
package NetFox; a3q\<"|  
import java.io.*; &p5&=zV}  
import java.net.*; HZ }6Q  
%>Bko,ET  
AD]e0_E  
public class SiteFileFetch extends Thread { =3*Jj`AV  
|rMq;Rgu?  
n)#Lh 7X"  
SiteInfoBean siteInfoBean = null; //文件信息Bean k oM]S+1  
long[] nStartPos; //开始位置 ! k,<|8(0  
long[] nEndPos; //结束位置 R<_?W#$j  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 M>T[!*nTj  
long nFileLength; //文件长度 rvic%bsk  
boolean bFirst = true; //是否第一次取文件 /D[dO6.  
boolean bStop = false; //停止标志 2F1ZAl  
File tmpFile; //文件下载的临时信息 *g1L$FBG  
DataOutputStream output; //输出到文件的输出流 *Bs^NU.  
ic-IN~J-  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ASW4,%cl  
public SiteFileFetch(SiteInfoBean bean) throws IOException ivfXat-  
{ #{x5L^v>]  
siteInfoBean = bean; @l~7 x  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); "tL2F*F"6X  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 7 _g+^e-"  
if(tmpFile.exists ()) >AG^fUArH  
{ " 9@,l!  
bFirst = false; cZ|lCy^  
read_nPos(); [Ct=F|  
} as r=m{C"  
else R2 lXTW*  
{ |5,<jyp  
nStartPos = new long[bean.getNSplitter()]; gg[ 9u-  
nEndPos = new long[bean.getNSplitter()]; D`VFf\7  
} Vclr2]eV4O  
=_ y\Y@J  
%cX"#+e  
M)JADX  
} +I5 2EXo  
rB%y6P B  
|SQ|qbe=  
public void run() )11W)G`w  
{ QR"bYQ  
//获得文件长度 =&Xdm(  
//分割文件 0|XKd24BN  
//实例FileSplitterFetch =Vb~s+YW  
//启动FileSplitterFetch线程 q[ ULG v  
//等待子线程返回 &>(gt<C$  
try{ 5 y   
if(bFirst) \"x>JW4w  
{ :)IV!_>'d  
nFileLength = getFileSize(); /L&M,OUcr.  
if(nFileLength == -1) cy|%sf`  
{ \}JrFc%O  
System.err.println("File Length is not known!"); dl0FQNz8@B  
} 0xCz'mJ  
else if(nFileLength == -2) q8xd*--#  
{ `T"rG }c  
System.err.println("File is not access!"); c@R; /m:R  
} *HE^1IEl  
else L8&D(wh/f  
{ 8>NwCjN  
for(int i=0;i<nStartPos.length;i++) x<ax9{  
{ M2@;RZ(|  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); -(#-I $z  
} mS%4gx~~_n  
for(int i=0;i<nEndPos.length-1;i++) lb~E0U`\E`  
{ MBw-*K'?zB  
nEndPos = nStartPos[i+1]; CPv iR<ms_  
} _1|$P|$P.  
nEndPos[nEndPos.length-1] = nFileLength; /L v1$~  
} 7I}P*%(f  
} #BY`h~&T  
``|AgIg  
6/tI8H3E  
//启动子线程 dE5D3ze  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >xg5z  
for(int i=0;i<nStartPos.length;i++) pQWHG#?7  
{ #NNewzC<*  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NfzF.{nh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^jD1vUL 2:  
nStartPos,nEndPos,i); v`DI<Lt  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sx 9uV  
fileSplitterFetch.start(); A:# k  
} =Z,5$6%)  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M#,Q ^rH#  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H&4~Uo.5  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Rc[0aj:  
nEndPos = " + nFileLength); zY=jXa)K~  
// fileSplitterFetch[nPos.length-1].start(); A\QJLWBv^$  
7:Zt uc]  
 ?=Db@97  
//等待子线程结束 o 3N]`xD'  
//int count = 0; \we\0@v  
//是否结束while循环 6f)2F< 7  
boolean breakWhile = false;  HpW 42  
SVWIEH0?  
x,8<tSW)Z  
while(!bStop) #=,imsW)  
{ p_2pU)%  
write_nPos(); DWiBG  
Utility.sleep(500); L":bI&V?:  
breakWhile = true; U|@V 74  
TgfrI  
Ev9 >@~^  
for(int i=0;i<nStartPos.length;i++) $ uh z  
{ izZ=d5+K  
if(!fileSplitterFetch.bDownOver) 06 mlj6hV  
{ 4Ysb5m)u  
breakWhile = false; {i [y9  
break; OB-Q /?0  
} zsXpA0~3s  
} ..W-76{  
if(breakWhile) #8h ;Bj  
break; r8/l P}(F  
c EnkU]  
<a^Oj LLU  
//count++; BR5BJX  
//if(count>4) LT@OWH  
// siteStop(); x/fX`y|(}*  
} ;_?MX/w|&  
K^[#]+nQ  
{+.r5py  
System.err.println("文件下载结束!"); Ao9R:|9  
} DcD{*t?x  
catch(Exception e){e.printStackTrace ();} %O[N}_XHEh  
} JXqr3 Np1  
?> D tw#}  
GqKsK r2%  
//获得文件长度 zaimGMJ ,  
public long getFileSize() B 0ee?VC  
{ Wp0 Dq(  
int nFileLength = -1; ]wVk+%e  
try{ YT#3n  
URL url = new URL(siteInfoBean.getSSiteURL()); aA'TD:&p1  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s5&@Cxzl  
httpConnection.setRequestProperty("User-Agent","NetFox"); #*%q'gyHT  
tY|8s]{2  
Nw_@A8-r  
int responseCode=httpConnection.getResponseCode(); G}d-(X  
if(responseCode>=400) nY%5cJ`"  
{ p#P~Q/;  
processErrorCode(responseCode); |N/G'>TS  
return -2; //-2 represent access is error iq$$+y,  
} ,m3e?j@;r  
PmpNAVE'  
K2)!h.W  
String sHeader; iBg3mc@OO  
b7`D|7D  
u{<"NR h  
for(int i=1;;i++) |*5 =_vF  
{ G3i !PwW  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =+:{P?*}  
//Utility.log(in.readLine()); =='Td[  
sHeader=httpConnection.getHeaderFieldKey(i); J:*-gwv9*m  
if(sHeader!=null) }T2xXbU  
{ D;}xr_  
if(sHeader.equals("Content-Length")) )!bUR\  
{ |SZo' 6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %r\n%$@_  
break; 21X`h3+=  
} eV^d6T$  
} "r4AY  
else D/ybFk  
break; [lzN !!B!  
} H6*^Ga  
} H`hnEOyLp  
catch(IOException e){e.printStackTrace ();} <x pph t<  
catch(Exception e){e.printStackTrace ();} ZUm?*.g\^  
\>. LW9  
M9\#Aq&\i  
Utility.log(nFileLength); }|OaL*|u  
'@|_OmcY  
1$/MrPT(b  
return nFileLength; $@-P5WcRs  
} zET^T5>:  
3f.b\4 U  
f"[J "j8  
//保存下载信息(文件指针位置) *D}0 [|O  
private void write_nPos() f5*k7fg  
{ <*ZJaBwWU~  
try{ 4rT*tW"U  
output = new DataOutputStream(new FileOutputStream(tmpFile)); S^@S%Eg  
output.writeInt(nStartPos.length); !^#jwRpeN  
for(int i=0;i<nStartPos.length;i++) C@ZK~Y_g  
{ 7w :ef0S  
// output.writeLong(nPos);  .~A*=  
output.writeLong(fileSplitterFetch.nStartPos); $,=6[T!z+e  
output.writeLong(fileSplitterFetch.nEndPos); SvM6iZ]  
} S_ MyoXV  
output.close(); jd]s<C3o  
} "xI"  
catch(IOException e){e.printStackTrace ();} aimarU  
catch(Exception e){e.printStackTrace ();} 6k{2 +P  
} ,_aM`%q?Fj  
{'sY|lou  
N[]Hc  
//读取保存的下载信息(文件指针位置) 1d"Z>k:mn  
private void read_nPos() T3UMCqc=  
{ zLs|tJOVp  
try{ : JzI>/  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g6@Fp7T  
int nCount = input.readInt(); c .3ZXqpI;  
nStartPos = new long[nCount]; G@FI0\t  
nEndPos = new long[nCount]; oBQ#eW aY  
for(int i=0;i<nStartPos.length;i++) $E<Esf$  
{ ZRxZume<f  
nStartPos = input.readLong(); 00I}o%akO  
nEndPos = input.readLong(); Ars687WB  
} F^"_TV0va  
input.close(); N7'OPTKt&  
} =L%DX#8  
catch(IOException e){e.printStackTrace ();} k Iw`P[  
catch(Exception e){e.printStackTrace ();} )[H{yQ  
} OaJB=J%  
;AR{@Fu.  
 ~\,w {  
private void processErrorCode(int nErrorCode) WV3|?,y]qm  
{ F|Mi{5G%  
System.err.println("Error Code : " + nErrorCode); ?]fF3SJk  
} 2XTPBZNe  
qPB8O1fyU  
mK+IEZV<3  
//停止文件下载 =9oP owq  
public void siteStop() 2" |2a@  
{ p.ANVA@:  
bStop = true; B\J^=W+`  
for(int i=0;i<nStartPos.length;i++) 9TF f8'?d  
fileSplitterFetch.splitterStop(); _Jwq`]Z  
T2}FYVj?!g  
S6}@I ,Q  
} u p.Q>28r  
} )1N 54FNO  
//负责部分文件的抓取 'O5'i\uz  
**FileSplitterFetch.java RZM"~ 0  
*/ }kw/W#)J  
package NetFox; QM3,'?ekRH  
f|^dD`  
5MFxo63  
import java.io.*; ,jXM3?>B  
import java.net.*; O^/Maa/D1  
I1[g&9,  
A7(hw~+@  
public class FileSplitterFetch extends Thread { u` oq(?|  
$0bjKy  
6KD `oUx  
String sURL; //File URL -':Y\:W  
long nStartPos; //File Snippet Start Position Hzrtlet  
long nEndPos; //File Snippet End Position ;a-$D]Db  
int nThreadID; //Thread's ID +/#Ei'do  
boolean bDownOver = false; //Downing is over uOa26kE4  
boolean bStop = false; //Stop identical C6O8RHg  
FileAccessI fileAccessI = null; //File Access interface z0|&W&&D  
 O+%WR  
 K;LZ-  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $P1O>x>LIL  
{ .(pN5JI*  
this.sURL = sURL; Q{k At%  
this.nStartPos = nStart;  Z%I  
this.nEndPos = nEnd; ;'81jbh  
nThreadID = id; jTLSdul+  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z4 &iK)x  
} u:aW 8  
TCT57P#b  
SQeRSz8bK4  
public void run() YF+n b.0.  
{ `ptj?6N-  
while(nStartPos < nEndPos && !bStop) n@ w^ V   
{ dt~YW  
gM [w1^lj  
m*$|GW9  
try{ ]f]<4HD=i  
URL url = new URL(sURL); V5p= mmnA,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :>p8zG  
httpConnection.setRequestProperty("User-Agent","NetFox"); h3T9"w[  
String sProperty = "bytes="+nStartPos+"-"; 9f\/\L  
httpConnection.setRequestProperty("RANGE",sProperty); \rVQQ|l   
Utility.log(sProperty); 7' S@3   
0afei4i~N  
3!5Ur&  
InputStream input = httpConnection.getInputStream(); FgLrb#  
//logResponseHead(httpConnection); qc#)!   
1sP dz L  
j5 g# M  
byte[] b = new byte[1024]; + >cBVx6  
int nRead; )K'N(w  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aZEn6*0B  
{ <C9 XX~  
nStartPos += fileAccessI.write(b,0,nRead); [F5h   
//if(nThreadID == 1) ""s]zNF}  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #2`D`>7456  
} ~rjTF!  
6sa"O89   
1heS*Fwn'  
Utility.log("Thread " + nThreadID + " is over!"); _ Ro!"YVX  
bDownOver = true; w '3#&k+  
//nPos = fileAccessI.write (b,0,nRead); gKOOHUCb  
} ,;M4jc {  
catch(Exception e){e.printStackTrace ();} !"+'A)Nve  
} iS5W>1]  
} O5H9Y}i]  
{QCf}@_]h  
z&V+#Ws/  
//打印回应的头信息  iD= p\  
public void logResponseHead(HttpURLConnection con) >Z1q j>  
{ &qS[%K )  
for(int i=1;;i++) w`l{LHrR  
{ &K/FyY5  
String header=con.getHeaderFieldKey(i); \^#~@9  
if(header!=null) E9V 5$  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B75k^ohfj  
Utility.log(header+" : "+con.getHeaderField(header)); M)sZSH.<O  
else 3pmWDG6L  
break; KFa_  
} 1xv8gC:6  
} `GXkF:f=  
?YeWH WM  
IF]lHB  
public void splitterStop() Cuc$3l(%  
{ .rPn5D Y  
bStop = true; rpw.]vnn  
} ZylJp8U  
7OjR._@  
+nQw?'9Z  
} 8( b tZt  
z"*/mP2  
7z~_/mAI  
/*  r[?1  
**FileAccess.java h[Gg}N!  
*//文件访问(定位,写) ^[15&T5  
package NetFox; Ew3ibXD  
import java.io.*; 8BvonY t=8  
M`6y@<  
m~uOXb  
public class FileAccessI implements Serializable{ P]z[v)}  
]jpu,jz:  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b~-%c_  
RandomAccessFile oSavedFile; <9> vO,n  
long nPos; ]:34kE}e5  
kp\\"+,VC  
t\$U`V)  
public FileAccessI() throws IOException R-^96fFBy  
{ ![f ![l  
this("",0); /t-fjB{=G  
} H~ u[3LQz  
6=N`wi  
w\}?(uO  
public FileAccessI(String sName,long nPos) throws IOException >[6{LAe~hp  
{ ?bw4~  
oSavedFile = new RandomAccessFile(sName,"rw"); K R"M/#  
this.nPos = nPos; ~H6r.:]  
oSavedFile.seek(nPos); _4cvX  
} ){r2T1+-%  
kF>o.uSV  
>hH0Q5aL  
public synchronized int write(byte[] b,int nStart,int nLen) S>.F_Jl  
{ 2Hum!p:1  
int n = -1; $4MrP$4TI  
try{ ~zHg[X*  
oSavedFile.write(b,nStart,nLen); >c-fI$]  
n = nLen; E\;ikX&1  
} +/D>|loRC  
catch(IOException e) (RtueEb.~E  
{ rWh6RYd<T  
e.printStackTrace (); Q?AmOo-a  
} N$[$;Fm:  
lg pW@g  
_bD/D!|  
return n; ~afg)[(  
} q$G,KRy/  
G^"Vo x4  
KN"S?i]X  
} T;L>P[hNn  
hm<}p&!J  
N8`?t5  
/* Z0De!?ALV\  
**SiteInfoBean.java 2DD:~Tbi  
*/ R}mn*h6  
package NetFox; ^s.V;R  
mZIoaF>t  
n&MG7`]N  
public class SiteInfoBean { e?bYjJ q  
lcV<MDS  
ET];%~ ^  
private String sSiteURL; //Site's URL &uUo3qXQ5l  
private String sFilePath; //Saved File's Path >yJ9U,Y  
private String sFileName; //Saved File's Name dz>;<&2Z  
private int nSplitter; //Count of Splited Downloading File a}SdW  
.WQ<jZt>  
,<DB&&EV8  
public SiteInfoBean() (z$r:p  
{//nSplitter的缺省值为5 ~ d^<_R  
//default value of nSplitter is 5 ;6 +}z~  
this("","","",5); .Wi{lt  
} 20rkKFk*  
{G*A.$-d  
ceGa([#!\_  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e4FM} z[  
{ PM":Vd/  
sSiteURL= sURL; )6~1 ^tD  
sFilePath = sPath; d3^OEwe  
sFileName = sName; rw)kAe31  
this.nSplitter = nSpiltter; 0ult7s}  
Hqh6:RuL  
b%f[p/no  
} kX:tc   
Hx$c N  
9;%CHb&  
public String getSSiteURL() *c[2C  
{ "!K'A7.^  
return sSiteURL; |+ge8uu?C  
} <\zCpkZ'B  
D}3XFuZs_  
6a}"6d/sTL  
public void setSSiteURL(String value) $>U # W:  
{ 9dh >l!2  
sSiteURL = value; `IINq{Zk  
} FI8Oz,  
A$g+K,.l  
G1 o70  
public String getSFilePath() ^7]"kg DA  
{ fQ>4MKLw=d  
return sFilePath; ]aCk_*U  
} ~tB;@e  
.ut{,(5  
j<%])  
public void setSFilePath(String value) 2fIRlrA$  
{ (eCFWmO  
sFilePath = value; HmK*bZ  
} %=j3jj[  
-VDo[Zy  
nxQ?bk}*d  
public String getSFileName() vFrt|JC_{  
{ mYB`)M*Y  
return sFileName; :"0J=>PH:  
} b{DiM098  
PC c|}*b  
=G~~?>=@2  
public void setSFileName(String value) zT~B 6  
{ t<:D@J]a  
sFileName = value; #0b&^QL  
} b4Y8N"hL%  
RnfXN)+P  
+kdySWF  
public int getNSplitter() 2W M\e lnA  
{ KRsAv^']  
return nSplitter; ,G^[o,hS  
} v}J;ZIb  
i54md$Q^  
^C&+ ~+  
public void setNSplitter(int nCount) z41_oG7   
{ 7=4A;Ybq  
nSplitter = nCount; VVWM9x  
} q&'Lbxc>c  
} /.5;in  
k6IG+:s  
E& 36H  
/* A CNfS9M_w  
**Utility.java 2=PBxDs;  
*/ ghk5rl$   
package NetFox; NCA {H^CL  
@D`zKYwX1  
i`%.  
public class Utility { ;)DzC c/  
!Q-wdzsp?  
V9x8R  
public Utility() e1 *__'  
{ ,$r2gr!_G  
)He#K+[}^4  
fm1X1T.  
} SP 2 8  
-7'#2P<)  
//线程睡眠 9CUimZ  
public static void sleep(int nSecond) IN^9uL]B  
{ 4lc)&  
try{ KGZ?b2N?Va  
Thread.sleep(nSecond); _J?SIm  
} zW{ 6Eg  
catch(Exception e) ;'RFo?u K  
{ yt.c5> B^  
e.printStackTrace (); VmQh$&h  
} @kngI7=E  
} 1TqF6`;+  
P`s(kIe  
//日志 !>;w!^U  
public static void log(String sMsg) %|3e.1oX  
{ }IUP5O6  
System.err.println(sMsg); <z#BsnjW{  
} Zcd7*EBdx  
67<CbQZoN3  
&B-[oqC?  
public static void log(int sMsg) /rF8@l  
{ &jts:^N>  
System.err.println(sMsg); #dJ 2Q_2  
} _=`x])mM  
} o0;7b>Tv  
Pw}_[[>$  
9rj('F & 1  
/* =xEk7'W6k  
**TestMethod.java cV$lobqO  
*/ L@|#Bbmx  
package NetFox; y{rn-?`{  
C@dGWAG  
F%6*Df;cSe  
public class TestMethod { #0MK(Ut/  
`6 Y33bQ  
xcSR{IZ  
public TestMethod() >7-y#SkXdo  
{ ///xx/weblogic60b2_win.exe SR*Gqx  
try{ 9$tl00  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N2~$r pU3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =Q?f96T  
SiteFileFetch fileFetch = new SiteFileFetch(bean); | 1V2tx  
fileFetch.start(); X7cWgo66T  
} *8!w&ME+.  
catch(Exception e){e.printStackTrace ();} A|vP$zy  
_%IqjJO{=r  
;e;\q;GP  
} >_Uj?F:  
k8&FDz  
Fe= "EDh  
public static void main(String[] args) ?R?Grw)`H  
{ 7~.ZE   
new TestMethod();  {;RF  
} ^tE_LL+ji|  
} 8$ DwpJ  
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