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http断点续传简单实现(java)

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/* "uZ'oN  
**SiteFileFetch.java %pTbJaM\U  
*/ I>9rfmmTI  
package NetFox; 4:6@9.VVT  
import java.io.*; ap;*qiNFQ  
import java.net.*; ^0X86  
n-H0cm  
E.6^~'/  
public class SiteFileFetch extends Thread { 8)R )h/E>  
=_ -@1 1a  
D }b+#G(m[  
SiteInfoBean siteInfoBean = null; //文件信息Bean f$(w>B7..  
long[] nStartPos; //开始位置 {wA@5+[  
long[] nEndPos; //结束位置 d&R/fIm  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ^IQC:2 1  
long nFileLength; //文件长度 WGp81DNS|  
boolean bFirst = true; //是否第一次取文件 xwK<f6H!y  
boolean bStop = false; //停止标志 o^DiIo or  
File tmpFile; //文件下载的临时信息 F_V~UX1D  
DataOutputStream output; //输出到文件的输出流 mE^6Zu  
9O}YtX2  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) m[Zz(tL  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1s!hl{n<~  
{ oleRQ=  
siteInfoBean = bean; fa<83<.D  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); k}jH  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %li'j|  
if(tmpFile.exists ()) ;O{AYF?,N  
{ E$8GXo00v  
bFirst = false; TS=p8@w}  
read_nPos(); }Qg9l|  
} tLV9b %i(  
else :Q&8DC#]  
{ .F 3v)  
nStartPos = new long[bean.getNSplitter()]; oSy[/Y44a  
nEndPos = new long[bean.getNSplitter()]; ]^aece t  
} ;Iv)J|*  
,gkxZ{Eh  
;QgJw2G  
D ZLSn Ax  
} qIO)Z   
WnHf)(J`"  
^pZ(^  
public void run() 2/>AmVM  
{ A")B<BK  
//获得文件长度 =I7#Vtd^K<  
//分割文件 -Ux/ Ug@  
//实例FileSplitterFetch r6MQ|@  
//启动FileSplitterFetch线程 HjV83S;  
//等待子线程返回 4MIL# 1s  
try{ |\N[EM%.@  
if(bFirst) 6!b96bV  
{ l'-iIbKX  
nFileLength = getFileSize(); D97oS!*  
if(nFileLength == -1) T#er5WOH  
{ f]o DZO%^  
System.err.println("File Length is not known!"); nm\n\j~  
} wf8vKl#Kfw  
else if(nFileLength == -2) N:gS]OI*  
{ 37 M7bB0  
System.err.println("File is not access!"); 7{<t]wQq  
} cWh Aj>?_Q  
else }$m_):t@@  
{ (:E^} &A  
for(int i=0;i<nStartPos.length;i++) 4*m\Zoq>  
{ f N t  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); . KRh59yg  
} 1N:eM/a  
for(int i=0;i<nEndPos.length-1;i++) !BK^5,4?--  
{ %{o5 }TqD  
nEndPos = nStartPos[i+1]; tTQ>pg1{qh  
} B`T9dL[E4  
nEndPos[nEndPos.length-1] = nFileLength; nQ/(*d  
} r1F5&?{q  
} y"2#bq  
tEf-BV;\y  
NIV&)`w  
//启动子线程 ?uh7m 2l0D  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5+,&9;'Y^  
for(int i=0;i<nStartPos.length;i++) pMs%`j#T  
{ 6=|Q>[K  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E/5w H/  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?WUu@Z  
nStartPos,nEndPos,i); %T1(3T{Li  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ))306*X\  
fileSplitterFetch.start(); kk^KaD4dA  
} Vf O0 z5&  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2BRY2EF  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Pm" ,7  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `q4\w[0+p  
nEndPos = " + nFileLength); ydoCoD w  
// fileSplitterFetch[nPos.length-1].start(); \kC/)d  
m#'u;GP]k  
w[]7{ D];  
//等待子线程结束 -C.eXR{s  
//int count = 0; gIRFqEz@o  
//是否结束while循环 b\6w[52m  
boolean breakWhile = false; `[CXxp  
/XnI>  
bha_bj  
while(!bStop) wGb{O  
{ P+oCcYp  
write_nPos(); [.|tD  
Utility.sleep(500); ]$KH78MTW  
breakWhile = true; 0'aZ*ozk  
S(/@.gI:f  
5E}0 <&  
for(int i=0;i<nStartPos.length;i++) H^'EY:|  
{ Q:@Y/4=  
if(!fileSplitterFetch.bDownOver) #YjV3O5<  
{ 9u"im+=:  
breakWhile = false; ZLo3 0*  
break; rpy`Wz/[  
} I"Y?vj9]  
} 31J7# S2  
if(breakWhile) pE15[fJ`  
break; .8fOc.h8h  
N[zI@>x  
7r*>?]y+  
//count++; ib uA~\5  
//if(count>4) x{RTI#a.  
// siteStop(); n |.- :Zy  
} q;Qpd]H  
F'|,(P  
(7-K4j`   
System.err.println("文件下载结束!"); gY;N>Yq,C  
} %xWmzdn  
catch(Exception e){e.printStackTrace ();} 9Q].cDe[  
} &[JI L=m5  
bNIT 1'v  
1gH5#_ ?  
//获得文件长度 QT^( oog=  
public long getFileSize() [xM07%:  
{ )mwY] !  
int nFileLength = -1; G{ F>=z"(l  
try{ m0/J3  
URL url = new URL(siteInfoBean.getSSiteURL()); O(WFjmHx  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =ngu*#?c4  
httpConnection.setRequestProperty("User-Agent","NetFox"); A+ Z3b:}~  
h-!(O^M  
&t p5y}=n  
int responseCode=httpConnection.getResponseCode(); Wpj.G  
if(responseCode>=400) -YS n 3=  
{ (;Lz `r'  
processErrorCode(responseCode); F)v+.5T1  
return -2; //-2 represent access is error @{t^8I#]  
} I~4 `NV0  
<*4=sX@  
`1pri0!  
String sHeader; 5)&e2V',y  
F~RUb&*/<  
gU+BRTZ&x  
for(int i=1;;i++) APK@Oq  
{ V 9=y@`;  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NP%ll e,l  
//Utility.log(in.readLine()); *7!}[ v_  
sHeader=httpConnection.getHeaderFieldKey(i); US> m1KsX  
if(sHeader!=null) d7KeJ$xy}p  
{ Y^3tk}yru  
if(sHeader.equals("Content-Length")) hRc\&+#/  
{ P+"#xH  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _k6N(c2Nd  
break; UP,0`fh(y  
} Jz3q Pr  
} ojyG|Y  
else j|+B|   
break; 5O)Z}  
} HJ_xg6.x  
} #1m!,tC  
catch(IOException e){e.printStackTrace ();} 1d-j_ H`s  
catch(Exception e){e.printStackTrace ();} [C7:Yg7  
RZ?>>Ll6  
p aMw88*u  
Utility.log(nFileLength); yd>kJk^~/  
Prjl ;[I}  
D8Ni=.ALL  
return nFileLength; 3OM\R%M  
} 'OF)`5sj  
cH2 nG:H  
<_42h|-  
//保存下载信息(文件指针位置) fI}-?@  
private void write_nPos() a&Z|3+ZA  
{ U*1~Zf  
try{ t'[vN~I'  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ugMJ}IGq  
output.writeInt(nStartPos.length); LM*9b  
for(int i=0;i<nStartPos.length;i++) EH4WR/x  
{ ,[cWG)-  
// output.writeLong(nPos); &dOV0y_  
output.writeLong(fileSplitterFetch.nStartPos); FK mFjqY  
output.writeLong(fileSplitterFetch.nEndPos); ^!kv gm<{$  
} $g 1p!  
output.close(); ]=]'*Z%  
} eeL%Yp3+  
catch(IOException e){e.printStackTrace ();} Uhg[#TUK  
catch(Exception e){e.printStackTrace ();} )FU4iN)ei  
} U ][.ioc  
)Hev -C"  
o8Bo%OjE  
//读取保存的下载信息(文件指针位置) O`@$YXuD  
private void read_nPos() c~$ipX   
{ CQv [Od  
try{ Tri.>@-u  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .h7b 4J  
int nCount = input.readInt(); VN$#y4  
nStartPos = new long[nCount]; n,AN&BZ  
nEndPos = new long[nCount]; *w@>zkBl  
for(int i=0;i<nStartPos.length;i++) mZq*o<kTA  
{ =U,;/f  
nStartPos = input.readLong(); tQwbIX-7/  
nEndPos = input.readLong(); ~t#'X8.)  
} +mF}j=k  
input.close(); oh:t ex<  
} kg !@i7  
catch(IOException e){e.printStackTrace ();} uO":\<1#  
catch(Exception e){e.printStackTrace ();} "BzRL g!J  
} px-*uh<  
x80~j(uVf  
F92n)*[  
private void processErrorCode(int nErrorCode) Y-,#3%bT;;  
{ O#k?c }  
System.err.println("Error Code : " + nErrorCode); `ZNjA},.  
} xt3IR0  
w$& 10  
c)$/Uu  
//停止文件下载 Hq%`DWus\  
public void siteStop() Qs,LK(1  
{ `NGCUGQ_7  
bStop = true; "M? (Ax  
for(int i=0;i<nStartPos.length;i++) *qq%)7  
fileSplitterFetch.splitterStop(); O %)+ w  
_$, .NK,6  
g8vN^nQf[  
} uF< F4m;  
} \k g2pF[V  
//负责部分文件的抓取 @A yC0}  
**FileSplitterFetch.java h,\_F#hi  
*/ A\:=p  
package NetFox; ^ qE4:|e  
#s]]\  
sA` bPhk  
import java.io.*; O:u^jcXA  
import java.net.*; ;APg!5X  
g0iV#i  
zlXkD~GV  
public class FileSplitterFetch extends Thread { UQTt;RS*zS  
bu$5gGWVf  
 _@d.wfM  
String sURL; //File URL .JH3,L"S^  
long nStartPos; //File Snippet Start Position 9g 2x+@5T^  
long nEndPos; //File Snippet End Position `N|WCiBV.  
int nThreadID; //Thread's ID O'!k$iJNb  
boolean bDownOver = false; //Downing is over S'?XI@t[  
boolean bStop = false; //Stop identical %3kqBH!d  
FileAccessI fileAccessI = null; //File Access interface %VwB ?  
d/* [t!   
FiIN \  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B8;ZOLAU  
{ 7dW9i7Aj  
this.sURL = sURL; R?I(f(ib   
this.nStartPos = nStart; nYE_WXY3V  
this.nEndPos = nEnd; 27 Lya!/  
nThreadID = id; RtF_p {s  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Rfgc^3:j  
} * y`^Fc  
Ebp8})P/~  
op}x}Ioz  
public void run() ,Cx5( ~kU  
{ (}Gl'.>\M  
while(nStartPos < nEndPos && !bStop) 3`="4  
{ 5 bMVDw/  
EJL45R>  
)V9$ P)  
try{ La3f{;|u5M  
URL url = new URL(sURL); ~6@~fhu  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *]F3pP[  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^t#]E#  
String sProperty = "bytes="+nStartPos+"-"; `uGX/yQ#=  
httpConnection.setRequestProperty("RANGE",sProperty); 8xL-j2w  
Utility.log(sProperty); 3+!N[6Od9  
5#:tL&q  
t}TtWI  
InputStream input = httpConnection.getInputStream(); ^DIN(0u)  
//logResponseHead(httpConnection); `ORDN|s6  
>5]Xl*{H)  
,g^Bu {?  
byte[] b = new byte[1024]; "7gS*v,r  
int nRead; 9}3W0F;  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @NX^__ sa  
{ |nocz]yU$  
nStartPos += fileAccessI.write(b,0,nRead); zwAuF%U  
//if(nThreadID == 1) \'1%"JWK   
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (<1DPpy95O  
} )vy<q/o+  
{feS-.Khv  
c*6o{x}K  
Utility.log("Thread " + nThreadID + " is over!"); z RsA[F#  
bDownOver = true; ,Hp9Gkm8I/  
//nPos = fileAccessI.write (b,0,nRead); [i&z_e)  
} (U-p&q>z  
catch(Exception e){e.printStackTrace ();} [IW@ mn>  
} 9:@os0^O  
} >) 5rOU  
J-u,6c  
L{(r@Vu  
//打印回应的头信息 }rGDM  
public void logResponseHead(HttpURLConnection con) c*\^6 1T  
{ *TMg.  
for(int i=1;;i++) 6bqJM#y@  
{ Jr1^qY`0+  
String header=con.getHeaderFieldKey(i); +ES.O]?>  
if(header!=null) zBc7bbK  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0.+iVOz+Y  
Utility.log(header+" : "+con.getHeaderField(header)); xD_jfAH'  
else -=g`7^qa>  
break; YQ?|Vb U  
} Y!Z@1V`  
} MjG .Ili$m  
',O@0L]L  
bfa5X<8  
public void splitterStop() iJsw:Nc  
{ h` n>6I  
bStop = true; OU{PVF={   
} X>Xpx<RY!  
0@xuxm/i  
V=S`%1dLN  
} 'TbA^U[  
r Ssv^W+  
J(l6(+8  
/* 2y<d@z:K  
**FileAccess.java z?7s'2w&{  
*//文件访问(定位,写) otPEJ^W&  
package NetFox; [NKWudq  
import java.io.*; ^_<pc|1  
M)b`~|Wt  
Th!S?{v   
public class FileAccessI implements Serializable{ NZ.aI{  
f0hi70\(X  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }  g  
RandomAccessFile oSavedFile; ow`\7qr  
long nPos; h@Hmo^!9J  
xt`znNN  
3@}_ F<"*  
public FileAccessI() throws IOException ?2G^6>O `  
{ '.^JN@  
this("",0); :;|x'[JoE?  
} RF6|zCWuI  
r+Z+x{  
/\\C&Px  
public FileAccessI(String sName,long nPos) throws IOException 7tr.&A^c  
{ :m+:%keK  
oSavedFile = new RandomAccessFile(sName,"rw"); wr#+q1 v  
this.nPos = nPos; [jLx}\]  
oSavedFile.seek(nPos); &GbCJ  
} k}<mmKB  
rhUZ9Fdv  
f,?7,?x  
public synchronized int write(byte[] b,int nStart,int nLen) RGxOb  
{ "<.b=mN-  
int n = -1; =+"XV8Fi,  
try{ 82w< q(  
oSavedFile.write(b,nStart,nLen); wYF)G;[wM  
n = nLen; Dic(G[  
} xbmOch}j6  
catch(IOException e) CiMN J  
{ W>, b1_k c  
e.printStackTrace (); }k ,Si9O  
} FEP\5d>  
xt-;7  
#p[=iP  
return n; 1`)R#$h  
} Sa@Xh,y Z  
0u0Hl%nl  
I4") ;T3  
} t Y^:C[  
&0o&!P8CB  
P|6m%y  
/* T$q]iSgu  
**SiteInfoBean.java 66BsUA.h  
*/ iI _Fbw8  
package NetFox; z#-&MJ  
*.K}`89T  
9^}GUJy?  
public class SiteInfoBean { VX- f~  
h<QXr'4+  
V&f3>#n\  
private String sSiteURL; //Site's URL [PU.lRq  
private String sFilePath; //Saved File's Path fNlUc  
private String sFileName; //Saved File's Name .jRXHrK;  
private int nSplitter; //Count of Splited Downloading File $U6)km4  
gmM79^CEF  
K3@UoR  
public SiteInfoBean() 4+uAd"  
{//nSplitter的缺省值为5 mM95BUB  
//default value of nSplitter is 5 \"uR&D  
this("","","",5); &-{4JSII  
} j0OxR.S  
OgzPX^q/=  
KQ2]VN"?_  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $60+}B`m  
{ &K\di*kN  
sSiteURL= sURL; B,A/ -B\  
sFilePath = sPath; &-&6ARb7o  
sFileName = sName; ^h' wZ7-\  
this.nSplitter = nSpiltter; {0[qERj"z  
XCk \#(VSE  
>uI|S  
} iveWau292  
T}zOM%]]  
2B*9]AHny  
public String getSSiteURL() '\\J95*`  
{ 4w\')@`[jk  
return sSiteURL; J \G8 g,@  
} BG=h1ybz  
{o;J'yjre1  
Z*leEwgz  
public void setSSiteURL(String value) `s.y!(`q  
{ @(ev``L5g  
sSiteURL = value; !,I}2,1%k  
} CjD2FnjT  
j]kx~  
\N!k)6\  
public String getSFilePath() ;Qw>&24h[  
{ i8EMjLBUR  
return sFilePath; P=eL24j  
} I]zCsT.  
 O'_D*?  
TqzkF7;k4  
public void setSFilePath(String value) 2#p6.4h=  
{ >/-<,,<\C  
sFilePath = value; \-c70v63X  
} l'mgjv~  
St'3e<  
D4[t@*m>7  
public String getSFileName() !m:SRNPg  
{ ECQ>VeP  
return sFileName; 29}(l#S}m  
} ;CFI*Wfp  
`WX @1]m  
^ WidA-  
public void setSFileName(String value) ^!?W!k!:V  
{ UoBmS 5  
sFileName = value; 1Hk`i%  
} I6zKvP8pb  
XWH~o:0<2  
[gx6e 44  
public int getNSplitter() 0c /xE<h  
{ |3QKxS0  
return nSplitter; "Lw[ $  
} @tR:}J*9s  
FK{Vnj0  
g >u{H:  
public void setNSplitter(int nCount) aF]4%E  
{ T}M!A|   
nSplitter = nCount; ^FIpkhw  
} sWa`-gc  
}  MV'q_{J  
aHuZzYQ*"j  
Xy5#wDRC  
/* $oDc  
**Utility.java O3 x9S,1i  
*/ !?#B*JGFS  
package NetFox; >cpT_M&C,  
:2ILN.&  
k[#<=G_=/E  
public class Utility { FN0)DN2d}  
Qqm'Yom%T  
d< j+a1&  
public Utility() 9EHhVi  
{ A6eIf  
z_nv|5"  
YS],o'T  
} 40h  
"Tt5cqUQoY  
//线程睡眠 ?V&# nA  
public static void sleep(int nSecond) w>S;}[fM  
{ `X)y5*##wq  
try{ Z{XF!pS%H  
Thread.sleep(nSecond); |2AMj0V~  
} {+Zj}3o  
catch(Exception e) [A\DuJx  
{ )IBvm1  
e.printStackTrace (); 9 n0 ?0mk  
} c`,'[Q5(O  
} C}jFR] x)  
*3@ =XY7  
//日志 [Z]%jABR  
public static void log(String sMsg) n Nu~)X  
{ G'#Uzwo  
System.err.println(sMsg); 7! sR%h5p  
} wHuz~y6  
S/,)X  
CWdpF>En  
public static void log(int sMsg) LS:^K  
{ 0q6xXNAX  
System.err.println(sMsg); :;Xh`br  
} {e!3|&AX  
} &TT vX% T  
:@@aIFRv  
"UYlC0 S\  
/* X*w7q7\8-:  
**TestMethod.java Se}&2 R  
*/ YQ|o0>  
package NetFox; w!_6*  
J.(mg D  
ZHM NG~!  
public class TestMethod { =JaxT90x  
Nr"gj$v  
.k -!/^  
public TestMethod() }vxRjO,  
{ ///xx/weblogic60b2_win.exe .^xQtnq  
try{ * ,L e--t  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Cy\ o{6  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (M# m BS  
SiteFileFetch fileFetch = new SiteFileFetch(bean); \MDhm,H<  
fileFetch.start(); %bp'`B=  
} 7Y.mp9,  
catch(Exception e){e.printStackTrace ();} Z&|Dp*Z  
7Hg;SK6t0  
Y )68  
} G:!3X)b  
nx Jx8d"  
weMufT  
public static void main(String[] args) R8>17w.  
{ Gs/G_E(T  
new TestMethod(); =4uO"o  
} $\#wsI(  
} q{}U5(,{0  
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