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http断点续传简单实现(java)

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/* 'EFyIVezg9  
**SiteFileFetch.java xJ2*LM-  
*/ 6ksAc%|5  
package NetFox; P9T5L<5  
import java.io.*; =vT<EW}[  
import java.net.*; ;E ec5w1  
@* il3h,  
^}f -!nf[  
public class SiteFileFetch extends Thread { fh^lO ^  
E\;ikX&1  
>3u ]OSb  
SiteInfoBean siteInfoBean = null; //文件信息Bean &F}"Z(B<wK  
long[] nStartPos; //开始位置 `mT$s,:h  
long[] nEndPos; //结束位置 s}j1"@  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 H:H6b  
long nFileLength; //文件长度 OCy0#aPRS  
boolean bFirst = true; //是否第一次取文件 BnRN;bu  
boolean bStop = false; //停止标志 NzKUtwnIz  
File tmpFile; //文件下载的临时信息 M,}|tsL  
DataOutputStream output; //输出到文件的输出流 .@Ut?G  
pWu LfX  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) h $N0 D !  
public SiteFileFetch(SiteInfoBean bean) throws IOException w-@6|o,S  
{ sE{pzPq!  
siteInfoBean = bean; kM`l  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Z/rTVAs@r  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); #yI.nzA*  
if(tmpFile.exists ()) "n:{ !1VGw  
{ )etmE  
bFirst = false; s( <uo{  
read_nPos(); D#S\!>m  
} 6!^[];%xN  
else #0 6-:  
{ Q%aU42?_1  
nStartPos = new long[bean.getNSplitter()]; !.1%}4@Q]  
nEndPos = new long[bean.getNSplitter()]; NA,C Z  
} c#N<"cy>  
_lW+>xQ  
!EQ@#qW/  
3sCFHn#c  
} 5X.e*;  
fJZp?e"  
S(aZ4{a@  
public void run() t:LcNlN|  
{ VOsqJJ3  
//获得文件长度 #y|V|nd  
//分割文件 ?[x49Ux,P  
//实例FileSplitterFetch H UoyLy  
//启动FileSplitterFetch线程 !6&W,0<  
//等待子线程返回 `MP|Ovns:H  
try{ fA48(0p  
if(bFirst) fri0XxF  
{ mW%?>Z1=>d  
nFileLength = getFileSize(); kj5Q\vr)  
if(nFileLength == -1) .lhn;*Yi  
{ ^[Cv26  
System.err.println("File Length is not known!"); w<9>Q1(  
} 5BR5X\f0  
else if(nFileLength == -2) juBw5U<  
{ ;d$qc<2uA  
System.err.println("File is not access!"); VGL#!4wK  
} ~"Gf<3^y+  
else d7Ur$K\=y  
{ FZiW|G  
for(int i=0;i<nStartPos.length;i++) A|}l)!%  
{ '2zL.:~  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 56hA]O29O  
} *]JdHO  
for(int i=0;i<nEndPos.length-1;i++) 7t9c7HLuj/  
{ h;lirvO|  
nEndPos = nStartPos[i+1]; W\f9jfD  
} avp; *G }  
nEndPos[nEndPos.length-1] = nFileLength; dMx4ykrR  
} 4;`Bj:.  
} j\RpO'+}  
Pag63njg?  
a'\By?V]  
//启动子线程 ')S;[=v  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vhr+g 'tf  
for(int i=0;i<nStartPos.length;i++) }G$]LWgQx  
{ yz+, gLY  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~#\i!I;RY}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6pE :A@  
nStartPos,nEndPos,i); ^0W(hA  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 52zGJ I*  
fileSplitterFetch.start(); zm9TvoC%}  
} CBf7]n0H  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CLKov\U\  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CGw--`#\  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pO<-.,  
nEndPos = " + nFileLength); 6)\dBOz  
// fileSplitterFetch[nPos.length-1].start(); m xw dugr`  
"HM{b?N  
OEr:xK2T  
//等待子线程结束 Q4s&E\}  
//int count = 0; O gmO&cE  
//是否结束while循环 8|twV35  
boolean breakWhile = false; NkxCs  
tNs~M4TVVH  
 &K^MN d  
while(!bStop) `P+(&taT  
{  0JRD  
write_nPos(); 9+YD!y  
Utility.sleep(500); 5H,G-  
breakWhile = true; M ixwK,  
>zY \Llv  
F)$K  
for(int i=0;i<nStartPos.length;i++) wN37zPnV~  
{ ;@ WV-bLe  
if(!fileSplitterFetch.bDownOver) WKA'=,`v  
{ D 7shiv|,  
breakWhile = false; J3S&3+2G  
break; r0m)j  
} 5CJZw3q  
} vd#,DU=p!  
if(breakWhile) 2>S~I"o0  
break; ?3sT" r_d@  
MWuXI1  
Y ?]G}5  
//count++; HW=xvA+  
//if(count>4) "C%!8`K{a*  
// siteStop(); D1,O:+[;.  
}  Kn+=lCk  
;i#LIHJ  
\9)[ #Ld  
System.err.println("文件下载结束!"); Mj0Cat=  
} p}]q d4j  
catch(Exception e){e.printStackTrace ();} >',y  
} }F`beoMAkM  
<l\N|+7R  
@kngI7=E  
//获得文件长度 1TqF6`;+  
public long getFileSize() FyD.>ot7M  
{ TW`mxj_J2  
int nFileLength = -1; 2]jPv0u  
try{ mp `PE=  
URL url = new URL(siteInfoBean.getSSiteURL()); O{KB0"s>i  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <Mgf]v.QS  
httpConnection.setRequestProperty("User-Agent","NetFox"); ~] =?b)B  
( (3t:  
[h}K$q  
int responseCode=httpConnection.getResponseCode(); vW.%[]  
if(responseCode>=400) Oo%!>!Lt,  
{ 3 %(Y$8U  
processErrorCode(responseCode); AfWl6a?T8:  
return -2; //-2 represent access is error rFag@Z"["  
} #!!AbuhzK{  
K, (65>86;  
993d/z|DX  
String sHeader; Mps *}9  
i|2$8G3  
'ND36jHcRD  
for(int i=1;;i++) FuP}Kec  
{ m% bE-#  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #0MK(Ut/  
//Utility.log(in.readLine()); `6 Y33bQ  
sHeader=httpConnection.getHeaderFieldKey(i); xcSR{IZ  
if(sHeader!=null) `ENP=kL(+  
{ ./maY1>T  
if(sHeader.equals("Content-Length")) lC9S\s  
{ I{n;4?  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jW5iqU"{*  
break; p?myuNd[  
} q@Kk\m  
} o<4D=.g7D  
else y/4ny,s"  
break; WEa>)@  
} Md9l+[@  
} Fn,k!q  
catch(IOException e){e.printStackTrace ();} vnsSy33K  
catch(Exception e){e.printStackTrace ();} (DJvi6\H  
>a]t<  
' Js?N  
Utility.log(nFileLength); eOrYa3hQ  
CM 9P"-  
J~J@ ]5/  
return nFileLength; 7Jx%JgF  
} )*[ ""&  
.)ST[G]WK  
O<`R~  
//保存下载信息(文件指针位置) &telCg:  
private void write_nPos() Dr 'sIH^  
{ [,7-w  
try{ ('WY5Yps  
output = new DataOutputStream(new FileOutputStream(tmpFile)); D9^7m j?e  
output.writeInt(nStartPos.length); oeN zHp_  
for(int i=0;i<nStartPos.length;i++) #\b ;2>  
{ agY5Dg7  
// output.writeLong(nPos); Qq0O0U  
output.writeLong(fileSplitterFetch.nStartPos); E/"SU*Co  
output.writeLong(fileSplitterFetch.nEndPos); 6GOg_P  
} $r"A@69^RS  
output.close(); wW()Zy0)  
} xKW"X   
catch(IOException e){e.printStackTrace ();} :Y.e[@!1x  
catch(Exception e){e.printStackTrace ();} ~L){O*Z  
} 1l]C5P}E  
A9 n41,h  
 4Iq5+Q  
//读取保存的下载信息(文件指针位置) VG\mo?G  
private void read_nPos() " Z;uu)NE  
{ " dT>KQ  
try{ !Zj#.6c9  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); no3Z\@%  
int nCount = input.readInt(); cj^bh  
nStartPos = new long[nCount]; Qu}N:P9l?X  
nEndPos = new long[nCount]; %]GV+!3S  
for(int i=0;i<nStartPos.length;i++) Vi,Y@+4  
{ Y`]rj-8f0B  
nStartPos = input.readLong(); ,eK2I Ao  
nEndPos = input.readLong(); q2Rf@nt  
}  QT_^M1%  
input.close(); N(7u],(Om  
} poY8 )2  
catch(IOException e){e.printStackTrace ();} `$Kes;[X  
catch(Exception e){e.printStackTrace ();} _FFv#R*4  
} -$ali[  
qvN"1=nJ  
~y@& }  
private void processErrorCode(int nErrorCode) Bt6xV<jD  
{ w 06gY  
System.err.println("Error Code : " + nErrorCode); '8={ sMy  
} Fva]*5  
S| "TP\o  
PHl4 vh#E!  
//停止文件下载 R25-/6_V>  
public void siteStop() GDmv0V$6  
{ W+/2c4$F3  
bStop = true;  h.D^1  
for(int i=0;i<nStartPos.length;i++) 4L $};L  
fileSplitterFetch.splitterStop(); i]@c.Q iFN  
YR8QO-7 .)  
wKLN:aRF2  
} D{3fhPNU<b  
} P|v ?  
//负责部分文件的抓取 lR[z<2w\  
**FileSplitterFetch.java &&*wmnWCS{  
*/ [[$Mh_MD  
package NetFox; dL(4mR8  
Hq-v@@0 *  
i2U/RXu  
import java.io.*; hvL6zCi  
import java.net.*; `{WCrw6)  
1V\1]J/  
N&,"kRFFo  
public class FileSplitterFetch extends Thread { {~"Em'}J  
XJ _%!  
ZgK@Fl*k  
String sURL; //File URL '1lx{U zD  
long nStartPos; //File Snippet Start Position G-s a L*  
long nEndPos; //File Snippet End Position |/t K-c6J  
int nThreadID; //Thread's ID JQr36U  
boolean bDownOver = false; //Downing is over >["Kd.ye  
boolean bStop = false; //Stop identical "|\94  
FileAccessI fileAccessI = null; //File Access interface hN}5u"pS  
&#%D.@L  
[@zkv)D6  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lvG3<ls0K$  
{ . *Z#cq0  
this.sURL = sURL; F-i&M1 \_  
this.nStartPos = nStart; |:}L<9Sq  
this.nEndPos = nEnd; 0x6@{0  
nThreadID = id; 8db6(Q~P  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *eMLbU7  
} /T{mS7EpYc  
|})rt5|f1!  
ruWye1X;  
public void run() bf{Ep=-  
{ VgUvD1v?}  
while(nStartPos < nEndPos && !bStop) hN!.@L  
{ y.%i  
cx<h_  
vDWr|M%``l  
try{ DU(X,hDBF  
URL url = new URL(sURL); Scf.4~H 0  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &,F elB0*  
httpConnection.setRequestProperty("User-Agent","NetFox"); PaA6Z":  
String sProperty = "bytes="+nStartPos+"-"; 1ME|G"$;  
httpConnection.setRequestProperty("RANGE",sProperty); !(}OBZ[*  
Utility.log(sProperty); <'VA=orD  
/^NJ)9IB  
x={kjym L  
InputStream input = httpConnection.getInputStream(); "rL"K  
//logResponseHead(httpConnection); Sw/J+FO2  
A<]&JbIt  
Xk;Uk[  
byte[] b = new byte[1024]; wX@H &)<s  
int nRead; L/c4"f|.*v  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T$f:[ye]Z  
{ zv&ePq\#  
nStartPos += fileAccessI.write(b,0,nRead); m<~>&mWr  
//if(nThreadID == 1) 9$8X> T^   
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L,tZh0  
} ]U#JsMS  
6_x}.bkIx=  
p^}L  
Utility.log("Thread " + nThreadID + " is over!"); ^"PfDTyA  
bDownOver = true; :A,O(   
//nPos = fileAccessI.write (b,0,nRead); T,A!5V>cX  
} 5R& x{jf$  
catch(Exception e){e.printStackTrace ();} & %@/Dwr  
} wbn^R'  
} 7cy+Nz  
Fa6H(L3  
j'#)~>b  
//打印回应的头信息 ^f!Zr  
public void logResponseHead(HttpURLConnection con) Xq[:GUnt  
{ xq8}6Q  
for(int i=1;;i++) X^u4%O['  
{ 3}v0{c  
String header=con.getHeaderFieldKey(i); nYo&x'  
if(header!=null) A&x ab  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >|y>e{P  
Utility.log(header+" : "+con.getHeaderField(header)); F0X5dv  
else "v*oga%  
break; yIn/Y0No  
} 6tDg3`w>  
} 8ct+?-3g  
oSpi{ $x  
oFX"F0rx  
public void splitterStop() m 4wPuW  
{ Cb4d|yiS8  
bStop = true; @'6S[zU  
} @&/s~3  
3U :YA&K(  
cg>!<T*  
} k8!hvJ)?  
UUt~W  
ZJiuj!  
/* $`-SVC  
**FileAccess.java 1jR=h7^=  
*//文件访问(定位,写) S.zg&   
package NetFox; ,<R>Hiwg/s  
import java.io.*; PmuEL@'^ U  
N` @W%  
PT 0Qzg  
public class FileAccessI implements Serializable{ z(8)1#(n7  
h0'8NvalQ  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dm/-}  
RandomAccessFile oSavedFile; LC~CPV'F  
long nPos; tuL\7 (R  
 hg<"Yg=  
,I 9][_  
public FileAccessI() throws IOException ?uNTUU,  
{ 4i ~eTb  
this("",0); ze#rYNvo/  
} 1Xk{(G<\  
}.fZy&_  
FF~on06!   
public FileAccessI(String sName,long nPos) throws IOException D;1 6}D  
{ .b!OZ  
oSavedFile = new RandomAccessFile(sName,"rw"); hlSB7D"d  
this.nPos = nPos; W>aQ tT  
oSavedFile.seek(nPos); %8rr*l5  
} I{*.htt{  
/r::68_KQP  
rw40<SS"Z  
public synchronized int write(byte[] b,int nStart,int nLen) i{1)=_$Vt`  
{ y{&{=1#  
int n = -1; !9ceCnwbNN  
try{ mM\!4Yi`7  
oSavedFile.write(b,nStart,nLen); df21t^0/  
n = nLen; 2yi*eR  
} [FeJ8P>z  
catch(IOException e) =Ov;'MC  
{ x`j$9XN5  
e.printStackTrace (); L:k@BCQM  
} l"~h1xk~  
\pBYWf  
>h/)r6  
return n; ~8Dd<4?F]  
} "R\\\I7u  
kcma/d  
dZ;~b(CA  
} 5sA>O2Rt>  
6a2w-}Fs  
{$u@6& B  
/* ^)%wq@Hi  
**SiteInfoBean.java lhIr]'?l  
*/ q6m87O9  
package NetFox; $J;=Ux)$  
q)z1</B-  
Xx9~  
public class SiteInfoBean { =w;xaxjL  
U(Hq4D  
}ii]c Y  
private String sSiteURL; //Site's URL RL]lt0O{  
private String sFilePath; //Saved File's Path j .yr 5%  
private String sFileName; //Saved File's Name [<3Q$*Ew  
private int nSplitter; //Count of Splited Downloading File yW6[Fpw  
#Ko+_Hm?4  
m?kIa!GM=  
public SiteInfoBean() t KqCy\-q  
{//nSplitter的缺省值为5 "#eNFCo7k  
//default value of nSplitter is 5 =-1^K  
this("","","",5); H$qdU!c  
} i5~ /+~  
~1wdAq`'a  
~M9 n<kmE  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PUFW^"LV  
{ NId~| &\  
sSiteURL= sURL; #*;fQ&p  
sFilePath = sPath; (j"~]T!)1  
sFileName = sName; qeO6}A"^|  
this.nSplitter = nSpiltter; <J_,9&\J  
A](}"Pi!n  
krnk%ug  
} n-| i  
0.+Z;j  
2O)Kn q  
public String getSSiteURL() *mhw5Z=!  
{ f!R^;'a  
return sSiteURL; }zfLm` vJ  
} p~zTRnm  
]2s Zu7  
XGup,7e9  
public void setSSiteURL(String value) [{!j9E?(  
{ OXCml(>{  
sSiteURL = value; $q@RHcj  
} 63dtO{:4  
e !x-:F#4j  
Vi -!E  
public String getSFilePath() 2] wf`9ZH  
{ Z$=$oJzB  
return sFilePath; eRqexqO!  
} DBh/V#* D  
BHBT=,sI  
BMsy}08dQ  
public void setSFilePath(String value) ;NVTn<Uj  
{ $8ww]}K  
sFilePath = value; :x5o3xE  
} 3/|{>7]1  
snzH}$Ls  
D2*Q1n  
public String getSFileName() jE5 9h  
{ U,3K6AZA 7  
return sFileName; *z:lq2"G  
} T[9jTO?W2  
ScmzbDu  
iW%0pLn  
public void setSFileName(String value) ;%.k}R%O@  
{ GN"LU>9|  
sFileName = value; -+2xdLa63  
} *E q7r>[  
n~cm?"  
91Sb= 9  
public int getNSplitter() M@ZpgAfq  
{ vh.tk^&  
return nSplitter; *ww(5 t  
} k#G7`dJl  
>-WO w  
3T^dgWXEG  
public void setNSplitter(int nCount) t-m,~IoW  
{ |y=F ( 6Z  
nSplitter = nCount; z`{zqP:  
} weadY,-H8  
} mP+yjRw  
T:5%sN;#O  
`%:(IGxz  
/* Mp}NUQHE  
**Utility.java m&c(N  
*/ 7n]%`Yb  
package NetFox; :u+#:8u  
I`>%2mP[C  
Gl:T  
public class Utility { vy y\^nL  
"< R 2oo)^  
#$T"QL@  
public Utility() euC,]n.  
{ ;P#*R3   
[`dipLkr  
dR{ V,H7N  
} r}Av"  
+>({pHZ<S  
//线程睡眠 nOzT Hg8  
public static void sleep(int nSecond) u6d~d\  
{ K<(sqH  
try{ m(]IxI  
Thread.sleep(nSecond); }-iOYSn  
} h(up1(x  
catch(Exception e) Xh!Pg)|E  
{ {Oszq(A  
e.printStackTrace (); )C6 7qY  
} vH8%a8V  
} %W@IB8]Vr  
fdHxrH >*  
//日志 YNk|UwJi  
public static void log(String sMsg) sR nMBW.  
{ ;Nij*-U4~  
System.err.println(sMsg); ;wB  3H  
} 9x,+G['Zt  
)CQ}LbXZy  
rNp#5[e  
public static void log(int sMsg) ??Ac=K\  
{ yK3z3"1M?  
System.err.println(sMsg); F tjm@:X  
} P2F>iK#U  
} OSk9Eb4ld  
B[50{;X  
nsk 6a  
/* E~^'w.1  
**TestMethod.java A4h/oMis  
*/ 1fZ:^|\  
package NetFox; P#PQ4uK \  
L~~Yh{<  
l[k$O$jo  
public class TestMethod { Q8i6kf!  
U)8]pUI+/P  
_TF>c:m3  
public TestMethod() =ndKG5  
{ ///xx/weblogic60b2_win.exe 6Tnzg`0I  
try{ t;3.;  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R3A^VE;qP  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (z7#KJ1+Aw  
SiteFileFetch fileFetch = new SiteFileFetch(bean); !)34tu2  
fileFetch.start(); ,vPF=wq  
} lH.2H  
catch(Exception e){e.printStackTrace ();} RSC-+c6 1  
M-Bw9`#Jw  
CgC wM=!r  
} eHR<(8c'f  
wQT'~'kL  
>^&+,*tsS4  
public static void main(String[] args) 2X_ef  
{ .&y1gh!=  
new TestMethod(); m@ YL Z  
} 3 6 ;hg #  
} 7}k8-:a%  
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