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http断点续传简单实现(java)

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/* ;;Tq$#vd  
**SiteFileFetch.java %/pc=i|+  
*/ &*gbK6JB  
package NetFox; QBihpA 1;  
import java.io.*; ^l(^z fsZ  
import java.net.*; ^P$7A]!  
FYl3c   
$[z<oN_Q  
public class SiteFileFetch extends Thread { ?cK]C2Ak  
$5A^'q  
<5IQc[3]aP  
SiteInfoBean siteInfoBean = null; //文件信息Bean (Ilsk{aB;A  
long[] nStartPos; //开始位置 0*yJ %  
long[] nEndPos; //结束位置 S>t>6&A  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 OZOb1D  
long nFileLength; //文件长度 [r9d<Zi}{  
boolean bFirst = true; //是否第一次取文件 nzuF]vo  
boolean bStop = false; //停止标志 xS+rHC  
File tmpFile; //文件下载的临时信息 eY}V9*.v  
DataOutputStream output; //输出到文件的输出流 wS$46M<  
u"FjwF?  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) "b%FmM  
public SiteFileFetch(SiteInfoBean bean) throws IOException 0( //D;j  
{ A*i_|]Q  
siteInfoBean = bean; : Ss3ck*=  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); n)RM+g  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); BIfi:7I;Q  
if(tmpFile.exists ()) CDCC1BG"  
{ G Y-M.|%  
bFirst = false; ti9}*8  
read_nPos(); ;_tO+xL&  
} ,8##OB(  
else w2zp#;d  
{ hW' HT  
nStartPos = new long[bean.getNSplitter()]; %?=)!;[  
nEndPos = new long[bean.getNSplitter()]; hQ';{5IKvC  
} $E.XOpl&I  
 SFpQ#  
d)KF3oA  
KlO(o#&N  
} 1X&B:_  
vGN3 YcH  
;J=:IEk  
public void run() !G+u j(  
{ Pfan7fq+  
//获得文件长度 d+5:Qrr  
//分割文件 P4 6,o  
//实例FileSplitterFetch >FF1)~  
//启动FileSplitterFetch线程 L_?$ayZ;  
//等待子线程返回 a5V=!OoMk  
try{ w+_Wc~f  
if(bFirst) 7#pZa.B)k  
{ }4h0bI  
nFileLength = getFileSize(); j@v-|  
if(nFileLength == -1) TQ'e  
{ 7cw]v"iv  
System.err.println("File Length is not known!"); KB+]eI-h  
} o](.368+4  
else if(nFileLength == -2) m[8 @Unt  
{ `%y5\!X  
System.err.println("File is not access!"); SRf5W'4y  
} H\+-cvl  
else !01i%W'  
{ h8.FX-0& =  
for(int i=0;i<nStartPos.length;i++) eP= j.$  
{ _}ele+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); {D,RU8&  
} l%<c6;  
for(int i=0;i<nEndPos.length-1;i++) 6LM9e0oxy  
{ Z,aGtJ.a'9  
nEndPos = nStartPos[i+1]; %U?)?iZdL  
} oMc1:=EG  
nEndPos[nEndPos.length-1] = nFileLength; 40.AM1Z0f  
} %nQmFIt  
} %3G;r\|r]  
P) 1 EA;  
sX'nn   
//启动子线程 *#h;c1aP  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3 Gd|YRtk  
for(int i=0;i<nStartPos.length;i++) (\& 62B1  
{ kzi|$Gs<  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zlkWU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @L8;VSI  
nStartPos,nEndPos,i); Z4@y?f v7s  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xA-jvu9@  
fileSplitterFetch.start(); =4>@8=JA  
} OX3Xy7  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %?dE{ir  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e5OVq ,  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q|//Z  
nEndPos = " + nFileLength); {US>)I  
// fileSplitterFetch[nPos.length-1].start(); !*bdG(pK  
oHsP?%U  
OjATSmZ@@  
//等待子线程结束 PL@7 KD Q  
//int count = 0; UABbcNW  
//是否结束while循环 #(dhBEXPW;  
boolean breakWhile = false; Q>%E`h  
o9+Q{|r  
WZK :.y  
while(!bStop) %zflx~  
{ OG}KqG!n  
write_nPos(); ?O7iK<5N  
Utility.sleep(500); @_Sp3nWdu  
breakWhile = true; h2;l1 G,  
QgZJ`G--  
vJThU$s-  
for(int i=0;i<nStartPos.length;i++) ?*+1~m>  
{ 7@a\*|K6  
if(!fileSplitterFetch.bDownOver) [gn[nP9  
{ vHc#m@4o  
breakWhile = false; 3+zzi  
break; `^%@b SE(  
} Tk](eQsy.v  
} PUKVn+h  
if(breakWhile) d?}hCo=/Xq  
break; #ovM(Mld  
xVTo4-[p  
UN(3i(d  
//count++; A^L?_\e6  
//if(count>4) PW)8aLU  
// siteStop(); =mLeMk/7 w  
} .hne)K%={y  
hgwn> p:S#  
oG\>--  
System.err.println("文件下载结束!"); ^'Y HJEK  
} r0uJ$/!  
catch(Exception e){e.printStackTrace ();} S}mm\<=1  
} CjV7q y  
$eMK{:$O  
eI?HwP{m  
//获得文件长度 K1-+A2snhV  
public long getFileSize() y($EK(cb  
{ 3P`WPph  
int nFileLength = -1; >uW^.e "F  
try{ -#OwJ*-U  
URL url = new URL(siteInfoBean.getSSiteURL()); b=G4MZQ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Yx 3|G  
httpConnection.setRequestProperty("User-Agent","NetFox"); q;No"_aAd  
Hh\ 4MNl  
MYu`c[$jZ  
int responseCode=httpConnection.getResponseCode(); -)>(8f  
if(responseCode>=400) ``6{T1fQS  
{ 4UVW#Rw{  
processErrorCode(responseCode); 1VGpq-4*j  
return -2; //-2 represent access is error 5Kee2s?*  
} j@CKO cn2  
G g(NGT  
yZ|+VXO  
String sHeader;  h,~tXj  
$$\V 2%v  
;Rs.rl>;t/  
for(int i=1;;i++) X&.:H~xS+  
{ Nuo^+z E   
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WV@X@]U  
//Utility.log(in.readLine()); Qxky^:B  
sHeader=httpConnection.getHeaderFieldKey(i); _hWuAJ9Qy  
if(sHeader!=null) yIWc\wv  
{ 7|{ B#  
if(sHeader.equals("Content-Length")) '9"%@AFxZ  
{ {=qEBbM  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [bsXF#  
break; T:6K?$y?  
} `ReGnT[  
} 9p4%8WhJ  
else X0!Bs-WFp  
break; Enu!u~1]F  
} 'H!V54 \j  
} v` $%G  
catch(IOException e){e.printStackTrace ();} W oWBs)E  
catch(Exception e){e.printStackTrace ();} HmW=t}!  
<c(&T<$  
_TrZ'iL}T  
Utility.log(nFileLength); N6WPTUQ1mF  
}a' cm!"  
.Jptj  
return nFileLength; )O9fhj)  
} WqR7uiCi  
lS#7x h  
X:U=MWc>  
//保存下载信息(文件指针位置) }\>+H  
private void write_nPos() H<$pHyxU  
{ x\6] ;SXX  
try{ JV&Zwbu  
output = new DataOutputStream(new FileOutputStream(tmpFile)); <r_3obRC  
output.writeInt(nStartPos.length); 5`{=`  
for(int i=0;i<nStartPos.length;i++) r1+c/;TpZ  
{ 9uKOR7.zbo  
// output.writeLong(nPos); D/e&7^iK  
output.writeLong(fileSplitterFetch.nStartPos); iQu^|,tHEM  
output.writeLong(fileSplitterFetch.nEndPos); +)?,{eE|  
} gji*Wq  
output.close(); Qg[heND  
} c5<kbe  
catch(IOException e){e.printStackTrace ();} 7&h\l6}Yh  
catch(Exception e){e.printStackTrace ();} >B`Cch/ 'U  
} *B %y`cj|  
zf`5>h|  
- Sx0qi'%  
//读取保存的下载信息(文件指针位置) 1]Gf)|  
private void read_nPos() o T:j:n  
{ h,]tQ#!s8  
try{ z/)$D  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]F !'M  
int nCount = input.readInt(); ";756'>  
nStartPos = new long[nCount]; JR] )xPI`  
nEndPos = new long[nCount]; ,tau9>!  
for(int i=0;i<nStartPos.length;i++) cD5w| rm?i  
{ ES^NBI j5P  
nStartPos = input.readLong(); E N)YoVk  
nEndPos = input.readLong(); KuIkul9^%  
} E2h(w_l  
input.close(); : 2_ 0L  
} nT_*EC<.  
catch(IOException e){e.printStackTrace ();} F ~*zC`>Y  
catch(Exception e){e.printStackTrace ();} p@vpd  
} " 98/HzR  
K1/ U (A  
uFz/PDOZ@  
private void processErrorCode(int nErrorCode) :wFb5"  
{ fdN45in=>  
System.err.println("Error Code : " + nErrorCode); "&@gX_%  
} cLn;,u4  
H3!,d`D.N  
pi|\0lH6W  
//停止文件下载 ]gb _Nv  
public void siteStop() b*cW<vX}~  
{ f+{c1fb>s  
bStop = true; a:=q8Qy  
for(int i=0;i<nStartPos.length;i++) $[)6H7!U)  
fileSplitterFetch.splitterStop(); ThjUiuWe  
@mvIt  
_2wAaJvA  
} joxS+P5#  
} Tnf&pu#5  
//负责部分文件的抓取 th5 X?so  
**FileSplitterFetch.java C_6GOpl  
*/ cR,'o'V/  
package NetFox; $Vo/CZW7  
8FAT(f//.  
^!q 08`0  
import java.io.*; r5D jCV"  
import java.net.*; z`c%?_EK  
0PYvey }[  
G%xb0%oi]%  
public class FileSplitterFetch extends Thread { 2O?Vr" A  
g7 .7E6%H  
=n> iQS  
String sURL; //File URL 3X,]=f@_  
long nStartPos; //File Snippet Start Position vEu Ka<5  
long nEndPos; //File Snippet End Position xylpiSJ  
int nThreadID; //Thread's ID [Bl $IfU  
boolean bDownOver = false; //Downing is over _`TepX R  
boolean bStop = false; //Stop identical Rbx97(wK  
FileAccessI fileAccessI = null; //File Access interface QIR4<]/  
Su$18a"Bc  
 ` 2Wl  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }9{dR4hD  
{ H|grbTv,  
this.sURL = sURL; 7xX;MB &  
this.nStartPos = nStart; `Af{H/qiI  
this.nEndPos = nEnd; D."cQ<sxpN  
nThreadID = id; ^`l"'6  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l\q*%'Pe  
} s@[C&v  
f 1sy9nQs  
sjkWz2]S  
public void run() C4&U:y<ju  
{ b7?U8/#'  
while(nStartPos < nEndPos && !bStop) MDMtOfe|  
{ }v_p gatC  
szf"|k!  
Zkf 3t>[  
try{ *54>iO- c  
URL url = new URL(sURL); ^</65+OT+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mle_*Gy8  
httpConnection.setRequestProperty("User-Agent","NetFox"); r^?)F?n!  
String sProperty = "bytes="+nStartPos+"-"; L!CX &  
httpConnection.setRequestProperty("RANGE",sProperty); hB|H9+  
Utility.log(sProperty); F?*Dr  
h$E\2lsE  
aK8bKlZe  
InputStream input = httpConnection.getInputStream(); )B -MPuB  
//logResponseHead(httpConnection); ^VSt9 &  
KC@k9e  
Fpy6"Z?z  
byte[] b = new byte[1024]; ^n\9AE3  
int nRead; L9E;Uii0  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l=oN X"l=  
{ ZA *b9W  
nStartPos += fileAccessI.write(b,0,nRead); 6Cz7A  
//if(nThreadID == 1) <C7M";54-  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5*s1qA0^  
} sN} s61  
<'PR;g^#  
v7s ]  
Utility.log("Thread " + nThreadID + " is over!"); h Jfa_  
bDownOver = true; A[sM{i~Z  
//nPos = fileAccessI.write (b,0,nRead); `_NnQ%  
} [VY8?y  
catch(Exception e){e.printStackTrace ();} &/b? I `  
} Nrab*K(][  
}  ET >S  
[@,OG-"&  
/>dB%*  
//打印回应的头信息 r1[E{Tpz  
public void logResponseHead(HttpURLConnection con) t_[M &  
{ GM)\)\kNF  
for(int i=1;;i++) 3::3r}g  
{ DhtU]w}  
String header=con.getHeaderFieldKey(i); Q3<bC6$r  
if(header!=null) Hs:4I  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m#5|J@]  
Utility.log(header+" : "+con.getHeaderField(header)); sD LVYD  
else Hmz=/.$  
break; S5:"_U  
} |i,zY{GI+2  
} OqfhCNAY  
Bo\a  
WUE)SVf  
public void splitterStop() =:xV(GK}  
{ 'Z*\1Ci  
bStop = true; u)q2YLK8  
} e3yorQ][  
KuIt[oM  
e.)yV'%L  
} }};j2  
1kB'sc3N!  
x&hvFG3  
/* Bi9 N  
**FileAccess.java { 4_I7r  
*//文件访问(定位,写) d-6sC@PB  
package NetFox; 2ru*#Z#(  
import java.io.*; f7EIDFX>pt  
&^CL] &/  
c]AKeq]  
public class FileAccessI implements Serializable{ mhHA!:Y  
rd&*j^?  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8{}Pj  
RandomAccessFile oSavedFile; ZI2K-z'e  
long nPos; gmF_~"^34  
Bo](n*i  
p`E|SNt/W  
public FileAccessI() throws IOException f"5lOzj`C  
{ &y#\1K  
this("",0); ^]#Ptoz^(l  
} [OFTP#}c  
Pi&fwGL  
B|]t\(~$ [  
public FileAccessI(String sName,long nPos) throws IOException ,(@Y%UW:  
{ 38x[Ad4%  
oSavedFile = new RandomAccessFile(sName,"rw"); (c|$+B^*  
this.nPos = nPos; Sa h<sb=  
oSavedFile.seek(nPos); }$&T O$LX  
} mr{k>Un\  
%:'1_@Ot 2  
@!L@UP0  
public synchronized int write(byte[] b,int nStart,int nLen) bl:a&<F  
{ |: 7EJkKZ  
int n = -1; FT*yso:X/  
try{ 6SW|H"!!  
oSavedFile.write(b,nStart,nLen); r)9i1rI+  
n = nLen; _g^K$+F'}  
} CI~hmL0  
catch(IOException e) wS F!Xx0  
{ #K<=xP  
e.printStackTrace (); uZqu xu.  
} z. _C*c  
?{@!!te@3v  
i#@v_^q  
return n; gqO%^b)6  
} b.mjQ  
TRr4`y%  
BRo R"#'  
} eLDL  "L  
a>)_ `m  
OUBgBr   
/* dN$D6*  
**SiteInfoBean.java }6uV]V{  
*/ X*0eN3o.  
package NetFox; C)&gL=O*$  
_-|yCo  
tKs4}vW  
public class SiteInfoBean { ;9!yh\\   
|h^G$guw  
vjs|!O=oH  
private String sSiteURL; //Site's URL wa(Wit"-  
private String sFilePath; //Saved File's Path T9<H%iF  
private String sFileName; //Saved File's Name ;i-D~Np|  
private int nSplitter; //Count of Splited Downloading File ^huBqEs  
^V XXq  
n7`.<*:  
public SiteInfoBean() Sq?6R}q%  
{//nSplitter的缺省值为5 eSvc/CU  
//default value of nSplitter is 5 ;4S [ba1/  
this("","","",5); ?v)"%.  
} $X.'W\o|  
(zM+7tJH  
j-I6QUd  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /\3XARt  
{ `F- Dd4B  
sSiteURL= sURL; T,xVQ4J?  
sFilePath = sPath; fr,CH{Uq  
sFileName = sName; 6gg#Z  
this.nSplitter = nSpiltter; <750-d!  
<@x+N%C  
RBv=  
} mk[d7Yt{O  
#/XK&(X  
}'w^<:RSy  
public String getSSiteURL() m|#(gX|F  
{ ]mD=Br*r~  
return sSiteURL; 8ZNd|\  
} e $/Zb`k  
qN`]*baS  
x%:> Ol  
public void setSSiteURL(String value) !cFE^VM_;  
{ ,h^;~|GT  
sSiteURL = value; @WDqP/4  
} X/;"CM  
R<0!?`b  
,39$iHk  
public String getSFilePath() z hR_qW+  
{ 6Ymo%OT  
return sFilePath; V)?x*R*T)  
} N?U&(@p  
`M pC<sit  
PE;0 jgsiI  
public void setSFilePath(String value) qI V`zZc  
{ 2)I'5 ?I  
sFilePath = value; z5o9\.y({  
} Fb<\(#t  
p-(ADQS  
9^Vx*KVrU  
public String getSFileName() w_z^5\u0  
{ a,0o{* (u$  
return sFileName; ?w5nKpG#RI  
} )Ido|!]0d  
si mX  
q2j}64o _S  
public void setSFileName(String value) `aWwF} +Y  
{ 2h? r![  
sFileName = value; fY\tvo%  
} 4K?H-Jco  
{If2[4!z  
^)0{42!]  
public int getNSplitter() {</$ObK  
{ )S;Xy`vO  
return nSplitter; `w+9j-  
} 3sg)]3jm2  
O,xAu}6f+  
?BWvF]p5/  
public void setNSplitter(int nCount) _^2[(<Gmv  
{ $85o%siS'  
nSplitter = nCount; 3xCA\*  
} C;:1CK  
} CyBM4qyH  
23n8,} H,  
* SON>BSF  
/* Kp=3\)&  
**Utility.java $d??(   
*/ )i6U$,]  
package NetFox; $b 71  
. =foXN  
k s`  
public class Utility { CR<pB)F?a  
)'I<xx'1  
PS<tS_.  
public Utility() W-ND<=:Up  
{ ,"MUfZ  
W9:{pQG  
vM3|Ti>a'  
} eS# 0-  
6~Oje>w;  
//线程睡眠 Vqp.jF1|  
public static void sleep(int nSecond) Sdu@!<?B  
{ uxJiec`&  
try{ [\M?8R$)  
Thread.sleep(nSecond); ! {o+B^^  
} PM?Ri^55<L  
catch(Exception e) ` Ehgn?6'  
{ }Yl8Q>t  
e.printStackTrace (); "s6_lhu=E7  
} bg3jo1J  
} H><mcah  
%Ja{IWz9L  
//日志 ]A<u eM  
public static void log(String sMsg) EV,NJ3V  
{  yURh4@  
System.err.println(sMsg);  !+VN   
} !J?=nSu  
FEi,^V  
Ly/~N/<\  
public static void log(int sMsg) _j<M}  
{ iuk8c.TAR  
System.err.println(sMsg); mS;Q8Crh  
} r_<i*l.  
} \C\y' H5  
A)a+LW'=u  
cz~11j#  
/* Ecl7=-y  
**TestMethod.java " 7g8 d  
*/ V'hz1roe  
package NetFox; !<^j!'2  
@ DKl<F  
pO+wJ|f  
public class TestMethod { 5Fm? ,^  
<?@46d?C  
Uo)<_nG  
public TestMethod() ~map5@Kd  
{ ///xx/weblogic60b2_win.exe nPX'E`ut-V  
try{ [&k k  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cZF;f{t  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v&,VC~RN-J  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]T$w7puaJ  
fileFetch.start(); QMpA~x_m  
} lfhKZX  
catch(Exception e){e.printStackTrace ();} DmA!+  
"1TM  
qvE[_1QCc  
} ['`'&+x&!  
;Wm)e~`,  
` Z V'7|  
public static void main(String[] args) U5%]nT"[]  
{ t"Rf67  
new TestMethod(); mpJ_VS`  
} ?Lb7~XKt\  
} Ps5wQaS  
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