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http断点续传简单实现(java)

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/* p&3> `C  
**SiteFileFetch.java '29WscU  
*/ aWaw&u  
package NetFox; ~_PYNY`"  
import java.io.*; x9V {R9_gf  
import java.net.*; +hH}h?K  
I; j3*lV_  
0.DQO;  
public class SiteFileFetch extends Thread { l3J$md|f  
D4Sh9:\  
=`p&h}h-L  
SiteInfoBean siteInfoBean = null; //文件信息Bean zj20;5o>U&  
long[] nStartPos; //开始位置 Z"tQp Jg  
long[] nEndPos; //结束位置 X8CVY0<o  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 _01Px a2.  
long nFileLength; //文件长度 %#k,6 ;m  
boolean bFirst = true; //是否第一次取文件 $Jf9;.  
boolean bStop = false; //停止标志 GZ3/S|SMP  
File tmpFile; //文件下载的临时信息 g42T#p8^  
DataOutputStream output; //输出到文件的输出流 )w"0w(   
;.s: X  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ~ hm`uP  
public SiteFileFetch(SiteInfoBean bean) throws IOException \cZfg%PN  
{ r~oSP^e'  
siteInfoBean = bean; rJ(OAKnY  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); s*JE)  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); }1>atgq]w  
if(tmpFile.exists ()) I,j3bC  
{ NG9vml  
bFirst = false; RWikJ   
read_nPos(); <SQ(~xYi  
} a8JN19}D  
else Mi74Xl i  
{ ;3 UvkN  
nStartPos = new long[bean.getNSplitter()]; ragSy8M  
nEndPos = new long[bean.getNSplitter()]; 'v`_Ii|-  
} vlQ0gsXK  
BKA]G)G7u!  
Wz{%"o  
$L&BT 0  
} W5/};K\.  
M(5D'4.  
76cEKHa<  
public void run() qLRE}$P  
{ @?/\c:cp  
//获得文件长度 k1iLnza%  
//分割文件 C BlXC7_Mi  
//实例FileSplitterFetch xid:"y=_&  
//启动FileSplitterFetch线程 )E`+BH  
//等待子线程返回 N D* ]gM  
try{ [ &daG:  
if(bFirst) kY!C_kFcn  
{ s3< F  
nFileLength = getFileSize(); ysVi3eq  
if(nFileLength == -1) [; @):28"  
{ ^ LbGH<#J  
System.err.println("File Length is not known!");  tgW kX  
} M.[wKGX(  
else if(nFileLength == -2) b,Lw7MY}[  
{ KpGUq0d@  
System.err.println("File is not access!"); p1^0{ILx  
} 4W-"|Z_x  
else ?cxr%`E  
{ Y^3)!>  
for(int i=0;i<nStartPos.length;i++) _H2tZ%RM  
{ * gHCy4u{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); `EVg'?pl  
} yM|g|;U  
for(int i=0;i<nEndPos.length-1;i++) *|poxT G  
{ 2_N/wR#=&  
nEndPos = nStartPos[i+1]; HTN$ >QTI  
} -p^'XL*Z  
nEndPos[nEndPos.length-1] = nFileLength; 4y>(RrVG  
} B{99gwMe]  
} m0C{SBn-M  
~4+8p9f  
19&)Yd1  
//启动子线程 WP!il(Gr  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  feN!_ -  
for(int i=0;i<nStartPos.length;i++) Of&"U/^  
{ %HVD^. V  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 369Zu4|u  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _j>L4bT  
nStartPos,nEndPos,i); -U:2H7  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]Y=S  
fileSplitterFetch.start(); TR?Bvy2s:g  
} !^-OfqIHfV  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *F..ZS'$[  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 90(UgK&Y  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u`+ 'lBE,  
nEndPos = " + nFileLength); qZP:@r"  
// fileSplitterFetch[nPos.length-1].start(); UT~4Cfb  
-`g J  
w O89&XZ<  
//等待子线程结束 ovSH}h!  
//int count = 0; ?F25D2[(  
//是否结束while循环 G4O3h Y.`  
boolean breakWhile = false; &rcdr+'  
RB *P0  
Z]7tjRvq)  
while(!bStop) cXMa\#P  
{ +2El  
write_nPos(); zNwc((  
Utility.sleep(500); t)KPp|&  
breakWhile = true; 1S&0  
c|+y9(0|y  
IE|, ~M2  
for(int i=0;i<nStartPos.length;i++) >r~|1kQ.  
{ ss*5.(y  
if(!fileSplitterFetch.bDownOver) i"vDRrDe  
{ VYHOk3  
breakWhile = false; "7:u0p!  
break; ["<5?!bU  
} UYH|?Jw!N  
} y>4p~  
if(breakWhile) R&gWqt/  
break; aE}=^%D  
80dSQ"y  
$f9 ,##/  
//count++; O0-> sR  
//if(count>4) xJ$Rs/9C  
// siteStop(); =Z^un&'  
} gNG.l  
8 qn{  
87R%ke  
System.err.println("文件下载结束!"); w' .'Yu6  
} LE<:.?<Z-  
catch(Exception e){e.printStackTrace ();} i[mC3ghM6,  
} $3lt{ %  
9fCiLlI  
SlR7h$r'  
//获得文件长度 *Rz!i m|  
public long getFileSize() d~w}NK[(  
{ \dC.%#  
int nFileLength = -1; N`J:^,H  
try{ :P HUsy  
URL url = new URL(siteInfoBean.getSSiteURL()); )Uc$t${en  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8}Fw%;Cb  
httpConnection.setRequestProperty("User-Agent","NetFox"); u}Lc|_ea`  
tq2-.]Y@U  
3| GNi~  
int responseCode=httpConnection.getResponseCode(); LZgwIMd  
if(responseCode>=400) )e @01l  
{ (xI)"{   
processErrorCode(responseCode); XYz,NpK  
return -2; //-2 represent access is error Y:DNu9  
} :!r9 =N9  
n$XMsl.>  
!l sy&6  
String sHeader; $q4XcIX 7  
)->-~E}p9  
K0d-MC   
for(int i=1;;i++) 0IoXDx  
{ w`H.ey  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }CB=c]p  
//Utility.log(in.readLine()); s!8J.hD'I  
sHeader=httpConnection.getHeaderFieldKey(i); F'$9en2I:  
if(sHeader!=null) L8,H9T#e  
{ -o=P85 V  
if(sHeader.equals("Content-Length")) r6gt9u:  
{ f;@ b a[  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rCnV5Yb0O  
break; PCV58n3  
} >/ *?4  
} pq/ FLYiv  
else 1C5kS[!  
break; r| 6S  
} ZNL;8sI?>  
} f)u*Q!BDD  
catch(IOException e){e.printStackTrace ();} {2'74  
catch(Exception e){e.printStackTrace ();} }iiG$?|.  
7gZVg@   
H3UX{|[  
Utility.log(nFileLength); eMpEFY  
Se;?j-  
qH {8n`  
return nFileLength; Nj3^"}V  
} V1CSXY\2  
web8QzLLB  
Hb@G*L$  
//保存下载信息(文件指针位置) ^J#*n;OQ3A  
private void write_nPos() V{AH\IV-  
{ <x>k3bD  
try{ dEAAm=K,<  
output = new DataOutputStream(new FileOutputStream(tmpFile)); +s*l#'Q  
output.writeInt(nStartPos.length); OH!$5FEc  
for(int i=0;i<nStartPos.length;i++) ]`/R("l[  
{ ?-.Ep0/  
// output.writeLong(nPos); \/x)BE,  
output.writeLong(fileSplitterFetch.nStartPos); o?Tp=Ge  
output.writeLong(fileSplitterFetch.nEndPos); _/z)&0DO  
} cV=_G E  
output.close(); "[".3V  
} iEJQ#5))0  
catch(IOException e){e.printStackTrace ();} :)+@qxTy  
catch(Exception e){e.printStackTrace ();} . ;ea]_Z  
}  z7.C\l  
^b `>/>  
G|6|;   
//读取保存的下载信息(文件指针位置) W_f"Gk  
private void read_nPos() $E9daUt8"J  
{ }JpslY*aS  
try{ C$..w80/1  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +N(YR3  
int nCount = input.readInt(); ]\9B?W(#  
nStartPos = new long[nCount]; hO<w]jV,  
nEndPos = new long[nCount]; (zTI)EV  
for(int i=0;i<nStartPos.length;i++) M5ySs\O4  
{ < jocfTBk  
nStartPos = input.readLong(); FOUs= E[  
nEndPos = input.readLong(); T>uWf#&pjs  
} Uc4 L|:  
input.close(); @#ho(_U8  
} xO9]yULgu  
catch(IOException e){e.printStackTrace ();} Zxxy1Fl#.[  
catch(Exception e){e.printStackTrace ();} j@?[vi  
} M;TfD  
1KIq$lG{ E  
v[yTk[zd0  
private void processErrorCode(int nErrorCode) <sWcS; x  
{ m5;[,He  
System.err.println("Error Code : " + nErrorCode); DneSzqO"o  
} k4AE`[UE  
x V 1Z&l  
A7,$y!D  
//停止文件下载 RnBmy^l"  
public void siteStop() m[Ac'la  
{ w KMk|y>  
bStop = true; ]{6yS9_tuI  
for(int i=0;i<nStartPos.length;i++) -x%`Wv@L  
fileSplitterFetch.splitterStop(); DGfQo5#  
'hi\98y  
Lvj5<4h;  
} {LJ6't 8y:  
} 'St= izhd  
//负责部分文件的抓取 %d#)({N  
**FileSplitterFetch.java pA,EUh| H  
*/ Z2j*%/  
package NetFox; 3;l>x/amk  
"%f5ltut3  
*=If1qZs  
import java.io.*; Q|H cg|  
import java.net.*; NUnc"@  
|%cO"d^ri  
FR6I+@ oX~  
public class FileSplitterFetch extends Thread { AW;) _|xM  
WKJL< D ]:  
%iS]+Sa.K  
String sURL; //File URL L(n~@ gq  
long nStartPos; //File Snippet Start Position =ObtD"  
long nEndPos; //File Snippet End Position +e4<z%1  
int nThreadID; //Thread's ID _,0!ZP-  
boolean bDownOver = false; //Downing is over U+r#Y E.  
boolean bStop = false; //Stop identical )"Br,uIv:/  
FileAccessI fileAccessI = null; //File Access interface IS4K$Ac.  
Y6%OV?}v!  
H_=[~mJ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException sr@XumT  
{ UpseU8Wo  
this.sURL = sURL; &trh\\I"  
this.nStartPos = nStart; o4'4H y  
this.nEndPos = nEnd; `&[:!U2]F  
nThreadID = id; _7"W\gn:9  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )hJjVitG  
} AbI*/ |sY  
@%G"i:HZ&  
\lIHC{V\  
public void run() )bU")  
{ +pViHOJu&V  
while(nStartPos < nEndPos && !bStop) zp-~'kIJ  
{ t}+c/ C%b=  
s^R2jueR  
!;C(pnE  
try{ j?hyN@ns  
URL url = new URL(sURL); JU1; /3(  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &0Zk3D4  
httpConnection.setRequestProperty("User-Agent","NetFox"); U9sub6w6  
String sProperty = "bytes="+nStartPos+"-"; @5VZ   
httpConnection.setRequestProperty("RANGE",sProperty); = d.W'q|  
Utility.log(sProperty); K5rj!*x.o  
u N0fWj]  
{&qsh9ob  
InputStream input = httpConnection.getInputStream(); Dx*oSP.qX  
//logResponseHead(httpConnection); ^l9 *h  
Awf = yE:  
ibUPd."W  
byte[] b = new byte[1024]; `|?$; )  
int nRead; zR_l ^NK  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop)  Jiylrf`o  
{ ~6i mkv^ F  
nStartPos += fileAccessI.write(b,0,nRead); &-Er n/[  
//if(nThreadID == 1) luog_;{h+  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K :ptfD  
} F4(U~n<  
~M1%,]  
c}s3c >`d  
Utility.log("Thread " + nThreadID + " is over!"); #N}}8RL  
bDownOver = true; t1s@Ub5);I  
//nPos = fileAccessI.write (b,0,nRead); {j*+:Gj0V  
} T7_rnEOO   
catch(Exception e){e.printStackTrace ();} =H?5fT^  
} oYx f((x  
} 3PeJPw  
x l=|]8w  
b?L43t,  
//打印回应的头信息 $& gidz/w  
public void logResponseHead(HttpURLConnection con) w*@Z-'(j  
{ S]@iS[|?  
for(int i=1;;i++) I@v.Hqg+7  
{ <WkLwP3^  
String header=con.getHeaderFieldKey(i); ~,1X>N"  
if(header!=null) 'Q,<_ L"  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q-CVq_\3I  
Utility.log(header+" : "+con.getHeaderField(header)); 2mG?ve%m)  
else ^E*C~;^S  
break;  /t P  
} FQ^uX]<3j  
} ` XY[ HK  
(b!DJ;(O9  
{ )K(}~VD  
public void splitterStop() vUA`V\  
{ xSZw,  
bStop = true; W0hLh<Go  
} <{j9|mt  
> xw+2<  
'KG`{K$  
} 9a unv   
#xB%v  
&2^V<(19  
/* cFQa~  
**FileAccess.java beoMLHp  
*//文件访问(定位,写) `dhK$jYD  
package NetFox; e{/\znBS%  
import java.io.*; L}+!<Ug  
S/aPYrk>6  
5E8P bV-l  
public class FileAccessI implements Serializable{ __[q`  
hJ :+*46  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f5v|}gMAX  
RandomAccessFile oSavedFile; !bg3  
long nPos; 4g9VE;Gd  
ufOaD7  
)Ec;krb+  
public FileAccessI() throws IOException dewu@  
{ b04~z&Xv  
this("",0); ~qF9*{~!  
} M?o`tWLhF  
s zg1.&  
M DpXth7  
public FileAccessI(String sName,long nPos) throws IOException ) AIZE?oX  
{ F=H=[pSe  
oSavedFile = new RandomAccessFile(sName,"rw"); $- L)>"  
this.nPos = nPos; 1/HZY0em  
oSavedFile.seek(nPos); f!yxS?j3  
} &wfM:a/c  
JkmL'Zk>:  
A`KTm(  
public synchronized int write(byte[] b,int nStart,int nLen) WJ@,f%=<~  
{ +qdK]RR}  
int n = -1; uIu0"pv`x  
try{ LYKepk  
oSavedFile.write(b,nStart,nLen); ~kL":C>2  
n = nLen; :;EzvRy  
} R[z6 c )  
catch(IOException e) ~(c<ioIf  
{ A-<qr6q  
e.printStackTrace (); sbVeB%k  
} D 6(w}W  
v1: 5 r  
C1_NGOvT  
return n; CA3.fu3(p  
} c{[d@jt O  
iL(E`_I<  
"371`!%  
} -Fb/GZt|  
Eb*DP_  
Uc&0>_Z  
/* 7HzKjR=B  
**SiteInfoBean.java 5d)G30  
*/ <J- aq;p  
package NetFox; #2}S83 k  
]fR 3f  
TGg*(6'z  
public class SiteInfoBean { #xO`k1W.  
|(wx6H:  
JO _a+Yl  
private String sSiteURL; //Site's URL `/"z.~8  
private String sFilePath; //Saved File's Path )%Y$F LB  
private String sFileName; //Saved File's Name I%%$O' S  
private int nSplitter; //Count of Splited Downloading File ?)9 6YX'  
M+Dkn3bx  
]^s4NXf+  
public SiteInfoBean() /({5x[  
{//nSplitter的缺省值为5 1[!Idl?m  
//default value of nSplitter is 5 \PL92HV  
this("","","",5); 1aSuRa  
} $BG9<:p  
nwz}&nR  
eM8u ;i  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :qI myaGQ  
{ o'W &gkb9  
sSiteURL= sURL; r&^4L  
sFilePath = sPath; *@n%K,$v  
sFileName = sName; Qg3 -%i/@  
this.nSplitter = nSpiltter; xe}"0'g  
bvAO(`  
J`\%'pEn  
} !DLIIKO78  
W(EU*~<UC  
#U'n=@U@(  
public String getSSiteURL() pS51fF9  
{ 8^+Q n/b_%  
return sSiteURL; 7qu hp\  
} |rsu+0Mtz  
>:8GU f*  
9-9`;Z  
public void setSSiteURL(String value) eml(F  
{ ! G,Ru~j5:  
sSiteURL = value; o:m:9dn  
} 0YW<>Y`6  
5 '.j+{"  
c}$?k@=  
public String getSFilePath() ]l`?"X|^  
{ Gu9Ap<>!  
return sFilePath; Gh|q[s*k  
} :QB Wy  
H2[ S]`?  
k'EP->r  
public void setSFilePath(String value) L7C!rS  
{ 'd'*4 )]k  
sFilePath = value; 0t'WM=W<!8  
} C {gYrz)  
]#KZ W)M  
,"5Fw4G6*  
public String getSFileName() 2Q0fgH2  
{ L:j;;9Sp{  
return sFileName; ,accw}G  
} J_<ENs-  
j8_WEjG  
Sycs u_je  
public void setSFileName(String value) >ouHR*  
{ g;D [XBp  
sFileName = value; _/]4:("  
} P]bI".A8  
u#ag|b/C:  
{?$-p%CF`8  
public int getNSplitter() 9YwK1[G6/  
{ $ nx&(V  
return nSplitter; ;n?H/(6X8>  
} 2 <y!3OeN  
L*"Q5NzB]  
vdyLwBz:  
public void setNSplitter(int nCount) =I-SQI8  
{ y_;LTCj?  
nSplitter = nCount; c!d>6:\  
} I&,gCZ#  
} f,wB.MN  
"u@)   
{=pRU_-^  
/* xxpvVb)mF  
**Utility.java (&npr96f  
*/ :7 Ro9z8  
package NetFox; vc0'x4  
]>M{Q n*  
p(-f$Q(  
public class Utility { zUF%`CR  
zZ@]Kq;.s  
7O84R^!|2  
public Utility() Dl_y[ 9  
{ 35|F?Jx.r  
//9Ro"  
J$JXY@mBSC  
} f?}~$agc  
B! $a Y  
//线程睡眠 +n_`*@SE  
public static void sleep(int nSecond) U{6i5;F#H  
{ w7GF,a  
try{ %%5K%z,R#  
Thread.sleep(nSecond); kq xX!  
} x=7hOI5u  
catch(Exception e) !|}(tqt  
{ >T: Yp<  
e.printStackTrace (); ZU\TA|  
} yyCx;  
} i]oSVXx4WC  
CvDy;'{y1  
//日志 eJD !dGa  
public static void log(String sMsg) Q%:#xG5AmE  
{ 0kEz i  
System.err.println(sMsg); TNs ;#Q  
} 2@ 4^ 81  
B^`'2$3  
kH$)0nK  
public static void log(int sMsg) $42%H#  
{ U6SgV 8  
System.err.println(sMsg); Hp`Mp)1s  
} 2pa: 3O  
} e+J|se4L5  
2Hltgt,  
[;O 6)W  
/* 5@_c<   
**TestMethod.java 1~X~"M  
*/ F=}-ngx8&  
package NetFox; Sg$14B  
XHq8p[F  
pMJK?- )  
public class TestMethod { X[pk9mha  
;-Bi~XD  
NUB3L  
public TestMethod() c o}o$}  
{ ///xx/weblogic60b2_win.exe WHh=ht s\  
try{ t%jB[w&,os  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'W0?XaEk-  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?R2`RvQ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ba_T:;';0  
fileFetch.start(); xv! QO  
} mRI W9V  
catch(Exception e){e.printStackTrace ();} i,G )kt'H  
{. r/tV5IH  
tmAc=?|Wa  
} =1D* JU  
/mST<{(_G\  
]@@3]  
public static void main(String[] args) [&mYW.O<  
{ GdN'G  
new TestMethod(); B@w Q [  
} nU Oy-c  
} UH8)r  
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