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http断点续传简单实现(java)

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/* 3_)I&RM  
**SiteFileFetch.java MvpJ0Y (  
*/ ?YW~7zG  
package NetFox; 3W7^,ir  
import java.io.*; :awkhx  
import java.net.*; OP1` !P y  
^$: w  
QFx3N%  
public class SiteFileFetch extends Thread { QT,T5Q%JP:  
d$3rcH1  
,!l_  
SiteInfoBean siteInfoBean = null; //文件信息Bean &`I(QY  
long[] nStartPos; //开始位置 T&_&l;syA  
long[] nEndPos; //结束位置 #gQn3.PX+y  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 'nq=xi@RC  
long nFileLength; //文件长度 'IX1WS&\"  
boolean bFirst = true; //是否第一次取文件 {!|4JquE_  
boolean bStop = false; //停止标志 3[ [oAp  
File tmpFile; //文件下载的临时信息 DzGUKJh6  
DataOutputStream output; //输出到文件的输出流 ~pRgTXbz  
#SHeK 4  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) R xMsP;be  
public SiteFileFetch(SiteInfoBean bean) throws IOException 7<xnE]jdq  
{ }qiZ%cT.G  
siteInfoBean = bean; %XG m\p  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); @wcF#?J  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 309 pl  
if(tmpFile.exists ()) O6hzOyNX@  
{ syR"p,3EC  
bFirst = false; RE;A 0E_3  
read_nPos(); " #iJ/vy  
} }*6BaB  
else =IC.FT}  
{ KQPu9f9  
nStartPos = new long[bean.getNSplitter()]; @PvO;]]%  
nEndPos = new long[bean.getNSplitter()]; .rtA sbp.!  
} L~6%Fi&n4  
BTkx}KK  
(  zo7h  
G]=z ![$  
} _Q5mPBO  
~</FF'Xz  
!1)aie+p6  
public void run() W'@ |ob  
{ M- ^I!C  
//获得文件长度 bp?5GU&Uy  
//分割文件 ln82pQD2Y~  
//实例FileSplitterFetch EH |+S  
//启动FileSplitterFetch线程 ,0! 2x"Q=  
//等待子线程返回 v1:.t  
try{ +yP!7]  
if(bFirst) uxf,95<g)  
{ $.jG O!  
nFileLength = getFileSize(); u(f   
if(nFileLength == -1) jA{5)-g  
{ dQj/ Sr  
System.err.println("File Length is not known!"); i5}Zk r  
} %4*c/ c6  
else if(nFileLength == -2) bCw{9El!K4  
{ ?#K.D vGJ  
System.err.println("File is not access!"); *C*ZmC5  
} n-ffX*zA(  
else uE's&H  
{ tY)L^.*7  
for(int i=0;i<nStartPos.length;i++) kZw"a*6  
{ C^ )Imr  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Nj>6TD81u  
} (TT=i  
for(int i=0;i<nEndPos.length-1;i++) ^~H}N$W"-q  
{ &42 ]#B"*  
nEndPos = nStartPos[i+1]; !vwio!  
} .==D?#bn  
nEndPos[nEndPos.length-1] = nFileLength; 6iU&9Z<%  
} 8o5[tl ?w  
} b&rBWp0#  
ps{4_V-3u  
zq};{~u(  
//启动子线程 ~~/,2^   
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; RAO+<m  
for(int i=0;i<nStartPos.length;i++) ETHcZ  
{ $wUYK%.  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =*\.zr  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xOTvrX  
nStartPos,nEndPos,i); _KH91$iW8m  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,R{&x7  
fileSplitterFetch.start(); Sb`[+i' `  
} 6^b)Q(Edut  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 64/ZfXD  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *O_fw 0jV  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \L*%?~  
nEndPos = " + nFileLength); _w\9 \<%  
// fileSplitterFetch[nPos.length-1].start(); 6eSo.@*l  
SxRJ{m~  
j[r}!;O  
//等待子线程结束 kk=n&M  
//int count = 0; ZsP^<  
//是否结束while循环 g Q\.|'%  
boolean breakWhile = false; GeR#B;{  
?Q]&;5o  
Z@Rm^g]o  
while(!bStop) .RxTz9(  
{ !PA:#]J  
write_nPos(); 6F (z6_<  
Utility.sleep(500); ^N={4'G)  
breakWhile = true; o[!'JUxZ  
geG0F}oC!  
Xw4Eti._D  
for(int i=0;i<nStartPos.length;i++) *?m)VvR>|  
{ ^Hn}\5  
if(!fileSplitterFetch.bDownOver) 'NtI bS  
{ R (f:UC  
breakWhile = false; %ztZ#h~g  
break; S\:^#Yi`  
} [K4cxqlfk  
} &ivU4rEG  
if(breakWhile) >#G%2Vp  
break; |Rf j 0+  
G+c&e:ip<  
xv]z>4@z,  
//count++; [7@blU  
//if(count>4) E/:U,u{  
// siteStop(); | #yu  
} %],BgLhS.  
)O[8 D  
rp@:i _]  
System.err.println("文件下载结束!"); |nQfgl=V  
} 3WwS+6R  
catch(Exception e){e.printStackTrace ();} Dge#e  
} >6C\T@{lJ  
!BoGSI  
\g34YY^L3  
//获得文件长度 @D9O<x  
public long getFileSize() p cLKE ZK  
{ 0!\gK <,z  
int nFileLength = -1; \lK?f]qJq  
try{ L~ &S<5?  
URL url = new URL(siteInfoBean.getSSiteURL()); ,Q"'q0hM=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k[x-O?$O@  
httpConnection.setRequestProperty("User-Agent","NetFox"); K&[0`sH!  
`:C1Wo^<  
n5QO'Jr%[  
int responseCode=httpConnection.getResponseCode(); x]7:MG$  
if(responseCode>=400) Vl^x_gs#_]  
{ &;$uU  
processErrorCode(responseCode); 2U./ Yfk\  
return -2; //-2 represent access is error =zn'0g, J4  
} dy6zrgxygP  
2? E;(]dQ  
1| sem(t  
String sHeader; VD.TosVeWo  
MXSD8]je  
g (&cq  
for(int i=1;;i++) H>+/k-n-  
{ t=7Gfv  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vC,FE )'  
//Utility.log(in.readLine()); (U 'n1s/X  
sHeader=httpConnection.getHeaderFieldKey(i); aqSOC(jU  
if(sHeader!=null) oRbWqN`F.  
{ g]f<k2  
if(sHeader.equals("Content-Length")) Szz j9K  
{ ;<i u*a  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |Y"XxM9  
break; Pim  
} j([b)k=  
} g V]4R"/  
else IgbuMEfL  
break; 'fn}I0Vc  
} [],[LkS  
} 'ON/WKJr|W  
catch(IOException e){e.printStackTrace ();} le5@WG/x  
catch(Exception e){e.printStackTrace ();} ;W{z"L;nX  
5j`sJvq  
-)-: rRx-  
Utility.log(nFileLength); T.#_v# oM  
xI<l1@  
'wPX.h?  
return nFileLength; #. Dl1L/  
} k)knyEUi  
r8(oTx  
3Y P! B=  
//保存下载信息(文件指针位置) 7T[L5-g  
private void write_nPos() OXLB{|hH80  
{ 2]fTDKh  
try{ <~|n}&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); #s~ITG #H  
output.writeInt(nStartPos.length); @6ckB (  
for(int i=0;i<nStartPos.length;i++) )nHMXZ>Td  
{ lZwjrU| _  
// output.writeLong(nPos); C 9%bD  
output.writeLong(fileSplitterFetch.nStartPos); 7Ydqg&  
output.writeLong(fileSplitterFetch.nEndPos); Ow-ejo  
} lz=DGm  
output.close(); pKLcg"{[F  
} Ps0 Cc_  
catch(IOException e){e.printStackTrace ();} `pbCPa{Y  
catch(Exception e){e.printStackTrace ();} b#7nt ?`7p  
} (B` NnL$  
1<9d[N*  
ky !Z JR  
//读取保存的下载信息(文件指针位置) K14.!m  
private void read_nPos() :/6:&7s  
{ bN?*p($/  
try{ L@MCB-@V  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lsV>sW4]Z  
int nCount = input.readInt(); uhq6dhhR  
nStartPos = new long[nCount]; 9ZOQNN<ex  
nEndPos = new long[nCount]; _ (b4|hJ'  
for(int i=0;i<nStartPos.length;i++) kYS#P(1  
{ /;_$:`|/  
nStartPos = input.readLong(); =)y$&Ydj  
nEndPos = input.readLong(); g,E)F90  
} jYU0zGpj  
input.close(); .NdsKhg b  
} T72Li"00  
catch(IOException e){e.printStackTrace ();} ~a=]w#-KD  
catch(Exception e){e.printStackTrace ();} AYNz {9  
} o<b  
Il/`#b@h  
fCa lR7!  
private void processErrorCode(int nErrorCode) ft8  
{ ++2a xRl  
System.err.println("Error Code : " + nErrorCode); [ GknE#p  
} UHY)+6qt]  
2;:]Q.g  
(QFZM"G  
//停止文件下载 i_L u  
public void siteStop() GF9iK|i/  
{  V13^SVM  
bStop = true; ~i-n_7+  
for(int i=0;i<nStartPos.length;i++) Q]/g=Nn ^~  
fileSplitterFetch.splitterStop(); P,S!Z&!  
k5&}bj-  
#5;4O{  
} SFWS<H(IN  
} 5UL5C:3R9  
//负责部分文件的抓取 `iuQ.I  
**FileSplitterFetch.java [9EL[}  
*/ fpNq  
package NetFox; 2wU,k(F_  
S@\&^1;4Hv  
un6W|{4]  
import java.io.*; {w>ofyqfp&  
import java.net.*; CNiJuj`  
5'Mw{`  
*[nS*D\:  
public class FileSplitterFetch extends Thread { _z^&zuO  
YbVZK4  
 mznE Cy  
String sURL; //File URL ;XY#Jl>tg  
long nStartPos; //File Snippet Start Position I<lkociUCG  
long nEndPos; //File Snippet End Position #r&yH^-  
int nThreadID; //Thread's ID \XY2s&"  
boolean bDownOver = false; //Downing is over MMRO@MdfV  
boolean bStop = false; //Stop identical #I yM`YB0  
FileAccessI fileAccessI = null; //File Access interface Ejf>QIB  
ku v<  
+DT tKj  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DKQQZ` PF  
{ c1%ki%J#  
this.sURL = sURL; a;7gy419<p  
this.nStartPos = nStart; blV'-Al  
this.nEndPos = nEnd; d#,   
nThreadID = id; tG,xG&  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YcaLc_pUx  
} _#UhXXD  
^oHK.x#{  
]N'4q}<5o  
public void run() "^pF2JI  
{ 5tb i};  
while(nStartPos < nEndPos && !bStop) bir tA{q  
{ )Z?\9'6e4  
Re\V<\$J  
"'8o8g  
try{ o AS 'Z|  
URL url = new URL(sURL); 53 ^1;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AQBr{^inH|  
httpConnection.setRequestProperty("User-Agent","NetFox"); #5kg3OO  
String sProperty = "bytes="+nStartPos+"-"; 5o~AUo{  
httpConnection.setRequestProperty("RANGE",sProperty); h1_KZ[X  
Utility.log(sProperty); jK=-L#hz  
eR1]<Z$W\  
=uR[Jewa  
InputStream input = httpConnection.getInputStream(); a67NWH  
//logResponseHead(httpConnection); doe u`  
( (mNB]sy  
[VB\ T|$  
byte[] b = new byte[1024]; 6v -2(Y  
int nRead; `_e1LEH  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop)  - zEQ/6  
{ W$Z""  
nStartPos += fileAccessI.write(b,0,nRead); g|3FJA/  
//if(nThreadID == 1) zQ eXN7$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -/qu."9(B  
} mK7egAo  
^nL_*+V`f  
wmS:*U2sc  
Utility.log("Thread " + nThreadID + " is over!"); $VE=sS.  
bDownOver = true; _1Iw"K49Qx  
//nPos = fileAccessI.write (b,0,nRead); nIP*yb}5  
} Z"<tEOs/En  
catch(Exception e){e.printStackTrace ();} oY%NDTVN  
} Jo ]8?U(^  
} _q\w9gN  
,e>N9\*  
(OK;*ZH+T@  
//打印回应的头信息 G0h7MO%x  
public void logResponseHead(HttpURLConnection con) bl B00   
{ n47v5.Wn  
for(int i=1;;i++) b{d@:"  
{ t?kbN\,  
String header=con.getHeaderFieldKey(i); n|iO)L\9aB  
if(header!=null) ~); 7D'[  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yX8$LOjE  
Utility.log(header+" : "+con.getHeaderField(header)); 5SY(:!  
else VJ(#FA2  
break; w+owx(mN@  
} =:=uV0jX\  
} Ih0kd i  
AUAJMS!m  
$'VFb=?XrK  
public void splitterStop() wg,w;Gle  
{ <[GkhPfZ  
bStop = true; wN!5[N"  
} !n/"39KT  
S-6 %mYf  
S(*SUH  
} )b AcU  
Hlq#X:DCn  
gg%OOvaj5  
/* O}#h^AU-BS  
**FileAccess.java ] Vbv64M3  
*//文件访问(定位,写) F .JvMy3  
package NetFox; S2fBZ=V8  
import java.io.*; "h}miVArS  
}%9A+w}o  
/g!', r,  
public class FileAccessI implements Serializable{ !N1DJd  
p9)'nU'\t  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +K%4jIm  
RandomAccessFile oSavedFile; LY^pmak  
long nPos; Hh8)d/D  
~O}LAzGb  
v [ 4J0  
public FileAccessI() throws IOException @nS+!t{  
{  + >oA@z  
this("",0); 7,2bR  
} Ie~#k[X  
J_A5,K*r|  
I vQ]-A}N  
public FileAccessI(String sName,long nPos) throws IOException zj^Ys`nl  
{ (TV ye4Z  
oSavedFile = new RandomAccessFile(sName,"rw"); =)3tVH&  
this.nPos = nPos; 3X&}{M:Qo  
oSavedFile.seek(nPos); 3R[5prE<  
} Q0_UBm^f  
jdGoPa\  
IOsitMOX:  
public synchronized int write(byte[] b,int nStart,int nLen) +idj,J|  
{ *s9 +  
int n = -1; s^b2H !~  
try{ /gKX%`ZF/r  
oSavedFile.write(b,nStart,nLen); !(soMv  
n = nLen; ["\Y-6"l  
} iii2nmiK  
catch(IOException e) Y\ len  
{ bCF"4KXK  
e.printStackTrace (); [g:ZIl4p\P  
} q]Cmaf(  
@<tkwu  
%_!YonRY|X  
return n; SAt{At  
} fKMbOqU_  
VSCOuNSc  
nTweQ  
} #s)Wzv%OX  
FaC;vuSpy  
M3350  
/* S3u>a\  
**SiteInfoBean.java '8v^.gZ  
*/ ;aip1Df  
package NetFox; k ckWBL  
~ FW@  
?1Lzbou  
public class SiteInfoBean { 1O0o18'  
r(IQ)\GR  
'dp3>4  
private String sSiteURL; //Site's URL vl<W`)'  
private String sFilePath; //Saved File's Path i*'6"  
private String sFileName; //Saved File's Name 1;R1Fj&  
private int nSplitter; //Count of Splited Downloading File V6Y:l9  
|~Hlv^6H  
w^?uBeqR  
public SiteInfoBean() T<"Hh.h  
{//nSplitter的缺省值为5 C{<qc,!4  
//default value of nSplitter is 5 s('<ms  
this("","","",5); SNB >  
} & Me%ZM0  
q/[)Z @&(  
QXnL(z  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6u`E{$  
{ b/='M`D}#G  
sSiteURL= sURL; %l!Gt"\xm  
sFilePath = sPath; f:gXXigY,  
sFileName = sName; xioL6^(Qk,  
this.nSplitter = nSpiltter; K)c`G_%G  
|T~C($9  
C3 ^QNhv  
} 5 iUT#  
1CFTQB>  
o/bmS57  
public String getSSiteURL() {%ZD ^YSA  
{ qh!2dj  
return sSiteURL; Np=IZ npt  
} mdW8RsR  
V8w!yc  
1H{M0e  
public void setSSiteURL(String value) 6H,n?[zTt  
{ L, L>cmpM  
sSiteURL = value; J fFOU!F\  
} 7KOM,FWKe  
vq|o}6Et  
T> cvV  
public String getSFilePath() {k=H5<FV  
{ p}%T`e=Z9  
return sFilePath; mrR~[533j  
} p.kJNPO\@  
#E%0 o  
(5y+g?9d;  
public void setSFilePath(String value) -NW7ncB|  
{ Sdl1k+u  
sFilePath = value; u6{= Z:  
} ,*SoV~  
[hE0 9W  
j] \3>.  
public String getSFileName() Z?yMy zT  
{ v`ckvl)(C  
return sFileName; Z<6XB{Nh\  
} 3[plwe  
1'wwwxe7  
rcUXYJCh-  
public void setSFileName(String value) O`_!G`E  
{ zWYm* c"n\  
sFileName = value; z yyt`  
} $Cw> z^}u  
!e?g"5r{Bv  
dGf:0xE"  
public int getNSplitter() D7.|UG?G  
{ .}W#YN$  
return nSplitter; JX%B_eUlAs  
} SXfuPM  
{//;GC*  
x9Veg4Z7  
public void setNSplitter(int nCount) /g}2QmvH  
{ C'mYR3?m;  
nSplitter = nCount; 5}d"nx  
} gPs%v`y)*D  
} v o vc,4}  
#p@8m_g  
$\BRX\6(-  
/* kk_$j_0  
**Utility.java W<<{}'Db/#  
*/ d7 )&Z:  
package NetFox; tW4|\-E"s4  
EHk(\1!V  
cNX,%  
public class Utility { OU&eswW  
7#K%Bo2pG  
wLyQ <[$  
public Utility() K?[*9Q'\  
{ Ml`tDt|;  
R[Y]B$XO  
zs! }P  
} Id`?yt  
|_q:0qo  
//线程睡眠 X=O}k&  
public static void sleep(int nSecond) <xOv0B  
{ gd~# uR\  
try{ zrD];DP  
Thread.sleep(nSecond); &?\'Z~B4  
} > <cK  
catch(Exception e) 1<Fh aK  
{ hs'J'~a  
e.printStackTrace ();  wfr+-  
}  g wM~W  
} kkfwICBI  
Q2[@yRY/z  
//日志 N\ nr  
public static void log(String sMsg) So &c\Ff  
{ T8|aFoHCK  
System.err.println(sMsg); +3B^e%`NPm  
} "YLH]9"=  
*LnY}#  
?@W=bJ8{  
public static void log(int sMsg) ,0ZkE}<=w  
{ \wW'Hk=  
System.err.println(sMsg); (ATvH_Z  
} Y@WCp  
} ? U~}uG^  
q}Wd`>VDR  
5r1{l%?  
/* 2p3ep,  
**TestMethod.java " jefB6k9h  
*/ -cW`qWbd  
package NetFox; xsjJ8>G  
O&=40"Dr  
> "G H Li  
public class TestMethod { Wl3jbupu _  
y>+xdD0 +  
_y~H#r9:  
public TestMethod() .eQIU$Kw!O  
{ ///xx/weblogic60b2_win.exe @bu5{b+8  
try{ 4 I}xygV  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qucw%hJr  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $.Fti-5  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0:K4,  
fileFetch.start(); "X/cG9Lw  
} ^fj):n5/  
catch(Exception e){e.printStackTrace ();} C^Jf&a  
rTJv>Jjld  
q3.L6M  
} ,BuN]9#  
7ky$9+~  
d~[^D<5,D  
public static void main(String[] args) *ml&}9  
{ J7. }2  
new TestMethod(); *h ~Y=#`8*  
} VKa-  
} =}@m$g  
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