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http断点续传简单实现(java)

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/* mbSJ}3c"  
**SiteFileFetch.java rQ. j$U  
*/ O zY&^:>  
package NetFox; 2A {k>TjQ  
import java.io.*; Mv JEX8M  
import java.net.*; <c^m |v  
f`P%aX'cBQ  
5H`k$[3V  
public class SiteFileFetch extends Thread { Fp|x,-  
m>:3Ku  
FtT+Q$q=  
SiteInfoBean siteInfoBean = null; //文件信息Bean (Kv[~W7lb  
long[] nStartPos; //开始位置 a{,EX[~b  
long[] nEndPos; //结束位置 _K8ob8)m  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 9Jaek_A`  
long nFileLength; //文件长度 X{<j%PdC  
boolean bFirst = true; //是否第一次取文件 OV Iu&6#  
boolean bStop = false; //停止标志 a*KB'u6&  
File tmpFile; //文件下载的临时信息 cPkN)+K  
DataOutputStream output; //输出到文件的输出流 dy#dug6j  
Z#nj[r!l}  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) bsR&%C  
public SiteFileFetch(SiteInfoBean bean) throws IOException NA!;#!  
{ D 0\  
siteInfoBean = bean; jvCk+n[  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); VO/" ot  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); pX*Oc6.0mu  
if(tmpFile.exists ()) ?UQE;0 B  
{ ,d@.@a] `  
bFirst = false; >/eQjp?:  
read_nPos(); VctAQ|h^  
} DpoRR`  
else C/tn0  
{ -D`*$rp,  
nStartPos = new long[bean.getNSplitter()]; \<]nv}1O  
nEndPos = new long[bean.getNSplitter()]; hA/K>Z  
} sGc4^Z%l?  
n\ZDI+X  
0ppZ~}&  
#p6#,PZ  
} 1j9.Q;9  
a&M{y  
Ik(TII_  
public void run() X+ h|sy  
{ km4::'(6  
//获得文件长度 t/#[At5p=  
//分割文件 =uIu0_v  
//实例FileSplitterFetch 9^c\$"2B  
//启动FileSplitterFetch线程 39BGwKXb  
//等待子线程返回 cc Z A  
try{ t%/Y^N;  
if(bFirst) Y*dzoN.sW  
{ v](7c2;  
nFileLength = getFileSize(); d {T3  
if(nFileLength == -1) ;sS N  
{ PGOi#x  
System.err.println("File Length is not known!"); )CSb\  
} AFF7fK  
else if(nFileLength == -2) /t01z~_  
{ w`UB_h#Bl  
System.err.println("File is not access!"); { P&l`  
} LTm2B_+  
else .UU BAyjm  
{ '&xv)tno  
for(int i=0;i<nStartPos.length;i++) K\`L>B. 1  
{ #y~^!fdp9  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); x$cs_q]J  
} GBGGV#_q'}  
for(int i=0;i<nEndPos.length-1;i++) ?Xx,[Z&  
{ (sq4  
nEndPos = nStartPos[i+1]; U:M?Ji5CY  
} 6NVf&;laQ  
nEndPos[nEndPos.length-1] = nFileLength; #e((F,1z  
} Mp:tcy,*  
} ^^qB=N[';  
rL w,?  
Ont4-AP   
//启动子线程 .>Gq/[c0|  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AhZ8B'Ee  
for(int i=0;i<nStartPos.length;i++) l(-6pP5`  
{ k+f!)7_  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :[ F`tDL  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jV;&*4if  
nStartPos,nEndPos,i); zZ3,e L  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eva-?+n\q  
fileSplitterFetch.start(); s+gZnne  
} )Fe-C  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F0t!k>  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #DXC 6f  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )c b e 4  
nEndPos = " + nFileLength); ]j(2FM)#  
// fileSplitterFetch[nPos.length-1].start(); cor?#  
x JQde 4  
}eXzs_  
//等待子线程结束 7?:7}xb-  
//int count = 0; GU8b_~Gk?  
//是否结束while循环 ]rO`e N[~U  
boolean breakWhile = false; WoHFt*e2  
g>_lU vSE  
.cdm@_Ls  
while(!bStop) /%\E2+6  
{ HF" v \  
write_nPos(); a;|C51GH  
Utility.sleep(500); *Em 9R  
breakWhile = true; ?"]fGp6y  
-o#HO_9  
$?YRy_SI  
for(int i=0;i<nStartPos.length;i++) T^x7w+  
{ m64 6|G5  
if(!fileSplitterFetch.bDownOver) J*Dj`@`4`g  
{ f^@`[MJj1C  
breakWhile = false; -x=abyD  
break; 3@kiUbq7Eu  
} *A':^vgk  
} 6q RZ#MC  
if(breakWhile) 7afD^H%  
break; D^W6Cq5\  
aL$m  
h?jy'>T?b2  
//count++; M:z)uLDw  
//if(count>4) aT$q1!U`j2  
// siteStop(); * xdS<  
} lG;RfDI-  
*G7$wW:?  
uvz}qH@j/Q  
System.err.println("文件下载结束!"); eN fo8xUG  
} 7d*SZmD  
catch(Exception e){e.printStackTrace ();} Ml1yk)3G  
} -g(&5._,ZW  
$=uyZTYF)}  
!Sx }~XB<  
//获得文件长度 H)(@A W+-  
public long getFileSize() !:PF |dZ  
{ FVNxjMm,  
int nFileLength = -1; =G2D4>q  
try{ S/Pffal  
URL url = new URL(siteInfoBean.getSSiteURL()); HUiW#x%;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <GC<uB |p  
httpConnection.setRequestProperty("User-Agent","NetFox"); OiH tobM  
1H`T=:P?  
6*u#^">,<  
int responseCode=httpConnection.getResponseCode(); ^UHt1[  
if(responseCode>=400) *9 M 5'  
{ Wly-z$\  
processErrorCode(responseCode); mO;X>~K  
return -2; //-2 represent access is error t<mT=(zt*  
} %p6"Sg*  
[,e[~J`C  
Aq@_^mq1A  
String sHeader; q[`)A?Ae  
7Gd)=Q{uur  
Is&z~Xy/  
for(int i=1;;i++) I9O!CQCTt  
{ {Tb(4or?=b  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,TPNsz|Q  
//Utility.log(in.readLine()); s1. YH?A;  
sHeader=httpConnection.getHeaderFieldKey(i); t"k6wv;Tq  
if(sHeader!=null) Fn.wd`'0  
{ ig:,:KN  
if(sHeader.equals("Content-Length")) A ^@:Ps  
{ P -0  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9r=@S  
break; ikf!7-,  
} W8+Daw1Nr  
} ,=whwl "tA  
else sJo]$/?F  
break; ,Q!sns[T  
} k0~mK7k  
} Se/VOzzg  
catch(IOException e){e.printStackTrace ();} U\'.rT[#  
catch(Exception e){e.printStackTrace ();} NKf][!bi  
6KC.l}Y*  
a<9gD,]P  
Utility.log(nFileLength); | Z'NMJU  
HTiqErD2_  
|!:ImX@  
return nFileLength; tn!z^W  
} n:d]Z2b  
HEHTj,T  
f(~xdR))eh  
//保存下载信息(文件指针位置) u&Ts'j  
private void write_nPos() |:Gz9u+  
{ .|`J S?L[  
try{ d 1VNTB  
output = new DataOutputStream(new FileOutputStream(tmpFile)); CnyCEIO-  
output.writeInt(nStartPos.length); qD Z?iTHQq  
for(int i=0;i<nStartPos.length;i++)  Ht| No  
{ YSERQo  
// output.writeLong(nPos); # 12  
output.writeLong(fileSplitterFetch.nStartPos); nTxeV%  
output.writeLong(fileSplitterFetch.nEndPos);  *X- 6]C  
} 0Ou;MU*v  
output.close(); H1X38  
} jq#gFt*  
catch(IOException e){e.printStackTrace ();} PhL}V|W>  
catch(Exception e){e.printStackTrace ();} Q`k=VSUk  
} ep`WYR|B  
tj/X 7|  
(PAkKY}  
//读取保存的下载信息(文件指针位置) 4#Wczk-b  
private void read_nPos() `(s&H8x#  
{ P @N7g`u3}  
try{ >MD['=J[d  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6U[`CGL66  
int nCount = input.readInt(); &1)4B  
nStartPos = new long[nCount]; m`luMt9  
nEndPos = new long[nCount]; 8JxJ>I-9p  
for(int i=0;i<nStartPos.length;i++) @b[{.m U  
{  x~p8Mcv  
nStartPos = input.readLong(); pJ35M  
nEndPos = input.readLong(); P(pw$ q$S  
} h{xC0NC)  
input.close(); vW,dJ[N6jm  
} wz^Q,Od  
catch(IOException e){e.printStackTrace ();} NFq&a i  
catch(Exception e){e.printStackTrace ();} *6D0>F  
} _aa3;kT_  
J60XUxf  
5u +U^D  
private void processErrorCode(int nErrorCode) :{@&5KQ8)  
{ s%F}4W2s  
System.err.println("Error Code : " + nErrorCode); .%)FK#s-  
} ;Q"xXT`;:  
2@K D '^(  
_h|rH   
//停止文件下载 `k b]tf  
public void siteStop() v5 STe`  
{ 9}p>='  
bStop = true; q SR\=:$  
for(int i=0;i<nStartPos.length;i++) -4ityS @  
fileSplitterFetch.splitterStop(); LVNq@,s  
j\l9|vpp  
H]&a}WQ_  
} &4 Py  
} 'p<lfT  
//负责部分文件的抓取 YjaEKM8*  
**FileSplitterFetch.java  1@Abs  
*/ +vOlA#t%Z  
package NetFox; T"7Ue  
7u[U%yd  
K;,zE6WD$$  
import java.io.*; ;UuCSfs{  
import java.net.*; O[ tD7 !1  
h tC~BK3(  
{A2EGUmF2  
public class FileSplitterFetch extends Thread { Bk,:a,  
Co[fq3iX#  
`-a](0Q U  
String sURL; //File URL ]WlE9z7:8  
long nStartPos; //File Snippet Start Position /d;C)%$  
long nEndPos; //File Snippet End Position Gx Z'"x  
int nThreadID; //Thread's ID J2A+x\{<  
boolean bDownOver = false; //Downing is over k#mQLv  
boolean bStop = false; //Stop identical 1>hY!nG h  
FileAccessI fileAccessI = null; //File Access interface X(s HFVU+  
Hy4c{Ij  
g/Q"%GN,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5(BB`)  
{ _,*ld#'s  
this.sURL = sURL; W/03L, 1  
this.nStartPos = nStart; k?r -%oJ7  
this.nEndPos = nEnd; 9G njJ  
nThreadID = id; hP1}Do  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _$s ;QI]x  
} pxm{?eBz  
-|E|-'  
R^8L^8EL  
public void run() 5G5P#<Vv  
{ zTA+s 2  
while(nStartPos < nEndPos && !bStop) 0 *!CJ;%N  
{ ]2O52r  
@JJ,$ ?  
CjtBQ5  
try{ <1")JDW  
URL url = new URL(sURL); SN w3xO!;&  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BET3tiHV  
httpConnection.setRequestProperty("User-Agent","NetFox"); B~S"1EE[  
String sProperty = "bytes="+nStartPos+"-"; _X ?W)]:  
httpConnection.setRequestProperty("RANGE",sProperty); LxD >eA  
Utility.log(sProperty); wHneVqI/U  
`qP <S  
FR%9Qb7  
InputStream input = httpConnection.getInputStream(); zadn`B#2  
//logResponseHead(httpConnection); XLwmXi  
IE/F =Wr  
z1wJ-l  
byte[] b = new byte[1024]; w-f[h  
int nRead; P#e1?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M#<U=Ha  
{ !~X[qT  
nStartPos += fileAccessI.write(b,0,nRead); s?qRy 2  
//if(nThreadID == 1) >`\f,yq l6  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ahezDDR-.i  
} e,j2#wjor  
5R^e  
pPI'0x  
Utility.log("Thread " + nThreadID + " is over!"); ~W?F.  
bDownOver = true; UO3QwZ4j;  
//nPos = fileAccessI.write (b,0,nRead); +Fn^@/?yC  
} luA k$Es  
catch(Exception e){e.printStackTrace ();} [!^Q_O  
} 8sMDe'  
} kjCXP  
&)(>e}es  
#jY\l&E  
//打印回应的头信息 9  Vn  
public void logResponseHead(HttpURLConnection con) ZUDdLJ  
{ Vz=ByyC  
for(int i=1;;i++) 82w;}(!  
{ l,z# : k  
String header=con.getHeaderFieldKey(i); _hM #*?}v  
if(header!=null) wUU Dq?!k\  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M5$YFGGR  
Utility.log(header+" : "+con.getHeaderField(header)); %}< e;t-O  
else VD=}GY33=  
break; z"cF\F  
} &/%A 9R,  
} XwI~ 0  
~ ^)D#Lo  
xZmO^F5KHj  
public void splitterStop() x3./  
{ Cxn<#Kf\-<  
bStop = true; *t_"]v-w  
} "EA6RFRD  
;3\oU$'  
E;$;g#ksf  
} BQX6Q<  
aT9+] Ig  
qN5 ru2  
/* gmCW__oR  
**FileAccess.java <Mdyz!  
*//文件访问(定位,写) j@yK#==k  
package NetFox; /O,>s  
import java.io.*; nC-=CMWWr  
G~$.Af!9W  
bfjC:"!H  
public class FileAccessI implements Serializable{ 4CUoXs'  
2(SU# /,  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <>gX'te  
RandomAccessFile oSavedFile; }}R?pU_  
long nPos; )@vhqVv?  
&sFEe<  
= [N= mC  
public FileAccessI() throws IOException x,CTB  
{ 79DzrLu  
this("",0); S5Hb9m&&  
} kTC'`xv  
:K:oH}4oh  
|E%i t?3M  
public FileAccessI(String sName,long nPos) throws IOException ~0;l\^  
{ Yf=an`"  
oSavedFile = new RandomAccessFile(sName,"rw"); 4trP*u,4  
this.nPos = nPos; Ry$zF~[   
oSavedFile.seek(nPos); we4k VAn  
} !ucHLo3:  
]xx}\k  
F&tU^(7<  
public synchronized int write(byte[] b,int nStart,int nLen) Dd:TFZo  
{ h/)kd3$*'  
int n = -1; *3uBS2Ld  
try{ >i6sJ)2?>  
oSavedFile.write(b,nStart,nLen); l**gM  
n = nLen; k-:wM`C  
} ^{V t  
catch(IOException e) #8Bs15aV  
{ u-8b,$@Z>'  
e.printStackTrace (); S.<aCN<@  
} a#huK~$~  
>yZe1CP  
J?oI%r7^  
return n; w5C$39e\G  
} m;_gNh8Ee  
\ oY/hT_  
6KvoHo  
} wjq;9%eXk  
Fjs:rZ#{  
KF4D)NM|  
/* Z<yLu'48)A  
**SiteInfoBean.java vz$_Fgsc.  
*/ {^5LolCCH  
package NetFox; Wz8 MV -D  
|)Q#U$ m  
kFRl+,bi~  
public class SiteInfoBean { gwA+%]  
N$!aP/b  
}Wk^7[Y  
private String sSiteURL; //Site's URL qG6?k}\\  
private String sFilePath; //Saved File's Path "jUM}@q5  
private String sFileName; //Saved File's Name |;(95  
private int nSplitter; //Count of Splited Downloading File P&>!B,f  
6>yfm4o  
~nVO%IxM4J  
public SiteInfoBean() azs lNL  
{//nSplitter的缺省值为5 gNWTzz<[f>  
//default value of nSplitter is 5 Lhts4D/V7  
this("","","",5); rIh"MQvi[  
} g3Xa b  
l.@v@T(/  
#`HY"-7m_  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +HXR ))X  
{ 8opd0'SNaB  
sSiteURL= sURL; rW P -Rm  
sFilePath = sPath; o]@Mg5(8Q  
sFileName = sName; n@JZ2K4  
this.nSplitter = nSpiltter; '^{:HR#i  
nF)b4`Nd  
f@j)t%mh  
} _.{I1*6Y2  
qk{+Y  
@W1F4HYds  
public String getSSiteURL() 2Y7u M;8  
{ n9%&HDl4  
return sSiteURL; b2tUJ2p  
} ppP0W `p  
R<L<kChg  
x 8/I"!gI  
public void setSSiteURL(String value) t:O"t G  
{ KLBX2H2^0  
sSiteURL = value; ( kKQs")  
} Gp9:#L!  
W]CsKN,K  
~Z>!SMXp<  
public String getSFilePath() 6Mj (B*c  
{ Z1y=L$t8  
return sFilePath; Mb^E  
} ,J4rKGG  
W\pO`FL  
WAUgbImc{  
public void setSFilePath(String value) Xl %ax!/  
{ ?'IY0^  
sFilePath = value;  Tb[1\  
} z[sP/{~z  
k d9<&.y{  
p.|M:C\xL  
public String getSFileName() a;h.I}*]  
{ V#,jUH|  
return sFileName; wj{[g^y%  
} >+FaPym  
s qEOXO  
nJhaI  
public void setSFileName(String value) _+6aD|7x  
{ ~QngCg-5q  
sFileName = value; Fl}{"eCF8  
} <}Hs@`jS  
n)uck5  
M-V{(  
public int getNSplitter() KK';ho,W  
{ O63:t$Yx#  
return nSplitter; UbEK2&q/8  
} .Y5o&at6s  
asZ(Hz%  
EXEB A&*  
public void setNSplitter(int nCount) 4de:hE   
{ GWa:C\YK  
nSplitter = nCount; ?0x=ascP  
} -d4|EtN  
} H7{I[>:  
928uGo5  
l{mC|8X  
/* EdTR]}8  
**Utility.java mlO\wn-F  
*/ ?`/DFI'_G  
package NetFox; WyU\,"  
=mYwO=:D  
Y=ksrs>w  
public class Utility { =$-+~  
a797'{j#PI  
2_Gb K-  
public Utility() WNSY@q  
{ gVI{eoJ  
Q*ixg$>  
*TgD{>s  
} [ 0z-X7=e  
)?;+<,  
//线程睡眠 [?55vYt  
public static void sleep(int nSecond) )m$MC25  
{ ;-^8lWt  
try{ ~7>D>!!  
Thread.sleep(nSecond); O_ d[{e=5`  
} g `(3r  
catch(Exception e) c<ORmg6  
{ dwqR,|  
e.printStackTrace (); \IP 9EFA  
} uH |:gF^  
} P?hB`5X  
+-:o+S`q~  
//日志 ?k^~qlye  
public static void log(String sMsg) b8LA|#]i  
{ 4x-K0  
System.err.println(sMsg); yVe<+Z\7  
} dK41NLGQ  
bJcO,M:2  
"i,ZG$S#E  
public static void log(int sMsg) ZkryoIQ%=  
{ :[&QoEZW  
System.err.println(sMsg); l?B=5*0  
}  a"D'QqtH  
} 8osP$"/o  
)%09j0y>l"  
'Pe;Tp>`  
/* #A&49a3^1  
**TestMethod.java ldnKV&N  
*/ :3[;9xCHj  
package NetFox;  }=d}q *  
k\X yR4r  
& zv!cf  
public class TestMethod { #$;}-*  
^/I.? :+  
gh `]OxA  
public TestMethod() \ #N))gAQ  
{ ///xx/weblogic60b2_win.exe ^p~QHS/  
try{ i`5Skr:M  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &Qmb?{S0  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $IqubC>O  
SiteFileFetch fileFetch = new SiteFileFetch(bean); :{9HsF"h0  
fileFetch.start(); z @?WhD  
} j&[u$P*K  
catch(Exception e){e.printStackTrace ();} ~KczP1p  
pM9M8d  
]app9  
} #nq_R  
%-[*G;c'w  
$Lz!04  
public static void main(String[] args) (9{qT>eJg=  
{ +g;{c+Kw:  
new TestMethod(); LkWY6 ?$U  
} z.^_;Vql_  
} Fj46~#ZZ  
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