http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?bq S{KF
} us_o{
for(int i=0;i<nEndPos.length-1;i++) U@6bH@v5
{ xYgG
nEndPos = nStartPos[i+1]; \h#,qTE
} XVlZ:kz
nEndPos[nEndPos.length-1] = nFileLength; }:b6WN;c
} )}G?^rDH(
} 0c$0<2D%
0Bo7EV
?tf/#5t}
//启动子线程 5q.d$K |
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >BDK?YMx
for(int i=0;i<nStartPos.length;i++) FLqF!N\G
{ 6<uJ}3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8@}R_GZc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +# 38
nStartPos,nEndPos,i); tm"9`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qh0tU<jG
fileSplitterFetch.start(); /9K,W)h_
} AB.gVw| 4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /z0X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); RSK~<Y@]q{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pZYcCc>6&
nEndPos = " + nFileLength); {N \ri{|
// fileSplitterFetch[nPos.length-1].start(); 9(\eL9^
yX {CV7%O
WeqE9@V
//等待子线程结束 'T '&OA
//int count = 0; |>Q]q
//是否结束while循环 ,vxxp]#5
boolean breakWhile = false; [YGPcGw
WT-BHB1
)*b dG'}
while(!bStop) pBd_BaN
{ yU e7o4Zm
write_nPos(); ed=pRb
Utility.sleep(500); s!vvAD;\
breakWhile = true; \NiW(!Z}
?^8CD.|
xbN)z
for(int i=0;i<nStartPos.length;i++) ]\qbe
{ Eeumi#$Z
if(!fileSplitterFetch.bDownOver) 2/T4.[`t
{ k^JV37;bl
breakWhile = false; 0`LR!X
break; {.D^2mj|
} zq:+e5YT?T
} 0ESxsba
if(breakWhile) e%Sw(=a
break; Q)n6.%V/e
P0Q]Ds|
gB&8TE~Y
//count++; t#fbagTON
//if(count>4) 17\5NgB
// siteStop(); 0wh4sKm[X
} ],?rFK{O
}!&Vcf
E8Rk b}
System.err.println("文件下载结束！"); Ih&rXQ$
} pG|+\k/B
catch(Exception e){e.printStackTrace ();} *2?-6
} y1oQ4|KSI
^`HP&V
2"'<Yk9
//获得文件长度 E1=WH-iA0
public long getFileSize() xw>\6VNt
{ oHW:s96e
int nFileLength = -1; FLb Q#c\
try{ 1TOT}h5
URL url = new URL(siteInfoBean.getSSiteURL()); ||}k99y +
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3pV^Oe^9
httpConnection.setRequestProperty("User-Agent","NetFox"); o_(@v2G`
O/?Lk*r
jMpV c E#
int responseCode=httpConnection.getResponseCode(); ;$VQRXq
if(responseCode>=400) L/YEW7M
{ 0xSWoz[i6~
processErrorCode(responseCode); rryC^Vma
return -2; //-2 represent access is error *ommU(r8
} 2b[R^O}
z-J?x-<
#835$vOe
String sHeader; \\Z{[{OZ
"%mu~&Ga
cnm*&1EzV
for(int i=1;;i++) Y]9AC
{ e hgUp =
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Fm|h3.`V
//Utility.log(in.readLine()); q JdC5z\[
sHeader=httpConnection.getHeaderFieldKey(i); ,4OH9-Q1
if(sHeader!=null) ]"*sp
{ (>LJv |wn
if(sHeader.equals("Content-Length")) oZ/z{`
{ /^2&@P7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wT taj08D
break; )zKZ<;#y
} 4P>4d +
} Dh4EP/=z
else 'X$J+s}6&
break; si!jB%^
} Qw,{"J
} mZ[tB/
catch(IOException e){e.printStackTrace ();} 0tFR. sS?
catch(Exception e){e.printStackTrace ();} jQV.U~25Q
5LkpfmR
zFFip/z\
Utility.log(nFileLength); KeGGF]=>
Os5Xejh`I
|})7\o
return nFileLength; >l$qE
} 3SeM:OYq]s
dw"Tv~
TTfU(w%&P
//保存下载信息（文件指针位置） Yu`KHvur
private void write_nPos() Hy*_4r
{ W`d\A3v
try{ m?@0Pf}xa
output = new DataOutputStream(new FileOutputStream(tmpFile)); bMrR
output.writeInt(nStartPos.length); pO10L`|
for(int i=0;i<nStartPos.length;i++) d~>d\K%v
{ ,WA[HwY-
// output.writeLong(nPos); hd'JXKMy
output.writeLong(fileSplitterFetch.nStartPos); Mq#sSBE<K
output.writeLong(fileSplitterFetch.nEndPos); x+%(z8wD
} l)d(N7HME
output.close(); 4(hHp6}b
} ,lUroO^^
catch(IOException e){e.printStackTrace ();} =8p *Ijs
catch(Exception e){e.printStackTrace ();} 1Fs:&*=
} hE9UWa.Q>
QrX 5Kwq
*=KX0%3
//读取保存的下载信息（文件指针位置） G|LJOq7QB
private void read_nPos() hk7kg/"
{ s4&JBm(33N
try{ E[nJ'h<h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gE}+`w/X
int nCount = input.readInt(); `nvm>u~[Hq
nStartPos = new long[nCount]; &y~~Z [.F,
nEndPos = new long[nCount]; HXg#iP^tv
for(int i=0;i<nStartPos.length;i++) z+=wql*Eo
{ 6z-&Zu7@
nStartPos = input.readLong(); KJLC2,
nEndPos = input.readLong(); 4Gsbcl{
} B.T|e,g26
input.close(); +YNN$i
} i+Fk
catch(IOException e){e.printStackTrace ();} h%0FKi^
catch(Exception e){e.printStackTrace ();} ,iy;L_N
} Z'V"nhL
y?}R,5k
]rY3bG'&
private void processErrorCode(int nErrorCode) zfBaB0P
{ q'
System.err.println("Error Code : " + nErrorCode); h=7eOK]
} `+c8;p'q
_ft)e3Gf
'y? HF@NJ
//停止文件下载 KsG>,# Q
public void siteStop() sZ7RiH+I
{ /BaXWrd+
bStop = true; {<k}U;uiO
for(int i=0;i<nStartPos.length;i++) p&O-]o8
fileSplitterFetch.splitterStop(); [? 1m6u;
YZHqy++x
/yd<+on^
} B'U;i5u4'
} AgU 7U/yk
//负责部分文件的抓取 B|zVq=l~
**FileSplitterFetch.java h]w5N2$}?
*/ qbunP!
package NetFox; -gzY~a
jwW6m@+
L>PPAI
import java.io.*; %(v<aEQtt
import java.net.*; @9}SHS
!vQDPLBL
n#fc=L1U
public class FileSplitterFetch extends Thread { Rc.8j,]
x#0B "{
Q|1X|_hs
String sURL; //File URL E{#Y=
long nStartPos; //File Snippet Start Position >.}ewz&9o
long nEndPos; //File Snippet End Position oKlOcws}
int nThreadID; //Thread's ID NW*qw q
boolean bDownOver = false; //Downing is over (r!d4
boolean bStop = false; //Stop identical NU#rv%p
FileAccessI fileAccessI = null; //File Access interface ;<~lzfs
B;6N.X(K
@?gN &Z)I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iJsa;|2/
{ ^;xO-;q
this.sURL = sURL; *]uj0@S
this.nStartPos = nStart; (d@ =
this.nEndPos = nEnd; 1 xu2$x.b
nThreadID = id; {zj<nu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -g6C;<Y
} {W5D)
KDW=x4*p
TXDb5ZCzM
public void run() j1hx{P'
{ CNRiK;nQ
while(nStartPos < nEndPos && !bStop) [ ]LiL;A&
{ "p[FFg
VJ'bS9/T
N:yyDeGyW
try{ 9tZ+?O5
URL url = new URL(sURL); 5%Xny8 ]|D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (qky&}H
httpConnection.setRequestProperty("User-Agent","NetFox"); r!,/~~mT
String sProperty = "bytes="+nStartPos+"-"; $>M A
httpConnection.setRequestProperty("RANGE",sProperty); 3~uWrZ.u
Utility.log(sProperty); A8by5qU
r:n-?P
Hswgv$n
InputStream input = httpConnection.getInputStream(); 9"RGf 1]
//logResponseHead(httpConnection); Jc74A=sT
U if61)+!i
B<A=U r
byte[] b = new byte[1024]; nRL2Z5iO-
int nRead; W2CQk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %!_%%p,f
{ "k%B;!We)
nStartPos += fileAccessI.write(b,0,nRead); _);;@T
//if(nThreadID == 1) n;5;D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `=B0NC.3
} j& x=?jX
]*Tnu98G}
=C[2"Y4JK0
Utility.log("Thread " + nThreadID + " is over!"); Nsd7?|@HI
bDownOver = true; 5csqu^/y
//nPos = fileAccessI.write (b,0,nRead); 6'^Gh B
} g\n0v~T+
catch(Exception e){e.printStackTrace ();} B&Igm<72x
} my|UlZ(qg
} )U':NV2
1sHaG
=yZiBJ
//打印回应的头信息 01-n_ $b
public void logResponseHead(HttpURLConnection con) nnm9pnx
{ UJX=lh.o
for(int i=1;;i++) :.k)!
{ \;%DDw
String header=con.getHeaderFieldKey(i); UFED*al#
if(header!=null) !UV/p"CfX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )&$Zt(
Utility.log(header+" : "+con.getHeaderField(header)); " ~X;u8m
else vMQvq9T}
break; >10pk
} .vbUv3NI
} p7YfOUo k
51\N+
]("5O V5
public void splitterStop() wv~?<DF
{ yye(^
bStop = true; )7j CEA03
} M-B-
Yiq8>|
s=uWBh3J
} h{sY5d'D
LE"t'R
Y.<&phv
/* p^s k?E
**FileAccess.java )L%i"=<Bdy
*//文件访问(定位，写) \AT]$`8@_
package NetFox; fy(i<L Z
import java.io.*; nOd'$q
DsY$
JmR) g
public class FileAccessI implements Serializable{ \"r*wae
y+C.2 ca
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8w[nY.#T
RandomAccessFile oSavedFile; g7|$JevR0
long nPos; r:&"#F
77Fpb?0`
iSZiJ4AUq
public FileAccessI() throws IOException l/JE}Eg(
{ zMXlLRC0
this("",0); :IZ(9=hs
} ?rD`'B
Ifc}=:nr
l{{wrU`
public FileAccessI(String sName,long nPos) throws IOException ,a$?KX
{ kUdl2["MZ
oSavedFile = new RandomAccessFile(sName,"rw"); nA\9UD<G.
this.nPos = nPos; ~[mAv#d&i
oSavedFile.seek(nPos); as{^~8B
} 1xJc[q
4+V+SD
%>cl0W3x
public synchronized int write(byte[] b,int nStart,int nLen) B~/LAD_
{ _V9 O,"DDc
int n = -1; tkG0xRH
try{ bs%lMa.o
oSavedFile.write(b,nStart,nLen); }Ot I8;>
n = nLen; G$5N8k[2
} O>E2G]K]\
catch(IOException e) $hkMJ),T~
{ $=c79Al(
e.printStackTrace (); CZ/bO#~
} T/_JXK>W
Y!kz0([
*hHy>(*
return n; Q/%(&4>'y
} EzDj,!!<w
`J>76WN
;?y*@*2u
} vFK&63
7H-,:8
P~)ndaQ
/* <&?gpRK
**SiteInfoBean.java GnE%C2L-
*/ R?Dbv'lp>
package NetFox; ~ E)[!y
)TceNH
.oJs"=h:m
public class SiteInfoBean { cm8-L[>E
7-oH >OF^
rpgr5>
private String sSiteURL; //Site's URL 5dVSir
private String sFilePath; //Saved File's Path brkR,(#L3
private String sFileName; //Saved File's Name 1`tE Hu.
private int nSplitter; //Count of Splited Downloading File VK*2`Z1
H:X=v+W
'JBf*p".
public SiteInfoBean() FTy`#*7Ul
{//nSplitter的缺省值为5 x9#>0 4s
//default value of nSplitter is 5 +$#YW5wy
this("","","",5); '8NKrI
} r@xMb,!H
ob
v5|X=B>&>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $XqfwlUu/4
{ @)8QxI^3[
sSiteURL= sURL; h^P>,dy0
sFilePath = sPath; g<[_h(xDeG
sFileName = sName; <ByR!Y
this.nSplitter = nSpiltter; zfE;)K^"
aW8Bx\q
SWjOJjn
} 3U&QonCV
rSIb1zJ
!*:Zcg?7n
public String getSSiteURL() u"K-mr#$[o
{ ~RVx~hh
return sSiteURL; J?XEF@?'G
} Ve,_;<F]S
H}NW?
C7(kV{h$d
public void setSSiteURL(String value) j:%~:
{ @L%9NqE`O
sSiteURL = value; R|T_9/#)
} )*@Oz
D<[4}og&]
\A\a=A[
public String getSFilePath() xo0",i f8
{ ,.`";='o
return sFilePath; WV5gH*uUa
} ex8mA6g
P5ii3a?R
X6mY#T'fQ
public void setSFilePath(String value) |X9YVZC
{ K1Tq7/N
sFilePath = value; `zHtfox!
} eR(PY{
J!,5HJh1
]6{G;f$
public String getSFileName() 29g("(}TK
{ (=${@=!z
return sFileName; t;9f7~
} [R j=k)aBm
<CL0@?*i9
D"F5-s7
public void setSFileName(String value) jxL5L[
{ Ys10r-kDS
sFileName = value; +XU*NAD,!
} NYD#I{h
[{_JO+)+n
6uQfe?aD
public int getNSplitter() 9hI4',(rE
{ o}p6qB=;1
return nSplitter; YJ]]6 K+
} 3OV#H%
xW{_c[oA
^;B vd!
public void setNSplitter(int nCount) 9)sGnD;
{ 0-EhDGa]r
nSplitter = nCount; 5AR\'||u
} 4J2NIFZ
} MpM-xz~
"A^9WhUpJ
Tn[DF9;?
/* qFmvc
**Utility.java |jW82L+!N%
*/ -san%H'
package NetFox; 7t\W{y
A>^\jIB>
i% k`/X;
public class Utility { 3|%Q{U
tv)x(MX
v\:>} <gc
public Utility() >Vc_.dR)E
{ AFL*a*
8ON$M=Ze$
Oh<[8S7]C
} RNuOwZ1m
;Gxp'y
//线程睡眠 .x$+7$G
public static void sleep(int nSecond) >t u3m2
{ J'y*;@4l^:
try{ 5<Cu-X
Thread.sleep(nSecond); y}ezjs
} E0}`+x
catch(Exception e) [i.2lt#]
{ N\DEY]
e.printStackTrace (); fR!'i):u
} R{kZKD=
} wQ[~7 ,o
nJ.pPzH2g
//日志 InMeD[*^
public static void log(String sMsg) DqrS5!C
{ di`Ql._M
System.err.println(sMsg); oddS~lW
} L~Epd.,Dt
K9}ppgL'$
pox\Gu~.0
public static void log(int sMsg) .Xh^L
{ g^"",!J/
System.err.println(sMsg); mgX0@#wFn
} /<s'@!W
} ROr$Sz
;JA2n\iP,
I-4csw<Qy
/* gIep6nq1`|
**TestMethod.java ' A= x
*/ aDR<5_Yb
package NetFox; k&ujr:)5Y5
"m):"
{ dwm>a
public class TestMethod { 5NbI Vz
Fkj\U^G
+wwpaR`
public TestMethod() J`;G9'n2
{ ///xx/weblogic60b2_win.exe =(K;z9OR
try{ L{Epkay,{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MOP %vS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e2UbeP
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ps7(4%
fileFetch.start(); +w:[By"
} Z<K[
catch(Exception e){e.printStackTrace ();} &G5+bUF,
%I;ej{*c
J6_Hlt
} 8vz9o <I
yC4JYF]JN
I,QJ/sI
public static void main(String[] args) @~'c(+<3
{ *-T3'beg
new TestMethod(); ()v[@"J
} {%^q8l4j
} gCz^JM
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