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)); /n(9&'H<
} -=}b;Kf-
for(int i=0;i<nEndPos.length-1;i++) rWJ*e Y
{ [4Y[?)7
nEndPos = nStartPos[i+1]; n9DbiL1{
} i9KTX%s5^
nEndPos[nEndPos.length-1] = nFileLength; Ga.0Io&}C
} <p09oZ{6
} [qiOd!
R^w}o,/
$cq!RgRn
//启动子线程 7iP5T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }0Y`|H\v
for(int i=0;i<nStartPos.length;i++) NJ<N%hcjK
{ ^dh=M5xz)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?<E0zM+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :aH%bk
nStartPos,nEndPos,i); MZ)T0|S_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (X*9w##x(
fileSplitterFetch.start(); E&'#=K[
} F%}7cm2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .`Sw,XL5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :xM}gPj"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YhS{$Z
nEndPos = " + nFileLength); u-kZW1wrQ
// fileSplitterFetch[nPos.length-1].start(); ~*,Wj?~+7
7g5@vYS+
ZlrhC= 0
//等待子线程结束 s*f1x N<
//int count = 0; qT$)Rb&
//是否结束while循环 ( :iPm<
boolean breakWhile = false; J=@xAVBc
V(r`.75
_@~PL>g"p
while(!bStop) |<1M&\oaQ'
{ BO"qD[S
write_nPos(); RYH)AS4w'
Utility.sleep(500); \p3v#0R{
breakWhile = true; bGu([VB
[$;,Ua-mt
V;k#})_-
for(int i=0;i<nStartPos.length;i++) o~;M"
{ @*SA$9/l
if(!fileSplitterFetch.bDownOver) w [L&*
{ 1#]B^D
breakWhile = false; J]dW1boT@
break; ^@K WYAAW5
} 8]HY. $E
} Si]X rub
if(breakWhile) gn^!"MN+g
break; $D}"k!H
G~(&3
'aZASPn[
//count++; S_$nCyaH2
//if(count>4) eKyqU9
// siteStop(); r,0@~;zA
} 8A!'I<S1
oK$'9c5<
*y?[<2"$
System.err.println("文件下载结束！"); $C$ub&D ~"
} js -2"I
catch(Exception e){e.printStackTrace ();} [<Q4U{F
} ?;_O 9
B>,A(X&
e+{BJN vz
//获得文件长度 ~@@ Z|w
public long getFileSize() W6i3Psjsw
{ 2 ZK%)vq0
int nFileLength = -1; 1LX)4TCC
try{ ~XKZXGw
URL url = new URL(siteInfoBean.getSSiteURL()); R B%:h-t4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4dD2{M
httpConnection.setRequestProperty("User-Agent","NetFox"); n7S; Xve#
djfU:$!j&
@i{]4rk lv
int responseCode=httpConnection.getResponseCode(); KJX>DL 9\
if(responseCode>=400) AX K95eS
{ (7~%B"
processErrorCode(responseCode); 2eHx"Ha
return -2; //-2 represent access is error &}E:jt}
} 2qjyFTT
m@[3~ 6A
/S[?{QA
String sHeader; f7 wmw2
o[oqPN3$Y
dWUUxKC
for(int i=1;;i++) h9jc,Xu5X
{ ?9Ma^C;}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E>"8/
//Utility.log(in.readLine()); {"t5\U6cKM
sHeader=httpConnection.getHeaderFieldKey(i); \FXp*FbQ
if(sHeader!=null) 8O9Gs
{ J)Ol"LXV
if(sHeader.equals("Content-Length")) c;^A)_/
{ (-J<Vy]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ) $J7sa
break; W"t"X ~T3
} \?dTH:v/E
} nd.hHQ
else C/)`<b(
break; *E7R(#,yC
} +KP_yUq[
} Mt=R*M}D0
catch(IOException e){e.printStackTrace ();} {[tZ.1.w
catch(Exception e){e.printStackTrace ();} #Z0-8<\
-"tY{}z
kT2Wm/L
Utility.log(nFileLength); qlvwK&W<QM
TL@mM
^e%k~B^
return nFileLength; =JxFp, Xr
} O"iak
MyFCJJ/
_ Mn6L=
//保存下载信息（文件指针位置） }uiPvO+&p
private void write_nPos() a ea0+,;
{ &(7$&Q
try{ V:>`*tlh
output = new DataOutputStream(new FileOutputStream(tmpFile)); 59Nd}wPO;
output.writeInt(nStartPos.length); \447]<u
for(int i=0;i<nStartPos.length;i++) Yt*vqm[WV
{ 4DM*^=9E
// output.writeLong(nPos); c=aO5(i0
output.writeLong(fileSplitterFetch.nStartPos); xl,ryc3J
output.writeLong(fileSplitterFetch.nEndPos); Y;eoTJ
} $ 9=8@
output.close(); d"GDZ[6
} ?Sw /(}|m
catch(IOException e){e.printStackTrace ();} !-,Ww[G>
catch(Exception e){e.printStackTrace ();} GV>&g
} Wn~ZA#
4 4`WYK l
|]tZ hI"3<
//读取保存的下载信息（文件指针位置） XWXr0>!,?
private void read_nPos() y!5:dvt
{ $L\@da?
try{ AqqHD=Yp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KSsWjF}d
int nCount = input.readInt(); RY<%'\A`~
nStartPos = new long[nCount]; [xf$VkjuF
nEndPos = new long[nCount]; `M0YAiG
for(int i=0;i<nStartPos.length;i++) ( OXY^iq
{ p[Hr39o
nStartPos = input.readLong(); & g$rrpTzv
nEndPos = input.readLong(); 73)Ll"(
} ZPvf-PqJl
input.close(); 3.FR C
} u#3)p
catch(IOException e){e.printStackTrace ();} 1daL y
catch(Exception e){e.printStackTrace ();} -=sf}4A
} {$|/|*
I=5dYq4 l
63C(Tp"
private void processErrorCode(int nErrorCode) PkO!'X
{ ll2Vk*xs
System.err.println("Error Code : " + nErrorCode); ZRPy~wy>
} j.B>v\b_3
H:{?3gk.P3
0R4akLW0
//停止文件下载 yKlU6t&` G
public void siteStop() i7s\CY
{ #fj[kq)&S
bStop = true; C=yD3mVz
for(int i=0;i<nStartPos.length;i++) uQ^hV%|"
fileSplitterFetch.splitterStop(); H0+:XF\M
q0g1EJar
k}s+ca!B
} gsfhH0
} `@MPkCy1
//负责部分文件的抓取 T5q-"W6\
**FileSplitterFetch.java 8,y{q9O
*/ m_$JWv\|\
package NetFox; K( z[}
y+RRg[6|
69iM0X!'u
import java.io.*; ftaBilkjp
import java.net.*; :G0+;[?N
4i`S+`#
>j:|3atb
public class FileSplitterFetch extends Thread { F^miq^K=
DyIV/
;:?*t{r4#
String sURL; //File URL OW#_ty_ul
long nStartPos; //File Snippet Start Position %",ULtZ+
long nEndPos; //File Snippet End Position ]zcV]Qj$~
int nThreadID; //Thread's ID bM5CDzH(#X
boolean bDownOver = false; //Downing is over lz}llLb1
boolean bStop = false; //Stop identical Pa[?L:E
FileAccessI fileAccessI = null; //File Access interface !-ZP*V3}h
1@@y]s_.a
*_#&"(P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g&kH'fR8
{ 9cz)f\
this.sURL = sURL; zuMO1s
this.nStartPos = nStart; 7jT#BWt
this.nEndPos = nEnd; E[ 0Sst x
nThreadID = id; {KsVK4\r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QY6O(=
} Az9J\V~"
8F)=n \
CC>($k"
public void run() L&QtHSzy
{ CWBbSGk
while(nStartPos < nEndPos && !bStop) ?R282l
{ Lrlk*
FCAJavOGH
/k) NP
try{ d=F)y~&'
URL url = new URL(sURL); L\YZT| K(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %UBPoq
httpConnection.setRequestProperty("User-Agent","NetFox"); O"8P#Ed
String sProperty = "bytes="+nStartPos+"-"; ;AltNGcM
httpConnection.setRequestProperty("RANGE",sProperty); 8;0^'Qr8
Utility.log(sProperty); ~T7\8K+ $
7BS/T
<\p&jk?
InputStream input = httpConnection.getInputStream(); ,[^o9u uB
//logResponseHead(httpConnection); Xj(>.E{~H
qhnapZJ
"raj>2@
byte[] b = new byte[1024]; v=>3"!*
int nRead; 6# R;HbkO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :/~_sJt C
{ )Yrr%f`\
nStartPos += fileAccessI.write(b,0,nRead); .jCk#@+
//if(nThreadID == 1) e_^KI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t9]r
} Fos1WH?\
1&}G+y
v >NTh
Utility.log("Thread " + nThreadID + " is over!"); kHZKj!!R
bDownOver = true; so'eZ"A:
//nPos = fileAccessI.write (b,0,nRead); aC4m{F[
} pIL`WE1'
catch(Exception e){e.printStackTrace ();} *6'_5~G
} w2' 3S#nZ
} /lru"R D
x7Eeb!s0f,
noFh p
//打印回应的头信息 WVj&0
public void logResponseHead(HttpURLConnection con) J09ZK8 hK
{ bnIf}ut-G
for(int i=1;;i++) ,znL,%s
{ gl Li
String header=con.getHeaderFieldKey(i); > d^r">!,
if(header!=null) RBPYGu'6B
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c'SM>7L
Utility.log(header+" : "+con.getHeaderField(header)); \/pVcR
else N0=b[%g;n
break; ?fm2qrV@fp
} V`U/'N-ay
} ;B(;2.<"J
E#m76]vkCU
H_v/}DEG
public void splitterStop() gr[D!D>
{ i;gw=Be
bStop = true; -g~iE]x6Y
} :LG}yq^
YK7gd|LR]
Ed4_<:
} x>'?IJZ
/\Jc:v#Q
-0/=k_q_
/* +38Lojb}
**FileAccess.java Sv~PXi^`H
*//文件访问(定位，写) 4D0(Fl
package NetFox; ?|\0)wrRf
import java.io.*; WReYF+Uen
aIY$5^x
>I{4
public class FileAccessI implements Serializable{ 3J23q
_ak.G=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \t[ hg
RandomAccessFile oSavedFile; ^a: Saq-}
long nPos; jp"XS
Ey 0>L
hn*}5!^
public FileAccessI() throws IOException ':9%3Wq]j
{ @w+WLeJ$40
this("",0); Z{Lmd`<w`j
} YN$ndqOP
Ov F8&*A
8uD8or
public FileAccessI(String sName,long nPos) throws IOException RRK^~JQI.2
{ Mp}!+K
oSavedFile = new RandomAccessFile(sName,"rw"); Nu>sp,|A
this.nPos = nPos; +F#=`+V
oSavedFile.seek(nPos); !]n{l_5r
} uMljH@xBc
2y&_Z^kI?
;F" kD
public synchronized int write(byte[] b,int nStart,int nLen) }?\#_BCjx(
{ sASAsGk<
int n = -1; dfYYyE
try{ h'z+8X_t
oSavedFile.write(b,nStart,nLen); OLhWkN,qA
n = nLen; T<w*dX7F0K
} cN0~;!{i
catch(IOException e) XY&]T'A
{ g^Ugl=f,
e.printStackTrace (); HPv&vdr3
} %`t]FV^#
*rujdQf
$_%2D3-;D
return n; 'US8"83
} )of5229
eHfG;NsV/
GFSlYG
} Jv '3](
Fj4l %=
a,F8+ Pb>
/* P"[ifsp
**SiteInfoBean.java +?J_6Mo@X
*/ >vNk kxWyQ
package NetFox; 8VBkIYgb
v)v{QNQp^
}kgjLaQ^N
public class SiteInfoBean { ,Yiq$Z{qQ
U>3%!83kF
$A5B{2
private String sSiteURL; //Site's URL ,_e/a
private String sFilePath; //Saved File's Path J7&.>y1%
private String sFileName; //Saved File's Name =X%R*~!#Of
private int nSplitter; //Count of Splited Downloading File !/=9VD{U!
[5}cU{M
wd2P/y42;;
public SiteInfoBean() W}<M?b4tP
{//nSplitter的缺省值为5 "OlI-^y
//default value of nSplitter is 5 ys~p(
this("","","",5); 8Pnqmjjj
} @ B}c4,
[|m>vY!
&})4?5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _mI:Lr#dT
{ Y`[HjS,
sSiteURL= sURL; (<AM+|
sFilePath = sPath; { 8|Z}?I
sFileName = sName; ?()E5 4y
this.nSplitter = nSpiltter; ]ZU:%Qhu
KY(l<pm
}hObtAS
} (pRy1DH~
S{`!9Pii
F?+Uar|-a
public String getSSiteURL() HCe-]nMd
{ o+6^|RP
return sSiteURL; Xoa<r9
} qNuv?.7
2C 8L\
eL]w' }\
public void setSSiteURL(String value) I_Mqh4];
{ 0 6G[^
sSiteURL = value; s/p>30Fg
} L;(3u'
2kmna/Qa6
sL[(cX?;2
public String getSFilePath() j_YZ(: =
{ 5e~{7{
return sFilePath; #/ gme
} S|u1QGB
KzFs#rhpn
zxynEdO
public void setSFilePath(String value) xVwi }jtG|
{ j{Qbzczy,
sFilePath = value; jW+VUF-t
} }1^tK(Am
aGzdur
VHXR)}
public String getSFileName() Z({`9+/>u
{ R~seUW7uv"
return sFileName; 1PT_1[eAR
} H&>>]DD
;wYwiSVd
L-X _b3E\
public void setSFileName(String value) #D*J5k>2
{ -fZShOBY`
sFileName = value; OHa{!SaL
} kosJ]q'U
Q/9vDv
IB]VPj5
public int getNSplitter() &V,-W0T_
{ W~@GK
return nSplitter; M$-(4 0
} =w>>7u$4
4@V<Suw
B#V4
public void setNSplitter(int nCount) m#}{"d&J
{ "lnk
nSplitter = nCount; + 1%^c(3
} =jd=Qs IL
} Dm`U|<o
%w|3:
]V]@Zna@g
/* ~6kA<(x
**Utility.java pQm!Bt L
*/ ]C:Ifh~
package NetFox; %cjGeS6}
}Us$y0W\
@snLE?g j
public class Utility { `LHfAXKN
I`}vdX)
EA{*%9 A
public Utility() @^4M~F%
{ k~EPVJh"
M&\?)yG
;cHI3V
} fyoB]{$p8
((IBaEq
//线程睡眠 !iz vY
public static void sleep(int nSecond) co%_~xO
{ L"^366M!
try{ J,M5<s[Xqt
Thread.sleep(nSecond); oP`M\KXau
} I z=w2\r
catch(Exception e) Xs,PT
{ rls#gw
e.printStackTrace (); \rnG 1o
} T|iF/p]F
} -v+^x`HR
`j"G=%e3.
//日志 59J$SE
public static void log(String sMsg) G78j$ ^/0
{ %_=R&m'n`
System.err.println(sMsg); fvfVBk#
} o 0 #]EMr
.Qw@H#dtW
D\&y(=fzf
public static void log(int sMsg) N'BctKL
{ /Gv$1t^a
System.err.println(sMsg); HnY"6gTNK
} DczF0Ow
} ]mT} \b
A =#-u&l
?{P6AF-xcf
/* scEQDV
**TestMethod.java r{jD,x2
*/ 1E_Ui1[
package NetFox; g~D6.OZU
Nn7@+g)
8t \>
public class TestMethod { A|OC?NZY
[jn;| 3
BiCa "
public TestMethod() ,ST.pu8N.
{ ///xx/weblogic60b2_win.exe M@@O50~
try{ O,Gn2Do
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v23Uh2[@Yy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q;~>h
SiteFileFetch fileFetch = new SiteFileFetch(bean); FAl6
fileFetch.start(); s3!LR2qiF
} y, _3Ks
catch(Exception e){e.printStackTrace ();} AFUl
R*fR?
myX0<j3G5
} I_s(yO4pw
!#s7 F
[t)i\ }V
public static void main(String[] args) F76h
{ Q31c@t
new TestMethod(); oT{yttSNo
} 9yAu<a
} 1Sk6[h'CL
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