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)); \PB~6
} 044*@a5f
for(int i=0;i<nEndPos.length-1;i++) [ZP8[Zl'?
{ zu Jl #3YP
nEndPos = nStartPos[i+1]; `+(|$?Cu
} GL_a`.=@
nEndPos[nEndPos.length-1] = nFileLength; .h8%zB#|i
} uoe5@j2
} JyX7I,0
>r"~t70C~]
}Rc8\,
//启动子线程 SEc3`y;j%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S6sw)
for(int i=0;i<nStartPos.length;i++) \KaWR
{ Q(2X$7iRq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &)p/cOiV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y+#e| x
nStartPos,nEndPos,i); 7gV"pa
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aQEMCWxZ
fileSplitterFetch.start(); J0U9zI4
} +{j? +4(B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 43;@m}|7$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _r}oYs%1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /WVnyz0
nEndPos = " + nFileLength); EMe6Z!k
// fileSplitterFetch[nPos.length-1].start(); MKdBqnM(F
ZN2g(
t_q`wKDE
//等待子线程结束 nJ|8#U7
//int count = 0; .wD>0Ig
//是否结束while循环 #(53YoV_8
boolean breakWhile = false; "kKIVlC
6SMGXy*]^
e_wz8]K)n
while(!bStop) }V3p <
{ Qj? G KO
write_nPos(); IA|V^Wmt;
Utility.sleep(500); pX]*&[X?
breakWhile = true; {37DrSOa
S< <xlW
|*N.SS
for(int i=0;i<nStartPos.length;i++) OjCT*qyU<
{ +SmcZ^\OZ
if(!fileSplitterFetch.bDownOver) _gY so]S^B
{ 7"r7F#D=G
breakWhile = false; -P5VE0
break; S#X$QD
} 2oAPJUPOJ
} ^b`}g
if(breakWhile) x,js}Mlw
break; >qjr7 vx
#(jozl_8
\>j._#t$h
//count++; +0=u]
//if(count>4) EvMhNq~y5
// siteStop(); Oah}7!a)
} S zOB{
:rb<mg[
P sD+?
System.err.println("文件下载结束！"); )@3ce'
} QJo)
catch(Exception e){e.printStackTrace ();} Xu$xO(
} -pj&|< h+9
2F3IC
Mz<4P3"H
//获得文件长度 mj<(qZh
public long getFileSize() {W}.z
{ %#NaM\=8v
int nFileLength = -1; kRskeMr:Rd
try{ qqSk*oH~
URL url = new URL(siteInfoBean.getSSiteURL()); /40Z-'Bl=(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W;,.OoDc>
httpConnection.setRequestProperty("User-Agent","NetFox"); pN&Dpz^
g!7/iKj:
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int responseCode=httpConnection.getResponseCode(); v|jBRKU99
if(responseCode>=400) E`>-+~ZUsk
{ 9p(s FQ [
processErrorCode(responseCode); K/G|MT)
return -2; //-2 represent access is error /yIkHb^c
} KS'? DO
:9c QK]O6
Mno4z/4{A
String sHeader; xrO:Y!C?
c\.4I4uy
[dsH0 D&T
for(int i=1;;i++) jh`&c{#*)M
{ G3 #c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i}RxTmG<
//Utility.log(in.readLine()); #:z.Br`
sHeader=httpConnection.getHeaderFieldKey(i); DI9x]CR
if(sHeader!=null) HPpKti7g
{ Aa.bE,W
if(sHeader.equals("Content-Length")) V_!hrKkL
{ Gy 'l;2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1c,$D5#
break; ,g{`M]Ov
} TH)gW
} J}KATpHs
else w*Sl
break; FgQd7p
} 52K3N^RgR
} 6ndt1W z
catch(IOException e){e.printStackTrace ();} j$zw(EkN
catch(Exception e){e.printStackTrace ();} ,jbj-b(
eqs.zL
9<P1?Q
Utility.log(nFileLength); !3$Ph
vgHMVzxj
+WK!}xZR
return nFileLength; NXDdU^w7B
} SwG:?T!"}
3yDa5q{
#+QwRmJdT!
//保存下载信息（文件指针位置） 4'?kyTO~
private void write_nPos() #=5/D@
{ Am!$\T%2
try{ &BCl>^wn}
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,#UaWq@7
output.writeInt(nStartPos.length); O|#^&d
for(int i=0;i<nStartPos.length;i++) )fpZrpLXE
{ D^I%tn=F
// output.writeLong(nPos); Cz Jze
output.writeLong(fileSplitterFetch.nStartPos); me$7\B;wy
output.writeLong(fileSplitterFetch.nEndPos); :^1 Xfc"
} jUZ84Gm{
output.close(); _*9eAeJ
} A/W0O;*q
catch(IOException e){e.printStackTrace ();} }X)mZyM[
catch(Exception e){e.printStackTrace ();} i=.zkIjSh
} Cz+>S3v M
6jiVz%`=Z
8"LvkN/v^
//读取保存的下载信息（文件指针位置） :u`
private void read_nPos() \$V~kgQ0
{ z(aei(U=
try{ y0M^oLx
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b(I-0<
int nCount = input.readInt(); (m\PcF
nStartPos = new long[nCount]; HzF
nEndPos = new long[nCount]; B~V^?."
for(int i=0;i<nStartPos.length;i++) 41^+T<+
{ 7<mY{!2iF?
nStartPos = input.readLong(); h:<pEL
nEndPos = input.readLong(); !BP/#
} "D2`=D!+
input.close(); ,*Tf9=z
} .4Jea#M&x
catch(IOException e){e.printStackTrace ();} `Ou\:Iz0u
catch(Exception e){e.printStackTrace ();} M8ZpNa
} 4H]Go~<
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TPt<(-}W
private void processErrorCode(int nErrorCode) /^G1wz2
{ 6OF&Q`*4
System.err.println("Error Code : " + nErrorCode); D1;H,
} CQW#o_\
^9%G7J:vGO
tz)aQ6p\X
//停止文件下载 R^<li;Km
public void siteStop() CbVUz<
{ MVs@~=
bStop = true; [,3o
for(int i=0;i<nStartPos.length;i++) PzWhB* iBR
fileSplitterFetch.splitterStop(); (g`G(K_
0hnN>?
!=3[Bm G
} /9,!)/j
} t Q385en
//负责部分文件的抓取 UIi;&[
**FileSplitterFetch.java Q35$GFj"jD
*/ Waj6.PCFm
package NetFox; X&8&NkH
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<xKer<D %
import java.io.*; ) kfA5xi[
import java.net.*; S4aN7.'Q
[ p$f)'
$d3al%Uo
public class FileSplitterFetch extends Thread { GF*8(2h2
X9K@mX
T ]hVO'z
String sURL; //File URL /X~l%Xm
long nStartPos; //File Snippet Start Position {~_X-g5|]
long nEndPos; //File Snippet End Position >k"Z'9l
int nThreadID; //Thread's ID U$&G_&*0a
boolean bDownOver = false; //Downing is over 0/S|h"-L
boolean bStop = false; //Stop identical ;!q _+P
FileAccessI fileAccessI = null; //File Access interface }A\s`Hm
vxhs1vh
7xTgG!>v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \ $;E,
{ RZ-=UIf
this.sURL = sURL; w=Ac/12
this.nStartPos = nStart; <u]M):b3
this.nEndPos = nEnd; ?`bi8 Ck
nThreadID = id; `w` f[dU-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C#d.3t
} [APwHIS
HQJ_:x Y
h+<vWo}H
public void run() m-Q!V+XQp
{ it.Lh'N;T
while(nStartPos < nEndPos && !bStop) UmUw>+A
{ 8[\F*H
Yj3j?.JJk
/'k4NXnW3
try{ [-5%[ty9X
URL url = new URL(sURL); <E/4/ ANN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); s!(O7Ub
httpConnection.setRequestProperty("User-Agent","NetFox"); ?f f!(U
String sProperty = "bytes="+nStartPos+"-"; 4r&DW'
httpConnection.setRequestProperty("RANGE",sProperty); e&sZ]{uD
Utility.log(sProperty); :,Z'/e0&
>-J%=P
_;L%? -2c
InputStream input = httpConnection.getInputStream(); }Q&zYC]d
//logResponseHead(httpConnection); h\| ~Q.kG
^YG'p?r.s
r@b M3V_o
byte[] b = new byte[1024]; mo+zq~,M
int nRead; v|fA)Ww
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;,2i1m0"
{ v;m`d{(i2
nStartPos += fileAccessI.write(b,0,nRead); o81RD#>E)
//if(nThreadID == 1) fy]z<SPhVJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bn:"qN~
} J<hqF4z
:/UO3 c(
ko<u0SjF)u
Utility.log("Thread " + nThreadID + " is over!"); }MQNzaXY^
bDownOver = true; [rk*4b^s
//nPos = fileAccessI.write (b,0,nRead); 8_byS<b8
} p+M#hF5o
catch(Exception e){e.printStackTrace ();} e.-+zkQ8EI
} cjK\(b3
} [PG#5.jwQ
zwJB.4@
(=&z:-52V
//打印回应的头信息 dpG l
public void logResponseHead(HttpURLConnection con) >=Bl/0YH
{ lw+Y_;
for(int i=1;;i++) WXHvUiFf
{ LX f r
String header=con.getHeaderFieldKey(i); U}f"a!
if(header!=null) DBTeV-G9~R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4`E[WE:Q
Utility.log(header+" : "+con.getHeaderField(header)); <"/b 5kc
else j IO2uTM~
break; (<GBhNj=c
} 3DjlX*
} qZQB"Q.*
, e^&,5b
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public void splitterStop() 9;2{=,
{ hA=.${uIO
bStop = true; WO;2=[#O;
} lU?8<X
/Ne;Kdp
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} hk*@<ff
1fgO3N
i ZU1w7Z
/* unX mMSz(
**FileAccess.java pW4O[v`
*//文件访问(定位，写) xWRkg$A
package NetFox; T-MC|>pv
import java.io.*; <Wrn/%tL
S?Y%}
OQnb^fabY
public class FileAccessI implements Serializable{ uuaoBf
?uAq goCl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A4K8DP
RandomAccessFile oSavedFile; y26?>.!
long nPos; gn-@OmIs
o?,c#g
FTgqE@
public FileAccessI() throws IOException $sILCn
{ k'6x_ G
this("",0); ol3].0Vc]
} =w!>/#U
9 AWFjoXl"
zrDcO~w
public FileAccessI(String sName,long nPos) throws IOException q"LE6?hs
{ '@6O3z_{
oSavedFile = new RandomAccessFile(sName,"rw"); S =5br
this.nPos = nPos; 3g79/w
oSavedFile.seek(nPos); m=[3"X3W1V
} \d)HwO
R6cd;| fan
$G<!+^T
public synchronized int write(byte[] b,int nStart,int nLen) } *:H\GL
{ ew+>?a'&L
int n = -1; !8Y$}
try{ V$Zl]f$S
oSavedFile.write(b,nStart,nLen); Kcu*Z
n = nLen; QZwZ4$jkiO
} tkIpeL[d
catch(IOException e) +b sc3
{ pQ,|l$^m
e.printStackTrace (); q<XleC
} fK/|0@B8
>,6%Y3
Zdfruzl&`
return n; byJR6f
} mYx6JU*`
b[U;P=;=
B;64(Vsa8
} 2}uSrA7n]
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4k_y;$4WN
/* % <1&\5f<5
**SiteInfoBean.java cj;k{Moc
*/ $Wn!vbL
package NetFox; @ JfQ}`
'O^<i`8U]
Xmny(j)g
public class SiteInfoBean { d-{1>\-_
"}Oj N\
y9U*E80q{
private String sSiteURL; //Site's URL Ghf/IXq#
private String sFilePath; //Saved File's Path \=2<< iv
private String sFileName; //Saved File's Name bQgtZHO
private int nSplitter; //Count of Splited Downloading File 0`QF:
GHRr+
XXg~eu?
public SiteInfoBean() 4+B&/}FDLo
{//nSplitter的缺省值为5 tk\)]kj
//default value of nSplitter is 5 [R0E4A?M
this("","","",5); =#T3p9
} cGM?r}zJ
YZy%]i=1
2TccIv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WRqpQEY
{ 06]%$-j
sSiteURL= sURL; exxH0^
sFilePath = sPath; F-=Xbyr3@
sFileName = sName; o`M.v[O
this.nSplitter = nSpiltter; 9GgXX9K
e~ %=H 0n
Z,I0<ecaD
} B8`!A
x/L(0z
Yn5a4
public String getSSiteURL() ;; ?OS
{ 'FM_5`&
return sSiteURL; #i 5@G*
} 888"X3.T
ms6dl-_t
PI&@/+
public void setSSiteURL(String value) b^q%p1
{ `^df la
sSiteURL = value; RjxFlKs8
} PTH'-G
-\&b&;_
R*O<(
public String getSFilePath() PUEEfq!%
{ 4Z0Y8y8)
return sFilePath; wCt!.<, .
} 'M35L30
f{j`d&|
}qg.Go
public void setSFilePath(String value) m](q,65 2
{ JN-W`2
sFilePath = value; -ZH6*7!
} HX#$ ^@Q(
,CIsZ1[VS
KkZS6rD\
public String getSFileName() dmYgv^t
{ L=&dJpyfT
return sFileName; yq6:7<
} %\B@!4]
3vj1FbY
LAH.PcjPa
public void setSFileName(String value) Yan,Bt{YJ
{ UIo jXR<
sFileName = value; )Ec /5=A
} E`#/m@:|-
@n;$Edza/
$bF3v=u`
public int getNSplitter() )sLXtV)nm6
{ lpnPd{kE
return nSplitter; BM[jF=0
} o)+Uyl
Q tl!f
'RpX&g
public void setNSplitter(int nCount) y eWB.M~X
{ C zxF
nSplitter = nCount; yDw#V`Y^M
} ;:aCZ8e
} Su]p6B
|W*i'E
O^r,H,3S
/* j[|mC;y.
**Utility.java ~m&q@ms&
*/ /-Y.A<ieN8
package NetFox; g]9A?#GyE
/3o@I5
aA=7x&z@
public class Utility { Gg3< }(
K?6#jT6#
]O0:0Z\
public Utility() @i(;}rx
{ {7^D!lis
p9gX$-!pbG
\*\)zj*r
} v4VP7h6uD)
z K6'wL!!I
//线程睡眠 }TG=ZVi
public static void sleep(int nSecond) =j~Xrytn
{ Z`x*Igf8
try{ :|N(:W>=$Y
Thread.sleep(nSecond); W$`p ,$.n
} HG&rE3@
catch(Exception e) ]L_h3Xz\X
{ oT*qMLdn
e.printStackTrace (); Cn.x:I@r
} hIFfvUl
} '\R/-.
6MmkEU z
//日志 %ql2 XAY
public static void log(String sMsg) ,rWej;CzN
{ O_^;wey0}?
System.err.println(sMsg); -$o4WSd~
} Iz9b5
1(jDBP!8
uolEX+
public static void log(int sMsg) AZfW
{ M{O8iq[
System.err.println(sMsg); m!Fx#
} aS&,$sR
} c. 06Sw*
|`Iispn
yc.9CTxx
/* W5R /
**TestMethod.java 4(TR'_X(
*/ rfYFS96
package NetFox; &nfGRb
L[O.]2
X*e<g=
public class TestMethod { ;0-Y),
e<r}{=1w
T[eb<
public TestMethod() !EB[Lutm
{ ///xx/weblogic60b2_win.exe #9(L/)^
try{ ev9ltl{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8"C[sRhz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Rp_)LA
SiteFileFetch fileFetch = new SiteFileFetch(bean); !+T29QYK8
fileFetch.start(); ~'#,*kA:6
} N_R(i3c6U!
catch(Exception e){e.printStackTrace ();} -p[!CI
aW(Hn[}^
G }U'?p
} ;lc/FV[/
s}bv o
,O`~ D~$
public static void main(String[] args) ^(~%'f
{ M&^Iun
new TestMethod(); 1XJLGMW,
} Wph@LRB]
} mH/9J
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