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)); =fve/_Q~
} HA`@7I
for(int i=0;i<nEndPos.length-1;i++) lR[qqFR
{ 'u_t<F]b
nEndPos = nStartPos[i+1]; .k9{Yv0
} AvSM^
nEndPos[nEndPos.length-1] = nFileLength; /D^"X 4!"
} gk+h8 LZ
} \X&H;xnC5
dBe`p5Z
T G{k0cdOT
//启动子线程 D]W$?(=4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N:tY":Hi
for(int i=0;i<nStartPos.length;i++) IlE_@gS8
{ z$GoaS(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S_v'hlrrT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?(m jx
nStartPos,nEndPos,i); C,NxE5?h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RE=+Dz{
fileSplitterFetch.start(); Sh,&{z!
} .G(llA}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YJ/zU52JK~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]M[#.EX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lGk{LO)
nEndPos = " + nFileLength); ,4,V4 N
// fileSplitterFetch[nPos.length-1].start(); +sx 8t
xIGfM>uq
jfx8EbQ
//等待子线程结束 M$d%p6Cv
//int count = 0; :%AL\n
//是否结束while循环 4)4+M
boolean breakWhile = false; b}wC|\s
e)IpPTj#
#E+gXan
while(!bStop) V0(o~w/W%!
{ Gqcz<=/
write_nPos(); [kzd(u
Utility.sleep(500); 2Nm>5l
breakWhile = true; _#s=h_ FD
l|+BC
F3lw@b3])
for(int i=0;i<nStartPos.length;i++) Z,;cCxE
{ ai^4'{#zi
if(!fileSplitterFetch.bDownOver) u!U"N*Y"
{ =!UR=Hq
breakWhile = false; qXW})(
break; Dbaf0
} hv$m4,0WB
} mNAY%Wn6k
if(breakWhile) xwZ8D<e-,
break; ]:$ O{y
lhYn5d)DV
xf>z@)e
//count++; LsGiu9~S
//if(count>4) %T=A{<[`
// siteStop(); 3PUAH
} @l(vYJ:f
NOK/<_/
PS" .R_"
System.err.println("文件下载结束！"); B 2.q3T
} wVA|!>v
catch(Exception e){e.printStackTrace ();} b~C$R[S
} YIp-Y}6
OAZ#|U
RQvVR
//获得文件长度 8g7,2f/ }
public long getFileSize() =`C4qC_
{ 4oXbPr>
int nFileLength = -1; w[Ep*-yeI
try{ nxap\Lf
URL url = new URL(siteInfoBean.getSSiteURL()); ? {F{;r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q1hMmMi
httpConnection.setRequestProperty("User-Agent","NetFox"); >1irSUj"~
dow^*{fqZ
VzRx%j/i
int responseCode=httpConnection.getResponseCode(); QI!i
if(responseCode>=400) *Wb=WM-.
{ 6j8<Q 2
processErrorCode(responseCode); ;+I4&VieK
return -2; //-2 represent access is error I/COqU7~
} xQlT%X;'
I(n* _bFq
L$Z(+6m5
String sHeader; YirC*
f!-Sz/c#
9g?xlue#?
for(int i=1;;i++) .1*DR]^`
{ 5>ST"l_ca
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); WY)^1Gb$ux
//Utility.log(in.readLine()); JAn1{<Ky
sHeader=httpConnection.getHeaderFieldKey(i); C'9 1d7E
if(sHeader!=null) `:-J+<`
{ eZO9GMO
if(sHeader.equals("Content-Length")) U?U(;nSR\A
{ udTxNl!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K ar~I
break; u5gZxO1J5
} yCM{M
} U=o Z.\
else o*7yax
break; bBE^^9G=Z
} `5"/dC
} T=? bdIl
catch(IOException e){e.printStackTrace ();} Tj,Nmb>Q7'
catch(Exception e){e.printStackTrace ();} 2uo8jF.h
R/N<0!HZ
( ji_o^
Utility.log(nFileLength); WX*cICb5
\FI^Vk
-iQsi4
return nFileLength; lgG8!Ja
} -g2{681`r
&8Wlps`
<jL#>L%%
//保存下载信息（文件指针位置） f sX;Nj]
private void write_nPos() Pw#2<>
{ Z)v)\l9d
try{ \2eFpy(
output = new DataOutputStream(new FileOutputStream(tmpFile)); /2:Q6J
output.writeInt(nStartPos.length); HU3Vv<lz
for(int i=0;i<nStartPos.length;i++) J:W'cH$cR
{ lWl-@*'
// output.writeLong(nPos); 'Fzuc^G(d
output.writeLong(fileSplitterFetch.nStartPos); Alh?0Fk3)
output.writeLong(fileSplitterFetch.nEndPos); wG6FS
} y%g`FC
output.close(); 9t\ [N/
} :,=Fx</H
catch(IOException e){e.printStackTrace ();} e>(Wvb&4
catch(Exception e){e.printStackTrace ();} 1(F'~i|5
} bn|DRy
)ldUayJ
<VgE39 [
//读取保存的下载信息（文件指针位置） c( 8W8R
private void read_nPos() cl#OvQ
{ {N@Y<=+:
try{ I]UA0[8X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o[H\{a>
int nCount = input.readInt(); X!?wL0n
nStartPos = new long[nCount]; oYGUjI
nEndPos = new long[nCount]; 92NC]_jw
for(int i=0;i<nStartPos.length;i++) kt5YgW
{ >T$7{ ~
nStartPos = input.readLong(); vzQyE0T/
nEndPos = input.readLong(); )m>6hk
} %!W6<ioW
input.close(); JiUT\y
} 4I+.^7d
catch(IOException e){e.printStackTrace ();} )<tzm'Rc
catch(Exception e){e.printStackTrace ();} %!#rrt,F
} u<J2p?`\&`
U0ns3LirP
q8tP29
private void processErrorCode(int nErrorCode) la1D2 lM
{ [_h.1oZp~
System.err.println("Error Code : " + nErrorCode); U5-zB)V
} Udg& eEF
8p3ZF@c~t
'XG:1Bpm
//停止文件下载 kz3?j<
public void siteStop() ,OFq'}q
{ ,$ho2R),Fn
bStop = true; _-YL!oP
for(int i=0;i<nStartPos.length;i++) @)S sKk|
fileSplitterFetch.splitterStop(); nA|gQibA
A;b=E[iv
Uv#>d}P
} ~k"eEV p
} gizmJ:<
//负责部分文件的抓取 ze-TBh/
**FileSplitterFetch.java jcT{ugpq
*/ V7Vbl?*n
package NetFox; n$}R/*
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|8&\N
import java.io.*; !4DGP28
import java.net.*; p3>Q<
,'/HcF?yf
(xjoRbU*
public class FileSplitterFetch extends Thread { .rD#1)O
9y d-&yDG
^!-E`<jW8
String sURL; //File URL _#y(w%
long nStartPos; //File Snippet Start Position ^59YfC<f
long nEndPos; //File Snippet End Position (25^r
int nThreadID; //Thread's ID KqG/a
boolean bDownOver = false; //Downing is over zyQ,unu
boolean bStop = false; //Stop identical c,{&
FileAccessI fileAccessI = null; //File Access interface fF9;lWt
P22y5z~
)l 4>=y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dvrvpDoE.
{ Q8M:7#ySji
this.sURL = sURL; 0k.#
this.nStartPos = nStart; ]ouUv7\
this.nEndPos = nEnd; p: Q%Lg_I
nThreadID = id; 6cgpg+-a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =F!",a~
} 2:6Y83
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nEZ-h7lzl(
public void run() nf+"vr}1
{ pRDON)$
while(nStartPos < nEndPos && !bStop) X,C/x)
{ f6aT[Nw<
I1}{~@
Fc{6*wtO
try{ hD9'`SQ
URL url = new URL(sURL); O. .@<.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VK@i#/jm
httpConnection.setRequestProperty("User-Agent","NetFox"); C6;](rN)N
String sProperty = "bytes="+nStartPos+"-"; ]Pg?(lr6)
httpConnection.setRequestProperty("RANGE",sProperty); ngH~4HyT
Utility.log(sProperty); y1jGf83
Xj@
K:lT-*+S
InputStream input = httpConnection.getInputStream(); dBD4ogo1
//logResponseHead(httpConnection); /9vMGef@
b\e)PUm#u@
T\$^>@
byte[] b = new byte[1024]; j}x O34
int nRead; `QyALcO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Kt&$Si
{ VlQwVe
nStartPos += fileAccessI.write(b,0,nRead); z6>ZV6(d2^
//if(nThreadID == 1) 5yN8%_)T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H* JC`:
} (Q p]0
j/`qd(=B
xYkgNXGs5
Utility.log("Thread " + nThreadID + " is over!"); />j+7ts
bDownOver = true; 576-X_a,
//nPos = fileAccessI.write (b,0,nRead); Z?j='/u>@
} kBQenMm
catch(Exception e){e.printStackTrace ();} $8yGY
} "GC]E8&>H
} :\= NH0M
$}"Wta
QT&Ws+@ s{
//打印回应的头信息 Rb>RjHo S
public void logResponseHead(HttpURLConnection con) &DhA$o"'
{ 1NHoIX
for(int i=1;;i++) {O,M}0Eg
{ )LMuxj
String header=con.getHeaderFieldKey(i); YM/3VD
if(header!=null) 4a50w:Jy]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W%<]_u[-}
Utility.log(header+" : "+con.getHeaderField(header)); 3 BhA.o
else [^BUhm3a
break; 2bG4,M
} b0x0CMf
} +jZg%$Q!#
5z mHb
!U~#H_
public void splitterStop() &)}:Y!qiu
{ Vwg|?sG_
bStop = true; cb&In<q
} )0V]G{QN
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J9t?]9.,:
} , p=8tf#
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*H<g9<Dn
/* QN8Hz/}\
**FileAccess.java V~"d`j
*//文件访问(定位，写) f9=X7"dzP
package NetFox; hg/&[/eodm
import java.io.*; 3Ty{8oUs^
l'8TA~
1gK3=Ys
public class FileAccessI implements Serializable{ eZkz 1j~
YHtI%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lXy@Cf
RandomAccessFile oSavedFile; #/=yz<B
long nPos; Nmq5Tv
p<['FRf"
8=AKOOU7>
public FileAccessI() throws IOException 3;gtuqwD$
{ K1nwv"
this("",0); S.>9tV2Ca
} ^K[tO54
=qQQ^`^F'~
2~'quA
public FileAccessI(String sName,long nPos) throws IOException 7ij=%if2@k
{ 3!UP>,!
oSavedFile = new RandomAccessFile(sName,"rw"); nQVBHL>
this.nPos = nPos; DQQjx>CK
oSavedFile.seek(nPos); ;$;/#8`>
} }#^F'%zf
j"=jK^
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public synchronized int write(byte[] b,int nStart,int nLen) E#]%e^
{ %/C[\wp81
int n = -1; )$g/PQ
try{ -*r';Mz;
oSavedFile.write(b,nStart,nLen); )j*qGsOg
n = nLen; |th )Q
} w;_=$L'H&G
catch(IOException e) 1nmWL0
{ [RuY'
e.printStackTrace (); -6>rR{z
} (#`o>G(
$sJfxh r
J n/=v\K@
return n; HPB1d!^
} 5}ah%
ocUu
#YdU,y=B
} N"y4#W(Z@
u>Hx#R<*%
IgJC>;]u
/* Qg=~n:j
**SiteInfoBean.java G=e[TR)i
*/ *ni|I@8
package NetFox; `!N?#N:b)
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cB^lSmu5
public class SiteInfoBean { pDQ,v"
,88}5)b[
u)-l+U.
private String sSiteURL; //Site's URL j*}xe'#
private String sFilePath; //Saved File's Path $-73}[UA 4
private String sFileName; //Saved File's Name YR2/`9s\QJ
private int nSplitter; //Count of Splited Downloading File TuL( /
C.O-iBVe#
u#<]>EtbB
public SiteInfoBean() 3(kZfH~
{//nSplitter的缺省值为5 SbY i|V,H
//default value of nSplitter is 5 cxV3Vrx@A
this("","","",5); [PT}!X7h
} wvD|c%
9L,T@#7
%Ok.XBS)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %BJ V$tO
{ hE${eJQ| U
sSiteURL= sURL; zQ~nS
sFilePath = sPath; nM#\4Q[}Jh
sFileName = sName; 2\n6XAQ*
this.nSplitter = nSpiltter; R4?/7
* -)aGL
~p&sd)
} x\WKsc
P$Nwf,d2u
NR" Xn7G
public String getSSiteURL() X(~NpLR
{ [||$1u\%
return sSiteURL; Ad(j&P
} @C#lA2(I4
o 0B`~7(
eG.?s;J0
public void setSSiteURL(String value) YvonZ
{ ;-59#S&?tB
sSiteURL = value; K=V)"v5o3
} GKX#-zsh79
czafBO6
,xGkE7=5
public String getSFilePath() o4xZaF4+
{ \O[Cae:^?
return sFilePath; :EZTJu
} 3/iGSG`
8D-g%Aj-
."${.BPn~
public void setSFilePath(String value) Tw$lakw
{ {=TD^>?
sFilePath = value; YkTEAI|i
} Jf2
"!2Fy-Y
qvCl mZ
public String getSFileName() uCx\Bt"VI
{ S>nM&758
return sFileName; OX!9T.j
} (V*ggii@
wJip{
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public void setSFileName(String value) }{s<!b
{ 99vm7"5hQ
sFileName = value; ]w({5i
} |iJ37QIM
%c):^;6p
q*8^938
public int getNSplitter() lf&g *%?1
{ M(xd:Fa?
return nSplitter; kP3'BBd,
} Iq MXd K|
p3&w/K{L6w
1s .Ose
public void setNSplitter(int nCount) npZ=x-ce
{ jU/0a=h9
nSplitter = nCount; 0@vSl%I+
} pPUKx=d
} &Nl:
hT]\*},
wS9EC}s:Q
/* '7 SFa]tH
**Utility.java Cwl#(;@
*/ U:"E:Bxz;m
package NetFox; *%bQp
\hoYQK j
$ac VJI?
public class Utility { T_i]y4dg
ED[`Y.;
d#'aTmu!
public Utility() MIGcV9hf
{ v!JQ;OX
=J:6p-\*
W6:ei.d+NS
} O0[.*xG
bxLeQWr6
//线程睡眠 [oqb@J2
public static void sleep(int nSecond) ))JbROBU,
{ c0h:Vqk-
try{ PZ06 _
Thread.sleep(nSecond); /Sy:/BQ
} .sCi9d WR
catch(Exception e) Pv,Q*gh`
{ +X#JCLD
e.printStackTrace (); pu3ly&T#a_
} #[=%+*Q
} VjsQy>5m
a$-:F$z
//日志 AM?62
public static void log(String sMsg) t|XQFb@}
{ A"ApWJ3
System.err.println(sMsg); " b?1Yc-
} 6'E3Q=}d
P4H%pm{-
H& L
public static void log(int sMsg) vOMmsU F
{ ]m&cVy&
System.err.println(sMsg); 0H;,~ WY
} n_ORD@$]
} dB`3"aSN7
uj 6dP
SI-G7e)3;>
/* VEUdw(-?s
**TestMethod.java B}Lz#'5_
*/ 3JnBKh\n
package NetFox; Y5rR
X"'c2gaa_
kWkAfzf4a
public class TestMethod { pyvZ[R9
+=Xgi$
[ vWcQ6m
public TestMethod() _hK83s4
{ ///xx/weblogic60b2_win.exe TttD}`\.
try{ 8+gti*C?\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qhNY<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d`M]>EDXp
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]gxt+'iAFS
fileFetch.start(); b ] W^_
} }\p>h
catch(Exception e){e.printStackTrace ();} c(:qid
)qi/>GR,
Ai99:J2k
} ,VtrQb)Yf
f(Hh(
T!GX^nn*O
public static void main(String[] args) .Fdqn?c|+
{ D'dE!CAUs
new TestMethod(); $M `%A
} hX?rIx
} |(mr&7O
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