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)); {Hktu|
} a7QlU=\
for(int i=0;i<nEndPos.length-1;i++) eyI-s9#t
{ &xPOp$Sx~
nEndPos = nStartPos[i+1]; `XQx$I
} A5&>!y
nEndPos[nEndPos.length-1] = nFileLength; <) >gg!
} |[lxV&SD.
} KUl Zk^a
r< d?
$ioaunQKP
//启动子线程 TMnT#ypf<5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; umq$4}T'$
for(int i=0;i<nStartPos.length;i++) &4ug3
{ !?tu! M<1?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $i1>?pb3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Hl4vLx@
nStartPos,nEndPos,i); &F@tmM~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (hD X4;4
fileSplitterFetch.start(); e#76h;
} -jcrXskb&N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "6|'&6&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7v4-hfN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Jgi{7J
nEndPos = " + nFileLength); ex;Yn{4
// fileSplitterFetch[nPos.length-1].start(); s+OvS9et_
NKIkd
'ugR!o1
//等待子线程结束 BP7<^`i&
//int count = 0; yKX:Z4I/
//是否结束while循环 \kua9bK
boolean breakWhile = false; $S"zxEJJ Y
ijR-?nrR
ss|6_H =
while(!bStop) VC_3ll]vr
{ ;&7qw69k
write_nPos(); .{-iq(3
Utility.sleep(500); +#i,87
breakWhile = true; JsAb q
YQfZiz}Fv
LiHXWi{s
for(int i=0;i<nStartPos.length;i++) r`mzsO-'
{ +ik N) D
if(!fileSplitterFetch.bDownOver) ]8q%bsl+
{ ]ci|$@V
breakWhile = false; (<5'ceF)X
break; B8BY3~}]
} ]%ZjD
} dxae2 tV
if(breakWhile) )nbyV a
break; Z;dwn~Tw
rsq'60
T^f&58{ 7
//count++; ] BP^.N=
//if(count>4) 2yVGEp^
// siteStop(); |eVTxeq
} lN]X2 4t
.[eSKtbc)
FHnHhB[
System.err.println("文件下载结束！"); SbQ{ >
} ni02N3R
catch(Exception e){e.printStackTrace ();} lzQ&)7`
} ,rvZW}=
MZhJ,km)
*Kp ^al
//获得文件长度 <T=o]M$
public long getFileSize() Di5Op(S((
{ B=nx8s
int nFileLength = -1; % 'L=
try{ KlSY^(kHR
URL url = new URL(siteInfoBean.getSSiteURL()); s3fGX|;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @%5F^Vbd
httpConnection.setRequestProperty("User-Agent","NetFox"); @)M.u3{\
)9;kzp/
X~/9Vd g
int responseCode=httpConnection.getResponseCode(); YRT}fd>R&
if(responseCode>=400) sjVl/t`l
{ 07HX5 Hd
processErrorCode(responseCode); =,}!Ns{k
return -2; //-2 represent access is error 2[bR6 T89
} hF{mm(qyv
Q=9VuTE
EzY scX.[
String sHeader; fh5^Gd~
s*A|9uf5
jak|LOp
for(int i=1;;i++) 0$dY;,Q.
{ 'rcsK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |Y,X=Ed
//Utility.log(in.readLine()); XQ?)
sHeader=httpConnection.getHeaderFieldKey(i); a6K$omu
if(sHeader!=null) 4QN6BZJ5
{ v|hKf6
if(sHeader.equals("Content-Length")) Bg 8t'dw?K
{ s t3]Yy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M3xi 0/.
break; )-6[Bw
} wE=8jl*
} NIcNL(]
else v(WL 3[y;
break; u>-uRz<)t
} rBL_]\$7}
} hrtN.4p[
catch(IOException e){e.printStackTrace ();} I[YfF
catch(Exception e){e.printStackTrace ();} )-7(Hv1
?(XX
UW~tS
Utility.log(nFileLength); (j\UoKLRt
TTjjyZ@
)}k`X<~k
return nFileLength; >?Y3WPB<F
} r;s3(@[,@
~o\]K
WW Kr & )
//保存下载信息（文件指针位置） "Mu$3w
private void write_nPos() .cnw?EI
{ jq]\oY8y
try{ ]{l O
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;Q%19f3,6
output.writeInt(nStartPos.length); ckkM)|kK
for(int i=0;i<nStartPos.length;i++) pRfHbPV?
{ =dJEcC_J
// output.writeLong(nPos); Mdq'> <ajL
output.writeLong(fileSplitterFetch.nStartPos); N_~Wu
output.writeLong(fileSplitterFetch.nEndPos); gj(l&F *@
} 8*X L19N
output.close(); d(cYtM,P
} )fcpE,g'
catch(IOException e){e.printStackTrace ();} [;\< 2=H
catch(Exception e){e.printStackTrace ();} r4qV}-E
} ^*T{-U'
B=qRZA!DQ?
AFnlt
//读取保存的下载信息（文件指针位置） REe%>|
private void read_nPos() [}B{e=`!
{ +vY`?k`
try{ jYssz4)tp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); QrRCsy70
int nCount = input.readInt(); (inwKRH
nStartPos = new long[nCount]; v6(l#,
nEndPos = new long[nCount]; gl4 f9Ff
for(int i=0;i<nStartPos.length;i++) )e$-B]>7z
{ ~<Qxw>S#
nStartPos = input.readLong(); EwJn1Mvq
nEndPos = input.readLong(); qQ\hUii
} }z%/6`7)|
input.close(); TEy.zzt
} k-p7Y@`+a
catch(IOException e){e.printStackTrace ();} ]0nC;|]@Lx
catch(Exception e){e.printStackTrace ();} H5rNLfw '
} +R jD\6bJb
h3ZL0Fi*
G?X,Y\Lp
private void processErrorCode(int nErrorCode) [}Yci:P_ +
{ j;c^pLUP
System.err.println("Error Code : " + nErrorCode); `Y9}5p
} Y@xeyMzE
)qQg n]
1+[|pXT}
//停止文件下载 3B]+]e~
public void siteStop() BwA~*5TFu
{ <i@jD
bStop = true; \%Ih 6
for(int i=0;i<nStartPos.length;i++) [IX!3I[J]
fileSplitterFetch.splitterStop(); {ca^yHgGy
o".O#^3H%
9S`b7U=P
} x6mq['_
} |UiykQ
//负责部分文件的抓取 z+`)|c4-
**FileSplitterFetch.java :BiR6>1:
*/ ymJw{&^am
package NetFox; B~?Q. <M
U0=zuRr n
246!\zf
import java.io.*; mLdyt-1
import java.net.*; "PP0PL^5F
hndRgCo
bGLp0\0[
public class FileSplitterFetch extends Thread { >.sN?5}y
?v*7!2;
{dH<Un(4Z
String sURL; //File URL Z4tq&^ :c=
long nStartPos; //File Snippet Start Position Q/SC7R&"t
long nEndPos; //File Snippet End Position 6R,b 8
int nThreadID; //Thread's ID YuuG:Kk
boolean bDownOver = false; //Downing is over "+C\f)
boolean bStop = false; //Stop identical y^fU_L?p
FileAccessI fileAccessI = null; //File Access interface *y$ry]
c7N9X 3A
SQ.Wj?W)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Dy'l]vN$
{ qt;Tfuo
this.sURL = sURL; J#5o
this.nStartPos = nStart; s:.XF|e{
this.nEndPos = nEnd; |1 6v4 R
nThreadID = id; ;'+cT.cmH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 z-E4-\a
} ^vz@d+\Kd
jCa;g{#@
,3[<C)'[
public void run() 2fA9L _:0
{ `)P_X4e]`
while(nStartPos < nEndPos && !bStop) TniKH(w/
{ S :|*wB
U6 R4UK
*XR~fs?/*W
try{ y`dzo`f
URL url = new URL(sURL); (NlEb'~+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [Y~s
httpConnection.setRequestProperty("User-Agent","NetFox"); a-hGpYJJG
String sProperty = "bytes="+nStartPos+"-"; H(m+rk
httpConnection.setRequestProperty("RANGE",sProperty); BGjTa.&
Utility.log(sProperty); =l9#/G#R
!Z)^c&
{NDe9V5
InputStream input = httpConnection.getInputStream(); .k(_j.v
//logResponseHead(httpConnection); \mGM#E
8hA=$}y&x
pdu
byte[] b = new byte[1024]; k,(_R=
int nRead; |g!# \
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I-hhHm<@
{ g>CQO,s;w
nStartPos += fileAccessI.write(b,0,nRead); m$g^On
//if(nThreadID == 1) (o\~2e:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (iP,YKG1?
} 9mm(?O~'p
SsZzYj.d
iHB)wC`u
Utility.log("Thread " + nThreadID + " is over!"); bc-)y3gHU
bDownOver = true; {D#`+uw
//nPos = fileAccessI.write (b,0,nRead); ARo5 Ss{
} z`SkKn0f Y
catch(Exception e){e.printStackTrace ();} 0rUf'S ?K
} 7L"/4w
} 2T9Z{v
`Mg "!n`
4N&}hOM'S
//打印回应的头信息 1doqznO
public void logResponseHead(HttpURLConnection con) ks$G6WC
{ (0S7
for(int i=1;;i++) sn%fE
{ nc)`ISI
String header=con.getHeaderFieldKey(i); 8b!_b2Za
if(header!=null) %#~Wk|8} Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1,,-R*x
Utility.log(header+" : "+con.getHeaderField(header)); P9vROzXK
else Ok!{2$P8U9
break; &@+;]t
} )3
} @T"385>
bv"S(
DP_\%(A
public void splitterStop() jYv !}
{ vCM'nkXY
bStop = true; ! ZEKvW
} /_\4(vvf
/Y:Zqk3
HFOp4
} ^Tx1y[hw$
Z/x~:u_
bkTj Q
/* ojri~erJE?
**FileAccess.java lRb)Tz6SE
*//文件访问(定位，写) |a+8-@-Tj
package NetFox; 26A#X
import java.io.*; ZUycJ-[
{YFru6$
al/~
public class FileAccessI implements Serializable{ Alz#zBGb
=[kv@p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x& S>Mr
RandomAccessFile oSavedFile; {$^|^n5j
long nPos; v]v f(]""
"'Ik{wGc
EZ4qhda
public FileAccessI() throws IOException _PF><ODX2
{ #~b9H05D
this("",0); `m5iZxhw
} V.J%4&^X
ZfU_4Pl->
@u^Ib33
public FileAccessI(String sName,long nPos) throws IOException UWHC]V?
{ Hg4Ut/0
oSavedFile = new RandomAccessFile(sName,"rw"); @)B_e*6>'
this.nPos = nPos; "<n{/x(
oSavedFile.seek(nPos); DWAU8>c+
} @,]v'l!u
<IYt*vlm
4.8,&{w<m
public synchronized int write(byte[] b,int nStart,int nLen) ; OsN^
{ Hi Yx(hY
int n = -1; %}/)_RzQ
try{ 4J s>yP
oSavedFile.write(b,nStart,nLen); r"+ WUU
n = nLen; dn Xc- <
} +]#>6/2q
catch(IOException e) V47Fp
{ @azS)4L
e.printStackTrace (); WKG=d]5
} -}%zus5
ep5aBrN]"
L>B0%TP^
return n; GCrN:+E0FJ
} N`M5`=.
xK/`XY
wgrYZ^]
} rO NLbrj
Hl#o& *Ui"
3]'3{@{}H
/* #xmUND`@
**SiteInfoBean.java *jYwcW"R{z
*/ -&c@c@dC
package NetFox; I ?1E}bv
o}T]f(>}
IAfYlS#<yD
public class SiteInfoBean { , Le_PJY)
n}l Z
HBt?cA '
private String sSiteURL; //Site's URL &5B+8>
private String sFilePath; //Saved File's Path Z"n]y4h
private String sFileName; //Saved File's Name <C&UDj
private int nSplitter; //Count of Splited Downloading File nJ,56}
Ac|`5'/Tx
o` e~1
public SiteInfoBean() }Eav@3h6
{//nSplitter的缺省值为5 @t_<oOI2
//default value of nSplitter is 5 kz#DBh!&
this("","","",5); !n7?w@2a'
} 5+U~ZW0|+
I0Vm^\8
:7R\"@V4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E(TY%wO
{ b`^$2RM&
sSiteURL= sURL; +G?3j,a\
sFilePath = sPath; )T>a|.
sFileName = sName; 3}"VUS0wh
this.nSplitter = nSpiltter; z >pq<}R6
U9JqZ!
m_pK'jc
} @FQ@*XD
;>PV]0bOm>
zIQ\_>
public String getSSiteURL() iB\d`NUf
{ ]Y3ALQr!
return sSiteURL; zRe0z2
} e@6}?q;
&P\T{d2"
9Vp$A$7M
public void setSSiteURL(String value) }>grGr%oR
{ pD){K
sSiteURL = value; dZZHk
} &B))3WFy
UPbG_ #"wZ
2+|[e_
public String getSFilePath() 6ds&n#n
{ V482V#BP
return sFilePath; ;$W|FpR2
} +ux,cx.U"
(j2]:BVu
z8gp<5=
public void setSFilePath(String value) n.XT-X^
{ poM VB{U
sFilePath = value; _N<8!(|w
} _Wgg=A"G
`/0FXb 8h
tf>?;
public String getSFileName() C3D1rS/I
{ ~V(WD;Mk
return sFileName; k&9 b&-=fk
} P*\.dAi
}APf^Ry
f9;M"Pd
public void setSFileName(String value) A6-JV8^
{ `>K;S!z
sFileName = value; T;I a;<mfE
} CnJO]0Op3
q'PA2a:
w@hm>6j
public int getNSplitter() La9dFe-uu{
{ H=B8'N
return nSplitter; X.g1 312~
} 0'a.Ypf
{AJspLcG
L>cTI2NB.
public void setNSplitter(int nCount) x H\5T!
{ !)ee{CwNc
nSplitter = nCount; "MlY G6
} ptX;-'j(
} >i=mw5`D]
|',MgA
yY8q{\G
/* ~Q5L)}8N
**Utility.java ao Y"uT+
*/ SeKU?\
package NetFox; !5pnl0DK*
O"^KX5
gR%fv
public class Utility { =p$1v{L8
-fYgTst2
I9H+$Wjd
public Utility() =! /S |
{ 9FK%"s`
xoPpu
%b0..Zz
} 98G>I(Cw%
HjLY\.S
//线程睡眠 L= hPu#&/
public static void sleep(int nSecond) @MTm8E6au
{ <!R~G-D#_T
try{ 0zetOlFbO
Thread.sleep(nSecond); nCJ)=P.d
} G,%R`Xns
catch(Exception e) G|v{[>tr
{ rD fUTfv|Q
e.printStackTrace (); ~gmj/PQ0
} :,% vAI
} <t&0[l
y?;&(Tcbt8
//日志 eA4@)6WP(
public static void log(String sMsg) an=8['X
{ ~[t%g9
System.err.println(sMsg); b v~"_)C
} P;{f+I|`
)mS Aog<
gm\P`~+o
public static void log(int sMsg) >`SIB; &>j
{ "I}3*s9Q-
System.err.println(sMsg); {+!m]-s
} *CMe:a
} ~+7q.XL$$K
.9PPWY;H
RdRF~~R%
/* q0&g.=;
**TestMethod.java +g>)Bur
*/ w/#k.YE
package NetFox; LW 8LD|@
f9?\Q'v8
jIaAx_
public class TestMethod { Z~CL|=
s,)Z8H
+QGZ2_vW
public TestMethod() 2c LIz@
{ ///xx/weblogic60b2_win.exe R#DnV[!\
try{ U@Y0z.Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ' cR||VX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >$j?2,Za(V
SiteFileFetch fileFetch = new SiteFileFetch(bean); .Ce30VE-
fileFetch.start(); K1Snag
} |>Qj]
catch(Exception e){e.printStackTrace ();} 1/:WA:]1,
ozy~`$;c
&A)AV<=>T
} fucG 9B
4"U/T1&
O4dJ> O
public static void main(String[] args) =W$ f+
{ f.-b.nNf
new TestMethod(); FCgr
} 7j| ^ZuI+
} * G!C 'w\$
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