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)); U.} =j'Us+
} 5W'|qmJ
for(int i=0;i<nEndPos.length-1;i++) XE%6c3s
{ GB Un" _J
nEndPos = nStartPos[i+1]; l_IX+4(@b|
} EB<tX`Wp
nEndPos[nEndPos.length-1] = nFileLength; 5 :>
} D)$k{v#~
} !H.lVA
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//启动子线程 #Ih(2T i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ozwqK oE
for(int i=0;i<nStartPos.length;i++) /'+JP4mK
{ +@v} (
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E&v-(0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A|nU _*
nStartPos,nEndPos,i); $ $+z^%'_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RtEkd_2
fileSplitterFetch.start(); (~o+pp!
} v65r@)\`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `N,Jiw;bw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2l%iXK[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6-}9m7#Y
nEndPos = " + nFileLength); n-WvIy
// fileSplitterFetch[nPos.length-1].start(); .6(i5K
:/Zh[Q@EG
qA[}\8}h
//等待子线程结束 Jrl xa3 [
//int count = 0; 6?~pjMV
//是否结束while循环 B-zt(HG
boolean breakWhile = false; +fmZ&9hFNJ
9 f+7vCA
ThB2U(Wf
while(!bStop) 5Ep
{ 3g?T,|2K
write_nPos(); *()#*0
Utility.sleep(500); _en8hi@Z
breakWhile = true; OMNdvrE*=O
:oQaN[3>_
AO]e^Q
for(int i=0;i<nStartPos.length;i++) Su^Z{ Ud`
{ CQ ?|=cN
if(!fileSplitterFetch.bDownOver) z""(M4
{ eSf:[^
breakWhile = false; -ybupUJcbv
break; n9ih^H
} 6<R U~Gh
} iBt5aUt
if(breakWhile) l0V@19Ec
break; &v88xs
P nDZi
z'*>Tk8h
//count++; ;!b(b%
//if(count>4) _\zfXHp
// siteStop(); TY}?>t+
} u^$ CR
G})mw
*{bqHMd4L
System.err.println("文件下载结束！"); "`wq:$R
} jTJ[2WaS
catch(Exception e){e.printStackTrace ();} IG\\RYr
} A_+WY|#M
?T"crX
=v}.sJ V?
//获得文件长度 Gy5W;,$q
public long getFileSize() '_%Jw:4k
{ fr7/%{s
int nFileLength = -1; u[u=:Y+
try{ X,b}d#\
URL url = new URL(siteInfoBean.getSSiteURL()); >=(e}~5y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &+sN=J.x
httpConnection.setRequestProperty("User-Agent","NetFox"); jdzV&
uo^>95lkv
g|oPRC$I'
int responseCode=httpConnection.getResponseCode(); C%&7,F7
if(responseCode>=400) L r,$98Dy
{ POf \l
processErrorCode(responseCode); @NF8?>!
return -2; //-2 represent access is error b]~M$y60q
} 7g$t$cZby,
w;:,W@K
U8dwb
String sHeader; j8b:+io
N=kACEo
z)0Fk
for(int i=1;;i++) 8CL05:&
{ z t1Q_;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Kr<O7t0X
//Utility.log(in.readLine()); X*sF-T$.
sHeader=httpConnection.getHeaderFieldKey(i); LTF%bAQ,
if(sHeader!=null) _VJb i,V
{ _MR2,mC
if(sHeader.equals("Content-Length")) =F`h2A;a
{ P_;oSN|>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &sW/r::,
break; IRQ(/:]
} ;RrfE8mGj
} H/b(dbs
else ecb[m2z
break; 1)%o:Xy o
} k;)L-ge9
} i|<*EXB"
catch(IOException e){e.printStackTrace ();} )z aMycW
catch(Exception e){e.printStackTrace ();} DN!EsQ6
GV9"8MZ6
k";;Snk
Utility.log(nFileLength); {kC]x2 U
$R^"~|m3M
h'bxgIl'`
return nFileLength; .RT5sj\d
} @=9QV3D
:{sX8U%
d+bTRnL
//保存下载信息（文件指针位置） /A>/]2(
private void write_nPos() i,~{{XS<
{ PBUc9/
try{ xGA%/dy,;
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?O_;{(F_
output.writeInt(nStartPos.length); ;c'jBi5W
for(int i=0;i<nStartPos.length;i++) | o?@Eh
{ Oz+>I^Q
// output.writeLong(nPos); |OC6yN *P)
output.writeLong(fileSplitterFetch.nStartPos); IE|$>q0Z
output.writeLong(fileSplitterFetch.nEndPos); }NUP[%
} rR7}SEa
output.close(); OaEOk57%de
} EZ$m4:{e
catch(IOException e){e.printStackTrace ();} +>s[w{Svy
catch(Exception e){e.printStackTrace ();} E)`+1j
} rc$G0O
9@!`,Co
ub-ZrC'
//读取保存的下载信息（文件指针位置） z-()7WY
private void read_nPos() N~a?0x
{ l9-(ofY*J
try{ i |C'_gw`n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2cww7z/B
int nCount = input.readInt(); fHM<6i<C
nStartPos = new long[nCount]; RhYf+?2
nEndPos = new long[nCount]; ^Zg"`&E
for(int i=0;i<nStartPos.length;i++) N5g!,3
{ or0f%wAF
nStartPos = input.readLong(); iLgWzA
nEndPos = input.readLong(); ]A'E61t<n
} Xbfn@7m
input.close(); H1N%uk=kV
} `,xKK+~YG-
catch(IOException e){e.printStackTrace ();} Z5+qb
catch(Exception e){e.printStackTrace ();} :]:q=1;c
} Lg-Sxz}P!
2jA-y!(e
kvKbl;<&#
private void processErrorCode(int nErrorCode) |o6B:NH,rg
{ YX-G>.Pc
System.err.println("Error Code : " + nErrorCode); Td?a=yu:J
} RHeql*`
?oP<sGp
`O*+%/(
//停止文件下载 H htAD Y
public void siteStop() 81`-xVd
{ tK0?9M.)
bStop = true; ~Sh8. ++}
for(int i=0;i<nStartPos.length;i++) R{u/r%
fileSplitterFetch.splitterStop(); %i$]S`A}
r65/O5F
~:v" TuuK
} $fL2w^ @
} UhXZ^k3
//负责部分文件的抓取 $SA8$!:
**FileSplitterFetch.java ^*`hJ48u
*/ d%8hWlffz
package NetFox; [O7:<co
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iW9G0Ay
import java.io.*; oYI7 .w
import java.net.*; ,p {|f}0
3%p^>D\
:*k
public class FileSplitterFetch extends Thread { fIWOo >)D
+a0q?$\
\c(R#*0,
String sURL; //File URL Z]jm.'@z@
long nStartPos; //File Snippet Start Position XmJu{RbS
long nEndPos; //File Snippet End Position !hdOH3h=
int nThreadID; //Thread's ID q&]I
boolean bDownOver = false; //Downing is over g 67;O(3
boolean bStop = false; //Stop identical [Wf%iwB
FileAccessI fileAccessI = null; //File Access interface 8A}cxk
8&t3a+8l
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G*I
{ |9jK-F6
this.sURL = sURL; a9-Mc5^'n
this.nStartPos = nStart; ,~Mf2Y#m0p
this.nEndPos = nEnd; '2.ey33V
nThreadID = id; /oT~CB..
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I=kqkuW
} pAOKy
Ddr.6`VJ
q[\3,Y
public void run() ,{PN6B
{ 8\rca:cF
while(nStartPos < nEndPos && !bStop) SaXt"Ju,AH
{ _d]{[& p4t
5p#0K@`n/
sfX~X/
try{ cy8>M))c
URL url = new URL(sURL); 6TW<,SM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VW*%q0i-
httpConnection.setRequestProperty("User-Agent","NetFox"); R4'.QZ-x
String sProperty = "bytes="+nStartPos+"-"; L<!h3n
httpConnection.setRequestProperty("RANGE",sProperty); p& _Z}Wv
Utility.log(sProperty); PA^*|^;Xh
ec!e
7KlL%\
InputStream input = httpConnection.getInputStream(); c +]r
//logResponseHead(httpConnection); >GIQT?O6
JPDxzp
1'hpg>U
byte[] b = new byte[1024]; 'l/l]26rO4
int nRead; (f&V 7n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1|p\rHGd
{ zu}uW,XH-
nStartPos += fileAccessI.write(b,0,nRead); NuO@Nr
//if(nThreadID == 1) dcrvEc_/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q?j7bp]
} ?*~ ~Ok
,O:4[M!$w
Ov(k:"N
Utility.log("Thread " + nThreadID + " is over!"); UT@Qo}:
bDownOver = true; y;ey(
//nPos = fileAccessI.write (b,0,nRead); l3u[
} $D`Kz*/.
catch(Exception e){e.printStackTrace ();} '@24<T]
} .B^tEBGVD
} J)g +I
Z84w9y7O<
0Y0z7A:
//打印回应的头信息 D Z~036
public void logResponseHead(HttpURLConnection con) ]fY:+Ru
{ GB+$ed5@<
for(int i=1;;i++) g1XpERsSEV
{ [ !~8TF
String header=con.getHeaderFieldKey(i); |xb;#ruR6
if(header!=null) `_DA!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l/?bXNt
Utility.log(header+" : "+con.getHeaderField(header)); 5aVZ"h"
else Z2;~{$&M+
break; di;~$rI!?
} |#-Oz#Eg'
} 6b]vHT|p
K} ;uH,
PMrvUM62
public void splitterStop() 8=2)I.
{ %"KBX~3+Kj
bStop = true; x`o_&09;CG
} Eydk645:3
~V./*CQ\c
;- cq#8S
} fqF1-%
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l[.pI];T
/* 5|>jz `
**FileAccess.java (TY^ kySr
*//文件访问(定位，写) Gm6^BYCk
package NetFox; /\=g;o'
import java.io.*; Ur@'X-
`[:f;2(@
J7l1-
public class FileAccessI implements Serializable{ G4=v2_]
;ga~ae=Fg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s\ ~r 8
RandomAccessFile oSavedFile; `U;4O)`n
long nPos; 5q8bM.k\7N
CF$^we
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public FileAccessI() throws IOException 7Y$p3]0e+
{ Qb SX'mx<
this("",0); \ (X~Z
} r?Z8_5Y
2?m'Dy'JE
av5lgv)3
public FileAccessI(String sName,long nPos) throws IOException z}pdcQl#
{ |#MA?oz3T
oSavedFile = new RandomAccessFile(sName,"rw"); 5X[=Q>
this.nPos = nPos; #|gt(p]C
oSavedFile.seek(nPos); 0_%u(?
} m"xw5aa>
u/``*=Y@
%+`$Lb?{
public synchronized int write(byte[] b,int nStart,int nLen) 3UBG?%!$f
{ JA1(yt
int n = -1; k.rZj|7 L
try{ {E!$<A9
oSavedFile.write(b,nStart,nLen); %pV/(/Q
n = nLen; 'GNT'y_
} 6{1c S
catch(IOException e) Qs*g)Yr
{ b~cN#w #
e.printStackTrace (); :,:r
} +e4o~p
CB6<Vng}C
EAx@a%
return n; 3;#v$F8R
} VBsS1!g
\J:/l|h
}cMb0`oA
} Xgc@cwd
k%JwS_F
@R>J\>
/* P b2exS(
**SiteInfoBean.java mZ*!$P:vy"
*/ ZOfyy E
package NetFox; `0Qzu\gRb
F}.<x5I-;h
BPe5c :z
public class SiteInfoBean { G'Jsk4:c
PJS\> N&u
9>\s81^
private String sSiteURL; //Site's URL t-i;
private String sFilePath; //Saved File's Path i5q VQo
private String sFileName; //Saved File's Name -AJe\ J 2
private int nSplitter; //Count of Splited Downloading File ;ukwKfs
-T`rk~A9A
HTvA]-AuM
public SiteInfoBean() s9@/(_
{//nSplitter的缺省值为5 U"af3c^2
//default value of nSplitter is 5 q:+,'&<D
this("","","",5); PW~+=,
} m "h{HgJd
+r"{$'{^
z*"zXLC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >7p?^*&7;
{ kW3V"twx
sSiteURL= sURL; kR3g,P{L
sFilePath = sPath; :B6hYx
sFileName = sName; y}FTLX $
this.nSplitter = nSpiltter; M6[&od
%!mJnc%
4%0eX]
} 4U*J{''L
DKx8<yEky
3Gubq4r
public String getSSiteURL() 67wY_\m9I
{ xlZ"F
return sSiteURL; D .oX>L#:
} 6*J`2U9Q
?suNA
:GBWQXb G
public void setSSiteURL(String value) <,$(,RX
{ n*D-01vYP
sSiteURL = value; u^8:/~8K
} 7Ps I'1v
(sHqzWh
meA=lg?
public String getSFilePath() tpwMy:<Ex
{ ]h3<r8D_#
return sFilePath; _~ZNX+4
} s<Px au+A
G1=GzAd$5
"l&=a1l
public void setSFilePath(String value) D~E1hr&Vd>
{ >~8;H x].d
sFilePath = value; rJ|Q%utYz
} kscZ zXv
#Drs=7w
%5Hsd
public String getSFileName() VJmX@zX9
{ [%7y !XD
return sFileName; C8 9c2
} (&HAjB
KJ M:-z@
>{?~cNO&
public void setSFileName(String value) Y /$`vgqs
{ (N{Rda*8
sFileName = value; Fr_esx
} #-*7<wN
HI)MBrj;r
t[*;v
public int getNSplitter() &D0suK#
{ *y<Ru:D
return nSplitter; })RT2zw}
} itClCEOA
feU]a5%XZ
+EK(r@eV
public void setNSplitter(int nCount) q/w<>u
{ 7ADh
nSplitter = nCount; kzU;24"K
} \9k$pC+l
} b Lag&c)
:?W {vV
|:yQOq|
/* g-lF{Z
**Utility.java 2r;^OWwr?
*/ lCT N dW+=
package NetFox; %{qJkjG
o"J>MAD
eLE9-K+
public class Utility { N5 ITb0Tv
~3-2Iu^F
at7|r\`?-
public Utility() 6&V4W"k
{ M7z>ugk"
wXw pKm
\bAsn89O
} $T* ##kyE9
obWBX'
//线程睡眠 8qwc]f$.w
public static void sleep(int nSecond) <qZ"W6&&
{ _\yrR.HIa
try{ +<&\*VR
Thread.sleep(nSecond); N!" ]e*q
} [XFZ2'OO
catch(Exception e) ;-84cpfu
{ %4QCUc*lr
e.printStackTrace (); e iS~*@
} SPKen}g
} VU,\OOp
il^SGH
//日志 pKK&+umg
public static void log(String sMsg) L'=e /&
{ .&2pZ
System.err.println(sMsg); 1lRqjnzve&
} .N~qpynY
!NuYx9L?L
4/D~H+k
public static void log(int sMsg) -,jJ{Y~
{ B.fLgQK0
System.err.println(sMsg); _DfI78`(
} Yjz'lWg
} wqo2iRql
ll;#4~iA
,-u | l
/* 01I5,Dm
**TestMethod.java r$ue1bH}|
*/ CaNZScnZ
package NetFox; z79L2lJn
S8j;oJ2d
.FK'TG
public class TestMethod { j}8IT
#I9|>XE1
Lc^nNUzPo
public TestMethod() "hz(A.THi
{ ///xx/weblogic60b2_win.exe A`u04Lm7
try{ `xe[\Z2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IDBhhv3ak
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `9Ngax=_
SiteFileFetch fileFetch = new SiteFileFetch(bean); HCQv"i}-
fileFetch.start(); q p|T,D%
} en7i})v\".
catch(Exception e){e.printStackTrace ();} 18w[T=7)
;nj'C1
T,(IdVlJ
} 'xZxX3
9<<$uf.B
;3\Fb3d
public static void main(String[] args) +`f gn9p
{ .^#{rk
new TestMethod(); @&+h3dV.V
} -a3+C,I8g
} P;KbS~ SlC
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