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/iY%NE
} .;8T*
for(int i=0;i<nEndPos.length-1;i++) 9#IKb:9k
{ al.~[T-O+
nEndPos = nStartPos[i+1]; w(zlHj
} S~.:B2=5K
nEndPos[nEndPos.length-1] = nFileLength; nb9qVuAGU
} xv4_q-r[
} lU`]yL
K!VIY|U
Po#;SG#Ee
//启动子线程 yZE"t[q#O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wO;\,zU
for(int i=0;i<nStartPos.length;i++) :,X,!0pWRp
{ 5zWxI]4d\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }SR}ET&z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VImcW;Xa
nStartPos,nEndPos,i); X>(?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N{U``LV
fileSplitterFetch.start(); @kw#\%Uz
} %6}S1fuA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \BOZhXfl'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {+_pyL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^Qt4}V=
nEndPos = " + nFileLength); !/^i\)j>](
// fileSplitterFetch[nPos.length-1].start(); *,A?lX,9A
EbZRU65J}O
E5(\/;[*`
//等待子线程结束 q{gt2OWqX
//int count = 0; z=J%-Hq>
//是否结束while循环 })rJU/
boolean breakWhile = false; i/N4uq}'A<
:Y`cgi0vkd
![YLY&}s
while(!bStop) tt2`N3Eu\
{ ?4GI19j
write_nPos(); "E =\Vz
Utility.sleep(500); X YO09#>&
breakWhile = true; &^KmfT5C
0*o)k6?q3
2iYf)MC
for(int i=0;i<nStartPos.length;i++) UE^_SZ
{ tkx1iBW=
if(!fileSplitterFetch.bDownOver) ;3wj(o0
{ 5RCZv\Wd&
breakWhile = false; qPY OO
break; Hg\+:}k&9
} ]V\qX+K
} :SjTkfU
if(breakWhile) *u^N_y
break; #K:|@d
`@eo <6
Y>LgpO.
//count++; E~Eh'>Y(B
//if(count>4) c|OIUc
// siteStop(); -h+=^,
} @|! 9~F
eJFGgJRIvF
{-;lcOD
System.err.println("文件下载结束！"); t>p!qKrE'J
} lL_M=td8W
catch(Exception e){e.printStackTrace ();} GInU7y904
} teh$W<C
*T\-iICw
0O+[z9
//获得文件长度 YcW[BMy5h
public long getFileSize() gU1E6V-Jm
{ eV$pza
int nFileLength = -1; Ej\EuX
try{ C,T9xm
URL url = new URL(siteInfoBean.getSSiteURL()); <Hw)},_*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %"Tn=fZIF
httpConnection.setRequestProperty("User-Agent","NetFox"); 'wB6-
7A'd55I4
<20rxOEnf
int responseCode=httpConnection.getResponseCode(); 04>dxw)8
if(responseCode>=400) <>\s#Jf/
{ PF5;2
processErrorCode(responseCode); pJkaP
return -2; //-2 represent access is error &iCE/
} vM@2C'
z'N_9=
~^jdiy5
String sHeader; .1R:YNx{/
P9h]Bu
rrBu6\D
for(int i=1;;i++) :l<)p;\
{ r_/=iYYJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f@U\2r
//Utility.log(in.readLine()); 5A(zQ'6
sHeader=httpConnection.getHeaderFieldKey(i); ]l\'1-/
if(sHeader!=null) -=_bXco}
{ P{2V@ <}
if(sHeader.equals("Content-Length")) o|#Mq"od
{ PR rf$& u
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2D|2/ >[
break; Omy4Rkj8bh
} b=[gK|fu
} ;4XvlcGo
else Bc%A aZ0x
break; ILdRN
} 5c50F{
} `@+}zE
catch(IOException e){e.printStackTrace ();} jM`)Nd
catch(Exception e){e.printStackTrace ();} P&PPX#%
{;.q?mj
~<b/%l>h1
Utility.log(nFileLength); O 1TJJ8
f+>l-6M+p
"JI FF_
return nFileLength; 5)X;q-
} ZI"L\q=|0#
!]]QbB
S |SN3)
//保存下载信息（文件指针位置） C? pi8Xg
private void write_nPos() +-_71rJc.
{ Wr3j8"f/
try{ fBCW/<Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); E({+2}=1
output.writeInt(nStartPos.length); u6&<Bv
for(int i=0;i<nStartPos.length;i++) r(sQI# P
{ ;A^0="x&
// output.writeLong(nPos); jwsl"zL
output.writeLong(fileSplitterFetch.nStartPos); w`Q"mx*
output.writeLong(fileSplitterFetch.nEndPos); !: e(-
} c)H(w
output.close(); 4dy2m!
} a^yBtb~,P
catch(IOException e){e.printStackTrace ();} |Z%I3-z_DS
catch(Exception e){e.printStackTrace ();} Xk#"rM< Y
} @\-i3EhR
J6x#c`Y
(!FUu
//读取保存的下载信息（文件指针位置） ftBbO8e
private void read_nPos() ]3.Un,F
{ 8`bQ,E+2
try{ |$[WnYP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q`$Q(/
int nCount = input.readInt(); LW?Zd=
nStartPos = new long[nCount]; ?39B(T
nEndPos = new long[nCount]; _?UW,5=O
for(int i=0;i<nStartPos.length;i++) DG_tmDT4
{ Wxjv=#3
nStartPos = input.readLong(); en\shc{R]`
nEndPos = input.readLong(); |ocIp/$
} cSdkhRAn
input.close(); CPRv"T;?
} ,:yv T6)p
catch(IOException e){e.printStackTrace ();} emZ^d/A
catch(Exception e){e.printStackTrace ();} En@] xvE
} `x;8,7W;B
1d49z9F
@8zp(1.
private void processErrorCode(int nErrorCode) .54E*V1
{ C+{du^c$
System.err.println("Error Code : " + nErrorCode); *We.?"X'].
} ?O1:-vpZ
qGndh
g8+w?Zn}
//停止文件下载 ]TTX<R ZLr
public void siteStop() 0,)Ao8
{ _ED,DM
bStop = true; **\BP,]}
for(int i=0;i<nStartPos.length;i++) }@IRReQ
fileSplitterFetch.splitterStop(); At5:X*vD
ZLA&<]Ad"$
T';<;6J**
} c*nH=
} + -e8MvP
//负责部分文件的抓取 tPO\e]
**FileSplitterFetch.java 1$,t:/'-4
*/ gI^);JrTE
package NetFox; r,p6J7/lfS
nquKeH
1VW;[ ocQ
import java.io.*; AF{k^^|H
import java.net.*; K`.wj8zGY
}qUNXE@
6bL+q`3>
public class FileSplitterFetch extends Thread { 7?6?`no~JJ
YT;b$>1v
3#>;h
String sURL; //File URL .K![<eZ
long nStartPos; //File Snippet Start Position /'|'3J]HP
long nEndPos; //File Snippet End Position m35Blg34
int nThreadID; //Thread's ID A`4Di8'Me
boolean bDownOver = false; //Downing is over Q(lj&!?1k
boolean bStop = false; //Stop identical |_l\.
FileAccessI fileAccessI = null; //File Access interface UA4Q9<>~
}g WSV
U\S%Jq*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?p{xt$<p
{ \jn[kQ+pJ
this.sURL = sURL; <j1l&H|ux,
this.nStartPos = nStart; a,Gd\.D
this.nEndPos = nEnd; 5,:tjn
nThreadID = id; s:Us*i=H,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yjvH)t/!.
} )c@I|L
$[VeZ-
DM6oMT
public void run() l*[.
{ myH:bc>6
while(nStartPos < nEndPos && !bStop) 9IL#\:d1
{ 4!lbwqo
iKB8V<[\T
x&3!z[m@@
try{ @aR! -}
URL url = new URL(sURL); 02X~' To"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *AXu_^^
httpConnection.setRequestProperty("User-Agent","NetFox"); i|>K
String sProperty = "bytes="+nStartPos+"-"; _I_Sq,Z#
httpConnection.setRequestProperty("RANGE",sProperty); fk!wq.a
Utility.log(sProperty); 8VvoPlo
:oF\?e
yWIM,2x}
InputStream input = httpConnection.getInputStream(); 8WWRKP1V
//logResponseHead(httpConnection); g#ZR,q
'l\V{0;mp
`gqBJi
byte[] b = new byte[1024]; 9vL`|`Vau
int nRead; G8`q-B}q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LGT\1u
{ e,zR
nStartPos += fileAccessI.write(b,0,nRead); /:>f$k4~h
//if(nThreadID == 1) Ygn"7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2F-!SI
} lj.z>
BQf}S +
87EI<\mP
Utility.log("Thread " + nThreadID + " is over!"); !lE (!d3M
bDownOver = true; ~\hA-l36
//nPos = fileAccessI.write (b,0,nRead); ,[+
} P0$q{ j
catch(Exception e){e.printStackTrace ();} (c(c MC'
} ?PWD[mQE\
} Ze~ a+%Sb
9QJ=?bIC#
>q <,FY!A
//打印回应的头信息 , j,[4^
public void logResponseHead(HttpURLConnection con) >H@ dgb
{ }M f}gCEW
for(int i=1;;i++) I"3Qdi
{ ?)Lktn9%
String header=con.getHeaderFieldKey(i); TJ`E/=J!
if(header!=null) uc%75TJ@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aEX;yy*
Utility.log(header+" : "+con.getHeaderField(header)); GZQ)TzR
else J),7ukLu^
break; [8Ub#<]]
} uf`o\wqU
} ~/[cZY@
po"M$4`9
H7"I+qE-G
public void splitterStop() _h_;nS.Y
{ 2Iz@lrO6
bStop = true; T~Jl{(s9)
} }K;@$B6,@
F=B>0Q5
]*}*zXN/E
} X=(8t2
Pf)<6?T
)aquf<u@
/* u4$d#0sA
**FileAccess.java dT,X8 "
*//文件访问(定位，写) i[d-n/)
package NetFox; KBzEEvx/$
import java.io.*; 6luCi$bL
A3&8@/6,
G#duZNBdc
public class FileAccessI implements Serializable{ $a\q<fN}
wx(|$2{h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NNutpA}s
RandomAccessFile oSavedFile; 0Qw?.#[9
long nPos; =DE5Wq19
Ym&_IOx
@Qruc\_
public FileAccessI() throws IOException @)VJ,Ql$Y
{ O:r<es1
this("",0); 2K, 1wqf'
} [$.oyjd
H|F>BjXn5
\R&`bAdk
public FileAccessI(String sName,long nPos) throws IOException K]@6&H-b|
{ 2|EHNy!
oSavedFile = new RandomAccessFile(sName,"rw"); BAmH2"
this.nPos = nPos; ReKnvF~
oSavedFile.seek(nPos); 8XX,(k_b
} K"Nq_Ddwd
:Iwe>;}
aU4'_%Y@
public synchronized int write(byte[] b,int nStart,int nLen) Zi7(lG
{ Fxv~;o#
int n = -1; @Z@yI2#e
try{ 5[I> l
oSavedFile.write(b,nStart,nLen); jSVb5P
n = nLen; N Ja]UZx
} {+ [rJ_
catch(IOException e) 3dadeu^{A
{ E'[pNU*"x-
e.printStackTrace (); /J{P8=x}_:
} uHz D
X/5tZ@
,X$S4>
return n; yKZ~ ^
} X,O&X
2)[81a
w'M0Rd]
} aH"tSgi
0%FC;v0
?{_dW=AQ1
/* [p4a\Qg0
**SiteInfoBean.java }qV4]*+{
*/ o>U%3-+T^J
package NetFox; seAkOIc
?/#HTg)!B
9IMRWtZWT
public class SiteInfoBean { EW2e k^
e;rs!I!Yw
\FVR'A1
private String sSiteURL; //Site's URL =\X<UA}
private String sFilePath; //Saved File's Path oH6(Lq'q
private String sFileName; //Saved File's Name 1Lj\"+.
private int nSplitter; //Count of Splited Downloading File )}G HG#D{
!3yR?Xem}
&e,xN;
public SiteInfoBean() _?q\tyf3
{//nSplitter的缺省值为5 ?A62VV51CN
//default value of nSplitter is 5 G-"#3{~2
this("","","",5); *#UDMoz<
} 0C3Yina9 *
e5`{*g$i).
Vx* =
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cO(|>&tJ
{ J=4S\0Z*
sSiteURL= sURL; f+<-Jc
sFilePath = sPath; 1RRvNZW
sFileName = sName; [>"qOFCr#:
this.nSplitter = nSpiltter; #B+2qD>E
&k1Ez
I &{dan2
} ZP%^.wxC
5^* d4[&+
X/gh>MJJ<
public String getSSiteURL() ",Q\A I
{ !EpP-bq'*
return sSiteURL; Grjm9tbX}
} CUxSmN2[
=9pFb!KX
;PS[VdV
public void setSSiteURL(String value) dC,F?^
{ uu#ALB Jm
sSiteURL = value; zKiKda%)
} {Qw,L;R
IUu[`\b=
w:N\]=Vh
public String getSFilePath() $)7-wCl</
{ p(0!TCBs
return sFilePath; 7z%zXDe~T[
} `]tXQqD
AFMAgf{bD
aYPzN<"%
public void setSFilePath(String value) EWqKd/
{ hrcR"OZ~X
sFilePath = value; )QI]b4[
} W&bh&KzCW
cHJ &a`;
M5%u>$2
public String getSFileName() M6 0(yTm
{ /1MO]u\
return sFileName; -u{k
} Q'Q+mt8u5
PkG+`N
\f{C2d/6j
public void setSFileName(String value) W*U\79H
{ AeUwih. 4
sFileName = value; FirmzB Il5
} AE7>jkHB
7Bmt^J5i&t
C'5i>;
public int getNSplitter() :Z=A,G
{ EzG7RjW
return nSplitter; #~p1\['|M
} `+* Mr
vn,L),"=
TSuHY0.cp
public void setNSplitter(int nCount) 'iL['4~.
{ l|N1u=Z
nSplitter = nCount; MR+ndB<
} })"9TfC
} }B0V$
vQIoj31
*5|\if\
/* #Va@4<4r
**Utility.java mH}AVje{ `
*/ q"]-CGAa
package NetFox; XM8C{I1
L"('gc!W
-?e~S\JH
public class Utility { |0-5-.
M%B]f2C
_Thc\{aV#
public Utility() 6o,,w^
{ JLg_oK6
C{Npipd}v
tk, HvE
} 0Y"==g+>f
pK$^@~DE
//线程睡眠 teM&[U
public static void sleep(int nSecond) Ye1P5+W(
{ l<qxr.X
try{ ]p#Zdm1EL
Thread.sleep(nSecond); /wvA]ooT
} nTYqZlI,
catch(Exception e) }-8K*A3
{ XPX{c|]>.
e.printStackTrace (); IlS{>6
} |4-Ey! P
} ]>`Q"g~0
>:wk.<Z-
//日志 9`c :sop
public static void log(String sMsg) ^. Pn)J
{ m'429E]\S
System.err.println(sMsg); k,q` ^E8k
} O gycP4z[
~8|$KD4I
][qZOIk@
public static void log(int sMsg) &|9?B!,`
{ 1` 9/[2z
System.err.println(sMsg); %7V?7BE
} jP}N^
} R\X=Vg
Dy8Go4
Z"E+ TX
/* 2Jj`7VH>
**TestMethod.java N*o+m~:y
*/ &O!d!Pf
package NetFox; c"0CHrd
flmcY7ZV
TYLf..i<
public class TestMethod { orL7y&w(v:
wBmbn=>#S
ExnszFX*
public TestMethod() 1lx\Pz@ol
{ ///xx/weblogic60b2_win.exe _ k>j?j-
try{ /?by4v73P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A 7TP1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TmUn/
SiteFileFetch fileFetch = new SiteFileFetch(bean); s]=kD
fileFetch.start(); r9u*c
} o]k[l;
catch(Exception e){e.printStackTrace ();} -4HI9Czts
W;0_@!?mr}
U;{VL!
} I:Z38xz-[
j&#p&`B
4V[+6EV
public static void main(String[] args) sb8SG_c.
{ K,^b=_]
new TestMethod(); I@x*>
} xi|iV1A
} <Ojf&C^Z
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