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)); y\Ic@-aWI
} r:f[mk"-"A
for(int i=0;i<nEndPos.length-1;i++) QdL`|
{ 1FlX'[vh
nEndPos = nStartPos[i+1]; gkES5Q
} }1Gv)l7
nEndPos[nEndPos.length-1] = nFileLength; kYG/@7f/
} wO'TBP
} D^l%{IG
=t9\^RIx)?
gl\\+VyU
//启动子线程 0ZZZoPo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sz:g,}~h
for(int i=0;i<nStartPos.length;i++) M+U9R@
{ L ^q""[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q"\Z-D0B4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NidIVbT.A
nStartPos,nEndPos,i); -I8=T]_D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QEz?w}b*
fileSplitterFetch.start(); B* ?]H*K
} iII=;:p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _I@9HC 4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0AZ")<^~7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c3jx+Q
nEndPos = " + nFileLength); .E`\MtA
// fileSplitterFetch[nPos.length-1].start(); pT=JP> nd^
f .Q\Z'S^
&J[:awQX
//等待子线程结束 \-h%O jf4
//int count = 0; W>) M5t4i
//是否结束while循环 >AVVEv18
boolean breakWhile = false; ;LcZ`1
z@!`:'ak
RRmz"j>
while(!bStop) zk$FkbX
{ ^E;kgED5
write_nPos(); 7m4aoK
Utility.sleep(500); i3tg6o4C
breakWhile = true; '@o;-'b
EMY/~bQW
4ezEW|S
for(int i=0;i<nStartPos.length;i++) !%CWZZ 6u
{ v- 2:(IV
if(!fileSplitterFetch.bDownOver) J\+0[~~
{ W0dSsjNio
breakWhile = false; $ `ov4W
break; 8EW_V$>R
} aOlT;h
} TrlZ9?3#D
if(breakWhile) smlpD3?va
break; 5eLtCsHz
'~5LY!H(pT
m8A#~i .
//count++; PQy4{0 _
//if(count>4) <^&ehy:7y
// siteStop(); 3eb%OEMYk
} s2h@~y
uZNTHD
e%svrJ2
System.err.println("文件下载结束！"); e^8 O_VB
} nEJq_
catch(Exception e){e.printStackTrace ();} zwhe
} f86XkECZ;`
^X=arTE
p2#)A"
//获得文件长度 H3z:ZTI
public long getFileSize() (ceNO4"cZ
{ C6VLy x
int nFileLength = -1; m4**~xfC
try{ Pr3qo4t.L
URL url = new URL(siteInfoBean.getSSiteURL()); HHA<IZ#;,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8L,5Q9 $
httpConnection.setRequestProperty("User-Agent","NetFox"); '}9x\3E
5&QJ7B,!
|t^E~HLm,
int responseCode=httpConnection.getResponseCode(); ZT'`hK_up
if(responseCode>=400) Q8T]\6)m
{ SON-Z"v
processErrorCode(responseCode); ohRjvJ'v|
return -2; //-2 represent access is error Jb0`42
} gR&Q3jlIV
aT{_0m$G10
MDnKX?Y
String sHeader; ?Y$JWEPJ
iJ-23_D
UvJ}b
for(int i=1;;i++) 4QH3fTv
{ Vy6qbC-Kt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t#V!8EpBg
//Utility.log(in.readLine()); sQ=]NF)\
sHeader=httpConnection.getHeaderFieldKey(i); Ghu#XJB?
if(sHeader!=null) 2POXj!N
{ ?ME6+Z\
if(sHeader.equals("Content-Length")) _Us#\+]_:
{ zpzK>DH(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :{PJI,
break; ]q;Emy
} x/NfZ5e0X
} SbND Y{5RO
else :yL] ;J
break; Cw iKi^m
} ({ 8-*
} O_2pIbh
catch(IOException e){e.printStackTrace ();} DjCqh-&L
catch(Exception e){e.printStackTrace ();} >NO[UX%yP
~,d,#)VE2q
&c`nR<
Utility.log(nFileLength); ~xbe~$$Q@
3]OE}[R
&VhroHO
return nFileLength; ++bf#qS<8D
} 7yG#Z)VE
T%x}Y#U'`
bh s5x
//保存下载信息（文件指针位置） T]R|qlZ
private void write_nPos() vV'EZ?
{ ko5@qNq
try{ w~.f
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~t@cO.c
output.writeInt(nStartPos.length); kj|6iG
for(int i=0;i<nStartPos.length;i++) a_[Eh fE
{ 5 z~1Dw
// output.writeLong(nPos); `uq8G
output.writeLong(fileSplitterFetch.nStartPos); d)B@x`
output.writeLong(fileSplitterFetch.nEndPos); :lX!\(E2
} 9V'%<pk''(
output.close(); @:;)~V
} ;5wn67'
catch(IOException e){e.printStackTrace ();} xqXo0
catch(Exception e){e.printStackTrace ();} ~{*7"o/
} O ~(pg
+y,T4^{
,ZKr.`B
//读取保存的下载信息（文件指针位置） 3ovWwZ8&
private void read_nPos() _geWE0 E
{ !*/*8re
try{ F@^~7ZmP`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y}@&h!
int nCount = input.readInt(); [M?}uK ^
nStartPos = new long[nCount]; h~A/y!s
nEndPos = new long[nCount]; -Q2, "
for(int i=0;i<nStartPos.length;i++) 2:*w~|6>}5
{ B*qi_{Gp
nStartPos = input.readLong(); iy6On,UL
nEndPos = input.readLong(); ]~844Jp
} |VKK#J/
input.close(); '#! gh?
} 3NZK*!@'
catch(IOException e){e.printStackTrace ();} ^m L@e'r
catch(Exception e){e.printStackTrace ();} d; [C6d
} PEN\-*Pv
< |e,05aM
~Xr=4V:a+
private void processErrorCode(int nErrorCode) 2C2fGYu
{ liEPCWl&
System.err.println("Error Code : " + nErrorCode); -VZ-<\uH
} ]5BX:%
;g8R4!J
siXr;/n"
//停止文件下载 w'L\?pI
public void siteStop() R{RwTN<
{ r[1i*b$
bStop = true; <wZQc
for(int i=0;i<nStartPos.length;i++) QS0:@.}$E)
fileSplitterFetch.splitterStop(); ( Wa
l|xZk4@_uE
@HT% n
} & SiP\65N
} 4f@o mAM
//负责部分文件的抓取 EJ@?h(O
**FileSplitterFetch.java )_a~} U]=.
*/ `/_o!(Z`
package NetFox; ^L0d/,ik
pqUCqo!m\
og4UhP^UET
import java.io.*; 9F6F~::l}
import java.net.*; NxSu3e~PS
vQ<90ZxqB
.b\$MZ"(
public class FileSplitterFetch extends Thread { 1[kMOp
qNI, 62
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String sURL; //File URL b:=TB0Fx?n
long nStartPos; //File Snippet Start Position FSUttg"
long nEndPos; //File Snippet End Position A3vUPWdDk
int nThreadID; //Thread's ID "nm FzN
boolean bDownOver = false; //Downing is over b'P eH\h{
boolean bStop = false; //Stop identical v4?x.I
FileAccessI fileAccessI = null; //File Access interface U;bK!&Z
$f,n8]
9V,!R{kO!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RZ6xdq}>
{ |"XPp!_uN
this.sURL = sURL; .udv"?!z
this.nStartPos = nStart; >:zK?(qu,N
this.nEndPos = nEnd; h\7fp.
nThreadID = id; 7uT:b!^f[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <F'X<Bau
} xO1[>W
1mfs4
Qhs/E`k4
public void run() kgy:Q'
{ T(AVlI6
while(nStartPos < nEndPos && !bStop) Vm5c+;
{ o[v\|Q`d
fq5_G~c=
[~kdPk
try{ ZeUvyIG
URL url = new URL(sURL); Au{<hQ=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3 N7[.I>A
httpConnection.setRequestProperty("User-Agent","NetFox"); I/M_p^
String sProperty = "bytes="+nStartPos+"-"; H~GQ;PhRx
httpConnection.setRequestProperty("RANGE",sProperty); u\LiSGePN
Utility.log(sProperty); |fxA|/s[<
Rp*R:3 C
&j?#3Qt'_
InputStream input = httpConnection.getInputStream(); `(v='$6}
//logResponseHead(httpConnection); wj[\B*$?
AtU v71D:
c~{9a_G
byte[] b = new byte[1024]; y_*PQZ$c<
int nRead; TpmwD{c[\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1BAgtd$3
{ %STliJ
nStartPos += fileAccessI.write(b,0,nRead); vo\fUT@k
//if(nThreadID == 1) CM<]ZG7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cTD!B% x
} 5k6mmiaKk
d0aCY
J8M$k/"X
Utility.log("Thread " + nThreadID + " is over!"); !(n4|Wd
bDownOver = true; VOc8q-hK
//nPos = fileAccessI.write (b,0,nRead); :C}2=
} ZDD..j
catch(Exception e){e.printStackTrace ();} p8kr/uMP ;
} ZunCKc
} ^qg?6S4
t6,wjN-J
,g7.rEA
//打印回应的头信息 {NPuu?&
public void logResponseHead(HttpURLConnection con) r'dr9"-{
{ Nru7(ag1~
for(int i=1;;i++) c&X{dJWD
{ t^xTFn
String header=con.getHeaderFieldKey(i); `+zWu55;
if(header!=null) K,6b3kk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); kloR#?8A
Utility.log(header+" : "+con.getHeaderField(header)); :Gu+m
else cooUE<a
break; ,bM-I2BR
} Ti2Ls5H}
} i.xXb[M+
7}GK%H-u
],ZzI
public void splitterStop() Dy]I8_
{ e/*$^i+S
bStop = true; 28hHabd|
} hY*0aZ|(
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t4qej
} g ^!C
W(25TbQ
l akp
/* ~ ^>417>
**FileAccess.java [w0/\]o
*//文件访问(定位，写) '`|AI:L
package NetFox; dLvJh#`o
import java.io.*; lJzl6&
aYn8^
~"lJ'&J}
public class FileAccessI implements Serializable{ >S1)YKgz
!j1[$% =#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v!42DA)
RandomAccessFile oSavedFile; .lBgp=!
long nPos; z305{B:Y
2/36dGFH
[EY`am8[
public FileAccessI() throws IOException ?( =p<TUw
{ B51kV0
this("",0); `_5GG3@Ff
} {SZ% Xbo
~P-*}q2J
?-OPX_i_
public FileAccessI(String sName,long nPos) throws IOException H@l}[hkP
{ C}?0`!Cc%
oSavedFile = new RandomAccessFile(sName,"rw"); p<`+sf}A:
this.nPos = nPos; #hL*rbpT
oSavedFile.seek(nPos); JI|6B
} }wwe}E-e
6QZ5|T ]
~vgA7E/XV
public synchronized int write(byte[] b,int nStart,int nLen) D);'pKl
{ hzY[ G:
int n = -1; }:z5t,u6
try{ Q0_>'sEM
oSavedFile.write(b,nStart,nLen); :XV} c(+d
n = nLen; 7m9"8
} (LJ@SeM;
catch(IOException e) C+K=[
{ ~2uh'e3
e.printStackTrace (); Y7U&Q:5'
} ~^N]yb
wH"kk4^
59rY[&|
return n; :Gh~fm3}
} C:\(~D*GS
Psa@@'w
U!e6FHj7
} -NM0LTF
R9r+kj_
UP2.]B!d
/* 6ri#Lw
**SiteInfoBean.java dL;HV8z^
*/ . p^xS6e{
package NetFox; V!|e#}1/
q42FPq
X;fy\HaU
public class SiteInfoBean { b>cafu
H3 m8
*M~.3$NN
private String sSiteURL; //Site's URL eZF'Ck y
private String sFilePath; //Saved File's Path 2HOe__Ns
private String sFileName; //Saved File's Name 0^_MN~s(X
private int nSplitter; //Count of Splited Downloading File 'M'w,sID
y7zkAXhJ
sms1%%~
public SiteInfoBean() aIvBY78o
{//nSplitter的缺省值为5 )&Z>@S^
//default value of nSplitter is 5 02 f9 wV
this("","","",5); ;;LuU<,$
} 3-Y=EH_0
{y);vHf$
T_L6 t66I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) wz@FrRP=
{ 6$B'Q30}r
sSiteURL= sURL; %{ ~>n"
sFilePath = sPath; l]vohLz 3!
sFileName = sName; SWoEt1w
this.nSplitter = nSpiltter; #)i&DJ^Y
1*R_"#
Xu<FDjr
} ABWb>EZ8
{a4xF2
}|He?[TR
public String getSSiteURL() Z% Z"VoxH
{ oYq,u@oM
return sSiteURL; my[,w$YM
} }=pOiILvD
<lx^aakk!
0}-#b7eR
public void setSSiteURL(String value) T#e4":A&x
{ LV=^jsQ5
sSiteURL = value; XWF7#xM
} a#R%8)
}B*,mn2N
AFtCqq#[
public String getSFilePath() W8uVd zQ
{ v|y<_Ya
return sFilePath; I3ho(Kdi
} Uf[T_
P7Z<0Dt\}
Bb_}YU2#
public void setSFilePath(String value) G*Ib^;$u
{ ~"5C${~{
sFilePath = value; zK /f$}
} wV %8v\
m\} =4b
P[1m0!,B
public String getSFileName() oEPNN'~3
{ iZu:uMoc
return sFileName; FB.!`%{
} q'fPNQg
J(&Gmk9&
kYTOldfY2
public void setSFileName(String value) ^VC7C~NZ!M
{ $ #t|(\
sFileName = value; "sSjVu
} g!.Ut:8L9
xan/ay>
0\ZaMu #
public int getNSplitter() +H?<}N*T
{ T:dX4=z
return nSplitter; n8 GF8a
} i)GeX:
*u<rU,C8
L;4[ k;5
public void setNSplitter(int nCount) s&Z35IM8|
{ .wM:YX'[G
nSplitter = nCount; A4}JZi6@
} - a
} LAizx^F
D l4d'&!
XX*'N+
/* L,yA<yrC
**Utility.java A8#.1uEgNb
*/ V@LN 1|
package NetFox; g&|4
[vZfH!vLP
e~tr^$/(
public class Utility { wBg<Q{J
)PsN_ 42~
cZCGnzy
public Utility() 4!NfQk>X
{ bnAT,v{
16a_GwfM
uWJ#+XK.
} aW52.X z%8
R>/QARX
//线程睡眠 =)mXCA^
public static void sleep(int nSecond) -d$8WSI8
{ vgUhN_rK
try{ I rtF4ia.
Thread.sleep(nSecond); /%N31
} 5KL9$J9k
catch(Exception e) %RCl+hOP.h
{ 2P;%P]~H
e.printStackTrace (); >reaIBT
} ZXFAuF
} I$3"|7[n
B[) [fE
//日志 N/`TrWVF
public static void log(String sMsg) .g6PrhzFbk
{ [4K9|/J
System.err.println(sMsg); o(Ua",|
} ]Ssw32yn
hQd@bN8
fPh}l
public static void log(int sMsg) CjC'"+[w
{ .IW_DM-
System.err.println(sMsg); X/- W8
} Z@>=&
} I,CAFq
FqT,4SIR
cu.*4zs
/* m>Yo9/XpZ
**TestMethod.java F#!@}K8
*/ okK/i
package NetFox; O X5Co<u
uv~qK:Nw(
${E[pT
public class TestMethod { U- *8%>Qp
3$96+A^M*
/P?|4D}<
public TestMethod() g "K#&
{ ///xx/weblogic60b2_win.exe !BvTJ-e)F
try{ E&s'uE=w+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9QX~aX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `\RX~ $^
SiteFileFetch fileFetch = new SiteFileFetch(bean); q5'yD;[hE
fileFetch.start(); St~SiTJU
} %X0NHta~@
catch(Exception e){e.printStackTrace ();} c5wkzY h
\CJx=[3(
[d^:
} n}9Msen
H.l,%x&K
n ]6 0
public static void main(String[] args) 9znx1AsN
{ NrI5uC7
new TestMethod(); k8x&aH
} <<W.x)#:
} zV_-rf
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