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)); NmXTk+,L#
} oyY,uB.|
for(int i=0;i<nEndPos.length-1;i++) s:{%1/
{ *a4eL [
nEndPos = nStartPos[i+1]; U^I'X7`r
} C7:Ry)8'I
nEndPos[nEndPos.length-1] = nFileLength; 0>Nq$/!
} iddT.
} $cedO']
75ob1h"
1:8: yFV
//启动子线程 9IMcp~zX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e)8iPu ..
for(int i=0;i<nStartPos.length;i++) bv0 %{u&
{ I Cs1=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vhW'2<(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?*0kQo'
nStartPos,nEndPos,i); 7y3; F7V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *!kg@ _0K
fileSplitterFetch.start(); sa($3`d
} hJM0A3(Cm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,#6\:i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /zM7G?y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <R$|J|
nEndPos = " + nFileLength); >F v8 -
// fileSplitterFetch[nPos.length-1].start(); AseY.0
!ywc).]e
#SmWF|/
//等待子线程结束 |SmN.*&(9
//int count = 0; U;/ )V
//是否结束while循环 /r6DPR0\
boolean breakWhile = false; D.~t#a A
*W l{2&
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while(!bStop) `y(3:##p
{ $Z4p$o dk
write_nPos(); hkY E7
Utility.sleep(500); Fu$otMw%l
breakWhile = true; A [JV*Dt
qA42f83
`:&{/|uP7
for(int i=0;i<nStartPos.length;i++) YH9BJ
{ KK}&4^q
if(!fileSplitterFetch.bDownOver) B5hGzplS
{ bPEAG=l"-
breakWhile = false; Fei$94a
break; ,>Q,0bVhH0
} 5sH ee,
} %9K@`v-
if(breakWhile) $uqlJG#`
break; 2= _.K(
#"|Ey6&
cVMTT]cj1
//count++; 3 V<8
//if(count>4) jB;+tDC!Co
// siteStop(); %AFy{l
} bYz:gbs]4|
7%tn+
&fcRVku
System.err.println("文件下载结束！"); Nb6HM~
} W*0KAC`m
catch(Exception e){e.printStackTrace ();} {!w]t?h
} l6~eb=u;9g
p5*Y&aKj
$FoNEr&q
//获得文件长度 9"rATgN1
public long getFileSize() px*MOHq K
{ l[xwH 9'
int nFileLength = -1; 5R4 dN=L*1
try{ 9M6&+1XE
URL url = new URL(siteInfoBean.getSSiteURL()); 8447hb?W$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @RC_Ie=#)
httpConnection.setRequestProperty("User-Agent","NetFox"); A U](pXK;
LakP'P6`E
@RjLDj+)S
int responseCode=httpConnection.getResponseCode(); v{9eEk1
if(responseCode>=400) })":F
{ c09uCito
processErrorCode(responseCode); `7LdF,OdE
return -2; //-2 represent access is error q&vr;fB2
} j<c_*^/'9
TM+7>a$
8L#sg^1V
String sHeader; D`ZYF)[}J
r`=d4dK-
mVxS[Gq
for(int i=1;;i++) @M1U)JoQ
{ f-Sb:O!V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5b&'gd^d
//Utility.log(in.readLine()); 30<^0J.1
sHeader=httpConnection.getHeaderFieldKey(i); bV"0}|A~K
if(sHeader!=null) :KQ<rLd
{ uwbj`lpf
if(sHeader.equals("Content-Length")) oyUf/Sl
{ 6|zA,-=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0P|WoCX
break; X/Ae-1!
} :G!Kaa,r
} lHx$F?
else ]!/1qF
break; (qaY,>je]D
} G B15
} j9Lc2'
catch(IOException e){e.printStackTrace ();} n7S[ F3
catch(Exception e){e.printStackTrace ();} 3V-pLs|
$I_aHhKt
0j*8|{|
Utility.log(nFileLength); WPPmh~:
g;-CAd5
H]SnM'Y
return nFileLength; Agl[Z>Q
} zEu*q7
=KX:&GU
NK#f Gz*,(
//保存下载信息（文件指针位置） k?_Miqr
private void write_nPos() hE>Mo$Q(
{ |[*b[O 1W
try{ B$fL);l-
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1e}wDMU(
output.writeInt(nStartPos.length); #{0c01JZ
for(int i=0;i<nStartPos.length;i++) RJ0w3T]7
{ wqw$6"~
// output.writeLong(nPos); 5@i/4%S
output.writeLong(fileSplitterFetch.nStartPos); %zWtPxAf
output.writeLong(fileSplitterFetch.nEndPos); rwU[dqBRhc
} =!Ok079{[
output.close(); U5" C"+ 3
} / JlUqC
catch(IOException e){e.printStackTrace ();} I(C_}I>Wb
catch(Exception e){e.printStackTrace ();} LNe-]3wB
} !dZC-U~
N/Z<v* i"
g4Tc (k#
//读取保存的下载信息（文件指针位置） +YP,LDJ!v
private void read_nPos() NO'-HKHj
{ [~x Ql
try{ ,<%],-Lt[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O<fbO7.-
int nCount = input.readInt(); 9'}m797I'
nStartPos = new long[nCount]; q$K^E
nEndPos = new long[nCount]; PQ1\b-I
for(int i=0;i<nStartPos.length;i++) xK /NzVt
{ D{c`H}/`
nStartPos = input.readLong(); ibEQ52
nEndPos = input.readLong(); q")}vN
} }E*#VA0/nY
input.close(); I"r*p?
} uA,K}sNRZ
catch(IOException e){e.printStackTrace ();} dqcfs/XhP
catch(Exception e){e.printStackTrace ();} s@0#w*N
} Qd$d*mwg:
PX+$Us
z1s9[5
private void processErrorCode(int nErrorCode) x#U?~6.6
{ WG9x_X&XJ
System.err.println("Error Code : " + nErrorCode); B+,Z 3*
} 41$7P[M;
[9X1;bO#f
mim]nRd2v
//停止文件下载 iB{O"l@w
public void siteStop() i,,UD
{ nXXyX[c4e
bStop = true; Y*J,9
for(int i=0;i<nStartPos.length;i++) ,myl9s
fileSplitterFetch.splitterStop(); \=1k29O
=Bl#CE)X
H~fZA)W 4Y
} 5X'[{'i,
} #k*e>d$
//负责部分文件的抓取 fZ$8PMZv
**FileSplitterFetch.java ;4%^4<+3
*/ Sa6}xe."M,
package NetFox; jrG@ +" }
IX$ $pdQ
't2"CPZ
import java.io.*; klv ]+F&[
import java.net.*; //g~1(
Vc}m_T]O
CKyX Z
public class FileSplitterFetch extends Thread { )~s(7 4`}
os"o0?
L=?Yc*vg
String sURL; //File URL }m(u oT~
long nStartPos; //File Snippet Start Position &*r YY\I
long nEndPos; //File Snippet End Position &?v^xAr?B
int nThreadID; //Thread's ID +!CG'qyN>
boolean bDownOver = false; //Downing is over c[f
boolean bStop = false; //Stop identical EX=Q(}9F<
FileAccessI fileAccessI = null; //File Access interface u9_ Fjm}&
UJ2Tj+
g#W)EXUR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v~9PS2
{ >}Za)
this.sURL = sURL; ZF>zzi+@
this.nStartPos = nStart; |s+y]3-_
this.nEndPos = nEnd; C&D!TR!K
nThreadID = id; RKx" }<#+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YOd0dKe
} Yc&yv
}]'Z~5T
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public void run() C5$1K'X@
{ i.C+{QH
while(nStartPos < nEndPos && !bStop) ULNU'6
{ ^/U-(4O05*
9m/v^
r1}YN<+,s
try{ W^Wr
URL url = new URL(sURL); =bi:<%"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g kT`C
httpConnection.setRequestProperty("User-Agent","NetFox"); cR*D)'/tl
String sProperty = "bytes="+nStartPos+"-"; ~K5eO-
httpConnection.setRequestProperty("RANGE",sProperty); X3P~z8_
Utility.log(sProperty); 1.6yi];6
WnyEdYA
RQ;pAO
InputStream input = httpConnection.getInputStream(); KC[ql}JP
//logResponseHead(httpConnection); D37N*9}
f![?og)I%
TmxhP nJ~
byte[] b = new byte[1024]; qH1[BsOx
int nRead; 4$oNh)+/h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 40w,:$
{ N7v7b<6
nStartPos += fileAccessI.write(b,0,nRead); ZEYT17g]
//if(nThreadID == 1) &!SdO<agZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p8aGM-+40W
} <%Zg;]2H`
_Ryt|# y
c|.~f+
Utility.log("Thread " + nThreadID + " is over!"); -~n^?0
bDownOver = true; *<c, x8\s9
//nPos = fileAccessI.write (b,0,nRead); 0Ihp`QGU:
} [+\=x[q
catch(Exception e){e.printStackTrace ();} 6vAq&Y{JB'
} *](maF~%C
} '[Ap/:/UY
.76T<j_
roSdcQTeT
//打印回应的头信息 3#<b!Yz
public void logResponseHead(HttpURLConnection con) A)/8j2
{ b{%p
for(int i=1;;i++) .fY1?$*6c
{ [#hpWNez(>
String header=con.getHeaderFieldKey(i); "%ou'\}
if(header!=null) 2.)xWCG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c5C 2xE}T
Utility.log(header+" : "+con.getHeaderField(header)); 094~ s
else WT;4J<O/
break; .0+=#G>
} :Aj8u\3!@
} GrPKJ~{6
ieo Naq
lQ(I/[qVd
public void splitterStop() -5B>2K F
{ (cAWT,
bStop = true; =;Ap+}
} s&&8~ )H
5-qk"@E W
v<CZ.-r\j
} &B?TX.
3>asl54
O=m_P}K
/* v%a)nv
**FileAccess.java utOATjB.z
*//文件访问(定位，写) *9Ta0e*
package NetFox; w{TZN{Y
import java.io.*; {x_SnZz&
#@%DY*w]v
sT8(f=^)8F
public class FileAccessI implements Serializable{ 9BR/zQ2
R. :~e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $.HZz
RandomAccessFile oSavedFile; ,'!x9 `
long nPos; Rn?Yz^ 1q
3lr9nBR
u*}[fQ`aF
public FileAccessI() throws IOException ]6s7?07m4
{ 8.JFQ/)i
this("",0); $[(amj-;l
} y950Q%B]
W3Gg<!*Uo
zy8Z68%E`*
public FileAccessI(String sName,long nPos) throws IOException Dnk}
{ b-!+Q)
oSavedFile = new RandomAccessFile(sName,"rw"); _UP=zW
this.nPos = nPos; c+S<U*
oSavedFile.seek(nPos); J)o.@+Q}
} :)JIKP%$\)
C?dQ QB$
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public synchronized int write(byte[] b,int nStart,int nLen) )T0%<(J
{ ~V34j:
int n = -1; _L8|ZV./
try{ "2'4b
oSavedFile.write(b,nStart,nLen); IhR;YM[K
n = nLen; pzr\<U`
} '0b!lVe
catch(IOException e) n<,:;0{
{ Sjb[v
e.printStackTrace (); vC#_PI
} fl@=h[g#t
x)}.@\&%
&JUHm_wd&S
return n; fI<|]c}P&J
} <b.O^_zQF
yj$a0Rgkv
o,NTIh
} ccR#<Pb6q
s8:-*VR9
P55QE+B
/* [k~}Fe)x
**SiteInfoBean.java ;bYS#Bid{V
*/ qQN|\u+co
package NetFox; %m/W4Nk
}R&5Ye
-tPia=^
public class SiteInfoBean { p[LPi5
VZz>)Kz:
2K:Rrn/cR
private String sSiteURL; //Site's URL 6[x6:{^J
private String sFilePath; //Saved File's Path ]&b>P ;j:
private String sFileName; //Saved File's Name u=QG%O#B
private int nSplitter; //Count of Splited Downloading File tRtoA5
C}'Tmi
{D{' \]+
public SiteInfoBean() 18eB\4NlD
{//nSplitter的缺省值为5 9B)<7JJX!J
//default value of nSplitter is 5 0 k(su
this("","","",5); 'G)UIjl
} QJ4=*tX)
ztEM>xsk
_8 C:Md`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {,X}Btnwp
{ F[@M?
sSiteURL= sURL; )lhPl
sFilePath = sPath; #@UzOQ>
sFileName = sName; aam6R/4
this.nSplitter = nSpiltter; S"<"e\\}"_
?9Hs,J
1 !8 b9
} X~2L
b# |
gm8FmjZtf
public String getSSiteURL() <$>Jsv
{ Bj`ZH~T
return sSiteURL; F1A7l"X]
} CT0 ~
a%YohfsY?U
lKSd]:3Xm
public void setSSiteURL(String value) S_ER^Pkg
{ }K.2
sSiteURL = value; 59MpHkr
} #?_8 *?
V44M=c7E
DG-XX.:z
public String getSFilePath() ]jRaR~[UN
{ HU1ZQkf
return sFilePath; bu:%"l
} `JAM]qB"
X/qLg+X
TgjM@ir
public void setSFilePath(String value) y#iQ
{ uGz>AW8a3
sFilePath = value; vuoD~=z
} .|g|X8X
s&)>gE\
i_{b*o_an
public String getSFileName() j3Ps<<eA
{ E[a|.lnV
return sFileName; G~X93J
} _I/uW|>
[XbNZ6
%8c2d
public void setSFileName(String value) M"\j7(
{ f=--$o0U~
sFileName = value; #V-0-n,`
} B,(zp#&yB
S{fFpe-
c( 8>|^M
public int getNSplitter() ?}ly`Js
{ "CY#_)
return nSplitter; Wi2Tg^
} > }fw7X
Bm$(4
_^MkC}8
public void setNSplitter(int nCount) x_oiPu.V
{ ?B['8ju
nSplitter = nCount; lN~V1(1B
} $'%.w|MJp
} 7GDrH/yK
jnIf(a
%f1>cO9[
/* .H#<yPty
**Utility.java UAEu.AT
*/ UlQS]f~
package NetFox; tDQuimYu7
]9PQKC2&
Me2qOc^Z-
public class Utility { sL!+&Id|
',bSJ4)Y
zPc kM)
public Utility() | IB4-p
{ P}~nL
f >$V:e([
/Bs42uJ3
} EWC{896,
uA;vW\fHr
//线程睡眠 C8W4~~1S
public static void sleep(int nSecond) 9D[Jn}E:
{ /8Ru O
try{ 0BrAgv"3a_
Thread.sleep(nSecond); $_f"NE}
} 3%L@=q
catch(Exception e) ><wYk)0E
{ O6"S=o&
e.printStackTrace (); 6%a:^f]
} @8eQ|.q]Q
} *?3c2Jg=E
Ku`u%5<
//日志 $(fhO
public static void log(String sMsg) .K`EflN
{ wCgi@\
System.err.println(sMsg); Ohn?>qQ
} d;hv_h
s2`Qh9R
H&SoVi_V
public static void log(int sMsg) o2rL&
{ S!8gy,7<J
System.err.println(sMsg); G$A=Tu~
} 0sfb$3y
} zVvL!
*ry}T=
-gB9476-
/* vHXCT?FuG
**TestMethod.java 8/s?Gz
*/ _b"K,[0o
package NetFox; `6xr:s
<7 xX/Z}M
"[dfb#0z`
public class TestMethod { O9ar|8y
^m['VK#?
''Hx&
public TestMethod() /Ref54
{ ///xx/weblogic60b2_win.exe N|e#&
try{ ?/q\S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '!<gPAVTzV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W<u,S
SiteFileFetch fileFetch = new SiteFileFetch(bean); CB^.N>'
fileFetch.start(); xi[\2g+
} )F_nK f"a
catch(Exception e){e.printStackTrace ();} 2rxz<ck(
&4{!5r
~@$RX:p
} K$KVm^`
\:4SN&I~
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public static void main(String[] args) \l1==,wk
{ 1ne3CA=
new TestMethod(); tID=I0D
} "\+.S]~
} 6d(D>a
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