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)); RwHXn]1
} Os]M$c_88
for(int i=0;i<nEndPos.length-1;i++) j~> #{"C
{ qiJ;v1
nEndPos = nStartPos[i+1]; j0NPd^
} I}3K,w/7mi
nEndPos[nEndPos.length-1] = nFileLength; *Z(C')7r
} 9 f/tNQ7W
} e';c8WF3E
[<Puh
#yxYL0CcA:
//启动子线程 Q#bo!]H{t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *3oQS"8
for(int i=0;i<nStartPos.length;i++) oQB1fs
{ ttt&sW`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +/8?+1E ^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O3GaxM\x
nStartPos,nEndPos,i); UZ0O j5B.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K`2DhJC
fileSplitterFetch.start(); OtqLigt&l
} \K=PIcH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IUG.q8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 45JLx?rN_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +@v} (
nEndPos = " + nFileLength); 2xm?,p`
// fileSplitterFetch[nPos.length-1].start(); Y0'^S<ox
#Jb$AA!z
Mi-9sW
//等待子线程结束 +& Qqu`)?F
//int count = 0; }('QIvq2
//是否结束while循环 6%axbB
boolean breakWhile = false; l'R`XGT
IMEoov-x
(jMp`4P
while(!bStop) }Ec"&
{ GY :IORuA4
write_nPos(); Ghe=hhZ
Utility.sleep(500); ai2}vR
breakWhile = true; 7nIMIkT:
ZS;kCdL
ZXkAw sr
for(int i=0;i<nStartPos.length;i++) AG=1TZI"
{ >qZRIDE5$
if(!fileSplitterFetch.bDownOver) %uMsXa
{ y[eNM6p
breakWhile = false; M,lu)~H
break; y5 +&P
} p 1fnuN |,
} (#BA{9T,^
if(breakWhile) Dn!V)T
break; Fm{y.URo
Etk<`GRfA
pswppC6f
//count++; w|#79,&
//if(count>4) 9 f+7vCA
// siteStop(); %QkvBg*
} ?os0JQVB
b6VAyTa
1Qkuxw
System.err.println("文件下载结束！"); }DwXs`M7
} Q5ao2-\
catch(Exception e){e.printStackTrace ();} s#sXr
} }])f^
.!! yj,bQz
sk/Mh8z
//获得文件长度 bZJiubBRI
public long getFileSize() ea/6$f9^
{ N~YeAe~+
int nFileLength = -1; X} 8U-N6)
try{ $S/8T
URL url = new URL(siteInfoBean.getSSiteURL()); D':A-E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *n\qV*|6bI
httpConnection.setRequestProperty("User-Agent","NetFox"); )nVx 2m4
U)6JJv
]5CFL$_Q{
int responseCode=httpConnection.getResponseCode(); dY^~^<{Lj
if(responseCode>=400) MDt4KD+bZ
{ .d,Zx
processErrorCode(responseCode); To95WG7G
return -2; //-2 represent access is error 2Ev,dWV
} +!wc(N[(2
xDS9gGr
&v88xs
String sHeader; b1"wQM9
0&@6NW&Mu
48VsHqG
for(int i=1;;i++) vF1$$7k
{ ,$>Z= ~x*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e V#H"fM
//Utility.log(in.readLine()); c{0?gt.
sHeader=httpConnection.getHeaderFieldKey(i); sy?W\(x
if(sHeader!=null) fC[gu$f][
{ CJ>=odK[
if(sHeader.equals("Content-Length")) O jmz/W
{ %G*D0pE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qK pU.rP
break; zjS<e XLs[
} EWi@1PAZK
} :yeTzIz]
else ?T&D@Ohsx
break; nNr3'6lz
} BH1To&ol
} aJts
catch(IOException e){e.printStackTrace ();} >#Yq&@G
catch(Exception e){e.printStackTrace ();} )sr]}S0
Qy%/+9L
=v}.sJ V?
Utility.log(nFileLength); Lj#6K@u@Z
'S\H% -
'lF|F+8
return nFileLength; 6 s/O\A
} nK[$ID
-=Hr|AhE
m[XN,IE#u
//保存下载信息（文件指针位置） rv[\2@}
private void write_nPos() 0 N(2[s_A
{ R:E:Y|&#
try{ LxO'$oKZV
output = new DataOutputStream(new FileOutputStream(tmpFile)); gYZgo
output.writeInt(nStartPos.length); xHmc8G$zu
for(int i=0;i<nStartPos.length;i++) ? "gy`oCv
{ 6r`g+Js/
// output.writeLong(nPos); 6)8']f
output.writeLong(fileSplitterFetch.nStartPos); +}!eAMQ
output.writeLong(fileSplitterFetch.nEndPos); $i hIHl6'
} C%&7,F7
output.close(); ))Nc|`
} 0#ph1a<
catch(IOException e){e.printStackTrace ();} -MZ Eli g
catch(Exception e){e.printStackTrace ();} pJIH_H
} RDbA"e5x
_gHJ4(?w
f{J7a1 `_
//读取保存的下载信息（文件指针位置） "(5}=T@,
private void read_nPos() pfG:PrZ
{ d$ /o\G
try{ (.cT<(TB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d0,I]"
int nCount = input.readInt(); U8dwb
nStartPos = new long[nCount]; S70ERRk
nEndPos = new long[nCount]; Co M8
for(int i=0;i<nStartPos.length;i++) oj/tim
{ %2{E'^#)p-
nStartPos = input.readLong(); BBDOjhik
nEndPos = input.readLong(); hf'3yEm
} n\ZFPXP
input.close(); 5"sF#Y&
} Q'N<jX[
catch(IOException e){e.printStackTrace ();} j(SQNSFD
catch(Exception e){e.printStackTrace ();} 6\`,blkX
} c:bB4ch}
s}.nh>Q
AxeWj%w@
private void processErrorCode(int nErrorCode) ;J:YNup
{ -%A6eRShk
System.err.println("Error Code : " + nErrorCode); _^B+Xo@E-
} tnsYY
;rFa I^
&45.*l|mo
//停止文件下载 ;RrfE8mGj
public void siteStop() ZE9*i}r
{ 'K`)q6m
bStop = true; F'K{=
for(int i=0;i<nStartPos.length;i++) 1+^c3Dd`
fileSplitterFetch.splitterStop(); o)$sZ{` ="
6l=n&YO
6 3HxQH
} 3K'3Xp@A
} (GeJBw,Q
//负责部分文件的抓取 6x{B
**FileSplitterFetch.java oyHjdPdY#
*/ 6@d( <Z
package NetFox; mr*zl*
\+,jM6l}-
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import java.io.*; n4:WM+f4
import java.net.*; 27MgwX NQ
%VdJ<=@
qP"m819m
public class FileSplitterFetch extends Thread { {\%x{
.VI2V-Q
PBUc9/
String sURL; //File URL )a.U|[:y[+
long nStartPos; //File Snippet Start Position .8,lhcpY
long nEndPos; //File Snippet End Position 2@ad!h
int nThreadID; //Thread's ID -Oo$\=d
boolean bDownOver = false; //Downing is over ;c'jBi5W
boolean bStop = false; //Stop identical F8pLA@7[
FileAccessI fileAccessI = null; //File Access interface g><sZqj8tt
/5o~$S
"e(Nh%t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @M(vaJB8u
{ , w_Ew
this.sURL = sURL; v/kYyz
this.nStartPos = nStart; eVy,7goh
this.nEndPos = nEnd; }NUP[%
nThreadID = id; 8T%z{A1T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 old}}>_
} <mpkkCl,
;xb:{?
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public void run() k`N)-`O7
{ eX=W+&lj
while(nStartPos < nEndPos && !bStop) AttDD{Ta
{ Q%85,L^U
fQv^=DI#
4WNWn#M
try{ <5nz:B/
URL url = new URL(sURL); O=yUAAD$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'a0$74fz
httpConnection.setRequestProperty("User-Agent","NetFox"); z-()7WY
String sProperty = "bytes="+nStartPos+"-"; k:c)|2
httpConnection.setRequestProperty("RANGE",sProperty); Oh|Hy/&6W
Utility.log(sProperty); j/9'L^]
M[X& Q
8&3G|m1-2
InputStream input = httpConnection.getInputStream(); i |C'_gw`n
//logResponseHead(httpConnection); @P%&Dha
S3 &L
TEY%OIzU+
byte[] b = new byte[1024]; 3.8d"
int nRead; [1N*mY;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wp} PQw:
{ rHP5;j<]
nStartPos += fileAccessI.write(b,0,nRead); -{ZRk[>Z
//if(nThreadID == 1) <Q%\pAP}b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (pAGS{{
} l2$6ojpo
Peb;XI
dC)@v]#h
Utility.log("Thread " + nThreadID + " is over!"); GUMO;rZs
bDownOver = true; ?-6oh~W<
//nPos = fileAccessI.write (b,0,nRead); z0c_&@uj*
} c$>Tfa'H
catch(Exception e){e.printStackTrace ();} Z5+qb
} './s'!Lj
} "/wZtc
oKzLt
X+iUT
//打印回应的头信息 b^rPw@
public void logResponseHead(HttpURLConnection con) _%Jqyc"-
{ 0p8(Q
for(int i=1;;i++) I>:M1Yc0
{ f~t*8rG~m
String header=con.getHeaderFieldKey(i); b1_HDC(
if(header!=null) *_@8v?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _},u[+
Utility.log(header+" : "+con.getHeaderField(header)); .h{`e>d
else B!6?+<J"
break; yyG:Kl
} 9z,V]v=
} .%.J Q
>/GVlXA'
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public void splitterStop() !@5B:n*
{ EE-jU<>|
bStop = true; ]Z6==+mCP
} E{|j
aNw8][
Y=\;$:L[
} jgbE@IA@!'
cjp H hoW
3lQGU
/* $fL2w^ @
**FileAccess.java "/g/Lc
*//文件访问(定位，写) a|{RK}|3
package NetFox; ^GHA,cSf
import java.io.*; F^z&s]^~
9F@Q
d%8hWlffz
public class FileAccessI implements Serializable{ 0escp~\Z
!-)Hog5\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9+_SG/@
RandomAccessFile oSavedFile; |]*]k`o<)
long nPos; v?vm-e
DavpjwSn
:[A>O(
public FileAccessI() throws IOException }y;s(4
{ *\L\Bzm
this("",0); ncjtv"2R
} z^'3f!:3
:*k
V]&0"HX2r!
public FileAccessI(String sName,long nPos) throws IOException <XDYnWz
{ &3#19v7/
oSavedFile = new RandomAccessFile(sName,"rw"); x(ue |UG
this.nPos = nPos; /J9|.];%r
oSavedFile.seek(nPos); unY+/p $
} /-4rcC
W!MO}0s
%L,mj
public synchronized int write(byte[] b,int nStart,int nLen) B}Qpqa=_c
{ BUvE~l.,|
int n = -1; $t}t'uJ
try{ __O@w.
oSavedFile.write(b,nStart,nLen); w7+3?'L
n = nLen; OXAr..
} $qO%lJ:
catch(IOException e) 8A}cxk
{ @|BaZq,g
e.printStackTrace (); Te_%r9P|2
} > yk2
?%K7IJ%
VB=$D|Ll
return n; #6* j+SX^
} %PW_v~sg
2)cq!Zv
2SVBuV/R
} }M*yE]LL;Z
ZgarxV*
3V2dN)\
/* D;nm~O%
**SiteInfoBean.java M^S <G
*/ :rR)rj'
package NetFox; f2ea|l
m?*}yM
OpWTw&B"+
public class SiteInfoBean { \%[sv@P9s
$S Kax#[
O1xK\ogv
private String sSiteURL; //Site's URL _ x8gEK8
private String sFilePath; //Saved File's Path t`%Xxxu
private String sFileName; //Saved File's Name 7\.{O$Q
private int nSplitter; //Count of Splited Downloading File oA+/F]XJ
}Y9= 3X
9eR4?^(3!
public SiteInfoBean() *,az`U
{//nSplitter的缺省值为5 b5!D('w>]
//default value of nSplitter is 5 .! 'SG6 q
this("","","",5); MEKsL7
} VO u/9]a
;[)O{%s
?E +[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Fw.df<
{ mQd L"caA
sSiteURL= sURL; z.Y`"B'j`
sFilePath = sPath; K)DpC*j
sFileName = sName; J> Z.2
this.nSplitter = nSpiltter; !pTi.3
VB&`S+-
[a201I0 -
} o|`%>&jP
<b>g^ `}?D
+PAb+E|,
public String getSSiteURL() {#U3A_y
{ W!jg
return sSiteURL; lf2Q
} <ddXvUCX
fmgXh)=
CqFk(Td9-D
public void setSSiteURL(String value) ag02=}Q'r
{ 2e_m>I
sSiteURL = value; 2-$O$&s.
} X^o0t^
1Y+g^Z;G
z*,J0)<Q
public String getSFilePath() A r,fmq
{ o{[w6^D7
return sFilePath; |&u4Q /0
} dQljG.PiK
BS*Y3$
XU5GmGu_+
public void setSFilePath(String value) AJYZ`
{ }t%2giJ
sFilePath = value; pE4yx5r5
} h[(.
.QVN&UyZ
9 `+RmX;m
public String getSFileName() T;C0t9Yew
{ 'f_[(o+n
return sFileName; 8{4SaT.-Rm
} P1G;JK
W!Fu7a
2H,n"-9+
public void setSFileName(String value) !-AK@`i.
{ *e,GXU@
sFileName = value; {ovW6#
} i+@t_pxc
%LjhK,'h
\%/Y(YVm
public int getNSplitter() &"6%D|Z0
{ +bdjZD3
return nSplitter; L)"E_
} JRr'81\
h?7@]&VJ
b}HwvS:
public void setNSplitter(int nCount) CaB@,L
{ S; Fj9\2)I
nSplitter = nCount; B`w@Xk'D
} pq +~|
} )0XJOm
eKvQS}11
@:w[(K[^b/
/* Qv B%X)J
**Utility.java Lq#$q>!K
*/ )(V!& w6
package NetFox; \AY*x=PF
#-7w|
UPcx xtC
public class Utility { 8~|tl,
'U*Kb
Y]neTX [ef
public Utility() g9G 8;
{ jM[]Uh
uRnSwJ"hE
?#gYu%7DN
} >A.m`w
2)T.Ci cx
//线程睡眠 +`&-xq76
public static void sleep(int nSecond) M32Z3<
{ l<-0@(x)
try{ ov|/=bzro
Thread.sleep(nSecond); WUK{st.z
} aTFT'(O,
catch(Exception e) PzH#tG&.j
{ t|]2\6acuc
e.printStackTrace (); D<J,3(Yu
} $.KDnl^
} 4fL/,j/^
n-x%<j(Xf
//日志 7-j=he/
public static void log(String sMsg) Om5+j:YM
{ #,;X2%c
System.err.println(sMsg); #xNXCBl]O
} \9%RY]TK3
ICm/9Onh&
4h$W4NJK
public static void log(int sMsg) VWT\wAL
{ (( {4)5}
System.err.println(sMsg); XAb-K?)
} \[Q*d
} |m>{< :
0u=FlQ }h
EL:Az~]V
/* uoMDf{d
**TestMethod.java [`U9
*/ dW9Ci"~v
package NetFox; f[+N=vr
Q}|QgN
(4"Azo*~![
public class TestMethod { L9^h.Y7
V[fcP;
!A=>B=.|D
public TestMethod() Q|Go7MQZ@k
{ ///xx/weblogic60b2_win.exe <~iA{sY)O
try{ 'w`3( ':=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vJfj1 f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pa2cM%48
SiteFileFetch fileFetch = new SiteFileFetch(bean); *,#T&M7D
fileFetch.start(); n+H);Dg<8
} DcX,o*ec!
catch(Exception e){e.printStackTrace ();} B`/p[U5
,#hx%$f}d
BiI`oCX
} $94l('B6H
ZuVes?&j
L%5g]=
public static void main(String[] args) }1? 2
{ /5r!Fhx
new TestMethod(); yQdoy^d/4
} I1fUV72
} BjAmM*k
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