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)); ('~LMu_
} &Qm@9Is
for(int i=0;i<nEndPos.length-1;i++) [hsds\
{ $Q0n
nEndPos = nStartPos[i+1]; 7[7"A
} JS77M-Ac
nEndPos[nEndPos.length-1] = nFileLength; 92{\B- l
} ?ubro0F:
} .C(tMF]D,
JI5Dy>u:
X?Au/
//启动子线程 a{e4it
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B<-Wea
for(int i=0;i<nStartPos.length;i++) (.,G=\!
{ >3bCTE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,?3G;-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z{>Rc"%\
nStartPos,nEndPos,i); GthYzd:'hJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8>V5dEbx'
fileSplitterFetch.start(); Ts9uL5i
} I:.s_8mH}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %znc##j)q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v,t:+ !8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]R*A
nEndPos = " + nFileLength); ]f3>-)$*
// fileSplitterFetch[nPos.length-1].start(); PW4q~rc=:
NVs@S-rpX
|hQ;l|SWg
//等待子线程结束 _4f;<FL
//int count = 0; aDCwI:Li(
//是否结束while循环 v>56~AJ
boolean breakWhile = false; 8ipez/
Debv4Gr;^
=lC7gS!U
while(!bStop) n:X y6H
{ = /8cp
write_nPos(); 3a|\dav%
Utility.sleep(500); m kexc~l
breakWhile = true; oU/5 a>9~
cNH7C"@GVu
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for(int i=0;i<nStartPos.length;i++) 54/=G(F
{ DI%saw
if(!fileSplitterFetch.bDownOver) r/1(]#kOX
{ [ 3HfQ
breakWhile = false; ctUp=po
break; YzWz|
} #Dac~>a'
} *h|U,T7ew
if(breakWhile) A=4OWV?
break; /j^
0`hdMLONR
n*$ g]G$
//count++; Je{ykL?N
//if(count>4) v2?ZQeHr_(
// siteStop(); Yw9GN2AG
} ry!!9Z>9n
W4N{S.#!
F5Va+z,jg
System.err.println("文件下载结束！"); j@9T.P1
} Q20%"&Xp]
catch(Exception e){e.printStackTrace ();} he4(hX^
} )*[3Vq
BzzTGWq\
:Sma`U&
//获得文件长度 g5yJfRLxp
public long getFileSize() ]?*wbxU0
{ r3Ykz%6
int nFileLength = -1; $C\BcKlmv
try{ :%.D78&
URL url = new URL(siteInfoBean.getSSiteURL()); ?8$Q-1=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z@Y;r=v
httpConnection.setRequestProperty("User-Agent","NetFox"); oQ#8nu{k
m2o0y++TjW
]tD]Wx%
int responseCode=httpConnection.getResponseCode(); SdWV3
if(responseCode>=400) =}*0-\QG
{ *or(1DXP8
processErrorCode(responseCode); putrSSL}
return -2; //-2 represent access is error ?EL zj
} _LPHPj^Pg
J *yg&
Ib`XT0k
String sHeader; /\Ef%@
9UkBwS`
}}[2SH'nH
for(int i=1;;i++) "#]$r
{ :0ep(<|;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +H.`MZ=
//Utility.log(in.readLine()); R8Tx[CJ5
sHeader=httpConnection.getHeaderFieldKey(i); z}@7'_iJ
if(sHeader!=null) G#CXs:1pd+
{ liZxBs :%i
if(sHeader.equals("Content-Length")) ?0SEMmp`H
{ *Uh!>Iv;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RpK@?[4s
break; sRW<me;
} K8~d^G
} +:f"Y0
else hc1N~$3!G
break; `gJ(0#ac
} SIllU
} yr6V3],Tp
catch(IOException e){e.printStackTrace ();} "zc l|@
catch(Exception e){e.printStackTrace ();} R=dC4;
O=lzT~G|4
?(PKeq6
Utility.log(nFileLength); nu^436MSOa
-12U4h<e
a}d@ T
return nFileLength; d1*<Ll9K
} ebq4g387X
mR~&)QBP.
: +u]S2u{
//保存下载信息（文件指针位置） &L:!VL{I
private void write_nPos() GVz6-T~\>
{ G)YcJv7
try{ *_e3 @g
output = new DataOutputStream(new FileOutputStream(tmpFile)); N;R^h? '
output.writeInt(nStartPos.length); q| 7(
for(int i=0;i<nStartPos.length;i++) ==B6qX8T
{ ,I9bNO,%JK
// output.writeLong(nPos); BWNi [^]
output.writeLong(fileSplitterFetch.nStartPos); >eaaaq9B-
output.writeLong(fileSplitterFetch.nEndPos); so; ]&
} G5!^*jf
output.close(); \^LFkp
} <$YlH@;)`a
catch(IOException e){e.printStackTrace ();} Lr+$_ t}r
catch(Exception e){e.printStackTrace ();} D=$)n_F
} #z(]xI)"
6LZCgdS{
+mPx8P&%
//读取保存的下载信息（文件指针位置） -/4P3SG/
private void read_nPos() Kq!3wb;
{ }b}m3i1
try{ yVfC-Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vX>)je5#
int nCount = input.readInt(); ta0|^KAA
nStartPos = new long[nCount]; _GPe<H
nEndPos = new long[nCount]; <%^&2UMg
for(int i=0;i<nStartPos.length;i++) Ni>[D"|
{ Smh,zCc>s
nStartPos = input.readLong(); vI?, 47Hj+
nEndPos = input.readLong(); [7-?7mp!B
} 3^ClAE"8
input.close(); TvM~y\s
} e.%nRhSs3
catch(IOException e){e.printStackTrace ();} 8|^7ai[am
catch(Exception e){e.printStackTrace ();} WxDh;*am:
} AX INThJ
]|@^1we
"4Nt\WQ
private void processErrorCode(int nErrorCode) +_!QSU,@
{ XZf$K_F&M
System.err.println("Error Code : " + nErrorCode); bD^owa
} YUb_y^B^
RCrCs
;a/E42eN;
//停止文件下载 :0/7,i
public void siteStop() ZcsZ$qt^
{ 5-V pJ
bStop = true; $qiya[&G4
for(int i=0;i<nStartPos.length;i++) 9sP0D
fileSplitterFetch.splitterStop(); B~mj 8l4
:s,Z<^5a)g
W_=f'yb:E
} Qrv<lE1V;
} 1 zZlC#V
//负责部分文件的抓取 kstIgcI
**FileSplitterFetch.java ?< />Z)
*/ 3Vwh|1?
package NetFox; x2EUr,7
F [M,]?
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import java.io.*; siaG'%@*r
import java.net.*; Gt1U!dP
PCvWS.{
!if
public class FileSplitterFetch extends Thread { _$'ashF
/z!%d%"
}C:r9?T
String sURL; //File URL E./2jCwI(Y
long nStartPos; //File Snippet Start Position :/#rZPPF
long nEndPos; //File Snippet End Position > I?IPQB
int nThreadID; //Thread's ID 8}[).d160
boolean bDownOver = false; //Downing is over XX@ZQcN
boolean bStop = false; //Stop identical T%Lx%Qn
FileAccessI fileAccessI = null; //File Access interface _#niyW+?~
do%&m]#;
IPk4 ;,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .H|-_~Yx|
{ *|0 -~u%q
this.sURL = sURL; j.Hf/vi`z
this.nStartPos = nStart; +0&/g&a\R
this.nEndPos = nEnd; "[k3kAm
nThreadID = id; #R"*c hLV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p?!/+
} xAr\gu
8mMQ[#0:}
3mgD(,(^
public void run() =&]L00u.
{ H)?z #x
while(nStartPos < nEndPos && !bStop) h\o.&6sd
{ j^'go&p
8Wx=p#_
%;_MGae
try{ %{|pj +
URL url = new URL(sURL); \<' ?8ri#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DF= *_,2/
httpConnection.setRequestProperty("User-Agent","NetFox"); CY1Z'
String sProperty = "bytes="+nStartPos+"-"; +R&gqja
httpConnection.setRequestProperty("RANGE",sProperty); -~1~I e2
Utility.log(sProperty); (e~Nq
| (93gJ
vQCy\Gi
InputStream input = httpConnection.getInputStream(); }j%5t ~Qa
//logResponseHead(httpConnection); XZ7Lk)IR
"x-j~u?
TDh5lI
byte[] b = new byte[1024]; N['.BN
int nRead; tA;}h7/Lc~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0;k# *#w
{ 3n _htgcv
nStartPos += fileAccessI.write(b,0,nRead); siI;"?
//if(nThreadID == 1) {.yB'.k?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WcAkCH!L
} *pq\MiD/
QV!up^Zso
N)T}P\l
Utility.log("Thread " + nThreadID + " is over!"); ]esC[r]PJ
bDownOver = true; ^sw?gH*
//nPos = fileAccessI.write (b,0,nRead); EwN}l
} :> '+"M2r
catch(Exception e){e.printStackTrace ();} d-qUtgqV86
} l**X^+=$
} dH!*!r>
6Oq7#3]
w{KavU5W
//打印回应的头信息 ]G\}k
public void logResponseHead(HttpURLConnection con) AH^/V}9H
{ w<#!h6Y=
for(int i=1;;i++) +[VXs~I q
{ Psf#c:*_)
String header=con.getHeaderFieldKey(i); kmW4:EA%
if(header!=null) J5qZFD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s[jTP(d)8
Utility.log(header+" : "+con.getHeaderField(header)); K0~rN.C!0
else ?4,T}@P
break; 1?}T=)3+$
} DQ3<$0
} dN q$}
h{Y",7]!
N7"W{"3D
public void splitterStop() .Mbz3;i0
{ &d!GImcxQ
bStop = true; *@5@,=d
} 9;{CIMg&
as|<}:V
qX%_uOw:%
} 1zv'.uu.,
:;}P*T*PU
?}oFg#m-<L
/* `?]k{ l1R
**FileAccess.java 9{l}bu/u
*//文件访问(定位，写) dPlV>IM$z
package NetFox; T)/eeZ$
import java.io.*; FPz9N@M%Q
o/E >f_k[
oR'm2d^
public class FileAccessI implements Serializable{ afVT~Sf{
+(Ae4{z"1+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /v{I
RandomAccessFile oSavedFile; )nkY_'BV
long nPos; 4(+PD&_J
y(#e}z:
Et$2Y-L.
public FileAccessI() throws IOException ^8WRqQdx
{ t.<i:#rj>l
this("",0); |Cv!,]9:r
} (.:e,l{U%
ah"o~Cbj
/uc>@!F
public FileAccessI(String sName,long nPos) throws IOException I7onX,U+
{ ="+#W6bZT
oSavedFile = new RandomAccessFile(sName,"rw"); z/-=%g >HA
this.nPos = nPos; d]9z@Pd
oSavedFile.seek(nPos); 2/?|&[
} ch]IzdD
#a#F,ZT
}jXfb@`K
public synchronized int write(byte[] b,int nStart,int nLen) O-wzz
{ -7ep{p-
int n = -1; sJZiI}Xc
try{ >4TO=i
oSavedFile.write(b,nStart,nLen); i-1op> Y
n = nLen; `5*}p#G
} sHj/;
catch(IOException e) 3o*YzwRt
{ -).C
e.printStackTrace (); )0`C@um
} 81F9uM0
vM={V$D&
e\rp)[>'
return n; Rq-ZL{LR7
} ]Wup/o
b%+Xy8a
zLQx%Yg!
} 0GLM(JmK
tQVVhXQ7
5P bW[
/* kh<2BOV
**SiteInfoBean.java h[ ZN+M
*/ ?6!LL5a.
package NetFox; u8^lB7!e/
6Wn1{v0
Iu{V,U
public class SiteInfoBean { gYj'(jB
%b0*H_ok7
ZSw.U:ep$s
private String sSiteURL; //Site's URL U$g?!Yl0
private String sFilePath; //Saved File's Path Ri'n
private String sFileName; //Saved File's Name l;U?Z'n
private int nSplitter; //Count of Splited Downloading File lZ0 =;I
`cO:<^%
xw%0>K[
public SiteInfoBean() x-c"%Z|
{//nSplitter的缺省值为5 d9ihhqq3}
//default value of nSplitter is 5 -Za/p@gM
this("","","",5); PF2nLb2-
} yZ:qU({KhD
L];b<*d
hZ3bVi)L\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #$vEGY}1
{ G3]4A&h9v~
sSiteURL= sURL; DIvHvFss
sFilePath = sPath; J,G lIv.A
sFileName = sName; GILfbNcd
this.nSplitter = nSpiltter; X]=t>
`/g UV
VQI3G
} ]_Xlq_[/r
E]6 6]+;0_
]Dzlp7Y}
public String getSSiteURL() zT/\Cj68
{ l2d{ 73h
return sSiteURL; +(*DT9s+
} 'yth'[
BY*Q_Et
h![#;>(
public void setSSiteURL(String value) >7r!~+B"9'
{ \9d$@V
sSiteURL = value; Qd6FH2Pl
} +V+a4lU14
K^$=dLp
H"KCK6
public String getSFilePath() 07)yG:q*x
{ +#By*;BJ
return sFilePath; eQ"E
} _U0f=m
t Pf40`@
jal-9NV)!
public void setSFilePath(String value) H-%v3d>3
{ YP9^Bp{0
sFilePath = value; ccnK#fn v
} -+5>|N#
fV:83|eQ
X|[`P<'N<
public String getSFileName() eq"]%s
{ +{>=^9%X
return sFileName; fatf*}eln
} |'.
Q^I\cAIB
,PZ ge
public void setSFileName(String value) o.\oA6P_
{ CNIsZv@Q
sFileName = value; ~v83pu1!2s
} <| &Npd'
or]IZ2^n
*qMY22X
public int getNSplitter() iO[<1?
{ -![|}pX
return nSplitter; _~pbqa,
} "mNq&$
X?$_Sd"G+5
QM]YJr3rE
public void setNSplitter(int nCount) FC*[*
{ oE~Bq/p
nSplitter = nCount; X jX2]
} VD:/PL
} qFNes)_r
CP{cAzHO
bF(f*u
/* M[uA@
**Utility.java &=Wlaa/,&
*/ LK"69Qx?5q
package NetFox; eY\yE"3
MS]r:X6
gdoLyxQ
public class Utility { `@ FYkH
k'"%.7$U!
MWL% Bz
public Utility() f9\X>zzB2|
{ g[t [/TV
`g})|Gx
)/EO&F
} 'ah[(F<*@e
)Beiu*
//线程睡眠 ?rup/4|
public static void sleep(int nSecond) 3&/Ixm:
{ ${)b[22":
try{ #=v~8
Thread.sleep(nSecond); +U.I( 83F
} 7!$^r$t
catch(Exception e) -tNUMi'
{ !YJs]_Wr
e.printStackTrace (); T n}s*<=V
} |&[EZ+[
} @fV9 S"TcM
69 o7EA
//日志 |a%Tp3Q~
public static void log(String sMsg) PzR[KUK
{ Z:7fV5b(
System.err.println(sMsg); z"4~P3>{g
} BX^tR1
sse.*75U
$a%MOKr
public static void log(int sMsg) M|[oaanY'
{ t.'!`5G
System.err.println(sMsg); 0C*7K?/
} EU/8=JA1
} kM@zyDn,
zA"`!}*
i2^>vYCsl
/* {91nL'-'
**TestMethod.java 0<B$#8
*/ tdaL/rRe
package NetFox; Lu0x (/
F*K_+ ?m
|B2+{@R
public class TestMethod { {GcO3G#FZ
~| 6[j<ziL
%9RF
public TestMethod() !#"zTj
{ ///xx/weblogic60b2_win.exe =4!e&o
try{ C\/L v.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6B ?twh)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @Pzu^
SiteFileFetch fileFetch = new SiteFileFetch(bean); E=w1=,/y
fileFetch.start(); 14'45
} .k \@zQ|Ta
catch(Exception e){e.printStackTrace ();} B !=F2
gOOPe5+ J
Vl!6W@g
} (NnH:J`
t>B;w14
<kd1Nrr!p
public static void main(String[] args) U~l$\c
{ '!a'ZjYyi
new TestMethod(); d$AWu{y
} 5-xX8-ElYz
} E1U",CMU
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