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)); )p9n|C
} 7/!C
for(int i=0;i<nEndPos.length-1;i++) SJ+-H83x
{ ;#yz i2f
nEndPos = nStartPos[i+1]; .cog9H'
} 'p]qN;`'O$
nEndPos[nEndPos.length-1] = nFileLength; 0\*<k`dY
} %$?Q%
} ]%hI-
vUeel%
xTm&`Xo
//启动子线程 gg_(%.>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x[6Bc
for(int i=0;i<nStartPos.length;i++) v"_#.!V
{ @sO.g_yM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z@A1+kUS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), RE$-{i
nStartPos,nEndPos,i); |XG7UH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kcUt!PL
fileSplitterFetch.start(); Te#[+B?
} b"bj|qF~E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TY?io@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ve) :I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (@ sKE
nEndPos = " + nFileLength); n\9*B##
// fileSplitterFetch[nPos.length-1].start(); S-|$sV^cG
Ooy96M~_G
6mLE-( Z7
//等待子线程结束 <P-r)=^
//int count = 0; K\Q 1/})
//是否结束while循环 j,jUg}b
boolean breakWhile = false; QNEaj\
-.{7;6:(k
,CF~UX% bU
while(!bStop) 8;3FTF
{ ^o:5B%}#[
write_nPos(); >UH=]$0N
Utility.sleep(500); +?tNly`
breakWhile = true; <{kj}nxz
J1t?Qj;f3
j<?4N*S
for(int i=0;i<nStartPos.length;i++) ABGL9;.8
{ o*'3N/D~
if(!fileSplitterFetch.bDownOver) WU_Q 7%+QS
{ 8+F2 !IM
breakWhile = false; 5]JXXdt
break; DLZ63'
} 6}2Lt[>O
} omP7|
if(breakWhile) 8/v_uEG
break; VZR6oia
:+$_(*Z
2c]O Mtk
//count++; j)Gr@F>
//if(count>4) ccAEN
// siteStop(); "p\KePc;@
} `0N/ /Q
\g/E4U.+
P6rL;_~e
System.err.println("文件下载结束！"); S)?B I
} m`aUz}Y>c
catch(Exception e){e.printStackTrace ();} p9J(,}
} l[Oxf|
3kg+*]tLx
Uz_{jAhW]
//获得文件长度 L^}kwu#
public long getFileSize() QKxuvW
{ #a|5A:g%
int nFileLength = -1; 9AaixI
try{ **"sru;@=
URL url = new URL(siteInfoBean.getSSiteURL()); V6N#%(?3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ww*F}}(
httpConnection.setRequestProperty("User-Agent","NetFox"); Emo]I[<&q
V qf}(3K0
:T2K\@
int responseCode=httpConnection.getResponseCode(); \)hmg
if(responseCode>=400) Sob+l'U$
{ 2J$Uz,@
processErrorCode(responseCode); gnt[l0m
return -2; //-2 represent access is error +H_Z!T.@
} nS#;<p$\
X8<ygci+.5
GS@ wG
String sHeader; +8"H%#~
URwFNOM2
Im=E?t
for(int i=1;;i++) &Jz%L^
{ m6}"g[nN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NH/H+7,o
//Utility.log(in.readLine()); XUWza=BR"
sHeader=httpConnection.getHeaderFieldKey(i); @EvnV.
if(sHeader!=null) h fNBWN
{ nr}H;wB
if(sHeader.equals("Content-Length")) v{+*/NQ_
{ +%^D)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [z?XVl<
break; 4Q.70
} O<5bsKw'r
} "[G P)nC
else V.}U p+WL
break; M II]sF
} zKZ6Qjd8!
} s_|wvOW)'
catch(IOException e){e.printStackTrace ();} 4YJs4CB
catch(Exception e){e.printStackTrace ();} ^H>vJT
{k>m5L
;X>KP,/r$
Utility.log(nFileLength); /D~:Ufw
&'Ch[Wo]H
tfsG P]9$
return nFileLength; ]yyfE7{q
} ;tj_vmZ@R
"dt3peH
PGJ?=qXr#
//保存下载信息（文件指针位置） cCwT0O#d
private void write_nPos() w% M0Mu
{ ?mMd6U&J
try{ 7be?=c)+"
output = new DataOutputStream(new FileOutputStream(tmpFile)); ) ":~`Z*@
output.writeInt(nStartPos.length); }9'rTLM
for(int i=0;i<nStartPos.length;i++) Jyn>:Yq(
{ J{91 t |
// output.writeLong(nPos); kZ2+=/DYN
output.writeLong(fileSplitterFetch.nStartPos); eL],\\q
output.writeLong(fileSplitterFetch.nEndPos); uE>}>6)b
} xH0Bk<`V:
output.close(); M@.1P<:h
} 5D'8 l@7
catch(IOException e){e.printStackTrace ();} A="h}9ok
catch(Exception e){e.printStackTrace ();} JprZ6 >
} jtA Yp3M-$
@0aUWG!k
St?vd+(>
//读取保存的下载信息（文件指针位置） ^+pmZw90
private void read_nPos() mZORV3bN
{ *`\>J.
try{ ,30&VW##
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y|X[NSA
int nCount = input.readInt(); 7XZ!UC;i
nStartPos = new long[nCount]; PR Y)hb;1
nEndPos = new long[nCount]; Tf+B<B:
for(int i=0;i<nStartPos.length;i++) [scPs,5Y
{ K[sfsWQ.
nStartPos = input.readLong(); D[<8(~VP
nEndPos = input.readLong(); !j- 7,
} >:s:`Au
input.close(); xi-^_I
} <K)^MLgN
catch(IOException e){e.printStackTrace ();} 4bmpMF-
catch(Exception e){e.printStackTrace ();} O,7P6
} K,J:i^2
~;{)S}U@R
\wMr[_LW
private void processErrorCode(int nErrorCode) C!:\H<gI
{ >2_J(vm>
System.err.println("Error Code : " + nErrorCode); TkK- r(=
} M6?*\9E
!X8:#a(
"g0Ln5&
//停止文件下载 w+Ag!O}.L
public void siteStop() ~6R| a
{ |n0 )s% 8`
bStop = true; !Y5O3^I=u
for(int i=0;i<nStartPos.length;i++) m'Wz0b^BO
fileSplitterFetch.splitterStop(); 8c#u"qF
& %1XYpA.0
&B[$l`1
} ?QZ\KY
} 9c<lFZb;
//负责部分文件的抓取 z"R-Sme
**FileSplitterFetch.java q[r|p"TGov
*/ 5pz%DhjLo
package NetFox; 4e9mN~
@HR]b^2E
S&9{kt|BI
import java.io.*; i_V~SC`
import java.net.*; 55fV\3F|R
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8JGt|,
public class FileSplitterFetch extends Thread { )Nk^;[
R}BHRmSQ
'AHI;Z~Gk
String sURL; //File URL qbmy~\ZY
long nStartPos; //File Snippet Start Position C";F's)
long nEndPos; //File Snippet End Position Qu!Lc:oM?
int nThreadID; //Thread's ID nKch_Jb
boolean bDownOver = false; //Downing is over :v=Yo
boolean bStop = false; //Stop identical <kt,aMw[*
FileAccessI fileAccessI = null; //File Access interface (eSa{C\
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m@)K]0g<f
{ 59IxY ?
this.sURL = sURL; J'|qFS
this.nStartPos = nStart; 5|";L&`
this.nEndPos = nEnd; nRJcYl~ Y
nThreadID = id; Td}#o!4!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _yumUk-QW
} Em-88=XO
<S%M*j
#"=_GA^.{
public void run() "^yTH/m
{ g*TAaUs|n
while(nStartPos < nEndPos && !bStop) 6;k#|-GU&
{ $s$z"<
t(}\D]mj
k?KKb /&b
try{ #O* ytZ
URL url = new URL(sURL); noV]+1#"V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =.f]OWehu.
httpConnection.setRequestProperty("User-Agent","NetFox"); (@>X!]{$
String sProperty = "bytes="+nStartPos+"-"; hU@9vU<U
httpConnection.setRequestProperty("RANGE",sProperty); $xJVUV
Utility.log(sProperty); Rcfh*"k
yuWoz*:t
5k{a(I
InputStream input = httpConnection.getInputStream(); dr'#
//logResponseHead(httpConnection); d\+smED
1^TOTY
.|;`qUo
byte[] b = new byte[1024]; x~rIr#o
int nRead; ?>LsIPa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I#tn/\n
{ 7g[T#B'/x,
nStartPos += fileAccessI.write(b,0,nRead); F_$eu-y
//if(nThreadID == 1) XOAZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y4^6I$M7V
} xQT`sK+
[RTB|0Q
615, P/
Utility.log("Thread " + nThreadID + " is over!"); "X=l7{c/
bDownOver = true; =0cyGo
//nPos = fileAccessI.write (b,0,nRead); -y;SR+
} -L}crQl.'c
catch(Exception e){e.printStackTrace ();} 89?$xm_m
} *+{umfZy
} aOFF"(]Cl
LxC*{t/>8
E`}KVi57
//打印回应的头信息 #XE`8$
public void logResponseHead(HttpURLConnection con) +q[puFfl
{ ;9MsV.n
for(int i=1;;i++) OQIQ
{ bsO78a~=P
String header=con.getHeaderFieldKey(i); Ii_X^)IL(
if(header!=null) fH-V!QYGF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BrcT`MM[(=
Utility.log(header+" : "+con.getHeaderField(header)); I"eXoqh
else rZm|7A)i
break; h(*!s`1
} { AdPC?R`
} gpB3\
Q&S\?cKe
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public void splitterStop() Rs_bM@
{ `VM@-;@w
bStop = true; R/&Bze
} ,{!~rSq-l
Z<T%:F
Ke@zS9
} #Y6'Q8gf
#0V$KC*>
q|xJ)[AO
/* A6v<+`?
**FileAccess.java O:3LA-vA
*//文件访问(定位，写) ~OO&%\$k
package NetFox; [R:\
import java.io.*; `],'fT|,S
&>y[5#qOl
,g\%P5
public class FileAccessI implements Serializable{ D^V0kC p!F
xFvDKW)_X7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 })f4`$qf
RandomAccessFile oSavedFile; G41 gil6k
long nPos; 0 UdAF
R1u1
`&]<_Jc1
public FileAccessI() throws IOException 4 qMO@E_
{ #/!fLU@
this("",0); c]3% wL
} s8 S[w
BBnW0vAZ*
F=)9z+l#
public FileAccessI(String sName,long nPos) throws IOException wn2+4> |~p
{ )bN|*Bw3
oSavedFile = new RandomAccessFile(sName,"rw"); ~u|k1
this.nPos = nPos; l+g\xUP
oSavedFile.seek(nPos); 3{OY&
} ernZfd{H
1|/P[!u
".aypD)W
public synchronized int write(byte[] b,int nStart,int nLen) 1haNca_6,
{ WrWJ!
int n = -1; &-^|n*=g6
try{ ]r++YIg!j
oSavedFile.write(b,nStart,nLen); ,9jq @_
n = nLen; 1 ?X(q
} fT9z 4[M
catch(IOException e) /HCd52
{ uFxhr2 <z
e.printStackTrace (); 1NJ,If]
} ;:(kVdb
2ZHeOKJ-
t[gz#'
return n; AL*P2\8
} I{>U7i 5
N$#518
4-lG{I_S:
} 8w,U[aJm
$r0~&$T&
x\HHu]
/* t\YN\`XD
**SiteInfoBean.java d:KUJ Y.
*/ .1F(-mLd
package NetFox; Tc{r;:'G<
UG)J4ZX
zQY|=4NP
public class SiteInfoBean { N~I2~f
Q.SLiI
#XSs.i{
private String sSiteURL; //Site's URL 00s&<EM
private String sFilePath; //Saved File's Path 8&?kr/_Vr
private String sFileName; //Saved File's Name )C>4?)
private int nSplitter; //Count of Splited Downloading File &E98&[`7
_3_d;j#G U
Yr9>ATR
public SiteInfoBean() j#KL"B_A
{//nSplitter的缺省值为5 V?KACYd@O
//default value of nSplitter is 5 9rhIDA(wc
this("","","",5); w]n ,`r^
} (#zSVtZ
b-sbRR
5HWVK.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K.A!?U=
{ n,KOQI;
sSiteURL= sURL; ?sF<L/P0 F
sFilePath = sPath; Koh`|]N
sFileName = sName; uc6;%=%+
this.nSplitter = nSpiltter; AiUICf?{
?Bg<74
UzLe#3MU
} We^!(G
Rg/*)SKj
o_un=ygU
public String getSSiteURL() 1PwqWg-\\
{ %lL^[`AR
return sSiteURL; Bq}p]R3X
} M,0@@:
KEfn$\
B?}ZAw>
public void setSSiteURL(String value) k M/cD`
{ x)'4u6;d
sSiteURL = value; }=kf52Am,}
} -49z.(@ki
JaC =\\B
y@&Cn
public String getSFilePath() rh;@|/<l
{ u&Ze$z
return sFilePath; !ueyVE$1
} &w{""'
kYxb@Zn=|
M[wd.\ %
public void setSFilePath(String value) &_Py{Cv@Dw
{ e}qG_*
sFilePath = value; [UJC/GtjS
} fV[(s7vW
.]_Ye.}
+8+@Az[e0
public String getSFileName() jR/YG ru
{ sP1wO4M?{
return sFileName; \Y[
} #&+0hS
"tuBfA+f
;aA,H&
public void setSFileName(String value) ]fH U/%
{ mmC&xZ5f
sFileName = value; ]<z4p'F1%
} &m=Xg(G~c
r81YL
$+` YP
public int getNSplitter() r3a$n$Qw
{ *%JncK'
return nSplitter; S4RvWTtQV
} }wmn v
cr!6qv1
@WIcH:_w-
public void setNSplitter(int nCount) w9D<^(_}/
{ 7.4Q
nSplitter = nCount; w3lR8R]
} neW_mu;~Z
} %GUu{n<6
!6_lD0
Kp") %p#
/* (g2?&b iuz
**Utility.java G)28#aH
*/ I(fq4$
package NetFox; @NMFurm
^p#f B4z
6 W/S?F~{
public class Utility { ;Ab`b1B
XE]YKJ?|k
=PXQX(_
public Utility() UkrqHHpy
{ "oZ]/(
EL+6u>\-k
8%s^>.rG
} WN9<
$"[1yQ<p
//线程睡眠 z)Xf6&
public static void sleep(int nSecond) @/}{Trmg/
{ Dt,b\6
try{ & f7{3BK
Thread.sleep(nSecond); R }M'D15
} =jvM$
catch(Exception e) /sY(/ JE
{ =T5vu~[J/e
e.printStackTrace (); +}c '4hRv
} 4,L(
} IVD1mk
Q!/<=95E
//日志 dzDh V{
public static void log(String sMsg) I}/o`oc
{ Gv[W)+3f
System.err.println(sMsg); 'Im7^!-d
} ?(GMe>
@AUx%:}0Y:
xZjl_bJ
public static void log(int sMsg) jR7 , b5
{ qq}EXq^
System.err.println(sMsg); vlCjh! x
} a5WVDh,cR
} DX.u"&Mm
\dj&4u3
lJ@2N$w
/* CBx1.xL
**TestMethod.java >nmby|XtW
*/ BMU}NZA
package NetFox; kzr9-$eb
]kLs2? \
R`ajll1
public class TestMethod { TF 6_4t6
KquHc-fzqr
"m +Eu|{
public TestMethod() N8(xz-6
{ ///xx/weblogic60b2_win.exe Nj||^k
try{ `*e',j2}UU
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P(G$@},W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L*bUjR,C
SiteFileFetch fileFetch = new SiteFileFetch(bean); fV*x2g7w
fileFetch.start(); s]`&9{=E
} I_.(&hMn
catch(Exception e){e.printStackTrace ();} QQPbKok>
BZEY^G
I9N?zmH
} 9Q-/Yh
'-3AWBWI1
]O',Ei^
public static void main(String[] args) XyJ*>;q
{ A/RHb^N
new TestMethod(); <aa#OX
} 4q[C' J
} *#e%3N05_
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