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)); t1y4 7fX6
} )TH@#1
for(int i=0;i<nEndPos.length-1;i++) 0=E]cQwh
{ $H>W|9Kg,
nEndPos = nStartPos[i+1]; *w&Y$8c(
} EJNU761
nEndPos[nEndPos.length-1] = nFileLength; fsWTF<Y
} 'CkIz"Wd
} 'y3!fN=h
ITT@,
OH(waKq2I
//启动子线程 +&2%+[nBZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =$Nq
for(int i=0;i<nStartPos.length;i++) Ak"m 85B
{ KNIn:K^/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5,6"&vU,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u^qT2Ss0
nStartPos,nEndPos,i); ah+iZ}E%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wx0j(:B]
fileSplitterFetch.start(); X*@dj_,
} xx%j.zDI]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r #cGop]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ge-vWf-RbB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?'{SX9
nEndPos = " + nFileLength); @7j AL-
// fileSplitterFetch[nPos.length-1].start(); C={Y;C1
VZmLS 4E
ByNn
//等待子线程结束 D\NKC@(M
//int count = 0; JB[~;nLlC
//是否结束while循环 )C]gld;8
boolean breakWhile = false; hp-<2i^"!
Y^EcQzLw
dvJM6W>^=
while(!bStop) >_"an~Ss
{ $6iX
write_nPos(); S2VA{9:m
Utility.sleep(500); Q:k}Jl
breakWhile = true; j yUCH*@
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8i#2d1O
for(int i=0;i<nStartPos.length;i++) !58@pLJw
{ !\.pq 2
if(!fileSplitterFetch.bDownOver) ]*[ 2$
{ XG{zlOD+
breakWhile = false; &H/'rd0M
break; %.-4!vj
} GM f `A,>
} T&u5ki4NE
if(breakWhile) Doyx[zZ
break; qm8B8&-
JNXq.;:`Q
2?ez,*-[
//count++; UIN<2F_
//if(count>4) hAnPXiD
// siteStop(); !/i{l
} }.m<
=QiI :|eRA
mQ26K~
System.err.println("文件下载结束！"); =Qj{T
} V_}"+&W9
catch(Exception e){e.printStackTrace ();} ;dZZ;#k%
} T{ XS")Vw
9u}Hmb
lbl?k5
//获得文件长度 a>I+]`g
public long getFileSize() W^LY'ypT
{ ex (.=X 1
int nFileLength = -1; :Cs4NF
try{ BdblLUGK#
URL url = new URL(siteInfoBean.getSSiteURL()); cZU=o\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); k(7&N0V%zz
httpConnection.setRequestProperty("User-Agent","NetFox"); " h~Zu
CiLg]va
`1{ZqRFQ
int responseCode=httpConnection.getResponseCode(); MSqVlj
if(responseCode>=400) q"sed]
{ ]e>w}L(gV
processErrorCode(responseCode); !_D0vI;
return -2; //-2 represent access is error 9YQb&
} ^{;oM^Q'
Z|j>gq
[KaAXv .X
String sHeader; <?}-$
V0.vQ/
/saIs%(fU
for(int i=1;;i++) ?5|>@>
{ Pz|>"'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q{I%Q)t)gU
//Utility.log(in.readLine()); j2.|ln"!
sHeader=httpConnection.getHeaderFieldKey(i); hl(hJfp
if(sHeader!=null) 1&evG-#<:
{ Gm.T;fc:
if(sHeader.equals("Content-Length")) ujq=F
{ 9gEwh<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?;+1)>{
break; )E@.!Ut4o
} JNYFD8J~
} z] PSpUd
else }mq6]ZrK
break; wyj{zWRJp
} BsqP?/
} #crQ1p) \
catch(IOException e){e.printStackTrace ();} #9}D4i.`}
catch(Exception e){e.printStackTrace ();} D] jzAx
(%e.:W${
T?soJ]A
Utility.log(nFileLength); ukfQe }I
ag#S6E^%S
*,8^@(th
return nFileLength; fg!__Rdi
} zrL$]Oy}x
w/S%YW3*
[OV"}<V
//保存下载信息（文件指针位置） ," Wr"
private void write_nPos() aa?b`[Xa
{ >WQMqQ^t@
try{ NI}yVV
output = new DataOutputStream(new FileOutputStream(tmpFile)); st3l2Q
output.writeInt(nStartPos.length); wh\}d4gN
for(int i=0;i<nStartPos.length;i++) Ng>5?F^v
{ l7259Ro~
// output.writeLong(nPos); 7BjJhs
output.writeLong(fileSplitterFetch.nStartPos); >:S?Mnv6
output.writeLong(fileSplitterFetch.nEndPos); ZaDyg"Tw+
} RO VW s/
output.close(); C]eSizS.
} 4Lh!8g=/
catch(IOException e){e.printStackTrace ();} [.8BTj1%
catch(Exception e){e.printStackTrace ();} %C'?@,7C
} &Gn 2tr
6]_pIf
]kG"ubHV?h
//读取保存的下载信息（文件指针位置） V2?=4mb
private void read_nPos() #ASz;$P
{ U;V7 u/{
try{ 9T}pT{~V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uK#4(eY=W
int nCount = input.readInt(); gA5/,wDO
nStartPos = new long[nCount]; ~xfP:[u
nEndPos = new long[nCount]; 7he,?T)vD
for(int i=0;i<nStartPos.length;i++) a 3b/e8c
{ Lh"<XYY
nStartPos = input.readLong(); f/NH:1)y
nEndPos = input.readLong(); |`Ntv}
} |`f$tj
input.close(); Z!#!Gu*V
} 7 60Y$/Wz
catch(IOException e){e.printStackTrace ();} ?m=N]!n
catch(Exception e){e.printStackTrace ();} 1k5Who@
} k\YG^I
UcDS9f_87
axRV:w;E<
private void processErrorCode(int nErrorCode) MS>Ge0P("~
{ P[#e/qnXu|
System.err.println("Error Code : " + nErrorCode); RtP2]O(F
} V>%rv'G8
V _/%b)*
dvx#q5f_S
//停止文件下载 }DEg-j,F
public void siteStop() WZejp}x
{ e7r-R3_
bStop = true; 9ni1f{k
for(int i=0;i<nStartPos.length;i++) $s c
fileSplitterFetch.splitterStop(); dA`IEQJL
#$+*;
3cyHfpx-W
} p8H'{f\G
} i2A81>68<
//负责部分文件的抓取 A*R^n}sh
**FileSplitterFetch.java |y# Jx
*/ S8w _ii3zd
package NetFox; v ~?qz5:K~
>,Ci?[pf
x{8xW0
import java.io.*; '!cCMTj
import java.net.*; TnOggpQ6X
qIE9$7*X
6V:U(g
public class FileSplitterFetch extends Thread { HTcb_a
2K6qY)/_
<X^@*79m
String sURL; //File URL mh{d8<Q2
long nStartPos; //File Snippet Start Position |`,2ri*5A
long nEndPos; //File Snippet End Position \fr~
int nThreadID; //Thread's ID IH&|Tcf\
boolean bDownOver = false; //Downing is over V`d,qn)i
boolean bStop = false; //Stop identical +wU@ynw
FileAccessI fileAccessI = null; //File Access interface S_4?K)n #
=^f<v_L
Y>T-af49
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $}q23
{ GPv1fearl
this.sURL = sURL; LTCb@L{^i
this.nStartPos = nStart; YnS#H"
this.nEndPos = nEnd; d-ZJL6-
nThreadID = id; =sU<S,a*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D~iz+{Q4
} -1_)LO&H
!bx;Ta.
e8!5I,I
public void run() .x.]`b(
{ ")5":V~fN
while(nStartPos < nEndPos && !bStop) rgv?gaQ>
{ l -mfFN
w"|L:8
1..+F0U
try{ a=1@*ID
URL url = new URL(sURL); NC`aP0S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nFe<w
httpConnection.setRequestProperty("User-Agent","NetFox"); q=m'^ ,gPS
String sProperty = "bytes="+nStartPos+"-"; aQcleTb
httpConnection.setRequestProperty("RANGE",sProperty); $am$EU?s
Utility.log(sProperty); Xp% v.M
"5!oi]@>(
uc\Kg1{
InputStream input = httpConnection.getInputStream(); \<>ih)J@tt
//logResponseHead(httpConnection); 7wqK>Y1a
CL;}IBd a
OU.6bmWy|
byte[] b = new byte[1024]; JPUW6e07o
int nRead; _pG-qK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qLG&WB
{ RFcv^Xf
nStartPos += fileAccessI.write(b,0,nRead); fk>aqm7D!
//if(nThreadID == 1) IGQFtO/x
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RnE4<Cy
} v^NIx q}U
>J?fl8
o4,6.1}
Utility.log("Thread " + nThreadID + " is over!"); 6]N;r5n
bDownOver = true; /NFj(+&g+
//nPos = fileAccessI.write (b,0,nRead); QXFo1m
} 1{.|+S Z!
catch(Exception e){e.printStackTrace ();} L,`LN>
} X-Kh(Z
} T!kN)#S
q`a'gJx#y
1#2 I
//打印回应的头信息 MUc$j&
public void logResponseHead(HttpURLConnection con) @ioJ]$o7
{ [5b--O
for(int i=1;;i++) a0E)2vt4
{ j0aXyLNX
String header=con.getHeaderFieldKey(i); KqJs?Won
if(header!=null) 50wulGJud
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9>/4W.
Utility.log(header+" : "+con.getHeaderField(header)); iC~^)-~H=w
else 9T9!kb
break; 5PJhEB
} }C?'BRX
} 4f@rv^f(X
WDD%Q8ejV&
itP,\k7>d
public void splitterStop() =BAr .m+"
{ _8J.fT$${
bStop = true; p38-l'{#
} JR21>;l#2
HM1Fz\Sf
aFm_;\
} &`r-.&Y
-3*]G^y2
mdg8,n
/* k%#EEMh
**FileAccess.java 4.aZ#c91_
*//文件访问(定位，写) FVbb2Y?R
package NetFox; Lg.gfny[(t
import java.io.*; s^9Voi.y
Y\P8v
7Q9 w?y~c
public class FileAccessI implements Serializable{ [l??A3G
H$t_Xw==
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &PHTpkaam
RandomAccessFile oSavedFile; Bm<`n;m
long nPos; ltSU fI
,w4(kcg%iQ
: *#-%0
public FileAccessI() throws IOException o5PO=AN
{ rXP,\ ]r+
this("",0); AV]2euyn
} my1@41 H
JyK3{wYS
3;9^
public FileAccessI(String sName,long nPos) throws IOException Mfuv0P~
{ 4F:\-O
oSavedFile = new RandomAccessFile(sName,"rw"); f'RX6$}\1X
this.nPos = nPos; eM6<%?b
oSavedFile.seek(nPos); Dml;#'IF3
} v;{#Q&(
_;y9$"A
Dx?,=~W9
public synchronized int write(byte[] b,int nStart,int nLen) LonxT&"!D
{ Bkc4TO
int n = -1; i&fuSk EP
try{ &6!)jIWJ
oSavedFile.write(b,nStart,nLen); 8dA~\a
n = nLen; #zs~," dRv
} T?0eVvM
catch(IOException e) (5YM?QAd
{ vA{-{Q
e.printStackTrace (); F/{!tx
} T'9'G M
Sz`,X0a
RtS+<^2a;
return n; ? OM!+O
} 1CZgb
<'oQ \eB
PC8Q"O
} (ZZ8L-s
tDcT%D {:
"(O>=F&
/* #trK^(
**SiteInfoBean.java (?c"$|^J
*/ Rhs/3O8k
package NetFox; dZ@63a>>@
{JT&w6Jz
f8dB-FlMm
public class SiteInfoBean { &p@O_0nF
6nvz8f3*r]
Yj49t_$b
private String sSiteURL; //Site's URL v\ )W?i*l
private String sFilePath; //Saved File's Path M%m4i9~!?
private String sFileName; //Saved File's Name (L&d!$,Dv
private int nSplitter; //Count of Splited Downloading File [z{1*Xc
g!|kp?
=dKtV.L
public SiteInfoBean() _B<X`L =
{//nSplitter的缺省值为5 rb.N~
//default value of nSplitter is 5 $UWZDD
this("","","",5); 6bC3O4Rw
} n7[V&`e_
1Pu~X \sO
S,UDezxg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b4kgFA
{ Jnov<+
sSiteURL= sURL; d$!RZHo10V
sFilePath = sPath; {EQOP]
sFileName = sName; g) jYFfGfH
this.nSplitter = nSpiltter; ~$^XP.a.
}Sv:`9=
T0)@pt7>
} DTL.Bsc-.
~f98#43
kl:Bfs)b
public String getSSiteURL() /U9"wvg
{ f]CXu3w(J
return sSiteURL; VTE .^EK!
} ;e*!S}C,
7!E,V:bt'
} q8ASYNc
public void setSSiteURL(String value) zrb}_
{ Q![@c
sSiteURL = value; 8d'0N
} (jE9XxQY
6i/(5 nQ
26h21Z16q
public String getSFilePath() b]KBgZ
{ R\[e!g*I
return sFilePath; 9yP;@y*d
} iH@UTE;
L!xi
Gd85kY@w7
public void setSFilePath(String value) iXjM.G
{ ?Ir:g=RP*
sFilePath = value; #ABZ&Z
} tR$NRMZ.
i/Zd8+.n$
-iZ`Y?
public String getSFileName() 3Y$GsN4ln
{ Q$"D]!G
return sFileName; ~t~|"u"P
} ;2QP7PrSY
T>W,'H
]Y&VT7+Z
public void setSFileName(String value) ;$g?T~v7
{ @r1_U,0e
sFileName = value; 5{,<j\#L
} 9pfIzs su3
ECmW`#Otb)
Z%UP6%
public int getNSplitter() 'I;zJ`Trd
{ $XH^~i;
return nSplitter; Eu3E-K@y
} Q~9^{sHZjP
`R^gU]Z,
@6-jgw>W2
public void setNSplitter(int nCount) VIf.q)_k
{ ;O,jUiQ
nSplitter = nCount; qHsA1<wg
} N;%6:I./
} %?/X=}sE
dWBA1p
m1AJ{cs
/* {)<v&'*c~
**Utility.java Ow,b^|
*/ 8z\xrY
package NetFox; ]Hv[IodJ
#/37V2E
8u]2xB=K
public class Utility { F!K>Kz
lyhiFkO iH
A=0'Ks
public Utility() Vxt+]5X
{ BZ^}J!Q'*
oXgcc*j
veECfR;
} (/] J3
tZo} ;|~'
//线程睡眠 '|=;^Z7.K
public static void sleep(int nSecond) zm;C\s rF
{ GC'O[q+
try{ j'K/22
Thread.sleep(nSecond); TA~{1_l
} `Q,H|hp;k;
catch(Exception e) X}0cCdW
{ k9F=8q
e.printStackTrace (); aw>#P
} _o~nr]zx
} 8q7b_Pq1U
3G4-^hY<
//日志 c:.eGH_f
public static void log(String sMsg) ?Mfw]z"\C)
{ ,R|BG
System.err.println(sMsg); 93hxSRw
} 0{SL&<&
ddR>7d}N
Z3!`J&
public static void log(int sMsg) Ek}A]zC
{ u]@['7
System.err.println(sMsg); tq?!-x+>
} TL#3;l^
} +"VP-s0
+"@ .8m
(7*}-Uy[C
/* 6W UrQFK
**TestMethod.java Gs[XJ 5%`~
*/ @KAI4LP
package NetFox; jz0T_\8D`
3;Fhg!ZO
vvOV2n.WD
public class TestMethod { 9nbLg5P
zx7{U8*`<
&kw@,];4Z
public TestMethod() &+R?_Ooibk
{ ///xx/weblogic60b2_win.exe ehY5!D1Q
try{ Rlirs-WQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :Ux_qB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ct}9i"H#1
SiteFileFetch fileFetch = new SiteFileFetch(bean); e(G|;a
fileFetch.start(); gZ1?G-Q
} sx<%2
catch(Exception e){e.printStackTrace ();} `P ,d$H "
PFK '$
n(]-y@X0_
} ;*&-C9b
Wv/=O}
ete.!*=
public static void main(String[] args) RpYERAgT
{ Sa5G.^XI
new TestMethod(); )\^-2[;
} pD]OT-8
} ~u+9J}
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