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)); nfB9M1Svn
} hiuPvi}
for(int i=0;i<nEndPos.length-1;i++) w+H=Xh4t
{ f;a6ux#
nEndPos = nStartPos[i+1]; U5=J;[w}N
} <'33!8 G
nEndPos[nEndPos.length-1] = nFileLength; $<PVzW,$o
} \SR
} XzsK^E0R
dx}!]_mlZ
)G&OX
//启动子线程 Kfl+8UR5=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =QRZ(2Wq
for(int i=0;i<nStartPos.length;i++) ZS]e}]Zwp
{ ,55`s#;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !2}Q9a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,;y^|X
nStartPos,nEndPos,i); Mt>DAk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o}z}79Z
fileSplitterFetch.start(); d-aF-
} hRu%> =7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q<qIlNE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @hPbD?)M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ja1*a,],L
nEndPos = " + nFileLength); XMdYted
// fileSplitterFetch[nPos.length-1].start(); 6D<A@DR9J
!$HWUxM;p
0M p>X
//等待子线程结束 Ygb#U'|
//int count = 0; Z(P#]jI]
//是否结束while循环 nFSa~M
boolean breakWhile = false; G$b4`wt
=%p{"<
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while(!bStop) p"Y=
{ H Vy^^$
write_nPos(); hAdEq$
Utility.sleep(500); *RO ~%g
breakWhile = true; gUcE,L
CgWj9 [
>KJ]\`2>)c
for(int i=0;i<nStartPos.length;i++) gMbvHlT
{ b;{C1aa>}
if(!fileSplitterFetch.bDownOver) )NK2uD
{ RWE%?`
breakWhile = false; M}>q>
break; bvG Vfr "
} >vhyKq|g<
} =Ao;[j)*!
if(breakWhile) tznT*EQr
break; $O#h4L_
Y~6pJNR
gE&f}M-
//count++; Jz6PqU|=
//if(count>4) `}bUf epMJ
// siteStop(); g=.5*'Xlp
} c/u;v69r
lMP7o&
F-6* BUqJ
System.err.println("文件下载结束！"); ?#'qY6 ^
} WBGYk);
catch(Exception e){e.printStackTrace ();} ,\M'jV"SK
} ?g&]*zc^\
\ gN) GR
|w5#a_adM
//获得文件长度 VF-d^AGt
public long getFileSize() h$!qb'|
{ 2-~oNJqX
int nFileLength = -1; fjb2-K
try{ ]8#{rQ(
URL url = new URL(siteInfoBean.getSSiteURL()); 5^k#fl2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'coqm8V[%
httpConnection.setRequestProperty("User-Agent","NetFox"); yQ}~ aA#h
2a^(8A`7W
VXa]L4jJ9
int responseCode=httpConnection.getResponseCode(); 1#V0g Q
if(responseCode>=400) eIO}/npT]Q
{ \?o%<c5{
processErrorCode(responseCode); gDv]n^&
return -2; //-2 represent access is error :X#(T-!t
} ch&r.
x[X.// :
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String sHeader; u0,~pJvX
`'>>[*06:a
WXM_H0K
for(int i=1;;i++) l@Ki`if
{ YW5E |z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gSC@uf
//Utility.log(in.readLine()); Pzqgg43Xf
sHeader=httpConnection.getHeaderFieldKey(i); kU /?#s
if(sHeader!=null) 1ysA~2
{ UaBR;v-.B3
if(sHeader.equals("Content-Length")) kBTuM"
{ \S9z.!7v$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #O~Y[''C5X
break; 5q<kt{06\
} JsC0^A;fM
} 5*CwQJC<
else 0\mzGfd
break; ?:ZH%R_`a
} ;(sb^O
} zb<+x(0y"
catch(IOException e){e.printStackTrace ();} &$=F$
catch(Exception e){e.printStackTrace ();} kK(633s
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@.0,ka,X
Utility.log(nFileLength); bhI8b/
x\=h^r#w
myo/}58Nv
return nFileLength; ;#+#W+0
} [kXe)dMX8
5Ql6?UHD
]Cj&C/(
//保存下载信息（文件指针位置） A-~)7-
private void write_nPos() gp}S1
{ oH;Y}h
try{ #\jPBLc
output = new DataOutputStream(new FileOutputStream(tmpFile)); V$@2:@8mo
output.writeInt(nStartPos.length); f9$98SI
for(int i=0;i<nStartPos.length;i++) VS`S@+p
{ ("aYjKk
// output.writeLong(nPos); * n[6H
output.writeLong(fileSplitterFetch.nStartPos); kSDV#8uZ
output.writeLong(fileSplitterFetch.nEndPos); Z` Aiw."|
} q<1@ut
output.close(); K,RIa0)
} D,7! /u'
catch(IOException e){e.printStackTrace ();} #8`G&S*
catch(Exception e){e.printStackTrace ();} R'F|z{8
} cr!I"kTgD
QEVjXJOt0
X[|>r@Aa!
//读取保存的下载信息（文件指针位置） ugCc&~`
private void read_nPos() ovHbs^H%
{ N&n{R8=^"
try{ ILQg@Jl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ":Q70*xSm
int nCount = input.readInt(); us]ah~U6A
nStartPos = new long[nCount]; s"'1|^od
nEndPos = new long[nCount]; 7yc:=^ )
for(int i=0;i<nStartPos.length;i++) 8'YL!moG|
{ /#XO!%=7
nStartPos = input.readLong(); X2{3I\'Ft
nEndPos = input.readLong(); (]pQ.3
} O-7 \qz
input.close(); |k)u..k{>
} CkP!4^J qQ
catch(IOException e){e.printStackTrace ();} xS.0u"[
catch(Exception e){e.printStackTrace ();} u/MIB`@,
} 5pDxFs=v
4uv }6&R
MDlCU
private void processErrorCode(int nErrorCode) 4, :D4WYWD
{ 7fVVU+y
System.err.println("Error Code : " + nErrorCode); w"D"9G
} X:dj5v
Ro1l:P)C`
$yt|nO
//停止文件下载 uIR_p\)
public void siteStop() X@cV']#V
{ "ZH1W9A
bStop = true; =gj]R
for(int i=0;i<nStartPos.length;i++) )FB)ZK;
fileSplitterFetch.splitterStop(); t512]eqhb(
T^79p$
)&w\9}B:
} ^!}lA9\gY
} )~J/,\
//负责部分文件的抓取 &K7g8x"x.
**FileSplitterFetch.java Lt*H|9
*/ Ah"RxA
package NetFox; !ine|NM
)S`A+M K]
&38Fj'l
import java.io.*; lmod8B
import java.net.*; 3:C *'@
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IXH;QwR:
public class FileSplitterFetch extends Thread { gcz1*3)
j;'NJ~NZ$
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String sURL; //File URL gh~C.>W}q+
long nStartPos; //File Snippet Start Position lr|-_snx2
long nEndPos; //File Snippet End Position F'"-4YV>&
int nThreadID; //Thread's ID bkY7]'.bz&
boolean bDownOver = false; //Downing is over _x:K%1_[
boolean bStop = false; //Stop identical ?=\h/C
FileAccessI fileAccessI = null; //File Access interface ve>8vw2
Ar\`OhR
6=zme6D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IX3r$}4
{ F|"NJ*o}
this.sURL = sURL; m1frN#3
this.nStartPos = nStart; X`22Hf4ct
this.nEndPos = nEnd; k<St:X%.O
nThreadID = id; #)\KV7f!;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vg)zk2O
} x|Q6[Y
Y!SD^Ie7!
Obw uyhjQ
public void run() =]D##R
{ '; qT
while(nStartPos < nEndPos && !bStop) JY /Cd6\
{ f",B;C
u2DsjaL
MF& +4$q
try{ F'Wef11Yz
URL url = new URL(sURL); ){6;o&CC:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T$+}Srb
httpConnection.setRequestProperty("User-Agent","NetFox"); kQj8;LU
String sProperty = "bytes="+nStartPos+"-"; H6~QSe0l
httpConnection.setRequestProperty("RANGE",sProperty); fc M~4yP?
Utility.log(sProperty); q k!Q2W
O ~"^\]\
9zX\ioT
InputStream input = httpConnection.getInputStream(); ^+}<Q#y-
//logResponseHead(httpConnection); ,,i;6q_f
WjA)0HL(
\tQRyj\|
byte[] b = new byte[1024]; &"d4J?io`
int nRead; LDbo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]ao]?=q C
{ \ii^F?+b
nStartPos += fileAccessI.write(b,0,nRead); x*_c'\F|
//if(nThreadID == 1) 5:YtBdP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H >RGX#|
} JNZKzyJ9K
R^K<u#>K
{gJOc,U4b
Utility.log("Thread " + nThreadID + " is over!"); ny#7iz/
bDownOver = true; ;Yi ;2ttW
//nPos = fileAccessI.write (b,0,nRead); 8(ZQD+U(9F
} tv?~LJYN
catch(Exception e){e.printStackTrace ();} ??k^Rw+0R
} oW-luC+
} "--rz;+K
Ar>-xCTD
P$qIB[Xi
//打印回应的头信息 vH`u
public void logResponseHead(HttpURLConnection con) Rk"_4zJk
{ %]NbTTL
for(int i=1;;i++) X3'z'5
{ G66vzwO
String header=con.getHeaderFieldKey(i); 0C3CqGP
if(header!=null) =m:0#&t,*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x; :[0(st}
Utility.log(header+" : "+con.getHeaderField(header)); ZY{,//
else ]T+{]t
break; f^nogw<z!
} iS02uVmBZ
} Mq6"7L
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G`w7dn;&
public void splitterStop() 4,uH 4[7
{ \+ K ^G
bStop = true; g{dyDN$5|w
} <~f/T]E,
\<V{6#Q=
uTOL
} .vwOp*3\
=:5yRP
U+nwLxe'
/* .(3B}}gB>
**FileAccess.java W4T>@b.
*//文件访问(定位，写) (3 B; V
package NetFox; ]W]Vkkg]
import java.io.*; sgFpZk
E@t^IGDr
-<qci3Ba}
public class FileAccessI implements Serializable{ U JY`P4(
$T~|@XH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nIXq2TzJ
RandomAccessFile oSavedFile; \9<aCJxN
long nPos; mM>{^%2Q:
z[V|W
.LdLm991,Y
public FileAccessI() throws IOException kE/>Ys@w
{ C S+6!F]
this("",0); wB"&K;t
} 4km=KOx[
c7S<ex,
f |aO9w
public FileAccessI(String sName,long nPos) throws IOException OyFBM>6gh
{ ^-mz!{
oSavedFile = new RandomAccessFile(sName,"rw"); T|r@:t[
this.nPos = nPos; S+_}=25
oSavedFile.seek(nPos); `[7&tOvSk
} X,^J3Ek>O
i3N _wv{
rAk*~OK
public synchronized int write(byte[] b,int nStart,int nLen) '^n2]<
{ EcFYP"{U
int n = -1; J*qepq`_
try{ HIeWgw^"
oSavedFile.write(b,nStart,nLen); }kGJ)zh
n = nLen; miEfxim
} =]&R6P>
catch(IOException e) NhXTt!S6C
{ bvs0y7M='
e.printStackTrace (); }8 fG+H.
} ]MRE^Je\h
8K7zh.E
$]!uX&
return n; }[$C=|>
} 5c`DkWne%
v~uQ_ae$>
"\]kK@,
} `)!)}PXl
Hk(w\
&EV|knW
/* *ofK|r
**SiteInfoBean.java K-(,,wS
*/ "pQM$3n(
package NetFox; I Yj\t?,0
FK;\Nce&
x]J{EA{+
public class SiteInfoBean { XBdC/DM[
No!P?
y2o?a6`
private String sSiteURL; //Site's URL {FteQ@(
private String sFilePath; //Saved File's Path tbl!{Qwx
private String sFileName; //Saved File's Name 6t<~. 2'
private int nSplitter; //Count of Splited Downloading File Ilsh Jo
`yNNpSdS1
)d_)CuUBe
public SiteInfoBean() &>p2N
{//nSplitter的缺省值为5 +);o{wfW
//default value of nSplitter is 5 "-90:"W
this("","","",5); }ZlJ
} YLJH?=2@
O"nY4
LX!16a@SxA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -;_NdL@
{ l3)(aay!
sSiteURL= sURL; z@{|Y;s
sFilePath = sPath; ko>SnE|w#
sFileName = sName; 2p8JqZMQb
this.nSplitter = nSpiltter; G]=U=9ZI
(<=qW_iW
lD _ u
} gU0}.b
p%G4Js.
;XZ5r|V}
public String getSSiteURL() TJ ;4QL
{ k;#$Oxa>t=
return sSiteURL; v$owG-_><
} :DR G=-M
rX{QgyY&
WB"$NYB
public void setSSiteURL(String value) tlA4oVII
{ N"2P&Ho]
sSiteURL = value; hm&{l|u{RU
} kS8srT /H
vWXj6}
sO~N2
public String getSFilePath() 1W"9u
{ JU1U=Lu."
return sFilePath; _Oh;._PS
} _|g(BK2}
Xa Yx avq
>OBuHqC
public void setSFilePath(String value) U3&*,xeU@H
{ I^qk`5w
sFilePath = value; /1gKc}rB2
} 7=6p
VQ$=F8ivG
mdoy1a
public String getSFileName() D-8%lGS
{ OHR9u
return sFileName; V89!C?.[]1
} 7Q/v#_e(
ZL+{?1&-
Wu2#r\
public void setSFileName(String value) T=A7f6`
{ Cc1sZWvz
sFileName = value; 49@ pA-
} (b GiBsb
L>).o%(R
KQNSYI7a
public int getNSplitter() VX[{X8PkS
{ ? Ls]k
return nSplitter; 3|[:8
} P(VQD>G
>6@*%LM
"a?k #!E
public void setNSplitter(int nCount) 6T;C+Y$
{ lF8B+
nSplitter = nCount; U-Fr[1I6p
} q@8Rlc&
} @j9yc
Z@RAdwjR`p
'lHtz~[
/* svU107?
**Utility.java +O*S>0
*/ i5(_.1X<#{
package NetFox; t8U)za
TEE$1RxV(
E"x 2jP
public class Utility { ;TEZD70r
YEXJh!X
9 /t}S6b{
public Utility() 66[yL(*+
{ H \.EKZ
0;!aO.l]K
tZk@ RX
} (=)+as"u9*
>M[rOu (d
//线程睡眠 U@BVVH?,o
public static void sleep(int nSecond) <*3wnpj_
{ '355Pce/
try{ _0oZgt)
Thread.sleep(nSecond); Ud*.[GRD~
} c42p>}P[
catch(Exception e) JLT':e~PX
{ "3Ag+>tuRW
e.printStackTrace (); [j1SX-NX
} 7`~h'(k
} KG4~t=J`
;k (}~_
//日志 t1n'Ecm(
public static void log(String sMsg) $B2* x$
{ GNZQj8
System.err.println(sMsg); shYcfLJ
} N{q5E,}
'"GdO;}&
6:330"9
public static void log(int sMsg) 0 -=onX
{ ZZ]/9oiF%
System.err.println(sMsg); E$F)z
} bpzB}nEp
} $O%lYQY]
B5=L</Aj
-x:Wp*,
/* f2uog$Hk
**TestMethod.java v9x $`
*/ n"@3d.21
package NetFox; 4w*F!E2H\}
/+JCi6{sHS
ag:#82C
public class TestMethod { VBIPB
BXZ( %tnY
!D7\$ g6g
public TestMethod() \X Nb9-
{ ///xx/weblogic60b2_win.exe '/z.\S
try{ sN5x\9U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NV36Q^Am[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TG{=~2
SiteFileFetch fileFetch = new SiteFileFetch(bean); Tk|0 scjE^
fileFetch.start(); MR#jI
} D7sw;{ns
catch(Exception e){e.printStackTrace ();} I@pnZ-5
c?V,a`6
44kY[jhf
} lY?TF
1YAy\F~`.
k3sP,opacX
public static void main(String[] args) jcXb@FE6
{ L7X._XBO[
new TestMethod(); TcauCL
} UF D_
} ;=_<\2
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