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)); zT#`qCbT'J
} :]WqfR)#
for(int i=0;i<nEndPos.length-1;i++) 0*F}o)n/m
{ sKL:p3r
nEndPos = nStartPos[i+1]; R_N:#K.M
} Y; ).+si
nEndPos[nEndPos.length-1] = nFileLength; s_Wyh !@M
} `u XQ z7
} wtH~-xSB|
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%d;ezY'2
//启动子线程 (sTuG}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %,UPJn
for(int i=0;i<nStartPos.length;i++) Vf $Dnu@}z
{ T .n4TmF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1^G{tlA-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,[!LCXp
nStartPos,nEndPos,i); rs;r $
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P_Hv%g
fileSplitterFetch.start(); ig!7BxM)<h
} d~9!,6XM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0 n vSvk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1G^#q,%X_v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Um.qRZ?
nEndPos = " + nFileLength); ae+*=,
// fileSplitterFetch[nPos.length-1].start(); {38bv.3'
o{WyQ&2N
n<7q`tM#
//等待子线程结束 F]+~x/!
//int count = 0; j/!H$0PN
//是否结束while循环 q(IQa@$SR
boolean breakWhile = false; @n+=vC.xO
?cy4&]s
@It>*B yB.
while(!bStop) & E}mX]t
{ z=Cr7-
write_nPos(); `[fxyg:u
Utility.sleep(500); .uz|/Zy
breakWhile = true; h6D^G5i
|> enp>
~d >W?A
for(int i=0;i<nStartPos.length;i++) quxdG>8
{ * ?Jz2[B
if(!fileSplitterFetch.bDownOver) r@G#[.*A>
{ CH#k(sy
breakWhile = false; f 2YLk
break; bBc-^
} c1XX~8
} f!_ ctp
if(breakWhile) 5*-3? <)e
break; 7^6uG6
K9Hqq7"%
fS&6
//count++; X[yNFW}S2W
//if(count>4) 6<76H
// siteStop(); ~NcQ1.
} aM3gRp51cj
BMyzjteS+
S.*~C0"
System.err.println("文件下载结束！"); K%5"u'
} e^1uVN
catch(Exception e){e.printStackTrace ();} |a^U]
} \}0-^(9zd
f58?5(Dc|
4,p;Km&
//获得文件长度 V ~{fB~
public long getFileSize() DGESba\2+
{ ;q>9W,jy
int nFileLength = -1; V^s0fWa
try{ gb|Q%LS9R
URL url = new URL(siteInfoBean.getSSiteURL()); =n(3o$r(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WYcA8X/
httpConnection.setRequestProperty("User-Agent","NetFox"); 5e8AmY8;
nw:-J1kWR
#'baPqdO
int responseCode=httpConnection.getResponseCode(); 9LJZ-/Wq
if(responseCode>=400) YX*x&5]lq
{ -V.d?A4"
processErrorCode(responseCode); !D^c3d
return -2; //-2 represent access is error f9$xk|2g
} +j14Q$
l! bv^
pKG<Nvgz&
String sHeader; (5L-G{4
+kK
s@4nWe
for(int i=1;;i++) cZ8.TsI~
{ zmuMWT;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xGk6n4Gg
//Utility.log(in.readLine()); FDzqL;I
sHeader=httpConnection.getHeaderFieldKey(i); O*6n$dUj3
if(sHeader!=null) \c,pEXG
{ DL^o_61
if(sHeader.equals("Content-Length")) "UFs~S|e
{ 0pb'\lA
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OPJ: XbG
break; Y$K!7Kq
} Cizvw'XDV
} 8)*2@-Rp
else Y*oDO$6
break; DE$q+j0P
} g^Yl TB
} K BE Ax3
catch(IOException e){e.printStackTrace ();} B;6]NCxD
catch(Exception e){e.printStackTrace ();} iRo.RU8>
;h=*!7:
#FOqP!p.E
Utility.log(nFileLength); Cs3^9m6;d
y;cUl, :v
8LkP)]4^sO
return nFileLength; W<ZK,kv
} ^>x|z.
qVqRf.-\
g6t"mkMY L
//保存下载信息（文件指针位置） /&#XhrT
private void write_nPos() lA(Q@yEW
{ /'2O.d0}.
try{ ) /vhclkb
output = new DataOutputStream(new FileOutputStream(tmpFile)); h5_G4J{1
output.writeInt(nStartPos.length); DhLqhME53
for(int i=0;i<nStartPos.length;i++) 85:NFa@J
{ N{SQ(%V
// output.writeLong(nPos); &.13dq
output.writeLong(fileSplitterFetch.nStartPos); MB ju![n
output.writeLong(fileSplitterFetch.nEndPos); wFh8?Z3u_
} }T^cEfX
output.close(); Y}*\[}l:&x
} 'nQVj
catch(IOException e){e.printStackTrace ();} o{b=9-V
catch(Exception e){e.printStackTrace ();} EJ}!F?o
} N]EcEM#
1LJuCI=~
f*{ YFg?*&
//读取保存的下载信息（文件指针位置） sxKf&p;
private void read_nPos() :AdDLpk3j
{ -~[9U,
try{ V"o7jsFH6n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Jf)bHjC_V
int nCount = input.readInt(); JCcZuwu[
nStartPos = new long[nCount]; \6?A!w~6
nEndPos = new long[nCount]; #o/H~Iv
for(int i=0;i<nStartPos.length;i++) `O?TUQGR
{ /M~!sPW&?
nStartPos = input.readLong(); cq&*.
nEndPos = input.readLong(); ,21 np
} <:/&&@2
input.close(); |s#'dS;
} `i) 2nNJ"
catch(IOException e){e.printStackTrace ();} @$"J|s3M
catch(Exception e){e.printStackTrace ();} mffn//QS
} V=He_9B
XY.5Rno4
$mmup|;(
private void processErrorCode(int nErrorCode) >h2%[j=
{ uJHu>M}~
System.err.println("Error Code : " + nErrorCode); iI@jZVk
} 02`$OTKz
v8gdU7Ll,
(6CN/A{qe
//停止文件下载 E9|eu\
public void siteStop() n,HE0Zn]Y_
{ H.<a`mm8
bStop = true; 07Gv*.
for(int i=0;i<nStartPos.length;i++) w;}@'GgL
fileSplitterFetch.splitterStop(); 93+"D`
h)1qp Qj
c^rOImZ
} M/?KV9Xk2
} 9odJr]
//负责部分文件的抓取 {8,<ZZ_
**FileSplitterFetch.java 5(W"-A}
*/ YCe7<3>J4
package NetFox; TSAU?r\P
& gJV{V5Ay
""Zp:8o
import java.io.*; ^JZ^>E~
import java.net.*; S-31-Zjw
]q-g[e'
id<:p*
public class FileSplitterFetch extends Thread { BR^7_q4q
7"7rmZ
cYx4~V^
String sURL; //File URL )%SkJ
long nStartPos; //File Snippet Start Position x:vu'A
long nEndPos; //File Snippet End Position zWpqJK
int nThreadID; //Thread's ID e__@GBG
boolean bDownOver = false; //Downing is over 9jN)I(^D6
boolean bStop = false; //Stop identical R(P%Csbqh
FileAccessI fileAccessI = null; //File Access interface $Y=T&O
%8*64T")
{7!UQrm<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )eUW5 tS
{ Zh5RwQNE~
this.sURL = sURL; 'Y$R~e^Y?
this.nStartPos = nStart; `c/*H29
this.nEndPos = nEnd; 48|s$K^
nThreadID = id; O\K_q7iO6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;!o]wHmA
} sS&Z ,A
KbL V'%D
\;VhYvEH
public void run() ve ~05mg
{ EFpIp4_Y
while(nStartPos < nEndPos && !bStop) #-3=o6DCK
{ K.G$]H
=.y*_Ja
HL/bS/KX
try{ *Nyev]8
URL url = new URL(sURL); ^qCkt1C-M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UA[,2MBp
httpConnection.setRequestProperty("User-Agent","NetFox"); Cv$ SJc
String sProperty = "bytes="+nStartPos+"-"; 9Rm/V5
httpConnection.setRequestProperty("RANGE",sProperty); k>dsw:
Utility.log(sProperty); ^gVT$A
8Qh#)hiW!
th6+2&B6
InputStream input = httpConnection.getInputStream(); Qn ^bVhG+
//logResponseHead(httpConnection); iv phlw
n~g)I&
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byte[] b = new byte[1024]; iX'rU@C
int nRead; Lokl2o`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '(f/~"9B
{ x^"ES%*
nStartPos += fileAccessI.write(b,0,nRead); Ladsw
//if(nThreadID == 1) Ca%g_B0t
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }SIGPVM
} axHK_1N{
]$U xCu
0y<wvLv2C
Utility.log("Thread " + nThreadID + " is over!"); 7W6cM%_B
bDownOver = true; [4fU+D2\d
//nPos = fileAccessI.write (b,0,nRead); \4"S7.% |
} `@i5i((
catch(Exception e){e.printStackTrace ();} Z%GTnG|rG
} 5Z4-Z
} |QV!-LK
jjJ2>3avY
0!z@2[Pe66
//打印回应的头信息 0Ok,oW{
public void logResponseHead(HttpURLConnection con) Qb8KPpd
{ Mv c`)_Md
for(int i=1;;i++) pfx3C*
{ 0l;<5
String header=con.getHeaderFieldKey(i); H+ h07\? %
if(header!=null) @!&}}"<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *9)SmSs
Utility.log(header+" : "+con.getHeaderField(header)); b3wM;jv
else mMMQ|ea
break; o]IjK
} IVr 2y8K
} >NB?&|
nm7;ieMfr
H:p Z-v*
public void splitterStop() fYE(n8W3
{ /6O??6g
bStop = true; 1FtM>&%4
} jGrN\D?h
RzhWD^bB
v(OBXa9
} i(?,6)9
{cpEaOyOM
+n}$pM|NKU
/* PSawMPw
**FileAccess.java tNVV)C
*//文件访问(定位，写) %gnM(pxl
package NetFox; gX{loG
import java.io.*; TpA\9N#$
fQLt=Lrp
y2O4I'/5<
public class FileAccessI implements Serializable{ (Qgde6
S4witIK5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CE15pNss
RandomAccessFile oSavedFile; Og;-B0,A
long nPos; EBtLzbj
yfU<UQ!1
Pmi#TW3X
public FileAccessI() throws IOException /~4"No@
{ %!ebO*8q
this("",0); b|SE<\
} K ~44i
&rDM<pO #-
?S?2 0
public FileAccessI(String sName,long nPos) throws IOException }HEvr)v9
{ >zkRcm
oSavedFile = new RandomAccessFile(sName,"rw"); @pGZLq
this.nPos = nPos; 7FN<iI&7\
oSavedFile.seek(nPos); W4;m H}#0
} $3D'4\X~?
qH"Gm
]]}tdn_
public synchronized int write(byte[] b,int nStart,int nLen) WWT",gio
{ Gu=STb
int n = -1; E{HY!L[
try{ EkT."K
oSavedFile.write(b,nStart,nLen); 5unG#szq
n = nLen; %LXM+<N8
} "o& E2#
catch(IOException e) (wc03,K^
{ +l^LlqA
e.printStackTrace (); >r &;3:"
} 9;yn}\N `
74<!&t
PNW \*;j
return n; 7^}Ll@
} /S:F)MO9
yBLK$@9
7=@jARW&
} )pw&c_x
.^)UO
2!N8rHRt
/* J==SZ v
**SiteInfoBean.java UR(-q
*/ W~_t~Vg5
package NetFox; }0,>2TTDN
dk8wIa"K`
`ovtHl3Q
public class SiteInfoBean { [nxE)D
X &2oPo
hP J4Oj1O
private String sSiteURL; //Site's URL X\p,%hk \
private String sFilePath; //Saved File's Path \b}~2oX
private String sFileName; //Saved File's Name MH|]\
private int nSplitter; //Count of Splited Downloading File #6Xs.*b5C
&iN--~}!$
79zJ\B_
public SiteInfoBean() .@iFa3
{//nSplitter的缺省值为5 \qi|Js*{
//default value of nSplitter is 5 ]E3U J!!
this("","","",5); qDWsvx]
} m?s}QGSka
# N~,F@t
w",? Bef
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G ;?qWB,
{ Bs`$i ;&
sSiteURL= sURL; JT[*3h
sFilePath = sPath; uhN%Aj\iu(
sFileName = sName; NGYyn`Lx
this.nSplitter = nSpiltter; h5 Vv:C
+b;hBb]R
W{XkVKe1a
} +@X5!S6
5)1+~B
mq/zTm
public String getSSiteURL() 9ykM3
{ o6"*4P|
return sSiteURL; }aB#z<B6
} 3*DXE9gA9
^GN8V-X4y
QbYc[8-[
public void setSSiteURL(String value) /Tz85 [%6
{ \(I6_a_{
sSiteURL = value; 3E} An%
} U7&x rif
hwnx<f '
ps1YQ3Ep&
public String getSFilePath() ;D ~L|
{ lfk9+)
return sFilePath; n)8Yj/5
} b syq*
G,&%VQ3P>
BpAB5=M0
public void setSFilePath(String value) &UAe!{E0
{ 5,+\`!g
sFilePath = value; )J/HkOj"V
} uMXc0fs!$
.uZ7 -l
@^nu#R
public String getSFileName() jRkC/Lw
{ h~HB0^|
return sFileName; ~QG?k
} fF?6j
>AD=31lq
#?}6t~
public void setSFileName(String value) ed~R>F>
{ "i'bTVs
sFileName = value; ,W5.:0Y;f[
} M\/XP| 7
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?`sy%G
public int getNSplitter() k/&]KYwu
{ P1 +"v*
return nSplitter; XOrfs sj
} 90 {tIX
7u11&(Lz
7-iIay1h"
public void setNSplitter(int nCount) lhn8^hOJ/
{ :,]S}R
nSplitter = nCount; ,-*iCs<
} jy$@a%FD
} ayp b
5P^U_
_&{%Wc5W~F
/* $B\E.ml.
**Utility.java |:iEfi]j
*/ ~P1_BD(
package NetFox; Unl?fXI
='Oj4T
H;vZm[\0N-
public class Utility { QrjDF>
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Vk<k+=7
public Utility() \&|CM8A
{ ?_4^le[;
tFU;SBt8Ki
M$#sc`4*
} =DgCC|p
\d68-JS@~
//线程睡眠 E1q%gi4Q%
public static void sleep(int nSecond) MZm'npRf
{ k0K A~
try{ 8Pmwzpk02
Thread.sleep(nSecond); nsJ:Osq|
} ;x[pM_
catch(Exception e) ")\aJ8
{ eqzTQen8q
e.printStackTrace (); =t+('
} _x\m|SF_g
} ~@M7&%]
k&Jo"[i&WO
//日志 )LFD6\z1pl
public static void log(String sMsg) ??xlA-E
{ t{(Mf2GR1
System.err.println(sMsg); 0<P(M:a
} g{ (@uzqG
?iz<
8]*Q79
public static void log(int sMsg) =y;@?=T
{ 19y 0$e_V
System.err.println(sMsg); OXtBJYe
} B3b,F#
} `ut)+T V
: ^(nj7D
y_%&]/%
/* h;Mu[`
**TestMethod.java "Pdvmur
*/ }MZan" cfo
package NetFox; Q]i[.ME
Y?!/>q
$%}>zqD1
public class TestMethod { {CP o<lz
75Fp[Q-
Ru7L>(Njs
public TestMethod() Yf(im
{ ///xx/weblogic60b2_win.exe HTNA])G
try{ +{vQSFW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &q>h*w4O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -Op@y2+c
SiteFileFetch fileFetch = new SiteFileFetch(bean); ABiC9[Q0
fileFetch.start(); -- S"w@
} lZ a?Y@
catch(Exception e){e.printStackTrace ();} vahf]2jEB
W:B}u\)C
= o+7xom
} @^HwrwRA
RK3.-
fk\5D[j^
public static void main(String[] args) 6aSM*S)
{ _h~p:=
new TestMethod(); c%yh(g
} onh?/3l
} AO8:|?3S
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