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)); fC:\Gh5
} z>#$#:Z4
for(int i=0;i<nEndPos.length-1;i++) 5 `mVe0uI
{ C 5!6k1TcE
nEndPos = nStartPos[i+1]; T[K?A+l
} w0OK.fj
nEndPos[nEndPos.length-1] = nFileLength; e/l?|+m 6
} }{PtQc6RL!
} Xq$0% WjG
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BU .G~0
//启动子线程 u9%:2$[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ov}{UP]a?
for(int i=0;i<nStartPos.length;i++) C'"6@-~
{ {i?K~| h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e q.aN3KB"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 35\0g&
nStartPos,nEndPos,i); 3Sb%]f5(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3Q6#m3AWY
fileSplitterFetch.start(); F=lj$?4{
} Q 7?4GxMj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Msdwv.jM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +1A<kJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @uWD>(D
nEndPos = " + nFileLength); 8XE0 p7
// fileSplitterFetch[nPos.length-1].start(); :\cJvm
hYx^D>}]
{=Y&q~:8v
//等待子线程结束 l0,O4k2'
//int count = 0; &0blHDMj{#
//是否结束while循环 N{@eV][Q
boolean breakWhile = false; Np)!23 "
3`I_
`hhG^O_
while(!bStop) 6<GWDO
{ J)+eEmrU
write_nPos(); Q?q m~wD
Utility.sleep(500); ;W"[,#2TM
breakWhile = true; w|ei*L
k#M W>
T9.gs}B0
for(int i=0;i<nStartPos.length;i++) ]].21
{ `_ L|Is=n
if(!fileSplitterFetch.bDownOver) D[?|\?
{ _u!G6
breakWhile = false; |0 VP^md
break; G)`MoVH1
} -"H9W:
} O@$i
if(breakWhile) _69\#YvCG
break; M>j)6?n`_
.})8gL7V
'%4,!
//count++; )$i3j 1[;
//if(count>4) q\"$~*
// siteStop(); 2:yv:7t/
} 4 n( f/
w5Z3e^g
4#uoPkLK
System.err.println("文件下载结束！"); SfR_#"Uu
} [8n4lE[)"
catch(Exception e){e.printStackTrace ();} ??;[`_h{bz
} Z5K,y19/~
I1jF`xQ&0
a{=~#u8
//获得文件长度 9|,AhyhO
public long getFileSize() <Th.}=
{ YVi]f2F%
int nFileLength = -1; hGLBFe#3
try{ P[~a'u
URL url = new URL(siteInfoBean.getSSiteURL()); 7y&`H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b7/4~_s
httpConnection.setRequestProperty("User-Agent","NetFox"); jLg4_N1SD
>E#4mm
L\5n!(,0
int responseCode=httpConnection.getResponseCode(); Qpc>5p![3
if(responseCode>=400) Vow+,,oh
{ t1S\M%?
processErrorCode(responseCode); 3ly|y{M",
return -2; //-2 represent access is error #<:khs6
} a>6p])Wh
(J;<&v}Gad
MG|NH0k
String sHeader; 6IA~bkc}
L '=3y$"],
P=.W.oS
for(int i=1;;i++) uWSG+
{ MLl:)W*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]v#Q\Q8>
//Utility.log(in.readLine()); d?JVB
sHeader=httpConnection.getHeaderFieldKey(i); .+.Pc_fv
if(sHeader!=null) q :gH`5N
{ e5dwq
if(sHeader.equals("Content-Length")) b1+Nm
{ PeOgXg)L`z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8@!SM
break; 2B|3`trY4x
} | =&r) ~
} h4U .wk
else q;+qIV&.:
break; 'sC{d&c
} Rh39x-`Z
} .[7m4iJf
catch(IOException e){e.printStackTrace ();} / wEr>[8S
catch(Exception e){e.printStackTrace ();} -7CkOZT
Z"A:^jZ<s
RSy1 wp4W
Utility.log(nFileLength); i^yQ; 2-
(1ebE
}wn GOr
return nFileLength; ,%u\2M
} 4JucNGv
&"=inkh
U7O2.y+
//保存下载信息（文件指针位置） l#Iof)@#
private void write_nPos() -k'=s{iy
{ sD M!Uv2n
try{ %"o4IYV#
output = new DataOutputStream(new FileOutputStream(tmpFile)); "p<f#s}
output.writeInt(nStartPos.length); 3N?uY2
for(int i=0;i<nStartPos.length;i++) |(Sqd;#v
{ Rzz*[H
// output.writeLong(nPos); zZkwfF
output.writeLong(fileSplitterFetch.nStartPos); !5ppA
output.writeLong(fileSplitterFetch.nEndPos); N52N ^X>
} lgU7jn
output.close(); k(et b#
} :[Fwc
catch(IOException e){e.printStackTrace ();} /@q_`tU
catch(Exception e){e.printStackTrace ();} 6x_8m^+m
} ${e{#
07n=H~yU
P'zA=Rd&~>
//读取保存的下载信息（文件指针位置） g=b'T-
private void read_nPos() $H?v
{ \SyfEcSf2v
try{ %h^; "|Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J-=&B5"O>
int nCount = input.readInt(); HyZh27PE
nStartPos = new long[nCount]; yhZ2-*pTg
nEndPos = new long[nCount]; 4W6gKY
for(int i=0;i<nStartPos.length;i++) 2: fSn&*/>
{ iX}EJD{f
nStartPos = input.readLong(); pX"f "
nEndPos = input.readLong(); I/t2c=f
} GDhg VOW(
input.close(); PE-VxRN)
} TEv3;Z*N
catch(IOException e){e.printStackTrace ();} fi`*r\
catch(Exception e){e.printStackTrace ();} F@[l&`7
} A+>+XA'
(;\JCeGA
iWO16=
private void processErrorCode(int nErrorCode) fE,\1LK4
{ .-uH ax0
System.err.println("Error Code : " + nErrorCode); K%)u zP
} o#CNr5/
Z+JPxe#7
_>0I9.[5
//停止文件下载 @}qMI
public void siteStop() Iy'a2@
{ :(E.sT"R
bStop = true; b@"#A8M
for(int i=0;i<nStartPos.length;i++) L~=h?C<
fileSplitterFetch.splitterStop(); Zg_ fec~6q
-6@#Nq_iWU
AfB,`l`k
} =[`B -?
} \9jEpE^Ju(
//负责部分文件的抓取 CN+[|Mz*p
**FileSplitterFetch.java M:rE^El
*/ ^,*!Qk<c
package NetFox; ,'Zs")Ydp
t,Ss3
v*U OD'tk
import java.io.*; Z7J8%ywQ
import java.net.*; imC>T!-7
`r+zNJ@q
bdbTK8-
public class FileSplitterFetch extends Thread { Lk#8G>U
8`Ih> Dc
4c0 =\v
String sURL; //File URL ,%6!8vX
long nStartPos; //File Snippet Start Position %=e^MN1
long nEndPos; //File Snippet End Position h6`v%7H?
int nThreadID; //Thread's ID lsq\CavbM
boolean bDownOver = false; //Downing is over +6-_9qRq
boolean bStop = false; //Stop identical zO)Bf(
FileAccessI fileAccessI = null; //File Access interface UXgeL2`;
b v5BV
~T">)Y~+xI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WstX>+?'
{ B:oE&Ahh{
this.sURL = sURL; +7E&IK
this.nStartPos = nStart; E7mB=bt>=
this.nEndPos = nEnd; J@$KF GUs
nThreadID = id; I'[gGK4F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &1 t84p:^=
} JP{Y Q:NF
(_IPz)F
eU(cn8/}
public void run() oDW)2*8yF
{ _O#R,Y2#
while(nStartPos < nEndPos && !bStop) zPm|$d
{ *E.uqu>I
CT{mzC8
A9Kt^HR
try{ H'a6] ]2
URL url = new URL(sURL); \uG^w(*)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ++\s0A(e
httpConnection.setRequestProperty("User-Agent","NetFox"); ze"`5z26|
String sProperty = "bytes="+nStartPos+"-"; lq}m0}9<
httpConnection.setRequestProperty("RANGE",sProperty); '"C& dia
Utility.log(sProperty); me@k~!e"z
_*wkTI+j
^i[bo3
InputStream input = httpConnection.getInputStream(); F81Kxcs
//logResponseHead(httpConnection); %_(Xn
2=IZD `{!
br;~}GR_h
byte[] b = new byte[1024]; %t*KP=@
int nRead; <g$bM;6%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w5<&b1:
{ k5gvo
nStartPos += fileAccessI.write(b,0,nRead); yRy^'E~
//if(nThreadID == 1) +k;][VC[O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6DVHJ+WTV
} g|Xjw Ti8$
s{uSU1lQn
:d1Kq _\K
Utility.log("Thread " + nThreadID + " is over!"); }Jo}K)>!
bDownOver = true; T&ib]LmR
//nPos = fileAccessI.write (b,0,nRead); sjy/[.4-
} vyBx|TR
catch(Exception e){e.printStackTrace ();} xey?.2K1A
} d1}cXSQ1T
} T s9go
o*5b]XWw
@{@DGc
//打印回应的头信息 (j&7`9<5
public void logResponseHead(HttpURLConnection con) \2Yo*jE}
{ m$`4.>J
for(int i=1;;i++) J3 xi5S
{ Ri/D>[
String header=con.getHeaderFieldKey(i); ,a3M*}Y~3
if(header!=null) af_bG;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1}q(Pn2
Utility.log(header+" : "+con.getHeaderField(header)); ~? n)/i("
else 5Z>+NKQ
break; \7WZFh%:
} {!*dk V
} | MXRNA~
|@rYh-5
QSx4M
public void splitterStop() N&G;`
{ 2OwO|n
bStop = true; RY}:&vWDk
} YK V"bI
W]5sqtF;6
mr+8[0
} &4m;9<8\
<3 I0$?xL
DfZ)gqp/Av
/* snVeOe#'S
**FileAccess.java ,#.9^J
*//文件访问(定位，写) 3J[ 5^
package NetFox; LIh71Vg/cc
import java.io.*; o(YF`;OhvS
Ym wb2]M
2 W Wr./q
public class FileAccessI implements Serializable{ a;v;%rs
A}CpyRVCn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Lu[xoQ~I
RandomAccessFile oSavedFile; J5zu}U?
long nPos; M5{vYk>,1Q
xL|4'8
71G00@&w9D
public FileAccessI() throws IOException (RLJ_M|;/b
{ GD<pqm`vVY
this("",0); 8]&lUMaqVZ
} hQLh}}B
k(wJ6pc
wb6$R};?
public FileAccessI(String sName,long nPos) throws IOException s/OXZ<C|
{ 8Og)(BC
oSavedFile = new RandomAccessFile(sName,"rw"); z1LY|8$G
this.nPos = nPos; D,SL_*r{
oSavedFile.seek(nPos); .GuZV'
} fqZ+CzH
Nu6]R677Y
l]mn4cn3
public synchronized int write(byte[] b,int nStart,int nLen) `bEum3l\6]
{ &;@U54,wV
int n = -1; DZ&AwF
try{ jIL$hqo
oSavedFile.write(b,nStart,nLen); z<s4-GJ)?
n = nLen; YbE1yOJ&m
} !' jXN82
catch(IOException e) UE/N-K)`
{ )4bZ;'B5
e.printStackTrace (); J9`[Qy\
} Gq^#.o]
Zbjj>*2%^
}{@RO./)[
return n; ]@7]mu:oL
} n`g:dz
l%9nA.M'
k<\]={|=
} ^1NtvQe@Y\
! jb{q bq
^p!bteA>
/* LdYaJh~h
**SiteInfoBean.java 7`6JK
*/ ^Sz?c_<2P
package NetFox; !YEU<9
Ue0Q| h
k0R;1lZ0n
public class SiteInfoBean { Eb=;D1)y]
"6%vVi6
9wC:8@`6E
private String sSiteURL; //Site's URL 9 ulr6
private String sFilePath; //Saved File's Path wq"AWyu
private String sFileName; //Saved File's Name yy-\$<j
private int nSplitter; //Count of Splited Downloading File me`(J y<
QZ54Osdl
mLn =SU{#
public SiteInfoBean() Q{Lsr,
{//nSplitter的缺省值为5 ^NTOZ0x~#
//default value of nSplitter is 5 Ctxx.MM
this("","","",5); :}18G}B
} _;+N=/l0
q3E_.{t
1f1J'du
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WtTwY8HC
{ weiqt *,8
sSiteURL= sURL; 'E,Bl]8C5
sFilePath = sPath; xbA% 'p
sFileName = sName; lYu1m
this.nSplitter = nSpiltter; jq&$YmWp
mckrR$>
S,,3h0$X
} #YSUPO%F
2JYt.HN
w{"GA~=
public String getSSiteURL() ;pNHT*>u,
{ U{>eE8l
return sSiteURL; Q(KLx)
} ]Zim8^n?`.
41TB
VPTT*a`
public void setSSiteURL(String value) WLWE%bDP
{ 'gojP
sSiteURL = value; BKm$H!u
} 97Qng*i
hqY9\,.C
'.@R_sj
public String getSFilePath() p\8cl/~
{ t?]6>J_V
return sFilePath; 1h+!<c q
} 0n,5"B
ys;e2xekg
v[6BESu
public void setSFilePath(String value) d/(=q
{ 0{Kl5>Z9M
sFilePath = value; zux+ooU
} |b/J$.R
=3oz74O[
Md {,@ G
public String getSFileName() <E BgHD)
{ asW1GZO
return sFileName; KW&&AuPb}
} q'2PG@
&bj :,$@
%i%Xi+{3
public void setSFileName(String value) :*&wnQMKR
{ =O)JPo&iwY
sFileName = value; u?g!E."v
} _u;^w}0
}C7tlA8,7
<'~8mV1
public int getNSplitter() G-3.-
{ !nj%n
return nSplitter; &,."=G
} 2c%}p0<;|?
@mJN
^MJGY,r6b
public void setNSplitter(int nCount) {|xwvTlJ
{ Uzb"$Ue4
nSplitter = nCount; ;$&-c/]F#
} YF>t{|
} 4!k={Pd
\ @N>38M
Lf0Hz")
/* 2J4|7UwJ
**Utility.java rY!uc!
*/ XFu@XUk!K
package NetFox; pXFNK"jm
GoEIY
@IiT8B
public class Utility { w ^<Y5K
dWqFP
J82{PfQ"
public Utility() iQ9#gPk_9
{ xD\Km>|i
gv[7h'}<
5GJ0EZ'X
} ZHC sv]l
-/gS s<"
//线程睡眠 %o"Rcw|
public static void sleep(int nSecond) +cV!=gDT
{ K%pmE?%,8
try{ ~o/^=:*
Thread.sleep(nSecond); /2@%:b)
} 5R=lTx/Hj
catch(Exception e) D} .t
{ {-Y_8@&
e.printStackTrace (); `C*!de]Y%
} $k`8Zx w
} KFZ[gqW8YY
7@lXN8_f
//日志 y2+a2
public static void log(String sMsg) p_z"Uwp
{ DYWC]*
System.err.println(sMsg); &16bZw
} R&4E7wrdP
"qj[[LQ
m_(hCY=Q$
public static void log(int sMsg) ,#E5/'c`
{ 13QCM0#
System.err.println(sMsg); WD\{Sdx:r
} %b{!9-n}
} k_a'a)`$6
wi9|
t~M<j|]k
/* vv0zUvmT
**TestMethod.java <=inogf
*/ 4jz]c"p-
package NetFox; tbPPI)lu
+zD'r5
2:N_c\Vi
public class TestMethod { ) ,hj7
jkP70Is
btF%}<o)
public TestMethod() 1ZL_;k
{ ///xx/weblogic60b2_win.exe u W|x)g11a
try{ 84!4Vz^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {^f0RGJg9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v 2GhR*
SiteFileFetch fileFetch = new SiteFileFetch(bean); |d5L Ifb(
fileFetch.start(); cA%U
} /a(zLHyz)
catch(Exception e){e.printStackTrace ();} 2SJh6U
9Bk}g50$#
)/Xrhhx
} |+:ZO5FaO
ee_\_"
oPy zk7{
public static void main(String[] args) "J5Pwvs-
{ J3x7i8
new TestMethod(); W`'|&7~
} W[>TqT63
} tKeO+6l
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