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)); r]}6iF.
} 3 u=\d)eq
for(int i=0;i<nEndPos.length-1;i++) ~%tVb c
{ (e_p8[x
nEndPos = nStartPos[i+1]; VxOWv8}|
} "Cvr("'O
nEndPos[nEndPos.length-1] = nFileLength; ;L",K?6#
} |j/Y#.k;{0
} _)LXD,LA
F~fN7<9R
Ht43G_.j
//启动子线程 }X])055S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O|Vc
for(int i=0;i<nStartPos.length;i++) D\ZH1C!d
{ Tw%1m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z;u3G4XlF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w?3ww7yf`
nStartPos,nEndPos,i); _"H\,7E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &RuTq6)r
fileSplitterFetch.start(); $uwz`N:
} b'FTyi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m0W3pf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lZkJ<*z#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?t}s3P!Q3w
nEndPos = " + nFileLength); ])v61B
// fileSplitterFetch[nPos.length-1].start(); C_;nlG6
B<myt79F_[
"tOm
//等待子线程结束 %Y/;jCY
//int count = 0; bFG?mG:
//是否结束while循环 {[bpvK
boolean breakWhile = false; pi70^`@'B
9I5AYa?
L|D9+u L
while(!bStop) Q|VBH5}1O
{ : maBec)
write_nPos(); qb=%W
Utility.sleep(500); ?&qQOM~b-\
breakWhile = true; 9%R"(X)
s9Tn|Pm+!\
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for(int i=0;i<nStartPos.length;i++) v0!(&g3Sd
{ | h"$
if(!fileSplitterFetch.bDownOver) [SKDsJRPP
{ eMEKR5*-O
breakWhile = false; 1f"}]MbLR
break; [".94(qs
} 5Uhxl^c
} 8.%wnH
if(breakWhile) VqD_FS;E
break; f]sR4mhO
RV]QVA*i
U![$7k>,pr
//count++; oFt_ yU-
//if(count>4) h1B_*L
// siteStop(); 8Bc2?NI=
} xHx_! )7
%y_pF?2@q
W7.RA>
System.err.println("文件下载结束！"); l ~xXy<
} a3:45[SO4e
catch(Exception e){e.printStackTrace ();} D;48VK/Q
} gQ{<2u
'%+LQ"Bp
Cnc=GTRi
//获得文件长度 zLxuxf~4@
public long getFileSize() Uw5&.aqn.b
{ 7bGOE_r
int nFileLength = -1; a>6M{C@pd
try{ Mx# P >.
URL url = new URL(siteInfoBean.getSSiteURL()); n Jz*}=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V'za,.d-
httpConnection.setRequestProperty("User-Agent","NetFox"); xrlyph5mE
(Xzq(QV
z#n+iC$9
int responseCode=httpConnection.getResponseCode(); SEu:31k{o
if(responseCode>=400) pp#!sRUKPV
{ %k"hzjXAw
processErrorCode(responseCode); &liFUP?
return -2; //-2 represent access is error 1Qjc*+JzO.
} vUL@i'0&o
S@ y! 0,
)Fqtb;W=
String sHeader; x a\~(B.
F7=\*U
"*c&[ALw
for(int i=1;;i++) t82*rCIB{
{ XfEp_.~JM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y+7+({w<
//Utility.log(in.readLine()); R+U*]5~R
sHeader=httpConnection.getHeaderFieldKey(i); LF(S"Of
if(sHeader!=null) ,#^2t_c/
{ 1b7?6CqV
if(sHeader.equals("Content-Length")) P=E10
{ TL-ALtG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z>=;Xe8P8n
break; sUkn.g!
} .G<Or`K^i
} l;h -`( 11
else !WB3%E,I
break; >*|Eyv_
} *Hv d
} Pc+,iK>
catch(IOException e){e.printStackTrace ();} or)fx/%h
catch(Exception e){e.printStackTrace ();} UpiZd/K
IG%x(\V-e
O!F"w!5@
Utility.log(nFileLength); FELW?Q?k
i!<(R$Lo
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return nFileLength; ep l1xfr
} O "Aeg|
-O@/S9]S)
6hFs{P7
//保存下载信息（文件指针位置） "`pg+t&
private void write_nPos() zR=g<e1xe
{ bDegIW/'w
try{ ~ihi!u%~}
output = new DataOutputStream(new FileOutputStream(tmpFile)); XNBzA3W
output.writeInt(nStartPos.length); # ?u bvSdU
for(int i=0;i<nStartPos.length;i++) ?]}=4
{ ;>]dwsA*P
// output.writeLong(nPos); Z]OX6G
output.writeLong(fileSplitterFetch.nStartPos); 0h('@Hb.K#
output.writeLong(fileSplitterFetch.nEndPos); 4i29nq^n
} y7z ,I
output.close(); LG?b]'#
} bvJ*REPL?
catch(IOException e){e.printStackTrace ();} n*~#]%4
catch(Exception e){e.printStackTrace ();} v=IcVHuf
} '?$<k@mJW
I wu^@
|g\CS4$
//读取保存的下载信息（文件指针位置） K=P LOC5
private void read_nPos() Ml_!)b
{ (+TL ]9P
try{ Wl,I%<&j}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g(F2IpUm/
int nCount = input.readInt(); Lf Y[Z4
nStartPos = new long[nCount]; "?Jf#
nEndPos = new long[nCount]; D]V&1n
for(int i=0;i<nStartPos.length;i++) AUaupNN
{ $BOIa
nStartPos = input.readLong(); <1U *{y
nEndPos = input.readLong(); Hxj8cXUF|
} /\pUA!G)BD
input.close(); )VG_Y9;Xk:
} H .sfM
catch(IOException e){e.printStackTrace ();} hSk
catch(Exception e){e.printStackTrace ();} S~y.>X3"P
} z+?48}
Ap}`Q(.
_`9WNJiL
private void processErrorCode(int nErrorCode) 9H%ixBnM
{ =mxj2>,&
System.err.println("Error Code : " + nErrorCode); I=8MLv
} "N=q>jaX
tqU8>d0^
z)*\njYe
//停止文件下载 1| xKb(_l
public void siteStop() OJLyqncw
{ YgkQF0+
bStop = true; ksqb& ux6
for(int i=0;i<nStartPos.length;i++) w6l56CB`
fileSplitterFetch.splitterStop(); vXR27
`u8=~]rblj
x=1Sbs w{
} pzDz@lAwR
} Z Mf,3
//负责部分文件的抓取 O$Dj_R#
**FileSplitterFetch.java T%2%*oa
*/ VmTgD96
package NetFox; &y7~
dQAo~]B
2-wgbC5
import java.io.*; 6c[ L*1
import java.net.*; Sr6?^>A@t
bB.Yq3KI
=ZARJ40L
public class FileSplitterFetch extends Thread { 3>^S6h}o
u$1^=
5S #6{Y =
String sURL; //File URL 7"k\i=
long nStartPos; //File Snippet Start Position I#CS;Yh95
long nEndPos; //File Snippet End Position N*Xl0m(Q
int nThreadID; //Thread's ID jx];=IC3tt
boolean bDownOver = false; //Downing is over %U&ztvR0C
boolean bStop = false; //Stop identical ]Ai!G7s8P
FileAccessI fileAccessI = null; //File Access interface YZ5[#E@l
6IL-S%EGK1
I8:G:s:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'i8?]` T
{ V}t8H
this.sURL = sURL; J2$=H1-
this.nStartPos = nStart; R!_1*H$
this.nEndPos = nEnd; 1++Fs
nThreadID = id; atfK?VK#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ; 5!8LmZ0#
} ;:ocU?
9!vimu)
G4,BcCPQ
public void run() `AELe_
{ ch0x*[N@
while(nStartPos < nEndPos && !bStop) DOWZhD
{ T;B/Wm!x
VD2o#.7*eu
}+ TA+;
try{ uulzJbV,K
URL url = new URL(sURL); O>arCr=H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fH;lh-
httpConnection.setRequestProperty("User-Agent","NetFox"); ]+AgXUrbOD
String sProperty = "bytes="+nStartPos+"-"; 4{ exv
httpConnection.setRequestProperty("RANGE",sProperty); ;HjT
Utility.log(sProperty); 2v1dSdX,W
6NzS<
#4?:4Im#
InputStream input = httpConnection.getInputStream(); U{-[lpd
//logResponseHead(httpConnection); c}#(,<8X
@-}!o&G0
Z+! 96LR
byte[] b = new byte[1024]; q3Y49d
int nRead; _1HEGX\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !o/;"'&E
{ Yk#$-"c/a
nStartPos += fileAccessI.write(b,0,nRead); l)91v"vJ
//if(nThreadID == 1) VV=6v;u`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]hA]o7k
} LfG$?<}hR
Kl+4A}Uo
~2?UEv6
Utility.log("Thread " + nThreadID + " is over!"); q|R$A8)L.
bDownOver = true; 4S,/Z{ J.
//nPos = fileAccessI.write (b,0,nRead); vTYgWR,h
} F[U0TP@&*
catch(Exception e){e.printStackTrace ();} 29h_oNO
} fuA8jx
} [IW6F
ZfIeq<8_
B7BikxUa
//打印回应的头信息 Ty"=3AvRLV
public void logResponseHead(HttpURLConnection con) k.w}}78N2N
{ U7Pn $l2!
for(int i=1;;i++) 97SG;,6
{ !fG`xZ~
String header=con.getHeaderFieldKey(i); V@1K
if(header!=null) >oc&hT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v`u>;S_
Utility.log(header+" : "+con.getHeaderField(header)); 7)v`l1
else N`i`[ f
break; Q##L|*Qy
} STQ~mFs"
} {_*$X
>{kPa|
~qmu?5
public void splitterStop() vD4<G{
{ 'O]Ja-
bStop = true; t%>x}b"2T
} U})Z4>[bvt
o[CjRQY]P
I~I$/j]e`
} ]%/a'[
<\5Y~!)
\%:]o-+"I
/* >iB-gj}>X
**FileAccess.java b'~IFNt*^
*//文件访问(定位，写) yzmwNsu
package NetFox; wPU<jAQyp
import java.io.*; <S%kwS
@IwVR
SB`"%6
public class FileAccessI implements Serializable{ Ty>g:#bogI
|MXv w6P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4 jeUYkJUM
RandomAccessFile oSavedFile; Pxm~2PAm
long nPos; o+Kh2;$)
;P4tqY@
ym)`<[T
public FileAccessI() throws IOException Z ]WA-Q6n
{ Sk,9<@
this("",0); 8q&*tpE
} XZ8;Ow=
g?caE)
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public FileAccessI(String sName,long nPos) throws IOException |K6hY-uC
{ H/6GD,0
oSavedFile = new RandomAccessFile(sName,"rw"); pu*vFwZ
this.nPos = nPos; wUz)9n 6j
oSavedFile.seek(nPos); uua1_#a
} *!y.!v*
lhA<wV1-9G
zx{O/v KG
public synchronized int write(byte[] b,int nStart,int nLen) r'ydjy
{ 5=.EngG
int n = -1; q#~]Hp=W5
try{ Tse Pdkk
oSavedFile.write(b,nStart,nLen); Wd_cNR\
n = nLen; #D{//P|;
} C=/nZGG
catch(IOException e) R?Or=W)i
{ ~:%rg H
e.printStackTrace (); |cBpX+D
} ,\K1cW~U5
#}A >B
z<F.0~)jb
return n; Ng} AEAFp
} Q`}n;DV
oGLSk(T&I
jF\J+:5M
} k+S 6)BQ7U
.baS mfc
zAxwM-`
/* ZK[S'(6q
**SiteInfoBean.java ~4mgYzOmD`
*/ Dn?P~%
package NetFox; kE".v|@
xe: D7
S{NfU/: dL
public class SiteInfoBean { %L./U$
%XqLyeOS
(r^IW{IndX
private String sSiteURL; //Site's URL +*Cg2`
private String sFilePath; //Saved File's Path eD, 7gC-
private String sFileName; //Saved File's Name XRI1/2YA
private int nSplitter; //Count of Splited Downloading File Nky%v+r
T]nZ3EZ
-NVk>ENL4
public SiteInfoBean() [PrR30:
{//nSplitter的缺省值为5 $2^V#GWo
//default value of nSplitter is 5 A]{8=
this("","","",5); V&_5q`L
} ~`MGXd"o
fwIZr~l
EYUr.#:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s&lZxnIjc
{ %t\`20-1<
sSiteURL= sURL; hSD)|
sFilePath = sPath; 0=s+bo1
sFileName = sName; / vge@bsE
this.nSplitter = nSpiltter; 79a{Zwdd9j
Ah &D5,3
QH4nb h4
} )E^4\3^:
>;QkV6i7
[6 !/
public String getSSiteURL() {61NLF\0H
{ +6f5uMKUvs
return sSiteURL; ''wWw(2O
} r}QW!^F
;=6++Oq
8@/]ki`>
public void setSSiteURL(String value) v^[Ny0cM
{ ,KIa+&vJW@
sSiteURL = value; 0ldde&!p
} g?i_10Xlp
`a2Oj@jP
q[q#cY:0
public String getSFilePath() KI$?0O
{ |zvxKIW;wd
return sFilePath; y3$' gu|
} \x x<\8Qr_
qEf)TW(
PF!Q2t5c3
public void setSFilePath(String value) f b_tda",}
{ eF}Q8]da
sFilePath = value; X<(h)&E
} k KL^U
(J<@e!@NE
mw`%xID*
public String getSFileName() \J-O b
{ r#]gAG4t\
return sFileName; uHQJ&
} 42Vy#t/HC
*s?&)][
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public void setSFileName(String value) : Ot\l
{ h.4;-&
sFileName = value; oRy?Dx+H
} & HphE2 h
dlK#V)
%o#D"
public int getNSplitter() X\ \\RCp
{ N(}7M~m>
return nSplitter; &N*S
} 0wZLkU_(
DZ ~|yH
5HL JkOV5
public void setNSplitter(int nCount) h:#
{ .rG Rdb
nSplitter = nCount; Ua V9T:)x
} Nf0b?jn-
} /n?5J`6
**-%5~
?$;_a%v6
/* cGsxfwD
**Utility.java 6l [TQ
*/ lbT<HWzNH
package NetFox; %MbjKw
Lvv`_
w*#k&N[X
public class Utility { WqY:XE+?\
;csAhkf:S
xYM/{[
public Utility() ^lRXc.c z
{ x}N+vK
fPK|Nw]b
&!/L^Y*+
} Ax0u \(p<^
qg:1
//线程睡眠 N_q7ip%z
public static void sleep(int nSecond) pR 1v^m|
{ Wz:MPdz3(
try{ k%NY,(:(
Thread.sleep(nSecond); -hp,O?PM
} 8,dCx}X
catch(Exception e) 0NpxqeIDY
{ )/bt/,M&}
e.printStackTrace (); S][:b
} : [aUpX=
} A+Y>1-=JO
Lkk'y})/
//日志 yn!LJT[~2
public static void log(String sMsg) c !P9`l~MQ
{ t ~U&a9&Z
System.err.println(sMsg); fn#b3ee
} dWD9YIYf
$CL=M
Yq`r>g
public static void log(int sMsg) lJKhP
{ X"iy.@7
System.err.println(sMsg); &}:Hp9n
} 79:x>i=
} fRaVY`|wK
^"6xE nA]
'n!;7*
/* U G^6I5
**TestMethod.java a/_sL(F{
*/ ] =>vv;L
package NetFox; ;?zb (2
>?U(w<
O~fRcf:Q
public class TestMethod { 0~Yg={IKhK
biKpV?Dp
I7BfA,mZ7
public TestMethod() /o8`I m
{ ///xx/weblogic60b2_win.exe [^ 7^&/0
try{ Ik;~u8j1e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4X#>;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Pm+H!x,
SiteFileFetch fileFetch = new SiteFileFetch(bean); )]>=Uo
fileFetch.start(); ]Z<{ ~
} s'~_pP
catch(Exception e){e.printStackTrace ();} 2c8,H29
z%+?\.oH
lOd[8|/
} N ?V5gi
^>g+:?x
y<)Lr}gP
public static void main(String[] args) JkQ4'$:
{ ! ~&X1,l1*
new TestMethod(); gA~Ih
} oPzt1Y
} fcJ#\-+E
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