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)); <1x u&Z7
} [x`),3qD
for(int i=0;i<nEndPos.length-1;i++) VtU2&
{ B(eiRr3
nEndPos = nStartPos[i+1]; f= }!c*l"
} <RH%FhT
nEndPos[nEndPos.length-1] = nFileLength; Y[rCF=ZVH
} W&I:z-VH
} 2'Kh>c2
jSdC1,wR
ajkpU.6E:
//启动子线程 ]S@DVXH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8W7ET@`
for(int i=0;i<nStartPos.length;i++) 7[R`52pP
{ fti0Tz'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {`>pigo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SF ^$p$mC
nStartPos,nEndPos,i); S~|\bnE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q 4Ok$~"I
fileSplitterFetch.start(); $t5>1G1j7
} ew c:-2Y^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~0Zy$L/D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \t&8J+%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a|]}uFr
nEndPos = " + nFileLength); N];K
// fileSplitterFetch[nPos.length-1].start(); s~5rP:
=4!m]*y
)! kl:
//等待子线程结束 ,d^HAg^j
//int count = 0; l Yj$3
//是否结束while循环 y^ st T^
boolean breakWhile = false; $}0\sj%
i"4;{C{s
9El{>&Fs4
while(!bStop) :#N]s
{ jF#Dc[*
write_nPos(); Q5 o0!w
Utility.sleep(500); mK^E@uxN
breakWhile = true; Cw5B p9
?+{_x^
:/>Zky8,k
for(int i=0;i<nStartPos.length;i++) g<8Oezi 65
{ >I+p;V$@
if(!fileSplitterFetch.bDownOver) I(/*pa?m{
{ ArT@BqWd
breakWhile = false; * COC&
break; <?Z]h]C^o
} I&% Z*H
} dI%Nwl%
if(breakWhile) %T}*DC$&S
break; _]0<G8|Rv
fzN?X=
O6\c1ha
//count++; ]KUeSg|
//if(count>4) +Je%8jH
// siteStop(); [[ll4|
} fM(~>(q&
*3fhVl=8^*
a3Xd~Qs
System.err.println("文件下载结束！"); ^--8 cLB n
} Y7')~C`up^
catch(Exception e){e.printStackTrace ();} ?lU(FK
} aR)w~s\6
q{xF7}i
yQN^F+.
//获得文件长度 |Rm_8n%m
public long getFileSize() /:C<{m.[}
{ @oD2_D2
int nFileLength = -1; n8z++T&
try{ L=I;0Ip9y
URL url = new URL(siteInfoBean.getSSiteURL()); (7"CYAe:;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >H,E3Z
httpConnection.setRequestProperty("User-Agent","NetFox"); )E^Pn|H
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1c*;Lr.K
int responseCode=httpConnection.getResponseCode(); Ggbz
if(responseCode>=400) [<wpH0lNoy
{ p& Kfy~
processErrorCode(responseCode); A~<cp)E
return -2; //-2 represent access is error tF.N
} !L2!:_
C;_00EQ=
R_ )PbFw
String sHeader; m\MI 6/
$dsLU5]1o
'#jZ`
for(int i=1;;i++) Fv:x>qZr@
{ \:2z!\iP`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VKSn \HT~
//Utility.log(in.readLine()); <s$Jj><
sHeader=httpConnection.getHeaderFieldKey(i); :G&:v
if(sHeader!=null) p!\GJ a",
{ B)dG:~
if(sHeader.equals("Content-Length")) BQB<+o'
{ ^4et; F%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PO,zP9
break; 6NSSuK3
} Q(4~r+
} {~XAg~
else ]2A2<Q_,
break; $"MGu^0;1
} ;jBS:k?
} }nSu7)3$B
catch(IOException e){e.printStackTrace ();} DQ c pIV
catch(Exception e){e.printStackTrace ();} 86a,J3C[
}'Ph^ %ox
K>n@8<7
Utility.log(nFileLength); TV`sqKW
-z%->OUu
G2b"R{i/,
return nFileLength; RMdU1@
} dV-6l6
d<E2=WVB6
tvJl&{-OX
//保存下载信息（文件指针位置） z0F55<i
private void write_nPos() {aUv>T"c
{ qxYCT$1
try{ 12: Q`
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9D;ono3
output.writeInt(nStartPos.length); ,uO_C(G/i
for(int i=0;i<nStartPos.length;i++) -OnKvpeI
{ KcW 5
// output.writeLong(nPos); qOa*JA`
output.writeLong(fileSplitterFetch.nStartPos); ]cMZ7V^
output.writeLong(fileSplitterFetch.nEndPos); ==trl#kQ%%
} nP|ah~ q
output.close(); {wO.nOB
} 735l&(3A\
catch(IOException e){e.printStackTrace ();} B[2t.d;h
catch(Exception e){e.printStackTrace ();} 2#cw_Ua
} G;USVF-'K
k0TQFx.A
K<WowU
//读取保存的下载信息（文件指针位置） ,'sDauFn
private void read_nPos() $_e{Zv[
{ K7/&~;ZwT
try{ , 10+Sh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); UQWv)
int nCount = input.readInt(); = \K/ulZo
nStartPos = new long[nCount]; -w'g0/fD
nEndPos = new long[nCount]; G/w@2lYx
for(int i=0;i<nStartPos.length;i++) [$fB]7A
{ !~j9Oc^
nStartPos = input.readLong(); >4HB~9dKU
nEndPos = input.readLong(); ^E%NYq_2l<
} {7v|\6@e3
input.close(); vq@"y%C4
} }"q#"s
catch(IOException e){e.printStackTrace ();} %f(4jQ0I
catch(Exception e){e.printStackTrace ();} kHQn'r6
} x_l8&RIB*
t*Z-]P
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private void processErrorCode(int nErrorCode) Eok8+7g0&
{ BL%&n*&
System.err.println("Error Code : " + nErrorCode); :JXcs39
} 2Ns<lh
!u`f?=s;
9yLPh/!Ob
//停止文件下载 DnN+W
public void siteStop() U)3?&9H
{ /N@NT/.M<
bStop = true; 472'P
for(int i=0;i<nStartPos.length;i++) TETfRnm
fileSplitterFetch.splitterStop(); P+3 ]g{2w
Q0xQxz
l 5f'R
} h5^We"}+
} 475jmQ{q
//负责部分文件的抓取 "`w*-O
**FileSplitterFetch.java :rvBx"
*/ LD,T$"
package NetFox; bnE&-N*
ycWY.HD
YT@H^=
import java.io.*; 26j-1c!NGd
import java.net.*; uYd_5 nw
rj<-sfs
{|e7^_ke
public class FileSplitterFetch extends Thread { nH[>Sff$
BJsN~`=r
pU u')y
String sURL; //File URL *mN8Qd
long nStartPos; //File Snippet Start Position GVdJ&d\x
long nEndPos; //File Snippet End Position e"2x!(&n(
int nThreadID; //Thread's ID wJ7Fnj>u%
boolean bDownOver = false; //Downing is over 4 @9cO)m
boolean bStop = false; //Stop identical #|Je%t}~
FileAccessI fileAccessI = null; //File Access interface F+V[`w*k
"fSK7%BP
Ge76/T%{Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #;'*W$Wk2
{ o7AI
this.sURL = sURL; o* QZf*M
this.nStartPos = nStart; 1rh2!4)7
this.nEndPos = nEnd; ay28%[Q b4
nThreadID = id; -"xC\R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |:d_IB@
} 9O:-q[K**
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0#F<JsO|u
public void run() ]Vf2Mn=]"
{ 6x8lnXtA
while(nStartPos < nEndPos && !bStop) W1Om$S1
{ {d,^tG}
x}N1Wl=8g
zM'2opiUY
try{ PO=A^b
URL url = new URL(sURL); cHwN=mg]S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q!W+vh
httpConnection.setRequestProperty("User-Agent","NetFox"); hHsO?([99
String sProperty = "bytes="+nStartPos+"-"; 0O?!fd n
httpConnection.setRequestProperty("RANGE",sProperty); ATI2
Utility.log(sProperty); et6@);F
/6p7k
|C\XU5}
InputStream input = httpConnection.getInputStream(); $60]RCu
//logResponseHead(httpConnection); XN'<H(G
5U(ry6fI=
Il<ezD{
byte[] b = new byte[1024]; &4Y@-;REt
int nRead; /f,*|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 74%Uojl"
{ .BZ3>]F3<
nStartPos += fileAccessI.write(b,0,nRead); lQer|?#
//if(nThreadID == 1) XO4rrAYvW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `"j_]
} " G0HsXi
@!Q\| <
Qx[ nR/
Utility.log("Thread " + nThreadID + " is over!"); %|By ?i
bDownOver = true; o!|TCwt
//nPos = fileAccessI.write (b,0,nRead); [moz{Y
} [Ma d~;
catch(Exception e){e.printStackTrace ();} N>+L?C
} ?rv5Z^D'
} .tRWL!
8E\6RjM
#5W-*?H
//打印回应的头信息 '~kAsn*/
public void logResponseHead(HttpURLConnection con) ,W~a%8*
{ KdkZ-.
for(int i=1;;i++) /s^O M`5
{ !l1ycQM
String header=con.getHeaderFieldKey(i); 0%<x>O
if(header!=null) Q:!.YSB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ih/MW_t=m=
Utility.log(header+" : "+con.getHeaderField(header)); L&SlUXyt.c
else 1t7S:IZ
break; `SO"F,
} M `bEnu
} *%xmCPJ
O U3KB
Ok&u4'<
public void splitterStop() `l8^n0-
{ jB!Q8#&Q
bStop = true; U.HeIJ#
} X"qC&oZmf
`FL!L59nz
@I^LmB9*
} Ad:)5R o
-I#1xJU
}2eP~3
/* SMdQ,n1]
**FileAccess.java #(G#O1+
*//文件访问(定位，写) &jHnM^nQ
package NetFox; @4N@cM0
import java.io.*; jP9)utEm6
0*KU"JcXd
T};fy+iq
public class FileAccessI implements Serializable{ FF"`F8-w>Z
kK[m=rTx1$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7#BpGQJQ
RandomAccessFile oSavedFile; ]"< `^
long nPos; F(i@Gm=J]
j7|r^
b4$-?f?V
public FileAccessI() throws IOException /~Q2SrYH
{ )J"Lne*"
this("",0); Ol9'ZB|R
} 9_mys}+
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jz_\B(m9%
public FileAccessI(String sName,long nPos) throws IOException eVZ/3o
{ #Cda8)jl(
oSavedFile = new RandomAccessFile(sName,"rw"); #lM :BO
this.nPos = nPos; 6+9inWTT(
oSavedFile.seek(nPos); b=!G3wVw<
} A7!=`yA$
8%s_~Yc
JR1/\F<}
public synchronized int write(byte[] b,int nStart,int nLen) ptXLWv`
{ V3'QA1$
int n = -1; AK/_^?zAs
try{ )/u?_)b4"
oSavedFile.write(b,nStart,nLen); q1Vh]d
n = nLen; S"iz fQ@
} xe;1D'(
catch(IOException e) fD#VI
{ LB|FVNW/S
e.printStackTrace (); *5bKJgwJ
} |RBgJkS;8
6_a42#
U[1Ir92:
return n; LY%`O#i.
} 2G'Au}q0n
/h=:heS4$
^d!(8vh
} _h4{Sx
G'/36M@
;Zb+WGyj
/* D&f(h][hH?
**SiteInfoBean.java )E<<
*/ @<5?q:9.8
package NetFox; UwuDs2 t
5Uc!;Gd?b
2YD;Gb[8
public class SiteInfoBean { I^pD=1Y]
/=9t$u|
`Z*k M VN
private String sSiteURL; //Site's URL vDgf}
private String sFilePath; //Saved File's Path _C3l2v'I$
private String sFileName; //Saved File's Name FpjpsD~Qu
private int nSplitter; //Count of Splited Downloading File ^Jb=&u$
1=x4m=wV
9IgozYj
public SiteInfoBean() Fa`/i v
{//nSplitter的缺省值为5 +~Ni7Dp]
//default value of nSplitter is 5 {O-,JCq/
this("","","",5); SqL8MKN)
} -I7"9}j3
=k#SQ/@
Yb8o`j+t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E9_aNYD
{ \hpD
sSiteURL= sURL; @G0k+
sFilePath = sPath; !BD+H/A.{
sFileName = sName; Ur`Ri?
this.nSplitter = nSpiltter; .!T]sX_P
.l$'%AG:~
^J3\ U{B
} %zx=rn(K
HCHZB*r[
;h>s=D,r
public String getSSiteURL() qrBo'@7
{ 4R5+"h:
return sSiteURL; &KC^Vn3Nj
} 8YJ8_$Z
GQXN1R
wehZ7eqm
public void setSSiteURL(String value) 5bZf$$b
{ eIjn~2^
sSiteURL = value; /PbN!r<1
} Bd$i%.r
h~rSM#7m
au'Zjj/Ai5
public String getSFilePath() vzVXRX
{ #8P9}WTno.
return sFilePath; |) {)w`
} `~'yy q
:4]^PB@dl
Iuk!A?XV
public void setSFilePath(String value) (rV#EA+6[`
{ D~W1["[
sFilePath = value; tPh``o
} J8[N!qDCj
EAYx+zI
C<Q;3w`#1j
public String getSFileName() .[Ezg(U}ze
{ < &[=,R0 @
return sFileName; Q C?*O?~#
} Yoy}Zdu}h
Z)B5g>
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public void setSFileName(String value) KTX;x2r
{ Ht.0ug
sFileName = value; noz&4"S.{
} SenDJv00
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:n36}VG|
public int getNSplitter() p7y8/m\6
{ Q)oO*CnM!-
return nSplitter; (vHB`@x
} cY1d6P0
8jyg1NN D
:BFecS&i5
public void setNSplitter(int nCount) Aa^%_5
{ CFqteY"
nSplitter = nCount; G?\\k[#,&
} Cf#[E~24
} cnfjOg'\{
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UR;FW`
/* sYlA{Z"
**Utility.java %<cfjo
*/ Qp9)Rc5
package NetFox; Z["[^=EP
D;%(Z!
5v:c@n
public class Utility { [0v`E5
8P8@i+[]W
,U9gg-.Lp
public Utility() 7VWq8FH`
{ dq$H^BB+>
|7G+O+j
Kfho:e,
} 'xO5Le(=M
ZuV/!9qU
//线程睡眠 pJ*x[y
public static void sleep(int nSecond) P{qi>FJqe
{ (<RZZ{m
try{ s?h=%;T[
Thread.sleep(nSecond); <[9{Lg*D
} N;4tvWI
catch(Exception e) (+Ia:D
{ sB|>\O#-
e.printStackTrace (); i}C9
} iC]=S}
} V-Ebi^gz5W
e))fbv&V
//日志 u(W%snl
public static void log(String sMsg) Rlvb@aXgy
{ p BU,"Yy&
System.err.println(sMsg); :CH?,x^!@
} R0>GM`{
^{L/) Xy5
3<:(Eda}
public static void log(int sMsg) FbxrBM
{ eJWcrVpn
System.err.println(sMsg); :G+8%pUX]
} @f<q&K%FJ
} j<+QGd%
!/pE6)a
mj\]oWS7d
/* a`]Dmw8@
**TestMethod.java "AH1)skB:
*/ Ja$Ple*XU8
package NetFox; u=epnz:<
kNW}0CDgs
\*5`@>_
public class TestMethod { C'4gve 7!
s d-5AE
1: cD\
public TestMethod() /5@4}m>Z@
{ ///xx/weblogic60b2_win.exe +Usy
try{ +4<Ij/}p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lLq9)+HGN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0FL PZaRP
SiteFileFetch fileFetch = new SiteFileFetch(bean); gQXB=ywF
fileFetch.start(); Yh=/?&*
} $JH_
catch(Exception e){e.printStackTrace ();} Knd2s~S
Kwc~\k
xMck A<E
} %<4ZU!2L
T@V<J'
z: x|;Ps!
public static void main(String[] args) b:OQ/
{ vjfV??XSU
new TestMethod(); pf_(?\oz>
} ~,199K#'
} \YV`M3O
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