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)); 8z}^jTM
} AbfZ++aJ
for(int i=0;i<nEndPos.length-1;i++) NYB "jKMk
{ . I==-|
nEndPos = nStartPos[i+1]; Vb!O8xV4;+
} c-B/~&
nEndPos[nEndPos.length-1] = nFileLength; /e1(? 20
} oa`#RC8N
} {DwIjy31T
m#\[m<F
,Dp0fauJ
//启动子线程 !9]d|8!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,lm=M5b
for(int i=0;i<nStartPos.length;i++) Z\ )C_p\-
{ %;|0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d1]i,C~Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H0>yi[2f
nStartPos,nEndPos,i); f~ZEdq8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hw=GR_,
fileSplitterFetch.start(); 89HsPB1"t
} #jA)>z\Q^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1e}8LH7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0<.RA%dj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "0Q1qZ
nEndPos = " + nFileLength); (3;@^S4&w
// fileSplitterFetch[nPos.length-1].start(); "=A>}q@;H
% frfSGf.#
HBiBv-=,
//等待子线程结束 ho.(v;
//int count = 0; a#[-*ou`
//是否结束while循环 3FNT|QF
boolean breakWhile = false; |=K_F3aJ
"2{%JFE
I ~$1Lu`~
while(!bStop) 4W;S=#1
{ (Rd$VYuf
write_nPos(); gzdG6"
Utility.sleep(500); obo&1Uv,/
breakWhile = true; 80;n|nNB
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P^)q=A8Z#
for(int i=0;i<nStartPos.length;i++) jc:s` 4
{ \/5RL@X}
if(!fileSplitterFetch.bDownOver) |+}G|hx@9
{ lzhqcL"
breakWhile = false; KzO,*M
break; Eu,`7iQ?(
} pqR\>d0
} 3BQ!qO17^d
if(breakWhile) Q5a)}6-5
break; yI3kvh
u:dx;*
d@ Ja}`
//count++; |E3X
//if(count>4) ynwG\V
// siteStop(); rs;r $
} P_Hv%g
ig!7BxM)<h
)rtomp:X
System.err.println("文件下载结束！"); o:p *_>&
} szmmu*F,U:
catch(Exception e){e.printStackTrace ();} dl~|Izm
} se9>.}zZN
j !H^-d}q
S\#17.=
//获得文件长度 bC6oqF'#
public long getFileSize() 9`B$V##-L
{ T+IF}4ed
int nFileLength = -1; /)L 0`:I#
try{ rcN 9.1
URL url = new URL(siteInfoBean.getSSiteURL()); (u1m]WYL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~nY]o"8D
httpConnection.setRequestProperty("User-Agent","NetFox"); }q[Bd
>BVoHt~;
e'9r"<>i
int responseCode=httpConnection.getResponseCode(); }} ZY
if(responseCode>=400) rS8 w\`_
{ ~O6\6$3b5E
processErrorCode(responseCode); nH-V{=**
return -2; //-2 represent access is error $XnPwOj
} >3.X?
tJ0NPI56yP
r 2:2,5_
String sHeader; +^|iZbZKx
aSutM
0<p{BL8
for(int i=1;;i++) R.9V,R5
{ j2 %^qL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \cJa;WM>
//Utility.log(in.readLine()); PkuTg";
sHeader=httpConnection.getHeaderFieldKey(i); (5Nv8H8|
if(sHeader!=null) +0l`5."d
{ 2?q(cpsN
if(sHeader.equals("Content-Length")) "sUyHt-&
{ ti@kKz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /~p+j{0L3W
break; =/0=$\Ws
} {w6/[-^
} `Ityi}
else .ic:`1
break; OQ&'Dti
} RP4Ku9hk
} ~ 5"JzT
catch(IOException e){e.printStackTrace ();} @OpNHQat9
catch(Exception e){e.printStackTrace ();} /0MDISQy9
*# {z3{+
R:aa+MX(1
Utility.log(nFileLength); V^s0fWa
gb|Q%LS9R
Xd `vDgD
return nFileLength; WYcA8X/
} 5e8AmY8;
}28=
9LJZ-/Wq
//保存下载信息（文件指针位置） c]k*}W3T
private void write_nPos() _QOZsEe
{ $.%rAa_H
try{ Fg]?zEa
output = new DataOutputStream(new FileOutputStream(tmpFile)); sBX-X$*N
output.writeInt(nStartPos.length); ^Q<mV*~
for(int i=0;i<nStartPos.length;i++) Wi.5Y{
{ t<iEj"5
// output.writeLong(nPos); X;F8_+Np
output.writeLong(fileSplitterFetch.nStartPos); I^\&y(LJF
output.writeLong(fileSplitterFetch.nEndPos); a?h*eAAc.
} &EGqgNl
output.close(); (.Y/
} 1 T<+d5[C
catch(IOException e){e.printStackTrace ();} bPKOw<
catch(Exception e){e.printStackTrace ();} y] oaO+
} PUJ2`iP1^3
68fiG
G"5D< ]
//读取保存的下载信息（文件指针位置） Lo.rvt
private void read_nPos() t&q N: J
{ jEdtJEPa
try{ T4/fdORS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SMr13%KN/
int nCount = input.readInt(); n{0Ld -zH
nStartPos = new long[nCount]; W*DVi_\$y
nEndPos = new long[nCount]; =<@2#E)
for(int i=0;i<nStartPos.length;i++) !|waK~jK
{ ?4H#G)F
nStartPos = input.readLong(); rf:XRJ<4
nEndPos = input.readLong(); VXBY8;+Yp
} pO Iq%0]
input.close(); eDI=nSo
} 8LkP)]4^sO
catch(IOException e){e.printStackTrace ();} IA zZ1#/3
catch(Exception e){e.printStackTrace ();} W<ZK,kv
} ^>x|z.
qVqRf.-\
g6t"mkMY L
private void processErrorCode(int nErrorCode) /&#XhrT
{ O43YY2
System.err.println("Error Code : " + nErrorCode); $q?$]k|M`
} Wm~` ~P
lH^^77"4Qo
%.v{N6
//停止文件下载 p^kUs0$GS
public void siteStop() 85:NFa@J
{ %sBAl.!BN
bStop = true; &.13dq
for(int i=0;i<nStartPos.length;i++) s'aip5P
fileSplitterFetch.splitterStop(); wFh8?Z3u_
[D"t~QMr
Y}*\[}l:&x
} 'nQVj
} o{b=9-V
//负责部分文件的抓取 EJ}!F?o
**FileSplitterFetch.java N]EcEM#
*/ 1LJuCI=~
package NetFox; gJiK+&8I
vr^~yEr
qLL,F
import java.io.*; x&Vm!,%:1
import java.net.*; AmPMY:1i"
0kQPJWF
AE`We$!
public class FileSplitterFetch extends Thread { X[s8X!#
]?1Y e8>Y<
SnlyUP~P
String sURL; //File URL Pz#7h*;cw.
long nStartPos; //File Snippet Start Position 9Ya<My
long nEndPos; //File Snippet End Position 1 2++RkL#
int nThreadID; //Thread's ID up3O|lj4
boolean bDownOver = false; //Downing is over -4rDbDsr
boolean bStop = false; //Stop identical XfE?C:v
FileAccessI fileAccessI = null; //File Access interface 1be %G [*
1axQ)},o@p
&c(WE RW?-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $mmup|;(
{ >h2%[j=
this.sURL = sURL; uJHu>M}~
this.nStartPos = nStart; iI@jZVk
this.nEndPos = nEnd; 02`$OTKz
nThreadID = id; .#u_#=g?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (6CN/A{qe
} M2x["
n,HE0Zn]Y_
OH^N" L
public void run() <e]Oa$
{ {qW~"z*
while(nStartPos < nEndPos && !bStop) f'Iz G.R
{ .x`M<L#M(
\;-fi.Hrf$
XoLJL]+?
try{ [ xOzzp4
URL url = new URL(sURL); ;=j@, yu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I$NhXZ)KT
httpConnection.setRequestProperty("User-Agent","NetFox"); EV#MQM
String sProperty = "bytes="+nStartPos+"-"; tt?58dm|
httpConnection.setRequestProperty("RANGE",sProperty); =~Ynz7 /x
Utility.log(sProperty); )#a[-.OI
JXG"M#{
& gJV{V5Ay
InputStream input = httpConnection.getInputStream(); ""Zp:8o
//logResponseHead(httpConnection); ^JZ^>E~
\\BCcr\l
~U(,TjJb
byte[] b = new byte[1024]; Qu=LnGo~P
int nRead; .6O"| Mqb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ri`R<l8
{ _LAS~x7,
nStartPos += fileAccessI.write(b,0,nRead); HkV1sT
//if(nThreadID == 1) IM$2VlC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w{~+EolK
} ms($9Lv/
nzjkX4KV
O%1v)AT&\
Utility.log("Thread " + nThreadID + " is over!"); ^JI o?R
bDownOver = true; Q%/<ZC.Mz6
//nPos = fileAccessI.write (b,0,nRead); ,\ 2a=Fp
} ^l^fD t
catch(Exception e){e.printStackTrace ();} Q6o(']0
} R1F5-#?'E
} {7!UQrm<
`r5$LaD
87}&`
//打印回应的头信息 fP3_d
public void logResponseHead(HttpURLConnection con) 6:U$w7P0 e
{ AC O)Dt(Y
for(int i=1;;i++) GV)<Q^9
{ A^ _a3$,0
String header=con.getHeaderFieldKey(i); !zPG?q]3
if(header!=null) nA|.t[v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S[tE&[$(p
Utility.log(header+" : "+con.getHeaderField(header)); nf1#tlIJd
else DjU9 uZT
break; SVjl~U-^
} Xi?b]Z
} pE{yv1Yg
)$w*V9d
r'CM
public void splitterStop() r1ws1 rr=
{ wU#F_De)R:
bStop = true; k>dsw:
} bX.ja;;
@i^~0A#q*
p^(&qk?ut
} Hk>79};
2=?tJ2E
^:9$@+a
/* >0{S
**FileAccess.java U yw-2]!n
*//文件访问(定位，写) s5RjIa0$7
package NetFox; pLMRwgzr
import java.io.*; eI1GXQ%
aNyvNEV3C
oG$)UTzGc
public class FileAccessI implements Serializable{ h._nK\
k{gLMl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C^QtSha
RandomAccessFile oSavedFile; 9}B`uJ
long nPos; /(O$(35
gPAX4'
[2ax>Yk$
public FileAccessI() throws IOException s>0Nr
{ [D5t{[i
this("",0); 7_2kDDW0
} <foCb%$(?
%>gW9}kB
#W.vX?-'0
public FileAccessI(String sName,long nPos) throws IOException &z"krM]G
{ jCTAKaq
oSavedFile = new RandomAccessFile(sName,"rw"); +0),xu
this.nPos = nPos; ~&\ f|%
oSavedFile.seek(nPos); 6t/`:OZC:
} SI:U0gUc
&V>fYgui
!v]b(z`Y
public synchronized int write(byte[] b,int nStart,int nLen) %{6LUn
{ OMwsbp&
int n = -1; A:<;M@q!
try{ X=8Y&#%
oSavedFile.write(b,nStart,nLen); I\qYkWg7
n = nLen; K[chjp!$l
} pT?Q#,fh
catch(IOException e) 0A{/B/r
{ #YDr%>j
e.printStackTrace (); nC {K$
} g*w<*
K78rg/`
86f2'o+
return n; CF|]e:
} 6<0n *&
;n\= R 5.
Y!6/[<r$~k
} s4_/&h
?PTk1sB
3]-_q"Co4f
/* `nUO l
**SiteInfoBean.java l"n{.aL
*/ >;z<j$;F<
package NetFox; PpLU
[sW.CK=3
Og;-B0,A
public class SiteInfoBean { EBtLzbj
yfU<UQ!1
Pmi#TW3X
private String sSiteURL; //Site's URL /~4"No@
private String sFilePath; //Saved File's Path %!ebO*8q
private String sFileName; //Saved File's Name b|SE<\
private int nSplitter; //Count of Splited Downloading File K ~44i
zi~5l#I
?S?2 0
public SiteInfoBean() }HEvr)v9
{//nSplitter的缺省值为5 >zkRcm
//default value of nSplitter is 5 @pGZLq
this("","","",5); 7FN<iI&7\
} W4;m H}#0
gn5)SP8
K;7f?52
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o;b0m;~
{ WWT",gio
sSiteURL= sURL; Gu=STb
sFilePath = sPath; E{HY!L[
sFileName = sName; EkT."K
this.nSplitter = nSpiltter; 5unG#szq
g~UUP4<$"
4h6k`ie!$
} `RMI(zI3g.
5-)#f?
>hY" 3
public String getSSiteURL() }AZc8o-
{ 6io, uh!
return sSiteURL; UZ8?[
} -st7_3
_ >`X]I;
@v\*AYr'M
public void setSSiteURL(String value) K.gEj*@
{ @?C#r.vgp
sSiteURL = value; * y^OV_n-8
} ,2oF:H
R~bC,`Bh
,n!vsIN
public String getSFilePath() a:~@CUD >I
{ _w@qr\4i=
return sFilePath; 7j5f ;O^+
} s=?aox7
Bh&Ew
W"L&fV+3
public void setSFilePath(String value) JcJmds
{ ~_9"3,~o5
sFilePath = value; (2?G:+C 7
} W:i?t8y\y
X5YiFLH>y\
ThW,Y" l
public String getSFileName() 1 4LI5T
{ *zO&N^X.4
return sFileName; cYNJhGY
} ,? E&V_5
9>/wUQs!]
HG/p$L*
public void setSFileName(String value) =TR,~8Z|
{ Gf8s?l
sFileName = value; -{h
} Lw1T 4n
K[ .JlIP
,n2i@?NHZ
public int getNSplitter() -#-p1^v}
{ 4!`bZ`_Bw
return nSplitter; \EbbkN:D
} Hy{ Q#fq
$]aBe !
Z?MoJ{.!?R
public void setNSplitter(int nCount) x0a.!
{ df+t:a
nSplitter = nCount; P`U<7xF~
} NV4g~+n
} }4co)B"
4([.xT
HEK-L)S. *
/* l? #xAZx&_
**Utility.java }aB#z<B6
*/ #s5 pz8v
package NetFox; Ju@Q6J5
cIXwiC8t
Kr L>FI
public class Utility { x4Rk<Th"o
\(I6_a_{
i5hD#
public Utility() G@S&1=nj3
{ WUAJjds
fbZibcQ%k
OH<?DcfeL
} UVf\2\Y
IL7`0cN(
//线程睡眠 jW*1E*"
public static void sleep(int nSecond) :ZdUx
{ ~Pk0u{,4XQ
try{ %R_{1GrL'c
Thread.sleep(nSecond); m$>iS@R
} =fc:6JR
catch(Exception e) ^ L:cjY/
{ zH)_vW
e.printStackTrace (); lQPqcZd
} 4C~UcGMv\
} " oy\_1|
%XhfXd'
//日志 Ft%hh|$5y
public static void log(String sMsg) &UAe!{E0
{ lp&!lb`
System.err.println(sMsg); jyW[m,#(go
} 1S%k
"u}9@}*
-237Lx$/
public static void log(int sMsg) $%2_{m_K:p
{ bv?0.{Z
System.err.println(sMsg); OVoO6F]
} L^9HH)Jc
} k/Mp6<?C:
~M?|Vn
1`r| op},
/* &ju-
**TestMethod.java ,W5.:0Y;f[
*/ c $;\i
package NetFox; TmEYW<
y93k_iq$S
!MZw#=D`
public class TestMethod { ateUpGM QU
q/@dR{-
[_DPxM=V
public TestMethod() Xer@A;c
{ ///xx/weblogic60b2_win.exe 7-iIay1h"
try{ lhn8^hOJ/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :,]S}R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +KK$0pL
SiteFileFetch fileFetch = new SiteFileFetch(bean); >POO-8Q
fileFetch.start(); f~& a-
} u'9gVU B
catch(Exception e){e.printStackTrace ();} _&{%Wc5W~F
D\L!F6taS
Yt1mB[&f^
} N}/>rD
8q_0,>w%
H9"= p
public static void main(String[] args) oC dGQ7G}
{ \4~AI=aw,T
new TestMethod(); HR{s&ho
} 10N,?a
} B< ;==|
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