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)); O! (85rp/
} JZw^W{
for(int i=0;i<nEndPos.length-1;i++) DaCblX
{ [yF^IlSs
nEndPos = nStartPos[i+1]; :`5;nl63
} |0]YA
nEndPos[nEndPos.length-1] = nFileLength; dk:xnX%
} rXDJ:NP
} ;-Ado8
`u=oeM:
5"uNj<.V
//启动子线程 y($EK(cb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3P`WPph
for(int i=0;i<nStartPos.length;i++) G<fS(q
{ 6VFirLd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UOJ*a1BM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kwc*is
nStartPos,nEndPos,i); 23k)X"5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]_\AHnJ
fileSplitterFetch.start(); q|Fjm]AF
} C(U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `GS cRhbh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W1`Dx(g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B'#4;R!8P=
nEndPos = " + nFileLength); iLQSa7
// fileSplitterFetch[nPos.length-1].start(); ->3uOF!q
F {/>u(@3
!G[f[u4Zg
//等待子线程结束 [9J:bD
//int count = 0; Lz?*B$h
//是否结束while循环 bw020@O*
boolean breakWhile = false; Z,SY N?@
(H2ylMpQt
GI?PGAT
while(!bStop) EoKo
{ LS{bg.e
write_nPos(); @o60c
Utility.sleep(500); M6&~LI.We=
breakWhile = true; wePI*."]
`ReGnT[
G LoiH#R
for(int i=0;i<nStartPos.length;i++) nPcxknl(pd
{ a^(2q{*
if(!fileSplitterFetch.bDownOver) n 3h^VQ*]G
{ <8*A\&
breakWhile = false; <5M_EJp
break; CuIqh BW!
} %uj[`
} C/bxfp{?
if(breakWhile) 1y 1_6TZ+
break; Q7L)f71i
*/4tJG1U
~Po\ En
//count++; "cNg:
//if(count>4) WejyYqr34-
// siteStop(); k~{Fnkt
} >n1h^AW
We\KDU\n
#jOOsfH|k
System.err.println("文件下载结束！"); dV)Y,Yx0${
} X=JFWzC
catch(Exception e){e.printStackTrace ();} J0Jr BXCh
} k&yQ98H$K"
:MK:TJV
1E8$% 6VV
//获得文件长度 uL bp.N8
public long getFileSize() (VfwLo>#
{ 6={IMkmA
int nFileLength = -1; u2Y N[|V
try{ re]%f"v:5
URL url = new URL(siteInfoBean.getSSiteURL()); Ndo}Tk!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J_|7$ l/
httpConnection.setRequestProperty("User-Agent","NetFox"); 4C6=77Jr
=Y/}b\9`T
&ycjSBK
int responseCode=httpConnection.getResponseCode(); 0T(O'v}.
if(responseCode>=400) E1#H{)G
{ K4_~ruhr
processErrorCode(responseCode); N`f!D>b:dn
return -2; //-2 represent access is error c$.UE
} FMoJ"6Q
Ih(:HFRMq6
$|rCrak;
String sHeader; ={\![{L
DE5d]3B
z'?SRK5+
for(int i=1;;i++) I; ^xAd3G
{ ?Y%}(3y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @<|6{N<
//Utility.log(in.readLine()); sf fV.cC`
sHeader=httpConnection.getHeaderFieldKey(i); "v@);\-V
if(sHeader!=null) 6euR'd^Qi
{ 1]"D%U=
if(sHeader.equals("Content-Length")) 2@rp<&s
{ WfRVv3Vm
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [|y`y%
break; W&HF?w}s
} uPI v/&HA
} K/!/M%GB6
else )gr}<}X)B
break; 0Wjd-rzc,
} m"5{D*|
} ~u};XhZ
catch(IOException e){e.printStackTrace ();} sq6>DuBZz
catch(Exception e){e.printStackTrace ();} T@B"BoKU
7We?P,A\;
su,`q
Utility.log(nFileLength); , - QR
q sv+.aW
@P*ylB}?Q
return nFileLength; ~o:rM/!Ba
} =s`XZkh
,?C|.5
J>&[J!>r
//保存下载信息（文件指针位置） CR%D\I$o
private void write_nPos() c$@`P
{ d,zp`S
try{ VEL:JsY
output = new DataOutputStream(new FileOutputStream(tmpFile)); FX{~"
output.writeInt(nStartPos.length); =n> iQS
for(int i=0;i<nStartPos.length;i++) 3X,]=f@_
{ vEu Ka<5
// output.writeLong(nPos); xylpiSJ
output.writeLong(fileSplitterFetch.nStartPos); E~'q?LJOB
output.writeLong(fileSplitterFetch.nEndPos); 7h(HG?2Y
} ) ~ l\
output.close(); VI(RT-S6
} >`<Ued
catch(IOException e){e.printStackTrace ();} Mr$# e
catch(Exception e){e.printStackTrace ();} ~sZqa+jB0
} Mi;}.K0J
K#_~ !C4L
:&xz5c`"04
//读取保存的下载信息（文件指针位置） D-'i G%)kA
private void read_nPos() ev~dsk6k
{ m"96:v
try{ ;M%oQ>].[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u)<Ysx8G
int nCount = input.readInt(); !Sh^LYqn
nStartPos = new long[nCount]; pYYqGv^oa
nEndPos = new long[nCount]; kqj;l\N
for(int i=0;i<nStartPos.length;i++) ck(CA(_
{ <f7?PAd
nStartPos = input.readLong(); <9Lv4`]GU5
nEndPos = input.readLong(); 5W*7qD[m
} O<}ep)mr
input.close(); JoZqLy!@
} &{X{36
catch(IOException e){e.printStackTrace ();} 5F'%i;)oq
catch(Exception e){e.printStackTrace ();} Yh}zt H
} LEYWH%y
EJWOXxU
f$:7A0
private void processErrorCode(int nErrorCode) !7ei1
{ ( rA\_FOJ
System.err.println("Error Code : " + nErrorCode); Mfnlue](
} OpWeW
yw;ghP;
UN cYu9[
//停止文件下载 ^n\9AE3
public void siteStop() AZh@t?)
{ l=oN X"l=
bStop = true; ZA*b9W
for(int i=0;i<nStartPos.length;i++) {DKXn`V
fileSplitterFetch.splitterStop(); <C7M";54-
!yoSMI-
)e4WAlg8c
} O"_erH\nk
} bBkm] >
//负责部分文件的抓取 !^c:'I>~
**FileSplitterFetch.java qZT 4+&y
*/ 3MNhH
package NetFox; 4+ASwN9
oUW)H
nz,Mqol
import java.io.*; 8zP:*|D
import java.net.*; ^CowJ(y(
OaD Alrm
Cfv L)f
public class FileSplitterFetch extends Thread { _hAj2%SL
)GiFkG
6vD]@AF
String sURL; //File URL mF6@Y[/B
long nStartPos; //File Snippet Start Position g@S@d&9
long nEndPos; //File Snippet End Position uM6CG0
int nThreadID; //Thread's ID W~XV
boolean bDownOver = false; //Downing is over JcvHJ0X~a
boolean bStop = false; //Stop identical A}>|tm7|
FileAccessI fileAccessI = null; //File Access interface 9[epr+f
_aXP ;kFMi
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "e1{V8 4
{ ]y1$F Ir+
this.sURL = sURL; -Z`(? k
this.nStartPos = nStart; 8]cv&d1f
this.nEndPos = nEnd; d&PE,$XC
nThreadID = id; "?2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Bo](n*i
} h/0<:eZ*
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D-TNFYYy2
public void run() EuKrYY]g
{ nhVK?
while(nStartPos < nEndPos && !bStop) 38x[Ad4%
{ b:}wR*Adc
OEy:#9<'
5p]urfN-f
try{ 2-"Lxe65f
URL url = new URL(sURL); $4$?M[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z._C*c
httpConnection.setRequestProperty("User-Agent","NetFox"); G:h;C].
String sProperty = "bytes="+nStartPos+"-"; SxLHFN]
httpConnection.setRequestProperty("RANGE",sProperty); 7})!>p )
Utility.log(sProperty); J[& 7,}
{L-{Y<fke
|*]X\UE
InputStream input = httpConnection.getInputStream(); C)&gL=O*$
//logResponseHead(httpConnection); ~ X]"P4 u
&dZ.+#8r
vjs|!O=oH
byte[] b = new byte[1024]; y0&V$uv/
int nRead; ;H m-,W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VuO)
{ $ sA~p_]
nStartPos += fileAccessI.write(b,0,nRead); xvdnEaWe$
//if(nThreadID == 1) }OX>(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T_(e(5
} >"sKfiM)b
hZss
xdbu|fC
Utility.log("Thread " + nThreadID + " is over!"); r$3~bS$]
bDownOver = true; Q8gdI
//nPos = fileAccessI.write (b,0,nRead); {R1Cxt}
} Ivt)Eg
catch(Exception e){e.printStackTrace ();} ^;bGP.!p
} X('Q;^`
} R+ #.bQg
&t.>^7ELF
0()9vTY+
//打印回应的头信息 Skk3M?
public void logResponseHead(HttpURLConnection con) VvMU)
{ Tl/Dq(8JH
for(int i=1;;i++) _!CvtUU0Vv
{ ,39$iHk
String header=con.getHeaderFieldKey(i); E3.W#=o
if(header!=null) e~2*>5\:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y?R <g^A
Utility.log(header+" : "+con.getHeaderField(header)); .U(SkZ`6
else +}G>M=t::
break; k.? T.9
} 8tFyNl`c
} d~z<,_r5c
%.6?\w1e
_>?8eC]4a
public void splitterStop() `>Kk;`
{ "'H7F,k'
bStop = true; k>z-Zg
} "]\":T
BorfEv} SN
P+zI9~N[
} +DV6oh
C)3$";$5)
h}B# 'e
/* 6 peM4X
**FileAccess.java woH3?zR
*//文件访问(定位，写) }Bod#|`
package NetFox; $O]E$S${
import java.io.*; ae(]9VW
f@.Q%+!4
G/RheH G
public class FileAccessI implements Serializable{ $qyM X[
>G3J3P(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OTFu4"]M
RandomAccessFile oSavedFile; Ci#5@Q9#w
long nPos; M3ZJt'|
aab4c^Ms=
Y,pS/
public FileAccessI() throws IOException %},S#5L3
{ XY t8vJ
this("",0); JpHsQ8<
} v,.n/@s|X
MPEBinE?
3v3Va~fm`
public FileAccessI(String sName,long nPos) throws IOException 6~Oje>w;
{ d<cbp[3F
oSavedFile = new RandomAccessFile(sName,"rw"); [\M?8R$)
this.nPos = nPos; AFhG{G'W
oSavedFile.seek(nPos); 8/kO9'.P
} -0W;b"]+A
,+JAwII>O
5%Q!R%
public synchronized int write(byte[] b,int nStart,int nLen) XW19hG
{ <%!@cE+y
int n = -1; ;%U`P8b!
try{ ,0~'#x>
oSavedFile.write(b,nStart,nLen); |OC6yN *P)
n = nLen; wk3yz6V2
} ]@'YlPU
catch(IOException e) ";jhj:Xj
{ 7~IAgjo,@
e.printStackTrace (); ICGBU>Db
} FNUue
|ey6Czm
7==Uoy*O
return n; 4g6d6~098;
} eX=W+&lj
>FY`xl\m}<
6l50IWj,T
} rc$G0O
[1E u6X6
nJ6bC^*)U
/* )37|rB E
**SiteInfoBean.java C9~CP8
*/ LTi0,03l<
package NetFox; LOp<c<+aW
$FD0MrB_+
N[AX29
public class SiteInfoBean { . [C~a
xL mo?Y*
fFsA[@5tul
private String sSiteURL; //Site's URL 2"NJt9w
private String sFilePath; //Saved File's Path TEY%OIzU+
private String sFileName; //Saved File's Name .~Td/o7
private int nSplitter; //Count of Splited Downloading File L"AZ,|wIk
"_9Dau$
R7vO,kZ6Q
public SiteInfoBean() Xbfn@7m
{//nSplitter的缺省值为5 %rYd=Ri
//default value of nSplitter is 5 M[SWMVN{
this("","","",5); :]:q=1;c
} Qq>M}
+Ge-!&.;A
)y._]is)b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x%0Q W
{ 40mgB4I
sSiteURL= sURL; F(mm0:lT
sFilePath = sPath; )/Ul"QF
sFileName = sName; c\7~_w2
this.nSplitter = nSpiltter; 0*x
3PPN_Z
g&&5F>mF
} ]M#_o]
`N$<]i]s5
gLU #\d]
public String getSSiteURL() 9z,V]v=
{ .%.J Q
return sSiteURL; >/GVlXA'
} tvavI9
'`^`NI`
iku) otUc
public void setSSiteURL(String value) aO6w:IO
{ {4\(HrGNk
sSiteURL = value; .t$~>e .
} NZCPmst
bfhap(F~(e
hjs[$,1
public String getSFilePath() fpu^
{ K8f;AK
return sFilePath; Wu?4oF
} 9*U3uyPi
Yq}(O<ol
p%ek)tT
public void setSFilePath(String value) \$W>@w0
{ n}}$-xl
sFilePath = value; rISg`-
} p78X,44xg
>Ta|#]{
{L4ta~2/T
public String getSFileName() ]gx]7
{ CM|?;PBuv
return sFileName; c/%i,N\5
} cba~
73 ix4C
09HlL=0q
public void setSFileName(String value) AQ7w5}g+V
{ %dw@;IZ#8{
sFileName = value; fIWOo >)D
} \ ?sM
~QQi{92
/p}^Tpu
public int getNSplitter() kzcl
{ H}Z\r2
return nSplitter; N D`?T &PK
} Y`.FSs
B}Qpqa=_c
BUvE~l.,|
public void setNSplitter(int nCount) lpi^<LQ@l
{ jv_z%`
nSplitter = nCount; Rf9;jwU
} m:_'r"o
} K*NCIIDh
s"gNHp.oF
A0~uv4MC
/* g]%sX6T
**Utility.java .EpcMXT%
*/ mO%F {'
package NetFox; qy|[V
FX}kH]
V $Y=JK@
public class Utility { rlV:% k
rY yB"|
Vz[tgb]-
public Utility() X+dLk(jI`u
{ 1g<jr.
%s&l^&ux
N/CL?Z>c
} ny'?Hl'Q
J'4Pp<
//线程睡眠 \k&2nYVHf
public static void sleep(int nSecond) \2]M&n GT
{ qD!qSM
try{ ,E ]vM&
Thread.sleep(nSecond); O1xK\ogv
} Ww\M3Q`h
catch(Exception e) RKru hF
{ :k&R]bc9
e.printStackTrace (); 5\S s`#g
} ^6g^ Q*"
} }Y9= 3X
d%?$UnQ
//日志 v%^"N_]
public static void log(String sMsg) dA03,s
{ lW6$v* s9
System.err.println(sMsg); xfegi$
} EnW}>XN
,r_%p<lOFu
?/3'j(Gk
public static void log(int sMsg) ^W#161&
{ Z/G`8|A
System.err.println(sMsg); 8=kIN-l_
} #X 1 GL
} X?f\j"v
\P~h0zg?
\%BII>VS
/* }o,-@R~
**TestMethod.java \k 9EimT}
*/ e2F{}N
package NetFox; b';oFUU>Q
~$PY6s
8@rddk
public class TestMethod { Ar{7H)V:
@y1:=["b
u7(<YSOs
public TestMethod() -}x( MZ
{ ///xx/weblogic60b2_win.exe GUDz>(
try{ lD9QS ;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0Ba*"/U]t~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oU`{6 ~;
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2p|ed=ly%
fileFetch.start(); `En>o~L;
} ^7l+ Ofb3
catch(Exception e){e.printStackTrace ();} z ?L]5m`H
}ebu@)r
"rVf{
} 4"^v]&I
}j`#s
_<^mi!Y
public static void main(String[] args) JfLoGl;pm
{ T;C0t9Yew
new TestMethod(); 'f_[(o+n
} 8{4SaT.-Rm
} P1G;JK
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