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)); ~G27;Npy
} 0flg=U9
for(int i=0;i<nEndPos.length-1;i++) E~LTb) !
{ U%h);!<
nEndPos = nStartPos[i+1]; $.Q$`/dF
} q5>v'ZSo
nEndPos[nEndPos.length-1] = nFileLength; z5W@`=D
} #GJ dZ
} QXF aAb=(7
;/j= Ny{9
&K/FyY5
//启动子线程 M>M`baM1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lY*[tmz)
for(int i=0;i<nStartPos.length;i++) M)sZSH.<O
{ D1nq2GwS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XJ2^MF2BU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v=('{/^~>
nStartPos,nEndPos,i); ;(}V"i7Hu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ={hX}"*D
fileSplitterFetch.start(); <L&m4O#|
} %r4q8-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @-OnHE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QMEcQV>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8( btZt
nEndPos = " + nFileLength); ^( Rvk
// fileSplitterFetch[nPos.length-1].start(); udeoW-_
Dde]I_f}
`Y?87f:SP
//等待子线程结束 w1;hy"zPsj
//int count = 0; :UJa&$)
//是否结束while循环 ~{}#)gGU
boolean breakWhile = false; GJqE!I,.
`gKf#f
)/t?!T.[
while(!bStop) uytE^
{ T)\"Xj
write_nPos(); M@W[Bz
Utility.sleep(500); 7^T^($+6s&
breakWhile = true; wW>)(&!F
g:0#u;j^7
'H7x L
for(int i=0;i<nStartPos.length;i++) ;l$ \6T
{ -X+H2G
if(!fileSplitterFetch.bDownOver) gl&5l1&
{ 6ksAc%|5
breakWhile = false; yUPIY:0
break; GA`PY-Vs)
} 2Hum!p:1
} q64k7<C,
if(breakWhile) )J?{+3
break; rxme(9M
i_][PTH
rWh6RYd<T
//count++; 5Zw1y@k(
//if(count>4) /.M+fr S
// siteStop(); 7OWbAu;
} ;+1RUv
fm~kM J
Ej7 /X ~
System.err.println("文件下载结束！"); $Ci0I+5w
} N8`?t5
catch(Exception e){e.printStackTrace ();} 8QK5z;E2~
} ?|e'Gbb_
1N2,mo?2
PQ|69*2G
//获得文件长度 Z!0]/mCE8
public long getFileSize() s( <uo{
{ 7=]i~7uy
int nFileLength = -1; 4.RG4Jq
try{ $BmmNn#
URL url = new URL(siteInfoBean.getSSiteURL()); fI\9\x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RllY-JBO
httpConnection.setRequestProperty("User-Agent","NetFox"); n41@iK2l
;6 +}z~
5X.e*;
int responseCode=httpConnection.getResponseCode(); $;G{Pyp
if(responseCode>=400) 09o~9z0
{ Q !qrNa6
processErrorCode(responseCode); a{Esw`
return -2; //-2 represent access is error ;v
} j]0^y}5f+s
/J)l/oI
#E0t?:t5bk
String sHeader; ,@z4I0cTi\
oPc\<$
9;%CHb&
for(int i=1;;i++) x_|F|9
{ !QmzrX}h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 97!>%d[0
//Utility.log(in.readLine()); xyr+_k-x&q
sHeader=httpConnection.getHeaderFieldKey(i); p1c3Q$>i
if(sHeader!=null) 1xf=_F0`&
{ fQ+VT|jzx
if(sHeader.equals("Content-Length")) 2}?wYI*:5|
{ OPBt$Ki
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &/.hx(#d
break; #[MJ|^\i
} 6I_Hd>4
} d+iR/Ssc
else Pag63njg?
break; -VDo[Zy
} JFL>nH0mk.
} =rPrPb
catch(IOException e){e.printStackTrace ();} t4Z
catch(Exception e){e.printStackTrace ();} t"j|nz{m
/\mKY%kyh
c':ezEaC
Utility.log(nFileLength); BcA31%
K7I&sS^x
&$`hQgi
return nFileLength; 6)\dBOz
} wxLXh6|6%_
1gO2C$
IGX:H)&*
//保存下载信息（文件指针位置） bt+,0\Vg5
private void write_nPos() i54md$Q^
{ &K^MNd
try{ l^NC]t
output = new DataOutputStream(new FileOutputStream(tmpFile)); M4Z@O3OIE
output.writeInt(nStartPos.length); ~#:e*:ro
for(int i=0;i<nStartPos.length;i++) k6IG+:s
{ ydWtvFuS
// output.writeLong(nPos); Mu_i$j$vvP
output.writeLong(fileSplitterFetch.nStartPos); 47 u@4"M
output.writeLong(fileSplitterFetch.nEndPos); Ccfwax+
} ZeasYSo4P
output.close(); MrE<vw@he
} jj\[7 O*
catch(IOException e){e.printStackTrace ();} ]8U ~Iy
catch(Exception e){e.printStackTrace ();} Kn+=lCk
} ;~HNpu$
<2
?SY<~i<K-
//读取保存的下载信息（文件指针位置） }\v^+scD
private void read_nPos() AZFWuPJo
{ pt:;9hA
try{ t\j!K2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >3;^l/2c
int nCount = input.readInt(); DOD6Liau{Q
nStartPos = new long[nCount]; (0*v*kYdL+
nEndPos = new long[nCount]; 'zSgCgCHX8
for(int i=0;i<nStartPos.length;i++) 0yof u
{ D#sf i,O
nStartPos = input.readLong(); &B-[oqC?
nEndPos = input.readLong(); [h}K$q
} s*,cF6
input.close(); -oBI+v&
} rFag@Z"["
catch(IOException e){e.printStackTrace ();} l^ 4OC
catch(Exception e){e.printStackTrace ();} }(i(Ar-
} {V2bU}5 [
$fArk36O#
m% bE-#
private void processErrorCode(int nErrorCode) ZW ye>]
{ *M!kA65'
System.err.println("Error Code : " + nErrorCode); <GWR7rUH
} LZWS^77
HY;oy(
:zL393(
//停止文件下载 .K9l*-e[=
public void siteStop() 7u%a/<
{ _%IqjJO{=r
bStop = true; H/i<_LP
for(int i=0;i<nStartPos.length;i++) S!j^|!
fileSplitterFetch.splitterStop(); >a]t<
F/<qE!(
(L#%!bd
} ^tE_LL+ji|
} Qyj(L[KJ
//负责部分文件的抓取 \REc8nsLy
**FileSplitterFetch.java J/S{FxNe]
*/ Dr'sIH^
package NetFox; QFzFL-H~N
W(k:Pl#
'0Zm#g
import java.io.*; LP>UU ,Z
import java.net.*; Kfjryo9
7zI5PGWw
P0#`anUr1
public class FileSplitterFetch extends Thread { vvh.@f
qz:]-A
:VFTVmr
String sURL; //File URL iBHw[X,b
long nStartPos; //File Snippet Start Position A9n41,h
long nEndPos; //File Snippet End Position )VY10R)$
int nThreadID; //Thread's ID {bTeAfbf]
boolean bDownOver = false; //Downing is over 6^ik|k|
boolean bStop = false; //Stop identical 0#`)Prop6
FileAccessI fileAccessI = null; //File Access interface &|z|SY]DL
e`ex]py<C
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 66dTs,C
{ bFn(w:1Q
this.sURL = sURL; U3VT*nj'
this.nStartPos = nStart; L<E/,IdE
this.nEndPos = nEnd; #ko6L3Pi
nThreadID = id; 96)v#B?p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]-EN/V
} j]4,6`b\
Bt6xV<jD
gUb "3g0
public void run() KT=a(QL
{ R_9 o!sTZ
while(nStartPos < nEndPos && !bStop) I9,8HtnA
{ }#|2z}!
h/9Sg*k
9/Wn!Ld
try{ h.D^1
URL url = new URL(sURL); DCK_F8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); } Ab_o#Zy
httpConnection.setRequestProperty("User-Agent","NetFox"); ^@N`e1
String sProperty = "bytes="+nStartPos+"-"; &&*wmnWCS{
httpConnection.setRequestProperty("RANGE",sProperty); ZZwBOGVU
Utility.log(sProperty); X$PS(_M
oo'iwq-\
a^x 0 l
InputStream input = httpConnection.getInputStream(); yW:AVqE)t
//logResponseHead(httpConnection); T#/11M$uQ
XJ _%!
^Wk0*.wg
byte[] b = new byte[1024]; X;5S
int nRead; H<{*ub4'L*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MKe *f%
{ Qv74?B@
nStartPos += fileAccessI.write(b,0,nRead); Upu%.[7
//if(nThreadID == 1) >7W"giWP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~(M*6b
} 0x6@{0
l2r>|CGQ[
|B,dEx/uU
Utility.log("Thread " + nThreadID + " is over!"); m9uUDq#GJ
bDownOver = true; (s.o
//nPos = fileAccessI.write (b,0,nRead); z^"?sd
} @!Y.935/0
catch(Exception e){e.printStackTrace ();} 3k`NNA
} <)"iL4 kDI
} J511AoQ{R
3!1&DII4
&KLvr|
//打印回应的头信息 !(}OBZ[*
public void logResponseHead(HttpURLConnection con) :E}6S
{ %OTQRe:
for(int i=1;;i++) Cnk#Ioz
{ Un~]Q?w
String header=con.getHeaderFieldKey(i); j`Tm\!q
if(header!=null) [+yGDMLs
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T$f:[ye]Z
Utility.log(header+" : "+con.getHeaderField(header)); IwOfZuS
else |YJ$c@
break; 7ucx6J]c
} 6 bYC
} .Ydr[
F%9e@{
T,A!5V>cX
public void splitterStop() Z^6A_:]j
{ USH@:c#t
bStop = true; ZE{aS4c
} %-T}s`Z
9@JlaY)0
V}j%gy`
} `"i^'VL,
wV7@D[8
YWybPD4\(
/* tj`tLYOZ@-
**FileAccess.java IY-(- a8
*//文件访问(定位，写) v#{G8'+%
package NetFox; Cij$GYkv
import java.io.*; oNh68ON:c
oUnq"]
ly9x1`?$
public class FileAccessI implements Serializable{ r_{)?B
^\xCqVk_R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UUt~W
RandomAccessFile oSavedFile; 0[_O+u
long nPos; k^L#,:\&V
LG"BfYy6
R (+h)#![
public FileAccessI() throws IOException oAIY=z
{ 4f_ZY5=
this("",0); T)$6H}[c
} F(?Fz8
[flu|v
(,d4"C
public FileAccessI(String sName,long nPos) throws IOException FN{H\W1cf
{ 5i}CzA96
oSavedFile = new RandomAccessFile(sName,"rw"); jV(xYA3
this.nPos = nPos; }z9I`6[
oSavedFile.seek(nPos); ze#rYNvo/
} )&b}^1
(:</R$I
E7d~#
public synchronized int write(byte[] b,int nStart,int nLen) 'qD'PLV
{ p 02nd.R6
int n = -1; 0xvMR&.H
try{ (Von;U
oSavedFile.write(b,nStart,nLen); >x|A7iWn{,
n = nLen; [RGC!}"mr
} nm{'HH-4
catch(IOException e) kx;xO>dC
{ 3[00-~&U
e.printStackTrace (); -$sl!%HO%
} bv:0EdVr
,u8ZS|9
iZDb.9@&t
return n; mM\!4Yi`7
} @M1yBN
Mdy0!{d
BJ:E,P`_
} pUCEYR
(IO\+
l\A}lC0?J
/* ^6N3nkyZ
**SiteInfoBean.java ?vL^:f["
*/ N>F2 c)rm
package NetFox; _^ CQ*+F
n{qa]3
4:%El+,_Y
public class SiteInfoBean { b3y,4ke"
dZ;~b(CA
$z`cMQ r
private String sSiteURL; //Site's URL I49=ozPP
private String sFilePath; //Saved File's Path SoM ]2^
private String sFileName; //Saved File's Name mTb2d?NS
private int nSplitter; //Count of Splited Downloading File @'NaA SB
(Ay4B*|!
>gS5[`xRE
public SiteInfoBean() RJ`/qXL
{//nSplitter的缺省值为5 ^}Dv$\;6
//default value of nSplitter is 5 bCY^.S-
this("","","",5); 2\iD;Z#gM
} mXN1b!
C7fi1~
644hQW&W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =-1^K
{ |0vHy7CE
sSiteURL= sURL; &|&YRHv
sFilePath = sPath; @u'27c_<d3
sFileName = sName; (1r>50Ge
this.nSplitter = nSpiltter; "=Fn.r4I
zf!\wY"`
MkV*+LXC
} t73Z3M
c_8mQ
2M(PH]D
public String getSSiteURL() w\8rh\Mvh
{ ZZ.0'
return sSiteURL; C_khd"
} ?\p%Mx?
G]3ML)l
Z@aL"@2]a
public void setSSiteURL(String value) 51(`wo>LS
{ r@@eC['
sSiteURL = value; f6_|dvY3
} :z,vJ~PW
F+m4
TAXkfj
public String getSFilePath() {HJ`%xN|
{ LXEu^F~{u#
return sFilePath; <n2{+eO
} ,tv9+n@x
D(ntVR
8!fAv$g0
public void setSFilePath(String value) e!x-:F#4j
{ ", Rw%_
sFilePath = value; [@?.}!
} Q{|'g5(O
TboHP/
iKEKk\j-w
public String getSFileName() >D^7v(&
{ &/#Tk>:
return sFileName; BMsy}08dQ
} nF y7gA|
U!UX"r
E$yf2Q~k
public void setSFileName(String value) Wes"t}[25
{ 6g,3s?aT
sFileName = value; wNZS6JF.d
} WMz|FFKVY
%|6Q7'@p
DdZ_2B2
public int getNSplitter() ^0?cyv\>LA
{ nsw8[pk
return nSplitter; !";$Zu
} (=/L#Yg_
]be2jQx3
+#"Ic:
public void setNSplitter(int nCount) P##(V!YR
{ ^>}[[:(6/
nSplitter = nCount; .?)oiPW#
} JRs[%w`kD
} <yaw9k+P
b0CaoSWo
0lq4
/* jl%eO.
**Utility.java lSv;wwEg
*/ ED_5V@
package NetFox; l{x#*~ga
DMpd(ws
\B+SzW
public class Utility { ?PtRb:RHt
exU=!3Ji
yFtf~8s3
public Utility() *wyLX9{:
{ X(q=,^Mp
tF1%=&ss
}n8;A;axi
} $=a$z"
nM}`H'0
//线程睡眠 A{T@O5ucj
public static void sleep(int nSecond) ~TIZumGB
{ Eu~wbU"%
try{ ITPpT
Thread.sleep(nSecond); "<R 2oo)^
} eV}Tx;1|}
catch(Exception e) m*,[1oeG&
{ ;P#*R3
e.printStackTrace (); RIx6& 7$
} ]a~LA7VHO
} 6MQ:C'8T&=
Oj\mkg
//日志 .Q@'Ob`
public static void log(String sMsg) l[{}ZKZ
{ 6;V1PK>9
System.err.println(sMsg); ;g9:0,xT4
} .?]_yX
\,t<{p_Q
ixpG[8s
public static void log(int sMsg) L#bQ`t
{ 8nR,GW\
System.err.println(sMsg); Vtk|WV?>P+
} izo $0
} rJj~cPwL"
>ON.ftZi
cNvcpv
/* _@76eZd
**TestMethod.java feHAZ.8rp+
*/ YNk|UwJi
package NetFox; I ^92b
wB"Gw` D
=1Jo-!{{
public class TestMethod { o|C{ s
!7?wd^C'f
@U5>w\
public TestMethod() O,#[m:Ejb
{ ///xx/weblogic60b2_win.exe Ev#aMK
try{ ~Wv?p4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Bk<P~-I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); X:/t>0e
SiteFileFetch fileFetch = new SiteFileFetch(bean); #IDCCD^1=
fileFetch.start(); %Ski5q
} E3.s8}}
catch(Exception e){e.printStackTrace ();} {*Pp^r
iq-o$6Pg
OK(d&
} {Wo7=aR
(7,Awf5D~
eRbO Hj1
public static void main(String[] args) n Lb 9$&
{ O?Tg`]EX
new TestMethod(); XvY-C
} q#Vf2U55m
} <X*8Xzmv
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