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)); Cch1"j<k$
} mIr{Wocx
for(int i=0;i<nEndPos.length-1;i++) 2r* o
{ -Xd/-,zPY
nEndPos = nStartPos[i+1]; WVo%'DtF`
} ZE=~ re
nEndPos[nEndPos.length-1] = nFileLength; ipbVQ7
} [C d2L&9
} U9N}6a=
}RoM N$r
WQK#&r*
//启动子线程 ;^ /9sLW?#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n%?g+@y,^
for(int i=0;i<nStartPos.length;i++) v-Br)lLv
{ !-;Me&"I=`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tDi=T]-bt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iT|+<h
nStartPos,nEndPos,i); |]`+@K,S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s*!2oj
fileSplitterFetch.start(); 9#3+k/A
} }7C{:H2d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5T;_k'qe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y.hrU*[J0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I &m~ cBj<
nEndPos = " + nFileLength); Az)P&*2:'`
// fileSplitterFetch[nPos.length-1].start(); p jrA:;
qi)(\
Hu'c)|~f
//等待子线程结束 |Y])|`_'G
//int count = 0; 0dgR;Dl(
//是否结束while循环 `i.f4]r
boolean breakWhile = false; RCmPZ
lv\2vRYw-
OOv"h\,
while(!bStop) O=-|b kO
{ w1GCjD*y
write_nPos(); 4bJ3uIP#
Utility.sleep(500); 2'x_zMV
breakWhile = true; P!vBS"S
~ib#x~Db
t>25IJG
for(int i=0;i<nStartPos.length;i++) f?{Y<M~]
{ >"Hj=?
if(!fileSplitterFetch.bDownOver) ,)QmQ^/
{ 8l}|.Q#--
breakWhile = false; k5ZwGJ#r
break; 3^fZUldf
} !~mN"+u&
} F`ihw[ Wn
if(breakWhile) dyx4_!fO
break; Q \{\uJ x
prm
qt1#P
//count++; qM9GW`CKA
//if(count>4) f/=0
// siteStop(); ec3('}X
} t7~mW$}O
nY*ODL
m?m,w$K
System.err.println("文件下载结束！"); qQom=x
} w?5b:W,
catch(Exception e){e.printStackTrace ();} /vQ^>2X%
} MDB}G '
W5x]bl#
UGN. ]#"#
//获得文件长度 &R8zuD`#
public long getFileSize() OE[/sv
{ zO+nEsf^O
int nFileLength = -1; Z os~1N]3
try{ )WFUAzuN,
URL url = new URL(siteInfoBean.getSSiteURL()); \u)(+t{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ("TI~
httpConnection.setRequestProperty("User-Agent","NetFox"); |FNP~5v
;N j5NB7
2+^#<Uok
int responseCode=httpConnection.getResponseCode(); C )PN
if(responseCode>=400) ?Rwn1.Z
{ :J<S-d=
processErrorCode(responseCode); \e=@h!p
return -2; //-2 represent access is error %v|,-B7Yx
} My[L3KTTp
J]~3{Mi
eR}d"F4W
String sHeader; k\%{1oRA
'Gc6ZSLM
%|u"0/
for(int i=1;;i++) \Js9U|lY
{ W35nnBU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a{8GT2h`4
//Utility.log(in.readLine()); #?-W.
sHeader=httpConnection.getHeaderFieldKey(i); F^w0TD8
if(sHeader!=null) 'shOSB
{ ]xS< \{og
if(sHeader.equals("Content-Length")) x##Iv|$
{ ce;9UBkOg2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7O{\^Jz1
break; bcZHFX
} \ 0CGS
} `\qU.m0(j
else ypsCyDQK`
break; 2T|L##C
} Fdzd!r1 v
} #._!.P
catch(IOException e){e.printStackTrace ();} @9L%`=]b^
catch(Exception e){e.printStackTrace ();} WL7:22nSHa
Jne)?Gt
p*N+B o
Utility.log(nFileLength); !^N/n5eoz
!#X^nlc
6^wiEnA
return nFileLength; !",@,$
} CZuxH
7i'vAOnw^
lE`ScYG
//保存下载信息（文件指针位置） dXOjaS# ~
private void write_nPos() {6KU.'#iF
{ ^@)+P/&
try{ Y<|L|b6
output = new DataOutputStream(new FileOutputStream(tmpFile)); N-NwGD{
output.writeInt(nStartPos.length); -x RsYYw
for(int i=0;i<nStartPos.length;i++) )wGC=,
{ wF&\@H
// output.writeLong(nPos); 0)84Z.k
output.writeLong(fileSplitterFetch.nStartPos); vCi:cIp/
output.writeLong(fileSplitterFetch.nEndPos); foN;Q1?lS
} 7kb`o y;(^
output.close(); 2/bck)p=
} m4%m0"Z
catch(IOException e){e.printStackTrace ();} !Q?4sAB
catch(Exception e){e.printStackTrace ();} 9np<r82
} jRBx7|ON
'-*r&:
~ugcfDJ
//读取保存的下载信息（文件指针位置） 'fgDe
private void read_nPos() mg3jm
{ !KF;Z|_(I
try{ &"CS1P|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qItI):9U
int nCount = input.readInt(); $4?%Z>'
nStartPos = new long[nCount]; 5G2u(hx
nEndPos = new long[nCount]; O_:Q#
for(int i=0;i<nStartPos.length;i++) qH(2 0Z!
{ o3`Z@-.G
nStartPos = input.readLong(); q!7\`>.2:{
nEndPos = input.readLong(); ?/u&U\P
} xr=f9?%R
input.close(); ;3-ssF}k*
} TLkkB09fvk
catch(IOException e){e.printStackTrace ();} f8n'9HOw>
catch(Exception e){e.printStackTrace ();} zb3ir|
} g-]td8}#
&v`kyc
v(0vP}[Q7E
private void processErrorCode(int nErrorCode) pLIBNo?
{ eygyVhJ
System.err.println("Error Code : " + nErrorCode); ES+&e/G"ds
} @.gCeMlOf
.)o5o7H
rXaL1`t*
//停止文件下载 a@X'oV`(2b
public void siteStop() Kzmgy14o
{ X31kHK5F_
bStop = true; "y`?KY$[N
for(int i=0;i<nStartPos.length;i++) x0#+yP
fileSplitterFetch.splitterStop(); o]FQ)WRB
EXzY4D ^
fHgfI@{=j
} v|e\o~2D`
} _l Jj6=
//负责部分文件的抓取 WRnUF[y+)
**FileSplitterFetch.java K}zw%!ex
*/ >y=%o~
package NetFox; w8on3f;6n#
UC0 yrV
$~2Ao[
import java.io.*; Ky=&C8b<
import java.net.*; H4pjtVBr
nQgn^z#
B[*i}k%i
public class FileSplitterFetch extends Thread { n1LS*-@
\K4m~e@!
Z,2uN!6
String sURL; //File URL n2QD*3i
long nStartPos; //File Snippet Start Position *7Mrng
long nEndPos; //File Snippet End Position *zx;81X=
int nThreadID; //Thread's ID /q^( uWu
boolean bDownOver = false; //Downing is over EUNG&U
boolean bStop = false; //Stop identical zL{KK9Or
FileAccessI fileAccessI = null; //File Access interface ?LW1D+
Z# :Ww
}skXh_Vu4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException HS2)vd@)
{ g"!B |
this.sURL = sURL; 5yQgGd)
this.nStartPos = nStart; lyT~>.?{
this.nEndPos = nEnd; 5n"'M&Ce
nThreadID = id; )PwDP
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C{,nDa?|
} ':fVb3A[*d
fu|I(^NV
rVO+ vhih
public void run() Lh0<A%
{ D]0#A|nF
while(nStartPos < nEndPos && !bStop) %++q+pa
{ p'R}z|d)
?$gEX@5h
mbd@4u
try{ SAqX[c
URL url = new URL(sURL); #\"5:.H Oz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @hCGV'4
httpConnection.setRequestProperty("User-Agent","NetFox"); Y/4B*>kl
String sProperty = "bytes="+nStartPos+"-"; ~+1t17
httpConnection.setRequestProperty("RANGE",sProperty); APF-*/K?
Utility.log(sProperty); [bZXzV(
N#UyAm<9
[#.QDe
InputStream input = httpConnection.getInputStream(); ge E7<"m%
//logResponseHead(httpConnection); VfQSfNsi
9iv!+(ni
}6o` in>M
byte[] b = new byte[1024]; w+JDu_9+A]
int nRead; EJRwyF5LK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Bt.WRRpAB
{ m7d? SU
nStartPos += fileAccessI.write(b,0,nRead); 6.k2,C4dT<
//if(nThreadID == 1) a|OX4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bq\%]2;eo{
} p{88v3b6
}3QEclZr
yYW>)
Utility.log("Thread " + nThreadID + " is over!"); w 5,-+&;
bDownOver = true; z S^:Ng5
//nPos = fileAccessI.write (b,0,nRead); K)&AR*Tc
} |{Oe&j3|
catch(Exception e){e.printStackTrace ();} VkUMMq{
} f>Ij:b`Z2
} X)'uTf0
C7nLa@
i5rAb<q`
//打印回应的头信息 b2ZKhS8
public void logResponseHead(HttpURLConnection con) VRT| OUq
{ |J8c|h<
for(int i=1;;i++) 5I@< 6S&X
{ vQ 5 p
String header=con.getHeaderFieldKey(i); sqsBGFeG
if(header!=null) \`x$@s?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qi$6y?
Utility.log(header+" : "+con.getHeaderField(header)); {6RT&w
else l.FkX
break; uNLA/hL+n
} 0b4QcfB1[
} pWeKN`
l].dOso$`
O,hT< s "
public void splitterStop() VBy=X\w]
{ V:yia^1
bStop = true; \]GBd~i<
} kWF, *@.B
)88z=5.
)]?sCNb
} XB^o>/|@S
lorjMS
C#+Gkzq
/* }5u$/c@f1
**FileAccess.java +Y6=;*j$
*//文件访问(定位，写) O*X]oX
package NetFox; 'tklz*
import java.io.*; Il,2^54q
4Y;z46yM%
5v6*.e'p
public class FileAccessI implements Serializable{ ]haZT\
%?^IS&]Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X`ee}C.D_
RandomAccessFile oSavedFile; Jzo|$W
long nPos; >2tYw,m
!T!U@e=u
xhWWl(r`5
public FileAccessI() throws IOException ,eW K~ pa
{ JN,4#,
this("",0); ^cn%]X#.
} Il`35~a
=# <!s!
JgEPzHgx
public FileAccessI(String sName,long nPos) throws IOException Se{}OG)
{ /0A9d-Qd<
oSavedFile = new RandomAccessFile(sName,"rw"); ]MKW5Kq
this.nPos = nPos; XShi[7
oSavedFile.seek(nPos); tZB"(\
} p D-k<8|
(_ HwU/
,( u-x!
public synchronized int write(byte[] b,int nStart,int nLen) )[oegfnn-
{ N2#Wyt8MC
int n = -1; bbCH(fYbu
try{ *j6KQZ"
oSavedFile.write(b,nStart,nLen); MAb*4e#
n = nLen; m:SG1m_6
} ;SnpD)x@)
catch(IOException e) g0O~5.f
{ V"K-aO&
e.printStackTrace (); Lyo!}T
} D<U^FT
?71?Vd
T+1:[bqK
return n; 69N/_V
} `1 A,sXfa
>}?jOB
A{NKHn>%`
} 4&N#d;ErC
Pw+PBIGn4
JbX"K< nQ
/* Mu: y9o95
**SiteInfoBean.java sE:~+C6o:
*/ H{M7_1T
package NetFox; G5A:C(r
JPO'1D)
.Q!_.LX
public class SiteInfoBean { wr5ScsNS
AS5'j
2S,N9(7
private String sSiteURL; //Site's URL RRRF/Z;))
private String sFilePath; //Saved File's Path !B|Aq- n,
private String sFileName; //Saved File's Name iq1HA.X(
private int nSplitter; //Count of Splited Downloading File .bYZkO:oy
&X3G;x2;
2i0 .x
public SiteInfoBean() 3']a1\sy^
{//nSplitter的缺省值为5 <$z6:4uN_
//default value of nSplitter is 5 W>#[a %R
this("","","",5); ahICx{hK
} {#`O'F>
(;!92ct[?
{'#1do}{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) B_Ul&V
{ wE3L,yx=
sSiteURL= sURL; WwUhwY1o!L
sFilePath = sPath; PaD6||1F
sFileName = sName; (fA>@5n
this.nSplitter = nSpiltter; d6^:lbj
*jR4OY|DXH
#B2a?
} <?Ln`,Duk
/Fk]>|*
z( \4{Y
public String getSSiteURL() M}fk[Yr>
{ jlxY|;gZ-0
return sSiteURL; YY zUg
} b1TIVK3m
]J1oY]2~
yopC <k
public void setSSiteURL(String value) =cR"_Z[8X
{ 9\'JtZO
sSiteURL = value; `' .;U=mF
} HVdy!J
CP'b,}Dd?I
\E(^<Af
public String getSFilePath() ~U r
{ X;bHlA-g
return sFilePath; y'5`Uo?\",
} oyT`AYa
6o0}7T%6
&t~NR$@
public void setSFilePath(String value) S;0z%$y
{ n1U!od
sFilePath = value; `5Bv2wlIV
} XL3m#zW&
J Bgq2
R 7h^ @
public String getSFileName() [I?[N.v
{ G! Y l0Zr
return sFileName; 9])Id;+91
} ,<=gPs;x
)2lB
$l $p|
public void setSFileName(String value) $d-$dM?R5
{ 3D-0 N0o
sFileName = value; w/z o
} b/{$#[oP`
s\zY^(v4
3,'LW}
public int getNSplitter() =Vm3f^
{ a<0q%Ax
return nSplitter; ExhK\J
} {'Y()p3kl
'7Mz]@
Ze!/b|`xI
public void setNSplitter(int nCount) GbC@ |
{ BG6.,'~7o
nSplitter = nCount; -5oYGLS$y3
} 2 g\O/oz
} *knN?`(x
CNe(]HIOH
kQ]4Bo
/* 0&u=(;Dr\
**Utility.java H_ a##z
*/ 97[wz C,
package NetFox; /lC,5y
H:EK&$sU
1M.#7;#B3
public class Utility { 3@nIoN'z
u/<ZGW(&s(
;m7~!m)
public Utility() ,)uW`7
{ * V7bALY
^&\pY
qnHjwMi
} ]- 6q`'?[
%"cOX
//线程睡眠 k')H5h+Q=
public static void sleep(int nSecond) nuDu
{ 9@ 4]t6h[
try{ x+DETRLP
Thread.sleep(nSecond); ;GE6S{~-
} dU*$V7
catch(Exception e) \!hd|j?&6
{ -Bq]E,Xf)
e.printStackTrace (); x ;~;Ah.p
} ;HBKOe_3
} a x)J!I18
pTaC$Ne
//日志 |)v}\-\#
public static void log(String sMsg) mU(v9Jpf7
{ rizjH+
System.err.println(sMsg); MQDLC7Y.p5
} 7O8 @T-f+2
$}IG+,L
2 FoLJ
public static void log(int sMsg) ^62z\Y
{ >0[:uu,'>
System.err.println(sMsg); r@zs4N0WP
} w2!:>8o:
} |Eh2#K0x4G
H0 Zo.Np
bHcBjk.\
/* </Y(4Xwf=
**TestMethod.java c#CV5J\Kk3
*/ Niu |M@
package NetFox; -+u}u=z%
7x77s
`\|@w@f|;
public class TestMethod { oOc-1C y
dl3;A_ 2
+*xc4
public TestMethod() r`"T{o\e
{ ///xx/weblogic60b2_win.exe %sPze]
try{ wd32q7lGo1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {]U \HE1w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [3sZ=)G
SiteFileFetch fileFetch = new SiteFileFetch(bean); XZ{rKf2
fileFetch.start(); CJh,-w{wJ"
} /}2Y-GOU
catch(Exception e){e.printStackTrace ();} F+*fim'NK
t9MCT$U
l.]wBH#RS
} T{^P
*/JYP +
E%;$vj'2
public static void main(String[] args) OiXO<1'$
{ vE8BB$D
new TestMethod(); %~k>$(u6
} tl{{Vc[
} @)0
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