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)); s4>xh=PoJ
} [q!)Y:|u_>
for(int i=0;i<nEndPos.length-1;i++) IF3V5Q
{ _x?S0R1
nEndPos = nStartPos[i+1]; VM"*@T
} 7s1LK/R|u
nEndPos[nEndPos.length-1] = nFileLength; NjSjE_S2B8
} Fprhu;h
} cS"PIelR
{1W,-%
U66oe3W
//启动子线程 K|.!)L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .,SWa;[iB
for(int i=0;i<nStartPos.length;i++) \K(# r=
{ dH0wVI<z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RTTEAh:.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'w}/o+x@
nStartPos,nEndPos,i); &qZ:"k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @fSqGsSk
fileSplitterFetch.start(); ,YmTx
} )X-TJ+d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mOx>p"n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~ *P9_<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U6oab9C?k
nEndPos = " + nFileLength); }ABHGr5[
// fileSplitterFetch[nPos.length-1].start(); ZAMS;e+e
,U'E!?=:VS
Y--Uo|H
//等待子线程结束 xsXf_gGu
//int count = 0; )"<:Md$7
//是否结束while循环 p\M\mK
boolean breakWhile = false; y?{YQ)fj
PWs=0.Wj
R~(_m#6`:
while(!bStop) uJ/&!q<3
{ Cg&cz]*q|
write_nPos(); -44''w?z
Utility.sleep(500); !u|s|6{\
breakWhile = true; Sc&p*G
R8R,!3 N
<4P"1#nHQ+
for(int i=0;i<nStartPos.length;i++) u\|Ys
{ Fv9n>%W&
if(!fileSplitterFetch.bDownOver) xGymQ|y84
{ 9$P*fx&m
breakWhile = false; MM4Eq>F/
break; CEp @-R
} > v ]-B"Y
} OPVcT
if(breakWhile) XRR`GBI
break; X7& ^"|:
p*(]8pDC
V .VV:`S
//count++; Fs)m;C
//if(count>4) qct:xviH<|
// siteStop(); a,*~wmg
} 1]Gp\P}
UI.>BZ6}
uSK<{UT~3
System.err.println("文件下载结束！"); $WK~|+"{>
} 3L(vZ2&
catch(Exception e){e.printStackTrace ();} z8hAZ?r1`
} :HG5{zP
rui]_Fn]I
>vY5%%}
//获得文件长度 j /=4f�
public long getFileSize() .[4Dvt|>6
{ F^|4nBd*ub
int nFileLength = -1; 6)~J5Fb
try{ 2s:$4]K D
URL url = new URL(siteInfoBean.getSSiteURL()); }N<> z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G8_|w6
httpConnection.setRequestProperty("User-Agent","NetFox"); xu7Q^F#u
S?Z"){
vS'5Lm
int responseCode=httpConnection.getResponseCode(); p-o!K\o-1
if(responseCode>=400) L5yv}:.U
{ iSxuor^;
processErrorCode(responseCode); VVyms7 VN
return -2; //-2 represent access is error ~!{y3thZ
} MUd 9R
_-/<bO
AjA.="3
String sHeader; Kwa$5qZI
-Lbi eS%
B7!dp`rPp
for(int i=1;;i++) w>ap8><4
{ @Iy&Qo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1ti4 ZM
//Utility.log(in.readLine()); B)4>:j:{?W
sHeader=httpConnection.getHeaderFieldKey(i); D#G(&<Q
if(sHeader!=null) {Jj vF
{ B#U:6Ty
if(sHeader.equals("Content-Length")) =Wj{J.7mf]
{ IDpW5Dc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2E":6:Wsw
break; +sc--e?
} eDPmUlC+-
} !Yan}{A,
else 5<y pK`Kq
break; x:O;Z~ |.
} .;xt{kK
} oj1,DU
catch(IOException e){e.printStackTrace ();} ;<=B I!
catch(Exception e){e.printStackTrace ();} n@Ar%%\
rpu{YC1C%
u`2[V4=L
Utility.log(nFileLength); 3'zm)SXJ
fudIUG.
*To5\|
return nFileLength; `Mxi2Y{vp
} Y([YDn
h^}r$k_n
TE.O@:7Z
//保存下载信息（文件指针位置） i!JVGs
private void write_nPos() Z/S7ei@56
{ c)tG1|Og]
try{ +$F_7Hx
output = new DataOutputStream(new FileOutputStream(tmpFile)); hvS4"%\
output.writeInt(nStartPos.length); *uq}jlD`!
for(int i=0;i<nStartPos.length;i++) d;$<K
{ nd[{DF?)/
// output.writeLong(nPos); TEK]$%2
output.writeLong(fileSplitterFetch.nStartPos); c=}#8d.
output.writeLong(fileSplitterFetch.nEndPos); *"pf3x6
} u#l@:p
output.close(); yLI)bn!"
} :6*FnKD
catch(IOException e){e.printStackTrace ();} /b)V=mcR
catch(Exception e){e.printStackTrace ();} `;9Z?]}`
} w<ol$2&B
[Ie;Jd>gG
}op0`-Xb
//读取保存的下载信息（文件指针位置） A80r@)i
private void read_nPos() 5Cp6$V|/kv
{ {iI"Lt
try{ QD}'2{M!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !4(X9}a
int nCount = input.readInt(); uq>\pO&P
nStartPos = new long[nCount]; VR@V3 ~
nEndPos = new long[nCount]; GYX/G>-r
for(int i=0;i<nStartPos.length;i++) SGd[cA Ko
{ O{^ET:K@
nStartPos = input.readLong(); e7(iMe
nEndPos = input.readLong(); .<<RI8A
} t@`w}o[#
input.close(); S<f]Y4A&
} LB1AjNJ
catch(IOException e){e.printStackTrace ();} =q%Q^
catch(Exception e){e.printStackTrace ();} KZ"&c~[
} R<J1bH1n3
}W:Rg}v
<@DF0x!
private void processErrorCode(int nErrorCode) 1gA9h-'w
{ ne=?'e4
System.err.println("Error Code : " + nErrorCode); ZB)`*z>*
} OM]d}}=Y
xH\#:DLY
Rd?8LLz
//停止文件下载 ']N1OVw^vf
public void siteStop() 4@b~)av)
{ oTtJ]`T
bStop = true; M x/G^yO9
for(int i=0;i<nStartPos.length;i++) T\(w}
fileSplitterFetch.splitterStop(); jvI!BZ
qHZ!~Kq,"'
jujhK'\
} lo1<t<w`
} 4jOq.j
//负责部分文件的抓取 i#&iT P`
**FileSplitterFetch.java K@JGGgrE`!
*/ *{t]fds
package NetFox; Ihd{@6m
Hwz.5hV"
tJ"8"T#6Vr
import java.io.*; iI!MF1
import java.net.*; `b11,lg
?06+"Z
BHNcE*U}@?
public class FileSplitterFetch extends Thread { _~l*p"PL<
X j>?P/=Z
%4=r .9
String sURL; //File URL XF6ed
long nStartPos; //File Snippet Start Position AHo4% 5
long nEndPos; //File Snippet End Position 'ie+/O@G
int nThreadID; //Thread's ID F*}.0SQ
boolean bDownOver = false; //Downing is over TFQX}kr]
boolean bStop = false; //Stop identical ;JD/4:
FileAccessI fileAccessI = null; //File Access interface m]7oTmS
!OCb^y
Y"n$d0%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException > [%ITqA$
{ |7pi9
this.sURL = sURL; P^)J^{r
this.nStartPos = nStart; 0b)q,]l]
this.nEndPos = nEnd; QY^v*+lr\
nThreadID = id; `y^tCJ2u*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2C@ui728
} ;Y^.SR"
yUyx&Y/
JZUf-0q
public void run() oEuV&m|yX
{ -4=\uvYh
while(nStartPos < nEndPos && !bStop) J"$Y`;
{ MYlPG1X=?
=o+js;3
G@N-+
try{ q83!PI
URL url = new URL(sURL); A*a:#'"*N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z8vR/
httpConnection.setRequestProperty("User-Agent","NetFox"); A7hWAq
String sProperty = "bytes="+nStartPos+"-"; ds#om2)
httpConnection.setRequestProperty("RANGE",sProperty); FQgc\-8tm
Utility.log(sProperty); skeXsls
mC,:.d
1UwpLd
InputStream input = httpConnection.getInputStream(); K]Rb~+a<
//logResponseHead(httpConnection); ~\QN.a
'ZXd|WI
v6#i>n~x,
byte[] b = new byte[1024]; 3m]8>1e1"
int nRead; .zQ'}H1.C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3yXSv1
{ <W2YG6^i
nStartPos += fileAccessI.write(b,0,nRead); Tg;1;XM%
//if(nThreadID == 1) xfFsW^w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \5q0nB@i5y
} FhAYk
Y *?hA'
}%lk$g';
Utility.log("Thread " + nThreadID + " is over!"); *`WD/fG
bDownOver = true; Ce.*yO<-
//nPos = fileAccessI.write (b,0,nRead); 8_h:_7e
} Y2&hf6BE
catch(Exception e){e.printStackTrace ();} #BOLq`9f
} F./$nwb
} tg#d.(
^a#
@Z[XV"w|
//打印回应的头信息 & Do|Hw
public void logResponseHead(HttpURLConnection con) %&\DCAFk
{ dxk~
for(int i=1;;i++) r(i!".Z
{ rpn&.#KS
String header=con.getHeaderFieldKey(i); 7Pp~)Kq=
if(header!=null) 9zac[tno
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =Dc9|WuHN
Utility.log(header+" : "+con.getHeaderField(header)); mJFFst,
else ^oH!FN`;{
break; lDF26<<\`
} 5 cz6\A&
} Ew$-,KC[
=CGB}qU l0
?<h|Q~JH
public void splitterStop() F2WMts
{ gVU&Yl~/^
bStop = true; oV,lEXz
} :j[a X7Sq2
Y1s3>`
y1*z,"dx
} qytH<UB
y_A7CG"^
)uxXG`,h
/* n.tJ-l5[
**FileAccess.java 5l,Q=V^@l
*//文件访问(定位，写) YdiXj |k+
package NetFox; ~h@<14c{X
import java.io.*; K.I\E
` 8OA:4).
=[x @BzH
public class FileAccessI implements Serializable{ BzyzOtBp3L
," ~4l&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /Q*cyLv
RandomAccessFile oSavedFile; l!9G
long nPos; I15g G.)
vddh 2G
x"xtILrI
public FileAccessI() throws IOException o^b4l'&o
{ qwmZOR#
this("",0); =h/0k y
} tW7*(D
q[T='!Z\
Xh*p\ $
public FileAccessI(String sName,long nPos) throws IOException PN@[k:5(
{ FdVWj 5 $a
oSavedFile = new RandomAccessFile(sName,"rw"); {8as _
this.nPos = nPos; ' *x?8-KP
oSavedFile.seek(nPos); 6:o?@%
} EPMdR66
]&kzIxh
a}]zwV&
public synchronized int write(byte[] b,int nStart,int nLen) JkMf+!
{ 7<?~A6
int n = -1; )s';m$
try{ .Lc<1s
oSavedFile.write(b,nStart,nLen); I];Hx'/<~
n = nLen; 5 LZ+~!2+
} ?[K\X
catch(IOException e) beM}({:`
{ Gj}P6V_
e.printStackTrace (); |(=`l
} jSyF]$"
1*!`G5c,}
5$ra4+k0
return n; MxXu&.|_
} i C nWb
T;u>]"S
L*VO2YI
} I}aiy.l
k^IC"pUc
XNU[\I
/* oKJj?%dHK9
**SiteInfoBean.java k8;
*/ }"'^.FG^_
package NetFox; B0KZdBRx}
HZ1e~IIw
_"PTO&E
public class SiteInfoBean { ZMHb
Bk~lE]Q3c7
~8-Z=-
private String sSiteURL; //Site's URL )bqfj>%#c
private String sFilePath; //Saved File's Path pOCLyM9c
private String sFileName; //Saved File's Name wv2
private int nSplitter; //Count of Splited Downloading File rmW,#
62&(+'$n
R18jju>Zr
public SiteInfoBean() ov=[g l
{//nSplitter的缺省值为5 L//Z\xr|
//default value of nSplitter is 5 Wh:SZa|
this("","","",5); ['MG/FKuv
} }'mBqn
A3p@hQl
-$E_L:M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8}\Lt
{ m"~^-mJ-
sSiteURL= sURL; 9ZL3p!
sFilePath = sPath; @LS*WJ< w-
sFileName = sName; );wSay>%(
this.nSplitter = nSpiltter; ^1vh5D
1@)8E`u
M%dXy^e
} JRkC~fv
4eym$UWw
;[]{O5TB
public String getSSiteURL() :!M/9D*}0
{ #ra~Yb-F
return sSiteURL; VfJYYR
} vs/.'yD/C
%pNK ?M+
-v4kW0G
public void setSSiteURL(String value) a W`q
{ _-&\~w
sSiteURL = value; ~Cx07I_lf
} [lpzUB}<Yp
.$/Su3]K/
C:/O]slH
public String getSFilePath() U5]{`C0H?
{ CBAMAr
return sFilePath; P {x`eD0
} bsw0+UY=9
0*MY4r|-
V]cD^Fqp
public void setSFilePath(String value) wuCiO;w
{ <FIc!
sFilePath = value; ZR<T\w
} QCFLi n+r
`Nn=6[]
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public String getSFileName() gnW`|-:\
{ <=A1d\
return sFileName; kh/n|2
} 8<Cu S
RU3:[(7
WG8}}`F|
public void setSFileName(String value) LfEeFF=#n
{ 7q<2k_3<
sFileName = value; &13qlc6
} k{<]J5{7
f"zXiUV
}>I|\Z0I
public int getNSplitter() )<bgZ, v
{ 5o 4\Jwt
return nSplitter; D<5;4Mb
} v/{LC4BF
luYkC@I@a
XBE+O7
public void setNSplitter(int nCount) A*jU&3#
{ M=$ qus
nSplitter = nCount; :DTKZ9>2D
} 095:"GvO
} ;LRY h?
S"ZH5O(
JsohhkJNGi
/* C?jk#T
**Utility.java >58N P1[k
*/ pj:s+7"t
package NetFox; 9P;}P!W
xT7JGQ[|
P` Hxj> {
public class Utility { InnjZ>$
Gf'qPLK0
G+2!+N\P
public Utility() u`I&&
{ ;i*<HNQ
| +osEHC
"]\sw"zO?
} D#}t)$"
n qSjP5
//线程睡眠 ME"B1Se\
public static void sleep(int nSecond) n1+1/
{ #zflU99d
try{ F!DDlYUz.
Thread.sleep(nSecond); LT7C>b
} -FRMal4Pg0
catch(Exception e) |[apLQ6
{ h"Qp e'D}
e.printStackTrace (); &[u%ZL
} U$+EUDFi3_
} ~d]X@(G&
b&[bfM<
//日志 \ng!qN
public static void log(String sMsg) `}t<5_
{ qxKW%{6o
System.err.println(sMsg); {j$:9 H
} 2P3,\L
[B<htD&
0c6b_%Rd
public static void log(int sMsg) KE>|,Ur
{ I`k%/ei38
System.err.println(sMsg); xQLVFgd
} 1iNq|~
} Vwxb6,}Z
P2la/jN
bMe/jQuL.$
/* &QHZ]2%U
**TestMethod.java gR7in!8
*/ D%[yAr;r
package NetFox; mX8k4$z
.[mI9dc
Hw"LoVh
public class TestMethod { r<< ]41
t&5N{C:
O5X@'.#rU
public TestMethod() in}d(%3h
{ ///xx/weblogic60b2_win.exe z~8`xn,
try{ JZ=ahSi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gY!+x=cx0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [;6,lI}
SiteFileFetch fileFetch = new SiteFileFetch(bean); C_CUk d[
fileFetch.start(); (*qMs)~]B
} >\f'QQ
catch(Exception e){e.printStackTrace ();} 4FwtC"G3
7]\_7L|>]
h 8Shf"
} g$X4ZRSel
b&wyp@k
KZeaM
public static void main(String[] args) ^w|D^F=o
{ SZ$~zT;c
new TestMethod(); K=Q<G:+&V
} Bs?B\k=
} eKpWFP0
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