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)); {eR9 ;2!
} {|6z+vR
for(int i=0;i<nEndPos.length-1;i++) gz61FW
{ 5B*qbM
nEndPos = nStartPos[i+1]; $.:3$et@/
} fHfY}BQS
nEndPos[nEndPos.length-1] = nFileLength; y5u\j{?Te
} HO5d%85
} a$m_D!b~_
9m8ee&,
[Oy >R
//启动子线程 ^ ulps**e
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7'OPjtM
for(int i=0;i<nStartPos.length;i++) !ZrB^?sO
{ |$e:*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /U*yw5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ETp'oh}?
nStartPos,nEndPos,i); M<(u A'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *jF#^=
fileSplitterFetch.start(); U$'y_}V
} C[YnrI!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +'XhC#:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l^r' $;<m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Mr*|9h
nEndPos = " + nFileLength); u+2Lm*M
// fileSplitterFetch[nPos.length-1].start(); 2EfflZL3
"HC)/)Mv@
c7qwNs*f
//等待子线程结束 [H,u)8)
//int count = 0; !8$RBD %
//是否结束while循环 YqU/\f+
boolean breakWhile = false; GuO`jz F
f1Zt?=
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while(!bStop) cNj*E =~;
{ io4aYB\
write_nPos(); D1Yh,P<CF\
Utility.sleep(500); ;+`uER
breakWhile = true; e<5Y94YE
<TxC!{<
lLCdmxbT
for(int i=0;i<nStartPos.length;i++) Y=Hz;Ni
{ xR908+>5
if(!fileSplitterFetch.bDownOver) uRQ_'l
{ o:UXPAj
breakWhile = false; `^##b6jH
break; R2LK.bTVn
} Y&~M7TYb
} s'L?;:)dyB
if(breakWhile) wPnybb{
break; *{5>XH{ x
Oh`2tc-
NHkL24ve
//count++; 1q]c7"
//if(count>4) AuCWQ~
// siteStop(); FT/amCRyT
} }Bff,q
U8O(;+
zj%cQkZ
System.err.println("文件下载结束！"); 1S%}xsR0
} "s]y!BLk
catch(Exception e){e.printStackTrace ();} >&Fa(o;*
} NHiq^ojk
jvs[ /
6c<ezEJ
//获得文件长度 Q6^x8
public long getFileSize() 6fwY$K\X
{ T=\!2gt
int nFileLength = -1; ~HDdO3
try{ Np)aS[9W
URL url = new URL(siteInfoBean.getSSiteURL()); dWR1cvB(wY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HomN/wKh
httpConnection.setRequestProperty("User-Agent","NetFox"); >.LKct*5K
l`gTU?<xd
]}LGbv"`A
int responseCode=httpConnection.getResponseCode(); Y\?j0X;
if(responseCode>=400) {4rQ7J4Ux
{ <k]qH-v4
processErrorCode(responseCode); 7GZq|M_:y
return -2; //-2 represent access is error ;V.vfar
} bPd-D-R
o^ h(#%O
_V@P-Ye
String sHeader; #WufZ18#
qY(:8yC36
T9)wj][ .
for(int i=1;;i++) ,7,;twKz
{ 9*}gl3y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +Me2U9
//Utility.log(in.readLine()); (@&I_>2Q
sHeader=httpConnection.getHeaderFieldKey(i); $']VQ4tZ
if(sHeader!=null) 40K2uT{cq
{ <NB41/
if(sHeader.equals("Content-Length")) xmH-!Da
{ \G;CQV#{9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7g6RiH}
break; 59!)j>f
} [7W(NeMk
} \&q=@rJp(z
else .3wY\W8Dr-
break; {}\CL#~y
} GLh]G(
} D1X{:#|
catch(IOException e){e.printStackTrace ();} ]\;xN~l
catch(Exception e){e.printStackTrace ();} 'G#SLqZy
Lk.h.ST
7BFN|S_l
Utility.log(nFileLength); agsISu(
cZ< \
GGE[{Gb9
return nFileLength; _#'9kx|)
} oR %agvc^^
i\p:#'zk5
lrys3
//保存下载信息（文件指针位置） Tbh'_F6
private void write_nPos() nj2gs,k
{ h>3H7n.
try{ Hj~O49%j&
output = new DataOutputStream(new FileOutputStream(tmpFile)); OM!=ViN(=
output.writeInt(nStartPos.length); I;j3*lV_
for(int i=0;i<nStartPos.length;i++) ^ d\SPZ
{ /V^sJ($V$~
// output.writeLong(nPos); "ahvNx;x
output.writeLong(fileSplitterFetch.nStartPos); Qpu3(`d<
output.writeLong(fileSplitterFetch.nEndPos); +qkMQETV6
} mJMq{6;
output.close(); nem@sB;v#
} r_2btpL^
catch(IOException e){e.printStackTrace ();} Y'N'hRD
catch(Exception e){e.printStackTrace ();} {;k_!v{
} nW5K[/1D
]Oso#GYD
>saI+u'o
//读取保存的下载信息（文件指针位置） GS%b=kc
private void read_nPos() _01Px a2.
{ A3s57.Z]|
try{ /77z\[CeYH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #x~_`>mDN
int nCount = input.readInt(); _^T}_
nStartPos = new long[nCount]; yGEb7I$h
nEndPos = new long[nCount]; v2J0u:#,
for(int i=0;i<nStartPos.length;i++) Q!$IQJ]|Y
{ D'L{wm
nStartPos = input.readLong(); ;Qa;@
nEndPos = input.readLong(); detLjlE
} ;.s:X
input.close(); t)I0lnbs
} \"d?=uFe
catch(IOException e){e.printStackTrace ();} ?}sOG?{
catch(Exception e){e.printStackTrace ();} o#e7,O
} grbTcLSF
B>|5xpZM12
<]Y[XI(kr
private void processErrorCode(int nErrorCode) z5EVG
{ [hU=mS8=^
System.err.println("Error Code : " + nErrorCode); K0<yvew
} kp`0erJqw
3*WS"bt
F]5\YYXO
//停止文件下载 I:t^S.,
public void siteStop() o!Fl]3F
{ H#+xKYrp
bStop = true; tpU D0Z)
for(int i=0;i<nStartPos.length;i++) ou6j*eSN
fileSplitterFetch.splitterStop(); 8^X]z|[d2
h7?.2Q&S
H8i+'5x,?
} AZwa4n}"
} ZQ[~*)
//负责部分文件的抓取 Wc;+2Hl[@
**FileSplitterFetch.java sqG`"O4W
*/ 2U%qCfh6|
package NetFox; }n95< {
[TCRB`nTQF
_,Q[2gQ5N
import java.io.*; !$r9C/k
import java.net.*; 3bts7<K=
^s*\Qw{Ii
evOb
public class FileSplitterFetch extends Thread { 7@P656{
h5!d
\)R-A '*U
String sURL; //File URL e\.HWV]I
long nStartPos; //File Snippet Start Position };p~A-E=
long nEndPos; //File Snippet End Position Gl>E[iO
int nThreadID; //Thread's ID }ecsGw
boolean bDownOver = false; //Downing is over (1 yGg==W.
boolean bStop = false; //Stop identical %#9P?COs&W
FileAccessI fileAccessI = null; //File Access interface .,mM%w,^O
^zeL+(@r/
A& =pw#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException stXda@y<p
{ o<J5!
this.sURL = sURL; [&daG:
this.nStartPos = nStart; STB-guia5
this.nEndPos = nEnd; mJ$Htyr
nThreadID = id; Tc_do"uU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6ZksqdP8
} :#SNpn=@
A^g>fv
s##Ay{
public void run() ^ LbGH<#J
{ ohplj`X[21
while(nStartPos < nEndPos && !bStop) z8tl0gd%D
{ ,'_(DJX
0||F`24
b,Lw7MY}[
try{ kW(Kh0x
URL url = new URL(sURL); A'~#9@l<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kaO{#i2-
httpConnection.setRequestProperty("User-Agent","NetFox"); yoW> BX
String sProperty = "bytes="+nStartPos+"-"; 5)*6V&
httpConnection.setRequestProperty("RANGE",sProperty); 4:`[qE3
Utility.log(sProperty); raHVkE{<
2Oi'E
% $.vOFP9
InputStream input = httpConnection.getInputStream(); 4d-q!lRpa
//logResponseHead(httpConnection); 0BFz7
97]4 :Zv
Y?t2,cm
byte[] b = new byte[1024]; `EVg'?pl
int nRead; H9E(\)@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R8uj3!3^
{ `WlH*p)z9
nStartPos += fileAccessI.write(b,0,nRead); *|poxT G
//if(nThreadID == 1) j"6:A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >KHp-|0pv
} ,-:a?#f>
P57GqT
m9Il\PoTq
Utility.log("Thread " + nThreadID + " is over!"); -p^'XL*Z
bDownOver = true; P'F~\**5
//nPos = fileAccessI.write (b,0,nRead); g8v[)o(qd
} P4[]qbfd,
catch(Exception e){e.printStackTrace ();} @it/$>R^)
} e&ts\0
} +9_,w bF
'$*[SauAG
D&f!( n
//打印回应的头信息 %r P !
public void logResponseHead(HttpURLConnection con) S;h&5.p
{ x97H(*
for(int i=1;;i++) wo]ks}9
{ oX*b<d{\N
String header=con.getHeaderFieldKey(i); Y2D>tpqNw
if(header!=null) [%?hCc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sL8>GtVo
Utility.log(header+" : "+con.getHeaderField(header)); GVZTDrC
else "?[7#d])
break; -U:2H7
} `/c@nxh
} I3An57YV].
M#T#:wf~
FSe5k5
public void splitterStop() Z:TFOnJ
{ S[^nSF
bStop = true; zQt1;bo
} u`+'lBE,
v!KJ|c@m
}Q;BQ2[
} Q2FQhc@L(:
X7b!;%3@
| F8]Xnds
/* L, #Byao
**FileAccess.java S<9gyW
*//文件访问(定位，写) ;xI0\a7
package NetFox; _^-D _y
import java.io.*; s_S$7N`ocS
G4O3h Y.`
SNN#$8\
public class FileAccessI implements Serializable{ w?i)/q
:S#i9# aB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x?gQ\0S<
RandomAccessFile oSavedFile; m'c#uU
long nPos; d#4Wj0x
\D ^7Z97
eq{ [?/
public FileAccessI() throws IOException )u-ns5
{ py=i!vb&Z%
this("",0); xmOM<0T
} !;jgzi?z
5Vm Eyb
4NJVW+:2
public FileAccessI(String sName,long nPos) throws IOException ePi Z
{ _=6vW^s
oSavedFile = new RandomAccessFile(sName,"rw"); Agz=8=S%
this.nPos = nPos; vLr&ay!w
oSavedFile.seek(nPos); {x|MA(NO
} =8@RKG`>;
qA04Vc[2
!@A|L#*
public synchronized int write(byte[] b,int nStart,int nLen) ps"9;4P
{ Vl-D<M+ih
int n = -1; ;tm3B2
try{ zWJKYFqK
oSavedFile.write(b,nStart,nLen); Ls(&HOK[p
n = nLen; |K6nOX!i
} qR_SQ VN
catch(IOException e) &hO$4qtN
{ 0:jsV|5B8
e.printStackTrace (); =I7[L{+~Y
} PMQb\%iE"
G%Y*q(VrEu
\_?yzgf
return n; pTN%;`) {
} xS-w\vbLV
b#e]1Q
@PKAz&0
} \6U 2-m'
UC.8DaIPN
DhHtz.6
/* N-Qu/,~+
**SiteInfoBean.java x4@MO|C
*/ Cy]"
package NetFox; a$A2IkD
xJ$Rs/9C
haN"/C^
public class SiteInfoBean { 7(H?k
9#ZzE/
:J<Owh@
private String sSiteURL; //Site's URL makaI0M
private String sFilePath; //Saved File's Path )7tV*=?Ic8
private String sFileName; //Saved File's Name e<kpcF5{\
private int nSplitter; //Count of Splited Downloading File XadG\_?t`
.[#xQ=9`
K6ciqwUO
public SiteInfoBean() YcPKM@xo
{//nSplitter的缺省值为5 \m@]G3=]
//default value of nSplitter is 5 uwmoM>I W^
this("","","",5); 6Q?BwD+>
} :vw0r`
1<;\6sg
eog\pMv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CZF^Wxk
{ 7?+5%7-
sSiteURL= sURL; ^tQPJ
sFilePath = sPath; cPV5^9\T
sFileName = sName; w{RNv%hJ$=
this.nSplitter = nSpiltter; K<D`(voL
N`J:^,H
L00Sp#$\
} 4 `j,&=
nZ"{y
E {I)LdAqK
public String getSSiteURL() D1oaG0
{ !IfI-Q
return sSiteURL; 9Ilfv
} tq2-.]Y@U
`\Uc4lRS
Iq^~
public void setSSiteURL(String value) c(QG4.)m
{ 1'(_>S5CG
sSiteURL = value; .`:oP&9r
} 'm
BERn _5gb
<\B],M1=s=
public String getSFilePath() z4 GN8:~x
{ ,R7=]~<io"
return sFilePath; SH .9!lQv
} Gw{Gt]liq
b #o}=m
le "JW/BD
public void setSFilePath(String value) &*Q|d*CP
{ ?j &V:kF
sFilePath = value; %i;r]z-
} {JCSR2BB
v!WU |=u
QC$=Fs5+
public String getSFileName() QCZ,K"y
{ U>e3_td3,
return sFileName; 6n2Vx1b
} _C7abw-
G1`mn$`kq
x@{G(W:W
public void setSFileName(String value) [Q2S3szbt6
{ 7j9D;_(.^$
sFileName = value; o=mq$Z:}
} hNu>s
dSA [3V
.WN;TjEg!
public int getNSplitter() I!C(K^
{ WLg6-@kxXs
return nSplitter; -o=P85V
} eXskwV+7
clPZd
YR^Ee8_H
public void setNSplitter(int nCount) gJ)h9e*m^
{ 'sT}DX(7M
nSplitter = nCount; MEdIw#P.}{
} \NvC
} ae9k[=-
23B^g
@p9e:[
/* o$[a4I
**Utility.java .ruz l(6
*/ rw}5nv
package NetFox; qv ;1$
')1}#V/I
r| 6S
public class Utility { eR#gG^o8
?3B t;<^
a<a&63
public Utility() E.7AbHph0
{ o{S}e!Vb
=F^->e0N
}iiG$?|.
} ne!j%9Ar
7gZVg@
//线程睡眠 jm#F*F vL
public static void sleep(int nSecond) Q G=-LXv:@
{ ,q'gG`M N
try{ eMpEFY
Thread.sleep(nSecond); g%fJyk'
} vV:MS O'r
catch(Exception e) WwCK K
{ LX(iuf+l
e.printStackTrace (); 4z-,M7iP
} @'F8|I 6
} Oo3qiw
_.Z&<.lJ
//日志 <'o'H
public static void log(String sMsg) A .jp<>
{ \gJapx(
System.err.println(sMsg); Hb@G*L$
} 4$q)e<-
_x,-d|9bd
$Z(g=nS>
public static void log(int sMsg) )\I? EU8
{ Up!ZCZ$RC
System.err.println(sMsg); buCm @@o
} "Dmw-
} vP87{J*DE1
0^)8*O9$
E{+c*sz
/* _($-dJ{
**TestMethod.java 5b{yA~ty
*/ ]`/R("l[
package NetFox; ^ T:qT*v
TYJnQ2m
c=jI.=mi3
public class TestMethod { mKf>6/s{c
jV|$? Rcl%
HhY2`P8
public TestMethod() ;f ;*Q>!
{ ///xx/weblogic60b2_win.exe p.TiTFu/
try{ yTq(x4]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K#6`LL m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~\@<8@N2a6
SiteFileFetch fileFetch = new SiteFileFetch(bean); :}3qZX
fileFetch.start(); 5>4A}hSe
} QE{;M
catch(Exception e){e.printStackTrace ();} dPyBY]`
z7.C\l
v{rK_jq
} ~D`oP/6
b0z{"
eB/hyC1
public static void main(String[] args) H>X>5_{}
{ Z.Y;[Y
new TestMethod(); {KpH|i
} utm+\/
} .'NO~
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