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)); Hf'G8vW
} D7Y)?Z5A;
for(int i=0;i<nEndPos.length-1;i++) ?USQlnr:R/
{ G} eUL|S
nEndPos = nStartPos[i+1]; 8WE{5#oi
} 0 a]/%y3V
nEndPos[nEndPos.length-1] = nFileLength; ??TMSH
} ^c~)/F/cF
} LjL[V'JL
f.24:Dw,
~GE$myUT\p
//启动子线程 E?(xb B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; o=FE5"t
for(int i=0;i<nStartPos.length;i++) eC5$#,HiC
{ ^pM+A6 XY
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +<,gB $j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NmMIQ@K
nStartPos,nEndPos,i); BCe_@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *:i1Lv@
fileSplitterFetch.start(); VG/3xR&y
} UhIDRR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K)TrZ 2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~|wbP6</:-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #:T-hRu
nEndPos = " + nFileLength); pJN${
// fileSplitterFetch[nPos.length-1].start(); 0$7.g!h?
VqL.iZ-
+[SgO}sF
//等待子线程结束 2pdvWWh3l
//int count = 0; pP(XIC
//是否结束while循环 cyxuK*x<
boolean breakWhile = false; E}%hz*Q)(
5[j`6l
T~h5B(J;
while(!bStop) JCAq8=zM
{ <~ JO s2
write_nPos(); 3\T2?w9u(
Utility.sleep(500); (KvROV);
breakWhile = true; &uC@|dbC5
[AV4m
Ltjbxw"Qd
for(int i=0;i<nStartPos.length;i++) `jST
{ ?\8?%Qk
if(!fileSplitterFetch.bDownOver) j~j\\Y
{ hHqh{:q{v
breakWhile = false; Kx_h1{
break; ]Qm]I1P
} wP,JjPUt
} fDx9iHGv
if(breakWhile) Mi~(aah
break; eT2*W$
t>8XTqqi
Scv#zuv_
//count++; iAa;6mH
//if(count>4) "`6n6r42
// siteStop(); (H+'X}1
} Zo>]rKeV
A.UUW
{BHI1Uw
System.err.println("文件下载结束！"); pRSOYTebP
} Gycm,Cy
catch(Exception e){e.printStackTrace ();} dg4vc][
} Vf(6!iRP@
bI|2@HV2
vM_:&j_?``
//获得文件长度 )}9rwZ
public long getFileSize() xC C:BO`pw
{ t43)F9!
int nFileLength = -1; <3,<\ub
try{ b,8{ X<
URL url = new URL(siteInfoBean.getSSiteURL()); 43V}#DA@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VY)s+Bx
httpConnection.setRequestProperty("User-Agent","NetFox"); q\\gpCgp
vFEQ7qI
DNP13wp@
int responseCode=httpConnection.getResponseCode(); .jMq
if(responseCode>=400) A<;SnXm
{ gk`zA
processErrorCode(responseCode); +**!@uY
return -2; //-2 represent access is error '=P7""mN5
} %,ngRYxT#
JmEj{K<3I
G9JAcO1
String sHeader; 7t.!lh5G%
KD^N)&k^Kp
h;3cd0
for(int i=1;;i++) 3j3N!T9
{ Fv<`AU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vzmc}y G
//Utility.log(in.readLine()); x`6<m!d`
sHeader=httpConnection.getHeaderFieldKey(i); ]vuwkn+)
if(sHeader!=null) _ 84ut
{ /rSH"$
if(sHeader.equals("Content-Length")) Ks}Xgc\
{ TwgrRtj'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :_QCfH
break; }%D^8>S
} LY+|[qka
} `Qeg
else )Pv9_XKJ
break; 2h%z ("3/
} @O[5M2|r
} YtO|D
catch(IOException e){e.printStackTrace ();} H*9~yT'Q
catch(Exception e){e.printStackTrace ();} r[K5w
bu51$s?B
V\6]n2
Utility.log(nFileLength); }CfqG?)
IIyI=WlpG
&?h,7 D;A
return nFileLength; a@R]X5[O
} xZV1k~C
VU@9@%TN
P\_`
//保存下载信息（文件指针位置） t:fFU1x
private void write_nPos() Q?X>E3=U
{ @$T 9Ll
try{ uw2hMt (N
output = new DataOutputStream(new FileOutputStream(tmpFile)); D.mHIsX6\
output.writeInt(nStartPos.length); }K3x
for(int i=0;i<nStartPos.length;i++) >a}f{\Q
{ <vwkjCA`
// output.writeLong(nPos); Onwp-!!.
output.writeLong(fileSplitterFetch.nStartPos); @Pt="*g
output.writeLong(fileSplitterFetch.nEndPos); @'GGm#<
} ]7e =fM9V;
output.close(); \m1~jMz*>k
} 2+X\}s1vN
catch(IOException e){e.printStackTrace ();} *E{2J:`
catch(Exception e){e.printStackTrace ();} GQ |Mr{.;
} t#2(j1
XU"~h64]
{GJ@psG*
//读取保存的下载信息（文件指针位置） J(6oL
private void read_nPos() L5,NP5RC
{ P@FHnh3}Z$
try{ -{ZWo:,r~q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0tU.(
int nCount = input.readInt(); 4^URX>nx8
nStartPos = new long[nCount]; QVtQx>K`
nEndPos = new long[nCount]; 9V5-%Iv
for(int i=0;i<nStartPos.length;i++) ooQQ-?"m
{ ttu&@ =
nStartPos = input.readLong(); 0'IBN}
nEndPos = input.readLong(); Q1+dCCY#F
} v;)..X30
input.close(); l]5w$dded~
} ,N0#!<}4
catch(IOException e){e.printStackTrace ();} /i77
catch(Exception e){e.printStackTrace ();} tPF.r
} g1(IR)U!z
/E\%>wv
o]opdw
private void processErrorCode(int nErrorCode) rEF0oJ.
{ #_u~/jhX
System.err.println("Error Code : " + nErrorCode); V5rST +
} KY~-;0x
o>VVsH
G["c\Xux
//停止文件下载 ZMq6/G*fD
public void siteStop() s)pbS}L
{ ukUGvK
bStop = true; v\{!THCSh
for(int i=0;i<nStartPos.length;i++) Q 7?#=N?
fileSplitterFetch.splitterStop(); Bs?^2T~%{
JeE;V![
dN$Tf
} E@b(1@
} )KAEt.
//负责部分文件的抓取 rh^mJUh
**FileSplitterFetch.java r3PT1'P?L
*/ cMOyo<F#^=
package NetFox; VzVc37Z>6
b1($R[
q7E~+p(>(
import java.io.*; =y!$/(H
import java.net.*; R~6$oeWAw
c??mL4$'N
{lc\,F*$
public class FileSplitterFetch extends Thread { hzvd t
`V04\05
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String sURL; //File URL &e!7Z40w@&
long nStartPos; //File Snippet Start Position FIsyiSY<j
long nEndPos; //File Snippet End Position kbe-1 <72
int nThreadID; //Thread's ID {Ja!~N;3
boolean bDownOver = false; //Downing is over 1|jt"Hz
boolean bStop = false; //Stop identical Dbz3;t
FileAccessI fileAccessI = null; //File Access interface ^t#&@-'(d
aSnFKB
eYvWZJa4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 55fC~J<
{ %B.yW`,X
this.sURL = sURL; %xyou:~0zs
this.nStartPos = nStart; b"{'T]"*j
this.nEndPos = nEnd; N=7pK&NHSG
nThreadID = id; #NryLE!/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ug<#en
} !/]WrGqbS
e\:+uVzz
FFEfI4&SfS
public void run() W*I(f]8:y`
{ ZG&>:Si;
while(nStartPos < nEndPos && !bStop) mmk=97
{ lp^<3o*1
Ev}C<zk*
#*UN >X
try{ $[a8$VY^Cm
URL url = new URL(sURL); |3KLk?2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^0\
httpConnection.setRequestProperty("User-Agent","NetFox"); Y<%@s}zc
String sProperty = "bytes="+nStartPos+"-"; aq@8"b(.
httpConnection.setRequestProperty("RANGE",sProperty); '?p<lu^^B
Utility.log(sProperty); XLrwxj0
$cU!m(SILQ
$arK(
InputStream input = httpConnection.getInputStream(); 5lUF7:A>#
//logResponseHead(httpConnection); %#xaA'? [
!'9Feoez
9~/J35
byte[] b = new byte[1024]; v: OR
int nRead; /^#;d UB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {C N~S*m
{ '$ t
nStartPos += fileAccessI.write(b,0,nRead); abfW[J
//if(nThreadID == 1) /Y2}a<3&0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _v> }_S
} hJpxf,?'K
GE%Z9#E
P 'od`
Utility.log("Thread " + nThreadID + " is over!"); ud'-;W
bDownOver = true; "4{LN}`
//nPos = fileAccessI.write (b,0,nRead); LQRQA[^
} F7EKoDt
catch(Exception e){e.printStackTrace ();} [R^iF
} (Fhs"
} WGZ9B^A
jYmR
%|q>pin2
//打印回应的头信息 sl`s_$J
public void logResponseHead(HttpURLConnection con) ~ls[Sl@
{ g'n7T|h ~
for(int i=1;;i++) Sp;G'*g
{ Vg>dI&O
String header=con.getHeaderFieldKey(i); ic#`N0s?
if(header!=null) VKG&Y_7N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8h*Icf
Utility.log(header+" : "+con.getHeaderField(header)); 'R'*kxf
else V8C:"UZ;
break; /)}q Xx&
} ($;77fPR
} `-J%pEIza
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L>aLqQ3
public void splitterStop() _4U5
{ lJ}_G>GJ
bStop = true; DpvI[r//'*
} L(|N[#
c]n1':FT"
7'W%blg!V
} QLvHQtzwX
J$GUB3 G
1VG4S){}\9
/* 2db3I:;E
**FileAccess.java ZQ%'`q\c
*//文件访问(定位，写) ~-_kM
package NetFox; Gi?/C&1T
import java.io.*; L\xk:j1[
Ez fN&8E
--HZX
public class FileAccessI implements Serializable{ H Y&DmE
'$ =>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Mh:L$f0A%O
RandomAccessFile oSavedFile; l3Q(TH~I
long nPos; #*K}IBz
t4zkt!`B
Oj3.q#)`Z
public FileAccessI() throws IOException c1k/UcEcg~
{ M3c$=>
this("",0); e.7EU
} IEsEdw]aZE
bYpntV
(_mnB W
public FileAccessI(String sName,long nPos) throws IOException 2Mc3|T4)U
{ )U7t
oSavedFile = new RandomAccessFile(sName,"rw"); dJeNbVd
this.nPos = nPos; ~J wb`g.
oSavedFile.seek(nPos); RKHyw08
} (2J: #
eg\v0Y!rI
cl[BF'.H
public synchronized int write(byte[] b,int nStart,int nLen) 5\5/
{ XHK<AO^
int n = -1; }Jy8.<Gd^
try{ AS'R?aX|C
oSavedFile.write(b,nStart,nLen); /YW>*?"N
n = nLen; CrC^1K
} :dl]h&C^
catch(IOException e) I7|Pi[e
{ ~?4PBq
e.printStackTrace (); ZkRx1S"m
} rb5~XnJk
\o}xF@sM5
z;{iM/Xe
return n; TN!j13,
} U\4g#!qj
M -cTRd-i
ww\CQ6/h
} l&OKBUG
2&:f&"
h)ECf?r<
/* QRc{vUR&
**SiteInfoBean.java w28o}$b`
*/ @=bLDTx;c)
package NetFox; A!s`[2 Z
jSh5!6O
ddJQC|xR}
public class SiteInfoBean { >kj`7GA
l2zFKCGF(
@Owb?(6?
private String sSiteURL; //Site's URL -BrMp%C
private String sFilePath; //Saved File's Path Su 586;\
private String sFileName; //Saved File's Name #I{h\x><?
private int nSplitter; //Count of Splited Downloading File :1cV;gJ
A-H&
NPhhD&W_
public SiteInfoBean() rn/ /%
{//nSplitter的缺省值为5 ] bM)t<
//default value of nSplitter is 5 6}gls}[0{e
this("","","",5); KyVQh8
} ocqU=^ta
g`{;(/M+
8{wwd:6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9oRy)_5Z(=
{ /[a~3^Gs^
sSiteURL= sURL; Tzt8h\Q^z
sFilePath = sPath; -[*,^Ti`
sFileName = sName; SN9kFFIPb=
this.nSplitter = nSpiltter; m'Amli@[
''q@>
k$R~R-'
} ~Sg5:T3
b*;Si7-
9oyE$S h]
public String getSSiteURL() 04LI]'
{ NO7J!k?
return sSiteURL; +6sy-<ZL:
} Ed0QQyC@9
_(_a*ml
j@W.&- _
public void setSSiteURL(String value) **w!CaqvY
{ (yu/l6[
sSiteURL = value; @oNH@a j%
} *?5*m+
oz,np@f)J
bx#>BK!
public String getSFilePath() F|d\k Q
{ o1-m1<ft
return sFilePath; 3B1XZm
} #ZJ _T`l
3AHlSX
G! ]k#.^A,
public void setSFilePath(String value) K#%&0D!
{ sd,J3
sFilePath = value; $h2){*5E{
} mPOGidxix
K{x\4
X>1,!I9
public String getSFileName() KK1gNC4R
{ ?zeJ#i
return sFileName; ^WHE$4U`
} o>).Cj
@E;=*9ek{u
4iqoR$3Fc
public void setSFileName(String value) LIS)(X<]?
{ 9%8"e>~
sFileName = value; D N'3QQn
} na#CpS;pc
qIVx9jNN
8qY79)vD4E
public int getNSplitter() %b%-Ogz;4
{ vL|SY_:4
return nSplitter; Keuf9u
} \.C+ue
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B:dB,3,`(
public void setNSplitter(int nCount) D2<fw#
{ t#Z-mv:(
nSplitter = nCount; {v=T [D
} vX{J' H]u
} $&y%=-]|
T?:Rdo!:u
u5O+1sZ"6
/* GS0;bI4ay
**Utility.java o}$XH,-9&
*/ aK&b{d
package NetFox; qmnZAk
!2 LCLN\
VLS0XKI)
public class Utility { ;Yx)tWQI
8}c$XmCM
?{\nf7Y
public Utility() ^$%S &W
{ M9Cv wMi
ZW-yP2
]=.\-K
} ?i)f^O
0)%YNaskj
//线程睡眠 6FUw"|\u{
public static void sleep(int nSecond) N96jJk
{ ~Fe${2
try{ )i~cr2Hk
Thread.sleep(nSecond); ~J5+i9T.)
} 1q~+E\x
catch(Exception e) 0]>u)%
{ +!k&Yje
e.printStackTrace (); H9KKed47d/
} N8!cO[3Oh
} {s)+R[?m<o
%u`8minCt
//日志 J1/?JfF
public static void log(String sMsg) BHd&yIyI
{ k]W[`
System.err.println(sMsg); GT~)nC9f
} ZtV9&rd7
]Oh@,V8
<p}R~zk
public static void log(int sMsg) aHs^tPg
{ {n(b{ibl
System.err.println(sMsg); ;6gDV`Twy
} 4,..kSA3iw
} h"Xg;(K
g+DzscIT
_6_IP0;
/* uG?_< mun
**TestMethod.java $u7;TW6QD
*/ wihH?~]
package NetFox; .9,zL=)Ba
1)9sf0LyU
j;']cWe
public class TestMethod { 2]I4M[|&z
+)kb(
UUSq$~Ct
public TestMethod() u*e.yN
{ ///xx/weblogic60b2_win.exe i#7DR>XF/
try{ D Gr> 2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IKABBW
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A&s:\3*Kh
SiteFileFetch fileFetch = new SiteFileFetch(bean); B,M(@5wz
fileFetch.start(); UV5Ie!\nm
} O>SLOWgha
catch(Exception e){e.printStackTrace ();} GRGzP&}@
-0?~
7P"| J\
} c#a@n 4
anIAM
E8>Rui@9
public static void main(String[] args) >^%7@i:@U
{ S7=Bd[4
new TestMethod(); q+P|l5_ t
} aT_&x@x
} 8S>&WR%jH]
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