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)); KeY)%{
} LkNC8V
for(int i=0;i<nEndPos.length-1;i++) $Nnz|y
{ % &{>oEQ
nEndPos = nStartPos[i+1]; trg+")a
} YQ2ie>C8
nEndPos[nEndPos.length-1] = nFileLength; YS/{q~$t
} =XyK/$
} fMd]P:B
nB"q
C$Ldz=d
//启动子线程 91`biVZfA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |fq1Mn8
for(int i=0;i<nStartPos.length;i++) N!aV~\E
{ F5:4 B]ZF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &QLCij5:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hG; NJx-=R
nStartPos,nEndPos,i); NSj}?hz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g,mcxXO
fileSplitterFetch.start(); wbVM'E/&
} (lT H EiX
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :,6dW?mun6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bvs0y7M='
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,??xW{*|
nEndPos = " + nFileLength); r(0I>|u
// fileSplitterFetch[nPos.length-1].start(); i$$\}2m{L
>\[sNCkf
qFt%{~a S
//等待子线程结束 nSmYa7
//int count = 0; tk2B\}6
//是否结束while循环 H+\rCefba
boolean breakWhile = false; d8/lEmv[
SO3WOR`3
hPP+lqY[
while(!bStop) 8&f}GdZh
{ +u:8#!X$RD
write_nPos(); 'l)@MXbGL
Utility.sleep(500); ?}bSQ)b
breakWhile = true; WUMx:a0!
x]J{EA{+
XBdC/DM[
for(int i=0;i<nStartPos.length;i++) No!P?
{ y2o?a6`
if(!fileSplitterFetch.bDownOver) {FteQ@(
{ tbl!{Qwx
breakWhile = false; 6t<~. 2'
break; Ilsh Jo
} `yNNpSdS1
} )d_)CuUBe
if(breakWhile) &>p2N
break; +);o{wfW
) yRC$7I
&X9#{:l=
//count++; V :*GG+4
//if(count>4) ?20y6c<
// siteStop(); _T<ney}Y<
} >5i1M^g(
SG$/v
kT[]^Jtc
System.err.println("文件下载结束！"); &7XB$
} yIh>j.P
catch(Exception e){e.printStackTrace ();} 0+m"eGwTm
} (<=qW_iW
lD _ u
'w^1re=R
//获得文件长度 {M$mrmG
public long getFileSize() !f V.#9AB#
{ *(& J^
int nFileLength = -1; &H-39;?u
try{ :DR G=-M
URL url = new URL(siteInfoBean.getSSiteURL()); ^4`q%_vm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EAqTXB@XU
httpConnection.setRequestProperty("User-Agent","NetFox"); sbQmPV
RT F9;]Ti
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int responseCode=httpConnection.getResponseCode(); U"<Z^)
if(responseCode>=400) 72@8M
{ \Llrs-0 M
processErrorCode(responseCode); gPd:>$
return -2; //-2 represent access is error hJrxb<9@Y0
} P5%DvZB$w
\"<&8
P (_:8|E
String sHeader; f)vD2_E
(IAl$IP63s
h,\^Sb5AP
for(int i=1;;i++) pIqPIuy
{ VQ$=F8ivG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mdoy1a
//Utility.log(in.readLine()); D-8%lGS
sHeader=httpConnection.getHeaderFieldKey(i); 0 jVuFl
if(sHeader!=null) &YmOXKf7
{ eWhv X9 <
if(sHeader.equals("Content-Length")) !3-mPG< ]
{ Cc1sZWvz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z=L' [6
break; 49@ pA-
} UFyGp>/06
} _r+9S.z
else v}M, M&?
break; G$xuHHZ'
} i('z~
} }^pnwo9vV
catch(IOException e){e.printStackTrace ();} _(0!bUs>
catch(Exception e){e.printStackTrace ();} O (tcu@vfl
q(\$-Dk.Vv
fp:j~a>E
Utility.log(nFileLength); '_4u, \SG
IhJ _Yed
v7\~OOoH]
return nFileLength; 3Nsb@0
} Ni(D[?mZ
@j9yc
Z@RAdwjR`p
//保存下载信息（文件指针位置） SdYES5aES
private void write_nPos() :{E3H3
{ Vj:)w<],
try{ 7Aq4YjbX
output = new DataOutputStream(new FileOutputStream(tmpFile)); #D .H2'_}
output.writeInt(nStartPos.length); <T+Pw7X
for(int i=0;i<nStartPos.length;i++) Yc"G="XP;
{ __-rP
// output.writeLong(nPos); qV@xEgW#r
output.writeLong(fileSplitterFetch.nStartPos); F'C]OMBE
output.writeLong(fileSplitterFetch.nEndPos); +G7A.d`V}
} g5M-Vu
output.close(); |2 g }i\
} Ipb4{A&"\
catch(IOException e){e.printStackTrace ();} U:J~Oy_Z
catch(Exception e){e.printStackTrace ();} 7 G~MqnO|
} !:c7I@
"sUe:F;
yV$p(+KkS
//读取保存的下载信息（文件指针位置） qusgX;)
private void read_nPos() n?YGXW/
{ ]Q6,,/nn
try{ c42p>}P[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JLT':e~PX
int nCount = input.readInt(); 4Qz
nStartPos = new long[nCount]; bO9F rEz5
nEndPos = new long[nCount]; R 7xV{o
for(int i=0;i<nStartPos.length;i++) f]J?-ks
{ c)rI[P7Q
nStartPos = input.readLong(); kFw3'OZ,
nEndPos = input.readLong(); {1#5\t>9yD
} 9cQKXh:R.
input.close(); <Zl0$~B:5
} oQjh?vm
catch(IOException e){e.printStackTrace ();} v)%EG
catch(Exception e){e.printStackTrace ();} $qP9EZ]JC
} s,]6Lri`\
nC_<pq^tr
jQ%}e"
private void processErrorCode(int nErrorCode) !r.X.C
{ b3#c0GL
System.err.println("Error Code : " + nErrorCode); :>F:G%(DK
} w^A8ZT0^7
|jEKUTv,G
yXg783B|v
//停止文件下载 yJ/m21f
public void siteStop() (x&#>5
{ 3543[W#a
bStop = true; {pd%I
for(int i=0;i<nStartPos.length;i++) pZlBpGQf
fileSplitterFetch.splitterStop(); %vxd($Ti"
zc*qmb
P]yER9'
} a_x$I?,
} I]~xs0$4#
//负责部分文件的抓取 rv9qF |2r{
**FileSplitterFetch.java qWw@6VvoQ
*/ "h2;65@
package NetFox; }{bO~L7
PcM:0(,G
>^+Q`"SN
import java.io.*; r1}7Q7-z
import java.net.*; u32wS$*8
44kY[jhf
lY?TF
public class FileSplitterFetch extends Thread { jMW|B
87YT;Z;U&
&EE6<-B-
String sURL; //File URL 8ENAif
long nStartPos; //File Snippet Start Position I"Ju3o?u
long nEndPos; //File Snippet End Position &{Uaa
int nThreadID; //Thread's ID hy W4=
boolean bDownOver = false; //Downing is over 4JU#3
boolean bStop = false; //Stop identical RNl%n}
FileAccessI fileAccessI = null; //File Access interface 43,- t_jV
K*7*`6iU
5\:#-IYJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rouD"cy
{ nFw&vR/q
this.sURL = sURL; e%wbUr]c2
this.nStartPos = nStart; [EB2o.EsO
this.nEndPos = nEnd; o'>jO.|
nThreadID = id; <2}"Y(zwKl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &X}9D)\UJ
} ]A<\d
14s+&
B,e@v2jO|
public void run() j(va#f#
{ ;6fkG/T
while(nStartPos < nEndPos && !bStop) SY>N-fW\H:
{ je_77G(F
nUd(@@%m
=1VY/sv
try{ 1?E\2t&K
URL url = new URL(sURL); hYb!RRGn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /bt@HFL|`
httpConnection.setRequestProperty("User-Agent","NetFox"); %QwMB`x
String sProperty = "bytes="+nStartPos+"-"; @B7;
httpConnection.setRequestProperty("RANGE",sProperty); _ky!4^B
Utility.log(sProperty); !%T@DT=l&
&b"PjtU.X
&|/C*2A
InputStream input = httpConnection.getInputStream(); IL YS:c58=
//logResponseHead(httpConnection); T{?!sB3
:_)Xe*O
zT!JHG
byte[] b = new byte[1024]; H{p+gj^J
int nRead; 8QFY:.h&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4&$hBn=!
{ >]ZojdOl)
nStartPos += fileAccessI.write(b,0,nRead); ^~=o?VtBg
//if(nThreadID == 1) `.L8<-]W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4)v\Dc/9i
} N<$uAns
UCvMW*gs
wQPjo!FEX
Utility.log("Thread " + nThreadID + " is over!"); *AZC{jP
bDownOver = true; bL swq
//nPos = fileAccessI.write (b,0,nRead); 34s:|w6y
} vlEd=H,LT
catch(Exception e){e.printStackTrace ();} Vu~mi%UH
} AL H^tV?
} { F.Ihw
.'__ [|-{;
pOnZ7(
//打印回应的头信息 >jN)9}3>-#
public void logResponseHead(HttpURLConnection con) Vwm\a]s
{ )JeiTh^
for(int i=1;;i++) M;\K+,
{ *Z)`:Gae
String header=con.getHeaderFieldKey(i); _F,@mQ$!
if(header!=null) 7F)HAbIS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h %MPppCEa
Utility.log(header+" : "+con.getHeaderField(header)); ?>4^e:
else .$99/2[90
break; !. q*bY
} s7a\L=#p(
} DX4 95<6*
=1`
OM}:1He
public void splitterStop() <Ni]\-*
{ }{j[
bStop = true; 47ir QK*
} eR8h4M~O
MFE~bU(h
)7c^@I;7
} 6M612
?w3f;v
z'fGHiX7.0
/* XK(<N<Z@|e
**FileAccess.java ew}C*4qH
*//文件访问(定位，写) .hETqE`E
package NetFox; 3<'SnP3mY
import java.io.*; KY2xKco
!{Y$5)Xh`]
7CrWsQl u
public class FileAccessI implements Serializable{ 33"{"2==`
;rd!kFd#bq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s{$c8
RandomAccessFile oSavedFile; @kI^6(.
long nPos; Jw;J$ u!d
i1|-
ffuV$#
public FileAccessI() throws IOException lEQn2+
{ V1#/+~
this("",0); t=A| K
} Wc-P= J*m
mP3:Fc_G
bLaD1rnGi
public FileAccessI(String sName,long nPos) throws IOException l3l[jDa,2
{ [dOPOA/d
oSavedFile = new RandomAccessFile(sName,"rw"); F4">go
this.nPos = nPos; WmOd1
oSavedFile.seek(nPos); |D`Zi>lv
} y5+-_x,
Ww)qBsi8
QJGRi
public synchronized int write(byte[] b,int nStart,int nLen) _y5b>+
{ %DzS~5$G
int n = -1; ]7'Q2OU7
try{ }ndH|,
oSavedFile.write(b,nStart,nLen); 3#0nus|=S
n = nLen; PJh\U1Z
} uop_bJ
catch(IOException e) j0:F E
{ ~mmI] pC
e.printStackTrace (); 0+cRUH9Ew
} 4.CLTy3W
GD~3RnGQ{
hMi!H.EX.
return n; f-4<W0%
} ad i5h
s~M!yuH
t2tH%%Rs
} |$7!u DU8
-D{~7&
`^F'af
/* >.J68x
**SiteInfoBean.java <[l2]"Q
*/ M*aE)D '
package NetFox; VY~WkSi[<
1sn!!
v_)cp9d]
public class SiteInfoBean { 6mMJ$FY+
t(Iy[-
!>9*$E |
private String sSiteURL; //Site's URL *"j_3vAx
private String sFilePath; //Saved File's Path G0y%_"[
private String sFileName; //Saved File's Name B^$l]cvZ
private int nSplitter; //Count of Splited Downloading File ?#slg8[
jVk|(
^x:4%%Q]l
public SiteInfoBean() B]Yj"LM)
{//nSplitter的缺省值为5 o.}^6.h"
//default value of nSplitter is 5 &&JI$x0;
this("","","",5); <fs2;
} klJDYFX=HK
] p'+F
M}/%t1^g:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EzzzH(!j
{ 3)42EM'9(
sSiteURL= sURL; -^\k+4;
sFilePath = sPath; p~Dm3^Y
sFileName = sName; UxD1+\N6?
this.nSplitter = nSpiltter; sOU_j4M{
R0*DfJS:Z
uTB;Bva
} otX#}} +
"Z}0A/y
#;}IHAR
public String getSSiteURL() V/>SjUNq
{ POUB{ba
return sSiteURL; ^D oJ='&
} BFj@Z'7P
Yg2z=&p-{"
.B#Lt,m
public void setSSiteURL(String value) "%A[%7LY
{ Z2*hQ`eE
sSiteURL = value; wrGd40
} ?R"5 .3
J,m.LpY
/x-Ja[kL
public String getSFilePath() UkXc7D^jwm
{ ><`.(Z5c
return sFilePath; R%3H"FU9w
} |W*f6F3
!!Mp;h'}-
#8nF8J<4
public void setSFilePath(String value) 9OT2yCT
{ &\Cvrxa
sFilePath = value; Zb);08X
} i&.F}bEi
4B (*{
K%Q^2"Eb0
public String getSFileName() t#Yyo$9
{ iVXR=A\er
return sFileName; WMh'<'wN_
} 0Xk;X1Xl
>+,1@R
R&PQ[Xc
public void setSFileName(String value) a7#Eyw^H{
{ Hvor{o5|tB
sFileName = value; \ov>?5
} Wc`Vcn1
|a\s}M1
3%|<U51
public int getNSplitter() l\$_t2U
{ \Xxx5:qM
return nSplitter; FopD/D{
} <w{W1*R9
q. BqOa:
yFJ(b%7
public void setNSplitter(int nCount) [k."R@?
{ t*.v!
nSplitter = nCount; )2rI/=R
} :peBQ{bj
} &[RC4^;\V
fjp>FVv3
vkbB~gr@*
/* ;;l(
**Utility.java .=^h@C*
*/ Mh3zl
package NetFox; B(^fM!_%-6
(T'inNbJe
@&EE/j^
public class Utility { 3]}W
66Hu<3X P
>|z=-hqPK
public Utility() #/1A:ig
{ |G%MiYd
dF1Bo
OQ!mL3f
} Hyee#fB
1egryp
//线程睡眠 -P'>~W,~
public static void sleep(int nSecond) cJE2z2uW0
{ `5GJ,*{z
try{ uLL#(bhDr
Thread.sleep(nSecond); Tb{,WUJg2
} UbQeN
catch(Exception e) WWE?U-o
{ vO4 &ZQ>6
e.printStackTrace (); 3_Oq4/
} n]8_]0{qi
} +;;fw |/
EidIi"sr
//日志 DlIfr6F
public static void log(String sMsg) Pu axS
{ T<!`~#kM
System.err.println(sMsg); )(DV~1r=
} dHOz;4_
Ii[rM/sG
MgtyO3GUAD
public static void log(int sMsg) &V$'{
{ v8pUt\m"
System.err.println(sMsg); jl:O~UL6i
} /9GqEQsfM
} c+4SGWmO
+m>Kb edl
GD< Afni
/* $L`7(0U-
**TestMethod.java bWMM[pnL
*/ typ*.j[q
package NetFox; R^8Opf_UN
< W&~tVv
2]4R`[#
public class TestMethod { Po^2+s(fY
zlFl{t
Bq:@ [pCQ
public TestMethod() OWq~BZ{
{ ///xx/weblogic60b2_win.exe w;#9 hW&
try{ 7Uj[0Awn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -,5g cD
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); L<Lu;KnY6
SiteFileFetch fileFetch = new SiteFileFetch(bean); rxDule3m
fileFetch.start(); 0U$6TDtmE
} &ul9N)A
catch(Exception e){e.printStackTrace ();} gNZ^TeT
1p8E!c{}j
}#yRaIp
} ;W+.]_$6)T
]pB~&0jg
*><] [|Y@H
public static void main(String[] args) PK+][.6H
{ 9:=a FP
new TestMethod(); y>~KeUC
} /6S/a*`<X
} n+!.0d}6
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