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)); {4m"S7O
} a&ByV!%%+_
for(int i=0;i<nEndPos.length-1;i++) ft6^s(t
{ A0X0t
nEndPos = nStartPos[i+1]; O.}gG6u5
} tB3CX\e
nEndPos[nEndPos.length-1] = nFileLength; yaR;
} V=*J9~K
} -5 W0K}
<d5vVn
I!<v$
//启动子线程 A7RX2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #f~a\}$I
for(int i=0;i<nStartPos.length;i++) d,+n,;6Cf
{ jb![ Lp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dS&8R1\>1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g^4FzJ
nStartPos,nEndPos,i); =U2Te
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C;) xjZiR
fileSplitterFetch.start(); _~(Xd@c(
} @ :4Kk 4g1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pNJM]-D]m~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .-Lqo=o\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n1/lE)
nEndPos = " + nFileLength); Wkk Nyg,
// fileSplitterFetch[nPos.length-1].start(); 1;gSf.naG
2!otVz!Mh
,< icW&a
//等待子线程结束 uWInx6p
//int count = 0; QPcB_wUqu
//是否结束while循环 >oNk(. %
boolean breakWhile = false; Z%{f[|h9}
GDB>!ukg
U44H/5/
while(!bStop) +=k|(8Js#
{ l.W:6",w
write_nPos(); oX4uRc7wR
Utility.sleep(500); GKtQ>39B
breakWhile = true; 5#o,]tP
(*x"6)`
k0IU~y%
for(int i=0;i<nStartPos.length;i++) ] zY
{ WO9/rF_
if(!fileSplitterFetch.bDownOver) bC{8yV=)
{ :Y3?,
breakWhile = false; m'B6qy!}6
break; K)@}Ok"#\4
} WLl9>v^1
} j1kc&(
if(breakWhile) `x VA]GR4c
break; zNf5OItx
UIj/Id
dZgfls
//count++; ):@%xoF5
//if(count>4) :GYv9OG
// siteStop(); R4(8]oUW
} /6c10}f
P[K=']c
m^.C(}
System.err.println("文件下载结束！"); %4Zy1{yKs_
} jf/9]`Hf
catch(Exception e){e.printStackTrace ();} 6I#DlAU@v
} $IT9@}*{
?63JQ.;
fLoVcl
//获得文件长度 ] O>7x
public long getFileSize() \pGO}{3e*
{ Z5[:Zf?h7J
int nFileLength = -1; LeyDs>!0
try{ 8Q -F
URL url = new URL(siteInfoBean.getSSiteURL()); \Agg6tYr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \W^+vuD8
httpConnection.setRequestProperty("User-Agent","NetFox"); 8!6*|!,:?n
hob$eWgr
*^Y0}?]qT
int responseCode=httpConnection.getResponseCode(); 3raA^d3!?
if(responseCode>=400) iGMONJRO
{ ZG<!^tj
processErrorCode(responseCode); pd3&AsU
return -2; //-2 represent access is error ,P@-DDJ
} *$C[![
yWtr,
u(Sz$eV
String sHeader; a?~csP^?}
!@Lc/'w
CHit
for(int i=1;;i++) %:?QE ;
{ xN8JrZE&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SqF.DB~
//Utility.log(in.readLine()); !gHWYWu)!
sHeader=httpConnection.getHeaderFieldKey(i); :[f`HY&
if(sHeader!=null) QS*cd|7J;
{ X",0VO
if(sHeader.equals("Content-Length")) qjzW9yV+
{ wP0+Xv,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c@7hLUaE2
break; TF-Ty
} So.P @CCd
} jY+S,lD
else ,GU/l)os`
break; ,D2_Z]
} gCr|e}w-
} PZRn6Tc
catch(IOException e){e.printStackTrace ();} .{a2z*o
catch(Exception e){e.printStackTrace ();} *;E+9^:V
{b0&qV
8Vhck-wF
Utility.log(nFileLength); X6GkJ R
+JS/Z5dl+}
6n\z53Mk
return nFileLength; kseJm+Hc
} _I-VWDCk
&Z!K]OSY
H&Y{jqua
//保存下载信息（文件指针位置） CN~NyJL H
private void write_nPos() PFy;qk
{ e)dWa'2<
try{ D8AIVK]
output = new DataOutputStream(new FileOutputStream(tmpFile)); !LOors za
output.writeInt(nStartPos.length); )z235}P
for(int i=0;i<nStartPos.length;i++) {a8^6dm*E
{ DE\bYxJ
// output.writeLong(nPos); uE#,c\[8
output.writeLong(fileSplitterFetch.nStartPos); g+ 1=5g
output.writeLong(fileSplitterFetch.nEndPos); /:{_|P\
} D>b5Uwt
output.close(); <-B"|u
} 'Rd*X6dv
catch(IOException e){e.printStackTrace ();} @@3,+7%1
catch(Exception e){e.printStackTrace ();} w1@b5-
} a<wQzgxG
FEZ"\|I|
5YI/Ec
//读取保存的下载信息（文件指针位置） F0'A/T'ht
private void read_nPos() fb.\V]K
{ F:o#
try{ I,4-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,o@~OTja*
int nCount = input.readInt(); =ch Af=
nStartPos = new long[nCount]; WCmNibj
nEndPos = new long[nCount]; m_!vIUOz
for(int i=0;i<nStartPos.length;i++) 4!~ .6cp3
{ Qj<{oZp&
nStartPos = input.readLong(); QK!:q{
nEndPos = input.readLong(); lAn+gDP
} "R2t&X[9
input.close(); DxKfWb5 R
} .d~]e2x
catch(IOException e){e.printStackTrace ();} V l~Y
catch(Exception e){e.printStackTrace ();} xPDA475Cw3
} F\=Rm
Vx6?@R
fHe0W
private void processErrorCode(int nErrorCode) yOUX E>-
{ (ND5CKCR^
System.err.println("Error Code : " + nErrorCode); S`@6c$y k
} *M&VqG4P9w
3_\{[_W
,> (bt%b
//停止文件下载 }x?H ~QQT
public void siteStop() 1KYbL8c
{ 8S1P&+iKs
bStop = true; RHx+HBZ
for(int i=0;i<nStartPos.length;i++) )0U3w#,JQ
fileSplitterFetch.splitterStop(); !<=%;+
EN-H4F
..q63dr
} v=*Bb3dt
} juCG?}di;
//负责部分文件的抓取 XnE %$NJ
**FileSplitterFetch.java 9jMC|oE
*/ H\=LE
package NetFox; g>!:U6K
2&gd"Ak(
jKj=#O
import java.io.*; sArje(5Eo
import java.net.*; t8AkdSU0
p<HTJ0
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public class FileSplitterFetch extends Thread { XatA8(_,5
s~Lfi.
:J Gl>V
String sURL; //File URL 'n^2|"$sH
long nStartPos; //File Snippet Start Position 0\cnc^Z
long nEndPos; //File Snippet End Position 1c)\
int nThreadID; //Thread's ID %Ui{=920
boolean bDownOver = false; //Downing is over %wt2F-u
boolean bStop = false; //Stop identical i5 L:L
FileAccessI fileAccessI = null; //File Access interface ` /I bWu
!f\?c7
Gpdv]SON{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dNUR)X#e
{ vXyuEEe
this.sURL = sURL; *|LbbRu
this.nStartPos = nStart; E[jXUOu-
this.nEndPos = nEnd; Q(IJD4
nThreadID = id; R%b*EBZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /`+Hwdk
} k<YtoV
8ji^d1G,
v}F4R $
public void run() aJ:A%+1
{ Xr?>uqY!M
while(nStartPos < nEndPos && !bStop) ='dLsh4P2N
{ 1 [Sv
YVB% kKv{
(px*R~}
try{ ]{IR&{EI-
URL url = new URL(sURL); lx{.H,1~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &GdL 9!hH
httpConnection.setRequestProperty("User-Agent","NetFox"); r]k*7PK
String sProperty = "bytes="+nStartPos+"-"; Kajkw>z
httpConnection.setRequestProperty("RANGE",sProperty); y)3~]h\a
Utility.log(sProperty); &l.x:eD
5-8]N>/b!
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InputStream input = httpConnection.getInputStream(); 6R;)
//logResponseHead(httpConnection); C9<4~IM w
45x,|h[F{5
xClRO,-
byte[] b = new byte[1024]; r=fE8[,
int nRead; !uWxRpT,7
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cVQatm
{ &sm @
nStartPos += fileAccessI.write(b,0,nRead); owE<7TGPI?
//if(nThreadID == 1) 29"mE;j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EHpu*P~W
} YXF#c)#
= :Po%Z%{
XnBm`vk?V!
Utility.log("Thread " + nThreadID + " is over!"); bnijM/73
bDownOver = true; sS, zzx<
//nPos = fileAccessI.write (b,0,nRead); C _8j:Z&
} .aNO( /kO
catch(Exception e){e.printStackTrace ();} 7w "sJ
} `FUFK/7 w\
} p QluGIX0V
[J~aAB
z*6$&sS\>
//打印回应的头信息 ZV!R#Xv
public void logResponseHead(HttpURLConnection con) EVR! @6@
{ r2RBrZ@1
for(int i=1;;i++) &&;ex9
{ P?^JPbfV
String header=con.getHeaderFieldKey(i); 3PfiQ|/b
if(header!=null) eh$G.-2N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q>kiVvc
Utility.log(header+" : "+con.getHeaderField(header)); saatU;V
else K<c2PFo)Q
break; y:Z$LmPc<
} z{%oJ_
} y k?SD1hj
j7f5|^/x3
Ll,I-BQ9
public void splitterStop() mHKJ
{ t-_#Q bzE{
bStop = true; f,|QAj=a
} 1{^CfamF
V {p*z
x@htx?
} eaEbH2J
W+KF2(lB
+|6`E3j%
/* O{~KR/
**FileAccess.java Gc wt7~
*//文件访问(定位，写) FtE90=$
package NetFox; ^Sw2xT$p{j
import java.io.*; \H^;'agA
veV_be{i
j(sLK &
public class FileAccessI implements Serializable{ i&JpM]N
+vf:z?I8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J2m"1gq,
RandomAccessFile oSavedFile; <P-$RX
long nPos; Q |%-9^
C ck#Y
Y.7}
public FileAccessI() throws IOException MZ WmlJ
{ w^3|(F
this("",0); E${J
} 6.[)`iF+#
?H`j>]%&
6F(hY !}5
public FileAccessI(String sName,long nPos) throws IOException wZQ)jo7*g
{ guU=NQZ
oSavedFile = new RandomAccessFile(sName,"rw"); $(3uOsy
this.nPos = nPos; >Co)2d]
oSavedFile.seek(nPos); "CMucK
} opXDm\
"e@n:N!
7{4w2)
public synchronized int write(byte[] b,int nStart,int nLen) YGETMIT(
{ Y3k[~A7X
int n = -1; e gI&epN
try{ 19p8B&
oSavedFile.write(b,nStart,nLen); uxb:^d?D!
n = nLen; :5jexz."M
} #BsW
catch(IOException e) P].eAAXnP
{ `kFiH*5%z
e.printStackTrace (); r_^)1w
} "Kq>#I'%W
FI$XSG
grspt}
return n; t{zBC?cR
} `;$h'eI9
->h5T%sn
h,t:]
} P3!Atnv2
z6I%wh
d*2u}1Jo8
/* NO2(vE
**SiteInfoBean.java Vc _:*
*/ WqE '(
package NetFox; !>3LGu,
;}K62LSR
6J\fF tB@V
public class SiteInfoBean { >La><.z~
q(Hip<6p
O[FZq47
private String sSiteURL; //Site's URL >I^9:Q
private String sFilePath; //Saved File's Path p?JQ[K7i
private String sFileName; //Saved File's Name Z/g]o#
private int nSplitter; //Count of Splited Downloading File >?I/;R.-
5$%XvM
doR4nRl9
public SiteInfoBean() 0q#"clw
{//nSplitter的缺省值为5 n1,S_Hs
//default value of nSplitter is 5 JRY_nX
this("","","",5); Zj!Abji=O
} FshC )[w,
2 x32U MD
e>AXXUEf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |@wyC0k!
{ f@d9Hqr+l;
sSiteURL= sURL; yQ%"U^.m
sFilePath = sPath; nxfoWy
sFileName = sName; ~8{sA5y
this.nSplitter = nSpiltter; Om9jtWk
_{)9b24(
s$ z2 c
} \f%.n]>
8EI:(NE*J
"%@v++4y
public String getSSiteURL() X{\jK]O
{ S)7/0N79A
return sSiteURL; J+ts
} Oaa"T8t
2w?hgNz
vy9dAl
public void setSSiteURL(String value) ]iVLHVqz
{ Ur3m[07H
sSiteURL = value; WbcS: !0
} 4TZ cc|B5
J# EP%
5FOqv=6S
public String getSFilePath() jDX>izg;V
{ -[heV|$;
return sFilePath; Wekqn!h
} #^0(
i=#F)AD^5#
!OAvD#
public void setSFilePath(String value) %u!b& 5]e
{ !MV@) (.
sFilePath = value; v* ~3Z1
} suVmg-d
FFvCi@oT
*x(Jq?5O7X
public String getSFileName() r4Q|5kT*i
{ zK;XFN#U^
return sFileName; e;(
} VaR/o#
E!mmLVa9
b1-&v|L
public void setSFileName(String value) v&;:^jJ8
{ D*2\{W/
sFileName = value; Gu;OVLR|
} bRsTBp;R`I
tj5giQ3DG)
z7T0u.4Ss
public int getNSplitter() tC)6
{ 6N" l{!
return nSplitter; ~x]9SXD%
} Dl,`\b@Fw3
2*1ft>Uty
RN9;kB)c
public void setNSplitter(int nCount) RUo9eQIPD
{ -LWK*q[J;*
nSplitter = nCount; +B"0{>n}F
} Gquuy7[&
} $NG++N
Mvcfk$pA
ar^i|`D
/* $k%Z$NSN=
**Utility.java :YO@_
*/ sWqM?2g
package NetFox; cUk*C
>*1}1~uU`'
qTmD'2
public class Utility { ,hRN\Kt)p
$>q@SJ1q
1cC1*c0Z
public Utility() z&}-8JykH
{ go'j/4Tp
/'wF2UR
^jSsa
} T@YGB]*Y
h{'t5&yY
//线程睡眠 }NCL>l;q
public static void sleep(int nSecond) /aqEJGG>
{ +%0z`E\?M#
try{ bS!\#f%9"
Thread.sleep(nSecond); vjUp *R>h
} bGmx7qt#
catch(Exception e) 8e2?tmWM
{ *hY2.t; X
e.printStackTrace (); X#p Wyo~
} K8[DZ)rO;Z
} 1hmc,c
%X1x4t]
//日志 z`3( ,V
public static void log(String sMsg) l67Jl"v
{ diT=x52
System.err.println(sMsg); cgT
} (<c7<_-H
=|U@
TzG]WsY_
public static void log(int sMsg) o l ({AYB
{ sen=0SB/
System.err.println(sMsg); zI;0&
} WF2-$`x
} ~r*P]*51x
dcfe_EuT
EqB)sK/3
/* Ip *g'
**TestMethod.java ~mp0B9L%
*/ H=^K@Ti:
package NetFox; <V&5P3)d9
IDFFc&
pPro }@@
public class TestMethod { 5/0j}_pP
1DJekiWf
NL"G2[e
public TestMethod() )A8v];.]3
{ ///xx/weblogic60b2_win.exe `BXS)xj
try{ c-4STPNQi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $'wq1u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %Y nmuZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); dA~ 3>f*b_
fileFetch.start(); 5K%Wa]W
} ~Ci{3j :]
catch(Exception e){e.printStackTrace ();} iz[gHB
MgMD\
lS5ny
} ^TdZ*($5
~N0sJ%
V!/:53
public static void main(String[] args) z8_XX$Mnt
{ KOSM]c\H
new TestMethod(); YK#fa2ng
} 0y#Ih {L
} |V,<+BEi
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