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)); qW|_|%{U+
} !4(QeV-=
for(int i=0;i<nEndPos.length-1;i++) 1R7w
{ cP>[H:\Xc
nEndPos = nStartPos[i+1]; a3SBEkC
} Q-y`IPtA<
nEndPos[nEndPos.length-1] = nFileLength; J*+[?FXRL
} jF0>wm
} 2 UPG8]
-5#cfi4^*
! +XreCw
//启动子线程 F4=V*/7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I@:"Qee
for(int i=0;i<nStartPos.length;i++) :r}C&3
{ ~Nn}FNe
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #7p!xf^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oR'u&\mB
nStartPos,nEndPos,i); ^BhS*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }sW%i#CV
fileSplitterFetch.start(); t-)d*|2n}o
} ygYy [IZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J)P7QTC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QeG3X+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,d$D0w
nEndPos = " + nFileLength); #.@-ng6C
// fileSplitterFetch[nPos.length-1].start(); o8u;2gZx
X \qG WpN%
8Cw3b\ne
//等待子线程结束 Tx|y!uHh
//int count = 0; }mOo=)C!
//是否结束while循环 gvoYyO#cm
boolean breakWhile = false; `zsooA Gt
eR:C?v
W7"UhM
while(!bStop) uFn?U)
{ #N;McF;W
write_nPos(); R0YWe
Utility.sleep(500); K#xL-
breakWhile = true; 2$FH+wuW
t"jiLOQ[6
D4$2'h
for(int i=0;i<nStartPos.length;i++) /o9 0O&
{ l;}3J3/qq]
if(!fileSplitterFetch.bDownOver) W}@IUCRs
{ q@vqhE4
breakWhile = false; jR>`Xz
break; -.l.@
} Q2<v: *L
} %#C9E kr
if(breakWhile) K>G.HN@
break; h`f$]_c
Ik-E_U2
fw)Q1"|
//count++; D 3Tqk^5
//if(count>4) rG3?Z^&R+
// siteStop(); moL3GV%]Gq
} 5:(/k\9+yv
"<&) G{
DcN!u6sJ
System.err.println("文件下载结束！"); ~]SCf@pRk
} DGNn#DP
catch(Exception e){e.printStackTrace ();} P=R-1V
} D.gD4g_O/
!wTrWD!
-quJX;~
//获得文件长度 2@Oz_?O=
public long getFileSize() J;'H],w}f
{ ]EdZ,`B4
int nFileLength = -1; B_ bZa
try{ &cwN&XBY
URL url = new URL(siteInfoBean.getSSiteURL()); C=qL0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ch33+~Nn
httpConnection.setRequestProperty("User-Agent","NetFox"); $i%#fN
{@hJPK8
8J:=@X^}
int responseCode=httpConnection.getResponseCode(); % _nmv
if(responseCode>=400) D~n-;T
{ d .%2QkL
processErrorCode(responseCode); Yz#E0aTTA
return -2; //-2 represent access is error _ Y7Um
} g)7@EU2
X0]{8v%
~ +h4i'
String sHeader; <!F".9c@A
8*Ty`G&v
vIf-TQw
for(int i=1;;i++) !,]2.:{0z
{ c#TV2@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U9jdb9 |
//Utility.log(in.readLine()); {.ypZ8JU
sHeader=httpConnection.getHeaderFieldKey(i); (__$YQ-
if(sHeader!=null) {vdY(
{ \&47u1B
if(sHeader.equals("Content-Length")) $gZiW8
{ =\G`g#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~RLWr.pK
break; @0(%ayi2Y
} y?U@F/^}N
} FC WF$'cO
else F}=_"IkZ
break; udmLHc
} n|Ts:>`V
} %xr'96d
catch(IOException e){e.printStackTrace ();} _0UE*l$t
catch(Exception e){e.printStackTrace ();} =J|jCK[r
BS(jC
\Foo:jON
Utility.log(nFileLength); m^ Epw4eg
%7QSBL
m_.9PZ
return nFileLength; L/In~'*-
} W]XM<# ^^
2_ 1RJ
[w!T
//保存下载信息（文件指针位置） iiF`2
private void write_nPos() +*,!q7Gt
{ {Qc,Nl [?
try{ xojt s;n
output = new DataOutputStream(new FileOutputStream(tmpFile)); Mdq|:^px
output.writeInt(nStartPos.length); Z_fwvcZ?05
for(int i=0;i<nStartPos.length;i++) P^!g0K
{ w 62m}5eA
// output.writeLong(nPos); eK5~YM:o
output.writeLong(fileSplitterFetch.nStartPos); %|D)U>o{
output.writeLong(fileSplitterFetch.nEndPos); -}PE(c1%?q
} #RbdQH !
output.close(); mG$N%`aG
} l(Dr@LB~
catch(IOException e){e.printStackTrace ();} `NsQ&G
catch(Exception e){e.printStackTrace ();} !&:Cp_
} ?8/r=
QUaV;6 4
+~ Hb}0ry
//读取保存的下载信息（文件指针位置） V^4v`}Wgx
private void read_nPos() ;u[:J
{ #!E`%' s]
try{ nCQ".G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RN|Bk
int nCount = input.readInt(); u})*6l.
nStartPos = new long[nCount]; mln4Vl(l2M
nEndPos = new long[nCount]; WrcmC$ff
for(int i=0;i<nStartPos.length;i++) + K`.ck
{ RyU8{-q
nStartPos = input.readLong(); 5*+DN U@
nEndPos = input.readLong(); 'J3yJ{
} !Z |_3
input.close(); 4_ypFuS^
} [VqiF~o,
catch(IOException e){e.printStackTrace ();} yf!7 Q>_G^
catch(Exception e){e.printStackTrace ();} @$!6u0x
} O2?yI8|Jn
EZ:? (|h
x2a ?ugQ
private void processErrorCode(int nErrorCode) S=lCzL;j"
{ wVFa51a)yy
System.err.println("Error Code : " + nErrorCode); IZm6.F
} `"PHhCG+z
&@'%0s9g
e$_gOwB
//停止文件下载 +nHr+7}
public void siteStop() B8?9L8M}
{ ah f,- ?S
bStop = true; kZo#Ny
for(int i=0;i<nStartPos.length;i++) w\0vP
fileSplitterFetch.splitterStop(); H }]Zp
H C,5j)1
1h(IrV5g
} oV;sd5'LG
} uD?RL~M
//负责部分文件的抓取 \At~94
**FileSplitterFetch.java %rJDpB{
*/ QH4m7M@ni
package NetFox; #pgD-0_
.P7q)lj36h
' `c \Dq
import java.io.*; f3qR7%X?
import java.net.*; Er|&4-9
&bfM`h'
qo7<g*kf~
public class FileSplitterFetch extends Thread { Mpyza%zj
!/tV}.*
}No#_{
String sURL; //File URL R.2i%cU
long nStartPos; //File Snippet Start Position n0gjcDHQ
long nEndPos; //File Snippet End Position -?:8sv*X
int nThreadID; //Thread's ID 1Az&BZU[
boolean bDownOver = false; //Downing is over qTRP2rH,L&
boolean bStop = false; //Stop identical h.]^o*DJ
FileAccessI fileAccessI = null; //File Access interface SmD#hE[
\)wVO*9*0
v;5-1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q]GS#n
{ d}fd^x/
this.sURL = sURL; Sz<:WY/(x
this.nStartPos = nStart; Gey-8
this.nEndPos = nEnd; _<jU! R
nThreadID = id; ,mvFeo;@f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H)E,([
} g.Qn,l]X/p
6Iv};f"Y
a@&qdp
public void run() TCzlu#w
{ :Zkjtr.\
while(nStartPos < nEndPos && !bStop) UJDI[`2
{ @ U"Ib
:UH*Wft1
m<z?6VC
try{ ^GrSvl}v'
URL url = new URL(sURL); K$D+TI)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [h-NX
httpConnection.setRequestProperty("User-Agent","NetFox"); PPrvVGP
String sProperty = "bytes="+nStartPos+"-"; \'u+iB g
httpConnection.setRequestProperty("RANGE",sProperty); [.Md_
Utility.log(sProperty); bZgo}`o%
L\"wz scn
Fje /;p
InputStream input = httpConnection.getInputStream(); '_Pb\ jK
//logResponseHead(httpConnection); 4clCZ@\K^
f%t N2k
!Sy9v
byte[] b = new byte[1024]; 3hBYx@jTO
int nRead; RrrlfFms
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0Bp0ScE|FA
{ 7Dl^5q.|
nStartPos += fileAccessI.write(b,0,nRead); 'Kkp!eZQ~
//if(nThreadID == 1) ,wg(}y'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |0uqW1
} <_pLmYI
@XL49D12c
Gdx%#@/
Utility.log("Thread " + nThreadID + " is over!"); *L>usLh
bDownOver = true; z;@<J8I
//nPos = fileAccessI.write (b,0,nRead); s0vcGh#w
} ] s 2ec
catch(Exception e){e.printStackTrace ();} DwFvM0O6\
} )>b1%x} =
} 5N6R%2,A
jt323hHth
fM:bXR2Y'
//打印回应的头信息 {Fyw<0 [@
public void logResponseHead(HttpURLConnection con) s2QgR37s>
{ \8a014
for(int i=1;;i++) !=;Evf
{ ?wmu0rR
String header=con.getHeaderFieldKey(i); knHrMD;
if(header!=null) XAF]B,h=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %jq R^F:J
Utility.log(header+" : "+con.getHeaderField(header)); veh=^K%G |
else ]5`A8-Q@
break; uQW[2f
} i>G:*?a
} rk,64(
V_v+ic^
wod{C!
public void splitterStop() ~ W8 M3(^
{ gGA5xkA
bStop = true; 6rG7/
} U:MZN[Cc[
TQ/#
_uJ6Vy
} 5HL>2 e[
a04S&ezj
{/?{UbU
/* em^2\*sxpA
**FileAccess.java WRAv>s9
*//文件访问(定位，写) >[T6/#M
package NetFox; }c4F}Cy
import java.io.*; uF|[MWcy0#
+U<Ae^V
o0b\<}
public class FileAccessI implements Serializable{ @N>rOA
2e ~RM2PQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HQ4WunH2Y
RandomAccessFile oSavedFile; rvnm*e,
long nPos; {"|GV~
5y0LkuRR:
T_)+l)
public FileAccessI() throws IOException r`u9MJ*
{ P:XX8&#
this("",0); j.c4
} flBJO.2
#^i+'Z=L
cx)x="c
public FileAccessI(String sName,long nPos) throws IOException J[K>)@I/
{ {=R vFA
oSavedFile = new RandomAccessFile(sName,"rw"); #LwDs,J:
this.nPos = nPos; zn*i
oSavedFile.seek(nPos); l`JKQk
} g8"{smP/
*;t_VlaZ
n1+J{EPH
public synchronized int write(byte[] b,int nStart,int nLen) )5;|mV
{ _J3\e%ys
int n = -1; W`wT0kP?*]
try{ `wLmGv+V
oSavedFile.write(b,nStart,nLen); 2V+[:>F
n = nLen; g@>y`AFnr
} CFY4PuI"!
catch(IOException e) a[lx&CHgI
{ 0b,{4DOD
e.printStackTrace (); {`L,F
} 9B3}LVg\
*(*XNd||
.8|5;!`WB
return n; '+S!>Lqb
} O,I7M?dRf
hM(Hq4ed,
Qcs0w(
} etP`q:6^c
=&U7:u
N9f;X{
/* Ahg6>7+R.
**SiteInfoBean.java kRzqgVr%
*/ P'Jb')m
package NetFox; G&0JK ,Y
<*{(>
-f(<2i
public class SiteInfoBean { gBd~:ZUa
_NbhWv
dFpP_U
private String sSiteURL; //Site's URL L w/ZKXDU2
private String sFilePath; //Saved File's Path MS%h`Ypo
private String sFileName; //Saved File's Name 8ax3"G
private int nSplitter; //Count of Splited Downloading File 'DH_ihZ
nZS*"O#L
g[xn0rG
public SiteInfoBean() y {Mh ?H
{//nSplitter的缺省值为5 $4TawFf"nc
//default value of nSplitter is 5 2 BwpxV8
this("","","",5); v|>'m#Ln2
} jZ69sDhE
qjvIp-
B;L^!sLP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2) A$bx
{ H*dQTy,
sSiteURL= sURL; }KrZ6cG9#
sFilePath = sPath; kI$X~s$r
sFileName = sName; zB{be_Tw
this.nSplitter = nSpiltter; JvLa@E)
:cTwp K
Dr"F5Wbg
} AyZBH&}RZ
~48mCD
TqMy">>
public String getSSiteURL() 4dvuw{NZ
{ V6 ,59
return sSiteURL; )'?@raB!
} .J|"bs9
^`!EpO>k9
o"A%dC_
public void setSSiteURL(String value) nF|m*_DW
{ <0)@Ikhx
sSiteURL = value; uI[lrMQYa
} IqONDdep9
P!2[#TL0
,t>/_pI+=
public String getSFilePath() $yg}HS7HC
{ !7[Rhk7bW
return sFilePath; dCMWv~>
} ~4~>;e
kv3jbSKCT
axi%5:I
public void setSFilePath(String value) V?Zvu9b&
{ Eq/%k $6#1
sFilePath = value; G;pxB,4s5
} $X;fz)u
X<"W@
%7rWebd-
public String getSFileName() t%<d}QuHW
{ zc-.W2"Hu
return sFileName; J;BG/VI1
} e c`3Qw
G@QZmuj&KH
<)(STo
public void setSFileName(String value) xlaBOKa%
{ wXsA-H/`
sFileName = value; QFf lx
} dPRGL hWF
e[8p/hId
6*2z^P9FRj
public int getNSplitter() cB7=4:U
{ GP/3r[MH
return nSplitter; 7nHlDPps)
} "VcG3.
5lC"10
GVp2|\-L
public void setNSplitter(int nCount) 8V3SZ17
{ O<h`[1eUjS
nSplitter = nCount; b9([)8
} S\jN:o#b
} RyxIJJui
rm4j8~Ef
Y&5h_3K;<
/* 8a1G0HRQ
**Utility.java a8%/Xwr~
*/ '?k*wEu
package NetFox; B9^@]
Jj'~\j
*(x`cf;k
public class Utility { l+Tw#2s$
%zB `Sd<
w]\O3'0Js
public Utility() |L7 `7!Z
{ (byFr9z
'5eW"HGU]`
G?d28p',.
} z6R<*$4
*Ta*0Fr=9|
//线程睡眠 0BIH.ZV#
public static void sleep(int nSecond) kf$0}T`
{ @$;"nVZ4v
try{ M(S:&GOU
Thread.sleep(nSecond); ]#[R^t
} 6?ylSQ]1
catch(Exception e) OY6lt.t
{ d7tH~9GX8
e.printStackTrace (); cX553&
} b07 MTDFH7
} Y]nY.5irL
e2%Y8ZJG.
//日志 Zcv1%hI
public static void log(String sMsg) e?G] fz
{ ?+b )=Z
System.err.println(sMsg); g(MeCoCc
} 6P!M+PO
mg*[,_3q33
z.pP~he
public static void log(int sMsg) W04-D
{ bY;ah;<
System.err.println(sMsg); oO>mGl36H
} `hL16S
} 5>JrTO5
dHzo_VV
>t O(S
/* X'WbS
**TestMethod.java 'zZN]P
*/ q!9SANTx
package NetFox; Ry0n_J:7
zrG&p Z
_Y*]'?g`
public class TestMethod { Q5/".x^@
5B@+$D[0?3
4?,N;Q
public TestMethod() +=^10D
{ ///xx/weblogic60b2_win.exe a4L8MgF&$-
try{ $v+Q~\'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); N'!a{rF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~(%nnG6x
SiteFileFetch fileFetch = new SiteFileFetch(bean); S!k cC-7
fileFetch.start(); o6ec\v!l-
} d?*=<w!A
catch(Exception e){e.printStackTrace ();} \:\rkc9LI
sUcx;<|BC
-D0kp~AO4N
} *<zfe.
Sim\+SL{#
}^^X-_XT
public static void main(String[] args) 0S;H`w_S
{ INE8@}e
new TestMethod(); -Yy,L%E]F:
} ;+`t[ go
} {d(@o!;Fi
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