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)); +}Pa/8ybJ
} wkGF&U
for(int i=0;i<nEndPos.length-1;i++) n_<]9
{ Fk43sqU6~
nEndPos = nStartPos[i+1]; P,wJ@8lv
} ?cvv!2B]T
nEndPos[nEndPos.length-1] = nFileLength; 9maw+c!~
} `dK\VK^
} jDoWSYu4tY
D-.>Dw:
|]Xw1.S.L
//启动子线程 N%a[Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %YXC-E3@O
for(int i=0;i<nStartPos.length;i++) ?r+tU
{ {e^llfj$#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]V_9[=%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]~P?
nStartPos,nEndPos,i); =h)H`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s$en5)
fileSplitterFetch.start(); X%dOkHarB
} ziOmmL(r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yZ{YIy~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M3V[p9>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F8/@/B
nEndPos = " + nFileLength); X DX_c@U
// fileSplitterFetch[nPos.length-1].start(); `uU@(
(F)zj<{f
mf3G$=[
//等待子线程结束 )mEF_ &
//int count = 0; ubLLhf
//是否结束while循环 =mZw71,
boolean breakWhile = false; >i~c>+R
h^s}8y
V= _8G3
while(!bStop) 2{&" 3dq
{ Gc'HF"w
write_nPos(); 7XY C.g
Utility.sleep(500); FKQnz/
breakWhile = true; IE6/ E
6f?DW-)jp/
8,R]R=
for(int i=0;i<nStartPos.length;i++) OjCT%6hy;
{ xv2;h4{<
if(!fileSplitterFetch.bDownOver) yZ 9 *oDs
{ J kA~Ol
breakWhile = false; ]-6 G'i?
break; gk&?h7P"<
} V>nY?
} %:y-"m1\u$
if(breakWhile) LP\ Qwj{
break; [bcqaT
Rl(b tr1w
LDNpEX~
//count++; }$o%^"[
//if(count>4) M *}$$Fe|
// siteStop(); r*g _
} Ne[O9D 7
giTlXz3D9
%ry>p(-pC(
System.err.println("文件下载结束！"); bcZuV5F&
} Y7p#K<y]9
catch(Exception e){e.printStackTrace ();} r1\.Jz
} n`hSn41A
l9Vim9R5T
X bg7mj9c
//获得文件长度 ug{F?LW[
public long getFileSize() jPd<h{js
{ MG<~{Y84}
int nFileLength = -1; *iR`mZb
try{ L{=z}QO
URL url = new URL(siteInfoBean.getSSiteURL()); K{iYp4pU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .UDZW*
httpConnection.setRequestProperty("User-Agent","NetFox"); MVCCh+,GI
vxgm0ZOMN
2H /a&uo@n
int responseCode=httpConnection.getResponseCode(); GZ e )QH
if(responseCode>=400) I@\{6hw
{ 3o?Lz7L
processErrorCode(responseCode); $D89|sy
return -2; //-2 represent access is error LY>JE6zTt
} p$V+IJtO(
<Du*Re6g
#Z.JOwi
String sHeader; l>]M^=,&7
-lp_~)j^
f]lDJ?+ M
for(int i=1;;i++) zknD(%a
{ c1/x,1LnMf
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?( '%QfT
//Utility.log(in.readLine()); %{{#Q]]&
sHeader=httpConnection.getHeaderFieldKey(i); UOu&sg*o2B
if(sHeader!=null) aJF`rLm
{ `MD/CFl4
if(sHeader.equals("Content-Length")) Bb o*
{ N3?d?+A$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); . FruI#99
break; 0jmlsC>
} IF}r%%'Y$
} mvw:E_
else WIghP5%W
break; 8ah]D
} pGFocw
} 3:gk:j#
catch(IOException e){e.printStackTrace ();} )t4C*+9<U
catch(Exception e){e.printStackTrace ();} lO *Hv9#
Yem\`; *
?,NAihN]
Utility.log(nFileLength); .DQ]q o]OG
\ C^D2Z6
c>g%oE
return nFileLength; I%Awj(9BS
} tu'MYY
F)@<ZE
e#('`vGB
//保存下载信息（文件指针位置） ~I<y^]2{
private void write_nPos() RBXoU'.
{ 2KEww3.{
try{ .phQ7":`
output = new DataOutputStream(new FileOutputStream(tmpFile)); DXt^Ym5Cv
output.writeInt(nStartPos.length); -}J8|gwwp
for(int i=0;i<nStartPos.length;i++) Oc.>$
{ ,b4&$W].
// output.writeLong(nPos); S&*pR3,u
output.writeLong(fileSplitterFetch.nStartPos); .tNB07=7
output.writeLong(fileSplitterFetch.nEndPos); m%&B4E#3T
} )sHPIxHI
output.close(); 'UxA8i(
} 5IK@<#wE
catch(IOException e){e.printStackTrace ();} 2"O Y]d
catch(Exception e){e.printStackTrace ();} #"_MY-
} Ei-OuDM;)
gISs+g
i'<1xd(`
//读取保存的下载信息（文件指针位置） BpT&vbY
private void read_nPos() W=?87PkJu
{ F!{SeH:
try{ UZra'+Wb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &UR/Txnu
int nCount = input.readInt(); fsd>4t:"\
nStartPos = new long[nCount]; }b`*%141
nEndPos = new long[nCount]; gwJu&HA/
for(int i=0;i<nStartPos.length;i++) #4M0%rN
{ Q_.Fw\l$`
nStartPos = input.readLong(); SfUUo9R(sm
nEndPos = input.readLong(); "=.|QKC1`
} {9 O`/|
input.close(); qgNK!(kWpr
} x(=x;X$[^
catch(IOException e){e.printStackTrace ();} v=VmiBq[
catch(Exception e){e.printStackTrace ();} U@nwSfp:G
} :8rCCop Uv
*\", qMp
5eA]7$ic
private void processErrorCode(int nErrorCode) dL(|Y{4
{ S!_?# ^t
System.err.println("Error Code : " + nErrorCode); CN(4;-so)
} sdQv:nd'R
Oy$BR <\
Z"X*FzFo
//停止文件下载 J-F_XKqH
public void siteStop() 0h4}RmS
{ ^ {f^WL=
bStop = true; NCt sx /C
for(int i=0;i<nStartPos.length;i++) 2]=I'U<E!
fileSplitterFetch.splitterStop(); 79H+~1Az
(}1f]$V
{LHe 6#
} EG4bFmcs
} /}_c7+//
//负责部分文件的抓取 3ohcHQ/a
**FileSplitterFetch.java F*VMS
*/ shIi,!bZ
package NetFox; N'P,QiR,z<
-oBas4J
9X9zIh]JV
import java.io.*; u7Y< ~
import java.net.*; 4!vUksM
@;D}=$x
NqE7[wH
public class FileSplitterFetch extends Thread { A5<Z&Y[
%C0O?q
w*%$ lhp!
String sURL; //File URL O)%kl
long nStartPos; //File Snippet Start Position (!5}" fj
long nEndPos; //File Snippet End Position oV>AFs6
int nThreadID; //Thread's ID %yM' Z[-
boolean bDownOver = false; //Downing is over #aY<J:Nx
boolean bStop = false; //Stop identical #r)1<}_e#
FileAccessI fileAccessI = null; //File Access interface _ZM9 "<M-X
Kx185Q'W
m_02"'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException [2 w<F[
{ ;AGs1j
this.sURL = sURL; *R\/#Y|
this.nStartPos = nStart; roj04|
this.nEndPos = nEnd; 6(^Upk=59
nThreadID = id; p$1Rgm\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +<WRB\W
} :Mu8W_
NQiecxvt=
]VG84bFm
public void run() 3^R][;
{ '=,rb
while(nStartPos < nEndPos && !bStop) /z)3gsF
{ ?WQd
7|M$W(P
~? FrI
try{ g[wP!y%V
URL url = new URL(sURL); {I9N6BQ&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :O'C:n<g
httpConnection.setRequestProperty("User-Agent","NetFox"); SeNF!k% Y
String sProperty = "bytes="+nStartPos+"-"; @6YBK+"
httpConnection.setRequestProperty("RANGE",sProperty); ?F87C[o
Utility.log(sProperty); #S53u?JV8
/x:(SR2,
]Z$TzT&@%
InputStream input = httpConnection.getInputStream(); MX`Wg
//logResponseHead(httpConnection); C*EhexK,}
'/u:,ar
k99gjL`
byte[] b = new byte[1024]; IglJEH[+
int nRead; tFvgvx\:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !M]%8NTt2
{ Ku0H?qft(
nStartPos += fileAccessI.write(b,0,nRead); Q@e*$<3
//if(nThreadID == 1) E)80S.V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B3cf] S%
} }c35FM,
Sqdc1zC
YHO;IQ5
Utility.log("Thread " + nThreadID + " is over!"); S_|9j{w)
bDownOver = true; (zS2Ndp
//nPos = fileAccessI.write (b,0,nRead); Y/^[qD
} % UW=:
catch(Exception e){e.printStackTrace ();} oN[Fza>
} -}_cO|kk
} qab) 1ft
Q\o$**+{
JNxW6 cK
//打印回应的头信息 g{A3W) [ b
public void logResponseHead(HttpURLConnection con) ` $.X[\*U
{ Avs7(-L+s
for(int i=1;;i++) d s|8lz,
{ d7W%zg\T
String header=con.getHeaderFieldKey(i); 9Qt)m fqM
if(header!=null) -GDV[Bg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /'&.aGW4%
Utility.log(header+" : "+con.getHeaderField(header)); `d}W;&c
else I%;Rn:zl
break; 2!{_/@I\Y
} 69[V <1
} Exep+x-
TnN^2:cU
wUru1_zjO
public void splitterStop() pG,<_N@P
{ ~a'nHy1
bStop = true; `"xk,fVYd
} dr|| !{\
vQ:x%=]
4r_!>['`"
} y!7B,
Hi]vHG(
y0scL7/
/* :0M'=~[
**FileAccess.java _, \y2&KT
*//文件访问(定位，写) -]Q3/"Q
package NetFox; **T:eI+
import java.io.*; Jq#[uX
dzgs%qtK
R&NpdW N
public class FileAccessI implements Serializable{ t*o7,
^D9 /
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l*QIoRYFW
RandomAccessFile oSavedFile; pZu?V"R
long nPos; d>^~9X
$|Q".dD
qzz[y#q(
public FileAccessI() throws IOException |2qR^Hd&5
{ w>v5oy8s-
this("",0); !IO&&\5
} $TR=3[j
M_tj7Q3 W
53bM+
public FileAccessI(String sName,long nPos) throws IOException {VBR/M(q
{ lxm*;?j`W
oSavedFile = new RandomAccessFile(sName,"rw"); gB>(xY>LrA
this.nPos = nPos; .H Fc9^.*
oSavedFile.seek(nPos); F\;2i:(
} k&OC&
0xN!DvCg>.
IS-}:~Pi
public synchronized int write(byte[] b,int nStart,int nLen) \.5F](:
{ *:?QB8YJ
int n = -1; :b"=KQ
try{ +IvNyj|
oSavedFile.write(b,nStart,nLen); <BZ_ (H
n = nLen; =ntftSH
} ,cLH*@
catch(IOException e) Og+)J9#
{ B i'd5B5
e.printStackTrace (); %z30=?VL
} `q^(SM
WmNA5;<Q
{JXf*IJ
return n; B<Ol+)@,}
} 3]N q@t
)W#T2Z>N1
L,#^&9bHa#
} (/-lV&eR
l/[pEUYU
)Q~C4C-j
/* KVg[#~3
**SiteInfoBean.java Cb4_ ?OR0
*/ {y1q7Z.M
package NetFox; V- /YNRV
aFyh,
04~}IbeJ
public class SiteInfoBean { eap8*ONl
Cpe#[mE
Zd$JW=KR]l
private String sSiteURL; //Site's URL t-x[:i
private String sFilePath; //Saved File's Path dIvy!d2l
private String sFileName; //Saved File's Name c+~LpSQ
private int nSplitter; //Count of Splited Downloading File &Bm&i.r
"w9`cz9a~J
x7HA722w
public SiteInfoBean() 9j0o&Xn
{//nSplitter的缺省值为5 se#@)LtZ
//default value of nSplitter is 5 {tc57jsr
this("","","",5); ?.Q3 pUT
} drI\iae{^
g>yry}>04%
zSKKr?{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6Kp}_^|z
{ yyjw?#\8
sSiteURL= sURL; $~G@
sFilePath = sPath; O5M2`6|As
sFileName = sName; x}|+sS,g
this.nSplitter = nSpiltter; Wxn#Rk#>
"W5rx8a
rI>LjHP
} >azEed<B
gHZqA_*T8U
<aXoB*Y
public String getSSiteURL() 2T?TM! \Q
{ `BjR.xMv
return sSiteURL; WL1\y|
} 8SZK:VE@
m]P/if7
<h@]Ri
public void setSSiteURL(String value) n]iyFZ`9
{ uXpv*i{R
sSiteURL = value; #1gO?N(<=
} #)]E8=}
WqQU@sA
E30Z`$cz:
public String getSFilePath() +>}o;`hPe
{ {m[Wyb(
return sFilePath; j^nu|
} =) }nLS3t
TF2KZL#A|
F&az":
public void setSFilePath(String value) 'Wp@b678
{ ?Oc -aa
sFilePath = value; T?rH ,$:
} q:]Q% IC^
``4?a7!!
b 4OnZ;FI
public String getSFileName() d.AC%&W
{ Z0\Iyc G
return sFileName; hZU1O
} M*`hDdS
x.UaQ |F
ShGp^xVj
public void setSFileName(String value) H+x#gK2l
{ F#|Z# Mu
sFileName = value; b#='^W3
} !8/gL
MGaiTN^_<
gDC2 >nV
public int getNSplitter() Hi8Y6|y$D
{ g~)3WfC$[
return nSplitter; B}\BeFt'
} m\-PU z&C
FYl3c
x{hn2]6+eB
public void setNSplitter(int nCount) wOg,SMiq
{ JA6";fl;
nSplitter = nCount; S>t>6&A
} #jP/k.
} <\aU"_D
A3q*$.[
l$M +.GB<
/* 1<,/ -H
**Utility.java A*i_|]Q
*/ jQ$BPEG&X
package NetFox; -J?~U2
vgThK9{m;
:Q-F9o J
public class Utility { ri+U0[e3
sfI N)jh
%?=)!;[
public Utility() m UgRm]
{ ~gddcTp
KlO(o#&N
( 3;`bvYH"
} I%xn,u
KyLp?!|>
//线程睡眠 \ja `c)x
public static void sleep(int nSecond) t)r1"oA
{ #{,h@g}W
try{ jdlG#j-\
Thread.sleep(nSecond); jVYH;B%%z
} Kv?;cu!
catch(Exception e) H.~bD[gA
{ HcO5?{2
e.printStackTrace (); n(R_#,Hs
} 8*Zvr&B,G
} [`nY2[A$
XKSX#cia
//日志 Le&;g4%
public static void log(String sMsg) ^'W%X
{ d?7BxYaa
System.err.println(sMsg); ) b:4uK A
} 5~l2!PY
7\%$>< K
CQ>]jQ,2
public static void log(int sMsg) 7I3:u+
{ 5i9Ub|!P
System.err.println(sMsg); 2AK}D%jfc
} 0N5bPb
} SRWg[H
usH%dzKK
^Y 7U1I
/* bQ.nFa']
**TestMethod.java V6*?$o
*/ FL&dv
package NetFox; !*bdG(pK
3EOyq^I%
@C_ =*
public class TestMethod { !.eAOuq
$W,zO|-
3:AU:
public TestMethod() ,`)OEI|1d
{ ///xx/weblogic60b2_win.exe PbN3;c3
try{ hS_.l}0yf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8A4TAT4,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {(0Id!
SiteFileFetch fileFetch = new SiteFileFetch(bean); G?ZC9w]rA
fileFetch.start(); !Bj^i cR
} t= *Jg/$
catch(Exception e){e.printStackTrace ();} A^L?_\e6
Tzf$*Uje3
yxY h?ka
} KBj@V6Q
r0uJ$/!
8<c'x]~
public static void main(String[] args) kQ[Jo%YT?E
{ 5p{25N_t
new TestMethod(); WG\Q5k4Ba
} -R8/`M8GbD
} t%HI1eO7h
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