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)); MvFM,
} ]a$Wxvgq
for(int i=0;i<nEndPos.length-1;i++) >H0) ph
{ JQ)4}t
nEndPos = nStartPos[i+1]; ioC@n8_[G
} hWq.#e6
nEndPos[nEndPos.length-1] = nFileLength; O!+nF]V4f
} QP6z?j.
} May&@x/oMS
7$!`p,@we/
|Z`M*.d+
//启动子线程 O^.%C`*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *:=];1O
for(int i=0;i<nStartPos.length;i++) v!NB~"LQ
{ Q~fwWp-J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ! jbEm8bt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5/& 1Oxo
nStartPos,nEndPos,i); cPpu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nK+lE0
fileSplitterFetch.start(); I2TD.wuIW
} ![^EsgEB*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B0f_kH~p~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3g4e']t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Dn~Z SrJ
nEndPos = " + nFileLength); +yzcx3<
// fileSplitterFetch[nPos.length-1].start(); <=q*N;=T,
r%0pQEl
G1}~.%J
//等待子线程结束 JXpoCCe
//int count = 0; hVMYB_<~
//是否结束while循环 y L*LJ
boolean breakWhile = false; YecT 96%
h^}_YaT\
n vm^k
while(!bStop) B;VH`*+X
{ hlX>K
write_nPos(); $bk>kbl P
Utility.sleep(500); b.QpHrnhtK
breakWhile = true; _1sP.0 t
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for(int i=0;i<nStartPos.length;i++) brb[})}
{ :Df)"~/mO+
if(!fileSplitterFetch.bDownOver) "X`RQ6~]>
{ hQXxG/yFm
breakWhile = false; _*Pfp+if
break; &]w#z=5SXi
} D/Rv&>Jh
} .N5'.3
if(breakWhile) z;J
break; 9hy'DcSy,
&`\ep9
/mc*Hc8R8
//count++; s}wO7Df=+
//if(count>4) i<mevL
// siteStop(); `aIG;@Z
} _74UdD{^o
H.:9:I[n
{gsW(T>)
System.err.println("文件下载结束！"); Jz0K}^Dj[
} T8U[xu.>
catch(Exception e){e.printStackTrace ();} _ \l HI
} x@Y|v@}BE
.:8[wI_f
bhYU5I 9
//获得文件长度 v;Es^ YI
public long getFileSize() ! tGiTzzp
{ Hq?&Qo
int nFileLength = -1; Tv\HAK<N
try{ c}%es=@
URL url = new URL(siteInfoBean.getSSiteURL()); BhLZ7*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hfg O
httpConnection.setRequestProperty("User-Agent","NetFox"); %*jGim~s
PK+ x6]x
;|!MI'Af
int responseCode=httpConnection.getResponseCode(); RJx{eck%
if(responseCode>=400) S6GMUaR
{ .Vmtx
processErrorCode(responseCode); )!eEO [\d
return -2; //-2 represent access is error F$h'p4$T
} 4:U0f;Fs
`E W!-v)
\-OC|\{32
String sHeader; E5gl^Q?Z
@^!\d#/M
'irGvex
for(int i=1;;i++) +*C^:^jA
{ EjSD4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pDOM:lGya
//Utility.log(in.readLine()); A#35]V06
sHeader=httpConnection.getHeaderFieldKey(i); ,]7XMU3
if(sHeader!=null) i=L8=8B`
{ Hd0Xx}3&
if(sHeader.equals("Content-Length")) VhvTBo<cw
{ VjB*{,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]RD5Ex!K?
break; | ]# +v@
} RM,'o[%
} 2ce'fMV
else q5p e~
break; BFh$.+D
} EeB3 }
} r?^"65=
catch(IOException e){e.printStackTrace ();} 1Nj=B_T
catch(Exception e){e.printStackTrace ();} 6m+W#]^
&$#99\/
h$Tr sO
Utility.log(nFileLength); h<Wg3o
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return nFileLength; FJwt?3\u5
} V#J"c8n
oLS7`+b$
0`n 5x0R
//保存下载信息（文件指针位置） 7Z0/(V.-
private void write_nPos() C[8KlD
{ 9p`r7:
try{ <hv7s,i
output = new DataOutputStream(new FileOutputStream(tmpFile)); *1bzg/T<
output.writeInt(nStartPos.length); GNU;jSh5
for(int i=0;i<nStartPos.length;i++) \_VmY!I5\
{ ?3jdg]&
// output.writeLong(nPos); y|sma;D
output.writeLong(fileSplitterFetch.nStartPos); tjxvN 4l
output.writeLong(fileSplitterFetch.nEndPos); _z8;lt
} Pp*}R2
output.close(); k1fRj_@WPT
} 5v9uHxy
catch(IOException e){e.printStackTrace ();} Rla4L`X;
catch(Exception e){e.printStackTrace ();} WZ?!!
} 9":2"<'+
]l[2hy= cV
&fSTR-8ev#
//读取保存的下载信息（文件指针位置） |zpx)8Q
private void read_nPos() .pvxh|V
{ 2Va4i7"X\
try{ nwf7M#3d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !8$RBD %
int nCount = input.readInt(); O<GF>
nStartPos = new long[nCount]; frqJN
nEndPos = new long[nCount]; lIh[|]
for(int i=0;i<nStartPos.length;i++) ]k*1KP
{ 'ere!:GJD
nStartPos = input.readLong(); 7lU.Nit
nEndPos = input.readLong(); lLCdmxbT
} #C\4/g?=,
input.close(); 4*M@]J "
} 5@P-g
catch(IOException e){e.printStackTrace ();} 3hS6jS
catch(Exception e){e.printStackTrace ();} xo WT*f
} L'9N9CR{i
6[?}6gQ
(vQ+e
private void processErrorCode(int nErrorCode) <xn;bp[
{ }Bff,q
System.err.println("Error Code : " + nErrorCode); 8Rxc&`_X
} 3ATjsOL
VJ{pN~_1
Vk7=7%xW
//停止文件下载 )i!^]|$
public void siteStop() Kx6y" {me|
{ g-@h>$< 1
bStop = true; j|K.i/
for(int i=0;i<nStartPos.length;i++) dWR1cvB(wY
fileSplitterFetch.splitterStop(); @2e2^8X7f
C5n?0I9
ZnXejpj)D
} arh@`'Q
} {4rQ7J4Ux
//负责部分文件的抓取 \0AiCMX[
**FileSplitterFetch.java uD)-V;}P@;
*/ J_xG}d
package NetFox; 8A{6j
8D~x\!(p\
P*G+eqX
import java.io.*; X\sm[_I
import java.net.*; T[.[ g/`
(@&I_>2Q
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public class FileSplitterFetch extends Thread { 77Q}=80GU;
9L)L|4A.l
^7u#30,}3~
String sURL; //File URL K.DXJ UR
long nStartPos; //File Snippet Start Position 1D{#rA.X
long nEndPos; //File Snippet End Position {}\CL#~y
int nThreadID; //Thread's ID 9 5 H?{
boolean bDownOver = false; //Downing is over X?dfcS*!n
boolean bStop = false; //Stop identical H(qm>h$bU
FileAccessI fileAccessI = null; //File Access interface p`>d7S>"
')o0O9/;
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }uQ${]&D
{ DO^y;y>
this.sURL = sURL; JO1 ,TtA
this.nStartPos = nStart; h%1Y6$
this.nEndPos = nEnd; 5py R~+
nThreadID = id; 9<cOYY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q}P-$X+/ n
} 6?SFNDQ"C
Tf-CEHWD
oI@9}*
public void run() %v4 [{ =fE
{ l$XA5#k
while(nStartPos < nEndPos && !bStop) ,")F[%v
{ Z"tQpJg
Z.Pi0c+
_01Px a2.
try{ YIOR$
URL url = new URL(sURL); 3k{ @.V?]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M+aEma
httpConnection.setRequestProperty("User-Agent","NetFox"); }O*WV1
String sProperty = "bytes="+nStartPos+"-"; ;[Tyt[
httpConnection.setRequestProperty("RANGE",sProperty); se,Z#H
Utility.log(sProperty); &O tAAE
kaFnw(xa
v*r9j8
InputStream input = httpConnection.getInputStream(); `C'}e
//logResponseHead(httpConnection); <]Y[XI(kr
d8:C3R
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byte[] b = new byte[1024]; &=zU611,
int nRead; :]c=pH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Jz$>k$!UD
{ #F4X}
nStartPos += fileAccessI.write(b,0,nRead); ou6j*eSN
//if(nThreadID == 1) 8^X]z|[d2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j9xXKa5
} ,qy&|4Jz
%fpsc_
Dh`=ydI5
Utility.log("Thread " + nThreadID + " is over!"); EcW1;wH
bDownOver = true; Zh,]J `
//nPos = fileAccessI.write (b,0,nRead); Wz{%"o
} $L&BT 0
catch(Exception e){e.printStackTrace ();} W5/};K\.
} M(5D'4.
} yW>RRE;
qLRE}$P
*<k&#D"m
//打印回应的头信息 }ecsGw
public void logResponseHead(HttpURLConnection con) C BlXC7_Mi
{ xid:"y=_&
for(int i=1;;i++) A& =pw#
{ la702)N{
String header=con.getHeaderFieldKey(i); W5I=X]&
if(header!=null) Ky6+~>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B^m!t7/,
Utility.log(header+" : "+con.getHeaderField(header)); ' =}pxyg
else GLcd9|H
break; 97]4 :Zv
} l/F!Bq[*g
} G"C;A`6
qmID-t"
C9pnU,[
public void splitterStop() >KHp-|0pv
{ en%B>]QI
bStop = true; hiIyaWU
} Y"oDFo,
"ZqEP R)
`:gYXeR
} OA5f}+
8~qlLa>jc
%r P !
/* b-4dsz'ai
**FileAccess.java uAT/6@
*//文件访问(定位，写) ,\}k~ U99
package NetFox; 8? F 2jv
import java.io.*; GVZTDrC
N5ci};?
7P c(<Ui+
public class FileAccessI implements Serializable{ k|5k8CRX
LGXZx}4@;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S<9gyW
RandomAccessFile oSavedFile; "G@E6{/
long nPos; ]6q*)q:`
d96fjj~
p_;r%o=
public FileAccessI() throws IOException _trpXkQp
{ e]Puv)S>{8
this("",0); ] .`_, IO
} r;$r=Ufr
IBDVFA
03C .Xh=!
public FileAccessI(String sName,long nPos) throws IOException C,(j$Id
{ CxkMhd8qz
oSavedFile = new RandomAccessFile(sName,"rw"); ?o8a_9+
this.nPos = nPos; X4Lsvvz%@
oSavedFile.seek(nPos); Agz=8=S%
} my]P_mE
vyujC`61d
g(1"GKg3K
public synchronized int write(byte[] b,int nStart,int nLen) y1nP F&_
{ yZ?$8r
int n = -1; 2G H)iUmc
try{ "7:u0p!
oSavedFile.write(b,nStart,nLen); }&C dsCM>2
n = nLen; n00z8B1j(l
} 50COL66:7
catch(IOException e) TX&[;jsj
{ raSF3b/0
e.printStackTrace (); 75<el.'H
} } mgVC
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@kS|Jz$iY
return n; 4^0\dq
} `..EQBM
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ybC-f'0
} makaI0M
HhzkMJR8
w' .'Yu6
/* ShsJ_/C2
**SiteInfoBean.java gfV]^v
*/ Tq.MubaO
package NetFox; <1TlW ~q<
cn@03&dAl
ex{)mE4Cd
public class SiteInfoBean { 7?+5%7-
g9M')8a n
@T9m}+fR
private String sSiteURL; //Site's URL 9zmD6G!}t
private String sFilePath; //Saved File's Path 7ZL,p:f
private String sFileName; //Saved File's Name HI}pX{.\
private int nSplitter; //Count of Splited Downloading File y?[5jL|Ue
~GAlNIv]
9yO{JgKA
public SiteInfoBean() +oE7~64LL
{//nSplitter的缺省值为5 +ZY2a7uI
//default value of nSplitter is 5 ^qE<yn
this("","","",5); `i"$*4#<
} PWADbu{+
H(
AN|jFSQ'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ry3+/]
{ b #o}=m
sSiteURL= sURL; !#}v:~[A
sFilePath = sPath; )6O\WB|
sFileName = sName; yBpW#1=
this.nSplitter = nSpiltter; )pkhir06t
2+c>O%L
Jnh;;<
} QO1A976o
C:|q'"F
}qgqb
public String getSSiteURL() D#vn {^c8O
{ '6Pu[^x
return sSiteURL; clPZd
} YyQf
'sT}DX(7M
T! &[
public void setSSiteURL(String value) pfJVE
{ N"q+UCRC
sSiteURL = value; CSd9\V
} rw}5nv
bc0)'a\
rR),~ @]sL
public String getSFilePath() w@gl
{ 89:?.'
return sFilePath; u8{@PlS
} W<cW;mO
^C,/T2>
7gZVg@
public void setSFilePath(String value) dw{#||
{ L.I}-n
sFilePath = value; bJG!)3cx
} (dO'_s&M]/
Rsa\V6N>
aPY>fy^8D
public String getSFileName() $BR=IYby
{ 8;+Hou
return sFileName; web8QzLLB
} WacU@L $A
7(+OsE
Eezlx9b
public void setSFileName(String value) -Fok%iQ'5
{ K[Egwk7
sFileName = value; :#Ex3H7
} 2EqsfU* I
{'=Nb 5F
>zfZw"mEP
public int getNSplitter() **w*hd]
{ n_xa)
return nSplitter; {g:/BFLr#
} |Ad6~E+aL-
ELkOrV~a{:
p0y0T|H^
public void setNSplitter(int nCount) X,JWLS J
{ D"(3VIglq
nSplitter = nCount; s:m<(8WRw
} wCC~tuTpr
} !rsqr32]
n|4D#Bd1w
dx?njR
/* ^b `>/>
**Utility.java o,''f_tRQ|
*/ [ilv/V<
package NetFox; Z.Y;[Y
"e7$q&R |
'j,Li(@}
public class Utility { 0P%|)Ae
yK>0[6l
eM1;Nl
public Utility() Pguyf2/w
{ :9rhv{6Wp
8a$jO+UvN
M:1F@\<
} ,0<F3h
+O!M>
//线程睡眠 }Cq9{0by?a
public static void sleep(int nSecond) A2O_pbQti
{ d`],l\oC
try{ ^s(X VVA
Thread.sleep(nSecond); 8yo6v3JqC
} b\|p
catch(Exception e) hZ\W ?r
{ tU2toV
e.printStackTrace (); I.\f0I'.
} T~~$=vP9
} f$S QhK5`
^B6i6]Pd=9
//日志 `@.s!L(V
public static void log(String sMsg) Sp$x%p0
{ e'?doP
System.err.println(sMsg); \`%Y-!H+v
} =!P?/
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d_7Xlp@
public static void log(int sMsg) $E_vCB_
{ {7~ $$AR(
System.err.println(sMsg); {LJ6't 8y:
} 'St= izhd
} %d#)({N
pA,EUh|H
Z2j*%/
/* 3;l>x/amk
**TestMethod.java "%f5ltut3
*/ JO^ [@
package NetFox; T[[
6p6Tse]
|tJ%:`DGw
public class TestMethod { FR6I+@ oX~
AW;)_|xM
].f,3itg&
public TestMethod() ~S_IU">E
{ ///xx/weblogic60b2_win.exe XM@i|AK M0
try{ ?G>TaTiK#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~q|e];tA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 42LXL*-4
SiteFileFetch fileFetch = new SiteFileFetch(bean); g!Yh=kA'N
fileFetch.start(); C<@1H>S4_
} x)wt.T?eL
catch(Exception e){e.printStackTrace ();} |QTqa~~B
tKsM}+fq
-Fc#
} nK'8Mo
A-Pwi.$
jMWwu+w
public static void main(String[] args) K/d&c]
{ 2xdJ(\JWM
new TestMethod(); <H@!Xw;
} :h^UC~[h 3
} g+r{>x
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