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)); o<-%)#e
} 'xb|5_D
for(int i=0;i<nEndPos.length-1;i++) VO(Ck\i}
{ ?w# >Cs(
nEndPos = nStartPos[i+1]; sVkR7 ^KsG
} XrC{{K
nEndPos[nEndPos.length-1] = nFileLength; "<6pp4*I
} [RD ^@~x
} !gy'_Y
aEdFZ
<-Q0WP_^
//启动子线程 U^Z[6u
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0s0[U
for(int i=0;i<nStartPos.length;i++) Xkl^!,
{ 4PiNQ'*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XoSjYG(>,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Bx&`$lW
nStartPos,nEndPos,i); 0P/A
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O( he
fileSplitterFetch.start(); w0SzK-&
} YO!,m<b^u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), = k3O4gE7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); U`6QD}c"s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i*_KHK
nEndPos = " + nFileLength); p{Pa(Z]G
// fileSplitterFetch[nPos.length-1].start(); V@>?lv(\
NJUYeim;
dGIu0\J\$
//等待子线程结束 <zZAVGb4I
//int count = 0; /N%f78 Z
//是否结束while循环 uc Z(D|a
boolean breakWhile = false; RW(AjDM
d?N"NqaN
pw>AQ
while(!bStop) r %0
{ U_}$QW0'
write_nPos(); 42p6l
Utility.sleep(500); ?RpT_u
breakWhile = true; #C+Gk4"w
a #@Q.wL
--.j&w
for(int i=0;i<nStartPos.length;i++) +1d\ZZA|6&
{ V"$t>pAG
if(!fileSplitterFetch.bDownOver) |B`-chK
{ C2<y(GU[Bh
breakWhile = false; NYP3uGH]
break; .yTk/x?
} sF+0v p
} IJ4"X#Q/
if(breakWhile) %-A8`lf<
break; 2)j\Lg_M
6S6nE%.3
t C6c4j
//count++; HAO/r`7*
//if(count>4) "rX=G=
// siteStop(); Ka_UVKwMro
} G)# ,39P
;g*X.d
(X>y)V
System.err.println("文件下载结束！"); @0 -B&w
} j%p~.kW5
catch(Exception e){e.printStackTrace ();} ]`. d%Vx
} ~|uCZ.;o
cJA:vHyw
# Jdip)
//获得文件长度 rB4#}+Uq
public long getFileSize() .qK=lHxT
{ i[\[xfk
int nFileLength = -1; ,6M-xSDs
try{ ,j_{IL690
URL url = new URL(siteInfoBean.getSSiteURL()); M%B[>pONb7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l m
httpConnection.setRequestProperty("User-Agent","NetFox"); e-e{-pB6
NPoXz
,O[vxN1X*
int responseCode=httpConnection.getResponseCode(); awkVjyqX
if(responseCode>=400) izC>-
{ Y43#];
processErrorCode(responseCode); Ra{B8)Q
return -2; //-2 represent access is error COHJJONR
} dlT\VWMha(
chd${ j
}MIH{CMH
String sHeader; >}4]51s
)F~>
3Aj_,&X.@(
for(int i=1;;i++) c%Gz{':+
{ eGTK^p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8PEOi
//Utility.log(in.readLine()); g$ 2M|Q
sHeader=httpConnection.getHeaderFieldKey(i); .R gfP'M
if(sHeader!=null) Iyc')\W&
{ mefmoZ
if(sHeader.equals("Content-Length")) `PW=_f={
{ he+[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9Np0<e3p
break; 6VE >$`m
} ##s!-.T
} i3%~Gc63
else ~qqtFjlG^
break; J.nVEqLZ
} xlwsZm{V
} /7lkbL
catch(IOException e){e.printStackTrace ();} iit`'}+U
catch(Exception e){e.printStackTrace ();} =TP>Y"
[e}]K:
4O`h%`M
Utility.log(nFileLength); mCE})S
EmUxM_T/2
7q^/.:wlf
return nFileLength; ?+|tPjg$
} Bjo&
6)3eB{$;
b?Jm)
//保存下载信息（文件指针位置） DA wzXsx
private void write_nPos() }2r08,m
{ :5*<QJuI#A
try{ 6=g7|}
output = new DataOutputStream(new FileOutputStream(tmpFile)); u]2k%TUY
output.writeInt(nStartPos.length); [.Y=~)7FB
for(int i=0;i<nStartPos.length;i++) ho20>vw#
{ l3afuD:
// output.writeLong(nPos); xsTxc&0^
output.writeLong(fileSplitterFetch.nStartPos); AO]lXa
output.writeLong(fileSplitterFetch.nEndPos); E^YbyJ=1
} 2"MI8EK
output.close(); 8;'n.SC{
} UA9LI<Y
catch(IOException e){e.printStackTrace ();} K$]QzPXS
catch(Exception e){e.printStackTrace ();} zh.c_>jS
} IW1\vfe
QVH_B+ Q
b5|p#&YK~
//读取保存的下载信息（文件指针位置） amSyGQ2
private void read_nPos() )aC+qhh
{ JdRs=#X
try{ >'jM8=o*Ax
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); CS{9|FNz
int nCount = input.readInt(); E+)Go-rS(
nStartPos = new long[nCount]; sWC"^ So
nEndPos = new long[nCount]; E\zhxiI
for(int i=0;i<nStartPos.length;i++) L[bGO|O
{ BJE <~"
nStartPos = input.readLong(); bT8UmR98
nEndPos = input.readLong(); =_H39)|T
} ul%bo%&~
input.close(); l xfdJNb
} kwL)&@
catch(IOException e){e.printStackTrace ();} Ih7Eq/iu
catch(Exception e){e.printStackTrace ();} d0=nAZZ
} a82mC r
G8s`<:9*
0/6&2
private void processErrorCode(int nErrorCode) ]]Z,Qu#<-
{ [o.zar82
System.err.println("Error Code : " + nErrorCode); C|I 1 m
} AWDjj\Q4
16>uD;G
vf=
//停止文件下载 XZInu5(
public void siteStop() 2T5xSpC
{ xAjQW=
bStop = true; gAj)3T@
for(int i=0;i<nStartPos.length;i++) `Z/IW
fileSplitterFetch.splitterStop(); 9CNHjs+-}s
"(NHA+s/
@5y(>>C}8%
} vxeT[/6i
} `Ek!;u>
//负责部分文件的抓取 KVR}Tp/R
**FileSplitterFetch.java H5s85"U#
*/ x/7G0K2\}
package NetFox; 752wK|o0|;
vdm?d/0(^
/pU6trIM
import java.io.*; (M+<^3c
import java.net.*; 95Qz1*TR
kpH;D=;
Q 8rtZ
public class FileSplitterFetch extends Thread { R`Lm"5w
p*0Ve21i,
#CPPdU$
String sURL; //File URL E(tBN]W.
long nStartPos; //File Snippet Start Position )sf~l6
long nEndPos; //File Snippet End Position {h"\JI!
int nThreadID; //Thread's ID @__;RVQ
boolean bDownOver = false; //Downing is over B@]7eVo
boolean bStop = false; //Stop identical `I8^QcP
FileAccessI fileAccessI = null; //File Access interface ymZ/(:3_
,}tdfkZFYl
o"FiM5L^.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Xa@wN/"F
{ SR& mHI-f0
this.sURL = sURL; skz]@{38
this.nStartPos = nStart; D-GU"^-9
this.nEndPos = nEnd; `#rfp 9w
nThreadID = id; /6?plt&CA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $3'+V_CZ3
} L"iyjL<M
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ak) -OL1
public void run() @MB _gt)7?
{ _vdxxhJ=P3
while(nStartPos < nEndPos && !bStop) 4Aew )
{ $ rYS
&=Zg0Q
CFm1c1%Hg
try{ HY4E
URL url = new URL(sURL); Pp_3 nyQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nb_^3K]r
httpConnection.setRequestProperty("User-Agent","NetFox"); 5j,qAay9
String sProperty = "bytes="+nStartPos+"-"; CS\tCw\Y
httpConnection.setRequestProperty("RANGE",sProperty); C94@YWs
Utility.log(sProperty); nV3 7` I
Z9m;@<%
LU,"i^T
InputStream input = httpConnection.getInputStream(); /:` i%E
//logResponseHead(httpConnection); aNC,ccm
0l:pWc
ph?0I:eU
byte[] b = new byte[1024]; <cv1$ x ~P
int nRead; lK,=`xe
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %hbLT{w
{ ,/6:bc:W
nStartPos += fileAccessI.write(b,0,nRead); +MZO%4
//if(nThreadID == 1) X8 )>}#:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cIvYfgIo9
} e=l5j"gq
Gd-.E7CH!
RLz`aBT
Utility.log("Thread " + nThreadID + " is over!"); ^D;D8A.
bDownOver = true; 6b]d|
//nPos = fileAccessI.write (b,0,nRead); PdH`_/6
} "&#WMi
catch(Exception e){e.printStackTrace ();} d^5SeCs6
} '[ g)v
} 8I\eromG
As~p1%nok
P5}[*k%DQw
//打印回应的头信息 < }wAP_y
public void logResponseHead(HttpURLConnection con) n [Xzo}
{ Ik5jwfz
for(int i=1;;i++) e( o/we{
{ R96o8#7Uv
String header=con.getHeaderFieldKey(i); IR dz(~CP
if(header!=null) z8(R.TB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y)/$ge_U
Utility.log(header+" : "+con.getHeaderField(header)); };m7FO
else !""!sFx)R
break; zt)PZff/YQ
} As'M39*V
} ^T&u!{82j
Z!-<rajl
gZ"{{#:}
public void splitterStop() >3`ctbe
{ nqxq@.L2
bStop = true; BgWz<k}5M
} sRyw\v-=P
sIRrEea
$',GkK{NX
} Xc2B2c
R;E"Qdt
g<iwxF
/* 03QEXm~|Q
**FileAccess.java #1't"R+3M
*//文件访问(定位，写) cCh5Jl@Z
package NetFox; j t`p<gI
import java.io.*; 7#9'2dI
380->
6Sb'Otw.
public class FileAccessI implements Serializable{ Ef`5fgp? S
sK 1m9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [B~zoB(
RandomAccessFile oSavedFile; L.0} UXd
long nPos; 32 1={\X
2Ph7qEBQ22
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public FileAccessI() throws IOException KBr5bcm4u
{ Wt+y-ES
this("",0); cUZ!;*
} 2rj/wakd
R)d99j^"
_.OMjUBZT
public FileAccessI(String sName,long nPos) throws IOException ~f=6?5.wa
{ dx13vZ3[U
oSavedFile = new RandomAccessFile(sName,"rw"); XW~ BEa
this.nPos = nPos; tT* W5
oSavedFile.seek(nPos); YZBzv2'\x
} qsft*&
^EUOmVN
LN.Bd,
public synchronized int write(byte[] b,int nStart,int nLen) *K}z@a_
{ :nKsZ1bX
int n = -1; \L9?69B~
try{ V8nz-DL{
oSavedFile.write(b,nStart,nLen); g^z5fFLg/8
n = nLen; Tw}?(\ya
} D0#T-B\#
catch(IOException e) @7Rt4}g
{ FI`nRFq)C
e.printStackTrace (); (pE\nuA\
} 7TV>6i+7
v#:+n+y\z
B;z>Dd,Y_x
return n; -Ap2NpZ"t
} )l!J$X+R
} T/}0W]0
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} )]/i
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[GR|$/(z=
/* FtFv<UV
**SiteInfoBean.java C`NBHRa>
*/ s`Yu"s 8}4
package NetFox; iJ`%yg,
qXrt0s[
I 9{40_
public class SiteInfoBean { A;fB6
-YzQ2#K
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private String sSiteURL; //Site's URL vLv|SqD
private String sFilePath; //Saved File's Path yN9$gfJC^
private String sFileName; //Saved File's Name <OR.q
private int nSplitter; //Count of Splited Downloading File `W"a!,s2
K2x6R
J.bFv/R
public SiteInfoBean() 0<]$v"`I
{//nSplitter的缺省值为5 7m|`tjQ1
//default value of nSplitter is 5 F@=e2e 4
this("","","",5); }[>RxHd
} io9y;S"+
VM-qVd-
_=|nOj39
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s6uF5]M;2
{ V17>j0Ev$W
sSiteURL= sURL; 7oZ@<QP'
sFilePath = sPath; saGRP}7?
sFileName = sName; qs6Nb'JvQR
this.nSplitter = nSpiltter; )myf)"l5
~/j$TT"
d98))G~W
} r/mA2
a&$Zpf!!
=@xN(](
public String getSSiteURL() h^o+E2<]
{ &K5C=]4
return sSiteURL; Y%78>-2L
} y2z{rd
qpb/g6g
a4A`cUt
public void setSSiteURL(String value) ]$m#1Kj
{ " Sc5qG
sSiteURL = value; Y3vX)D}
} rQ`\JE&`
DNm(:%)0
u iBl#J Q
public String getSFilePath() |7svA<<[
{ BCBEX&0hk{
return sFilePath; X|X4L(i
} t2=a(N-/,
p//T7rs
a$C2}
public void setSFilePath(String value) %==G+S{
{ N7e`6d!
sFilePath = value; <\ y!3;
} k0H?9Z4k5
44\!PYf7
6N9 c<JC
public String getSFileName() b->eg 8|
{ 1pd 9s8CA
return sFileName; lemVP'cn
} pTcbq
h7bPAW=(
EfFz7j&X
public void setSFileName(String value) Yuwc$Qp)
{ ~c9>Nr9|`
sFileName = value; j(0Ilx|7v
} cwk+#ur
uzHT.iBn
YSqv86
public int getNSplitter() *,"jF!C&[
{ By2s']bw
return nSplitter; Ee{`Y0
} i~9?:plS
}P#Vsqe V
K@q&HV"'.
public void setNSplitter(int nCount) qOW#Q:T
{ t:\l&R&
nSplitter = nCount; _~tm7o+js
} FXS^^p P
} i][f#e4
t2"@Ps&1|
g.9L)L
/* As0 B\
**Utility.java d'ZS;l
*/ q<n[.u1@
package NetFox; F;#zN
haCKv
92ZWU2"
public class Utility { Ffnk1/Zy
CK2B
y>$1UwQ
public Utility() XcOA)'Py
{ '0Lov]L
nt=x]wEC
Vr 8:nP:
} a>U6Ag<
,"B?_d6
//线程睡眠 RL6Vkd?
public static void sleep(int nSecond) 4AQ[igTDP
{ y`4{!CEyLW
try{ ;>DHD*3X
Thread.sleep(nSecond); }<=3W5+
} ZP-dW|<[x
catch(Exception e) !K[/L< Kv
{ |8bE9qt.P
e.printStackTrace (); lK*jhW?3:
} fmFzW*,E
} <|a=hHPi:
\^9pW 2v
//日志 EJ`Q8uz
public static void log(String sMsg) :/6()_>bO
{ s _~IZ%+<.
System.err.println(sMsg); A#(`9
} ur6e&bTp
#,&8&
]BfS270
public static void log(int sMsg) -^Xy%
{ UgC)7 K1
System.err.println(sMsg); oCVku:.
} OqBC/p B
} ZZ("-#?
#F!Kxks
fz3lR2~G
/* {(}yG_Q]!
**TestMethod.java *hF^fxLbl
*/ Ad/($v5+
package NetFox; xI?0N<'.*q
eRs&iK2y
ox[ .)v
public class TestMethod { (0OM"`j
r2nBWA3
}#6xFTH
public TestMethod() Q4?EZ_O
{ ///xx/weblogic60b2_win.exe 9OyNi
try{ ? Vp%=E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0 _A23.Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hU"F;4p
SiteFileFetch fileFetch = new SiteFileFetch(bean); o\4CoeG
fileFetch.start(); BxdX WO
} ?ok)>P
catch(Exception e){e.printStackTrace ();} w>[T&0-N
> H BJk:
s]Gd-j
} .*Vkua
j0x5@1`6G
ZVL gK}s
public static void main(String[] args) >aG=T{
{ +AoP{x$Ia
new TestMethod(); U;U08/y
} g*y/j]
} O9^T3~x[V
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