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)); ii0{$}eoh
} Xx.4K>j+j
for(int i=0;i<nEndPos.length-1;i++) 3O{*~D&n
{ c?@WNv
nEndPos = nStartPos[i+1]; +rT%C&ze
} RM^3Snd=V
nEndPos[nEndPos.length-1] = nFileLength; H{XbKLU
} E0F8FR'
} P''5A6#5
2oY.MQD7iW
4J#F;#iA
//启动子线程 PwF 1Pr`r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <d2?A}<
for(int i=0;i<nStartPos.length;i++) (~C_zG
{ c!,&]*h"k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '.Ww*N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aQ@9(j> F
nStartPos,nEndPos,i); l/=2P_8+Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x2-i1#j`;
fileSplitterFetch.start(); WCa>~dF>
} /g|H?F0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }>)e~\Tdzb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j=raS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o+9b%I^1V
nEndPos = " + nFileLength); %[1\d)
// fileSplitterFetch[nPos.length-1].start(); Y}db<Cz X
5|T[:m
C!]R0L*
//等待子线程结束 KyQO>g{R
//int count = 0; 1_AB;^
//是否结束while循环 Ino$N|G[
boolean breakWhile = false; [73 \jT
i=m5M]Ef
,r$k79TI
while(!bStop) M%*D}s-QE
{ HR.^ y$IE
write_nPos(); X@ zw;Se
Utility.sleep(500); yH\3*#+
breakWhile = true; 'VgdQp$L$
M @|n"(P
IJWUNKqo=
for(int i=0;i<nStartPos.length;i++) H2f!c{t$p
{ =[N=mC
if(!fileSplitterFetch.bDownOver) 2kP0//
{ y.xt7 F1
breakWhile = false; }6Ut7J]a|
break; 1z.
} O9+Dd%_KS#
} h8nJt>h
if(breakWhile) -?jI{].:8
break; A*1-2
.G ^-.p
#hp7@ Tu
//count++; {}sF?wZf
//if(count>4) gD13(G98
// siteStop(); uX.^zg]}%
} 2)iwAu
+ESEAi91
iy<|<*s2D
System.err.println("文件下载结束！"); nC:>1kt
} UN FQ`L
catch(Exception e){e.printStackTrace ();} Q9i&]V[`
} S]}hh,A
w^AY= Fc
X.q,
//获得文件长度 TFfV?rBI
public long getFileSize() &dH[lB
{ 5Kadh2nz
int nFileLength = -1; Aof)WKo
try{ R6(sWN-
URL url = new URL(siteInfoBean.getSSiteURL()); nrhzNW>]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |S0w>VH>
httpConnection.setRequestProperty("User-Agent","NetFox"); QLs9W&PG
@r.w+E=
n7|8`?R^
int responseCode=httpConnection.getResponseCode(); Az+k8=?
if(responseCode>=400) [~aRA'qJ{V
{ r<%ua6@
processErrorCode(responseCode); H^VNw1.
return -2; //-2 represent access is error lQ8h-Tz
} h_( #U)z_3
/?ZO-]q
BR*'SF\T
String sHeader; K@f@vyw]
d@0p<at>~
L:.z FW,
for(int i=1;;i++) Bf21u9
{ xJ$/#UdP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ; ,vGw<|o
//Utility.log(in.readLine()); 7J[DD5
sHeader=httpConnection.getHeaderFieldKey(i); .83{NF
if(sHeader!=null) Cr7T=&L
{ wV604eO(
if(sHeader.equals("Content-Length")) N4[`pXM6
{ gNWTzz<[f>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [%0{7pz}
break; rN3qTp
} g3Xab
} l.@v@T(/
else hfJeVT-/v
break; +HXR ))X
} 8opd0'SNaB
} @TQzF-%#7
catch(IOException e){e.printStackTrace ();} o]@Mg5(8Q
catch(Exception e){e.printStackTrace ();} 5LX%S.CW
!y$:}W?_
r6b;v2!8
Utility.log(nFileLength); cXd?48O
FxFRrRRH@
up@I,9C/
return nFileLength; j;MQ_?"iN
} L0Ycf|[s,
iwXMe(k
*el~sor;S
//保存下载信息（文件指针位置） 1_jd1UT
private void write_nPos() NimW=X;c
{ N^TE ;BM
try{ @Y&UP
output = new DataOutputStream(new FileOutputStream(tmpFile)); XkEJ_;:
output.writeInt(nStartPos.length); m|M'vzu1
for(int i=0;i<nStartPos.length;i++) H{BP7!t[V
{ Wik8V0(
// output.writeLong(nPos); W>o>Y$H
output.writeLong(fileSplitterFetch.nStartPos); W{is2s
output.writeLong(fileSplitterFetch.nEndPos); O a%ZlEUF
} 8Y,imj\(v
output.close(); xU!eT'Y
} \C}_l+nY
catch(IOException e){e.printStackTrace ();} mm:g9j
catch(Exception e){e.printStackTrace ();} ;ztt*py
} W^k|*Y|
*}P=7TuS
3FgTM(
//读取保存的下载信息（文件指针位置） CX}==0od
private void read_nPos() fP KFU
{ bzWWW^kNL
try{ k9_c<TSzu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ncr*F^J4
int nCount = input.readInt(); k0v&U@+-J
nStartPos = new long[nCount]; fe4Ki
nEndPos = new long[nCount]; TF%MO\!
for(int i=0;i<nStartPos.length;i++) a;h.I}*]
{ V#,jUH|
nStartPos = input.readLong(); wj{[g^y%
nEndPos = input.readLong(); >+FaPym
} di4>Ir~]
input.close(); M(Tlkr
} 'JRYf;9c
catch(IOException e){e.printStackTrace ();} >X_5o^s2s
catch(Exception e){e.printStackTrace ();} m#,AD,s
} \|YIuzlO4
:V!F~
=v{Vl5&>?
private void processErrorCode(int nErrorCode) ,<t)aZL,A;
{ O%)Wo?)HM
System.err.println("Error Code : " + nErrorCode); ["1Iz{
} };;k5z I%
ms{iQ:'9
_]t^F9l
//停止文件下载 L}\ oFjVju
public void siteStop() EM7Z g 65
{ f 0r?cZ
bStop = true; AF\gB2^
for(int i=0;i<nStartPos.length;i++) w(oi6kg
fileSplitterFetch.splitterStop(); })yB2Q0
gLK_b;:
V0G"Z6
} ( u^`3=%n
} +A-z>T(
//负责部分文件的抓取 #GuN.`__n,
**FileSplitterFetch.java 6qd?&.=r
*/ =mYwO=:D
package NetFox; Y=ksrs>w
=$-+~
a797'{j#PI
import java.io.*; ,92wW&2
import java.net.*; ]ne
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*6aIDFNl
public class FileSplitterFetch extends Thread { \P;2s<6i\
jdX*
85_Qb2<'r
String sURL; //File URL (3?W)i
long nStartPos; //File Snippet Start Position BMO&(g
long nEndPos; //File Snippet End Position >zo_}A!
int nThreadID; //Thread's ID rlQ=rNrG&E
boolean bDownOver = false; //Downing is over wE3fKG.
boolean bStop = false; //Stop identical LUzn7FZk
FileAccessI fileAccessI = null; //File Access interface hjq@.5
*t300`x
R.KznJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6E{(_i
{ 2&zklXuo:
this.sURL = sURL; 9/JBn
this.nStartPos = nStart; V~sfR^FQ'
this.nEndPos = nEnd; ]@uuB\u
nThreadID = id; C@3UsD\s(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mRIBE9K+&
} ;;K ~
97k}{tG
7hhv/9L1
public void run() 8?LHYdJ
{ x c|1?AFj
while(nStartPos < nEndPos && !bStop) E5yn,-GyE0
{ J^-a@'`+
8`z
DJb9] ,=a
try{ snYyxi
URL url = new URL(sURL); [nf5<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L:\>)6]Ls
httpConnection.setRequestProperty("User-Agent","NetFox"); oFKTBH:I
String sProperty = "bytes="+nStartPos+"-"; xEg@Y"NQ
httpConnection.setRequestProperty("RANGE",sProperty); NwN3T]W
Utility.log(sProperty); .q<5OE(f
SQJ+C%
7U!-_)n{
InputStream input = httpConnection.getInputStream(); U%n>(!d
//logResponseHead(httpConnection); H.< F6
@RHG@{x{K
~3)d?{5
byte[] b = new byte[1024]; `R*SHy! _
int nRead; "fC>]iA8I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I2WWhsNC
{ &Qmb?{S0
nStartPos += fileAccessI.write(b,0,nRead); $IqubC>O
//if(nThreadID == 1) :{9HsF"h0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]Pe8G(E!
} )jjL'
*|ef#-|D
1&RB=7.h
Utility.log("Thread " + nThreadID + " is over!"); Vqr]Ui
bDownOver = true; P4:Zy;$v!
//nPos = fileAccessI.write (b,0,nRead); 0),fY(D2T
} Fl!D2jnN
catch(Exception e){e.printStackTrace ();} &88c@Ksn
} 2U3e!V
} eV"s5X[$
(}rBnD
Sd/7#
//打印回应的头信息 vxS4YRb
public void logResponseHead(HttpURLConnection con) V n+a-v
{ (7ujJ}#,
for(int i=1;;i++) qJE_4/<^!
{ Sx1|Oq]
String header=con.getHeaderFieldKey(i); [ldBI3
if(header!=null) "m`}J*s"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X\kWJQ:
Utility.log(header+" : "+con.getHeaderField(header)); ??f,(om
else ZiPz~G0[^
break; \Vpv78QF;
} $Gcjm~
} r>gf&/Pl
]cM8TT
juI)Do2_
public void splitterStop() 5Z:T9F4
{ N'CWSf.e
bStop = true; ' e %>Ip
} ~x^Ra8A
{Ve3EYYm
qP-_xpu]R
} sL,|+>7T^M
#pyFIUr=w
RL[F 9g
/* xo4lM
**FileAccess.java [+L!c}#
*//文件访问(定位，写) RKZBI?@4
package NetFox; i-9W8A
import java.io.*; jX0^1d@
+BDW1%
I+( b!(H
public class FileAccessI implements Serializable{ G#ELQ/Q
_St":9'uU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;p7R~17
RandomAccessFile oSavedFile; JXHf$k
long nPos; P/xEn_*v
BF 0#G2`h>
`KZu/r-M9
public FileAccessI() throws IOException UCj:]!P
{ _GM?`
this("",0); > H&v
} P 5.@LN
MS:,I?
Dp4x\97O
public FileAccessI(String sName,long nPos) throws IOException uzT+,
{ /N#=Tol
oSavedFile = new RandomAccessFile(sName,"rw"); 6&QOC9JW+7
this.nPos = nPos; Lq2jXy5#n
oSavedFile.seek(nPos); `q`ah_
} zG{jRth
i'.D=o
XMz*}B6GQ
public synchronized int write(byte[] b,int nStart,int nLen) {Us^4Xe
{ B@S~v+Gr
int n = -1; |bhv7(_
try{ *>2e4j]
oSavedFile.write(b,nStart,nLen); {jv+ JL"5
n = nLen; ohs`[U=%~
} B`||4*
catch(IOException e) `+0dz,
{ e tL?UF$
e.printStackTrace (); |UB)q5I
} zeq")A
@n=&muC}
vvs2:87zvJ
return n; 6=qC/1,l
} =M}tet }
/r2S1"(q
ZpMv16
} V(:wYk?ZR
%YbL%i|U
a5aHv/W#P
/* 3t9CN )*
**SiteInfoBean.java cucmn*o?
*/ -ssmj8:Q\|
package NetFox; L8H:,} 2
1wH6 hN,
^>>9?
public class SiteInfoBean { ,F*HZBNFZ
~]].i~EV(
_CTg")0o
private String sSiteURL; //Site's URL ng~LCffpY
private String sFilePath; //Saved File's Path cNN0-<#c
private String sFileName; //Saved File's Name on"ENT
private int nSplitter; //Count of Splited Downloading File C<(qk_
zbr^ulr
<6s@eare8
public SiteInfoBean() `'*4B_.
{//nSplitter的缺省值为5 :_]0 8
//default value of nSplitter is 5 MppT"t
this("","","",5); z}B8&*>
} {'[VL;k
V;^N:I\js
FFcIOn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P;K LN9/4
{ CrSBN~
sSiteURL= sURL; N-t"CBTO
sFilePath = sPath; N=7iQ@{1
sFileName = sName; sdiWQv
this.nSplitter = nSpiltter; _sZ&=-FR
w\UAKN60
=,C]d~
} ~kj96w4eAR
?m+];SJk
wjZ Q.T!
public String getSSiteURL() Gy;Fe=
{ zGNW5S9G
return sSiteURL; mlLqQ<
} 'n1$Y%t
[b&V^41W
4mKH |\g
public void setSSiteURL(String value) SSTn|
{ *M*WjEOA
sSiteURL = value; xWqV~NnE
} :475FPy]
<}h<By)
$tI<MZ&Z
public String getSFilePath() J]w3iYK
{ )siWc_Z4
return sFilePath; Xit@.:a;
} Nd_A8H,&B
eM5-v-
n%G[Y^^,
public void setSFilePath(String value) /OB)\{-
{ )db:jPkwd
sFilePath = value; V~ MsGj
} -3ANNj
k3e6y
6Vncr}
public String getSFileName() G<k.d"<
{ mPqKk
return sFileName; :-<30LS$
} nqx0#_K-E
63_#*6Pv28
Ayv:Pv@
public void setSFileName(String value) 7=yjd)Iy9m
{ w^^l,
sFileName = value; nd,\<}uP9
} Y<kz+d,C
W(Md0*
K'e,9P{
public int getNSplitter() u"%D;
{ It/hXND`
return nSplitter; ~3%\8,0
} 4}t&yu<P>
1Y;.fZE
isy[RAP<
public void setNSplitter(int nCount) =R 4]Kf
{ Y:#B0FD,gC
nSplitter = nCount; [u=yl0f
} gdoaXw;Sy
} 3Nwix_&S
yB/F6/B~
;($xAAR
/* <gGO
**Utility.java L[<Y6u>m!1
*/ BNA1"@9q
package NetFox; xdDe@G;"
lq]8zm<\)]
rZ5xQ#IA
public class Utility { =8TBkxG
;I80<SZ
=./PY10'
public Utility() :f%kkatO
{ JUj.:n2e
(CH6Q]Wi_!
K>LS8,8V
} .iP>?9$f"
BB9eQ: xO
//线程睡眠 $cuBd
public static void sleep(int nSecond) Vr"'O6
{ ^+-]V9?+
try{ 5-k gGOt
Thread.sleep(nSecond); _ W#Km
} d0|{/4IWw;
catch(Exception e) 3djw
{ .@EzHe ^W
e.printStackTrace (); :?= 1aiS
} ( xzruI5P
} oOLA&N-A~
Zn40NKYc
//日志 t2.jg?`k
public static void log(String sMsg) E BoC,{R#
{ 4 #KC\C
System.err.println(sMsg); wS?Kc^2O
} .I]v D#o
Mae2L2vc
d(d3@b4Ta
public static void log(int sMsg) z.\\m;s
{ y!:vX6l
System.err.println(sMsg); zFipuG02
} TOgH~R=
} vN@04a\h
N+5f.c+S-
VKu_l
/* <0hVDk~
**TestMethod.java ubsv\[:C
*/ 7bE`P[
package NetFox; =B'Yx
$G}k'[4C
)+hJi/g
public class TestMethod { aO?KRn
5T9[a
$7xfLS8Vo
public TestMethod() uh#E^~5S
{ ///xx/weblogic60b2_win.exe jjv'"K2
try{ F3$8l[O_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [; $:Lr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Mh3L(z]/E
SiteFileFetch fileFetch = new SiteFileFetch(bean); |HJ`uGN<b
fileFetch.start(); `*yOc6i]
} _Gb7n5p
catch(Exception e){e.printStackTrace ();} -iW>T5f
S;iD~>KP
WLh!L='{BK
} mI:D
E5|GP
t1oTZ
public static void main(String[] args) FEopNDy@y
{ NU{eoqaT
new TestMethod(); 0pB'^Q{
} P@n rcgM.
} 3BLHd<
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