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)); JTdcLmL
} WF`
for(int i=0;i<nEndPos.length-1;i++) `XK#sCC
{ =g<Y[Fi2
nEndPos = nStartPos[i+1]; G&@vTcF
} U{ZKxE
nEndPos[nEndPos.length-1] = nFileLength; a~A"uLBR
} Z1sRLkR^
} 2O " ~k
8c'5P
<59G
//启动子线程 1)!?,O\ey
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c'uDK>
for(int i=0;i<nStartPos.length;i++) ~5 e 1&
{ 6;p"xC-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yCZ[z A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %40+si3c
nStartPos,nEndPos,i); )mE67{YJh~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4]m?8j) 6b
fileSplitterFetch.start(); 'aJm4W&j
} o{xA{ @<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B5MEE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); f\c%G=y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AN4(]_]
nEndPos = " + nFileLength); Jk,}3Cr/
// fileSplitterFetch[nPos.length-1].start(); Qvm[2mb
cPg$*,]
mmBZ}V+&=
//等待子线程结束 +YnQOh%v0s
//int count = 0; 7!('+x(>
//是否结束while循环 jU_#-<'r
boolean breakWhile = false; E9#.!re|^
YA*E93J0
W24n%Ps
while(!bStop) A=l1_8,`h
{ ;1L7+.A
write_nPos(); 8e}8@[h
Utility.sleep(500); %\?Gzc_
breakWhile = true; &~sk7iGi
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'~OKt`SfIo
for(int i=0;i<nStartPos.length;i++) &T[BS;
{ Sn-D|Z
if(!fileSplitterFetch.bDownOver) D0@d}N
{ !)h?2#V8;
breakWhile = false; of>}fJ_p
break; <PTi>C8;r
} Y"'k $jS-
} F>co#
if(breakWhile) g0"KCX
break; YV"LM6`
q.69<Rs
["XS|"DM
//count++; iYl$25k/1
//if(count>4) 9Li.B1j
// siteStop(); {uji7TB
} 4&'_~qU
77o&$l,A|
v9+1[Y";
System.err.println("文件下载结束！"); s&~.";b
} aFVd}RO0
catch(Exception e){e.printStackTrace ();} kU$M 8J.
} /7-qb^V
DU.[Sp
/dt'iai~l
//获得文件长度 *r]Mn~3
public long getFileSize() M}W};~V2ng
{ z]F4Z'(e.
int nFileLength = -1; V0'_PR@;
try{ {;j@-=pV
URL url = new URL(siteInfoBean.getSSiteURL()); x:WxEw>R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _HkB+D0v
httpConnection.setRequestProperty("User-Agent","NetFox"); C*fSPdg?
x8wal[6
RXU#.=xvy
int responseCode=httpConnection.getResponseCode(); bLpGrGJs
if(responseCode>=400) -(YdK8
{ 1O]27"9
processErrorCode(responseCode); #3o]Qo[Sc
return -2; //-2 represent access is error 8ncgTCH:
} Nd.Tda!Kg
.4-I^W"1
x#s=eeP1
String sHeader; smt6).o
Uv"GG: K_
6X.lncE@p
for(int i=1;;i++) m+/-SG
{ Ug|o($CY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L?5OWVX!v
//Utility.log(in.readLine()); !.ot&EbE
sHeader=httpConnection.getHeaderFieldKey(i); $@blP<I
if(sHeader!=null) ^"d!(npw
{ Aa;s.:?
if(sHeader.equals("Content-Length")) ii:h E=
{ jW-j+WGSM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \Ow-o0
break; HLy}ta\
} L('G1J}
} "wPFQXU
else $*{$90Q
break; )2P4EEs[
} {m/\AG)1I
} $I7/FZP
catch(IOException e){e.printStackTrace ();} hC.7Z]
catch(Exception e){e.printStackTrace ();} %q@eCN
t;@VsQ8
@:~O
Utility.log(nFileLength); M_2[Wypw
m$xyUv1
y^gazr"
return nFileLength; .wD>0Ig
} $e|G#mMd-
%&yD^q_
nNIV(
//保存下载信息（文件指针位置） ]8q5k5~
private void write_nPos() 1a)NM#
{ SrN;S kS
try{ B(mxW8y
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?'K}bmdt}.
output.writeInt(nStartPos.length); m%$z&<!
for(int i=0;i<nStartPos.length;i++) 'A,&9E{%1
{ @\_tS H
// output.writeLong(nPos); ih?_ fW
output.writeLong(fileSplitterFetch.nStartPos); 8kih81tx"U
output.writeLong(fileSplitterFetch.nEndPos); vL13~q*F
} 9jiZtwRpk
output.close(); r6Z&i^cMe
} <}%>a@
catch(IOException e){e.printStackTrace ();} 2F3IC
catch(Exception e){e.printStackTrace ();} Y$EqBN
} ,{7wvXP
w?.0r6j
.bvB8VOrW
//读取保存的下载信息（文件指针位置） Xt/T0.I
private void read_nPos() A0M)*9 f
{ pCA(>(
try{ uj&^W[s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Nm<3bd
int nCount = input.readInt(); N40.GL0s
nStartPos = new long[nCount]; 'oHtg @
nEndPos = new long[nCount]; lMp)T**
for(int i=0;i<nStartPos.length;i++) !l_1r$
{ :SSe0ZZ_6b
nStartPos = input.readLong(); %Md;=,a:6
nEndPos = input.readLong(); _C"W;n'
} V_!hrKkL
input.close(); c3!d4mC:
} Hbx=vLQ6
catch(IOException e){e.printStackTrace ();} 9wC q
catch(Exception e){e.printStackTrace ();} bR49(K$~
} A;w,m{9<
bWwc2##7jo
s9qr;}U.`
private void processErrorCode(int nErrorCode) 9<P1?Q
{ 9pStArF?F0
System.err.println("Error Code : " + nErrorCode); {DBgW},
} GKtG#jZ&
3yDa5q{
#+QwRmJdT!
//停止文件下载 ,S:LhgSP
public void siteStop() EdE,K1gD
{ 2>.B*P
bStop = true; 4&r^mGs,
for(int i=0;i<nStartPos.length;i++) @1gX>!
fileSplitterFetch.splitterStop(); }!(cm;XA"
yu<sd}@
_%;$y5]v
} AlIFTNg:"
} {*`qL0u]^
//负责部分文件的抓取 5)2lZ(5.A#
**FileSplitterFetch.java |9jeOV}/
*/ 4rc4}Yu,JI
package NetFox; y!."FoQ
/'u-Fr(Q+
tqAh&TW3+
import java.io.*; O]~cv^
import java.net.*; GG5wiN*2S
!GURn1vcAe
D^]7/w:$-
public class FileSplitterFetch extends Thread { ]P<u^ `{*
k!>MZ
U{} bx
String sURL; //File URL e54wAypPOl
long nStartPos; //File Snippet Start Position H@qA X
long nEndPos; //File Snippet End Position /d&zE|!
int nThreadID; //Thread's ID "b8<C>wY
boolean bDownOver = false; //Downing is over * h!gjbi
boolean bStop = false; //Stop identical /=*h\8c~
FileAccessI fileAccessI = null; //File Access interface -[|R\'i
!0CC&8C`
SHOg,#mV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5(^&0c>P
{ x?9rT 0D
this.sURL = sURL; Waj6.PCFm
this.nStartPos = nStart; >u ,Ac:
this.nEndPos = nEnd; Fc M
nThreadID = id; S4aN7.'Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L%}k.)yev
} o|*ao2a
T ]hVO'z
f',n'
public void run() @#hd8_)A.
{ y4PR&^l?g
while(nStartPos < nEndPos && !bStop) V##=-KZ
{ Q0K2md_%x
@e8b'w3
ig5 d-A
try{ :hr% 6K7
URL url = new URL(sURL); 9fj3q>Un,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b R> G%*a
httpConnection.setRequestProperty("User-Agent","NetFox"); 0+L:+S
String sProperty = "bytes="+nStartPos+"-"; 1G$fU zS
httpConnection.setRequestProperty("RANGE",sProperty); M{cF14cQ
Utility.log(sProperty); <ZcJC+k
/'k4NXnW3
YRa{6*M
InputStream input = httpConnection.getInputStream(); |ZZl3l=]
//logResponseHead(httpConnection); 4r&DW'
ntR@[)K
2[!#Xf
byte[] b = new byte[1024]; Wi7!J[ B
int nRead; B_R J;.oH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @`R#t3)8JP
{ T'_#Dwmj*
nStartPos += fileAccessI.write(b,0,nRead); yvR3|
//if(nThreadID == 1) &O8vI,M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )45~YDS;t
} Q^13KWvuV
c=d` DJ
v~E\u
Utility.log("Thread " + nThreadID + " is over!"); 7Z%EXDm4/c
bDownOver = true; @jh\yjrW
//nPos = fileAccessI.write (b,0,nRead); 1i=lJmr
} %!DdjC&5*
catch(Exception e){e.printStackTrace ();} JTGA\K
} zplAH!s5''
} P:D@5
?{=&Ro
hc7"0mVd{
//打印回应的头信息 @M( hyS&on
public void logResponseHead(HttpURLConnection con) kXW5bR
{ JG^fu*K
for(int i=1;;i++) _*iy *:(o
{ PmjN!/
String header=con.getHeaderFieldKey(i); !O)je>A
if(header!=null) vciO={M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <Wrn/%tL
Utility.log(header+" : "+con.getHeaderField(header)); 8O^<#lh
else Rtywi}VV2
break; RnV#[bM{
} B`<a~V
} o|7ztpr
hl}iw_e
*ggai?
public void splitterStop() G/ sRiwL
{ Pk?M~{S
bStop = true; aU\R!Y$/"
} xaN[ru@
aHR+4m~)
=|+%^)E
} 62.)fCQ^
8*x/NaH /\
U{C&R&z
/* tD^$}u6
**FileAccess.java yDapl(
*//文件访问(定位，写) 'Lu d=u{
package NetFox; F:~k4uTW\b
import java.io.*; pQ,|l$^m
=w;~1i%.k
~'#yH#o
public class FileAccessI implements Serializable{ aG&t gD{
aN5"[&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zI7iZ"2a
RandomAccessFile oSavedFile; 4k_y;$4WN
long nPos; W0+m A
<SKzCp\
Oh=E!
public FileAccessI() throws IOException A.+Qa
{ 1v~1?+a\2
this("",0); dbG902dR
} ~ugyUpY"
{i"th(J$
[;Y*f,UG_-
public FileAccessI(String sName,long nPos) throws IOException ,p' ;Xg6ez
{ ,a34=,
oSavedFile = new RandomAccessFile(sName,"rw"); HVz|*?&6
this.nPos = nPos; 3f-J%!aH
oSavedFile.seek(nPos); g1{2E<b5
} F\2<q$Zn+
Dqg01_O9O
=))VxuoN
public synchronized int write(byte[] b,int nStart,int nLen) Yln[ZmK9g
{ ,1 ^IFBJ
int n = -1; B8`!A
try{ '/F% ff
oSavedFile.write(b,nStart,nLen); !j%#7
n = nLen; @(CJT-Ak
} h4E[\<?
catch(IOException e) PI&@/+
{ B=)tq.Q7
e.printStackTrace (); ==npFjB
} +W+o~BE
FT6~\9m(
IFbN ]N0
return n; G2yQHTbl
} si1Szmx,
m't8\fo^w
-ZH6*7!
} XP(fWRT1
8,L)=3m-
-5y=K40
/* AP9>_0=
**SiteInfoBean.java ldWrv7.P
*/ ^WUG\@B
package NetFox; )@_5}8
c,Yd#nokC
A>C8whx
public class SiteInfoBean { 4tlLh`-8
@DuSii#.S
!h70<Q^
private String sSiteURL; //Site's URL Ap!Y 3C
private String sFilePath; //Saved File's Path FvVM}l'
private String sFileName; //Saved File's Name r2=4Wx4(
private int nSplitter; //Count of Splited Downloading File >k8FUf(c
IN?rPdY
&+")~2 +
public SiteInfoBean() evlz R/
{//nSplitter的缺省值为5 78kT}kgW
//default value of nSplitter is 5 g]9A?#GyE
this("","","",5); ;v m$F251
} ^q\9HBHT
QFU1l"(qGk
eT@,QA(3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;oWak`]f
{ ok/{ w
sSiteURL= sURL; PvW~EJ
sFilePath = sPath; QygbfW6u
sFileName = sName; Jj7he(!_1
this.nSplitter = nSpiltter; %Wa. 2s
:,Mg1Zf
C/YjMYwKgv
} c52S2f7
O[^u<*fi{
x%%OgO+>
public String getSSiteURL() h`pXUnEZ
{ kB=\a(
return sSiteURL; .iZo/_
} O_^;wey0}?
-$o4WSd~
Iz9b5
public void setSSiteURL(String value) aUbmEHFTV
{ ~ ":}Rs
sSiteURL = value; 8}{W.np_
} %Mr^~7nN
N.?)s.D(
M6H#Y2!ZbC
public String getSFilePath() W5R /
{ ~ }?*v}
return sFilePath; b9TsuY
} -HUlB|Q8r
A3Oe=rB
$kd9^lj#[
public void setSFilePath(String value) 5'S~PQka*
{ [)t1"
sFilePath = value; 1Y{pf]5Wx
} Q$8K-5U%
OpFm:j3
PEPf=sm
public String getSFileName() Q=#N4[W'
{ !Hx[ `3
return sFileName; ,O`~ D~$
} rvp#[RAaS}
.?)gn]#
6Ej.X)~'K
public void setSFileName(String value) C(}N*e1
{ h+j{;evN
sFileName = value; !M;><b}=5
} m.w.h^f$&
tWaM+W
FS7@6I2Ts
public int getNSplitter() @3Gr2/a
{ ^n9)rsb
return nSplitter; ayrCLv
} aM|;3j1p
I8Q!`KJ
J4#rOS
public void setNSplitter(int nCount) &sg~owz
{ ;3Z6K5z*f
nSplitter = nCount; ^]X\boWlI
} ?<STl-]&
} DE!c+s_g4
!z2KQ 4C
q}cm"lO$
/* GGez!?E%
**Utility.java K(}g!iT)~
*/ +{L=cWA"
package NetFox; l$ufW|
!yD$fY
D+"+m%^>C
public class Utility { GBYwS{4
)Y:C'*.r
og`K!d~
public Utility() rmJ`^6V
{ Z7dyPR
HcCT=x7:
y&6 pc
} Cq[<CPAS
fVz0H1\J&
//线程睡眠 w@x||K=Z
public static void sleep(int nSecond) ^NXxMC(e+
{ '+v[z=.8]
try{ #Q@~TW
Thread.sleep(nSecond); ).IK[5Q`
} #oJ%i+V
catch(Exception e) J~|:Q.Rt`
{ 4(&sw<k
e.printStackTrace (); ffR<G&"n~b
} pvhN.z
} ..Bf-)w
zKfY0A R
//日志 c7A]\1 ~
public static void log(String sMsg) [Gc9 3PA7q
{ ',]^Qu`a
System.err.println(sMsg); x9\]C'*sO
} }p `A>
7V-uQ)*
5M\bH'1
public static void log(int sMsg) ,c|Ai(U
{ 7)*q@
System.err.println(sMsg); rmeGk&*R8
} Y'yGhpT~
} $0*D7P^8
B^Hhrz!
a xz-H`oq4
/* %xdyGAl:
**TestMethod.java 4o<' fY
*/ #N'bhs
package NetFox; O?0`QMY
w%$J<Z^-?
gP`CQ0t
public class TestMethod { Hb\['VhzM
Cy6%f?j
vF9fXY=
public TestMethod() p8MN>pLP%
{ ///xx/weblogic60b2_win.exe Bi7&yS5V
try{ A().1h1_k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Bh;N:{&^Eu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lsU`~3nr
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?@QcKQ@
fileFetch.start(); iN1_T
} ?8YbTn1f)
catch(Exception e){e.printStackTrace ();} s#FX2r3=Fg
o @nsv&i
d$y?py
} g/gaPc*86
a}[rk*QmZ
'^(qlCI
public static void main(String[] args) (3&P8ZGNR
{ q-qz-cR
new TestMethod(); aX? tnDv
} W!JEl|]
} 4xgfm.9I^
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