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)); $.C-_L
} m W>Iib|
for(int i=0;i<nEndPos.length-1;i++) >v, si].
{ 9s_^?q
nEndPos = nStartPos[i+1]; &*"*b\
} JDR_k
nEndPos[nEndPos.length-1] = nFileLength; deaB_cjdI
} 6d/Q"As
} n"RV!{&
;PC!
"P#1=
//启动子线程 izcaWt3 a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5b/ ~]v
for(int i=0;i<nStartPos.length;i++) m-azd~r[
{ .Ja].hP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~Z/,o)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NW5OLa")J<
nStartPos,nEndPos,i); X uE: dL?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W9w*=W )Z
fileSplitterFetch.start(); @I-gs(
} }NyQ<,+mq&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u$^tRz9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); WN=0s
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0D2I)E72o
nEndPos = " + nFileLength); CnL=s6XD'
// fileSplitterFetch[nPos.length-1].start(); PlH~um[J
MuOKauYa
nyi!D
//等待子线程结束 tXtNK2-1
//int count = 0; f%.Ngf9
//是否结束while循环 Z[IM\# "
boolean breakWhile = false; LWJ ?p-X
Y&yfm/Ru
M\4`S&
while(!bStop) K [DpH&
{ t?G6|3
write_nPos(); 0c`zg7|
Utility.sleep(500); 2H4vK]]Nl
breakWhile = true; hm73Zy
RVV`
pAatv;Ex
for(int i=0;i<nStartPos.length;i++) uEJ8Lmi
{ 3<W%z]k@M
if(!fileSplitterFetch.bDownOver) :6lvX$
{ MBg[hu%
breakWhile = false; lvWwr!w
break; ?< b{
} L>~Tc
} )L:e0u
if(breakWhile) 1X5g(B
break; <EUR:
kd^H}k
B ktRA
//count++; A/<u>cCW
//if(count>4) 4{F1GW
// siteStop(); ErNYiYLi]
} Oq.ss!/z
=J]WVA,GqA
DBHy%i
System.err.println("文件下载结束！"); 3U>-~-DS
} &;-zy%#l
catch(Exception e){e.printStackTrace ();} U)bv,{-q
} ,J|,wNDU!K
RX>P-vp
0uDDaFS
//获得文件长度 IANSpWea?
public long getFileSize() o0C&ol_
{ eo9/
int nFileLength = -1; ~I5hV}ZT
try{ >E<ib[vK[
URL url = new URL(siteInfoBean.getSSiteURL()); RN(I}]]a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CfU|]<
httpConnection.setRequestProperty("User-Agent","NetFox"); 0mSP
.fl r
A!bG2{r
int responseCode=httpConnection.getResponseCode(); nFn!6,>E
if(responseCode>=400) NV4g5)D&L
{ >l&]Ho
processErrorCode(responseCode); Y'|,vG
return -2; //-2 represent access is error 4uIYX
} EpAgKzVpJ
Z71m(//*}
D|9+:Y
String sHeader; *(Dmd$|0|
PoF3fy%.
<R$ 2x_
for(int i=1;;i++) h`|04Q
{ ]j*2PSJG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Lg7A[\c ~
//Utility.log(in.readLine()); EhHxB fAQ
sHeader=httpConnection.getHeaderFieldKey(i); m]2xOR_
if(sHeader!=null) {=[>N>"
{ 3^y(@XFt
if(sHeader.equals("Content-Length")) hN'])[+V
{ _f[Q\gK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0y9 b0G
break; p' >i3T(
} lDYgtUKG
} GF ux?8A:%
else SQ>i:D;
break; ZUQ _u
} >Wr%usNxc
} d<a|dwAeh
catch(IOException e){e.printStackTrace ();} 1Nt &+o
catch(Exception e){e.printStackTrace ();} K29/7A/
EG>?>K_D
!?>V^#c
Utility.log(nFileLength); }S/i3$F0~
dgw.OXa
QadguV6|
return nFileLength; Ym6d'd<9(
} {.:$F3T
q?(] Y*
Yb+A{`
//保存下载信息（文件指针位置） OT{"C"%5t
private void write_nPos() @z@%vr=vX
{ D!&(#Vl _
try{ y+(\:;y$7
output = new DataOutputStream(new FileOutputStream(tmpFile)); k]@]a
output.writeInt(nStartPos.length); +Y%6y]8
for(int i=0;i<nStartPos.length;i++) y"q aa
{ qNEp3WY:
// output.writeLong(nPos); "bo0O7InOV
output.writeLong(fileSplitterFetch.nStartPos); TQ4@|S:OF
output.writeLong(fileSplitterFetch.nEndPos); {6'Xz
} L|'^P3#7`
output.close(); Z4] n<~o
} }g}Eh>U
catch(IOException e){e.printStackTrace ();} 5}#wp4U
catch(Exception e){e.printStackTrace ();} ,S-h~x
} \Rny*px
(&:gD4.
D4=*yP
//读取保存的下载信息（文件指针位置） 79h~w{IT@
private void read_nPos() fW-C`x
{ ShB]U5b:k
try{ 3"y 6|e/5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ! xCo{U=
int nCount = input.readInt(); z]G|)16
nStartPos = new long[nCount]; s*izhjjX
nEndPos = new long[nCount]; \/NF??k,jk
for(int i=0;i<nStartPos.length;i++) ukWn@q*
{ 1-_r\sb
nStartPos = input.readLong(); \fA{sehdL
nEndPos = input.readLong(); 3'4+3Xo
} ^po@U"
input.close(); gF)9a_R%p
} "%-Vrb=:Y
catch(IOException e){e.printStackTrace ();} 5>x_G#W
catch(Exception e){e.printStackTrace ();} ffrIi',@
} vQMBJ&
8`q7Yss6F
}E 'r?N
private void processErrorCode(int nErrorCode) _Iy\,<
{ 8%[pno |0I
System.err.println("Error Code : " + nErrorCode); @Wu-&Lb
} _;1{feR_
d?2V2`6
=kd$??F
//停止文件下载 9njl,Q:
public void siteStop() "z~ba>,-\
{ ux;?WPyr
bStop = true; Ke$_l]}
for(int i=0;i<nStartPos.length;i++) [xMa^A>p
fileSplitterFetch.splitterStop(); fj_23{,/"g
/at7H!
qkb'@f=
} EApKN@<"
} Z>rY9VvWD
//负责部分文件的抓取 nr!N%Hi
**FileSplitterFetch.java F-yY(b]$
*/ ^#/FkEt7bp
package NetFox; 3nxG>D7
v4P"|vZ$&
#.Rn6|V/4
import java.io.*; f9De!"*&
import java.net.*; l:85 _E
(j: ptQ2$
^jdU4
public class FileSplitterFetch extends Thread { t^rw@$"}
)Z}AhX
>yBqi^aL
String sURL; //File URL ?8b19DMK6
long nStartPos; //File Snippet Start Position !|cg=
long nEndPos; //File Snippet End Position yeo&Qz2vU
int nThreadID; //Thread's ID P?54"$b
boolean bDownOver = false; //Downing is over c`a(
boolean bStop = false; //Stop identical FcDS*ZEk!
FileAccessI fileAccessI = null; //File Access interface %Sr+D{B
/R)wM#&
+&EXTZ@o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mDB
{ \/a6h
this.sURL = sURL; M([#Py9h
this.nStartPos = nStart; ud1M-lY\U
this.nEndPos = nEnd; .Eao|;
nThreadID = id; \CbJU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 UtZ,q!sg
} C-'hXh;hQ
{1W:@6tl
ccD+AGM.
public void run() WyL+HB}
{ Fnw:alWr
while(nStartPos < nEndPos && !bStop) dAo;y.3
{ Rj8%% G-pt
P]_d;\ !"v
2eT?qCxqc
try{ K1B9t{T
URL url = new URL(sURL); MmuT~d/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kB\{1;
httpConnection.setRequestProperty("User-Agent","NetFox"); E~'mxx~i
String sProperty = "bytes="+nStartPos+"-"; x(_[D08/TT
httpConnection.setRequestProperty("RANGE",sProperty); UO/sv2CN
Utility.log(sProperty); :+rGBkw1m
7s9h:/Lu
wj|Zn+{"nF
InputStream input = httpConnection.getInputStream(); ,"(L2+Yp
//logResponseHead(httpConnection); ]Bw0Qq F#
sDY~jP[Oa
:6^7l/p
byte[] b = new byte[1024]; ?$r`T]>`2
int nRead; J=4>zQLW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) PNU(;&2<
{ E-e(K8R
nStartPos += fileAccessI.write(b,0,nRead); $6hPTc<C
//if(nThreadID == 1) =YO ]m<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5j%G7.S\
} jmok]-pC
f8 d 3ZK
AOf4y&B>q
Utility.log("Thread " + nThreadID + " is over!"); jG5HW*>k0
bDownOver = true; nB[-KS
//nPos = fileAccessI.write (b,0,nRead); ~(5r+Z}*`
} *{o7G a
catch(Exception e){e.printStackTrace ();} 0D X_*f
} .6B\fr.za
} <g4}7l8
.R9Z$Kbq
e|~MJu+1
//打印回应的头信息 XR5KJl
public void logResponseHead(HttpURLConnection con) Xlo7enzY
{ 5E:$\z;
for(int i=1;;i++) 5of3&
{ zM0NRERi
String header=con.getHeaderFieldKey(i); =W(*0"RM
if(header!=null) B5e9'X^ [
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p6VD*PT$&
Utility.log(header+" : "+con.getHeaderField(header)); Z6jEj9?O
else *6uccx7{
break; ?GhyVXS y.
} p7?
} Fe+ @;
s?SspuV
x3@-E
public void splitterStop() oFY!NMq}:
{ ~MpikBf
bStop = true; ;"3B,Yj
} jYsAL=oh,*
c/{FDN
>.h:Y5
} Fsx?(?tCMo
4 1_gak;
*O?c~UJhhV
/* _n&Nw7d2 M
**FileAccess.java rS8a/d~;0
*//文件访问(定位，写) &)eg3P)7
package NetFox; (FuIOR
import java.io.*; 4<s.|W`
bOY;IB _
c:R?da
public class FileAccessI implements Serializable{ J~YT~D2L
WJ7|0qb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '<Z[e`/
RandomAccessFile oSavedFile; ^0VL](bD>
long nPos; h}bfZL
E?m~DYnU
q76POytV|
public FileAccessI() throws IOException 'CLZ7pV
{ i`,FXF)
this("",0); ;C]Ufk
} h}b:-a
8hRcB[F~S
1MelHW
public FileAccessI(String sName,long nPos) throws IOException v=`yfCX-qX
{ x2"iZzQlD
oSavedFile = new RandomAccessFile(sName,"rw"); LQ0/oYmNc
this.nPos = nPos; yNu_>!Cp5
oSavedFile.seek(nPos); ?^|`A}q#
} 18g_v"6o
:_{8amO
Cu"Cpt[
public synchronized int write(byte[] b,int nStart,int nLen) .UyE|t4
{ HL)!p8UHJ
int n = -1; J3$>~?^1
try{ ~lj~]j
oSavedFile.write(b,nStart,nLen); 0D-`>_
n = nLen; ]`^! ]Ql
} M .#}
catch(IOException e) $JE,u'JQ
{ !(sn9z#
e.printStackTrace (); e3~MU6
} >mGH4{H
0^;2
Kg@'mG
return n; f%Q)_F[0D4
} +`y(S}Z
=KRM`_QShg
TS<d?:
} /-=fWtA
lFBdiIw
<}a?<):S
/* +X?ErQm
**SiteInfoBean.java ~ELY$G.xl
*/ =w2 4(S
package NetFox; PK*Wu<<
K+g[E<x\=
X-pbSq~5
public class SiteInfoBean { [g}Cve#i
_0H oJ
0zt]DCdY
private String sSiteURL; //Site's URL dj gk7
private String sFilePath; //Saved File's Path }nx)|J*p
private String sFileName; //Saved File's Name U>5^:%3
private int nSplitter; //Count of Splited Downloading File 16NHzAQ
=C\Tl-$\f
4vhf!!1
public SiteInfoBean() MlO OB
{//nSplitter的缺省值为5 -Cf)`/
//default value of nSplitter is 5 }$6L]
this("","","",5); sqkWQ`Ur
} ~uQ*u.wi
)'shpRB;1
Spm 0`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6F\ 6,E
{ V&mkS
sSiteURL= sURL; I16FVdUun4
sFilePath = sPath; ;Iu _*U9)
sFileName = sName; Met?G0[
this.nSplitter = nSpiltter; {gMe<y
<'Q6\R}:vC
rxCzPF
} $H:!3-/
?d')#WnC
+NlnK6T/
public String getSSiteURL() F>;Wbk&[|
{ U)}]Z@I-
return sSiteURL; d)%WaM%V
} SX4*804a_
A#U! KX
Koa9W>!
public void setSSiteURL(String value) xd Z$|{,
{ ^F^g(|(K
sSiteURL = value; Q_mphW:[
} -jH|L{Iyq}
@@d_F<Ym[
#UGSn:D<i
public String getSFilePath() T"wg/mT
{ *d._H1zT
return sFilePath; '%$Vmf)=
} >?g@Nt8
j^G=9r[,
>%/x~UFc5
public void setSFilePath(String value) :!gNOR6Lh
{ CmEqo;Is
sFilePath = value; 'g#%>
} )~2\4t4|g
2mLZ4r>WE
@K;b7@4y
public String getSFileName() `}X3f#eO&
{ 5F kdGF
return sFileName; F5)`FM^R
} IjI'Hx
!do`OEQKR
KEAXDF&#
public void setSFileName(String value) dx%z9[8~{.
{ 3%v)!dTa<^
sFileName = value; *l5?_tF
} #W\}v(Ke
8Vu@awz{L
Okq,p=D6
public int getNSplitter() DrRK Sc(u9
{ +n^M+ea;
return nSplitter; OGZD$j
} +!lDAkW0
qS?o22
~aC ?M&
public void setNSplitter(int nCount) PD#,KqL:
{ <4r8H-(%
nSplitter = nCount; reu[rZ&
} %;`Kd}CO
} (j}7|*.
<J509j
j>8DaEfwx
/* ;|Cdq
**Utility.java b.*LmSX#
*/ c^}G=Z1@
package NetFox; .*zN@y3
^O|fw?,
tYA@J["^
public class Utility { /x3*oO1
pBtO1x6x/
`[H^`
public Utility() !Asncc G
{ #GM^:rF
D e&,^"%
5lsslE+:J
} ^'QO!{7f
U]hqRL
//线程睡眠 [@@{z9c
public static void sleep(int nSecond) fPeS;
{ *p/,Z2f
try{ ^h?fr`
Thread.sleep(nSecond); @O"7@%nu
} ^\}MG!l
catch(Exception e) |E+.y&0;
{ ZRMim6a4X
e.printStackTrace (); vQrxx
} i6Z7O)V
} B=A!hXNa
cSL6V2F
//日志 *\ii+f-
public static void log(String sMsg) I`_2Q:r
{ Snr(<u
System.err.println(sMsg); l";Yw]:^
} f' A$':Y
rLTBBvV
SZGR9/*^
public static void log(int sMsg) Yxq!7J
{ ]zx%"SUM
System.err.println(sMsg); h@RpS8!Bi
} YsmRY=3
} fcq8aW/z_
bPVk5G*ruP
461g7R%r
/* 8063LWV
**TestMethod.java SkuR~!
*/ JrcbJt
package NetFox; b1Vr>:sK47
4,y7a=qf3
f*%kHfaXgN
public class TestMethod { !Yof%%m$;
X>I3N?5
U["0B8
public TestMethod() h$5[04.Q
{ ///xx/weblogic60b2_win.exe U7WYS8
try{ y[N0P0r l:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )rEl{a
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [!uzXVS3
SiteFileFetch fileFetch = new SiteFileFetch(bean); @i#JlZM_
fileFetch.start(); B:h<iU:'D
} |_?e.}K
catch(Exception e){e.printStackTrace ();} >XtfT'
5 `1
gnJ8tuS
} a0NiVF-m%
jG>W+lq
9#9 UzKX#
public static void main(String[] args) @gN"Q\;F
{ O2fq9%lk
new TestMethod(); Avw=*ZW
} ///Lg{ie
} 96w2qgc2
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