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)); xl ,(=L]
} W]I+Rlv)U
for(int i=0;i<nEndPos.length-1;i++) Wgb L9'}B
{ @G^m+-
nEndPos = nStartPos[i+1]; Hv-f :P O
} Dbw{E:pq
nEndPos[nEndPos.length-1] = nFileLength; vbEO pYCS
} T!Nv
} jJyS^*.X
w@x||K=Z
v,d'SR.
//启动子线程 /wU4^8Hz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ::sk)
for(int i=0;i<nStartPos.length;i++) 0SV4p.
{ "Pa y2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b=XXp`h~a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r<5i
nStartPos,nEndPos,i); Y|cj&<o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gN.n_!
fileSplitterFetch.start(); c' Q4Fzj0'
} om2)Cd9~7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tL]T_]z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d~#:t~ $,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;k (M4?
nEndPos = " + nFileLength); @ RP?)*8}&
// fileSplitterFetch[nPos.length-1].start(); @:t2mz:^i
22@w:
n;e.N:p
//等待子线程结束 sFw;P`
//int count = 0; [oOV@GE
//是否结束while循环 a/xnf<(H
boolean breakWhile = false; }U@(S>,%
9k;%R5(
<-"[9 w
while(!bStop) w+gPU1|(r
{ KJ cuZ."wX
write_nPos(); 4}NCdGD
Utility.sleep(500); Qrw:Bva)
breakWhile = true; b<j*;n.
5M\bH'1
v]y=+* A
for(int i=0;i<nStartPos.length;i++) y wmC>`0p
{ <&l@ ):a
if(!fileSplitterFetch.bDownOver) E|y
{ @#"6_{!j_X
breakWhile = false; '?1g_C QsS
break; <Aqo[']
} e\.
} r*UE>_3J
if(breakWhile) a xz-H`oq4
break; X*t2h3"}
-nqq;|%
u1`JvfLrL
//count++; G UK%RC8
//if(count>4) auAwZi/
// siteStop(); |!L0X@>
} o]<J&<WM
Dlg9PyQ
+S@[1 N
System.err.println("文件下载结束！"); !M}ZK(
} YL/B7^fd8
catch(Exception e){e.printStackTrace ();} Hb\['VhzM
} t:YMF$Z
KM/c^a4V
ufJHC06
//获得文件长度 OlM3G^1e1
public long getFileSize() p8MN>pLP%
{ 9\>{1"a
int nFileLength = -1; 4VhKV JX
try{ kOQ!]-;
URL url = new URL(siteInfoBean.getSSiteURL()); nw0Tg= P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V W(+sSQ
httpConnection.setRequestProperty("User-Agent","NetFox"); 7 lu_E.Bv
4wPP/`
7n7UL0Oc1
int responseCode=httpConnection.getResponseCode(); ?@QcKQ@
if(responseCode>=400) ~^l;~&
{ Q+*@!s
processErrorCode(responseCode); KebC$g@W
return -2; //-2 represent access is error A'n{K#
} 7MIrrhk
+iw4>0pi
0+NGFX\p
String sHeader; x{S2
,zh_-2^X
;0-R"c)-
for(int i=1;;i++) hbm#H7Y
{ d(C5i8d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (};/,t1#$
//Utility.log(in.readLine()); R]0tG
sHeader=httpConnection.getHeaderFieldKey(i); (3&P8ZGNR
if(sHeader!=null) L=&}s[5
{ ; jrmr`l=
if(sHeader.equals("Content-Length")) n&8SB'-r
{ Wa9yyc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W!JEl|]
break; %v[KLMo'(
} 9>=S@hVMd
} bT`et*]
else ^GNL:D%6d
break; 36}&{A
} zGa V^X
} ,,;vG6^a
catch(IOException e){e.printStackTrace ();} NG?g(
catch(Exception e){e.printStackTrace ();} t(UdV
04:QEC"9mj
uG(XbDZZ1W
Utility.log(nFileLength); =d/$B!t{
P?Kg7m W
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return nFileLength; $Y8iT<nP
} 7#C3E$gn?
[X ]XH
KxDfPd+j[
//保存下载信息（文件指针位置） y<PQ$D)
private void write_nPos() zA|)9Dq
{ 6 2t9SY
try{ gSkY c{b
output = new DataOutputStream(new FileOutputStream(tmpFile)); wI?AZd;`'
output.writeInt(nStartPos.length); :VE0eJ]J6
for(int i=0;i<nStartPos.length;i++) oo|Nu+
{ K+`deH_d
// output.writeLong(nPos); &}d5'IRT
output.writeLong(fileSplitterFetch.nStartPos); f<>CSjQ4c
output.writeLong(fileSplitterFetch.nEndPos); fzUG1|$e
} Nb)Mh
output.close(); oG c9 6B%
} "Rn@yZV
catch(IOException e){e.printStackTrace ();} UQjYWXvi
catch(Exception e){e.printStackTrace ();} pW_mS|
} G-'CjiMu
izR#XeBm
nI/kX^Pd
//读取保存的下载信息（文件指针位置） 3e1%G#fu
private void read_nPos() MJU*Sq
{ 68~5Dx
try{ PNH>LT^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M6y|;lh''c
int nCount = input.readInt(); #v*3-) 8
nStartPos = new long[nCount]; AI-ZZ6lzR
nEndPos = new long[nCount]; fJ+4H4K
for(int i=0;i<nStartPos.length;i++) b^"mQ
{ qyjVB/ko
nStartPos = input.readLong(); =]o2{d
nEndPos = input.readLong(); ~Xc1y!"9*
} z&z5EtFUTh
input.close(); ,r;E[k@
} p]jG ,S
catch(IOException e){e.printStackTrace ();} `bWc<4T
catch(Exception e){e.printStackTrace ();} @{ L|&Mk!
} bjq.nn<=
o)8VJ\ &
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private void processErrorCode(int nErrorCode) -/_hO$|W
{ rdH^"(
System.err.println("Error Code : " + nErrorCode); #4V->I
} d}wE4(]b
seb/rxb
(^m~UN2@~m
//停止文件下载 sn+ kFvk}S
public void siteStop() o;>qsn8
{ +ZkJ{r0,(
bStop = true; w I[Hoi V
for(int i=0;i<nStartPos.length;i++) Nhtc^DX
fileSplitterFetch.splitterStop(); WLH ;{
~;uU{TT
B^.:dn
} }S{VR(i`J
} lYU?j|n
//负责部分文件的抓取 df/7u}>9
**FileSplitterFetch.java 5kCXy$"%
*/ nLR
package NetFox; % @!hf!
h<7@3Ur
zrwzI+4
import java.io.*; K{XE|g
import java.net.*; Mtn{63cK
uJa.]J~L=
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public class FileSplitterFetch extends Thread { ;8cTy8
ek d[|g
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String sURL; //File URL ~|ha91
long nStartPos; //File Snippet Start Position wdIJ?\/763
long nEndPos; //File Snippet End Position rj/nn)vv;
int nThreadID; //Thread's ID 31N5dIi,
boolean bDownOver = false; //Downing is over fn8|@)J
boolean bStop = false; //Stop identical Q)5V3Q]@^
FileAccessI fileAccessI = null; //File Access interface 'fZ\uMdTx
hJ?PV@xy
^~s!*T)\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H-eHX3c7
{ NleMZ
this.sURL = sURL; 9 $^b^It
this.nStartPos = nStart; eL [.;_
this.nEndPos = nEnd; {&J OO
nThreadID = id; ITD&wg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L#fK ,r8
} c`oW-K{
+y\o^w4sT
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public void run() W)L*zVj~
{ pz"}o#R"x
while(nStartPos < nEndPos && !bStop) - x;xQ
{ 2`Ihrz6
k|$?b7)"@
bpa'`sf
try{ PmtXD6p3(
URL url = new URL(sURL); Lc(eY{CY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [{zfI`6
httpConnection.setRequestProperty("User-Agent","NetFox"); M3eFG@,
String sProperty = "bytes="+nStartPos+"-"; bQdu=s[
httpConnection.setRequestProperty("RANGE",sProperty); Rpj{!Ia
Utility.log(sProperty); #P {|7}jk
;,xM*
bd2QQ1[1vh
InputStream input = httpConnection.getInputStream(); !Oi':OQG
//logResponseHead(httpConnection); 2rHQ7
<KX+j,4
Nl^uA
byte[] b = new byte[1024]; z Ece>=C
int nRead; }taG/kE62
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B/Ltb^a
{ wJu9.
nStartPos += fileAccessI.write(b,0,nRead); QkYKm<b
//if(nThreadID == 1) NTVaz.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p[}~Z|(
} Ao\Im(?
8EU/}Ym
B?4Iu)bCxI
Utility.log("Thread " + nThreadID + " is over!"); 5>hXqNjP2
bDownOver = true; @QE&D+NS
//nPos = fileAccessI.write (b,0,nRead); yTf/]H]d
} vi` VK&+r
catch(Exception e){e.printStackTrace ();} uvi&! )x
} g"\JiBb5
} )!;20Po
T=CJUla
%eGI]!vf
//打印回应的头信息 *77Y$X##k
public void logResponseHead(HttpURLConnection con) q9c-UQB(!
{ }/Qj8l.
for(int i=1;;i++) h+Y>\Cxg
{ 2SlI5+u
String header=con.getHeaderFieldKey(i); N$u: !
if(header!=null) 1?G%&X@ X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lUw=YM
Utility.log(header+" : "+con.getHeaderField(header)); IuMJ-"
else 7Rn 4gT
break; B_RF)meux
} &ViK9
} fZQ2<*)pqO
Z6&bUZF$bE
cH707?p/I
public void splitterStop() yE;S6 O
{ j}w
bStop = true; ^FZ9q
} +^%)QH>9
KL"_h`UW
6q,CEm
} (px3o'lsh
'Z)#SzY
AYDAt5K_
/* }|)T<|Y;
**FileAccess.java *\*]:BIe&v
*//文件访问(定位，写) `/<f([w
package NetFox; hsJGly5H
import java.io.*; )~IOsTjI
X_)x Fg'k
w=^~M[%w
public class FileAccessI implements Serializable{ xmtD0U1
"G Jhx/zt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ! 6R|
RandomAccessFile oSavedFile; k#Qjm9V
long nPos; h?vny->uJ
<- R%
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public FileAccessI() throws IOException %BQ?DTtb7'
{ ZA}!Rzo
this("",0); i8%Z(@_`
} <[=[|DS l
8C*xrg#g:
sXYXBX[
public FileAccessI(String sName,long nPos) throws IOException 5C9 .h:c4y
{ rS+ >oP}
oSavedFile = new RandomAccessFile(sName,"rw"); olm'_{{
this.nPos = nPos; .=) *Qx+
oSavedFile.seek(nPos); ONUa7
} j"+6aD/lv
:*-O;Yw?S@
!uA'0U?ky
public synchronized int write(byte[] b,int nStart,int nLen) c?6(mU\x
{ +~7[T/v+n
int n = -1; [8vqw(2Tm(
try{ =FMrVE
oSavedFile.write(b,nStart,nLen); dP"cm0
n = nLen; Wxgs66
} 6U,:J'5gP
catch(IOException e) Q+'fTmT[,
{ s"~,Zzy@j
e.printStackTrace (); 4C3i
} u,~+ho@
^ '_Fd
a(uQGyr[k1
return n; ?OGs+G
} IvI;Q0E-3
Z/:W.*u
^P`I"T d
} '1zC|:,
SN`L@/I
nO;ox*Bk+8
/* }S%}%1pG7
**SiteInfoBean.java ES#q/yab5
*/ rMJ4w['J=
package NetFox; 24fN3
9e&*++vf
mXu";?2
public class SiteInfoBean { J3'0^JP*
PGb}Y {
0:x+;R<P*w
private String sSiteURL; //Site's URL $U2Jq@G*
private String sFilePath; //Saved File's Path @f-rS{
private String sFileName; //Saved File's Name X.rbJyKe
private int nSplitter; //Count of Splited Downloading File z;>O5a>z
J+`gr_&
TC ;Aj|)N
public SiteInfoBean() [7[$P.MS{
{//nSplitter的缺省值为5 ]ed7Q3lq
//default value of nSplitter is 5 [?da BXS
this("","","",5); :ra[e(l9
} y }h2
YL[y3&K
=wa5\p/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e)i-$0L"
{ K%SfTA1TCB
sSiteURL= sURL; D:(h^R0;
sFilePath = sPath; @s\}ER3
sFileName = sName; =4Jg6JKYg
this.nSplitter = nSpiltter; 2O2d*Ld>
rNgAzH
~\zIb/ #
} _b &Aa%
o/!a7>xO4
C%P.`NxA
public String getSSiteURL() 7f~7vydZ}
{ MF$NcU
return sSiteURL; P[e#j
} 5=!aq\ 5
`$/M\aM%
x o72JJ
public void setSSiteURL(String value) U*T :p>&
{ Kn\$\?u
sSiteURL = value; ,- _ReL
} J^Wqa$<;"
OW8TiM mK
; d}
public String getSFilePath() ;bq EfV0`2
{ hiaTJE|J?
return sFilePath; ;kVo? W]
} pf0uwXo
> !HC ?
m h|HEkM
public void setSFilePath(String value) fJY b)sN
{ B_%O6
sFilePath = value; w_q=mKu
} 1$"wN z
O[^zQA
MO79FNH2\
public String getSFileName() %5<t3H"
{ 2f9%HX(5
return sFileName; &oDu$%dkT
} 1:"ZS ]i
TJb&f<
4_\]zhS
public void setSFileName(String value) vpk~,D07yR
{ 1{wOjq(4
sFileName = value; 2K2jko9'a
} (' i_Xe
79U7<]-!
d.NB@[?*
public int getNSplitter() _\FA}d@N
{ ~|e H8@o
return nSplitter; 7JP.c@s
} Zg!E}B:z
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f&Meiu+
public void setNSplitter(int nCount) f/=H#'+8
{ ;[-y>qU0
nSplitter = nCount; N,`<:'
} , pr ",=
} U,$^|Iz
=v=H{*dWA
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/* fOO[`"'Pq
**Utility.java f@IL2DL}\
*/ rW9ULS2d
package NetFox; h}P""
bC]GL$ph9*
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public class Utility { .{k^ tf4
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<' b%
public Utility() HoKN<w
{ -ID!kZx
n15lX,FI
cBnB(t%
} L+"5g@
'=m ?l
//线程睡眠 3?DM AV
public static void sleep(int nSecond) -o0~xspF
{ `]g}M,
try{ affig
Thread.sleep(nSecond); }^B=f_Ag
} \o,`@2H+'
catch(Exception e) p\7(IhW@
{ 81U(*6
e.printStackTrace (); Nv_"?er+y
} <rFY$ ?x
} 2qUC@d<K
qnR{'d
//日志 Mo+HLN
public static void log(String sMsg) 6 {tW$q
{ 8'Ph/L,
System.err.println(sMsg); }c*6|B@f
} *HN0em
|(a<b
pUaGrdGxzQ
public static void log(int sMsg) p)=Fi}#D\
{ YvjRJ
System.err.println(sMsg); bi[gyl#
} lTpmoDa%
} $mG&4Y
%8yX6`lH
P$i?%P~
/* |^E#cI
**TestMethod.java UGJ# "9
*/ q#N8IUN}4
package NetFox; CEos`
D+vHl}
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public class TestMethod { 3pKr {U92
?$xZ$zW
3YF*TxKx
public TestMethod() 2@S{e$YK`
{ ///xx/weblogic60b2_win.exe HLcK d`$/
try{ &Q"Ox{~W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '\X<+Sm'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q2[D|{Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); @l:\Ka~TS
fileFetch.start(); u;*Wc9>sU
} &Rx-zp&dJ
catch(Exception e){e.printStackTrace ();} ISuye2tExq
+9mnxU>
ye)CfP=ID\
} ?5!>k^q
X}v]iX
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public static void main(String[] args) ~h{v^}
{ 3N,!y
new TestMethod(); uiIY,FL$
} +;Jb)8
} v/BMzVi
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