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)); ^|(F|Z
} u9_ Fjm}&
for(int i=0;i<nEndPos.length-1;i++) UJ2Tj+
{ Ub%5# <k|-
nEndPos = nStartPos[i+1]; yS %J$o&
} ohOze\T)=
nEndPos[nEndPos.length-1] = nFileLength; Kb#py6
} Syo1Dq6z.
} Bzw~OB{!=J
5l}v
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//启动子线程 d?.ewsC
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8W9kd"=U
for(int i=0;i<nStartPos.length;i++) "xi)GH]H_
{ )L<NW{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n'K,*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NN>,dd3T
nStartPos,nEndPos,i); twq!@C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \IQf|
fileSplitterFetch.start(); %[l5){:05
} T32C=7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +' QX`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iG!tRNQ{y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Dqs{n?@n
nEndPos = " + nFileLength); %@Bl,!BJ,
// fileSplitterFetch[nPos.length-1].start(); 4 bw8^
!"Jne'f
RQ;pAO
//等待子线程结束 lQ {k
//int count = 0; oYG9i=lZ
//是否结束while循环 <j+DY@*
boolean breakWhile = false; bx#GOK-
/PafIq
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while(!bStop) x* ?-KS|
{ Rt}H.D #
write_nPos(); |@`F!bnLr
Utility.sleep(500); `A_CLVE
breakWhile = true; KmG*`Es
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8M<q-sn4B
for(int i=0;i<nStartPos.length;i++) d="Oge8
{ Dp3&@M"^yY
if(!fileSplitterFetch.bDownOver) 0z1m!tr
{ ~oWCTj-
breakWhile = false; 1RgtZp%
break; D2z" Z@
} 7o_1PwKS6
} G:7HL5u
if(breakWhile) ry)g<OA
break; ?Z9C}t]
_bRd2k,
Uus%1hC%a
//count++; ?%-VSL>$w=
//if(count>4) XHKiz2Pc1
// siteStop(); ND $m|V-C
} I|8'#QX
^yL6A1
2.)xWCG
System.err.println("文件下载结束！"); c5C 2xE}T
} 3M\~#>
catch(Exception e){e.printStackTrace ();} @TBcVHy
} a~ sU
iI\bD
7)SG#|v[$
//获得文件长度 ]/g&y5RG
public long getFileSize() W}{RJWr
{ JcV'O)&
int nFileLength = -1; HqC 1Dkw
try{ s\O4D*8
URL url = new URL(siteInfoBean.getSSiteURL()); -!V+>.Oh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R-QSv$
httpConnection.setRequestProperty("User-Agent","NetFox"); V{4=,Ax
<cS"oBh&u0
cetHpU,
int responseCode=httpConnection.getResponseCode(); E}6q;"[
if(responseCode>=400) v8 rK\
{ Kcf1$`F24
processErrorCode(responseCode); J< Ljg<t+
return -2; //-2 represent access is error *9Ta0e*
} `s1>7XWf
@pq2Z^SQH
cBcfGNTJ~
String sHeader; 9n9Z
t~_vzG
ggn C #$
for(int i=1;;i++) wzX(]BG
{ [.:SV|AF#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XK#~w:/fB
//Utility.log(in.readLine()); E/+H~YzO
sHeader=httpConnection.getHeaderFieldKey(i); T1$=0VSEa+
if(sHeader!=null) B}S!l>.z
{ K!~j}z*
if(sHeader.equals("Content-Length")) }\ kLh(
{ r:N =?X`N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LL% Aw)Q`
break; $mgamWNE8w
} 5\!t!FL_
} J34/rL/s
else WX~:Y,l+u
break; ]]Bqte
} l$_q#Kd
} c+S<U*
catch(IOException e){e.printStackTrace ();} J)o.@+Q}
catch(Exception e){e.printStackTrace ();} 2-G6I92d
?OjZb'+=K
hSkI]%
Utility.log(nFileLength); lQ&"p+n
G42J
A$ 2AYQ
return nFileLength; 0nOkQVMk>
} Z2P DT
;@ <E
??5y0I6+
//保存下载信息（文件指针位置） Dfhu
private void write_nPos() =:fN
{ 0+3_CS++r
try{ >;qAj!'
output = new DataOutputStream(new FileOutputStream(tmpFile)); =1ltX+
output.writeInt(nStartPos.length); }^Ymg7wA
for(int i=0;i<nStartPos.length;i++) G.{)#cR
{ qe/dWJBa
// output.writeLong(nPos); 1Jm'9iy3
output.writeLong(fileSplitterFetch.nStartPos); E^s<5BC;
output.writeLong(fileSplitterFetch.nEndPos); o,NTIh
} ccR#<Pb6q
output.close(); kz!CxI (
} S"=y>.#
catch(IOException e){e.printStackTrace ();} L/Tsq=
catch(Exception e){e.printStackTrace ();} WNnB s
} b;;mhu[D
vQH6CB"
C\`*_t
//读取保存的下载信息（文件指针位置） ]`+J!G,
private void read_nPos() U3t$h
{ Ty&Ok*
try{ ob.Br:x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y,/Arl}yc
int nCount = input.readInt(); W^e"()d/Z
nStartPos = new long[nCount]; JX)%iJq#
nEndPos = new long[nCount]; wjzR 8g0bQ
for(int i=0;i<nStartPos.length;i++) fvE:'( #?
{ <Jc :a?ICe
nStartPos = input.readLong(); %VH{bpS|i:
nEndPos = input.readLong(); ?zpN09e
} 0 k(su
input.close(); 8el\M/u{
} uD=FTx
catch(IOException e){e.printStackTrace ();} *`]#ntz9
catch(Exception e){e.printStackTrace ();} D[H #W[
} eo [eN.
U0m 5Rc
\8^c"%v,:
private void processErrorCode(int nErrorCode) zk++#rB
{ Hd_W5R
System.err.println("Error Code : " + nErrorCode); j1~'[
} 0rrNVaM
)JsmzGC0
"/kTEp
//停止文件下载 w}rsboU
public void siteStop() E+"m@63
{ c0U=Hj@@
bStop = true; 1F,>siuh ,
for(int i=0;i<nStartPos.length;i++) FW@(MIH
fileSplitterFetch.splitterStop(); zn)Kl%N^
"?HDv WP=w
"3;b,<0
} 'eYM;\%('
} bXNM.K
//负责部分文件的抓取 #S|DoeFs
**FileSplitterFetch.java }7HR<%<7
*/ qdNt2SO
package NetFox; ISDeLUihY
+1pY^#A
5H^"
import java.io.*; ExxD w_VGT
import java.net.*; Ri<'apl
eEmuE H@X
'DdR2
public class FileSplitterFetch extends Thread { "6t#
pNNvg,hS8
))xP]Muv
String sURL; //File URL 7x''V5*j
long nStartPos; //File Snippet Start Position FzzV%
long nEndPos; //File Snippet End Position gp(: o$
int nThreadID; //Thread's ID b?]Lx.l-
boolean bDownOver = false; //Downing is over D.ERt)l>
boolean bStop = false; //Stop identical )|N_Q}
FileAccessI fileAccessI = null; //File Access interface X3zpU7`Av+
0`Hr(J`F
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M"\j7(
{ f=--$o0U~
this.sURL = sURL; +t7n6
this.nStartPos = nStart; ?,z/+/:
this.nEndPos = nEnd; _O;2.M%@
nThreadID = id; hdN[wC]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p*C|kEqk
} vp4NH]fJ
^~DDl$NH
De`p@`+<#~
public void run() 5H79-QLd
{ z@Uf@~+U
while(nStartPos < nEndPos && !bStop) 5Z_7Sc
{ `Kb"`}`_vm
6d{&1-@>
(iJ9ekB
try{ 3aUWQP2
URL url = new URL(sURL); Vo`,|3^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8Cef ]@x
httpConnection.setRequestProperty("User-Agent","NetFox"); rE?Fp
String sProperty = "bytes="+nStartPos+"-"; "n%0L4J
httpConnection.setRequestProperty("RANGE",sProperty); kNk$[Yfs
Utility.log(sProperty); Hw1:zro
8nE}RD7bx
0K'^g0G
InputStream input = httpConnection.getInputStream(); ]AB'POa
//logResponseHead(httpConnection); r7Zx<c
PD$' ~2
z,K;GZuP
byte[] b = new byte[1024]; =berCV
int nRead; f >$V:e([
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )8&;Q9'o
{ jBMGm"NE
nStartPos += fileAccessI.write(b,0,nRead); hCpcX"wND
//if(nThreadID == 1) 05ovz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I[w;soI
} ZwOX ,D
bnZ~jOHl
py }`thx
Utility.log("Thread " + nThreadID + " is over!"); >_|$7m.?n[
bDownOver = true; 4GqwY"ja
//nPos = fileAccessI.write (b,0,nRead); L0X/
} %4,v2K
catch(Exception e){e.printStackTrace ();} #5X535'ze
} gZ@z}CIw'
} N%Uk/ c'
n^iq?u
ZG$PW<73~
//打印回应的头信息 u:w
public void logResponseHead(HttpURLConnection con) Ohn?>qQ
{ d;hv_h
for(int i=1;;i++) ~-f"&@){,
{ -*[:3%
String header=con.getHeaderFieldKey(i); _lMSW6
if(header!=null) D~b_nFD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !hjA
Utility.log(header+" : "+con.getHeaderField(header)); Ox%p"xuP,
else (sqI:a
break; e#odr{2#4u
} :^rt8>~
} 0b(x@>
h.jO3q
mlix^P
public void splitterStop() iHKX#*
{ y$y!{R@
bStop = true; sc&u NfJ
} X'J!.Jj
6~^ M<E
n?:%>Os$
} * zt?y
H b?0?^#
bbs'>D3
/* :Z&<5
**FileAccess.java ^v5<*uf%m
*//文件访问(定位，写) <Uc?#;%Y}
package NetFox; Q!y%N&
import java.io.*; `8/D$
J%FF@.)k
s("\]K
public class FileAccessI implements Serializable{ 7 T
vYg>^!Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n7/>+V+
RandomAccessFile oSavedFile; Hu$y8_Udw
long nPos; <DZ$"t
+Ze;BKZ3
mtmTlGp6Lc
public FileAccessI() throws IOException M(?0c}z
{ 4'5|YGQj
this("",0); $.x,[R aN
} B[s
w:+&i|H>
2ElZ&(RZJF
public FileAccessI(String sName,long nPos) throws IOException 5x"eM=
{ \}71pzw(
oSavedFile = new RandomAccessFile(sName,"rw"); L;-V Yo#
this.nPos = nPos; an2Yluc;
oSavedFile.seek(nPos); <q&4Y+b
} 8d7 NESYl
^[6el_mj
8j)*T9
public synchronized int write(byte[] b,int nStart,int nLen) m5v IS
{ :-Ml?:0_X
int n = -1; [@_W-rA
try{ %-woaj
oSavedFile.write(b,nStart,nLen); /2'l=R5#
n = nLen; A(*c|Aj9
} E>iN>
catch(IOException e) xqb*;TBh*
{ 3EHB~rL/C
e.printStackTrace (); :(iBLO<x
} C55Av%-=
tl;b~k
20# V?hX3
return n; l5#SOo\
} =!\Y;rk
p\R&vof*
!Df>Q5~g
} .C` YO2,
zpjE_|
]$=#:uf
/* x4K A8
**SiteInfoBean.java @N]]Cf>x
*/ Lg~ll$ U
package NetFox; G6dUm_iB
m}7Nu
cn Ohj
public class SiteInfoBean { A*g-pJh
msY6zJc`
"W~vSbn7
private String sSiteURL; //Site's URL R.cR:fA
private String sFilePath; //Saved File's Path >p'{!k
private String sFileName; //Saved File's Name K^ ALE
private int nSplitter; //Count of Splited Downloading File S=j pn
O7p=N8V
3m| C8:
public SiteInfoBean() THARr#1b};
{//nSplitter的缺省值为5 O?O=]s u
//default value of nSplitter is 5 ?:h*=0>
this("","","",5); N=\weuED
} ^GlzKl
bjo}95
9s1^hW2%Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7Ie=(x8):
{ LmytO$?2(
sSiteURL= sURL; fm L8n<1
sFilePath = sPath; d8iq9AP\o
sFileName = sName; 6bPl(.(3
this.nSplitter = nSpiltter; 0U~*uDU
Mi;Pv*
o{hX?,4i
} B$n1k45
OJd/#KFm
U(LLIyZv
public String getSSiteURL() +~~2OUL
{ 0HUylnXf0
return sSiteURL; 2$ &B@\WY
} QIg'js$W
C T\@>!'f
7WwE] ^M
public void setSSiteURL(String value) b;%t*?t
{ lh[?`+A
sSiteURL = value; Z #T
} Y2;2Exp^
T];dFv-GT
uuxVVgWp{
public String getSFilePath() qXhdU/ =
{ e,&#,O
return sFilePath; ^,,}2dsb>
} [Ky3WppR
x FWhr#5,
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public void setSFilePath(String value) lj UdsUw
{ l&}}Io$?@
sFilePath = value; NSBcYObX
} b]fx
TDUY&1[
#qh ,
public String getSFileName() \H~zN]3^
{ vP=68muD
return sFileName; O=;jDWE
} IrMB=pWo
i")0 3b
8XG';K_
public void setSFileName(String value) .r2*tB).
{ 9Msy=qvYG
sFileName = value; z~ywFk}KGd
} R|v'+bv
H]pI$t3~
yIrJaS-
public int getNSplitter() Zk`yd8C
{ 'E+"N'M|
return nSplitter; AYgXqmH~+
} u*TC8!n
B\v+C!/f|
Xl$,f`f~
public void setNSplitter(int nCount) 76wNZv)9
{ '3Lu_]I-
nSplitter = nCount; ICvV}%d
} pF4Z4?W
} __2<v?\
P RWb6
Qr9;CVW
/* ?oFd%|I
**Utility.java 6,aH[>W
*/ *<\K-NSL
package NetFox; Xv|=RNz
@phVfP"M
\ l#eW x
public class Utility { mL=d EQ
ocFk#FW
z -!w/Bv@
public Utility() Aeb(b+=
{ XzHR^^;u"*
b:D92pH
qD4]7"9
} S0)JIrrHC
&CQO+Yr$l
//线程睡眠 Y.\x.Hg
public static void sleep(int nSecond) $[A\i<#
{ tqZ+2c<W3
try{ PDuc;RG
Thread.sleep(nSecond); @kqxN\DE
} @Fb1D"!
catch(Exception e) +yp:douERi
{ Z*ip=FYR
e.printStackTrace (); P"8Ix
} N+=|WeZ
} 80Dn!9j*
RqtBz3v
//日志 eHyUY&N/
public static void log(String sMsg) U}RBgPX!
{ &ASR2J
System.err.println(sMsg); ujZ`T0
} bI55G#1G
h6Z:+
`8ac;b
public static void log(int sMsg) f9W:-00QD
{ kFv*>>X`
System.err.println(sMsg); t$18h2yOL
} yQiY:SH
} -GAF>
c]PTU2BB8
G}fBd
/* @kWL "yy,
**TestMethod.java <X:JMj+
*/ }l|S]m!
package NetFox; 6OAs%QZ
#$I@V4O;#
D\AVZ76F1
public class TestMethod { Uj):}xgi'
`m7<_#Y
X0VSa{
public TestMethod() >u?.gJm~
{ ///xx/weblogic60b2_win.exe OG/b5U
try{ At'CT5=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DB5J3r81
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iT>u&0B-
SiteFileFetch fileFetch = new SiteFileFetch(bean); R}ki%i5|
fileFetch.start(); x b"z%.j
} :A8}x=K
catch(Exception e){e.printStackTrace ();} H~a ~'tm
fQJ`&9m*BF
qq/>E*~
} d:@+dS
<+_XGOt0<
jk9f{Iu
public static void main(String[] args) D\acA?d`
{ {^WK#$]
new TestMethod(); RdYmh>c
} EtKq.<SJ
} +/~]fI
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