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)); AU-n&uX
} &>e-(4Xu
for(int i=0;i<nEndPos.length-1;i++) Og=*R6i
{ ^c:Fy+fb
nEndPos = nStartPos[i+1]; "#(T
} rx(2yf
nEndPos[nEndPos.length-1] = nFileLength; /'31w9
} 6s0_#wZC
} \(t@1]&jw
}%Bl>M
\:'%9 x
//启动子线程 u%~igt@x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r5!/[_l
for(int i=0;i<nStartPos.length;i++) ?c0xRO%y
{ rvr-XGK36\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p~*UpU8u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L%>n>w
nStartPos,nEndPos,i); pp7$J2s+j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tv!_e$CR
fileSplitterFetch.start(); H\XP\4#u
} ChCrL[2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f4L`.~b'hb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6xD#?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h6} lpd
nEndPos = " + nFileLength); pZtu&R%GU
// fileSplitterFetch[nPos.length-1].start(); ;j4?>3
r\AyN= y
ID#I`}h.k
//等待子线程结束 765p/**
//int count = 0; -?(E_^ng
//是否结束while循环 1KjU ] r2
boolean breakWhile = false; )Tk1 QHU
6;|n]m\Vd
97ql5
while(!bStop) Z!U)I-x&
{ F'hHK.tT
write_nPos(); 8T(e.I
Utility.sleep(500); @xB*KyUW
breakWhile = true; r2k2%nI-J
e^ v.)
jg?x&'u\)
for(int i=0;i<nStartPos.length;i++) ar:+;.n
{ byv[yGa`
if(!fileSplitterFetch.bDownOver) !"eIV@7
{ Y5F]:gs@
breakWhile = false; ( H6c{'&
break; U#3J0+!
} sP ls zC[
} +|tC'gCnV
if(breakWhile) =2@B&
break; Yot?=T};3{
D$T%\ P
Br`IW
//count++; WD1G&5XP
//if(count>4) ,Jd ',>3
// siteStop(); /{|fyKo\?
} R9B&dvG
+"1NC\<*
`3:.??7N
System.err.println("文件下载结束！"); sqW* pi
} %Qj;,#z
catch(Exception e){e.printStackTrace ();} %Q.&ZhB
} =9j8cC5y
F+@5C:<?
s>^dxF!+
//获得文件长度 e[8LmuIZ
public long getFileSize() v'e[GB0
{ ;X?mmv'
int nFileLength = -1; X,LD
try{ `\+@Fwfx
URL url = new URL(siteInfoBean.getSSiteURL()); 7e<c$t#H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p ZZc:\fJ
httpConnection.setRequestProperty("User-Agent","NetFox"); Kw#i),M
7^g&)P
Aj0Tfdxy
int responseCode=httpConnection.getResponseCode(); 2 aL)
if(responseCode>=400) VZ\B<i
{ A,`8#-AX
processErrorCode(responseCode); Qci4J
return -2; //-2 represent access is error i F+vl]
} =KR NvW
f aLtdQi
&9Xhl''
String sHeader; Mb]rY>B4
0pbtH8~
;g~TWy^o
for(int i=1;;i++) #y%!\1M/:A
{ ~{Mn{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); n(el]_d
//Utility.log(in.readLine()); pZeE61c/
sHeader=httpConnection.getHeaderFieldKey(i); Q_t`.jus
if(sHeader!=null) Ry|!pV
{ $H-!j%hV
if(sHeader.equals("Content-Length")) (`:O~>[N
{ AhNq/?Q Q~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xe*aC
break; 6qaulwV4t
} &SrO)
} 65Cg]Dt71
else W]nSR RWco
break; 1n@8Kv
} 2"B_At
} 0q'w8]m
catch(IOException e){e.printStackTrace ();} )4&cph';
catch(Exception e){e.printStackTrace ();} {\(L%\sV@
^g`&7tX
TsGE cxIg
Utility.log(nFileLength); o9H^?Rut
3#TV5+x*"`
w.0qp)}
return nFileLength; 1u6^z
} HTyLJe
B~_d^`
~SnSEhE
//保存下载信息（文件指针位置） 7bV{Q355P
private void write_nPos() /;utcc
{ a(0*um(
try{ smry2*g
output = new DataOutputStream(new FileOutputStream(tmpFile)); TEaJG9RU>v
output.writeInt(nStartPos.length); Ck!VV2U#
for(int i=0;i<nStartPos.length;i++) +*hm-lv?
{ :Cp'm'omb
// output.writeLong(nPos); /=gOa\k|p
output.writeLong(fileSplitterFetch.nStartPos); 2^l[(N
output.writeLong(fileSplitterFetch.nEndPos); =hMY2D
} R<=zCE`:
output.close(); ~>+]%FPv
} LH@j8YB5u
catch(IOException e){e.printStackTrace ();} Yx>"bv
catch(Exception e){e.printStackTrace ();} A$a1(8H
} n2fbp\I
<Ce2r"U1e
(owrdPT!
//读取保存的下载信息（文件指针位置） uECsh2Uin
private void read_nPos() Gqy,u3lE
{ F 3'9u#
try{ 1hziXC0WY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); th&[Nt7
int nCount = input.readInt(); P[k$vD
nStartPos = new long[nCount]; a!u rew#
nEndPos = new long[nCount]; 1rDqa(7
for(int i=0;i<nStartPos.length;i++) y})70w@+_
{ w18y}mS"H
nStartPos = input.readLong(); @!8ZPiW<
nEndPos = input.readLong(); ryFxn|4
} 6O}`i>/6M
input.close(); *Otg*,\
} Z%n(O(^L
catch(IOException e){e.printStackTrace ();} ]| +<P-
catch(Exception e){e.printStackTrace ();} Co3:*nbRv
} ]hbyELs
^*fxR]Y
-G|G_$9
private void processErrorCode(int nErrorCode) /0eYMG+K=
{ rQaxr!
System.err.println("Error Code : " + nErrorCode); W[}s o6
} &CG*)bE
vVgg0Y2
R%c SJ8O#
//停止文件下载 XB_B4X1R
public void siteStop() Jzp#bgq}|
{ Nq@+'<@p$
bStop = true; ~O1&@xX
for(int i=0;i<nStartPos.length;i++) L^{|uP15N
fileSplitterFetch.splitterStop(); PtTHPAKj
5=1^T@~#&
D2,z)O%VK
} wWp(yvz
} =lVK IW
//负责部分文件的抓取 +|ycvHd
**FileSplitterFetch.java zrU{@z$l
*/ Usta0Ag
package NetFox; uZ=NSbYsA
H/"lAXfb
v%RP0%%{s
import java.io.*; 3dDX8M?
import java.net.*; kn/Ao}J74z
YXI'gn2b#
l3IWoa&sh
public class FileSplitterFetch extends Thread { >(snII
bl'z<S, '
<~)kwq'
String sURL; //File URL jH6&q~#
long nStartPos; //File Snippet Start Position J;prC
long nEndPos; //File Snippet End Position $/7pYl\n
int nThreadID; //Thread's ID +Lnsr\BA
boolean bDownOver = false; //Downing is over ku..aG`
boolean bStop = false; //Stop identical hnznp1[#@
FileAccessI fileAccessI = null; //File Access interface wGZR31
\{EpduwZ
&wB\ ~Ie-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :(H>2xS,s
{ Zx d~c]n
this.sURL = sURL; Z?O*'#yn
this.nStartPos = nStart; K_ci_g":
this.nEndPos = nEnd; C*G=cs\i
nThreadID = id; D3x/OyG(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q@jq0D)g
} k`x=D5s\
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}`NU@O#
public void run() [S@}T zE
{ 0V!l,pg
while(nStartPos < nEndPos && !bStop) 1DA1N<'
{ {Ions~cO)
T_lsGu/
ymNnkFv
try{ NVl [kw
URL url = new URL(sURL); zR32PG>9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yu;SH[{Wi
httpConnection.setRequestProperty("User-Agent","NetFox"); .&x}NYX4
String sProperty = "bytes="+nStartPos+"-"; ]K*8O<
httpConnection.setRequestProperty("RANGE",sProperty); sQ8s7l0D
Utility.log(sProperty); 7K{Nb
84{Q\c
A%2:E^k(s
InputStream input = httpConnection.getInputStream(); Y1arX^Zb
//logResponseHead(httpConnection); ?}B:
8L1ohj
%xQ.7~
byte[] b = new byte[1024]; .WQ+AE8Q
int nRead; oQL59XOT4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8+Td-\IMk
{ {vE(l'
nStartPos += fileAccessI.write(b,0,nRead); aceZ3U>W
//if(nThreadID == 1) C8L'si
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); . ]8E7
} n\ Hs@.
>~\89E02
MJ\eh>v&
Utility.log("Thread " + nThreadID + " is over!"); %riK+
bDownOver = true; k'PQ} ,Vb
//nPos = fileAccessI.write (b,0,nRead); 3.)b4T
} o#[ KS:Y
catch(Exception e){e.printStackTrace ();} Q_vW3xz
} U #~;)fZ
} :>81BuMvg
b,IocD6v;P
&ciN@nJ|$z
//打印回应的头信息 S{K0.<,E
public void logResponseHead(HttpURLConnection con) 8/"fWm/
{ q-Qxbg[>e
for(int i=1;;i++) P6Mhbmt9*
{ wP/A^Rs
String header=con.getHeaderFieldKey(i); Eaqca{%/^
if(header!=null) ?J,AB #+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j.:h5Y^N
Utility.log(header+" : "+con.getHeaderField(header)); x3zj?-
else 'r\ V.4
break; S:61vD
} |0z;K:5s
} "Y=+Ls(3o(
U'*t~x<
-ti{6:H8
public void splitterStop() "3F;cCDv]
{ pDhse2
bStop = true; #pHs@uvO
} _U{&@}3
&J!aw
6q>+!kXh
} [/_+>M
p*l$Wj
F6hmku>\1
/* A!63p$VT;
**FileAccess.java |([R'Orm
*//文件访问(定位，写) /1`cRyS
package NetFox; }!TL2er_
import java.io.*; Bg8#qv
C;~*pMAYe
%/.a]j!
public class FileAccessI implements Serializable{ ,pBh`av
T$=4O9G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q7bq
RandomAccessFile oSavedFile; pA4*bO+
long nPos; ]h9!ei [
[ REf>_R
C}5M;|%3)
public FileAccessI() throws IOException u? fTL2~
{ #?B%Ja% ;W
this("",0); 1=2^90
} u z\0cX_
q/1Or;iK
z}Jr^>
public FileAccessI(String sName,long nPos) throws IOException s4H2/EC
{ 4ujvD^
oSavedFile = new RandomAccessFile(sName,"rw"); t_ur&.^SB
this.nPos = nPos; A`6ra}U<
oSavedFile.seek(nPos); )$Z(|M4
} P;]F=m+*V
[hRU&z;W
:!zC"d9@
public synchronized int write(byte[] b,int nStart,int nLen) V,ZY*f0
{ m?[5J)eR
int n = -1; H0"=Vs,n
try{ n+1y
oSavedFile.write(b,nStart,nLen); Qju`e Eo
n = nLen; V^il$'
} -p-0;Hy
catch(IOException e) 3_5XHOdE
{ W0cgI9=9
e.printStackTrace (); %}>dqUyQ
} a1N!mQ^
Wd(86idnc
}vt%R.u
return n; v0l_w
} $WW)bP d4^
lnbmoHv
'YSuQP>
} ;,OfJ'q^
;\%sEcpT
RD<75]**{
/* l|/:Ot
**SiteInfoBean.java Z"I/ NGiU
*/ MQcr^Y_
package NetFox; |Wj;QO$C
\0FT!} L
~9$X3.+
public class SiteInfoBean { y:}sD_m0W
{fSfq&o
1q.(69M
private String sSiteURL; //Site's URL p D=w>"
private String sFilePath; //Saved File's Path tu%[p 4
private String sFileName; //Saved File's Name ]qw0V
private int nSplitter; //Count of Splited Downloading File bZipm(e
")lw9t`
84&XW
public SiteInfoBean() oYM,8 K
{//nSplitter的缺省值为5 uL?vG6% ^1
//default value of nSplitter is 5 7]22"mc
this("","","",5); d @rs3Q1z
} t"s5\;IJ
UU@fkk
19d6]pJ5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q9}m!*8e
{ ?$%%Mp(
sSiteURL= sURL; q'(z #h,cv
sFilePath = sPath; Q1tpCT
sFileName = sName; =7ydk"xM*
this.nSplitter = nSpiltter; 0-2"FdeQU
hRTMFgO
PCfo
} @Z\~
;6DnId2Zh
&$ p[
public String getSSiteURL() LP`CS849z2
{ PJ 9%/Nrh
return sSiteURL; E20 :uZ7\
} U w Eiz
%%g-GyP 1
{K7YTLWY
public void setSSiteURL(String value) 0rzVy/Z(
{ _ 6:ww/
sSiteURL = value; $3\yf?m}q
} F=&;Y@t
3q &k
QB 77:E
public String getSFilePath() t=dO
{ `mB.pz[
return sFilePath; 4#Eul
} l C\E
wq72%e
e.X@] PQJQ
public void setSFilePath(String value) n,KA&)/s
{ 3ps,uozj
sFilePath = value; C{Blqf3V0
} D@vMAW
\f"?Tv-C'
N8+P
public String getSFileName() ,k*F`.[
{ &=-PRza%j
return sFileName; o'qm82* =
} vR]mSX3)?
l\}25 e
/PC`0/b
public void setSFileName(String value) #%cR%Z
{ jzrt7p*k}
sFileName = value; 6An{3"
} `$-lL"
r'd/qnd
}[,3yfiX
public int getNSplitter() ~n]NyVFP
{ ?'2 v.5TQt
return nSplitter; %CT!$Y'n
} ahp1!=Z-=
u33zceE8
UB&2f>
public void setNSplitter(int nCount) J~dTVBx
{ o>!JrH
nSplitter = nCount; N5\{yV21",
} #Wx=v$"
} nW&$~d
rv?!y8\
2nx9#B*/T
/* WF)s*$'uz;
**Utility.java r~[B_f!
*/ K\X: G-C9
package NetFox; Mdky^;qq3;
gfVDqDF
E$T(Qu<-
public class Utility { A\C'dZ <N
'bm:u
IHVMHOq}'
public Utility() yfq>,
{ yjeL9:jH[
q u:To7
Ws>i)6[
} 6!RikEAh
-aN":?8(G
//线程睡眠 ,cS0
public static void sleep(int nSecond) 3k{c$x}
{ ._ih$=
try{ ^^ j/
Thread.sleep(nSecond); _3U|2(E
} l4Y1(
catch(Exception e) "7?t)FOo
{ xSOoIsL[
e.printStackTrace (); t 2G1[j!
} u#VweXyU
} 8GW ut=D
SW=aHM
//日志 *2#FRA#q
public static void log(String sMsg) `uhL61cMp
{ .$^wy3:F"
System.err.println(sMsg); CLktNR(45
} ?w8pLE~E
.m!s". ?[
sZEgsrJh
public static void log(int sMsg) (NM6micc
{ H8<m9zDvl
System.err.println(sMsg); !?n50
} 7BK46x
} 776 nWw)
!*8#jy
PAr|1i)mB
/* .f+9 A>
**TestMethod.java RSFJu\0}N
*/ jDJ.
package NetFox; Hz5;Ruw'
sM0c#YK?
Kv1vx*>
public class TestMethod { <]c#)xg
o6/Rx#A
X-v~o/r7
public TestMethod() UCn.t
{ ///xx/weblogic60b2_win.exe 5{HtJ?sKc5
try{ 6s&qZ+v-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); { $X X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &EGY+p|2Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); n)Hk8)^8
fileFetch.start(); RAdvIIQp:
} T[m ~6
catch(Exception e){e.printStackTrace ();} Q{8qm<0g
SUo^c1)G
rEg+i@~
} <gR`)YF7
8 `o{b"l+
C*$|#.l
public static void main(String[] args) s7vPI
{ ]}/mFY?7
new TestMethod(); |o|gP8
} yIlV[_
} F1E.\l
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