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)); %UQ{'JW?K
} jO,<7FPs5
for(int i=0;i<nEndPos.length-1;i++) aydal9M
{ r6$=|Yto
nEndPos = nStartPos[i+1]; 0wkLM-lN
} eYcx+BJ
nEndPos[nEndPos.length-1] = nFileLength; k_a'a)`$6
} ob00(?;H
} NZTYT\7
'u3+k.
? w?k-v
//启动子线程 =+"'=o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;yZ N "r
for(int i=0;i<nStartPos.length;i++) o 4b{>x
{ KB"iF}\P0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r{Q< a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V^{!d}
nStartPos,nEndPos,i); xI<dBg|]+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f oVD+\~Y
fileSplitterFetch.start(); )j6>b-H
} *h4m<\^U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Az-!LAu9 R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3EZwF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =CVT8(N*
nEndPos = " + nFileLength); [;=ky<K0E
// fileSplitterFetch[nPos.length-1].start(); cLU*Tx\
Q$vr`yV#=6
9(l'xuX
//等待子线程结束 =_dd4`G&<
//int count = 0; *i{.@RX?
//是否结束while循环 8QN8bGxK
boolean breakWhile = false; m6x. "jG
Yy)a,clZ*$
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while(!bStop) Zd(d]M_x
{ 7:L~n(QpP
write_nPos(); 668bJ.M\O
Utility.sleep(500); U(N$6{i_
breakWhile = true; M([H\^\:
~yi&wbTjM
\!QF9dP4
for(int i=0;i<nStartPos.length;i++) =Yj[MVn
{ ]'h)7
if(!fileSplitterFetch.bDownOver) Rdg0WT*;j
{ O|RO j
breakWhile = false; DjIswI1I
break; X{xJ*T y'
} 7h]R{_
} a1`cI5n
if(breakWhile) +7/*y}.U
break; `Y\/US70{c
3K!0 4\
|2<f<k/UT
//count++; $cOD6Xr)d
//if(count>4) %gMpV
// siteStop(); W-PZE|<
} -NPkN%h
wDhcHB
'h^DI`
System.err.println("文件下载结束！"); otSPi7|k
} C55n
catch(Exception e){e.printStackTrace ();} Kg`x9._2
} ]0i2]=J&,
pmyM&'#Id
IA`8ie+
//获得文件长度 87(^P3;@
public long getFileSize() ;]M67ma7C
{ 'D"K`Vw
int nFileLength = -1; R[9PFMn
try{ ]XGn2U\
URL url = new URL(siteInfoBean.getSSiteURL()); 9BD|uU;0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m90R8 V
httpConnection.setRequestProperty("User-Agent","NetFox"); .XKvk(9
V&oT':%q
g**%J Xo
int responseCode=httpConnection.getResponseCode(); *z"1MU
if(responseCode>=400) OEE{JVeI
{ =P;;&j3Z
processErrorCode(responseCode); ZU.)K>'
return -2; //-2 represent access is error :ZfUjqRE
} f5b`gvCY,#
pd>a6 lI`
\Tf{ui
String sHeader; /N]Ow
fd"~[z[
sR>;h /
for(int i=1;;i++) 4`-?r%$,:
{ 31sgf5 s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C$RAJ
//Utility.log(in.readLine()); Vc52s+7=8
sHeader=httpConnection.getHeaderFieldKey(i); b)hOzx
if(sHeader!=null) HA.NZkq.tV
{ y]pN=<*h5
if(sHeader.equals("Content-Length")) ]6%%X+$7
{ Q xF8=p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~:}XVt0%8
break; qv*uM0G6i
} h NOYFH
} "4k=(R?
else r{!"%03H_
break; uU ?37V
} S[hJ{0V
} E"1;i
catch(IOException e){e.printStackTrace ();} ]b~2Dap
catch(Exception e){e.printStackTrace ();} YV3TxvXMR
1yaIV+_y/
~\:j9cC
Utility.log(nFileLength); V0'p1J tD
.FbZVYc]
h>^jq{yu
return nFileLength; : 9?Cm`
} c7l!G~yx'
So\|Ye
>_0 i=.\
//保存下载信息（文件指针位置） Q"6hD?6.
private void write_nPos() #:vDBP05.m
{ qgC-@I
try{ 4=F]`Lql
output = new DataOutputStream(new FileOutputStream(tmpFile)); `\|3 ~_v
output.writeInt(nStartPos.length); _/]:=_bf_z
for(int i=0;i<nStartPos.length;i++) @Uj_+c q
{ t1:S!@
// output.writeLong(nPos); 4'{hI;&a&
output.writeLong(fileSplitterFetch.nStartPos); 3^A/`8R7K
output.writeLong(fileSplitterFetch.nEndPos); ,F?~'-K
} i9@;,4f
output.close(); b?2X>QJ
} ;+ Co!L
catch(IOException e){e.printStackTrace ();} ^0-e,d 9h
catch(Exception e){e.printStackTrace ();} sPE)m_u
} yrE,,N%I
w-'D*dOi
_5U%'\5s
//读取保存的下载信息（文件指针位置） tgvpf/cQ
private void read_nPos() "\zj][sL
{ _Xk03\n6
try{ L VU)W^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n<%=~1iY+
int nCount = input.readInt(); *t?~)o7
nStartPos = new long[nCount]; J+cAS/MYX
nEndPos = new long[nCount]; {Ukc D+.Y
for(int i=0;i<nStartPos.length;i++) }[KDE{,V
{ 6& &}P79
nStartPos = input.readLong(); Pi"~/MGP$
nEndPos = input.readLong(); iFwyh`Bcg
} EBIa%,
input.close(); vNK`Y|u@
} ezg^5o;
catch(IOException e){e.printStackTrace ();} p'Y&Z?8
catch(Exception e){e.printStackTrace ();} '?`@7Eol
} FD XWFJ
E*r
@tE&<[e
private void processErrorCode(int nErrorCode) Rg8m4xw
{ s}[A4`EWH
System.err.println("Error Code : " + nErrorCode); 38w.sceaT
} C)J_lI{^
s0\f9D
n{.*El>{
//停止文件下载 C-a*EG
public void siteStop() 3WO#^}t
{ t?]\M&i&
bStop = true; 55>" R{q
for(int i=0;i<nStartPos.length;i++) +7i7`'9pd
fileSplitterFetch.splitterStop(); I=4Xv<F
8 l'bRyuS
>bX-!<S
} b(.-~c('
} Xr@l+zr
//负责部分文件的抓取 e(OwS?K
**FileSplitterFetch.java D4=..;
*/ IdV,%d{
package NetFox; ,YP1$gj
"<PoJPh
[):{5hMA
import java.io.*; 97qtJ(ESI
import java.net.*; 5"-una>D
} * ?n?'
h*;g0QBkl
public class FileSplitterFetch extends Thread { V-D}U$fw
Sk6b`W7$
;mf4U85
String sURL; //File URL =_$XP
long nStartPos; //File Snippet Start Position dN$ 1$B^k
long nEndPos; //File Snippet End Position a"0B?3*r46
int nThreadID; //Thread's ID 4 [R8(U[g
boolean bDownOver = false; //Downing is over RLYU\@kK?
boolean bStop = false; //Stop identical 18DTv6?QG
FileAccessI fileAccessI = null; //File Access interface M>*0r<qn
E;6Y? vJ
~-XOvKJb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YMc8Q\*B
{ X+]L-o6I2
this.sURL = sURL; ~q0I7M
this.nStartPos = nStart; [,OJX N-4s
this.nEndPos = nEnd; W]@gQ(Ef
nThreadID = id; 'GEBxNH:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;;EDN45
} Qqd6.F
pP|,7c5
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public void run() 82j'MgGP
{ (Oxz'#TX
while(nStartPos < nEndPos && !bStop) A[u)wX^`f^
{ Vk MinE
l,*yEkU
JP{UgcaF
try{ 5SoZ$,a<e
URL url = new URL(sURL); NoFs-GGGh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dO>k5!ge|:
httpConnection.setRequestProperty("User-Agent","NetFox"); 1^Kj8*O8e
String sProperty = "bytes="+nStartPos+"-"; Yw6DJY
httpConnection.setRequestProperty("RANGE",sProperty); 6B7<
Utility.log(sProperty); 1vB-M6(
eq^TA1>T
vS7/~:C
InputStream input = httpConnection.getInputStream(); O0@w(L-
//logResponseHead(httpConnection); K^"w]ii=
NJn&>/vM
aQ(`6DQv
byte[] b = new byte[1024]; 7cIC&(h5
int nRead; k4S} #!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l%rx#;=u
{ q:vz?G
nStartPos += fileAccessI.write(b,0,nRead); 1*Sr5N[=
//if(nThreadID == 1) \n[ 392
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?k [%\jq{a
} 3LKB;
CD^CUbGk
c]6V"Bo}A
Utility.log("Thread " + nThreadID + " is over!"); *f79=x
bDownOver = true; K1:a]aU?Iu
//nPos = fileAccessI.write (b,0,nRead); Wm<z?.lS
} ;KZrl`
catch(Exception e){e.printStackTrace ();} .4wTjbO6
} fJX\'Rc\
} u K'<xM"%T
A:kkCG!~Nf
?3`q+[:
//打印回应的头信息 3>i>@n_
public void logResponseHead(HttpURLConnection con) ;4!=DFbU
{ }c} ( 5
for(int i=1;;i++) Yx6hA#7I
{ RXBb:f
String header=con.getHeaderFieldKey(i); W@l+ciZ_
if(header!=null) 3@&bxYXm
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o>2e!7
Utility.log(header+" : "+con.getHeaderField(header)); |</"N-#S
else 6^Ph '
break; 'g]hmE
} IQT cYl
} 3=Z<wD s
;P3>>DZ
2-~a P
public void splitterStop() wDDxj
{ \3r3{X _<`
bStop = true; lY.B
} B]1HS`*7
x"vwWJNQ
Xq|nJ|h
} WM/#.
Mec{_jiH&D
8 4z6zFv?Q
/* 2 #KoN8%
**FileAccess.java qtHfz"p
*//文件访问(定位，写) +O'vj
package NetFox; {1~9vHAZ
import java.io.*; CD}Ns
Yb}w;F8(
F+Z2U/'a
public class FileAccessI implements Serializable{ \k;U}Te<
`|]e6Pb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e$/&M*0\f
RandomAccessFile oSavedFile; h2% J/69
long nPos; uyFn}y62
B s,as
@44P4?;
public FileAccessI() throws IOException +jtA&1cf
{ " \:ced
this("",0); &s:=qQa1
} @;m$ua*|:
;`kWpM;
~n6[$WjZA
public FileAccessI(String sName,long nPos) throws IOException ;-Ss# &
{ a+41Ojv (
oSavedFile = new RandomAccessFile(sName,"rw"); ('t kZt%8
this.nPos = nPos; >!}`%pk(
oSavedFile.seek(nPos); -u|l}}bh
} -l "U"U"F
0O~p7D
M/{g(|{
public synchronized int write(byte[] b,int nStart,int nLen) A:eG5K}
{ _R7 w?!t8
int n = -1; ?>V6P_r>
try{ Tr&E4e
oSavedFile.write(b,nStart,nLen); o'Pu'y
n = nLen; A W)a">|
} t[EfOQ
catch(IOException e) &!jq!u$(
{ #.<V^
e.printStackTrace (); Pd~MiyO;K
} 2J<&rKCF
[T`}yb@
r~8;kcu7
return n; "!H@k%eAM|
} 5lTD]d
Q.k :\m*h
/s c.C
} ]>Si0%
i[150g?K
W&(f&{A
/* LmQ/#Gx
**SiteInfoBean.java Z)&D`RCf
*/ =-~;OH/
package NetFox; EA|k5W*b
(R'+jWH
Fk1.iRVzi
public class SiteInfoBean { ni6r{eSQ
2yKz-"E
$%PVJs
private String sSiteURL; //Site's URL &[@\f^~
private String sFilePath; //Saved File's Path :.iyR
private String sFileName; //Saved File's Name S &JJIFftO
private int nSplitter; //Count of Splited Downloading File 3bs4mCq
7 ({=*
^7aN2o3{
public SiteInfoBean() >fzwFNdo
{//nSplitter的缺省值为5 sG,+
//default value of nSplitter is 5 [$a<b/4
this("","","",5); 5|w&dM
} g:<?
M=y0PCD
}"zC >eX&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }q!_!q,@
{ E=u/tpj
sSiteURL= sURL; ;;V\"7q'
sFilePath = sPath; KWhZ +i`
sFileName = sName; - 8bNQU
this.nSplitter = nSpiltter; H"CUZ
6;oe=Q:Q
;GsQR+en
} A+ 0,i
E'c%d[:H,
;=jr0\|e
public String getSSiteURL() &|5GB3H=
{ 44sy`e
return sSiteURL; # |^^K!%
} a<m-V&4x
h qmSE'8
[s` G^
public void setSSiteURL(String value) ?4[H]BK
{ :\yc*OtX
sSiteURL = value; XM~~y~j
} jm3G?Vnq
pCU*@c!
fSA)G$b]
public String getSFilePath() nl1-kB)$e|
{ 61_f3S(u
return sFilePath; PlCc8Zy
} !gP0ndRJ=
~xyw>m+o.
v6uxxsI>Hm
public void setSFilePath(String value) ;(6P6@+o
{ n56;m`IU
sFilePath = value; I*\^,ow
} mlu 3K
~ 3T,&?r
&L4 q10-N
public String getSFileName() 2 x4=
{ lKV"Mh+6
return sFileName; ULBg{e?l8
} UQT'6* !
.q;ED`G
mBk5+KyT
public void setSFileName(String value) ijUzC>O+q
{ :&VcB$
sFileName = value; z4M1D9iPY
} O}Le]2'
w'ybbv{c
=%qEf
public int getNSplitter() @"|i"Hk^
{ \ijMw
return nSplitter; GAEO$e:
} rZwB>c
TGV
S~F`
public void setNSplitter(int nCount) 7#-y-B]l
{ :w-`PYJ%G
nSplitter = nCount; Jb(Y,LO^
} sR_xe}-
} >a>fb|r
\pY^^ l*
\4bWWy
/* `M@Ak2gcR+
**Utility.java Y2T$BJJ
*/ kA#vByf`v
package NetFox; '$m7ft}
8i0
hW2.8f$
public class Utility { &M"ouy Zo9
py<_HyJ
\2X$C#8E
public Utility() F 3RB
{ s& yk
3$p#;a:=n
Utt>H@t[
} E{Vo'!LY
n9hm790x-
//线程睡眠 ;b%{ilx:
public static void sleep(int nSecond) A7-r<s
{ <94G
try{ *\XH+/]+
Thread.sleep(nSecond); RtV.d\
} 8^yJqAXK
catch(Exception e) .y4&rF$n
{ ?nFO:N<
e.printStackTrace (); e~\QE0Oe:
} zlf}.
} Hi,t@!!
ffcLuXa
//日志 @}LZ! y
public static void log(String sMsg) RA/EpD:H
{ ps1@d[n
System.err.println(sMsg); sH!O0WL
} lZ+!H=`
<!'M} s
x:z0EYL
public static void log(int sMsg) x8[MP?Wz
{ =dH$2W)G
System.err.println(sMsg); HFtf
} UTk r.T+2X
} :jem~6i
*^XbDg9
(GU9p>2
/* lAASV{s{
**TestMethod.java 4tc:.
*/ )ly ^Ox
package NetFox; g`,AaWlF
;Ss$2V'a
y{=NP
public class TestMethod { d#_m.j
Vb4;-?s_
Tj/GClD:%
public TestMethod() ;!u;!F!i
{ ///xx/weblogic60b2_win.exe Kn}ub+ "J
try{ dbF M,"^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Nw<P bklz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SN">gmY+
SiteFileFetch fileFetch = new SiteFileFetch(bean); vA&Vu"}S
fileFetch.start(); ;5S}~+j
} \C|cp|A*&
catch(Exception e){e.printStackTrace ();} lpC @I^:
+1`t}hO
9`Q@'(m
} IB$7`7
jj&s}_75
q~Jq/E"f
public static void main(String[] args) SS3-+<z
{ fC<m^%*zgA
new TestMethod(); z@h~Vb&I
} s3QEi^~
} "^rNr_
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