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)); \wp8kSzC
} }7i}dyQv}
for(int i=0;i<nEndPos.length-1;i++) b{,vZhP-
{ .p'\@@o5
nEndPos = nStartPos[i+1]; #B__-"cRv
} 7 .xejz
nEndPos[nEndPos.length-1] = nFileLength; ,%KMi-w]q,
} YVO~0bX:
} XeXK~
!/Wv\qm
9$^v*!<z\
//启动子线程 KA."[dVa
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +}C M2>M
for(int i=0;i<nStartPos.length;i++) G 'CYvV
{ %sS7o3RW\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zU# OjvNk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KvEZbf3f
nStartPos,nEndPos,i); mZ.E;X& ,*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t`0(5v
fileSplitterFetch.start(); ^ |>)H
} wtQ(R4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TZ:dY x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); EU()Nnm2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?D]T|=EZY
nEndPos = " + nFileLength); u &{|f
// fileSplitterFetch[nPos.length-1].start(); %/wfYRp*
9z(h8H
m A|"
//等待子线程结束 cKAZWON8;v
//int count = 0; j*jq2u
//是否结束while循环 u_S>`I
boolean breakWhile = false; "HbrYYRb'
\JGRd8S[
p+R8Mo;I
while(!bStop) <$`udP@
{ pl.=u0 *
write_nPos(); <~Tfi*^+
Utility.sleep(500); 7@i2Mz/eV
breakWhile = true; [oS.B\Vc
JmVha!<qk
;%PdSG=U
for(int i=0;i<nStartPos.length;i++) ]I0(_e|z}
{ +isaqfy/
if(!fileSplitterFetch.bDownOver) ]TKM.[[
{ d?(eL(W
breakWhile = false; H@8 ;6D
break; o#F03
} I\ y>I?X
} #|{^k u
if(breakWhile) Y&DC5T]
break; fpvzx{2
E%>){Y)
_:l<4u!
//count++; HltURTbI
//if(count>4) ,_yf5 a
// siteStop(); As*59jkB
} lb`2a3W/
y8\4TjS1
V~qlg1h
System.err.println("文件下载结束！"); oNBYJ]t
} g/m%A2M&aH
catch(Exception e){e.printStackTrace ();} ,h$j%->U
} 3mM.#2=@>
atWAhN
XWFuAE
//获得文件长度 w~=@+U$f
public long getFileSize() t2vo;,^euL
{ Ic&Jhw;]z
int nFileLength = -1; [KjL`
try{ @g'SH:}
URL url = new URL(siteInfoBean.getSSiteURL()); @y`7csbp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =9vmRh?8
httpConnection.setRequestProperty("User-Agent","NetFox"); j*;/Cah]k
xkebel`%
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int responseCode=httpConnection.getResponseCode(); EYF]&+ 9
if(responseCode>=400) '5"`H>[
{ %j?<v@y
processErrorCode(responseCode); a=3{UEi'o
return -2; //-2 represent access is error +']S
} !U!}*clYL
zos#B30
@VcSK`
String sHeader; T5di#%: s
2*1s(Jro
~2*8pb 4
for(int i=1;;i++) $:MO/Suz{
{ B%Spmx8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K%"cVqb2V
//Utility.log(in.readLine()); 0UT2sM$
sHeader=httpConnection.getHeaderFieldKey(i); ?QXo]X;f&
if(sHeader!=null) D2}nJFR ]
{ {CR'Z0
if(sHeader.equals("Content-Length")) .4wp
{ xN#. Pm~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8TnByKZz
break; $?u ^hMU=
} i bwnK?ZA
} Ka\%kB>*`
else SggS8$a`
break; fX2PteA0qX
} `&yUU2W
} OVm $
catch(IOException e){e.printStackTrace ();} pJE317 p'
catch(Exception e){e.printStackTrace ();} U ]6Hml;l
pB;p\9A*q
jE{2rw$ZJ?
Utility.log(nFileLength); l`R/WC
K-nf@o+
hOSkxdi*^
return nFileLength; nn_j"Nu
} #ab=]}2W_g
Mb(aI!;A
^KJIT3J(#
//保存下载信息（文件指针位置） Gm.n@U p
private void write_nPos() ryq95<lF
{ Y?z@)cL
try{ +cVnF&@$
output = new DataOutputStream(new FileOutputStream(tmpFile)); j5:{H4?
output.writeInt(nStartPos.length); {>cO&eiCt
for(int i=0;i<nStartPos.length;i++) ivbuS-f=r
{ Whq@>pX8
// output.writeLong(nPos); ymBevL
output.writeLong(fileSplitterFetch.nStartPos); _KkLH\1g$
output.writeLong(fileSplitterFetch.nEndPos); V4OhdcW{
} /*bS~7f1
output.close(); ?Q]{d'g(sx
} Kj_hCSvf3e
catch(IOException e){e.printStackTrace ();} _azg 0.)
catch(Exception e){e.printStackTrace ();} l*]*.?m/5
} GiN\nu<!
ccJ@jpXI
>]k'3|vV
//读取保存的下载信息（文件指针位置） yjVPaEu]aU
private void read_nPos() <"@~
{ Nd~?kZZu
try{ %Y` @>P'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )-2o}KU]>
int nCount = input.readInt(); E VBB:*q6
nStartPos = new long[nCount]; j#b?P=|l
nEndPos = new long[nCount]; :hG?} [-2
for(int i=0;i<nStartPos.length;i++) $3sS&i<
{ !0~$u3[b
nStartPos = input.readLong(); Fr)G h>
nEndPos = input.readLong(); u4=j!Zb8}
} |wZ8O}O{E
input.close(); F}A@H<?
} O=#FpPHrdw
catch(IOException e){e.printStackTrace ();} g`!:7|&,_
catch(Exception e){e.printStackTrace ();} J8$G-~MeJ
} DLkNL?a
$@t-Oor;
_gB`;zo
private void processErrorCode(int nErrorCode) lu(<(t,Lbs
{ V,($I'&/
System.err.println("Error Code : " + nErrorCode); 92GO.xAD?
} p IXBJk
5yO6szg
j3rBEQ,R
//停止文件下载 o)7gKWjujP
public void siteStop() -tSWYp{
{ tH<v1LEZN
bStop = true; 9/MUzt
for(int i=0;i<nStartPos.length;i++) `av8|;
fileSplitterFetch.splitterStop(); 8ltHR]v
AyKaazm]9
](vshgp2
} Z xLjh
} l,*v/95h
//负责部分文件的抓取 =/"Of
**FileSplitterFetch.java rO/mK$
*/ >'/G:\M>A
package NetFox; k=O2s'F`
)kl| 5i
Mu18s}
import java.io.*; 3mgFouX2x,
import java.net.*; vt[4"eU
zqqpBwk#
j[yGfDb
public class FileSplitterFetch extends Thread { A8hj"V47
sf]y\_zU
h%(dT/jPL)
String sURL; //File URL {>G\3|^D
long nStartPos; //File Snippet Start Position s@f4f__(]
long nEndPos; //File Snippet End Position l0g#&V--
int nThreadID; //Thread's ID Zbxd,|<|
boolean bDownOver = false; //Downing is over 7ju7QyR
boolean bStop = false; //Stop identical Gu<3*@Ng
FileAccessI fileAccessI = null; //File Access interface I~MBR2$9
yE-&TW_q:>
@dcT8 YC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _Q/D%7[pa
{ (^Xp\dyZL
this.sURL = sURL; pK4I?=A'
this.nStartPos = nStart; m~#S76!w
this.nEndPos = nEnd; '!Vn
nThreadID = id; *~M=2Fj;i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Tn/T:7C
} iqghcY)
!'B.ad
i)\`"&.j>N
public void run() (hd^
{ q~r)B}
while(nStartPos < nEndPos && !bStop) \CB{Ut+s
{ LS4c|Dv
cg<10KT
o)cd!,h
try{ r~u/M0h `
URL url = new URL(sURL); BXaA#} ;e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,>2ijk#
httpConnection.setRequestProperty("User-Agent","NetFox"); }.4`zK&SB
String sProperty = "bytes="+nStartPos+"-"; KSuP'.l
httpConnection.setRequestProperty("RANGE",sProperty); 1#Dpj.cO#
Utility.log(sProperty); xzy7I6X
,Vt7Kiu
' G-]>
InputStream input = httpConnection.getInputStream(); `Qv7aY
//logResponseHead(httpConnection); OqY8\>f-
B>t$Z5Q^X
O:RPH{D
byte[] b = new byte[1024]; 9C$b^wHd
int nRead; 8=T;R&U^M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T%KZV/
{ %]>c4"H
nStartPos += fileAccessI.write(b,0,nRead); T^aEx.`O}`
//if(nThreadID == 1) +XJj:%yt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KB7CO:
} 9<WMM)
2<yi8O\
_C&2-tnp
Utility.log("Thread " + nThreadID + " is over!"); -fz |
bDownOver = true; I_'S|L
//nPos = fileAccessI.write (b,0,nRead); }-)2CEj3L%
} [U]*OQH`e
catch(Exception e){e.printStackTrace ();} A"\kdxC
} 4t|g G`QW7
} Vur$t^zE
LSNa
%U)/>Z
//打印回应的头信息 $91c9z;f^
public void logResponseHead(HttpURLConnection con) 22`W*e@6h
{ p<'#f,o
for(int i=1;;i++) ~o= Sxaf
{ L"1UUOKy
String header=con.getHeaderFieldKey(i); m7^aa@^m
if(header!=null) wS <d8gw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Eg5|XV
Utility.log(header+" : "+con.getHeaderField(header)); &iR>:=ksN
else 6/wAvPB$
break; CwTx7 ^qa
} A0cC)bd&
} X +*@
m-dne/%_
za1MSR
public void splitterStop() *|Q'?ty(x
{ e4ydn
bStop = true; .rD@Q{e50
} 2+TCFpv
*.ri8
92WvD
} :qc@S&v@]
XN5EZ#
8*H-</ =
/* vmvk
**FileAccess.java EJ.oq*W!*J
*//文件访问(定位，写) hewX)
package NetFox; x %L2eXL
import java.io.*; U voX\
GX&BUP\
\$/)o1SG
public class FileAccessI implements Serializable{ x:88E78
yN5g]U.Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4cRF3$amd
RandomAccessFile oSavedFile; $}jp=?,t
long nPos; 'LpJ:Th
tlV>
BdG~y1%:
public FileAccessI() throws IOException 84DneSpHsp
{ VtUe$ft
this("",0); sczN0*w&C
} ,u#uk7V
=GL}\I
cZk?o
public FileAccessI(String sName,long nPos) throws IOException 8E&}+DR?
{ 2xhwi.u
oSavedFile = new RandomAccessFile(sName,"rw"); Sf B+;i'D
this.nPos = nPos; Yewn
oSavedFile.seek(nPos); cNtGjLpx;
} Ah;2\0|t
^G[xQcM73
-X'HZ\)
public synchronized int write(byte[] b,int nStart,int nLen) bvuoGG*
{ `ky< *
int n = -1; &8_]omuNV
try{ ]iRE^o6
oSavedFile.write(b,nStart,nLen); *&q\)\(3w
n = nLen; WM.JoQ
} 0Jm6 r4s?
catch(IOException e) KiT>W~
{ ,aeQXI#@
e.printStackTrace (); 8;ke,x
} S(.AE@U
~YA* RCe
\{t#V ~
return n; a*$to/^r
} mvO!Y
k<Z^93 S
@*]l.F
} ^ llZf$`
}&I\a
]>E*s3h
/* PUV)w\!&is
**SiteInfoBean.java 9W:oo:dK F
*/ _T&?H&#
package NetFox; J0*hJ-/u
_G|hKk^,
K 4QJDC8
public class SiteInfoBean { HYyO/U9z|I
p~6/+ap
8W#/=Xh?
private String sSiteURL; //Site's URL ?:vp3f#
private String sFilePath; //Saved File's Path y >r7(qg
private String sFileName; //Saved File's Name n$ $^(-g@)
private int nSplitter; //Count of Splited Downloading File lqn7$
B8UtD
5ppOG_
public SiteInfoBean() 'MRvH lCM
{//nSplitter的缺省值为5 $}_N379&
//default value of nSplitter is 5 bXF>{%(}E
this("","","",5); Oi AZA<
} -$**/~0zU
U`N|pPe:w
AD#]PSB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V>ML-s9
{ '9c`[^
sSiteURL= sURL; GL[#XB>n
sFilePath = sPath; 4z#{nZG
sFileName = sName; NdGIH/Y;M
this.nSplitter = nSpiltter; p4Cw#)BaS
ZQXv-"
[zl@7X1{_
} _8P"/( `Rw
) DXN|<A
_x&;Fa%
public String getSSiteURL() gD10C,{
{ <f.*=/]W2
return sSiteURL; k"D6Vyy`
} n8UQIa4&=
$R(?@B(
5b45u 6
public void setSSiteURL(String value) x|U~?
{ F-[zuYGp
sSiteURL = value; 7[h_"@_A7
} XK??5'&{
IROX]f}r(
4)0 %^\p
public String getSFilePath() QEKSbxL\W
{ [zv>Wlf,%
return sFilePath; !l|vO(
} 2_M+akqy^
4 AZ~<e\
Ls{z5*<FM
public void setSFilePath(String value) b&[9m\AX`
{ aSdh5?
sFilePath = value; HeABU(o4
} !>fYD8Ft,
yTzP{I
oJa6)+b(3
public String getSFileName() YL-/z4g
{ xFxl9oM."
return sFileName; WA}<Zme3[
} _J(n~"eR
xxkUu6x#
/WlK*8C
public void setSFileName(String value) nv&uhu/q
{ 1{+x >Pv:
sFileName = value; g?N~mca$
} N1,=5P$
#=F"PhiX`
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public int getNSplitter() rE0?R(_
{ h07Z.q ;
return nSplitter; pm$2*!1F(
} K*iy^}
,<?iL~> %
Vij P;
public void setNSplitter(int nCount) ?#; oqH<
{ = ms(dr^n
nSplitter = nCount; Rs_0xh
} 8|^dM$
} Ww5c9orXn
6BM[RL?T
[ []'U'
/* 0^'A^
**Utility.java MV +R$
*/ ^kZfE"iE2
package NetFox; "<o[X ?u
M S 3?#b
wKF #8Y
public class Utility { - s[=$pDU
piYv}4;:(
OQzJRu)mF#
public Utility() F*V<L
{ jv$Y]nf
RtVy^~=G
r/v'h@
} <;O=h; ~|
,XT#V\qne
//线程睡眠 nk.Y#+1)
public static void sleep(int nSecond) [Du@go1C
{ GT\, @$r
try{ 3t<XbHF9
Thread.sleep(nSecond); +|}R^x`z
} :g)0-gN
catch(Exception e) k.bzh.
{ E)==!T@E
e.printStackTrace (); v*Tliw`-U
} hsV+?#I
} )aoB-Lu
is=sV:j:
//日志 +mRFHZG
public static void log(String sMsg) /H#- \r&r
{ ?^Sk17G
System.err.println(sMsg); WrK!]17or
} rZRcy9$y>
eXJt9olI
5dffFe
public static void log(int sMsg) ]zp5 6U|xa
{ 3:Bwf)*
System.err.println(sMsg); _XT],"
} '[#a-8-JY_
} ~3}Gu^@
g\MHv#v*k
Pn@k)g
/* %bI(
**TestMethod.java |8I #`
*/ 8r '
package NetFox; .DSn H6O
(IXiwu
^l1tQnj)7
public class TestMethod { =H*}{'#
shW$V93<
U3r[ysf
public TestMethod() ( Lj{V}^
{ ///xx/weblogic60b2_win.exe \)'nxFKqV
try{ `|K,E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b?Wg|D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3L/qU^`
SiteFileFetch fileFetch = new SiteFileFetch(bean); =ark?<E
fileFetch.start(); ~~:w^(s9
} j,Sg?&"%=
catch(Exception e){e.printStackTrace ();} ~ILig}I
;9r Z{'i+|
Q(SVJ
} 9xWC<i
EubR]ckB
\RN,i]c-g/
public static void main(String[] args) _'&N01
{ '!`%!Xg
new TestMethod(); e;b,7Qw
} ~82[pY
} o?\)!_Z|
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