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)); 'y:+w{I2o
} OD1>s6uA7
for(int i=0;i<nEndPos.length-1;i++) sJcwN.s
{ kF"G {5
nEndPos = nStartPos[i+1]; h<f]hJ`ep
} zlN<yZB^
nEndPos[nEndPos.length-1] = nFileLength; lJXihr
} P'CDV3+
} { BDUl3T
vWpkU<&3|
h*X u/aOg
//启动子线程 ^U@Erc#d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; w}QU;rl8q
for(int i=0;i<nStartPos.length;i++) J@pCF@'
{ )3KQ QGi8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j.y8H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7<3eB)S
nStartPos,nEndPos,i); ;AK@Kb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;K<W<v5m0N
fileSplitterFetch.start(); n42XqR
} xs3t~o3y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !8i[.EAT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sa>}wz<o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FrBJv<
nEndPos = " + nFileLength); =WP`i29j9}
// fileSplitterFetch[nPos.length-1].start(); 3XomnL{
/tGj`C&qtw
4^rO K
//等待子线程结束 ,~,{$\p
//int count = 0; a6fqtkZ x
//是否结束while循环 vT>ki0P_;
boolean breakWhile = false; WAt| J2
5PU$D`7it
D%k]D/
while(!bStop) $Sfx0?'
{ i=G.{.
write_nPos(); ?sBbe@OC?
Utility.sleep(500); LxC"j1wfl
breakWhile = true; 4chSo.= 4V
a\m@I_r.N
]ZOzqh_0C
for(int i=0;i<nStartPos.length;i++) Tp0^dZM+
{ [J.-gN$X@
if(!fileSplitterFetch.bDownOver) r6*~WM|Sq7
{ MHVHEwr.{
breakWhile = false; s&7,gWy}BE
break; ")87GQ(R
} !(EJ.|LH
} zT5@wm
if(breakWhile) p;VHg
break; `II/nv0jn
ekj@;6 d]
s*U~Q=Z
//count++; ?!J{Mrdn
//if(count>4) \y G//
// siteStop(); ITu6m<V
} ,!RbFME&H
=fZ)2q
`/mcjKQ&9y
System.err.println("文件下载结束！"); HjO-6F#s
} !?7c2QRN
catch(Exception e){e.printStackTrace ();} Ws;}D}+
} T53|*~u
MWS=$N)v*
q! +?
//获得文件长度 *y;(c)_w/%
public long getFileSize() <d\Lvo[
{ 9aE!! (E
int nFileLength = -1; {T]^C
try{ Lit@ m2{\
URL url = new URL(siteInfoBean.getSSiteURL()); l 6;}nG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5Y\wXqlY
httpConnection.setRequestProperty("User-Agent","NetFox"); XD8MF)$9
od7 [h5r
W7a aL
int responseCode=httpConnection.getResponseCode(); #O<2wMb2<
if(responseCode>=400) o1"MW>B,4
{ `&"-|
processErrorCode(responseCode); Qifjv0&;u
return -2; //-2 represent access is error g$\Z-!(
} RQZ|:SvV
=?} t7}#
HY,+;tf2r
String sHeader; Q]Fm4
94umk*ib
3@r_t|j
for(int i=1;;i++) CV~\xYY
{ .cTK\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s:j"8ZH
//Utility.log(in.readLine()); p=Nord
sHeader=httpConnection.getHeaderFieldKey(i); i9.~cnk
if(sHeader!=null) L,&R0gxi
{ Mb6#97
if(sHeader.equals("Content-Length")) 9Se7 1
{ @?A39G{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); asDq(J`sQ
break; Mt@P}4
} S aCa
} 8:%=@p>$
else qV%t[>
break; KKR@u(+"a
} s}]qlg
} k\T,CZ<
catch(IOException e){e.printStackTrace ();} $td=h)S^`
catch(Exception e){e.printStackTrace ();} }nDKSC/[V!
%rpJZ t
$'I+] ;
Utility.log(nFileLength); =#@eDm%
2 0Xqs,
[b:$sR;
return nFileLength; !%' 1x2?
} ?j^[7
K|-?1)Um
b_&;i4[
//保存下载信息（文件指针位置） ffuV158a&
private void write_nPos() -_bHLoI
{ VZ?"yUZ Id
try{ %[:\ZwT,-
output = new DataOutputStream(new FileOutputStream(tmpFile)); VtX9}<Ch~
output.writeInt(nStartPos.length); as1ZLfN.
for(int i=0;i<nStartPos.length;i++) `mro2A
{ oT7=
// output.writeLong(nPos); 6&pI{
output.writeLong(fileSplitterFetch.nStartPos); $MF U9<O
output.writeLong(fileSplitterFetch.nEndPos); IL?mt2IQ>
} cTO\Vhg
output.close(); gU7@}P
} ?)$+W+vK
catch(IOException e){e.printStackTrace ();} 4Gl0h'!(
catch(Exception e){e.printStackTrace ();} HS{a^c%
} `I(#.*
W\s ]qsLS
2%YtMkC5
//读取保存的下载信息（文件指针位置） 0n25{N
private void read_nPos() fk%yi[
{ cPh U qET
try{ xjHOrr OQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XeD9RMT
int nCount = input.readInt(); *Mf;
nStartPos = new long[nCount]; jseyT#2
nEndPos = new long[nCount]; 8+no>%L
for(int i=0;i<nStartPos.length;i++) :3k&[W*
{ 5BvCP
nStartPos = input.readLong(); %vjLw`
nEndPos = input.readLong(); zGrUl|j
} `8Y& KVhu
input.close(); [AzQP!gi
} gxEa?QH
catch(IOException e){e.printStackTrace ();} d\aarhD8*
catch(Exception e){e.printStackTrace ();} k!e \O>+
} 90)0\i+P
F+A"-k_\T#
808E)
private void processErrorCode(int nErrorCode) ?CB*MWjd
{ UUy%:t
System.err.println("Error Code : " + nErrorCode); Nz`4q%+
} e0O2>w
IwC4fcZX6
v)|[=
//停止文件下载 pkjf5DWp
public void siteStop() RZm}%6##ZC
{ # Ny
bStop = true; kt8P\/~*i
for(int i=0;i<nStartPos.length;i++) NET?Ep
fileSplitterFetch.splitterStop(); 1JIL6w_
k=,,s(]tx
ZV}"k_+-
} 5y7rY!]Bf
} y2k'^zE
//负责部分文件的抓取 ]3tg|?%B
**FileSplitterFetch.java ]M AB
*/ <7HVkAa
package NetFox; {9sA'5
QFOmnbJg
J+f .r|?
import java.io.*; t0_o.S
import java.net.*; J(*qOGBD
_{CMWo"l
wjk-$p
public class FileSplitterFetch extends Thread { Js7(TFQE
EL!V\J`S_
6~8A$:
String sURL; //File URL }} cz95
long nStartPos; //File Snippet Start Position < aeBhg%
long nEndPos; //File Snippet End Position ,]?Xf>
int nThreadID; //Thread's ID ,L#Qy>MOb
boolean bDownOver = false; //Downing is over 1@Dp<Q
boolean bStop = false; //Stop identical K;jV"R<9
FileAccessI fileAccessI = null; //File Access interface v3|-eWet^
sg"J00
^)ouL25Z*2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `ER">@&
{ &7* |rshZ
this.sURL = sURL; VU+`yQp
this.nStartPos = nStart; 3`PPTG
this.nEndPos = nEnd; f8`K8Y]4
nThreadID = id; QC7Ceeh]4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @y%4BU&>0
} x`8rR;N!
aty"6~
/]H6'
public void run() D=}UKd
{ c$?(zt;
while(nStartPos < nEndPos && !bStop) &phers
{ f%n],tE6
]v=*WK
|J:n'}
try{ +We_[Re`<
URL url = new URL(sURL); Il(p!l<Xz#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *0>![v
httpConnection.setRequestProperty("User-Agent","NetFox"); pME17 af
String sProperty = "bytes="+nStartPos+"-"; +_Nr a
httpConnection.setRequestProperty("RANGE",sProperty); r[xj,eIb
Utility.log(sProperty); 4yhan/zA
OO?d[7Wt0
`.3!
InputStream input = httpConnection.getInputStream(); oej5bAi
//logResponseHead(httpConnection); Yud]s~N
V1Yab#
eQh@.U*S)
byte[] b = new byte[1024]; >B)&mC$$S
int nRead; e~#;ux
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I&9_F%rX
{ wQR>S>p
nStartPos += fileAccessI.write(b,0,nRead); %LBa;M
//if(nThreadID == 1) KU,KEtf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D^cv 8 8<
} USgZ%xk2
[ kI|Thx
Tb~|p_;o
Utility.log("Thread " + nThreadID + " is over!"); gO>XNXN{
bDownOver = true; zrt\]h+
//nPos = fileAccessI.write (b,0,nRead); 2$=U#!OtU
} x*}41;j}C
catch(Exception e){e.printStackTrace ();} B|%(0j8
} DONXq]f:,"
} 12 y=Eh
p,_,o3@~
!|!k9~v!
//打印回应的头信息 ><<(6
public void logResponseHead(HttpURLConnection con) @qP uYFnw
{ 0$RZ~
for(int i=1;;i++) !*2cK>`
{ e/+_tC$@p@
String header=con.getHeaderFieldKey(i); YU=Q`y[k
if(header!=null) +Sz%2Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5u/dr9n
Utility.log(header+" : "+con.getHeaderField(header)); l%vX$Kw
else r\#_b4-v3h
break; UC3&:aQ!
} WiDl[l"{9
} pib i#
-Ky<P<@ezm
R _#x
public void splitterStop() Be~__pd
{ ?D 8<}~Do
bStop = true; Fjnp0:p9X
} R]dN-'U
_=%F6}TE
e6?iQ0
} ?= G+L0t
12{F
a1^CpeG~
/* d|I_SI1
**FileAccess.java "LwLTPC2
*//文件访问(定位，写) n6AN
package NetFox; KGM9 b
import java.io.*; _H{6{!=y
UCu0Xqf
8'K~+L=}
public class FileAccessI implements Serializable{ qV;E%XkkS
}j+Af["W?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #@pgB:~lB
RandomAccessFile oSavedFile; F747K);_
long nPos; VtP^fM^{
o7gYj\
W4OL{p-\/
public FileAccessI() throws IOException 0B}O&DC%|
{ C8{bqmlm@
this("",0); Bb[WtT}=
} {^J/S}L]
'iY~F0U
Fb2,2Px
public FileAccessI(String sName,long nPos) throws IOException jF$bCbAUce
{ \eF_Xk[
oSavedFile = new RandomAccessFile(sName,"rw"); <QuIXA
this.nPos = nPos; xL&evG#
oSavedFile.seek(nPos); rt rPRR\:"
} h+gaKh=k+
G_m$?0\
%IA1Y>`
public synchronized int write(byte[] b,int nStart,int nLen) |~K 5]
{ H^Mfj!S
int n = -1; )])nd"E
try{ gg0rkg
oSavedFile.write(b,nStart,nLen); ~mF^t7n]
n = nLen; 'c&[kMR
} !1b}M/Wx
catch(IOException e) |2Vhj<6
{ Y9/`w@"v
e.printStackTrace (); @$Xl*WT7
} {4n
r*q
OXxgnn>W'
return n; /3`yaYkSh
} QGCg~TV;
@~z4GTF9i
6%a9%Is!O
} N&uRL_X.
&lCOhP#
uIy$|N
/* Iq0[Kd0.j
**SiteInfoBean.java (+CNs
*/ #0"Pd8@
package NetFox; lC=-1*WH
6`h}#@ (
[59g]')
public class SiteInfoBean { bhl9:`s
y$}o{VE{x
| |u
private String sSiteURL; //Site's URL }Ug O$1
private String sFilePath; //Saved File's Path oO3X>y{gN
private String sFileName; //Saved File's Name p)qM{`]G\
private int nSplitter; //Count of Splited Downloading File `t>A~.f
Ez/>3:;
kt#t-N;}x
public SiteInfoBean() xrZzfg
{//nSplitter的缺省值为5 /u&7!>,
//default value of nSplitter is 5 =o)B1(v@.
this("","","",5); H -K%F_#
} FvJkb!5*e_
+gyGA/5:d$
=E$B0^_2RC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pkE4"M!3=
{ #Q1 |]
sSiteURL= sURL; YO9ofT
sFilePath = sPath; I&%KOe0
sFileName = sName; V2SHF
this.nSplitter = nSpiltter; kxLWk%V
vd[?73:C
M1q_gHA
} ydTd.`
o3X0c6uU
$!vK#8-&{
public String getSSiteURL() #0f6X,3
{ d}2(G2z^
return sSiteURL; yf2P6b\
} M2nWvU$
2@!B;6*8q
4$y P_3
public void setSSiteURL(String value) !A:d9 k
{ _/J`v`}G
sSiteURL = value; P&h]uNu
} Ae;mU[MK/
]G~Z'fs<(
-br): }f
public String getSFilePath() wg4Ol*y'
{ )~CNh5z6Y
return sFilePath; XE8%t=V!c$
} $>zqCi2tB<
PDS?>Jg(
2v<O}
public void setSFilePath(String value) y"|gC!V}
{ %us#p|Ya
sFilePath = value; \[d~O>k2
} 6MpV,2:>
D?G'1+RIT~
^vJy<
public String getSFileName() 9TZ6c
{ @V Sr'?7-
return sFileName; (K('@W%\?
} AYAbq}'Yt
'?6j.ms M
)|GYxG;8C
public void setSFileName(String value) r)Ja\;
{ 8v)iOPmDC
sFileName = value; A@eR~Kp ^
} _K B%g_{
kz G W/
#itZ~tol
public int getNSplitter() /i{V21(%
{ }^ =f%EjV
return nSplitter; U_RWqKL
} 2|&SG3e+(I
.vie#,la
/CUBs!
public void setNSplitter(int nCount) &(m01
{ RN$>!b/
nSplitter = nCount; qCB{dp/
} vSY YetL
} S~>R}=
et/v/Hvw1
/iL*)
/* \}!/z]u
**Utility.java j9X|c7|
*/ !;K zR&
package NetFox; 7nsovWp
r5y*SoD!
Tv9\`F[
public class Utility { tO?-@Qf/9<
r[wjE`Z/T
@)wsHW%cjz
public Utility() [c XSk
{ hVl@7B~
>I',%v\?@
w&e3#p
} @1i<=r
q7I!wD9Cff
//线程睡眠 @<&u;8y-Cn
public static void sleep(int nSecond) v3G$9(NE;
{ pK ^$^*#
try{ Y[W:Zhl;
Thread.sleep(nSecond); IZGRQmi"
} ";/ogFi
catch(Exception e) YABi`;R]'
{ C;%dZ
e.printStackTrace (); 2XEE/]^
} ;%k C?Vzi
} B*9?mcP\
xdVsbW)L2
//日志 IVVX3RI
public static void log(String sMsg) :98:U~d1
{ $/$Hi U`.
System.err.println(sMsg); wk{]eD%
} ~SmFDg$/m
0{I-x^FI
/x4L,UJ= P
public static void log(int sMsg) yYP>3]z
{ +(W7hK4ip
System.err.println(sMsg); 0g~Cdp
} ,9MNB3
} qz.l
Q- w_@~
bR;.KC3C
/* sk*vmxClY
**TestMethod.java 7-C])9
*/ ^8YBW<9
package NetFox; 18p4]:L
k3KT':*
ig .
public class TestMethod { <;uM/vSi
z:
{;6a_L@q;|
public TestMethod() [)kuu
{ ///xx/weblogic60b2_win.exe $=`d[04
try{ <_]W1V:0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LFZ*mRiuKE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); REh\WgV!u
SiteFileFetch fileFetch = new SiteFileFetch(bean); &0H_W xKeB
fileFetch.start(); L)1\=[Ov
} z@ `u$D$n
catch(Exception e){e.printStackTrace ();} F/[m.!Eo
P,(_y8
b|;h$otC
} Pjxj$>&;*j
W}%"xy]N
WF_QhKW|k
public static void main(String[] args) _Vf>>tuW
{ cd=K=P}p
new TestMethod(); >_G'o
} ruyQ}b:zS
} bUds E1f
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