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)); {:6VJ0s\
} q n=6>wP
for(int i=0;i<nEndPos.length-1;i++) =C`v+NPM)|
{ qf)]!wU9
nEndPos = nStartPos[i+1]; eDaVoc3
} 2$\1v*:
nEndPos[nEndPos.length-1] = nFileLength; ocdXzk`
} /^#} \<;
} QREIr |q'
wfo}TGhC
mXhr: e
//启动子线程 y;<jE.7>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <LBMth
for(int i=0;i<nStartPos.length;i++) ]t(g7lc}U
{ *:\QD 8^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !vImmhI!I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9oc[}k-M
nStartPos,nEndPos,i); PCw.NJd$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )j6S<mn
fileSplitterFetch.start(); zKT \i
} ;yHA.}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m{b(^K9}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4jG@ #
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vtL)
nEndPos = " + nFileLength); G4g},p!
// fileSplitterFetch[nPos.length-1].start(); Bljh'Qp>C
uidE/7
m1+DeXR_g
//等待子线程结束 c!kbHZ<Z
//int count = 0; bZ3CJ f&mE
//是否结束while循环 &=02.E@
boolean breakWhile = false; s[xdID^3.
60`y=!?f
Qz<v. _
while(!bStop) N4HnW0
{ B623B HwS
write_nPos(); Dhef|E<
Utility.sleep(500); `^_.E:f
breakWhile = true; "h:xdaIE/p
?+5K2Zk
{BKI8vy
for(int i=0;i<nStartPos.length;i++) zH|!O!3"4
{ 9KAXc(-
if(!fileSplitterFetch.bDownOver) {0Leua
{ "]JS,g {m
breakWhile = false; )ZiJl5l@
break; B&.XGo)
} a<vCAFQ
} Gia_B6*Y[
if(breakWhile) Qz/=+A/4
break; ;PLby]=O
bLf }U9
{},GxrQm
//count++; Bd\p!f<
//if(count>4) F;MFw2G
// siteStop(); (?J&Ar0
} _jnH!Mw
@-u/('vpB
,T1t`
System.err.println("文件下载结束！"); (<3'LhFII
} V1"+4&R^T_
catch(Exception e){e.printStackTrace ();} UHR)]5Lt
} WH'[~O
\UN7lDH
4'_uN$${$
//获得文件长度 nP_s+k
public long getFileSize() Y{2\==~
{ ^*Rrx
int nFileLength = -1; Vl'|l)b4W
try{ \Dr@n^hk@[
URL url = new URL(siteInfoBean.getSSiteURL()); o1kLT@VCl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W~DY-;
httpConnection.setRequestProperty("User-Agent","NetFox"); 9~u1fk{
~":?})
rF 7EO%,
int responseCode=httpConnection.getResponseCode(); Af*^u|#
if(responseCode>=400) {]|};E[}m
{ kS+*@o
processErrorCode(responseCode); ^$yr-p%-
return -2; //-2 represent access is error ##yi^;3Y
} (wvDiW5
.cle^P
%'EOFv]
String sHeader; @KNp?2a
K3 "co1]u
/t ,ujTK
for(int i=1;;i++) 9<-AukK m
{ SAXjB;VH6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [O(78n$$
//Utility.log(in.readLine()); H VG'v>s@
sHeader=httpConnection.getHeaderFieldKey(i); nvpdu)q<
if(sHeader!=null) tQ] R@i
{ :E'38~
if(sHeader.equals("Content-Length")) sx(yG9
{ -Z]?v3 9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Gl}=Q7
break; #p*OLQ3~
} I)DLnnQQ
} Px'%5TKN
else vNi7=3
break; TZPWMCN4
} C6O1ype
} F]SexP4:A
catch(IOException e){e.printStackTrace ();} hRGK W
catch(Exception e){e.printStackTrace ();} S 8h/AW6l
Q)HVh[4
u`K+0^)T`
Utility.log(nFileLength); %E~4Ur
,Ea.ts>
Vx-HW;,
return nFileLength; .|KxQn}
} CI$F#j
QQ1+uY
<k}>eGn
//保存下载信息（文件指针位置） T"8>6a@}E
private void write_nPos() 4$d|}ajH
{ $U"/.Mh\
try{ %+FM$xyJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8uS1HE\%
output.writeInt(nStartPos.length); d<(1^Rto
for(int i=0;i<nStartPos.length;i++) HC}D<FX|
{ 8~\Fpz|Og
// output.writeLong(nPos); @+B .<@V
output.writeLong(fileSplitterFetch.nStartPos); +6uun
output.writeLong(fileSplitterFetch.nEndPos); hG&RGN_<6+
} $*8c0.{U
output.close(); 3 +BPqhzf
} qmOGsj`#
catch(IOException e){e.printStackTrace ();} 8p>%}LX/
catch(Exception e){e.printStackTrace ();} htlsU*x
} ,N<;!6e
~$!eB/6ty
!);}zW!
//读取保存的下载信息（文件指针位置） &g.w~KWa
private void read_nPos() t<}'/ )
{ ^=E4~22q
try{ u#la+/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9%kY8#%SV
int nCount = input.readInt(); -!(3fO:
nStartPos = new long[nCount]; \9@*Jgpd6*
nEndPos = new long[nCount]; KW^s~j
for(int i=0;i<nStartPos.length;i++) VlXIM,
{ Z]uN9c
nStartPos = input.readLong(); $//18+T
nEndPos = input.readLong(); N, ;'oL+
} ^7F!>!9Ca
input.close(); fcD$km
} u%VO'}Gz
catch(IOException e){e.printStackTrace ();} p0`Wci
catch(Exception e){e.printStackTrace ();} \*!g0C8 o
} "{qhk{
p^ 9QYR
REnRpp$
private void processErrorCode(int nErrorCode) 7b:oz3?PI
{ |3Oe2qb
System.err.println("Error Code : " + nErrorCode); &Mo=V4i>
} a%*W^R9Ls
` n@[=l~
jr"yIC_
//停止文件下载 &Vvy`JE
public void siteStop() 4h:Oo
{ )8st
bStop = true; w v9s{I{P
for(int i=0;i<nStartPos.length;i++) =h5&\4r=
fileSplitterFetch.splitterStop(); m\"M`o B
JWlH(-U4|
j4ypXPY``!
} {BY`Wu:w
} ruB&&C6)v
//负责部分文件的抓取 hSp[BsF`,
**FileSplitterFetch.java s3/->1#i
*/ UyD=x(li
package NetFox; jWUN~#p!
6jPaS!E
R4E0avt
import java.io.*; _ nS';48
import java.net.*; 7s<v06Wo
oel3H5Nz
i3rvDch
public class FileSplitterFetch extends Thread { I;uZ/cZ|/
D'|#5>G
}I;=IYrN
String sURL; //File URL >fdS$,`A
long nStartPos; //File Snippet Start Position %}+j4n
long nEndPos; //File Snippet End Position , $78\B^
int nThreadID; //Thread's ID ',*I=JW;
boolean bDownOver = false; //Downing is over h"#^0$f
boolean bStop = false; //Stop identical YPf&y"E&H
FileAccessI fileAccessI = null; //File Access interface (aiE!c
eZI&d;i
5t:4%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException JQQD~J1)E
{ {LR?#.
this.sURL = sURL; |+x;18
this.nStartPos = nStart; Ju)2J?Xs5
this.nEndPos = nEnd; 31Zl"-<#-
nThreadID = id; 6.KR(V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ?!Rlp/
} &q``CCOF&
`"A\8)6-
g9GE0DbT`
public void run() y9Yh%M(
{ !_l W#feR
while(nStartPos < nEndPos && !bStop) c6E@+xU
{ r\` R$
/_26D0}UuF
:Oa|&.0l?
try{ _9\ayR>d
URL url = new URL(sURL); +)L 'qbCSM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q4CxtY
httpConnection.setRequestProperty("User-Agent","NetFox"); SZK~<@q5
String sProperty = "bytes="+nStartPos+"-"; 5c3)p^]g
httpConnection.setRequestProperty("RANGE",sProperty); 1 /7H` O?
Utility.log(sProperty); i,<TaW*I
L$i&>cF\_>
l_>^LFOA
InputStream input = httpConnection.getInputStream(); wKXKc\r
//logResponseHead(httpConnection); wEQV"I
f{^C+t{r
|DwI%%0(F
byte[] b = new byte[1024]; :T5l0h-eC
int nRead; TP'EdzAT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ol{)U;,`
{ vZhN% DfY
nStartPos += fileAccessI.write(b,0,nRead); $-jj%x\}
//if(nThreadID == 1) `:-{8Vo7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^qS[2Dy
} ?9OiF-:n
9~ K1+%!
"9&6bBa
Utility.log("Thread " + nThreadID + " is over!"); [0Z r z+q
bDownOver = true; cqRIi~`
//nPos = fileAccessI.write (b,0,nRead); &]16Hb~
} W*}q;ub;
catch(Exception e){e.printStackTrace ();} 8e[kE>tS._
} %fJ*Ql4M
} k .KN9=o
xzz[!yJjG
)+u|qT3%
//打印回应的头信息 A_CEpG]
public void logResponseHead(HttpURLConnection con) =5[}&W
{ FC.y%P,
for(int i=1;;i++) a%Q.8
{ ?h<I:[oZ
String header=con.getHeaderFieldKey(i); hz>&E,<8q
if(header!=null) b_W0tiyv%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o'D{ql
Utility.log(header+" : "+con.getHeaderField(header)); (`<l" @:_*
else (SkI9[1\@3
break; O<)"kj 7
} <6Y o%xt
} A+iQH1C0h
:@`Ll;G
I,_wt+O&j
public void splitterStop() &g\D-At
{ >C*q
bStop = true; gk>A
} i(a2FKLy
Yih^ZTf]O?
n,wLk./`
} Fm#4;'x5E
G!ty@ Fx
:cnH@:
/* "e&S*8QhM
**FileAccess.java |FS79Bv
*//文件访问(定位，写) 3R !Mfz*
package NetFox; c#<v:b
import java.io.*; w3:Y]F.ot
JcvWE $
17a'C
public class FileAccessI implements Serializable{ isLIfE>
VuN= JX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RnE=T/VZJ
RandomAccessFile oSavedFile; Q$iYhR
long nPos; $A`D p{e"
]uI#4t~
q=M!YWz
public FileAccessI() throws IOException Hq?-e?Nc
{ 5%mc|
this("",0); ;[R{oW Nw
} C&^"]-t
ZxlQyr`~a(
9fp1*d
public FileAccessI(String sName,long nPos) throws IOException EJ`JN|,M
{ @/@#,+
oSavedFile = new RandomAccessFile(sName,"rw"); 6D_3Hwrs
this.nPos = nPos; 2j9Mr
oSavedFile.seek(nPos); iq)4/3"6
} {9q~bt
IP~*_R"bM
8%S5Fc#am
public synchronized int write(byte[] b,int nStart,int nLen) y*0bHzJ
{ /~yk
int n = -1; +@ga
try{ I,OEor6%R(
oSavedFile.write(b,nStart,nLen); J+r\EN^9
n = nLen; Z&e_yl
} :8cp]vdW
catch(IOException e) Oz<{B]pEul
{ N2[EdOJT_
e.printStackTrace (); KP`{ UD)
} 4loG$l+a1
[1K\ _
f'` QW@U
return n; G[z!;Zuf
} FJDx80J
r8x<-u4
T2|dFKeWG
} 6}zargu(;
'yd<<BM`
lcR53X
/* 4n_f7'GZg
**SiteInfoBean.java b2]1Dfw
*/ {WfZE&B
package NetFox; ?*lpu
;K]6/Wt
%2>ya>/M
public class SiteInfoBean { b3]QH h/
Wm_:1~
',`GdfAsH
private String sSiteURL; //Site's URL ?Ho~6q8O@
private String sFilePath; //Saved File's Path yzJ VU0s
private String sFileName; //Saved File's Name d(!W
private int nSplitter; //Count of Splited Downloading File d/oxRzk'L
Qv=F'
&cy@Be}|T
public SiteInfoBean() }@JPvIE
{//nSplitter的缺省值为5 KtH-QQDluj
//default value of nSplitter is 5 t<~$?tuZ
this("","","",5); !U,W; R
} ?VVtEmIN
:2^j/
<Sw>5M!j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &,~0*&r0
{ lU6?p")F1
sSiteURL= sURL; q=Cc2|Ve
sFilePath = sPath; , H$1iJ?
sFileName = sName; N0`v;4gF$]
this.nSplitter = nSpiltter; 3@xn<eu
v 809/c*
zg)-RCG
} ,D#ssxV
`rt?n|*QF
9a4Xf%!F>z
public String getSSiteURL() c*iZ6j"iI
{ jvGGIb"&1
return sSiteURL; EtVRnI@
} =2-!ay:
7&ty!PpD
>SS YYy
public void setSSiteURL(String value) hRKAs ]^j
{ df@r2 /Y
sSiteURL = value; ~CTe5PX c
} urM=l5Sx
frsqnvm;+
btb$C
public String getSFilePath() Na6z1&wS
{ Q[5j5vry
return sFilePath; yWsJa)e3*@
} 1^F !X=
55aJ=T
os<YfMM<:/
public void setSFilePath(String value) ="yN4+0-p
{ ?<_yW#x6
sFilePath = value; "Q{)H8,E)x
} (+M]C]
d#Hl3]wT
.\/jy]Y
public String getSFileName() f=$w,^)M
{ &nJH23h^
return sFileName; }@+3QHwYU
} n+ot. -
M|HW$8V3_2
cM'\u~m{
public void setSFileName(String value) gd#j{yI/Xf
{ % ~!A,
sFileName = value; w+,Kpb<x[0
} Ib8*rL0p<L
s7789pR
5#WyI#YNG
public int getNSplitter() |/YwMBi
{ j#f7-nHyz8
return nSplitter; i&di}x
} '(6 ^O=
%v"qFYVX"
bTd94
public void setNSplitter(int nCount) 17C"@1n-
{ ^*$lCUv8p
nSplitter = nCount; vl"{ovoC
} f|r+qe
} o4U[;.?c
_!K@(dl
Cqra\
/* `pJWZ:3
**Utility.java FSNzBN
*/ gP^p7aYwn
package NetFox; |bM?Q$>~
aj|gt
a*N<gId
public class Utility { R)Y*<Na
vK7J;U+cJ
a{y"vVQOF
public Utility() qJZ:\u8oO
{ h+ggrwg'
F<Y>
:dML+R#Ymh
} Eo@b)h
+]*hzWbe
//线程睡眠 ln&9WF\I
public static void sleep(int nSecond) VM"z6@
{ [7+dZL[
try{ ;p] f5R^
Thread.sleep(nSecond); IS[&V&.n
} 6d#:v"^,
catch(Exception e) QP={b+8
{ F8En)#
e.printStackTrace (); JZom#A. dt
} 5a^b{=#Y
} 7jtDhsVz
x/]]~@:
//日志 O~L/>Ya
public static void log(String sMsg) \|< 5zL
{ BSc5@;
System.err.println(sMsg); Ip&Q'"HYj
} n1;y"`gHk
3B6"T;_
.`5BgX7W
public static void log(int sMsg) \4FKZ>1+R
{ W%&'EJ)62
System.err.println(sMsg); 5IfyD ]<
} Xb/^n.>
} NUjo5.7
=0gfGwD{
)gb gsQZ
/* ^a?H"
**TestMethod.java rZSX fgfr
*/ Q?7:XbN
package NetFox; ~V?3A/]
"JBTsQDj!
S-D=-{@
public class TestMethod { _WeN\F~^
TexSUtx@$
mok%TK
public TestMethod() ;xMieqz
{ ///xx/weblogic60b2_win.exe @b,&b6V
try{ 'D1Sm&M2%e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ocbNf'W;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r|!r!V8j
SiteFileFetch fileFetch = new SiteFileFetch(bean); !v`C-1}70
fileFetch.start(); PRi3=3oF
} 2B<0|EGtzw
catch(Exception e){e.printStackTrace ();} hD I}V1)
sM0o,l(5
^,;AM(E
} /H m),9NN
xM6v0Ua
IX]K"hT
public static void main(String[] args) 7HkQ|~zGT
{ 2-#:Y
new TestMethod(); ,O[Maj/ch
} nL[zXl
} X|3l*FL
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