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)); B#x.4~YX
} -$kAWP8P4
for(int i=0;i<nEndPos.length-1;i++) l0{R`G,
{ 1"} u51
nEndPos = nStartPos[i+1]; d}]jw4
} 1bJrEXHXy
nEndPos[nEndPos.length-1] = nFileLength; LD)P. f
} g E;o_~
} SH M@H93
U>kL|X3 V
%$SO9PY
//启动子线程 '"Y(2grP
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3n=ftkI
for(int i=0;i<nStartPos.length;i++) XVkCYh4,
{ yj C@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q96^rjY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H~r":A'"*
nStartPos,nEndPos,i); d,caOE8N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *4|]=yPU
fileSplitterFetch.start(); X=i",5;
} ; )J\k2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VRa>bS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "AUHe6Yv
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !qF t:{-h
nEndPos = " + nFileLength); jz72~+)T
// fileSplitterFetch[nPos.length-1].start(); 2io~pk>
3Ja1|;(2
x 2Cp{+}
//等待子线程结束 Dk`(Wgk2
//int count = 0; Sn!5/9Y
//是否结束while循环 zyi;vu
boolean breakWhile = false; A 2Rp
yRv4,{B}X>
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while(!bStop) y$C\b\hM
{ C6{\^kG^j2
write_nPos(); UY$Lqe~
Utility.sleep(500); 8%Hc%T[RnT
breakWhile = true; !{%BfZX<&
@UCr`>
;2jH;$HZ
for(int i=0;i<nStartPos.length;i++) FEwPLViso
{ ni`uO<\U
if(!fileSplitterFetch.bDownOver) @[. 0,
{ SM8Wg>
breakWhile = false; hWD%_"yhd
break; >JckN4v
} r!e:sJAB.
} !}PZCbDhL
if(breakWhile) iw\yVd^]:k
break; qbD>)}:1
' >R?8Y
<b#1L
//count++; >PmnR>x-rj
//if(count>4) #Q'j^y7=z
// siteStop(); +nU=)x?38
} '4"c#kCKL
PB(I3R9
)wyC8`&-
System.err.println("文件下载结束！"); 8$`$24Wx
} yB2}[1
catch(Exception e){e.printStackTrace ();} @<`P-+m
} oFL7dL
dwJnPJ=z
'|J~2rbyr
//获得文件长度 '@dk3:3t
public long getFileSize() F_-}GN%
{ )0?u_Z]w9
int nFileLength = -1; 7 >-(g+NF!
try{ tE WolO[\
URL url = new URL(siteInfoBean.getSSiteURL()); }?^]-`b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H7%q[O
httpConnection.setRequestProperty("User-Agent","NetFox"); vR4omB{
|'qvq/#^
sT'j36Nc<,
int responseCode=httpConnection.getResponseCode(); F4PWL|1
if(responseCode>=400) U%)-_ *`z
{ fUq:`#Q
processErrorCode(responseCode); `z$=J"%? y
return -2; //-2 represent access is error "</A)y&
} [*U.bRs
7:e5l19 uI
@{{6Nd5
String sHeader; sB8v:
)F+wk"`+6
w@WPp0mny
for(int i=1;;i++) 089v; d 6
{ S!66t?vHB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K-[;w$np0
//Utility.log(in.readLine()); k)R~o b
sHeader=httpConnection.getHeaderFieldKey(i); a66Ns7Rb
if(sHeader!=null) B#r"|x#[
{ {Z1KU8tp
if(sHeader.equals("Content-Length")) CbwQbJ/v7
{ RFPcH8-u7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <%.lPO]&E
break; XT?wCb41R
} Jl<pWjkZZ
} o)n=n!A
else T:SqENV
break; ;3XOk+
} 2!R+5^Iy
} NOmFQ)/ &
catch(IOException e){e.printStackTrace ();} _2hZGC%&E
catch(Exception e){e.printStackTrace ();} 9_O6Sl
<}T7;knO
+j %y#_~
Utility.log(nFileLength); tUt_Q;%yC
-A@/cS%p
hj}PL
return nFileLength; Ym.{ {^=
} ](FFvqA
c dWg_WBC
I^HwXp([
//保存下载信息（文件指针位置） yb,X }"Et
private void write_nPos() &8I}q]'k
{ > `mV^QD
try{ %CrTO(
output = new DataOutputStream(new FileOutputStream(tmpFile)); Km,%p@`m
output.writeInt(nStartPos.length); q\-P/aN_
for(int i=0;i<nStartPos.length;i++) ^#IE t#
{ -{q'Tmst
// output.writeLong(nPos); ~nb(e$?N
output.writeLong(fileSplitterFetch.nStartPos); $ w+.-Tr
output.writeLong(fileSplitterFetch.nEndPos); j+rY
} |o+*Iy)
output.close(); [H{@<*
} @AM11v\:
catch(IOException e){e.printStackTrace ();} " %qr*|
catch(Exception e){e.printStackTrace ();} #d06wYz=
} W 1u!&:O
7&9w_iCkV
'1(6@5tyWk
//读取保存的下载信息（文件指针位置） (#Xs\IEVF
private void read_nPos() {> <1K6t
{ V]GF53D
try{ q#SEtyJL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I9Uj3cL\
int nCount = input.readInt(); vCNq2l^CW
nStartPos = new long[nCount]; b(CO7/e>
nEndPos = new long[nCount]; !v(^wqna\
for(int i=0;i<nStartPos.length;i++) a 9{:ot8,
{ N&eo;Ti
nStartPos = input.readLong(); 2W`WOBz
nEndPos = input.readLong(); _/'VD!(MV
} H XFY
input.close(); S;jD@j\t&
} G+Bk!o
catch(IOException e){e.printStackTrace ();} >MSK.SNh
catch(Exception e){e.printStackTrace ();} q |FOU
} Kn<+Au_]L
-FI)o`AE
M@P%k`6C
private void processErrorCode(int nErrorCode) ?{jey_]M
{ /zb/am1#
System.err.println("Error Code : " + nErrorCode); %P M#gnt@
} D[?;+g/
WG@3+R>{
Kh[l};/F
//停止文件下载 TnKv)%VF
public void siteStop() [f! { -T
{ DB65vM
bStop = true; g1}:;VG=
for(int i=0;i<nStartPos.length;i++) [7d(PEQL`
fileSplitterFetch.splitterStop(); ^_g%c&H
('Qq"cn#
RgUQ:
} "]kzt ux
} &VA^LS@b
//负责部分文件的抓取 c"-X:m"
**FileSplitterFetch.java :Yn.Wv-
*/ +Ugy=678Tr
package NetFox; m;\nMdn
s]OZ+^Z
{?Y\T
import java.io.*; ?upd
import java.net.*; -gk2$P-
{:*G/*1[.
&M<"Fmn
public class FileSplitterFetch extends Thread { @'):rFr@F
nW"O+s3
k}qQG}hB
String sURL; //File URL x{Utf$|
long nStartPos; //File Snippet Start Position *?d\Zcj85[
long nEndPos; //File Snippet End Position G4*&9Wo
int nThreadID; //Thread's ID Yl>Y.SO
boolean bDownOver = false; //Downing is over Yj>4*C9
boolean bStop = false; //Stop identical ,b -
FileAccessI fileAccessI = null; //File Access interface " "m-5PGYo
0m]QQGvJ{
8 yi#] 5`Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %G\nl
{ %(p9AE
this.sURL = sURL; w(aj'i
this.nStartPos = nStart; 3^%2,
this.nEndPos = nEnd; jT$J~MpHh
nThreadID = id; PN?;\k)"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !J<Xel{
} C]8w[)d[`;
}A@:JR+|
X,aRL6>r
public void run() aT IzfqCM
{ f~\H|E8(
while(nStartPos < nEndPos && !bStop) hBnUpYec
{ 035jU'
YcX"Z~O6j=
5NUaXQ
try{ RHn3\N
URL url = new URL(sURL); B E8_.>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }(!Uq
httpConnection.setRequestProperty("User-Agent","NetFox"); B-w`mcqp$
String sProperty = "bytes="+nStartPos+"-"; rf|Nu3AJ
httpConnection.setRequestProperty("RANGE",sProperty); %m f)BC
Utility.log(sProperty); -O?HfQ
O.X;w<F/V
JD0s0>q_
InputStream input = httpConnection.getInputStream(); ~Yg)8
//logResponseHead(httpConnection); 4hxP`!<
n.8870.BW
y*X.DS 1(w
byte[] b = new byte[1024]; Xwo+iZ(a
int nRead; syg{qtBz^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |3E|VGm~
{ 4[x`\
nStartPos += fileAccessI.write(b,0,nRead); %La7);SeY
//if(nThreadID == 1) 0]*W0#{Zj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DFQ`(1Q
} b3[[ Ah-
*5oQZ".vA*
@fmp2!?6
Utility.log("Thread " + nThreadID + " is over!"); fi>.X99(G
bDownOver = true; mMllen
//nPos = fileAccessI.write (b,0,nRead); +JC"@
} wMN;<
catch(Exception e){e.printStackTrace ();} dl8f]y#Q
} 5lD`qY
} "}1cQ|0a
5<`83;R9
zE1=P/N
//打印回应的头信息 n=JV*h0
public void logResponseHead(HttpURLConnection con) xLFMC?I
{ +{=U!}3|
for(int i=1;;i++) zL}`7*d:v
{ %pOxt<
String header=con.getHeaderFieldKey(i); Ig?9"{9p
if(header!=null) rp<~=X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b49h @G
Utility.log(header+" : "+con.getHeaderField(header)); q9{ h@y
else cE`qfz
break; eQ)*jeD
} vv2[t
} 4@\$k+v
&g90q
! jApV
public void splitterStop() xbw;s}B
{ K@2"n| S;
bStop = true; E>-I |X"L1
} dQrz+_
A9]&w
iuXXFuh
} R#y"SxD()
[OOQ0c~
A2L"&dl
/* #b)`as?!1
**FileAccess.java P~lU`.X}
*//文件访问(定位，写) GNuIcy
package NetFox; +3XaAk
import java.io.*; .]4MtG
F/LMk8RgR
pZ*%zt]-a
public class FileAccessI implements Serializable{ [FF}HWf
yDZm)|<.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,gG RCp
RandomAccessFile oSavedFile; (`#z@,1
long nPos; ^ZS!1%1
=6 zK1Z
"LkBN0D
public FileAccessI() throws IOException fdwP@6eh
{ =w`uZ;l$Q
this("",0); Gl|n}wo$
} Svo\+S
Val"vUZ
c1a$J`
public FileAccessI(String sName,long nPos) throws IOException ]=i('|YG
{ k#\j\t-
oSavedFile = new RandomAccessFile(sName,"rw"); (@!K tW
this.nPos = nPos; PP!-*~F0Jr
oSavedFile.seek(nPos); y4IQa.F
} ?GhMGpdMq
0m> 8
N`?/kubD
public synchronized int write(byte[] b,int nStart,int nLen) o%;ly
{ #6D>e~>n
int n = -1; 4]p#9`j
try{ yVGf[~X
oSavedFile.write(b,nStart,nLen); ,#GB
n = nLen; E11C@%
} @+p(%
catch(IOException e) i_r708ep6
{ |7A}LA
e.printStackTrace (); =v<A&4
} yoF*yUls^E
5|pF*8*
EH M59s|B
return n; QZ;DZMP
} 4J(-~
P*|=Z>%[0
Ac|dmu
} 6H U*,
SVd@- '-K
:KXI@)M
/* ;]>)6
**SiteInfoBean.java `\;Z&jlpT
*/ +'olC^?5 }
package NetFox; aTeW#:m
7D:rq 8$\
L'aB/5_%
public class SiteInfoBean { lic-68T
oCI\yp@a
^_P?EJ,)`
private String sSiteURL; //Site's URL ]a~sJz!
private String sFilePath; //Saved File's Path &zEBfr
private String sFileName; //Saved File's Name 9Sd?,z
private int nSplitter; //Count of Splited Downloading File * O?Yp%5NH
4`:POu&
zP2X}VLMo
public SiteInfoBean() rrj.]^E_~
{//nSplitter的缺省值为5 w4TQ4 Y
//default value of nSplitter is 5 >.K%W*t
this("","","",5); m&xVlS
} 7'i{JPm
p0zC(v0*
BQg3+w:>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) to&,d`k=-
{ R0tT4V+
sSiteURL= sURL; Z^as ?k(iM
sFilePath = sPath; Ny/eYF#
sFileName = sName; wi jO2F
this.nSplitter = nSpiltter; vGh>1U:
=MJB:
_FE uQ9E
} `\\s%}vZ*T
j_<!y(W
'#LzQ6Pn
public String getSSiteURL() "uIaKb
{ C<(oaeQY
return sSiteURL; *kqC^2t
} 5toa@#Bc%
@/^mFqr2
<Ohi+a%6
public void setSSiteURL(String value) HNBmq>XDc
{ ; xp-MK
sSiteURL = value; y||RK`H
} v7./u4S|V
A7+ZY,
.yXqa"p
public String getSFilePath() >Q=^X3to
{ 2 Kjd!~Z$
return sFilePath; pUqC88*j
} G(#t,}S}@
&U|c=$!\
\2a;z<(
public void setSFilePath(String value) ~:T@SrVI
{ hd9HM5{p
sFilePath = value; -#;xfJE
} (iir,Ks2C
EC,`t*<
w($a'&d`0
public String getSFileName() Gg9MAK\C9
{ T&]-p:mg^
return sFileName; /^nIOAeE
} qq&U)-`
..u{v}4&
9c)#j&2?H
public void setSFileName(String value) &Z]}rn
{ A<)n H=G&
sFileName = value; N?vb^?
} ,k4pW&A
?cRF;!o"
(=7"zECq#
public int getNSplitter() ~KS@Ulrox
{ e~lFjr]
return nSplitter; xE?KJ
} r]p3DQ
63u%=-T%a
kMch
public void setNSplitter(int nCount) 4joE"H6
{ J Ah!#S(
nSplitter = nCount; lgU!D |v
} OmWEa
} d[3me{Rs
gE\ ^ vaB
e*}zl>f
/* 6Oy:5Ps8a
**Utility.java St%x\[D
*/ T"Y#u
package NetFox; R'c dEoy
S#C-j D
?;W"=I*3
public class Utility { GE!nf6>Km
%MHL@Nn>e
m6e(Xk,)
public Utility() '69)m~B0a
{ # atq7tX
2T2<I/")O
x/<]/D
} $GRwk>N
Hl8-q!
//线程睡眠 Sr6'$8#>Y
public static void sleep(int nSecond) |9S8sfw
{ ^aAs=KditO
try{ ?`?Tg&W
Thread.sleep(nSecond); u/j\pDl.
} #1J,!seJ
catch(Exception e) mU4(MjP?
{ *x2!N$b
e.printStackTrace (); j67a?0<C2U
} a8T9=KY^
} y+iRZ%V^
kQ\ $0=6N9
//日志 a.%ps:
public static void log(String sMsg) q&@s/k
{ r[Pp[g-J
System.err.println(sMsg); 9]=J+ (M
} ^ou)c/68aQ
6t;;Fz
Gn 9oInY1
public static void log(int sMsg) 2Ty]s~
{ _=I1
System.err.println(sMsg); s&nat4{B
} xbCR4upS
} ~2rQ80_
>|%3j,<U
kNWTM%u9
/* "G>d8GbIh
**TestMethod.java Lm}.+.O~d
*/ m@kLZimD
package NetFox; :|V650/
u=nd7:bv
7 w,D2T
public class TestMethod { hA 5p'a+K
&'^.>TJ\
[#Apd1S_
public TestMethod() DQ+6VPc^o
{ ///xx/weblogic60b2_win.exe fWJpy#/^*K
try{ eef&ZL6g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2Pm}wD^`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l9uocP:D
SiteFileFetch fileFetch = new SiteFileFetch(bean); C)j/!+nh
fileFetch.start(); \;MP|:{pU
} R/"f
catch(Exception e){e.printStackTrace ();} 4r4 #u'Om
,&@GxiU
v@QnS
} }&/>v' G
Az y`4
Q(-&}cY
public static void main(String[] args) >x*[izr/K
{ + Fo^NT
new TestMethod(); D|(\5]:R
} zx<PX
} 4o M~
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