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)); U=o Z.\
} U %:c],Fk
for(int i=0;i<nEndPos.length-1;i++) ^)cM&Bxt%
{ l6B.6 '4)w
nEndPos = nStartPos[i+1]; &R\XUxI
} .{N\<01
nEndPos[nEndPos.length-1] = nFileLength; x9`ZO<L$
} K M]Wl_z
} ~{ .,8jE
eECj_eH-
wd`R4CKhP]
//启动子线程 `QCD$=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f0F#Yi{fw
for(int i=0;i<nStartPos.length;i++) "<dN9l>
{ >7FSH"8[,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $u,GVq~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [oHOHp/V
nStartPos,nEndPos,i); Pt3[|4L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dt.-C_MO
fileSplitterFetch.start(); >DmRP7v
} jg^^\n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), anitqy#E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0N1' $K$\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", qi[(*bFK7
nEndPos = " + nFileLength); xucIjPi]
// fileSplitterFetch[nPos.length-1].start(); s#Q_Gu
wG6FS
}Ch[|D=Wd6
//等待子线程结束 3z$\&& BR
//int count = 0; NQ3|\<Wt
//是否结束while循环 .??rqaZ=
boolean breakWhile = false; - coy@S=.'
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B(EtXB9
while(!bStop) bn|DRy
{ wO\!xW:
write_nPos(); /op/g]O}
Utility.sleep(500); 'v`~(9'Rcj
breakWhile = true; .kzms
6NKF'zh
[EcV\.
for(int i=0;i<nStartPos.length;i++) 6 cr^<]v!
{ !%)L&W_
if(!fileSplitterFetch.bDownOver) |<2JQ[]
{ HO G=c!b
breakWhile = false; A&?WP\_z
break; E-[:. &
} Bzwx0c2VY8
} qFGB'mIrFz
if(breakWhile) #s/{u RYQ
break; zZw@c?
o|BFvhg
%!W6<ioW
//count++; ]qF<Zw7
//if(count>4) ]b!R-G!gV
// siteStop(); sF, uIr/
} L)=8mF.
c[6zX#{`
A1Ibx|K
System.err.println("文件下载结束！"); SSo~.)J
} .w=:+msL{(
catch(Exception e){e.printStackTrace ();} }$&);7(w
} <(ubZ
" Tw0a!
/:Rn"0
//获得文件长度 Udg& eEF
public long getFileSize() t PAt?
{ o7hH9iY
int nFileLength = -1; h7)VJY
try{ X~`.}
URL url = new URL(siteInfoBean.getSSiteURL()); 8dYk3sk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oT$(<$&<
httpConnection.setRequestProperty("User-Agent","NetFox"); Bl:{p>-q
S]Sp Z8
nDwq!LEx%5
int responseCode=httpConnection.getResponseCode(); 3/yt*cr
if(responseCode>=400) `mh-pBVD1
{ $ $W{HsX
processErrorCode(responseCode); gizmJ:<
return -2; //-2 represent access is error )<m=YI ;<
} Mt]=v}z
JuKk"tr~RB
I%.jc2kK
String sHeader; )UxQf37
f]{1ZU%4
!- Cs?
for(int i=1;;i++) "P>$=X~Zi
{ 2D\x-!l/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z{8exym
//Utility.log(in.readLine()); dlU JYI
sHeader=httpConnection.getHeaderFieldKey(i); '2Mjz6mBDA
if(sHeader!=null) -k|g04Q?
{ ^!-E`<jW8
if(sHeader.equals("Content-Length")) ;C7BoHB9
{ \#IJ=+z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t1*BWY
break; /\oyPD`((
} gdkLPZ<<
} ~_/<PIm
else (mOqv9pn
break; 5yO#N2jY\
} oX=*MEfX
} =DQdPA\K
catch(IOException e){e.printStackTrace ();} ^=heen<S%
catch(Exception e){e.printStackTrace ();} xIq"[?m
6qmo ZAg
hSLwiX~
Utility.log(nFileLength); CrQA :_Z(7
@[[Cs*-
"`8H:y
return nFileLength; Q T0IW(A
} JaB tX'
P_^|KEz
8E.5k@
//保存下载信息（文件指针位置） !)l%EJngL
private void write_nPos() 4P-'(4I)
{ /o}0oo5B
try{ s$+: F$Y0
output = new DataOutputStream(new FileOutputStream(tmpFile)); D KMbs
output.writeInt(nStartPos.length); r~Is,.zZ}
for(int i=0;i<nStartPos.length;i++) C7c|\T
{ 1Q2k>q8
// output.writeLong(nPos); 2+r)VF:
output.writeLong(fileSplitterFetch.nStartPos); X<@y*?D9D
output.writeLong(fileSplitterFetch.nEndPos); $.x?in|_
} ~[ ks|
output.close(); 04T*\G^:=
} }GU6Q|s[u[
catch(IOException e){e.printStackTrace ();} $'I$n
catch(Exception e){e.printStackTrace ();} "*H'bzK
} A=YEY n
:b3lJ-dB
l52n/w#qFB
//读取保存的下载信息（文件指针位置） sLpCWIy
private void read_nPos() #mz,HK0|aC
{ f>, Qhl
try{ 4-?`#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |Bf:pG!
int nCount = input.readInt(); Stp*JU
nStartPos = new long[nCount]; =LeVJGF
nEndPos = new long[nCount]; z6>ZV6(d2^
for(int i=0;i<nStartPos.length;i++) tRrY)eElS
{ l4BO@
nStartPos = input.readLong(); Xta>
nEndPos = input.readLong(); aK=3`q
} qKb-aP-
input.close(); /IQ-|Qkg
} 3lrZ-k+S{
catch(IOException e){e.printStackTrace ();} N~K)0RETn
catch(Exception e){e.printStackTrace ();} Gv2./<{#
} X-) ]lAP
@W5hrei
3x;y}:wQa
private void processErrorCode(int nErrorCode) zZjLt1
{ jX8C2}j
System.err.println("Error Code : " + nErrorCode); YPJx/@Z`
} $}"Wta
%K f. F
z%gtV'
//停止文件下载 hm} :Me$[)
public void siteStop() UFY~D"%/
{ 1NHoIX
bStop = true; GbrPtu2{@V
for(int i=0;i<nStartPos.length;i++) qYiK bzy
fileSplitterFetch.splitterStop(); XTXo xZ#w
3usA
$Aoqtz d\
} 4JQ`&:?r
} O0*L9C/Q
//负责部分文件的抓取 byxehJ6[V
**FileSplitterFetch.java )B5gs%u]
*/ .p*D[o2 9
package NetFox; d`][1rZk
6XCX#4'i%
nXaX=
import java.io.*; d"`>&8*
import java.net.*; v.&*z48
o*ED!y7
Lj* =*V
public class FileSplitterFetch extends Thread { p:>?
8PVs!?Nne
Dj&bHC5%
String sURL; //File URL |}y}o:(
long nStartPos; //File Snippet Start Position W%ZU& YBc
long nEndPos; //File Snippet End Position Uht:wEr
int nThreadID; //Thread's ID |}.B!vg(4
boolean bDownOver = false; //Downing is over wgP3&4cSUc
boolean bStop = false; //Stop identical T@.m^|~
FileAccessI fileAccessI = null; //File Access interface ={vtfgxl
f]65iE?x
x9 L\"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g;Q^_4@
{ >w;W&[
this.sURL = sURL; !PTbR4s
this.nStartPos = nStart; &{{f|o=u.
this.nEndPos = nEnd; 0c6AQP"=V
nThreadID = id; i4Cb&h^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w3UJw
} 6Tmb@<I_
#IA(*oM
mzR @P$:36
public void run() ;//qjo
{ Y[]t_o)
while(nStartPos < nEndPos && !bStop) <?}g[]i
{ K1nwv"
pg`;)@
6_><W"r:]
try{ +6-!o,(
URL url = new URL(sURL); 1OeDWEcB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /kVc7LC
httpConnection.setRequestProperty("User-Agent","NetFox"); n=MYv(Pp}
String sProperty = "bytes="+nStartPos+"-"; )BrqE uX@"
httpConnection.setRequestProperty("RANGE",sProperty); na; ^/_U@
Utility.log(sProperty); L,GtIZkE
}=4".V`-o
BJrNbo;T
InputStream input = httpConnection.getInputStream(); f|E'eFrFk
//logResponseHead(httpConnection); `t2! M\)
`Pbn
\./2Qc,
byte[] b = new byte[1024]; d7gSkna`5c
int nRead; ^/,yZ:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &NnMz9
{ ]gk1h=Y~h
nStartPos += fileAccessI.write(b,0,nRead); !g:UM R
//if(nThreadID == 1) =MLL-a1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )j*qGsOg
} }H.vH
j(2T,WM
e:R[
Utility.log("Thread " + nThreadID + " is over!"); c:TP7"vG
bDownOver = true; (k45k/PAP
//nPos = fileAccessI.write (b,0,nRead); x{5*%}lX8
} ^Y |s^N
catch(Exception e){e.printStackTrace ();} zb$U'D_-f
} J n/=v\K@
} np(<Ap r
G8'3.;"W5
D._r@~o
//打印回应的头信息 w:v:znQrW
public void logResponseHead(HttpURLConnection con) u>#'Y+7
{ ;zODp+4@Q
for(int i=1;;i++) (%, '
{ #n r1- sf|
String header=con.getHeaderFieldKey(i); Qg=~n:j
if(header!=null) H;ib3?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2ra4t]f6
Utility.log(header+" : "+con.getHeaderField(header)); \PJ89u0
else $_kU)<e3
break; ^lj>v}4fkW
} RqR X
} g=Jfp$*[
g^FH[(P[G
ipG+qj/=
public void splitterStop() AaVlNjB
{ 'z/hj>B<
bStop = true; \)*qW[C$a
} k$c!J'qL&
Dlp::U*N'
L\I/2aiE
} bql6Z1l
"^`AS"z'
|EunDb[Y
/* f{0PLFj
**FileAccess.java 1|--Xnv
*//文件访问(定位，写) /DCUwg=0
package NetFox; 9L,T@#7
import java.io.*; KC'{>rt7
7JbrIdDl|
,O(uuq
public class FileAccessI implements Serializable{ %|Vq"MW,I
xp= ]J UQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CAfG3;
RandomAccessFile oSavedFile; G8VWx&RE
long nPos; PYGHN T
u-,=C/iU
G6FknYj
public FileAccessI() throws IOException <#sK~G
{ $|KbjpQ
this("",0); v2NzPzzyb
} t$b`Am
X(~NpLR
tP3Upw"U
public FileAccessI(String sName,long nPos) throws IOException :7gIm|2"]
{ %5b2vrg~*
oSavedFile = new RandomAccessFile(sName,"rw"); JdE=!~\8
this.nPos = nPos; $|AxQQ%f
oSavedFile.seek(nPos); ~O!v?2it8q
} ==&=3
;TYkJH"
&12.|
public synchronized int write(byte[] b,int nStart,int nLen) dXZV1e1b&#
{ u7K0m! jW
int n = -1; 3LG)s:p$/
try{ FKPI{l
oSavedFile.write(b,nStart,nLen); :7'anj
n = nLen; 72aj4k]^
} tq{ aa
catch(IOException e) Gmc0yRN
{ 278 6tZF,
e.printStackTrace (); |#k1a:
} N7XRk=J
rxO|k0x^C
9i n&\
return n; h-V5&em"_
} ^XV$J-
>#SQDVFf
l78zS'
} |VIBSty2d
#8cY,%<S]
ds`a6>746
/* 5E$)Ip
**SiteInfoBean.java zUeS7\(l
*/ ACs?m\$Q
package NetFox; 2s~X
C]82Mt
!9B)/Xi
public class SiteInfoBean { OPar"z^EV
BDpeAF8z
B+ +:7!
private String sSiteURL; //Site's URL F]xo*
private String sFilePath; //Saved File's Path ,JX/`7y
private String sFileName; //Saved File's Name u9J;OsnHK
private int nSplitter; //Count of Splited Downloading File 9 u{#S}c`
w[t!?(![>
Drz#D1-2
public SiteInfoBean() jT%k{"+>+?
{//nSplitter的缺省值为5 1s .Ose
//default value of nSplitter is 5 ^8-CUH\
this("","","",5); b k 30d
} p\1-.
6s@'z<Ct
!>TH#sU$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1t6VS3
{ 5#~u U
sSiteURL= sURL; Mz_*`lRN
sFilePath = sPath; 6p])2]N>p
sFileName = sName; \^i/:
this.nSplitter = nSpiltter; #}3$n/
'7 SFa]tH
pbt/i+!
} lOYzo
jw]~g+x#$
A70x+mjy^T
public String getSSiteURL() *H8(G%a!^
{ 8SR~{
return sSiteURL; u6j\@U6I
} 8K=sx@l
}j;*7x8(
.IXkdy
public void setSSiteURL(String value) eTw sh]
{ BxVo>r
sSiteURL = value; &z8I@^<
} PRa#;Wb
&==X.2XW
nO.RB#I$F
public String getSFilePath() gTa6%GM>
{ vau0Jn%=ck
return sFilePath; b\&|030+
} dz3chy,3
pCb3^# &o
/i.3v45t"
public void setSFilePath(String value) '[V}]Z>-
{ oP vk ^H
sFilePath = value; b+7!$
} :!Ea.v
<_(UAv
K)=<hL
public String getSFileName() jg%HaA<zO
{ tj<a , l
return sFileName; |:Q`9;
} jG~zpZh
D_VAtz
N{rC#A3
public void setSFileName(String value) @'XxMO[Z!<
{ ` 9iB`<
sFileName = value; cVk&Yp;[*
} ,z8<[Q-#
8y:c3jzP_
vOMmsU F
public int getNSplitter() A|Z'\D0
{ <B"M} Y>_P
return nSplitter; &"G4yM
} ~m@v ~=
%uA\Le
wX7|a/|@
public void setNSplitter(int nCount) SI-G7e)3;>
{ PH$fDbC8
nSplitter = nCount; 1"7Rs}l7
} *}\}@0%
} h0;PtQb1
b3$aPwv
#I]5)XT
/* ,AX7~;hpq
**Utility.java 8}5dyn{cvE
*/ 0qND2_
package NetFox; z^xrB$8 u
mI;#Zq_j
fYv= yP~
public class Utility { KB3zQJY
|gl~wG1@
Nhq&Sn2
public Utility() ~i3/Ec0\
{ dM|&Y6
e<Pbsj
9t`
} 1K<4Kz~
=Tdh]0
//线程睡眠 c(:qid
public static void sleep(int nSecond) !sbKJ+V7
{ o'9K8q\1
try{ 4s{_(gy
Thread.sleep(nSecond); 7hQf T76h
} qT U(]O1
catch(Exception e) aahAUhF
{ &PfCY{_
e.printStackTrace (); BPFd'-O)
} g\Gx oR
} z% ln}
BC/oh+FW3
//日志 IYJS>G%*
public static void log(String sMsg) rkp 1tv
{ %&D,|Yl6
System.err.println(sMsg); ,(%?j]_P2
} p^=>N9
8|\0\Wd;vu
32DSZ0
public static void log(int sMsg) }8+rrzMUB
{ vXdz?
System.err.println(sMsg); ^>?E1J3u
} OK=lp4X
} D/T&0
=N_7DT
}7`HJ>+m)H
/* zvvF9
**TestMethod.java +3@d]JfMh
*/ (WW*yv.J
package NetFox; D)yCuw{M:
VxlK:*t`
5kX#qT=
public class TestMethod { |*~=w J_
M"q]jeaM
4v@urW s
public TestMethod() xB&kxW.;
{ ///xx/weblogic60b2_win.exe ^H0`UKE
try{ lq4vX^S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DXbzl +R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /7EeM{,~
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5<%]6cx}
fileFetch.start(); F vJJpPS
} XM0;cF
catch(Exception e){e.printStackTrace ();} Je|D]w
q&eUw<(F
Hk65c0
} ~:65e 8K
o6@Hj+,,
c=S-g 9J
public static void main(String[] args) Ol;}+?[Q
{ D$sG1*@s-
new TestMethod(); b4_"dg~gK
} Q?Au.q],
} }]-SAM
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