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)); LsO}a;t5
} *cAI gO7
for(int i=0;i<nEndPos.length-1;i++) D`3`5.b
{ -rlCE-S
nEndPos = nStartPos[i+1]; RAj>{/E#W
} ZY=a[K
nEndPos[nEndPos.length-1] = nFileLength; OTzuOP8
} SVBo0wvz-
} bW^C30m
Z7p!YTA
M< /
//启动子线程 ;@xlrj+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;b!qt-;.<
for(int i=0;i<nStartPos.length;i++) DB3qf>@?
{ (nAL;:$x2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v?0F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T{)_vQ
nStartPos,nEndPos,i); _$i)bJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MI)v@_1d
fileSplitterFetch.start(); %Ni"*\
} i!)\m0Wm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p0hE`!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lBGYZ--
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hkMVA
nEndPos = " + nFileLength); 1Eb2X}XC
// fileSplitterFetch[nPos.length-1].start(); nF$HWp&gt
?AK`M #M
/xj`'8
//等待子线程结束 ^h^.;Iqr=
//int count = 0; a|#TnSk
//是否结束while循环 d/!\iLF
boolean breakWhile = false; 7}vI/?r
~LQzt@G4
%OOkPda
while(!bStop) b0Dco0U(
{ O]'2<;
write_nPos(); 2M=h:::W
Utility.sleep(500); 4AMe>s
breakWhile = true; sNM ]bei
Y&H<8ez
h'?v(k!
for(int i=0;i<nStartPos.length;i++) 5?Pf#kq
{ `]^W#6l
if(!fileSplitterFetch.bDownOver) *2pf>UzL
{ @JGFG+J}
breakWhile = false; )ZI#F]
break; 3?&v:H
} 5z =}o/?
} k7j.VpN9
if(breakWhile) t+_\^Oa)
break; t<ZBp0
KIp^| k7>
zXD/hM
//count++; 3!$+N\ #w
//if(count>4) Va?i#<a
// siteStop(); 8d_J9Ho
} e^oGiL~
bN7m[GRO.
mPHto-=fB
System.err.println("文件下载结束！"); 4hc[rN,]
} /QWXEL/M=
catch(Exception e){e.printStackTrace ();} |'z24 :8
} NyT%S?@y<
;S \s&.u
ZuybjV1/f6
//获得文件长度 0G6aF"
public long getFileSize() >KL=(3:":p
{ Xdx8HB@L
int nFileLength = -1; l5.k2{'
try{ qdn_ZE
URL url = new URL(siteInfoBean.getSSiteURL()); {kw%7}!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ox%j_P9@:
httpConnection.setRequestProperty("User-Agent","NetFox"); 1Y*k"[?dW
Kei0>hBi
(WJ)!
int responseCode=httpConnection.getResponseCode(); EQ ee5}
if(responseCode>=400) CgmAxcK
{ VnVBA-#r|
processErrorCode(responseCode); T[)!7@4r
return -2; //-2 represent access is error / Ws>;0
} %~x?C4L8
ZnRT$ l O
;Mo_B9
String sHeader; tT>LOI_z
{0w2K82
tE_n>~Zs
for(int i=1;;i++) hNsi 8/
{ r'j88)^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); '(FC
//Utility.log(in.readLine()); bsDA&~)s
sHeader=httpConnection.getHeaderFieldKey(i); @;`'s
if(sHeader!=null) tiE|%jOzt
{ :MY=Q]l
if(sHeader.equals("Content-Length")) EW(bM^dk}
{ 3a.!9R>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'mbLK#q
break; ,AweHUEn
} lUB?eQuN_
} ofV0L
else Ba8=nGa4KY
break; %L*EB;nK
} l;0([_>*j
} Qgj# k
catch(IOException e){e.printStackTrace ();} pT->qQ3;
catch(Exception e){e.printStackTrace ();} 0S$k;q
lbda/Zx
m..ajYSQ
Utility.log(nFileLength); /HLI9
17Cb{Q
BYXc 'K
return nFileLength; IZj`*M%3
} V^n6~O
8#yu.\N.xt
5m0\ls\
//保存下载信息（文件指针位置） ;6P>S4`w
private void write_nPos() uL^; i""
{ ?'6@m86d
try{ }x`Cnn
output = new DataOutputStream(new FileOutputStream(tmpFile)); {WrEe7dLy
output.writeInt(nStartPos.length); mG\QF0h
for(int i=0;i<nStartPos.length;i++) 5<dg@,\
{ ?'TK~,dG/
// output.writeLong(nPos); W:]2Tp
output.writeLong(fileSplitterFetch.nStartPos); g,._3.D
output.writeLong(fileSplitterFetch.nEndPos); ;yomaAr
} aYaEy(m
output.close(); Gy/w #4xj
} XYzaSp=bb
catch(IOException e){e.printStackTrace ();} C*b[J
catch(Exception e){e.printStackTrace ();} s)]jX
} Dhn7N8(LF!
+_7a/3kh
=4eJ@EVM
//读取保存的下载信息（文件指针位置） dR]-R/1|
private void read_nPos() Lmte ~oBi
{ {1OxJn1hd
try{ jG[Vp b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xUdGSr50
int nCount = input.readInt(); `xBoNQai
nStartPos = new long[nCount]; {oqbV#/&
nEndPos = new long[nCount]; '|SO7}`;Q
for(int i=0;i<nStartPos.length;i++) c9-$^yno
{ |X8?B=
nStartPos = input.readLong(); e%JIqKS
nEndPos = input.readLong(); BI`)P+K2
} H:c5 q0O^x
input.close(); Z&n[6aV'F
} /9R0}4i7
catch(IOException e){e.printStackTrace ();} %v8&
catch(Exception e){e.printStackTrace ();} L?[m$l!T}
} M_ukG~/
@.W;3|~qc
[;z\bV<S
private void processErrorCode(int nErrorCode) QXZXj#`
{ ;-Yvi,sS+
System.err.println("Error Code : " + nErrorCode); jhm3:;Z
} ^w^e~0 S
=-si| 1Z
@A1f#Ed<
//停止文件下载 g{]6*`/Z
public void siteStop() K<J,n!zc
{ u8zL[]>
bStop = true; 0DicrnH8
for(int i=0;i<nStartPos.length;i++) G]ek-[-
fileSplitterFetch.splitterStop(); ;gZ ^c]\
S&!(h {O
Nnh\FaI
} R2Tt6
} z{W Cw
//负责部分文件的抓取 {nKw<F2
**FileSplitterFetch.java h< r(:.%!}
*/ WA(x]""
package NetFox; hQ@k|3=Re
fmuh9Z
D0\>E}Y E
import java.io.*; DPT6]pl"y
import java.net.*; bSsg`
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8 MO-QO
public class FileSplitterFetch extends Thread { &gp&i?%X9b
_^BA;S@
V$ H(a`!
String sURL; //File URL kGV:=h
long nStartPos; //File Snippet Start Position -hXKCb4YU
long nEndPos; //File Snippet End Position ,MXU]{
int nThreadID; //Thread's ID j,j|'7J%
boolean bDownOver = false; //Downing is over +Hu\b&g
boolean bStop = false; //Stop identical G<7M;vRvP
FileAccessI fileAccessI = null; //File Access interface ^bv^&V&IB
DquLr+s~
kkjugm{D7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'f<N7%eZ
{ e-rlk5k%f
this.sURL = sURL; g=t`3X#d
this.nStartPos = nStart; ]6e(-v!U
this.nEndPos = nEnd; _Tj&gyS
nThreadID = id; LI%dJ*-V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FoetP`
} >/A]C$?3
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zr|DC] 3
public void run() M8~3 0L
{ HEVjK$
while(nStartPos < nEndPos && !bStop) ^sf,mM~D
{ O^cC+@l!4
Rf!v{\
["D!IqI:
try{ %+l95Dv1
URL url = new URL(sURL); -Rpra0o. C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /wLBmh1"
httpConnection.setRequestProperty("User-Agent","NetFox"); ]Kt@F0U<o
String sProperty = "bytes="+nStartPos+"-"; E:K4k <
httpConnection.setRequestProperty("RANGE",sProperty); 3Q$4`p;
Utility.log(sProperty); "SMJ:g",
}i8y/CA
#4Z e2T|
InputStream input = httpConnection.getInputStream(); B$g\;$G
//logResponseHead(httpConnection); ~P'.R.e
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A`uHZCwJ5
byte[] b = new byte[1024]; _bCAZa&&
int nRead; t"4* ]S
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c]uieig0~
{ ?z.?(xZ 6
nStartPos += fileAccessI.write(b,0,nRead); g[(@@TiG
//if(nThreadID == 1) W4o8]&A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E4% -*n
} DO(};R%=
{d.z/Buu
or*{P=m+R
Utility.log("Thread " + nThreadID + " is over!"); A1prYD
bDownOver = true; Kzrd<h]`)
//nPos = fileAccessI.write (b,0,nRead); &<;T$Y
} )Jjp^U3Ub
catch(Exception e){e.printStackTrace ();} PgA<pfEHE
} _|u}^MLO
} 84WDR?
:XhF:c[.:
i9L]h69r
//打印回应的头信息 {g.YGO
public void logResponseHead(HttpURLConnection con) p9)YRLOh.
{ rC!O}(4t%$
for(int i=1;;i++) AAQ!8!
{ j{Px}f(=
String header=con.getHeaderFieldKey(i); 1gV?}'jq
if(header!=null) sMMOZ'bT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D\_nqx9O
Utility.log(header+" : "+con.getHeaderField(header)); WOn<;'}M&
else "Ol:ni1
break; -|FHv+
} I$.lFQ%(
} 7dY_b
)pl5nu#<
2A\b-;4EP
public void splitterStop() +%XByY5
{ #ELeW3 S}
bStop = true; r2SZC`Z}-M
} ?^Aj\z>
:6(\:
d0)]^4HT|y
} /p<9C?
Md~SzrU
q7lC}'2fu
/* a[nSUlT&
**FileAccess.java lC#wh2B6
*//文件访问(定位，写) yo[Sh6r/9b
package NetFox; B6dU6"
import java.io.*; MU$tX
MZ}0.KmaZ
^mq(j_E.
public class FileAccessI implements Serializable{ B}TY+@
n,FyK`x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h"ZIh= j@
RandomAccessFile oSavedFile; tF),Sn|*
long nPos; 48wt
he~8V.$
^>E>\uz0v
public FileAccessI() throws IOException `n>|rd
{ fof}I:vO
this("",0); bIGcszWr
} kKlNhP(
qfXt%6L
nnn\
public FileAccessI(String sName,long nPos) throws IOException XB!qPh.
{ 0JtM|Mg
oSavedFile = new RandomAccessFile(sName,"rw"); BlpyE[h T
this.nPos = nPos; *KNfPh#wi}
oSavedFile.seek(nPos); ?Ojv<L-f.:
} [KR%8[e
P@@MQ[u?!.
J.JD8o9sa
public synchronized int write(byte[] b,int nStart,int nLen) zV}:~;w
{ *eHa4I
int n = -1; lt-3OcC
try{ iA{q$>{8
oSavedFile.write(b,nStart,nLen); ez32k[eV!
n = nLen; >N al\
} %ud-3u52M8
catch(IOException e) jywS<9c@
{ o*A, 6y
e.printStackTrace (); 5{(4%
} [{2v}
q`mxN!1[
DX!dU'tj
return n; ! 7V>gWhR
} [5'HlHK
_w\i~To!
kttJTP77t
} (<_kq;XtN0
WYF8?1dt +
H0&wn#);6R
/* 9nVb$pfe#
**SiteInfoBean.java ym5@SBqIx
*/ J>#hu3&UOQ
package NetFox; (z8ZCyq7r[
t0fgG/f'
517"x@6Q
public class SiteInfoBean { ShL!7y*rT{
oU,8?(}'~
MR,I`9Pe
private String sSiteURL; //Site's URL HqsqUS3[
private String sFilePath; //Saved File's Path <D:q4t
private String sFileName; //Saved File's Name " 4#&tNQ
private int nSplitter; //Count of Splited Downloading File UH0l8ixc
Cxq|N]E
::{\O\w
public SiteInfoBean() 5cf?u3r!qJ
{//nSplitter的缺省值为5 sg-^ oy*^
//default value of nSplitter is 5 DcFYb|p
this("","","",5); G*EF_N.G0
} u9Adu`
W=EcbH9/.)
7L/LlO/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DjaXJ?'
{ m$W2E.-$'#
sSiteURL= sURL; clyp0`,7
sFilePath = sPath; _;^x^
sFileName = sName; +JG05h%'
this.nSplitter = nSpiltter; >QJDO ]~V
5N>flQ
(rJ-S"^u
} a0]GQyIG
03)irq%l;
}@6yROy.
public String getSSiteURL() e8):'Cb
{ TDfloDxA
return sSiteURL; [u*7( 4e
} yqK_|7I+
jtfC3E,U
B>'J5bZsw
public void setSSiteURL(String value) %!-t7K^mFq
{ gktlwiCZ
sSiteURL = value; nm\f$K>Pg
} ?>ZrdfTwz,
C$q-WoTM(
c]VK%zl
public String getSFilePath() Ow1+zltgj-
{ p cUccQ
return sFilePath; lMW6D0^
} E)Qg^DHP/
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xzz@Wc^_
public void setSFilePath(String value) g3vbskY|
{ %vf;qVoA~
sFilePath = value; Vm@VhCsp
} =&-.]|t
hC{2LLu;n
[`h,Ti!m<
public String getSFileName() uCW}q.@4
{ ~ cu+QR)
return sFileName; P*Jk 8MK#G
} gBI?dw
xzMpTZQ
k-*k'S_
public void setSFileName(String value) p8F$vx4,
{ <.lN'i;(
sFileName = value; 4u|6^wu.I
} KVoi>?a
`ALQSo~l
xXV15%&
public int getNSplitter() 3!*`hQ;s
{ U!"RfRD.<
return nSplitter; ;SA+|,
} _mQ~[}y+?
bX`]<$dr3
Y\1& Uk
public void setNSplitter(int nCount) =5pwNi_S
{ {iLr$89
nSplitter = nCount; '+^XL6$L
} V^9%+L+E5
} /xA`VyHO
@M }`nKXM
+x:VIi
/* M@.?l=1X
**Utility.java Q6X}R,KA1
*/ [nsTO5G$u
package NetFox; eLN(NSPoS
k|_ >I
#>$w9}gFi
public class Utility { C\[g>_J
i6h0_q8 >
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public Utility() 37,)/8]lG
{ 6^p>f:5
[;INVUwG^
o648 xUP
} <J1$s_^`
bzMs\rj\
//线程睡眠 F>3fP
public static void sleep(int nSecond) Zf`ddT
{ +Mh9Jf
try{ }JWk?
Thread.sleep(nSecond); 2!bE|
} laFF/g;sRC
catch(Exception e) F a'2i<
{ cm7>%g(oQo
e.printStackTrace (); y {1p#
} i_;]UvP
} EabZ7zFoN
R_DZJV O
//日志 MU&P+Wr
public static void log(String sMsg) (hX}O>
{ uO`YA]
System.err.println(sMsg); Bx&wS|-)D
} #6<9FY#
cS1BB#N0
76*5/J-
public static void log(int sMsg) (PCv4:`g
{ [P_1a`b
System.err.println(sMsg); sh"\ kk9
} %sLij*
} FPPGf!Eq
Z-+p+34ytq
0SziTM
/* LA^H213N|
**TestMethod.java 3l@={Ts
*/ VXAgp6
package NetFox; L~jKx)S%
9f4#b8
`cr.C|RT:
public class TestMethod { ^dR5fAS
<4Jo1
93d ht
public TestMethod() [ Q6v#I
{ ///xx/weblogic60b2_win.exe MW+]w~7_Q
try{ r`L$[C5I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~l@SGHx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `_'I 9,.a
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,9f$an
fileFetch.start(); i-E~ZfJ
} 89'XOXl&1
catch(Exception e){e.printStackTrace ();} &6E^<v?]
M+ gYKPP
bd2"k;H<o
} BS#@ehdig
ET`;TfqM
:R<n{%~
public static void main(String[] args) -_ [Z5%B
{ e}e\*BL
new TestMethod(); fmvv q1G&
} -<i&`*zG
} )A['+s
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