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)); /Pvk),ca
} w9f _b3
for(int i=0;i<nEndPos.length-1;i++) Stxp3\jEn
{ '.(~
nEndPos = nStartPos[i+1]; *YtB )6j
} %X>FVlPm
nEndPos[nEndPos.length-1] = nFileLength; X4wH/q^
} zBY~lNB
} +~Tu0?{Z 0
mu[Op*)
N}b^fTq
//启动子线程 {,?ss$L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r|GY]9
for(int i=0;i<nStartPos.length;i++) 6)}B"Qd
{ K]/Od
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !`&\Lx_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?mx\eX{
nStartPos,nEndPos,i); +;Cr];b3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M0L&~p_F
fileSplitterFetch.start(); :et#0!
} PcC/_+2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $6h*lT<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a460|w6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", icgJ;Q 5
nEndPos = " + nFileLength); w^q7n
// fileSplitterFetch[nPos.length-1].start(); 1%~[rnQ
>&U@f
G:IP? z]
//等待子线程结束 #.._c?%4/
//int count = 0; UDEj[12S
//是否结束while循环 w0w1PE-V=
boolean breakWhile = false; 6>`c1 \8f
'yY>as
IP3E9z_L
while(!bStop) !eI2r
{ $q_R?Eay
write_nPos(); *?t%0){
Utility.sleep(500); V'DA[{\*
breakWhile = true; 9Uf j
9GU]l7C=z
S`!-Cal`n
for(int i=0;i<nStartPos.length;i++) (JUZCP/\
{ upy\gkpnGO
if(!fileSplitterFetch.bDownOver) xQ4%e[/
{ :E&g%'1
breakWhile = false; <S?#@F\"S
break; -/P\"c
} 7f{=w, U
} ~" i0x
if(breakWhile) U_B((Z(g
break; W-efv
bBc[bc>R
4_/?:$KO
//count++; z (?=Iv3
//if(count>4) 72W s K"
// siteStop(); P"/G
} jszK7$]^
Az;t"
)wvHGecp*
System.err.println("文件下载结束！"); iBTYY{-wF
} sEJC-$
catch(Exception e){e.printStackTrace ();} 7!WA)@6
} vw,rF`LjZ
Jg}K.1Hs
RTh`ENCKR
//获得文件长度 ~*A8+@\R
public long getFileSize() z`UhB%-?
{ .mLK`c6
int nFileLength = -1; 5,-U.B}
try{ H,nec<Jp
URL url = new URL(siteInfoBean.getSSiteURL()); y*pUlts<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W\&8auds
httpConnection.setRequestProperty("User-Agent","NetFox"); 0j"8@<
CCBfKp
I M-L'9
int responseCode=httpConnection.getResponseCode(); (3J$>Na
if(responseCode>=400) Szbb_i{_ `
{ }J">}j]/
processErrorCode(responseCode); Qham^
return -2; //-2 represent access is error +t5U.No
} 26&'X+n&
&0 >Loja`^
R}^~^#
String sHeader; 6f')6X'x
"#[!/\=?:
MjlP+; !
for(int i=1;;i++) Q8!)!r%
{ $hivlI-7Ko
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4RSHZAJg
//Utility.log(in.readLine()); b2b^1{@h;v
sHeader=httpConnection.getHeaderFieldKey(i); e/0<[s*#Q
if(sHeader!=null) M`rl!Ci#
{ 91=OF*w
if(sHeader.equals("Content-Length")) n2)q}_d
{ 3s/H2fz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Fa'k0/_j
break; 3;S,3
} [0"'T[ok
} Llr>9(|
else Vn*tpbz
break; > ;/l)qk,
} Zt.'K(]2h
} Y. ,Kl~
catch(IOException e){e.printStackTrace ();} xx[9~z=d
catch(Exception e){e.printStackTrace ();} ZI=%JU(
"@??Fw!
*h}XWBC1q
Utility.log(nFileLength); $s9Vrw0Z
{r@Ty*W} L
C(00<~JC
return nFileLength; S30?VG9U0f
} kS bu]AB
UrqRx?#
+=O5YR!{
//保存下载信息（文件指针位置） 7;KwLT9
private void write_nPos() zIh['^3.n
{ ?OkWe<:4
try{ c-B cA
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^$b Y,CE
output.writeInt(nStartPos.length); WZ.@UN,
for(int i=0;i<nStartPos.length;i++) 1oc3$A
{ rg^'S1x|
// output.writeLong(nPos); 8C*c{(4
output.writeLong(fileSplitterFetch.nStartPos); z^'gx@YD*v
output.writeLong(fileSplitterFetch.nEndPos); HZ'_r cv
} 9I&xfvD,
output.close(); ;7}VBkH
} eAE`#t
catch(IOException e){e.printStackTrace ();} R}O_[
catch(Exception e){e.printStackTrace ();} ~_/(t'9
} ibj87K
e 9;~P}
hDF@'G8F
//读取保存的下载信息（文件指针位置） >m$1Xx4#GV
private void read_nPos() `@`CG[-9
{ KV(Q;~8"X
try{ bbE!qk;hEP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #d6)#:uss
int nCount = input.readInt(); <0Xf9a8>
nStartPos = new long[nCount]; k$blEa4
nEndPos = new long[nCount]; 'uBu6G
for(int i=0;i<nStartPos.length;i++) 'Gj3:-xqL
{ YtmrRDQs
nStartPos = input.readLong(); 8Vr%n2M
nEndPos = input.readLong(); 2LF/H$]o5
} ]'&LGA`
input.close(); {*G9|#[/@
} Q'=x|K#xj
catch(IOException e){e.printStackTrace ();} c2l@6<Ww
catch(Exception e){e.printStackTrace ();} B38]~'8
} "\w 7q
La`NPY_:>
-t!~%_WCv
private void processErrorCode(int nErrorCode) wW>A_{Y
{ ;U/&I3dzV
System.err.println("Error Code : " + nErrorCode); "\:`/k3
} q'T4w!V(V
|d{PA.@33
'DP1,7
//停止文件下载 cr7 }^s
public void siteStop() _kef0K6
{ ]L5@,E4.
bStop = true; rV` #[d
for(int i=0;i<nStartPos.length;i++) J,'M4O\S
fileSplitterFetch.splitterStop(); 'j#*6xD
A8muQuj]~~
p|U?86t
} fK>L!=Q
} 9+Np4i@
//负责部分文件的抓取 Cio 1E-4
**FileSplitterFetch.java @LF,O}[2J
*/ f,U.7E
package NetFox; ;17E(tl
_>&X\`D
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import java.io.*; ` Fa~
import java.net.*; kMIcK4.MH
8V'~UzK
)}Hpi<5N
public class FileSplitterFetch extends Thread { Vh|*p&
^UP`%egR
*7uH-u"5d
String sURL; //File URL ZF!h<h&,
long nStartPos; //File Snippet Start Position @a! #G
long nEndPos; //File Snippet End Position Dj"F\j 1
int nThreadID; //Thread's ID Wf+cDpK
boolean bDownOver = false; //Downing is over $0W|26;
boolean bStop = false; //Stop identical g2+2%6m0
FileAccessI fileAccessI = null; //File Access interface h79}qU
yb<fpM
y8]B:_iU9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p*XANGA
{ ROH|PKb7
this.sURL = sURL; !z\h|wU+
this.nStartPos = nStart; 8SMxw~9$
this.nEndPos = nEnd; <$D`Z-6
nThreadID = id; ?qb}?&1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /2&c$9=1
} ;YaQB#GK%
\[;0KV_
g_;\iqxL
public void run() )*u8/U
{ on4HKeO
while(nStartPos < nEndPos && !bStop) _P!m%34|
{ 3/P1!:g9
=}~hWL
Na<pwC
try{ ]=\].% >
URL url = new URL(sURL); z}.e]|b^H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1y:-N6
httpConnection.setRequestProperty("User-Agent","NetFox"); FnwJ+GTu
String sProperty = "bytes="+nStartPos+"-"; -M\<nx
httpConnection.setRequestProperty("RANGE",sProperty); l5~os>
Utility.log(sProperty); ko!)s
!hm]fh_j
T~-ycVc
InputStream input = httpConnection.getInputStream(); irZ])a
//logResponseHead(httpConnection); ,>:U2%
%:i7s-0w
Jx:Y-$
byte[] b = new byte[1024]; Xu{1".\
int nRead; t^&Cxh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HVRZ[Y<^
{ 7 W5@TWM
nStartPos += fileAccessI.write(b,0,nRead); td$E/h=3
//if(nThreadID == 1) X;$+,&M"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z'Hw
} yNPVOp*
e1yt9@k,
0S"mVZ*P
Utility.log("Thread " + nThreadID + " is over!"); hDDn,uzpd
bDownOver = true; dRYqr}!%n
//nPos = fileAccessI.write (b,0,nRead); 3<Lx&p~%T
} ~g91Pr
catch(Exception e){e.printStackTrace ();} /PVk{3
} PI {bmZ
} 8]c2r%J
gb1V~
}J}-//[A
//打印回应的头信息 cVv=*81\
public void logResponseHead(HttpURLConnection con) X0HZH?V+
{ )$2QZ qX
for(int i=1;;i++) hPkp;a #
{ G[PtkPSJ
String header=con.getHeaderFieldKey(i); #~]zhHI
if(header!=null) [jQp~&nY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x8 2cT21b
Utility.log(header+" : "+con.getHeaderField(header)); 7sCG^&Y
else qz_7%c]K[
break; LENq_@$
} [>I<#_^~
} /8'NG6"H`
tAd%#:K
Wu/]MBM
public void splitterStop() 5Pc;5 o0C
{ Qp5VP@t
bStop = true; ^LnTOdAE
} 5{WE~8$
KfEx"94
/KaZHR.
} bSlF=jT[S
)u&|_&g{}J
n+9=1Oo"
/* ?=msH=N<l
**FileAccess.java DCO\c9
*//文件访问(定位，写) 4"(Bu/24
package NetFox; [85spub&}
import java.io.*; \.{$11P#
x8B}ZIbT9
cl3K<'D
public class FileAccessI implements Serializable{ a5^]20Fa
<NY^M!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _.Nbt(mz
RandomAccessFile oSavedFile; s$k<Ks
long nPos; 1-uxC^u?|#
?=7cF
|Zpfq63W
public FileAccessI() throws IOException ^)S;xb9
{ UgSB>V<?
this("",0); {<p?2E
} ZQsJL\x[UK
{]!mrAjD
8 >EWKI9
public FileAccessI(String sName,long nPos) throws IOException M)+H{5bt
{ 8^2oWC#U(
oSavedFile = new RandomAccessFile(sName,"rw"); gfd"v
this.nPos = nPos; rU:`*b<
oSavedFile.seek(nPos); D/xbF`
} dq6m>;`
%N6A+5H
%lhEM}Sm
public synchronized int write(byte[] b,int nStart,int nLen) CyFrb`%
{ jD]~ AwRJ
int n = -1; ZY={8T@
try{ #U4F0BdA
oSavedFile.write(b,nStart,nLen); iN\4gQ!
n = nLen; Yui3+}Ms
} 85$m[+md
catch(IOException e) L.2^`mZs
{ S(lO(gY
e.printStackTrace (); tjGn|+|k
} %6,SKg p
(O?.)jEW(.
faX#**r
return n; yCR?UH;
} $N9aV
3?9IJ5p
J.b9F:&}
} )h4f\0
M61xPq8y5
wLH>:yKUU
/* &*,#5.
**SiteInfoBean.java .-c4wm}
*/ Y@vTaE^w3
package NetFox; W=><)miQ@
!8d{q)JZ
-t'jNR'
public class SiteInfoBean { L:j<c5
^z IW+:
h$>-.-
private String sSiteURL; //Site's URL uAJx.>$b
private String sFilePath; //Saved File's Path T|eu
private String sFileName; //Saved File's Name 3g,`.I_
private int nSplitter; //Count of Splited Downloading File +>{2*\cZ5}
m@2QnA[4
V)HG(k
public SiteInfoBean() =JEv,ZGT3
{//nSplitter的缺省值为5 /<=u\e'rE
//default value of nSplitter is 5 %KhI>O<
this("","","",5); Ys!82M$g
} ^e_hLX\SW
x7&B$.>3
wr/"yQA]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qZtzO2Mt
{ !mJ"gg
sSiteURL= sURL; v!6 c0a
sFilePath = sPath; P6-s0]-g
sFileName = sName; DS(}<HK{
this.nSplitter = nSpiltter; qFCOUl
N1}sHyVq7
u<tbbKM
} yy^q2P
'4+ ur`
{9&;Q|D z
public String getSSiteURL() !Y0Vid
{ @]%IK(|
return sSiteURL; /tx]5`#@7]
} TOB-aAO
I(L,8n5
J s@hLP`
public void setSSiteURL(String value) \O3m9,a
{ A5I)^B<(
sSiteURL = value; rxvx
} MDZ640-Y
KK/tu+"
2>xF){`
public String getSFilePath() kzQ+j8.,U
{ X; \+<LE
return sFilePath; &ZlVWK~v
} =vCY?I$P
45@ I*`
SuJ aL-;
public void setSFilePath(String value) u^+7hkk
{ C\Wmq [
sFilePath = value; }_M~2L?i
} ~?Qe?hB
9iIhte.
YW,tCtI0_
public String getSFileName() Cx@);4arj
{ n`?aC|P2s
return sFileName; 1y@i}<9F
} 8sWJcmVo
17%,7P9pg
]3],r?-tJ
public void setSFileName(String value) p?%y82E
{ lHY+}v0
sFileName = value; v!-/&}W)1
} M>xK+q?O
K*vt;L
D(@S+r_ota
public int getNSplitter() O'p9u@kc
{ T"}5}6rSG
return nSplitter; y{B=-\O]
} O-0x8O^B
93)sk/j
T?CdZc.
public void setNSplitter(int nCount) 4<w.8rR:A
{ }#RakV4
nSplitter = nCount; `t>l:<@%
} X6w6%fzOH>
} \$~|ZwV{
Fc)@,/R"v
R6<X%*&%
/* Z!a=dnwHz
**Utility.java $lfn(b,
*/ hn7# L
package NetFox; !3c\NbU
L^/5ux
u OmtyX
public class Utility { [: n'k
>;aWz%-
oz\!V*CtK
public Utility() c)6m$5]
{ ]`!>6/[
pGP7nw_g
8rAg\H3E
} :DK {Vg6
[r\Du|R-*
//线程睡眠 ^&9zw\x;z
public static void sleep(int nSecond) +B,}Qr
{ L81ZbNU?$
try{ <6%?OJhp
Thread.sleep(nSecond); bi',j0B
} wQ:)KjhHH
catch(Exception e) y;m|
{ 5zK4Fraf
e.printStackTrace (); ANAVn@ [
} Ljm[?*H#
} nSDMOyj+
o)M}!MT
//日志 $8)+XmsCr
public static void log(String sMsg) <`8n^m*
{ H5/6TX72N
System.err.println(sMsg); kUb>^- -K
} B-RjMxX4>
2lZ Q)
j7Yu>cr
public static void log(int sMsg) hE:9{;Gf
{ &~cBNw|
System.err.println(sMsg); ^ox=HNV
} rET\n(AJ
} >.Pnkx*
~gJwW+
etQCzYIhn
/* dohA0
**TestMethod.java EgEa1l!NSQ
*/ ?d\N(s9F
package NetFox; B B{$&Oh
d"1]4.c
mX"oW_EK
public class TestMethod { +uF>2b6'
n1ZbRV
df8k7D;~e
public TestMethod() ^'MT0j
{ ///xx/weblogic60b2_win.exe etDk35!h~,
try{ 1/B>XkCJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @,j*wnR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /obfw^
SiteFileFetch fileFetch = new SiteFileFetch(bean); G6Axs1a
fileFetch.start(); 4d4ZT?V[
} *}qWj_RT
catch(Exception e){e.printStackTrace ();} sPpH*,(
-a}Dp~j
5+0gR &|j
} Lz}OwKl
0@0w+&*"@
4&lv6`G `
public static void main(String[] args) D(op)]8
{ GRIti9GD
new TestMethod(); [T4J{y64Y
} )2KF}{
} S&5&];Ag
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