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)); m >'o&Hj
} AQ-PY
for(int i=0;i<nEndPos.length-1;i++) IcaF4#
{ YZmD:P
nEndPos = nStartPos[i+1]; GMiWS:`;v`
} \y<n{"a
nEndPos[nEndPos.length-1] = nFileLength; G>H&M#7K
} 0iHK1Pt}
} w#-rl@JQ4
NShA-G N5
%,)[%>#{
//启动子线程 T>L6 X:d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `U?;9!|;6
for(int i=0;i<nStartPos.length;i++) `cf&4Hn
{ Ip<STz]-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }rOO[,?Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [kn`~hI
nStartPos,nEndPos,i); oOSw>23x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sLB{R#Pt
fileSplitterFetch.start(); ;pC-0m0Y
} P$w0.XZa
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7';PI!$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JLs7[W)O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &)`A4bf%
nEndPos = " + nFileLength); 3Vt-]DGX
// fileSplitterFetch[nPos.length-1].start(); PUucYc
A$%%;O
B_@>HZ\&
//等待子线程结束 b-~Gt]%>m
//int count = 0; 8$@gAlI^
//是否结束while循环 Z7Mc.[C
boolean breakWhile = false; Imi_}NB+
LN_6>u
dD!} P$
while(!bStop) dNbN]gHC
{ wUl}x)xo
write_nPos(); 9jJ&QACn
Utility.sleep(500); DJ=miJI'
breakWhile = true; 9 ?h)U|J?G
=Y /
3hb1^HNT
for(int i=0;i<nStartPos.length;i++) nCYicB
{ ^ zo"~1
if(!fileSplitterFetch.bDownOver) jh}[7M
{ Tb~(?nY5
breakWhile = false; GHH1jJ_[7
break; |} .Y&1@U
} 22(0Jb\_
} \{abyi;
if(breakWhile) g+)T\_#u
break; 54tpR6%3p
y%3Yr?]
[@.%6aD
//count++; qhiQ!fMQ
//if(count>4) Gu&zplB
// siteStop(); ~Kt.%K5lgt
} \e( h6,@
<7u*OYjA
_ @ \
System.err.println("文件下载结束！"); .Ml}cE$L
} ]cFqKs
catch(Exception e){e.printStackTrace ();} eWcS>N
} e7 5*84
HJoPk'p%
{ \r{$<s
//获得文件长度 R.+QK6B&
public long getFileSize() lvk(q\-f
{ +loD{
int nFileLength = -1; IO|">a6
try{ 4,TS1H
URL url = new URL(siteInfoBean.getSSiteURL()); /GfC/)1_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K)F;^)KDHf
httpConnection.setRequestProperty("User-Agent","NetFox"); uFG]8pj2V1
3'*SSZmnOB
kS3wa3bT
int responseCode=httpConnection.getResponseCode(); (<2PhJ|
if(responseCode>=400) +KXg&A/^
{ HWD
processErrorCode(responseCode); Oh-HfJyi
return -2; //-2 represent access is error t\u0\l>
} lSl=6R
\jZvP`.2
^!N_Nx/M
String sHeader; UiF?Nx~
1JJQ(b
>8oRO
for(int i=1;;i++) LlX 7g_!
{ T%?<3/Ev!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #![b9~%WTh
//Utility.log(in.readLine()); 7BdvJ"
sHeader=httpConnection.getHeaderFieldKey(i); Cc/?-0a2!
if(sHeader!=null) o= N=W
{ ~kw[Aw3?D\
if(sHeader.equals("Content-Length")) MQw{^6Z>1
{ B%cjRwOT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FZb\VUmnV
break; V+cHL
} DX4uTD
} zeNvg/LI^
else pH'#v]"
break; ep>S$a*|
} U!^\DocAY
} :Uj+iYE8Z8
catch(IOException e){e.printStackTrace ();} W UDQb5k
catch(Exception e){e.printStackTrace ();} .B_)w:oF
3($%AGKJ
l 0jjLqm:
Utility.log(nFileLength); xgnt)&7T
#Ubzh`v
vgo-[^FiP$
return nFileLength; 4Poi:0oOys
} _`*x}
|j<b?
uZ\ >
//保存下载信息（文件指针位置） xG\&QE
private void write_nPos() *ZF7m_8u{
{ M[@).4h
try{ (X QgOR#
output = new DataOutputStream(new FileOutputStream(tmpFile)); ld$LG6[PA
output.writeInt(nStartPos.length); Quc9lL
for(int i=0;i<nStartPos.length;i++) N-4LdC
{ P ;PS+S9
// output.writeLong(nPos); R0, Q`
output.writeLong(fileSplitterFetch.nStartPos); aKkQXq*
output.writeLong(fileSplitterFetch.nEndPos); nW!rM($q
} _(TavL>l =
output.close(); 2< w/GX.
} Xc"S"a^\%
catch(IOException e){e.printStackTrace ();} TY5<hPU=
catch(Exception e){e.printStackTrace ();} 2?nK71c"
} qun#z$
$xa#+
l7 j3;Ly
//读取保存的下载信息（文件指针位置） k2_ "
private void read_nPos() #/MUiV
{ sq*d?<:3
try{ srw5&s(3X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9{^:+r
int nCount = input.readInt(); M g1E1kXe
nStartPos = new long[nCount]; ePP-&V"`"
nEndPos = new long[nCount]; Xu3o,k
for(int i=0;i<nStartPos.length;i++) 4\Mh2z5
{ ?SkYFa`u*
nStartPos = input.readLong(); v|<Dc8i+
nEndPos = input.readLong(); 71mdU6Kq
} blk~r0.2
input.close(); QjVP]C}p
} YFy5>*W
catch(IOException e){e.printStackTrace ();} O}*[@uv/
catch(Exception e){e.printStackTrace ();} xT#j-T
} oJvF)d@gU
=Bu d!
-A[iTI"
private void processErrorCode(int nErrorCode) #x"4tI
{ ijw'7d|,
System.err.println("Error Code : " + nErrorCode); 0jro0f'
} {ckA
QA+qFP
gmJiKuAL5
//停止文件下载 3^xTZ*G
public void siteStop() k?o(j/
{ Azxy!gDT"
bStop = true; ^ RU"v>
for(int i=0;i<nStartPos.length;i++) C(Yk-7
fileSplitterFetch.splitterStop(); K!lGo3n]
A=Q"IdK
H :}|UW
} h?p&9[e`
} %TyR8 %
//负责部分文件的抓取 X25cU{
**FileSplitterFetch.java {()8 Wr
*/ lGwX.cA!'
package NetFox; w[qWr@
hvnZ 2x.?d
#5-0R7\d7
import java.io.*; .\7R/cP}{A
import java.net.*; ,/BBG\mJ
lCr
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public class FileSplitterFetch extends Thread { 7N+No.vR.
uZ&,tH/
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String sURL; //File URL 8B"jvrs
long nStartPos; //File Snippet Start Position =1!wep"
long nEndPos; //File Snippet End Position ~T|?!zML
int nThreadID; //Thread's ID 9?:SxI;v
boolean bDownOver = false; //Downing is over -4mUGh1dy
boolean bStop = false; //Stop identical wv|:-8V
FileAccessI fileAccessI = null; //File Access interface l'fUa
4(B{-cK
Z,.*!S=?h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N1jj\.nB
{ %u-l6<w#R
this.sURL = sURL; #*:y2W%H
this.nStartPos = nStart; nzmv>s&UW
this.nEndPos = nEnd; w&8gA[y*u
nThreadID = id; v[T5D:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~M6Q8Y9
} ~Y<x-)R
$cHA_$ `
2_6x2Ia4
public void run() MM"{ehd{^a
{ a.L ?J
while(nStartPos < nEndPos && !bStop) 2VyLt=mdh
{ f*04=R?w7>
UxzZr%>s
w8:~LX.n
try{ 1tHTjEG4^3
URL url = new URL(sURL); V lN&Lz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RcitW;{|Kg
httpConnection.setRequestProperty("User-Agent","NetFox"); M$dDExd~
String sProperty = "bytes="+nStartPos+"-"; KGS=(z
httpConnection.setRequestProperty("RANGE",sProperty); r3<yG"J86
Utility.log(sProperty); *IJctYJaX
7Q7z6p/\v
ZY-W~p1:G
InputStream input = httpConnection.getInputStream(); |XzqP +t
//logResponseHead(httpConnection); nqg=I
,~`R{,N`
g!(j.xe
byte[] b = new byte[1024]; '9>z4G*Td
int nRead; xV @X%E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a$.(Zl
{ f'Dl*d
nStartPos += fileAccessI.write(b,0,nRead); `%EMhk
//if(nThreadID == 1) BX;Z t9"*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }:P/eY
} !run3ip`Z
m7Nm!Z7
W]{mEB
Utility.log("Thread " + nThreadID + " is over!"); P(8zJk6h),
bDownOver = true; *D!$gfa
//nPos = fileAccessI.write (b,0,nRead); N%'=el4L
} *aT3L#0(
catch(Exception e){e.printStackTrace ();} 3#}5dO
} ?u{y[pI6
} cd)yj&:?Bt
%Ak"d+OH4
pi[:"}m]/P
//打印回应的头信息 /xj^TyWM
public void logResponseHead(HttpURLConnection con) SsiAyQ|Ma
{ Z6\OkD
for(int i=1;;i++) (dvCejc^p
{ vG`R.
String header=con.getHeaderFieldKey(i); _ #288`bU
if(header!=null) .YKqYN?y4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C vfm ,BL
Utility.log(header+" : "+con.getHeaderField(header)); dp\pkx7
else WDNuR#J?
break; =t\HtAXn[
} @2cGx/1#
} w0(A7L:L
xH#R_
usnbGkq
public void splitterStop() UmZ#Cm
{ ig3HPlC
bStop = true; Vi[* a
} : &>PN,q>
zBV7b| j
A q;]al
} ORHs1/L`j
yPL1(i;
i7v> 9p7
/* BR*,E~%
**FileAccess.java Z;`ts/?SY]
*//文件访问(定位，写) eD5.*O
package NetFox; {0 d/;
import java.io.*; &[ejxK"
2'UWPZgE
PMC5qQ%x
public class FileAccessI implements Serializable{ AAUFX/}8P
W;en7v;#I}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =S7Xj`/
RandomAccessFile oSavedFile; ?G%C}8a
long nPos; MlVN'w
'F.Da#st!}
H`|8x4
public FileAccessI() throws IOException kBg,U8|S
{ pLi_)(#z_
this("",0); #e:cB'f
} ?_*X\En*3
77?/e^K\S
xsn2Qn/P
public FileAccessI(String sName,long nPos) throws IOException UPQ?vh2F2
{ wxU@M1w}
oSavedFile = new RandomAccessFile(sName,"rw"); },zP,y:cH
this.nPos = nPos; 31v0V:j
oSavedFile.seek(nPos); tjYqdbA)
} g.$a]pZz
706-QE^
^ur?da9z'
public synchronized int write(byte[] b,int nStart,int nLen) tGv5pe*r
{ ,Axk\7-
int n = -1; DtLga[M
try{ OOJg%y*H
oSavedFile.write(b,nStart,nLen); BnJpC<xm
n = nLen; r/o1a't;
} uL| Wuq
catch(IOException e) o6L\39v_
{ hq[;QF:B
e.printStackTrace (); Bc{j0Su
} sI>I
&f48MtE
[H ^ktF
return n; /Ilve U`E
} 6Q\0v
gD`|N@W$5
{}>s0B
} i[,9hp
5Us$.p
_D<=Yo
/* 4h% G %>j
**SiteInfoBean.java TKJs'%Q7F6
*/ IqEE.XhaK
package NetFox; !C ]5_
x -CTMKX
fL-lx-~
public class SiteInfoBean { S~L;oX?(!
REqQJ7a/
C{Y0}ZrmlF
private String sSiteURL; //Site's URL oN3DM;
private String sFilePath; //Saved File's Path "&!7wH ,A
private String sFileName; //Saved File's Name }XHB7,
private int nSplitter; //Count of Splited Downloading File !j8.JP}!)
j~DTvWg<Jl
]/31@RT
public SiteInfoBean() vZhC_G+tGd
{//nSplitter的缺省值为5 Bgw=((p
//default value of nSplitter is 5 _"nzo4e0
this("","","",5); 3(?V!y{@
} S)`%clN}J
B8J_^kd
7T7 A[A\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l=+hs
{ aYy+iP'$
sSiteURL= sURL; 7nsn8WN[
sFilePath = sPath; 8rZJvE#c
sFileName = sName; y^OT0mZkg
this.nSplitter = nSpiltter; QlxzWd3=q
| R\PQ/)
P_7QZ0k/
} OO$YwOKS
4th*=ku
>aw`kr
public String getSSiteURL() 'c]Fhe fb
{ "INIP?
return sSiteURL; 5B:%##Ug5
} *yX5g,52-|
VPC7Dh%.
TPE1}8p17
public void setSSiteURL(String value) ?LxBH-o(
{ %X|fp{C
sSiteURL = value; kh7RQbNY<I
} ([g[\c,H
kJP`C\4}f
E}qW'
public String getSFilePath() d1[;~)
{ 3rdrNc
return sFilePath; ;,WI_iP(w
} O%Hc%EfG
Qk5pRoL_
'sII/sq`(
public void setSFilePath(String value) W{@,DQ
{ e@j&c:p(Y
sFilePath = value; 6VUkZKc
} ?b,4mDptE
^pc?oDPSg
frh!dN
public String getSFileName() '?gF9:
{ Qq7%{`<}
return sFileName; ]?un'$%e
} fpPB_P{Ua
tZL|;K
s@$SM,tnn
public void setSFileName(String value) s!g06F
{ 59R%g .2Y
sFileName = value; ;:WM^S
} uge~*S
yhPO$L
xGkc_
public int getNSplitter() 6d;_}
{ L>3-z>u,
return nSplitter; #qnK nxD
} O-3R#sZ0
w/49O;rV
m=K46i+NE
public void setNSplitter(int nCount) vB?(|
{ [gkOwU=?
nSplitter = nCount; Zws[C
} 8MZ:=
} S Boi|
0F5QAR O
,5XDH6L1
/* -J& b~t@
**Utility.java W Te1E,M
*/ lj US-6
package NetFox; )x<oRHx]
)k~{p;Ke
1m{c8Z.h/d
public class Utility { SHA6;y+U/~
6uu49x_^L4
^1\[hyZ!
public Utility() hpBn_
{ -)pVgf
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~a ]R7X7
} }Q1m
Fs_zNN
//线程睡眠 qKjUp"
public static void sleep(int nSecond) zI&).
{ E%&E<<nhZ
try{ &0Bs?oq_
Thread.sleep(nSecond); )VM'^sV?
} Fo;.
catch(Exception e) JTS<n4<a
{ 5T-CAkR{n
e.printStackTrace (); 8b|m66#|
} s~b!3l`gu
} vO 3-B
yyv<MSU8
//日志 '{F Od_uk%
public static void log(String sMsg) VthM`~3
{ 8eDKN9kq
System.err.println(sMsg); SrT=XX,
} 6xW17P
XJguw/[wm
btDPP k'
public static void log(int sMsg) B@K =^77
{ {SJnPr3R
System.err.println(sMsg); rhH !-`m
} Sd?+j;/"
} cS;O]>/5
y"nL9r.,:
,0^9VWZV
/* E>L_$J-A-
**TestMethod.java a-Ne!M[
*/ 3IYbgUG
package NetFox; rrc>O*>{i
*<l9d
#(dERET*
public class TestMethod { +]S!pyZ"
tKLAA+Z
be(p13&od
public TestMethod() `\Hs{t]
{ ///xx/weblogic60b2_win.exe x-Fl|kwX.5
try{ QV*W#K\7q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qy,X#y'FuE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VK/i5yT5N
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y^ti;:
fileFetch.start(); -FW'i10\2+
} nOdAp4{:q%
catch(Exception e){e.printStackTrace ();} vy{YGT
9 Xx4,#?
S+M:{<AR
} n||!/u)*
<^YZ#3~1T
nH(Hk%~
public static void main(String[] args) !k0t (.
{ A]%hM_5s
new TestMethod(); E?^A+)<"
} zmpQ=%/H
} *h Bo,
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