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)); SiUu**zC
} yOt#6Vw
for(int i=0;i<nEndPos.length-1;i++) Fn7OmxfD
{ Qn,6s%n
nEndPos = nStartPos[i+1]; ZP5 !O[Ut
} IzJq:G.
nEndPos[nEndPos.length-1] = nFileLength; 2 rr=FJ
} [orL.D]
} =MMd&
}zx ~
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//启动子线程 ),-gy~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QeG9CS)E}j
for(int i=0;i<nStartPos.length;i++) N@L{9ak1
{ -sfv"?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;}j(x;l>t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X.#)CB0c1Q
nStartPos,nEndPos,i); P6R_W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RFyMRE!?
fileSplitterFetch.start(); y;uR@{
} z V\+za,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t2s/zxt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wV"`Du7E;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "J`&"_CyZ
nEndPos = " + nFileLength); +l/v`=C
// fileSplitterFetch[nPos.length-1].start(); CF2Bd:mfZ
:Ys~Lt54
VOLj#H
//等待子线程结束 l6&\~Z(
//int count = 0; EgU#r@7I
//是否结束while循环 &8z<~q
boolean breakWhile = false; d.^g#&h
+)iMJ]>
(rd [tc
while(!bStop) M{Z ;7n'
{ m$kQbPlatN
write_nPos(); %KXiB6<4
Utility.sleep(500); {VL@U$'oI
breakWhile = true; =I'3C']Z W
o[T+/Ej&
{@^;Nw%J
for(int i=0;i<nStartPos.length;i++) B+j]C$8}
{ <ZF|2
if(!fileSplitterFetch.bDownOver) r~lZ8$KC
{ . \"k49M`
breakWhile = false; 0{|HRiQH9+
break; R<Lf>p>_
} `daqzn
} iU;e!\A
if(breakWhile) WXl+w7jr
break; )&Oc7\J,
6JDHwV
>w@+cUto
//count++; `x#Ud)g
//if(count>4) @)?]u U"L
// siteStop(); K"H\gmV_g
} `X6JZxGyd
&$F<]]&
Jpj=d@Of70
System.err.println("文件下载结束！"); #_@cI(P
} 3KkfQ{
catch(Exception e){e.printStackTrace ();} XiE`_%NW
} pn gto
TZAd{EZa
~,b^f{7`!
//获得文件长度 CwA_jOp
public long getFileSize() ViPC Yt`of
{ \=AA,Il
int nFileLength = -1; 'J|)4OG:
try{ $(aq;DR
URL url = new URL(siteInfoBean.getSSiteURL()); _1p8(n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HYmC3
httpConnection.setRequestProperty("User-Agent","NetFox"); l%0bF9\
U]iI8c
QO/0VB42
int responseCode=httpConnection.getResponseCode(); f'^uuO#x
if(responseCode>=400) d,b4q&^X8
{ a/sjW
processErrorCode(responseCode); `hi=y BO
return -2; //-2 represent access is error //q(v,D%Q
} vxOqo)yO
&12KpEyf
_\ToA9m
String sHeader; b-&iJ &>'
(+> 2&@@<
[1VA`:?W
for(int i=1;;i++) QPJ\Iu@D$
{ d(T4Kd$r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {r,Uik-nL
//Utility.log(in.readLine()); .$qa?$@
sHeader=httpConnection.getHeaderFieldKey(i); G<;~nAo?f0
if(sHeader!=null) T{k P9 4
{ <v:VA!]
if(sHeader.equals("Content-Length")) 5ilGWkb`'X
{ tnRf!A;m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oJz2-PmX
break; 5i!Q55Yv=,
} "is(
} )/H;5 cn
else 7A)\:k
break; Km` SR^&\
} jT{T#_
} sgX!4wG&Z
catch(IOException e){e.printStackTrace ();} EKwQ$?I
catch(Exception e){e.printStackTrace ();} I0Pw~Jj{
M&Ka^h;N
LVj1NP
Utility.log(nFileLength); 8M,*w6P
eqo0{e
Ps!MpdcL3
return nFileLength; { mi}3/
} SB_Tzp
]pax,|+$C
ef5)z}B
//保存下载信息（文件指针位置） iC gZ3M]
private void write_nPos() :Ha/^cC/3
{ LKIMT
try{ xM*_1+<dT$
output = new DataOutputStream(new FileOutputStream(tmpFile)); B$4*U"tk
output.writeInt(nStartPos.length); >XD?zF)6
for(int i=0;i<nStartPos.length;i++) {3~VLdy
{ 5)k8(kH
// output.writeLong(nPos); uN|A}/hr]
output.writeLong(fileSplitterFetch.nStartPos); pP. _%5
output.writeLong(fileSplitterFetch.nEndPos); 8Bf>
} 3Vb4zZsl
output.close(); _4ag-'5
} 6>>; fy2
catch(IOException e){e.printStackTrace ();} Kc/1LeAik
catch(Exception e){e.printStackTrace ();} rhJ&* 0M
} 8+zW:0"[
3db{Tcn\@]
w?Te%/s.
//读取保存的下载信息（文件指针位置） V]=22Cxi'~
private void read_nPos() LW %AZkAx
{ :QE5 7.
try{ +\/Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |VBt:dd<
int nCount = input.readInt(); Yh":>~k?SY
nStartPos = new long[nCount]; {ZJO5*
nEndPos = new long[nCount]; m|a9T#B(
for(int i=0;i<nStartPos.length;i++) :RaQ =C
{ C"{^wy{sL
nStartPos = input.readLong(); (o^tmH*
nEndPos = input.readLong(); "HMEoZ
} {keZ_2
input.close(); 1|bXIY.J*
} +#}GmUwPG$
catch(IOException e){e.printStackTrace ();} d>NGCe
catch(Exception e){e.printStackTrace ();} 7FB?t<x
} B VBn.ut
]P4WfV d
Kb.qv)6i*
private void processErrorCode(int nErrorCode) D!<F^mtl
{ wu41Mz7
System.err.println("Error Code : " + nErrorCode); vwCQvt
} rPV Q#iB
8Sbz)X
[);oj<
//停止文件下载 DiCz%'N
public void siteStop() H?$dnwR
{ uZqL'l+/y
bStop = true; B=_w9iVN
for(int i=0;i<nStartPos.length;i++) o`U}uqrO
fileSplitterFetch.splitterStop(); ,+=9Rp`md
}V?m =y [
%b6$N_M{H1
} 6x+ujUBkK
} i_Kwxn$
//负责部分文件的抓取 iSW2I~PD
**FileSplitterFetch.java d t/AAk6
*/ 0YH5B5b
package NetFox; =7Ln&tZ
O[@!1SKT0
xQoZ[
import java.io.*; u?osX;'w
import java.net.*; <Xf6?nyZ(
rTPgHK]?l
J2mHPVA3
public class FileSplitterFetch extends Thread { ^7gGtz2
zj 6I:Qr
&i#$ia r
String sURL; //File URL _y@28t
long nStartPos; //File Snippet Start Position -IPo/?}
long nEndPos; //File Snippet End Position <r%K i`u(p
int nThreadID; //Thread's ID +;N]34>S7
boolean bDownOver = false; //Downing is over LGP"S5V
boolean bStop = false; //Stop identical EX8JlA\-W
FileAccessI fileAccessI = null; //File Access interface %I1@{>OxG
PmR].Ohzi
> p`,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mH o#"tc
{ .<x6U*)\O
this.sURL = sURL; C{exvLQ
this.nStartPos = nStart; S?J!.(
this.nEndPos = nEnd; KX)n+{
nThreadID = id; 2d)Dhxzxk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /6x&%G:m#
} 8 Rx@_
]\,?u /
["-rDyP
public void run() {)YbksrJ{
{ @rl5k(
while(nStartPos < nEndPos && !bStop) J_Lmy7~xbD
{ 7!O"k#
IH|zNg{\Y
TI>5g(:3\
try{ mF4W4~"
URL url = new URL(sURL); 0PzSp ]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qu=~\t1[6
httpConnection.setRequestProperty("User-Agent","NetFox"); $?= $F
String sProperty = "bytes="+nStartPos+"-"; ^q7V%{54
httpConnection.setRequestProperty("RANGE",sProperty); 727#7Bo
Utility.log(sProperty); S%SYvA
&@~K8*tmK
-amo8V;2H
InputStream input = httpConnection.getInputStream(); UXm_-/&b9
//logResponseHead(httpConnection); ,d"T2Hy
&<&tdShI
m+QS -woHn
byte[] b = new byte[1024]; MZgaQUg
int nRead; Cbbdq%ySI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'gwh:
{ T:^.; ZY
nStartPos += fileAccessI.write(b,0,nRead); 5 jrR]X
//if(nThreadID == 1) HqGI.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ysaRH3M
} +a,SP
QiCia#_
pdu1 kL
Utility.log("Thread " + nThreadID + " is over!"); .K C* (}-
bDownOver = true; O=K lc+Oo
//nPos = fileAccessI.write (b,0,nRead); TWP@\ BQ
} >AEp\*
catch(Exception e){e.printStackTrace ();} WQ|Ufl;
} $^x=i;>aK.
} Fh~9(Y#
/b+~BvTh
"4b{YWv
//打印回应的头信息 o&JoeKXor
public void logResponseHead(HttpURLConnection con) `bP`.Wm
{ <ZC.9
for(int i=1;;i++) Kz'GAm\
{ oj8r*
String header=con.getHeaderFieldKey(i); YwVA].p@TI
if(header!=null) Xo PJ?63
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vo/x`F'ib
Utility.log(header+" : "+con.getHeaderField(header)); pY&6p~\p
else 3u@,OE
break; #2=l\y-#
} ~WrpJjI[
} ZflB<cI
s_^`t+5
|d0X1(
public void splitterStop() F|%PiC,,qO
{ }Qo]~/
bStop = true; '5}hm1,
} ;~3;CijJ8
2/SUEnaLy_
"8QRYV~Z
} =!Ik5LiD
{i>AQ+z61f
_L,~WYRo
/* MN: {,#d0
**FileAccess.java &A:&2sP8
*//文件访问(定位，写) Dj/Hz\
package NetFox; Df"PNUwA"
import java.io.*; ?K-4T
PKlR_#EB?
Zma;An6
public class FileAccessI implements Serializable{ C(>!?-.
r] /Ej!|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f2.=1)u.
RandomAccessFile oSavedFile; 2Z; !N37U
long nPos; XX=OyDLqP
2)EqqX[D
:7{GOx
public FileAccessI() throws IOException |5>Tf6$(
{ g? vz\_
this("",0); 2j f!o
} ;CO qu#(
F=\ REq
8UB2 du@?
public FileAccessI(String sName,long nPos) throws IOException 'IU3Xu[-.
{ G}U <^]c
oSavedFile = new RandomAccessFile(sName,"rw"); `8ob Xb
this.nPos = nPos; lhM5a \
oSavedFile.seek(nPos); S @[]znH
} % J\G[dl
S{llpp{E
1 -Z&/3T]
public synchronized int write(byte[] b,int nStart,int nLen) O0}uY:B
{ 7\@c1e*e
int n = -1; UDHOcb
try{ NXD-
oSavedFile.write(b,nStart,nLen); y,?=,x}o#
n = nLen; >4g!ic~O
} C\{A|'l!x
catch(IOException e) m9h<)D'>
{ =2q#- ,t
e.printStackTrace (); S6bW r0XR
} dr)*.<_+a(
%=z>kU1|
auI`'O`/
return n; s<*+=aIfu
} e;v7!X
7,)E1dx -V
I(UK9H{0$
} cO:lpsKYQ
IAA_Ft
F]RPM(!5O)
/* ,wf_o%'eW
**SiteInfoBean.java x,: k/]
*/ Ztk%uc8_lM
package NetFox; c,#=In2
eNfH9l2k
5H'Iul<Os
public class SiteInfoBean { ,b^Y8_ltoT
5]mH.{$x$?
e@c8Ce|0
private String sSiteURL; //Site's URL $c*fbBM(&n
private String sFilePath; //Saved File's Path ^5Y<evjm
private String sFileName; //Saved File's Name 7(5d$W
private int nSplitter; //Count of Splited Downloading File ]prw=rD
E2l"e?AN~
h~QQ-
public SiteInfoBean() y%|Ez
{//nSplitter的缺省值为5 aP(~l_
//default value of nSplitter is 5 aGWO3Nk
this("","","",5); N?3p,2
} .|"E:qTD
Ud"_[JtGM
<IU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CUB;0J(
{ 5>dA7j^v
sSiteURL= sURL; [cFD\"gJAr
sFilePath = sPath; f2tCB1[D+
sFileName = sName; +%<kcc3
this.nSplitter = nSpiltter; ZK?V{X{";
nls$ wE
*QNX?8Fm_
} l`75BR
}2Ge??!
wBlE!Pm
public String getSSiteURL() t.&JPTK-H
{ l_((3e[)
return sSiteURL; t<+>E_Xw
} Z$i?p;HnW
j*?E~M.'1K
|0^IX
public void setSSiteURL(String value) V6>{k_0{V
{ `?^<r%*F.
sSiteURL = value; zgS)j9q}
} ys)
8/B8yY-O
qi^kf
public String getSFilePath() 3f>9tUWhTy
{ 8bw,dBN
return sFilePath; Ur[ai6LNG
} c.Izm+9k
{OQ)Np!
uR=*q a
public void setSFilePath(String value) AN,3[Sh
{ s!W{ru
sFilePath = value; {y|.y~vW
} f% 8n?f3;u
.$f0!` t
8\)4waz$
public String getSFileName() 3Zz_wr6
{ dr8Q>(ZY
return sFileName; %U<lS.i
} a@_n>$LZL
bTx4}>=5l
Yjy%MR
public void setSFileName(String value) |Eu#mN
{ Q(WfWifu-|
sFileName = value; 8z-wdO\
} ]Gj%-5G
D41.$t[
}WR@%)7ay
public int getNSplitter() NUBzc'qb
{ zzC{I@b
return nSplitter; e*<pO@Uy
} nbw8YO(=
wd,6/5=lh
0p,_?3nX
public void setNSplitter(int nCount) ?+c-m+;wj
{ %h_N%B$7c1
nSplitter = nCount; D1]?f`
} 8XfOMf~d`
} svCm}`
EAs^i+/
RR`\q>|
/* zYis~+
**Utility.java pm}_\_
*/ 5:~ zlg
package NetFox; n>o=RQ2
_Fkb$NJ"]Q
us#ji i.<
public class Utility { %@I= $8j
ip|l3m$Mi
=m;cy0))
public Utility() ;F2"gTQS
{ r"7 !J[u
.L)j ql%
x` 4|^u
} 4{$ L]toP
}y|_v^
//线程睡眠 1LmbXH]%
public static void sleep(int nSecond) Z'wGZ(
{ gE23C*!'&:
try{ H'@@%nO(
Thread.sleep(nSecond); "NV~lJS%
} f1\mE~#}
catch(Exception e) P?=}}DI
{ |l~#qeZ%
e.printStackTrace (); pSx}:u^am
} ?R@u'4yK
} V4*/t#L/
_k)EqPYu@
//日志 tac_MtW?
public static void log(String sMsg) `:gXQmt
{ UE/iq\a>
System.err.println(sMsg); oJc v D
} m.yt?`
,_'Z Jlx
@ &GA0;q0t
public static void log(int sMsg) RHI?_gf&
{ y<ZT~e
System.err.println(sMsg); 4g+o/+6!4
} 1mv8[^pF
} /p{$HkVw
\NL*$SnxP
q] '2'"k
/* !imjfkG
**TestMethod.java |x ir93|
*/ 9+'*
package NetFox; ATD4%|a9h
opReAU'I
xc?=fv
public class TestMethod { `! )^g/>0i
NE?tfj
JPe<qf-
public TestMethod() ,/-DAo~O
{ ///xx/weblogic60b2_win.exe Zu ![v0
try{ RPTIDA))
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E`q)vk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &*qAB)**
SiteFileFetch fileFetch = new SiteFileFetch(bean); _lw:lZM?
fileFetch.start(); n?NUnFA
} )jH|j
catch(Exception e){e.printStackTrace ();} %bB:I1V\
~T\:".C
J'yiVneMw
} 4='/]z
<xD6}h/
j2%M-y4E
public static void main(String[] args) E(an5x/r
{ V}/AQe2m&
new TestMethod(); R@[1a+}5
} UmP\;
} ^%RIz!}
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