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)); iP#=:HZu;
} a+Ab]m8`
for(int i=0;i<nEndPos.length-1;i++) A=X-;N#
{ QPs:RhV7
nEndPos = nStartPos[i+1]; =EpJZt
} p411 `]Zf
nEndPos[nEndPos.length-1] = nFileLength; qfrNi1\9-
} NR3`M?Hjf
} .6m_>Y6
x8\<qh*:
"SR5wr
//启动子线程 "!KpXBc,>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Pl78fs"L@
for(int i=0;i<nStartPos.length;i++) 6P*O&1hv
{ r~>,$[|n})
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n8u*JeN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !ni>\lZ
nStartPos,nEndPos,i); ]JMl|e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Qn|+eLY
fileSplitterFetch.start(); Js{=i>D
} HnU Et/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,@.EpbB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VLdB_r3lQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", IzUo0D*@
nEndPos = " + nFileLength); &{z<kmc$6
// fileSplitterFetch[nPos.length-1].start(); P^i.La,
E\$C/}T
S_\ F
//等待子线程结束 Cj^{9'0
//int count = 0; x8"#!Pw:`"
//是否结束while循环 N wtg%;
boolean breakWhile = false; `@XehSQ
Wi$dZOcSJ
cj g.lzYH
while(!bStop) .Dw,"VHP
{ ~xDw*AC-
write_nPos(); x_!ZycEa
Utility.sleep(500); CS@&^SEj
breakWhile = true; Lh ap4:
/!T> b:0
R#eg^7HfX
for(int i=0;i<nStartPos.length;i++) F,T~\gO5,
{ -^SA8y
if(!fileSplitterFetch.bDownOver) |/T43ADW
{ ?KP}#>Ba@
breakWhile = false; >|*yh~
break; 'jjb[{g^}}
} CdZ BG
} v\%G|8+]
if(breakWhile) 33a uho
break; L`[z[p{?
>EP(~G3u
YI@Fhr &NU
//count++; JhX=l-?
//if(count>4) fn}UBzED\
// siteStop(); vAi$[p*im
} "A[ b rG
FWY2s(5p
S$[k Q|Am
System.err.println("文件下载结束！"); 2Z/K(J"&J
} 50~K,Jx6B
catch(Exception e){e.printStackTrace ();} J4aBPq`
} ll<NIdf\r
g/Wh,f3
0KvVw rWJ
//获得文件长度 k6**u
public long getFileSize() lMifpK
{ jbmTmh1q
int nFileLength = -1; jirbUl
try{ ;*cLG#&'M
URL url = new URL(siteInfoBean.getSSiteURL()); %2l7Hmp4H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B'weok
httpConnection.setRequestProperty("User-Agent","NetFox"); <J{'o`{
MI#mAg<
>e&:`2%.
int responseCode=httpConnection.getResponseCode(); QIU,!w-3X
if(responseCode>=400) Es'Um,ku
{ Re=WfG
processErrorCode(responseCode); 0ejdKdYN
return -2; //-2 represent access is error vO@s$qi
} uCP>y6I
=o=1"o[
F%/h*
String sHeader; TprtE.mP
A(d5G^
s0W2?!>)
for(int i=1;;i++) @QEqB_W
{ slW3qRT\k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8E^@yZo{
//Utility.log(in.readLine()); 6][1<}8
sHeader=httpConnection.getHeaderFieldKey(i); !|G(Yg7C
if(sHeader!=null) \5><3*\
{ >cR)?P/o
if(sHeader.equals("Content-Length")) +M\8>/0oA
{ V5rp.~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); IB5BO7J
break; } :?.>#
} z;}6f
} /Z%>ArAx
else +a+`Z>
break; m <k!^jp
} 'cdN3i(
} _YHu96H;
catch(IOException e){e.printStackTrace ();} EeQ5vqU
catch(Exception e){e.printStackTrace ();} kODK@w V-
c6AWn>H
Ca>&
Utility.log(nFileLength); ~,gXaw
Qvoqx>2p5
nKh&-E
return nFileLength; lC?Icn|o
} 9s$U%F6}
~Pf5ORoe
/!xF?OmVd
//保存下载信息（文件指针位置） '/%zi,0
private void write_nPos() NeOxpn[
{ "5|Lz)=
try{ #Z!b G?="
output = new DataOutputStream(new FileOutputStream(tmpFile)); uQCo6"e
output.writeInt(nStartPos.length); WMuD}s
for(int i=0;i<nStartPos.length;i++) MtmOUI&'
{ ^CT&0
// output.writeLong(nPos); yX/";Oe
output.writeLong(fileSplitterFetch.nStartPos); NYB[Zyp
output.writeLong(fileSplitterFetch.nEndPos); 12`_;[37
} v> z@
output.close(); P&A|PY,P
} pxINw>\Qv
catch(IOException e){e.printStackTrace ();} 30cd| S?
catch(Exception e){e.printStackTrace ();} &XLD S=j
} 9uB(Mx(-:`
wsfd8T4
\}]iS C.2
//读取保存的下载信息（文件指针位置） |QZ58)>
private void read_nPos() ' P"g\;Ij
{ [IBQvL
try{ yubSj*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =!MY4&YX
int nCount = input.readInt(); P>QpvSd_#
nStartPos = new long[nCount]; %"$@%"8;3
nEndPos = new long[nCount]; WOytxE
for(int i=0;i<nStartPos.length;i++) O9h+Q\0\W
{ gPC@Yy
nStartPos = input.readLong(); W0`Gc {
nEndPos = input.readLong(); H:{7X1bV
} {{yt*7k{
input.close(); Owv+1+B
} YoODR
catch(IOException e){e.printStackTrace ();} QL7>;t;
catch(Exception e){e.printStackTrace ();} Hgc=M
} Oxx^[ju~
,w)p"[^b
,d,\-x-+/
private void processErrorCode(int nErrorCode) $a;]_Y
{ 'Pltn{iq[
System.err.println("Error Code : " + nErrorCode); f<jb=\}x
} hq>Csj==@
!$qKb_#nC
6)gd^{
//停止文件下载 }OShT+xeX
public void siteStop() k)(Biz398E
{ ?:rx1}:F
bStop = true; /'DwfX
for(int i=0;i<nStartPos.length;i++) XAOak$(j
fileSplitterFetch.splitterStop(); p#d+>7
*gsAn<
5MxL*DB=b
} N]/!mo?
} F_;tT%ywfx
//负责部分文件的抓取 fp>.Owt%.
**FileSplitterFetch.java 8Z#j7)G
*/ Zy"=y+e!E;
package NetFox; USML~]G z
S4NL "m
Mio>{%/
import java.io.*; @)YY\l#
import java.net.*; XFZ~ #DT&
.5HQ
HaNboYW_K
public class FileSplitterFetch extends Thread { M++0zhS
MLVB^<qkeH
5rxA<Gs
String sURL; //File URL Y#V8(DTyH
long nStartPos; //File Snippet Start Position +54aO
long nEndPos; //File Snippet End Position Tt# bg1
int nThreadID; //Thread's ID ;I6s-moq_
boolean bDownOver = false; //Downing is over A/*%J74v
boolean bStop = false; //Stop identical %"3 )TN4
FileAccessI fileAccessI = null; //File Access interface ~.tvrxg
`d]Z)*9
\y Hen|%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^y.UbI
{ cL7g}$W$
this.sURL = sURL; aC=['a>)
this.nStartPos = nStart; ~Vh=5J~
this.nEndPos = nEnd; my\&hCE
nThreadID = id; Iq5pAHm>M6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b}z`BRCc
} ?2J?XS>
T`YwJ6N
]TpU"JD
public void run() U\<-mXv
{ :>3=gex@^0
while(nStartPos < nEndPos && !bStop) @|-OJ4[5
{ Qc-(*}
;6;H*Y0,|E
s'I)A^i+
try{ V-W'RunnW
URL url = new URL(sURL); L^Wz vv]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w_-+o^
httpConnection.setRequestProperty("User-Agent","NetFox"); 3x*z\VJ
String sProperty = "bytes="+nStartPos+"-"; `x8Bn"
httpConnection.setRequestProperty("RANGE",sProperty); mX# "+X|
Utility.log(sProperty); Y>6.t"?Q^
<lwuTow
F3E[wdT
InputStream input = httpConnection.getInputStream(); nS.G~c|
//logResponseHead(httpConnection); w<wV]F*
D@54QJ<
1i|.h
byte[] b = new byte[1024]; $g8}^1
int nRead; HxwlYx,4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $xW**&
{ V^fV7hw<
nStartPos += fileAccessI.write(b,0,nRead); :-+4:S
//if(nThreadID == 1) S'i;xL>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kToOIx
} bY8GA
M?&zY "c
Lubrn"128
Utility.log("Thread " + nThreadID + " is over!"); o+?@5zw-&
bDownOver = true; [=M%
//nPos = fileAccessI.write (b,0,nRead); |7F*MP
} K'b*A$5o
catch(Exception e){e.printStackTrace ();} L4'[XcY
} `iixq9xi
} 02b6s&L
a+z2Zd!u\x
tai Vk4
//打印回应的头信息 2:^njqX
public void logResponseHead(HttpURLConnection con) HCnf2td
{ F9o6V|v
for(int i=1;;i++) |m>}%{
{ ~1 ZD[@
String header=con.getHeaderFieldKey(i); b5`KB75sbo
if(header!=null) v548ysE)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o#hI5
Utility.log(header+" : "+con.getHeaderField(header)); ?[1SiJT
else __N.#c/l{
break; .KA V)So"
} |ng%PQq)
} s@@1 *VQ
[?KIN_e#
'CV^M(o'9
public void splitterStop() vgG}d8MW37
{ ;)/@Xx
bStop = true; J\`^:tcG
} knHv?#
#uvJH8)D
W'/>et
} L]bVN)JU
<0j{ $.
Ol+Kp!ocY
/* pM$ @m]
**FileAccess.java @p!Q1-]=
*//文件访问(定位，写) x mo&![P
package NetFox; ZwJciT!_~
import java.io.*; sBW3{uK
;;#nV$
McP.9v}H0_
public class FileAccessI implements Serializable{ "sbBe73 m
Lo`F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4M`Xrfwm'[
RandomAccessFile oSavedFile; `iYc<N`
long nPos; :t$A8+A+0
{8CWWfHCD
&=w|vB)(p
public FileAccessI() throws IOException VTw/_Hf2p
{ 2P}I'4C-
this("",0); Mtp%co)f
} 4XG]z_+I
:JV\){P
L3c*LL
public FileAccessI(String sName,long nPos) throws IOException $WaZ_kt
{ +VOb
oSavedFile = new RandomAccessFile(sName,"rw"); Yn<)k_kp
this.nPos = nPos; qei$<j'b
oSavedFile.seek(nPos); }98-5'u.X
} SMO*({/
.ZX2^)`XD
xZ ;bMxZ
public synchronized int write(byte[] b,int nStart,int nLen) j#igu#MB*
{ "$@,n7k
int n = -1; \y~)jq:d"
try{ 'p)QyL`d
oSavedFile.write(b,nStart,nLen); {nRUH*(d9
n = nLen; I'A:J
} l>Av5g)
catch(IOException e) K-@bwB7~s
{ M,..Kw/ }~
e.printStackTrace (); l%PnB )F
} %$9:e J?
wZ>Y<0,
=J3`@9;
return n; chLeq
} w%u5<
n-OWwev)
.<w)Bmh
} !sK#zAR2
DQ_ 2fX~)
<!!nI%NC
/* )%#?3X^sI
**SiteInfoBean.java aL)$b
*/ O5MDGg
package NetFox; Q\WXi
u}CG>^0C
@_O3&ZK
public class SiteInfoBean { PP4d?+;V
LUul7y'"
M,G8*HI"
private String sSiteURL; //Site's URL g RU-g
private String sFilePath; //Saved File's Path *1,=qRjL
private String sFileName; //Saved File's Name 88YC0!Ni
private int nSplitter; //Count of Splited Downloading File _LsYMUe
L9J;8+ge
gvr]]}h:O
public SiteInfoBean() .+uVgSN
{//nSplitter的缺省值为5 j4vB`Gr]
//default value of nSplitter is 5 J/[7d?hI/
this("","","",5); Zh? V,39
} .h6Y< E
k(9s+0qe
lb95!.av+I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) VO|u8Z"
{ P2QRvn6v
sSiteURL= sURL; ir+8:./6
sFilePath = sPath; "i(U
sFileName = sName; _Q^y_f
this.nSplitter = nSpiltter; E6Q91Wz9f
QRiF!D)Nk
>vxWx[fRu
} c}'Xoc
2{gwY85:
8E=vR 8
public String getSSiteURL() C#T)@UxBZ
{ PbQE{&D#
return sSiteURL; ]3 j[3'
} qw)Key
%0 qc@4
x' ?.~
public void setSSiteURL(String value) 8z0Hx
{ /t5g"n3
sSiteURL = value; 9?!u2 o
} F*. /D~K
\CDAFu#
P 4H*jy@?
public String getSFilePath() `43vxcMg
{ uzO{{S-
return sFilePath; % dYI5U89
} k|fh\F+$
Q>V?w gZ
\Qp}|n1JY
public void setSFilePath(String value) 4t*<+H%
{ sq48#5Tc^r
sFilePath = value; ~{9x6<g!
} '%:5axg?]
z(jU|va{_1
9M;I$_U`vj
public String getSFileName() %qONJP
{ )v};C<
return sFileName; Jfe~ ,cI
} C\J@fpH(t`
#'#4hJ*YC
Vj29L?3
public void setSFileName(String value) [KD}U-(Wg
{ M Ey1~h/
sFileName = value; @H3|u`6V
} Re7{[*Q4
rx{#+iw
+$'e4EwqV
public int getNSplitter() e1oFnu2R
{ _pJX1_vD
return nSplitter; fO0-N>W'P
} +Z )`inw
y B1W>s8&
Cx$9#3\
public void setNSplitter(int nCount) BzN/6VEw
{ rffVfw
nSplitter = nCount; <.: 5Vx(Aw
} }1l}-w`F
} #3YdjU3w
w"yK\OE
NT'Ie]|
/* Dy98[cL
**Utility.java {E3;r7
*/ HE9. k.sS
package NetFox; -v;iMEZ)
//VG1@vaVX
#@IQlqJfY7
public class Utility { "pR $cS
o@Dk%LxP
(q055y
public Utility() 7&#'c8]/qh
{ B[C7G7<B
GE{8I<7c
rD_Ss.\^g
} C,V|TF.i2
r7zf+a]
//线程睡眠 cKaL K#~
public static void sleep(int nSecond) ER0TY,
{ <t% Ao,"
try{ E>o&GYc
Thread.sleep(nSecond); #Lu4OSM+
} 8Ng))7g!
catch(Exception e) 1t!&xvhG
{ |j\eBCnH3
e.printStackTrace (); OFJJ-4[_3
} c }g$1of87
} z1z=P%WK
\UVT_=Y
//日志 F0DPS:c
public static void log(String sMsg) DK2c]i^|=
{ TiwHLb9
System.err.println(sMsg); :FEd:0TS
} Lqy|DJ%
1',+&2)oj
k i~Raa/e
public static void log(int sMsg) ":5~L9&G
{ VKl~oFKXJ
System.err.println(sMsg); HJ2O@e
} g;| n8]
} N9~'P-V
{FrHm
D_L'x"
/* B'<O)"1w
**TestMethod.java c~Q`{2%+
*/ #l8K8GLuf
package NetFox; ;tZ}i4Ud
F5b]/;|
p1[WGeV
public class TestMethod { f)!{y>Q
uhPIV\
l%vhV&
public TestMethod() >B|ofwm*
{ ///xx/weblogic60b2_win.exe ulJ+:zwq$
try{ zwF7DnW<<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZVCv(J
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #CBo
SiteFileFetch fileFetch = new SiteFileFetch(bean); #RsIxpc
fileFetch.start(); PDa06(t7
} ~XN]?5GQf
catch(Exception e){e.printStackTrace ();} |wl")|b%
* S+7BdP
^+.e5roBKj
} JJ= ~o@|c
^$^Vd@t>a
Av\0GqF
public static void main(String[] args) WoN]eO
{ c"jhbH!u4
new TestMethod(); ?j ;,q
} s`dkEaS
} $txWVjR?\
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