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)); 9I1tN
} 8h3=b[
for(int i=0;i<nEndPos.length-1;i++) [U}+sTQ
{ [Vd[-
nEndPos = nStartPos[i+1]; *Do/+[Ae
} ;Op3?_
nEndPos[nEndPos.length-1] = nFileLength; +4[^!q* H
} Vd".u'r
} b KTcZG
LmlXMia
E$W{8?:{
//启动子线程 w%WF-:u7|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }X x(^Zh
for(int i=0;i<nStartPos.length;i++) A(?\>X 9g
{ #-pc}Y|<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gu#-O?B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,yd MU\so(
nStartPos,nEndPos,i); X;<BzA!H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o]nw0q?
fileSplitterFetch.start(); <;E
} g{W;I_P^9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x~.:64
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wi9DhVvc 0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0ye!R
nEndPos = " + nFileLength); 4}`
// fileSplitterFetch[nPos.length-1].start(); R'kyrEO
(D@A74q\'
"ZTTg>r
//等待子线程结束 | 8qBm
//int count = 0; bSVlk`
//是否结束while循环 'V8N
boolean breakWhile = false; +?p.?I
4w#``UY)'
Yvn\xph3
while(!bStop) +C1QY'>I
{ _qbIh
write_nPos(); {Fzs@,|W.
Utility.sleep(500); WL`9~S
breakWhile = true; \*,=S52
p>_;^&>&
Vy_2.
for(int i=0;i<nStartPos.length;i++) JG9`h#
{ Wrrcx(
if(!fileSplitterFetch.bDownOver) :4^\3~i1X
{ hFiIW77s2
breakWhile = false; piU/&
break; G_>#Js
} _+ .\@{c
} o)OUWGjb/K
if(breakWhile) 9-]i.y
break; w8g,a]p
O?<&+(uMTT
_EF&A-kX|u
//count++; *^([ ~[
//if(count>4) '#(v=|J
// siteStop(); 4t)%<4
} %pXAeeSY`;
<C9 XX~
{O|'U'
System.err.println("文件下载结束！"); {EdH$l>94
} $T :un.TM
catch(Exception e){e.printStackTrace ();} g;ZxvR)ZJk
} ICAH G7,
ID.n1i3
.S(,o.
//获得文件长度 }du XC[6
public long getFileSize() :VF<9@t
{ >DPB!XA3
int nFileLength = -1; OgF+OS
try{ w '3#&k+
URL url = new URL(siteInfoBean.getSSiteURL()); gKOOHUCb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,;M4jc{
httpConnection.setRequestProperty("User-Agent","NetFox"); nenU)*o
~EK'&Y"1
lo'W1p
int responseCode=httpConnection.getResponseCode(); q5>v'ZSo
if(responseCode>=400) F@R1:M9*
{ ~tOAT;g}q
processErrorCode(responseCode); Q[+ac*F=Y
return -2; //-2 represent access is error 31EyDU,W
} &qS[%K )
w`l{LHrR
y>*xVK{D
String sHeader; S$2b>#@UJ
I|# 5NE6
W+*5"h
for(int i=1;;i++) UX]L;kI
{ F#|:`$t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gIA@l`"
//Utility.log(in.readLine()); sBV4)xM
sHeader=httpConnection.getHeaderFieldKey(i); w&xDOyW]
if(sHeader!=null) O$IjNx
{ 3BpZX`l*p
if(sHeader.equals("Content-Length")) D~o$GW%
{ yjJ5P`j]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /O]t R
break; D5~n/.B"
} pH`44KAuM
} p _d:eZ
else KRjV}\}
break; 4e;QiTj
} =}PdH`S
} BcD&sQ2F
catch(IOException e){e.printStackTrace ();} )]#aauC+
catch(Exception e){e.printStackTrace ();} Z@Ae$ '9H
wu"&|dt
b=3H
Utility.log(nFileLength); c*UvYzDZL
qH['09/F6
X*,Kb(3
return nFileLength; =!m}xdTP
} u !!X6<
$cu00K
wCk~CkC?
//保存下载信息（文件指针位置） P]z[v)}
private void write_nPos() ]jpu,jz:
{ %p X6QRt?
try{ gNGr!3*)w
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y'e eA 2O
output.writeInt(nStartPos.length); \p%3vRwS%p
for(int i=0;i<nStartPos.length;i++) sZ?mP;Q
{ :a:l j
// output.writeLong(nPos); #Wu*3&a]yU
output.writeLong(fileSplitterFetch.nStartPos); Mkq( T[)
output.writeLong(fileSplitterFetch.nEndPos); S.!UPkWH
} :$+-3_oLMQ
output.close(); @|'5n
} S(:l+JP
catch(IOException e){e.printStackTrace ();} t20PP4FWM
catch(Exception e){e.printStackTrace ();} .UoOO'1K
} ZIdA\_c
fb da
;l$ \6T
//读取保存的下载信息（文件指针位置） ITy/eZ"&:
private void read_nPos() _e9:me5d"$
{ ?JxbSK#
try{ ]\ngX;h8G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (LHp%LaZ\;
int nCount = input.readInt(); e$Y[Z{T5
nStartPos = new long[nCount]; e6_ZjrQf
nEndPos = new long[nCount]; )#F]G$51r
for(int i=0;i<nStartPos.length;i++) CIVnCy z
{ 9_sA&2P{uV
nStartPos = input.readLong(); l]<L [Y,E-
nEndPos = input.readLong(); `>o?CIdp
} {,OS-g
input.close(); TE )gVE]
} `mT$s,:h
catch(IOException e){e.printStackTrace ();} <W]g2>9o9
catch(Exception e){e.printStackTrace ();} qaim6a
} XhsTT2B
t*@z8<H
KgN)JD>
private void processErrorCode(int nErrorCode) ps$7bN C
{ WL+]4Wiz
System.err.println("Error Code : " + nErrorCode); L#)(H^[
} 8QK5z;E2~
sE{pzPq!
kM`l
//停止文件下载 Z/rTVAs@r
public void siteStop() M/Pme&%
{ "n:{!1VGw
bStop = true; 6oSQQhge
for(int i=0;i<nStartPos.length;i++) c%*($)#
fileSplitterFetch.splitterStop(); h d~$WV0#
wv^rS^~
lnGq :-
} ~XeFOMq
} *Ei|fe$sa
//负责部分文件的抓取 PA w-6;
**FileSplitterFetch.java _7DkS}NJs
*/ (z$r:p
package NetFox; ~ d^<_R
;6 +}z~
#"fJa:IYG7
import java.io.*; S(aZ4{a@
import java.net.*; Z>)][pL
F_uY{bg
q %A?V_
public class FileSplitterFetch extends Thread { DP/J(>eG
aQ j*KMc
/MQU >&
String sURL; //File URL VDB;%U*D
long nStartPos; //File Snippet Start Position oPc\<$
long nEndPos; //File Snippet End Position 4(l?uU$
int nThreadID; //Thread's ID aAu>Tn86D.
boolean bDownOver = false; //Downing is over -yDs< Xl
boolean bStop = false; //Stop identical .k4W_9
FileAccessI fileAccessI = null; //File Access interface MzIq"3
e4OeoQ@ >
juBw5U<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;d$qc<2uA
{ VGL#!4wK
this.sURL = sURL; ~"Gf<3^y+
this.nStartPos = nStart; ]\RRqLDzkg
this.nEndPos = nEnd; FZiW|G
nThreadID = id; P\CDd=yWc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )Z+{|^`kJ
} 2}?wYI*:5|
I &*_,d
YJxw 'U >P
public void run() &/.hx(#d
{ VE2tq k%
while(nStartPos < nEndPos && !bStop) +MK6zf
{ c^8o~K>w84
+*oS((0s
>Q,zNs
try{ e7u^mJ
URL url = new URL(sURL); 9s +z B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hgRVwX
httpConnection.setRequestProperty("User-Agent","NetFox"); nxQ?bk}*d
String sProperty = "bytes="+nStartPos+"-"; vFrt|JC_{
httpConnection.setRequestProperty("RANGE",sProperty); acd:r%y
Utility.log(sProperty); :"0J=>PH:
b{DiM098
UkCnqNvx
InputStream input = httpConnection.getInputStream(); /\mKY%kyh
//logResponseHead(httpConnection); /RLq>#:h**
`nR%Cav,U
t<:D@J]a
byte[] b = new byte[1024]; CLKov\U\
int nRead; CGw--`#\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &@"]+33
{ ?B.~AUN
nStartPos += fileAccessI.write(b,0,nRead); nA>sHy
//if(nThreadID == 1) }2)DPP:ic
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5sde
} bt+,0\Vg5
0h$GI"dR
)_zlrX
Utility.log("Thread " + nThreadID + " is over!"); RANPi\]
bDownOver = true; #y]3LC#)^G
//nPos = fileAccessI.write (b,0,nRead); yj@tV2
} M4Z@O3OIE
catch(Exception e){e.printStackTrace ();} YC_3n5F%
} #iSFf
} r^$~>!kZ|
dEM?~?
o?Sla_D
//打印回应的头信息 ;@ WV-bLe
public void logResponseHead(HttpURLConnection con) WKA'=,`v
{ u"$a>S_
for(int i=1;;i++) 0BkV/v1Uc
{ PM$Ee #62R
String header=con.getHeaderFieldKey(i); &ntBU]<q
if(header!=null) &;H{cv`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Iy {U'a!
Utility.log(header+" : "+con.getHeaderField(header)); ZeasYSo4P
else $7I]`Jt
break; NnxM3*
} %R0v5=2'
} qUhRu>
. ,NB( s`
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public void splitterStop() z)F#u:t
{ J."{<&
bStop = true; fUag1d
} rlok%Rt4Z
Wf02$c0#K
yt.c5>B^
} {g/wY%u=
dGH_ z8
`!\ivIi^
/* 0/]_nd
**FileAccess.java !>;w!^U
*//文件访问(定位，写) DOD6Liau{Q
package NetFox; =.m6FRsU
import java.io.*; X<Za9
b5ie <s
0yof u
public class FileAccessI implements Serializable{ i8V0Ty4~N
]S8LY.Az5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n~z\?Y=*
RandomAccessFile oSavedFile; G=M] 8+h
long nPos; !awh*Xj6
Oo%!>!Lt,
#t71U a
public FileAccessI() throws IOException RJJ1
{ {KaN,td9
this("",0); d O A%F$Mk
} _[E\=
;?9A(q_Z
7#4%\f+'t
public FileAccessI(String sName,long nPos) throws IOException "!&B4
{ 0*(K DDv
oSavedFile = new RandomAccessFile(sName,"rw"); GXb47_b^
this.nPos = nPos; `ypL]$cW
oSavedFile.seek(nPos); Md(JIlh3
} q&M:17+:Q
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+802`eax
public synchronized int write(byte[] b,int nStart,int nLen) lC9S\s
{ I{n;4?
int n = -1; jW5iqU"{*
try{ +BB0wY
oSavedFile.write(b,nStart,nLen); eYP=T+
n = nLen; ]UUI~sFE
} \ZnN D1A
catch(IOException e) OCx5/ 88X
{ ~"mj;5Id
e.printStackTrace (); NM L|"R;
} DA <ynBQ
n85r^W
RebTg1vGu
return n; 5gNLO\
} `mErF%b
huAyjo
\y*j4 0
} vj3isI4lU
*C_[jk@6
O<`R~
/* &telCg:
**SiteInfoBean.java _om[VKJd
*/ w??c1)
package NetFox; nUqy1(
oeNzHp_
*( *z|2
public class SiteInfoBean { 7Dl%UG]
<ZrFOb
hPPB45^
private String sSiteURL; //Site's URL kME^tpji
private String sFilePath; //Saved File's Path rA#s
private String sFileName; //Saved File's Name G.ud1,S#
private int nSplitter; //Count of Splited Downloading File :ej_D}
AP@<r
3i(Jon/p
public SiteInfoBean() uu3M{*}
{//nSplitter的缺省值为5 ??I:H
//default value of nSplitter is 5 jaqV[*440U
this("","","",5); 4Iq5+Q
} VG\mo?G
" Z;uu)NE
LVmY=d>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N*1
{ *tG11gR,&
sSiteURL= sURL; ~u2w`H?V
sFilePath = sPath; Ars,V3ep
sFileName = sName; #NJ<[Gew
this.nSplitter = nSpiltter; E._hg+ (Hi
.Cfp'u%\;
#11RLvDQd
} $NCm;0\B|
P CsK()
JjDS"hK#
public String getSSiteURL() Gt'/D>FE0
{ .D3`'K3t{[
return sSiteURL; ^N{X"
} \P@S"QO
pE(sV{PD
lbofF==(
public void setSSiteURL(String value) z`@z
{ 82.HH5Z{
sSiteURL = value; gUb "3g0
} C M^r|4K
>Qk97we'9
h&$Py
public String getSFilePath() Bn_g-WrT
{ 7?"9J`*
return sFilePath; H` Lu"EK
} .)0gz!Z
e#m1X6$.e
(-'PD_|
public void setSFilePath(String value) /xf.\Z7<
{ YR8QO-7 .)
sFilePath = value; pLJeajv)z
} |DGCdB|`G
:W%4*-FP
7H?!RYrx
public String getSFileName() _0*=u$~R
{ ,L~snR'w
return sFileName; T"B8;|
} sOC| B
p Mh++H]"
)=Y-f?o!
public void setSFileName(String value) _[0I^o
{ c*jr5 Y
sFileName = value; acy"ct*I
} uAQg"j
3m~U(yho
(Y>U6
public int getNSplitter() ) _#T c
{ |/t K-c6J
return nSplitter; JQr36U
} s1v{~xP
%27G2^1
H'']J9O
public void setNSplitter(int nCount) Mi;Tn;3er
{ :g/{(#E@Z
nSplitter = nCount; {YfYIt=.
} DSTx#*
} !Am =v=>
%K`4k.gN
'oT|cmlc
/* hPS/CgLq
**Utility.java }0krSzcn#,
*/ EtPgzw[#c9
package NetFox; =$[W,+X6f
cUYX1a)8
9/^d~ZO
public class Utility { we @Yw6<
y.%i
cx<h_
public Utility() l; */M.B
{ hg!x_Eq|
;Xz(B4N~o
aTi0bQW{
} !(}OBZ[*
9B& }7kk
//线程睡眠 >&g2 IvDS
public static void sleep(int nSecond) 0;'j!`l9
{ ))$ CEh"X
try{ *?s/Ho &'
Thread.sleep(nSecond); n2H&t>N
} t% <pbZO
catch(Exception e) 5BZ+b_A>VV
{ EwC5[bRjUp
e.printStackTrace (); x!Y(Y=i>
} wbo{JQ
} F1zT )wW
3@%BA(M
//日志 pFG]IM7o/u
public static void log(String sMsg) 6 bYC
{ _3*: y/M_
System.err.println(sMsg); e_tZja2s
} iz,]%<_PE
l A 0-?k
^V_ku@DY
public static void log(int sMsg) |)~Ex 9%ev
{ wbn^R'
System.err.println(sMsg); 7cy+Nz
} -Cg`x=G;z
} @263)`9G
!^n1
eUi> Mp
/* PV5-^Y"v
**TestMethod.java &IIJKn|_
*/ D:+)uX}MOf
package NetFox; >B@i E
R994R@gz
MYKs??]Y1
public class TestMethod { "h^A]t;qe
F0X5dv
"v*oga%
public TestMethod() ^U R-#WaQ
{ ///xx/weblogic60b2_win.exe gNG0k$nP
try{ vsOdp:Yp9!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); oSpi{ $x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oFX"F0rx
SiteFileFetch fileFetch = new SiteFileFetch(bean); ee4KMS
fileFetch.start(); nNkyOaK*4
} :Bdipc
catch(Exception e){e.printStackTrace ();} #JHy[!4
(jD'+ "?
zZS>+O
} J r=REa0
r3*+8D~a_
$w 5#2Za
public static void main(String[] args) 0[_O+u
{ 9/@FADh
new TestMethod(); ahK?]:&QO
} ,+swH;=7#r
} |?4~T:
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