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)); \I;cZ>{u"}
} h-7A9:
for(int i=0;i<nEndPos.length-1;i++) 't7Z] G
{ 9qEOgJ
nEndPos = nStartPos[i+1]; [6H}/_nD
} b7bSTFZxC
nEndPos[nEndPos.length-1] = nFileLength; bZ/ hgqS
} h0|[etaf
} qmEoqU
z OtkC3hY
0{Bf9cH
//启动子线程 _74UdD{^o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ' PELf P8
for(int i=0;i<nStartPos.length;i++) >)LAjwhBp
{ u*hH}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >rKhlUD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zhX;6= X2
nStartPos,nEndPos,i); /9pbnzn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X<Z(]`i
fileSplitterFetch.start(); _ \l HI
} V~85oUc\-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GA\2i0ow
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Twx{' S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H<,bq*@
nEndPos = " + nFileLength); Uj,g]e8e
// fileSplitterFetch[nPos.length-1].start(); okz]Qc>G
EY~7oNfc`R
>PIPp7C
//等待子线程结束 8 }-7{
//int count = 0; "J& (:(:
//是否结束while循环 w,Q)@]_
boolean breakWhile = false; &3I$8v|!?
c}%es=@
'j}g
while(!bStop) ehE-SrkU'
{ 4`s)ue
write_nPos(); DwXU
Utility.sleep(500); -bA!PeI
breakWhile = true; Pg Syt
*Rq`*D>:U}
3T1P$E" m
for(int i=0;i<nStartPos.length;i++) +C_*Vs@4
{ RyuEHpN}
if(!fileSplitterFetch.bDownOver) t@)my[!
{ 8"i/wMP]
breakWhile = false; M6_-f ;.
break; 12lEs3
} 4:U0f;Fs
} dKm`14f]@G
if(breakWhile) Aq"PG}Ic
break; yX'IZk#_L
j7}lF?cJ2
i:d`{kJ|[
//count++; V\AK6U@r^
//if(count>4) Y%g "Y
// siteStop(); V9T 4+
} aM$=|%9/
K_>/lirE?
'0RRFO
System.err.println("文件下载结束！"); Ff<)4`J
} r1G8]agO
catch(Exception e){e.printStackTrace ();} 4\ FP
} |'<vrn
< eQ[kM
5mavcle{4r
//获得文件长度 D#jX6
public long getFileSize() ?L\z}0#
{ @Dj:4
int nFileLength = -1; VhvTBo<cw
try{ @8zT'/$
URL url = new URL(siteInfoBean.getSSiteURL()); dF e4K"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /PqUXF
httpConnection.setRequestProperty("User-Agent","NetFox"); :G 5C ]'t
+i=p5d5
C8.W5P[U
int responseCode=httpConnection.getResponseCode(); PBrnzkoY
if(responseCode>=400) %K zbO0
{ O&V[g>x"U
processErrorCode(responseCode); &Mj1CvCv
return -2; //-2 represent access is error ;& ~929
} !BUi)mo
6e#wR/
Cw#V`70a
String sHeader; G3dhM#!
mgVML&^
f=m/ -mAA
for(int i=1;;i++) o?wt$j-
{ ln#\sA?iG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &SmXI5>Bo0
//Utility.log(in.readLine()); ~^7r?<aKc
sHeader=httpConnection.getHeaderFieldKey(i); JYV\oV{
if(sHeader!=null) wAh#
{ ltSh'w0
if(sHeader.equals("Content-Length")) S?4KC^Y5
{ x: ~d@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oy5+}`
break; L/x(RCD
} L\L"mc|O
} 7|Dn+=
else +"uwV1)b"
break; <d"Gg/@a
} 0`n 5x0R
} 8=F%+
catch(IOException e){e.printStackTrace ();} Hf%_}Du /`
catch(Exception e){e.printStackTrace ();} SF< [FM%1
"PzP;Br
:l"dYfl
Utility.log(nFileLength); v`B4(P1Z
J3=BE2L
J=*K"8Qr
return nFileLength; )GJP_*Ab
} v[&'k\
,I`_F,
^|?1_r
//保存下载信息（文件指针位置） ?3jdg]&
private void write_nPos() HO5d%85
{ G),db%,X2
try{ Yy h=G
output = new DataOutputStream(new FileOutputStream(tmpFile)); Hku=pr3Gn
output.writeInt(nStartPos.length); 4RQ5(YTTuR
for(int i=0;i<nStartPos.length;i++) /{X_ .fv<v
{ ]:et~pfW
// output.writeLong(nPos); k1fRj_@WPT
output.writeLong(fileSplitterFetch.nStartPos); w>vH8f
output.writeLong(fileSplitterFetch.nEndPos); :JlDi>B
} D|Si)_ Iz
output.close(); C9jbv/c
} -H\,2FO
catch(IOException e){e.printStackTrace ();} V]c5 Z$Bd
catch(Exception e){e.printStackTrace ();} }V]eg,.BJ
} z-@-O
GwQn;gkF
$]*d#`Sy{%
//读取保存的下载信息（文件指针位置） <xlm K(
private void read_nPos() Mm#[&j[Y
{ gs`> C(
try{ tcA;#^jc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =i6:puf
int nCount = input.readInt(); ^~l $&~
nStartPos = new long[nCount]; f&yQhe6q
nEndPos = new long[nCount]; *#2Rvt*Ox
for(int i=0;i<nStartPos.length;i++) O,mip
{ hZN<Yd8:
nStartPos = input.readLong(); ~G`J r
nEndPos = input.readLong(); C3S`}o.
} -t4 [oB
input.close(); 1TRN~#ix
} <TxC!{<
catch(IOException e){e.printStackTrace ();} A]?^ H<
catch(Exception e){e.printStackTrace ();} `o si"o9
} 8i:[:Z
p4wr`"Zz
V`k8j-*s
private void processErrorCode(int nErrorCode) Y&~M7TYb
{ C4NRDwU|.
System.err.println("Error Code : " + nErrorCode); a+?~;.i~
} 'm O2t~n
Oh`2tc-
NHkL24ve
//停止文件下载 1q]c7"
public void siteStop() %;O}FyP
{ / L~u02?
bStop = true; Y8ehmz|g]J
for(int i=0;i<nStartPos.length;i++) H06Bj(Y!
fileSplitterFetch.splitterStop(); U CY2]E
)#`H."Z
=nVmthGw
} 6vp0*ww
} SI*^f\lu
//负责部分文件的抓取 <y>:B}9'
**FileSplitterFetch.java B*@6xS[IL
*/ Dg2uE8k
package NetFox; V8"Wpl9Cz
0YS?=oi
O3%[dR
import java.io.*; s#^pC*,'
import java.net.*; &U&%ka<*
iZ;TYcT
@J vZ[T/
public class FileSplitterFetch extends Thread { >V!LitdJ
~L4eZ
D;js.ZF
String sURL; //File URL Ze ? g
long nStartPos; //File Snippet Start Position s[c^"@HT
long nEndPos; //File Snippet End Position eb!_ie"D
int nThreadID; //Thread's ID hI~SAd ,#A
boolean bDownOver = false; //Downing is over !k<:k "7
boolean bStop = false; //Stop identical ]rW8y%yD
FileAccessI fileAccessI = null; //File Access interface TnE+[.Qu
/F~X,lm*~
^M|K;jt>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oJY[{-qW
{ #@Y/{[s|@
this.sURL = sURL; & _K*kI:
this.nStartPos = nStart; ]d'^Xs
this.nEndPos = nEnd; z\.1>/Z=
nThreadID = id; nyhMnp#<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zWIeHIt
} "=|t~`
?_ RYqolz
ek)Xrp:2
public void run() 6/2v
{ JBcY!dy-d
while(nStartPos < nEndPos && !bStop) \6sQJq
{ 2QayM?k8
e.;M.8N#SQ
#":a6%0Q
try{ JJf<*j^G
URL url = new URL(sURL); 59!)j>f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fLB1)kTS
httpConnection.setRequestProperty("User-Agent","NetFox"); \&q=@rJp(z
String sProperty = "bytes="+nStartPos+"-"; .3wY\W8Dr-
httpConnection.setRequestProperty("RANGE",sProperty); {}\CL#~y
Utility.log(sProperty); GLh]G(
b!a %YLL
(pYYkR"
InputStream input = httpConnection.getInputStream(); +d39f-[
//logResponseHead(httpConnection); 7BFN|S_l
I/s.xk_i
_t-7$d"
byte[] b = new byte[1024]; f a5]a
int nRead; ;$!I&<)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aWaw&u
{ Rd! 2\|
nStartPos += fileAccessI.write(b,0,nRead); )HVcG0H1
//if(nThreadID == 1) Tsz NlRxc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D ,M@8h,
} M|%c(K#E,3
|.w;r
8(A{;9^g
Utility.log("Thread " + nThreadID + " is over!"); #T%zfcUj
bDownOver = true; yQ[u3tI
//nPos = fileAccessI.write (b,0,nRead); w0Ij'=:
} Y@}FL;3
catch(Exception e){e.printStackTrace ();} -:]@HD:
} -JTG?JOd]
} #IX&9 aFB}
xzikD,FV
wkikD
//打印回应的头信息 H;I~N*ltJ(
public void logResponseHead(HttpURLConnection con) Z.Pi0c+
{ }gCHQ;U7`
for(int i=1;;i++) yJ/#"z=h?
{ #s+Q{2s
String header=con.getHeaderFieldKey(i); %#k,6;m
if(header!=null) |Fv?6qw+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2k+16/T
Utility.log(header+" : "+con.getHeaderField(header)); -e*BqH2t
else v2J0u:#,
break; RvW.@#EH0
} _4R,Ej}
} -P#nT 2
;.s:X
t)I0lnbs
public void splitterStop() \"d?=uFe
{ ?}sOG?{
bStop = true; o#e7,O
} !Zs,-=^D
295w.X(J
rJ(OAKnY
} 7a<_BJXx
xNgt[fLpS
n`<U"$*
/* (,LL[&;:
**FileAccess.java 'F5)ACA%
*//文件访问(定位，写) :]c=pH
package NetFox; NG9vml
import java.io.*; d@g2k> >
#F4X}
<SQ(~xYi
public class FileAccessI implements Serializable{ QS\ x{<e/
v@_in(dk
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kF-TG3
RandomAccessFile oSavedFile; QymD-A"P
long nPos; O71BM@2<
RgGA$HN/
p >aw
public FileAccessI() throws IOException 'v`_Ii|-
{ Yy@g9mi
this("",0); `Zf9$K|
} &@; RI~
XGIpUz
wLMvC{5
public FileAccessI(String sName,long nPos) throws IOException bi,mM,N/
{ l* Y[^'
oSavedFile = new RandomAccessFile(sName,"rw"); |<Bpv{]P
this.nPos = nPos; 1Z:R,\+L
oSavedFile.seek(nPos); +/q0Y`v
} yW>RRE;
J3&Sj{ o
JS7dsO0;
public synchronized int write(byte[] b,int nStart,int nLen) (C\r&N
{ ifrq
int n = -1; !!+Da>
try{ t/ eo]
oSavedFile.write(b,nStart,nLen); PYieD}'
n = nLen; RbAt3k;y
} J wFned#T
catch(IOException e) o?dR\cxj
{ DMMLzS0A
e.printStackTrace (); _8S4Q!
} d*%Mv[X:<
o7arxo\
D3.VXuKn6
return n; V}:'Xgp*N
} ;+/NjC1
1;`Fe":;vC
CJA+v-
} KZ3B~#oQ
w\DspF
\G3!TwC%
/* [B,p,Q"
**SiteInfoBean.java 2 `&<bt[g
*/ dXO=ZU/N
package NetFox; CWvlr nv
n?Zf/T
Y)OBTX
public class SiteInfoBean { M5u_2;3
6ZEdihBei
8m7;x/0ld
private String sSiteURL; //Site's URL LE|<O
private String sFilePath; //Saved File's Path f9F2U )
private String sFileName; //Saved File's Name m&cvU>lC
private int nSplitter; //Count of Splited Downloading File I-{^[pp
%^!aB
e>!E=J)j
public SiteInfoBean() kjX7- ZPY
{//nSplitter的缺省值为5 b[0S=e G
//default value of nSplitter is 5 zn^v!:[
this("","","",5); O+vcs4
} Nm"<!a<F
C9pnU,[
N(BiOLZL6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j%5a+(H,z;
{ x~Cz?ljbn
sSiteURL= sURL; HTN$ >QTI
sFilePath = sPath; 3W'FcE)|E
sFileName = sName; o}W;Co
this.nSplitter = nSpiltter; ',#
"ZqEP R)
ZM 8U]0[X
} BPiiexTV9
E[*0Bo]
dq2@6xd
public String getSSiteURL() Z>h{` X\2
{ yDuq6`R*
return sSiteURL; Pl?}>G
} "5(W[$f*]v
952V@.Zp
< GU
public void setSSiteURL(String value) Of&"U/^
{ ?V?<E=13
sSiteURL = value; yF;?Hg
} o"4E+1qwM
GVZTDrC
"?[7#d])
public String getSFilePath() -U:2H7
{ `/c@nxh
return sFilePath; 1~L\s}|2d
} 5f{wJb2
[x|)}P7%s
w_!%'9m>
public void setSFilePath(String value) 2$Wo&Q^_
{ Onyh1
sFilePath = value; n5\}KZh
} w-M7opkq
>'.[G:b
vuW-}fY;
public String getSFileName() 01o [!nT
{ G1TANy
return sFileName; LGXZx}4@;
} 1Df,a#,y"
%2,/jhHL
:-U53}Iy
public void setSFileName(String value) tStJ2-5*t
{ ]6q*)q:`
sFileName = value; St_Sl:m$
} 1[px`%DR~
>-eS&rma
SNN#$8\
public int getNSplitter() RB *P0
{ K9^"NS3
return nSplitter; ~7dF/Nn5
} oHk27U G
[)0 R'xL6
y%FYXwR{
public void setNSplitter(int nCount) gz#+
{ sX Z4U0#
nSplitter = nCount; 0yKhp:^
} C,(j$Id
} 2zM-Ob<U`
>I|<^$/
UL[uh@4
/* `LqnEutzc
**Utility.java \Me"'.F?
*/ lqauk)(A0
package NetFox; 8'n#O>V@
HMhLTl{;
!@A|L#*
public class Utility { ps"9;4P
_E&U?>g+
y&h~Oa?,;
public Utility() VYHOk3
{ #U:0/4P(
&D)Hz
DVbYShB
} ^^7gDgT
X:DMT>5k
//线程睡眠 @f\ X4!e*y
public static void sleep(int nSecond) :bI,rEW#_
{ " xlJs93c
try{ M.X}K7Z_/
Thread.sleep(nSecond); lu3Q,W
} =#jTo|~u4o
catch(Exception e) [+_\z',u
{ } mgVC
e.printStackTrace (); aE}=^%D
} a!&bc8J7
} ?~{rf:Y
I{Rz,D uAL
//日志 7bHE!#L`0
public static void log(String sMsg) =%xIjxYl
{ ta@ISRK
System.err.println(sMsg); wQ@Zwbx
} &:-GI)[o
5VuCU
B5D3_iX]
public static void log(int sMsg) 9#ZzE/
{ :J<Owh@
System.err.println(sMsg); 8qn{
} $tEdBnf^ca
} HhzkMJR8
r}Ltv?4
nMLU-C!t
/* Ct-rD79l
**TestMethod.java hZ%2?v`
*/ !'+\]eA
package NetFox; <##|311o
kBQ5]Q"
C+DG+_%V*S
public class TestMethod { _xa}B,H
2-QuT"Gkd
{_rZRyr
public TestMethod() nh _DEPMq
{ ///xx/weblogic60b2_win.exe Z&AHM &,yj
try{ b #o}=m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); le "JW/BD
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6 ,7/8
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?j &V:kF
fileFetch.start(); %i;r]z-
} {JCSR2BB
catch(Exception e){e.printStackTrace ();} v!WU |=u
eD>-`'7<
}S'I DHla
} ]2hF!{wc
_C7abw-
n's2/9x
public static void main(String[] args) x@{G(W:W
{ [Q2S3szbt6
new TestMethod(); 7j9D;_(.^$
} o=mq$Z:}
} hNu>s
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