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)); ,(-V<>/*.|
} z]SEPYq:
for(int i=0;i<nEndPos.length-1;i++) :nR80]
{ "G~!J\
nEndPos = nStartPos[i+1]; NMfHrYHbh
} J<0d"'
nEndPos[nEndPos.length-1] = nFileLength; xJAQ'ANr
} b !y
} IU5T5p
0%< hj
+Adk1N8
//启动子线程 G[JWG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `)5WA{z
for(int i=0;i<nStartPos.length;i++) X(eW+,H
{ c-5AI{%bl6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l$pz:m]Id
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (sQXfeMz
nStartPos,nEndPos,i); =+K?@;?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S9r?= K
fileSplitterFetch.start(); =Gu&0f
} ?>U=bA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), pDYJLh-C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +or<(%o @
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .D ^~!A
nEndPos = " + nFileLength); GS=E6
// fileSplitterFetch[nPos.length-1].start(); =cZ24I
qEXN}Pq<
#) :.1Z?
//等待子线程结束 #+p-
//int count = 0; A.("jb@I
//是否结束while循环 i0$*):b
boolean breakWhile = false; >W8"Ar
I/O/*^T
tuIZYp8tIN
while(!bStop) B~ i
{ aQ$sn<-l
write_nPos(); 65dMv*{
Utility.sleep(500); KcpYHWCa.
breakWhile = true; cQuL9Xo
p*,T~(A6
!hZ: \&V
for(int i=0;i<nStartPos.length;i++) RG'76?z
{ z2t+1In,
if(!fileSplitterFetch.bDownOver) 7`;f<QNo
{ Pb>/b\&JS
breakWhile = false; |@'O3KA
break; eGq7+
} KzO"$+M
} S}VS@KDO
if(breakWhile) )Ln".Bu,
break; hBpa"0F
$'3xl2T
p__wBUB
//count++; f\dfKNm6
//if(count>4) 7$lnCvm
// siteStop(); B8T$<
} Rv9jLH
30uPDDvar
6 Ln~b<I
System.err.println("文件下载结束！"); \\<=J[R.M
} iOURS
catch(Exception e){e.printStackTrace ();} WM ?a1j
} hk4t #Km
( ~5M{Xh
kaekH*m~
//获得文件长度 v}Ju2}IK
public long getFileSize() 'v V7@@
{ mvZ#FF1,J
int nFileLength = -1; MHK|\Z&e7
try{ `nl n@ ;
URL url = new URL(siteInfoBean.getSSiteURL()); 6j<!W+~G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gk%@& TB/
httpConnection.setRequestProperty("User-Agent","NetFox"); g5@g_~ g
b[<RcM{r}
Df^F)\7!N?
int responseCode=httpConnection.getResponseCode(); Fa )QDBz)
if(responseCode>=400) MWh Y&I+
{ @9B*V~ <
processErrorCode(responseCode); VWE>w|'
return -2; //-2 represent access is error ;Nj9,Va(t
} lQ;BI~
2aM7zP[Z
'*b]$5*p
String sHeader; Jo\P,-\(
!=YKfzE
_VKI@
for(int i=1;;i++) A#=TR_@:
{ Mu?|<#s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tR|dnC4U
//Utility.log(in.readLine()); 5 aA* ~\
sHeader=httpConnection.getHeaderFieldKey(i); v4n< G-
if(sHeader!=null) nMyl(kF[
{ +P2oQ_Fk`9
if(sHeader.equals("Content-Length")) !5o j~H
{ e|\xFV=4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gA!@oiq@
break; Wb-C0^dTn
} pd|KIs%jl
} Jay"
else yfZNL?2x
break; "o&8\KSs
} cs+3&T:,*
} eThaH0
catch(IOException e){e.printStackTrace ();} $eYL|?P50h
catch(Exception e){e.printStackTrace ();} KC6Cg?y^
lvO6&sF1
e7RgA1
Utility.log(nFileLength); K*>%,mP$i
VVas>/0qr
5qb93E"C
return nFileLength; {]T?)!Vm
} @Vre)OrN#
0<uek
Ek_5% n
//保存下载信息（文件指针位置） hIJtu;}zU
private void write_nPos() }5;4'l8
{ >rCD5#DG
try{ {o}U"b<+Ra
output = new DataOutputStream(new FileOutputStream(tmpFile)); )L:zr#
output.writeInt(nStartPos.length); [IL*}M!
for(int i=0;i<nStartPos.length;i++) 0[MYQl`
{ Jb QK$[z"
// output.writeLong(nPos); ZZY#.
output.writeLong(fileSplitterFetch.nStartPos); K~TwyB-h
output.writeLong(fileSplitterFetch.nEndPos); e&}W#
} IfK~~XYG
output.close(); =-h^j
} Y[{:?i~9,
catch(IOException e){e.printStackTrace ();} Ie.*x'b?y
catch(Exception e){e.printStackTrace ();} AW]\n;f
} D.K""*ula
\MP~}t}c
W[ l
//读取保存的下载信息（文件指针位置） .XJ'2yKof
private void read_nPos() 7n7Xyb
{ XX8HSw!w
try{ vMTf^V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q(bOar5
int nCount = input.readInt(); {R}F4k
nStartPos = new long[nCount]; DB/~Z
nEndPos = new long[nCount]; mmTpF]t ?`
for(int i=0;i<nStartPos.length;i++) 7Sx|n}a-3
{ z'YWomfZm
nStartPos = input.readLong(); ,;$OaJFT
nEndPos = input.readLong(); p F-Lz<V
} xXe3E&
input.close(); V8^la'_j
} ~:ASv>m
catch(IOException e){e.printStackTrace ();} >JpBX+]5m
catch(Exception e){e.printStackTrace ();} im<bo Mv
} v:t;Uk^Y
%{u@{uG0'3
nip6|dN
private void processErrorCode(int nErrorCode) |oY{TQ<<d
{ 'f5 8Jwql
System.err.println("Error Code : " + nErrorCode); fiGTI}=P
} UA>=# $
u]yy%@U1
PkvW6,lS
//停止文件下载 ;4nY{)bD
public void siteStop() >y3FU1w5d
{ >q"dLZ
bStop = true; `i.BB jx`
for(int i=0;i<nStartPos.length;i++) ,mHME~
fileSplitterFetch.splitterStop(); n'~==2
9@ k8$@
#T=iS(i
} yHeL&H
} 'C]w3Rh'
//负责部分文件的抓取 xl&@g)Jj
**FileSplitterFetch.java EXDDUqZ5\
*/ L&pR#
package NetFox; CX|W$b)%
1oQw)X
/<rvaR
import java.io.*; J"`VA_[
import java.net.*; @<\oM]jX
bMO^}qR`
gv*b`cl
public class FileSplitterFetch extends Thread { OoB|Eh|),
eZ'8JU]
L'+bVP{L
String sURL; //File URL ] ZV[}7I.
long nStartPos; //File Snippet Start Position [`n_> p!
long nEndPos; //File Snippet End Position =U]9>
int nThreadID; //Thread's ID OX_y"]utU
boolean bDownOver = false; //Downing is over +_5*4>MC
boolean bStop = false; //Stop identical LV:L0D7y
FileAccessI fileAccessI = null; //File Access interface R(1:I@<?E
hA7=:LG
sscbf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5YY5t^T
{ :""HyjY!
this.sURL = sURL; 'RjEdLrI
this.nStartPos = nStart; Lq(=0U\"P
this.nEndPos = nEnd; wvv+~K9jq
nThreadID = id; Z"`w>c.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )lG}B U.
} UG2+Y']
yE:y[k0E
|E8sw a
public void run() 2js/>L0
{ Ac:`xk<
while(nStartPos < nEndPos && !bStop) UqK.b}s
{ ]s\r3I]
z !K2UTX
!0;AFv`\
try{ Y{} ub]i
URL url = new URL(sURL); fn}E1w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~+Wx\:TT
httpConnection.setRequestProperty("User-Agent","NetFox"); vjEDd`jYZ
String sProperty = "bytes="+nStartPos+"-"; K~L&Z?~|E
httpConnection.setRequestProperty("RANGE",sProperty); Z RVt2
Utility.log(sProperty); NI?O
K#R]of~/
\{h_i FU!
InputStream input = httpConnection.getInputStream(); Zbczbnj
//logResponseHead(httpConnection); &g:(I
kWr1>})'
U0&myj 8L
byte[] b = new byte[1024]; _Ewh:IM-
int nRead; %' DOFiU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R"cQyG4
{ iOiFkka
nStartPos += fileAccessI.write(b,0,nRead); 6n9/`D!
//if(nThreadID == 1) kV'zAF v
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *zdD4I=
} "f91YX_)
2S8;=x}/
<cTX;&0=
Utility.log("Thread " + nThreadID + " is over!"); 9D3W_eIc
bDownOver = true; wd`p>
//nPos = fileAccessI.write (b,0,nRead); AiHU*dp6
} %]P{)*y-?
catch(Exception e){e.printStackTrace ();} [2@:jLth=
} IdmP!(u
} ![z2]L+TB
R27'00(Z0
`l|Oj$
//打印回应的头信息 oCT,v0+4O
public void logResponseHead(HttpURLConnection con) e$9a9twl
{ +`d92Tz
for(int i=1;;i++) |f_'(-v`E
{ c.>f,vtcn
String header=con.getHeaderFieldKey(i); >Na.C(DZ
if(header!=null) &M|rRd~*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /stvNIEa
Utility.log(header+" : "+con.getHeaderField(header)); -Q? i16pM
else [n"eD4)K|
break; Xt$qjtVM
} 6wp1jN
} ?mNB:-Q
3zsp6kV
JD*HG]
public void splitterStop() h0F=5| B
{ { j_-iF
bStop = true; ]xRR/S4
} i!YfR]"}
6 IvAs-%W
-6)nQNj|
} rWr'+v?
`l45T~`]$
c/Pql!h+
/* 0moAmfc
**FileAccess.java ;1&"]N%
*//文件访问(定位，写) "L.k m
package NetFox; =-^A;AO(
import java.io.*; &$s:h5HoX
1uw1(iL+
i$kB6B#==
public class FileAccessI implements Serializable{ JV_`E_!
<y7{bk~i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dNR/|
RandomAccessFile oSavedFile; 0er|QC
long nPos; #`y[75<n
h[dJNawL
k (AE%eA
public FileAccessI() throws IOException Rxdj}xy
{ O.jm{x!m
this("",0); Z"c-Ly{vEj
} "6C a{n1hk
;BuMzG:tmZ
A\?t^T
public FileAccessI(String sName,long nPos) throws IOException ]#NfH-T
{ _N;@jq\q
oSavedFile = new RandomAccessFile(sName,"rw"); ou0TKE9 _
this.nPos = nPos; |ufT)+:
oSavedFile.seek(nPos); 4Pr^>m
} z#G\D5yX[*
,q%X`F rc
RF*>U a
public synchronized int write(byte[] b,int nStart,int nLen) n ^9?(a4u
{ 8^EWD3N`
int n = -1; `XF[A8@h
try{ !84Lvg0&
oSavedFile.write(b,nStart,nLen); uKzx >\}?1
n = nLen; W'"hjQ_
} >3&
catch(IOException e) }c||$
{ l`~$cK!
e.printStackTrace (); <Z t]V`-
} V=fu[#<@Ig
Q}Ah{H0C
Ur 1k3
return n; ()j)}F#Z`
} Fep@VkN
o#"yFP1
#IGcQY
} 8\E=p+C
AHr^G'
IZdWEbN1
/* DEu0Z
**SiteInfoBean.java $'}|/D
*/ /Gnt.%y&
package NetFox; tYMr
!!A(A^s
|H=5Am
public class SiteInfoBean { [qxpu{
&OFVqm^
/(||9\;
private String sSiteURL; //Site's URL ^xk4HF
private String sFilePath; //Saved File's Path ;s~xS*(C
private String sFileName; //Saved File's Name Y,mo}X<>
private int nSplitter; //Count of Splited Downloading File .z$UNB(!M
<NDV 5P
%1cxZxGT
public SiteInfoBean() o9ys$vXt*
{//nSplitter的缺省值为5 #2\M(5d
//default value of nSplitter is 5 Y&M{7
this("","","",5); x$Wtkb0<
} &Odrq#o?R
xP9R d/xa|
IecD41%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8WLh7[
{ I_Z?'M
sSiteURL= sURL; g<F+Ldgj
sFilePath = sPath; I|bX;l
sFileName = sName; Gn6\n'r0
this.nSplitter = nSpiltter; .@r{Tq,%q8
[GM!@6U
ZJ)>gV
} 1IgTJ" \
CNj |vYj
F*z>B >{)
public String getSSiteURL() {a>JQW5=
{ UC`sq-n
return sSiteURL; ?3LV$S)U
} |]:6IuslJ
q 7W7sw
V[^AV"V
public void setSSiteURL(String value) 1mh7fZgn
{ k,OxGG
sSiteURL = value; 7"eIZ
} kVeY} 8
%;_EWs/z8
i5WO)9Us
public String getSFilePath() dqU)(T=C
{ -NzOX"V]3
return sFilePath; ^755LW
} @VND}{j
1*#hIuoj'
mWoN\Rwj
public void setSFilePath(String value) )abH//Pps.
{ &a >UVs?=
sFilePath = value; yWN'va1+$
} 5^qs>k[mN
BD.l5~:
:hB6-CZkqN
public String getSFileName() A[Ce3m
{ .ezko\nU
return sFileName; b V_<5PHP
} rCGKE`H
v!S(T];)
F_}y[Yn^
public void setSFileName(String value) `LwZ(M-hI
{ %0u5d$bq
sFileName = value; bLggh]Fh
} Mu" vj*F
X)TZ S
8BY`~TZO$q
public int getNSplitter() E9.1~ )
{ djdSD
return nSplitter; D+BflI~9mP
} j9%vw.3b
H?=[9?1wI5
L]X Lv9J0
public void setNSplitter(int nCount) ][\ uH|
{ 6!U~dt#a
nSplitter = nCount; E_z,%aD[
} ! OVi\v 'm
} 4/x.qoj
wqE2n
=xH>,-8}
/* zyK11
**Utility.java #)T'a
*/ <qoPBm])
package NetFox; c!$~_?]
1JGww]JZo
{v3@g[:|
public class Utility { MzW!iG
~vZ1.y4
b3=XWzK5
public Utility() v9D[|4
{ c)QOgXv
.p~.S&)
X-"0Zc
} -zH-9N*c
TU| 0I
//线程睡眠 Pj^Ccd'>=
public static void sleep(int nSecond) >LU !Z
{ xLbF9ASim
try{ CS xB)-
Thread.sleep(nSecond); MA mjoH
} V2 }.X+u&<
catch(Exception e) SwH#=hg
{ H[/^&1P
e.printStackTrace (); 2ZxZ2?.uJ
} DY87NS*HF
} Ban"H~
NA$ODK-
//日志 <U/r U9O
public static void log(String sMsg) rqM_#[Y?
{ ${UH!n{
System.err.println(sMsg); k~1{|HxrE
} )B^T7{
K!G/iz9SB
Kku@!lv
public static void log(int sMsg) _ =(v? 2:?
{ K+U0YMRmz
System.err.println(sMsg); cn ;2&
} Fz$^CMw5K
} W$R@Klz
{f>e~o
]"vpCL
/* nlx~yUXL4
**TestMethod.java d:n.Vp
*/ I\6^]pi,
package NetFox; B{Lzgw u;
L<N=,~
$I3}%'`+
public class TestMethod { }Do$oyAV$G
VC NQ}h[D
3_Re>i
public TestMethod() 'p,54<e
{ ///xx/weblogic60b2_win.exe `9VRT`e
try{ 3{- 8n/4 k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9\R+g5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4V5h1/JPm
SiteFileFetch fileFetch = new SiteFileFetch(bean); Nu%MXu+
fileFetch.start(); _ Av_jw`m
} 4p(\2?B%f
catch(Exception e){e.printStackTrace ();} u,Cf4H*xS
rge/qUr/^
:LR>U;2
} )G|'PXI@,
(DKQHL;
iC<qWq|S_m
public static void main(String[] args) !*-|s}e
{ Jpo(O>\P
new TestMethod(); NFb<fD[C
} , *Z!Bd8
} &;%LTF@I,
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