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)); hrU.QF8
} i&mu=J[
for(int i=0;i<nEndPos.length-1;i++) W>wE8? _,
{ YXrTm[P
nEndPos = nStartPos[i+1]; m[ay
} `u%//m_(
nEndPos[nEndPos.length-1] = nFileLength; ReZ|q5*
} e_k1pox]l
} B wtD!de$
f]T#q@|lE
9y.C])(2
//启动子线程 q6H90Zb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |5e/.T$
for(int i=0;i<nStartPos.length;i++) HQ/PHUg2
{ ZzzQXfA#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3|9)A+,#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1ReO.Dd`R
nStartPos,nEndPos,i); f IQ$a>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mOGcv_L
fileSplitterFetch.start(); _)2NFq
} {Swou>X4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -a&wOn-W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e3)rF5pp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~}83\LI}
nEndPos = " + nFileLength); r6PiZgR
// fileSplitterFetch[nPos.length-1].start(); kRSu6r9
$qg5m,1?
e)!X9><J
//等待子线程结束 p7zHP
//int count = 0; 1tQZyHc42;
//是否结束while循环 si3i#l&.b_
boolean breakWhile = false; ',m,wp`
;[gv-H
1MfRFv
while(!bStop) |],{kUIXO
{ |I)xK@7
write_nPos(); }-: d*YtK
Utility.sleep(500); <C# s0UX
breakWhile = true; YA{Kgc^
2[j|:Ng7
xhg{!w
for(int i=0;i<nStartPos.length;i++) wnt^WW=a[
{ ;bP7|
if(!fileSplitterFetch.bDownOver) -}4H'%Z(i
{ PJO;[: .I
breakWhile = false; j1**Ch/
break; I`Rxijz
} u+8_et5T
} P4R.~J ;8
if(breakWhile) +n2x@ 0op
break; d@8_?G}
3Y=T8Gi#
47$JN}qI0
//count++; O!Mm~@MoA
//if(count>4) 7F}I.,<W
// siteStop(); -W+dsZ Sv8
} 0A5xG&
(z^2LaM `8
;h/Y9uYn
System.err.println("文件下载结束！"); 1REq.%/=
} A{&Etu(K
catch(Exception e){e.printStackTrace ();} e|+uLbN&;c
} V!]e#QH;
G>#L
t@4X(i0
//获得文件长度 El"XF?OgpP
public long getFileSize() = 2My-%i
{ sI*( MhU
int nFileLength = -1; :*}tkr4&eh
try{ wx<5*8zP
URL url = new URL(siteInfoBean.getSSiteURL()); Ix1ec^?f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bs_I{bCu?
httpConnection.setRequestProperty("User-Agent","NetFox"); jUBlIVl]
[0)iY%^
:,GsbNKW
int responseCode=httpConnection.getResponseCode(); QbOmJQ
if(responseCode>=400) zg8m(=k'
{ 8&`s wu&
processErrorCode(responseCode); 8MW|CM4Q
return -2; //-2 represent access is error 3@6f%Dyj
} K")-P9I6-f
m#%5H
@["Vzg!I6"
String sHeader; xA&G91|s
{/#?n["
I"<~!krt%
for(int i=1;;i++) BT`/OD@
{ ?P"ht
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1iF |t5>e
//Utility.log(in.readLine()); &?zJ|7rh@|
sHeader=httpConnection.getHeaderFieldKey(i); ;y"E}h
if(sHeader!=null) XPWK"t01
{ 27,WP-qie
if(sHeader.equals("Content-Length")) _NqEhf:8
{ ^f3F~XhY3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \>,{)j q;
break; RJBNY;0
} 3+n&Ya1
} n:k~\-&WJ
else ShGR!r<
break; RQ/X{<lQ)
} wPqIy}-
} =;@5Ue J
catch(IOException e){e.printStackTrace ();} gDAA>U3|$
catch(Exception e){e.printStackTrace ();} UN,@K9
O a-ZeCq
#( X4M{I
Utility.log(nFileLength); =A=er1~%
M-|4cd]6
]9A9q<lZ
return nFileLength; M[TgNWl/[
} >rYP}k
5^P)='0*
<=jE,6_|
//保存下载信息（文件指针位置） (h`||48d
private void write_nPos() PlBT H
{ skZxR5v3~L
try{ 8$3Tu"+;
output = new DataOutputStream(new FileOutputStream(tmpFile)); W@pVP4F0xM
output.writeInt(nStartPos.length); >`s2s@Mx
for(int i=0;i<nStartPos.length;i++) Y.Gr(]tk
{ 4[+n;OI
// output.writeLong(nPos); #^Sd r-
output.writeLong(fileSplitterFetch.nStartPos); Fwho.R-.
output.writeLong(fileSplitterFetch.nEndPos); ?~u"w OH'
} :K2N7?shA
output.close(); hc~--[1c:
} GH^i,88
catch(IOException e){e.printStackTrace ();} ZJ+q<n_4}
catch(Exception e){e.printStackTrace ();} n%Nf\z
} HOu<,9?>Q
?c=l"\^x
1 ht4LRFi
//读取保存的下载信息（文件指针位置） p,ZubRJ"
private void read_nPos() oOQnV(I
{ #sNa}292"
try{ #i:p,5~")
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w*Kw#m'U
int nCount = input.readInt(); ;:"~utL7
nStartPos = new long[nCount]; IVEvu3
nEndPos = new long[nCount]; c67O/ B(
for(int i=0;i<nStartPos.length;i++) Ep?a1&b
{ `\O[9.B
nStartPos = input.readLong(); iFga==rw
nEndPos = input.readLong(); 0g`WRe
} jd(=? !_
input.close(); p&XbXg-
} WY<ip<
catch(IOException e){e.printStackTrace ();} h2uO+qEsu
catch(Exception e){e.printStackTrace ();} "$ u"Py
} uOm fpgO
YZ/mTQn_D
N"HN]Y@w
private void processErrorCode(int nErrorCode) SM0=
{ HM ^rk
System.err.println("Error Code : " + nErrorCode); EeL~`$f
} s g6
%;ny
Z>Sv[Ec
//停止文件下载 sowkxw.^Q
public void siteStop() z2nDD6N
{ ){8^l0b
bStop = true; ~EX/IIa{
for(int i=0;i<nStartPos.length;i++) nA%-<
fileSplitterFetch.splitterStop(); 5UjXpS
C]eb=rw$
:5C9uW#
} #gi&pR'$
} :)mV-(+o
//负责部分文件的抓取 =Z%&jul
**FileSplitterFetch.java 2b3x|9o8
*/ *3. ]
package NetFox; !U=;e?o
/z5j.TMs
6VCw>x
import java.io.*; DQ~+\
import java.net.*; IsnC_"f
iOzw)<
JnPA;1@/
public class FileSplitterFetch extends Thread { qmJFXnf
2nOQ48haT
1xcx2L+R
String sURL; //File URL 0'aZ*ozk
long nStartPos; //File Snippet Start Position S(/@.gI:f
long nEndPos; //File Snippet End Position 5E}0<&
int nThreadID; //Thread's ID H^'EY:|
boolean bDownOver = false; //Downing is over Q:@Y/4=
boolean bStop = false; //Stop identical #YjV3O5<
FileAccessI fileAccessI = null; //File Access interface 9u"im+=:
ZLo3 0*
rpy`Wz/[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I"Y?vj9]
{ ?Yz.tg
this.sURL = sURL; ;jI\MZ~l\
this.nStartPos = nStart; o$Hc5W([Z
this.nEndPos = nEnd; zg|yW6l)9
nThreadID = id; N!Kd VDdT|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jZ.+b j >
} {s_0[>
`p'L3u5H-
5M*q{kX)
public void run() .DCp)&m l;
{ l.b
while(nStartPos < nEndPos && !bStop) %Sxy!gGz%%
{ vjbot^W9
R)G'ILneV
,cgC_%
try{ *1%=?:$(r6
URL url = new URL(sURL); `M"b L|[R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1gH5#_?
httpConnection.setRequestProperty("User-Agent","NetFox"); 213D{#2
String sProperty = "bytes="+nStartPos+"-"; [xM07%:
httpConnection.setRequestProperty("RANGE",sProperty); )mwY] !
Utility.log(sProperty); r_ r+&4n
EYG&~a>L*
r|0C G^:C
InputStream input = httpConnection.getInputStream(); c|ZZ+2IYd
//logResponseHead(httpConnection); ChGwG.-%L
zCPjuS/~ Q
$m{\<A
byte[] b = new byte[1024]; t41\nTZr
int nRead; 8v(Xr}q,r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "B)DX*-\?
{ 9YB~1M
nStartPos += fileAccessI.write(b,0,nRead); AGrGZ7p]
//if(nThreadID == 1) & }k=V4L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w)DO"Z7
} ?;uzx7@F
/?2yo{Fg
t"RgEH@
Utility.log("Thread " + nThreadID + " is over!"); ilFM+x@
bDownOver = true; ?Vt$
//nPos = fileAccessI.write (b,0,nRead); S,Tm=} wj
} ?V*>4A
catch(Exception e){e.printStackTrace ();} qxd{c8
} &+%CC
} ]l+2Ca:-[j
<|.S~HLTQ
=X+DC&]%!
//打印回应的头信息 (m.]0v*&c
public void logResponseHead(HttpURLConnection con) 6jF~zI^
{ F(SeD)ml
for(int i=1;;i++) 4Ag+
{ T_YN^za(q
String header=con.getHeaderFieldKey(i); <-FZ-asem
if(header!=null) xB9^DURr\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }3)$aI_
Utility.log(header+" : "+con.getHeaderField(header)); ~zYp(#0op
else |bd5aRS9
break; |L]dJ<
} U0)(k}Q)
} RZ?>>Ll6
5'oWd e
Ep0Aogp29
public void splitterStop() `bt]v$
{ QRt(?96
bStop = true; 3OM\R%M
} >E)UmO{S
GI6 EZ}.MZ
hA/FK
} ZO0_:T#Z
ixfkMM,W
C"0gAN
/* dcXtT3,kpX
**FileAccess.java oZOFZ-<
*//文件访问(定位，写) `=CF |I
package NetFox; H<1C5-
import java.io.*; M5P63=1+
45ct*w
/md`tqI>i<
public class FileAccessI implements Serializable{ -,XS2[
~r>WnI:vg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 's&Vg09D,
RandomAccessFile oSavedFile; !q7M+j4
long nPos; @?e;Jp9
hXMC!~Th
[3/P EDkw
public FileAccessI() throws IOException c~$ipX
{ CQv [Od
this("",0); Tri.>@-u
} tQ|b?3
sav2.w
e=2;z
public FileAccessI(String sName,long nPos) throws IOException 4)XN1r:
{ ?*4]LuK6
oSavedFile = new RandomAccessFile(sName,"rw"); 6^ /C+zuX
this.nPos = nPos; -u8@ .
oSavedFile.seek(nPos); ~zRW*pd
} yK}#|b'cM
59EAqz[:
T /]ayc:
public synchronized int write(byte[] b,int nStart,int nLen) ^2=Jv.2{|
{ ? 4.W _
int n = -1; L(8Q%oX%o
try{ Zr$PSp}
oSavedFile.write(b,nStart,nLen); BwL:B\
n = nLen; "`&?<82
} KDn`XCnk,
catch(IOException e) KNK0w5
{ [n< U>up
e.printStackTrace (); pwu5Fxn)
} uIWCVR8`Y
67n1s
Zj}DlNkVu
return n; 'nCBLc8
} kB~:HQf
y:v0&9L
.#+rH}=Z
} lhxhAe
J@R+t6$3O
$jw!DrE
/* bBDgyFSI<
**SiteInfoBean.java *1elUI2Rg
*/ &Nec(q<
package NetFox; @AyC0}
h,\_F#hi
7p~@S4
public class SiteInfoBean { 6X'RCJu%
Mr`u!T&sc
sA` bPhk
private String sSiteURL; //Site's URL ^K;,,s;0
private String sFilePath; //Saved File's Path S&R~*
private String sFileName; //Saved File's Name g/Qr]:;
private int nSplitter; //Count of Splited Downloading File pR~PB
/,B"H@J
[u-~<80
public SiteInfoBean() &[kwM395
{//nSplitter的缺省值为5 *1>XlVx,
//default value of nSplitter is 5 fEgZ/p!g
this("","","",5); D6v0n6w
} O'!k$iJNb
}uZhoA
qWP1i7]=/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WQ6E8t)
{ S&]JY
sSiteURL= sURL; blS*HKw
sFilePath = sPath; >~ne(n4qy
sFileName = sName; ~v<r\8`OI2
this.nSplitter = nSpiltter; z3a te^PJF
0gt/JI($
x.45!8Zb
} OP<@Xz
P;A"`Il
a+J :1'
public String getSSiteURL() o'yR^`
{ xat)9Yb}0
return sSiteURL; hDz_BvE
} }F@`A?k
SXgpj
/e\} qq
public void setSSiteURL(String value) Jk(b=j
{ W_M]fjL.
sSiteURL = value; iRPd=)
} hbN*_[
SHhg&~B
{_Ke'" k
public String getSFilePath() =Ybbh`$<
{ Iye
return sFilePath; Wp>W?'`
} |!&,etu
`uGX/yQ#=
6 rmK_Y
public void setSFilePath(String value) 8mx5K-/,y^
{ ! 4i
sFilePath = value; v<;,x
} BHU(Hd
}g(aZ
spFsrB
public String getSFileName() x}F.<`
{ "7gS*v,r
return sFileName; GK\'m@k
} V1j&>-]]9*
Ry/NfF=
&Vl,x/
public void setSFileName(String value) 7b Gzun&
{ l`,`N+FG
sFileName = value; f'r/Q2{n
} 5t0i/&zX
!.p!
,[~Ydth
public int getNSplitter() m,=$a\UC
{ `DJIY_{-2
return nSplitter; hW/*]7AM^
} z.[L1AGa|s
H&%=>hyX
Bt.W_p
public void setNSplitter(int nCount) S%Ja:0=}?
{ #=$4U!yL
nSplitter = nCount; ydlH6>
} M2V.FYV{j>
} 8N|*n"`}
L@G)K
SxQ|1:i%
/* s$Roe(J
**Utility.java VgoQz]z
*/ %/'[GC'y!
package NetFox; +mxsjcq0
` 6"\.@4
3V,X=
public class Utility { W#??fae
H|,{^b@9
!!` zz
public Utility() f \4Qp
{ S - 7JDE>
{CGk5`g~
gc(1,hv
} 9jvg[H
kfmIhHlYQ
//线程睡眠 *nC<1.JW
public static void sleep(int nSecond) BkO"{
{ 89 SsSb
try{ WUqAPN
Thread.sleep(nSecond); }1$8)zH
} s&fU|Jk8
catch(Exception e) )3u[btm
{ WMI/Y9N
e.printStackTrace (); FyY;F;4P
} heh!cDK
} i.fDH57
6 a$%
//日志 c9ghR0WM
public static void log(String sMsg) }f({03$
{ ,fYO>l';`f
System.err.println(sMsg); )p!dqlK
} uM4,_)L
4Uwt--KtFh
{'vvE3iZ
public static void log(int sMsg) E+3~w?1
{ -R\}Q"
System.err.println(sMsg); 1hMk\ -3S
} MM5#B!BB
} {O"dj;RU
16aaIK
9ge$)q@3
/* Xt~/8)&
**TestMethod.java Xi|v!^IT
*/ wTTQIo60
package NetFox; [jLx}\]
8zY)0
NuXU2w~
public class TestMethod { kW(8i}bg
oiR`\uY
UbuxD})
public TestMethod() \LS%bO,Y|
{ ///xx/weblogic60b2_win.exe I~mw\K{.3M
try{ "/\:Fdc^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dk7"#q@kx
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iu:e>r
SiteFileFetch fileFetch = new SiteFileFetch(bean); o@>5[2b4
fileFetch.start(); bRIb'%=+GA
} nDPfr\\
catch(Exception e){e.printStackTrace ();} AM}OLHj
3Yr
) .]Z}g&
} ?s_q|d_
q|6lw 74`
X'3F79`
public static void main(String[] args) *J$=UG,u
{ D1Fc7!TV
new TestMethod(); BS{">lPmx
} {!EbGIh
} vR`KRI`{
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