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)); eccJt
} F$nc9x[S
for(int i=0;i<nEndPos.length-1;i++) u.9syr
{ "*JyNwf
nEndPos = nStartPos[i+1]; p|RFpn2ygF
} \wM8I-f!
nEndPos[nEndPos.length-1] = nFileLength; <&MY/vV
} F*J@OY8i
} z( ^ r
8/BWe ;4
!63]t?QXMG
//启动子线程 owKOH{otf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &E0L 2gbI
for(int i=0;i<nStartPos.length;i++) Q1^kU0M}
{ v)s; wD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cVuT|b^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9`Zwa_Tni
nStartPos,nEndPos,i); 45U!\mG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ? uu,w
fileSplitterFetch.start(); V8-*dE
} 'wd&O03&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~Hb2-V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t*(buAx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @;`d\lQ
nEndPos = " + nFileLength); "U o~fJ
// fileSplitterFetch[nPos.length-1].start(); BVe c
Y"UB\_=
u=f}t=3
//等待子线程结束 D V=xqC6}
//int count = 0; |$G|M=*LN
//是否结束while循环 =l+~}/7'Z
boolean breakWhile = false; D0VbD" y
6`V~cVu
[Nv)37|W
while(!bStop) g\Akf
{ ..;ep2jSs
write_nPos(); s_4y^w]aX
Utility.sleep(500); "pTU&He
breakWhile = true; ),5|Ves;t[
cg).b?g
&at>sQ'
for(int i=0;i<nStartPos.length;i++) B'8T+qvA
{ 91\]Dg
if(!fileSplitterFetch.bDownOver) M&J$9X
{ 'h3yxf}\
breakWhile = false; r O-=):2
break; K_o[m!:jU
} ':#DROe!
} :)DvZxHE@
if(breakWhile) ^ RIWW0
break; h)pYV>!d
qt`HP3J&
3F?_{A
//count++; !~fy".|x
//if(count>4) M+GtUE~"
// siteStop(); F42?h:y8I
} ^2\-zX!bt
,?(U4pzX
O*udVE>
System.err.println("文件下载结束！"); 6~tj"34_
} BXa.XZ<n(
catch(Exception e){e.printStackTrace ();} 9^1li2zk{
} @~C C$Y$
h%8C_mA
o@uZU4MM
//获得文件长度 y7U?nP ')+
public long getFileSize() g[ O6WZ!F_
{ 4`]
int nFileLength = -1; $8WeWmY
try{ Rg%Xy`gS
URL url = new URL(siteInfoBean.getSSiteURL()); :b"&Rc&s.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hh`HMa'q
httpConnection.setRequestProperty("User-Agent","NetFox"); >TG#
-fT}Nj\
7_CX6:
int responseCode=httpConnection.getResponseCode(); 80"oT'ZFh
if(responseCode>=400) 3='Kii=LA
{ bEB9J- Q
processErrorCode(responseCode); +O!4~k^
return -2; //-2 represent access is error (o518fmR
} +6Ye'IOG
rbc7CPq_^
35n'sVn
String sHeader; Zy=DY
]/{iIS_
V@pUU~6R
for(int i=1;;i++) m_h$fT8 _
{ Wiere0 2*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }S 6h1X
//Utility.log(in.readLine()); )*nZ6Cg'
sHeader=httpConnection.getHeaderFieldKey(i); {-1N@*K
if(sHeader!=null) y,Z2`Zmu
{ ("P]bU+'>
if(sHeader.equals("Content-Length")) h.4FY<
{ DA^!aJ6iF
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ib2n Bg>j
break; L3Ivm:
} .Z(Q7j^
} pMV?vH
else *X8Pa;x
break; +c' n,O~3
} !112u#V
} I|. <
catch(IOException e){e.printStackTrace ();} Yd]
catch(Exception e){e.printStackTrace ();} a^7QHYJ6
R#4f_9e<Z
cf%aOHYI*
Utility.log(nFileLength); E'^ny4gL
8u7QF4 Id
<['ucp
return nFileLength; d"OYq
} 3hfv^H
Qb8Z+7
o]@'R<F(u
//保存下载信息（文件指针位置） ?G 'sb}.
private void write_nPos() K)GpQ|4:<
{ ?^WX]SAl
try{ wo9`-o6
output = new DataOutputStream(new FileOutputStream(tmpFile)); S~U5xM^s
output.writeInt(nStartPos.length); OlX#1W]
for(int i=0;i<nStartPos.length;i++) -%TwtO<$']
{ rm4t
// output.writeLong(nPos); V(;c#%I2
output.writeLong(fileSplitterFetch.nStartPos); DWupLJpk;c
output.writeLong(fileSplitterFetch.nEndPos); +do*C=z
} RmJ|g<
output.close(); J~)JsAXAI
} ^f9>tI{
catch(IOException e){e.printStackTrace ();} `$XgfMBf |
catch(Exception e){e.printStackTrace ();} #6mr'e1
} XwDt8TxL
8@r>`c
>%A~ :
//读取保存的下载信息（文件指针位置） y(X^wC
private void read_nPos() S^{tRPF%d
{ c3(0BSv
try{ s:ojlmPb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &'u%|A@
int nCount = input.readInt(); ';LsEI[
nStartPos = new long[nCount]; <K <|G
nEndPos = new long[nCount]; FTu<$`!1L
for(int i=0;i<nStartPos.length;i++) &Z%'xAOGR
{ *1h@Jb34
nStartPos = input.readLong(); 0u bf]Z
nEndPos = input.readLong(); SK5__Ix
} y\R-=Am".
input.close(); :PNhX2F
} \jr-^n]
catch(IOException e){e.printStackTrace ();} #g~]2x
catch(Exception e){e.printStackTrace ();} Se|h]+G
} |8fdhqy_
FpZ5@
+de5y]1H,|
private void processErrorCode(int nErrorCode) 4iY <7l8
{ 1rV9dM#F
System.err.println("Error Code : " + nErrorCode); 7pM&))R
} Y4N)yMSl"
e#@u&+K/f
RmQ>.?
//停止文件下载 /w2NO9Q
public void siteStop() *~^%s+b
{ j]m|}n
bStop = true; -BH T'zq1S
for(int i=0;i<nStartPos.length;i++) dTqL[?wH?
fileSplitterFetch.splitterStop(); 4KY@y?H g
}[OEtd{
5uU{!JuSa
} |;R-q8
} )2J#pz?.
//负责部分文件的抓取 i}@5<&J
**FileSplitterFetch.java CJ[e^K{
*/ Lbu,VX
package NetFox; ' wKTWmf?\
}DQ[C&
N@8tf@BT
import java.io.*; ;0}C2Cz'
import java.net.*; 2ZKy7p0/
:-~x~ah-
KJ_L>$ ]*
public class FileSplitterFetch extends Thread { |UN#utw{^Y
A/.z. K
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String sURL; //File URL *2Q x69`
long nStartPos; //File Snippet Start Position *-gmWATC6
long nEndPos; //File Snippet End Position `tm(3pJ
int nThreadID; //Thread's ID Y^gIvX
boolean bDownOver = false; //Downing is over j&0t!f.Rv
boolean bStop = false; //Stop identical q,]57s
FileAccessI fileAccessI = null; //File Access interface MT<3OKo?:
0p=
Jo9c|\4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException PRK*7-(
{ EC?U#!kv
this.sURL = sURL; Tx/KL%X
this.nStartPos = nStart; !={QL:
this.nEndPos = nEnd; 6e;8\1^
nThreadID = id; -;$jo-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w^/"j_p@
} ;h#CT#R2
$'bb)@_
M B,Z4 ^
public void run() dfs1BV'
{ z_a7HCG2
while(nStartPos < nEndPos && !bStop) i>;6Z s>S
{ _RX*Ps=
D66!C{
=A;79@bY
try{ j4h?"
URL url = new URL(sURL); ; .hTfxE0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]v.Yt/&C{
httpConnection.setRequestProperty("User-Agent","NetFox"); >|JMvbje
String sProperty = "bytes="+nStartPos+"-"; sE0,b
httpConnection.setRequestProperty("RANGE",sProperty); O9Yk5b;
Utility.log(sProperty); ? \NT'CG
E9j(%kQ2
eb<'>a
InputStream input = httpConnection.getInputStream(); g=s2t"&
//logResponseHead(httpConnection); X($@E!|
,@t#)HV
(ce"ED`1
byte[] b = new byte[1024]; =[o/D0-Kn
int nRead; 0*o=JM]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G[!<mh4h|
{ a0Q\]S
nStartPos += fileAccessI.write(b,0,nRead); CvqUaHW@
//if(nThreadID == 1) KQ.cd]6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IFWP&20
} ~<[]l~`
O9F#gO|!
Y+"Gx;F>
Utility.log("Thread " + nThreadID + " is over!"); JDBNi+t
bDownOver = true; }fz;La:b
//nPos = fileAccessI.write (b,0,nRead); *1_A$14l
} 9R4q^tGR\
catch(Exception e){e.printStackTrace ();} 5<?/M<i
} ]BBjFs4#
} ]yA_N>k2K
t8-LPq
!_h<w?)
//打印回应的头信息 }Yp]A
public void logResponseHead(HttpURLConnection con) HO;,Ya^l
{ }pv<<7}|
for(int i=1;;i++) U KdCG.E9^
{ jI807g+
String header=con.getHeaderFieldKey(i); vC5y]1QDd
if(header!=null) CB?,[#r5f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,T7(!)dR
Utility.log(header+" : "+con.getHeaderField(header)); L!kbDbqn
else )nUTux0K\
break; Y--Uo|H
} xsXf_gGu
} D~%h3HM
pw1&WP&?3
{NV=k%MTmi
public void splitterStop() -Tr*G4
{ xr-v"-
bStop = true; j es[a
} cGe-|>:
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)L:p.E
} u< .N\/
X3rvM8
Q GDfX_
/* kM/;R)3t4/
**FileAccess.java ;923^*\:F{
*//文件访问(定位，写) Mhze!!
package NetFox; b `.h+=3
import java.io.*; JV9Ft,xk
X.!|#FWb+
8Wyv!tL
public class FileAccessI implements Serializable{ I;Bcim;
OAtn.LU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *|k/lI
RandomAccessFile oSavedFile; i fbO<
long nPos; &(HIBF'O
8&9'1X5)8_
;yg9{"O
public FileAccessI() throws IOException 2:& [r*
{ 2u'h,on?
this("",0); "WHt9 yZ
} 4';(\42
bO?Us
C\p _
public FileAccessI(String sName,long nPos) throws IOException }z8HS< #Q
{ `=cOTn52
oSavedFile = new RandomAccessFile(sName,"rw"); m;KD@E!
this.nPos = nPos; 8?&u5
oSavedFile.seek(nPos); .m\'|%
} ^{Y9!R*9U*
0|_d{/VK4
6,;7iA]
public synchronized int write(byte[] b,int nStart,int nLen) %{M&"Mv
{ :0RfA%
int n = -1; U49 `!~b7
try{ +cnBEv~y
oSavedFile.write(b,nStart,nLen); RP4P"m(
n = nLen; I<ta2<h
} AVbGJ+
catch(IOException e) ygquQhf5
{ kI>PaZ`i)
e.printStackTrace (); ThSB\
} wsLfp82
fbK`A?5K
x4vowF
return n; vtVc^j4
} /xcl0oe(
2k$~Mv@L
Qcf5*]V
} )j>BvO
<i!7f26r
CA{(x(W\:
/* COf>H0^%Q
**SiteInfoBean.java .IJgkP)!]
*/ ESAFsJ$r;
package NetFox; [Vaw$c-+[y
6:vdo~
Xm!;
public class SiteInfoBean { WMLsKoby
i5 F9*
R87e"m/C%
private String sSiteURL; //Site's URL B> LL *
private String sFilePath; //Saved File's Path 9>k-";
private String sFileName; //Saved File's Name fer~NlX
private int nSplitter; //Count of Splited Downloading File o7W1sD1O
\6U$kMGde
$pg1Av7l
public SiteInfoBean() yl[6b1
{//nSplitter的缺省值为5 bM"crRG"
//default value of nSplitter is 5 e2PM^1{_
this("","","",5); `vPc&.-K
} w,QO!)j!
0'9zXJ"
%>G(2)Fb\\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >1n[Y- r
{ H(TY.
sSiteURL= sURL; ]TmxCTVL
sFilePath = sPath; !:^lTvYWZH
sFileName = sName; q|+`ihut
this.nSplitter = nSpiltter; T[YGQT|B
B:Xmc,|,
7#BUd/
} ()>,L?y
%!i|"FNc
7pY7iR_
public String getSSiteURL() C`0;
{ M@/Hd0$
return sSiteURL; ^ |^Q(
} LiF(#OuZ
`:I<Jp
h NCoX*icd
public void setSSiteURL(String value) ZOK,P
{ f2"1^M
sSiteURL = value; nBA0LIb
} ?{ 0MF
WTcrfs)T
hvS4"%\
public String getSFilePath() Zh]FL8[ nc
{ (haYY]W\
return sFilePath; @m=xCg.Z
} b&V}&9'[M;
_26<}&]b*
=R <X!@
public void setSFilePath(String value) /T_ G9zc
{ c=}#8d.
sFilePath = value; LZB=vc|3/
} 5fdB<& 9
XOe8(cXa9
j}CZ*
public String getSFileName() G-)Q*p{i|
{ %;r0,lN|II
return sFileName; [0(+E2/:2
} o=1M<dL
M;{btu^a
kq SpZoV0'
public void setSFileName(String value) Nn_n@K
{ zNs8yMnFr
sFileName = value; J}9 I5O
} DhAQ|SdCf
A80r@)i
tX$v)O|
public int getNSplitter() #0WGSIht<
{ Jmp%%^
return nSplitter; n!r<\4I
} _U"9#<
Whd2mKwiO
;ss,x
public void setNSplitter(int nCount) uq>\pO&P
{ &pCNOHi|
nSplitter = nCount; [a<ucJ
} XPhC*r
} )r)3.|wJm
H40~i=.
/2!Wy6p
/* 5VU 5kiCt
**Utility.java 8pQx6QE
*/ OUd&fUmH
package NetFox; QD6in>+B@
(Mk9##R#
|Mj2lZS
public class Utility { (W~')A"hC'
FG^Jh5
ld-Cb3R^
public Utility() 6,707h
{ '9+JaB
`n*e8T
V5MLzW\8
} %q~YJ*\
e-Xr^@M*Q
//线程睡眠 nNCG*Vu
public static void sleep(int nSecond) fr\"MP
{ H}R/_5g
try{ {!lC$SlJ
Thread.sleep(nSecond); :/c40:[
} DcO$&)Eb
catch(Exception e) }-ly'4=l
{ L*Gk1'
e.printStackTrace (); wN|;_~h2
} 6`tc]a"#Zb
} Rd?8LLz
6%hr]>L
//日志 7wivu*0
public static void log(String sMsg) Y;X_E7U
{ m5wfQ_}}ss
System.err.println(sMsg); yh
} (Q_J{[F
fd{75J5%
b"lzR[X,e
public static void log(int sMsg) Y+,ii$Ce~
{ A)2eo<ij4
System.err.println(sMsg); Ej\Me
} k$kOp *X
} ;.O#|Z[
xnuu#@f
qT<OiIMj^
/* KI@OEy
**TestMethod.java 4jOq.j
*/ 5Iql%~_x
package NetFox; ma!rZn
9hJlc
I`$"6 Xy
public class TestMethod { ma +iIt;
Y<4%4>a
-x~4@~
public TestMethod() X]Aobtz
{ ///xx/weblogic60b2_win.exe N)kZ2|oD
try{ kB2]Z}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P}2i[m.*,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3 #8bG(
SiteFileFetch fileFetch = new SiteFileFetch(bean); f: j9ze
fileFetch.start(); G^G= .9O
} >@g+%K]
catch(Exception e){e.printStackTrace ();} HX;JO[0
9!``~]G2
_~l*p"PL<
} ;p/%)WW
`X["Bgk$!T
S%^*h{9u"
public static void main(String[] args) %kHeU=
{ %`4\ 8H`
new TestMethod(); ;?{N=x8
} vKcZgIR
} IL]Js W
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