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)); Vk_L*lcN
} (~#PzE:
for(int i=0;i<nEndPos.length-1;i++) L,kF]
{ sU}e78mh
nEndPos = nStartPos[i+1]; Z=H fOC
} i([A8C_A
nEndPos[nEndPos.length-1] = nFileLength; Ns9g>~
} MoFZ
} |]]fcJOBP
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\dc`}}Lc
//启动子线程 j/Kw-h ,5"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l/I W"A
for(int i=0;i<nStartPos.length;i++) iCEX|Tj;
{ n+i}>3'A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FP\[7?ZLn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?QMs<
nStartPos,nEndPos,i); A=3U4L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @LmUCP~
fileSplitterFetch.start(); QTyl=z7
} :D/R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #e0+;kBh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <St`"H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (HJ60Hj
nEndPos = " + nFileLength); Yp;x
// fileSplitterFetch[nPos.length-1].start(); Sn+Yi
JL$RBr
O,;SA
//等待子线程结束 M>^IQ
//int count = 0; ;}PL/L$L6;
//是否结束while循环 N,1wfOE
boolean breakWhile = false; TUUBC%
PQs9@]w[
2KX *x_-
while(!bStop) }$UFc1He\J
{ P6?Q;-\q0
write_nPos(); w7W-=\Hvh
Utility.sleep(500); b13>>'BMB
breakWhile = true; #*`|}_6L
8_LDS
:H87x?e[
for(int i=0;i<nStartPos.length;i++) :=8vy
{ @GV^B'}*
if(!fileSplitterFetch.bDownOver) 1hN! 2Y:
{ Yk5kC0B
breakWhile = false; lV1|\~?4
break; MWuVV=rd8a
} 0'<S7?~|
} $pKS['J0
if(breakWhile) _96&P7
break; JSL3.J
&0"`\~lA
(+@.L7>m+t
//count++; )Qc$UI8L
//if(count>4) #-`lLI:w0
// siteStop(); cZ(XY}
} "&ks83
-/</7I
v7R&9kU{
System.err.println("文件下载结束！"); ^Ve^}|qPc
} (1o^Dn3
catch(Exception e){e.printStackTrace ();} <vrx8Q*6
} Em7q@
8?$2;uGL
jL8zH
//获得文件长度 /IC'R"V a
public long getFileSize() j{PX ~/
{ :8ZxOwwv
int nFileLength = -1; Y `{U45
try{ ^/+sl-6/F
URL url = new URL(siteInfoBean.getSSiteURL()); g[$B90
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `#]\Wnp~y
httpConnection.setRequestProperty("User-Agent","NetFox"); fS~.K9
1m0':n Vdu
f.= E.%
int responseCode=httpConnection.getResponseCode(); (X9V-4
if(responseCode>=400) 40<&0nn
{ u%pief
processErrorCode(responseCode); { nV zN(
return -2; //-2 represent access is error >&VL2xLy
} %L/=heBBd
(pmo[2kg
6~}H3rvO}
String sHeader; EDo (
|h7v}Y
H07j&
for(int i=1;;i++) |}`5<a!6U
{ 5c"kLq6r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E;qwoTmul
//Utility.log(in.readLine()); 1bBK1Uw
sHeader=httpConnection.getHeaderFieldKey(i); JvDsr0]\#
if(sHeader!=null) WdT|xf.Q&
{ _(hwU>.
if(sHeader.equals("Content-Length")) vf2K2\fn
{ l;.BlHyu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /K^cU;E,
break; (Y>MsqwWfC
} xR:h^S^W ~
} ueR42J%s
else .bE,Q9:
break; zgqw*)C~
} ZYA(Bg^
} +RkYW*|$S
catch(IOException e){e.printStackTrace ();} tX251S
catch(Exception e){e.printStackTrace ();} @>Keu\)
x}{VHp`|ld
h,x]
Utility.log(nFileLength); fDd!Mt
<IVz mzpL
yShHFlO=
return nFileLength; (5> ibe
} sYXS#;|M
e@OA>
lQ/XJw
//保存下载信息（文件指针位置） 'T[zh#v>S
private void write_nPos() kgz{m;R
{ ]lUu%<-;
try{ ZhsZywM
output = new DataOutputStream(new FileOutputStream(tmpFile)); qN@a<row&~
output.writeInt(nStartPos.length); D@^ZpN8r
for(int i=0;i<nStartPos.length;i++) 9HX+sB M
{ ;X(n3F
// output.writeLong(nPos); GcR`{ 3hO
output.writeLong(fileSplitterFetch.nStartPos); .jp]S4~
output.writeLong(fileSplitterFetch.nEndPos); D.(G9H
} yUO|3ONT
output.close(); 7g)3\C
} er0D5f R
catch(IOException e){e.printStackTrace ();} BuTIJb+Q\
catch(Exception e){e.printStackTrace ();} 86#mmm)
} ozC!q)j
hli10p$
|lxy< C4V
//读取保存的下载信息（文件指针位置） ?Z>.G{Wm@
private void read_nPos() "Vq]|j,B/c
{ K;[%S
try{ W(h8!}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }4SSo)Uv/
int nCount = input.readInt(); jJZsBOW[8
nStartPos = new long[nCount]; JtpY][}"~3
nEndPos = new long[nCount]; N@6OQ:,[F
for(int i=0;i<nStartPos.length;i++) N?;o_^C
{ </gp3WQ.
nStartPos = input.readLong(); SDHc[66'
nEndPos = input.readLong(); {X<4wxeTo
} )7GLS\uf<%
input.close(); p &>A5
} 5xDN&su
catch(IOException e){e.printStackTrace ();} HhmVV"g
catch(Exception e){e.printStackTrace ();} PgLS\_B
} kQVDC,d
2BDan^:-Av
k0_$M{@Y
private void processErrorCode(int nErrorCode) qQOD
{ _1<'"u#6w
System.err.println("Error Code : " + nErrorCode); ,|X+/|gm
} 3g[j%`k
p*`SGX
^Opy6Bqb
//停止文件下载 GrR0RwnH)?
public void siteStop() tx5T^K7[
{ oNB,.:
bStop = true; ?[VpN2*
for(int i=0;i<nStartPos.length;i++) ej%;%`C-
fileSplitterFetch.splitterStop(); !?o$-+a|
^YR|WKY
UIOEkQ\Wl
} R pI<]1
} ncattp
//负责部分文件的抓取 /%YiZ#
**FileSplitterFetch.java E0eQ9BXh
*/ ]1d,O^S
package NetFox; ^8NLe9~p3?
HCG@#W<wc
B>Cs&}Y!
import java.io.*; xs'kO=
import java.net.*; O R<"LTCL
4su_;+]
s`=/fvf.
public class FileSplitterFetch extends Thread { 'B (eMnLg
LuP?$~z
hiRR+`L%
String sURL; //File URL cZr G:\A
long nStartPos; //File Snippet Start Position hyb +#R
long nEndPos; //File Snippet End Position Q"|kW[Sg
int nThreadID; //Thread's ID ("E!Jyc!
boolean bDownOver = false; //Downing is over ~sU?"V
boolean bStop = false; //Stop identical l>D-Aan
FileAccessI fileAccessI = null; //File Access interface qX{X4b$
?#m<\]S<
AL]h|)6QpC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pSQCT
{ yYToiW *
this.sURL = sURL; n<?SZ^X{,/
this.nStartPos = nStart; R+E_#lP_$
this.nEndPos = nEnd; DVl[t8K!
nThreadID = id; W&e'3gk_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "65||[=8
} *:9 >W$0u
>H}jR[H'
Ty3CBR{6
public void run() .3a:n\tY
{ .6#cDrK
while(nStartPos < nEndPos && !bStop) ],\sRQbv&
{ IAP/G5'Q
hu P^2*c
&^&$!Xmu9
try{ eb!s'@
URL url = new URL(sURL); DhLr^Z!h3;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l*K I
httpConnection.setRequestProperty("User-Agent","NetFox"); O xT}I
String sProperty = "bytes="+nStartPos+"-"; mN\%fJ7
httpConnection.setRequestProperty("RANGE",sProperty); U['JFLF
Utility.log(sProperty); T2DF'f3A
j?\$G.Y
>'aG/(
InputStream input = httpConnection.getInputStream(); d$fvg8^
//logResponseHead(httpConnection); X<~k =qwA
7-".!M
6[*;M
byte[] b = new byte[1024]; SqXy;S@
int nRead; %'L].+$t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |Bx||=z`
{ eQU-&-wt0
nStartPos += fileAccessI.write(b,0,nRead); .!yWF?T8
//if(nThreadID == 1) 1mHwYT+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]6{(Hjt
} qGnPnQc
&so-O90
-RG8<bI,
Utility.log("Thread " + nThreadID + " is over!"); g.I(WJX0
bDownOver = true; -ca7x`yo
//nPos = fileAccessI.write (b,0,nRead); .[T'yc:=
} %n05Jitl
catch(Exception e){e.printStackTrace ();} @up&q
} }_{y|NW
} 5/B#)gm
D:wnO|:
+`;+RDKY*
//打印回应的头信息 0A#*4ap
public void logResponseHead(HttpURLConnection con) & u$(NbK
{ vG]GQ#
for(int i=1;;i++) 6FL?4>MZ
{ _urG_~q
String header=con.getHeaderFieldKey(i); c ]>DI&$;J
if(header!=null) 6OL41g'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lSH ZV Fd
Utility.log(header+" : "+con.getHeaderField(header)); XkPv*%Er8
else EKZA5J7kn
break; |',M_ e]
} m`hGDp3
} -#LjI.
CO-Iar
/8xH$n&xoC
public void splitterStop() N'I(P9@
{ ?gLR<d_
bStop = true; 1ZT^)/G
} ,*/Pg52?
!|:RcH[
$hh+0hs
} 8h2D+1,PZC
OmB TA=E<
,H>W:O
/* XZ.7c{B<
**FileAccess.java wJ6_I$>
*//文件访问(定位，写) :qxm !P
package NetFox; RX:R*{]-
import java.io.*; kMM'[w
`9/0J-7*
0|g[o:;fl_
public class FileAccessI implements Serializable{ WtIMvk
>Q; g0\I_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O?CdAnhQc`
RandomAccessFile oSavedFile; d]U`?A,
long nPos; ~?gzq~~t
Te# ]Cn|
PPEq6}
public FileAccessI() throws IOException >-!r9"8@
{ +A@m9
this("",0); <mL%P`Jj
} C 8N%X2R
C1b*v&1{
z. 'Fv7
public FileAccessI(String sName,long nPos) throws IOException $; ?c?n+
{ %NNj9Bl<VV
oSavedFile = new RandomAccessFile(sName,"rw"); DKX/W+#a
this.nPos = nPos; W3)\co
oSavedFile.seek(nPos); 7%e1cI
} 6 jmrD
yE#g5V&
4sTMgBzw
public synchronized int write(byte[] b,int nStart,int nLen) !x>,N%~
{ 69>/@<
int n = -1; ymYBm:"
try{ :$Q`>k7A
oSavedFile.write(b,nStart,nLen); 1Pm4.C)
n = nLen; eH %Ja[
} GWhE8EDT
catch(IOException e) ?=<~^Lk
{ JnY$fs*"
e.printStackTrace (); FQ`(b3.
} }`9jH:q-Z
?ty>}.c t
>z(wf>2J
return n; yNBv-oe5
} <:">mV+/
e!GZSk
YxXqI
} 9UV9h_.x
U9 #w
=-w;zx
/* EkjgNEXq
**SiteInfoBean.java V43TO
*/ SrFx_n
package NetFox; |d[5l^6
dN< ,%}R
$E\^v^LW
public class SiteInfoBean { >TY6O.]
R::zuv
'S*k_vuN
private String sSiteURL; //Site's URL wjrG7*_Y4v
private String sFilePath; //Saved File's Path M%I@<~wl
private String sFileName; //Saved File's Name 7\Co`J>p2
private int nSplitter; //Count of Splited Downloading File ,[* ;UR
*$S#o#5
^*0'\/N&
public SiteInfoBean() <`)iA-Df;9
{//nSplitter的缺省值为5 L_Q S0_1
//default value of nSplitter is 5 (!3;X"l
this("","","",5); Hkege5{
} ##cnFQCB
&dr@6-xaq
i)MEK#{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {]^O:i"
{ /,2rjJ#b
sSiteURL= sURL; ;'0=T0\
sFilePath = sPath; D/CIA8h3
sFileName = sName; X%4Kj[I^
this.nSplitter = nSpiltter; [*Uu#9
~W-cGb3c
5!(?m~jJ
} ^`XCT
.XS9,/S
I-DXb M
public String getSSiteURL() \F{:5,Du)
{ :5b0np!
return sSiteURL; WF[bO7:
} F'FP0t!S
O6X"RsI}
2:SO_O4C
public void setSSiteURL(String value) v+xB7w
{ '#.#$8l
sSiteURL = value; "g0(I8
} 0 ipN8Pg+
PyBD
hr/o<#OW
public String getSFilePath() r|eZv<6
{ @kxel`,$e
return sFilePath; IeP WOpj3
} u5+|Su
*2e!M^K<
}r%X`i|
public void setSFilePath(String value) O"Q7Rx
{ sOpep
sFilePath = value; <%P2qgz5
} D+RiM~LH8
y(iY
h&;t.Gdf
public String getSFileName() nB5zNyY4
{ kXrlSaIc
return sFileName; KOhA)
} fuMJdAuY7d
Pw[g
2VoKr)
public void setSFileName(String value) _>yoX
{ Uz dc
sFileName = value; aG%,cQ1
} 'e!J06
; )Eo7?]-
Qdf=XG5
public int getNSplitter() S1S;F9F
{ A/}W&bnluD
return nSplitter; yZkyC'/
} S/tIwG ~e3
Ig6T g ?
\ck+GW4&
public void setNSplitter(int nCount) (Pbg[AY
{ t#i,1aHA
nSplitter = nCount; n6<V+G)T
} SUM4Di7
} #oni:]E!m
<RNJ>>0
T~:|!`
/* 4\M.6])_
**Utility.java EYX$pz(x;
*/ rXfy!rD_P_
package NetFox; p-SJ6Gg 9
]#2Y e7+
alq%H}FF
public class Utility { vVl; |
m P'^%TE
kwpK1R4zs
public Utility() BV#78,8(
{ [*:6oo98'
Pr ]Ka
U}k9 Py
} E&$yuW^z
Yz$3;
//线程睡眠 $%R$G`.KM
public static void sleep(int nSecond) &<RpWAk{
{ ~m^ #FJu
try{ 26vp1
Thread.sleep(nSecond); {gbn/{
} L;Z0`mdz
catch(Exception e) :Bu2,EL*O
{ d5 7i)=
e.printStackTrace (); <FI-zca
} ma'FRt
} '6y}ZE[
MY#
//日志 B=8Iu5m
public static void log(String sMsg) GVHV =E
{ Xce0~\_A
System.err.println(sMsg); >K9#3 4hP
} 4;`oUt'.
V'*~L\;pU
!`41q=r
public static void log(int sMsg) l>*"mh
{ y\dEk:\)
System.err.println(sMsg); %\|'%/"`2(
} :0& X^]\
} B/~%h|
~vlype3/EF
yeDsJ/L
/* W"^wnGa@a
**TestMethod.java a<}#HfC;'
*/ g<{xC_J
package NetFox; Mi'8 ~J
26T"XW'_
5%sE]Y#
public class TestMethod { 2MZCw^s>
{:@tQdM:i8
w2_bd7Wp<
public TestMethod() >h0-;
{ ///xx/weblogic60b2_win.exe M9zfT!-
try{ {pM?5"MMJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hW!)w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V,rq0xW
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3gd&i
fileFetch.start(); oy<WsbnS
} a:QDBS2Llv
catch(Exception e){e.printStackTrace ();} Uf}\p~;
C4TE-OM8
s(X;Eha
} P(F+f`T
|$5[(6T|
#9K-7je;j
public static void main(String[] args) ")=X4]D
{ P#=`2a#G
new TestMethod(); 8 r_>t2$
} Aq3}Ng
} 5^^XQ?"
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