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)); KM&bu='L^
} 0/~20KD{s
for(int i=0;i<nEndPos.length-1;i++) 0V!@*Z
{ |jw{7\+
nEndPos = nStartPos[i+1]; p8bAz
} f$I$A(0P
nEndPos[nEndPos.length-1] = nFileLength; y=k!>Y|E
} -q")qNt.
} ig}H7U2q@
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8HxtmFqG
//启动子线程 pY"&=I79tb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L8.u7(-#
for(int i=0;i<nStartPos.length;i++) zYZ^/7)
{ A` )A=L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qQ^bUpk0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FS^ie|8{D-
nStartPos,nEndPos,i); )>+J`NFa
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _Y8RP%
fileSplitterFetch.start(); 0m>?-/uDx
} o7^u@*"F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hr}pO"%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kgGMA 7Jy
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t}m"rMbt
nEndPos = " + nFileLength); @S#Ls="G
// fileSplitterFetch[nPos.length-1].start(); _2p D
K!A;C#b!
(+w.?l
//等待子线程结束 M?I^Od'8
//int count = 0; 96P3B}Dk
//是否结束while循环 ~z&Ho
boolean breakWhile = false; 9{Xh wi)z
|*te69RX
5 cz6\A&
while(!bStop) -l i71.M
{ 3uJ>:,~r
write_nPos(); =cKrp'
Utility.sleep(500); T.B}k`$
breakWhile = true; *R8qnvE\()
M7. fz"M
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for(int i=0;i<nStartPos.length;i++) ^ygh[.e,
{ RAY.]:}jr
if(!fileSplitterFetch.bDownOver) ,mm9X\ '
{ -h1FrDBt
breakWhile = false; ~9h/{$
break; ZB5u\NpcW
} v3Xt<I=4y
} vI1UFD D
if(breakWhile) 5nh:S0M6V
break; -gR }^D
qytH<UB
z3|)WS^
//count++; eW.[M?,
//if(count>4) {q^?Rw
// siteStop(); wW1>#F
} !dZpV~g0
<h[l)-86
u(bPdf@kz
System.err.println("文件下载结束！"); r>.^4Z@
} Y&y5^nG
catch(Exception e){e.printStackTrace ();} 8iKupaaOX
} 4M3{P
<F#/wU^9
f3M~2jbv'p
//获得文件长度 d`ESe'j:
public long getFileSize() 6j5?&)xJ
{ M%@=BT
int nFileLength = -1; ]YqeI*BX
try{ A_xUP9g@?
URL url = new URL(siteInfoBean.getSSiteURL()); Yt#e[CYnu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ," ~4l&
httpConnection.setRequestProperty("User-Agent","NetFox"); MsLQ'9%Au
t]PO4GA
UCDvN
int responseCode=httpConnection.getResponseCode(); u[yUUYe
if(responseCode>=400) ZW>?y$C+
{ {H$m1=S
processErrorCode(responseCode); BBUXoz
return -2; //-2 represent access is error i=DoK{`L
} \[F4ooe
.pd_SQ~
L7 f'
String sHeader; WzxDnd<B
(%^Bp\.02!
Lf}@v
for(int i=1;;i++) 5p5S_%R$e
{ ?Rg8u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); RBM(>lU:
//Utility.log(in.readLine()); G>H',iOI
sHeader=httpConnection.getHeaderFieldKey(i); ^"hsbk&Yu
if(sHeader!=null) "J(7fL$!
{ T.R(
if(sHeader.equals("Content-Length")) A"`(^#a
{ .f~x*@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ' *x?8-KP
break; FMBzTD
} M+q|z0U
} ~.'NG? %7P
else 1XvB,DhJ
break; #w<:H1,4
} jf'#2-
} BoMf#l.3B
catch(IOException e){e.printStackTrace ();} KXy|Si8w
catch(Exception e){e.printStackTrace ();} ob3Z I
`fUem,$)1F
<D!\"C
Utility.log(nFileLength); )s';m$
9azk(OL6
#7~i.8L
return nFileLength; cr_Q,*
} rBUdHd9
Ikbz3]F^V
=W Q_5}
//保存下载信息（文件指针位置） ?[K\X
private void write_nPos() USrg,A
{ QA3q9,C"
try{ 3%$nRP X
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0W1=9+c|X
output.writeInt(nStartPos.length); |(=`l
for(int i=0;i<nStartPos.length;i++) .5PcprE/
{ ixFuqPij
// output.writeLong(nPos); &bO0Rn1F
output.writeLong(fileSplitterFetch.nStartPos); xo46L\
output.writeLong(fileSplitterFetch.nEndPos); 38hAguZX
} Im\{b=vT
output.close(); c>*RQ4vE
} @'yD(ZMAz
catch(IOException e){e.printStackTrace ();} Y=#g_(4*
catch(Exception e){e.printStackTrace ();} s)~60c
} '[h|f
^KsiTVY
5YG?m{hyn_
//读取保存的下载信息（文件指针位置） ,.ln
private void read_nPos() Y:0SrB!\
{ z7H[\4A!>
try{ 3B<$6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j+c<0,Kj
int nCount = input.readInt(); h6dVT9
nStartPos = new long[nCount]; 3Hli^9&OX_
nEndPos = new long[nCount]; ^BruRgc+
for(int i=0;i<nStartPos.length;i++) MOIH%lpe
{ `<C/-Au
nStartPos = input.readLong(); B0^0d*8t|@
nEndPos = input.readLong(); i-b++R/WN
} 7xOrG],E
input.close(); 'RlPj0Cg
} JKkR963 O
catch(IOException e){e.printStackTrace ();} jI8qiZ);~
catch(Exception e){e.printStackTrace ();} yBPaGZ{f
} `.FvuwP
h>6'M
d2x|PpmH
private void processErrorCode(int nErrorCode) $Qv+*%c
{ ~8-Z=-
System.err.println("Error Code : " + nErrorCode); H?P:;1A]c
} C NNyz$
mGXjSWsd
w6fVZY4
//停止文件下载 tBp146`
public void siteStop() ^+JpI*,
{ }/yhwijg
bStop = true; - T,;Fr'
for(int i=0;i<nStartPos.length;i++) /hef3DV5I
fileSplitterFetch.splitterStop(); (=H%VXQH
Q`qHzb~%
O6^>L0'
} l!plw,PYC
} &sp7YkaW
//负责部分文件的抓取 6BihZ|H04
**FileSplitterFetch.java X;7gh>Q'4
*/ m"~^-mJ-
package NetFox; 9ZL3p!
Bf;dp`(/
8"4&IX
import java.io.*; '*5I5'[ X,
import java.net.*; LFCcV<~
oyBBW?m
$/aZ/O)F
public class FileSplitterFetch extends Thread { xq2{0q
^G+1nY4?J
x?:[:Hf
String sURL; //File URL }jM&GH1
long nStartPos; //File Snippet Start Position -bo5/`x
long nEndPos; //File Snippet End Position eU"!X9
int nThreadID; //Thread's ID jmbwV,@Q2
boolean bDownOver = false; //Downing is over (KDUX t.
boolean bStop = false; //Stop identical }@Ij}Ab>
FileAccessI fileAccessI = null; //File Access interface `/:ZB6
_-&\~w
~Cx07I_lf
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YK/?~p9:
{ |hjm^{!TpW
this.sURL = sURL; u=h:d+rq@
this.nStartPos = nStart; $ZD1_sJ.
this.nEndPos = nEnd; {$,e@nn
nThreadID = id; :A\8#]3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 njveZav
} r^mP'#
,YYyFMC7S
XO+^q9
public void run() ugEh}3
{ bwG2=
while(nStartPos < nEndPos && !bStop) ^[noGjy
{ 1D03Nbh|5
\`\& G-\
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try{ .eAN`-t;
URL url = new URL(sURL); QAigbSn]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G[1:<Vg8
httpConnection.setRequestProperty("User-Agent","NetFox"); N/QTf1$
String sProperty = "bytes="+nStartPos+"-"; Z~o6%_xe
httpConnection.setRequestProperty("RANGE",sProperty); \WG6\Zg0A
Utility.log(sProperty); cv(9v =](
C9[Jr)QX
,y}?Z8?63
InputStream input = httpConnection.getInputStream(); 7q<2k_3<
//logResponseHead(httpConnection); &13qlc6
@vdBA hXk
'c3P3`o,;
byte[] b = new byte[1024]; Vu '3%~
int nRead; TT3GFP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \kU0D
{ /s"mqBXCG
nStartPos += fileAccessI.write(b,0,nRead); ;Bk?,g
//if(nThreadID == 1) rmS.$h@7 m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n`Pwo&
} HV-c DL
eAh~`
?!=yp#
Utility.log("Thread " + nThreadID + " is over!"); :DTKZ9>2D
bDownOver = true; ?El8:zt?|
//nPos = fileAccessI.write (b,0,nRead); _FXvJ}~m
} f]MKNX
catch(Exception e){e.printStackTrace ();} ,U+y)w]ar
} /EF0~iy
} U|QLc
4.:2!Q
a>x3UVf_
//打印回应的头信息 F+mn d,3
public void logResponseHead(HttpURLConnection con) hI.@!$~=
{ +;uP) "Q/L
for(int i=1;;i++) e^)+bmh
{ N t]YhO
String header=con.getHeaderFieldKey(i); 8yEN)RqI
if(header!=null) W($}G_j[B1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4RCD<7
Utility.log(header+" : "+con.getHeaderField(header)); o$]wd*+
else (_h<<`@B
break; C7#ji"t
} b^[Ab:`}[V
} oc+TsVt
fgrflW$
wVU.j$+_#
public void splitterStop() K.s\xA5`_
{ EXDZehLD<]
bStop = true; .)L%ANf
} \c1u$'|v
5VD(fW[OW]
cPD&xVwq>
} IE7%u92
}71a3EUK
\ng!qN
/* M0Y#=u.
**FileAccess.java +XV7W=
*//文件访问(定位，写) Y+vG]?D
package NetFox; Dv~W!T i
import java.io.*; 0LEJnl
84g$V}mp
a6\0XVU
public class FileAccessI implements Serializable{ N 4Kj)E@
2d),*Cvf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nn[OC=cDN
RandomAccessFile oSavedFile; ?=zF]J:G1w
long nPos; A[W3.$s
c>I(6$
%d-|C.
public FileAccessI() throws IOException L'(ei7Z
{ 7i-G5%w7
this("",0); \ZN>7?Vs
} ^pgVU&-~]/
n~ w.\939@
}7?n\I+n"
public FileAccessI(String sName,long nPos) throws IOException sz;B-1^6
{ P1cI]rriW
oSavedFile = new RandomAccessFile(sName,"rw"); u!4i+7}
this.nPos = nPos; ViZ Tl~
oSavedFile.seek(nPos); xF4S
} VcI'+IoR?
P){b"`f
$?x;?wS0V
public synchronized int write(byte[] b,int nStart,int nLen) -|F(qf
{ s{g^K#BoFi
int n = -1; R( 2,1f=d
try{ vwF#;jj\
oSavedFile.write(b,nStart,nLen); O_vCZW a3
n = nLen; KHnq%#
} tqok.h
catch(IOException e) f/"?(7F
{ }Pi}? 41!
e.printStackTrace (); M N-j$-y}
} iO$Z?Dyg9
95cIdF 6m
c+dmA(JC
return n; =:neGqd\_E
} >)`yG'[
#bIUO2yVo
%?2:1o
} <!qN<#$y
O+f'Ql
{HF,F=W
/* Y\7WCaSgi
**SiteInfoBean.java LIah'6qR
*/ ;@5N
package NetFox; XC*!=h*
_8QHx;}
U5[,UrC
public class SiteInfoBean { 4hl`~&yDf
z4!Y9
FaA'%P@
private String sSiteURL; //Site's URL n]nb+_-97
private String sFilePath; //Saved File's Path Z'Uc}M'U
private String sFileName; //Saved File's Name Fu%D2%V$/
private int nSplitter; //Count of Splited Downloading File i!yu%>:M
VbU*&{j
Nbyc,a[o
public SiteInfoBean() :`Sd5b>
{//nSplitter的缺省值为5 +HAd=DU
//default value of nSplitter is 5 [B_(,/?
this("","","",5); &$H7vdWNy
} XEX-NE"]
7Be\^%
I_.Jo `lK~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qI=j>x
{ w^EUBRI-
sSiteURL= sURL; =6YffXa_s
sFilePath = sPath; w *Txc}
sFileName = sName; [}*xxy
this.nSplitter = nSpiltter; 0?80V'
;NoD4*
fkHCfcU
} &YpWfY&V
wJ>.I<F6B
^J-"8%
public String getSSiteURL() PSB@yV <
{ =@\Li)Y
return sSiteURL; nqv#?>Z^OT
} e0e3b]
fU^6h`t
`mp3ORR;$
public void setSSiteURL(String value) Y I?4e7Z+
{ dN)@/R^E;
sSiteURL = value; 8GKqPS+
} du5|/
u27*-X 5
BpR#3CfW
public String getSFilePath() g[D`.
{ }"\jB
return sFilePath; &Jf67\N
} \L5h&
eb*w$|y6"
n38l!m(.
public void setSFilePath(String value) Su>UXuNdE#
{ D//uwom
sFilePath = value; gZ 6Hj62D
} ,!I'0x1OR
r>kDRIHB
i-W!`1LH'
public String getSFileName() 6$'0^Ftm'
{ oc0z1u
return sFileName; LVAnZ'h/|
} iJ%`ym4Y
hcrx(oJ5
:ySQ[AJ"
public void setSFileName(String value) F7N4qq1
{ -guVl4 V
sFileName = value; ;e#bl1%#
} I]jK]]@
LQ'VhNU
UEh-k"
public int getNSplitter() *<IQ+oat,a
{ U66}nN9
return nSplitter; Y)KO*40c
} R1/87eB
B`;DAsmT
_ ATIV
public void setNSplitter(int nCount) ?5Ub&{
{ #fkOm Y7X
nSplitter = nCount; ~'3hK4
} !1{kG%B=
} ZNjqH[
8pE0ANbq
MoP,a9p
/* j|c6BdROl
**Utility.java 6JZ$;x{j
*/ "PtOe[Xk
package NetFox; 9xZ?}S:d
@K}8zMmW#
h"849c;C.
public class Utility { ?D]qw4J
o<f|jGY0
otSF8[
public Utility() {S=gXIh(y
{ $0wF4$)
|vf /M|
t1%<l
} Q"QL#<N
vp#r:+=
//线程睡眠 ^{(i;IVG
public static void sleep(int nSecond) 5^GFN*poig
{ VQ]MJjvb
try{ .0H!B#9
Thread.sleep(nSecond); F)Qj<6
} O,A}p:Pgs
catch(Exception e) l0g`;BI_
{ Da WzQe=
e.printStackTrace (); /c9%|<O%
} Vo-]&u&cr
} i<]Y0_?s
#&jr9RB
//日志 9'S~zG%{
public static void log(String sMsg) Uk0]A
{ dtT2h>h9
System.err.println(sMsg); DHO+JtO
} A_\ZY0Xt
sJ(q.FRM'
A[.5Bi
public static void log(int sMsg) A1u|L^
{ ;N/=)m
System.err.println(sMsg); !s:v UY58
} H%:u9DlEK/
} Z<t(h=?
fqgm`4>
6opubI<
/* <0hJo=6a8
**TestMethod.java uY5Gn.Y
*/ S.kFs{;1x
package NetFox; dPfDPb
N;BS;W5I
raPUx_$PH
public class TestMethod { 9&t!U+
;"@FLq(n
H%\\-Z$#
public TestMethod() D@yuldx'/
{ ///xx/weblogic60b2_win.exe 8*V8B=q}K
try{ uVBMI.&w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l8_TeO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^"Nsb&
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1q[vNP=g&
fileFetch.start(); +^6v%z
} :i24@V~){
catch(Exception e){e.printStackTrace ();} P=jbr"5Q:
U2(|/M+
ZdJer6:Z}
} c*"TmDY
s3LR6Z7;i
J&IFn/JK$
public static void main(String[] args) G3G"SJ np
{ }813.U
new TestMethod(); 5E#koy7 $s
} fWBI}~e
} u+RdC;_
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