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)); D`hg+64}
} 8\BYm|%aa
for(int i=0;i<nEndPos.length-1;i++) _BPp=(|
{ ,wB)hp
nEndPos = nStartPos[i+1]; L 4Sa,ZL
} @E%fAC
nEndPos[nEndPos.length-1] = nFileLength; -Zfq:Kr
} ~aL&,0
} +T8]R7b9
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//启动子线程 [{-5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wCw_aXqq
for(int i=0;i<nStartPos.length;i++) ^<`uyY))Q
{ 5]F4.sa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), HzZ.q2Zz%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kB]?95>Wx
nStartPos,nEndPos,i); `^'0__<M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3!Cab/T
fileSplitterFetch.start(); &2//\Qz
} }@<Ru
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L',7@W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TFYp=xK(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sL4+O P-
nEndPos = " + nFileLength); flS_rY5
// fileSplitterFetch[nPos.length-1].start(); :BVYS|%
J"?jaa2~
7z9[\]tt
//等待子线程结束 V\P .uOI
//int count = 0; 5z@QAQ
//是否结束while循环 }c,:uN
boolean breakWhile = false; ;wF)!d
~=/.ZUQNX
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while(!bStop) ]>oI3&6s
{ v])R6-T-
write_nPos(); JVq`v#8
Utility.sleep(500); hO..j
breakWhile = true; B/gI~e0
:r+F95e
J 7]LMw7
for(int i=0;i<nStartPos.length;i++) K?gO]T{6
{ #|;;>YnZ
if(!fileSplitterFetch.bDownOver) y2:Bv2}
{ Igb%bO_
breakWhile = false; ^^kL.C Ym
break; Dy^A??A[E}
} .v[!_bk8C
} (Z#j^}G_l
if(breakWhile) {9|S,<9
break; Q'c[yu
/[=U$=uH
m?]= =9
//count++; '=1@,Skj-
//if(count>4) uYMH5Om+i
// siteStop(); =aCd,4B}
} 4ad-'
Tk:%YS;=
~NBlJULS
System.err.println("文件下载结束！"); Oz4yUR
} u=&$Z
catch(Exception e){e.printStackTrace ();} =:(<lKf,<F
} Azag*M?
G[s/M\l
n*y@3.
//获得文件长度 WS2@; 8.N
public long getFileSize() UjcKvF
{ z]n&,q,5g
int nFileLength = -1; 9B2`FJ
try{ s,]z6L0
URL url = new URL(siteInfoBean.getSSiteURL()); +9]CGYj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /A>1TPb09"
httpConnection.setRequestProperty("User-Agent","NetFox"); sp&g
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;-d2~1$
int responseCode=httpConnection.getResponseCode(); z.0!FUd
if(responseCode>=400) ydf;g5OZ
{ cBDOA<]r,
processErrorCode(responseCode); != u S
return -2; //-2 represent access is error e*hCf5=-
} 1SY3
3y]rhB
+Q&CIo
String sHeader; H;Cv]-
k*o>ZpjNH
g<5G#
for(int i=1;;i++) QI{<q<
{ R\:t 73
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <:I]0|[
//Utility.log(in.readLine()); 8npjQ;%4>
sHeader=httpConnection.getHeaderFieldKey(i); AS]jJc^
if(sHeader!=null) L0>w|LpRc
{ 0=c:O
if(sHeader.equals("Content-Length")) :my@Oxx4@
{ k{ibD5B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0]MI*s>&
break; p5 )+R/
} n%I9l]
} x(bM
else B6"pw0
break; )`-vN^1S-
} of>}fJ_p
} H'wh0K(
catch(IOException e){e.printStackTrace ();} jWJ/gv~ $
catch(Exception e){e.printStackTrace ();} u,),kj<
k=JT%
F>co#
Utility.log(nFileLength); (*dJ
HQtUNtZ
o!}/& '(
return nFileLength; {pM3f
} Uiu9o]n
V SUz+W
2~q(?wY
//保存下载信息（文件指针位置） R4Si{J*O
private void write_nPos() O>sE~~g]?
{ Ll'!aar,
try{ \'Ewn8Qv8
output = new DataOutputStream(new FileOutputStream(tmpFile)); iWMgU:T
output.writeInt(nStartPos.length); dX;G[\
for(int i=0;i<nStartPos.length;i++) Jej-b<HmQ
{ q<!KtI4
// output.writeLong(nPos); 2-.%WhE/
output.writeLong(fileSplitterFetch.nStartPos); }*3#*y "
output.writeLong(fileSplitterFetch.nEndPos); wVY;)1?
} "U%jG`q
output.close(); 7T@"2WYat
} ~AG."<}
catch(IOException e){e.printStackTrace ();} kU$M 8J.
catch(Exception e){e.printStackTrace ();} ljRR{HOl
} v}-jls
{GM8}M~D&
SWM6+i p
//读取保存的下载信息（文件指针位置） ]#Q'~X W
private void read_nPos() FAP1Bm
{ Ax"I$6n>
try{ h2#S ?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W(&9S[2
int nCount = input.readInt(); rkC6-9V
nStartPos = new long[nCount]; P g1EE"N@
nEndPos = new long[nCount]; ]z_C7Y"4BR
for(int i=0;i<nStartPos.length;i++) {_5PN^J
{ DC8,ns]!y
nStartPos = input.readLong(); >5}jM5$
nEndPos = input.readLong(); Dt8wd,B
} C*fSPdg?
input.close(); I\peO/w
} |? l6S
catch(IOException e){e.printStackTrace ();} n*U+jc
catch(Exception e){e.printStackTrace ();} _I}rQfPJ
} xtP=/B/
5Pu F]5
hg=BXe4:
private void processErrorCode(int nErrorCode) 1O]27"9
{ uSi/|
System.err.println("Error Code : " + nErrorCode); Je~d/,^WU
} ~ E|L4E
MX#MDA-4
Z`lCS o;
//停止文件下载 *^5..0du
public void siteStop() %Jc>joU
{ 4yu ^cix(
bStop = true; Q8r 7
for(int i=0;i<nStartPos.length;i++) |xQq+e}l<
fileSplitterFetch.splitterStop(); "3Z<V8xB
6X.lncE@p
!rMl" Y[
} =#c?g Wb56
} 34P5[j!h
//负责部分文件的抓取 !^*I?9P
**FileSplitterFetch.java <r{ )*]#l
*/ k(v8zDq*
package NetFox; ET7(n0*P}]
4?a!6
2!^[x~t
import java.io.*; `X7ns?
import java.net.*; (iZE}qf7g
X@ Gm:6
I=3e@aTZ,
public class FileSplitterFetch extends Thread { uY;2tZldf=
{%;KkC8=R
Ck0R%|
String sURL; //File URL Z 7M%}V%
long nStartPos; //File Snippet Start Position $&|*v1rH
long nEndPos; //File Snippet End Position {!C';^
int nThreadID; //Thread's ID boR&'yX
boolean bDownOver = false; //Downing is over tT;=l[7%
boolean bStop = false; //Stop identical p8q9:Tz
FileAccessI fileAccessI = null; //File Access interface $N#f)8v
' 1aU0<
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "A_WU|
{ >cPB:kD'
this.sURL = sURL; O/(qi8En
this.nStartPos = nStart; w*Gv#B9G
this.nEndPos = nEnd; 3 TN?yP)
nThreadID = id; >Rbgg1^]5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *YFe
} r4~Bn7j2
5M{DJ/q
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public void run() eiF!yk?2
{ *eO@<j?
while(nStartPos < nEndPos && !bStop) &!{wbm@
{ ~OXC6z
U$`)|/8
>_biiW~x:
try{ qK4E:dD
URL url = new URL(sURL); %8T:rS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {daNw>TH
httpConnection.setRequestProperty("User-Agent","NetFox"); h !~u9
String sProperty = "bytes="+nStartPos+"-"; 6SMGXy*]^
httpConnection.setRequestProperty("RANGE",sProperty); e_wz8]K)n
Utility.log(sProperty); }V3p <
Qj? G KO
IA|V^Wmt;
InputStream input = httpConnection.getInputStream(); pX]*&[X?
//logResponseHead(httpConnection); {37DrSOa
*a@pZI0'
.Jz$)R
byte[] b = new byte[1024]; "9-duDg
int nRead; Y'n TyH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HB4Hz0Fa
{ [ed%"f
nStartPos += fileAccessI.write(b,0,nRead); %TUljX K}
//if(nThreadID == 1) ! G%LYHx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8Us5Oi
} k})Ag7c
9BGPq)#
}B_n}<tjD
Utility.log("Thread " + nThreadID + " is over!"); ~$f+]7
bDownOver = true; (9BjZ&ej
//nPos = fileAccessI.write (b,0,nRead); ?J+[|*'yK
} u!%]?MSc
catch(Exception e){e.printStackTrace ();} I'o9.B8%#
} S zOB{
} :rb<mg[
P sD+?
ML0o:8Bd\
//打印回应的头信息 [S":~3^B6
public void logResponseHead(HttpURLConnection con) d> Y9g
{ !5 %c`4
for(int i=1;;i++) _p7c<$;
{ p[&'*"o!/
String header=con.getHeaderFieldKey(i); IQdiVj
if(header!=null) D<}KTyG]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Cdiu*#f
Utility.log(header+" : "+con.getHeaderField(header)); m$A|Sx&sG$
else f6^H Q1SSt
break; (I,PC*:
} j0o_``
} 8;.WX
g!D?Yj4
Bfaj4i;_
public void splitterStop() zp"sM z]
{ kwK<?\D
bStop = true; R#Id"O
} a)4.[+wnRf
bWwc2##7jo
A[;R_
} F[115/
;hmy7M1%
fT/;TK>z>
/* 2M= gpy
**FileAccess.java ,/|"0$p2x
*//文件访问(定位，写) Q9X_aB0
package NetFox; GKtG#jZ&
import java.io.*; $~50M5&K#
Oh~JyrZy
W:b8m Xx
public class FileAccessI implements Serializable{ # o)a`,f
[Pby d
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pb}QP
RandomAccessFile oSavedFile; e!ar:>T
long nPos; vz,l{0v
.'p_j(uv
+l2{EiQw
public FileAccessI() throws IOException 1>4'YMdZi
{ S!2M?}LU
this("",0); *xM4nUu<~
} CP'?Om2
br>"96A1l
E*.D_F
public FileAccessI(String sName,long nPos) throws IOException _%;$y5]v
{ OYgD9T.8^
oSavedFile = new RandomAccessFile(sName,"rw"); 3F[z]B
this.nPos = nPos; 1N1MD@C?P
oSavedFile.seek(nPos); 4{X5ZS?CkI
} 5)2lZ(5.A#
:Y0*P
U=QV^I Qm
public synchronized int write(byte[] b,int nStart,int nLen) =5oE|F%
{ ,S2D/Y^>
int n = -1; H{E223
try{ d5\w'@Di
oSavedFile.write(b,nStart,nLen); c@~\ FUr
n = nLen; W7S`+Pq
} BE:HO^-.1
catch(IOException e) ; GRSe
{ #)tt}GX
e.printStackTrace (); 7*M+bZ`x
} ckBcwIXlP&
8U*}D~%!
siZw-.
return n; cMsm[D{b
} cc*A/lD
%/CCh;N#
't{~#0d=
} 1xar L))
e54wAypPOl
BYyR-m
/* p./zW )7+
**SiteInfoBean.java x/#*M
*/ >pbO\=j]X
package NetFox; LS+ _y<v=
mMS%O]m,|
kTT!gZP$
public class SiteInfoBean { /G9wW+1
7;) T;X
'mp@!@_
private String sSiteURL; //Site's URL kKr7c4q
private String sFilePath; //Saved File's Path 'mXf8
private String sFileName; //Saved File's Name A/|To!R
private int nSplitter; //Count of Splited Downloading File c]v$C&FX
(xBS~}e
(Gp/^[.%&
public SiteInfoBean() TIbiw
{//nSplitter的缺省值为5 t4/d1qW0
//default value of nSplitter is 5 3J32W@}.K
this("","","",5); Ya<S/9c
} G<#9`
}Ry:})
S4aN7.'Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [ p$f)'
{ $d3al%Uo
sSiteURL= sURL; GF*8(2h2
sFilePath = sPath; X9K@mX
sFileName = sName; C}<j8a?
this.nSplitter = nSpiltter; 3vfm$sx@
uPr'by
@#hd8_)A.
} I} m\(TS-"
W,9. z%
Q0K2md_%x
public String getSSiteURL() S}f3b N
{ ig5 d-A
return sSiteURL; :hr% 6K7
} 3gV 17a
XZD9vFj1Z
zePVB-@u
public void setSSiteURL(String value) 2a|9D\
{ As }:~Jy|
sSiteURL = value; FNL[6.!PV
} ?{[ISk)
M{cF14cQ
d]{wZ#x
public String getSFilePath() B9^@d
{ D!Pv`wm
return sFilePath; C62:G+W&o
} &TJMopVn
X|zQZ<CO
Hof@,w
public void setSFilePath(String value) :,Z'/e0&
{ >-J%=P
sFilePath = value; _;L%? -2c
} }Q&zYC]d
h\| ~Q.kG
^YG'p?r.s
public String getSFileName() (k/[/`3ST
{ U l8G R
return sFileName; #JMww
} kDbDG,O
m}ZkNWH
E[q:65xl
public void setSFileName(String value) E-gI'qG\(
{ {w:*t)@j
sFileName = value; U4)x"s[CP
} :0@R(ct;>
/e5' YVP
cq:<,Ke
public int getNSplitter() zG-pqE6
{ fy9mS
return nSplitter; 011 N
} DQ%bcXs
Q+@/.qJ
_=0%3Sh
public void setNSplitter(int nCount) zwJB.4@
{ (=&z:-52V
nSplitter = nCount; dpG l
} >=Bl/0YH
} lw+Y_;
ASGV3r(
6d~[j<@2
/* 8xf]zM"Q
**Utility.java ^97u0K3$
*/ t&|M@Ouet
package NetFox; QguRU|y
9dS<^E(ZF
HGycF|]2
public class Utility { efzS]1Jpz
X%(1C,C(
a|}v?z\
public Utility() L#huTKX}
{ U$,-F**
B:mtl?69g
h]6m+oPW
} z`]sWi F0
Oq3aboAt
//线程睡眠 D[jPz0
public static void sleep(int nSecond) n[[2<s*YJ
{ .)(5F45Wg
try{ Rtywi}VV2
Thread.sleep(nSecond); Gx)U~L$B
} =;L44.,g
catch(Exception e) ,I|3.4z
{ bi{G :xt
e.printStackTrace (); o|7ztpr
} ~K$dQb])
} TmviYP gb
(V(8E%<c
//日志 mETGYkPUa
public static void log(String sMsg) C[ma!he
{ hqDnmzG
System.err.println(sMsg); Mi^/`1
} m>FP&~2
4De2miq
xaN[ru@
public static void log(int sMsg) D( \c?X"
{ kR0/jEz C
System.err.println(sMsg); }[;{@Zn
} R1cOUV,y[/
} )L+>^cJI<
J;DTh ]z?:
bVxbQ$
/* !kW~s_gUb*
**TestMethod.java ;$.^
*/ F[q)ME+`)
package NetFox; N({0"7
-3GlpC22
q2+`a;_S
public class TestMethod { MA1y@
sq rY<@%
S7v# `#
public TestMethod() }'`iJb\
{ ///xx/weblogic60b2_win.exe Mg~62u
try{ V}aZ}m{J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %\f<N1~*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `RlMfd
SiteFileFetch fileFetch = new SiteFileFetch(bean); @f!r"P]
fileFetch.start(); ]mR!-Fqj
} mI>=S
catch(Exception e){e.printStackTrace ();} oUd R,;h9
)BeBxo7lv
-|DBO0q
} %n{ue9
W0+m A
ooA%/
public static void main(String[] args) B<{Yj}..
{ e;8nujdG"
new TestMethod(); (jI_Dk;
} {Gvv^.H7
} IkP; i_|
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