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)); 6BY(Y(z
} dhCrcYn
for(int i=0;i<nEndPos.length-1;i++) m> YjV>5
{ k8S`44vj
nEndPos = nStartPos[i+1]; ypy
} =}OcMM`f
nEndPos[nEndPos.length-1] = nFileLength; 3T)_(SM"
} h}n?4B~Gi
} ["~T)d'
+]$c+!khj
<HXzcWQ$
//启动子线程 4%"Df1U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4V7=VZ,@3
for(int i=0;i<nStartPos.length;i++) iw=~j
{ l<8+>W`_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,\'E<O2T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), y.,li<
nStartPos,nEndPos,i); XQI!G_\+C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &S9O:>=*
fileSplitterFetch.start(); pp1kcrE\M
} \}EJtux q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .:9XpKbt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VxqoE]Dh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +&*Ybbhb
nEndPos = " + nFileLength); D^<5gRK?
// fileSplitterFetch[nPos.length-1].start(); I/k/5
|h%0)_
myqQqVW
//等待子线程结束 v:zKn[;o
//int count = 0; mBON>Z[4.
//是否结束while循环 XgPZcOzYB
boolean breakWhile = false; Rxl/)H[Lc"
6vr8rJ-
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while(!bStop) Tr$37suF
{ 3hPp1wZd
write_nPos(); -Zfq:Kr
Utility.sleep(500); `6FH@" |I
breakWhile = true; f=kt0
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for(int i=0;i<nStartPos.length;i++) (RafidiH
{ abtYa
if(!fileSplitterFetch.bDownOver) byN4?3F
{ H|I.h{:
breakWhile = false; n<3{QqF
break; DP08$Iq
} jm&PGZ#n=R
} J5L[)Gd)D
if(breakWhile) #]}]ZE
break; B]wfDUG
FKU)# Eo
&.chqP(|
//count++; 39oI &D>8
//if(count>4) `(&GLv[i^2
// siteStop(); 2bt).gGm
} +O?`uV
_qU;`Q
~ea&1+Z[3
System.err.println("文件下载结束！"); jUCDf-_ m
} evro]&N{
catch(Exception e){e.printStackTrace ();} iXD=_^^o .
} VdE$ig@
M2piJ'T4u
dhmrh5Uf
//获得文件长度 \(`,z}Ht _
public long getFileSize() k!ac_}&NNv
{ sUN9E4
int nFileLength = -1; @jT=SFf
try{ T&u25"QOf
URL url = new URL(siteInfoBean.getSSiteURL()); Y8Z-m (OQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?V$@2vBVX4
httpConnection.setRequestProperty("User-Agent","NetFox"); H5/w!y@
J 7]LMw7
K?gO]T{6
int responseCode=httpConnection.getResponseCode(); #|;;>YnZ
if(responseCode>=400) 22gh,e2o
{ 6bd{3@
processErrorCode(responseCode); N7#,x9+E
return -2; //-2 represent access is error yq,%<%+
} IvJ5J&!
Cg&:+
~09kIO)
String sHeader; a~A"uLBR
g<s;uRA4O9
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for(int i=1;;i++) Dac ,yW
{ >+F +"NAN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9ve)+Lk
//Utility.log(in.readLine()); b0h>q$b
sHeader=httpConnection.getHeaderFieldKey(i); `V=F>s$W
if(sHeader!=null) Oi$$vjs2
{ R0bWI`$Z
if(sHeader.equals("Content-Length")) ^9`~-w
{ -MuKeCgi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~5 e 1&
break; q|S,^0cU
} .(X!*J]G
} 2PQY+[jx
else #p/'5lA&j
break; t[%ELHV
} 9}#9i^%}
} &n9srs
catch(IOException e){e.printStackTrace ();} {IT;g9x
catch(Exception e){e.printStackTrace ();} 31{)~8
VCc57Bo
iuHs.k<z
Utility.log(nFileLength); V u1|5
$##LSTA
YfJQ]tt1
return nFileLength; "xp>Vj
} *%jd>e7d
Na{&aqdz
Xf*}V+&WN
//保存下载信息（文件指针位置） *@[N~:z/
private void write_nPos() e<-^
{ R~d{Yv
try{ w_9[y
output = new DataOutputStream(new FileOutputStream(tmpFile)); +YnQOh%v0s
output.writeInt(nStartPos.length); c2Up<#t
for(int i=0;i<nStartPos.length;i++) U'Fc\M5l/l
{ &OP =O*B
// output.writeLong(nPos); M =6
output.writeLong(fileSplitterFetch.nStartPos); E9#.!re|^
output.writeLong(fileSplitterFetch.nEndPos); MVZ9x%
} z:p9&mi
output.close(); U?(+ {4l
} ^|lG9z%Foy
catch(IOException e){e.printStackTrace ();} 6M X4h
catch(Exception e){e.printStackTrace ();} ~[`*)(4E
} .MI 5?]_
a 8.Xy])!
[*v-i%U}
//读取保存的下载信息（文件指针位置） 0=c:O
private void read_nPos() ^9 {r2d&c
{ ZY-mUg
try{ V(<(k,8=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .tt=\R
int nCount = input.readInt(); Su/}OS\R
nStartPos = new long[nCount]; CpdQ]Ai[
nEndPos = new long[nCount]; Sn-D|Z
for(int i=0;i<nStartPos.length;i++) ZA8FX
{ GL8 N!,
nStartPos = input.readLong(); B6"pw0
nEndPos = input.readLong(); )`-vN^1S-
} p^i]{"sjbU
input.close(); *kKdL
} LAPCL&Z
catch(IOException e){e.printStackTrace ();} XYHVw)
catch(Exception e){e.printStackTrace ();} *&vi3#ur
} V|G[j\]E<
6uubkt
gfmaO]
private void processErrorCode(int nErrorCode) XaR(~2
{ g@IYD
System.err.println("Error Code : " + nErrorCode); wm s@1~I
} rKr2 K'
egy#8U)Z
OvtiFN^s'
//停止文件下载 =%R|@lz_x
public void siteStop() 4Vrx9 sA1
{ kH>^3(Q\
bStop = true; +d/^0^(D\5
for(int i=0;i<nStartPos.length;i++) MD=VR(P?eq
fileSplitterFetch.splitterStop(); kG|pM54:^
HK!Vd_&9,
Y~uqKb;A
} v9+1[Y";
} ~7"6Y]
//负责部分文件的抓取 ~#V1Gunq
**FileSplitterFetch.java ts~$'^K[-
*/ iMXK_O%
package NetFox; AAld2"r
IX y $
qD/FxR-!
import java.io.*; X]AbBzy
import java.net.*; } P/ x@N
DU.[Sp
R22P ol
public class FileSplitterFetch extends Thread { %QKRl5RM-
"f3KE=cUm
?ne!LDlE|
String sURL; //File URL 7COJ.rA
long nStartPos; //File Snippet Start Position Mv^G%zg2
long nEndPos; //File Snippet End Position i=8){GX4
int nThreadID; //Thread's ID V0'_PR@;
boolean bDownOver = false; //Downing is over LTt|"D
boolean bStop = false; //Stop identical 1$adX
FileAccessI fileAccessI = null; //File Access interface sKuPV
7{:g|dX
5N4[hQrVJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B^sHFc""V
{ Zfn390_
this.sURL = sURL; gC}D0l[
this.nStartPos = nStart; 'P5|[du+
this.nEndPos = nEnd; kFF)6z:2
nThreadID = id; W_z?t;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^7&0Pm
} M/^kita
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{ei,>5K
public void run() w=S7zzL)
{ (Jb[_d*
while(nStartPos < nEndPos && !bStop) GDj ViAFm
{ {|Pz9a-:
KV$J*B Y
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try{ ^XQr`CqI
URL url = new URL(sURL); V`z2F'vT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H<6/i@ly
httpConnection.setRequestProperty("User-Agent","NetFox"); ,0R2k `m!
String sProperty = "bytes="+nStartPos+"-"; W!G2$e6
httpConnection.setRequestProperty("RANGE",sProperty); pr(16P
Utility.log(sProperty); CF k^(V"
N}2xt)JZz
Fl^}tC
InputStream input = httpConnection.getInputStream(); Y8yRQzu
//logResponseHead(httpConnection); * 5Y.9g3)Q
KU}HVM{
2!^[x~t
byte[] b = new byte[1024]; `X7ns?
int nRead; M1f^Lx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) X@ Gm:6
{ I=3e@aTZ,
nStartPos += fileAccessI.write(b,0,nRead); ;qF#!Kb5
//if(nThreadID == 1) (~>L \]!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ck0R%|
} `y!6(xI
_,2P4
Nl^{w'X0h
Utility.log("Thread " + nThreadID + " is over!"); #j{!&4M
bDownOver = true; L('G1J}
//nPos = fileAccessI.write (b,0,nRead); ,~_)Cf#CB
} F+@E6I'g
catch(Exception e){e.printStackTrace ();} G;%Pf9o26
} 6T_Mk0Sf+
} buhn~ c
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@9QtK69
//打印回应的头信息 {A2SG#}
public void logResponseHead(HttpURLConnection con) 6*,8 H&
{ _~`\TS8
for(int i=1;;i++) ]<;m;/H
{ Svmyg]
String header=con.getHeaderFieldKey(i); b:}`O!UBw
if(header!=null) ZTx~+'(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Hop$w
Utility.log(header+" : "+con.getHeaderField(header)); <4W"ne28
else <M1XG7_I
break; g&*pk5V>
} 2dr[0tE
} y/m^G=Q6g#
|Aw(v6
,Jf)A/_
public void splitterStop() d/GP.d
{ x hFQjV?V
bStop = true; *My?l75
} 3d.JV'C'c
C'hI{4@P
_|ucC$*
} )-9G*3
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Xz=MM0o
/* w49Wl>M
**FileAccess.java 8E/]k\
*//文件访问(定位，写) SrN;S kS
package NetFox; Es kh=xA {
import java.io.*; h@72eav3+
G^F4c{3c~
l|ZwZix
public class FileAccessI implements Serializable{ -0Q:0wU
0:**uion
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :XMw="u=
RandomAccessFile oSavedFile; <,l&),
long nPos; | %af}# FQ
q0 :Lb
\K)"@gdW
public FileAccessI() throws IOException I~qS6#%r
{ Fz16m7.
this("",0); 8=7u,t
} 2;4Of~
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]do0{I%\eq
public FileAccessI(String sName,long nPos) throws IOException ";j/k9DE
{ 56*}}B$?
oSavedFile = new RandomAccessFile(sName,"rw"); >Ge&v'~_|
this.nPos = nPos; aT F}
oSavedFile.seek(nPos); QzIK580%t
} }Xs=x6Mj
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UUv&X+Y
public synchronized int write(byte[] b,int nStart,int nLen) Nora<
{ IR>^U
int n = -1; 2"nd(+QH
try{ 'r4 j;Jn
oSavedFile.write(b,nStart,nLen); K3?7Hndf2
n = nLen; r,i^-jv;
} >E?626*
catch(IOException e) W)V"QrFK
{ [Y*p I&f
e.printStackTrace (); d>NElug
} r M'snW)
4NwGP^n
Y{@ez
return n; &^1DNpUZ
} ~LHG
Qm,|'y:Tg
Rs8`M8(4%
} Ol"p^sqwj
vN7a)s
aD3'gc,l
/* S8<O$^L^
**SiteInfoBean.java R{@WlkG}
*/ hti)<#f
package NetFox; "VkraB.i
$t-HJ<!
.BlGV2@^#
public class SiteInfoBean { T\b e(@r
s9qr;}U.`
j;1X-
private String sSiteURL; //Site's URL kwZ8q-0
private String sFilePath; //Saved File's Path |>GtClL
private String sFileName; //Saved File's Name 3Zdkf]Gh
private int nSplitter; //Count of Splited Downloading File ;-@^G 3C:
w^NE`4 -
`>'E4z]-_
public SiteInfoBean() -GCGxC2u
{//nSplitter的缺省值为5 N(]6pG=
//default value of nSplitter is 5 LwkZ(Tt
this("","","",5); 4'?kyTO~
} Fc7mAV=
@xB"9s
kfg9l?R$I<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D>~z{H%\
{ 4&r^mGs,
sSiteURL= sURL; o{?s\)aBa
sFilePath = sPath; DK&J"0jz,
sFileName = sName; uOs 8|pj,
this.nSplitter = nSpiltter; 0~R0)Q,
>Rjk d>K3
,K6s'3O(LW
} \NS\>Q+d
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public String getSSiteURL() %-i2MK'A
{ QgC
return sSiteURL; EP'2'51
} B:a&)Lwp0
%[-D&flKC
Sh*LD QL<?
public void setSSiteURL(String value) /{d7%Et6
{ fZ]Y
sSiteURL = value; V3xC"maA@
} gx#xB8n
`3SY~&X
7z)Hq./3@
public String getSFilePath() BE:HO^-.1
{ ; GRSe
return sFilePath; #)tt}GX
} 7*M+bZ`x
ckBcwIXlP&
My76]\Psh
public void setSFilePath(String value) n87B[R
{ x;99[C!$
sFilePath = value; +S5"4<
} \d2Ku10v[
; ob>$ _
*ELbz}Q
public String getSFileName() w{UVo1r:
{ C!]hu)E
return sFileName; 35?et-=w
} s|dcO
0[7\p\Q
<6)Ogv",
public void setSFileName(String value) PP.QfY4
{ * h!gjbi
sFileName = value; {PnvQ?|Z
} S2kFdx*Zf
T+9#P4
-[|R\'i
public int getNSplitter() Nj5Mc>_
{ 'mXf8
return nSplitter; A/|To!R
} yJ c#y
5(^&0c>P
|yx]TD{~P
public void setNSplitter(int nCount) h<f_Eoz-a
{ Waj6.PCFm
nSplitter = nCount; X&8&NkH
} oa?bOm
} G<#9`
}Ry:})
S4aN7.'Q
/* [ p$f)'
**Utility.java $d3al%Uo
*/ GF*8(2h2
package NetFox; X9K@mX
T ]hVO'z
/X~l%Xm
public class Utility { {~_X-g5|]
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U$&G_&*0a
public Utility() @@"}i7
{ >\y|}|?
+3dWnBg?
qT$;ZV #
} Aw~ =U!
rU=qr&f"B
//线程睡眠 brx 7hI
public static void sleep(int nSecond) zc01\M
{ Uoe;4ni
try{ ?& qMC
Thread.sleep(nSecond); 9fj3q>Un,
} 7g8}]\i+
catch(Exception e) +F.{:
{ VNBf2Va
e.printStackTrace (); %nk]zf..
} sG[v vm
} T2<?4^xN
{VtmQU?cJ
//日志 cVYDO*N2T
public static void log(String sMsg) B+[ri&6X\
{ M!Q27wT8O
System.err.println(sMsg); F6 ?4&h?n
} r"sK@
C62:G+W&o
V`7
public static void log(int sMsg) I .jB^
{ meey5}
System.err.println(sMsg); r6S-G{o
} qM= $,s*
} y (@j;Q3(r
ySAkj-< /P
:FB-GNd
/* w.Cw)#N
**TestMethod.java qWX%[i%
*/ 7iMBDkb7
package NetFox; Hvqvggfi
A#;6~f
aO8n\'bv
public class TestMethod { < %@e<,8
HHVCw7r0
4efIw<1_
public TestMethod() $/*19e~
{ ///xx/weblogic60b2_win.exe HYU-F_|N=
try{ uq?((
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }p,#rOX:A
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _3@[S F
SiteFileFetch fileFetch = new SiteFileFetch(bean); yvR3|
fileFetch.start(); `#@#eZ
} 7QV@lR<C2R
catch(Exception e){e.printStackTrace ();} )aSj!X'`;
.)=T1^[hI
jB)RvvMU5
} *nS}1(u]
i!0w? /g9
RN:VsopL
public static void main(String[] args) "/H B#
{ 7Z%EXDm4/c
new TestMethod(); }_Y&kaM
} K^32nQX
} [0c7fH`8V
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