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)); P*j|.63
} 3Y$GsN4ln
for(int i=0;i<nEndPos.length-1;i++) #H~64/
{ M\BRcz
nEndPos = nStartPos[i+1]; 0g8NHkM:2a
} y:uE3Apm
nEndPos[nEndPos.length-1] = nFileLength; M_DwUS1?
} +NUG
} abVmkdP_s
eHUOU>&P]
kAUymds;O
//启动子线程 f!X[c?Xy"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !4+<<(B=E
for(int i=0;i<nStartPos.length;i++) CrTw@AW9)
{ p!%pP}I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G3T]`Atf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -QNh
nStartPos,nEndPos,i); ~k5W@`"W
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YoFxW5by
fileSplitterFetch.start(); Q7CsJzk~)
} Q"#J6@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t]G:L}AOl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X:{!n({r=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @H8EWTZ
nEndPos = " + nFileLength); seJ^s@H5l
// fileSplitterFetch[nPos.length-1].start(); {'H(g[k
:ShT|n7
f|gg
//等待子线程结束 aN3;`~{9
//int count = 0; HGg@ _9tW
//是否结束while循环 )4;`^]F
boolean breakWhile = false; BiBOr}ZQ
9Mcae31
_yR^*}xJb
while(!bStop) e*1_8I#2
{ R4d=S4i
write_nPos(); Tlr v={
Utility.sleep(500); Xch~ 1K
breakWhile = true; .=; ;
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~gt@P
for(int i=0;i<nStartPos.length;i++) K*dCc}:`
{ @C aG9]
if(!fileSplitterFetch.bDownOver) G3v5KmT
{ %;!.n{X
breakWhile = false; Y_P!B^z3
break; |y!A&d=xYn
} mX|ojZ
} 7{Wny&[0
if(breakWhile) dAj$1Ke
break; ]]yO1x$Kk
I%Z
Dvln/SBk
//count++; !}$$:
//if(count>4) TD_Oo-+\
// siteStop(); *Pg2c(Vg
} hE-M$LmN@
/qw.p#
QS`]
System.err.println("文件下载结束！"); 1h5 Akq
} 5F"jkd+
catch(Exception e){e.printStackTrace ();} 9N3eN
} d'sZxU
kcxAd
x,Vr=FB
//获得文件长度 kU`r)=1"
public long getFileSize() 2J;g{95z
{ /Ci<xmP
int nFileLength = -1; ;A[Q2(w+
try{ $ME)#(
URL url = new URL(siteInfoBean.getSSiteURL()); !|>"o7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0m ? )ROaJ
httpConnection.setRequestProperty("User-Agent","NetFox"); :BTq!>s
#e5\j\#.
T[j,UkgGo
int responseCode=httpConnection.getResponseCode(); ml$o5&sN
if(responseCode>=400) k VQ\1!
{ rrv%~giU
processErrorCode(responseCode); vfo~27T{(
return -2; //-2 represent access is error rVsJ`+L
} Af{"pzY
Rx}Gz$
A5w6]:f2
String sHeader; cN9t{.m
H>@+om
t |oR7qa{w
for(int i=1;;i++) CJI~_3+K
{ ;A!BVq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7xa>
//Utility.log(in.readLine()); Q NVa?'0"Y
sHeader=httpConnection.getHeaderFieldKey(i); 8dyg1F
if(sHeader!=null) >&k-'`Nw
{ {]|J5Dgfe
if(sHeader.equals("Content-Length")) 0SPk|kr
{ dcT80sOC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); */DO ex"y
break; {1 94!S4z
} 0qT%!ku&
} Wo,?+I
else 29q _BR *:
break; ~F7gP{r
} ^G-@06/!
} dC4'{n|7
catch(IOException e){e.printStackTrace ();} 4xJQ!>6
catch(Exception e){e.printStackTrace ();} >yh2Lri
kO-(~];
RCLeA=/N@0
Utility.log(nFileLength); SK.: Q5:
61 ~upQaR
t&Og$@
return nFileLength; BL58] P84
} xAP+FWyV
$u6 3]rypm
'[O;zJN;
//保存下载信息（文件指针位置） h`.&f
private void write_nPos() y18Y:)DkL
{ &G$Ucc `
try{ KCDE{za
output = new DataOutputStream(new FileOutputStream(tmpFile)); P L+sR3bR
output.writeInt(nStartPos.length); B,fo(kG
for(int i=0;i<nStartPos.length;i++) ^y4Z+Gu[
{ Vs{|xG7WD
// output.writeLong(nPos); FNId;
output.writeLong(fileSplitterFetch.nStartPos); *k>n<p3dd
output.writeLong(fileSplitterFetch.nEndPos); !$>R j
} 9JKEw
output.close(); $,fX:x
} cPc</[x[W
catch(IOException e){e.printStackTrace ();} 5+ MS^H
catch(Exception e){e.printStackTrace ();} ~.lPEA %%
} ;P&OX5~V
B^jc3 VsR
FN) $0
//读取保存的下载信息（文件指针位置） BJo*'US-Q
private void read_nPos() R_S.tT!
{ ib791
try{ xFg>SJ7]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u,Kly<0j
int nCount = input.readInt(); S?BG_J6A7
nStartPos = new long[nCount]; 26x[X.C:
nEndPos = new long[nCount]; 1 I",L&S1
for(int i=0;i<nStartPos.length;i++) {P#|zp4C{
{ U\!X,a*ts{
nStartPos = input.readLong(); CQDkFQq-dq
nEndPos = input.readLong(); -1ub^feJ,
} n>U5R_T
input.close(); 6/dI6C!
} Tkgs]q79
catch(IOException e){e.printStackTrace ();} IRqy%@)
catch(Exception e){e.printStackTrace ();} 42ivT_H
} iM3V=&)
i8HTzv"J
8Kk(8a&v
private void processErrorCode(int nErrorCode) DrK{}uM
{ 8BNi1Qn$
System.err.println("Error Code : " + nErrorCode); I ?.^ho
} LvYB7<zk>
x# 5A(g
>t_6B~x9
//停止文件下载 5rZ
public void siteStop() F`]2O:[
{ WQO) =n
bStop = true; G9<X_
for(int i=0;i<nStartPos.length;i++) /fV;^=:8c
fileSplitterFetch.splitterStop(); ?#UO./"
OprkR
OY@ %p}l
} vd4ytC
} PXNh&N
//负责部分文件的抓取 )q3p-)@kQ
**FileSplitterFetch.java 6<(.4a?
*/ fXQNHZ|4
package NetFox; }U5yQ%N
'K,:j 388
UU0,!?o4
import java.io.*; 8E]F$.6U
import java.net.*; "@,}p\
ZO c)
o J;$sj
public class FileSplitterFetch extends Thread { rguCp}r
Gjo`&#
u!qP
String sURL; //File URL h>OfOx/{q9
long nStartPos; //File Snippet Start Position 85xR2<:
long nEndPos; //File Snippet End Position f^XOUh
int nThreadID; //Thread's ID {%6`!WW[
boolean bDownOver = false; //Downing is over Ck7uJI<x
boolean bStop = false; //Stop identical pBA7,z"`mP
FileAccessI fileAccessI = null; //File Access interface ~Vjl7G\7i
q.`NtsW!\+
5(HG|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x{/g(r={}
{ 5iydZ
this.sURL = sURL; zi`o#+
this.nStartPos = nStart; ]+:^W^bs:
this.nEndPos = nEnd; 8StgsM
nThreadID = id; _/5H l`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Pw!MS5=r
} Otm0(+YB7
-Wi` G
p|D/;Mk
public void run() 9|CN8x-
{ LOV)3{m
while(nStartPos < nEndPos && !bStop) l3F6AlPql
{ Jz *;q~
\7'{g@C(
?"g2v-jTK
try{ &m:uO^-D
URL url = new URL(sURL); /{--+ C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =^50FI|
httpConnection.setRequestProperty("User-Agent","NetFox"); <1\Nb{5
String sProperty = "bytes="+nStartPos+"-"; *N'p~LJ
httpConnection.setRequestProperty("RANGE",sProperty); "d5n \@[t
Utility.log(sProperty); OMg<V
>_ 2dvg=U
/HRFAqep
InputStream input = httpConnection.getInputStream(); ThbGQ"/
//logResponseHead(httpConnection); zi*R`;_`,
naznayy
.$)
byte[] b = new byte[1024]; 2Ny"O.0h
int nRead; ,>+p-M8ZL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WKa~[j|-K
{ R/>@+
nStartPos += fileAccessI.write(b,0,nRead); PxkOT*
//if(nThreadID == 1) GD_hhDyD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2{G:=U
} 2n"V}p>8i#
|T)6yDL
+l{=
Utility.log("Thread " + nThreadID + " is over!"); t"'7m^j
bDownOver = true; LsS
//nPos = fileAccessI.write (b,0,nRead); R2]Z kg
} .O}%
catch(Exception e){e.printStackTrace ();} dP]\Jo=Yh
} `W/>XZl+t
} CDR@ `1-
h/hmlnOQl
[>5-$YOT
//打印回应的头信息 $F+ LDs
public void logResponseHead(HttpURLConnection con) vJOw]cwq
{ XtSkh] #z!
for(int i=1;;i++) uurh??R
{ !6>~?gNd
String header=con.getHeaderFieldKey(i); Hm'=aff6A
if(header!=null) \WB<86+z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !AfHk|
Utility.log(header+" : "+con.getHeaderField(header)); @;?p&.W`D
else oij}'|/Jc
break; (uZ&V7l
} wLJ:\_Jaf
} "J8vjr1/
0Bi.6r
v+#}rUTF
public void splitterStop() 7f!YoW;1
{ ^mO~W!"
bStop = true; V"G*N<q
} WQL\y3f5
S<@7_I
%Ax3;g#
} % *INT
NmJWU:W_@
hD*SpVIU
/* [dIXR
**FileAccess.java WE.{p>
*//文件访问(定位，写) aa#Y=%^
package NetFox; Jx7C'~,J
import java.io.*; EZ$>.iy{
"~7>\>UFh
eMY<uqdw
public class FileAccessI implements Serializable{ A5R<p+t6
xQXXC|T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8hJ%JEzga
RandomAccessFile oSavedFile; RA'M8:$
long nPos; $jI3VB
>$7v ;Q
f"SD/]q-
public FileAccessI() throws IOException m\r@@!
{ ![_*(8v}S
this("",0); \T:i{.i
} 6BbGA*%{
$r8 ^0ZRr
QoIT*!
public FileAccessI(String sName,long nPos) throws IOException wFsyD3
{ ';jYOVe
oSavedFile = new RandomAccessFile(sName,"rw"); >TnTnFWX
this.nPos = nPos; Be=u&T:~
oSavedFile.seek(nPos); X"e5Y!:M-
} dP<=BcH>f
GyIT{M}KV
*|C^=*j9
public synchronized int write(byte[] b,int nStart,int nLen) T;y>>_,
{ >dG;w6y'
int n = -1; =Og)q$AL
try{ B43HNs
oSavedFile.write(b,nStart,nLen); _%!c+f7
n = nLen; *@v)d[z_
} S^>,~R.TX
catch(IOException e) MLje4
{ ke]Lw
e.printStackTrace (); rrqR}}l
} 4Thn])%I
Ix!Iw[CNd
L>W'LNXCv
return n; n%C>E.Tq
} NS%xTLow-
IE&!YP(U(
Vp*KfS]
} F6OpN"UM'
m)v"3ib
Nj xoTLI
/* Ba*,-i3ZK
**SiteInfoBean.java m4&h>9. 8
*/ gL[yA?GoM
package NetFox; !GLz)#SBl
+"cq(Y@
(k) l=]`}
public class SiteInfoBean { o-{[|/)Tk
Ov4y%Pj
o( RG-$
private String sSiteURL; //Site's URL =/Mq5.
private String sFilePath; //Saved File's Path -pa )K"z
private String sFileName; //Saved File's Name ?_$=l1vf
private int nSplitter; //Count of Splited Downloading File y?m/*hh`
G_{&sa
6@e+C;j=
public SiteInfoBean() 8U>B~9:JO
{//nSplitter的缺省值为5 L[H5NUG!
//default value of nSplitter is 5 KJ=6n%6
this("","","",5); ^xHTWg%9
} v'qG26
Co9QW/'i
hMUs" <.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) GCX G/k?w:
{ E4W -hq~
sSiteURL= sURL; 2FF4W54I
sFilePath = sPath; 8:>1F,
sFileName = sName; 8x8uo
this.nSplitter = nSpiltter; YN2sdG
L ugn3+
H!nr^l'+
} `m>*d!h=
RGg(%.
n'01Hh`0
public String getSSiteURL() oA7;.:3
{ V7[zAq
return sSiteURL; LbG_z =A
} J'fQW<T4wU
jbu8~\"
8p9bCE>\
public void setSSiteURL(String value) #u"k~La
{ j>x-"9N
sSiteURL = value; T[uiPs/xD
} !z<%GQ CT
9C[ywp
lR[qqFR
public String getSFilePath() 2?,EzBeal
{ "D'B3; uWK
return sFilePath; I8/DR z$A
} n;U`m$vL%
Tekfw
h0-hT
public void setSFilePath(String value) /D^"X 4!"
{ :GW&O /Yo
sFilePath = value; 1_ C]*p
} %1O[i4s:-
H5]^ 6 HwX
2eC(Ijq[a
public String getSFileName() J-) XQDD
{ \XM^oE#G
return sFileName; ZAUQJS 91E
} 92d6U2T4&
4Hn`'+b
no]z1D
public void setSFileName(String value) wUQw!%?>
{ AUNQA
sFileName = value; $m+sNEAa
} UIAj]
x-<)\L&
gV`=jAE_
public int getNSplitter() [],1lRYI9_
{ 13%t"-@bh
return nSplitter; ^;maotHn
} MpqZH{:?G
CI :`<PZ\-
t" 7yNs(I
public void setNSplitter(int nCount) ;VNMD 6H
{ OhmQ,
nSplitter = nCount; 199]WHc
} <~!Hx+j
} eKz?"g/j
iNWo"=J
\uq/x^?yo
/* !$Tw^$n
**Utility.java n;p:=\uN
*/ T<@cd|`
package NetFox; Fxqp-}:
n?ctLbg
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public class Utility { #8bsxx!s
ofMY,~w
U uM$~qf/K
public Utility() ;)I'WQ]Q
{ NeBsv= [-
jhX[fT1m
@81Vc<dJ
} >'xGp7}y
p=B>~CH
//线程睡眠 u#A<hq;
public static void sleep(int nSecond) -0Tnh;&=
{ M- 2Tz[
try{ ls`,EFF
Thread.sleep(nSecond); +|{RE.DL
} #E+gXan
catch(Exception e) o|iYd n\
{ c8M2 ^{O,`
e.printStackTrace (); aJe^Tp(
} ^eGNgE
} CWG6;NT6m
wHv]ViNvXE
//日志 3bd5FsI^pU
public static void log(String sMsg) \U?n+6 7g
{ 1s*.A6EP"
System.err.println(sMsg); je4w=]JV
} tpEI(9>
5P+t^\
:@xm-.D
public static void log(int sMsg) ~!d/8?!
{ wpt='(
System.err.println(sMsg); Bo+DJizu
} _l], "[d
} a=$t&7;,
gx:;&4AD
lvpc*d|K
/* X$\i{p9jw
**TestMethod.java fiI $T:g.
*/ w[-Fm+A>
package NetFox; e{9jn>\,a
j! NO|&k
-/dEsgO
public class TestMethod { C4#rA.nF|
oM1 6C|
(zYy}g#n
public TestMethod() ]:$ O{y
{ ///xx/weblogic60b2_win.exe L~/qGDXC?
try{ qxMnp}O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4Kv[e]10(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \mN[gT}LHm
SiteFileFetch fileFetch = new SiteFileFetch(bean); W*:,m8wk
fileFetch.start(); LFp]7Dq
} .LRxP#B
catch(Exception e){e.printStackTrace ();} 3PUAH
4^'3&vu
m&oi8 P-6
} x/MZ(A%D
^D_/=4rz8
6V+ qnUk
public static void main(String[] args) &>jAe_{",
{ QIn/,Yd
new TestMethod(); "4j:[9vR\
} rba;&D;
} }T0K^Oe+eS
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