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)); :zCm$@
} +q(D]:@,[
for(int i=0;i<nEndPos.length-1;i++) .T7ciD
{ Kj7Osqu2bE
nEndPos = nStartPos[i+1]; hH\(>4l
} `@90b4u
nEndPos[nEndPos.length-1] = nFileLength; oj/tim
} %2{E'^#)p-
} BBDOjhik
hf'3yEm
2+'&||h
//启动子线程 z"-Urd^O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <5.{+!BM
for(int i=0;i<nStartPos.length;i++) ` mi!"pmw
{ m-:k]9I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Oj2[(7mO/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TCYnErqk
nStartPos,nEndPos,i); +1Uw<~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !(]|!F[m
fileSplitterFetch.start(); $t]DxMd
} _ n>0!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sTb/l!=o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^ZsME,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1_'ZbZv4h
nEndPos = " + nFileLength); tnsYY
// fileSplitterFetch[nPos.length-1].start(); r&qD!l5y
BBX4^;t
0Ec -/
//等待子线程结束 2aG<^3
//int count = 0; P>H'od
//是否结束while循环 Av'H(qB\K
boolean breakWhile = false; 4DNZ y2`
I|.B-$gH
,Ubnz
while(!bStop) $?GF]BT
{ zUh(b=,
write_nPos(); a8N!jQc_m
Utility.sleep(500); 1ayxE(vMcX
breakWhile = true; mHP1.Z`
:+YFO.7
lfhB2^^
for(int i=0;i<nStartPos.length;i++) pyNPdEy
{ ?vhW`LXNB
if(!fileSplitterFetch.bDownOver) rScmUt
{ au8)G_A
breakWhile = false; 2XE4w# [j
break; r"n)I$
} h'bxgIl'`
} []@Mk
if(breakWhile) zIL.R#|D=
break; {3;4=R3
ScI9.{
W] lFwj
//count++; qP"m819m
//if(count>4) NENbr$,G
// siteStop(); {\%x{
} .VI2V-Q
Un<~P@T%
'HC4Q{b`
System.err.println("文件下载结束！"); 4fN<pG,
} jQc0_F\
catch(Exception e){e.printStackTrace ();} ?O_;{(F_
} H1X6f7`
{{O1C~
y.>r>o"0
//获得文件长度 {U4%aoBd8
public long getFileSize() h7*m+/O
{ ,0~'#x>
int nFileLength = -1; |OC6yN *P)
try{ wk3yz6V2
URL url = new URL(siteInfoBean.getSSiteURL()); )qKfTtN`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n>@(gDq
httpConnection.setRequestProperty("User-Agent","NetFox"); L0|u^J
~h1'_0t
xD~:= ]G
int responseCode=httpConnection.getResponseCode(); EZ$m4:{e
if(responseCode>=400) k`N)-`O7
{ ON$u581 y
processErrorCode(responseCode); >FY`xl\m}<
return -2; //-2 represent access is error 6l50IWj,T
} rc$G0O
I|p(8R!
6VA@;g0$
String sHeader; ^rx]Y;
UCl,sn
Q4UaqiL
for(int i=1;;i++) O*30|[
{ N~a?0x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d9E:LZy
//Utility.log(in.readLine()); YS;Ql\4
sHeader=httpConnection.getHeaderFieldKey(i); nY6^DE2f
if(sHeader!=null) gHTo|2 Q{
{ v67o>`<$
if(sHeader.equals("Content-Length")) FzNs >*
{ %=GnGgu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \s,ZE6dQ
break; #/YKA{
} ^Zg"`&E
} #wt#-U;
else 7^ER?@:W
break; oJ5V^.
} "_9Dau$
} &u.t5m7(
catch(IOException e){e.printStackTrace ();} ]A'E61t<n
catch(Exception e){e.printStackTrace ();} B[8
snX5mD
z0c_&@uj*
Utility.log(nFileLength); 8)T.[AP
;Lz96R@}
O[$&]>x]]
return nFileLength; 8E|S`I
} `|Ih"EZ
Lg-Sxz}P!
]81P<Y(7
//保存下载信息（文件指针位置） }"A.[9 b
private void write_nPos() |E|d"_Ma
{ $yG=exh3v
try{ y_QK _R<f
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3^C
output.writeInt(nStartPos.length); 2b2/jzO}J
for(int i=0;i<nStartPos.length;i++) hbn2(e;FZ
{ IRD?.K]*
// output.writeLong(nPos); |LWG7 ZE
output.writeLong(fileSplitterFetch.nStartPos); ]M#_o]
output.writeLong(fileSplitterFetch.nEndPos); iFpJ/L
} .]P@{T||Y
output.close(); }ufH![|[r
} rtC.!].;%
catch(IOException e){e.printStackTrace ();} iE>T5XV8$B
catch(Exception e){e.printStackTrace ();} tK0?9M.)
} |s=)*DZv
u|i.6:/=
fmFh.m.+N
//读取保存的下载信息（文件指针位置） 6/ F]ncwG
private void read_nPos() aNw8][
{ d'q,:="c
try{ ?bW|~<X~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u6;SgPw
int nCount = input.readInt(); 3lQGU
nStartPos = new long[nCount]; $fL2w^ @
nEndPos = new long[nCount]; "/g/Lc
for(int i=0;i<nStartPos.length;i++) a|{RK}|3
{ ^GHA,cSf
nStartPos = input.readLong(); F^z&s]^~
nEndPos = input.readLong(); 9F@Q
} !3E33
input.close(); }GRZCX>
} [O7:<co
catch(IOException e){e.printStackTrace ();} tWT@%(2~0
catch(Exception e){e.printStackTrace ();} }HRM6fR1S
} a;8q7nC
~{/"fTif
r< sx On
private void processErrorCode(int nErrorCode) |aIY
{ ,p {|f}0
System.err.println("Error Code : " + nErrorCode); 9/'zk
} [AA'Ko
AQ7w5}g+V
%dw@;IZ#8{
//停止文件下载 fIWOo >)D
public void siteStop() 4'_PLOgnX
{ 1U^;fqvja
bStop = true; TldqF BX
for(int i=0;i<nStartPos.length;i++) Q!9AxM2K
fileSplitterFetch.splitterStop(); PS7ta?V QC
Db3#;
1<IF@__
} 3+ JkV\AF
} HN?NY
//负责部分文件的抓取 ^`?2g[AA
**FileSplitterFetch.java g 67;O(3
*/ ~|QhWgq
package NetFox; Wo+fMn(O
sba+J:#w
/?C}PM
import java.io.*; 8&t3a+8l
import java.net.*; *.qm+#8W
$q%r}Cdg
^}8qPBz
public class FileSplitterFetch extends Thread { ;n`SF~CU
\W:~;GMeD
LpN_s#
String sURL; //File URL =n7QLQU
long nStartPos; //File Snippet Start Position :|%k*z
long nEndPos; //File Snippet End Position %zsY=qT
int nThreadID; //Thread's ID @A?Ss8p'
boolean bDownOver = false; //Downing is over tX)l_?jVH
boolean bStop = false; //Stop identical R+}7]tva6C
FileAccessI fileAccessI = null; //File Access interface aGSix}b1P
8=\}#F
dX^ ^ @7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (]ToBju
{ \2]M&n GT
this.sURL = sURL; )jc`_{PQg
this.nStartPos = nStart; F/.nr
this.nEndPos = nEnd; s aY;[bz}
nThreadID = id; #$-{hg{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *5T^wZpj)
} H;D5)eJ90
N=%4V
x)GpNkx:
public void run() xw2dNJL
{ /h6K"w=='!
while(nStartPos < nEndPos && !bStop) U4s)3jDw
{ cCa+UTxaJ
}3HN$Fwo
-,YoVB!T
try{ |YEq<wbQ
URL url = new URL(sURL); xNAX)v3Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); we?# Dui
httpConnection.setRequestProperty("User-Agent","NetFox"); ,v\^efc:%
String sProperty = "bytes="+nStartPos+"-"; |f67aN
httpConnection.setRequestProperty("RANGE",sProperty); x#)CH}J
Utility.log(sProperty); m!#'4
skeH~-`M@
9fQ[:Hl"
InputStream input = httpConnection.getInputStream(); 1/\JJ\
//logResponseHead(httpConnection); }%)]b*3
V$o]}|
k7ye,_&>
byte[] b = new byte[1024]; 9^+8b9y
int nRead; {(#2G,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )wqG^yv
{ ^L4"X~eM
nStartPos += fileAccessI.write(b,0,nRead); -HQ(t
//if(nThreadID == 1) hlKM4JT\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @{V bu
} $@utlIXA'
6>DmcG:.
2UbTKN
Utility.log("Thread " + nThreadID + " is over!"); 2e_m>I
bDownOver = true; 2-$O$&s.
//nPos = fileAccessI.write (b,0,nRead); X^o0t^
} 1Y+g^Z;G
catch(Exception e){e.printStackTrace ();} U,Q
} IEmjWw4
} 0#y i5U
&) qs0
6Cj$x.-K
//打印回应的头信息 nF1}?
public void logResponseHead(HttpURLConnection con) W#Eg\nT
{ [%LIW%t|
for(int i=1;;i++) 5.M82rR;~
{ 2e?a"Vss
String header=con.getHeaderFieldKey(i); Yx[B*] 2
if(header!=null) P!xN]or]u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r}nz )=\Cj
Utility.log(header+" : "+con.getHeaderField(header)); ~8 S2BV3@
else eXA@J[-M:
break; 4ux^K:z
} }kZ)|/]kn
} 3Z_\.Z1R@
-^ceTzW+
+?9. &<?
public void splitterStop() 7MZ(tOR
{ A<p6]#t#X)
bStop = true; XlJA}^e
} [cso$Tv
'5etZ!:
b}HwvS:
} p N+1/m,
Mwtd<7<!A
hMnJH_siY
/* ~5:-;ZbZ
**FileAccess.java ~O8Xj6
*//文件访问(定位，写) H^fErl
package NetFox; v43FU3
import java.io.*; 2fFGS.l
'U*Kb
g9G 8;
public class FileAccessI implements Serializable{ q?$<{Z"
hQ_gOI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _FxQl]@
RandomAccessFile oSavedFile; 5:vy_e&
long nPos; gJYX
?4sF:Y+\
pxV@fH+`
public FileAccessI() throws IOException Z(c2F]
{ ~{$5JIpCm
this("",0); aTFT'(O,
} m\eYm;RVj
~8tb^
3:MAdh[w
public FileAccessI(String sName,long nPos) throws IOException -p*j9 z
{ N VBWF
oSavedFile = new RandomAccessFile(sName,"rw"); d9pZg=$8
this.nPos = nPos; tdi^e;:?
oSavedFile.seek(nPos); n-x%<j(Xf
} 7-j=he/
Om5+j:YM
#,;X2%c
public synchronized int write(byte[] b,int nStart,int nLen) #xNXCBl]O
{ \9%RY]TK3
int n = -1; ICm/9Onh&
try{ 4h$W4NJK
oSavedFile.write(b,nStart,nLen); VWT\wAL
n = nLen; s5&v~I;>e
} :d}@Z}2sD
catch(IOException e) ;t5e]
{ !cA4erBP
e.printStackTrace (); Uu(FFd~3
} cIOM}/gqv
Rdl^-\BV
=*=qleC3
return n; 'eg;)e:`b+
} ";*Iwd*V
A[Pz&\@
0Q5fX}
} s^>1rV]=(`
J`[He$7)
]}A3Pm- t*
/* Wer.VL
**SiteInfoBean.java j7v?NY
*/ woyeKOr
package NetFox; ZuVes?&j
L%5g]=
}1? 2
public class SiteInfoBean { /5r!Fhx
yQdoy^d/4
I1fUV72
private String sSiteURL; //Site's URL e>Q_&6L
private String sFilePath; //Saved File's Path b^C2<'
private String sFileName; //Saved File's Name 'G8.)eTA'
private int nSplitter; //Count of Splited Downloading File [.LbX`K:
n81z0lnr
zMbz_22*
public SiteInfoBean() 65AG#O5R
{//nSplitter的缺省值为5 D&nVkZP>
//default value of nSplitter is 5 K[M[0D
this("","","",5); IrTMZG
} f) @-X!
^gd[UC-"w
2Pic4Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jLCZ JSK
{ nEbJ,#>Z
sSiteURL= sURL; ylPDM7Ka
sFilePath = sPath; _H)>U[
sFileName = sName; 4@1C$|k
this.nSplitter = nSpiltter; QTbv3#
9vw0box
'.1_anE]
} ~"8)9&
>'e(|P4
kzXmiBL<9
public String getSSiteURL() 5$Da\?Fpn
{ q}MPl2
return sSiteURL; W=ar&O~}n
} HZEDr}RN
:8jaW?~
}.74w0~0^
public void setSSiteURL(String value) =6^phZ(
{ Kfk/pYMDq
sSiteURL = value; -1<*mbb0
} 6y}|IhX?z
7<7 /NZ<I
2SlOqH1
public String getSFilePath() Z0Df~ @
{ 2m0laJ3p9
return sFilePath; I'>r
} $pGdGV\H
5&N55?G6
*g~\lFX,u
public void setSFilePath(String value) GMJ</xG
{ p7eRAQ\'
sFilePath = value; e9@7GaL`"S
} 8nQjD<-
0VBbSn}Z<
jce^Xf
public String getSFileName() flzHZH
{ d/!R;,^
return sFileName; VMb r@9
} G~fM!F0
uIb,n5
M qG`P
public void setSFileName(String value) c037#&Q%#
{ )%D>U
sFileName = value; |)WN%#v
} XLxr@1
xv:VW<
VdetY\
public int getNSplitter() WPu{ ]<pl
{ eh5j
return nSplitter; N]iu o.
} j@4AY}[tX
>4@/x{{
fBRU4q=^T
public void setNSplitter(int nCount) [mJmT->
{ [K4wd%+
nSplitter = nCount; AHl1{* [
} 5}"@$.{i
} oGXndfd"
N6wCCXd
%}0B7_6B+@
/* @.SuHd
**Utility.java xhmrep6+<
*/ 67{>x[
package NetFox; g7r_jj%ow
^qP}/H[QT
jt?.g'
public class Utility { gvl3NQQ%t
1YxG<K]
Yl#|+xYA5[
public Utility() l=.h]]`;
{ W$bQS!7y
SV}C]<
dqu+-43I|
} yl'@p5n
(yB)rBh>n
//线程睡眠 xG|T_|?
public static void sleep(int nSecond) J jp)%c#_
{ yv2N5IQ>{V
try{ ?cRGdLP'D
Thread.sleep(nSecond); b!J%s
} Sl7x>=
catch(Exception e) ZgD%*bH*B
{ swGp{wJ
e.printStackTrace (); ~?#B(t
} +91j 1?
} VvSe`E*
~ WO
//日志 8nSEAr~
public static void log(String sMsg) Jv+N/+M47
{ yy*8Aw}
System.err.println(sMsg); CfMCc:8mL
} rQ*Fc~^L
2/ES.>K!.
<RaM@E
public static void log(int sMsg) ZJ Ke}F`l
{ N">4I)
System.err.println(sMsg); eGF+@)K1"
} >&g^ `
} 0!fT:Ra
1;8%\r[|5^
B2/d%B
/* 6J""gyK.
**TestMethod.java 7}r6mr0vpm
*/ ?Xq"Q^o4#e
package NetFox; =}1)/gcM
}#Gq*^w
EpsjaOmAF
public class TestMethod { Q 2mTu[tx
7XU$O$C
b$W~w*O
public TestMethod() %&[=%zc
{ ///xx/weblogic60b2_win.exe #PJHwvr
try{ "z6xS;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aF!Im}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \Hs*46@TC
SiteFileFetch fileFetch = new SiteFileFetch(bean); &h<\jqN/
fileFetch.start(); )nM<qaI{
} XTro;R=#
catch(Exception e){e.printStackTrace ();} t|jp]Vp
{IgLH`@
=lOdg3#\a
} qe3d,!
bK69Rb@\A
k+5l
public static void main(String[] args) BV-(`#~:y
{ <<M1:1
new TestMethod(); LyuA("xB#
} &`^PO$
} FD[o94`%
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