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)); 5S9i>B
} jmORKX+)
for(int i=0;i<nEndPos.length-1;i++) I3I1<}>]Z
{ '@0Z#A
nEndPos = nStartPos[i+1]; 1j_gQ,'20
} *VX"_C0Jy=
nEndPos[nEndPos.length-1] = nFileLength; !k3 eUBF
} C(%b!Q,2
} "1P[D'HV4|
ayGcc`
ohJo1}{
//启动子线程 y:HH@aa)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bmzY^ %a
for(int i=0;i<nStartPos.length;i++) +,Ud 3iS
{ L*6R5i>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WqO4_;X6/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4j1$1C{
nStartPos,nEndPos,i); oBS m>V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hk8lHja+\
fileSplitterFetch.start(); ^j!2I&h1
} Z g.La<#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), | LXVf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 41v#|%\w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b!<\#[ A4
nEndPos = " + nFileLength); *t{^P*pc
// fileSplitterFetch[nPos.length-1].start(); O#@G .~n?
diWi0@
[.Rdq]w6
//等待子线程结束 $L4h'(s
//int count = 0; "h5.^5E6
//是否结束while循环 ^~1Z"kAnT
boolean breakWhile = false; <y=+Gh
H?_wsh4J
4aiI&,
while(!bStop) 6b1AIs8
{ |jB/d@RE
write_nPos(); #F=!g?
Utility.sleep(500); *.6m,QqJ(
breakWhile = true; MW2{w<-]7
hLr\;Swyp
nN2huNTf:
for(int i=0;i<nStartPos.length;i++) ES\=MO5a7
{ }60/5HNr
if(!fileSplitterFetch.bDownOver) g/4ipcG;N
{ gtnu/Q
breakWhile = false; 0VZC7@
break; 7NRm\%^q
} *zwo="WA\t
} 7Bym?
if(breakWhile) v~A*?WU;n
break; [pC2#_}
X4<Y5?&0
d2?#&d'aq
//count++; l<;~sag
//if(count>4) qfX26<q
// siteStop(); RF= $SMTk
} '5(T0Ws/w
?vfZ>7Q
-zzoz x]S=
System.err.println("文件下载结束！"); 81H9d6hqcD
} _C)\X(;
catch(Exception e){e.printStackTrace ();} H*P[tyz$
} 1ozb tn
v_Hy:O}R
*L~?.9R
//获得文件长度 "d`u#YmR
public long getFileSize() &xpvHKJl
{ c^<~Y$i
int nFileLength = -1; uvAJJIae'
try{ 8F&Y;
URL url = new URL(siteInfoBean.getSSiteURL()); Iw^Q>MrT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pqTaN=R8
httpConnection.setRequestProperty("User-Agent","NetFox"); %=Y=]g2
tAPf#7{|
dvM%" k
int responseCode=httpConnection.getResponseCode(); w"37sv
if(responseCode>=400) mGa:~x
{ 6Jq3l_
processErrorCode(responseCode); H:P7G_!\
return -2; //-2 represent access is error Dr76+9'i
} PuhvJHT
7X)4ec9H\
;XQ27,K&
String sHeader; 5,4m_fBoW
sm;kg=
=\k:]
for(int i=1;;i++) =kf"%vFV
{ {5fL!`6w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); do*aE
//Utility.log(in.readLine()); nEPTTp+B
sHeader=httpConnection.getHeaderFieldKey(i); ` Z/ MQ
if(sHeader!=null) Abi(1nXdQ
{ f7|Tp m
if(sHeader.equals("Content-Length")) ^KnK \
{ 1{wbC)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J7qTE8W=
break; +,]VXH<y
} kv6nVlI)B
} 0m=57c$O
else =6+99<G|%M
break; B,&QI&k`~
} ($>m]|
} awI{%u_(nA
catch(IOException e){e.printStackTrace ();} }'faf{W
catch(Exception e){e.printStackTrace ();} I!Z"X&
m=+x9gL2
o(H.1ESk
Utility.log(nFileLength); $PI9vyS
H cyoNY
?3 k_YN"
return nFileLength; 89;@#9
} 9zS
.c:h!-D;
3Pllxq<n
//保存下载信息（文件指针位置） .Zj`_5C
private void write_nPos() D,R',(3
{ kY!zBk
try{ Aq*?Q/pV
output = new DataOutputStream(new FileOutputStream(tmpFile)); ><Zu+HX
output.writeInt(nStartPos.length); T1*.3_wtP
for(int i=0;i<nStartPos.length;i++) h6OQeZ.
{ "bDj00nwh
// output.writeLong(nPos); AWYlhH4c?t
output.writeLong(fileSplitterFetch.nStartPos); %Zbm%YaW5
output.writeLong(fileSplitterFetch.nEndPos); q\x.e.@
} @4D{lb"{
output.close(); zL9~gJ
} 7s#8-i
catch(IOException e){e.printStackTrace ();} R ZQH#+*t}
catch(Exception e){e.printStackTrace ();} ZJQFn
} R y#C#0
]X77?Zz9
Um6}h@>
//读取保存的下载信息（文件指针位置） <Q/)SN6_E
private void read_nPos() VXWV Pj#
{ {_\cd.AuT
try{ pCrm `hy(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5cinI^x)f
int nCount = input.readInt(); N`,\1hHMT
nStartPos = new long[nCount]; cS7\,/4S
nEndPos = new long[nCount]; `D |/g;
for(int i=0;i<nStartPos.length;i++) %" 7UYLX
{ ^@O7d1&y
nStartPos = input.readLong(); R"V90bCf
nEndPos = input.readLong(); MiIxj%,(
} qar{*>LCG
input.close(); l^nvwm`f#:
} D@gC(&U/6
catch(IOException e){e.printStackTrace ();} 05T?c{ ;
catch(Exception e){e.printStackTrace ();} T+&fUhSy
} XLCqB|8`V
R|M]mwa^w
Y;_F,4H
private void processErrorCode(int nErrorCode) <tFq^qB
{ yzp#
System.err.println("Error Code : " + nErrorCode); qe{;EH*
} 9QXsbd6
#jg-q|nd
GHd1?$
//停止文件下载 v0oVbHO5<
public void siteStop() ]zaTX?F:
{ 7;AK=;
bStop = true; &d2L9kTk
for(int i=0;i<nStartPos.length;i++) 1L4-;HYJm
fileSplitterFetch.splitterStop(); q%])dZ!lE
U|tacO5w`
SDO:Gma
} G&^8)S@1
} TS9<uRO0
//负责部分文件的抓取 3=sBe HL
**FileSplitterFetch.java g^+p7G
*/ 9X4[Zk
package NetFox; h>D;QY
}k-8PG =
:G@z?ZJ[
import java.io.*; 8Lx/ZGy
import java.net.*; L7buY(F(
?# FYF\P
lr~ |=}^
public class FileSplitterFetch extends Thread { 1m"WrTen
7:?\1a
~:7y!=8#
String sURL; //File URL !;,\HvEZYw
long nStartPos; //File Snippet Start Position x;yvv3-$
long nEndPos; //File Snippet End Position I*.nwV<
int nThreadID; //Thread's ID 5s3QN{h8
boolean bDownOver = false; //Downing is over {Z8GG
boolean bStop = false; //Stop identical 56<UxIa~
FileAccessI fileAccessI = null; //File Access interface |Qcz5M90e
;X<Ez5v3
Jk(V ]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #;ObugY,
{ @,.D]43
this.sURL = sURL; V9$T=[
this.nStartPos = nStart; 0)d='3S
this.nEndPos = nEnd; W..*!UGl
nThreadID = id; jdJTOT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EOu[X'gLr
} ,M{G X
H%Gz"
!xck ~EAS
public void run() %p
{ oFP8s[B
while(nStartPos < nEndPos && !bStop) ^zV_vB)n
{ #tu>h
a_P|KRl
XjL3Ar*
try{ Fdhgm{Y2s
URL url = new URL(sURL); z7IJSj1gQI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \O "`o4
httpConnection.setRequestProperty("User-Agent","NetFox"); 1xS+r)_n@
String sProperty = "bytes="+nStartPos+"-"; WC<[<uI*
httpConnection.setRequestProperty("RANGE",sProperty); /J-'[Mc'D[
Utility.log(sProperty); I9G^T' W
nQOdM#dP
1Mp-)-e
InputStream input = httpConnection.getInputStream(); ni{'V4A
//logResponseHead(httpConnection); ~|S0E:*.
yR|2><A
Lq>lj`>
byte[] b = new byte[1024]; ;dUKFdKH}
int nRead; $Okmurnn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GgY8\>u
{ %:`v.AG
nStartPos += fileAccessI.write(b,0,nRead); 1Zc=QJw@
//if(nThreadID == 1) d*{Cv2A.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZcjLv
} WcqR; Nm
+^(_S9CO
N,qo/At}R[
Utility.log("Thread " + nThreadID + " is over!"); FCNYfjB%
bDownOver = true; 2LUsqL\m}.
//nPos = fileAccessI.write (b,0,nRead); 7d>w]R,Z
} G?$o+Y'F
catch(Exception e){e.printStackTrace ();} Z(|$[GZP[
} <}[ !k<
} I ==)a6^
f> Jj5he/
8d5#vm
//打印回应的头信息 + GQ{{B
public void logResponseHead(HttpURLConnection con) \0 h>!u
{ -&7?!<f
for(int i=1;;i++) ^AU-hVj
{ W8^A{l4
String header=con.getHeaderFieldKey(i); >xo<i8<Miv
if(header!=null) n~yHt/T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3@x[M?$
Utility.log(header+" : "+con.getHeaderField(header)); El9T>!Z
else ?1\I/'E9
break; n+sv2Wv:
} q-Z<.GTq
} p35)K5V
aPxSC>p
,H6P%
public void splitterStop() j;}-x1R
{ BN]o!Y
bStop = true; 0-uj0"r`
} Xk|a%%O*H
9U<WR*H
YG0/e#5
} ktqFgU#rT
W gyRK2#!
Pq+|*Y<|&
/* [/hoNCH!
**FileAccess.java #0r^<Yn
*//文件访问(定位，写) A94:(z;{
package NetFox; hb*Y-$Zp
import java.io.*; 83vZRQw
moFrNcso
-<x%
public class FileAccessI implements Serializable{ aK6dy\
e:-pqZT`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aoW2c1`?Z
RandomAccessFile oSavedFile; r+%3Y:dZE
long nPos; Y{j~;G@Wl
QyTNV
4Wz1O$*
public FileAccessI() throws IOException ?pJ2"/K
{ *.w6=}
this("",0); Oi|cTZ@A-
} _s#J\!F
Yf[Cmn
V8F!o
public FileAccessI(String sName,long nPos) throws IOException <k1muSe
{ :fRta[
oSavedFile = new RandomAccessFile(sName,"rw"); MbYgGE,LA
this.nPos = nPos; BIMX2.S1o
oSavedFile.seek(nPos); 1H">Rb30@
} )2EvZn
<^;~8:0]
qYe`</
public synchronized int write(byte[] b,int nStart,int nLen) @+~URIG)
{ _0naqa!JyH
int n = -1; cyd_xB5K
try{ Fi+DG?zu
oSavedFile.write(b,nStart,nLen); +-t&li%F
n = nLen; -+qg
} 2@_3V_
catch(IOException e) K;THYMp/[
{ ec^{ez@`
e.printStackTrace (); gYho$E
} hUi5~;Q5Fi
K ..Pn17t
Pt-mLINvG
return n; 8M3DG=D
} 56c3tgVF
, =*^XlO=c
p `oB._ R
} }3 ~*/30V
;gaTSYVe
fUq}dAs*K
/* U\{I09@E 0
**SiteInfoBean.java 7]5+%[Dg!
*/ nF3Sfw,
package NetFox; kMzDmgoxNg
5B1,,8P
/HqD4GDoug
public class SiteInfoBean { =RWY0|f
kotKKs
~h+B&F+5
private String sSiteURL; //Site's URL |Cfo(]>G
private String sFilePath; //Saved File's Path Ak`?,*LM
private String sFileName; //Saved File's Name G'HLnx}Yi
private int nSplitter; //Count of Splited Downloading File (7~vOWs:[
ex|)3|J
Uq%|v
public SiteInfoBean() sSiZG
{//nSplitter的缺省值为5 E>QEI;
//default value of nSplitter is 5 )OlYz!#?
this("","","",5); ;%>X+/.y0
} Jx&+e,OST
nu|?F\o!
D*HK[_5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) da8 R.1o
{ (Zy=e?E,
sSiteURL= sURL; jNIz:_c-~
sFilePath = sPath; HqOnZ>D
sFileName = sName; !C.{nOfyv
this.nSplitter = nSpiltter; ov>`MCS,v
FQJFq6l
3fop.%(
} 9I|Q`j?p`
R,zp&L
4x/u$Ixzh=
public String getSSiteURL() "bjbJC&T
{ mL,{ZL ^
return sSiteURL; \>eFs} Y/
} B7'2@+(
t6+>Zr
C|ou7g4'p
public void setSSiteURL(String value) S7hfwu&7F
{ 1T3YFt@&I
sSiteURL = value; Y7yzM1?t
} %bnjK#o"Q
69C ss'
<DdzDbgax
public String getSFilePath() klj.\wg/p{
{ Q[Tbdc%1EG
return sFilePath; o\yqf:V8
} (b1rd
N<lf,zGw
%{P." ki
public void setSFilePath(String value) D-5~CK4`
{ (WS<6j[q
sFilePath = value; n<sA?T
} ~_SVQ7P
&sPu3.p
yz=6 V%
public String getSFileName() Z@:R'u2Lk
{ n%P,"V
return sFileName; 'P)[=+O?t
} %6<2~
X1h*.reFAL
3qH`zYgh
public void setSFileName(String value) DWJkN4}o
{ 4=n%<U`Z/
sFileName = value; cE]#23
} @sb00ad2q
b(gcnSzM2
9]/ju
public int getNSplitter() 7wc{.~+
{ s((_^yf
return nSplitter; FUTDR-q O
} Y~bGgd]T
!J@pox-t
gbRdng7(}
public void setNSplitter(int nCount) -[`FNTTV C
{ c)o[3o7
nSplitter = nCount; 5Bc)QKh`l|
} }GTy{Y*&
} pNzGpCk
4.mbW
<ByDT$E_
/* IsCJdgG
**Utility.java pBu~($%d
*/ !bCLi>8
package NetFox; %z0@4Gq
!P26$US%P
U!x\oLP
public class Utility { Qmh*Gh?v
KhV; />(
B1Iq:5nmoS
public Utility() *ha9Vq@X
{ "]`QQT-{0
ZvO:!u0+"
G1'w50Yu
} )FqE8oN-
<cz~q=%v2&
//线程睡眠 v+=_
public static void sleep(int nSecond) 7iKbd
{ SwuadN
try{ ~+$l9~`{
Thread.sleep(nSecond); ':w6{b
} OkO"t
catch(Exception e) 9aC>gye!
{ `"CF/X^
e.printStackTrace (); [P{Xg:0
} `czXjZE
} q+o(`N'~G
8YN+ \
//日志 tZXtt=M w
public static void log(String sMsg) I/)dXk~
{ ]yVB66l
System.err.println(sMsg); X>|.BvY|
} hoeTJ/;dm
<$njU=YE&
>8tE`2[i*
public static void log(int sMsg) W#y)ukRv
{ {YbqB6zaM
System.err.println(sMsg); Vq'&t<K#
} ,_lwT}*w
} :({lXGc}4?
4'rk3nT8
V`WfJ>{;Z
/* "3j0)
**TestMethod.java c@q>5fR/c
*/ .(1$Q6yG
package NetFox; JrL/LGY
uV 6f~cQ
WD?V1:>+
public class TestMethod { nQ(#'9
w pCS]2
_1R`xbV
public TestMethod() *j*jA/
{ ///xx/weblogic60b2_win.exe @e0Q+t
try{ Zz3#Kt5t3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n'h )(^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6|dUz*Pr|\
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7e=a D~f
fileFetch.start(); [ $"iO#oO
} eO9nn9lql
catch(Exception e){e.printStackTrace ();} gaCGU<L
Z?Q2ed*j
.N+xpxdG,
} PvB?57wkF
7kwG_0QO
*/+s^{W7
public static void main(String[] args) =}"hC`3e
{ V[bc-m
new TestMethod(); BxT~1SBFq
} Sd\@Q% }o\
} p.\KmEx
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