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)); CF+:v(NL
} 7=A @P
for(int i=0;i<nEndPos.length-1;i++) tg~7^(s
{ )_l(WF.
nEndPos = nStartPos[i+1]; Ax4;[K\Q
} eW_EWVH
nEndPos[nEndPos.length-1] = nFileLength; nxuR^6Ai
} x ;]em9b
} E_xk8X~
%!L*ec%,
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//启动子线程 %VrMlG4hx
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2T"[$iH!7
for(int i=0;i<nStartPos.length;i++) PJh97%7
{ `KP}pi\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sJ_3tjs)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n8&x=Z}Xs
nStartPos,nEndPos,i); ~}G#ys\1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6x@]b>W
fileSplitterFetch.start(); 368H6 Jj
} s%N6^}N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z2dW)_fU$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k{\a_e`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NE@P8pQ>
nEndPos = " + nFileLength); A&Q!W)=
// fileSplitterFetch[nPos.length-1].start(); Ez>!%Hpn\
&{x`K4N
u3PM 7z!~
//等待子线程结束 ZgzYXh2
//int count = 0; Ak\"C4s
//是否结束while循环 ^P*+0?aFr
boolean breakWhile = false; <yKyM#4X
c+<gc:#jy
_b[Pk;8}j;
while(!bStop) \@7 4I7
{ &KeD{M%
write_nPos(); ZD8E+]+
Utility.sleep(500); b$B-LvHd1
breakWhile = true; Z Mf,3
O$Dj_R#
J]&nZud`
for(int i=0;i<nStartPos.length;i++) VmTgD96
{ #XAH`L\
if(!fileSplitterFetch.bDownOver) 7"{CBbT
{ 2AjP2
breakWhile = false; Nbm$ta
break; PE+{<[n
} DJH,#re>
} leJ3-w{ 2
if(breakWhile) /<IXCM.
break; jTok1k
l @r`NFWD@
RgVg~?A@
//count++; rGSi !q
//if(count>4) #Xun>0
// siteStop(); 1h?:gOig
} A)TO<dl
}ev+WIERQV
h56s~(?O
System.err.println("文件下载结束！"); G*^4CJ
} ~#JX 0J=
catch(Exception e){e.printStackTrace ();} |Fzt| \
} Ua>.k|>0
V5]\|?=
d%ncI0f`
//获得文件长度 au7@-_
public long getFileSize() bY=Yb
{ Hd~fSXFl
int nFileLength = -1; <V4"+5cJ8
try{ ^|%7}=e
URL url = new URL(siteInfoBean.getSSiteURL()); +PHuQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _dn*H-5hO
httpConnection.setRequestProperty("User-Agent","NetFox"); boIFN;Aq"
-k@Uo(MB
ch0x*[N@
int responseCode=httpConnection.getResponseCode(); /C[XC7^4'
if(responseCode>=400) N|s8PIcSp
{ x@<!#d+
processErrorCode(responseCode); N_y#Y{c{(
return -2; //-2 represent access is error (7}Zh|@W
} 2H`;?#Uq:
vb k4
:j% B(@b
String sHeader; kX'a*AG
KU;m.{
unkA%x{W;
for(int i=1;;i++) ~RnBs`&!
{ qnU$Pd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vXcgl
//Utility.log(in.readLine()); c}#(,<8X
sHeader=httpConnection.getHeaderFieldKey(i); @-}!o&G0
if(sHeader!=null) Z+! 96LR
{ -<gQ>`(0
if(sHeader.equals("Content-Length")) x!9bvQT
{ ut9R]01:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Yk#$-"c/a
break; l)91v"vJ
} VV=6v;u`
} ]hA]o7k
else LfG$?<}hR
break; R~XNF/QMl
} I$Fr8R$
} K|{&SU_m
catch(IOException e){e.printStackTrace ();} q|R$A8)L.
catch(Exception e){e.printStackTrace ();} 4S,/Z{ J.
D$bJs O
<e'l"3+9(
Utility.log(nFileLength); vTYgWR,h
}{ "RgT-qG
\E2S/1p
return nFileLength; h>jp.%oOu
} [IW6F
ZfIeq<8_
}zV#?;}
//保存下载信息（文件指针位置） 3})0p
private void write_nPos() 1 ,4V8gp
{ &pLCN[a
try{ ]7_O#MY1
output = new DataOutputStream(new FileOutputStream(tmpFile)); 97SG;,6
output.writeInt(nStartPos.length); !fG`xZ~
for(int i=0;i<nStartPos.length;i++) V@1K
{ >oc&hT
// output.writeLong(nPos); v`u>;S_
output.writeLong(fileSplitterFetch.nStartPos); %Z6\W; (n
output.writeLong(fileSplitterFetch.nEndPos); Zl`sY5{1
} N`i`[ f
output.close(); %c,CfhEV%&
} 55|.MXzq
catch(IOException e){e.printStackTrace ();} 7!E7XP6,~>
catch(Exception e){e.printStackTrace ();} E 5bo60z
} Z~Z+Yt;,9a
`_H^k!^
_<G%
//读取保存的下载信息（文件指针位置） |m>n4-5QL
private void read_nPos() "]{"4qV1=
{ 8\ WOss)al
try{ cK+y3`.0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r=pb7=M#LN
int nCount = input.readInt(); vE+OL8V
nStartPos = new long[nCount]; $;%dQ!7*
nEndPos = new long[nCount]; QCk(qlN'h9
for(int i=0;i<nStartPos.length;i++) Z8_QKw>
{ x<e-%HB*-
nStartPos = input.readLong(); .TWX,#
nEndPos = input.readLong(); mdD9Q N01
} ) "Toh=x]
input.close(); /2PsC*y
} *;C8g{
catch(IOException e){e.printStackTrace ();} n`)wD~mk
catch(Exception e){e.printStackTrace ();} M4TFWOC1
} #2*2xt
t#[u X?
-,#LTW<.
private void processErrorCode(int nErrorCode) z;EnAy{9
{ l<mEGKB#
System.err.println("Error Code : " + nErrorCode); k@= LR
} P(BV J_n
r=ds'n"
w~(x*R}
//停止文件下载 tqo!WuZAj
public void siteStop() x2gP, p-
{ a0ze7F<(
bStop = true; ~_Mz05J-\_
for(int i=0;i<nStartPos.length;i++) :-kXZe
fileSplitterFetch.splitterStop(); IW'2+EGc
juuV3et
iy_\1jB0
} zx{O/v KG
} r'ydjy
//负责部分文件的抓取 5=.EngG
**FileSplitterFetch.java 8QGj:3
*/ |.Pl[y
package NetFox; +tXOP|X
!zNMU$p
C=/nZGG
import java.io.*; #dgWXO
import java.net.*; D%Y{(l+X
z3[0BWXs
-f-2!1&<3h
public class FileSplitterFetch extends Thread { :J}@*>c
8HLcDS#
7E9h!<5v
String sURL; //File URL .1F^=C.w
long nStartPos; //File Snippet Start Position H19CVc\B
long nEndPos; //File Snippet End Position k98}Jx7J)"
int nThreadID; //Thread's ID L){rv)?="
boolean bDownOver = false; //Downing is over _8'FI_E3
boolean bStop = false; //Stop identical P2Ja*!K]
FileAccessI fileAccessI = null; //File Access interface vK\;CSk
oGLSk(T&I
K>`7f]?H*e
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E@_M|=p&
{ nJ4CXSdE
this.sURL = sURL; e1RtoNF^
this.nStartPos = nStart; ;U|^Tsuc`
this.nEndPos = nEnd; h?:lO3)TL=
nThreadID = id; zAxwM-`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q#RVi8('
} WqC6c&NM
TvWhy`RQ
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public void run() ),-4\!7
{ 6tbH(
while(nStartPos < nEndPos && !bStop) Ir*,fyl
{ kE".v|@
@:. 6'ji,`
gi7As$+E
try{ n8M/Y}mH
URL url = new URL(sURL); M,Px.@tw.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *s6MF{Ds
httpConnection.setRequestProperty("User-Agent","NetFox"); pAV}hB
String sProperty = "bytes="+nStartPos+"-"; T@]vjXd![
httpConnection.setRequestProperty("RANGE",sProperty); (r^IW{IndX
Utility.log(sProperty); /y,~?
g'`J'6Pn
x=qACoq
InputStream input = httpConnection.getInputStream(); jBEt!Azur
//logResponseHead(httpConnection); XRI1/2YA
kl|KFdA;
!o 7uZC\
byte[] b = new byte[1024]; .JpYZ |
int nRead; BcT|TX+ct
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -NVk>ENL4
{ T!hU37g h?
nStartPos += fileAccessI.write(b,0,nRead); 2f]9I1{
//if(nThreadID == 1) 2I'\o7Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wv"[,5 Z13
} 'Z7oPq6
0n_Cuh\
O4&/g-
Utility.log("Thread " + nThreadID + " is over!"); IjDG
bDownOver = true; ~`{HWmah
//nPos = fileAccessI.write (b,0,nRead); mLO{~ruu
} IrXC/?^h
catch(Exception e){e.printStackTrace ();} n\ma5"n0=\
} F,e_`
} '8>#`Yba
T"Wq:
)*^PMf
//打印回应的头信息 ;1cX|N=
public void logResponseHead(HttpURLConnection con) /s=TLPm
{ 1C=}4^Pu
for(int i=1;;i++) L`+\M+
{ E<a~ `e
String header=con.getHeaderFieldKey(i); *kxk@(lT?
if(header!=null) 6yF4%Sz9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =?57*=]0M
Utility.log(header+" : "+con.getHeaderField(header)); >;QkV6i7
else fZXJPy;n
break; 5-w6(uu
} 5Lt&P 5BY
} 9r7QE&.
D|Z,eench
P!m~tu}B
public void splitterStop() @-;-DB]j
{ Xig+[2zS
bStop = true; 7BF't!-2F
} ^$_a_ft#
e9q/[xMi
iYv6B6o/99
} P7E}^y`e
5gV8=Ml"V
ag?@5q3J}
/* L"tj DAV
**FileAccess.java ^?toTU
*//文件访问(定位，写) _q=$L eO5
package NetFox; c?eV8h1G
import java.io.*; mxQS9y
s+^o[R T3
:M ix*NCf
public class FileAccessI implements Serializable{ r[M]2h
'8k\a{t_z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (1(3:)@S6
RandomAccessFile oSavedFile; Os8]iNvW\
long nPos; 8R:H{)o~s}
`/]8C&u
uHQJ&
public FileAccessI() throws IOException 42Vy#t/HC
{ *s?&)][
this("",0); 8{JTR|yB
} : Ot\l
h.4;-&
oRy?Dx+H
public FileAccessI(String sName,long nPos) throws IOException & HphE2 h
{ dlK#V)
oSavedFile = new RandomAccessFile(sName,"rw"); %o#D"
this.nPos = nPos; $}OU~d1q
oSavedFile.seek(nPos); 0c7&J?"wE
} f;pR8
~?-U J^#
{*t'h?b
public synchronized int write(byte[] b,int nStart,int nLen) Fm,A<+l@u
{ xwT"Q=|kW
int n = -1; @OFl^U0/
try{ ERGDo=j
oSavedFile.write(b,nStart,nLen); X'jEI{1w
n = nLen; 0V}vVAa(B
} @w6^*Z_hQ
catch(IOException e) [CRy>hfV
{ ~@BV
e.printStackTrace (); vo uQ.utl
} b\gl9"X
'|4/aHU
TR{8A^XhE8
return n; \#2,1W@
} ?_W "=WpC
)R9>;CuC9?
Tr/wG
} 1(hgSf1WH
qJ"dkT*
9qwVBu ;
/* -1S+fUkiK/
**SiteInfoBean.java wXXv0OzK
*/ Xj+1]KRN
package NetFox; |mk$W$h
s4MP!n?gB
+Z$X5Th
public class SiteInfoBean { !j%)nU
@/anJrt
3'u%[bx E
private String sSiteURL; //Site's URL T_jwj N
private String sFilePath; //Saved File's Path =#T6,[5
private String sFileName; //Saved File's Name 5[X^1
private int nSplitter; //Count of Splited Downloading File ;5"r)F+P
cdzzS?$)
MZ+8wr/y
public SiteInfoBean() Gk799SDL
{//nSplitter的缺省值为5 ?)4|WN|c_
//default value of nSplitter is 5 8dIgw
this("","","",5); i]hFiX
} wOHK dQ'
wc~a}0uz
I.y|AQB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e#kPf 'gL
{ E;VW6[M
sSiteURL= sURL; ]4uIb+(S
sFilePath = sPath; JZu7Fb]L9
sFileName = sName; \)y5~te*
this.nSplitter = nSpiltter; 09|d<
dW8'$!@!!
.__X[Mzth3
} b*dRNu
c0!bn b
q*Ns]f'a
public String getSSiteURL() ;13lu1
{ (.%:Q0i1
return sSiteURL; 7ou2SL}k
} |`qur5h`
?PyI#G
/o8`I m
public void setSSiteURL(String value) [^ 7^&/0
{ <&l3bL
sSiteURL = value; W.zA1S
} 4X#>;
Pm+H!x,
JsfbY^wz
public String getSFilePath() H -.3r
{ A3'i -
return sFilePath; K{M_ 4'\
} @] )a
"-v9V7KCM
g"#R>&P
public void setSFilePath(String value) )F4er'
{ .t"s>jq 1
sFilePath = value; 'cH),~ z
} *|euC"5c
(X>r_4W$
ms;Lu-UR
public String getSFileName() 4"l(rg
{ bhe|q`1,E
return sFileName; I \vu?$w
} 6G@_!i*2F
"-ZuH
v`y{l>r,
public void setSFileName(String value) Uy_`=JZ
{ |P5?0{
sFileName = value; 86IAAO`#
} eSa ]6
xiA9X]FB
_6=6 b!hD
public int getNSplitter() G_j`6v)
{ ^Y #?@
return nSplitter; 0qJ(3N
} bG.aV#$FIg
N1#*~/sXh
<-}6X
public void setNSplitter(int nCount) wQM(Lm#Q
{ C+y:<oo)
nSplitter = nCount; y3;G<9K2c]
} "5Kx]y8
} z%*ZmF^K
+` Em&
ub,Sj{Mq"
/* wG^{Jf&@$
**Utility.java 5"XcVH4g
*/ oh& PQ{
package NetFox; IWm|6@y
aeH 9:GQ6
7|,5;
public class Utility { InPq1AH
;"joebZ/
E@t~juF!
public Utility() +(cs,?`\
{ TmzEZ<} &7
x,>@IEN7
zpg*hlv
} 9-bDgzk
WNd(X}
//线程睡眠 RMLs(?e
public static void sleep(int nSecond) DJrA@hm/Y
{ s'} oVx]
try{ gtCd#t'(V
Thread.sleep(nSecond); `n5)oU2q
} !n)2HDYhx,
catch(Exception e) lXv{+ic
{ @BW~A@8
e.printStackTrace (); ~Qzm!Po,
} uiDR}
} 47 m:z5;
Dyt}"r\
//日志 D}\% Q #
public static void log(String sMsg) (MNbABZQ
{ 5^0W\
System.err.println(sMsg); 7*@qd&
} #G9S[J=xe
(hd2&mSy
QabF(}61
public static void log(int sMsg) K-p1v!IC
{ bS* "C,b~s
System.err.println(sMsg); K[T?--H
} 5;dnxhf
} l4r09"S|V
j>?c]h{-
.D)'ZY
/* X<Vko^vlj
**TestMethod.java Qy@chN{eP
*/ ]_F%{8|
package NetFox; wCn W]<+
~p8-#A)X,)
L6 hTz'
public class TestMethod { _E&*JX
Z4E:Z}~''
_?O'65
public TestMethod() DFR.F:O%
{ ///xx/weblogic60b2_win.exe a{Tv#P*!
try{ 1_GUi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MlS<txFPS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =wI,H@
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~{U~9v^v(
fileFetch.start(); JsVW:8QO~
} I.q nA
catch(Exception e){e.printStackTrace ();} A9$q;8= <
qBKIl= ne
ETjlq]@j
} vxZz9+UbF
2hmV1gj
"{L%5:H@
public static void main(String[] args) In^$+l%O[
{ N55;oj_K
new TestMethod(); Ngh9+b6[
} Q@/wn
} !cp ,OrO\
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