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)); R0dIxG%
} Uf#.b2]
for(int i=0;i<nEndPos.length-1;i++) UV}\#86!
{ ,f ..46G
nEndPos = nStartPos[i+1]; /,v>w,
} wg<UCmfu!
nEndPos[nEndPos.length-1] = nFileLength; %$K2$dq5
} "LyMw){
} 34ij5bko_)
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acd8?>%[
//启动子线程 <T?H H$es)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P%`|Tu!B
for(int i=0;i<nStartPos.length;i++) "iFA&$\
{ jiS|ara"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Vsh7>|@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), s ~'><ioh
nStartPos,nEndPos,i); H'N$Vv2q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6[g~p< 8n}
fileSplitterFetch.start(); XRi/O)98o
} X2>qx^jT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?;1^8 c0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t?JY@hT*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bvZTB<rA
nEndPos = " + nFileLength); KLqn`m`O;
// fileSplitterFetch[nPos.length-1].start(); )NG{iD{_]
%Z|]"=;6
. C_\xb
//等待子线程结束 .kO!8Q-;%
//int count = 0; WVaIC$Y
//是否结束while循环 _jkH}o '
boolean breakWhile = false; ~ KNdV
/">A3bq
-:92<G\D
while(!bStop) H"hL+F^
{ .yp"6S^b
write_nPos(); 'Oyx X
Utility.sleep(500); Y{yN*9a79
breakWhile = true; =Kdd+g!
Z]-C,8MM
NPjh2 AJm
for(int i=0;i<nStartPos.length;i++) #$trC)?~q
{ o(iv=(o
if(!fileSplitterFetch.bDownOver) XEd|<+P1
{ @Y2"=QVt
breakWhile = false; JN;92|x
break; V. sIiE
} ~I^}'^Dbb
} 1o5DQ'~n
if(breakWhile) 6n9;t\'Gt
break; -P!_<\q\l
TUeW-'/1
7bBOV(/s
//count++; 56!>}!8!
//if(count>4) 6L--FY>.-
// siteStop(); XI6LPA0%
} >?b<)Q*<
CRsgR)
F$a?} }
System.err.println("文件下载结束！"); UO-<~DgH
} FQNw89g
catch(Exception e){e.printStackTrace ();} 0:K4,
} =X6+}YQ"
zPwU'TbF
['F,
//获得文件长度 G/tah@N[7
public long getFileSize() rSTc4m1R
{ 3wRk -sl
int nFileLength = -1; 7ky$9+~
try{ cI#2MjL
URL url = new URL(siteInfoBean.getSSiteURL()); |E+tQQr%'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v]*(Wd~|
httpConnection.setRequestProperty("User-Agent","NetFox"); FS.z lk\D=
_;*|"e@^
=}@m$g
int responseCode=httpConnection.getResponseCode(); }hT1@I
if(responseCode>=400) z!09vDB^
{ '8g/^Y@
processErrorCode(responseCode); :UuPy|>
return -2; //-2 represent access is error B Z:H$v
} @&f3zq
"z+Z8l1.
Ve<3XRq|8
String sHeader; -BWkPq!
!X 3/2KRP7
p^_E7k<ag
for(int i=1;;i++) [oOA@
{ #A|~s;s>N
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .hh2II
//Utility.log(in.readLine()); Up|\&2_
sHeader=httpConnection.getHeaderFieldKey(i); ZB-+bY
if(sHeader!=null) -"L)<J@gQ?
{ D7Y5q*F
if(sHeader.equals("Content-Length")) <&'Ye[k
{ QC:/xP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \Yv<TzJ9
break; W68d"J%>_
} 1k@k2rE
} =2%EIZ0oW
else \!8`kC
break; .ON+ ( #n
} a7G0
} gIA{6,A
catch(IOException e){e.printStackTrace ();} c"+N{$ vp
catch(Exception e){e.printStackTrace ();} jjgY4<n
$q}}w||e~0
*!De(lhEc
Utility.log(nFileLength); x/$s:[0B#
WWF#&)ti
Y=3:Q%X
return nFileLength; "4FL<6
} &k3'UN!&Ix
k fx<T
AR\?bB~`c
//保存下载信息（文件指针位置） S3"js4a
private void write_nPos() M%7H-^{
{ JL1%XQ i
try{ z"BV+
output = new DataOutputStream(new FileOutputStream(tmpFile)); @URLFMFi
output.writeInt(nStartPos.length); nbYkr*: "t
for(int i=0;i<nStartPos.length;i++) H3 _7a9
{ FAu G`zu
// output.writeLong(nPos); an3HKfv
output.writeLong(fileSplitterFetch.nStartPos); T6f{'.w
output.writeLong(fileSplitterFetch.nEndPos); 6Rn_@_Nn)f
} WNTm
output.close(); vx=I3o
} n5_r 3{
catch(IOException e){e.printStackTrace ();} '3uj6Wq2
catch(Exception e){e.printStackTrace ();} ~B%EvG7:n
} :>lica_
v>Il#
|dNtM^
//读取保存的下载信息（文件指针位置） ZNPzQ:I@
private void read_nPos() /2oTqEqaV
{ vCwDE~
try{ ?,r bD1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "fLGXbNQ
int nCount = input.readInt(); *qg9~/
nStartPos = new long[nCount]; /qF7^9LtaY
nEndPos = new long[nCount]; O?@1</r^
for(int i=0;i<nStartPos.length;i++) {xt<`_R
{ yy?|q0
nStartPos = input.readLong(); ] K7>R0
nEndPos = input.readLong(); ?Gl'-tV
} EU,4qO
input.close(); 6<H[1PI`,G
} e4NT
catch(IOException e){e.printStackTrace ();} @6GM)N\{[
catch(Exception e){e.printStackTrace ();} sTqy-^e7
} +7<{yP6wU
_u}v(!PI
:EyH'v
private void processErrorCode(int nErrorCode) /#$bb4
{ R_*b<~[/
System.err.println("Error Code : " + nErrorCode); xy$FS0u
} Xvs{2
5fb,-`m.
8{Y ?;~G
//停止文件下载 &RXd1>|c2
public void siteStop() ~U8#Iq1
{ ;-=y}DK
bStop = true; }Iub{30mp
for(int i=0;i<nStartPos.length;i++) 8BNsh[+
fileSplitterFetch.splitterStop(); ^Gv<Xl
^g[\.Q
nx=#QLi
} %R;cXs4r
} ]T^m>v)X
//负责部分文件的抓取 d^ !3bv*h
**FileSplitterFetch.java H'I|tPs
*/ |dD!@K
package NetFox; -/
zx(j6
Kggf!\MR8
import java.io.*; >^:g[6Sj
import java.net.*; nAF@47Wo
YH<F~F _
C?rL>_+71
public class FileSplitterFetch extends Thread { '*>LZo4
Beqhe\{
mkBQX
String sURL; //File URL j %TYyL-
long nStartPos; //File Snippet Start Position ^yK94U;<Gy
long nEndPos; //File Snippet End Position q22cp&gmX
int nThreadID; //Thread's ID Hh;w\)/%j
boolean bDownOver = false; //Downing is over }U'5j/EFZ
boolean bStop = false; //Stop identical '! 1ts@
FileAccessI fileAccessI = null; //File Access interface ;~]&$2sk
e%bERds
CR934TE+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException w#F+rh3
{ |@nvg>mu
this.sURL = sURL; ZX-9BJ`Q
this.nStartPos = nStart; jT::o
this.nEndPos = nEnd; d?N"NqaN
nThreadID = id; kTiQO2H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pw>AQ
} zp4ru\
U_}$QW0'
!u6~#.7
public void run() ?RpT_u
{ bwVv#Z\r
while(nStartPos < nEndPos && !bStop) a #@Q.wL
{ YGWb!|Z$
+1d\ZZA|6&
#-'}r}1ZT
try{ |B`-chK
URL url = new URL(sURL); ]Vb#(2<2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =V5.c+
httpConnection.setRequestProperty("User-Agent","NetFox"); .yTk/x?
String sProperty = "bytes="+nStartPos+"-"; h!K B%4V
httpConnection.setRequestProperty("RANGE",sProperty); IJ4"X#Q/
Utility.log(sProperty); sTG+c E
2zFdKs,
Qmn5umd=?\
InputStream input = httpConnection.getInputStream(); WP]<\_r2
//logResponseHead(httpConnection); l7s=b4}c
k 5"3*
izFu&syv)
byte[] b = new byte[1024]; T@yH.4D
int nRead; CPVKz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VdeK~#k
{ $#RD3#=?u
nStartPos += fileAccessI.write(b,0,nRead); ~Y'e1w$`
//if(nThreadID == 1) m6;Xo}^w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yFpHRfF}
} w|L~+
/#:RYM'Tu
?G?=,tV
Utility.log("Thread " + nThreadID + " is over!"); 2M&4]d
bDownOver = true; K6Gc)jp:b
//nPos = fileAccessI.write (b,0,nRead); ,6M-xSDs
} ,j_{IL690
catch(Exception e){e.printStackTrace ();} &us8,x6yg
} _5`M( ;hL2
} K&)a3Z=(.
5)nv
}qKeX4\-
//打印回应的头信息 >`{i[60r
public void logResponseHead(HttpURLConnection con) {Y0I A97,
{ rM?D7a{q
for(int i=1;;i++) Ap!UX=HBb
{ 0H>Fyl2_
String header=con.getHeaderFieldKey(i); e< CPaun
if(header!=null) >}4]51s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3Aj_,&X.@(
Utility.log(header+" : "+con.getHeaderField(header)); c%Gz{':+
else zr[~wM
break; 8PEOi
} grfF\_[:
} 1)YFEU&]
J:(Shd'4D
%ly;2HIk
public void splitterStop() lwY{rWo
{ > T-O3/KN
bStop = true; ,B#Y9[R
} ^m+W
,gOQIS56
J,D{dYLDD
} &U=f,9H
|E~X]_Y
/GXO2zO
/* 9{TOFjsF
**FileAccess.java ReE3742@
*//文件访问(定位，写) 3?%kawO&
package NetFox; P9>C!0 -x
import java.io.*; 6AwnmGL(;;
#!5Nbe
e`~q;?:
public class FileAccessI implements Serializable{ WuNu}Ibl}m
Dw#&x/G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yBe/UFp+
RandomAccessFile oSavedFile; _bd#C
long nPos; PR'FSTg
]bR'J\Fwl
ib&qH_r/
public FileAccessI() throws IOException xaS
{ uc<@ Fh(
this("",0); p!a%*LfND
} xsTxc&0^
GawO>7w8
AO]lXa
public FileAccessI(String sName,long nPos) throws IOException ~Afs
{ 3>(`Y
oSavedFile = new RandomAccessFile(sName,"rw"); 9@1W=sl
this.nPos = nPos; ~>C>LH>8
oSavedFile.seek(nPos); kp6x6%{K\
} M[{Cy[ta
7_3O]e[8
"J.jmR;
public synchronized int write(byte[] b,int nStart,int nLen) Tk!b`9
{ }dHiW:J>
int n = -1; u#,]>;
try{ 4bBxZY
oSavedFile.write(b,nStart,nLen); G6,8Xwk
n = nLen; MYPcH\K$h
} "pPNlV]UA^
catch(IOException e) KC(Ug4
{ UQR"wUiiV
e.printStackTrace (); |pgkl`
} :L[6a>"neE
vjb?N
m#ie{u^
return n; Imwx~eo
} 8`t%QhE2
ks5'Z8X
Vj]kJ,j\y
} X^W> "q
5oKc=iX_3
xY S%dLE"
/* 9y4rw]4zI
**SiteInfoBean.java (=/F=,w
*/ H_j<%VW
package NetFox; _+N^yw,r*
Pc7:hu
p~.@8r(
public class SiteInfoBean { <e^/hR4O
DPwSg\*)
#'8PFw\zw
private String sSiteURL; //Site's URL SIlg
private String sFilePath; //Saved File's Path BQU5[8l
private String sFileName; //Saved File's Name "(NHA+s/
private int nSplitter; //Count of Splited Downloading File IebS~N E
5);#\&B
JqUVGEg
public SiteInfoBean() e%U*~{m+
{//nSplitter的缺省值为5 .vv*bx
//default value of nSplitter is 5 8j'*IRj*q
this("","","",5); 752wK|o0|;
} _}&]`,s>
m%[t&^b}T
9NP l]iA)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tv$7aVi!
{ 'oz={;
sSiteURL= sURL; YfPo"uxx
sFilePath = sPath; #:|Y(,c
sFileName = sName; cDiz!n*.q
this.nSplitter = nSpiltter; +29\'w,
{h"\JI!
@__;RVQ
} B@]7eVo
`I8^QcP
ymZ/(:3_
public String getSSiteURL() ,}tdfkZFYl
{ o"FiM5L^.
return sSiteURL; Xa@wN/"F
} (UF!Zb]{
Gme$FWa
F}]_/cY7B
public void setSSiteURL(String value) Q:O>kCDV
{ RfBb{?PP)
sSiteURL = value; y!gM)9vq
} j7 =3\SO
LJwMM
M0SH-0T;Z
public String getSFilePath() t^,Qy.L0
{ 358/t/4{p
return sFilePath; Pm^N0L9?q
} ~(j'a!#Vvk
xLI{=sL
U 0RfovJ
public void setSFilePath(String value) HF: T]n,
{ (nD$%/uK'
sFilePath = value; yXA f
} BozK!"R_<
<83gn :$
qb4;l\SfT
public String getSFileName() %vtSeJ
{ ;p 5v3<PC
return sFileName; DBBBpb~~
} K$cIVsfr
1=Zw=ufqV
\Byk`} 9
public void setSFileName(String value) B bw1k
{ SECQVA_y`
sFileName = value; RQCQGa^cP
} V;-.38py
Ue#yDTjc
_IV@^v
public int getNSplitter() )v=G}j^
{ cXcx_-
return nSplitter; (VaN\+I:T
} *ZR@z80i
AaYrVf 9!
YC&jKx.>
public void setNSplitter(int nCount) 8Wx@[!
{ Om2X>/V%C
nSplitter = nCount; _P<lG[V
} KWJgW{{v
} C9U{^
+;*(a3Gp
18"VB50b}
/* 2nU NI U
**Utility.java D}/=\J/
*/ Hu9R.[u
package NetFox; lF8dRIav
o,Zng4NY
O*03PF^
public class Utility { ]cqZ!4?_
z|]oM#Gt
!mxh]x<e
public Utility() SxZ^ "\H
{ %<C G|]W
F|Dz]ar
]jVSsSv
} bp>ps@zFq
; G59}d p~
//线程睡眠 tOM3Gs~o6z
public static void sleep(int nSecond) 4@]xn
{ #* gU[9U~
try{ {vT55i<mk
Thread.sleep(nSecond); abaQJ|
} DV[ Jbl:)
catch(Exception e) @`;Y/',
{ W B*`zCM
e.printStackTrace (); 5Ue^>8-
} v^],loi<V
} 6G<Hi"I
g<iwxF
//日志 HCjn9
public static void log(String sMsg) ^?X^+
{ j t`p<gI
System.err.println(sMsg); "26B4*
} '^ e/F)0
@CaD8%j{
B~!G lT
public static void log(int sMsg) ]tQDk4&i
{ 6I cM:x
System.err.println(sMsg); V1`5D7Z
} #HM\a
} I4<{R
/s8%02S
L_~I~
/* e}R2J`7
**TestMethod.java 9O=05CQ
*/ o?va#/fk
package NetFox; CS;W)F
4ljvoJ}xjr
]\a\6&R
public class TestMethod { \buZ?
<Sprp]n 7
YZBzv2'\x
public TestMethod() 64!ame}n+
{ ///xx/weblogic60b2_win.exe W\>^[c/
try{ HhWwc#B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }r~v,KDb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ll(e,9.D
SiteFileFetch fileFetch = new SiteFileFetch(bean); xV,4U/T
fileFetch.start(); c#n4zdQd]5
} /+4^.Q*
catch(Exception e){e.printStackTrace ();} FU5LYXCs
lpfwlB'~9
r%TLv
} b 5F4+
5xMA~I0c
V<HOSB7
public static void main(String[] args) AU\xNF3
{ t*Vao
new TestMethod(); co<2e#p;
} 4aalhy<j
} 1=/doo{^
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