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)); daIL> c"
} b'1d<sD
for(int i=0;i<nEndPos.length-1;i++) ,imvA5
{ n+qVT4o
nEndPos = nStartPos[i+1]; ewrWSffe
} EO&ACG
nEndPos[nEndPos.length-1] = nFileLength; /HuYduGdP
} ZGpTw[5ql
} nbASpa(
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O_Rcd&<mr
//启动子线程 U[QD!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aoDD&JE
for(int i=0;i<nStartPos.length;i++) E^ok`wfO
{ F>QT|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `f+8WPJPZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r^A#[-VyNP
nStartPos,nEndPos,i); =b<<5N s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N4H+_g|
fileSplitterFetch.start(); Yc82vSG'
} iEpq*Qj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;:4P'FWm^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d%lHa??/h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =*g$#l4
nEndPos = " + nFileLength); l}0V+
// fileSplitterFetch[nPos.length-1].start(); [9O~$! <%
E,LYS"%_
F[kW:-ne@Z
//等待子线程结束 V`\f+Uu
//int count = 0; `cP'~OT
//是否结束while循环 E ;!<Z4
boolean breakWhile = false; *?bk?*?s
AM[jL'r|
%R|"Afa=
while(!bStop) Q*:h/Lhb&
{ vV.~76AD5
write_nPos(); 6%kJDY.
Utility.sleep(500); S&3X~jD(1
breakWhile = true; =~hsKBt*
%XI"<Y\yL
Wzqb>.
for(int i=0;i<nStartPos.length;i++) `(,*IK a
{ adI!W-/R:
if(!fileSplitterFetch.bDownOver) 8pPC 9ew\=
{ ^.#X<8hr
breakWhile = false; < m enABN4
break; M%&A.j[
} KR=d"t Qw
} 2]D$|M?$~
if(breakWhile) 'cZMRRc<
break; RM&H!E<#
b6nZ55 h
$>r>0S#+\&
//count++; ^m_^
//if(count>4) #*$_S@
// siteStop(); 0\'Q&oTo
} "J pTE \/
{?*<B=c
TF=k(@9J?
System.err.println("文件下载结束！"); * -KJh_
} j/H>0^
catch(Exception e){e.printStackTrace ();} c6,s+^^
} i_=?eUq%q/
%o@['9U[j
vm\wO._
//获得文件长度 9q1HSJ1)
public long getFileSize() 5wH54gj}
{ ]3t1=+
int nFileLength = -1; ]$~Fzs
try{ I7dm \|#
URL url = new URL(siteInfoBean.getSSiteURL()); 2.LJp}>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #zS1Zf^KP
httpConnection.setRequestProperty("User-Agent","NetFox"); Vvm=MBgN
h `\$sT!Z
nn@^K6
int responseCode=httpConnection.getResponseCode(); U!&_mD# c
if(responseCode>=400) _F`$ d2
{ !/Iq{2LX
processErrorCode(responseCode); P+dA~2k
return -2; //-2 represent access is error Y=vVxVI\
} mRhd/|g*
><NI'q*cQ
)MWUS;O<
String sHeader; A%Bgp?B
[1{SY=)
6<x~Mk'u)
for(int i=1;;i++) Xhcn]
{ qH#r-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zoZ<)x=;
//Utility.log(in.readLine()); ic*->-!
sHeader=httpConnection.getHeaderFieldKey(i); erx5j\
if(sHeader!=null) L*g. 6+2
{ ZV'$k\
if(sHeader.equals("Content-Length")) lWx
{ %G;0T;0L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I|,pE**T
break; Y5dD|]F|
} No`|m0 :j
} GE1i+.+-.
else /g_9m
break; %#~((m1
} n*4lz^LR
} oZTgN .q
catch(IOException e){e.printStackTrace ();} 4k8*E5cx
catch(Exception e){e.printStackTrace ();} bIgh@= 2
P$Z}
z]kwRWe`j
Utility.log(nFileLength); Y3-gUX*w0
25 CZmsg
x_*%*H
return nFileLength; ^SZw`]
} %*wzO9w4
!^m%O0DT
B:4Ka]{YO
//保存下载信息（文件指针位置） I@2uF-
private void write_nPos() pO%{'%RA
{ Ve{n<{P
try{ Cye T]y
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4/S=5r}
output.writeInt(nStartPos.length); Hd9XfU
for(int i=0;i<nStartPos.length;i++) Ju!(gh
{ [r)eP({
// output.writeLong(nPos); +l`65!"
output.writeLong(fileSplitterFetch.nStartPos); 'Qa5n\HX$
output.writeLong(fileSplitterFetch.nEndPos); eD%HXGe
} 96d~~2p
output.close(); -fE.<)m=!
} /~De2mq1
catch(IOException e){e.printStackTrace ();} bEm7QgV{X
catch(Exception e){e.printStackTrace ();} *5_V*v6
} ~q)u(WC|
.XXW|{
7R}9oK_I
//读取保存的下载信息（文件指针位置） uG!:Z6%p
private void read_nPos() /F.Wigv
{ ,P{mk%=9
try{ xH-X|N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f-Jbs`(+
int nCount = input.readInt(); )qL&%xz
nStartPos = new long[nCount]; :ygWNK[6D
nEndPos = new long[nCount]; >ys[I0bo
for(int i=0;i<nStartPos.length;i++) ! QM.P t7c
{ j~;;l!({i
nStartPos = input.readLong(); H~noJIw#
nEndPos = input.readLong(); OS-sk!
} ^W~p..DF
input.close(); &(EHq
} j[I`\"
catch(IOException e){e.printStackTrace ();} T*?s@$)m4
catch(Exception e){e.printStackTrace ();} V A<5uk04K
} FmEc`N9\v
}bH$O%
z-dFDtiA
private void processErrorCode(int nErrorCode) -w1@!Sdd
{ J'b<z.OW
System.err.println("Error Code : " + nErrorCode); > _ <'D
} @@@=}!<H=
=pcF:D#+
&?0:v`4Y
//停止文件下载 >-.e AvD
public void siteStop() !v|FT. T`
{ O}Hf62"
bStop = true; fH\X
for(int i=0;i<nStartPos.length;i++) $=B8qZ+
fileSplitterFetch.splitterStop(); 8"%RCE
-'`TL$
K_~h*Yc
} <[Q3rJ
} Xd<t5{bD!
//负责部分文件的抓取 S4N(cn&
**FileSplitterFetch.java ('O}&F1
*/ ZrO!L_/
package NetFox; +x=)/;:
?^i1_v7 Bi
0V$k7H$Z
import java.io.*; 4[yIOs
import java.net.*; ?WUF!Jk
DZ$` 4;C[
W#'c5:m 4
public class FileSplitterFetch extends Thread { VA]e
lx |5?P
,E;;wdIt
String sURL; //File URL 0p(L'
long nStartPos; //File Snippet Start Position ,HB2hHD
long nEndPos; //File Snippet End Position .pPm~2]z
int nThreadID; //Thread's ID R!(ZMRMn
boolean bDownOver = false; //Downing is over >(r{7Qg
boolean bStop = false; //Stop identical ht=P\E
FileAccessI fileAccessI = null; //File Access interface g13 rx%-
cc}Key@D
0nJE/JZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iD`d99f8O
{ l[Q:}y
this.sURL = sURL; K4Sk+ v
this.nStartPos = nStart; yNg9X(U
this.nEndPos = nEnd; $P z`$~
nThreadID = id; ,CvG 20>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <eN_1NTH_
} @%/]Q<<q
j}1zdA
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public void run() "{D6J809
{ |4(~%| 8{
while(nStartPos < nEndPos && !bStop) G{Yz8]m
{ 3S*AxAeg
Yd EptAI
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try{ kDvc" ,SD#
URL url = new URL(sURL); 0NDftcB]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N8toxRu
httpConnection.setRequestProperty("User-Agent","NetFox"); TlZT1H
String sProperty = "bytes="+nStartPos+"-"; =(v^5
httpConnection.setRequestProperty("RANGE",sProperty); O.G'?m<:#
Utility.log(sProperty); O.`Jl%
ko;>#::
=U8Ek;Drp
InputStream input = httpConnection.getInputStream(); );V2?G`/
//logResponseHead(httpConnection); *N'K/36;
{-3LIO
)s_n
byte[] b = new byte[1024]; cD*}..-/4
int nRead; lot%N(mB`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ub1hHA*)
{ %`MQmXgM
nStartPos += fileAccessI.write(b,0,nRead); !RB)_7
//if(nThreadID == 1) <"N_j]wD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sm,VYYs
} {n#k,b&9B
E>b2+;Jv
r3E!dTDWq
Utility.log("Thread " + nThreadID + " is over!"); G!w"{Bk?9
bDownOver = true; /1N6X.Zb
//nPos = fileAccessI.write (b,0,nRead); uvDzKMw~R
} &QRE"_g
catch(Exception e){e.printStackTrace ();} qgIb/6;xQ
} +gd4\ZG
} ca i<,3H
zgx&Pte
6E(Qx~iL
//打印回应的头信息 Y8M]Lwj
public void logResponseHead(HttpURLConnection con) }En
{ !+>v[(OzM
for(int i=1;;i++) qm/Q65>E
{ :NJ_n6E
String header=con.getHeaderFieldKey(i); pl@O N"=[
if(header!=null) ,B?~-2cCz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )?+$x[f!*
Utility.log(header+" : "+con.getHeaderField(header)); vgY3L
else Z;9>S=w!
break; ^b:(jI*l
} ;!:U((wv
} :w}{$v}#D;
T134ZXqqz
ojYbR<jn9
public void splitterStop() 'z76Sa
{ sn7AR88M;
bStop = true; f}g\D#`]/
} Lg8nj< TF
*I}`dC[
'iLpE7
} 4tL<q_
~wg:!VWA)
X%yO5c\l2
/* ]7-&V-Ct*
**FileAccess.java F, U*yj
*//文件访问(定位，写) SGb;!T*
package NetFox; J>fQNW!{
import java.io.*; +"9hWb5
RMMd#/A@}
W3`>8v1?o
public class FileAccessI implements Serializable{ zJe#m|Z
f{SB1M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @`\VBW
RandomAccessFile oSavedFile; OL4z%mDZi
long nPos; LU!dN"[k
&-(463
3u%{dGa
public FileAccessI() throws IOException 3?Y2L
{ +P.+_7+:
this("",0); ^C2\`jLMY
} U,nEbKJgk
+`?Y?L^ J
WJI[9@^I~
public FileAccessI(String sName,long nPos) throws IOException [O: !(Gje
{ SG6sw]x
oSavedFile = new RandomAccessFile(sName,"rw"); j*~T1i
this.nPos = nPos; L^Jk=8
oSavedFile.seek(nPos); =zwOq(Bh W
} ~-wPP{!
jxYc2
(O0Urm
public synchronized int write(byte[] b,int nStart,int nLen) R|i/lEq
{ H'Yh2a`!o
int n = -1; sz9L8f2
try{ CI3XzH\IX*
oSavedFile.write(b,nStart,nLen); Z7 E
n = nLen; bWOS `5
} re> rr4@
catch(IOException e) ?%H):r
{ _X@v/sAy
e.printStackTrace (); cQ9q;r`%
} {Zp\^/
Nk {XdrY
V!)O6?l
return n; T#bu V
} ZvcJK4hi
g-Pwp[!qkf
Web|\CH
} OyqNLR
fu~+8CE.
Bn>8&w/P
/* `a9L%z
**SiteInfoBean.java ZE%YXG
*/ ~on(3|$
package NetFox; b(9FZ]7S
>I=2!C1w
ZJlEKib%2
public class SiteInfoBean { xW92ch+t
Wb S4pdA
>[X{LI(_<<
private String sSiteURL; //Site's URL 6~*9;!th
private String sFilePath; //Saved File's Path 4DTzSy:x
private String sFileName; //Saved File's Name G7D2{J{1
private int nSplitter; //Count of Splited Downloading File ;E'"Ks[GH
[Y`,qB<B
9{:O{nl
public SiteInfoBean() eI@ q|"U
{//nSplitter的缺省值为5 ,^S@EDq
//default value of nSplitter is 5 !0N7^Z"gtz
this("","","",5); iOG[>u0h
} ?&Pg2]g<
*cyeO*
a ^%"7Ri
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @)K%2Y`
{ M,ir`"s
sSiteURL= sURL; C:G8c[
sFilePath = sPath; %Q!`NCe+[
sFileName = sName; x\QY@9
this.nSplitter = nSpiltter; 2.d|G`
t='# |');
cW+t#>'r
} ,K^4fL$C;3
Oh4AsOj@
`c'W-O/
public String getSSiteURL() Yq/.-4y
{ hTwA%
return sSiteURL; 'g9"Qv?0{`
} [V}S<Xp
]D,MiDph
5aa<qtUjH
public void setSSiteURL(String value) j^`hzh3S
{ A19;1#$=
sSiteURL = value; A4ISNM7R[
} J/3_C6UZ
'TAUE{{
Zy_V9j[n
public String getSFilePath() M?;y\vS?.
{ +&["HoKg}&
return sFilePath; b=/curl&
} cCR+D.F
Dr6A,3B
c5mZG7-
public void setSFilePath(String value) U"50_O
{ +d|mR9^([
sFilePath = value; asC_$tsMe
} +CI1V>6^
?Mee 6
'FYJMIs
public String getSFileName() *s;|T?~i
{ O2"gj"D
return sFileName; vp.ZK[/`
} O-4C+?V
r:]1O*
@9&P~mo/
public void setSFileName(String value) t3+Py7qv
{ SI8%M=P>
sFileName = value; gsn)Wv$h
} 1 1cWy+8D
07hF2[i
~ Uo)0
public int getNSplitter() }Nb8}(6
{ 72,rFYvpK
return nSplitter; EKp@9\XBC
} \.g\Zib )
@UdfAyL
lqb/eN9(t
public void setNSplitter(int nCount) IVW1]y
{ i.:. Y
nSplitter = nCount; ~i.k$XGA
} $2%f 8&
} _$>pw<
yOvm`9
lq"f[-8a2q
/* BAO|)~1Pd
**Utility.java 0T>H)c6:\
*/ 72veLB
package NetFox; 5 B=^v#m
P#:?ok
wYlf^~#"
public class Utility { J6jwBo2m
u~)`&1{%
Y\0}R,]a-
public Utility() Uw4>v:
{ qn,O40/]
f$'2}'.!$
S'HnBn /
} ko^\HSXl
eW>3XD4
//线程睡眠 XerbUkZ
public static void sleep(int nSecond) 95<EN(oUD
{ %2V-~.Ro6
try{ Rml2"9"`
Thread.sleep(nSecond); RDtU43
} Q#IG;
catch(Exception e) nQGQWg`
{ FV,4pi
e.printStackTrace (); ,y%3mR_~
} _Ob@`
} Iz[@^IUx=
jM:Y'l]
//日志 mYU9 trHV
public static void log(String sMsg) |]Qg7m,O
{ _uJ"m8Tl
System.err.println(sMsg); a[2vjFf#C
} X<R?uI?L
jVH|uX"M5Y
2[gFkyqe
public static void log(int sMsg) ykrr2x
{ ujJI 1I
System.err.println(sMsg); ` }3qhar
} yAN=2fZm
} G"T',~
Z;h<6[(
A*|cdY]HP
/* [le)P$#z
**TestMethod.java O 1oxZj <
*/ vF?5].T
package NetFox; [ 4;Ii
qp}Ma8+
'<0J@^vZ
public class TestMethod { a {ab*tM
}^(}HBT
XO <y+
public TestMethod() /\)a
{ ///xx/weblogic60b2_win.exe @x/T&67k
try{ N4*G{g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cJgBI(S5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,TRTRb;
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~8m=1)A{(
fileFetch.start(); jLJ1u/l>;
} Jxqh)l
catch(Exception e){e.printStackTrace ();} F]mgmYD%
$3,ryXp7
d(:3
} H'qG/@u-l
=YG _z^'
` gW<M
public static void main(String[] args) mm5$> [%U
{ Uje|`<X
new TestMethod(); ,/O[=9l36R
} v2,%K`pAU
} QKE9R-KTE
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