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)); O<XNI(@
} 6+C]rEY/o
for(int i=0;i<nEndPos.length-1;i++) >R.!Qze\G
{ ): r'IR
nEndPos = nStartPos[i+1]; h*sL' fJ]
} n:Dr< q.
nEndPos[nEndPos.length-1] = nFileLength; 6^FUuj.
} Lo"s12fr
} =H^~"16
(: mF+%(
t1G2A`
//启动子线程 jtqU`|FSQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1J&hm[3[K
for(int i=0;i<nStartPos.length;i++) Hq,NOP
{ nQn=zbZ3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gV'=uz v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7'@~TM
nStartPos,nEndPos,i); wB<cW>6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tcI Z 2H%
fileSplitterFetch.start(); t~Ic{%bdA
} ZKi?;ta=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I#W J";kqB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VY0-18 o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -or)NE
nEndPos = " + nFileLength); T'N/A9{q
// fileSplitterFetch[nPos.length-1].start(); gpCWXz')i
g=Nde2d?
;3Q3!+%j
//等待子线程结束 lnV!Xuf
//int count = 0; cQ0+kX<
//是否结束while循环 Tcq@Q$H
boolean breakWhile = false; PW9tZx#
lW]&a"1$
%B| Ca&
while(!bStop) <S0gIg`)
{ 'jKCAU5/0;
write_nPos(); |;YDRI
Utility.sleep(500); +V#dJ[,8;.
breakWhile = true; / 6DW+!
1#2L9Bi
1\5po^Oioy
for(int i=0;i<nStartPos.length;i++) ,LL=b-Es
{ xJFxrG'c
if(!fileSplitterFetch.bDownOver) Nxm '* -A
{ h6D1uM"o
breakWhile = false; X C'|
break; <h`}I3Ao
} =z}M(<G
} Ul:M=8nE%
if(breakWhile) &VVvZ@X;
break; [kI[qByf
quFNPdP
q]y{ 4"=5
//count++; SqoO"(1x
//if(count>4) eW[](lGWM
// siteStop(); 0'R}'
} AQ,%5MeqJ
; VQ:\fG
L0ZAF2O
System.err.println("文件下载结束！"); ) =|8%IrB
} ` )~CT
catch(Exception e){e.printStackTrace ();} kO,vHg$
} <ol?9tm
+^%0/0e
XZ|\|(6Cc
//获得文件长度 {.r9l
public long getFileSize() H8!lSRq
{ H7Pw>Ta ;
int nFileLength = -1; Wk]E6yz6
try{ j8ac8J,}c
URL url = new URL(siteInfoBean.getSSiteURL()); uecjR8\e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CbT ;#0
httpConnection.setRequestProperty("User-Agent","NetFox"); wd Di5-A4
2c5)pIVEy
8ZDWaq8^2N
int responseCode=httpConnection.getResponseCode(); !:1BuiL
if(responseCode>=400) |PLWF[+t8
{ "T6s;'k
processErrorCode(responseCode); ^i17MvT'
return -2; //-2 represent access is error #LG<o3An
} N\x<'P4q
H(Ad"1~.#
_(KzjOMt
String sHeader; {)-3g~
q}J Eesf
Vc "+|^
for(int i=1;;i++) -4S4I
{ g"D:zK)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 37|EG
//Utility.log(in.readLine()); :tLMh08h
sHeader=httpConnection.getHeaderFieldKey(i); e`%<D[-
if(sHeader!=null) }9L;|ul6
{ jft@ 'W53
if(sHeader.equals("Content-Length")) h ?+vH{}j
{ BNbz{tbX"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2O0</^Z%E
break; E1|:t$>Ld
} r5uX?^mJ0
} Q_|Lv&
else .vpx@_;]9
break; .WW|v
} iMp_1EXe
} !A"-9OS2
catch(IOException e){e.printStackTrace ();} ^L's45&_
catch(Exception e){e.printStackTrace ();} !GZ{UmwA
'zYx4&s
CSMx]jbb
Utility.log(nFileLength); [3(lk_t
f`p"uLNo<
N1'$;9 c
return nFileLength; '6Yx03t
} iKgH :[j
E^V4O l<
:z+l=d:4
//保存下载信息（文件指针位置） f >\~h,SLL
private void write_nPos() oo!JAv}~
{ !Bb^M3iA
try{ ngH_p>
output = new DataOutputStream(new FileOutputStream(tmpFile)); S{qsq\X
output.writeInt(nStartPos.length); r1|;V~a$~
for(int i=0;i<nStartPos.length;i++) 6 kAXE\T
{ s!/Q>A
// output.writeLong(nPos); fMRMQR=6B
output.writeLong(fileSplitterFetch.nStartPos); UjS,<>fm
output.writeLong(fileSplitterFetch.nEndPos); /@K1"/fqH
} lhJZPnx~
output.close(); &y:SK)
} /??nOVvt
catch(IOException e){e.printStackTrace ();} +rOd0?
catch(Exception e){e.printStackTrace ();} <0H^2ekd
} b'G!)n
=' #yG(h
etH]-S
//读取保存的下载信息（文件指针位置） |&rxDf}W
private void read_nPos() (/Dr=D{ `
{ |(rTz!!-
try{ -{S:sK.o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y kcN-
int nCount = input.readInt(); O.OSLezTQ
nStartPos = new long[nCount]; &e1(|qax
nEndPos = new long[nCount]; Z=>#|pW,)
for(int i=0;i<nStartPos.length;i++) [xg&`x9,.
{ .V|o-~c
nStartPos = input.readLong(); J, vEZT<Mt
nEndPos = input.readLong(); 6?KJ"Ai9
} EnXTL]=0S
input.close(); X##hSGQM
} BW&)Zz
catch(IOException e){e.printStackTrace ();} _.3O(?p,
catch(Exception e){e.printStackTrace ();} #Ue_
} ]jwF[D
.06[*S
w:o,mzuXK
private void processErrorCode(int nErrorCode) kY`L[1G$
{ _0qp!-l}
System.err.println("Error Code : " + nErrorCode); DsF<P@O6
} _tpqo>
Y'2 |GJc2
;TG<$4N
//停止文件下载 yX|0R H
public void siteStop() +(J{~A~
{ SHP_
bStop = true; ($Ck5`_MK
for(int i=0;i<nStartPos.length;i++) y4~;H{!
fileSplitterFetch.splitterStop(); wdTjJfr
Ce_ES.
$${9 %qPzb
} D$G:#z*
} R(N5K4J
//负责部分文件的抓取 X2hyxTOp
**FileSplitterFetch.java fkK42*U@r
*/ \Dr?}D
package NetFox; P+[\9Gg
8iwqy0<
tJ!s/|u(
import java.io.*; NU$?BiB?R
import java.net.*; UqaV9
8!u8ZvbFG
a 9f%p
public class FileSplitterFetch extends Thread { }o MY
y(0";\V
IJV1=/NJW
String sURL; //File URL pcjb;&<
long nStartPos; //File Snippet Start Position 5t~p99#?
long nEndPos; //File Snippet End Position [DO UIR9
int nThreadID; //Thread's ID E]j2%}6Z%
boolean bDownOver = false; //Downing is over \dw*yZ^
boolean bStop = false; //Stop identical zeG_H}[2&
FileAccessI fileAccessI = null; //File Access interface D "9Hv3
gl~>MasV&
mu}T,+9\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t^-yK;`?q:
{ JVeb$_0k
this.sURL = sURL; Ju.B!)uS#
this.nStartPos = nStart; {P@OV1
this.nEndPos = nEnd; COk;z.Kn
nThreadID = id; yCT:U&8%F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6`Af2Y_
} eW^_YG%(
4` zfrT^
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public void run() *%wfR7G[B
{ j=~c( B
while(nStartPos < nEndPos && !bStop) l2LUcI$ x
{ aL%amL6CX
?A7_&=J%
dwAFJhgh
try{ N++jI(
URL url = new URL(sURL); P(#by{s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7Ta",S@m
httpConnection.setRequestProperty("User-Agent","NetFox"); m?Qr)F_M
String sProperty = "bytes="+nStartPos+"-"; 3>t^Xu~
httpConnection.setRequestProperty("RANGE",sProperty); ME%W,B.|"s
Utility.log(sProperty); ;.4A,7w#
(( D*kd"
o:irwfArv
InputStream input = httpConnection.getInputStream(); ,3tcti~sZ
//logResponseHead(httpConnection); pk0Cx
V)8d1S
7$&3(#!N
byte[] b = new byte[1024]; }^np
int nRead; o<r|YRzQl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kxp, ZP
{ g1s\6%g
nStartPos += fileAccessI.write(b,0,nRead); b;XUv4~V
//if(nThreadID == 1) *.]M1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UfUboxT
} Zw`vPvb!
;>duY\$<
!$i*u-%4
Utility.log("Thread " + nThreadID + " is over!"); <p74U( V
bDownOver = true; !K~:crUV|S
//nPos = fileAccessI.write (b,0,nRead); tuF hPqe {
} lSzLR~=Au
catch(Exception e){e.printStackTrace ();} `Z:5E
} <cn{S`
} v9qgfdBS5
@GpM4>:
dE[nPtstb
//打印回应的头信息 &eHhj9
public void logResponseHead(HttpURLConnection con) |_^A$Hv
{ I*Q^$YnM
for(int i=1;;i++) N5%zbfKM
{ 9j;L-
String header=con.getHeaderFieldKey(i); "X }@VT=
if(header!=null) SXW8p>1Jw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }(/")i4h
Utility.log(header+" : "+con.getHeaderField(header)); " tUS>c/
else )d\u_m W^
break; q{?ku!cL
} V{j>09u
} ?!:$Z4G
cJnAwIs_e`
} :@s
public void splitterStop() >K2Md*[P3q
{ (\UA+3$4
bStop = true; YGj3W.eH
} Rt[zZv
t'@qb~sf
!u0qF!/W
} lo%:$2*'p
nK"XyZ&
;%j1'VI
/* pS3TD"p
**FileAccess.java ;gC.fpu
*//文件访问(定位，写) #=G[~m\
package NetFox; .UUY9@
import java.io.*; "AzA|zk')"
0?tn.<'B8T
%$)[qa3
public class FileAccessI implements Serializable{ FM)Es&p&
YtzB/q8I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ptrQ~m-
RandomAccessFile oSavedFile; 5jTBPct
long nPos; Aqwjs 3
B4yC"55
*[-% .=[7
public FileAccessI() throws IOException e*7nq~ B5
{ wIv_Z^%V
this("",0); Tq r]5
} )Bl0 W
b0A*zQA_)
UKBVCAK
public FileAccessI(String sName,long nPos) throws IOException }w0>mA0=H
{ xMAfa>]{n
oSavedFile = new RandomAccessFile(sName,"rw"); Iq@:n_~
this.nPos = nPos; q\P"AlpC!
oSavedFile.seek(nPos); LG0z|x(
} fI5]ed eS
]ZQ3|ZJ?<
"QWF&-kAI
public synchronized int write(byte[] b,int nStart,int nLen) =,/08Cs
{ :3z`+5Y*
int n = -1; ~JJuM
try{ GvL)SVv?
oSavedFile.write(b,nStart,nLen); E,F'k2yU
n = nLen; 1 h.=c
} \a|FhhI
catch(IOException e) P,2FH2Eyj
{ Hqel1J
e.printStackTrace (); ;^q@w
} j{i3lGaN
7gLN7_2
: "|M
return n; V'XmMn)!
} T+OQa+E@P
\,-t]$9
e;y\v/A
} k* ayzg3F>
lzQmD/i*
. C g2Y
/* I.[2-~yf
**SiteInfoBean.java QBg~b{h
*/ YceX)
package NetFox; y~.k-b<{[
p7UdZOi2
bZ-"R 6a$
public class SiteInfoBean { Op&i6V}<s
xQ[~ c1
b h%@Lo
private String sSiteURL; //Site's URL 7~2b4"&
private String sFilePath; //Saved File's Path (vq0Gl
private String sFileName; //Saved File's Name i?.7o*w8
private int nSplitter; //Count of Splited Downloading File IXm}WTgF!
wUGSM"~ |
mgIB8D+6
public SiteInfoBean() 7QXA*.' F
{//nSplitter的缺省值为5 rOt`5_2f
//default value of nSplitter is 5 C%$:Oq
this("","","",5); 7oPLO(0L
} Y#>'.$(Az
C@{#OOa
|i)7jG<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hL1q9%
{ cs]N%M^s
sSiteURL= sURL; OF$0]V
sFilePath = sPath; [Yo3=(7J
sFileName = sName; 'W!N1W@
this.nSplitter = nSpiltter; 8oM]gW;J~
?-40bb
|\yVnk!c
} 1o&]=(
IFrq\H0
%\5wHT+)
public String getSSiteURL() 3#{{+5G
{ 83 O+`f
return sSiteURL; gnW]5#c@
} c-|~ABtEpX
8VbHZ9Q
fOE8{O^W
public void setSSiteURL(String value) X2X.&^
{ 5H (CP
sSiteURL = value; dKs^Dq
} J^}w,r*=
o5!"dxR
Q_ zGs6
public String getSFilePath() *h+@a
{ {`2R<O
return sFilePath; Y<~Nx~w{
} X6+2~'*t
(AHZmi V
\E9Hk{V:6
public void setSFilePath(String value) + 9vd(c
{ c6IFt4)g
sFilePath = value; h5+qP"n!?q
} K"p$ga{
>Oary
c,ccavv{I
public String getSFileName() }(x|
{ ']nB_x7
return sFileName; u"rK5'
} tCT-cs
-P|EV|8=
oV4+w_rrLc
public void setSFileName(String value) S >E|A%
{ 1b4aY> Z
sFileName = value; "`b"PQ<x
} ,XD'f
@,Je*5$o"
#41fRmzC
public int getNSplitter() kOv2E]
{ [;bZQ6JR
return nSplitter; TTg>g~t`
} @]*b$6tt
v&BKl
gv&%2e}_
public void setNSplitter(int nCount) nZ;h&N-_-
{ pEUbP,3M:
nSplitter = nCount; ]<9=%m
} VieX5
} O>zPWVwa
I y?_2m
y[U/5! `zV
/* x/nlIoT
**Utility.java U) tqo_
*/ g+5{&YD
package NetFox; 4@,d{qp~
Y{].%xM5
{`Ekv/XWa
public class Utility { yY,O=yOjq
("2ukHc
H*#L~!]
public Utility() @"M%ZnFu
{ :HSqa9>wa
~vD7BO`
sE*A,z?
} ENlqoj1
T*,kBJ
//线程睡眠 V^O dTM
public static void sleep(int nSecond) j, SOL9yg
{ (kpn"]^'
try{ zYf`o0U
Thread.sleep(nSecond); .&:GOD
} GA19=gow
catch(Exception e) bM]\mo>z<
{ @(XX68
e.printStackTrace (); &Gp~)%
} x+j5vzhG)
} W"9?D
!V~`e9[rl
//日志 al/3$0#U
public static void log(String sMsg) {}Y QB'}
{ SHw%u~[hu
System.err.println(sMsg); sb 3l4(8g
} fo63H'7
y'(bp=Nq
tw.2h'D
public static void log(int sMsg) >QwZt
{ pfj%AP:
System.err.println(sMsg); d*%-r2K
} yZf+*j/a7
} (<ybst6+I
?b',kN,(
az7<@vSXi
/* 9Y:JA]U&8
**TestMethod.java 65FdA-4
*/ iz'#K?PF_
package NetFox; }D5*
qaBjV6loy
&KfRZ`9H
public class TestMethod { #JAU5d
(bfHxkR.
D#>+]}5@x
public TestMethod() pdnkHR$
{ ///xx/weblogic60b2_win.exe Xg*IOhF6x
try{ lk $S"OH!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &FrW(>2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]?P9M<0PM
SiteFileFetch fileFetch = new SiteFileFetch(bean); x)6yWr[ri%
fileFetch.start(); te?R(&
} @kR/=EfS
catch(Exception e){e.printStackTrace ();} V1R=`
.e2qa
Hu$]V*rAG
} >S /Zd
&*TwEN^h
du2q6"
public static void main(String[] args) iqecm]Z0
{ (5@9j
new TestMethod(); 8+Lig
} 5TlPs_o
} '>:mEXK}w
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