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)); W;%$7&+0
} `o|Y5wQ@
for(int i=0;i<nEndPos.length-1;i++) <% #Dwo}
{ xVYy`_|
nEndPos = nStartPos[i+1]; F[am2[/<A
} NMJX `
nEndPos[nEndPos.length-1] = nFileLength; w]<V~X
} b>g&Pf#N!
} xE>H:YPm
6L5j
Q8-;w{%
//启动子线程 N,kPR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xAJ N(8?
for(int i=0;i<nStartPos.length;i++) 9~3;upWu!
{ 4-j3&(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /`6Y-8e2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8(d Hn
nStartPos,nEndPos,i); 0QJ :
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DpD19)ouy
fileSplitterFetch.start(); RHO|g0
} |T`ZK?B+u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c,@&Z#IZ`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |w; hu]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {"kEu
nEndPos = " + nFileLength); Y=G9|7*lO
// fileSplitterFetch[nPos.length-1].start(); .M(')$\U
>-S?rXO
/wAx#[c[
//等待子线程结束 Nk JOD3>U
//int count = 0; 9t$#!2z
//是否结束while循环 *Wbs{>&No
boolean breakWhile = false; [d"]AF[#
2Xw=kwu
RBOb/.$
while(!bStop) pg<m0g@W*;
{ D;?cf+6$
write_nPos(); sF.oZ>
Utility.sleep(500); stxei 6
breakWhile = true; 6chcpP0
h2S!<
TA4>12C6
for(int i=0;i<nStartPos.length;i++) 5:R$xgc
{ Zc!rL0T
if(!fileSplitterFetch.bDownOver) DsJ ikg(J
{ 5r2A^<)
breakWhile = false; mYUR(*[
break; 1s-dqHz"s
} {beu
} D;1?IeS
if(breakWhile) `GDWy^-Q+!
break; -G'U\EXT
UY5wef2sF
8'sT zB]
//count++; }H5~@c$
//if(count>4) 7!qO*r
// siteStop(); xdLMy#U2
} ()}(3>O-
'@0Z#A
#}xw *)3
System.err.println("文件下载结束！"); s78MXS?py
} /]1$Soo
catch(Exception e){e.printStackTrace ();} b#%$y
} uqotVil,
nsA}A~(E
jT'09r3P
//获得文件长度 60\`TsFobT
public long getFileSize() PEr &|H2
{ r5,V-5b
int nFileLength = -1; ?td`*n~,
try{ REg&[e+%
URL url = new URL(siteInfoBean.getSSiteURL()); G-6k[-@-v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bmzY^ %a
httpConnection.setRequestProperty("User-Agent","NetFox"); | V:9 ][\
:kMF.9U:
L*6R5i>
int responseCode=httpConnection.getResponseCode(); b)+;=o%
if(responseCode>=400) w!%"b03q
{ P:#KBF;a
processErrorCode(responseCode); :{LNr!I?I
return -2; //-2 represent access is error (-D^_*f
} H8x66}
A+=K<e
@fQvAok
String sHeader; 5r1u_8)'
A.9ZFFz
c4f3Dr'xw
for(int i=1;;i++) ;x|7"lE
{ O0^?VW$y_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]?7q%7-e.a
//Utility.log(in.readLine()); h/oC9?v
sHeader=httpConnection.getHeaderFieldKey(i); rD;R9b"J
if(sHeader!=null) C+L_f_6]
{ *t{^P*pc
if(sHeader.equals("Content-Length")) Lcz`
{ XfQK kol
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J))U YJO
break; fi~jT"_CI
} ,W|cyQ
} $L4h'(s
else I~ 1Rt+:
break; e?7Oom
} 4%$#
} it$w.v+W7V
catch(IOException e){e.printStackTrace ();} } *jmWP
catch(Exception e){e.printStackTrace ();} %a:>3! +
X \BxRgl},
w{WEYS
Utility.log(nFileLength); qKD Nw8>
b5S4C2Ynq
9vckQCLM
return nFileLength; g)1`A24
} sj3[ny;b
~f:"Q(f+
msVi3`q~
//保存下载信息（文件指针位置） Qt\^h/zjG
private void write_nPos() Q*N{3G!
{ sOO_J!bblP
try{ Aw]kQ\P&
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ys0N+
output.writeInt(nStartPos.length); x#XxD<y
for(int i=0;i<nStartPos.length;i++) | Rj"}SC
{ )A$xt)}P!{
// output.writeLong(nPos); \ZtKaEXnx
output.writeLong(fileSplitterFetch.nStartPos); af'gk&%
output.writeLong(fileSplitterFetch.nEndPos); w|1O-k`
} 050V-S>s
output.close(); 9S|a!9J
} []$L"?]0uk
catch(IOException e){e.printStackTrace ();} jN AS'JV
catch(Exception e){e.printStackTrace ();} 6~-,.{Y
} IuY4R0Go
[pC2#_}
4"pU\g
//读取保存的下载信息（文件指针位置） w! PguP
private void read_nPos() '!F'B:
{ 6HZVBZhM
try{ W]5Hc|!^^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w$Z%RF'p
int nCount = input.readInt(); "r~/E|Da<
nStartPos = new long[nCount]; )x<BeD
nEndPos = new long[nCount]; `B~zB=}
for(int i=0;i<nStartPos.length;i++) Ig<# {V
{ CK#i 6!~r
nStartPos = input.readLong(); _3IRj=Cs
nEndPos = input.readLong(); )O2IEwPd.
} 2;K2|G7
input.close(); &O5O@3:7]
} &x\cEI)!
catch(IOException e){e.printStackTrace ();} 4t-l@zFWb
catch(Exception e){e.printStackTrace ();} [V_+/[AA)
} CFUn1^?0
#;=sJ[m4
Tol"D2cyf
private void processErrorCode(int nErrorCode) X/_89<&
{ &xpvHKJl
System.err.println("Error Code : " + nErrorCode); ,n2"N5{jw
} "A> _U<Y
>Q=Q%~
!4T!@"#
//停止文件下载 m8V}E&6
public void siteStop() Q_Wg4n5
{ `2/V.REX$h
bStop = true; yJ="dEn>i"
for(int i=0;i<nStartPos.length;i++) y\})C-&
fileSplitterFetch.splitterStop(); kA> e*6
lD{*Z spz
f40OVT@g
} .%!^L#g
} s\< @v7A
//负责部分文件的抓取 Q/q>mN"#1
**FileSplitterFetch.java ' &3,qT
*/ wD:2sri
package NetFox; :cf#Tpq"
r@}8TE*|P
A+j!VM
import java.io.*; B>4/[ YHr;
import java.net.*; 7X)4ec9H\
0cDP:EzR;
RL)~J4Y
public class FileSplitterFetch extends Thread { 8rjD1<
tyWDa$u,u
dtE"1nR
String sURL; //File URL rP}[>
long nStartPos; //File Snippet Start Position i5=~tS
long nEndPos; //File Snippet End Position @t;726
int nThreadID; //Thread's ID \._|_+HiW
boolean bDownOver = false; //Downing is over DN iH" 0%
boolean bStop = false; //Stop identical -L<FVB
FileAccessI fileAccessI = null; //File Access interface uQ&> Wk
` Z/ MQ
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'tDUPm38
{ _''un3eCY
this.sURL = sURL; /\;m/cwrl"
this.nStartPos = nStart; E*IP#:R
this.nEndPos = nEnd; 1{wbC)
nThreadID = id; ef)zf+o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LlS~J K
} 2[;~@n1P
,p#r; O<O
&r,)4q+
public void run() E[6:}z<
{ 6^!fuIZ;_
while(nStartPos < nEndPos && !bStop) C,A/29R,s
{ 4UUbX
Ni%@bU $
##}7cFX
try{ i]s%tEZ1
URL url = new URL(sURL); CUHT5J*sY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "Zx<hL*
httpConnection.setRequestProperty("User-Agent","NetFox"); `23][V
String sProperty = "bytes="+nStartPos+"-"; 9UVT]acq
httpConnection.setRequestProperty("RANGE",sProperty); }-J0cV
Utility.log(sProperty); o(H.1ESk
Vh>cV
rlA/eQrS
InputStream input = httpConnection.getInputStream(); 1D38T
//logResponseHead(httpConnection); Dx`-h#
<5,|h3]-#
(Q @'fb9z
byte[] b = new byte[1024]; 6Ol9P56j
int nRead; H9PnJr8 \
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) `uUzBV.FR
{ rmo\UCD
nStartPos += fileAccessI.write(b,0,nRead); FUlhEH
//if(nThreadID == 1) )TKn5[<4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~%C F3?e6
} [0hahR
Lr5{c5M
<,rOsE6
Utility.log("Thread " + nThreadID + " is over!"); O`@- b#
bDownOver = true; 1_#;+S
//nPos = fileAccessI.write (b,0,nRead); w^ OB
} ~#jiX6<I
catch(Exception e){e.printStackTrace ();} 7Xu#|k
} zA8@'`Id
} wpN3-D
fISK3t/=C
gua7<z6=eh
//打印回应的头信息 <nN.$4~X
public void logResponseHead(HttpURLConnection con) 5OtdB'UITd
{ oC*a;o
for(int i=1;;i++) l_yF;5|?z
{ ;>f\fhi'
String header=con.getHeaderFieldKey(i); eBs.RR ]O
if(header!=null) HKJBR)T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o5 fV,BJZO
Utility.log(header+" : "+con.getHeaderField(header)); [U8/nT
else 'vZIAnB8
break; \~z$'3H`
} gwQMy$
} <n06(9BF
N0-J=2
N0Y4m_dm*
public void splitterStop() y.J>}[\&x
{ }8#Ed;%K
bStop = true; Ie!&FQe2q
} l>b'b e9
#IZh}*$
r A(A$VR
} 5cinI^x)f
MTZCI}
Z#-N$%^F
/* MO0NNVVi%U
**FileAccess.java WV.hQX9P
*//文件访问(定位，写) 1=C12
package NetFox; 2/folTR7
import java.io.*; =g!Pw]
k]5tU\;Yw
~{tO8 ]
public class FileAccessI implements Serializable{ |xcC'1WU
sdg2^]|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RuIBOo\XL7
RandomAccessFile oSavedFile; >MN"87U6
long nPos; 9N'fU),I
vm_]X{80;
W/xPVmnV
public FileAccessI() throws IOException S-q"'5>
{ R|M]mwa^w
this("",0); ]!"w?-h Si
} ufIvvZ*
(w)%2vZ^
yzp#
public FileAccessI(String sName,long nPos) throws IOException r8:"\%"f>
{ !zF07.(E
oSavedFile = new RandomAccessFile(sName,"rw"); Q|h$D~
this.nPos = nPos; X5[vQ3^
oSavedFile.seek(nPos); ,^8':X"A{!
} `1(ED= |
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"WQ6[;&V
public synchronized int write(byte[] b,int nStart,int nLen) *)-@'{]uB
{ 7;AK=;
int n = -1; I V#8W
try{ B os`+Y
oSavedFile.write(b,nStart,nLen); .Iqqjk
n = nLen; xm1di@
} YR-G:-(#b
catch(IOException e) C 8wGbU6`
{ [;Lgbgt3f
e.printStackTrace (); PHqg~q;*
} 4~h0/H"
(9I(e^@]
u1M8nb
return n; fEXFnQ#
} \ opM}qZ
e[u}Vf
ajk}&`Wj"
} B2Y.1mXq
NL$z4m0
zhs@YMY
/* n({%|O<|
**SiteInfoBean.java b.RU%Y#>\
*/ rP7 QW)NF
package NetFox; B._YT
D1ZyJs#
{:!>Y1w>
public class SiteInfoBean { gR# k'
1m"WrTen
g{6jN
private String sSiteURL; //Site's URL oio{@#DX`
private String sFilePath; //Saved File's Path ?SFQx\/
private String sFileName; //Saved File's Name uc@4fn
private int nSplitter; //Count of Splited Downloading File 0l[52eZ/
L}rZ1wV6
27ZqdHd
public SiteInfoBean() FNH)wk
{//nSplitter的缺省值为5 }6-olVg
//default value of nSplitter is 5 8bdO-LJ9
this("","","",5); X;W0r5T
} TS|Bz2(
mP }<{oh`x
Y,0Z&6 <
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UMRFTwY
{ ?g4Rk9<!i
sSiteURL= sURL; ]-X6Cl
sFilePath = sPath; bpZA%{GS
sFileName = sName; uPl}NEwU|
this.nSplitter = nSpiltter; f^1J_}cL
/Z:NoTGn
{guOAT-w
} AH&RabH2
<DR|r
u:|^L]{
public String getSSiteURL() G7"(,L` 5
{ P1rjF:x[*
return sSiteURL; zO"De~[9
} s,#We} bv
d%0Gsga}
q`r| DcN~
public void setSSiteURL(String value) v%cCJ SO#
{ lM4Z7mT /
sSiteURL = value; rIFW1`N}i
} o!+%|V8Y
D(']k?
f4P({V
public String getSFilePath() ^zV_vB)n
{ o=7,U/{D!
return sFilePath; hQj@D\}
} } uS0N$4
N!~]D[D
]$L5}pE3
public void setSFilePath(String value) i%.NP;Qq]M
{ Oe\(=R
sFilePath = value; N gF7$@S
} "LB MYZ
X$6NJ(2G
2T+-[}*
public String getSFileName() e,}h^^"
{ 46NuT]6/4
return sFileName; #'1dCh vZ
} /Z?o%/bw:
_?O'A"
LJ <pE;`d
public void setSFileName(String value) _"Bj`5S
{ [A =0fg5
sFileName = value; f#:3TJV
} 1Mp-)-e
qA)YYg/G
s$pXn&:
public int getNSplitter() 8&8!(\xv
{ 7u&l]NC?y
return nSplitter; Hh;lT
} Lq>lj`>
*tj(,:!
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public void setNSplitter(int nCount) 082iEG
{ FulFEnSV
nSplitter = nCount; ,==_u
} v}u]tl$,
} c|.te]!ds
rmA?Xlh\
d*{Cv2A.
/* 50Gr\
**Utility.java Qb?a[[3
*/ ZH\t0YhrVe
package NetFox; (4 ZeyG@
:lo5,B;k
lFt!
public class Utility { }_KzF~
^OQP;5 #K
|#o' =whTl
public Utility() VB*c1i
{ 7d>w]R,Z
Ygk_gBRiC
R q@|o5O
} K' `qR
hT-^1:N
//线程睡眠 hQx*#:ns
public static void sleep(int nSecond) +'gO%^{l
{ BkB_?^Nv8
try{ 5&Yt=)c\
Thread.sleep(nSecond); 8d5#vm
} \u`P(fI!K%
catch(Exception e) 69r%b7#
{ =5Db^
e.printStackTrace (); xK_UkB-$i
} z9IW&f~~P
} 2o<*rH
trrNu
//日志 .q MxShUU
public static void log(String sMsg) %HpPTjAW
{ <jJ'T?,
System.err.println(sMsg); QxW+|Gt._
} L@T/4e./
(Z$7;OAI
]2f-oz*hU
public static void log(int sMsg) z{OL+-OY
{ /Q@4HV
System.err.println(sMsg); WMC^G2 n
} 6w &<j&V
} Hb*Z_s
+3.9)w
xwsl$Rj
/* agwbjkU/
**TestMethod.java 7WmLC
*/ s:6K'*
package NetFox; jGo%Aase
IQ\!wWKmY
&_Cc
public class TestMethod { tZ62T{, a
=I'iD0eR
I>.pkf<V
public TestMethod() YG0/e#5
{ ///xx/weblogic60b2_win.exe &M@ .d$<C
try{ 'L O3[G{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Te}gmt+#%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d>F7i~W
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;/+<N
fileFetch.start(); [/hoNCH!
} WDxcV%
catch(Exception e){e.printStackTrace ();} yWZ_
kXhd]7ru
`TO Xktj
} 6 DQOar>d
UUWRC1EtI
.CEC g*f
public static void main(String[] args) I_f%%N%
{ Jk}3c>^D
new TestMethod(); ?&:N|cltD
} I\1E=6"
} *%jXjTA0D
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