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)); M&e8zS
} ,cQA*;6
for(int i=0;i<nEndPos.length-1;i++) yQ-hnlzn~
{ Wo3'd|Y~i
nEndPos = nStartPos[i+1]; .<w)Bmh
} !sK#zAR2
nEndPos[nEndPos.length-1] = nFileLength; DQ_ 2fX~)
} !R{em48D
} )%#?3X^sI
aL)$b
x5vzPh`
//启动子线程 A2_Ls;]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; EXHR(t}e
for(int i=0;i<nStartPos.length;i++) C'<'7g4
{ _3&/(B%H
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A$m<@%Sz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m/?h2McS
nStartPos,nEndPos,i); ~XQ$aRl&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NcM3P G
fileSplitterFetch.start(); LUul7y'"
} Fwv\pJ}$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y:9?P~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); vU9ek:.l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uu@<&.r\C
nEndPos = " + nFileLength); ;MZbL)
// fileSplitterFetch[nPos.length-1].start(); 1.dX)^\
ZbyG*5iq
>w2f8tW`PP
//等待子线程结束 yk#rd~2Z0
//int count = 0; ~2 Oc K
//是否结束while循环 sD2Qm
boolean breakWhile = false; %*p^$5L<
Hn^sW LT
]ut?&&*
while(!bStop) I+~\ w N
{ k(9s+0qe
write_nPos(); Cz[5Ug'V
Utility.sleep(500); )<Ob
breakWhile = true; d'q&Lq
"c EvFY
8J^d7uC
for(int i=0;i<nStartPos.length;i++) +7^w9G
{ i&pMF O
if(!fileSplitterFetch.bDownOver) Ej5^Y ?-6
{ #:I^&~:
breakWhile = false; N.vG]%1"
break; d3(+ztmG!
} 2{gwY85:
} x{j+}'9
if(breakWhile) ++gPv}:$X
break; ZR2\dH*
-G!6U2*#
`|JI\&z
//count++; 4V>vg2 d
//if(count>4) K"I{\/x@
// siteStop(); D/*vj|
} l`qP~k#
s)Gb!-``
'N|2vbi<
System.err.println("文件下载结束！"); C?(y2p`d\
} w4aiI2KFq
catch(Exception e){e.printStackTrace ();} Uv'uqt
} 9QZ}Hn`p
rr>IKyI'
nDF&EE
//获得文件长度 63SVIc~wT
public long getFileSize() V"BVvSNu
{ uiuTv)pwF
int nFileLength = -1; KG-UW
try{ I,w^?o
URL url = new URL(siteInfoBean.getSSiteURL()); dkETM,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~{9x6<g!
httpConnection.setRequestProperty("User-Agent","NetFox"); '%:5axg?]
z(jU|va{_1
9M;I$_U`vj
int responseCode=httpConnection.getResponseCode(); {#0Tl
if(responseCode>=400) % hNn%Oy:E
{ <w;D$l}u
processErrorCode(responseCode); L#[HnsLp_
return -2; //-2 represent access is error G1A$PR
} Dn: Yi8=
VDPxue
g8Ok ^
String sHeader; A?\h|u<
s~/57S
]m RF[b$
for(int i=1;;i++) Fu#Y7)r
{ &8zk3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q~mcjbLz
//Utility.log(in.readLine()); :S#eg1y.w]
sHeader=httpConnection.getHeaderFieldKey(i); ADTU{6UPS
if(sHeader!=null) {~":;
{ X3<SP
if(sHeader.equals("Content-Length")) Yo>%s4_,
{ Cx$9#3\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BzN/6VEw
break; 3HXh6( e
} ;U8dm"
} YHJ'
else 7eTA`@v5A
break; ;.L!%$0i#
} `Uu^I
} G &m>Ov$#&
catch(IOException e){e.printStackTrace ();} )0'Y et}
catch(Exception e){e.printStackTrace ();} >h|UCJ1 `
fQ^h{n
imC&pPBB/G
Utility.log(nFileLength); 1LV|t+Sex
"tpvENz2s
"sC$%D<oc
return nFileLength; \?J=mE@;1
} _CHKh*KHML
6ch@Be5*
VOD1xWrb
//保存下载信息（文件指针位置） qdKh6{
private void write_nPos() 7&#'c8]/qh
{ Ty)gPh6O
try{ ]eY Qio!
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5L/Yi
output.writeInt(nStartPos.length); Q,ZkeWQ7%
for(int i=0;i<nStartPos.length;i++) v\J!yz
{ =#7s+d-
// output.writeLong(nPos); C,V|TF.i2
output.writeLong(fileSplitterFetch.nStartPos); avF&F
output.writeLong(fileSplitterFetch.nEndPos); Vjv6\;tt8
} t201ud2$
output.close(); hj%}GP{{
} aMe%#cLI
catch(IOException e){e.printStackTrace ();} =iA"; x
catch(Exception e){e.printStackTrace ();} r9U[-CX:"
} <6~/sa4GN
`PXoJl
!.x=r
//读取保存的下载信息（文件指针位置） O%rS;o
private void read_nPos() :==UDVP
{ lsTe*Od
try{ 7N&3FER
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EuhF$L1
int nCount = input.readInt(); 2n<qAl$t
nStartPos = new long[nCount]; $u/8Rp
nEndPos = new long[nCount]; W+fkWq7`Xx
for(int i=0;i<nStartPos.length;i++) zW|$x<M^
{ LA(f]Xmc
nStartPos = input.readLong(); XyN`BDFi
nEndPos = input.readLong(); U`},)$
} ',v0vyO8
input.close(); h9@gs,'
} p8E;[
catch(IOException e){e.printStackTrace ();} kW*W4{Fth
catch(Exception e){e.printStackTrace ();} 3?-V>-[G_
} LWp?U!N
LGdf_M-f
0~LnnDN
private void processErrorCode(int nErrorCode) &q kl*#]
{ wpPxEp/
System.err.println("Error Code : " + nErrorCode); c/,|[t
} + xkMW%e<
zwF7DnW<<
6"#Tvj~-8
//停止文件下载 y0W`E/1t
public void siteStop() ?Vb=4B{~
{ sZ\i(eIU
bStop = true; ^^W`Lh%9
for(int i=0;i<nStartPos.length;i++) dW] Ej"W
fileSplitterFetch.splitterStop(); "'LOaf$X
tFb|y+
2l;ge>DJ
} LS?` {E
} >xk:pL*o`
//负责部分文件的抓取 oQE_?">w
**FileSplitterFetch.java 3M5=@Fwkr
*/ ^$^Vd@t>a
package NetFox; c{r6a=C
p)AvG;
f]^J,L9qz
import java.io.*; K1qY10F:_
import java.net.*; c"jhbH!u4
V3.vE,
e3bAT.P
public class FileSplitterFetch extends Thread { [9##Kb
-bG#h)yj
$txWVjR?\
String sURL; //File URL )Q N=>J
long nStartPos; //File Snippet Start Position }T&;*ww
long nEndPos; //File Snippet End Position 0Mzc1dG:
int nThreadID; //Thread's ID }pU!1GsO
boolean bDownOver = false; //Downing is over `^@g2c+d
boolean bStop = false; //Stop identical 6 I>xd
FileAccessI fileAccessI = null; //File Access interface G=0}IPfp
?7uStqa
YV>VA<c
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^U|CNB%.
{ ^Ypb"Wx8
this.sURL = sURL; _@}MGWlAPt
this.nStartPos = nStart; <CdG[Ih
this.nEndPos = nEnd; RaJ}>e
nThreadID = id; VA*79I#_q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i(TDJ@}
} tI6USN%
}G0.Lq+a
Q{)F$]w
public void run() CuGOjQ-k~
{ 5>^ W}0s
while(nStartPos < nEndPos && !bStop) jmwQc&
{ .>\>F{#~
hwb(W?*
2&G1Q'!
try{ q=L* 99S
URL url = new URL(sURL); <]SSgQ9/"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q2"'W|I
httpConnection.setRequestProperty("User-Agent","NetFox"); `'{%szmD
String sProperty = "bytes="+nStartPos+"-"; ,1.([%z+r
httpConnection.setRequestProperty("RANGE",sProperty); L@x8hUG"
Utility.log(sProperty); js$a^6
&B>uPZ]
u{dN>}{
InputStream input = httpConnection.getInputStream(); =<27qj
//logResponseHead(httpConnection); RHA>fXp
WSX@0A.&)
z]R!l%`
byte[] b = new byte[1024]; mk3e^,[A
int nRead; !n?*vN=S
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 77[;J
{ .]d tRH<
nStartPos += fileAccessI.write(b,0,nRead); y{},{~FA"
//if(nThreadID == 1) "5z6~dq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @):NNbtA
} M`,Z#)Af
,,-[P*@
28L'7
Utility.log("Thread " + nThreadID + " is over!"); %l$&_xV-
bDownOver = true; %emPSBf@
//nPos = fileAccessI.write (b,0,nRead); 4m~stDlN
} 2wimP8
catch(Exception e){e.printStackTrace ();} kl<B*:RqH
} R S_lQ{'
} f4;8?
7)5$1
}R] }@i~i
//打印回应的头信息 JV*,!5
public void logResponseHead(HttpURLConnection con) lDM~Z3(/b
{ "a_D]D(d5
for(int i=1;;i++) i1H80m s
{ F/,<dNJ
String header=con.getHeaderFieldKey(i); ;<ma K*f\S
if(header!=null) d+| !6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +!Gr`&w*)
Utility.log(header+" : "+con.getHeaderField(header)); \:)o'-
else >"My\o
break; !/lYq;$R
} o_^d>Klb8
} C36.UZoc
aGkVC*T
1H@rNam&
public void splitterStop() 4Xho0lO&
{ wjGjVTtHs
bStop = true; HC`3AQ12!&
} ,(Hmk(,
!`Yi{}1_
9Q5P7}%p
} 9^h%}>
VX@G}3Ck
qc4"0Ap'
/* .L|ax).D
**FileAccess.java (+v*u]w4
*//文件访问(定位，写) Y{:/vOj
package NetFox; [";5s&)q
import java.io.*; 7%x+7
"ddH7:(k<
U@AfRUF&
public class FileAccessI implements Serializable{ y!D`.'
-"tgEC\tD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 PKs%-Uk
RandomAccessFile oSavedFile; e{+{,g{iu
long nPos; @BW8`Ky1
=}KbE4D+8
~F6gF7]z
public FileAccessI() throws IOException 4gNRln-
{ tLXw&hFk`g
this("",0); 4'=N{.TtO
} \uPTk)oaB
`*!>79_2C
I*R$*/)
public FileAccessI(String sName,long nPos) throws IOException 3^UsyZS)
{ oVsazYJ|?
oSavedFile = new RandomAccessFile(sName,"rw"); ll09j Ef
this.nPos = nPos; ~J{{n_G{
oSavedFile.seek(nPos); +E[)@;T
} w[G_w:$a
~,1q :Kue
)t=u(:u]
public synchronized int write(byte[] b,int nStart,int nLen) WYzaD}
{ fb;"J+
int n = -1; |;-r};
try{ L2$L.@
oSavedFile.write(b,nStart,nLen); 4N0nU
n = nLen; -d)n0)9
} !QspmCo+
catch(IOException e) dkp[?f)x
{ `R?W @,@'
e.printStackTrace (); sB/s17ar
} p>O< "X@
W A}@n
K! j*:{
return n; 28yxX431S
} AAY UXY!
y]%,Y=%X
F ;&e5G
} m3-J0D<
_=x_"rzx
xB+H7Ya
/* eF1%5;" W
**SiteInfoBean.java XOU$3+8q5
*/ ]w_)Spo.
package NetFox; =lD]sk
34:EpZO@
0M98y!A 5^
public class SiteInfoBean { a $%[!vF
uy:=V}p
<J`xCm K
private String sSiteURL; //Site's URL elB 8
private String sFilePath; //Saved File's Path d~8~RT2m
private String sFileName; //Saved File's Name RZ%X1$
private int nSplitter; //Count of Splited Downloading File A$6b=2hc>
PlUjjJU
mkA|gM[g7
public SiteInfoBean() 7#3)&"j
{//nSplitter的缺省值为5 1z:N$O_v
//default value of nSplitter is 5 )c !S@Hs
this("","","",5); GA}^Rh`T-
} Uroj%xN
aB'@8[]z
e5]AB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LS;anNk@.}
{ sdD[`#
sSiteURL= sURL; = h( n+y<
sFilePath = sPath; Ti'kn{ Zv
sFileName = sName; Y sV
this.nSplitter = nSpiltter; D.`\ ^a
<DS6-y
N2e<Y_T
} 7k|(5P;
@~3c;9LkY
3wl>a#f
public String getSSiteURL() X+8p2xSO|
{ BB$>h-M/%#
return sSiteURL; ,&G M\FTeb
} R2W_/fsG
-+_&#twU
.?RjH6W
public void setSSiteURL(String value) 2,0F8=L
{ (=rv `1
sSiteURL = value; UUqj?'Nv
} pa-4|)qY
jF9CTL<
YYW70k:
public String getSFilePath() aM!#
{ G- WJlu
return sFilePath; I_7EfAqg(
} It-*CD9
F\bI6gj
Sw'?$j^3
public void setSFilePath(String value) lJ#>Y5Qg
{ \S@6@UGv
sFilePath = value; zX`RN)C
} F9w&!yW:
/ u6$M/Cf>
Lm#d.AD)
public String getSFileName() kELyD(^P`
{ 1A-EP@# J
return sFileName; #jiqRhm
} k5(yf~!c
n^#LB*q
&S]v+wF
public void setSFileName(String value) i{qURP}.
{ !3# }ZC2
sFileName = value; puF Z~WZ
} o#/iR]3
D7/Bp4I#o
<t{AY^:r
public int getNSplitter() dC#\ut%l
{ [)n}!5fE
return nSplitter; c@M@t0WT[
} b0 `9wn
%QLYNuG
Dj(7'jT
public void setNSplitter(int nCount) }j*/>m
{ _1Gut"!{\
nSplitter = nCount; @8yFM%
} *!@x<Hf<
} tC-KW~&
[HDO^6U
! -@!u
/* Qe.kNdT+_
**Utility.java ^?[<!VBI
*/ cLC7U?-
package NetFox; NI:N W-!
VTfaZ/e.
L-{r*ccIW
public class Utility { rF3]AW(
g>P9hIl
{`CWzk?
public Utility() ZY$@_DOB}
{ *Bsmn!_cB{
BK SK@OV
f`=T@nA
} ^VPl>jTg
)m;qv'=!
//线程睡眠 ABmDSV5i
public static void sleep(int nSecond) Uy|=A7Ad c
{ 7#qL9+G
try{ s/H"Ab
Thread.sleep(nSecond); h]$?~YE
} kA=~8N
catch(Exception e) IF}c*uGj}
{ l0xFt ~l
e.printStackTrace (); LlY*r+Cgl1
} }(EOQ2TI
} ]GKx[F{)
)'`AX\
//日志 f<p4Pkv
public static void log(String sMsg) ~9YA!48
{ a;(zH*/XK
System.err.println(sMsg); JMlhBh
} \[I .
$=xQX
~<OjXuYu
public static void log(int sMsg) vD9D:vK
{ 05I39/T%
System.err.println(sMsg); A=]F_
} 810<1NP
} k|Yv8+XT
f.)F8!!
Cy:`pYxhd
/* @Qjl`SL%O^
**TestMethod.java -7z y
*/ %7d@+ .
package NetFox; 5po'(r|U
1za'u_
=C>`}%XT}
public class TestMethod { jNG?2/P6&
b_gN?F7_
f"<@6Axq
public TestMethod() D6)Cjc>a
{ ///xx/weblogic60b2_win.exe 'S4EKV]
try{ |iUfM3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RR"WO
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y\Qxdq
SiteFileFetch fileFetch = new SiteFileFetch(bean); mQ60@_"Y=,
fileFetch.start(); K#f`_SCW
} u$=ogp=0
catch(Exception e){e.printStackTrace ();} w*xUuwi
>{qK]xj
0ij~e<
} 0"qim0%|DF
/\a]S:V-j
) UDJ[pL@
public static void main(String[] args) avt>saR
{ ~{,vg4L
new TestMethod(); <_a70"i
} j_'rhEdLP
} @f5@0A\0
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