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)); (vte8uQe
} bqugo
for(int i=0;i<nEndPos.length-1;i++) s2Gi4fY?
{ UeWEncN(
nEndPos = nStartPos[i+1]; 1I({2@C
} G| 7\[!R
nEndPos[nEndPos.length-1] = nFileLength; a<X8l^Ln
} blxAy
} .G[y^w)w}
o(xRq;i
#_yQv?J
//启动子线程 rfqw/o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xdWfrm$;ZA
for(int i=0;i<nStartPos.length;i++) ^NJ]~h{n$
{ Zgp]s+%E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [6x-c;H_4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0_yE74i
nStartPos,nEndPos,i); F#=XJYG1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t~pA2?9@
fileSplitterFetch.start(); {MmHR
} `@GqD
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >cwyb9;!kK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z09FW>"u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K/RQ-xd4
nEndPos = " + nFileLength); H5t 9Mg|
// fileSplitterFetch[nPos.length-1].start(); (H*-b4]/
"8K>Yu17
R'a%_sACj>
//等待子线程结束 wu?ahNb.`Y
//int count = 0; H <CsB
//是否结束while循环 @rs(`4QEh
boolean breakWhile = false; ZJ(/cD
Z=%+U _,
?fv?6r
while(!bStop) qGMM3a)Q
{ ';`fMcN
write_nPos(); Ke-Q>sm2Q
Utility.sleep(500); M0!;{1
breakWhile = true; +3.Ik,Z}zq
$iQ>c6
\~xI#S@
for(int i=0;i<nStartPos.length;i++) kg[u@LgvoN
{ Ke[doQ#c
if(!fileSplitterFetch.bDownOver) .(o]d{ '-}
{ Li ,B,
breakWhile = false; E_&Hje|J_[
break; ".L+gn}u-
} 9fD4xkRS
} OJE<2:K
if(breakWhile) :PtpIVAosg
break; QFoZv+|
n<MMO=+bg
XfA3Ez,}
//count++; zM6yUEg
//if(count>4) 3_=~7B) 8
// siteStop(); {ZFa +
} WtI1h`Fo
H3{x;{.b
:QgC Zq
System.err.println("文件下载结束！"); GZT}aMMSJ
} \C.%S +u
catch(Exception e){e.printStackTrace ();} 1A^iUC5)
} i} 96,{
P8NKpO\
>JT{~SRB|Y
//获得文件长度 U`q[5U"
public long getFileSize() ^B@4 w\t
{ zjgK78!<
int nFileLength = -1; gd<8RVA
try{ oTZ?x}Z1
URL url = new URL(siteInfoBean.getSSiteURL()); Sp)KtMV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SCeZt [
httpConnection.setRequestProperty("User-Agent","NetFox"); 6QdNGpN
O%v(~&OSl
9[DQ[bL
int responseCode=httpConnection.getResponseCode(); nPq\J~M
if(responseCode>=400) ~\dpD
{ >_M}l@1
processErrorCode(responseCode); >V(>2eD'S
return -2; //-2 represent access is error .jMm-vox}
} mFayU w
]i*q*]x2u
@_YEK3l]l
String sHeader; zF/}s_><*
[i[G" %Q
vZ 4Z+;.
for(int i=1;;i++) Y~1}B_
{ jIE>t5 fy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kFv\V
//Utility.log(in.readLine()); 7UHqiA`L
sHeader=httpConnection.getHeaderFieldKey(i); ?97MW a
if(sHeader!=null) DGY#pnCu
{ yb/< 7
if(sHeader.equals("Content-Length")) W9 y8dw.
{ Orh5d7+S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uZZ[`PA(
break; QxnP+U~N
} 3DK^S2\zBm
} (Wr;:3i
else Y^LFJB|b4
break; 8DTk<5mW~
} ;]fpdu{
} `.aL>hf
catch(IOException e){e.printStackTrace ();} F$r8hj`
catch(Exception e){e.printStackTrace ();} 567ot|cc
5!#"8|oY
el!Bi>b9c!
Utility.log(nFileLength); w|WZEu:0|
A`(p6 H"s
V$ 38
return nFileLength; *wt yyP@
} qh$D;t1=
{#QFDA
2`5(XpYe
//保存下载信息（文件指针位置） 7tAWPSwf
private void write_nPos() *" <tFQ
{ {N5g52MN
try{ N=D Ynz_~
output = new DataOutputStream(new FileOutputStream(tmpFile)); .u7d
output.writeInt(nStartPos.length); S !c/"~X+
for(int i=0;i<nStartPos.length;i++) d!8q+FI
{ 1ISA^< M
// output.writeLong(nPos); Qm`f5-d
output.writeLong(fileSplitterFetch.nStartPos); uW>AH@Pij
output.writeLong(fileSplitterFetch.nEndPos); M0Z>$Az]t
} _WK+BxH
output.close(); QZ{&7mc>
} NJqALm!(
catch(IOException e){e.printStackTrace ();} (m;P,*
catch(Exception e){e.printStackTrace ();} !qrF=a
} 4NR,"l)
miS+MK"
{J})f>x<xM
//读取保存的下载信息（文件指针位置） %>I!mD"X\
private void read_nPos() !P@u4FCs
{ QX%m4K/a
try{ n_Um)GI>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TG?;o/
int nCount = input.readInt(); ?P`wLS^;
nStartPos = new long[nCount]; 5[l3]HOO
nEndPos = new long[nCount]; 0O-p(L=
for(int i=0;i<nStartPos.length;i++) 9Z*`{
{ R5]R pW=G
nStartPos = input.readLong(); %h|z)
nEndPos = input.readLong(); #PXl*~PrQ/
} )2S0OY.
input.close(); s+zb[3}
} 7]e]Y>wZap
catch(IOException e){e.printStackTrace ();} 6/4OFvL1
catch(Exception e){e.printStackTrace ();} w41#?VC/
} hph 3kfR
Jq6p5jr"
W[^XG\
private void processErrorCode(int nErrorCode) ac+7D:X
{ +Yi=Wo/
System.err.println("Error Code : " + nErrorCode); oeIB1DaI
} XQj`KUO@
5\|[)~b
DP;B*s4{U
//停止文件下载 \!cqeg*53
public void siteStop() 8.-PQ
{ *<9D]
bStop = true; I$f:K]|.m!
for(int i=0;i<nStartPos.length;i++) Fi5,y;]R
fileSplitterFetch.splitterStop(); Ce5 }+A}
K:'pK1zy
FC]? T
} *3"C"4S
} 9HTb
//负责部分文件的抓取 00;=6q]TA
**FileSplitterFetch.java uU5:,Wy+dg
*/ &<_sXHg<x
package NetFox; ][G<CO`k
-D!F|&$
I*lq0&
import java.io.*; boN)C?"^h
import java.net.*; *[.\S3K`
6Ir ?@O1'!
T$}<So|
public class FileSplitterFetch extends Thread { 42m`7uQ
8 6L&u:o:
h)y"?Jj
String sURL; //File URL :hMuxHr
long nStartPos; //File Snippet Start Position /_}v|E0
long nEndPos; //File Snippet End Position H>M%5bj
int nThreadID; //Thread's ID (^Nf;E
boolean bDownOver = false; //Downing is over &q":o 'q
boolean bStop = false; //Stop identical d+&V^qLJ
FileAccessI fileAccessI = null; //File Access interface (5yg\3Jvp
"sg$[)I3n
i}wu+<Mk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hJd#Gc~*M
{ :nwcO3~`
this.sURL = sURL; GuDus2#+
this.nStartPos = nStart; +,|-4U@dl
this.nEndPos = nEnd; Rb9Z{Clq>
nThreadID = id; aaaC8;.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3[V|C=u0
} 3Ji,n;QLm
*f4KmiQ~%
M/1Q/;0P
public void run() 4&y_+
{ L\-T[w),z7
while(nStartPos < nEndPos && !bStop) q>Q|:g&:
{ siD Sm
&0>{mq}p,:
e9%6+9Y
try{ K/%aoTO}
URL url = new URL(sURL); QGshc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Upv2s:wa}z
httpConnection.setRequestProperty("User-Agent","NetFox"); C62<pLJf
String sProperty = "bytes="+nStartPos+"-"; .Zwn{SMtu
httpConnection.setRequestProperty("RANGE",sProperty); Np/[MC
Utility.log(sProperty); iOJgZuP
}VFSF/\^
c89RuI `B~
InputStream input = httpConnection.getInputStream(); Hy `r}+
//logResponseHead(httpConnection); @EZXPU
g` h>:5]
MI@ RdXkY
byte[] b = new byte[1024]; zM@iG]?kc
int nRead; o_5|L9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0\h2&
{ Ft>ixn
nStartPos += fileAccessI.write(b,0,nRead); R#T6Ii
//if(nThreadID == 1) RuXK` ySv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CLYcg$V
} nEGku]pCH{
lZ.,"F@
Q`//HOM,
Utility.log("Thread " + nThreadID + " is over!"); G)e 20Mst
bDownOver = true; k~q[qKb8y:
//nPos = fileAccessI.write (b,0,nRead); [j![R
} <v2R6cj5
catch(Exception e){e.printStackTrace ();} \\/X+4|o'
} -_314j=`/
} +QHhAA$
u{3KV6MS
#Kh`ATme
//打印回应的头信息 ntF(K/~Y
public void logResponseHead(HttpURLConnection con) GB !3Z
{ "^trHh8=
for(int i=1;;i++) ~z aV.3#
{ ~P/G^cV3s
String header=con.getHeaderFieldKey(i); L9kSeBt
if(header!=null) b#y}VY)?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QWxQD'L'
Utility.log(header+" : "+con.getHeaderField(header)); k[zf`x^
else CY7REF
break; v(t&8)Uu
} 3;M!]9ms
} 3$kZu
&G"]v]V
XSxya.1
public void splitterStop() 3(}?f
{ A5/h*`Q\\
bStop = true; t)m4"p7
} 8ziYav
%idnm
$jzk4V
} u(~s$ENl
,J~1~fg89
]':C~-RV{
/* (%r:PcGMEV
**FileAccess.java u3<])}I'
*//文件访问(定位，写) WkO .
package NetFox; I3L1|!
import java.io.*; x[?_F
wXZ-%,R-D
Th8Q~*v
public class FileAccessI implements Serializable{ S4(IYnwN
S_QDYnF)`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 t^[{8,N
RandomAccessFile oSavedFile; I&vB\A
long nPos; ~kHir]jc
;zOZu~Q|'
Qz<-xe`o8]
public FileAccessI() throws IOException Hc+<(g
{ S2NsqHJr
this("",0); bHMlh^{`%
} fSP~~YSeU
]I]dwi_g)
_<~05Eh
public FileAccessI(String sName,long nPos) throws IOException '0=U+Egp
{ 4 '+)9&g
oSavedFile = new RandomAccessFile(sName,"rw"); ~W#f,mf
this.nPos = nPos; $K iMu
oSavedFile.seek(nPos); kQb0pfYs
} 4v!@9.!vQ
6JL 7ut
|-R::gm
public synchronized int write(byte[] b,int nStart,int nLen) f>'7~69
{ =?2y <B
int n = -1; c]LH.
try{ u)V*o
oSavedFile.write(b,nStart,nLen); PQ[TTLG\&
n = nLen; K4rr.f6
} t.zSJ|T_&O
catch(IOException e) z6!X+`&
{ 'l}3Iua6qk
e.printStackTrace (); vIREvj#U
} m=K XMX
mA."*)8VNg
@Yg7F>s
return n; ::R^ w"
} a} /Vu"
jn7}jWA
$-y+97
} Uyh
^U =`Rx
!Q#b4f
/* l:ED_env:
**SiteInfoBean.java _5)#{o<
*/ M{S7ia"s
package NetFox; 0{,zE
s%:fB(
5[3hw4
public class SiteInfoBean { GWW@8GNI
4 hj2rK'y
VgdkCdWRm_
private String sSiteURL; //Site's URL Q(sbClp"
private String sFilePath; //Saved File's Path ;L[9[uQ[C
private String sFileName; //Saved File's Name Ntqc=z
private int nSplitter; //Count of Splited Downloading File I45A$nV#Q
{)[i\=,`{
BOWTH{KR<<
public SiteInfoBean() ^DH*@M
{//nSplitter的缺省值为5 sH]AB=_
//default value of nSplitter is 5 *HC8kD a%$
this("","","",5); </%H'V@
} ? vlGr5#
9t[278B6
WNx^Rg" >'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZChY:I$<
{ e!8_3BE
sSiteURL= sURL; R*y[/Aw
sFilePath = sPath; .~8+s.y
sFileName = sName; :+5afv}
this.nSplitter = nSpiltter; gv,T<A?Z2
<\8
=oTYwU
} U&5zs r
W wE)XE
WU4i-@Bm8
public String getSSiteURL() sHuz10
{ V588Leb?
return sSiteURL; qh'BrYu*
} GlZ9k-ZRF
[E^X=+Jnz
g-^m\>B
public void setSSiteURL(String value) oD7H6\_
{ oL@ou{iQ
sSiteURL = value; -7$'* V9$
} {q)B@#p
JXAyF6 $
zJ:r0Bt
public String getSFilePath() &>jkfG
{ C{Ug ?hVP
return sFilePath; U{_s1
} 7`/qL "
rrWk&;?
L8zqLDi&
public void setSFilePath(String value) a7|&Tbv
{ ;40m goN
sFilePath = value; <f6PULm
} J){\h-4
ZX;k*OrW
}^<zVdwp
public String getSFileName() FNM"!z
{ _PbfFY #
return sFileName; Mh|`XO.5I
} w3N%J>4_E
DRoxw24
iq:[+
public void setSFileName(String value) 48Lmy<}*
{ O-5U|wA
sFileName = value; hyKg=Foq
} Zsogx}i-
w2+]C&B*
#}(Df&
public int getNSplitter() |w2AB7EU
{ }#x3IE6'
return nSplitter; 55LF
} 1hyah.i]Y
Q/n.T0Z^
I 6YT|R
public void setNSplitter(int nCount) Bqi2n'^O2
{ *`-29eR"8
nSplitter = nCount; zjS:;!8em
} cmU+VZ#pk
} h3EDN:FQ
1$VI\}
E@6r{uZ#
/* $tHwJ!<$&
**Utility.java &U*J{OP|
*/ !O6Is'%B
package NetFox; ls\E%d
6a7iLQA
{l&2Kd*
public class Utility { %QgAilj,
|a$w;s>\
Z{4aGp*
public Utility() AdW2o|Uap
{ rOHW
TQd FC\@f"
FqxOHovE
} 1GE%5
nj0AO0
//线程睡眠 k3[h'.ps
public static void sleep(int nSecond) 6xIYg^
{ _`{{39 F
try{ 5b`xN!c
Thread.sleep(nSecond); 25c!-.5D
} .0E4c8R\X
catch(Exception e) by]|O
{ <lmJa#
e.printStackTrace (); OG+r|.N;
} CPNN!%-
} v6-~fcX0G
'xZPIj+
//日志 K}<!{/fi)
public static void log(String sMsg) ,."(Gp
{ nl9Cdi]o
System.err.println(sMsg); :KP'xf.
} B=bI'S8\
F2`htM@,
'#i]SU&*
public static void log(int sMsg) AOx3QgC^NO
{ FT/5 _1i
System.err.println(sMsg); 9>&tMq
} QcG5PV
} EhPVK6@
.hlQ?\
Qy^z*s
/* )cKtc
**TestMethod.java /D$+b9FR<
*/ k?/vy9
package NetFox; \*%i#]wO@
9X$#x90
uWB:"&!^
public class TestMethod { T E&Q6
vMX6Bg8
dHq )vs,L
public TestMethod() e9`uD|KAS|
{ ///xx/weblogic60b2_win.exe wvmg)4,
try{ #}!>iFBcH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r d6F"W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @>Ghfh>~D
SiteFileFetch fileFetch = new SiteFileFetch(bean); &:;;u\
fileFetch.start(); f;Bfh3
} .eabtGO,
catch(Exception e){e.printStackTrace ();} R=amKLD?
4-+ozC{
#A/]Vs$
} \l]pe|0EW
'y6!%k*
{y&\?'L'
public static void main(String[] args) a()6bRc~T
{ BgkB x
new TestMethod(); {Bq"$M!Y
} Oh/b?|imG
} :q>oD-b$}
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