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)); `C=p7%
} m+!%+S1
for(int i=0;i<nEndPos.length-1;i++) J^?O]|
{ >:K3y$]_
nEndPos = nStartPos[i+1]; c1z5t]d
} N1SRnJu<f
nEndPos[nEndPos.length-1] = nFileLength; / )EB~|4']
} v<-D>iJ
} |UBJu `%
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.Kv@p jOr
//启动子线程 O}%=c\Pb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <Q8bn?Z
for(int i=0;i<nStartPos.length;i++) _}\&;
{ : Z.mM5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aRV!0?fS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |g9^]bT
nStartPos,nEndPos,i); ]:f1r8<3p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .3Ap+V8?
fileSplitterFetch.start(); kBT cND|
} j9qN!.~mM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b/G0EcRw+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s}A]lY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]~oM'?&!
nEndPos = " + nFileLength); Rp|:$5&nE
// fileSplitterFetch[nPos.length-1].start(); ?K]k(ZV_+Y
fHgfI@{=j
K;Xn!:) V:
//等待子线程结束 dxd}:L~z
//int count = 0; y3xP~]n
//是否结束while循环 xq]&XlA:ug
boolean breakWhile = false; ZBYmAD
712i|
O-|3k$'\z
while(!bStop) ~q9RZ#g13J
{ 4gZN~_AI<
write_nPos(); DQRt\!
Utility.sleep(500); ' ZB%McS
breakWhile = true; f]hW>-B(q
(Hsfrc
.!`j3W]
for(int i=0;i<nStartPos.length;i++) ,rN7X<s54
{ >s>5k O
if(!fileSplitterFetch.bDownOver) dp?uq'
{ ]f\rB8k|&
breakWhile = false; o 1b#q/
break; 8=e\^Q+
} ?@XO*|xkSk
} '.bMkty#
if(breakWhile) F%Xq}LMd
break; (O&b:D/Y
;uJVY)7a
\GkcK$Y
//count++; 6D+9f{~r
//if(count>4) t2E_y6
// siteStop(); c]O4l2nCL
} Rbl(oj#
</}[x2w?]
.h6h&[TEU
System.err.println("文件下载结束！"); %AJdtJ@0H
} )HmpVH
catch(Exception e){e.printStackTrace ();} i7p3GBXh[
} $;">/"7m
~p8!Kb6
O 8fh'6
//获得文件长度 |ST&,a$(
public long getFileSize() =]"PSY7p
{ abF_i#
int nFileLength = -1; L2:C6Sc
try{ %URyGS]*
URL url = new URL(siteInfoBean.getSSiteURL()); <;Xj4 J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rUuM__;d
httpConnection.setRequestProperty("User-Agent","NetFox"); )PwDP
U@*z#T#"m
d9^h YS{
int responseCode=httpConnection.getResponseCode(); `Ffn:=Do
if(responseCode>=400) \t(/I=E8/
{ xE}q(.]
processErrorCode(responseCode); rVO+ vhih
return -2; //-2 represent access is error ClEtw
} Io:xG6yG
N@) D,~
ei"FN3Rm
String sHeader; 1b't"i M
y<gmp
4iw+3 Q|
for(int i=1;;i++) +[>m`XTq
{ 2qEy"DKu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mbd@4u
//Utility.log(in.readLine()); 4u;W1=+Vn
sHeader=httpConnection.getHeaderFieldKey(i); w ggl,+7
if(sHeader!=null) 'Kq%tM26!
{ &^Xm4r%u_
if(sHeader.equals("Content-Length")) `fL$t0"
{ Ms$kL'/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sQ_{zOUPh
break; zi5;>Iv0}
} mO\6B7V!
} Ltu;sw
else -PX {W)Aw
break; EBn7waBS
} -yC},tK
} _qGkTiP
catch(IOException e){e.printStackTrace ();} .|rpj&>g
catch(Exception e){e.printStackTrace ();} d6Z;\f7[
;Z8K3p
o|UZdGu
Utility.log(nFileLength); Bkcs4 x
8 /\rmf\
3cs'Oz<w
return nFileLength; *l5/q\D
} rSa3u*xB
\ET7
FkRrW^?5G
//保存下载信息（文件指针位置） m7d? SU
private void write_nPos() )Z]8SED
{ ,H|V\\
try{ ('>!dXA$
output = new DataOutputStream(new FileOutputStream(tmpFile)); H*!E*_
output.writeInt(nStartPos.length); BK-{z).)
for(int i=0;i<nStartPos.length;i++) w 5,-+&;
{ z S^:Ng5
// output.writeLong(nPos); K)&AR*Tc
output.writeLong(fileSplitterFetch.nStartPos); |{Oe&j3|
output.writeLong(fileSplitterFetch.nEndPos); VkUMMq{
} 6 s*#y[$
output.close(); =i `o+H
} oo/#]a
catch(IOException e){e.printStackTrace ();} aiz_6@Qfz*
catch(Exception e){e.printStackTrace ();} ;]'mx
} }PoB`H'K5
Xo'_|-N+
0(64}T)
//读取保存的下载信息（文件指针位置） .)Du ;
private void read_nPos() &'i>5Y
{ 6)Kg!.n%f
try{ /9i2@#J}W1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }2G'3msx
int nCount = input.readInt(); ?*Jv&f#
nStartPos = new long[nCount]; &,bJ]J)8O
nEndPos = new long[nCount]; !x&/M*nBE
for(int i=0;i<nStartPos.length;i++) [X;yJ$
{ cE[4CCpy
nStartPos = input.readLong(); X62GEqff
nEndPos = input.readLong(); g }5lGz4
} T,5]EHea
input.close(); N5o jXX!l%
} 0<fN<iR`
catch(IOException e){e.printStackTrace ();} meE&, {
catch(Exception e){e.printStackTrace ();} 3!#d&
} 6=iz@C7r
f7\$rx
YQ;?N66
private void processErrorCode(int nErrorCode) wOn.m
{ |tyVC=${
System.err.println("Error Code : " + nErrorCode); )]?sCNb
} :6%wVy5
<Knl6$B
PjDYdT[
//停止文件下载 l(*`,-pv:
public void siteStop() 6"z:s-V
{ Q.@9"&)t
bStop = true; YG$Y4h" @"
for(int i=0;i<nStartPos.length;i++) jq%Qc9y
fileSplitterFetch.splitterStop(); #T&''a
0)+F}SyyD
gm(`SC?a
} 3+0$=ef
} R>yoMk/u
//负责部分文件的抓取 E&/#Ov
**FileSplitterFetch.java T5Yu+>3
*/ KHI-m9(
package NetFox; 4uwI=UUB
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EH=[!iW;
import java.io.*; ol[
import java.net.*; H)ud?vB6
MQ7N8@!t
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public class FileSplitterFetch extends Thread { JN,4#,
^cn%]X#.
Il`35~a
String sURL; //File URL =# <!s!
long nStartPos; //File Snippet Start Position JgEPzHgx
long nEndPos; //File Snippet End Position ">@]{e*
int nThreadID; //Thread's ID `O5wM\Z
boolean bDownOver = false; //Downing is over [RoOc)u
boolean bStop = false; //Stop identical VG_ PBG(
FileAccessI fileAccessI = null; //File Access interface AAb3Jf`UW
fp^{612O?
&gR)Y3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eVGO6 2|!
{ jb|al[p\
this.sURL = sURL; EyO=M~nsS
this.nStartPos = nStart; UP'~D]J
this.nEndPos = nEnd; .nl!KzO6g
nThreadID = id; [3"k :
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xf% _HMKc
} JZ3CCf
zmB6Y t
hSr2<?yk
public void run() 8iA[w-Pv
{ f#f<Ii
while(nStartPos < nEndPos && !bStop) V"K-aO&
{ mSdByT+dG
D<U^FT
?71?Vd
try{ K2|2Ks_CS
URL url = new URL(sURL); |Tv}leJF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xt} 4B#
httpConnection.setRequestProperty("User-Agent","NetFox"); H{hd1
String sProperty = "bytes="+nStartPos+"-"; $lVR6|n
httpConnection.setRequestProperty("RANGE",sProperty); W T~UEK'
Utility.log(sProperty); 79`OB##
1 etl:gcEC
+-2o b90_m
InputStream input = httpConnection.getInputStream(); [J{\Ke0<e1
//logResponseHead(httpConnection); S#Q0aGj
71b0MHNkvv
QiKci%=SX
byte[] b = new byte[1024]; EmG':K(
int nRead; F\0>/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RRRF/Z;))
{ )SU\s+"M
nStartPos += fileAccessI.write(b,0,nRead); fVJlA
//if(nThreadID == 1) p+7G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G`D rY;
} )+7|_7 !x
R5Pk>-KF
p>oC.[:4a
Utility.log("Thread " + nThreadID + " is over!"); (;!92ct[?
bDownOver = true; $;iMo/
//nPos = fileAccessI.write (b,0,nRead); aC90IJ8^
} =M6Ph%
catch(Exception e){e.printStackTrace ();} *qa.hqas
} |VX )S!
} I|n?32F
f`<elWgc"
pq"Z,9,F%
//打印回应的头信息 yE&WGpT
public void logResponseHead(HttpURLConnection con) YY zUg
{ &L[i"1a
for(int i=1;;i++) !MXn&&e1
{ ej,)<*
String header=con.getHeaderFieldKey(i); %?`O .W
if(header!=null) &=^YN"=Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %1oB!+tv
Utility.log(header+" : "+con.getHeaderField(header)); LwlO)|E
else I1pnF61U
break; S;0z%$y
} `5Bv2wlIV
} WKAG)4
;FGS(.mjlC
))%f"=:wt
public void splitterStop() 5jq @ nq6
{ B[.$<$}G
bStop = true; wrQ02?
} 1=Kt.tuf
[g bFs-B2/
EQWRfx?d
} t`1M}}.
h#p[6}D
}a!ny
/* 2qdc$I&$
**FileAccess.java eQz.N<f"
*//文件访问(定位，写) Ay7PU
package NetFox; +Wl]1 c/
import java.io.*; (mr*Thy`@
@HzK)%@
;Fo7 -kK
public class FileAccessI implements Serializable{ IL`LIJ:O
1N_T/I8_F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2n+ud ?|l
RandomAccessFile oSavedFile; 1M.#7;#B3
long nPos; XuWX@cK
]4ck)zlv
kbL7Xjk
public FileAccessI() throws IOException *LMzq9n3o
{ .sc80i4
this("",0); [,MaAB
} T Xiu/g(
;GE6S{~-
4X",:B}
public FileAccessI(String sName,long nPos) throws IOException (t){o>l
{ <)pPq+
oSavedFile = new RandomAccessFile(sName,"rw"); y4! :l=E^
this.nPos = nPos; E,F^!4 rJ$
oSavedFile.seek(nPos); )3A+Ell`
} aS[y\9(**
^62z\Y
]&;In,z
public synchronized int write(byte[] b,int nStart,int nLen) giH#t< )W
{ =E$bZe8
int n = -1; [NJ2rQ/w7
try{ TV0sxod6
oSavedFile.write(b,nStart,nLen); mZXtHFMu
n = nLen; FA>.1EI
} k]C k%[d
catch(IOException e) +=Q:g,kP
{ $9j>oUG
e.printStackTrace (); FaWDAL=Vhk
} St(jrZb
+)bn}L>Rl
PjX V.gz
return n; j^;P=L0=
} <7>1Z 82)
/_HTW\7,
T`pDjT
} l.]wBH#RS
]'?Ue7
Z m%,L$F*L
/* C-)d@LWI
**SiteInfoBean.java /F9Dg<#a
*/ Aqmw#X
package NetFox; O9-`e
aeI0;u
\2=I//YF
public class SiteInfoBean { m&b1H9ymd
@%*2\8}C!
!s^XWsb8
private String sSiteURL; //Site's URL z. X hE \
private String sFilePath; //Saved File's Path M9o/6
private String sFileName; //Saved File's Name oK-d58 sM
private int nSplitter; //Count of Splited Downloading File u{va2n/
'K02T:\iZ
yH]Q;X'
public SiteInfoBean() ]" e'z
{//nSplitter的缺省值为5 MRXw)NAw
//default value of nSplitter is 5 F!g1.49""
this("","","",5); 8m=R" %h
} tFc<f7k
gE$Uv*Gj
$M4Z_zle)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [<{r~YFjWW
{ 1fsNQ!vQP
sSiteURL= sURL; tY]?2u%)
sFilePath = sPath; &4KUXn[F
sFileName = sName; -0<vmU
this.nSplitter = nSpiltter; j;b>~_ U%
) 3"!Q+
Al6%RFt
} mjg@c|rTG
9XtO#!+48
(yi zM
public String getSSiteURL() HfhI9f_x
{ yA"?Hv\o;
return sSiteURL; {DKZ~
} :L+xEL
1goRO
OomC%9/=,
public void setSSiteURL(String value) U^GVz%\
{ ,g}$u'A+d
sSiteURL = value; j!!s>7IZ
} mF~]P8
,D*bLXWh
[^ r8P:Ad
public String getSFilePath() ps:`rVQ7
{ 4v_Hh<%
return sFilePath; cf$ hIB)Oi
} r ~UDK]?V
BF2U$-k4
Ri`6X_xU
public void setSFilePath(String value) !*~QB4\2b
{ i.W*Go+
sFilePath = value; W!\%v"
} $ -<(geI
#yR&|*@
s+fxv(,"c
public String getSFileName() LXxQI(RO
{ _+aR|AEC
return sFileName; /D;ugc*3
} U7jDm>I
k*6"!J%A
ReM]I<WuY
public void setSFileName(String value) {*hvzS{1d
{ n!~ $Z/
sFileName = value; 3b0|7@_E
} fgj$ u
Yl'8" \HF
_6c/,a8;*J
public int getNSplitter() *tRsm"}
{ R\7r!38
return nSplitter; V[*>}XQER
} . 70=xH
c u";rnj
AhA&=l i;
public void setNSplitter(int nCount) ~XWBLU<
{ 4OJD_
nSplitter = nCount; `^^t#sT
} >jmHe^rH
} iZ}c[hC'3`
#T>?g5I
oGI'a:iff
/* ackeq#
**Utility.java :tnW ivrwR
*/ (X\]!'A
package NetFox; T_UJ?W
_U4@W+lhX_
)nj fqg
public class Utility { OS<GAA0
z3L=K9)
}{@y]DcdM4
public Utility() !Z\Gv1
{ z>,tP
_fY9u2Y
ey9hrRMR
} jwLZC
9a]o?>`E
//线程睡眠 z<fd!g+^
public static void sleep(int nSecond) Rsq EAdZw[
{ kjsj~jwvv
try{ owA8hGF
Thread.sleep(nSecond); C<9GdN
} 3[_WTwX0
catch(Exception e) PbS1`8|4
{ *3={s"a.(
e.printStackTrace (); v_U/0 0
} &XI9%h9|
} -^`s#0( y^
,ZY\})`p
//日志 45[,LJaMd
public static void log(String sMsg) <Dgf'GrJ
{ gq*W 0S
System.err.println(sMsg); T@P~A)>yo
} NCzabl
@@\px66
HRbv%
public static void log(int sMsg) <<gW`KF
{ #Q["[}flVv
System.err.println(sMsg); "O$WfpKX
} OIw[sum2
} bw/mF5AsW
qHyOaKMd
Z{l`X#':
/* `#!>}/m
**TestMethod.java q\jq9)
*/ e2V;6N
package NetFox; ft@#[Bkx
Y?K?*`Pkc1
.+?]"1>]
public class TestMethod { '?.']U,: $
5$>buYF
S[y_Ewzq
public TestMethod() 0<4'pO.6Hq
{ ///xx/weblogic60b2_win.exe xfX|AC
try{ T1Z*>(M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Glx{Zu=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); daSx^/$R
SiteFileFetch fileFetch = new SiteFileFetch(bean); u^]Gc p
fileFetch.start(); u-jc8W`Zd
} B+R|fQ
catch(Exception e){e.printStackTrace ();} Z]2z*XD
nB :iG
{hf_Xro&
} ^e_uprZWm
QALr
@J6r;4|&
public static void main(String[] args) z.)*/HGJm
{ @QnKaZ8jW
new TestMethod(); %1GKN|7
} ~X<$l+5
} 7tJ#0to
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