http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); K!Y71_#
} qiD@'Va\
for(int i=0;i<nEndPos.length-1;i++) :>f )g
{ %RRNJf}z
nEndPos = nStartPos[i+1]; 3ym',q
} YfKdR"i+.
nEndPos[nEndPos.length-1] = nFileLength; :bq8N@P/
} s)D;a-F
} D'PI1 0t
ZG8DIV\D7
'4Bm;&6M
//启动子线程 vw/J8'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `e&Suyf4B
for(int i=0;i<nStartPos.length;i++) 2-v%`fA
{ sBg.u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~P**O~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -zeG1gr3
nStartPos,nEndPos,i); 0pd'93C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Moza".fiN
fileSplitterFetch.start(); pO3SUOP
} V&2l5v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v$wIm,j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $G@5qxcV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B%6)}Nl[
nEndPos = " + nFileLength); #h ]g?*}OJ
// fileSplitterFetch[nPos.length-1].start(); `dN@u@[\ks
y??XIsF
_Q4)X)F
//等待子线程结束 0~/_|?]`7
//int count = 0; &n:.k}/P
//是否结束while循环 }|NCboM^_
boolean breakWhile = false; 9qzHS~l
fr6fj
5Yq@;e
while(!bStop) VjZ|$k
{ T:yE(OBf
write_nPos(); . 3T3EX|G
Utility.sleep(500); A$0fKko
breakWhile = true; 7ZWgf"1j
&d^m 1
F{;((VboN
for(int i=0;i<nStartPos.length;i++) je=a/Y=%U{
{ >_T-u<E
if(!fileSplitterFetch.bDownOver) >U27];}y
{ .p" xVfi6
breakWhile = false; vV-`jsq20H
break; Pw"-S?`(
} 9EibIOD^/
} Y&Z.2>b
if(breakWhile) cU!vsdR3
break; =MDysb&:
@<EO`L)Z
ar+9\
//count++; jasy<IqT!{
//if(count>4) 1?+St`+{B-
// siteStop(); 60?%<oJ oH
} dSV8q ,D
i2SR{e8:GF
>@ .
System.err.println("文件下载结束！"); Ry6@VQ"NLb
} >e5qv(y]
catch(Exception e){e.printStackTrace ();} wgGl[_)
} }y gD3:vN7
CryBwm
t&e{_|i#+
//获得文件长度 4zFW-yy
public long getFileSize() e^1Twz3z
{ ,/|T-Ka
int nFileLength = -1; $X,D(
try{ Vp@?^imL
URL url = new URL(siteInfoBean.getSSiteURL()); A_q3KB!$=+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1\I}2;
httpConnection.setRequestProperty("User-Agent","NetFox"); $kp{Eg '
8VXH+5's
p9{mS7R9T
int responseCode=httpConnection.getResponseCode(); 8[{ Vu0R
if(responseCode>=400) ^SrJu:Q_
{ j*r{2f4Rt
processErrorCode(responseCode); BR;D@R``}
return -2; //-2 represent access is error /jJw05;L
} WCixKYq
bY~pc\V:`w
k~1?VQ+?M
String sHeader; amY!qg0P*
9InVQCf2J
u.xnOcOH!
for(int i=1;;i++) S;`A{Mow
{ .U]-j\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v):Or'$~M
//Utility.log(in.readLine()); Y`a3tO=Pd
sHeader=httpConnection.getHeaderFieldKey(i); r3UUlR/Do
if(sHeader!=null) t;\Y{`
{ ePo}y])2
if(sHeader.equals("Content-Length")) ##"HF
{ YT(AUS5n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aAUvlb
break; 7J<5f)
} +ksVtG,
} 6(ol1 (U
else 0flRh)[J
break; A2Gevj?F$
} 7hPY_W y
} *gWwALGo5
catch(IOException e){e.printStackTrace ();} {3aua:q
catch(Exception e){e.printStackTrace ();} HN|%9{VeB
)\$|X}uny&
R8'RA%O9J
Utility.log(nFileLength); 0n{=%Q
pFjK}JOF
}*]-jWt1J\
return nFileLength; C;^X[x%h7$
} Qzw;i8n{
]~siaiN[
$6poFo)U+
//保存下载信息（文件指针位置） e$rZ5X
private void write_nPos() u]UOSfn
{ 92oFlEJ
try{ hp|YE'uYT
output = new DataOutputStream(new FileOutputStream(tmpFile)); >fQMXfoY
output.writeInt(nStartPos.length); 1bwOmhkS
for(int i=0;i<nStartPos.length;i++) ysY*k`5
{ :^h$AWR^f
// output.writeLong(nPos); uoh7Sz5!^
output.writeLong(fileSplitterFetch.nStartPos); |P?*5xPB
output.writeLong(fileSplitterFetch.nEndPos); 6(-N FnT
} 63IM]J
output.close(); O?#7N[7
} e$Pj.>-<=
catch(IOException e){e.printStackTrace ();} 5\VWCI
catch(Exception e){e.printStackTrace ();} $/Uq0U
} a0H+.W+]
l+0oS'`V*L
5]:U9ts#
//读取保存的下载信息（文件指针位置） o-B$J?
private void read_nPos() g*+>H1}
{ a/xn'"eli
try{ PXNuL&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0?|<I{z2
int nCount = input.readInt(); ysnx3(+|
nStartPos = new long[nCount]; QS;f\'1bb
nEndPos = new long[nCount]; yyTnL 2Y9
for(int i=0;i<nStartPos.length;i++) nKj7.,>;:<
{ {(Es(Sb}c
nStartPos = input.readLong(); XC#oB~K'
nEndPos = input.readLong(); ]JQULE)
} dft!lBN
input.close(); ":N9(}9
} >9Vn.S
catch(IOException e){e.printStackTrace ();} <<O$ G7c
catch(Exception e){e.printStackTrace ();} SOaoo^,O
} zX i'kB
i SQu#p@
1s;Saq+
private void processErrorCode(int nErrorCode) a(ZcmYzXU
{ w5 Li&m
System.err.println("Error Code : " + nErrorCode); gbD KE{
} H3oFORh
pT6$DB#
%E;'ln4h&,
//停止文件下载 Zx>=tx}
public void siteStop() 86a\+Kz%%L
{ 9} .z;prz
bStop = true; 8zq=N#x
for(int i=0;i<nStartPos.length;i++) NvX[zqNP_R
fileSplitterFetch.splitterStop(); }c:M^Ff
J]r^W)O
u9p$YJ
} 'dc#F3
} +1!ia]
//负责部分文件的抓取 >=w)x,0yX
**FileSplitterFetch.java %\:Wi#w>
*/ 4?01s-Y
package NetFox; xN'I/@ kb
&BSn?
;mi%F3
import java.io.*; w&.aQGR#
import java.net.*; +aAc9'k
_)iCa3z
y8xE 6i
public class FileSplitterFetch extends Thread { V|R,!UND
b7ZSPXV
62NsJ<#>
String sURL; //File URL pTuS*MYz
long nStartPos; //File Snippet Start Position 2B`JGFcdcB
long nEndPos; //File Snippet End Position iU:cW=W|M\
int nThreadID; //Thread's ID K@%].:
boolean bDownOver = false; //Downing is over TkF[x%o
boolean bStop = false; //Stop identical z0Z%m@
FileAccessI fileAccessI = null; //File Access interface ez[Vm:2K
-tU'yKhn
Ew$C ;&9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1AFA=t:]p
{ 2 ? 4!K.
this.sURL = sURL; @E8+C8'
this.nStartPos = nStart; YchH~m|
this.nEndPos = nEnd; 4 H&#q>
nThreadID = id; O33`+UV"W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x|29L7i
} e~(5%CO>#j
7x8 yxE
K|s,ru
public void run() DIUjn;>k8
{ VG~Vs@c(
while(nStartPos < nEndPos && !bStop) ]K%!@O!
{ /<BI46B\
nT)vNWT=
Ht&YC<X
try{ NZz8j^
URL url = new URL(sURL); D3K8F@d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =?`c=z3~i$
httpConnection.setRequestProperty("User-Agent","NetFox"); 7o}J%z
String sProperty = "bytes="+nStartPos+"-"; FE;x8(;W8
httpConnection.setRequestProperty("RANGE",sProperty); ,"0:3+(8;
Utility.log(sProperty); N4HqLh23H
|vzl. ^"-
M"To&?OI
InputStream input = httpConnection.getInputStream(); !Xw5<J3L-
//logResponseHead(httpConnection); uXl3k:_n
BfiD9ka-z
9(<@O%YU
byte[] b = new byte[1024]; k~z Iy;AZ
int nRead; Qe(:|q_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _h1mF<\ X^
{ S`Rs82>
nStartPos += fileAccessI.write(b,0,nRead); T&7qC=E#5
//if(nThreadID == 1) 6D_D';o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MnW+25=N
} -`6+UkOV[x
%e}Saf
""~ajy
Utility.log("Thread " + nThreadID + " is over!"); UJ6v(:z<
bDownOver = true; Eu04e N
//nPos = fileAccessI.write (b,0,nRead); "@8li^
} zT-_5uZQ
catch(Exception e){e.printStackTrace ();} FHI ;)wn=
} 2^yU ~`#
} ;i+#fQO7Q
\Y}8S/]
SMK_6?MZ
//打印回应的头信息 A&jlizN7
public void logResponseHead(HttpURLConnection con) Aq7osU1B
{ "g8M0[7e3
for(int i=1;;i++) uY'HT|@:{
{ @U}1EC{A
String header=con.getHeaderFieldKey(i); FzC'G57Kl
if(header!=null) \dQNLLg/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c~ V*:$F
Utility.log(header+" : "+con.getHeaderField(header)); .#pU=v#/[
else 3=ymm^
break; v|2T%y_ u
} }RqK84K
} *CHX
*~i ])4
L*JjG sTH
public void splitterStop() ;4~hB
{ cYt!n5w~W
bStop = true; N]sAji*
} HyWCMK6b
u;c?d!E
J-hbh
} wD)XjX
V "h +L7T
L;I]OC^J
/* }`~+]9<
**FileAccess.java wAW5 Z0D
*//文件访问(定位，写) C3YT1tK
package NetFox; [q #\D
import java.io.*; uW36;3[f#1
kPLxEwl
:6\qpex
public class FileAccessI implements Serializable{ @I!0-OjL
b1?'gn~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RrQJ/ts7}
RandomAccessFile oSavedFile; B0]~el
long nPos; &KRX[2
`+Q%oj#FF
WI-1)1t
public FileAccessI() throws IOException y_lU=(%Jd
{ SI-Ops~e
this("",0); OpYY{f
} g7W"
v^ VitLC
w&T9;_/
public FileAccessI(String sName,long nPos) throws IOException [3|P7?W/
{ :&9s,l
oSavedFile = new RandomAccessFile(sName,"rw"); W|63Ir67
this.nPos = nPos; V[Ui/M!9Z
oSavedFile.seek(nPos); HCC#j9UN6
} o:Sa, !DK
?2Py_gkf
u5f9Jw}
public synchronized int write(byte[] b,int nStart,int nLen) rCdu0 gYT
{ + @s"zp;F
int n = -1; !."D]i;
try{ YGCL2Y
oSavedFile.write(b,nStart,nLen); {[?(9u7R
n = nLen; ExL0?FemWV
} q6V>zi
catch(IOException e) CdjI`
{ .jjG(L
e.printStackTrace (); *mvlb (' &
} %^1V4
;,:`1UI
Q:d]imw!O
return n; ,M ^<CJ
} >V8-i`
=R$u[~Xl2X
Ls+2Zbh
} o9yJf#-En
_H7x9 y=
q ,]L$
/* }Sh?S]]`
**SiteInfoBean.java p}pjfG
*/ eiaFaYe\
package NetFox; rlSeu5X6
q Y?j#fzi
^EQ<SCh
public class SiteInfoBean { }-2 2XYh
i#Bf"W{F
r1{@Ucw2
private String sSiteURL; //Site's URL ~H<6gN<j(.
private String sFilePath; //Saved File's Path 9`X\6s
private String sFileName; //Saved File's Name 3<f}nfB%r?
private int nSplitter; //Count of Splited Downloading File >7T'OC
,K"U>&
:vQrOn18p
public SiteInfoBean() `MN4uC
{//nSplitter的缺省值为5 By",rD- r
//default value of nSplitter is 5 A>;bHf@
this("","","",5); ?(F6#"/E
} ep)n_!$OH"
Y0dEH^I
Y>dzR)~3[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E`usknf>l
{ /cQueUME`
sSiteURL= sURL; +RMSA^
sFilePath = sPath; jTtu0Q|
sFileName = sName; }"P|`"WW
this.nSplitter = nSpiltter; CMG&7(MR
)|R)Q6UJ
IT7wT+
} :tB1D@Cb6
{14fA)`%
{{D)YldtA
public String getSSiteURL() H.|#c^I
{ m_?~OL S
return sSiteURL; PI:4m%[
} lH x^D;m6
):68%,
BB!THj69a6
public void setSSiteURL(String value) Ms5ap<q#
{ 6azGhxh
sSiteURL = value; n,V[eW#m'L
} L:pYn_
[P=Jw:E
p;59?
public String getSFilePath() 8:c-k|CX
{ Bs_s&a>
return sFilePath; fF$<7O)+]
} vMi;+6'n>
tqvN0vY5
6xe*E[#k\
public void setSFilePath(String value) dGYn4i2k?
{ .9on@S
sFilePath = value; ['X]R:3h
} Pmr5S4Ka
@fZ,.2ar
b9KP( _
public String getSFileName() 3LJ+v5T~
{ L%*!`TN
return sFileName; av}k)ZT_
} +eWQa`g
_(W+S`7Z
'8RsN-w
public void setSFileName(String value) *v jmy/3
{ E"\<s3
sFileName = value; @w#-aGJO
} xaq-.IQAM$
=r?hgGWe
;v)JnbsH}
public int getNSplitter() 67JA=,EE
{ _JzEGpeG
return nSplitter; VuhGx:Xl
} Gv!2f
vsCCB}7\
iW]j9}t
public void setNSplitter(int nCount) )0.kv2o.
{ KVoS C@w
nSplitter = nCount; acajHs
} P%V'4pc
} 0rQMLx
>a!/QMh
m)ky*"(
/* Q04al=
**Utility.java vjbASFF0=
*/ !_]Y~[
package NetFox; tVYF{3BhA
O40?{v'
SB;&GHq"n
public class Utility { !fV+z%:
?qv !w~m<
0cv{
public Utility() -P(efYk
{ gDQ^)1k
bQzZy5,
!j8FIY'[
} ,Q3T Tno ,
:(E@Gf
//线程睡眠 QGMV}y
public static void sleep(int nSecond) 2 ~dE<}
{ A6
try{ NJ%P/\ C
Thread.sleep(nSecond); on!,c>nNa
} z 4e7PW|
catch(Exception e) SpIv#?
{ gT6z9
e.printStackTrace (); %e8@*~h@
} Eh)fnqs_d}
} 3p$?,0ELH
0.Q Ujw
//日志 PF0_8,@U
public static void log(String sMsg) s-NX o
{ #JqB ;'\
System.err.println(sMsg); Gf%~{@7=u
} xBj9yu
(fhb0i-
"syI#U{
public static void log(int sMsg) ]]HNd7Vh
{ "-Mp_O]
System.err.println(sMsg); SjK
} FBG4pb9=~
} OMky$d#
i:dR\|B
\Zb;'eDv
/* 2/U.|*mH
**TestMethod.java 1wii8B6
*/ i}(LqcYU
package NetFox; xPdG*OcX!
Q1lyj7c#x
l&[O
public class TestMethod { 1Te%F+7
y1z4ik)Sd@
|o7[|3:M
public TestMethod() IM*y|UHt
{ ///xx/weblogic60b2_win.exe )J=!L\
try{ j<upRS,$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PhLn8jNti
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yER(6V'\iQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); @ 8(q$
fileFetch.start(); {.`vs;U
} 53_Hl]#qZ
catch(Exception e){e.printStackTrace ();} K&u_R
:S]%6gb8G
#{0HYg?(f
} ~ZaY!(R<
]dVGUG8
'I|v[G$l
public static void main(String[] args) "> ypIR<
{ t[HE6ea
new TestMethod(); #Bze,?@
} u$z`
} Brw@g8w-X
点击下载更多相关资料