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)); #G{}Rd|!
} gVCkj!{
for(int i=0;i<nEndPos.length-1;i++) ||hy+f[A
{ udB:ys
nEndPos = nStartPos[i+1]; nk9hQRP? 8
} *{tn/ro6a
nEndPos[nEndPos.length-1] = nFileLength; a{Y:hrd:Z
} o*97Nbjn
} h*)spwF-
? Ldw\
mU:C{<Z
//启动子线程 tp$NT.z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >#dNXH]9
for(int i=0;i<nStartPos.length;i++) H7G*Vg
{ "[@-p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7;KmJ}$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ',8]vWsl
nStartPos,nEndPos,i); isHa4 D0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $f>Mz|j
fileSplitterFetch.start(); W-=~Afy
} : QSlctW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CZE5RzG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t)g1ICt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Zb-TCS+3l
nEndPos = " + nFileLength); &9PzBc
// fileSplitterFetch[nPos.length-1].start(); xuO5|{h
N-jFA8n
TJ7on.;
//等待子线程结束 lE08UEk1i
//int count = 0; JI )+
//是否结束while循环 1Y@6oT
boolean breakWhile = false; gj\r>~S
;3Fgy8T
2i', e
while(!bStop) #^<7VS!x
{ N::_JH?^=
write_nPos(); `y0ZFh1>X
Utility.sleep(500); 5ejdf
breakWhile = true; *gHOH!K,S
&PD4+%!
IvetQ+
for(int i=0;i<nStartPos.length;i++) gd.P%KC!g
{ `j[)iok
if(!fileSplitterFetch.bDownOver) v"O{5LM"
{ _]1dm)%
breakWhile = false; `kyr\+hp
break; ^SxB b,\
} eznw05U
} 8U\;N
if(breakWhile) 9%oLv25{)
break; xBG&ZM4"^f
/#9O{)
HoymGU`w
//count++; M]jzbJ3Q
//if(count>4) $ePAsJ
// siteStop(); )HS|pS:
} wGd8q xa
({Fus@/
"vH@b_>9|
System.err.println("文件下载结束！"); Y {Klwn
} + }(
catch(Exception e){e.printStackTrace ();} z|}Anc[\
} eL^,-3JA(]
EU ThH.
=w".B[r
//获得文件长度 ~Ht[kO
public long getFileSize() 8l>/ZZ.NXi
{ Cv{rd##Y8
int nFileLength = -1; g Gg8O? Z
try{ %&Z!-k(
URL url = new URL(siteInfoBean.getSSiteURL()); !rb)Y;WQt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J\_tigd
httpConnection.setRequestProperty("User-Agent","NetFox"); (o{QSk\
VyCBJK
.zlUN0oe
int responseCode=httpConnection.getResponseCode(); ; z:}OD
if(responseCode>=400) :Ff1Js(Z
{ h\C
processErrorCode(responseCode); 9g"a`a?c
return -2; //-2 represent access is error \PU|<Ru.
} V5K`TC^
?OYu BZF
PAH; +
String sHeader; Niou=PI@
g[-'0d\1
fbNVmjb$)
for(int i=1;;i++) 93)&
{ Da_g3z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0%k`*8
//Utility.log(in.readLine()); RFDwL~-p
sHeader=httpConnection.getHeaderFieldKey(i); ;.!AX|v
if(sHeader!=null) ?&)<h_R4p
{ ;*wZgl
if(sHeader.equals("Content-Length")) >8t3a-/
{ DB:Ia5|*i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .cQwjL
break; kxWf1hIz0
} %l,p />r
} O9=vz%
else #p*{p)]HiA
break; p[hA?dXn
} n8A*Y3~R
} +_06{7@h
catch(IOException e){e.printStackTrace ();} KSqWq:W+
catch(Exception e){e.printStackTrace ();} pHni"iT
fseHuL=~
>LFhu6T
Utility.log(nFileLength); bCdEItcD
A"I:cw"KY
epW;]> l
return nFileLength; !(w\%$|
} 7tUl$H;I/R
q,^^c1f
)+N%!(ki
//保存下载信息（文件指针位置） \2: JX?Jw!
private void write_nPos() 53=s'DZ
{ I Vq9z
try{ _yJd@
output = new DataOutputStream(new FileOutputStream(tmpFile)); @/`b:sv&*
output.writeInt(nStartPos.length); <{9E.6G`n
for(int i=0;i<nStartPos.length;i++) [US.n+G6
{ fwf]1@#
// output.writeLong(nPos); ;l &mA1+
output.writeLong(fileSplitterFetch.nStartPos); HMS9_#[kE
output.writeLong(fileSplitterFetch.nEndPos); 72&xEx
} /(E)|*~6
output.close(); -1:yqF.x
} FoInJ(PDH
catch(IOException e){e.printStackTrace ();} 1}QU\N(t
catch(Exception e){e.printStackTrace ();} 1;4TA}'H
} D/9&pRsO
%S]5wR6;_
f<!eJO:<'
//读取保存的下载信息（文件指针位置） zRD{"uqi
private void read_nPos() z4&|~-m,
{ (JL{X`gs#
try{ y2TJDb1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PC7U&*x@
int nCount = input.readInt(); * "~^k^_b}
nStartPos = new long[nCount]; 31 QT
nEndPos = new long[nCount]; i.)kV B
for(int i=0;i<nStartPos.length;i++) Jf|J":S
{ F[l{pc "C
nStartPos = input.readLong(); ]{0 2!
nEndPos = input.readLong(); F9]GEBLr
} elJLTG
input.close(); (Y)$+9
} lmp0Ye|
catch(IOException e){e.printStackTrace ();} mmu{K$9}I
catch(Exception e){e.printStackTrace ();} ORA+>
} @L=xY[&{
ZvkO#j
}Rt?p8p
private void processErrorCode(int nErrorCode) <nvz*s
{ !n}"D:L(
System.err.println("Error Code : " + nErrorCode); Qg%B<3 <
} R8W{[@
hof:36 <
<FRYt-+
//停止文件下载 bfQ+}|;
public void siteStop() WDP$w(M
{ rMH\;\ I|U
bStop = true; GW]Ygf1t
for(int i=0;i<nStartPos.length;i++) K`M8[ %S
fileSplitterFetch.splitterStop(); @@# ^G8+l
va:5pvt2&
KaauX m
} f]qPxRw
} {3i.U028]
//负责部分文件的抓取 0AZ Vc
**FileSplitterFetch.java ido'<;4>
*/ ?N~rms e
package NetFox; Vge9AH:op
jRmv~]
!eMz;GZ
import java.io.*; ry*b"SO
import java.net.*; GASDkVoij
$GSn#} yz
^Cst4=:W
public class FileSplitterFetch extends Thread { !.?2zp~
,@;",
N41)?-7F
String sURL; //File URL o3#qp>R
long nStartPos; //File Snippet Start Position :3gtc/pt>
long nEndPos; //File Snippet End Position 2>Xgo%
int nThreadID; //Thread's ID *_}ft-*w
boolean bDownOver = false; //Downing is over Ovq-rI{
boolean bStop = false; //Stop identical A%-*M 'J
FileAccessI fileAccessI = null; //File Access interface z|Q)^
}G]6Rip3
#e}Q|pF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $>hPB[[
{ `k+ci7;
this.sURL = sURL; `1=n H/E
this.nStartPos = nStart; H!y1&
this.nEndPos = nEnd; _rdEur C6
nThreadID = id; ': 87.8$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yTm/P!1S
} 2`9e20
%?Yf!)owh
)>QpR8 G-
public void run() ^RAst1q7
{ fZw/kjx@
while(nStartPos < nEndPos && !bStop) p9 <XaJ}
{ 1Mn=m w
DI{VJ&n66
9. 6"C<eYt
try{ p[2`H$A
URL url = new URL(sURL); F0qpJM,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y'(( tBWa!
httpConnection.setRequestProperty("User-Agent","NetFox"); s/"&k
String sProperty = "bytes="+nStartPos+"-"; n0bm 'qw
httpConnection.setRequestProperty("RANGE",sProperty); Hz) Xn\x
Utility.log(sProperty); RP9#P&Qk
(u-K^xC
w[YiH $
InputStream input = httpConnection.getInputStream(); iH<:wLY&J
//logResponseHead(httpConnection); J&CA#Bg:w
}`ox;Q
oJ734v[X
byte[] b = new byte[1024]; Xia4I* *
int nRead; R.@I}>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wW EnAW~
{ <tXk\cOg
nStartPos += fileAccessI.write(b,0,nRead); t1}R#NB
//if(nThreadID == 1) !w2J*E\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q"7vzri
} Y&!-VW
MKPxF@N(
|L[/]@|
Utility.log("Thread " + nThreadID + " is over!"); {k*rD!tT
bDownOver = true; ^ >JAl<k
//nPos = fileAccessI.write (b,0,nRead); i=T!4'Zu
} Tsg;i;
catch(Exception e){e.printStackTrace ();} .;}vp*
} UCV1{
} !0!m |^c5
$ha,DlN
3V=wW{;x
//打印回应的头信息 >!sxX = <
public void logResponseHead(HttpURLConnection con) C$WUg<kcK'
{ r&+8\/{
for(int i=1;;i++) +i^@QNOa
{ cZC%W!pT
String header=con.getHeaderFieldKey(i); 5QN~^
if(header!=null) 3w!8PPl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'tvX.aX2
Utility.log(header+" : "+con.getHeaderField(header)); cQ}3? v
else xKl\:}Ytp
break; AK$&'t+$}7
} *ThP->&:(
} 4FQB%3>*
*Tc lcu
e_=TkG1E6
public void splitterStop() StLFq6BO
{ O{^8dwg
bStop = true; ~H`m"4zQ
} i&mcM_g32
Fi)(~ji:
RK)1@Tz7!
} <ks+JkW_
Hq$&rNnq\
{$qE>ic
/* M/?eDW/
**FileAccess.java &~=FXe0S
*//文件访问(定位，写) _cvA1Q"
package NetFox; ['m7Wry
import java.io.*; $,u>,
*!oV?N[eA'
%9vl
public class FileAccessI implements Serializable{ Fz11/sKz
?}g^/g !
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q7z`oK5
RandomAccessFile oSavedFile; 1A%0y)]
long nPos; lT^/8Z<g
-.xiq0
Mc,3j~i
public FileAccessI() throws IOException *T6*Nxs0k
{ +~(SeTY
this("",0); KE[!{O^(a
} C&|K7Zp0v
jYUN:
L:j3
public FileAccessI(String sName,long nPos) throws IOException *Xcqnu('
{ uM)#T*(
oSavedFile = new RandomAccessFile(sName,"rw"); JAx0(MZO
this.nPos = nPos; x52#md-Z
oSavedFile.seek(nPos); fHK.q({Qc
} &R5zt]4d&
A=W:}szt]
_mWVZ1P
public synchronized int write(byte[] b,int nStart,int nLen) ]*?lgwE
{ &&% oazR=
int n = -1; 7F2 WmMS
try{ | |"W=E
oSavedFile.write(b,nStart,nLen); t"JE+G
n = nLen; "7q!u,u
} F[(ocxQZ3
catch(IOException e) E)%DLZ
{ .8wf {y
e.printStackTrace (); ZJe^MnE (G
} `=V p 0tPI
EDT9O
O!!N@Q2g
return n; j*\oK@
} 40%fOu,u`
qxB|*P`
gLm,;'h%u
} x8w l
?;VsA>PV
+=:_a$98
/* `>0%Ha
**SiteInfoBean.java 577#A,O
*/ 3n,jrX75u
package NetFox; cO$xT;kK
!>\&*h-Cm#
5^D094J|^
public class SiteInfoBean { )SZzA'
QLH!>9Ch
i50E#+E8
private String sSiteURL; //Site's URL en>n\;U
private String sFilePath; //Saved File's Path > ^=n|%
private String sFileName; //Saved File's Name q68CU~i*
private int nSplitter; //Count of Splited Downloading File JC0#pU;
{]bmecz
Y'{}L@"t
public SiteInfoBean() tD*k
{//nSplitter的缺省值为5 )T6:@n^]h
//default value of nSplitter is 5 qt(4?_J
this("","","",5); z3Yi$*q <
} 5dGfO:Dy_
9wlp AK
-T}r$A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 15@2h
{ r+8)<Xt+p
sSiteURL= sURL; yAAV,?:o[
sFilePath = sPath; #+QJ5VI:
sFileName = sName; uI$n7\G!
this.nSplitter = nSpiltter; NN#k^[i1
4> uNH5
n}b{u@$
} ^k*%`iQ
[>N#61CV5
0SU v5c
public String getSSiteURL() p>,D F9W`
{ |sI@m@
return sSiteURL; 0BNH~,0u
} wmww7
j!@T@ 8J
~/X8Hy!-
public void setSSiteURL(String value) vf zC2
{ Nyt*mbd5 {
sSiteURL = value; k-H6c
} [;yKbw!C
{+zG.1o^
V:#rY5X
public String getSFilePath() gg.]\#3g
{ &#JYh=#
return sFilePath; 118lb]
} fP:]s@$
mKjTJzS
O&MH5^I
public void setSFilePath(String value) ;O1jf4y
{ LofpBO6^
sFilePath = value; b}fC' h
} BYu(a
>|, <9z`D
P4HoKoj2`
public String getSFileName() 7m ou
{ -.r"|\1X
return sFileName; TFG? EO
} :8(jhs
8!0fT}
1$1>cuu
public void setSFileName(String value) 3b\s;!
{ ]?)uYot
sFileName = value; c&1_lI,tH
} (V&8 WN
pj<aMh
2Y%7.YX"
public int getNSplitter() lX%-oRQ/os
{ sVr|kvn2
return nSplitter; KAXjvZN1
} t #Kucde
KB^8Z@(+
V,=5}qozQ
public void setNSplitter(int nCount) XlD=<$Nk7
{ VQ,5&-9Y3
nSplitter = nCount; 1TX3/]:
} tH&eKM4G
} tvf5b8(Y-
K\KQ(N8F
y{&%]Fq <5
/* k-a1^K3
**Utility.java A9N8Hav
*/ bl&9O
package NetFox; hxj\
&"WgO!pzD
>]anTF`d
public class Utility { nBd]rak'
w>\oz
j94~cYV
public Utility() O'B3sy
{ +,,dsL
.wp[uLE
cLp_\\
} 5=8v\q?)c
M"W#_wY;
//线程睡眠 BKO^ux%
public static void sleep(int nSecond) cWyf04-?
{ WMnSkO
try{ 7D,nxx(`
Thread.sleep(nSecond); @I|kY5'c
} kP}l"CN4
catch(Exception e) VRgckh m
{ n|?sNM<J3
e.printStackTrace (); OM^`P
} =$+0p3[r
} wl%ysM|x
ZbVn"he
//日志 )X," NJG
public static void log(String sMsg) "=K3sk
{ V~#5^PF{
System.err.println(sMsg); I$S*elveG
} jl}!UG
Xs|d#WbX
*;McX
public static void log(int sMsg) ;F*^c )
{ *g %bdO
System.err.println(sMsg); rXzq:
} [kpQ:'P3
} $L( ,lB
mE1Vr
=SuJ*
/* /eU\B^k
**TestMethod.java KPDJ$,:
*/ V1Ojr~iM
package NetFox; w8~R=k
(=WbLNBS
olr#3te
public class TestMethod { N.+A-[7,W
x^_c4,i)
a!4p$pR
public TestMethod() = 03G~7B>
{ ///xx/weblogic60b2_win.exe _-H,S)kI`
try{ Vt \g9-[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =jh^mD&'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TD*AFR3Oz
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^tSwAanP\
fileFetch.start(); h?;03>6A&]
} A@?-"=h}
catch(Exception e){e.printStackTrace ();} ns~bz-n
rQNm2h
+~YoP>
} 2Mq@5n
)(yaX
v!DK.PZbi
public static void main(String[] args) )Ghw!m
{ qhG2j;
new TestMethod(); ^K::g)
} ^\ln8!;
} ^8bc<c:P
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