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)); T1TZ+\
} ~}l,H:jk@
for(int i=0;i<nEndPos.length-1;i++) G#M]\)f%
{ VL1z$<vVXt
nEndPos = nStartPos[i+1]; LOo#
} WYUU-
nEndPos[nEndPos.length-1] = nFileLength; /JYi^rZ
} x1ex}_\
} h^X.e[
l3$?eGGM
U?C{.@#w
//启动子线程 fxa^SV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /1GZN *I
for(int i=0;i<nStartPos.length;i++) a{6|[aR
{ AFA*_9Ut
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aM1JG$+7G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U7'oI;C$e
nStartPos,nEndPos,i); wBGxJ\+M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u _^=]K;
fileSplitterFetch.start(); bhT]zsBK
} 9~af\G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {u][q &n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); id9T[^h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", I[Y?f8gJ
nEndPos = " + nFileLength); ? +!?$h
// fileSplitterFetch[nPos.length-1].start(); &^>r<~]
sbIhg/:ok
ZU6a
//等待子线程结束 4<HJD&@V
//int count = 0; MM7gMAA.mz
//是否结束while循环 o8"xoXK5xf
boolean breakWhile = false; )&-+:u0
3xY]Lqwv
<C xet~x
while(!bStop) W%:zvqg v
{ zYJxoC{
write_nPos(); '^AXUb
Utility.sleep(500); o%7yhCY
breakWhile = true; ?2Dz1#%D
a-=apD1RvG
w+D5a VJ
for(int i=0;i<nStartPos.length;i++) 9)X<}*(qo
{ 4\RuJx
if(!fileSplitterFetch.bDownOver) )QT+;P.
{ ddxv.kIj.
breakWhile = false; S?<Qa;
break; l"#,O$x"#@
} &*-2k-16
} 6dlPS{H#U
if(breakWhile) 1j(,VW
break; =jh:0Q<43+
zt6ep=
K.Ir+SB
//count++; 548BM^^"r
//if(count>4) _FgeE`X
// siteStop(); !ZdUW]
} .? /J
Rl8-a8j$f.
~VKXL,.
System.err.println("文件下载结束！"); Q0q$ZK6C
} VVOt%d
catch(Exception e){e.printStackTrace ();} 9NAlgET
} sq$|Pad[
XjNu|H/
$x*GvI1D
//获得文件长度 >kT~X ,o
public long getFileSize() c i>=45@J
{ >Fh@:M7z
int nFileLength = -1; '@P[fSQ
try{ rG6/h'!|
URL url = new URL(siteInfoBean.getSSiteURL()); ~Otf "<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?HTwTi5!)
httpConnection.setRequestProperty("User-Agent","NetFox"); l|{<!7a
O'(vs"eN
95/C4q
int responseCode=httpConnection.getResponseCode(); 8!fwXm
if(responseCode>=400) I 3PnyNZ
{ :W"ITY(
processErrorCode(responseCode); 3[4]G@
return -2; //-2 represent access is error JZ [&:
} I6_+3}Hm{
I5,Fh>
3IIlAzne;
String sHeader; YzqhFFaj.
V Euv
^8)d8?}
for(int i=1;;i++) *k -UQLJ
{ "-sz7}Mb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3 a`-_<
//Utility.log(in.readLine()); TEtZPGFl
sHeader=httpConnection.getHeaderFieldKey(i); K"61i:F
if(sHeader!=null) q!4dK4`#5
{ =*I9qjla[?
if(sHeader.equals("Content-Length")) E;N8{Ye_
{ <jF<_j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n>'}tT)U
break; #XZ?,neY
} \=JKeL|6[S
} ' BpRiN
else R0WJdW#
break; ]3G2mY;`"%
} t@\0$V \X
} p5\b&~ g
catch(IOException e){e.printStackTrace ();} NbdaP{{
catch(Exception e){e.printStackTrace ();} p|%)uA3'/
JT+P>\\];'
gd*\,P
Utility.log(nFileLength); !TcjB;q'
+?8nY.~,'
o,L!F`W
return nFileLength; Kfh"XpWc$
} 6 S8#[b
Y`wi=(
WG,{:|!E
//保存下载信息（文件指针位置） IaB A2
private void write_nPos() #X+)
{ YL]x>7T~4t
try{ /D12N'VaE
output = new DataOutputStream(new FileOutputStream(tmpFile)); VCIG+Gz
output.writeInt(nStartPos.length); DIY WFVh
for(int i=0;i<nStartPos.length;i++) s$Mj4_p3l
{ YAO0>T<F
// output.writeLong(nPos); 97lwPjq
output.writeLong(fileSplitterFetch.nStartPos); :3k(=^%G!
output.writeLong(fileSplitterFetch.nEndPos); JW$#~"@r
} `WVQp"m
output.close(); )9$Xfq/
} AbB%osz}Ed
catch(IOException e){e.printStackTrace ();} >.A{=?
catch(Exception e){e.printStackTrace ();} +.=a R<Q
} kciH
F n\)*; ^
y(HR1vQ;Z
//读取保存的下载信息（文件指针位置） q(C+D%xB
private void read_nPos() %}@^[E)
{ &\A$Rj)
try{ j JW0a\0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x|Dj
int nCount = input.readInt(); S}>rsg!
nStartPos = new long[nCount]; IzG7!K
nEndPos = new long[nCount]; i<l)To-
for(int i=0;i<nStartPos.length;i++) g$ h!:wW
{ J;qHw[6
nStartPos = input.readLong(); _.j KcDf
nEndPos = input.readLong(); u+*CpKR}
} )gE:@3
input.close(); 5i0<BZDTef
} bAgKOfT
catch(IOException e){e.printStackTrace ();} q o'1Pknz
catch(Exception e){e.printStackTrace ();} GYBM]mW^ W
} fQ<V_loP.@
[bAv|;
7w9) ^
private void processErrorCode(int nErrorCode) b3Do{1BV
{ E0YXgQa
System.err.println("Error Code : " + nErrorCode); l)?c3
} ]5^u^
"ey~w=B$M
`H\^#Zu
//停止文件下载 rHMsA|xz6
public void siteStop() t{$t3>p-t
{ VB Ce=<
bStop = true; yCwQ0|
for(int i=0;i<nStartPos.length;i++) | #,b1|af
fileSplitterFetch.splitterStop(); 18Ty)7r'
$ _ gMJ\{
$]O\Ryf6
} :g Ze>
} &.d~ M1Mz
//负责部分文件的抓取 aFLm,
**FileSplitterFetch.java JV@>dK8
*/ ce@(Ct
package NetFox; -IPc;`<
il*bsnwpZv
9khD7v
import java.io.*; sx6` g;
import java.net.*; *p VKMmU
I` /'\cU9
~(}zp<e|
public class FileSplitterFetch extends Thread { +_+}^Nf]Y3
R!:1{1
x ha!.&DO
String sURL; //File URL .*8.{n5
long nStartPos; //File Snippet Start Position na<g /&
long nEndPos; //File Snippet End Position 8G9V8hS1#B
int nThreadID; //Thread's ID BH=vI<D
boolean bDownOver = false; //Downing is over eI- ~ +.
boolean bStop = false; //Stop identical $L?stgU
FileAccessI fileAccessI = null; //File Access interface &DgIykqN
Y1+f(Q
WO]dWO6Mm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m~#O ~)
{ zp d4uto5
this.sURL = sURL; A\WgtM
this.nStartPos = nStart; %6 Bt%H
this.nEndPos = nEnd; U:ZklDW
nThreadID = id; qV5ME#TJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZYg="q0x&
} -BR&b2
Ucv-}oa-?
HZR~r:_ i
public void run() ns@b0'IF]
{ "",V\m
while(nStartPos < nEndPos && !bStop) 8He^j5
{ "Y4tt0I
*2@Ne[dYEF
R:=i/P/
try{ X)`?P*[
URL url = new URL(sURL); nsYS0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V+_L9
httpConnection.setRequestProperty("User-Agent","NetFox"); ;[&g`%-H<
String sProperty = "bytes="+nStartPos+"-"; w<5w?nP+Oh
httpConnection.setRequestProperty("RANGE",sProperty); 7|\[ipVX:3
Utility.log(sProperty); U1dz:OG>
BH\qm (X
aiea&aJ
InputStream input = httpConnection.getInputStream(); Z?X ^7<
//logResponseHead(httpConnection); -]HO8}-Rjs
!<@Zf4m
)t0t*xu#
byte[] b = new byte[1024]; IeE+h-3p
int nRead; eo"6 \3z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0/;T\9
{ +\SbrB P
nStartPos += fileAccessI.write(b,0,nRead); "h\{PoG
//if(nThreadID == 1) DqbN=[!X~n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W%) foJ
} R|Y)ow51
yjc:+Y{5'
^qGH77#z
Utility.log("Thread " + nThreadID + " is over!"); cvi+AZ=
bDownOver = true; C^]bXIb
//nPos = fileAccessI.write (b,0,nRead); ,Epg&)wC]
} mq>Ag
catch(Exception e){e.printStackTrace ();} s+9q:
} @:X~^K.
} %=%jy
KR#Bj?fz-H
[p|-G*=00
//打印回应的头信息 Q lql(*
public void logResponseHead(HttpURLConnection con) $GPenQ~},
{ -fn["R]
for(int i=1;;i++) :U^a0s%B
{ 4>gkXfTF
String header=con.getHeaderFieldKey(i); XV]`?
if(header!=null) %.[t(F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |{<g-)
Utility.log(header+" : "+con.getHeaderField(header)); q#F;GD
else %mg |kb6n
break; =D<46T=(RB
} 1vu=2|QN
} UPA))Iv>
hI]KT a
=k'3rm*ld
public void splitterStop() aV,>y"S
{ c"v#d9
bStop = true; >?'cZTNk]
} ~"iCx+pr
(F +if
% =br-c
} &CG3_s<2
\@3i=!
+kmPQdO;*/
/* x/R|i%u-s
**FileAccess.java +(QGlRd
*//文件访问(定位，写) -%NT)o
package NetFox; ma?$@]`k
import java.io.*; r. =_=V/t
U_y)p Cd
:;#Kg_bz
public class FileAccessI implements Serializable{ L00,{g6wqb
$*{PUj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o *S"`_
RandomAccessFile oSavedFile; 1B}6 zJ
long nPos; |r$Vb$z
@I_A\ U{
J#!:Z8b
public FileAccessI() throws IOException eOE7A'X
{ P BpjE}[Q
this("",0); ?x%HQ2`
} 1.]#FJe
R4%!W~K
&1{RuV&t
public FileAccessI(String sName,long nPos) throws IOException !Z`~=n3bk
{ gQCkoQi:j
oSavedFile = new RandomAccessFile(sName,"rw"); ZjF$zVk
this.nPos = nPos; +MIDq{B
oSavedFile.seek(nPos); 3W5|Y@0
} 0bVtku K;G
FDkRfhK
nxA Y]Q
public synchronized int write(byte[] b,int nStart,int nLen) 1.4]T, `
{ b,cA mZ
int n = -1; 'RC(ss1G
try{ =;9Wh!{
oSavedFile.write(b,nStart,nLen); Y7zg
n = nLen; s0~a5Ti3
} 2kp.Ljt@
catch(IOException e) kVCSFF*
{ |[)t4A"}
e.printStackTrace (); =hH>]$J[
} k9vr6We'
I QS|
lc,{0$ 1<
return n; ={o>g'
} !vHnMY~AG
<=l!~~%
qH: ` O%,
} snK$? 9vh
Zm>Q-7r9
4/&Us
/* ><mZOTn e;
**SiteInfoBean.java A|,\}9)4X[
*/ ce0TQ
package NetFox; nw+L _b
$6Lgaz
|CexP^;!U
public class SiteInfoBean { 47ppyh6@
0m(/hK
rUvqAfE&+
private String sSiteURL; //Site's URL Xp[[ xV|
private String sFilePath; //Saved File's Path I3uaEv7OZc
private String sFileName; //Saved File's Name gLa#y
private int nSplitter; //Count of Splited Downloading File d+[yW7%J
Cg?D<l4
#'^!@+)
public SiteInfoBean() tV<}!~0,*
{//nSplitter的缺省值为5 KwndY,QD
//default value of nSplitter is 5 m"t\@f
this("","","",5); ^/47*vcN5
} Ek~Qp9B
2asA]sY
>pW8K[
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Am'5|
{ EDcR:Dw3
sSiteURL= sURL; AyB-+oTf(
sFilePath = sPath; /pan{.< k
sFileName = sName; 8p,q9Ey
this.nSplitter = nSpiltter; BNw^ _j1
16_HO%v->
T;XEU%:LK
} @s}I_@
OB)Vk
S7N3L."
public String getSSiteURL() ,%w_E[2
{ @Ck6s
return sSiteURL; wj!p6D;;S
} #O6SEK|Z
@>,3l;\Zh
qL091P\F
public void setSSiteURL(String value) {+r pMUs#
{ rk*Igqf
sSiteURL = value; Q#wASd.
} yH#zyO4fD-
uc<XdFcu
VT96ph
public String getSFilePath() ;{ u{FL
{ QU|{(c
return sFilePath; FY)vrM*yh
} w|pk1~c(_
PX65Z|~>_
m(,vymt
public void setSFilePath(String value) "aHY]E{
{ nud,ag
sFilePath = value; PwU}<Hrl]
} zNofI$U
Z#BwJHh
H=?v$! i
public String getSFileName() 060<wjX6
{ l~!Tnp\M
return sFileName; &Y%Kr`.h
} "%dWBvuO
\j !JRD+j
%Rj:r!XB:
public void setSFileName(String value) SL" ;\[uI
{ {:xINQ=}D
sFileName = value; *M\Qt_[
} U>7"BpC
hSSF]
0kS[`a(}J
public int getNSplitter() M;OY+|uA
{ Vh$~]>t:f
return nSplitter; :BKY#uH~
} +8Yt91
:P#
-BfZ P5
public void setNSplitter(int nCount) 3Wxl7"!x m
{ b)9bYkd
nSplitter = nCount; wUHuykF
} Z+`mla
} S!A)kK+
Zy,U'Dv
A\ds0dUE
/* !;.i#c_u
**Utility.java } R!-*Wk
*/ 8fFURk
package NetFox; 9_V'P]@
..V6U"/
]Cnj=\'
public class Utility { #x$.
o)F^0t
*X+T>SKL
public Utility() SoeL_#+^W
{ wr,X@y%(!
i`Fg kABw
4N& VT"
} |(N4ZmTm
dDbPM9]5
//线程睡眠 vT"T*FKh:
public static void sleep(int nSecond) oRFHq>-.g
{ |VbF&*v`
try{ rD<G_%hP
Thread.sleep(nSecond); N(q%|h<Z/=
} <\!+J\YTA
catch(Exception e) J7W]Str
{ +C1/02ZJ
e.printStackTrace (); eyBLgJt8P
} pqFgi_2m
} h~{TCK+I
sCU<1=
//日志 z1wy@1o'
public static void log(String sMsg) 3$[!BPLFO
{ :"7V,UP @
System.err.println(sMsg); 9iGUE
} ^dFdw\
ag^EH"%zw
r7o63]
public static void log(int sMsg) |_/q0#"
{ y3@R>@$
System.err.println(sMsg); M@EML @~
} \&ra&3o
} hE0 p>R8
XBe!9/'k>
W}#eQ|oCV
/* }D/0&<1
**TestMethod.java ++D-,>.
*/ K.4t*-<`[
package NetFox; JYA$_T
RhIRCN9
?ORG<11a
public class TestMethod { dPgN*Bdv
Jj4!O3\I
+#7e?B
public TestMethod() 3<sYxA\?w
{ ///xx/weblogic60b2_win.exe pE<dK.v6
try{ pe$" nUy|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \)'s6>58|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ts/rV#s~
SiteFileFetch fileFetch = new SiteFileFetch(bean); FB-?{78~
fileFetch.start(); jPU:&1(_ n
} $,Y\
catch(Exception e){e.printStackTrace ();} !4TMgM
&QFg=
bzD <6Z
} hi4#8W
DjUif "v
oe`t ? (U
public static void main(String[] args) 2iC7c6hc
{ k44sV.G4L
new TestMethod(); L;$Gn"7~
} xR `4<
} ^[6eo8Ck>
点击下载更多相关资料