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)); Mli`[8@(
} Iq[Z5k(K
for(int i=0;i<nEndPos.length-1;i++) >C|i^4ppI
{ L'?0*t
nEndPos = nStartPos[i+1]; 9G@ J#vsqr
} T[YGQT|B
nEndPos[nEndPos.length-1] = nFileLength; ZNEWUt{+;^
} (NBq!;_2,x
} 7pY7iR_
eBW=bK~[VP
R~R?0aq
//启动子线程 8#MiM . f
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q{0!N8']"
for(int i=0;i<nStartPos.length;i++) 'sCj|=y2Qc
{ ZCbnDj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VV1I2YcKt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tM$w0Cj
nStartPos,nEndPos,i); #,KjJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ny]R,D0
fileSplitterFetch.start(); f2y:K6$'l*
} @m=xCg.Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nd[{DF?)/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Tl9;KE|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fv",4L
nEndPos = " + nFileLength); c=}#8d.
// fileSplitterFetch[nPos.length-1].start(); LZB=vc|3/
O*ql!9}E{
x(Us O}
//等待子线程结束 0Lo)Ni^"
//int count = 0; ;x=kJ@
//是否结束while循环 TvzqJ=
boolean breakWhile = false; 9"H]zfW
;m+*R/
Oa'DVfw2J
while(!bStop) ,L"1Ah
{ h!L/ZeRaV
write_nPos(); AMhHq/Dw
Utility.sleep(500); m*d {pX
breakWhile = true; !Deg!f\g
}op0`-Xb
}? W[D
for(int i=0;i<nStartPos.length;i++) 8a^E{x@HT
{ ,/=Fm
if(!fileSplitterFetch.bDownOver) n8.W$&-ia
{ .ZB(!v/2
breakWhile = false; 9f ^c9@=
break; x dT1jI
} >2[\WF*"X
} /@<&{_sybp
if(breakWhile) "0(H! }D
break; U '#Xwax
<&+\X6w[
,p,$(V
//count++; J\BTrN7
//if(count>4) ;e>pu"#
// siteStop(); o-))R| ~z
} 8pQx6QE
\C )S3!h
?4kM5NtP
System.err.println("文件下载结束！"); t@`w}o[#
} _i=431Z40
catch(Exception e){e.printStackTrace ();} 7$l!f
} ._uXK[c7P
"lFS{7
}'y=JV>l
//获得文件长度 JFyw,p&xB
public long getFileSize() {*Ag[HS0u
{ }W:Rg}v
int nFileLength = -1; H+oQ L(i|_
try{ t4RI%m\
URL url = new URL(siteInfoBean.getSSiteURL()); &.zG?e.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 't+ J7
httpConnection.setRequestProperty("User-Agent","NetFox"); V6:S<A
,-11w7y\
J 8z|ua
int responseCode=httpConnection.getResponseCode(); "h-G=vo,kl
if(responseCode>=400) <}@*i
{ XA&Vtgu
processErrorCode(responseCode); oV)#s!
return -2; //-2 represent access is error DHUK_#!
} ,:I:F
vqC!Ajm
U.fLuKt
String sHeader; 5 (Lw-_y#
E^)>9f7
JH4hy9i
for(int i=1;;i++) m~[4eH,
{ i;u#<y{E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *Vbf;=Mb
//Utility.log(in.readLine()); VO (KQx
sHeader=httpConnection.getHeaderFieldKey(i); }=dUASL
if(sHeader!=null) &%@b;)]J
{ B#>7;xy>
if(sHeader.equals("Content-Length")) Y ,Iv<Hg
{ \F$Vm'f_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r9nyEzk
break; " vW4"R6
} LFzL{rny!U
} -W/Lg5eK
else b9F:X
break; i#&iT P`
} r%craf
} I`$"6 Xy
catch(IOException e){e.printStackTrace ();} ma +iIt;
catch(Exception e){e.printStackTrace ();} 1BA/$8G
Ihd{@6m
8=GgTpO5
Utility.log(nFileLength); JE a~avyJ
tJ"8"T#6Vr
6aw1
return nFileLength; zS9HR1
} FO"sE`
Qj1qx;S
Jv,*rQH
//保存下载信息（文件指针位置） ^\ N@qL
private void write_nPos() #~_ZG% u
{ |61W-9;
try{ gMGX)Y ,=/
output = new DataOutputStream(new FileOutputStream(tmpFile)); AYVkJq?
output.writeInt(nStartPos.length); I"=a:q
for(int i=0;i<nStartPos.length;i++) c#ahFpsnlw
{ 6njwrqo
// output.writeLong(nPos); n A<#A
output.writeLong(fileSplitterFetch.nStartPos); 9JDdOjqo
output.writeLong(fileSplitterFetch.nEndPos); ]4uY<9VL
} F*}.0SQ
output.close(); w$aiVOjgT
} X6T*?t3!9[
catch(IOException e){e.printStackTrace ();} \>DMN #
catch(Exception e){e.printStackTrace ();} R{3?`x!fY
} bAUruTn
O`;e^PhN
L@|xpq
//读取保存的下载信息（文件指针位置） #OQT@uF!
private void read_nPos() fEWXC|"
{ j3Sz+kOf,
try{ 0SHF 8kek
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z]twh&^1L
int nCount = input.readInt(); j>}<FW-N
nStartPos = new long[nCount]; 6h5,XcO4
nEndPos = new long[nCount]; 0b)q,]l]
for(int i=0;i<nStartPos.length;i++) {:63% j
{ iI]E%H}
nStartPos = input.readLong(); I+!?~]AUuq
nEndPos = input.readLong(); @VzD>?)
} N!{waPbPi
input.close(); ,\DSi&T
} !,(6uO%
catch(IOException e){e.printStackTrace ();} 8mmHefZ}2!
catch(Exception e){e.printStackTrace ();} yUyx&Y/
} WZ A8D0[
[X\<C '<
\#hp,XV>
private void processErrorCode(int nErrorCode) [ r<0[
{ j><8V Qx
System.err.println("Error Code : " + nErrorCode); k"L?("~
} 8fH.E
2Hp<(
A.v'ws+VDP
//停止文件下载 Fv )H;1V
public void siteStop() o6v'`p'
{ #cAX9LV
bStop = true; evLZ<|
for(int i=0;i<nStartPos.length;i++) 0dKv%X#\
fileSplitterFetch.splitterStop(); 7`G FtX}
t0"2Si
b~u53
} Qp5YS
} j1sgvh]D
//负责部分文件的抓取 [b?[LK}.
**FileSplitterFetch.java ?r%kif)
*/ rIhe}1
package NetFox; H6vO}pq)r
6+iZJgwAy
gz~)v\5D/
import java.io.*; &~ .n}h&
import java.net.*; &$x1^
!D!1%@ e
,WKWin
public class FileSplitterFetch extends Thread { 9EU0R H
DOa%|H'P
ukAE7O(W&
String sURL; //File URL :W6R]y
long nStartPos; //File Snippet Start Position KB\A<(o,
long nEndPos; //File Snippet End Position +FGw)>g8'm
int nThreadID; //Thread's ID 5/f"dX
boolean bDownOver = false; //Downing is over gNj~o^6|@
boolean bStop = false; //Stop identical jg3X6/'
FileAccessI fileAccessI = null; //File Access interface z7PmyU >
q(nPI
0+m4 }]6l
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <W2YG6^i
{ i\yp(tE%^
this.sURL = sURL; _KSlIgQ }0
this.nStartPos = nStart; @@QB,VS;{<
this.nEndPos = nEnd; ol#4AU`
nThreadID = id; so]p1@K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RX cfd-us
} W02t6DW
+DR,&;
_C&XwCIm
public void run() r1R\cor
{ ./r#\X)dc
while(nStartPos < nEndPos && !bStop) 8IQqDEY^
{ -NL=^O$G
SbX#$; ks~
^dP]3D1 @
try{ 4^uwZ:
URL url = new URL(sURL); )"sJaHx<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G>?'b
httpConnection.setRequestProperty("User-Agent","NetFox"); 6jpfo'uB$
String sProperty = "bytes="+nStartPos+"-"; +j!$88%Z{
httpConnection.setRequestProperty("RANGE",sProperty); $Ao iH{f
Utility.log(sProperty); yM`QVO!;
-S6^D/(;
0\DlzIO
InputStream input = httpConnection.getInputStream(); yq]/r=e!k
//logResponseHead(httpConnection); g5>c-i
"(NJ{J#A
<)4>"SN&^
byte[] b = new byte[1024]; mgL{t"$c
int nRead; D@iE2-n&V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (V:)`A_-
{ ll#_v^
nStartPos += fileAccessI.write(b,0,nRead); h#?)H7ft
//if(nThreadID == 1) G$7!/O%#_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hG!|ts
} dxk~
1_MaaA;ow"
ps&p|
Utility.log("Thread " + nThreadID + " is over!"); *;!p#qL
bDownOver = true; c[zaYcbl
//nPos = fileAccessI.write (b,0,nRead); &$<7]a\dM
} +|c1G[Jh
catch(Exception e){e.printStackTrace ();} eGE[4Z
} b8~7C4
} 'joE-{
{+@M!
/`H{n$
//打印回应的头信息 ^oH!FN`;{
public void logResponseHead(HttpURLConnection con) Fb^f`UI
{ k.K;7GZC
for(int i=1;;i++) &:}}T=@M1
{ Y. 1dk
String header=con.getHeaderFieldKey(i); OtD!@GQ6
if(header!=null) F0 ^kUyF|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E As1 =
Utility.log(header+" : "+con.getHeaderField(header)); A>Y!d9]ti
else 0?/vcsO
break; dePI&z:
} LvbS")
} +~l`rJ
@(I)]Ca%O
snti*e4"V
public void splitterStop() Rf0F`D k
{ }&qr"z4
bStop = true; z>9gt
} jQRl-[n
NoD\t(@h
;{S7bH'6m
} m[E#$JZtG
y_A7CG"^
NI)q<@ju
/* a,~}G'U
**FileAccess.java .In8!hjYy4
*//文件访问(定位，写) <h[l)-86
package NetFox; u(bPdf@kz
import java.io.*; 5l,Q=V^@l
`@#,5S$ E
HP G*o
public class FileAccessI implements Serializable{ g)UYpi?p-}
3X]\p}]z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d`ESe'j:
RandomAccessFile oSavedFile; 6j5?&)xJ
long nPos; 0\a;} S'g#
=[x @BzH
;&?l1Vu
public FileAccessI() throws IOException ^iz2=}Q8
{ w/Ej>OS
this("",0); ," ~4l&
} O({vHqN>
+t`QHvxv
W y%'<f
public FileAccessI(String sName,long nPos) throws IOException 1 6G/'Hb
{ 9<Kc9Z
oSavedFile = new RandomAccessFile(sName,"rw"); lL]8~3b
this.nPos = nPos; v.pj PBU1
oSavedFile.seek(nPos); }Pf7YuUZZ
} #M5[TN!
Tt*n.HA
bWOn`#+&
public synchronized int write(byte[] b,int nStart,int nLen) =sa bJsgL
{ dt=5 Pnf[y
int n = -1; dX>l"))yR
try{ tW7*(D
oSavedFile.write(b,nStart,nLen); {nl4(2$
n = nLen; L.1pO2zPe
} Bp:i[9w
catch(IOException e) a eo/4
{ BR[f{)a5
e.printStackTrace (); b*@y/ e\u`
} ?iQA>P9B
f7Fr%*cO
4RU/y+[o
return n; i~04P
} ~e@pL*s
+w'{I`QIL0
jhmWwT/O8^
} *[?DnF+
8E9W\@\
2(Ez H
/* =|G l
**SiteInfoBean.java glvtumv
*/ #6 yi
package NetFox; {2,OK=XM|
a|\ZC\(xI
3kl\W[`?
public class SiteInfoBean { \hcb~>=C
cr_Q,*
rBUdHd9
private String sSiteURL; //Site's URL 'G-zJcU
private String sFilePath; //Saved File's Path *=O~TY<](
private String sFileName; //Saved File's Name /92m5p
private int nSplitter; //Count of Splited Downloading File sG~5O\,E
h0)Wy>B=,
qp@:Zqz8
public SiteInfoBean() wt@q+9:
{//nSplitter的缺省值为5 {}TR'Y4
//default value of nSplitter is 5 R0v5mD$:G
this("","","",5); z9#iU>@
} 1*!`G5c,}
{Noa4i
8}0O @ wq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i C nWb
{ k_c8\::p#
sSiteURL= sURL; 2Hp#~cE+.
sFilePath = sPath; ^KsiTVY
sFileName = sName; 5YG?m{hyn_
this.nSplitter = nSpiltter; f/:XIG
=Qcz:ng
{t;{={$
} XNU[\I
O)tZ`X;
>/DyR+?>4
public String getSSiteURL() nD$CY K
{ ?`oCc[hY
return sSiteURL; p7A&r:qq#
} W&U Nk,
=N9a!ii|
K] ^kUN_
public void setSSiteURL(String value) M)U 32gI:
{ HZ1e~IIw
sSiteURL = value; @qfVt
} v_gQCS
1o;+.]B
5$e|@/(0
public String getSFilePath() s C9j73vf
{ .cQ<F4)!tu
return sFilePath; ~8-Z=-
} H?P:;1A]c
C NNyz$
mGXjSWsd
public void setSFilePath(String value) ^]$x/1I;
{ wv2
sFilePath = value; >HUU`= SC
} \I@=EF- &
5Z7<X2
N%A[}Y0;MW
public String getSFileName() \V|\u=@H
{ _d'x6$Jg
return sFileName; 24)3^1P\V
} D! 1oYr
E0<9NFQr7
_M/ckv1q@
public void setSFileName(String value) D-/K'|b
{ 6BihZ|H04
sFileName = value; X;7gh>Q'4
} dooS|Mq
Ocq.<#||H
_(}{=:M?
public int getNSplitter() 99@uU[&IJ
{ n# %mL<
return nSplitter; u6AReL'f
} IRemF@
<|NP!eMsw8
4eym$UWw
public void setNSplitter(int nCount) ;[]{O5TB
{ :!M/9D*}0
nSplitter = nCount; #ra~Yb-F
} VfJYYR
} b8QA>]6A
%pNK ?M+
-v4kW0G
/* a W`q
**Utility.java _-&\~w
*/ ~Cx07I_lf
package NetFox; [lpzUB}<Yp
fQ5VRpWGn
C:/O]slH
public class Utility { U5]{`C0H?
CBAMAr
]A:n]mL
public Utility() C`z[25o
{ bsw0+UY=9
)\C:|
J#7\R':}zl
} 'ao<gTUbu
(PjC]`FK
//线程睡眠 %vvA'WG
public static void sleep(int nSecond) I @TR|
{ H3YFbR
try{ .eAN`-t;
Thread.sleep(nSecond); |1zoT|}q
} `Ym7XF&
catch(Exception e) epsh&)5a*
{ 4=S.U`t7
e.printStackTrace (); .7Zb,r
} tr6<89e(o
} r#^/qs(~
P#(BdKjM
//日志 (+d7cln
public static void log(String sMsg) /s"mqBXCG
{ \jDD=ew
System.err.println(sMsg); n`Pwo&
} HV-c DL
;0ap#6T
)mw#MTv<[
public static void log(int sMsg) !63p?Q=
{ 7U>Xi'?
System.err.println(sMsg); tLXwszR0r
} #T1py@b0zA
} YIv!\`^ \
3-z;pk
]zEatY
/* 1*\JqCR
**TestMethod.java 8"L#5MO t
*/ 4}@J]_]Z
package NetFox; wQ /IT}-
'thWo wE
n4;
public class TestMethod { '\8gY((7
k%|7H,7
4RCD<7
public TestMethod() SJb+:L>
{ ///xx/weblogic60b2_win.exe (- `h8M
try{ h/E+r:2]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b^[Ab:`}[V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~.99H
SiteFileFetch fileFetch = new SiteFileFetch(bean); #@s[!4)_I
fileFetch.start(); lXH?*
} e P]L
catch(Exception e){e.printStackTrace ();} #=mLQSiQ
yd#SB)&
P_S^)Yo
} %5#ts/f
Y 3W_Z
eT33&:n4
public static void main(String[] args) )Qe<XJH!
{ 77D>;90>?
new TestMethod(); jFbj)!;
} dU`kJ,=Z
} nBw4YDR!
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