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)); 3e(ehLc4DJ
} P(t[ eXe
for(int i=0;i<nEndPos.length-1;i++) w`q%#qRk
{ ew"v{=X
nEndPos = nStartPos[i+1]; =0;^(/1Mc
} F<!)4>2@
nEndPos[nEndPos.length-1] = nFileLength; /4xki_}
} 'uq#ai[5I
} 4.IU!.Uo
L[=a/|)TBV
5Hcf;P7
//启动子线程 Q>n|^y6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MNSbtT*^
for(int i=0;i<nStartPos.length;i++) (PfqRk1Y
{ >3c@x
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), msVOH%wH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), LVJxn2x6
nStartPos,nEndPos,i); sJ]taY ou
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;A#`]-i C
fileSplitterFetch.start(); [,TkFbDq"J
} JwJ7=P=c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }d<}FJ-,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ve\X3"p#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lkBdl#]9
nEndPos = " + nFileLength); V{<xff
// fileSplitterFetch[nPos.length-1].start(); `X3^fg
1x[)/@.'f
=+AS/Jq
//等待子线程结束 :UQTEdc{
//int count = 0; RIIitgV_
//是否结束while循环 nxr!`^Mne
boolean breakWhile = false; ATR!7i\|
+wkjS r`e
YfRkwKjy(
while(!bStop) /{|fyKo\?
{ P3oI2\)*i
write_nPos(); R+Y4|
Utility.sleep(500); %rxO_
breakWhile = true; H/Llj.-jg
g&`pgmUX
fJ ,1Ef;Z
for(int i=0;i<nStartPos.length;i++) ",!1m7[wF
{ :sCqjz
if(!fileSplitterFetch.bDownOver) Fy.\7CL>
{ 9~l hsH
breakWhile = false; _U/!4A
break; HeG)/W?r
} KCWc`Oz
} {#{DH?=^)u
if(breakWhile) B9wPU1
break; 8cA~R-
aXL{TD:]
{RF-sqce
//count++; &B|D;|7H
//if(count>4) Q9Q|lO
// siteStop(); $]8h $
} *cEob b
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nB!&Zq
System.err.println("文件下载结束！"); $#]]K
} rta:f800z
catch(Exception e){e.printStackTrace ();} -N"&/)
} 0@EwM
qM.bF&&Go
4T=u`3pD7l
//获得文件长度 kV38`s>+
public long getFileSize() ~j<+k4I~
{ 3"P }n
int nFileLength = -1; 5sb\r,kW
try{ 1CHeufQ
URL url = new URL(siteInfoBean.getSSiteURL()); Ry|!pV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8KRba4[
httpConnection.setRequestProperty("User-Agent","NetFox"); 6qp%$>$Vt;
[/X4"D-uOK
ldp%{"ZZ
int responseCode=httpConnection.getResponseCode(); Hbpqyl%O>
if(responseCode>=400) /"B?1?qc,=
{ DoeiW=
processErrorCode(responseCode); 0fYj4`4=n
return -2; //-2 represent access is error W>O~-2
} CjiVnWSz<
d$ ^ ,bL2p
?`4+cx}n
String sHeader; zSFDUZ]A3
phgm0D7
aAB`G3
for(int i=1;;i++) A7n\h-b
{ CXC`sPY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); f{FDuIln
//Utility.log(in.readLine()); 8)4P Ll
sHeader=httpConnection.getHeaderFieldKey(i); o";Z$tAJkC
if(sHeader!=null) &0`) Q
{ {>F7CT'G6
if(sHeader.equals("Content-Length")) %%4t~XC#
{ %wSj%>&-R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *Q,0W:~-
break; z-b*D}&
} u07pq4Ly
} WoBo9aR
else =X.9,$Y
break; nI*v820,
} rW0FA
} /jRRf"B
catch(IOException e){e.printStackTrace ();} qu-/"w<3$
catch(Exception e){e.printStackTrace ();} $bsG]
B|&"#Q
EcCFbqS4W
Utility.log(nFileLength); 9F*+YG!
ETXZ?\<a5
!Uq^7Mw
return nFileLength; @0SC"CqM
} TEaJG9RU>v
uNHF'?X
+*hm-lv?
//保存下载信息（文件指针位置） :Cp'm'omb
private void write_nPos() /=gOa\k|p
{ 4Z/Q=Mq2
try{ Iwc{R8BV
output = new DataOutputStream(new FileOutputStream(tmpFile)); GPGm]Gt
output.writeInt(nStartPos.length); 4A2?Uhpy
for(int i=0;i<nStartPos.length;i++) 0eS)&GdR
{ n2fbp\I
// output.writeLong(nPos); <Ce2r"U1e
output.writeLong(fileSplitterFetch.nStartPos); $]A/ o(
output.writeLong(fileSplitterFetch.nEndPos); uECsh2Uin
} Gqy,u3lE
output.close(); $n^gmhp
} NvvUSyk\;s
catch(IOException e){e.printStackTrace ();} ;asP4R=
catch(Exception e){e.printStackTrace ();} QJ7L7S
} l!g]a2x*
/)>s##p*
kVy\b E0o
//读取保存的下载信息（文件指针位置） a@0BBihz
private void read_nPos() 6%VV,$p
{ gw}Mw
try{ ~mR'Q-hi<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >z.<u|r2
int nCount = input.readInt(); ?|ZTaX6A
nStartPos = new long[nCount]; ti<;7Yb
nEndPos = new long[nCount]; 4M^G`WA}t9
for(int i=0;i<nStartPos.length;i++) D7S'*;F
{ `8Lo{P
nStartPos = input.readLong(); Z%n(O(^L
nEndPos = input.readLong(); ZE/o?4k*c1
} FTeu~<KpM
input.close(); $O*O/iG
} Z%x\~)~
catch(IOException e){e.printStackTrace ();} T N!=@Gy
catch(Exception e){e.printStackTrace ();} ^*fxR]Y
} lf!FTm7
/0eYMG+K=
rQaxr!
private void processErrorCode(int nErrorCode) W[}s o6
{ &CG*)bE
System.err.println("Error Code : " + nErrorCode); HuVJ\%.
} R%c SJ8O#
XB_B4X1R
Jzp#bgq}|
//停止文件下载 Nq@+'<@p$
public void siteStop() HX6Ma{vBk
{ &|`C)6[C
bStop = true; kGN+rHo
for(int i=0;i<nStartPos.length;i++) "&%#!2
fileSplitterFetch.splitterStop(); E]6z8juO6
'gt-s547
I'@Ydt2
} Q(\4]i< S
} IEcf
//负责部分文件的抓取 kWrp1`
**FileSplitterFetch.java e~"fn*"
*/ $]q8, N|1
package NetFox; Bk+{RN(w
<$hu
(k|_J42[
import java.io.*; is@b&V]
import java.net.*; M_%B|S {
fks)+L'
bN3#{l-`
public class FileSplitterFetch extends Thread { bl'z<S, '
<~)kwq'
jH6&q~#
String sURL; //File URL J;prC
long nStartPos; //File Snippet Start Position @ G4X
long nEndPos; //File Snippet End Position +Lnsr\BA
int nThreadID; //Thread's ID ku..aG`
boolean bDownOver = false; //Downing is over hnznp1[#@
boolean bStop = false; //Stop identical wGZR31
FileAccessI fileAccessI = null; //File Access interface \{EpduwZ
"hy.GWF|*
0pSmj2/,.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @GvztVYo
{ Z*FrB58
this.sURL = sURL; K_ci_g":
this.nStartPos = nStart; T =2=k&|
this.nEndPos = nEnd; Vy|6E#U
nThreadID = id; oaK%Ww6~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t>uN'oCyC
} a<h1\ `H7
7YAIA%8
y7|P-3[ 4w
public void run() 0{j&6I2
{ "t0kAG
while(nStartPos < nEndPos && !bStop) k}#;Uy=5
{ 8Y#\xzod
DU=dLE6-P;
Tc+gdo>G
try{ 0Ld@H)
URL url = new URL(sURL); <Tot|R;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G\a8B#hg
httpConnection.setRequestProperty("User-Agent","NetFox"); ,<Q~b%(3
String sProperty = "bytes="+nStartPos+"-"; W'on$mB5<
httpConnection.setRequestProperty("RANGE",sProperty); -D^}S"'
Utility.log(sProperty); Kb^>-[Yx
>[1W:KQA
2>l,no39t+
InputStream input = httpConnection.getInputStream(); ZoB{x*IH
//logResponseHead(httpConnection); nA~E "*
U bYEEY#
g(|6~}|o+
byte[] b = new byte[1024]; /CIh2 ]#e
int nRead; XhPe]P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g%k`
{ P(a.iu5
nStartPos += fileAccessI.write(b,0,nRead); w\19[U3
//if(nThreadID == 1) g5q$A9.Jl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U-^[lWn[@4
} tM#lFmdd\P
@;?T~^nGj
_0 m\[t.
Utility.log("Thread " + nThreadID + " is over!"); PG]%Bv57
bDownOver = true; Gx 72
//nPos = fileAccessI.write (b,0,nRead); WW@d:R
} rP(eva
catch(Exception e){e.printStackTrace ();} !(t,FYeH
} ]1gx#y 2
} YKa0H%B(
kHv[H]+v
<s@-:;9~
//打印回应的头信息 U/NBFc:[y:
public void logResponseHead(HttpURLConnection con) JO'>oFv_W
{ c)7j QA
for(int i=1;;i++) :h1pBEiH
{ zW8*EE+,
String header=con.getHeaderFieldKey(i); T{}fHfM
if(header!=null) &''WRgZ}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); K]xa/G(
Utility.log(header+" : "+con.getHeaderField(header)); Cb:gH}j
else WGAXIQ
break; !7d*v3)d
} %5*@l vy
} U'*t~x<
5IKL#V`3a
5#E |R
public void splitterStop() wJlX4cT4YV
{ pN&c(=If
bStop = true; m~'? /!!
} D.%B$Y;G
Y[SU&LM
|/ }\6L]
} y3<Y?M4
1h7+@#<:a
]/cd;u
/* vOgC>_x7
**FileAccess.java *x>3xQq&
*//文件访问(定位，写) j(#%tIv
package NetFox; z* <y5
import java.io.*; 0ji q-3V)
*{o UWt
=?X$Yaw*
public class FileAccessI implements Serializable{ T$=4O9G
Q7bq
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 pA4*bO+
RandomAccessFile oSavedFile; ]h9!ei [
long nPos; QjPj[c
$t-n'Qh^2
jtm?z c
public FileAccessI() throws IOException ]8;n{ }X
{ #;#3%?
this("",0); },[;O^Do^{
} Pj?Dmk~
st'D
gf)t)-E
public FileAccessI(String sName,long nPos) throws IOException j6ut}Uq
{ B%\gkl
oSavedFile = new RandomAccessFile(sName,"rw"); 5HS~op2n/
this.nPos = nPos; q*)+K9LRk
oSavedFile.seek(nPos); rbqo"g`
} ,LOQDIyn
N]YtLa,t
Jg$xO@.
public synchronized int write(byte[] b,int nStart,int nLen) kVS?RHR
{ Ov82ibp_1
int n = -1; #2xSyOrmf
try{ Rb}KZ+o"Z
oSavedFile.write(b,nStart,nLen); <ale$[
n = nLen; gBk5wk_j|
} H g5++.Bp
catch(IOException e) =22ALlxk
{ A 699FQ
e.printStackTrace (); B8I4[@m>w\
} SNT5Amz!
zX7q:Pt
)$x_!=@1
return n; $(q>mg:H
} N6Z{BLZ
]|:uU
vs&8wbS)
} _U)%kY8
iz]rFNR
rSVgWr8
/* !Ngw\@f
**SiteInfoBean.java KbxR Lx]w
*/ xU9@$am
package NetFox; `&$B3)Eb
R UTnc
qI3NkVA'C
public class SiteInfoBean { G6`J1Uk
V7t!?xOL
gd6Dm4q(
private String sSiteURL; //Site's URL +1;'B4
private String sFilePath; //Saved File's Path \.s`n2.w
private String sFileName; //Saved File's Name hh.Q\qhubB
private int nSplitter; //Count of Splited Downloading File #-cTc&$O;
*9gD*AnM,
gY9\o#)<
public SiteInfoBean() sY;lt.b
{//nSplitter的缺省值为5 J7i+c];!<
//default value of nSplitter is 5 D>wZ0p b-
this("","","",5); R21~Q:b!
} u@.>WHQN
VS/;aG$&y
PK rek
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $R^lo$(
{ #2%([w
sSiteURL= sURL; M2T|"Q"=
sFilePath = sPath; [B6DC`M
sFileName = sName; qs=tJ^<<o
this.nSplitter = nSpiltter; d$;/T('
s\0Ko1
@%W]".*'}
} Yr&Ka:
@C.GKeM*
Nw](".
public String getSSiteURL() C9KWa*3
{ S_8r\B[>P
return sSiteURL; &/ouW'oP
} !E&MBAKy
=l`OHTg
?~2Bi^W5
public void setSSiteURL(String value) !0fI"3P@r
{ x,Y5U+]E
sSiteURL = value; |pWaBh|r
} # .q#OC
u.6P-yh
u3dsQU
public String getSFilePath() .2X2b<%)
{ vD=%`G[m
return sFilePath; ]h~o],:
} D[>W{g $
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2@MN]Low
public void setSFilePath(String value) Jgi Iq
{ (@]tG?I=
sFilePath = value; H=.K
} Hq xK\m%,.
*W^=XbG
8B@JFpg^
public String getSFileName() \f"?Tv-C'
{ N8+P
return sFileName; ,k*F`.[
} 4MX7=!E
x N`T
$A?}a
public void setSFileName(String value) En5!"w|j
{ KU2$5[~j
sFileName = value; fI11dE9&?[
} $!`L"szqD*
5G?.T?
W/v|8-gcK
public int getNSplitter() `s}BXKIv}
{ "T*I|
return nSplitter; F!~l MpuE
} $^Ca:duk
/2h][zrZ[.
G?[-cNdk
public void setNSplitter(int nCount) ]p$zvMf}
{ !0dX@V'r
nSplitter = nCount; @)z*BmP
} ;E's4jWq
} _0]QS4a][c
uL>:tb
eycV@|6u*
/* jYdV?B
**Utility.java ;](h2Z`3s
*/ .&(8(C
package NetFox; 4e/cqN6
sV'v* 1|
|#cAsf_{
public class Utility { 9cOx@c+/
E$T(Qu<-
0pNo`Bm
public Utility() #HDesen
{ !Mil?^
_m7co :
{]M>Y%j48
} .93S>U<_
)l{A{f6O
//线程睡眠 YOKR//|3
public static void sleep(int nSecond) N ^f}ui i
{ > Z++^YVE
try{ .Qk{5=l6P
Thread.sleep(nSecond); `]hCUaV
} ZvyjMLf
catch(Exception e) ;o%:7&
{ IQoH@l&Xk
e.printStackTrace (); uWrFunh%
} }s6G!v^2""
} ;/aB)JZ5=
O=`o'%K<
//日志 iUCwKpb9
public static void log(String sMsg) U IQ 6SvM
{ K#;txzi
System.err.println(sMsg); )"-fHW+fy
} `uhL61cMp
?.j,Bq5At
2MT_#r_
public static void log(int sMsg) *JS"(. '(
{ i^/DiWdyf
System.err.println(sMsg); .h!9wGi`
} r?afv.@L2
} ^#7viZ*
fOJj(0=y
xcnt?%%M
/* [>wzl"cHW
**TestMethod.java Pzptr%{
*/ W60Q3
package NetFox; x{2o[dK4}
iBS0rT_
1>yha j(K
public class TestMethod { taixBNv
Z]p8IH%~92
2| $k`I,
public TestMethod() y\@SC\jk|
{ ///xx/weblogic60b2_win.exe excrXx
try{ :SQLfOQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L-MiaKcL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Lv^a+'
SiteFileFetch fileFetch = new SiteFileFetch(bean); v2(U(Tt
fileFetch.start(); fX""xTNPi
} 9yDFHz w
catch(Exception e){e.printStackTrace ();} p/4S$ j#Tn
,?fN#gc :
l&$*}yCK
} H}(=?}+
< )Alb\Z
(Q\\Gw
public static void main(String[] args) at=D&oy4"+
{ ?U$}Rsk{#
new TestMethod(); <gR`)YF7
} 8 `o{b"l+
} C*$|#.l
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