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)); * 30K}&T
} ZIa,pON
for(int i=0;i<nEndPos.length-1;i++) ^~-YS-.J#,
{ s5{=lP
nEndPos = nStartPos[i+1]; >h\u[I$7
} qe#5;#
nEndPos[nEndPos.length-1] = nFileLength; C0/^6Lu"o
} \Z3K ~
} 2[Lv_<i|
aIFlNS,y
J_Tz\bZ3)
//启动子线程 {eI'0==
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nOL.%
for(int i=0;i<nStartPos.length;i++) WYTqQqQk
{ ap )B%9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ur8+k4]\"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c/tB_]
nStartPos,nEndPos,i); 96<oX:#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j;y~vX b
fileSplitterFetch.start(); "E\mj'k
} U< Xdhgo?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v;e8W9M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9/{zS3h3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =n"kgn
nEndPos = " + nFileLength); CUI+@|]%
// fileSplitterFetch[nPos.length-1].start(); 30uPDDvar
C$6FI`J
ap}p?r
//等待子线程结束 &Q~W{.
//int count = 0; q/U-6A[0
//是否结束while循环 i m;6$3
boolean breakWhile = false; Ha-]U:Vcx
gx9Os2Z|3
kaekH*m~
while(!bStop) g) oOravV
{ R>"Fc/{y
write_nPos(); )Q =>7%ZA
Utility.sleep(500); X>o9mW
breakWhile = true; vlbZ5
O[ird`/
~SQxFAto
for(int i=0;i<nStartPos.length;i++) ,<tJ`,0X
{ f<@!{y2Xe
if(!fileSplitterFetch.bDownOver) |cma7q}p
{ pVy=rS-
breakWhile = false; JyMk @Y
break; xeU|5-d'
} VjM3M<!g>M
} Q p>b
if(breakWhile) b/z-W`gw
break; >J:=)1`
V[nPTYO4
=WY'n l'
//count++; LOx+?4|y
//if(count>4) +r8bGS]ki
// siteStop(); eA4:]A"
} [v"Z2F<.=
K4!-%d$
LBK{-(%
System.err.println("文件下载结束！"); (E0
} tbRW6
catch(Exception e){e.printStackTrace ();} c 3QgX4vq
} Z;.-UXat
|NfFe*q0;8
=*,SD
//获得文件长度 6^"QABc
public long getFileSize() +'?Qph6o,7
{ u-TT;k'
int nFileLength = -1; l/X_CM8y~
try{ iNA3Y
URL url = new URL(siteInfoBean.getSSiteURL()); 5.~Je6K U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !2LX+*;
httpConnection.setRequestProperty("User-Agent","NetFox"); xPm. TPj
X(N~tE
dE7x SI
int responseCode=httpConnection.getResponseCode(); Y.viOHL
if(responseCode>=400) lYx_8x2
{ nj[TTndJt
processErrorCode(responseCode); K~ eak\=
return -2; //-2 represent access is error d/7fJ8y8
} xo"GNFh!
2Xt4Rqk$
n$/|r
String sHeader; x%B_v^^^
_gT65G~z
?*fa5=ql
for(int i=1;;i++) Ma^jy.
{ }@r23g%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5p0~AN)
//Utility.log(in.readLine()); AjVC{\Ik
sHeader=httpConnection.getHeaderFieldKey(i); t%=7v)IOE
if(sHeader!=null) r6DLShP-Ur
{ :;k?/KU7
if(sHeader.equals("Content-Length")) ;,4*uU'vq
{ =z.j{%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uC'-: t#
break; pHeG{<^
} >ED;_L*_o
} E'AR.!
else U4!bW
break; UUt"8]@[
} F]$ Nu
} VeA@HC`?"
catch(IOException e){e.printStackTrace ();} Xoe|]@U`
catch(Exception e){e.printStackTrace ();} y~9wxK
noZbsI4
0,Ds1y^
Utility.log(nFileLength); 22l'kvo4"
7)rQf{q7
BIx*t9wA
return nFileLength; N1t4o~
} V}E['fzBFV
"#d$$ 8
?%O>]s
//保存下载信息（文件指针位置） V6g*"e/8
private void write_nPos() V+gZjuN$
{ vt EfH
try{ ]iV]7g8:
output = new DataOutputStream(new FileOutputStream(tmpFile)); a5a ;Fp
output.writeInt(nStartPos.length); x ytrd.
for(int i=0;i<nStartPos.length;i++) >.?yz
{ $fb%?n{
// output.writeLong(nPos); j*%#~UFw
output.writeLong(fileSplitterFetch.nStartPos); NLsF6BX/-
output.writeLong(fileSplitterFetch.nEndPos); <a R
} uLdHE5vr
output.close(); WBjJ)vCA.
} uKx:7"KD
catch(IOException e){e.printStackTrace ();} v^9eTeFO
catch(Exception e){e.printStackTrace ();} L$ T2 bul
} hb[ThQ
rZI63S
`,O7S9]R+
//读取保存的下载信息（文件指针位置） !'$*Z(
private void read_nPos() Q& [!+s:2J
{ 1j2U,_-
try{ xW"O|x$6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); U][E`[m#
int nCount = input.readInt(); ekx(i QA
nStartPos = new long[nCount]; dsIbr"m
nEndPos = new long[nCount]; jOhAXe;~X{
for(int i=0;i<nStartPos.length;i++) 9SC1A-nF
{ I Fw7?G,
nStartPos = input.readLong(); H{cOkuy
nEndPos = input.readLong(); $1=7^v[U
} L=(-BYS
input.close(); DgEdV4@p
} cqU6 Y*n
catch(IOException e){e.printStackTrace ();} ?y|&Mz'XJ(
catch(Exception e){e.printStackTrace ();} Q<>u)%92@
} t[|rp&xG
aT^ $'_ G
B7Ket8<J
private void processErrorCode(int nErrorCode) sI\NX$M
{ jTwSyW
System.err.println("Error Code : " + nErrorCode); &>-'|(m+2
} PTHxvml
bWL!=
Gza= 0
//停止文件下载 t__f=QB/
public void siteStop() Y6wr}U
{ gV)/lDEM5
bStop = true; /5 z+N(RFC
for(int i=0;i<nStartPos.length;i++) a;$V;3C{b&
fileSplitterFetch.splitterStop(); zd_N' :6
YusmMsN?
:%sG'_d
} `n,RC2yo
} P)VQAM
//负责部分文件的抓取 /yU#UZ4;
**FileSplitterFetch.java '&Ur(axs
*/ n\9IRuYO
package NetFox; nZiwR4kM
xkf2;
N5 sR
import java.io.*; 4UbqYl3|a
import java.net.*; i:Y5aZc/Ds
~_BjcY
7 @\i5
public class FileSplitterFetch extends Thread { (KO]>!t
OGEe8Z9Jt
5_A*IC]
String sURL; //File URL tIn`L6b
long nStartPos; //File Snippet Start Position 1.%|Er 4
long nEndPos; //File Snippet End Position JCxQENsVqB
int nThreadID; //Thread's ID ['>ZC3?"h
boolean bDownOver = false; //Downing is over #^9bBF/
boolean bStop = false; //Stop identical +Zi+ /9Z(H
FileAccessI fileAccessI = null; //File Access interface uPho|hDp
y?cN
RKrNmD*rk*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Sa)sDf1+`
{ RKzO$T
this.sURL = sURL; ;E{jn4B'
this.nStartPos = nStart; ,e|"p[z~T
this.nEndPos = nEnd; \v+>qY<q
nThreadID = id; ,XscO7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `]]5!U2
} ;\|GU@K{hC
W*iTg%a\k
C@;e<
public void run() &I-T
{ D]>Z5nr |
while(nStartPos < nEndPos && !bStop) W3ms8=z
{ t<c7%i#Od
3ouy-SQ
C ]B P}MY<
try{ byP<!p*
URL url = new URL(sURL); Y8%l)g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y(aUB$"
httpConnection.setRequestProperty("User-Agent","NetFox"); tKyGD|g S
String sProperty = "bytes="+nStartPos+"-"; L[:AUe
httpConnection.setRequestProperty("RANGE",sProperty); vC1fKo\p
Utility.log(sProperty); 3 ;"[WOv
}; 7I
@x*xgf
InputStream input = httpConnection.getInputStream(); 2Y9u9;ah
//logResponseHead(httpConnection); bLWY Tj
Yx,E5}-
THy?Y
byte[] b = new byte[1024]; uDJ;GD[yc
int nRead; ;:oXe*d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H;<>uELie
{ trjpq{,[U
nStartPos += fileAccessI.write(b,0,nRead); 'y>Y*/
//if(nThreadID == 1) YH+(N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ) x+edYw
} (#6Fg|f4Y
&ID! lEd
o+8H:7,o'
Utility.log("Thread " + nThreadID + " is over!"); <L*`WO]\l
bDownOver = true; 7l/ZRz}1
//nPos = fileAccessI.write (b,0,nRead); %t6-wWM97
} H)S!%(x4
catch(Exception e){e.printStackTrace ();} F#L1~\7
} Yj bp:
} OXpN8Dh5
V'RbTFb9Z
8PVjNS/
//打印回应的头信息 p-\->_9)y`
public void logResponseHead(HttpURLConnection con) yEjiMtQll]
{ [aA@V0l
for(int i=1;;i++) 2?6]Xbs{
{ 2<!IYEyT
String header=con.getHeaderFieldKey(i); j[R.UB3J
if(header!=null) YL!{oHs4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4X/UyBk
Utility.log(header+" : "+con.getHeaderField(header)); .vy@uT,
else HnjA78%i
break; ZI1]B944ni
} 5oCg&aT
} $v#`2S(7
}6.@
k{vbi-^6rf
public void splitterStop() ZCZ@ZN
{ / yBrlf
bStop = true; <)!,$]S
} +ansN~3
OE0G*`m
Wq+GlB*
} /i27F2NQm
Q~0>GOq*
AIn/v`JeX
/* LWTPNp:"{w
**FileAccess.java H I_uR$m
*//文件访问(定位，写) Q 318a0
package NetFox; `#l3a
import java.io.*; NZ i3U
6YNL4HE?
2'-"&d+O
public class FileAccessI implements Serializable{ NNbdP;=:u
2YKa <?_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I-g/)2
RandomAccessFile oSavedFile; j:'g*IxM_
long nPos; ARf{hiV6Wt
:EQ{7Op`
X|Y(*$?D7
public FileAccessI() throws IOException UsFn!!+
{ I-r+1gty
this("",0); =HsE:@
} M:}u|
!*"fWahv
&5R|{',(Y
public FileAccessI(String sName,long nPos) throws IOException Ws`ndR
{ T{3nIF
oSavedFile = new RandomAccessFile(sName,"rw"); "#o..?K
this.nPos = nPos; =s4(Y
oSavedFile.seek(nPos); +Z|3[#W
} J,CwC)
gHstdp_3
A)C)5W
public synchronized int write(byte[] b,int nStart,int nLen) 9)'f)60^
{ -g2l-N{&
int n = -1; Yjjh}R#
try{ J>}J~[ap\J
oSavedFile.write(b,nStart,nLen); 3)W zX
n = nLen; LO{Axf%
} :+PE1=v
catch(IOException e) X^ Is-[OvE
{ 0Z8"f_GK
e.printStackTrace (); 6j<!W+~G
} gk%@& TB/
BtC*]WB"_'
2Ckx.m&
return n; z2uL[deN'"
} rtj`FH??11
'V]&X.=zC
_rwJ:r
} ]h,rgO;
8XB[CbO
Q< :RLKVT
/* ">oySo.B?
**SiteInfoBean.java @m#OhERv
*/ 06S R74
package NetFox; _VKI@
;2<5^hgk
{p84fR1P
public class SiteInfoBean { aaR& -M@
W#p7M[
I x%>aee
private String sSiteURL; //Site's URL PW5]+ |#
private String sFilePath; //Saved File's Path L"m^LyU
private String sFileName; //Saved File's Name kyJbV[o<#
private int nSplitter; //Count of Splited Downloading File pd|KIs%jl
}4A] x`3
i41~-?Bc
public SiteInfoBean() eThaH0
{//nSplitter的缺省值为5 C!VhVOy>d
//default value of nSplitter is 5 hO=L|BJ?I
this("","","",5); K*>%,mP$i
} ^+_rv
q!$s<n
~3F'X
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .[Sis<A]%
{ VeYT[Us"
sSiteURL= sURL; s#9q3JV0
sFilePath = sPath; J}#gTG( '
sFileName = sName; !T{+s T
this.nSplitter = nSpiltter; } oPO`
0bTj/0G?
VdlT+'HF
} !g@Ky$
$DY#04Je\=
:@(('X(".
public String getSSiteURL() uJw?5kEbv<
{ V}jGxt0
return sSiteURL; Mog>W&U
} im<bo Mv
bA^uzE
r9[S%Def
public void setSSiteURL(String value) )?F&`+
{ !HY^QK
sSiteURL = value; fN&,.UB^p
} \|HEe{nA
pbH!u+DF
!oWB5x~:P
public String getSFilePath() i,6OMB $
{ TSB2]uH
return sFilePath; ~gDYb#p
} Cv**iW
'C]w3Rh'
8A>OQR
public void setSFilePath(String value) i2=- su
{ 1oQw)X
sFilePath = value; &6eo;8 `U
} Rb6BY-/J
YYWD\Y`8
rzfLp
public String getSFileName() w!F>fcm
{ j4$nr=d.6
return sFileName; Fs/CW\
} msl.{
'S`l[L:.8
cl& w/OJ#
public void setSFileName(String value) oD2:19M@p
{ on_h'?2
sFileName = value; uo"<}>iJ
} E'08'8y
?;XO1cs
IiPX`V>RC
public int getNSplitter() .?Eb{W)^br
{ H$`U] =s|
return nSplitter; $$9H1)Ny
} Y{} ub]i
F9%_@n
cYSn
public void setNSplitter(int nCount) 4.O)/0sU
{ q[s,q3n~
nSplitter = nCount; TU|#Pz7n-Z
} f_c\uN@f
} K[T0);hZR
,6^<Vg
"laf:Ty1
/* 6#z8 %kaX
**Utility.java [ V.67_~
*/ 2S8;=x}/
package NetFox; Cl0kR3Y
.j4y0dh33
|"*P`C=
public class Utility { <B6md i'R
N9-0b
7KgaXi3r
public Utility() xlv(PVdn
{ =xk>yw!O)
9PB%v.t5y
7Z>vQf B
} [N,+mX
/stvNIEa
//线程睡眠 vHi%UaD-y
public static void sleep(int nSecond) P'KA-4!
{ ?mNB:-Q
try{ 6,q0F*q
Thread.sleep(nSecond); k$$SbStD
} <X*oW".
catch(Exception e) 0>Y3xNb
{ -6)nQNj|
e.printStackTrace (); OU{c|O
} "}()/
} P00G*iY~\
lf"w/pb'
//日志 {IOc'W-C#2
public static void log(String sMsg) C@a I*+@-"
{ !Q\*a-C
System.err.println(sMsg); vA6`};|
} `,AOxJ:$
4q.;\n
/Xi21W/
public static void log(int sMsg) Bw;isMx7
{ q{h,}[U=
System.err.println(sMsg); B W*8
} 8Yc-3ozH
} zU1D@
faOiNR7;h
/T6bc^nOW
/* e (]]
**TestMethod.java A{>w5T
*/ bIm4s
package NetFox; 8(`e\)%l0
u^xnOVE
4- QlIIf
public class TestMethod { @7}XBg[pI
e(wc [bv
=x+1A)Q
public TestMethod() 4Pr^>m
{ ///xx/weblogic60b2_win.exe &&CrF~
try{ o|>=<l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;40Z/#FI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n ^9?(a4u
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q>Ct]JW&
fileFetch.start(); Lu^uY7 ?}
} vRtERFL
catch(Exception e){e.printStackTrace ();} OybmyGHY
6<@mBZ
^6# yL6E,~
} Ak3^en
^/Hf$tYI!`
1PxRj
public static void main(String[] args) W/A@qo"
{ Q1Qw45$
new TestMethod(); )'jGf;du
} ]*]*O|w
} ,Gy,bcv{
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