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)); +SJd@y@fR
} \W1/p`
for(int i=0;i<nEndPos.length-1;i++) [9:9Ql_h
{ a&vY!vx3
nEndPos = nStartPos[i+1]; 4tY ss
} 6;b~Ht
nEndPos[nEndPos.length-1] = nFileLength; ]l8^KX'
} W456!OHa
} |JCU<_<
(XoH,K?{z
F2X0%te
//启动子线程 RejQ5'Neh
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bV/jfV"%E
for(int i=0;i<nStartPos.length;i++) Jaz?Ys|S
{ p,"g+ MwP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6AocmR0D'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EYA,hc
nStartPos,nEndPos,i); .bio7c6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1^gl}^|B
fileSplitterFetch.start(); Z1"v}g
} hpU2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2;w*oop,O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5h;+Ky!I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~Jf{4*>y
nEndPos = " + nFileLength); k1Q?'<`
// fileSplitterFetch[nPos.length-1].start(); j&k6O1_
0Fu~%~#E$
4>J
//等待子线程结束 y+7PwBo%e
//int count = 0; oY, %Iq
//是否结束while循环 Nz)l<S9>
boolean breakWhile = false; u{L!n$D7
<_Q1k>
d^`?ed\1
while(!bStop) %j7XEh<'
{ @V!r"Bkg.
write_nPos(); bV"G~3COy
Utility.sleep(500); 5 (A5Y-B
breakWhile = true; cph:y
NFv>B>
^Ox3XC
for(int i=0;i<nStartPos.length;i++) 0V?F'<qy
{ 8g7<KKw
if(!fileSplitterFetch.bDownOver) -44&#l^}_u
{ j)q\9#sI/(
breakWhile = false; Dl}$pN
break; Dwzg/F(
} |ZQ@fmvL/p
} X]'7Ov
if(breakWhile) aM;W$1h
break; ]LM-@G+Jz
7x<i :x3
- |gmQG
//count++; n93=8;&
//if(count>4) A%^ILyU6c
// siteStop(); 0x!2ihf
} Fgh]KQ/5
QPq7R
KZeQ47|
System.err.println("文件下载结束！"); 0Zg%+)iy@
} '}9JCJ
catch(Exception e){e.printStackTrace ();} Lco&Fp
} {%C7EAq*
\J6j38D5
F;>!&[h}G
//获得文件长度 \nP>:5E1
public long getFileSize() D$x_o!JT
{ (IPY^>h
int nFileLength = -1; PsZ >P|e1
try{ |n] d34E
URL url = new URL(siteInfoBean.getSSiteURL()); 'g{9@PkGn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jQ)T67
httpConnection.setRequestProperty("User-Agent","NetFox"); ^,]B@t2
.c$316
}-@`9(o`)
int responseCode=httpConnection.getResponseCode(); }RP@!=
if(responseCode>=400) d \35a4l
{ GDuMY\1
processErrorCode(responseCode); dc rSz4E|>
return -2; //-2 represent access is error )Qvk*9OS
} x)_0OR2lkp
n\Lb.}]1~
l\n@cQR
String sHeader; kTvd+TP4
9 '2_
ERN>don2
for(int i=1;;i++) !e?.6% %
{ R,Vd.-5M
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c?@T1h4
//Utility.log(in.readLine()); OiP!vn}k
sHeader=httpConnection.getHeaderFieldKey(i); n-@j5w+k4
if(sHeader!=null) -xP!"
{ q?ix$nKOv
if(sHeader.equals("Content-Length")) NhYLtw^u
{ Q6r7.pk"SU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pn^ d]rou?
break; G2FXrkU
} J^g!++|2P
} |.3DD"*
else S)/_muP
break; to$h2#i_
} a.zpp'cEb
} j.@\3'
catch(IOException e){e.printStackTrace ();} ,#kIr
catch(Exception e){e.printStackTrace ();} pt}X>ph{
wLH] <k
nxl[d\ap+n
Utility.log(nFileLength); VZl6t;cn
+) m_o"hl
Pp5^@A
return nFileLength; lO_UPC\@fw
} $-*!pRaVU
"%x<ttLl
h?azFA~
//保存下载信息（文件指针位置） C;vtY[}<
private void write_nPos() Vkc#7W(
{ w/K_B:s
try{ HC}YY2
output = new DataOutputStream(new FileOutputStream(tmpFile)); :]1TGfS
output.writeInt(nStartPos.length); 2Roc|)-47
for(int i=0;i<nStartPos.length;i++) Kp,M"Y
{ -Zz$~$
// output.writeLong(nPos); w4d--[Q
output.writeLong(fileSplitterFetch.nStartPos); .>IhN 5
output.writeLong(fileSplitterFetch.nEndPos); MHC^8VL
} wg]j+r@
output.close(); yYH0v7vx+
} $ <#KA3o\
catch(IOException e){e.printStackTrace ();} 8M`#pN^
catch(Exception e){e.printStackTrace ();} HF.^ysI
} 82DmG@"s2
KkE9KwZ]W
}7.PH'.8
//读取保存的下载信息（文件指针位置） 1[vi.
private void read_nPos() oTuOw|[
{ .?Gd'Lp
try{ jav#f{'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1wP-
int nCount = input.readInt(); #"5 Dk#@
nStartPos = new long[nCount]; aqc?pqM
nEndPos = new long[nCount]; v3jg~"!
for(int i=0;i<nStartPos.length;i++) $"H{4x`-
{ bG(3^"dS
nStartPos = input.readLong(); AlIpsJ[UU
nEndPos = input.readLong(); ut I"\1hQ
} Aj4T"^fv
input.close(); UTH_^HAN#G
} Sh8"F@P8
catch(IOException e){e.printStackTrace ();} " _ka<R..
catch(Exception e){e.printStackTrace ();} ;hjwD
} vt9)pMs
e;[F\ov%
Pw61_ZZ4B\
private void processErrorCode(int nErrorCode) @>U-t{W
{ KSNPkd6
System.err.println("Error Code : " + nErrorCode); N D2L_!g:(
} mA=i)Ga
Oal3rb
<h'5cO
//停止文件下载 oT>(V]*5
public void siteStop() Yn G_m]
{ 2mGaD\?K
bStop = true; qCnZhJ
for(int i=0;i<nStartPos.length;i++) wGP;Vbk
fileSplitterFetch.splitterStop(); 6Z%U`,S
sU{NHC)5
(X3Tav
} x" L20}
} :FTMmW,>'
//负责部分文件的抓取 D 'Zt
**FileSplitterFetch.java AQ[GO6$,%H
*/ C .~+*"Vw
package NetFox; % V8U(z
#Ibp(
2P@sn!*{1
import java.io.*; uvG]1m#
import java.net.*; dKxyA"@
_`:1M2=
csW43&
public class FileSplitterFetch extends Thread { trp0V4b8
[S>2ASj
AGYc |;
String sURL; //File URL 7*Ej. HK
long nStartPos; //File Snippet Start Position j+,d^!
long nEndPos; //File Snippet End Position @-!}BUs?
int nThreadID; //Thread's ID suzZdkMA
boolean bDownOver = false; //Downing is over 65aK2MS@
boolean bStop = false; //Stop identical !74S
FileAccessI fileAccessI = null; //File Access interface W|g4z7Pb
hj.a&%
bKN@j'M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <yH4HY
{ J.xPv)1'
this.sURL = sURL; *=I}Qh(1
this.nStartPos = nStart; #/<&*Pu5t
this.nEndPos = nEnd; U5.LDv;
nThreadID = id; /q`xCS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0p}D(m2B
} 2 Cv4=S
?1K#dC52#
vbC\?\_
public void run() W1|0Yd ;P
{ zIu E9l
while(nStartPos < nEndPos && !bStop) 7B\Vs-d
{ zPjHsulK
9E>|=d|(d
xY^%&n
try{ NP/Gn6fr
URL url = new URL(sURL); f m)pulz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'g m0)r
httpConnection.setRequestProperty("User-Agent","NetFox"); A"G 1^8wvX
String sProperty = "bytes="+nStartPos+"-"; ^Uf]Q$uCjE
httpConnection.setRequestProperty("RANGE",sProperty); G'ei/Me6{
Utility.log(sProperty); .@@?Pj?)
K)DDk9*
j;-1J_e5
InputStream input = httpConnection.getInputStream(); ?-dX`n
//logResponseHead(httpConnection); 6&!PmKFO.
Pu*6"}#~
lY?QQ01D
byte[] b = new byte[1024]; F.=2u"[*&
int nRead; C8V/UbA /
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BlA_.]Sg$
{ :<bB?N(
nStartPos += fileAccessI.write(b,0,nRead); #0P$M!%
//if(nThreadID == 1) :?g:~+hfO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $',K7%y
} V4'YWdTi
HoRg^Ai?\
)quM4=u'
Utility.log("Thread " + nThreadID + " is over!"); j)/nKh4O
bDownOver = true; c*L0@Ak%
//nPos = fileAccessI.write (b,0,nRead); YSTv\y
} 'kL#]
catch(Exception e){e.printStackTrace ();} <~n"m
} @oV9)
} <FcG oGK
e} P I^bc
06c>$1-?
//打印回应的头信息 OHb[qX\
public void logResponseHead(HttpURLConnection con) +RYls|f
{ '":lB]hS
for(int i=1;;i++) ]pNvxXbeW
{ y)W@{@{kl
String header=con.getHeaderFieldKey(i); %'s>QF]'
if(header!=null) D*gFV{Ws
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;U.hxh;+
Utility.log(header+" : "+con.getHeaderField(header)); d(:8M
else iB%gPoDCL@
break; w~"KA6^
} Kgi<UkFP
} X[&Wkr8x '
ymx>i~>7J
DVB{2~7 4
public void splitterStop() -ZRO@&tMD
{ N343qU
bStop = true; Py@wJEo
} OZ |IA:,}
qUob?| ^
2\jPv`Ia
} LWz&YF#T-
/ zB0J?
b\$}>O
/* Rv$[)`&T
**FileAccess.java &U5{Hm9Ynr
*//文件访问(定位，写) _m gHJ0v'
package NetFox; {B?Wu3-
import java.io.*; !'&n-Q
jv%kOovj
-EkWs/'h
public class FileAccessI implements Serializable{ D6>2s\:>vp
CF&6J$ZBgJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z$/_I0[
RandomAccessFile oSavedFile; ;*:]*|bw
long nPos; f78An 8
.<x&IJ /
gv)P]{%^
public FileAccessI() throws IOException lOuHVa*}
{ \{Z;:,S
this("",0); TarIPp
} ,9}h
ES.fOdx
ZniB]k1
public FileAccessI(String sName,long nPos) throws IOException -QM: q
{ #h8Sq~0
oSavedFile = new RandomAccessFile(sName,"rw"); zF8dKFE~
this.nPos = nPos; :Q $K<)[
oSavedFile.seek(nPos); 9F)z4
} J'SZ
4'g;TI^
wVicyiY]
public synchronized int write(byte[] b,int nStart,int nLen) ;t<QTGJ
{ PE}:ybsX
int n = -1; l_P-j96WD
try{ {*0<T|<n
oSavedFile.write(b,nStart,nLen); w)kNkD
n = nLen; dZ rAn
} aqRhh=iS
catch(IOException e) 2Ga7$q
{ =BSzsH7
e.printStackTrace (); "a ueL/dgN
} F)&@P-9+
aY'C%^h]
]iN'x?Fo
return n; _aFl_\3>
} rz wF~-m +
Oiz ,w7LRh
Ljxz.2LGr
} tyXuG<
4C<jdv_J
JJ}0gZ
/* ^)(bM$(`
**SiteInfoBean.java z3&]%Q&
*/ ,SynnE68
package NetFox; -8:&>~4`
Ghx3EVqnx"
E^ P,*s
public class SiteInfoBean { q|o}+Vr
DoJ\ q+
J&[@}$N
private String sSiteURL; //Site's URL ,0*&OXt
private String sFilePath; //Saved File's Path t2F_uCr
private String sFileName; //Saved File's Name zVXC1u9B
private int nSplitter; //Count of Splited Downloading File Ir`eL
/<@SFF.
*c~T@m~DR
public SiteInfoBean() !46RGU:I
{//nSplitter的缺省值为5 k9 "[H'
//default value of nSplitter is 5 {1V($aBl
this("","","",5); "= 6_V?&w
} :3XA!o&.T3
@&%'4j&+
2z6yn?'&L
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \>jLRb|7Ts
{ (]0%}$Fo
sSiteURL= sURL; SB1upTn
sFilePath = sPath; @.b+av4J
sFileName = sName; ])|d"[ur=
this.nSplitter = nSpiltter; //T>G_1
)PG6gZYW
T]t+E'sQ
} A )^`?m3
GN ]cDik
]ndvt[4L
public String getSSiteURL() _hRcc"MS`
{ f!oT65Vmi
return sSiteURL; %+8F'&X
} P_?gq>E8
';TT4$(m
b8V~S'6VqO
public void setSSiteURL(String value) tZ} v%3
{ o7J
sSiteURL = value; PZE0}>z
} 0Fk5kGD,&K
:*ing
0y 7"SiFY
public String getSFilePath() -BRc8 /
{ bSfpbo4(
return sFilePath; 6|aKL[%6
} a:"Uh**
^* J2'X38I
UUzYbuS>&l
public void setSFilePath(String value) =NnNN'}
{ CK,7^U
sFilePath = value; _d"b;4l
} ^HV>`Pjd}=
(eCJ;%%k
}`W){]{kO
public String getSFileName() J6U$qi
{ \R|4( +]x
return sFileName; HG+%HUO$
} ]bj&bk#
.q `Hjmg<
Xe<sJ.&Wf
public void setSFileName(String value) ]$Yvj!K*Q
{ Fs{x(_LOr
sFileName = value; q;<h[b?
} _CW(PsfY
:uWw8`
v}1QH
public int getNSplitter() ]8Q4BW
{ k 8UO9r[
return nSplitter; 1u: gFUb
} 6^]!gR#B
E"+QJ~!
Svondc 4
public void setNSplitter(int nCount) cWi}V
{ T(f/ ?_%
nSplitter = nCount; Po ZuMF
} -u2P ?~
} SS$[VV
*a58ZI@
k p<OJy
/* 3[O=xXB
**Utility.java pPcTrN'
*/ |/09<F:L[
package NetFox; x$1]M DAGb
fb{``,nO
RLbKD>
public class Utility { m=}B,']O
P"W2(d
c|M6<}
public Utility() U@-^C"R
{ ;?8_G%va
zx-81fx+k
|QU <e
} vU767/
f7=((5N
//线程睡眠 MrDc$p W G
public static void sleep(int nSecond) @&1ZB6OCb:
{ G*-b}f
try{ BaSZ71>9]r
Thread.sleep(nSecond); !{^PO<9
} huJ&]"C
catch(Exception e) d5oIH
{ '=Rs/EDME
e.printStackTrace (); z"0I>gl
} 8Le||)y,\
} (>r[-Bft
Cq%IE^g<
//日志 )rekY;
public static void log(String sMsg) <$X3Hye
{ BZR:OtR^
System.err.println(sMsg); nPye,"A Ol
} CitDm1DXt/
_NMm/]mN /
oZ!m
public static void log(int sMsg) MOn
{ 8P1=[i]
System.err.println(sMsg); ',:*f8Jk
} CE/Xfh'44
} mT.u0KUIy
[/e<l&y
bI:zp!-.
/* hJZV}a|
**TestMethod.java y *fDwd~
*/ fp+gyTnd3
package NetFox; H[S%J3JI
qYlhlHD
T~Gvp0r}h
public class TestMethod { U-R6xxPZ
jpO7'ivG
BK,{N0
public TestMethod() 4iKgg[)7`=
{ ///xx/weblogic60b2_win.exe X{\F;Cb*
try{ `NgAT 3zq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b/C`Jp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ><gG8MH0'
SiteFileFetch fileFetch = new SiteFileFetch(bean); pKit~A,Q
fileFetch.start(); bT^I"
} %?p1d!
catch(Exception e){e.printStackTrace ();} ~v6OsH%vx
px}|Mu7z~
>_|O1H./4
} EUN81F?
$shoasSuI
:9^;Qv*
public static void main(String[] args) ,u`B<heoLU
{ { S3ZeN,kZ
new TestMethod(); $`)/0{qY-
} ug+io mZ
} MLRK74D
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