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)); p/HGI)'
} 3U'l'H,
for(int i=0;i<nEndPos.length-1;i++) A@eR~Kp ^
{ 30O7u3Zrb
nEndPos = nStartPos[i+1]; *6G@8TIh
} "|BSGV!8
nEndPos[nEndPos.length-1] = nFileLength; "-Pz2QJY
} iZ4"@G:,
} Fw8b^ew
;u=%Vn"2a
qYQ vjp
//启动子线程 @SI,V8i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pwRCfR)"X
for(int i=0;i<nStartPos.length;i++) 7gx?LI_e
{ o?^Rw*u0/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ByacSN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0]zMb^wo
nStartPos,nEndPos,i); +p$lVnAt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F##xVmR~
fileSplitterFetch.start(); 03.\!rZZ
} e@1A_q@.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aMGyV"6(-6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !;K zR&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", viJP6fh
nEndPos = " + nFileLength); i.^:xZ
// fileSplitterFetch[nPos.length-1].start(); &UNQ4-s
EMDYeXpV
?Iu=os>*
//等待子线程结束 ff]fN:}V
//int count = 0; r[wjE`Z/T
//是否结束while循环 PsZ>L
boolean breakWhile = false; g@.e%
99"8d^{z
GE? \Vm
while(!bStop) `lrNH]B
{ r]U8WM3r
write_nPos(); w&e3#p
Utility.sleep(500); wB:<ICm
breakWhile = true; nX\mCO4T
l&5Tft
IG:2<G
for(int i=0;i<nStartPos.length;i++) 13 %:3W(
{ !L<z(dV|(
if(!fileSplitterFetch.bDownOver) Xpt9$=d
{ Xc4zUEO9
breakWhile = false; <+<Nsza
break; /(?s\}O
} clk]JA (
} n}- _fx
if(breakWhile) 8c>xgFWp9
break; C;%dZ
S~R[*Gk_uT
;%k C?Vzi
//count++; z`p9vlS[
//if(count>4) ~z,qr09
// siteStop(); <AK9HPxP
} .Hk.'>YR
R7KV @n
$<"I*l@
System.err.println("文件下载结束！"); y(#6nG@S
} o' v!83$L
catch(Exception e){e.printStackTrace ();} yivWT;`
} ~SmFDg$/m
IfT: 9 &
/x4L,UJ= P
//获得文件长度 p 16+(m
public long getFileSize() +DO<M1uE
{ LXZI|K[}k
int nFileLength = -1; 3`)ej`
try{ G&t|aY-
URL url = new URL(siteInfoBean.getSSiteURL()); 7#SfuZ0@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8n:N#4Dh^
httpConnection.setRequestProperty("User-Agent","NetFox"); 0JKTwLhC
i52JY&N
jfVw{\l
int responseCode=httpConnection.getResponseCode(); sk*vmxClY
if(responseCode>=400) i|xz
{ .&`apQD}
processErrorCode(responseCode); QjD=JC+
return -2; //-2 represent access is error 1f'msy/
} 6!N2B[9
A8o)^T(vJ
ig .
String sHeader; Ps<k2
5X9Lh_p
Pa?{}A
for(int i=1;;i++) fsWIz1K
{ nrX+ '
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i r'C(zD=
//Utility.log(in.readLine()); \(&&ed:
sHeader=httpConnection.getHeaderFieldKey(i); cmAdQ)(Kzd
if(sHeader!=null) <_]W1V:0
{ '=eVem=
if(sHeader.equals("Content-Length")) fJ6Q:7
{ $*LBZcL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sZ7~AJ
break; j)#yyK{k2s
} 7j29wvSp5
} @1' Y/dCyD
else EWY'E;0@5
break; ZE= Yn~XM
} *xITMi
} Xbrc_V\_
catch(IOException e){e.printStackTrace ();} WJ LqH<
catch(Exception e){e.printStackTrace ();} }%<_>b\
9XhH*tBn7(
?YUL~P
Utility.log(nFileLength); VDZOJM)(
]EUQMyR
Z[B:6\oQ
return nFileLength; E|jU8qz>P
} l2YA/9.
g_A#WQyh\'
7%[ YX
//保存下载信息（文件指针位置） |.$7.8g
private void write_nPos() MOay^{u
{ NFC/4
try{ C\vOxBAB
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,yvS c
output.writeInt(nStartPos.length); tOxH9
for(int i=0;i<nStartPos.length;i++) d0&
{ mahNQ5W*)
// output.writeLong(nPos); =+I-9=
output.writeLong(fileSplitterFetch.nStartPos); <M}O&?N 8x
output.writeLong(fileSplitterFetch.nEndPos); #{^qBP[
} g#Ta03\
output.close(); yy[Y=
} YU!s;h
catch(IOException e){e.printStackTrace ();} cSNeWJKA6
catch(Exception e){e.printStackTrace ();} 4i5b.bU$
} |sl^4'Ghc
3+vVdvu%
rvK%m_r
//读取保存的下载信息（文件指针位置） 8j :=D!S
private void read_nPos() K V
{ v(=0hY9 O
try{ g!o2vTt5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,V^$Meh
int nCount = input.readInt(); *OIBMx#qxn
nStartPos = new long[nCount]; I_kA!^
nEndPos = new long[nCount]; n3qRt
for(int i=0;i<nStartPos.length;i++) )CmHC3
{ ]0MuXiR
nStartPos = input.readLong(); p=zTY7L
nEndPos = input.readLong(); y~\uS
} F%af05L[
input.close(); rkR~%U6V
} 5tzO=gO[
catch(IOException e){e.printStackTrace ();} <`NsX 6t
catch(Exception e){e.printStackTrace ();} 5hDy62PRr
} [N}QCy
<"xqt7f
GCX?W`
private void processErrorCode(int nErrorCode) JNJ6HyCU
{ 9sd}Z,l
System.err.println("Error Code : " + nErrorCode); l4(FM}0X5}
} &-X51O C
8V9OMOt!
=dQ/^C_hj
//停止文件下载 4\g[&
public void siteStop() ;DVg[#
{ :^xNHMp!
bStop = true; *[BtW56-
for(int i=0;i<nStartPos.length;i++) P=\Hi.]%
fileSplitterFetch.splitterStop(); gW9`k,U
R,=8)OI2
q">}3`k
} zjSl;ru
} 7zJ2n/`m*
//负责部分文件的抓取 IN;9p w
**FileSplitterFetch.java `&xdSH
*/ [TFp2B~)#
package NetFox; 8lS RK%
wzJdS}Yy!y
n2Mpo\2
import java.io.*; pG"hZB3)
import java.net.*; AZA5>Y
@$ lX%p>
gjzWW0C
public class FileSplitterFetch extends Thread { Dhfor+Epy
6pfkv2.}
&GvSgdttv
String sURL; //File URL ~l{Qz0&
long nStartPos; //File Snippet Start Position W}}ZP];
long nEndPos; //File Snippet End Position {fX~%%c"
int nThreadID; //Thread's ID JG1q5j##]b
boolean bDownOver = false; //Downing is over s0/m qZ]s
boolean bStop = false; //Stop identical 2tCw{Om*
FileAccessI fileAccessI = null; //File Access interface VB T66kV
W tHJG5
q5@Nd3~h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 51H6 W/$
{ |W@Ko%om
this.sURL = sURL; {?EmO+![}
this.nStartPos = nStart; |$ZS26aYw}
this.nEndPos = nEnd; ZM<UiN
nThreadID = id; 81(\8#./
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sG[qlzR=8
} J$sp6g>K
'zT7$ .L
a|#pl!
public void run() 1 XJZuv,T:
{ [7[Qw]J
while(nStartPos < nEndPos && !bStop) pF8:?p['z
{ * LWihal
p>:.js5.a
(njTS+?
try{ 4;gw&sFF
URL url = new URL(sURL); ggYi7Wzsd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F MYcZ+4
httpConnection.setRequestProperty("User-Agent","NetFox"); jVN=_Y}\
String sProperty = "bytes="+nStartPos+"-"; d(R8^v/L
httpConnection.setRequestProperty("RANGE",sProperty); -vk/z+-^!
Utility.log(sProperty); ,# .12Q!
JP {`^c
jUR* |
InputStream input = httpConnection.getInputStream(); $ndBT+i
//logResponseHead(httpConnection); ]Y76~!N
LTH,a?lD
X*d!A >s
byte[] b = new byte[1024]; dnXu(e%
int nRead; ,!g/1m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9f5~hBlo
{ LmJ _$?o
nStartPos += fileAccessI.write(b,0,nRead); #UI`+2w
//if(nThreadID == 1) Yl$@/xAa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l[m*csDk"
} H1KXAy`&
M(C}2.20
)`\Q/TMl5
Utility.log("Thread " + nThreadID + " is over!"); ^T1caVb|>
bDownOver = true; Us2> 5 :\
//nPos = fileAccessI.write (b,0,nRead); ,1JQjsR
} hb/Z{T'
catch(Exception e){e.printStackTrace ();} XpK Y#
} es.Y
} >TawJ"q-6R
Nlwt}7
Z("N *`VP;
//打印回应的头信息 \_(0V"
public void logResponseHead(HttpURLConnection con) qNrLM!Rj
{ eoQt87VCU
for(int i=1;;i++) ^nOh8L;
{ H_Sv,lwz;c
String header=con.getHeaderFieldKey(i); P*PJ
if(header!=null) CL-?Mi=Uc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g/P1lQ)
Utility.log(header+" : "+con.getHeaderField(header)); *`/4KMrq
else w T_l>u
break; <@+L^Ps~z
} NE)w$>0M
} M\7F1\ X
48G^$T{
BC1smSlJ
public void splitterStop() ;4/ n~
{ Jcs /i
bStop = true; vQnhb%
} E piF$n
'xaEG,P
YZnFU( j
} -y?ve od#
*H=h7ESq
T%Zfo7
/* 6Rq +=X
**FileAccess.java e},:QL0X
*//文件访问(定位，写) xt`a":lru
package NetFox; HL>l.IG?
import java.io.*; wq1s#ag<
`w@z Fc!"
rd[mC[ r
public class FileAccessI implements Serializable{ T<yfpUzX
~G6xk/+n-m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7X>@r"9<
RandomAccessFile oSavedFile; X`eX+9
long nPos; dBN:
{`J!DFfur
(r}StR+
public FileAccessI() throws IOException oq1wU@n
{ l-h[I>TW
this("",0); ^U,C])n
} a_b+RMy
By}ZHK94I
,,#6SR(n
public FileAccessI(String sName,long nPos) throws IOException 78?{;iNv
{ WUQa2$.
oSavedFile = new RandomAccessFile(sName,"rw"); \X]I: 0^j
this.nPos = nPos; p#rqe<Ua
oSavedFile.seek(nPos); 16.?45
} >Apa^Bp
dI=&gz
&fkH\o7)
public synchronized int write(byte[] b,int nStart,int nLen) B/3xV:Gy
{ 19oyoi"
int n = -1; d+ $:u
try{ 3(.Y>er%U
oSavedFile.write(b,nStart,nLen); k{ZQM
n = nLen; ?A*<Z%}1?
} A4;~+L:M
catch(IOException e) )2Y]A^Y
{ jC?l :m?
e.printStackTrace (); b0se-#+
} 3k8.5W
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!Ow M-t
return n; X;vUz
} 8hyXHe
#X'su`+
3qV\XC+
} Z*NTF:6c
9uX15a
]Al)>
/* RcO.1@2
**SiteInfoBean.java [?2?7>D8
*/ u'Hh||La"
package NetFox; X~\O]
n4H'FZ
9]/:B8k
public class SiteInfoBean { s,Fts3+
-h8Z@r~a/
6D{70onY+
private String sSiteURL; //Site's URL *$1F|G
private String sFilePath; //Saved File's Path X>]<rEh
private String sFileName; //Saved File's Name lx?v .:zl\
private int nSplitter; //Count of Splited Downloading File c+whpQ=01
wp:Zur5Y
65mfq&"P?
public SiteInfoBean() ,k9.1kjO*)
{//nSplitter的缺省值为5 1$m{)Io2(
//default value of nSplitter is 5 2) 2:KX
this("","","",5); c<Q*g
} }ZiJHj'<
eV;nTj
Q yQ[H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \y7Gi}nI
{ C}9|e?R[Rz
sSiteURL= sURL; {q;_Dd
sFilePath = sPath; .I^Y[_.G
sFileName = sName; -Wre4^,v
this.nSplitter = nSpiltter; 7.kH="@
'CG% PjCO
t[G7&ovj
} 9p4SxMMO
:)+)L@By
M}=fdH
public String getSSiteURL() uY3#,
{ Uqly|FS &n
return sSiteURL; Ms+SJ5Lg
} !rG-[7K
6eNBldP!
bp}]'NA
public void setSSiteURL(String value) Ngm/5Lc
{ 8'v:26
sSiteURL = value; n# FkgXP$
} ._.Qf<7
Yb:F,d-Ya
/7-FVqDx8
public String getSFilePath() `)BZk[64
{ 9wdX#=I
return sFilePath; t0^)Q$
} _u~`RlA
scrss
izu_KBzy
public void setSFilePath(String value) rDc$#
{ c/(Dg$DbX
sFilePath = value; (8/&
} !!~r1)zN
NZwi3
MOuEsm;
public String getSFileName() O8LIKD_I[
{ D8$4PT0u
return sFileName; $?pfst~;O
} ykGA.wo7/P
Ffd;aZ4n
]XYD2fR2qA
public void setSFileName(String value) Emk:@$3{r
{ w`zS`+4
sFileName = value; UyDq`@h
} }5B\:*yW
koj*3@\p/
gf/<sH2}
public int getNSplitter() fA),^
{ /\E3p6\*
return nSplitter; nD=N MqQ &
} =%b1EYk
.j"@7#tW
LftGA7uGJ)
public void setNSplitter(int nCount) zq|NltK
{ ]l
nSplitter = nCount; SUsdX[byb
} _0Y?(}
} bhfC2@
TEC#owz
}rWg']
/* DMKtTt[}
**Utility.java JDOn`7!w
*/ Z)}2bJwA
package NetFox; 0}g~69Z1=
T?7++mcA
t\n'Kuk`
public class Utility { 2>Qy*
[X@JH6U r
DJ!pZUO{
public Utility() Pup%lO`.0
{ =n8M'
X*&Thmee
;i?R+T
} ~/2OK!M
B}N1}i+
//线程睡眠 IPt !gSp
public static void sleep(int nSecond) z|$9%uz"
{ FY/F}C,o
try{ U8<C4
Thread.sleep(nSecond); s/P+?8'9
} cSmy M~[
catch(Exception e) iaRCV6cl
{ "Sw raq
e.printStackTrace (); GX*9R>
} r<Q0zKW!jN
} pK0@H"$8
LFvZ 7M\\
//日志 9)4_@rf%
public static void log(String sMsg) jQ-2SA O
{ +Y>oNX1KN
System.err.println(sMsg); ]y"=/Nu-Ja
} .P ??N
8,&Y\b`..
C8} ;,
public static void log(int sMsg) O! _d5r&,
{ KNOVb=#f_
System.err.println(sMsg); 2M+*VO
} va0}?fy.O%
} VWqZ`X
wv Mp~
+HG*T[%/
/* P4 #j;k4P
**TestMethod.java KD--w(4
*/ `A8ErfA
package NetFox; 2{B ScI5K
iMQ0Sq-%1
(N`GvB7;
public class TestMethod { 4Ujy_E?^
ej\Sc7.
Epm8S}6K
public TestMethod() #IU^(W
{ ///xx/weblogic60b2_win.exe 6S0Gjekr
try{ y8} /e@&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); c Ze59
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kX+98?h-C
SiteFileFetch fileFetch = new SiteFileFetch(bean); aF>&X-2
fileFetch.start(); 9VSi2p*
} 'p[B`Ft3F
catch(Exception e){e.printStackTrace ();} \[ 4y
=uR3|U(.|u
(]zi;
} -oB=7+g
@0 [^SU?
Dd:^ {
public static void main(String[] args) $ k_6
{ @\W-=YKLg
new TestMethod(); NnaO!QW%
} K@a#^lmd
} xT!<x({
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