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)); z}Qt6na]-
} i[gq8%
for(int i=0;i<nEndPos.length-1;i++) fvW7a8k3
{ gtcU'4~
nEndPos = nStartPos[i+1]; `%8byy@$
} =Ws-s f]
nEndPos[nEndPos.length-1] = nFileLength; mP1EWh|
} }RGp)OFY&
} &&N]u e@>
2>E.Q@c
i.0}d5Y
//启动子线程 yJt0KUw@!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a<Ru)Q?=
for(int i=0;i<nStartPos.length;i++) LX4*3c|i,
{ rPK)=[MZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z3ucJH/)V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5LT{]&`9
nStartPos,nEndPos,i); EF7Y4lp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \]uo^@$bm
fileSplitterFetch.start(); $)L=MEdx
} g;bfi{8s_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H.8f-c-4we
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JN{.-k4Ha
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g$++\%k&
nEndPos = " + nFileLength); i+I%]
// fileSplitterFetch[nPos.length-1].start(); LuM[*_8
rek89.p
-ejH%CT
//等待子线程结束 REyk,s2"6
//int count = 0; @O;gKFx
//是否结束while循环 {X=gjQ9
boolean breakWhile = false; qOyg&]7
P= e3f(M2
QEl:>HG
while(!bStop) IF<?TYy=3B
{ D[.;-4"_
write_nPos(); >x(3p@6p
Utility.sleep(500); +V"t't7
breakWhile = true; 8vhg{L..
ail%#E8
&dqC =oK]
for(int i=0;i<nStartPos.length;i++) 9=(*#gRd
{ J|DID+M
if(!fileSplitterFetch.bDownOver) 3y}0J @
{ k<mfBNvuo
breakWhile = false; N# Ru`;
break; 80X #V
} a$f$CjQ
} Kh)SgJ3B@
if(breakWhile) b%w?YR
break; [B}$U|V0
gbP]!d:I
AxD&_GT
//count++; l{:7*U{d
//if(count>4) uG1)cm B}
// siteStop(); YlI/~J
} `0@onDQVc=
/8Sg<
B~/:["zTh&
System.err.println("文件下载结束！"); @M[t|
} (Rqn)<<2
catch(Exception e){e.printStackTrace ();} dgLE/r?
} oDY $F%
!J3dlUFRO
qpo3b7(N
//获得文件长度 ,KXS6:1%5Y
public long getFileSize() )aW;w|#n
{ d!+8
int nFileLength = -1; OH2Xxr[bQ
try{ N5>ioJj
URL url = new URL(siteInfoBean.getSSiteURL()); by 'P}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9oOr-9t3
httpConnection.setRequestProperty("User-Agent","NetFox"); _*d8:|qw
`|Aj3a3sND
))y`q@
int responseCode=httpConnection.getResponseCode(); [TUy><Z
if(responseCode>=400) Hw 7
{ ),9^hJ1+@
processErrorCode(responseCode); 9#K,@X5 j
return -2; //-2 represent access is error ?:D#\4=US
} i:9f#
.>4Zt'gCt
`)sC".b7
String sHeader; W@R\m=e2
.h!oo;@
jV83%%e
for(int i=1;;i++) RR,gC"cTi
{ -+^E5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,+0#.Ns$
//Utility.log(in.readLine()); f+#^Lngo
sHeader=httpConnection.getHeaderFieldKey(i); rkdf htpI
if(sHeader!=null) *D&(6$[^
{ W_w^"'
if(sHeader.equals("Content-Length")) $a'n{EP
{ ^gP pmb<x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,BGaJ|k
break; A*;I}F
} T06BrX
} 3q{op9_T7
else [)K?e!c8
break; El3Y1g3+3
} \k?Fu=@
} U?vG?{A
catch(IOException e){e.printStackTrace ();} T#ktC0W]h
catch(Exception e){e.printStackTrace ();} `zQ2i}Uju
TQXp9juK
W{pyU\
Utility.log(nFileLength); +;Yd<~!c Z
s&T"/4
.UxbwTup
return nFileLength; YVcFCl
} 5](-(?k}~
6Vr:?TI7
G/l 28yt
//保存下载信息（文件指针位置） [sxJ<
private void write_nPos() >ZAb9=/M)F
{ {bQi z
try{ xa7~{ E,
output = new DataOutputStream(new FileOutputStream(tmpFile)); A1VbqA
output.writeInt(nStartPos.length); l/(|rl#6
for(int i=0;i<nStartPos.length;i++) BSe{HmDq
{ j2@19YXe@
// output.writeLong(nPos); /Y NV
output.writeLong(fileSplitterFetch.nStartPos); ;ps0wswX
output.writeLong(fileSplitterFetch.nEndPos); 6N7^`ghTf
} Ie12d@
output.close(); %}T' 3
} 2n/cqK
catch(IOException e){e.printStackTrace ();} 3aD\J_
catch(Exception e){e.printStackTrace ();} ]+C;C
} XTzz/.T;Z
^0 zWiX
,hMdxZJd
//读取保存的下载信息（文件指针位置） 9j[lr${A
private void read_nPos() dfo_R
{ w(>mP9Cb
try{ fdU`+[_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]UtfI
int nCount = input.readInt(); /UwB6s(
nStartPos = new long[nCount]; n U0
nEndPos = new long[nCount]; -SyQ`V)T7N
for(int i=0;i<nStartPos.length;i++) #Uc0W
{ BWtGeaW/sr
nStartPos = input.readLong(); U|[+M@F_L
nEndPos = input.readLong(); #*J+4aw3
} 2u B66i
input.close(); V:<NQd
} 6[\b]I\Q
catch(IOException e){e.printStackTrace ();} {x&"b-
catch(Exception e){e.printStackTrace ();} A.f!SYV6
} ymNL`GYN[
C rA7lu'
w+^z{3>
private void processErrorCode(int nErrorCode) WUEjWJA-MB
{ fga{b7
System.err.println("Error Code : " + nErrorCode); &]d-R
} a$}n4p
cJIA/HQe
dfU z{
//停止文件下载 CLQE@kF;
public void siteStop() 7v{X?86&
{ y<r@zb9
bStop = true; B#zu<z
for(int i=0;i<nStartPos.length;i++) EZN38T
fileSplitterFetch.splitterStop(); 0j'H5>m"
)MV`(/BC*
oU\Q|mN(
} y2_^lW%
} (]Zyk,[
//负责部分文件的抓取 do-mkvk
**FileSplitterFetch.java 0=WZ 8|R
*/ Q!%C:b
package NetFox; {c#{dT
8!{;yz
5.]eF$x2
import java.io.*; D&)w =qIu
import java.net.*; |i/Iv
P&6hk6#
Q&JnF`*
public class FileSplitterFetch extends Thread { U]8 @
@c>a
o?9k{
String sURL; //File URL lZ\Si
long nStartPos; //File Snippet Start Position G!%Cc0d"7
long nEndPos; //File Snippet End Position nVSuvq|S
int nThreadID; //Thread's ID xJ0Q8A
boolean bDownOver = false; //Downing is over QH)uh"
boolean bStop = false; //Stop identical /4Df 'd
FileAccessI fileAccessI = null; //File Access interface 5O7x4bY
PkqOBU*|=
\G+uK:PC,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +nLsiC{&
{ 31FQ=(K
this.sURL = sURL; .q!U@}k.
this.nStartPos = nStart; AV t(e6H
this.nEndPos = nEnd; C>A*L4c]F
nThreadID = id; CH`_4UAX%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xs'vd:l.Pp
} h8ND=(
~9tPT0^+
P S$6`6G
public void run() p!XB\%sv'"
{ dxz.%a@PW
while(nStartPos < nEndPos && !bStop) xlhc`wdm
{ T#>1$0yv
7GyJmzEE
)|d]0/<
try{ c~bTK" u
URL url = new URL(sURL); =}8:zO 2'{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GfG!CG^%
httpConnection.setRequestProperty("User-Agent","NetFox"); z }t{bm
String sProperty = "bytes="+nStartPos+"-"; F74^HQ*J
httpConnection.setRequestProperty("RANGE",sProperty); 6)@Y41H]C
Utility.log(sProperty); 4a]$4LQV
~EV7E F
0/vmj,&B(
InputStream input = httpConnection.getInputStream(); 7,pn0,HI
//logResponseHead(httpConnection); 0_A|K>7
oD@~wcMIT0
M6X`]R'
byte[] b = new byte[1024]; vz~QR i*
int nRead; 1TuN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @Yl&Jg2l'
{ :X66[V&eH
nStartPos += fileAccessI.write(b,0,nRead); u4W2{
//if(nThreadID == 1) "1#piJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~boTh
} aYmC LLj
Ki8]+W37
`Dn"<-9:
Utility.log("Thread " + nThreadID + " is over!"); O%Mi`\W@
bDownOver = true; (|*CVI;
//nPos = fileAccessI.write (b,0,nRead); 7I_1Lnnf
} q@"0(Oj
catch(Exception e){e.printStackTrace ();} Bq20U:f
} A-8[8J
} `Tt;)D
)J['0DUrZK
rEM#J"wF
//打印回应的头信息 $;1TP|
public void logResponseHead(HttpURLConnection con) WZ3GI l
{ NJe^5>4`
for(int i=1;;i++) G(;C~kHX
{ 6oQSXB@
String header=con.getHeaderFieldKey(i); -=+@/@nV
if(header!=null) {p70( ]v
//responseHeaders.put(header,httpConnection.getHeaderField(header)); G!^}z(Mgi
Utility.log(header+" : "+con.getHeaderField(header)); w7;,+Jq
else .o&Vu,/H
break; v&8%t 7|
} -9f> rH\3
} pc=f,
;;3oWsil}
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public void splitterStop() Ag6^>xb^
{ 8,l~e8&
bStop = true; $z"1&y)
} gXQ s)Eyv
??7c9l5,
8vuA`T!~G
} j~'a %P
qkg`4'rLg
BbV@ziL
/* fBi6% #
**FileAccess.java X<j(AAHE
*//文件访问(定位，写) $U]KIHb
package NetFox; P>i!f!o*I
import java.io.*; %#zqZ|q
UP})j.z
:d!qZFln
public class FileAccessI implements Serializable{ uE}A-\G
{tN?)~ZQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WqHsf1?N
RandomAccessFile oSavedFile; %+{[%?xh
long nPos; 5g$]ou
k^Gf2%k
RTJ\|#w
public FileAccessI() throws IOException t.ci!#/d
{ !qQB}sAf
this("",0); &.ilku/
} V=?qU&r<+
k v>rv37u
!I8m(axW
public FileAccessI(String sName,long nPos) throws IOException ZSUbPz
{ Kz>Bw;R(
oSavedFile = new RandomAccessFile(sName,"rw"); EV$$wrohQ`
this.nPos = nPos; jnu!a.H
oSavedFile.seek(nPos); X>$s>})Y
} $1F$3"k
G 5T{*
!L=RhMI
public synchronized int write(byte[] b,int nStart,int nLen) +'@j~\>^yJ
{ nc.(bb),
int n = -1; qpCNvhi
try{ ]m(C}}
oSavedFile.write(b,nStart,nLen); CHojF+e
n = nLen; I_k!'zR[N
} cu~\&3R
catch(IOException e) .EXe3!J)!
{ :|V`QM
e.printStackTrace (); T[<deQ
} PE\.JU
,ezC}V0M
RM(MCle}
return n; jmH=W)
} ~@Wg3'&
.C=I~Z
eBs4:R_i
} BS@x&DB
vK10p)ZV
9bxBm
/* e-`=?tct
**SiteInfoBean.java m,"N4a@
*/ tS@J)p+_(
package NetFox; yG ,oSp|
b;O@|HK&~
x&N!SU6
public class SiteInfoBean { l5*sCp*Z
6HK dBW$/
=rB=! ;
private String sSiteURL; //Site's URL R'Uw17I
private String sFilePath; //Saved File's Path eM1=r:jgE
private String sFileName; //Saved File's Name &{5v[:$
private int nSplitter; //Count of Splited Downloading File N"M?kk,
O.HaEg/-
6bacU#0o
public SiteInfoBean() 6iZ:0y0t+6
{//nSplitter的缺省值为5 ,e{|[k
//default value of nSplitter is 5 ))<1"7D^^
this("","","",5); Q6e;hl
} O5lP92],
*Bj7\8cKC
nB+UxU@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p# 4@
{ '/[9Xwh9
sSiteURL= sURL; Shm$>\~=
sFilePath = sPath; "+@>!U
sFileName = sName; iYE7BUH=
this.nSplitter = nSpiltter; uK_R#^
,Q2?Z:l
OZ9ud ]@\
} r@.3.Q
9cO m$
~ZN]2}
public String getSSiteURL() pp!>:%
{ n1mqe*Mvs/
return sSiteURL; ZnVx'Y
} 3ZhB 8 P
YM(`E9{h
]\8{z"
public void setSSiteURL(String value) yOQEF\
{ Y2B",v"
sSiteURL = value; |*5QFp
} 1I1Z),
|K jy4.2
M10u?
public String getSFilePath() / >As9|%
{ cfg_xrW0^
return sFilePath; -$8M#n,
} j. m(Z}
x|6# /m
dl%KD8
public void setSFilePath(String value) #G/ _FRo`
{ Z\)emps
sFilePath = value; OGC|elSM
} [8b,}i 1
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'g$a.75/-
public String getSFileName() x9Qa.Jmj
{ 7LB#\2
return sFileName; eL7rX"!
} sHr!GF
*YhX6J1
8r 4 L4
public void setSFileName(String value) qZ8V/
{ yzml4/X
sFileName = value; o (OC3
} | gou#zi
7T)J{:+0!|
pKM5<1J
public int getNSplitter() .-0;:>
{ wU|Y`wJmF
return nSplitter; "* Qwaq_
} v8<MAq
ZV=)`E`I|
QCI-YJ&o
public void setNSplitter(int nCount) qZ:--,9+
{ p(5'|eqBV
nSplitter = nCount; Hsoe?kUHF
} o#IQz_
} E7*z.3
2yFXX9!@
4/rdr80
/* n<x NE%
**Utility.java &>!WhC16
*/ tVf1]3(_>
package NetFox; LAoX'^6
gXR1nnK
%mda=%Yn
public class Utility { x7s75
$jDp ^ -
?2g\y@
public Utility() !7:~"kk
{ 3j2% '$>E^
jx=2^A/i2-
^H,oI*
} 9J$z/j;X
fYU-pdWPT
//线程睡眠 #\&jM -.-
public static void sleep(int nSecond) KL4Z||n
{ D/jS4'$vA
try{ @'K+
Thread.sleep(nSecond); e:BKdZGW
} CPI7&jqu
catch(Exception e) hE-u9i
{ N o}Ly{
e.printStackTrace (); 8#Q=CTjF
} iCouGd}
} =;1MpD
^[d|^fRH Q
//日志 e/?>6'6 5
public static void log(String sMsg) YdI|xu>0A^
{ xl(];&A3
System.err.println(sMsg); Z'%k`F
} X3KPN
*lN>RWbM%
&k5 Z|d|
public static void log(int sMsg) T/V 5pYl
{ Q6cF<L`bW
System.err.println(sMsg); Um k9
} K4vl#*qn
} O;qerE?i`
X9f!F2x
`]^JOw5o
/* N'fE^jqU
**TestMethod.java Os?`!1-
*/ r lalr+Rf
package NetFox; HNA/LJl[VU
,qgph^C
i0($@6Lh
public class TestMethod { N1RZ
,H3~mq]
"%aJ'l2
public TestMethod() Xi'y-cV ^
{ ///xx/weblogic60b2_win.exe +h6cAqm]
try{ )g9&fGYf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R4<}kA,.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Tn+6:<OFdO
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9L}=xX`>?
fileFetch.start(); ta*B#2D>
} ,X&lVv#
catch(Exception e){e.printStackTrace ();} w.gI0`
P9/5M4]tt
/q4<ZS#
} z?HP%g'M~
).TQYrs
~+{OSx<S
public static void main(String[] args) 7m6@]S6
{ We#u-#k_O
new TestMethod(); n>tYeN)F<
} sXm/+I^
} [YY[E 7
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