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)); ithewup
} nPs7c %
for(int i=0;i<nEndPos.length-1;i++) /F4pb]U!*
{ 81hbk((
nEndPos = nStartPos[i+1]; .\8X[%K9nc
} y_HN6
nEndPos[nEndPos.length-1] = nFileLength; T"&)&"W*U
} FL8g5I
} ^Ve<>b
esHQoIhd
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//启动子线程 "Ae@lINn[y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WBNw~|DO]
for(int i=0;i<nStartPos.length;i++) >0dv+8Mn
{ qwK2WE%T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MY/3]g<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .[Ap=UYI>
nStartPos,nEndPos,i); +=]!P#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (`6T&>(4
fileSplitterFetch.start(); 9elga"4:'
} OKi\zS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k6Uc3O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u~3%bJ]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vk>b#%1{
nEndPos = " + nFileLength); l#lF +Q;
// fileSplitterFetch[nPos.length-1].start(); &q`q4g&7
A8q;q2
2MATpV#BT
//等待子线程结束 0vVV%,v
//int count = 0; bJYda)
//是否结束while循环 P ~#>H{
boolean breakWhile = false; w,O,W[C
%0$qP0|`3I
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while(!bStop) i~3u>CT
{ 3d-%>?-ee
write_nPos(); DhX#E&
Utility.sleep(500); ,o^y`l
breakWhile = true; {tThy#
M;0]u.D*=
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for(int i=0;i<nStartPos.length;i++) U,+[5sbo
{ v^ /Q 8Q
if(!fileSplitterFetch.bDownOver) Fbu5PWhlc
{ RN)dS>$
breakWhile = false; 3SSm5{197
break; 4;HJ;0-ps
} }lK3-2Pk
} 4GR!y)
if(breakWhile) ->h6j
break; /'Pd`Nxl.
7HVZZ!>~
9}c8Xt^&
//count++; 3:{yJdpg
//if(count>4) %lX%8Z$v
// siteStop(); k"g._|G
} -QyhwG=
CiR%Ujf
sHcTd>xS
System.err.println("文件下载结束！"); ]`bQW?
} MWNPPYww
catch(Exception e){e.printStackTrace ();} 11|Rdd+}
} PlYm&
L{E^?iX
wBQF~WY
//获得文件长度 * ,v|y6
public long getFileSize() jqH3J2L
{ U:MPgtwe
int nFileLength = -1; G60R9y47c
try{ @Kf_z5tm:
URL url = new URL(siteInfoBean.getSSiteURL()); hLDA]s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XyMG.r-,
httpConnection.setRequestProperty("User-Agent","NetFox"); RUr=fEH
[]0mX70N
DAg58 =qJ
int responseCode=httpConnection.getResponseCode(); RNPbH.
if(responseCode>=400) N$xtHtz8"
{ 7~ztwL
processErrorCode(responseCode); +fx8muz:y
return -2; //-2 represent access is error PyA&ZkX>
} ^1Xt]T`e
m=Q[\.Ra
<*t4D-os
String sHeader; l88A=iLgv
kD) $2I?
}pa9%BQI
for(int i=1;;i++) v`V7OD#:j]
{ l;sy0S"DO]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >a1{397Y}
//Utility.log(in.readLine()); ;.wX@
sHeader=httpConnection.getHeaderFieldKey(i); n6(i`{i
if(sHeader!=null) /%A;mlf{
{ M(d6Z2ibh
if(sHeader.equals("Content-Length")) '!P"xBVAu
{ YUQtMf9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hUz[uyt
break; N$TL;T>
} ;pD)m/$h`
} htm{!Z]s0
else q>s-Y|
break; h;V,n
} w[_x(Ojq;
} =SD\Q!fA
catch(IOException e){e.printStackTrace ();} y fSM
catch(Exception e){e.printStackTrace ();} WZ!WxX>zO
0t#g}
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Utility.log(nFileLength); "+?Cz!i
okq[ o90
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return nFileLength; g\GdkiIj
} I _i6-<c.Q
MHL("v(@B
tn|,O.t
//保存下载信息（文件指针位置） s cdtWA
private void write_nPos() 7([h4bg{
{ 0)Rw|(Fpo]
try{ =2y8CgLj
output = new DataOutputStream(new FileOutputStream(tmpFile)); \n9A^v`F/
output.writeInt(nStartPos.length); F8e<}v&7R
for(int i=0;i<nStartPos.length;i++) xt4)Ya
{ fag^7rz
// output.writeLong(nPos); 7n)&FXK`
output.writeLong(fileSplitterFetch.nStartPos); Q,Z*8FH=
output.writeLong(fileSplitterFetch.nEndPos); `(0LK%w
} bXYA5wG
output.close(); ==/n(LBD
} $jI>[%
catch(IOException e){e.printStackTrace ();} TP1S[`nR
catch(Exception e){e.printStackTrace ();} Gjz[1d
} Sd IX-k.
BpO9As 1um
ZyR_6n>L$
//读取保存的下载信息（文件指针位置） z"DkFvA
private void read_nPos() # x>ga
{ I\\QS.2
try{ Sx] T/xq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gQ~5M'#
int nCount = input.readInt(); .BO<
nStartPos = new long[nCount]; lH|LdlX
nEndPos = new long[nCount]; 7:h!Wj-a]
for(int i=0;i<nStartPos.length;i++) ?IX!+>.H
{ ^TXfsQs
nStartPos = input.readLong(); 92dF`sv
nEndPos = input.readLong(); 1u]P4Gf=
} vMSW$Bx ;
input.close(); |0bc$ZY:
} <Y'>F!?#
catch(IOException e){e.printStackTrace ();} v| z08\a[
catch(Exception e){e.printStackTrace ();} A%Z)wz{
} V'Qn sI
$e\N+~KNCy
%@ mGK8
private void processErrorCode(int nErrorCode) i(2y:U3[@
{ v7trr W}
System.err.println("Error Code : " + nErrorCode); {bF1\S]2
} &h$|j
Y9r3XhVI
daZQz"PP
//停止文件下载 )_jSG5k
public void siteStop() =Pe><k
{ ED![^=
bStop = true; ARh6V&Hi-
for(int i=0;i<nStartPos.length;i++) w#G2-?aj
fileSplitterFetch.splitterStop(); KA]*ox6j;
yno('1B@
E@QA".
} 6k])KlJ2;
} 4ax|Vb)D
//负责部分文件的抓取 W^g[L:s
**FileSplitterFetch.java w,.qCpT$_
*/ !UV5zmS
package NetFox; N:+ taz-
fW0$s`
/k:$l9C[
import java.io.*; 83]PA<R
import java.net.*; 'bW5Fr>W
b_$1f>
qFRdg V>8
public class FileSplitterFetch extends Thread { 1H4fJ3-
y@vj;3:
Q]JX`HgPaU
String sURL; //File URL &hZwZgV+3
long nStartPos; //File Snippet Start Position ?Z %:
long nEndPos; //File Snippet End Position p5]_}I`+2
int nThreadID; //Thread's ID BQgoVnQo_c
boolean bDownOver = false; //Downing is over {_ V0
boolean bStop = false; //Stop identical "/x_>ui1F
FileAccessI fileAccessI = null; //File Access interface LZ~`29qw(
~o15#Pfn/
T|'&K:[TJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b#Kq[}
{ (wt+`_6
this.sURL = sURL; k{Lv37H
this.nStartPos = nStart; *:_~Nn9_R;
this.nEndPos = nEnd; W=-|`
nThreadID = id; OHp5z? z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R"6;NPeo
} 2z2`
=fG:A(v%}
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public void run() 2:v<qX
{ 4L:>4X[T
while(nStartPos < nEndPos && !bStop) z%"Ai)W/{
{ \SYvD y]
LPE)
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try{ oh}^?p
URL url = new URL(sURL); ,jh~;, w2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *v #/Y9}
httpConnection.setRequestProperty("User-Agent","NetFox"); \aSz2lxEHn
String sProperty = "bytes="+nStartPos+"-"; ZCiY,;c
httpConnection.setRequestProperty("RANGE",sProperty); oKKz4
Utility.log(sProperty); Pern*x9$
{sc[RRN~C
h W.2p+
InputStream input = httpConnection.getInputStream(); .|]IwyD &
//logResponseHead(httpConnection); $B _Nc*_e
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byte[] b = new byte[1024]; !EFBI+?&
int nRead; y lL8+7W
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |>utWT]S
{ 9Q[>.):
nStartPos += fileAccessI.write(b,0,nRead); kojG-M
//if(nThreadID == 1) r,'O).7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /7p>7q9g
} #( uj$[o
<'*4j\*
qZ\L
Utility.log("Thread " + nThreadID + " is over!"); @ ^.*$E5
bDownOver = true; Ml`vx
//nPos = fileAccessI.write (b,0,nRead); %8D?$v"#Z
} 1X@b?6
catch(Exception e){e.printStackTrace ();} A@ VaaX
} @l>Xnqx)
} 8R/ *6S=&
7*'@qjTos
rWr/p^~
//打印回应的头信息 vgk9b!Xd
public void logResponseHead(HttpURLConnection con) euZ(}+N&
{ ?`. XK}
for(int i=1;;i++) M_&4]\PkCy
{ =~,l4g\
String header=con.getHeaderFieldKey(i); n6cq\@~A
if(header!=null) &>=#w"skb6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); BJIQ zn3
Utility.log(header+" : "+con.getHeaderField(header)); 0zV 4`y
else |cu`f{E2]
break; wgZrrq/W|
} 3j&B(aLy
} 'G Y/Q5
8A/>JD3^
;Q90Y&{L=$
public void splitterStop() TcZN%
{ H-a^BZ&iU
bStop = true; -A;w$j6*
} "^"'uO$
@XBH.A^7r
q)oN2-
} E\!n49
!3x*k;0
+S0u=u65
/* ,>w}xWSYpG
**FileAccess.java pzSqbgfrQ
*//文件访问(定位，写) + (=I8s/
package NetFox; 1*c>I@I;
import java.io.*; |Mlh;
)k~1,
=h[yAf
public class FileAccessI implements Serializable{ @YB85p"]J.
u_Zm1*'?B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -$L(y@%X^
RandomAccessFile oSavedFile; X7&U3v
long nPos; @ RX`>r{_
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*[ #*n n
public FileAccessI() throws IOException ^Y<M~K972
{ ?%;B`2 nDR
this("",0); L5C2ng>
} w .l|G,%=
o'^phlX
Z"N(=B
public FileAccessI(String sName,long nPos) throws IOException x_|>n<Z
{ qOgtGN}k
oSavedFile = new RandomAccessFile(sName,"rw"); bQV("~#
this.nPos = nPos; 2$)mC9
oSavedFile.seek(nPos); 1gk0l'.z
} x Ty7lfSe
PvuAg(?
*k[kV
public synchronized int write(byte[] b,int nStart,int nLen) _Z.;u0Zp8
{ khS/'b
int n = -1; /x O{ .dr
try{ Vku#;:yUb^
oSavedFile.write(b,nStart,nLen); p_gA/. v=
n = nLen; PS/W h
} -;<>tq'3`
catch(IOException e) i\vpGlx
{ Z?C4a}
e.printStackTrace (); w Oj88J)
} &58 {
V0S6M^\DK
Z !Z,M' "
return n; F`3^wHw^
} +i4P,Lp
$>(9~Yh0
*bU% @O
} ik1XGFy?
15JsmA*Q
<B=[hk!
/* {9Xm<}%u]]
**SiteInfoBean.java *f?S5.
*/ o[n<M>@
package NetFox; qr9Imr0w<
!^]q0x
+#9xA6,AE
public class SiteInfoBean { {sl~2#,}b1
avVmY|I
wn{]#n=|l
private String sSiteURL; //Site's URL InP[yFV-z
private String sFilePath; //Saved File's Path ~@?"'!U
private String sFileName; //Saved File's Name ,,Jjr[A_j
private int nSplitter; //Count of Splited Downloading File /[6:LnaE
[~!.a\[RW
,5=kDw2
public SiteInfoBean() e7lo!(>#
{//nSplitter的缺省值为5 .@Hmg
//default value of nSplitter is 5 a" ^#!G<+
this("","","",5); TG4^_nRl
} gh'kUZG a
89db5Dx
LH,]vuXh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E`(5UF*>
{ @|E;}:?u
sSiteURL= sURL; Lp!0H `L
sFilePath = sPath; R !Fx)xj
sFileName = sName; Kyu@>9Ok
this.nSplitter = nSpiltter; ,cPkx~w0
[6G=yp
{uEu>D$8
} Z4\tY^NI
+{S Maq
%l%=Dkss
public String getSSiteURL() 6W]OpM
{ QN3qF|))
return sSiteURL; \)p4okpR
} ^4RO
<|B$dz?r
Tm%WWbc
public void setSSiteURL(String value) aD?# ,
{ ;,mBT[_ZO
sSiteURL = value; %Fs*#S
} K?$9N}+
a^%8QJW
^dheJ]n=k
public String getSFilePath() [y_yPOv
{ /4(Z`e;0
return sFilePath; 'lxLnX
} }!eF
\moZ6J
!p-'t]
public void setSFilePath(String value) ~wa%fM
{ p .lu4
sFilePath = value; qK{|Q
} ?OdV1xB
b=V)?"e-
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public String getSFileName() RA#\x.
{ {bW"~_6}
return sFileName; qw6EPC
} Q-M rH
7ytm.lU
.L~fFns/
public void setSFileName(String value) n'! -Pv
{ O)Xd3w'
sFileName = value; k,a,h^{}j
} Lr K9F^c
"1_{c *ck
yW%&_s0
public int getNSplitter() >oVc5}
{ zC<'fT/rG
return nSplitter; M|1eqR%x-?
} N5[_a/
&*X3ch
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public void setNSplitter(int nCount) s4!|v`+$M
{ H?rSP0.
nSplitter = nCount; cZPbD;e:
} cjCE3V9X
} zG&WWc`K
[6Uudiw
QWU5-p9e8
/* bv.EM
**Utility.java ON:LPf>"-
*/ 8yY"x ['
package NetFox; jXc5fXO N
c2tEz&=G
L-^# 02
public class Utility { Bq~AU#
\W3+VG2cA
s#'|{
public Utility() 43UJ#rF
{ bx+(.F
NTXws4'D
{Bav$kw;?e
} wJ;9),fL
J`U$b+q6
//线程睡眠 =g{_^^n
public static void sleep(int nSecond) F2Nb5WT
{ #R~">g:w
try{ g_3rEvf"4
Thread.sleep(nSecond); O JZ!|J8?
} pkrl@jv >
catch(Exception e) f]@[4<Ny
{ !Ei Ze.K
e.printStackTrace (); AlPL;^Y_l
} O^QR;<t'
} P^'>dOI0w
\#h})`
//日志 `D&#U'wB
public static void log(String sMsg) Bbn832iMUY
{ #o(?g-3
System.err.println(sMsg); *!-}lc^4
} h$#4ebp
(.jO:#eE%
?^e*UJNM
public static void log(int sMsg) e B9m4
{ ;XD>$t@
System.err.println(sMsg); IqR[&T)lj
} :X1`wBu
} xEd#~`Jmr
mI{CM: :
.#:@cP~v
/* r9p?@P\:[
**TestMethod.java g7E`;&f
*/ ONg<
package NetFox; ~m,mvRS
\?5[RR
JCCx 5
public class TestMethod { :O>Nd\UtO
z9OMC$,V
K-g=td/@
public TestMethod() =CD:.FG.
{ ///xx/weblogic60b2_win.exe A;/Xt
try{ ;iwD/=Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LN,$P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J.CZR[XF#
SiteFileFetch fileFetch = new SiteFileFetch(bean); zD#+[XI]K
fileFetch.start(); XY$cx~
} RPScP
catch(Exception e){e.printStackTrace ();} #/&q
)VSGqYr#
_zVbqRHlw
} g*"J10hyP
y$;zTH_6j
j,gM+4V^
public static void main(String[] args) 7+A-7ci
{ _S%OX_UMn^
new TestMethod(); \k$]GK-
} .PA?N{z
} !'6J;Fb#
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