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)); )K -@{v^|
} /XEcA5C<
for(int i=0;i<nEndPos.length-1;i++) eg~$WB;1
{ vlw2dY@^
nEndPos = nStartPos[i+1]; /8q7pwV
} |iLeOztuE
nEndPos[nEndPos.length-1] = nFileLength; DGO_fR5L
} p+snBaAo}
} J;+tQ8,AP
S"CsY2;
'1~mnmiP
//启动子线程 0fxA*]h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?Vbe
for(int i=0;i<nStartPos.length;i++) 9Vxsv*OR,
{ yrR<F5xge
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RQy|W}d_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _:+W0YS
nStartPos,nEndPos,i); J^hj R%H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S-gL]r3G8
fileSplitterFetch.start(); ?#ndMv!$
} ZL#4X*zT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \s`'3y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); G2ZF`WQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Dgj`_yd
nEndPos = " + nFileLength); YgQ_P4B;
// fileSplitterFetch[nPos.length-1].start(); }!pC}m
$7jJV(B
0h^upB#p
//等待子线程结束 w?Nvm?_]
//int count = 0; qXt2m
//是否结束while循环 cm%QV?
boolean breakWhile = false; Q {3"&
@'?<92A
_T6WA&;8
while(!bStop) [`=|^2n?
{ ?:s`}b
write_nPos(); L=Dd`
Utility.sleep(500); 5Jp@n .
breakWhile = true; {ogGi/8
VHM,W]
|n=m8X
for(int i=0;i<nStartPos.length;i++) p!AQ
{ 2!~j(_TA
if(!fileSplitterFetch.bDownOver) 2etcSU(y>
{ &1F)/$,v
breakWhile = false; Q6_!I42Y`
break; ul(1)q^
} OC#oJwC
} k^ B'W{
if(breakWhile) 4sSQ nK
break; !Lb9KDk
Kk!D|NKLC
r444s8Y
//count++; J*.Nf)i
//if(count>4) tU!"CX
// siteStop(); .P# c/SQp
} ``1#^ `
P{)&#HXUVb
5f=e JDo=x
System.err.println("文件下载结束！"); FxKH?Rl
} 7xVI,\qV
catch(Exception e){e.printStackTrace ();} bo$xonV@y
} b}9K"GT
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:)q/8 0@
//获得文件长度 ykRKZYfsw(
public long getFileSize() 4^w>An6
{ RB\>$D
int nFileLength = -1; bG^E]a/D
try{ CmJI"
URL url = new URL(siteInfoBean.getSSiteURL()); G-Sw`HHo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xaoaZ3Ko
httpConnection.setRequestProperty("User-Agent","NetFox"); A>%fE 6FY
H[*.Jd
HOsq _)K
int responseCode=httpConnection.getResponseCode(); 67}y/C]<
if(responseCode>=400) bRLmJt98P
{ lR{eO~'~V
processErrorCode(responseCode); #|A @
return -2; //-2 represent access is error Y%^&aacZ
} =5oFutg`
}dAb}0XK.
Zul]ekv
String sHeader; 2OAh7'8<
"%A/bv\u
VaZS_qGe:
for(int i=1;;i++) gpHI)1i'H
{ o8KlY?hX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7w@.)@5
//Utility.log(in.readLine()); ^\e:j7@z
sHeader=httpConnection.getHeaderFieldKey(i); $*b>c:
if(sHeader!=null) b-M[la}1"
{ $Z+N*w~8
if(sHeader.equals("Content-Length")) t<|=-
{ hAfRHd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )}~k7bb}Y
break; zXbTpm
} vo!:uvy;2
} dB<BEe\$g.
else ZA1?'
break; , y{o!w
} _S,2j_R9
} \&2GLBKpe
catch(IOException e){e.printStackTrace ();} ;#EB0TK
catch(Exception e){e.printStackTrace ();} cw/g1,p
UmiW_JB
^^jF*)DT@
Utility.log(nFileLength); @2CYv>
l"IBt:
%Q1v8l.}
return nFileLength; R@=ve %a-
} Rk"VFe>r
viD+~j18
#ZCgpg$wM
//保存下载信息（文件指针位置） 67 7p9{:
private void write_nPos() 0w8Id . ,
{ <rRmbFH#
try{ 15iCJ p
output = new DataOutputStream(new FileOutputStream(tmpFile)); vFL3eu#
output.writeInt(nStartPos.length); ,":"Op61
for(int i=0;i<nStartPos.length;i++) Tx/
{ :n0(gB
// output.writeLong(nPos); >]T(}S~
output.writeLong(fileSplitterFetch.nStartPos); +3si=x\=/
output.writeLong(fileSplitterFetch.nEndPos); [5)1 4% x
} '3[Ecy#
output.close(); &5(|a"5+G
} ]AERi] B
catch(IOException e){e.printStackTrace ();} $w[@L7'(
catch(Exception e){e.printStackTrace ();} NvJu)gI%
} z|+L>O-8
o7/_a/
]'~'V2Ey
//读取保存的下载信息（文件指针位置） 1^!=J<`K;
private void read_nPos() |]+m<Dpyr2
{ Arir=q^2
try{ 0Hff/~J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H",yVD
int nCount = input.readInt(); 73Mh65
nStartPos = new long[nCount]; x:xKlPGd
nEndPos = new long[nCount]; Ad@))o2
for(int i=0;i<nStartPos.length;i++) F8_pwJUpf-
{ P%'bSx1
nStartPos = input.readLong(); "!E(=W?
nEndPos = input.readLong(); n_$lRX5
} :Q+rEjw+
input.close(); 9VV
} H$(%FWzQ%
catch(IOException e){e.printStackTrace ();} "}7K>|a
catch(Exception e){e.printStackTrace ();} kVkV~
} >5/dmHPc
&m>`+uVBP
CyzvQfpZr
private void processErrorCode(int nErrorCode) *r:8=^C7S
{ 3c@Cb`w@
System.err.println("Error Code : " + nErrorCode); kL*Q})
} n3isLNvIp
ETSBd[
Vfg144FG'
//停止文件下载 ;lW0p8
public void siteStop() 0u'2f`p*
{ TQE3/IL
bStop = true; hS*3yCE"8
for(int i=0;i<nStartPos.length;i++) zoC/Hm
fileSplitterFetch.splitterStop(); >AN`L`%2
Ulj2Py}
i&mu=J[
} EZ1H0fm
} 5SR29Z[
//负责部分文件的抓取 ;]Y.2 J
**FileSplitterFetch.java ZS>}NN
*/ m[ay
package NetFox; K`(STvtM
g@MTKqs
{n$9o
import java.io.*; eW\7X%I
import java.net.*; ll[U-v{
KDRIy@[e
a3R#Bg(
public class FileSplitterFetch extends Thread { u;!CQ w/
7k+UCiu>
lsJ'dS
String sURL; //File URL tz1iabZ{
long nStartPos; //File Snippet Start Position h(GgkTj4+
long nEndPos; //File Snippet End Position "*%=k%'
int nThreadID; //Thread's ID cQ*:U@
boolean bDownOver = false; //Downing is over oIoJBn
boolean bStop = false; //Stop identical Iimz
FileAccessI fileAccessI = null; //File Access interface f*W<N06EZ
l:j9lBS
[ {lF1+];@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {s=QwZdR
{ d?b2jZ$r]
this.sURL = sURL; )l[ +7
this.nStartPos = nStart; UbY-)9==
this.nEndPos = nEnd; `hM]5;0
nThreadID = id; j#-ZL-N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -a&wOn-W
} <gf:QX!
?v8RY,Q30
\&@Tq-o
public void run() #^!oP$>1
{ RX?Nv4-
while(nStartPos < nEndPos && !bStop) Zp- Av8
{ g 4Vt"2|
1swh7
d/Zt}{
try{ lNqXx{!k
URL url = new URL(sURL); S3)JEZi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S U2`H7C*
httpConnection.setRequestProperty("User-Agent","NetFox"); 6M+~{9(S
String sProperty = "bytes="+nStartPos+"-"; *=@Z\]"?
httpConnection.setRequestProperty("RANGE",sProperty); ;&Eu<%y
Utility.log(sProperty); |=jgrm1yj
p_B,7@Jl
<| Xf4.
InputStream input = httpConnection.getInputStream(); $'?CY)h{
//logResponseHead(httpConnection); jpm}EOq<%
8{%/!ylJz
L!mQP
byte[] b = new byte[1024]; akJ{-
int nRead; mQVduG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1m}'Y@I
{ rZ:
nStartPos += fileAccessI.write(b,0,nRead); ?kE2S6j5
//if(nThreadID == 1) W 86S)+h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'qQDM_+
} !Aunwq^
}-: d*YtK
() b0Sh=
Utility.log("Thread " + nThreadID + " is over!"); =*8"ci$
bDownOver = true; !QcgTW)T
//nPos = fileAccessI.write (b,0,nRead); lSXhHy
} }! zjj\g^
catch(Exception e){e.printStackTrace ();} XRP/E_4
} a^4(7
} F_YZV)q!W
z7HC6{g%X
0e:KiUr
//打印回应的头信息 J +<|8D
public void logResponseHead(HttpURLConnection con) ;PG'em
{ clG3t eC
for(int i=1;;i++) 4sNM#]%|
{ 4J94iI>S.l
String header=con.getHeaderFieldKey(i); jDH)S{k
if(header!=null) I`Rxijz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )bPNL$O
Utility.log(header+" : "+con.getHeaderField(header)); u`E_Q8
else ~g1@-)zYxK
break; Qbt fKn95
} |])%yRAGQ
} ,1^)JshZ~
zs[t<`2
^C<dr}8
public void splitterStop() h>bmHQ
{ 5'+g'9
bStop = true; Og30&a!~F
} xv4nYm9
r8^1JJ~\
7@+0E2'
} s_D7?o
K8284A8v
FY#`]124*
/* }@1LFZx
**FileAccess.java ^Ud`2 OW;2
*//文件访问(定位，写) tet
package NetFox; "TN}=^A\F
import java.io.*; 2R<1^
6D0uLh
nU`vj`K
public class FileAccessI implements Serializable{ \Cx3^ iX
->8n.!F}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nqiy)ZN#R
RandomAccessFile oSavedFile; Y*w<~m
long nPos; -pg7>vOq
4XX21<yn
M7jDV|Go
public FileAccessI() throws IOException sI*( MhU
{ b-~`A;pr
this("",0); :4(7W[r6
} e5veq!*C?
6"ZQN)7
hrEKmRmF-
public FileAccessI(String sName,long nPos) throws IOException 3bE^[V8/
{ VMHiuBz:
oSavedFile = new RandomAccessFile(sName,"rw"); $JX_e
this.nPos = nPos; x%cKTpDh!
oSavedFile.seek(nPos); M{O2O(
} 5 0~L(<
s2w.V O
\ZCc~muR
public synchronized int write(byte[] b,int nStart,int nLen) )o9CFhFB
{ /SN.M6~
int n = -1; ^z0[{1
try{ [gQ~B1O
oSavedFile.write(b,nStart,nLen); 3@6f%Dyj
n = nLen; @jwUH8g1
} 6 D!,vu
catch(IOException e) ;]<$p[m
{ mRQ F5W6
e.printStackTrace (); cC4*4bMm
} DPy"FQYZb
nNBxT+3*i
KwpNS(]I
return n; 7sHtJr
} {wA@5+[
BT`/OD@
< >f12pu
} hr]NW>;
1iF |t5>e
WGp81DNS|
/* 0m*0I>
**SiteInfoBean.java *pI3"_
*/ W&+UF'F2
package NetFox; ly,d =
F_V~UX1D
0 w@~ynW[
public class SiteInfoBean { 2!&:V]
9O}YtX2
,YH^jc
private String sSiteURL; //Site's URL p1X lni%=
private String sFilePath; //Saved File's Path Ev$?c9*>
private String sFileName; //Saved File's Name B;G|2um:$
private int nSplitter; //Count of Splited Downloading File oleRQ=
LX*T<|c`'
`"-)ObOj}
public SiteInfoBean() OmKT}D~ 4
{//nSplitter的缺省值为5 ShGR!r<
//default value of nSplitter is 5 HESwz{eSS
this("","","",5); }>)"!p;t_
} ;O{AYF?,N
.bnoK
CXA)Zl5#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fyQAQZT
{ ?CmW{9O
sSiteURL= sURL; _Vp9Y:mX2
sFilePath = sPath; LZ\}Kgi(!T
sFileName = sName; qx`*]lX
this.nSplitter = nSpiltter; ,Sz*]X
/H!I90
M-|4cd]6
} oSy[/Y44a
+-8uIqZ
CE*@CkC0z
public String getSSiteURL() 7b'XQ/rs
{ K mL PWj
return sSiteURL; 5^P)='0*
} w6#hsRq[C
i]F,Y;&|
/=Q7RJ@P
public void setSSiteURL(String value) DZLSn Ax
{ Cww$ A %}
sSiteURL = value; _W?}%;
} oN)K2&M0
:X2B+}6_&
c&F"tLl
public String getSFilePath() >@y5R^B`
{ >`s2s@Mx
return sFilePath; PiAA,
} p^~lQ8t
? )0U!)tK
*,pG4kh!
public void setSFilePath(String value) 0XXu_f@]9
{ X$%RJ3t e
sFilePath = value; uCUQxFp
} ?~u"w OH'
{!6!z,
qZA?M=NT?
public String getSFileName() Ibpk\a?A{
{ G9}[g)R*
return sFileName; =_Qt&B)
} \zgRzO'N
fqvA0"tv
N}\$i&Vi
public void setSFileName(String value) 3go!P])
{ rq2XFSXn
sFileName = value; o.Q|%&1
} E: XzX Fxx
#7gOtP#{
&\c$s
public int getNSplitter() #sNa}292"
{ i"|'p/9@q
return nSplitter; `2S%l,>)#
} M,cI0i
MLa]s* ; d
BflF*-s ^
public void setNSplitter(int nCount) bQ
{ (:E^} &A
nSplitter = nCount; Jq?ai8
} Ep?a1&b
} ,'82;oP4
Zf(ucAhL
8]2S'mxE
/* #M{}Grg
**Utility.java 4S03W
*/ 1N:eM/a
package NetFox; d![EnkyL;
@@!t$dD
)"j_NlO
public class Utility { TKj9s'/
% J+'7'g
^R K[-tVV
public Utility() "$ u"Py
{ nQ/(*d
8!:4m"Y
YZ/mTQn_D
} MO/l(wO
L`];i8=I
//线程睡眠 c5O1h8
public static void sleep(int nSecond) NIV&)`w
{ 4my8 p Fk
try{ FC vR
Thread.sleep(nSecond); H(n_g QAX
} 6,cyi|s
catch(Exception e) w3,QT}WvY
{ PksHq77
e.printStackTrace (); lc[\S4
} QN*'MA"M
} tJ'U<s
(8H "'
//日志 |@V<}2zCZ
public static void log(String sMsg) %H%>6z x
{ ?t?!)#X
System.err.println(sMsg); Vf O0 z5&
} D>LdDhNn,`
k('2K2P
|A5]hL
public static void log(int sMsg) gqGl>=.m
{ 9)mJo(
System.err.println(sMsg); AL,|%yup
} 7j._3'M=Kc
} K$f~Fft
ob-be2EysH
`?`\!uP"
/* ?vM{9!M
**TestMethod.java Hyc19|
*/ Xj|j\2$ 0
package NetFox; ;QW)tv.y
3%k@,Vvt
FnL~8otPF'
public class TestMethod { |A0kbC.
3osAWSCEL
okr'=iDg
public TestMethod() o2F6K*u}
{ ///xx/weblogic60b2_win.exe coU`2n/
try{ zXp{9P\c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \s+<w3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s)_sLt8?
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9SMM%(3, r
fileFetch.start(); u3ce\
} ><^A4s
catch(Exception e){e.printStackTrace ();} tXPS@4F
i[WTp??Uv
U4^dDj
} rK)%n!Z
S(/@.gI:f
5E}0<&
public static void main(String[] args) d4A}BTs1
{ 6t*=.b,N
new TestMethod(); 8fZ\})t
} qdO^)uJJ
} N=:yl/M
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