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)); 92/_!P>
} G8b`>@rZ
for(int i=0;i<nEndPos.length-1;i++) ?ViU%t8J5
{ 'FG@Rg(
nEndPos = nStartPos[i+1]; `] Zil8n
} *!}bU`
nEndPos[nEndPos.length-1] = nFileLength; Xh*NuHH
} ;xu&%n[6@
} Uee$5a>(
zhI"++
0T:U(5Y9
//启动子线程 5^{).fig
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %hRH80W|
for(int i=0;i<nStartPos.length;i++) `k9a$@Xg
{ 0(^N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $ 3.Y2&$T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y0o{@)Y:
nStartPos,nEndPos,i); eqU y>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7<93n`byM
fileSplitterFetch.start(); o-<.8Z}>at
} :CXm@yF~4=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f(c#1AJE53
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mqQC`Aqx:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @dhnpR:L
nEndPos = " + nFileLength); 6J3<k(#:
// fileSplitterFetch[nPos.length-1].start(); 'u:J "
8+&Da
D[K!xq
//等待子线程结束 edfb7prfTl
//int count = 0; jh~E!%d77
//是否结束while循环 7hKfxw-X@
boolean breakWhile = false; SJ&+"S&
S@WT;Q2Z
z3|5E#m
while(!bStop) *7yrm&@nG
{ SA,+oq(
write_nPos(); *V@t]d$=#
Utility.sleep(500); %$+bO/f
breakWhile = true; O|&SL03Z8
aydf# [F
*#o2b-[V
for(int i=0;i<nStartPos.length;i++) ])Z p|?Y
{ W!b'nRkq
if(!fileSplitterFetch.bDownOver) |k/;1.b!9(
{ -^$IjK-N
breakWhile = false; < _<?p&
break; \|R\pS}4
} k6|/ik9C
} 7,R ~2ss5z
if(breakWhile) cg}lF9;d
break; zw%1a 3!
Xcci)",!
S 0mt8/ M
//count++; a)M3t
//if(count>4) ujeN|W
// siteStop(); d{c06(#_
} #9]O92t2UV
<*db%{
`s_k+ g
System.err.println("文件下载结束！"); HurF4IsHk
} nMH:7[x3
catch(Exception e){e.printStackTrace ();} O?qM=W
} 8AmB0W>e
6JE_rAab
xPP]RoPR
//获得文件长度 tx}=c5
public long getFileSize() xZ`h8
{ -y8>c0u
int nFileLength = -1; @8|i@S@4
try{ 9&OhCrxW-
URL url = new URL(siteInfoBean.getSSiteURL()); Y]+KsiOL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -;&-b>b
httpConnection.setRequestProperty("User-Agent","NetFox"); _5v]69C#
Jr,**,wA
Qa,$_,E
int responseCode=httpConnection.getResponseCode(); jFwJ1W;?-
if(responseCode>=400) vk|xYDD
{ ;% l0Ml>
processErrorCode(responseCode); _?;74VWA
return -2; //-2 represent access is error fI-f Gx
} Eyg F,>.4
v=?/c-J*
7y=1\KW(
String sHeader; CjmF2[|
:2AlvjvjZ
Qsr+f~"W
for(int i=1;;i++) (bGk=q=M
{ NnO%D^P]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u~1 ,88&U
//Utility.log(in.readLine()); .N Z
sHeader=httpConnection.getHeaderFieldKey(i); GBGna3
if(sHeader!=null) r5PZ=+F
{ *~8g:;u
if(sHeader.equals("Content-Length")) Kd7Lpw1u]
{ \!Ap<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BYb"[qPV
break; J''lOj(@
} \NQ[w7
} kQO5sX$;
else QzV%m0
break; ZEG~ek=jM
} hGU 3DKHT
} .}iRe}=
catch(IOException e){e.printStackTrace ();} <l$ vnq
catch(Exception e){e.printStackTrace ();} co>IJzg
(iY2d_FQ[
rnM C[
Utility.log(nFileLength); O5A]{W
Z#s-(wf
rh6 e
return nFileLength; X6n8Bi9Ik
} L#`X;:
,o [FUi(#@
D1Q]Z63,
//保存下载信息（文件指针位置） ]|B_3*A
private void write_nPos() p}|<EL}Z9
{ H.)J?3
try{ G PL^!_
output = new DataOutputStream(new FileOutputStream(tmpFile)); G(#EW+
output.writeInt(nStartPos.length); !r9~K^EI
for(int i=0;i<nStartPos.length;i++) 3tCT"UvTD
{ y+$a}=cb0
// output.writeLong(nPos); Ba9"IXKH
output.writeLong(fileSplitterFetch.nStartPos); }C5Fvy6uz
output.writeLong(fileSplitterFetch.nEndPos); /_tN&[
} <(BIWm*
output.close(); ])vqXjN6"
} 8hZc#b;
catch(IOException e){e.printStackTrace ();} 8FgF6ip
catch(Exception e){e.printStackTrace ();} yUg'^SEbLk
} )4jS}
@Qd5a(5WM
s"X0Jx}
//读取保存的下载信息（文件指针位置） H=*2A!O[_
private void read_nPos() {&pBy
{ a0hgF_O1
try{ Fhs/<w-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _`xhP-,`S
int nCount = input.readInt(); s~g]`/h$r
nStartPos = new long[nCount]; UDHMNubB
nEndPos = new long[nCount]; #kAk d-QY6
for(int i=0;i<nStartPos.length;i++) ?)e6:T(
{ 'o1lJ?~kH
nStartPos = input.readLong(); z"V`8D
nEndPos = input.readLong(); >UV?nXP}
} "cDc~~3/@
input.close(); 2\G[U#~bi
} r,wC5%&Za
catch(IOException e){e.printStackTrace ();} Q-||A
catch(Exception e){e.printStackTrace ();} Q57Z~EsF
} ?7w7Y;FuR
$2$jV1s
6bBNC2K$-
private void processErrorCode(int nErrorCode) U sV?}
{ B'D~Q
System.err.println("Error Code : " + nErrorCode); zu``F]B
} +3?.Vb%jY
@gm!D`YL
l/56;f\IA
//停止文件下载 Bx0=D:j
public void siteStop() _>G=xKA#e
{ 2.&%mSN
bStop = true; *r iWrG
for(int i=0;i<nStartPos.length;i++) #Z}YQ$g
fileSplitterFetch.splitterStop(); U (A#}
ccgV-'IG9
b`|,rfq^AZ
} m<|fdS'@
} S,RC;D7
//负责部分文件的抓取 I<hMS6$<LE
**FileSplitterFetch.java 7:wf!\@I
*/ 36yIfC,
package NetFox; FK;2u$:
M3H^s_
v|2+7N:[;
import java.io.*; Ol*|J
import java.net.*; =${ImMwj
# 0/,teJk
l,ra24
public class FileSplitterFetch extends Thread { d 2z!i^:
I3dUI~}u
='fN xabB
String sURL; //File URL me@EKspX
long nStartPos; //File Snippet Start Position ]?~[!&h
long nEndPos; //File Snippet End Position 1K[y)q
int nThreadID; //Thread's ID -7A2@g
boolean bDownOver = false; //Downing is over {Ty?OZ
boolean bStop = false; //Stop identical 3s Mmg`
FileAccessI fileAccessI = null; //File Access interface \n0MqXs#
%?!TqJT?{
Z+Ppd=||,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qz|xow/ns@
{ qj,^"rp1:
this.sURL = sURL; sKDL=c;?j
this.nStartPos = nStart; JO\KTWtjO
this.nEndPos = nEnd; 5} 1qo7;
nThreadID = id; 5>~q4t)6z}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >;k~B
} q #X[oVq
\"$jj<gc
.<-~k@ P
public void run() x$6FvgP(
{ P@Av/r
while(nStartPos < nEndPos && !bStop) ` NWmwmWB"
{ H:X(><J
e)]DFP[n
/UiB1-*b
try{ iI!g1
URL url = new URL(sURL); YG>6;g)Zm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0<]]q[pr
httpConnection.setRequestProperty("User-Agent","NetFox"); -d6PXf5
String sProperty = "bytes="+nStartPos+"-"; ]0;,M
httpConnection.setRequestProperty("RANGE",sProperty); G3de<?K.[V
Utility.log(sProperty); eLk:">kj
}~! D]/B
vf['$um
InputStream input = httpConnection.getInputStream(); K2-nP2Go?
//logResponseHead(httpConnection); 'o-J)+oa
UUxP4
,~7+r#q7
byte[] b = new byte[1024]; .KF(_ 92
int nRead; 'z">4{5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "IJcKoB
{ ?)FY7[x.
nStartPos += fileAccessI.write(b,0,nRead); LH>h]OTQF
//if(nThreadID == 1) \-I)dMm[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;;n=(cM|z
} /P/::$
v#$}3+KVC
&%@>S.
Utility.log("Thread " + nThreadID + " is over!"); ' g Fewo
bDownOver = true; RJLhR_t7n
//nPos = fileAccessI.write (b,0,nRead); jN2Xoh9
} T$s)aM
catch(Exception e){e.printStackTrace ();} eEg>EI_U
} /5C>7BC
} +!<{80w
jx8hh}C
gEnc;qb
//打印回应的头信息 r%^XOw<'
public void logResponseHead(HttpURLConnection con) a,\GOy(q{
{ +(vL~
for(int i=1;;i++) KPI[{T\`ZM
{ >2;KPV0H
String header=con.getHeaderFieldKey(i); G>W:3y
if(header!=null) Q?-uJ1J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); scR+F'M
Utility.log(header+" : "+con.getHeaderField(header)); 30L/-+r1
else N"/be
break; =N{-lyr)
} H9rZWc"*
} qN6GLx%
Oa-~}hN
lK #~lC
public void splitterStop() 2%t!3F:
{ vmT6^G
bStop = true; 2Jn?'76`
} Zz56=ZX*_
0p!N'7N
\t]aBT,
} "'mr0G9X
_tVrLb7`s
]=m0@JTbG
/* j0IuuJ+
**FileAccess.java !6{b)P
*//文件访问(定位，写) >s"kL^
package NetFox; &3'zG)
import java.io.*; ?1lx8+
N;XJMk_ H
\DRYqLT`
public class FileAccessI implements Serializable{ UQ)7uYQ5
;X[23A{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R=s^bYdoy
RandomAccessFile oSavedFile; v9vY#W
long nPos; u"M^qRhD
k0!D9tk
*(]@T@yN
public FileAccessI() throws IOException Op:7EdT#
{ ($:JI3e[;
this("",0); =/F\_/Xw
} S[oRq
xm}`6B^f
QzA/HP a
public FileAccessI(String sName,long nPos) throws IOException 8rgNG7d
{ J`{HMv
oSavedFile = new RandomAccessFile(sName,"rw"); /A/k13 J
this.nPos = nPos; Q OP8{~O
oSavedFile.seek(nPos); Se&%Dr3Nv
} AC/82$
)ia$pes
d#wK
public synchronized int write(byte[] b,int nStart,int nLen) 8sxH)"S
{ ?u /i8
int n = -1; { w:9w
try{ _K|513I
oSavedFile.write(b,nStart,nLen); ]mmL8%B@_
n = nLen; NI% ()
} @awN*mO
catch(IOException e) &fWYQ'\>
{ OL)M`eVQ'
e.printStackTrace (); p(Bn!
} |p{FSS
?$FvE4!n
B|n<{g[-cM
return n; /-jk_8@a
} @^93q
@Xe[5T
FR@##i$
} B|+tK
S)d_A
rJl'+Ae9N|
/* Gn%gSH/
**SiteInfoBean.java [sH[bmLR
*/ JK9}Kb};
package NetFox; YKs^aQm#
:ift{XR'
gAgP("
public class SiteInfoBean { 4`+hX'
0q ^dpM
/R44x\nhr
private String sSiteURL; //Site's URL [{!5{k!
private String sFilePath; //Saved File's Path 1p9+c~4l:
private String sFileName; //Saved File's Name }];_ug* "
private int nSplitter; //Count of Splited Downloading File ^04|tda
RW. >;|m
/K]<7
public SiteInfoBean() oZ(T`5
{//nSplitter的缺省值为5 {|J'd+
//default value of nSplitter is 5 E64d6z^7u
this("","","",5); I*^3 Z
} +e%U6&l{
q^hL[:ms#
<e&*Tx<8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !xxu~j^T
{ Z[{: `
sSiteURL= sURL; 1RF? dv
sFilePath = sPath; *@,>R6)jI
sFileName = sName; m*S[oy&
this.nSplitter = nSpiltter; =a.avOZ
^J=l] l
xPi/nWl`|
} `?ijKZ}y5
\kGi5G]
@n##.th
public String getSSiteURL() /hMD Me
{ 'M#'BQQ5
return sSiteURL; 6M`N| %
} Q+\?gU]
D,rs)
&LS&O
public void setSSiteURL(String value) LGm>x
{ -a[]#v9
sSiteURL = value; v*7lJNN.
} 75V?K
>9.xFiq<
fscAG\>8
public String getSFilePath() 5/O;&[lYy
{ $3Ct@}=n
return sFilePath; I(dMiL
} bNG;`VZ%
Ge>%?\
^{T3lQvt
public void setSFilePath(String value) )c#m<_^
{ ]jz%])SzH
sFilePath = value; Ppzd.=E
} H0YxPk)
bt,^-gt@
&ns !\!
public String getSFileName() 89@e &h*
{ {g>k-.
return sFileName; })R8VJ&C/
} Tej-mr3P
eswsxJ/!
Jn>7MuG
public void setSFileName(String value) `!j|Ym
{ v^h \E+@
sFileName = value; P/'~&*m-
} cia4!-#
I"]5B
JxP=[>I
public int getNSplitter() oAkF
{ ?[K+Ym+
return nSplitter; 3 G?^/nB
} pH%cbBm
Ab<4F7
-k p~pe*T
public void setNSplitter(int nCount) D@i,dPz5Zl
{ [UVxtMJ
nSplitter = nCount; $C UmRi{T
} |yi3y `f
} Ok+zUA[Wu
'|b {
q9RCXo>Y+1
/* T{={uzQeJJ
**Utility.java u":D{+wC|
*/ ^IxT.g
package NetFox; B8^tIq
,*2%6t`N?
UlHRA[SCv
public class Utility { zv]-(<B
iAX\F`
j w)Lofn
public Utility() dUtxG ~9
{ YWSo:)LY
pCz;km
"msCiqF{z
} x=yU }lsV
x-0IxWD%
//线程睡眠 )>atoA
public static void sleep(int nSecond) Z1FO.[FV
{ N7%+n*Z
try{ 8u$Krq
Thread.sleep(nSecond); PXcpROg56
} oW-Tw@D
catch(Exception e) N5rY*S
{ cWl)ZE<hM
e.printStackTrace (); (XJehdB0
} JbG\Ywi0]
} 0Ng6Xg(QHc
Bo?uwi
//日志 CJ_X:Frj)
public static void log(String sMsg) ~4[2{M.0>@
{ X6~y+R
System.err.println(sMsg); Jp.Sow
} jMUE&/k
&J_|P43
z12[vN
public static void log(int sMsg) pr\yc
{ kL^;^!Nt
System.err.println(sMsg); )#MKOsOct
} |2XEt\P
} =YBwO. !%
5M{N-L_eC
lph3"a^
/* -[s*R%w
**TestMethod.java 0k>NuIIP
*/ J={$q1@lq
package NetFox; 7Nc@7_=
_> .TB\
6)P~3C'
public class TestMethod { M}}9
sMli!u
M|FwYF^
public TestMethod() r_]wa
{ ///xx/weblogic60b2_win.exe VG+Yhm<SL
try{ B8 -/C\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3=)/-l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z-uJ+SA
SiteFileFetch fileFetch = new SiteFileFetch(bean); zzuDI_,/
fileFetch.start(); B4R!V!Z*
} *#Hi W)
catch(Exception e){e.printStackTrace ();} ]c+qD,wqt>
iwCnW7:
Eszwg
} 8[,,Kr)-
A$A7F=x
2Ua_7
public static void main(String[] args) \P!v9LX(
{ a2UER1Yp"
new TestMethod(); 7i~::Z <
} g8mVjM\B;
} [+gX6
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