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)); CjUYwAy$k
} Yp;?Zq9
for(int i=0;i<nEndPos.length-1;i++) 7Nlk:f)*-
{ >AUzsQ
nEndPos = nStartPos[i+1]; `z<I<
} 2 UPG8]
nEndPos[nEndPos.length-1] = nFileLength; \MB$Cwc
} RZqou|ki
} 6l&,!fd
(A\\s$fE/1
L_R(K89w
//启动子线程 o'|B|oZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DN;3VT.-
for(int i=0;i<nStartPos.length;i++) z?'z{+HY
{ "g&hsp+i"A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wg]VG,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Oc%W_Gb7
nStartPos,nEndPos,i); *apkw5B}C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CK(`]-q>,
fileSplitterFetch.start(); ]Yk)A.y
} "*ww>0[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "WzD+<oL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -nDY3$U/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b>L?0p$ej
nEndPos = " + nFileLength); r&Qq,koE
// fileSplitterFetch[nPos.length-1].start(); 7(C:ty9
9G^gI}bY
yVgHu#?PM
//等待子线程结束 40HhMTZ0-
//int count = 0; EjP9/VG@=
//是否结束while循环 c]R27r E
boolean breakWhile = false; N}KL'
t_jnp $1m
Ar'k6NX
while(!bStop) >1RL5_US
{ '>[Ut@lT;
write_nPos(); %'.3t|zH
Utility.sleep(500); zQaD&2 q
breakWhile = true; -|4 Oq
R$i-%3
)8;At'q}
for(int i=0;i<nStartPos.length;i++) ~9n30j%]s
{ L"}tJM.d
if(!fileSplitterFetch.bDownOver) H7(D8.y )
{ zV8{|-2]No
breakWhile = false; z"f+;1
break; vF1Fcp.@
} #|=Q5"wU
} I %|;M%B
if(breakWhile) "D'"uMS`H
break; 61](a;Di
zJo?,c
F(|XJN
//count++; H:cAORLB
//if(count>4) %a']TX
// siteStop(); k{D0&
} ZP'0=
m}6Jdt'|
-`UOqjb]3
System.err.println("文件下载结束！"); "v/Yw'! )
} P|t2%:_
catch(Exception e){e.printStackTrace ();} o+Fm+5t;
} Ako]34Rl,
IYv.~IQO
CV)K=Br5&_
//获得文件长度 a9NIK/9
public long getFileSize() "EwzuM8f
{ 8J:=@X^}
int nFileLength = -1; % _nmv
try{ D~n-;T
URL url = new URL(siteInfoBean.getSSiteURL()); d .%2QkL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /QT>"
httpConnection.setRequestProperty("User-Agent","NetFox"); P=l 7m*m
*P8CzF^>\&
[,(+r7aB
int responseCode=httpConnection.getResponseCode(); AkCy C1
if(responseCode>=400) AG><5 }
{ 6sG5n7E-A
processErrorCode(responseCode); 6j95>}@
return -2; //-2 represent access is error }42Hhu7j
} RK=Pm7L:`y
8:[ l1d86
HuR774f[
String sHeader; 3)I]bui
uU%Z%O
?TJ4L/"(k6
for(int i=1;;i++) >Y(JC#M;
{ o`G6!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E\TWPV'/
//Utility.log(in.readLine()); "Mz#1Laby`
sHeader=httpConnection.getHeaderFieldKey(i); ;hF}"shJN
if(sHeader!=null) ;YSe:m*
{ p=3t!3
if(sHeader.equals("Content-Length")) X}Om)WCr
{ 4ETHaIiWp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #<X4RJ
break; JI cm$
} [XttT
} <v/aquLN
else g/}d> 6
break; ^VW]Qr!
} Bh'!aipk
} &xA>(|a\&-
catch(IOException e){e.printStackTrace ();} vxOnv8(
catch(Exception e){e.printStackTrace ();} (E7"GJ
&nwS7n1eb
pU'${Z~b
Utility.log(nFileLength); M?DZShkV_
EV-sEl8ki
_>BYUPY
return nFileLength; bDudETl
} v(GnG
}a#T\6rY
||fw!8E
//保存下载信息（文件指针位置） Ghc U~
private void write_nPos() bRrSd:e
{ v_Df+
try{ *JfGGI_E
output = new DataOutputStream(new FileOutputStream(tmpFile)); L>mM6$l
output.writeInt(nStartPos.length); v9FR
for(int i=0;i<nStartPos.length;i++) ,]nRnI^
{ ''D7Bat@
// output.writeLong(nPos); ."gq[0_YS
output.writeLong(fileSplitterFetch.nStartPos); j}d):3!
output.writeLong(fileSplitterFetch.nEndPos); mZc;n.$U
} _|W&tB*
output.close(); ?iV}U
} dQ~GE}[
catch(IOException e){e.printStackTrace ();} 'wtb"0 }
catch(Exception e){e.printStackTrace ();} {&XTa`C
} tzfyS#E
B9[vv;lzu
~cyKPg6
//读取保存的下载信息（文件指针位置） ^#C+l
private void read_nPos() U;TS7A3
{ |d-x2M[
try{ xQU//kNL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H }]Zp
int nCount = input.readInt(); H C,5j)1
nStartPos = new long[nCount]; d}tmZ*q
nEndPos = new long[nCount]; 4n@>gW
for(int i=0;i<nStartPos.length;i++) uD?RL~M
{ \At~94
nStartPos = input.readLong(); .ahY 1CO
nEndPos = input.readLong(); >N2kWSa
} ^;h\#S[%
input.close(); :\'1x
} 5z9hcQAS
catch(IOException e){e.printStackTrace ();} p`rjWpH
catch(Exception e){e.printStackTrace ();} f3qR7%X?
} Er|&4-9
&bfM`h'
qo7<g*kf~
private void processErrorCode(int nErrorCode) Mpyza%zj
{ !/tV}.*
System.err.println("Error Code : " + nErrorCode); g!' x5#]n
} y9]7LETv\M
8{!|` b'f
{D^ )%{
//停止文件下载 ULu@"
public void siteStop() k{lo'
{ w'A*EWO
bStop = true; V6](_w!
for(int i=0;i<nStartPos.length;i++) :RukW.MR
fileSplitterFetch.splitterStop(); lK7:qo
}~=<7|N.
@%2crJnkS
} A'7Y{oPHX
} $H.U ~
//负责部分文件的抓取 WRkuPj2
**FileSplitterFetch.java W( sit;O
*/ :h(3Ep
package NetFox; BTj1C
H_3WxfO
;<[!;8
import java.io.*; /DH`7E
import java.net.*; OmZZTeGg1s
iG"v
.sQV0jF{
public class FileSplitterFetch extends Thread { !`7evV:
ME]7e^
:|S[i('
String sURL; //File URL f. >[ J
long nStartPos; //File Snippet Start Position mt0v (
long nEndPos; //File Snippet End Position "N_@q2zF
int nThreadID; //Thread's ID ## vP(M$
boolean bDownOver = false; //Downing is over e 2NF.
boolean bStop = false; //Stop identical Fw(
FileAccessI fileAccessI = null; //File Access interface eYoc(bG(+
0vDvp`ie#4
roAHkI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2B6u) 95
{ *^7^g!=z2
this.sURL = sURL; |}e"6e%
this.nStartPos = nStart; uEr.LCAS
this.nEndPos = nEnd; R\n@q_!`X
nThreadID = id; W7~_XI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <3tf(?*,k]
} SJO*g&duQ
z=>PjIW
>k@{NP2b
public void run() C"`\[F`.k
{ il{x?#Wrb
while(nStartPos < nEndPos && !bStop) /8`9SS
{ @>~S$nw/
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P|?nx"c
try{ qFDy)4H)
URL url = new URL(sURL); #')]~Xa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U v>^ Z2
httpConnection.setRequestProperty("User-Agent","NetFox"); Yz0HBEA
String sProperty = "bytes="+nStartPos+"-"; PIFZ '6gn
httpConnection.setRequestProperty("RANGE",sProperty); JUDZ_cGr
Utility.log(sProperty); Bs`='w%7
.3Smqwm=Y
>b3IZ^SB#$
InputStream input = httpConnection.getInputStream(); )PU\|I0|)e
//logResponseHead(httpConnection); v[x 5@$
jL4"FTcE]3
s:,fXg25J
byte[] b = new byte[1024]; _3f/lG?&-
int nRead; #&S<{75A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) <>-gQ9
{ .g}Y! l
nStartPos += fileAccessI.write(b,0,nRead); 93w$ck},?G
//if(nThreadID == 1) ci(BPnQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (lYC2i_b#
} ^H<VH
YWi Y[
3+U2oI:I
Utility.log("Thread " + nThreadID + " is over!"); j.c4
bDownOver = true; ;yZY2)L
//nPos = fileAccessI.write (b,0,nRead); d]=>U^K
} T~}g{q,tR
catch(Exception e){e.printStackTrace ();} B]7QOf"
} "6?Y$y/wm
} ]Qx-f* D6
RhjU^,%
;Oqbfl#%
//打印回应的头信息 q>#P|
public void logResponseHead(HttpURLConnection con) ,Qe`(vU*s
{ aO\@5i_r
for(int i=1;;i++) _&@cU<bdee
{ i2Gh!5]f
String header=con.getHeaderFieldKey(i); jN7Z}1`
if(header!=null) a9nXh6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xU9^8,6
Utility.log(header+" : "+con.getHeaderField(header)); &gm/@_
else +n8,=}
break; N_.`5I;e
} `jDmbD +=
} {y:+rh&
NsSl|m
f6HDfJmE
public void splitterStop() N%?8Bm~dP
{ gJZ9XLPC
bStop = true; P$;_YLr
} Tj=g[)+K
h"Q&E'0d
=G<S!qW
} Tq >?.bq9
:cTwp K
=CO#Q$
/* d4-cZw}+
**FileAccess.java ~E7=c3:"
*//文件访问(定位，写) r+Y]S-o:
package NetFox; 8,(5Q
import java.io.*; .J|"bs9
^`!EpO>k9
V|dKKb[Lve
public class FileAccessI implements Serializable{ '^M3g-C[Jg
b*qC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K<tkNWasQ
RandomAccessFile oSavedFile; 8DNGqaH;dt
long nPos; $yg}HS7HC
nbz?D_
ma26|N5
public FileAccessI() throws IOException )u'("
{ }vdhk0
this("",0); /!0{9F<
} =zW.~(c{
f_Q_qckB%x
J;BG/VI1
public FileAccessI(String sName,long nPos) throws IOException enJE#4Z5&s
{ /ZKO\q
oSavedFile = new RandomAccessFile(sName,"rw"); T|[o
this.nPos = nPos; Y1vSwS%{T
oSavedFile.seek(nPos); l*yJU3PW
} /CN^">|_
.Su9fjy%
SQbnn"
public synchronized int write(byte[] b,int nStart,int nLen) yN~: 3
{ Lw.N3!e[
int n = -1; l2!4}zI2
try{ m/0t; cx
oSavedFile.write(b,nStart,nLen); `795K8
n = nLen; QJ s/0iw
} X"{s"Mc0G
catch(IOException e) l4d2i;4BK
{ u37@9
e.printStackTrace (); &sQtS
} `W[oLQ
]7^YPFc+
ef!V EtEOv
return n; !g~xn2m$R
} ~z!U/QR2
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vf(\?Js,
} kqA`d
=GjxqIv
)vk$]<$
/* t <#Yr%a
**SiteInfoBean.java 7@Qz
*/ mOyBSOad4
package NetFox; ,.fGZ4
*,o)`
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public class SiteInfoBean { |k> _ jO
pFD L5
C sn"sf
private String sSiteURL; //Site's URL 810u+%fu
private String sFilePath; //Saved File's Path Zcv1%hI
private String sFileName; //Saved File's Name pXCmyLQ
private int nSplitter; //Count of Splited Downloading File >+fet ,
dM7-,9Vc
[>4Ou^=1
public SiteInfoBean() Uw][U
{//nSplitter的缺省值为5 nYMdYt04sl
//default value of nSplitter is 5 R b6`k^
this("","","",5); )}7rM6hv
} X'WbS
'zZN]P
q!9SANTx
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ry0n_J:7
{ zrG&p Z
sSiteURL= sURL; _Y*]'?g`
sFilePath = sPath; Q5/".x^@
sFileName = sName; 5B@+$D[0?3
this.nSplitter = nSpiltter; o|AV2FM)
b4s.`%U
Z@ *^4Ve
} FU~ Ip
izow=}
+^!&-g@(
public String getSSiteURL() >ZuWsA0q
{ N%:QaCZKw
return sSiteURL; 4r5?C;g
} zN {'@B
gz-}nCSi
Y+sycdq
public void setSSiteURL(String value) ">lu8F
{ ;2-,Xzz8
sSiteURL = value; Q'&oSPXSDd
} p0UR5A>p
Edc< 8-
HkD6aJ:kA!
public String getSFilePath() }i./,
{ <MI>>$seiJ
return sFilePath; \;}F6g
} u)MdFz
m49GCo k+
egxh
public void setSFilePath(String value) ksT2_Ic
{ lh&Q{t(+8
sFilePath = value; M;,Q8z%
} ]i)m
,n}X,#]
xg k~y,F
public String getSFileName() 1j "/}0fx
{ r:2G11[
return sFileName; Zx7Y ,0
} kFW9@!9
\vXo~_-&
<V#9a83JP
public void setSFileName(String value) ds,NNN<HW
{ 9sifc<za
sFileName = value; "m.jcKt
} iVLfAN @
r'#5ncB
r1yz ?Y_P
public int getNSplitter() \L-o>O
{ h.E8G^}@
return nSplitter; 0 Ji>drn
} !v;N@C3C
O{uc h
!jGe_xB}~
public void setNSplitter(int nCount) ,&rlt+wE
{ k*d0ws#<l
nSplitter = nCount; bf|s=,D
} Jw)Uk< \
} t23uQR#>b_
D |kdk;Xv
//n$#c_}u
/* Z1 %"w*U
**Utility.java OOn{Wp
*/ NKd}g
package NetFox; U,Ya^2h%
:*Lr(-N-
?55t0
public class Utility { |*ss`W7F,2
n]^zIe^6
E1IT>_
public Utility() YEH /22
{ p'{B|ujj6
oJb${k<3
)voJq\Y)%
} r#rL~Rsd}
A[:0?Ez=
//线程睡眠 P0VXHE1p
public static void sleep(int nSecond) $`,10uw
{ *;cvG?V
try{ :}'5'oVG
Thread.sleep(nSecond); $p:RnH\H1
} vy&'A$ H
catch(Exception e) sG{fxha
{ ,Ta k',
e.printStackTrace (); B;x5os
} (7Su{tq
} ]!CMo+
KUJCkwQ
//日志 )` ~"o*M
public static void log(String sMsg) 9U~fc U6
{ :%G_<VAo!
System.err.println(sMsg); U9"g;t+/
} a',6WugIP
{txW>rZX
by07l5
public static void log(int sMsg) 'Ur1I"
{ Ckd j|
System.err.println(sMsg); 5j'7V1:2
} ZHu"&&
} uoJ@Jt'j
u@&e{w~0
J9aqmQj('
/* x[u4>f
**TestMethod.java 7R5m|h`M
*/ a]H&k$!c
package NetFox; ^IQtXae6M
DVJuX~'|!
gq%U5J"x;J
public class TestMethod { e={ ?d6
BD.&K_AW
arK(dg~S
public TestMethod() 3Z0ez?p+5
{ ///xx/weblogic60b2_win.exe 4,g_$)
try{ 1S[4@rZ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U:r^4,Mz*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p :{,~ 1
SiteFileFetch fileFetch = new SiteFileFetch(bean); :m]KVcF.
fileFetch.start(); ql/K$#u
} ":v^Y 9
catch(Exception e){e.printStackTrace ();} B*Z}=$1j
DpCe_Vb%M
Fs$mLa
} tJe5`L
rX(Ol,&oP
\jmT#Gt`9
public static void main(String[] args) d9iVuw0u<
{ ]hMs:$}
new TestMethod(); QLxe1[qI
} .R^R32ln
} sA~Ijg"6
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