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)); ]aRD6F:L
} `|w#K28t"
for(int i=0;i<nEndPos.length-1;i++) +m.8*^
{ ) T1oDk
nEndPos = nStartPos[i+1]; *N r|G61
} >FHsZKJ
nEndPos[nEndPos.length-1] = nFileLength; Fdw[CYHz
} ."X~?Nk
} Yel(}Ny
2P ?Iu&
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//启动子线程 h6e$$-_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rsv!mY,Em
for(int i=0;i<nStartPos.length;i++) r8%,xA&
{ C6M/$_l&a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `.W;ptZ6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DxgT]F%
nStartPos,nEndPos,i); gk1S"H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); orHD3T%&
fileSplitterFetch.start(); 5r<(Z0
} j*u9+.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0_ \ g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h /QP=Zd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uq%3;#[0
nEndPos = " + nFileLength); Nj_sU0Dt
// fileSplitterFetch[nPos.length-1].start(); C<t>m_t9
m#$za7
}?J5!X
//等待子线程结束 RM1uYFs<
//int count = 0; CD1=2
//是否结束while循环 _0["J:s9
boolean breakWhile = false; /A.i5=k
/&:9VMMj
UMwMXmZNJ
while(!bStop) ~ p.W*skD
{ dO;vcgvb
write_nPos(); &i^NStqu
Utility.sleep(500); &n.uNe
breakWhile = true; ]~Vu-@ /}
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8ysK VF
for(int i=0;i<nStartPos.length;i++) &]F|U3
{ W+ '}O<
if(!fileSplitterFetch.bDownOver) >Mz|e(6
{ J<#`IaV
breakWhile = false; SzlfA%4+GR
break; F6c[v|3
} ONq/JW$?LV
} o;>3z*9?3
if(breakWhile) 0,$-)SkT
break; x5z4Yv^ m
OG+r|.N;
CPNN!%-
//count++; v6-~fcX0G
//if(count>4) 'xZPIj+
// siteStop(); Hq\E06S@
} M|#5gKXd
Z)i1?#
([CnYv
System.err.println("文件下载结束！"); ]|t.wr3AU
} Y+u-J4bj
catch(Exception e){e.printStackTrace ();} UxcDDa/j2T
} {dA ~#fW<
BH0#Q5
LL[#b2CKa
//获得文件长度 MupW=3.38
public long getFileSize() C$td{tM
{ 7;}3{z
int nFileLength = -1; Y-3[KHD
try{ Ipz 1+ #s'
URL url = new URL(siteInfoBean.getSSiteURL()); d6@jEa-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #O9*$eMw
httpConnection.setRequestProperty("User-Agent","NetFox"); k\c &2T]W
<%>n@A
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int responseCode=httpConnection.getResponseCode(); b({Nf,(a2
if(responseCode>=400) RD$tc~@UB
{ >@^yj+k
processErrorCode(responseCode); 4%fN\f
return -2; //-2 represent access is error ]6BmCh
} @>Ghfh>~D
&:;;u\
f;Bfh3
String sHeader; .eabtGO,
R=amKLD?
4-+ozC{
for(int i=1;;i++) ,M@m4bx
{ nKh%E-c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xZP>g
//Utility.log(in.readLine()); 5hJYy`h~
sHeader=httpConnection.getHeaderFieldKey(i); (9KDtr*(2i
if(sHeader!=null) =(.mf
{ Rnj Jg?I=
if(sHeader.equals("Content-Length")) 5fegWCJ
{ -4vHK!l
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); YBtq0c
break; "y~muE:.
} "$W|/vD+
} q: TT4MUj<
else b=K6IX;
break; 9iGE`1N%E
} &Mhv XHI
} [ZKtbPHb
catch(IOException e){e.printStackTrace ();} GX7 eRqz>
catch(Exception e){e.printStackTrace ();} 2q-:p8
sb}K%-
(ET ;LH3
Utility.log(nFileLength); P /c Q1
Zk/' \(5
*(d6Z#
return nFileLength; s%N`
} Mhv1K|4s
}fJ:wku
rnn2u+OG
//保存下载信息（文件指针位置） Y]~ HAv '
private void write_nPos() ]27>a"p59Y
{ FJa[ToZ4+
try{ :BL'>V
output = new DataOutputStream(new FileOutputStream(tmpFile)); I|KY+k> /
output.writeInt(nStartPos.length); s-,=e
for(int i=0;i<nStartPos.length;i++) `Di ^6UK(
{ C#U<k0R
// output.writeLong(nPos); z^gQ\\,4
output.writeLong(fileSplitterFetch.nStartPos); nDHHYp
output.writeLong(fileSplitterFetch.nEndPos); H.YIv50E
} 5q5 )uv"
output.close(); L_THU4^j
} xFBh?
catch(IOException e){e.printStackTrace ();} {{V;:+62
catch(Exception e){e.printStackTrace ();} 6R1wn&8
} r6d0x
3>-[B`dD(
ydwK!j0y
//读取保存的下载信息（文件指针位置） T}n N=Q4
private void read_nPos() ,|T*|2Gm
{ MU_!&(X_
try{ J)9 AnGWe
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wGEWr2$
int nCount = input.readInt(); = EQN-{#
nStartPos = new long[nCount]; 5f;n<EPy
nEndPos = new long[nCount]; e>L5.~i
for(int i=0;i<nStartPos.length;i++) q';&SR#"`K
{ :3f-9aRC!
nStartPos = input.readLong(); S~+O`y^
nEndPos = input.readLong(); E2^ KK:4s
} Uc_jQ4e_
input.close(); B#FHf Z
} 9#v-2QY
catch(IOException e){e.printStackTrace ();} F>(qOH.I
catch(Exception e){e.printStackTrace ();} Err4 %-
} <Z{vC
:PgF
7JbY}@
private void processErrorCode(int nErrorCode) =nJ{$%L\x,
{ B$cOssl
System.err.println("Error Code : " + nErrorCode); 89hF)80
} 2dHM
u?Fnlne4@
Oo FgQEr@
//停止文件下载 &MCy.(jN
public void siteStop() L +L9Y}
{ ;tJWOm
bStop = true; T"n{WmVQ
for(int i=0;i<nStartPos.length;i++) -glugVq
fileSplitterFetch.splitterStop(); Rw{$L~\
IikG/8lP
V?OuIg%=:
} :1:3Svb<Y
} 8]S,u:E:N
//负责部分文件的抓取 3^{8_^I
**FileSplitterFetch.java }1 $hxfb
*/ + c`AE
package NetFox; AT"!{Y "H
Vwjk[ DOL
ov8 ByJc
import java.io.*; ?Phk~ jE
import java.net.*; kW#S]fsfU
q[-|ZA bbr
n'THe|:I
public class FileSplitterFetch extends Thread { N? M
b`$yqi<[
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String sURL; //File URL G3G/xC"
long nStartPos; //File Snippet Start Position e|yX QTlvL
long nEndPos; //File Snippet End Position J0=7'@(p
int nThreadID; //Thread's ID UcgG
boolean bDownOver = false; //Downing is over rVY?6OMkd
boolean bStop = false; //Stop identical t{!/#eQC
FileAccessI fileAccessI = null; //File Access interface )IQ*
X:>$8^gS
`)T&~2n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >QXzMN}o
{ _IWxYp
this.sURL = sURL; 2d-{Q8Pi
this.nStartPos = nStart; tE@FvZC'=
this.nEndPos = nEnd; l';pP^.q
nThreadID = id; <j;]!qFR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ',GV6kt_k
} o7.e'1@
$*k)|4
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public void run() %;7.9%
{ z5'ZN+
while(nStartPos < nEndPos && !bStop) X/l;s
{ o+NMA (
mb&lCd^-
wqUQ"d
try{ w!\3ICB
URL url = new URL(sURL); n0Go p^3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3)3Hck
httpConnection.setRequestProperty("User-Agent","NetFox"); KF+mZB
String sProperty = "bytes="+nStartPos+"-"; @D)Z{=>{=5
httpConnection.setRequestProperty("RANGE",sProperty); L7]]ZAH!1
Utility.log(sProperty); pE2QnNr'
Ea-bC:>
4jQ'+ 2it
InputStream input = httpConnection.getInputStream(); 61} i5o
//logResponseHead(httpConnection); /t*YDWLg
&f-hG3/M
ND5$bq Nu?
byte[] b = new byte[1024]; \@K~L4>
int nRead; gw^'{b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tmO`|tn&
{ +TH3&H5I_A
nStartPos += fileAccessI.write(b,0,nRead); 6g"C#&{@
//if(nThreadID == 1) ?R|th Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W m . }Zh
} }x:0os
-p`L%xj\
4J5pXlzV
Utility.log("Thread " + nThreadID + " is over!"); FbAW_Am(
bDownOver = true; <C'Z H'p
//nPos = fileAccessI.write (b,0,nRead); v`x|]-/M&
} g\Ak;03n
catch(Exception e){e.printStackTrace ();} 9C/MRmv`
} v>H=,.`0\
} D<bI2
G(/DtY]
aE)by-'
//打印回应的头信息 T/l1qcf`wT
public void logResponseHead(HttpURLConnection con) Lg4YED9#
{ /ylc*3e'4
for(int i=1;;i++) {:bN/zV#
{ 0}]SUe^
String header=con.getHeaderFieldKey(i); uFG<UF
if(header!=null) gzf-)J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]]2k}A[-I
Utility.log(header+" : "+con.getHeaderField(header)); 5dl,co{q
else QB&BTT=!
break; T_LLJ}6M
} $'{=R 45Z
} jnJZ#=)
]a?bzOr,
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public void splitterStop() X:EEPGE
{ (RE2I
bStop = true; Q9c)k{QZ
} #H~_K}Ks
\S ."?!U
P|xG\3@Z
} O)]v;9oER
Xgat-cy'DA
[&#/|zH'j:
/* =sgdkAYwP
**FileAccess.java <41ZZ0<EwY
*//文件访问(定位，写) NmpnJu|8
package NetFox; [=uIb._Wv
import java.io.*; eKG2*CV
/Vww?9U;
%w ) +V
public class FileAccessI implements Serializable{ z-r2!^q27
r2\c'9uH
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -Q"hZ9
RandomAccessFile oSavedFile; Fky?\ec
long nPos; D-&an@
]s_8A`vm
H'DVwnn>ik
public FileAccessI() throws IOException ,<`)>2 'o
{ )OP){/
this("",0); 8e&p\%1
} S,{tV=&m]
s{}]D{bc
*if`/N-q(m
public FileAccessI(String sName,long nPos) throws IOException CvDxq:x
{ 6RoAl$}'
oSavedFile = new RandomAccessFile(sName,"rw"); =qu(~]2(
this.nPos = nPos; w7TJv4_
oSavedFile.seek(nPos); vScjq5"p
} r!GW=u'
8b(!k FxD
7DD&~ZcD
public synchronized int write(byte[] b,int nStart,int nLen) "_1)CDqP
{ J G$Z.s
int n = -1; )[Z!*am
try{ [?0d~Q(R#
oSavedFile.write(b,nStart,nLen); F3Maqr y
n = nLen; j;0vAf
} G`0V)S
catch(IOException e) 3=mr "&]r:
{ 8LzBh_J?
e.printStackTrace (); ?-)I+EAnE
} Na{Y}0=^y
L2UsqVU
1q7tiMvV-
return n; ino:N5&;;
} UL$}{2N,_
#xh_
Vvp[P>
} 4rg2y]
3uWkc3
}H> ^o9
/* tq1CwzRX
**SiteInfoBean.java > L2HET
*/ IxZb$h[
package NetFox; V)ig)(CT
Yf@e=:
L{-LX=G^
public class SiteInfoBean { =c.5874A`
fWnD\mx?0
QS[L~97m2M
private String sSiteURL; //Site's URL $'rG-g!f\
private String sFilePath; //Saved File's Path w"Y` ]2
private String sFileName; //Saved File's Name RE2&mYt
private int nSplitter; //Count of Splited Downloading File 58Xzup_"
e'%v1-&sP
"qz3u`[o
public SiteInfoBean() rwLAW"0Qz
{//nSplitter的缺省值为5 B;>{0 s
//default value of nSplitter is 5 K<`osdp=&
this("","","",5); `F YjQe"p
} =@&cHY
DyJ.BQdk)
AlE8Xu9UB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \_V-A f{6
{ /P|fB]p
sSiteURL= sURL; dO> VwP
sFilePath = sPath; '7^M{y/dU
sFileName = sName; RD7^&
this.nSplitter = nSpiltter; sUJ%x#u}Fk
`.jzuX
b//B8^Eong
} %ts^Z*3u
2Y\ d<.M
{9Y+.46S
public String getSSiteURL() -VxTx^)>
{ 4fk8*{Y
return sSiteURL; y;wx?1)
} U4f5xUY0)
!* Ti}oIo&
g9D^)V
public void setSSiteURL(String value) 9vUO*D
{ !U9|x\BqJ2
sSiteURL = value; h,aAw#NE*
} v\16RD
O/AaYA&
xsd_Uu*
public String getSFilePath() (wDm*bZ*
{ voP7"Dl[
return sFilePath; wN1niR'
} |8>3`w!
[[PEa-992
poGc a1
public void setSFilePath(String value) !tfb*@{;'
{ ;c~cet4
sFilePath = value; S#)Eom?V
} /Jf.y*;
L^2FQti>
B~o\+n
public String getSFileName() wW>zgTG
{ xh7cVE[UM
return sFileName; ]#7zk9
} }bY;q-
jK \T|vGJa
VE+IKj!VG0
public void setSFileName(String value) &%})wZ+Dj
{ m'P1BLk
sFileName = value; J)P$2#
} JJ;[,
zi`b2h
| N0Z-|
public int getNSplitter() ;};wq&b#
{ lY|Jr{+Ln
return nSplitter; U2uF&6v
} }*.0N;;C
*K> l*l(f]
=]:>"_jN
public void setNSplitter(int nCount) GKN%Tv:D_
{ GpZc5c
nSplitter = nCount; !Mi;*ZR
} f|O{#AC
} o-}R?>
:ba5iMa
2M#r]
/* 3nZo{p:E
**Utility.java ,%\o4Rc'o
*/ t#q<n:WeYU
package NetFox; pZ/>[TP(%F
': N51kC
FQ g~l4WX
public class Utility { O_Oj|'bBC
ZPbpp@,
nstUMr6
public Utility() yAoe51h?
{ LpR3BP@At
`rf_7
w)Covz'uf
} @V03a )6,h
Eb=}FuV
//线程睡眠 ^Z:~91Tv-_
public static void sleep(int nSecond) rn<PR*
{ H$I=W>;
try{ L!=QR8?@E
Thread.sleep(nSecond); fk_o@ G!0
} 5nsq[Q`
catch(Exception e) ]Dw]p!@
{ 6/rFHY2q
e.printStackTrace (); X7s `U5'l
} mEG#>Gg$
} )/z@vY
Mn)@{^
//日志 mdRU^n
public static void log(String sMsg) jQ:OKh<Y
{ d/i`l*
System.err.println(sMsg); &197P7&o
} =}.EY iD
m9/}~Y#k
m=YU2!Mb
public static void log(int sMsg) K_dOq68_
{ DZi!aJ
System.err.println(sMsg); o865(<p
} 5}`_x+$%(`
} M)U{7c$c7
dPhQ :sd>
-|E!e.^7:
/* OoWyPdC+P
**TestMethod.java .k,kTr$S
*/ )I3NeKWz
package NetFox; ?Wz8[u
EVoEszR
TYy.jFT-
public class TestMethod { V{JAB]?^
6L)%T02C
-;'1^
public TestMethod() R)c'#St
{ ///xx/weblogic60b2_win.exe 3D2E?$dX
try{ U~pV)J
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P>Ez'C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?mwD*LN3o
SiteFileFetch fileFetch = new SiteFileFetch(bean); 92EWIHEWZ
fileFetch.start(); Z?\2F%
} }mAa}{_
catch(Exception e){e.printStackTrace ();} ~$~5qwl
p\<u6v ~J
%"P,1&\^
} Dc_yM
kXf'5p1
1PpyVf
public static void main(String[] args) qzTuxo0B
{ )a-Du$kd
new TestMethod(); "sG=wjcw^
} ariLG [:X
} nJo`B4'U
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