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)); e J6$-r
} `\}v#2VJ
for(int i=0;i<nEndPos.length-1;i++) )c)vTZy
{ s,]z[qB#$
nEndPos = nStartPos[i+1]; zx)z/1
} Y\No4w ^|d
nEndPos[nEndPos.length-1] = nFileLength; , GP?amh
} k7T`bYv
} neLAEHV
"thdPZ
Eea*s'
//启动子线程 4rLL[??
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]@phF _
for(int i=0;i<nStartPos.length;i++) S[J}UpV
{ _no*k?o*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ee^{hQi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?!` /m|"
nStartPos,nEndPos,i); ~XOTs
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |>dI/_'
fileSplitterFetch.start(); =w{Z@S(ukz
} ?`PvL!'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lE4HM$p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $w`=z<2yo1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =`H@%
nEndPos = " + nFileLength); 'F9jq
// fileSplitterFetch[nPos.length-1].start(); OG>}M$Ora
=Jyu4j *}
oYH^_V
//等待子线程结束 y.< m#Zzt
//int count = 0; woK&q7Vn
//是否结束while循环 RO'7\xvn
boolean breakWhile = false; }E50>g
Na]:_K5Dp
;z$(nhJ
while(!bStop) hvsWs.;L'
{ ?fi,ifp*|l
write_nPos(); ]QlwR'&j/n
Utility.sleep(500); huh6t !
breakWhile = true; b?tB(if!I
j}.\]$J
CDK5
for(int i=0;i<nStartPos.length;i++) l*d(;AR
{ o<pf#tifv
if(!fileSplitterFetch.bDownOver) m8d!< h
{ Bf~vA4
breakWhile = false; i#vYyVr[
break; gc-@"wI?
} PgF* 1
} Lh!J >
if(breakWhile) YUtC.TR1
break; RC7]'4o
4NheWM6
UCB/=k^m
//count++; Qp_isU
//if(count>4) Bg x'9p/
// siteStop(); 3z{?_;bR
} 1W^taJH]
Krqtf
.6+Z^,3
System.err.println("文件下载结束！"); =5~jx
} FQ<Ju.
catch(Exception e){e.printStackTrace ();} [+n*~
} o,AAC
,St#Vla
qNB<T('
//获得文件长度 7:plQ!7^
public long getFileSize() oAODp!_c
{ #S!)JM|4wk
int nFileLength = -1; N4F.Y"R$(
try{ 6xTuNE1
URL url = new URL(siteInfoBean.getSSiteURL()); MyJ%`@+1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {?}E^5Z*g
httpConnection.setRequestProperty("User-Agent","NetFox"); 0zmE>/O+
Z>:NPZODf
Vc&!OE
int responseCode=httpConnection.getResponseCode(); cQy2"vtU
if(responseCode>=400) zPn+V7F
{ "O3tq=Q
processErrorCode(responseCode); vWzm@
return -2; //-2 represent access is error ` Mjj@[
} *\+\5pu0
PUp6Q;AdQ
CkOz
String sHeader; c|e~BQdRw
[%y';`( x
[1g8*j~L
for(int i=1;;i++) zy/@ WFPE
{ /?5 1D@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +Vb.lH[av
//Utility.log(in.readLine()); U)fc*s
sHeader=httpConnection.getHeaderFieldKey(i); Rr&h!YMb
if(sHeader!=null) }~e8e
{ ,<(}|go
if(sHeader.equals("Content-Length")) } gyj0
{ z+0I#kM"1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3]}D`Qs6
break; %?0:vn
} k]F[>26k
} h\fjBDU^
else ^ Edfv5
break; +\d56j+D
} I8hz(2jI
} n{n52][J]
catch(IOException e){e.printStackTrace ();} dk[!V1x4\
catch(Exception e){e.printStackTrace ();} o4G?nvK-
CGW.I$u
lA| 5E?
Utility.log(nFileLength); oK6tTK
(-UYB9s
O,{6*[)@
return nFileLength; xgVeN["
} eVjBGJ=2e
<=zQ NBtx
}aa'\8
//保存下载信息（文件指针位置） ,>bh$|
private void write_nPos() SA&Rep^
{ kJ'[K!r
try{ :;t:H] f
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^me-[ 5
output.writeInt(nStartPos.length); u%&`}g
for(int i=0;i<nStartPos.length;i++) SD"FErJ
{ Yg]-wQrH
// output.writeLong(nPos); QO<jI#
output.writeLong(fileSplitterFetch.nStartPos); +nrbShV
output.writeLong(fileSplitterFetch.nEndPos); M'?,] an
} 2V- 16Q'%
output.close(); Z3"%`*Tmq-
} k^3>Y%^1
catch(IOException e){e.printStackTrace ();} EU2$f
catch(Exception e){e.printStackTrace ();} D=q:*x
} l: HTk4$0
-u6bAQ
\:%(q/v"X
//读取保存的下载信息（文件指针位置） 9&-dTayIz
private void read_nPos() Sq>dt[7
{ cvn@/qBq*t
try{ "%`1]Fr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1{)5<!9!l
int nCount = input.readInt(); K[I=6
nStartPos = new long[nCount]; d~9A+m3b_
nEndPos = new long[nCount]; zGb|)A~,
for(int i=0;i<nStartPos.length;i++) F+YZE[h%
{ f',Op1o
nStartPos = input.readLong(); \j@OZ
nEndPos = input.readLong(); R/~p>apg8
} 6dq(T_eG
input.close(); !j9t*2m[
} epA:v|S
catch(IOException e){e.printStackTrace ();} ;5]Lf$tZ
catch(Exception e){e.printStackTrace ();} 5Yg'BkEr
} |kyX3~
~8q)^vm>f?
q}i]'7
private void processErrorCode(int nErrorCode) F|SXn\
{ dPW#C5dm
System.err.println("Error Code : " + nErrorCode); m ifxiV
} \r/rBa\
pj\u9 L_
du<tGsy
//停止文件下载 R5N%e%[
public void siteStop() G?L HmTHg
{ x>**;#7)
bStop = true; @x*c1%wg
for(int i=0;i<nStartPos.length;i++) lEH65;Nh*
fileSplitterFetch.splitterStop(); S5gyr&dm
!y\'EW3|G
{BP{C=p
} "M<8UE\n
} \o z#l'z
//负责部分文件的抓取 -R|,9o^
**FileSplitterFetch.java \{Y 7FC~
*/ H`*LBqDk
package NetFox; p)KheLiZ
&y\prip
Gw}%{=D9
import java.io.*; m]'#t)B_m
import java.net.*; y*4=c_Z
|6.l7u?d
p2hB8zL
public class FileSplitterFetch extends Thread { =mO vs
$h+1u$po
.T}Wdng
String sURL; //File URL 2":pE U{E
long nStartPos; //File Snippet Start Position Q1U\D
long nEndPos; //File Snippet End Position u}#(.)a:
int nThreadID; //Thread's ID 1vS#K=sb
boolean bDownOver = false; //Downing is over Ow+GS{-q
boolean bStop = false; //Stop identical ] ]u s %
FileAccessI fileAccessI = null; //File Access interface 1auIR/=-
KI.q@zO6|
6/f7<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k9<;woOBO
{ qLO4#CKCL6
this.sURL = sURL; +jAGGv^)
this.nStartPos = nStart; fW{(lPx
this.nEndPos = nEnd; oI?3<M^
nThreadID = id; :">!r.Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ` )/vq-9
} pd:WEI ,
ts,ZvY]
3OrczJ=[UF
public void run() F8nYV
{ G0CW}e@)
while(nStartPos < nEndPos && !bStop) +>8'mf
{ C/q'=:H;
Jz\%%C
'*Z1tDFS
try{ C(eTR1
URL url = new URL(sURL); a4mn*,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JYMiLph<
httpConnection.setRequestProperty("User-Agent","NetFox"); ?fQ'^agq
String sProperty = "bytes="+nStartPos+"-"; @bi}W`
httpConnection.setRequestProperty("RANGE",sProperty); RF`.xQ26=
Utility.log(sProperty); S4Pxc ]!
(9tX5$e6N
eVEV}`X
InputStream input = httpConnection.getInputStream(); 4n#M
//logResponseHead(httpConnection); 3$9s\<j
j%Y#(Q>
z{8bvuE
byte[] b = new byte[1024]; TtK[nP
int nRead; #oS<E1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F3y9@dA]
{ lXx=But
nStartPos += fileAccessI.write(b,0,nRead); J-[,KME_^
//if(nThreadID == 1) _F4Ii-6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Y/UM3/
} C>ICu*PW
d8DV[{^
jSJqE_1
Utility.log("Thread " + nThreadID + " is over!"); \e:7)R2<!x
bDownOver = true; F6LH $C
//nPos = fileAccessI.write (b,0,nRead); ;d@#XIS&-(
} ,dv+p&Tz2
catch(Exception e){e.printStackTrace ();} DMAIM|h
} FDv<\2+ c
} "x#-sZ=
l94b^W}1)W
~Sdb_EZ
//打印回应的头信息 )~&CvJ
public void logResponseHead(HttpURLConnection con) Je';9(ZK
{ 7dN*lks
for(int i=1;;i++) PoHg,n]
{ 3>3Kwc~E
String header=con.getHeaderFieldKey(i); |sa]F5
if(header!=null) SDC4L <!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -fM1nH&
Utility.log(header+" : "+con.getHeaderField(header)); UI0(=>L
else |+{)_?
break; gx-2v|pZ
} XP`Nf)3{Yd
} zp6C3RG(
Cw~q4A6'
'%>=ZhO
public void splitterStop() -Sqz5lo
{ xv46r=>
bStop = true; Z3%}ajPu[
} 3D6RLu
LmRy1T,act
We)xB
} T!uM+6|Y
]GUvV&6@(
HsxVZ.dS
/* &g#@3e1>
**FileAccess.java }?lrU.@zg
*//文件访问(定位，写) sm9k/(-
package NetFox; _qU4Fadgm
import java.io.*; C=-=_>Q,L<
3W V"U
V#v`(j%
public class FileAccessI implements Serializable{ ( B!uy`
3N8t`N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zh%#Y_[R
RandomAccessFile oSavedFile; PoNi"Pv
long nPos; 9q)Kfz
6o^,@~:R
`34zkPB??
public FileAccessI() throws IOException j 'FVz&
{ ?}qttj
this("",0); W,D4.w$@'
} Ig$(3p
?llXd4
i|c'Lbre`
public FileAccessI(String sName,long nPos) throws IOException U1Q:= yD
{ Yy5h"r
oSavedFile = new RandomAccessFile(sName,"rw"); }~2LW" 1'
this.nPos = nPos; \1d(9jR
oSavedFile.seek(nPos); Ltv]pH}YN
} iky|Tp
&)2i[X
>u>5{4
public synchronized int write(byte[] b,int nStart,int nLen) -N6f1>}pE
{ toLV4BtIG
int n = -1; >f^r^P
try{ dMPc:tJT
oSavedFile.write(b,nStart,nLen); ^/uA?h:]\
n = nLen; H-WJp<_
} lvdf^b/ j
catch(IOException e) LuNc,n%
{ D!@Ciw
e.printStackTrace (); Q`~jw>x
} q6@Lp^f
$:BKzHmg
|<HPn4 ,X
return n; \4&fxe
} .rO]M:UY
7z/|\D_{
F7 5#*
} %]Fd[pzF
>i_2OV
? 8)'oMD
/* :C7_Jp*Qv
**SiteInfoBean.java aL*&r~`&e'
*/ . kQkC:~9
package NetFox; !4]TXH0f
2-&k^Gl!:
hM@ HA
public class SiteInfoBean { WgR).Yx
|"?M1*g
X]'{(?Ch
private String sSiteURL; //Site's URL xRJ\E }/7
private String sFilePath; //Saved File's Path 7zA'ri3w
private String sFileName; //Saved File's Name W_||6LbZy
private int nSplitter; //Count of Splited Downloading File >5_2_Y$"
0bz'&
?@BTGUK"C
public SiteInfoBean() .Fs7z7?Y
{//nSplitter的缺省值为5 2n3W=dF
//default value of nSplitter is 5 0f~C#/[t7
this("","","",5); wE[]6\_x1
} 5*E]ETo@R
O#b6mKPt;t
O|\J}rm'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c$ao:nP)D
{ dUsYZdQs
sSiteURL= sURL; wy yWyf
sFilePath = sPath; RzxNbeki[W
sFileName = sName; hq%?=2'9?
this.nSplitter = nSpiltter; 05z,b]>l
?<V?wsp
R,gR;Aarw
} |h-QP#]/
N2B|SO''
H+1-]'g`
public String getSSiteURL() >go,K{cK6
{ ahuGq'
return sSiteURL; BZ:H`M`n
} E7NV ^4h
prYs $j
lH-/L(h2
public void setSSiteURL(String value) Q7*SE%H
{ b8~Bazk
sSiteURL = value; lH#u
} %oq{L]C(rf
Kw-gojZ
^.KwcXr
public String getSFilePath() >XK PTC5H
{ uZM{BgXXD
return sFilePath; ~T9/#-e>BF
} Kh,V.+7k
O/,aJCe
e91aK
public void setSFilePath(String value) m=?KZ?U`
{ &f"-d
sFilePath = value; q-.,nMUF
} xGu r
"7!;KHc
)T';qm0w
public String getSFileName() 5V6G=H
{ t?q@H8
return sFileName; ' qWALu
} uxW~uEh
{)"iiJ
n1JRDw"e$$
public void setSFileName(String value) o}W%I/s
{ C 'v+f=
sFileName = value; &S( .GdEf
} N03HQp)g
/`f^Y>4gD
]DOX?qI i
public int getNSplitter() <\Eh1[F
{ @W vatD V
return nSplitter; fBalTk;G{U
} :A1{d?B
b?TO=~k,
&{>cZh}\
public void setNSplitter(int nCount) [onGNq?#
{ P/c&@_b
nSplitter = nCount; /4c\K-Z;
} L!rw[x
} X}tVmO?
e?opkq\f
R#2t)y
/* 2W/?q!t
**Utility.java Q,p}:e
*/ 9A}# 6
package NetFox; \=uKHNP?#
q8s0AN'@t'
^~G8?]w
public class Utility { %F!1
Gs9:6
@c<3b2
public Utility() BlXB7q,
{ Fe]B&n
5#> 8MU?&
_acE:H
} [* @5\NWR}
>c9a0A
//线程睡眠 rypTKT|U;
public static void sleep(int nSecond) >)spqu]
{ AT9q3
try{ lD"(MQV@0
Thread.sleep(nSecond); 4zJtOK?r"
} JS*m65e
catch(Exception e) 89\n;5'f4
{ cgm81+[%r
e.printStackTrace (); mH Ic f{RG
} s}jHl8
} GFel(cx:K
}RHn)}+
//日志 ,!dh2xNH^
public static void log(String sMsg) Eo#u#IY
{ %,D<O,N
System.err.println(sMsg); A-4h
} mf}O-Igte
gF[z fDm
JMH8MH*
public static void log(int sMsg) 6`]$qSTS
{ i?fOK_d
System.err.println(sMsg); m|=H#
} =dII- L=`
} 'Y56+P\u
UEozAY
]`&Yqg
/* P@,nA41,j
**TestMethod.java w9,iq@
*/ Gm(b/qDDe
package NetFox; [1F*bI
&2`Fn!m
6(G?MW.
public class TestMethod { %,Ap7X3:QT
iK12pw
\'9PZ6q{
public TestMethod() ,t`Kv1
{ ///xx/weblogic60b2_win.exe "g'jPwFG
try{ !!Aj<*%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *,Za6.=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wc!onZX5
SiteFileFetch fileFetch = new SiteFileFetch(bean); LxpuhvIO
fileFetch.start(); 'A:x/iv}^
} fH)YFn/
catch(Exception e){e.printStackTrace ();} x-?{E
4H|(c[K;
hWKJ,r%9;
} PSPmO'C+
sgO'wXcoP
$dA-2e10
public static void main(String[] args) s%2v3eb
{ "R3d+p
new TestMethod(); LrATSq@
} L~IhsiB
} KyzFnVH3)
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