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)); ;S0Kf{DN2
} H< 51dJn~
for(int i=0;i<nEndPos.length-1;i++) ^pwT8Bp
{ 2fN2!OT
nEndPos = nStartPos[i+1]; ur\<NApT;
} m55|&Ux|
nEndPos[nEndPos.length-1] = nFileLength; Q?xA))0
} SR_<3WW
} ]"ou?ot }
s k_TKN`+
y90wLU9f
//启动子线程 4Dy|YH$>S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *\gYs{,
for(int i=0;i<nStartPos.length;i++) TAB'oLNp
{ 1 K(0tG:5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sD#*W<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m)Ta5w^
nStartPos,nEndPos,i); 3LRBH+Tt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y7^E`LKK
fileSplitterFetch.start(); {f"oqry_g
} ~)CGwST[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z2a~1BL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7w\L<vFm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", };Pdn7;1G:
nEndPos = " + nFileLength); g~p43sVV
// fileSplitterFetch[nPos.length-1].start(); {'cm;V+
fj|X`,TiZ;
cS#yfN,
//等待子线程结束 T{:8,CiW
//int count = 0; `:.a5
//是否结束while循环 t#d{hEr
boolean breakWhile = false; *[Im].
rHiBW!
xciwKIpS
while(!bStop) *47HN7
{ 0@yw#.j
write_nPos(); Q@ua G,6
Utility.sleep(500); G,e!!J
breakWhile = true; (1e,9!?
ULH<FDot
@)XR
for(int i=0;i<nStartPos.length;i++) Tm\a%Z`U>
{ O@HL%ha
if(!fileSplitterFetch.bDownOver) QpCTHpZ
{ uN&UYJ'B
breakWhile = false; U0=: `G2l
break; R =kXf/y
} YWAH(
} xL [3R
if(breakWhile) mor[AJ
break; +wp!hk&C5
1z3>nou2{
fG zx;<0P!
//count++; U4=m>Ty
//if(count>4) qC6@
// siteStop(); J4%"38l
} #f@}$@
1>=%TIO)
m*|G2
System.err.println("文件下载结束！"); @4G{L8Q}
} .cm9&&"Z
catch(Exception e){e.printStackTrace ();} o-<XR9,N*
} &'k:?@J[
,Cd4Q7T
!K6:5V%q$
//获得文件长度 ";jKTk7
public long getFileSize() n"w>Y)C(X)
{ '""s%C+
int nFileLength = -1; :{,k F
try{ cs9"0&JX
URL url = new URL(siteInfoBean.getSSiteURL()); ioBYxbY`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^+w1:C5
httpConnection.setRequestProperty("User-Agent","NetFox"); .On3ZN
:28[k~.bo
; GEr8_7
int responseCode=httpConnection.getResponseCode(); s14D(:t(
if(responseCode>=400) Vkfc&+
{ G/ H>M%M
processErrorCode(responseCode); qND:LP\_v
return -2; //-2 represent access is error SohNk9u[8
} E|3[$?=R
</pt($
@HE<\Z{ KI
String sHeader; .P#t"oW}
uuQsK. S
_ h/:r1
for(int i=1;;i++) =)}Yw)
{ 5/R ~<z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); woa|h"T
//Utility.log(in.readLine()); 5 qMP u|A
sHeader=httpConnection.getHeaderFieldKey(i); N)/7j7c~;
if(sHeader!=null) tzY?LX[3
{ 9a#Y D;-p
if(sHeader.equals("Content-Length")) F. I\?b
{ EMPujik-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0ybMI+*
break; BoXPX2:
} =zR9^k
} Gd`s01GKQ
else +TAyCxfmt
break; m=TZfa^r
} F$ckW'V
} 5S[:;o
catch(IOException e){e.printStackTrace ();} x\IuM
catch(Exception e){e.printStackTrace ();} kZ;Y/DH
IOa@dUh7a,
OepQ Z|2
Utility.log(nFileLength); Gzp*Vr
v%kl*K`*
X/buz
return nFileLength; tkmzOc H
} 3e>U(ES
e~SRGyIww
+i[@+`
//保存下载信息（文件指针位置） v|dt[>G
private void write_nPos() ~Rx`:kQ
{ ^A=2#j~H\
try{ '!`| H 3
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9rIv-&7'm
output.writeInt(nStartPos.length); - _~\d+>w
for(int i=0;i<nStartPos.length;i++) /i
{ _88X-~.
// output.writeLong(nPos); zDBm^ s
output.writeLong(fileSplitterFetch.nStartPos); nchpD@'t
output.writeLong(fileSplitterFetch.nEndPos); wb%4f6i
} Ce~Pms]
output.close(); V+zn` \a
} +Ht(_+To1
catch(IOException e){e.printStackTrace ();} _;R#B`9Iu
catch(Exception e){e.printStackTrace ();} ~>Y^?l
} Q3'P<"u
;X:Bh8tEV
8K@e8p( y
//读取保存的下载信息（文件指针位置） Md0`/F:+2
private void read_nPos() RRro.r,
{ d6ifJ
try{ ,."wxP2u
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RU~Pa+H
int nCount = input.readInt(); N'PK4:
nStartPos = new long[nCount]; ~Lq`a@]A
nEndPos = new long[nCount]; %.wx]:o
for(int i=0;i<nStartPos.length;i++) )LNKJe+
{ P`S'F_IN
nStartPos = input.readLong(); !=HxL-`j
nEndPos = input.readLong(); 3BAQ2S}
} A8k$.E
input.close(); k@pEs# a
} t*fH&8(
catch(IOException e){e.printStackTrace ();} 3EH@tlTl
catch(Exception e){e.printStackTrace ();} XjmAM/H4
} Nrq/Pkmy
%TO&
VF+g+~
private void processErrorCode(int nErrorCode) q^uCZnkb=
{ NZlCn:"
System.err.println("Error Code : " + nErrorCode); [!Djs![O
} '*EKi
[x- 9m\h
1@}<CWE9
//停止文件下载 ftQ;$@
public void siteStop() Js.G hTs
{ +HjSU2
bStop = true; (!?%"e
for(int i=0;i<nStartPos.length;i++) 3HNm`b8G4m
fileSplitterFetch.splitterStop(); i~3\dp
brK7|&R<
b&]z^_m)
} @1qdnU
} Nfv` )n@
//负责部分文件的抓取 .krEfY&
**FileSplitterFetch.java LoOw]@>
*/ z@~mu
package NetFox; bM }zGFt
2IP<6l8N
=$T[
import java.io.*; 'H"!%y{:i
import java.net.*; ?m9=Me
Nr}O6IJ>Sg
xZ* B}O{{H
public class FileSplitterFetch extends Thread { b2RW=m-
>"z`))9
FE:}D;$
String sURL; //File URL s#aane
long nStartPos; //File Snippet Start Position xgtx5tg
long nEndPos; //File Snippet End Position ~S<}q6H.
int nThreadID; //Thread's ID i[wnG)
boolean bDownOver = false; //Downing is over :f7:@8
boolean bStop = false; //Stop identical /g8nT1k
FileAccessI fileAccessI = null; //File Access interface Pa=xc>m^
L>lxkq8!Q
vst;G-ys
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $7-S\sDr
{ gc b8eB,
this.sURL = sURL; fp`m>} -
this.nStartPos = nStart; n?S)H=
this.nEndPos = nEnd; R*lq.7
nThreadID = id; 9|NF)~Q}'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G @]n(\7Y
} 'R#MH
oW>e.}d!
dnM.
public void run() uH7!)LE#
{ Ef3="}AI;
while(nStartPos < nEndPos && !bStop) e@5w?QzW
{ ? :A%$T
Tm0\Oue0
M5xMTP-
try{ DYrci?8Ith
URL url = new URL(sURL); #MviO!@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |`|zo+aW
httpConnection.setRequestProperty("User-Agent","NetFox"); 9`CJhu
String sProperty = "bytes="+nStartPos+"-"; iAeq%N1(0
httpConnection.setRequestProperty("RANGE",sProperty); \5a;_N[Ed
Utility.log(sProperty); @y6^/'
aU$80
#WE lL2&
InputStream input = httpConnection.getInputStream(); i3)7Qa[
//logResponseHead(httpConnection); |Qpd<L
g6$\i m
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byte[] b = new byte[1024]; hVCxwTg^X
int nRead; LaL{ ^wP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rKTc6h:)
{ f:AfMf>m
nStartPos += fileAccessI.write(b,0,nRead); X|4Kdi.r@
//if(nThreadID == 1) B->oTC`5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J/rF4=j%xy
} <"S`ZOn
umpa!q};
n"vO?8Sx
Utility.log("Thread " + nThreadID + " is over!"); YllW2g:
bDownOver = true; !G<gp4Js+N
//nPos = fileAccessI.write (b,0,nRead); gQeoCBCE
} #UvWS
catch(Exception e){e.printStackTrace ();} cKIA.c}N
} n:}'f- :T
} *8/cd0
l=a<=i
hn$jI5*`
//打印回应的头信息 YWDd[\4
public void logResponseHead(HttpURLConnection con) &x@N5j5Q
{ sqj8I"<`
for(int i=1;;i++) rT;_"y}
{ ,0i72J
String header=con.getHeaderFieldKey(i); MB6lKLy6~
if(header!=null) nFefDdP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @-ir
Utility.log(header+" : "+con.getHeaderField(header)); ,fhwDqR ?
else yATXN>]l
break; {axRq'=
} ApcE)mjpc
} d1NKVMeWr
$SzuUI
vJQ_mz
public void splitterStop() >/.Ae8I)
{ S@ItgG?X
bStop = true; TUQe.oAi
} jzI,B
1NAtg*`
D e$K
} )$O'L7In&
3)l<'~"z<
o%h[o9i
/* &hWYw+yH\
**FileAccess.java Q:]v4/MT
*//文件访问(定位，写) }dEf |6_
package NetFox; Slp_o\s$@
import java.io.*; (cp$poo
%.:]4jhk
|jKFk.M
public class FileAccessI implements Serializable{ 2p*L~! iM
n,p \~Tu,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,!98VJmr
RandomAccessFile oSavedFile; !!])~+4pP
long nPos; Ft@ZK!'@
rWp+kV[Ec>
\obM}caT
public FileAccessI() throws IOException z~jk_|?|?
{ P_Exh]P
this("",0); 0}\8,U
} ~tB9kLFG
.Txwp?};
?1H>k<Jp
public FileAccessI(String sName,long nPos) throws IOException B\>3[_n
{ x' 3kHw
oSavedFile = new RandomAccessFile(sName,"rw"); %;O# y3,
this.nPos = nPos; okBaQH2lUl
oSavedFile.seek(nPos); B,A\/%<
} '~pZj"uy
^!K 8nW{*
E{'\(6z_
public synchronized int write(byte[] b,int nStart,int nLen) -M-y*P)
{ f/i[? gw
int n = -1; \>e>J\t:
try{ deutY.7g
oSavedFile.write(b,nStart,nLen); n:JG+1I
n = nLen; i]0$7s9!
} LhKUZX,P8
catch(IOException e) B_0]$D0 ^
{ ?xo<Fv
e.printStackTrace (); 3\5I4#S
} }ct*<zj[~u
XKbTjR
S@C"tHD
return n; <##aD3)
} qjIcRue'"
TA+/35^?
<}AmzeHr+
} OJ}aN>k
mtNB09E(
62>/0_m5
/* w6'8L s
**SiteInfoBean.java o6S`7uwJ*/
*/ kk/vgte-)e
package NetFox; cqb]LC
|d_ rK2
l4q7,%G
public class SiteInfoBean { ~#iAW@
w%f51Ex
+9_E+H'?!
private String sSiteURL; //Site's URL }-paGM@'Nd
private String sFilePath; //Saved File's Path fq0[7Yb
private String sFileName; //Saved File's Name \V9);KAOj
private int nSplitter; //Count of Splited Downloading File -257g;
3$kElq[
bt?)ryu
public SiteInfoBean() ~;nW+S$o
{//nSplitter的缺省值为5 "'6R|<u=:
//default value of nSplitter is 5 2$oGy
this("","","",5); CIf""gL9
} Xd9<`gu
W7 9.,#
Bqb3[^;~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -o sxKT:
{ .t{?doOT
sSiteURL= sURL; .n)0@X!
sFilePath = sPath; %gXNWxv
sFileName = sName; Y^uYc}
this.nSplitter = nSpiltter; 8j!(*'J.
p9iCrqi
_ 4+=S)$
} ]Oe[;<I
m{0u+obi&w
JT 5+d ,
public String getSSiteURL() , -S n
{ o`[X _
return sSiteURL; ?a-}1A{
} XBHv V05mv
Uc|MfxsL
7=]Y7"XCf
public void setSSiteURL(String value) +@K8:}lOW
{ Z!qF0UDj
sSiteURL = value; P+;@?ofB
} =v/x&,Uj@6
tD}HL_
.;~K*GC
public String getSFilePath() W[j7Vi8v
{ BcD%`vGJ
return sFilePath; e\>g@xE%
} WjMP]ND#c
f= l*+QY8f
U*em)/9
public void setSFilePath(String value) Voc&T+A m
{ 9TW
sFilePath = value; -qRO}EF
} ;:pd/\<
;={Z Bx
EAjo>GLI
public String getSFileName() WP0{%
{ SvGs?nUU
return sFileName; .:#6dG\0z
} {:9P4<%H
I UxsvW+
A'X, zw^}
public void setSFileName(String value) QabYkL5@
{ ;M Z@2CO
sFileName = value; 8RR6f98FF
} yLlAK,5P0o
3 ,?==?
rfNt
public int getNSplitter() gJ>HFid_C
{ Af"vSL
return nSplitter; cZ~\jpK
} ;i><03
DweWFipyPi
\i#0:3s.
public void setNSplitter(int nCount) 'Kj8X{BSFb
{ 5&r2a}K
nSplitter = nCount; J;wA
} N]sX r
} Ma3Hn
dj76YK
6gfdXVN5
/* +<ey Iw
**Utility.java Up$vBE8i]
*/ k]`3if5>
package NetFox; []M+(8Z_P
uv[e0,@
n[/|M
public class Utility { %j=,c{`Q
7>m#Y'ppl@
9bT,=b;
public Utility() ngJES`0d
{ oB$D&
rkl/5z??
'4A8\&lQO
} cZ7b$MZ%9
-j9R%+YW<
//线程睡眠 Q'^]lVY
public static void sleep(int nSecond) !lF|90=
{ 6X:-Z3
try{ #|8!0]n'
Thread.sleep(nSecond); Sk$XC
} T`=N^Ca1!`
catch(Exception e) )N2yhdcqI
{ .n`MPx'
e.printStackTrace (); k>Qr14F
} $sO}l
} WDiF:@^K
qD4e] 5
//日志 ^dP@QMly6
public static void log(String sMsg) R#bg{|
{ RS/%uxS?
System.err.println(sMsg); Nu{RF
} |[|X
'F+O+-p+
q#PGcCtu
public static void log(int sMsg) MT#9x>
{ nZN]Q9
System.err.println(sMsg); k>n^QHM
} "O|fX\}5
} $(}kau
DD'<zL[
(w% hz']
/* cuquA ~
**TestMethod.java a(8]y.`Tv
*/ mI in'M
package NetFox; s$:]$&5
4aB`wA^x
Y@u{73H
public class TestMethod { Li=l/
!HDk]
=fi.*d?$7
public TestMethod() ^m8\fCA*
{ ///xx/weblogic60b2_win.exe ;wprHXjq
try{ fC%;|V'Nd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qBX<{[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5 |C;]pq
SiteFileFetch fileFetch = new SiteFileFetch(bean); XW]|Mv[M
fileFetch.start(); %_SE$>v^
} ?-\KVha
catch(Exception e){e.printStackTrace ();} 8N-~.p
kC9A
`Xmpm4 ]
} G68N@g
h/(9AO}t
3[aJ=5
public static void main(String[] args) i$:CGUb
{ x_Ais&Gc
new TestMethod(); r?/>t1Z
} HNjkRl)QR
} 2 >xV&
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