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)); 'C!b($Y
} 2Pasmh
for(int i=0;i<nEndPos.length-1;i++) mvlK~c8
{ n"-cX)
nEndPos = nStartPos[i+1]; gfFP-J3cN
} x^;nQas;
nEndPos[nEndPos.length-1] = nFileLength; qbFzA i
} _hM3p
} +mYD DlvI
N@)tU;U3O
zf4@:GM`
//启动子线程 `4gm'C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }`\+_@w
for(int i=0;i<nStartPos.length;i++) ;HgV(d#X
{ owJPEx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }I9\=jT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O5LB&s
nStartPos,nEndPos,i); ie=tM'fb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (KK9/k
fileSplitterFetch.start(); 7P.C~,+D%P
} YSs9BF:a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $:t;WXc.<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r,EIOcz:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X-e)w
nEndPos = " + nFileLength); Z~9\7QJn
// fileSplitterFetch[nPos.length-1].start(); |*e >hk
OtrO"K
yv[s)c}
//等待子线程结束 ^kzw/.I{
//int count = 0; Cn[`]
//是否结束while循环 WpWnwQY`#
boolean breakWhile = false; w f,7
U;LbP-{B
m("! M~1
while(!bStop) 9=&LMjTQ
{ ZBB^?FF
write_nPos(); ~NMal]Fwx
Utility.sleep(500); C3:4V2<_
breakWhile = true; wMT?p/9Blm
OGzth$7A
A|O7W|"W
for(int i=0;i<nStartPos.length;i++) x{6/di
{ L/_OgL]YdI
if(!fileSplitterFetch.bDownOver) Ir_K83VM
{ (B}+uI{
breakWhile = false; r~si:?6:
break; Q+U}
} %mAgE\y25
} l+*^P'0u
if(breakWhile) u0Fu_Rtr
break; pBG(%3PpW
eZ(<hE>
4Sfv
//count++; e@Q<hb0<eU
//if(count>4) YrS%Yvhj0
// siteStop(); 0-oR { {
} >c|u|^3zt
%J!+f-:=
,)@Q,EHN;
System.err.println("文件下载结束！"); 3tMs613
} hCQzD2
catch(Exception e){e.printStackTrace ();} D ?1$I0=
} xVao3+r
#Wey)DI
b?hdWQSW7
//获得文件长度 7q<I7Wt
public long getFileSize() QU2\gAM
{ !NUsfd
int nFileLength = -1; Rf+ogLa=
try{ %`t;5kmR
URL url = new URL(siteInfoBean.getSSiteURL()); }H&NR?Ax
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]!E|5=q
httpConnection.setRequestProperty("User-Agent","NetFox"); ^z-e"
hw:zak#j,
CLg;
int responseCode=httpConnection.getResponseCode(); >?ZH[A
if(responseCode>=400) }xJ9EE*G/
{ bJj<xjBM
processErrorCode(responseCode); .3l'&".'
return -2; //-2 represent access is error )2C_6eR
} O['gp~P"
.cdm@_Ls
OW<i"?0
String sHeader; k6_RJ8I
{w$1_GU
7hqa|
for(int i=1;;i++) %3M(!X:[
{ #/Y t4n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); AF g*
//Utility.log(in.readLine()); w4H3($ K
sHeader=httpConnection.getHeaderFieldKey(i); _Pjo9z 9
if(sHeader!=null) (1T2?mO
{ , |CT|2D>
if(sHeader.equals("Content-Length")) rR@ t5
{ ,F`:4=H%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D642}VD
break; h@7Shp
} W'hE,
} zM%ILv4
else Wky=]C%
break; =W"BfG
} v|C)Q %v
} m=b~Wf39
catch(IOException e){e.printStackTrace ();} lG;RfDI-
catch(Exception e){e.printStackTrace ();} *G7$wW:?
D *RF._
V'sp6:3*\
Utility.log(nFileLength); ??5qR8n.
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8aQ\Yx
return nFileLength; B<i)je!
} F2WUG
)T/"QF}<T
{y0#(8-&
//保存下载信息（文件指针位置） p:U9#(v)
private void write_nPos() !Sx}~XB<
{ B.vg2N
try{ :j)H;@[I
output = new DataOutputStream(new FileOutputStream(tmpFile)); S^? @vj
output.writeInt(nStartPos.length); ?}\aG3_4
for(int i=0;i<nStartPos.length;i++) |q"WJQ
{ c+c3C8s*8
// output.writeLong(nPos); <GC<uB |p
output.writeLong(fileSplitterFetch.nStartPos); OiH tobM
output.writeLong(fileSplitterFetch.nEndPos); 1H`T=:P?
} 6*u#^">,<
output.close(); t33/QW r
} *9M 5'
catch(IOException e){e.printStackTrace ();} 'L4@|c~x
catch(Exception e){e.printStackTrace ();} 9`yG[OA
} i,=greA]"
t$^1A1Ef
Z[<rz6%cB
//读取保存的下载信息（文件指针位置） ,rVm81-2
private void read_nPos() gq~>S1
{ r\Nf309~
try{ !7"-9n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o_ka'|
int nCount = input.readInt(); 0Aw.aQ~E8i
nStartPos = new long[nCount]; zc>/1>?M
nEndPos = new long[nCount]; VRurn>y0
for(int i=0;i<nStartPos.length;i++) 4vKp341B
{ 6*9hAnH
nStartPos = input.readLong(); Tu2BQ4\[
nEndPos = input.readLong(); 2mN>7Tj:
} WW82=2rJ9
input.close(); 7t=e"|^
} m,NUNd#)\
catch(IOException e){e.printStackTrace ();} ~9c?g(0
catch(Exception e){e.printStackTrace ();} *@[DG)N
} "W$,dWF
fx(^}e
L"6qS3[=
private void processErrorCode(int nErrorCode) NPy{ =#k4
{ y33+^
System.err.println("Error Code : " + nErrorCode); RO?5WJpPj
} ZnSDq_Uk
3qU#Rg ;7
q'~?azg:
//停止文件下载 H~UxVQLPp
public void siteStop() Njsz=
{ Tn2nd
bStop = true; ?JO x9;`
for(int i=0;i<nStartPos.length;i++) :%cL(',Q
fileSplitterFetch.splitterStop(); ~`)`Ip
( P|Ph
9,wd,,ta
} n*~=O'
} 8wz%e(
//负责部分文件的抓取 t:NTk(
**FileSplitterFetch.java vn<z\wVbf
*/ g]?&qF}
package NetFox; {E`[`Kf
m?bd6'&FR
YSERQo
import java.io.*; xp-.,^q\w
import java.net.*; p.^glz>B
mpfc2>6Il.
-3`S;Dmn
public class FileSplitterFetch extends Thread { Q-o}Xnj*!L
_ #]uk&5a
^*(*tS|M
String sURL; //File URL V)#se"GV
long nStartPos; //File Snippet Start Position lj0"2@z3"E
long nEndPos; //File Snippet End Position VL=.JwK
int nThreadID; //Thread's ID 2>BWu
boolean bDownOver = false; //Downing is over G;:n*_QXE
boolean bStop = false; //Stop identical ^]:w5\DG
FileAccessI fileAccessI = null; //File Access interface epM;u
/.{4 KW5
oe,I vnt
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N"Y)
{ =>nrU8x
this.sURL = sURL; jf25Ky~
this.nStartPos = nStart; ]G.ttfC
this.nEndPos = nEnd; :ad
nThreadID = id; 1vKc>+9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *ub]M3O
} 88(h`RGMh
h?E[28QB
Gq%q x4
public void run() 3\_ae2GW
{ T(t@[U2^
while(nStartPos < nEndPos && !bStop) kSx^Uu*
{ L1=+x^WQ
T\7z87Q
w@w(AFV9/
try{ i}teY{pyc
URL url = new URL(sURL); s;V~dxAiv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `kb]tf
httpConnection.setRequestProperty("User-Agent","NetFox"); d,kh6'g2@
String sProperty = "bytes="+nStartPos+"-"; b|mWEB.p
httpConnection.setRequestProperty("RANGE",sProperty); A;~lG3j4
Utility.log(sProperty); lnuf_;0
GPBp.$q+B
QHOA__?
InputStream input = httpConnection.getInputStream(); 9qc<m'MZ
//logResponseHead(httpConnection); G"w ?{W@
0kxo
"FA&Qm0
byte[] b = new byte[1024]; R gY-fc0
int nRead; r}kQ<SRx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &)`xlIw}
{ i#Tm] ++
nStartPos += fileAccessI.write(b,0,nRead); Qvc "?yx8}
//if(nThreadID == 1) K;,zE6WD$$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wh4ik`S 1
} ;UuCSfs{
7<{g+Q~7*
p!qV!:
Utility.log("Thread " + nThreadID + " is over!"); Ip#BR!$n
bDownOver = true; xs+pCK|
//nPos = fileAccessI.write (b,0,nRead); 0/{$5gy&
} .B2?%2S
catch(Exception e){e.printStackTrace ();} Q72}V9I9
} WJH-~,u
} +M4X r*
thG;~W
&+V6mH9m@
//打印回应的头信息 Z*&y8;vUQ
public void logResponseHead(HttpURLConnection con) n8W+q~sW%
{ N-XOPwx'
for(int i=1;;i++) /5cFa
{ 6mcxp+lm|
String header=con.getHeaderFieldKey(i); _}MO.&Y
if(header!=null) =eG?O7z&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DmDsn
Utility.log(header+" : "+con.getHeaderField(header)); hM}rf6B
else QTZfe<m0
break; pxm{?eBz
} %`*`HU#X
} 1Rrp#E}
P<<?7_ ??
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public void splitterStop() &!/E&e$_
{ "rhU2jT=c
bStop = true; OZ{YQ}t{^1
} }dnO7K
I+nKaN+8i
G@s]HJ:
} j7LuN
+; /]'
\:>GF-Z(
/* `qP <S
**FileAccess.java Bw5zh1ALC;
*//文件访问(定位，写) h)S223[
package NetFox; XLwmXi
import java.io.*; IE/F =Wr
z1wJ-l
E?$|`<o{|`
public class FileAccessI implements Serializable{ uu08q<B5b)
TL^af-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nR%ASUx:Y
RandomAccessFile oSavedFile; 06hzCWm#
long nPos; zj~(CNE
CM$q{;y
3&H#LGoV$
public FileAccessI() throws IOException LjZvWts?
{ D@jG+k-Lm
this("",0); 2hZ>bg
} KDx~^OO
j_=A)B?
B 4s^X`?z
public FileAccessI(String sName,long nPos) throws IOException #jY\l&E
{ :exgdm;N
oSavedFile = new RandomAccessFile(sName,"rw"); c?@WNv
this.nPos = nPos; +rT%C&ze
oSavedFile.seek(nPos); &yu3nA:7D
} 4k}3^.#
)-2sk@y
9\2<#,R1q
public synchronized int write(byte[] b,int nStart,int nLen) <5Ft3sd
{ U[l7n3Y=
int n = -1; +y%"[6c|
try{ lrn3yDkR?
oSavedFile.write(b,nStart,nLen); CcF$?07 i
n = nLen; uJBs3X
} !m7`E
catch(IOException e) ].E89_|O
{ jZRf{
e.printStackTrace (); *t_"]v-w
} "EA6RFRD
N?Wx-pK
X<pg^Y0
return n; >[,ywRJ#_}
} h6Femis
/(/Z~J[
d!BQ%a
} C!]R0L*
KyQO>g{R
JnC$}amr
/* /O,>s
**SiteInfoBean.java nC-=CMWWr
*/ k,)xv?
package NetFox; zWN/>~}U\
tyEa5sy4
(s:ihpI
public class SiteInfoBean { cr}T ? $\K
v|\<N!g
(lNV\Za
private String sSiteURL; //Site's URL 'VgdQp$L$
private String sFilePath; //Saved File's Path M @|n"(P
private String sFileName; //Saved File's Name IJWUNKqo=
private int nSplitter; //Count of Splited Downloading File H2f!c{t$p
=[N=mC
x,CTB
public SiteInfoBean() 79DzrLu
{//nSplitter的缺省值为5 S5Hb9m&&
//default value of nSplitter is 5 }rWEa^
this("","","",5); =H<I` J'
} |E%i t?3M
~0;l\^
Yf=an`"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4trP*u,4
{ Ry$zF~[
sSiteURL= sURL; we4k VAn
sFilePath = sPath; !ucHLo3:
sFileName = sName; `"7}'|
this.nSplitter = nSpiltter; 7P+qPcRaP
JEw+5MO@
4tQ~Z6Jn;
} -<g&U*/E
_T96.~Q
3MmpB9l#H
public String getSSiteURL() u-8b,$@Z>'
{ Su4&qY
return sSiteURL; `Z#0kpXk_
} t2L}
?S*Cvr+=4
#[ H4`hZ
public void setSSiteURL(String value) &oz^dlw
{ p)u?x)w=
sSiteURL = value; Po)!vL"
} j&(Yk"j+
_/Sqw
xj ?#]GR
public String getSFilePath() p#\JKx
{ |)Q#U$ m
return sFilePath; 6#J>b[Q
} yt5Sy
s6DmZ^Y%
Rudj"OGO
public void setSFilePath(String value) xJ$/#UdP
{ ; ,vGw<|o
sFilePath = value; ;u(#-C2^{l
} *]7$/%.D
-ho%9LW%|
8[k:FGp>
public String getSFileName() OV"uIY[%8V
{ $fzO:br5WJ
return sFileName; rexNsKRK_
} zu,F 0;De
<M y+!3\A
3)6TnY/u6{
public void setSFileName(String value) u~C,x3yr
{ xg;o<y KF
sFileName = value; D2y[?RG
} #VvU8"u
H@'f=Y*D
&Hi;>
public int getNSplitter() %W(/W9B$/F
{ -MK9IO]i
return nSplitter; FxFRrRRH@
} up@I,9C/
8PB 8h
L0Ycf|[s,
public void setNSplitter(int nCount) +W%3VV$
{ %tE#%;Z
nSplitter = nCount; >p`ZcFNs"
} vG{lxPIj
} d:L|BkQ7*
6CV9ewr
m]?C @ina
/* .eHOG]H
**Utility.java V0/PjD,jP
*/ Q,m&XpZ
package NetFox; J#*%r)
rRQKW_9mB
O a%ZlEUF
public class Utility { 8Y,imj\(v
xU!eT'Y
0! W$Cz[
public Utility() /Xm4%~b_gj
{ MS~+P'
JW}O`H9
+V`*
} l+UUv]:1
T&q0TBT
//线程睡眠 \3WQ<t)W
public static void sleep(int nSecond) Wb%t6N?
{ V{{Xz:
try{ Bnfp_SM
Thread.sleep(nSecond); g}OZ!mKd
} 1!=^mu8
catch(Exception e) 6bwzNY 7
{ ZnAXb S
e.printStackTrace (); wj{[g^y%
} UOa n
} :pCv!g2
P#l"`C /
//日志 MJM<
public static void log(String sMsg) *~\R0ddz
{ [e`e bn[C
System.err.println(sMsg); )>]@@Trx
} J=t@2
SMn(c
eUVhNg
public static void log(int sMsg) 63fgl+
{ ms{iQ:'9
System.err.println(sMsg); _]t^F9l
} wZ%a:Z4TcM
} #oD;?Mi
$4:Se#nl
He)!Ez\X
/* Db K(Rh_ K
**TestMethod.java Yv/T6z@
*/ ".7\>8A#a
package NetFox; EdTR]}8
mlO\wn-F
?`/DFI'_G
public class TestMethod { WyU\,"
%PlA9@:IZ
uZml.#@4
public TestMethod() phi9/tO\u
{ ///xx/weblogic60b2_win.exe z'9U.v'M)
try{ +`f3_Xd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <lgX=wx L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vLs*}+f
SiteFileFetch fileFetch = new SiteFileFetch(bean); c->.eL%
fileFetch.start(); (b8ZADI*
} :pdl2#5H^
catch(Exception e){e.printStackTrace ();} 85_Qb2<'r
(3?W)i
n.7-$1
} &&ZX<wOM
dCA! R"HD
)Ah7
public static void main(String[] args) 5ENEx
{ ~X<?&;6
new TestMethod(); FWW*f _L
} d]K$0HY
} uH |:gF^
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