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)); D JLiZS
} vkd[:CC
for(int i=0;i<nEndPos.length-1;i++) B4]AFRI
{ m#oh?@0}
nEndPos = nStartPos[i+1]; )W&o?VRfO
} xGYSi5}z
nEndPos[nEndPos.length-1] = nFileLength; EY+/.=$x
} _W)`cr
} 4$yV%[j
-1qZqU$h
qqnclqkw&
//启动子线程 hi!L\yi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m7$8k@r
for(int i=0;i<nStartPos.length;i++) A2m_q>> !
{ P^ptsZ%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wL4ZW8_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2R^O,Vu*W
nStartPos,nEndPos,i); `J72+RA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wgCvD
fileSplitterFetch.start(); w3^NL(>
} CF]i}xpWV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =%!e(N'p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ePf+[pV3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", S8 :"<B)
nEndPos = " + nFileLength); &J8Z@^
// fileSplitterFetch[nPos.length-1].start(); hf;S]8|F
V,V*30K5
6}ce1|mkg/
//等待子线程结束 41u*w2j
//int count = 0; 1hl]W+9
//是否结束while循环 <0CzB"Ap
boolean breakWhile = false; #EJhAJ
fJaubDxa
J.#(gFBBl\
while(!bStop) e# t3u_
{ ,eR8~(`=
write_nPos(); 6SE6AL<b
Utility.sleep(500); $:Rn;
breakWhile = true; /\ytr%7,'
&~RR&MdZ2
=WC-Sj{I
for(int i=0;i<nStartPos.length;i++) !RS9%ES_?
{ (=1)y'.
if(!fileSplitterFetch.bDownOver) U4Z[!s$
{ ,Du@2w3Cq
breakWhile = false; N;uUx#z
break; Ab/j(xr=
} W+_RhJ
} p8Iw!HE
if(breakWhile) 7_-w_"X
break; 3P1&;
~ |6dH
P` #QGZ>
//count++; [r(Qs|
//if(count>4) ;x-(kIiE
// siteStop(); #?dUv#
} f\fdg].!
|'tW=
d{f@K71*
System.err.println("文件下载结束！"); b/t
} P.djd$#
catch(Exception e){e.printStackTrace ();} 6R`Oh uN.>
} Y2C9(Zk U
b.s9p7:J
%JtbRs(~q
//获得文件长度 mLwoi!]m
public long getFileSize() Ow3P-UzU3
{ p,F^0OU2}:
int nFileLength = -1; <\" .L
try{ (zG.aaz*C
URL url = new URL(siteInfoBean.getSSiteURL()); SVagT'BB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H6gU?9%
httpConnection.setRequestProperty("User-Agent","NetFox"); '_dzcN,z
~]BMrgn
ZsZcQj6G,
int responseCode=httpConnection.getResponseCode(); YzAFC11,
if(responseCode>=400) Po(]rQbE
{ 9GgA6#
processErrorCode(responseCode); NBjeHtT
return -2; //-2 represent access is error @b2`R3}9R
} z%1{
9I`Y-D
C9qJP^F
String sHeader; 3NIUW!gr
|ETiLR=&
][d,l\gu+s
for(int i=1;;i++) 'xnnLCm.
{ X<]qU3k5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HRB[GP+
//Utility.log(in.readLine()); fTqC:r|st
sHeader=httpConnection.getHeaderFieldKey(i); *f5l=lDOB
if(sHeader!=null) EVt?C+
{ ?7[alV~
if(sHeader.equals("Content-Length")) '9s5OTkN ;
{ 1tB[_$s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); BByCMY
break; a{SBCy
} B&Y_2)v
} Ue*C>F
else #eK=
break; fQ 7vL~E
} w8iR|TV
} @*MC/fe
catch(IOException e){e.printStackTrace ();} C5W>W4EM
catch(Exception e){e.printStackTrace ();} b.F^vv"]]
Vw#{C>
:!fG; )=
Utility.log(nFileLength); WKmbNvN^
W0XF~
Xf d*D
return nFileLength; 9!U@"~yB
} -?6MU~"GK
GX&b;N
p'n4)I2#
//保存下载信息（文件指针位置） 4v'A\~ZU
private void write_nPos() la <npX
{ ceT&Y{T
try{ ^j)BKD-
output = new DataOutputStream(new FileOutputStream(tmpFile)); K93p"nHN
output.writeInt(nStartPos.length); EE=3
for(int i=0;i<nStartPos.length;i++) ZH,4oF
{ w$|l{VI
// output.writeLong(nPos); dQb.BOI)h
output.writeLong(fileSplitterFetch.nStartPos); N]N4^A'
output.writeLong(fileSplitterFetch.nEndPos); !k&Q 5s:
} @}s$]i$|-
output.close(); 7v7G[n
} _:`!DIz~9}
catch(IOException e){e.printStackTrace ();} CO?Xt+1hR
catch(Exception e){e.printStackTrace ();} nZy X_J,Vd
} sC"}8+[)S3
{@Y
CHJ>{b`O
//读取保存的下载信息（文件指针位置） _qXa=|}V.
private void read_nPos() xJs;v
{ ($nrqAv4
try{ ~8T(>!hE1h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !yOeW0/2[
int nCount = input.readInt(); SC &~s$P;
nStartPos = new long[nCount]; C\ZkGX
nEndPos = new long[nCount]; !? 5U|
for(int i=0;i<nStartPos.length;i++) sZ&G%o
{ "xRBE\B
nStartPos = input.readLong(); oslJC$cy'
nEndPos = input.readLong(); <?Wti_ /M
} q2rUbU_A(
input.close(); $2~\eG=u H
} vhuw&.\
catch(IOException e){e.printStackTrace ();} <plC_{Y:wu
catch(Exception e){e.printStackTrace ();} D]s]"QQ8
} M$Zo.Bl$(
,)!u)wz
TXXy\$
private void processErrorCode(int nErrorCode) p&-'|'![l
{ ;Xvp6.:
System.err.println("Error Code : " + nErrorCode); _c$9eAe
} '1^B+m
3jH\yXj
k n[Y
//停止文件下载 ;a{:%t
public void siteStop() WY:&ugGx
{ llV3ka^!
bStop = true; &sXRN&Fp
for(int i=0;i<nStartPos.length;i++) <#GB[kQa
fileSplitterFetch.splitterStop(); gb=/#G0R
6[E|
F0vM0e-
} '_k+WH&
} :!a2]-D}
//负责部分文件的抓取 YW@#91.
**FileSplitterFetch.java hwN?/5
*/ 9[c%J*r
package NetFox; 6r:?;j~l
vIl+#9L0
so$(_W3E,
import java.io.*; 1?*
import java.net.*; 0[?ny`Y
;Vik5)D2D
*=V7@o
public class FileSplitterFetch extends Thread { D?yG+%&9
|t iUej
%1 vsN-O}8
String sURL; //File URL C;QAT
long nStartPos; //File Snippet Start Position Vm}%ttTC
long nEndPos; //File Snippet End Position #rO8Kf
int nThreadID; //Thread's ID oh"O07
boolean bDownOver = false; //Downing is over 65h @}9,U
boolean bStop = false; //Stop identical {U<xdG
FileAccessI fileAccessI = null; //File Access interface l!}:|N Yh!
-<v~snq'
`@[c8j7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vx_o(wof
{ +YLejjQ
this.sURL = sURL; iy.2A!f^.
this.nStartPos = nStart; ,lA.C%4au~
this.nEndPos = nEnd; $N:Vo(*
nThreadID = id; N,2s?Y_!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V7G7&'
} {!|}=45Z
DrnJ;Hi"
;,i]w"*
public void run() i wxVl)QL
{ )[mwP.T=
while(nStartPos < nEndPos && !bStop) ay "'#[
{ \I"Z2N>^z
R8rfM?"W
\0lnxLA
try{ Ev7J+TmXM
URL url = new URL(sURL); mWR4|1(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o9xlu.QL{c
httpConnection.setRequestProperty("User-Agent","NetFox"); 2aJS{[
String sProperty = "bytes="+nStartPos+"-"; Le<wR
httpConnection.setRequestProperty("RANGE",sProperty); :1t~[-h^
Utility.log(sProperty); O=SkAsim
ZxV"(\$n
/kt2c[9
InputStream input = httpConnection.getInputStream(); lrfv+
//logResponseHead(httpConnection); X#3et'
!RyO\>:q
\#o2\!@`
byte[] b = new byte[1024]; K=!Bh*
int nRead; fwK}/0%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (b'B%rFO
{ V $z} K
nStartPos += fileAccessI.write(b,0,nRead); =@k%&* Y?
//if(nThreadID == 1) mUS_(0q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); OHiQ7#y
} w =.Fj
8-y{a.,u.
x(<(t:?o
Utility.log("Thread " + nThreadID + " is over!"); ^rvx!?zO
bDownOver = true; O6IB. >T
//nPos = fileAccessI.write (b,0,nRead); vSi_t K4
} WTImRXK4
catch(Exception e){e.printStackTrace ();} K'K2X-E
} TuW%zF/
} rx(2yf
~QvqG{bFB
"\0v,!@
//打印回应的头信息 6JKqn~0Kk
public void logResponseHead(HttpURLConnection con) PJcwH6m
{ G$ _yy:
for(int i=1;;i++) Y&/]O$<
{ DJgTA]$&
String header=con.getHeaderFieldKey(i); <SI}lQ'i
if(header!=null) U|g:`v7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4C}bJzZ
Utility.log(header+" : "+con.getHeaderField(header)); +}f9
else &\apwD
break; F(t=!k,4\
} ?c0xRO%y
} _`64gS}^
JK.ZdY%
3;%5Yu
public void splitterStop() ^bEc6`eE
{ QWMdn
bStop = true; \GHiLs,!
} =gcM%=*'
lFTF ,G
o] mD"3_
} 2h[85\4
x3PD1JUf
YZ%Hu)
/* P-ri=E}>
**FileAccess.java TDd{.8qf
*//文件访问(定位，写) 6oF7:lt
package NetFox; s}N#n(
import java.io.*; * S=\l@EW
Ur*6Gi6
e9Nk3Sj]
public class FileAccessI implements Serializable{ l x,"EOP
fu90]upz~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^h{)Gf,+\
RandomAccessFile oSavedFile; ;|UF)QGa2
long nPos; bQ~j=\[r
sg+uBCGB
ss5m/i7
public FileAccessI() throws IOException da (km+
{ @:KJYm[
this("",0); C-iK$/U
} yRo-EP
:O(^w}sle
jg?x&'u\)
public FileAccessI(String sName,long nPos) throws IOException {J^lX/D
{ d6W SL;$
oSavedFile = new RandomAccessFile(sName,"rw"); c+2FC@q{l
this.nPos = nPos; b$Vz2Fzx
oSavedFile.seek(nPos); /%Nr?V
} EY \H=@A
JGuN:c$
%'[&U#-
public synchronized int write(byte[] b,int nStart,int nLen) 1 5A*7|
{ _1U1(^)
int n = -1; 8=]Tr3
try{ Uh][@35 p
oSavedFile.write(b,nStart,nLen); n_'s=]~
n = nLen; ;pnD0bH
} ij?
catch(IOException e) IEU^#=n
{ C:Hoq(
e.printStackTrace (); Zfyo-Wk
} qG<$Ajiin
&gjF4~W]
qbv#I;
return n; < P`u}
} 4Z/f@ZD
F{UP;"8'
e@IA20
} d9q(xZ5
:H c0b=
5|1T}Z#;
/* /tUy3myJ
**SiteInfoBean.java i\dc>C ;
*/ 3\Xbmq8}
package NetFox; 0Q^Ikiv
CxfRVL`7
hXA6D)
public class SiteInfoBean { ]8T!qS(UJd
sVl-N&/
VZ\B<i
private String sSiteURL; //Site's URL A,`8#-AX
private String sFilePath; //Saved File's Path VqS#waNrx
private String sFileName; //Saved File's Name kcQ'$<Mz<
private int nSplitter; //Count of Splited Downloading File FXs*vg`
%?m$`9yU
HQB(*
public SiteInfoBean() 8H_l:Z[:i
{//nSplitter的缺省值为5 D_x+:1(
//default value of nSplitter is 5 4T=u`3pD7l
this("","","",5); 6,9o>zT%H
} ~j<+k4I~
3"P }n
E<c9#I=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HcqfB NM
{ lIProF0
sSiteURL= sURL; Jej` ;I
sFilePath = sPath; _vZ"4L+Iw+
sFileName = sName; LA`*_|}qcR
this.nSplitter = nSpiltter; ak;*W
A]DTUdL
mVR P~:+
} *guoWPA|Ij
NM06QzE
ZfB" E
public String getSSiteURL() YJo["Q
{ E>}4$q[r
return sSiteURL; t1%_DPD%W
} qs QNjt
,%)6jYHRw
T,VY.ep/
public void setSSiteURL(String value) )LyojwY_g
{ 'Tc]KXD6
sSiteURL = value; ~t~-A,1
} oIefw:FE,a
WH= EPOR,
u&n' ITH
public String getSFilePath() TsGE cxIg
{ }6@pJG
return sFilePath; $k2*[sn,
} tuhA 9}E
Q*b]_0Rb
w.0qp)}
public void setSFilePath(String value) <^lRUw
{ -k"^o!p
sFilePath = value; ;W^o@*i{>
} #cCL.p"]
u5Ftu?t
>2Kh0rIH
public String getSFileName() VL*ovD%-
{ Et/&^&=\-
return sFileName; !Uq^7Mw
} smry2*g
TEaJG9RU>v
uNHF'?X
public void setSFileName(String value) +*hm-lv?
{ :Cp'm'omb
sFileName = value; /=gOa\k|p
} 2^l[(N
G^`1]?
-]t,E,(!
public int getNSplitter() ]~E0gsq
{ %y%j*B!%
return nSplitter; Sx8OhUyux
} {1b Zg
nTz6LVF
rhb@FE)Mc
public void setNSplitter(int nCount) $9ky{T?YG
{ Y2?.}ZO
nSplitter = nCount; 9s_,crq5
} #jxe%2'Ot
} q2et|QCru
fOMvj%T@2
zBe8,, e
/* :=[XW?L%x
**Utility.java n8DxB@DI
*/ KFFSv{m[
package NetFox; |K|h+fgG6*
g'|MA~4yB
3dRr/Ilc
public class Utility { cJL'$`gWf
I;1lX L
?A )hN8
public Utility() &[;HYgp
{ MKWyP+6`
[/BE8]M~
Y>&Ew*Y
} Z"uY}P3
.fdL&z
//线程睡眠 _X'"w|0
public static void sleep(int nSecond) PfZ+PqS
{ [Ts"OPb%~
try{ hjQ~uqbg
Thread.sleep(nSecond); I*`*Q$
} h`H,a7
catch(Exception e) +fnK/%b
{ PxfY&;4n!
e.printStackTrace (); z$kenhFG/
} J:kmqk!
} Yp:KI7
($~RoQ=0S
//日志 Y)}Rb6qGW
public static void log(String sMsg) s$a09x
{ iIP8`! O
System.err.println(sMsg); g{P%s'%*
} fa<v0vb+
eEn;!RS)
bk\yCt06y;
public static void log(int sMsg) VV9_`myN7
{ -k7X:!>QHC
System.err.println(sMsg); bHI<B)=`
} V,[d66H=N
} -c}, :G"
+(+Itmx2&
7H|$4;X^
/* 5Fz.Y}
**TestMethod.java =lu/9 i6
*/ @_LN3zP
package NetFox; g=e71DXG2
<Engi!
_{ZqO;[u
public class TestMethod { %=BMZRn
EKzAd
&RTX6%'KY
public TestMethod() z1Ov|Q`
{ ///xx/weblogic60b2_win.exe ~D|5u\D-
try{ +EAT:,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Uk,gJR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <3j"&i]Tm*
SiteFileFetch fileFetch = new SiteFileFetch(bean); k{<,\J
fileFetch.start(); ;-Jb1"5
} ScSZGs 5&
catch(Exception e){e.printStackTrace ();} "$}vP<SM
"XT"|KF|D
1\r|g2Z :
} 9Fr3pRIJ
>X51$wBL
%b^OeWip
public static void main(String[] args) MW+b;0U`#
{ p^pOuy8
new TestMethod(); OGY"<YH6
} chEn|>~
} 41_SRh7N
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