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)); 5k`e^ARf
} )O-sWh4
for(int i=0;i<nEndPos.length-1;i++) (E]"Srwh
{ rH^/8|}&s
nEndPos = nStartPos[i+1]; }moz9a
} AuM:2N2
nEndPos[nEndPos.length-1] = nFileLength; lvig>0:M
} QW:Z[?39^
} Pb=rFas*C
][N) 2_^M
Q~CpP9%
//启动子线程 ?ZM^%]/+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !Ba3`B5l
for(int i=0;i<nStartPos.length;i++) ;op'V6iG
{ JbVi1?c
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Uc>LFX& -B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YmA) @1@U
nStartPos,nEndPos,i); a#6,#Q"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t;~-_{
fileSplitterFetch.start(); \Qb>:
} _/8y1)I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vzQyE0T/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Hm<M@M$aG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EsNk<Ra
nEndPos = " + nFileLength); rGAFp,}-f
// fileSplitterFetch[nPos.length-1].start(); N+[}Gb"8q
>cSi/a,L
+&zb^C`J
//等待子线程结束 c[6zX#{`
//int count = 0; Y~}QJ+`?
//是否结束while循环 .M`LUb"!
boolean breakWhile = false; S@;&U1@h
GZ}*r{
^$ZI>L0+
while(!bStop) "&s9cO.H
{ -!JlM@
write_nPos(); [_h.1oZp~
Utility.sleep(500); FK?mS>G6
breakWhile = true; /:Rn"0
v^57j:sD
V&$ J;
for(int i=0;i<nStartPos.length;i++) t PAt?
{ CD$u=E ]
if(!fileSplitterFetch.bDownOver) /7S-|%1
{ Rs^jk)Z:)
breakWhile = false; "o~N42DLB%
break; D'Jm!Ap
} dW:w<{a!R
} T;xHIg4
if(breakWhile) U=_~{[/
break; =t~+63)
Kn3YI9
$&c<T4$d
//count++; $a)JCErN
//if(count>4) -DbH6u3
// siteStop(); k,yc>3P;U
} 3m?@7F
pXGK:ceFu
_wIBm2UO
System.err.println("文件下载结束！"); Y8{T.\%\+
} h0&>GY;i
catch(Exception e){e.printStackTrace ();} f/$-Nl.
} 00$ @0
`ja`#%^\u
$4#=#aKW.
//获得文件长度 mdmZ1:PBM
public long getFileSize() a 5~G
{ OtrXYiKB
int nFileLength = -1; 8ItCfbqa6
try{ S&;T_^|
URL url = new URL(siteInfoBean.getSSiteURL()); 8YT_DM5iI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^59YfC<f
httpConnection.setRequestProperty("User-Agent","NetFox"); `[g#Mxw
&Sa_%:*D(
tk]_QX %
int responseCode=httpConnection.getResponseCode(); qcpG}o+&D
if(responseCode>=400) uM}dZp 1
{ i`ZHjW~`
processErrorCode(responseCode); '? !7 Be
return -2; //-2 represent access is error !=k*hl0h
} 6qmo ZAg
rTm>8et
`CTkx?e[
String sHeader; ouu-wQ|(mM
0&SrKn
x3p;H02i\
for(int i=1;;i++) OLd$oxKR
{ _dJVnC1 !
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0|wKR|zW
//Utility.log(in.readLine()); af`f*{Co3
sHeader=httpConnection.getHeaderFieldKey(i); s$+: F$Y0
if(sHeader!=null) Sx4UaV~"
{ qQ?,|4)y
if(sHeader.equals("Content-Length")) tSh}0N)
{ E-7a`S
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B[U.CAUn
break; $.x?in|_
} \CEnOq
} L2V $%*6
else X=!n,=xI
break; c+G:@%
} V+"*A
} D/%b@Ls2ze
catch(IOException e){e.printStackTrace ();} "YdDaj</
catch(Exception e){e.printStackTrace ();} ^w.(*;/
xhVq
VQW)qOR9
Utility.log(nFileLength); XQg%*Rw+t
cO"Xg<#y
]@j"0F/`
return nFileLength; ;^H+ |&$>
} a?Qcf;o
O]4 x;`)
+h\W~muR
//保存下载信息（文件指针位置） kAe-d
private void write_nPos() f'?6D+Yw~
{ 9 %.<V_$
try{ (HX[bG`
output = new DataOutputStream(new FileOutputStream(tmpFile)); q.hc%s2?
output.writeInt(nStartPos.length); I5<#SW\a?
for(int i=0;i<nStartPos.length;i++) 6w`}+3
{ (Q p]0
// output.writeLong(nPos); FoelOq6
output.writeLong(fileSplitterFetch.nStartPos); \]e w@C
output.writeLong(fileSplitterFetch.nEndPos); !kk %;XSZ
} gm%bxr@X~
output.close(); />j+7ts
} BNKo6:wy
catch(IOException e){e.printStackTrace ();} N=?kEX O
catch(Exception e){e.printStackTrace ();} i!+3uHWu`)
} "ih>T^|
Ok{:QA~#
_F$t#.o
//读取保存的下载信息（文件指针位置） 3x;y}:wQa
private void read_nPos() C9;X6
{ ?}>Z_ ("
try{ lO[jf6gB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OB I8~k
int nCount = input.readInt(); QIz N#;g
nStartPos = new long[nCount]; g(}8n bTA
nEndPos = new long[nCount]; =A&*SE o5
for(int i=0;i<nStartPos.length;i++) 5]n<%bP\
{ .)pRB7O3
nStartPos = input.readLong(); hm} :Me$[)
nEndPos = input.readLong(); v>cE59('0
} z o))x(
input.close(); QRG)~
} M$hw(fC|m1
catch(IOException e){e.printStackTrace ();} ..]X<
catch(Exception e){e.printStackTrace ();} ~9'4w-Sy
} */dsMa
2P>za\
M,!no
private void processErrorCode(int nErrorCode) u|*|RuY
{ 0-; P&m!!
System.err.println("Error Code : " + nErrorCode); H?bsK~
} o0+BQ&A)s*
la{:RlW
VKJ~ZIO@A
//停止文件下载 +jZg%$Q!#
public void siteStop() U.sPFt
{ FveK|-
bStop = true; ~5dq5_
for(int i=0;i<nStartPos.length;i++) zc~xWy+
fileSplitterFetch.splitterStop(); |DS@90}
(GOrfr
)0V]G{QN
} Saq>o.
} v?"ee&Y6
//负责部分文件的抓取 7,VWvmWJex
**FileSplitterFetch.java bh6wI%8H
*/ +dpj?
package NetFox; ^dKaa
Gqb-3ngH
q@Yt`$VTN
import java.io.*; .wOLi Ms
import java.net.*; JkDZl?x5
w*kFtNBfU
h_"/@6
public class FileSplitterFetch extends Thread { Z8n%=(He
W$&Ets8zo
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String sURL; //File URL L*oLKigT
long nStartPos; //File Snippet Start Position 8VGXw;(Y,d
long nEndPos; //File Snippet End Position (mr`?LI}
int nThreadID; //Thread's ID _q}%!#4
boolean bDownOver = false; //Downing is over T.N7`
boolean bStop = false; //Stop identical 1gK3=Ys
FileAccessI fileAccessI = null; //File Access interface Dk6\p~q
/1 %0A
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #;\;F PuZ
{ `%I{l
this.sURL = sURL; vszAr( t
this.nStartPos = nStart; *K)53QKlE
this.nEndPos = nEnd; )@|Fh@|
nThreadID = id; =C2C~Xd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r>@/XYK&\
} O*CX@Ne
uKzz/Y{
U>jk`?zW
public void run() 3;gtuqwD$
{ qf$|z`c
while(nStartPos < nEndPos && !bStop) hRcJ):Wyb
{ zQfxw?~A
yC$7XSr=
BV:,bS
try{ j!n> d
URL url = new URL(sURL); 1OeDWEcB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )O(Gw-jWE
httpConnection.setRequestProperty("User-Agent","NetFox"); %K,,Sl_
String sProperty = "bytes="+nStartPos+"-"; n=MYv(Pp}
httpConnection.setRequestProperty("RANGE",sProperty); Zul32]1r
Utility.log(sProperty); l@jJJ)Qyk
.HJHJ.Js8X
:m)?+
InputStream input = httpConnection.getInputStream(); /Loe y
//logResponseHead(httpConnection); FJiP>S[]
N Uml"
?bA]U:
byte[] b = new byte[1024]; 9}_f\Bs
int nRead; 55KL^+-~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) haK5Oe/cE
{ IsL/p3|
nStartPos += fileAccessI.write(b,0,nRead); WF0>R^SpZ
//if(nThreadID == 1) P6'I:/V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $QnfpM%+=
} py4_hj\v
tTamFL6
<a3XV
Utility.log("Thread " + nThreadID + " is over!"); ~`fB\7M
bDownOver = true; h:90K
//nPos = fileAccessI.write (b,0,nRead); .r"?w
} :M`BVZ1t
catch(Exception e){e.printStackTrace ();} "VCr^'
} :UciFIa
} ["/x~\c'N
j(2T,WM
bm?TMhC
//打印回应的头信息 1nmWL0
public void logResponseHead(HttpURLConnection con) PdnK@a
{ +y(h/NcQ
for(int i=1;;i++) v[GHqZ
{ C"WZsF^3
String header=con.getHeaderFieldKey(i); wUndNE
if(header!=null) SQx):L)P6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~`.%n7
Utility.log(header+" : "+con.getHeaderField(header)); q;JQs:U!
else y9<Fv|Ric
break; rJwJ5U
} A/aQpEb%
} WKML#U]5T
-]%@,L^@
w:v:znQrW
public void splitterStop() H_]kR&F8
{ | w -W=v
bStop = true; ;zODp+4@Q
} sJ=B:3jS0
{D< ?.'
#n r1- sf|
} M$9h)3(B
`SrVMb(
PN=yf@<V3F
/* 9b6h!(
**FileAccess.java "Q4{6FH+mB
*//文件访问(定位，写) ;<H2N0qJ(
package NetFox; !}?]&[N=
import java.io.*; zZ-*/THB@R
n9DFa3
0jH2.d=
public class FileAccessI implements Serializable{ l:HuG!
e+U o-CO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *fZ'#C~x
RandomAccessFile oSavedFile; g=8e.Y*Fr
long nPos; rD gl@B3
l"CONzm!
Pipif.
public FileAccessI() throws IOException <LY+" Y
{ g;T`~
this("",0); H#K|SSqY?
} wC~Uy%
_45"Z}Zx
,@xZuq+K<
public FileAccessI(String sName,long nPos) throws IOException ;C'*Ui
{ mDUS9>
oSavedFile = new RandomAccessFile(sName,"rw"); PoZBiw@
this.nPos = nPos; fsoS!6h0k
oSavedFile.seek(nPos); F44")fY
} \&fK8H1
R}FN6cH
PR0]:t)E
public synchronized int write(byte[] b,int nStart,int nLen) %VCHM GP=
{ wvD|c%
int n = -1; qI9 BAs1~}
try{ NG ~sE&,7
oSavedFile.write(b,nStart,nLen); rcCMx"L=
n = nLen; :M16ijkx
} %BJ V$tO
catch(IOException e) IV76#jL
{ =zdRoXBY[b
e.printStackTrace (); A7se#"w
} Rd/!CJ@g
nM#\4Q[}Jh
QMP:}
return n; W;7cF8fu4
} :v`o="
gueCP+a_
#\qES7We6
} MeC@+@C
u56cT/J1
3f0RMk$pH
/* H|]Q;,C
**SiteInfoBean.java %y'#@%kO:S
*/ =x>KA*O1
package NetFox; iM-@?!WF
/OEj]DNY
hz!.|U@,{<
public class SiteInfoBean { q-'zZ#
8l6R.l
Y&nY]VV
private String sSiteURL; //Site's URL Ktoxl+I?
private String sFilePath; //Saved File's Path L fhd02
private String sFileName; //Saved File's Name YRFM1?*
private int nSplitter; //Count of Splited Downloading File _ ._'\
K\#+;\V
~_Aclm?
public SiteInfoBean() hq|/XBd||
{//nSplitter的缺省值为5 ^VD14V3
//default value of nSplitter is 5 ] '..G-
this("","","",5); umY4tNe]$
} k2~j:&p
0=NB[eG
c(fwl`y!x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %j yLRT]H
{ 0oD?4gn
sSiteURL= sURL; +]G;_/[2
sFilePath = sPath; B|tP3<
sFileName = sName; (c;$^xZK
this.nSplitter = nSpiltter; ;tO(,^
!^w+<p
` 6PdMvF
} w;XXjT
qSON3Iid
2!A/]:[F
public String getSSiteURL() d:3G4g
{ uXXwMc<p
return sSiteURL; @l 1 piz8
} 1r$q $\
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Y`%:hvy~
public void setSSiteURL(String value) %%*t{0!H+
{ =KkHck33
sSiteURL = value; JVRK\A|R
} ws@;2?%A
"!2Fy-Y
US-P>yF
public String getSFilePath() HA| YLj?|g
{ y 2bZo'Z
return sFilePath; mDtD7FzJ
} t<rhrW75P
N/(&&\3
VK8 5A
public void setSFilePath(String value) 5E$)Ip
{ %A04'dj`zQ
sFilePath = value; .-{B
} H13|bM<
QHOem=B
C;_10Rb2ut
public String getSFileName() ? r^+-
{ 7^=O^!sa
return sFileName; 0EOpK%{
} t68h$u
OPar"z^EV
~)ls.NXI
public void setSFileName(String value) rk `x81
{ +h"RXwlBM
sFileName = value; q*8^938
} $5l8V
VUk2pEGO.
in$Pk$ c
public int getNSplitter() X2~>Z^, U
{ kP3'BBd,
return nSplitter; {2A/@$?
} z>~Hc8*]3
Ji gc@@B.
IWX%6*Zz
public void setNSplitter(int nCount) !ce5pA
{ a8''t_Dp
nSplitter = nCount; npZ=x-ce
} qlO(z5Ak
} 5P [b/.n
O.Z<dy+
,*Jm\u
/* GHfsq|*j,Z
**Utility.java s+l)Q
*/ $3k5hDA0e
package NetFox; 5^+>*z
;CD@RP{$n
&Nl:
public class Utility { /aP4'U8ov
x xWnB
wS9EC}s:Q
public Utility() ND77(I$3s
{ +Ccj@#M;
pbt/i+!
L'M'I0"/
} w|7<y8#qC
NLf6}
//线程睡眠 LNPwb1)
public static void sleep(int nSecond) Q0s!]Dk
{ Q)#+S(TG
try{ lku}I4
Thread.sleep(nSecond); QE1DTU
} w-LMV>+6|
catch(Exception e) l.Iov?e1S
{ l@Uo4b^4x
e.printStackTrace (); x8+W9i0[1
} v@(Y:\>
} |]y]K%
v!JQ;OX
//日志 gP:mZ7
public static void log(String sMsg) `KgIr,Q)
{ HG{r\jh
System.err.println(sMsg); \4zb9CxOZ
} !lpKZG
!36jtKdM
n$&xVaF|
public static void log(int sMsg) gTa6%GM>
{ Y%m^V?k
System.err.println(sMsg); lu2"?y[2
} uczOSd
} '[g@A>xDvW
z]:{ruvH
9x$Kb7'F
/* uY{V^c#mv
**TestMethod.java J=Q?_$xb}
*/ u2}zRC=
package NetFox; =wE1j
Pv,Q*gh`
G;Jqby8d
public class TestMethod { ^UOVXRn
~?`V$G=?,
:!Ea.v
public TestMethod() WCJ$S\#
{ ///xx/weblogic60b2_win.exe QU{|S.\
try{ w eu3c`-a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T$)N2]FE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FyY<Vx'yQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); >..C^8 "
fileFetch.start(); m$6u K0
} :.u[^_
catch(Exception e){e.printStackTrace ();} rRgP/E#_
ksb.]P d.
Twl>Pn>
} bruM#T@}
&ZmWR
x"7`,W
public static void main(String[] args) a8$gXX-2
{ R{N9'2l:
new TestMethod(); b9FfDDOq"
} /1OzX'5f
} 8y:c3jzP_
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