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)); J- %YmUc)
} GJ>vL
for(int i=0;i<nEndPos.length-1;i++) .x$!Rc}
{ X%+FM]
nEndPos = nStartPos[i+1]; $,vZX u|Qw
} -0KQR{LI
nEndPos[nEndPos.length-1] = nFileLength; $Cr? }'a
} )~hsd+ 0t
} #}^kMD >
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{.W$<y (j7
//启动子线程 G\ twx ;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; V24i8Qx
for(int i=0;i<nStartPos.length;i++) |"[[.Adw9"
{ |51z&dG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )^&,[Q=i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M2[ywab
nStartPos,nEndPos,i); ~I0I#_$'P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B_u+$Odo
fileSplitterFetch.start(); &Wj %`T{
} b"Hg4i)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NN<kO#c+2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t7VXW{3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", N=) E$h
nEndPos = " + nFileLength); LK8K=AA3P
// fileSplitterFetch[nPos.length-1].start(); 3r=IO#
WMB~? EDhv
JwzA'[tM
//等待子线程结束 w%,Iy,G@
//int count = 0; tS2P|fl
//是否结束while循环 ]xf lfZ
boolean breakWhile = false; 7y",%WYSD
Qtmsk:qm
MSPzOJQPy
while(!bStop) K5x&:z
{ >w:px$g4
write_nPos(); ziuhS4k
Utility.sleep(500); H'uRgBjWJ
breakWhile = true; 0T!_;IQ
u7!X#<
axOdGv5
for(int i=0;i<nStartPos.length;i++) e_6@oh2s-
{ V Iof4?i
if(!fileSplitterFetch.bDownOver) C\7qAR\
{ cdL$T6y
breakWhile = false; EP#3+BsH
break; mw<LNnT{8
} 5S'89 r3m
} XUUl*5^
if(breakWhile) 89F^I"Im(
break; dMsX}=EI<
'?+q3lps
Aa*UV6(v
//count++; M*)}F
//if(count>4) B7qm;(?X&
// siteStop(); wi]|"\
} |H&2[B"l
g/+P]c6/
o.5w>l!9K
System.err.println("文件下载结束！"); q#Y%Y
} 62&E]>A(i
catch(Exception e){e.printStackTrace ();} 4/S% eZB
} gIS<"smOo
}q-_|(b;
WpX)[au
//获得文件长度 tP2hU[7Z
public long getFileSize() >Pv#)qtm
{ ]|[,N>
int nFileLength = -1; rlYAy5&
try{ Q4Mp[
URL url = new URL(siteInfoBean.getSSiteURL()); C=}YKsi|R|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l]whL1N3
httpConnection.setRequestProperty("User-Agent","NetFox"); kUAjQ>
]zHUF!a*
vMJv.O>HW
int responseCode=httpConnection.getResponseCode(); ^JF6L`Tp
if(responseCode>=400) p=6Q0r|'
{ bit&H
processErrorCode(responseCode); //VgPl
return -2; //-2 represent access is error +*[lp@zU{
} lmb5Z-xB
qp>O#tj[
|yiM7U,i
String sHeader; t&(}`W
j+Nun
d^X;XVAvP
for(int i=1;;i++) <5MnF
{ 2.O;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~4o2!!^tI
//Utility.log(in.readLine()); <Yfk7Un
sHeader=httpConnection.getHeaderFieldKey(i); XA}!
if(sHeader!=null) ']1j Mn
{ {20^abUAS
if(sHeader.equals("Content-Length")) gQf'|%)AJ
{ q#Az\B:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KumbG>O
break; uWR\#D'
} zzi%r=%r&
} bLoAtI
else Ia:n<sZU
break; $x]'6
} [;II2[5 ,
} ]V J$;v'{[
catch(IOException e){e.printStackTrace ();} <R>qOX8
catch(Exception e){e.printStackTrace ();} 9RwD_`D(MN
%..{c#V
H27_T]\
Utility.log(nFileLength); TI:-Y@8
A:F*Y%ZW
\?&P|7N
return nFileLength; 6sBS;+C
} LhC%`w
m\|I.BUG
MGeHccqh2
//保存下载信息（文件指针位置） a6"Pe07t
private void write_nPos() |Vc8W0~0
{ L%9DaK
try{ kL,bM.;
output = new DataOutputStream(new FileOutputStream(tmpFile)); |XOD~Plo^
output.writeInt(nStartPos.length); cP63q|[[
for(int i=0;i<nStartPos.length;i++) NK]X="`
{ aH'Sz'|E
// output.writeLong(nPos); E[HXbj"
output.writeLong(fileSplitterFetch.nStartPos); :9q=o|T6D
output.writeLong(fileSplitterFetch.nEndPos); #4_'%~-e
} zbZ0BD7e
output.close(); =@;uDu:Q
} ]N}80*Rl
catch(IOException e){e.printStackTrace ();} c.m8~@O5+
catch(Exception e){e.printStackTrace ();} j`Fsr?]/
} />_Mz
D Cx3_
B25@6
//读取保存的下载信息（文件指针位置） vtG_A{l
private void read_nPos() 61>@-55k9
{ oe,L&2Jz@
try{ 3{ i'8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +[Nc";Oy
int nCount = input.readInt(); qT^R>p
nStartPos = new long[nCount]; -m)N~>{qS
nEndPos = new long[nCount]; AB40WCu]*
for(int i=0;i<nStartPos.length;i++) 5an#,vCn{
{ L31B:t^
nStartPos = input.readLong(); :%Na-j9hV)
nEndPos = input.readLong(); Xu $_%+46
} @x?7J@:
input.close(); #rM/
} ST1PSuC~
catch(IOException e){e.printStackTrace ();} _x_om#~n
catch(Exception e){e.printStackTrace ();} W&dYH 4O
} c*$&MCh
6f/>o$
Q-fi(UP
private void processErrorCode(int nErrorCode) 8nw_Jatk1
{ V6Ie\+@.\
System.err.println("Error Code : " + nErrorCode); U`sybtuBP'
} hK*:pf
z8FeL5.(
1\t}pGSOeh
//停止文件下载 KW|X\1H
public void siteStop() )3PQ|r'
{ ?it49
bStop = true; 4^(u6tX5|+
for(int i=0;i<nStartPos.length;i++) nBv|5$w:
fileSplitterFetch.splitterStop(); F-g(Hk|v
833KU_ N
l/0TNOA
} 9{_D"h}}
} !fUrDOM0E
//负责部分文件的抓取 syhTOhOX
**FileSplitterFetch.java UO$z_ p]w
*/ nAv@^G2
package NetFox; 52K_kB5
+[M5x[[$
;|&Ak_I2G
import java.io.*; _!6~o>
import java.net.*; OnFx8r:q@%
V}(snG,
pH5"g"e1
public class FileSplitterFetch extends Thread { vk:@rOpl
nf?;h!_7
Cp(,+dD
String sURL; //File URL >:%YAR`
long nStartPos; //File Snippet Start Position o\u31,
long nEndPos; //File Snippet End Position 1"ko wp
int nThreadID; //Thread's ID \hv1"WaJ
boolean bDownOver = false; //Downing is over 1c_qNI;:p
boolean bStop = false; //Stop identical J&4LyIpQ
FileAccessI fileAccessI = null; //File Access interface +ew2+2
S*~v9+
,!U5;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]^:l?F\h
{ Vvu+gP'z.
this.sURL = sURL; A7SBm`XJ)p
this.nStartPos = nStart; 1V(tt{
this.nEndPos = nEnd; i3g;B?54
nThreadID = id; 9NLO{kN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M6U/. n
} os*QWSs
|9.`qv
"J^M@k\!
public void run() 3Qmok@4e)
{ ^,[V;3
while(nStartPos < nEndPos && !bStop) `r;e\Cp
{ U WYLT-^x
Q|Uq.UjY
Q| > \{M
try{ Wo=Q7~
URL url = new URL(sURL); =+`I%>wc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {<%zcNKl^L
httpConnection.setRequestProperty("User-Agent","NetFox"); 4KF 1vw
String sProperty = "bytes="+nStartPos+"-"; 1HK5OT&
httpConnection.setRequestProperty("RANGE",sProperty); ~_=ohb{
Utility.log(sProperty); O{hGh{y
"P;_-i9O
4Sv&iQ=vh
InputStream input = httpConnection.getInputStream(); ,p6X3zY
//logResponseHead(httpConnection); [X[d`@rXv
L>Bf}^
r2H_)Oi
byte[] b = new byte[1024]; qg?O+-+
int nRead; Fn0Rq9/@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /Y|oDfv
{ tkU"/$Vi\
nStartPos += fileAccessI.write(b,0,nRead); vy\;#X!
//if(nThreadID == 1) -ZqN~5>j)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *fVs|
} A8Q1x/d(
J2H/z5YRJ4
)P>Cxzs
Utility.log("Thread " + nThreadID + " is over!"); h7mJXS)t|
bDownOver = true; bAv>?Xqa
//nPos = fileAccessI.write (b,0,nRead); /pzEL
} Gr6XqO_
catch(Exception e){e.printStackTrace ();} E ?(+v
} KA1Z{7UK%
} =\H.C@r
_uU}J5d.
~3 4Ly
//打印回应的头信息 ]5b%r;_
public void logResponseHead(HttpURLConnection con) O@St^o*A}
{ )u~LzE]{_
for(int i=1;;i++) %9hzz5#
{ =BW>jD
String header=con.getHeaderFieldKey(i); l(|@ dp
if(header!=null) [H$37Hx!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OpeK-K
Utility.log(header+" : "+con.getHeaderField(header)); _ Js& _d
else FaO=<jYi
break; HVG9 C$
} 2@WF]*Z
} `h+ia/
wlr/zquAE9
IKSe X
public void splitterStop() e-vL!&;2
{ H/m -$;cF3
bStop = true; CbTYt6DC
} 6u^MfOc
$r})j~c
M;*f(JY$
} {2?o:
qv|geBW
%|md0
/* 3uA%1 E
**FileAccess.java .zf#S0y%(
*//文件访问(定位，写) aV3:wp]Gn
package NetFox; `PK1zSr
import java.io.*; T^YdAQeE
iW\cLp "
'&4W@lvyz
public class FileAccessI implements Serializable{ KO/Z|I
I_xvg >i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4A(kM}uRB
RandomAccessFile oSavedFile; 1+6)0 OH{
long nPos; 3}{od$3G
Yg@k+
"e<Z$"7i
public FileAccessI() throws IOException J*s!(J |Q
{ V;$ME4B\{
this("",0); MzLnD D^
} W]cJP
_ S%3?Q
`?)ivy>\:
public FileAccessI(String sName,long nPos) throws IOException kd^CZ;O
{ IfF@$eO
oSavedFile = new RandomAccessFile(sName,"rw"); *|S.[i_7
this.nPos = nPos; ^6Y4=
oSavedFile.seek(nPos); $w{!}U2+-
} x#z}A&
%7WQb]y
}nNZp
public synchronized int write(byte[] b,int nStart,int nLen) Kp[ F@A#
{ Ul#||B .c{
int n = -1; @C7iflo6
try{ ht _fbh(l
oSavedFile.write(b,nStart,nLen); P)bS ;w\(Y
n = nLen; f4Aevh:
} uN1(l}z$
catch(IOException e) 1I< <`7'
{ 3_k.`s_Z
e.printStackTrace (); 2L}F=$zz
} ;ew j
<:=}1t.Z
B;f\H,/59
return n; U_!Wg|
} QRbiO
PYWp2V/
X1Vx6+[
} \%Wu`SlDp9
[_W#8{
p^1s9CM%
/* /.!ytHw8
**SiteInfoBean.java o'nju.'
*/ _ZUtQ49
package NetFox; Y] Q=kI
+dd\_\
{.=4;
public class SiteInfoBean { !Cse,6/Z
UzZzt$Kw
VB x,q3.
private String sSiteURL; //Site's URL ]7SX _:'*
private String sFilePath; //Saved File's Path HPM ggRs
private String sFileName; //Saved File's Name (80 Tbi~+
private int nSplitter; //Count of Splited Downloading File ;Y<Hi\2oy
^id9_RU
YCJcDab
public SiteInfoBean() {s^vAD<~x3
{//nSplitter的缺省值为5 s~OGlPK
//default value of nSplitter is 5 uA]Z"
this("","","",5); w@ 1g_dy
} Jo%5NXts4
""-#b^DQ
@2H"8KX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $Pw@EC]
{ t As@0`x9
sSiteURL= sURL; J,@SSmJ`
sFilePath = sPath; %mLQ'$
sFileName = sName; bvVEV
this.nSplitter = nSpiltter; dg#w/}}m
3/+r*lv>X
lP$bxUNt
} JBY`Y]V3
\KmgFyF
tuZA q;X
public String getSSiteURL() }O=QXIF5
{ u#TRm?s
return sSiteURL; v/dyu
} frB~ajXK
v2X>%
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public void setSSiteURL(String value) ""LCyKu
{ u~kfz*hz
sSiteURL = value; (sX=#<B%
} & w%%{lM
RY8Ot2DWi
#Av6BGM|,
public String getSFilePath() QuEfV?)_4
{ CUz1q*):
return sFilePath; Snm m(.
} R.KqTEs<k
<zmtVE*>g
0#K?SuY.eN
public void setSFilePath(String value) ;%u'w;sgq
{ +C`h*%BW
sFilePath = value; y_aKW4L+
} gWlv;oq
NI(fJ%U
'FVh/};Y.D
public String getSFileName() ^.']-XjC
{ :Bk!YK
return sFileName; v.eNWp
} G-5wv
%Pl 7FHfB
h!c6]D4!L
public void setSFileName(String value) w.tQ)x1h
{ Q<TD5t9
sFileName = value; 6O|B'?]Pf
} TRB)cJZ?
vkFfHzR$
EVovx7dr
public int getNSplitter() :`FL95
{ iF.eBL%
return nSplitter; /]0-|Kg+R
} )HLe8:PG~
?`& l Y
M]\p9p(_
public void setNSplitter(int nCount) >FrF"u:kM
{ P F#X8+&J
nSplitter = nCount; (``EBEn
} =P* YwLb
} \FVm_)
o;.6Y `-fJ
x6=Yt{
/* ;QMRm<CLV
**Utility.java Gp}:U>V)
*/ #;4afj:2g
package NetFox; Z0fl]3p
q]1HCWde
1h.Ypzu
public class Utility { wI\ n%#
YX||\
nveHLHvC7
public Utility() .=y-T=}
{ e1*<9&S
o6{[7jI
Mi|PhDXMh
} >]6inS9
;.%Ii w&WG
//线程睡眠 bnll-G|
public static void sleep(int nSecond) z|';Y!kQ
{ `5VEGSP]
try{ ~d+.w%Z`
Thread.sleep(nSecond); < 5%:/j
} 43i@5F]
catch(Exception e) g>])O
{ Vl91I+Ev
e.printStackTrace (); iy{n"#uX
} xG802?2i/;
} "rV-D1Dki
YMlnC7?_/
//日志 f:/[
public static void log(String sMsg) q7itznQSKc
{ sbWen?
System.err.println(sMsg); BvXA9YQ3
} D1Yc_
y)`f$Hl@1
NGA8JV/U
public static void log(int sMsg) O26'|w@$
{ ]_8bX}_n
System.err.println(sMsg); u`%Kh_
} (A\X+S(
} 2WKYf0t
0+a-l[!p
;<aT|4
/* Zd2B4~V
**TestMethod.java Mqy5>f)
*/ |sQC:y>
package NetFox; \S]"nHX
$:{r#mM
o\n9(ao
public class TestMethod { ;S+UD~i[Bu
O8&=qZ6T
@P1#)
public TestMethod() 4#pn]
{ ///xx/weblogic60b2_win.exe wi7a_^{
try{ 3^ct;gz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %kod31X3<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zv1#PfO@)
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5PaOa8=2f
fileFetch.start(); h.A@o#x
} KW3Dr`A
catch(Exception e){e.printStackTrace ();} )<]*!
4|?y [j6
~ULD{Ov'F
} 9VEx0mkdd
'p%\fb6`
7Wd}H Z
public static void main(String[] args) k0%*{IVPN
{ 0|1)cO}Dy
new TestMethod(); ~OuKewr\
} i,[S1g
} 0^5*@vt
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