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)); K2TcOFQ
} J]{QB^?
for(int i=0;i<nEndPos.length-1;i++) ]^h]t~
{ Uwf+
nEndPos = nStartPos[i+1]; yv t.
} ]A~WIF
nEndPos[nEndPos.length-1] = nFileLength; >V-A;S:
} [@VP?74
} */sS`/Lx
^E;kgED5
U#lCj0iUt,
//启动子线程 IwQ"eUnK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; eD,.~Y#?=
for(int i=0;i<nStartPos.length;i++) _zY#U9
{ FHj" nB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ur)9x^y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Of*Pw[vD
nStartPos,nEndPos,i); &S~zNl^m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z* ^_)Z
fileSplitterFetch.start(); wH>a~C:
} VCV"S>aVf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q-_N2W?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l3Xfc2~ 2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Sc\*W0m
nEndPos = " + nFileLength); u(@$a4z
// fileSplitterFetch[nPos.length-1].start(); $ `ov4W
zd2)M@
I(i}c~R
//等待子线程结束 ~ksi</s
//int count = 0; mWoAO@}Y
//是否结束while循环 o} J&E{Tk
boolean breakWhile = false; ]D?"aX'q>
JZ)RGSG i
)#?"Gjf~
while(!bStop) |n2qVR,
{ PQy4{0 _
write_nPos(); -.1y(k^4E
Utility.sleep(500); '*K: lx
breakWhile = true; Bal$+S
GzhYY"iif#
kjIAep0rT
for(int i=0;i<nStartPos.length;i++) ^yWL,$
{ 6</xL9#/
if(!fileSplitterFetch.bDownOver) zBCtd1Xrni
{ A 9( x
breakWhile = false; /a{la8Ni
break; * aN
} ,k24w7K%d
} YN/|$sMD|
if(breakWhile) &Y!-%{e
break; ?M8dP%&r
U>YAdrx2a
"Lzi+1
//count++; ^H~h\,;zQ
//if(count>4) fY{1F
// siteStop(); 9Vg?{v!yn
} K18}W*$ d
bWH&P/>
C6VLy x
System.err.println("文件下载结束！"); 6c}h(TkB
} "H7dft/
catch(Exception e){e.printStackTrace ();} ,BH@j%Jmy
} z6U\axO6
APvDP?
W<bGDh
//获得文件长度 @P#N2:jwj
public long getFileSize() '}9x\3E
{ hpHr\g
int nFileLength = -1; #*D)Q/k
try{ =b%MXT
URL url = new URL(siteInfoBean.getSSiteURL()); 1a?!@g)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O9G[j=U
httpConnection.setRequestProperty("User-Agent","NetFox"); qU+t/C.
VrHv)lUr
m}C>ti`VD
int responseCode=httpConnection.getResponseCode(); B;M?,<%FRU
if(responseCode>=400) rA3$3GLQ-
{ Jb0`42
processErrorCode(responseCode); tRs [ YK
return -2; //-2 represent access is error lNz7u:U3
} _tiujP
:y+2*lV
rNrxaRQ
String sHeader; RmI]1S_=
{ d=^}-^
iJ-23_D
for(int i=1;;i++) 2a-w% (K
{ )Lk639r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QiQ_bB!\
//Utility.log(in.readLine()); w^?>e;/\
sHeader=httpConnection.getHeaderFieldKey(i); /$ w%Q-p
if(sHeader!=null) Ok|*!!T
{ &:;:"{t}Do
if(sHeader.equals("Content-Length")) @D.}\(
{ &TnS4O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9Z|jxy
break; rx'RSo#1O
} !`k1:@NZ
} - \5v^l
else Z 8S\@I
break; ],>@";9u"
} aAZZ8V
} }{,^@xdyW
catch(IOException e){e.printStackTrace ();} FTX=Wyr
catch(Exception e){e.printStackTrace ();} n3T>QgK
<Q3oT
RU'=ERYC
Utility.log(nFileLength); Pj[PIz
Cw iKi^m
1Lc#m`Jln
return nFileLength; VEH&&@d
} xmNB29#
<C_jF
w;;BSJ]+[
//保存下载信息（文件指针位置） c>,'Y)8
private void write_nPos() c#XXp"7k2
{ FTH|9OP
try{ &SIq2>QA
output = new DataOutputStream(new FileOutputStream(tmpFile)); Gk. ruQW"
output.writeInt(nStartPos.length); |!1Y*|Q%s
for(int i=0;i<nStartPos.length;i++) (jnzT=y
{ &x=.$76
// output.writeLong(nPos); F<ZYh
output.writeLong(fileSplitterFetch.nStartPos); =qoWCmg"&
output.writeLong(fileSplitterFetch.nEndPos); zbXI%
} uX"H4lO~
output.close(); bh s5x
} 1[mXd
catch(IOException e){e.printStackTrace ();} szb_*)k
catch(Exception e){e.printStackTrace ();} i#&z2h-b
} >] qc-{>&
_mzW'~9wN
O#n8=B4
//读取保存的下载信息（文件指针位置） Htay-PB }
private void read_nPos() ynmWW^dg
{ <>n0arAn
try{ >Y&N8PHD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); wc0jhHZO ?
int nCount = input.readInt(); IrR7"`.i
nStartPos = new long[nCount]; V8e>l[tH
nEndPos = new long[nCount]; @y e4q.m
for(int i=0;i<nStartPos.length;i++) G[B=>Cy
{ V("{)0~O
nStartPos = input.readLong(); T!-\@PB !
nEndPos = input.readLong(); y>R=`A1b
} 4qN{n#{+]
input.close(); Rh3eLt~|(
} }elc `jj
catch(IOException e){e.printStackTrace ();} ~<P 0]ju
catch(Exception e){e.printStackTrace ();} a[v0%W ]u
} 5uGqX"
]O Z5fd
*w$W2I>b7
private void processErrorCode(int nErrorCode) w:??h4lt
{ IW)()*8;/
System.err.println("Error Code : " + nErrorCode); cec9l65d
} n?oW< &
]fm'ZY&
4]rnY~
//停止文件下载 tN[L@t9#cr
public void siteStop() _geWE0 E
{ #mlS}~n
bStop = true; Hh%I0#
for(int i=0;i<nStartPos.length;i++) Jx_cf9{
fileSplitterFetch.splitterStop(); 9lTv
,K>I%_!1
y6@0O%TDN
} Q0$8j-1I
} T`/AY?#
//负责部分文件的抓取 sI43@[
**FileSplitterFetch.java ,V'o4]H
*/ ,4hJT
package NetFox; he#J|p
H12Fw'2
h-g+g#*
import java.io.*; ke{8 ^X~#
import java.net.*; 7t3X)Ah
4)E_0.C
#w;v0&p
public class FileSplitterFetch extends Thread { rI{=WPI&WU
"B8Q:
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String sURL; //File URL D,m]CK'
long nStartPos; //File Snippet Start Position ;1#H62Z*
long nEndPos; //File Snippet End Position c@YI;HS_g
int nThreadID; //Thread's ID gep;{G}
boolean bDownOver = false; //Downing is over g6nkZyw
boolean bStop = false; //Stop identical K7$x<5+)
FileAccessI fileAccessI = null; //File Access interface yZd +^QN
H!vax)%-\
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |yvQ[U~PQ
{ 2`.cK 3
this.sURL = sURL; hS_6
this.nStartPos = nStart; L%">iQOG#
this.nEndPos = nEnd; P<oehw'>
nThreadID = id; S(QpM.9*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dCb`xR}
} | H!28h
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public void run() %mL-$*
{ YTAmgkF\4
while(nStartPos < nEndPos && !bStop) k")R[)92b?
{ Z/Eb:
<wZQc
QS0:@.}$E)
try{ J5*tJoCYS
URL url = new URL(sURL); ckV`OaRw4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oV)~@0B&0
httpConnection.setRequestProperty("User-Agent","NetFox"); avjpA?Vz
String sProperty = "bytes="+nStartPos+"-"; aGK?x1_
httpConnection.setRequestProperty("RANGE",sProperty); @*>@AFnf\Z
Utility.log(sProperty); )@N2
^<;V]cY`
,_|]Ufr!a
InputStream input = httpConnection.getInputStream(); hp8%.V$f
//logResponseHead(httpConnection); U93}-){m
ygOd69
Gn&-X]Rrl
byte[] b = new byte[1024]; uC.K<jD%
int nRead; -g)9R%>-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UU'|Xz9~
{ pqUCqo!m\
nStartPos += fileAccessI.write(b,0,nRead); `J]fcE%T0R
//if(nThreadID == 1) ttXXy3G#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); syk!7zfK
} nv)2!mAh\
;V^ 112|C
1D16
Utility.log("Thread " + nThreadID + " is over!"); El<]b7
bDownOver = true; Rfn9s(m
//nPos = fileAccessI.write (b,0,nRead); l6(-I Tb
} #G|qD
catch(Exception e){e.printStackTrace ();} 7:Ax(El
} ;_8#f%Y#R
} 0- ><q
pkP?i5,
e'~Zo9`r6
//打印回应的头信息 5'0xz.)!
public void logResponseHead(HttpURLConnection con) X_qf"|i
{ g wz7krUTe
for(int i=1;;i++) rX*H)3F
{ TqNadHQ
String header=con.getHeaderFieldKey(i); b5,x1`#7k
if(header!=null) J~%K_~Li
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XIvn_&d;G
Utility.log(header+" : "+con.getHeaderField(header)); jxiC Kx,G
else U;bK!&Z
break; }>)@WL:q
} lJ+0P2@h*
} J%V-Q>L
XEC(P
Av?2<
public void splitterStop() \2nUa ;
{ |"XPp!_uN
bStop = true; :]rJGgK#
} 3VI4X
Q s.pGi0W
[(o7$i29|%
} h\7fp.
cKN$ =gd
qud\K+
/* GFfq+=se
**FileAccess.java o]Ol8I
*//文件访问(定位，写) D,;\o7V
package NetFox; wtmB+:I
import java.io.*; !icT/5
iZPCNS"
y'(Ne=y
public class FileAccessI implements Serializable{ M(RZ/x
/D5`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;=geHiQHA
RandomAccessFile oSavedFile; I+Jm>XN
long nPos; L,SGT8lL
dcLA1sN,
k4,BNJt'Z
public FileAccessI() throws IOException ?6(I V]
{ UJ0<%^f
this("",0); Dw=gs{8D
} wUiys/OVM
3= DNb+D!
Au{<hQ=
public FileAccessI(String sName,long nPos) throws IOException ^M%uV
{ %@;6^=
oSavedFile = new RandomAccessFile(sName,"rw"); d}LRl"_n
this.nPos = nPos; w$H^q !(
oSavedFile.seek(nPos); 9Q(+ZG=JkV
} 5K^69mx
7@Zx@
#mZpeB~
public synchronized int write(byte[] b,int nStart,int nLen) CqHK%M
{ ^Y u6w\QM
int n = -1; nt;haeJ
try{ S{FROC~1R
oSavedFile.write(b,nStart,nLen); %YSpCI
n = nLen; ?q(\=;Y
} uHH/rMV
catch(IOException e) %7#-%{
{ CNQC^d\ h
e.printStackTrace (); TT50(_8
} *.~6S3}
cCo`~7rE
+j(d| L\
return n; $={:r/R`i
} +E1I");
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2-=\~<)
} j<2m,~k`V
w?zKjqza=v
{GKy'/[
/* b !%hH
**SiteInfoBean.java 7M<'ddAN
*/ `W dD8E
package NetFox; 5k6mmiaKk
<'fdkW
R)F;py8)I
public class SiteInfoBean { >w-;Z>3Q@
j.*VJazb;
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private String sSiteURL; //Site's URL TMs,j!w?I
private String sFilePath; //Saved File's Path Mva3+T
private String sFileName; //Saved File's Name O(tX8P Q5N
private int nSplitter; //Count of Splited Downloading File W%.v.0
L KCb_9
U\veOQ;mW
public SiteInfoBean() rsF\JQk
{//nSplitter的缺省值为5 J4"mK1N(
//default value of nSplitter is 5 -+7uy.@cS
this("","","",5); ?lbH02P{v
} ;<$H)`*
|o2sbLp
7_.11$E=H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,g7.rEA
{ +2K:qvzZ
sSiteURL= sURL; i^_#%L
sFilePath = sPath; q}/WQ]p} <
sFileName = sName; uKz,SqX
this.nSplitter = nSpiltter; i `s|,"0o
e$u4vC~
c&X{dJWD
} o\88t){/kB
%&->%U|'
L lw&& K
public String getSSiteURL() %/c+`Wd/l$
{ b+6"#/s
return sSiteURL; {&P FXJ
} ?Zc"C
Rx*BwZ
`%E8-]{uS
public void setSSiteURL(String value) >_c5r?]SG
{ P+!"wX0*N
sSiteURL = value; i]=&
} n:0}utU4
bn(`O1r[(
JXixYwm
public String getSFilePath() &-czStQ
{ [U@*1
return sFilePath; "+z?x~rk
} K]qM~v<A
R64!>o"nED
T;diNfgg
public void setSFilePath(String value) s-Aw<Q)d
{ :LWn<,4F&
sFilePath = value; RbGJ)K!
} 9prU+9
SFb{o<0 =
]l@ qra
public String getSFileName() q;fKcblKj
{ l"{Sm6:;-
return sFileName; X*g(q0N<S
} >Jw6l0z
qC_mu)6
8 F2|
public void setSFileName(String value) xy8#2
{ ~ ^>417>
sFileName = value; Ku/~N#
} ~XydQJ^*
9D 0dg(
-UZ@G~K
public int getNSplitter() ]&ixhW
{ 7QVuc!V
return nSplitter; Uz608u
} R7s|`\
hKNY+S})g
[xfaj'j=@
public void setNSplitter(int nCount) SVa6V}"Iv
{ `gpQW~*R-;
nSplitter = nCount; ExSO|g]%
} Q \]Xm>
} 5tv<8~:K
uNHdpni
TZ;p0^(
/* !Y<oN~<%)
**Utility.java Uw/l>\
*/ vBvNu<v7te
package NetFox; Olfn
g7CXlT0Q6
W%e_~$H0
public class Utility { Sf/q2/r?6[
x|0:P sE
#5&jt@NS
public Utility() $&Kq*m 0g
{ kvGCbRC
'r} zY-FM`
3L_I[T$s
} TwvAj#j
LF?P> 1%-
//线程睡眠 Sd))vS^g
public static void sleep(int nSecond) w?mEuXc
{ K'1~^)*
try{ F_ 7H!F
Thread.sleep(nSecond); 8ga_pNe
} xMs]Hs
catch(Exception e) /u`3VOn
{ WlV z,t'if
e.printStackTrace (); F?u^"}%Fc
} E2AW7f(/
} Nt:8ogk/
kax\h
//日志 W3&tJ8*3
public static void log(String sMsg) _M,lQ~
{ ciMM^ZRIb
System.err.println(sMsg); D H^T x
} J$9:jE-4
u/Fj'*M
m-V02's
public static void log(int sMsg) .5> 20\b2
{ Nf9fb?
System.err.println(sMsg); y69J%/c ra
} P20|RvE
} k_GP>b\"k
YCy22@C
PoShQR<
/* t~M $%)h
**TestMethod.java ]Z4zF"@
*/ R^MiP|?ZH
package NetFox; C+K=[
.G>t72DpU
T~gW3J
public class TestMethod { >qn/<??
zzZg$9PT[
9.M{M06;
public TestMethod() Bmo$5$
{ ///xx/weblogic60b2_win.exe pKJK9@Ad
try{ LD(C\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C:\(~D*GS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $v}<'
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ulqh@CE)
fileFetch.start(); $_j1kx$
} y/_wx(2
catch(Exception e){e.printStackTrace ();} qJ8-9^E,L
oP,9#FC|(
t7F.[uWD
} !0 Q8iW:
xi'<y
8NimZ(
public static void main(String[] args) lQ*eH10H
{ 7w58L:)B.
new TestMethod(); TYjA:d9YH
} kJ=L2g>W<.
} 3gfimD$_E
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