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)); TR([u
} JHCV7$RS
for(int i=0;i<nEndPos.length-1;i++) lS:R##
{ B>TI dQ
nEndPos = nStartPos[i+1]; .7EZB
} &ivPY
nEndPos[nEndPos.length-1] = nFileLength; }bxx]rDl
} `+go| 5N2
} Q8sCI An{
%=O$@.%Zc
HxmCKW!
//启动子线程 YvP u%=eF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gc6T`O-_;
for(int i=0;i<nStartPos.length;i++) 0XNj!^&
{ T2$V5RyX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .Iret:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !agtgS$qII
nStartPos,nEndPos,i); /\B[lRn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gUq)M
fileSplitterFetch.start(); {=Ku9\
} v8L&F9 o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +v}R-gNR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (KDv>@5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w'b|*_Q4Q
nEndPos = " + nFileLength); xp>p#c
// fileSplitterFetch[nPos.length-1].start(); 95G*i;E
9ywPWT[^
.+"SDtoX
//等待子线程结束 T'TxC)
//int count = 0; `*1059
//是否结束while循环 ^9Je8 @Yu
boolean breakWhile = false; @Fl&@ $
cKj6tT"=O
[Bz'c1
while(!bStop) uPtHCP6
{ sa71Vh{
write_nPos(); &2!F:L
Utility.sleep(500); .7nr:P
breakWhile = true; &$?i
"w\Iz]
W]v[Xm$q
for(int i=0;i<nStartPos.length;i++) Je6=N3)
{ oVc l (
if(!fileSplitterFetch.bDownOver) r|WoM39bp
{ 0*.> >rI
breakWhile = false; :K)=Hf2y
break; 9N[vNg<n
} *<**rY*
} Z`l97$\
if(breakWhile) EPz$`#Sh"
break; /?; 8F
_S(]/d(c
5[Ryc[
//count++; n+EK}=DK
//if(count>4) oR=^NEJv
// siteStop(); \c! LC4pE
} rX%qWhiEJ
jnK8 [och
U?6YY`A8
System.err.println("文件下载结束！"); l_!.yV{
} 'xdM>y#S
catch(Exception e){e.printStackTrace ();} "=unDpq]
} X^#.4:>.
}[u9vZL
R0y@#}JH
//获得文件长度 3mIX9&/
public long getFileSize() _[SP*" ]H
{ A}#@(ma7
int nFileLength = -1; ]]s_ 8u3
try{ #EpDIL
URL url = new URL(siteInfoBean.getSSiteURL()); &Z+a (
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lHpo/R:
httpConnection.setRequestProperty("User-Agent","NetFox"); E(M\U5o:
[FKmZzEy
%8kbX
int responseCode=httpConnection.getResponseCode(); j\nnx8`7
if(responseCode>=400) 3:a}<^DuCS
{ aW3yl}`{
processErrorCode(responseCode); VwoCRq*
return -2; //-2 represent access is error fV3!x,H
} AAsl)
H{x}gBQ
unmuY^+<
String sHeader; n>\BPiz
YtNoYOB
AQ-P3`bCb
for(int i=1;;i++) d8g3hyI5\
{ Q=yQEh|Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Dd*T5A?
//Utility.log(in.readLine()); HPAg1bV:-
sHeader=httpConnection.getHeaderFieldKey(i); -9{}rE
if(sHeader!=null) y^zVb\"4
{ R,A|"Q
if(sHeader.equals("Content-Length")) p]:~z|.Ba
{ g~%=[1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O'm&S?>
break; @]dN
} +*g[hRw[
} 5.xvOi|.
else <27B*C M
break; h^$>{0"
} IgC)YIhd
} V0L^pDLOV
catch(IOException e){e.printStackTrace ();} "8Pxf=
catch(Exception e){e.printStackTrace ();} `NV =2T
<P( K,L?r
LaJc;Jt$
Utility.log(nFileLength); G`w,$:,
-nO('(t
uavts9v<
return nFileLength; 7(~^6Ql!
} 96vv85g
3OFv_<6
7 .+kcqX
//保存下载信息（文件指针位置） S'Q$N-Dy
private void write_nPos() Y_%\kM?7
{ AY0o0\6cw
try{ "[H9)aAj7
output = new DataOutputStream(new FileOutputStream(tmpFile)); sb(,w
output.writeInt(nStartPos.length); " %|CD"@
for(int i=0;i<nStartPos.length;i++) {Y'DUt5j
{ RgQ\Cs24Q
// output.writeLong(nPos); Yq/|zTe{
output.writeLong(fileSplitterFetch.nStartPos); QE!cf@~n"
output.writeLong(fileSplitterFetch.nEndPos); |82V`CV
} >Q+a'bd w
output.close(); .Rc&EO
} [O [N_z
catch(IOException e){e.printStackTrace ();} d[rxmEXht
catch(Exception e){e.printStackTrace ();} lyZof_/*
} g@nk0lQewj
+ 7E6U*
WLNkO^zb
//读取保存的下载信息（文件指针位置） +zs;>'Sf
private void read_nPos() <g,k[
{ O(/K@e
try{ 1WcT>_$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J~<:yBup}
int nCount = input.readInt(); 4pq>R
nStartPos = new long[nCount]; ?Dm!;Z+7
nEndPos = new long[nCount]; H:9( XW
for(int i=0;i<nStartPos.length;i++) DfV_08
{ PpU : 4;en
nStartPos = input.readLong(); 3=dGz^Zdv:
nEndPos = input.readLong(); MkJL9eG
} o|alL-
input.close(); $z@e19gT
} f*5=,$0
catch(IOException e){e.printStackTrace ();} IO>Cyo
catch(Exception e){e.printStackTrace ();} Fw"~f5O
} ,[Cl'B
2HQ'iEu$
~z|/t^
private void processErrorCode(int nErrorCode) 3u{[(W}08
{ f#JLE+0Y
System.err.println("Error Code : " + nErrorCode); = "c _<?=[
} iyH<!>a
rIge6A>I
sd8o&6
//停止文件下载 51;(vf
public void siteStop() do=VPqy
{ ]X?+]9Fr
bStop = true; s o~p+]
for(int i=0;i<nStartPos.length;i++) f^%vIB ~[
fileSplitterFetch.splitterStop(); %7 J
"[GIW+ui
mvUYp,JECl
} R"O9~s6N
} M_79\Gz"
//负责部分文件的抓取 =nid #<X
**FileSplitterFetch.java %Si3t2W/
*/ #0xvxg%{
package NetFox; %$]u6GKabi
h.2!d0j]
#llc5i;
import java.io.*; hH[JY(V
import java.net.*; LDPo}ogs
Nob(bD5SpE
?m?e2{]u,
public class FileSplitterFetch extends Thread { 'd6hQ4Vw4
8zVXQ!'
&]vd7Q.t
String sURL; //File URL u3k+Xg:
long nStartPos; //File Snippet Start Position 'a"<uk3DT
long nEndPos; //File Snippet End Position ZklidHL');
int nThreadID; //Thread's ID C7+TnJ
boolean bDownOver = false; //Downing is over k9R1E/;
boolean bStop = false; //Stop identical 1Tiq2+hmf
FileAccessI fileAccessI = null; //File Access interface HHEFX9u
>Q5 SJZ/
h Qu9ux
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kN]#;R6
{ Xd|5{
this.sURL = sURL; 3tLh{S?uJ
this.nStartPos = nStart; mDV 2vg
this.nEndPos = nEnd; `RmB{qgB
nThreadID = id; 9wWjl}%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4-3B"
} |{oKhC^yG
dr/!wr'&hS
{5%<@<?)
public void run() W8":lpp
{ 7d4RtdI
while(nStartPos < nEndPos && !bStop) f"-<Z_
{ w$B7..r
IRS^F;)
v"$; aJ
try{ -OkKLub
URL url = new URL(sURL); A>k+4|f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^R<= }
httpConnection.setRequestProperty("User-Agent","NetFox"); W%h<@@c4,
String sProperty = "bytes="+nStartPos+"-"; ORHC bw9
httpConnection.setRequestProperty("RANGE",sProperty); 8g0& (9<)
Utility.log(sProperty); w[|!$J?
}%XNB1/`
'QW 0K]il
InputStream input = httpConnection.getInputStream(); }y[o[>
//logResponseHead(httpConnection); {O^1WgGc[
HQUL?URt
41C=O@9m
byte[] b = new byte[1024]; ?xG #4P<C=
int nRead; /?J_7Lg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \h0e09& I
{ A6UtpyS*'
nStartPos += fileAccessI.write(b,0,nRead); )?TJ{'m
//if(nThreadID == 1) 7NXT.E~2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KY"~Ta`
} -#Wc@\;
<B``/EX^
< )?&Jf>_
Utility.log("Thread " + nThreadID + " is over!"); =8J\;h
bDownOver = true; hQet?*diU
//nPos = fileAccessI.write (b,0,nRead); 6Q wL
} `zsKc 6%
catch(Exception e){e.printStackTrace ();} ]mqB&{g
} u>? VD%
} !*\^-uvaK
t(_XB|AKm
"thu@~aC
//打印回应的头信息 /aPq9B@
public void logResponseHead(HttpURLConnection con) hi ]+D= S
{ n1;V2k{uV
for(int i=1;;i++) YWdlE7 y
{ (PB|.`_<H
String header=con.getHeaderFieldKey(i); Aw|3W ]
if(header!=null) '$U"RP^(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <Jvrmm[
Utility.log(header+" : "+con.getHeaderField(header)); j5HOdy2
else dm 2_Fj
break; Q,DumOq
} k~hL8ZT[
} v~xG*e
Em?skUnG,
X:!%"K%}
public void splitterStop() x)GoxH~#
{ DV.MvFV
bStop = true; y1AS^'
} ^1nf|Xj[
&#)3v8
lW2qVR
} oC?b]tzj
yqYX<<!V
RoiMvrJQP
/* onmO>q*
**FileAccess.java x Dr^&rC
*//文件访问(定位，写) Uexb>|
package NetFox; Y/hay[6
import java.io.*; Fd91Y
<l6CtK@
>/n/n{{
public class FileAccessI implements Serializable{ w5|"cD#8A
lWdE^-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :kUH>O
RandomAccessFile oSavedFile; {B}0LJIpL
long nPos; m|y]j4
#z~oc^J^T
5eU/ [F9
public FileAccessI() throws IOException -yAIrvO1q
{ &0lNj@/
this("",0); f[v??^
} ~Ch`A@=5
ULJI`I|m
\\T I4A^#
public FileAccessI(String sName,long nPos) throws IOException D"Xm9 (
{ xv ja
oSavedFile = new RandomAccessFile(sName,"rw"); -OHG1"/
this.nPos = nPos; xM*v!J,
oSavedFile.seek(nPos); '2vlfQ@8a~
} FJ!>3V;}
+X&B'
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public synchronized int write(byte[] b,int nStart,int nLen) 3! +5MsR+
{ ;js7rt
int n = -1; +:t1PV;l
try{ W,<Vr2J[
oSavedFile.write(b,nStart,nLen); g5"g,SFGr
n = nLen; 78Gvc~j
} m ;KP
catch(IOException e) EbW7Av
{ }cP3i
e.printStackTrace (); Gq{v)iN
} w_-{$8|
qle\c[UM5
(u*]&yk
return n; dfrq8n]
} *7R3EUUk
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!pN,,H6Y
} @M,_mX
[W2p}4(
PaZFM
/* |9%>R*
**SiteInfoBean.java A6sBObw;
*/ kgQEg)A]!x
package NetFox; 5|Y4GQVz
!98s[)B:
Gzs x0%`)
public class SiteInfoBean { $0 li"+
hcBfau;r
z><JbSE?
private String sSiteURL; //Site's URL n8iN/Y<%U
private String sFilePath; //Saved File's Path 9xSAWKr,l
private String sFileName; //Saved File's Name ="u(o(j"
private int nSplitter; //Count of Splited Downloading File bH=5[
LHacHv
,:#prT[P"
public SiteInfoBean() [Ea5Bn;~!
{//nSplitter的缺省值为5 :l6sESr
//default value of nSplitter is 5 ;Y~;G7
this("","","",5); ~MXPiZG?
} [<%yUy
G,XFS8{%
:hevBBP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b\^.5SEw
{ >g F
sSiteURL= sURL; IUZsLNW
sFilePath = sPath; q<7Nz]Td
sFileName = sName; iWvgCm4
this.nSplitter = nSpiltter; P_qxw-s
`R; ct4-
o30PI
} bFTWuM
51rM6 BT
B0YY7od
public String getSSiteURL() ]=pEs6%O3
{ r%o!P`
return sSiteURL; #<?j784
} @P~u k
ir\
7tyn?t0n
public void setSSiteURL(String value) KcSvf;sx
{ ly{~X
sSiteURL = value; 5[@4($q8
} q_W NN/w
ha(hG3C
Ya>cGaLq
public String getSFilePath() )JZfC&,
{ ZkK +?:9
return sFilePath; >`lf1x
} M r@M~ -
8HWY]:|oh
1&m08dZm5
public void setSFilePath(String value) ^beW*O!
{ myXp]=Sb?
sFilePath = value; D9Q%*DLd$_
} ]r#tJT`M
{UwJg
"7gHn0e>
public String getSFileName() 9,F(f}(t
{ M,<%j
return sFileName; =si<OB
} 8Y4YE(x5
z?cRsqf
!Dun<\
public void setSFileName(String value) AA@J~qd u
{ 3<Cd>o.
sFileName = value; 578Dl(I#)
} t<$yxD/R
)ll}hGS
=JEnK_@?K\
public int getNSplitter() &yYK%~}t[
{ AJq'~fC;I
return nSplitter; (3_2h4O
} esxU44
ofN|%g /
*%g*Np_P
public void setNSplitter(int nCount) <FGM/e4
{ gBrIqM i5
nSplitter = nCount; vL-%"*>v
} B_:K.]DK`
} cDLS)
& 8e~<
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/* R`/nsou
**Utility.java KaO8rwzDN
*/ ncu> @K$n
package NetFox; Z\NC+{7k]
/X8b=:h
Mc{1Cdj
public class Utility { Vrz<DB^-e
qxE~Moht
0PTB3-
public Utility() 9t;aJFI
{ 3A'd7FJ0G
b7HS3NYk
I_N"mnn@Nr
} m3.d!~U\
9;q@;)'5
//线程睡眠 pNE!waR>
public static void sleep(int nSecond) ]%G[<zD,1
{ /&dC?bY
try{ T w/CJg
Thread.sleep(nSecond); U<o,`y[Tn
} Qx$Yj
catch(Exception e) Jw9|I)H
{ DUY#RJf
e.printStackTrace (); < R0c=BZ>
} <L:v28c
} \@gs8K#
#y2="$V
//日志 MNkysB(
public static void log(String sMsg) `}Q+:
{ W0l|E&fj[
System.err.println(sMsg); aS:17+!
} `W{Ye=|[d#
qH"e: wgL
@;Yb6&I;
public static void log(int sMsg) |jc87(x<
{ 03_tt7
System.err.println(sMsg); a\^DthZ!;|
} #^#N%_8
} =suj3.
aRg- rz
RIb< 7
/* N2=gSEY
**TestMethod.java .2Gn)dZU
*/ fs7JA=?:
package NetFox; >:h 8T]F
:^! wQ""
kLADd"C
public class TestMethod { e-\J!E'1F
CKrh14ul
2"JIlS;J}7
public TestMethod() v"=^?5B
{ ///xx/weblogic60b2_win.exe (9@6M8A
try{ f4]nz:2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]D%D:>9|/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); NCl$vc;,
SiteFileFetch fileFetch = new SiteFileFetch(bean); R&=Y7MfZ
fileFetch.start(); qvhTc6oH
} `{8Sr)
catch(Exception e){e.printStackTrace ();} e,|"9OK
NuW9.6$Jrf
?Tt/,Hl?D
} yz,ak+wp
{_KuztJGA
4?1Ac7bE
public static void main(String[] args) !Kd/ lDY
{ {#0B~Zr
new TestMethod(); bG;vl;C
} JKGUg3\~
} Z9 }qds6 y
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