http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); YT)jBS~&
} 5ua`5Hb;
for(int i=0;i<nEndPos.length-1;i++) CzP?J36W^
{ Cr?|bDv}o
nEndPos = nStartPos[i+1]; $wL zaZL|
} W^}fAcQKH
nEndPos[nEndPos.length-1] = nFileLength; 0dv# [
} 6,nws5dh
} IMaa#8,
5PY,}1`
B}Q.Is5
//启动子线程 jf_xm=n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i%jti6z$Hr
for(int i=0;i<nStartPos.length;i++) p 8,wr )
{ ~x:\xQti
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sEpY&6*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m+y5Q&;f
nStartPos,nEndPos,i); ~YQC!x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9ihB;m'C)
fileSplitterFetch.start(); ao2NwH##
} oBfh1/<<a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ElJM. a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?`wO \>y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,BGaJ|k
nEndPos = " + nFileLength); cg16|
// fileSplitterFetch[nPos.length-1].start(); &L&6y()G
F` /mcyf
H/qv%!/o
//等待子线程结束 +n]z'pijb
//int count = 0; }.j<kmd
//是否结束while循环 drr W?U
boolean breakWhile = false; e^;<T9Esr
T(Q(7
x+?P/Ckg
while(!bStop) L>4!@L5)
{ S;pKL,d>r
write_nPos(); ^[]q/v'3m!
Utility.sleep(500); ]: VR3e"H
breakWhile = true; )U6-&-07
"eqNd"~
>_R,^iH"
for(int i=0;i<nStartPos.length;i++) ="~yD[S
{ jc%
if(!fileSplitterFetch.bDownOver) \6]Uj+
{ @xKfqKoqg
breakWhile = false; 8GGC)2
break; ,C4gA(')K
} 9j[lr${A
} nSMw5
if(breakWhile) eSAB :L,K
break; Bo)N<S_=^
dm;C @.ML
W3AtO
//count++; w.AF7.X`1
//if(count>4) puv/+!q
// siteStop(); x{GKz#
} rMV<}C ^
k15fy"+Ut
`E@TPdu
System.err.println("文件下载结束！"); @ V_@r@A
} .ty^k@J|]
catch(Exception e){e.printStackTrace ();} **RW 9FU
} ]]R!MnU:$
khXp}p!Zm
:6N'%LKK
//获得文件长度 am+'j5`Ys
public long getFileSize() D@-'<0=
{ ~s$ jiA1
int nFileLength = -1; !)!<.x
try{ XIS.0]~
URL url = new URL(siteInfoBean.getSSiteURL()); F9N/_H*+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KNI* :
httpConnection.setRequestProperty("User-Agent","NetFox"); ;usv/8
f:w#r.]
a>_Cxsb&`
int responseCode=httpConnection.getResponseCode(); tf:4}6P1
if(responseCode>=400) bVLuv`A/
{ NWNPq"
processErrorCode(responseCode); J)148/
return -2; //-2 represent access is error E~b Yk6
} l^LYSZg'R8
RyAss0Sm^
K #f*LV5
String sHeader; W-72&\7
31FQ=(K
BGe&c,feIc
for(int i=1;;i++) [~%\:of70n
{ r@|{mQOxa
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yjq~O~
//Utility.log(in.readLine()); ^")SU(`
sHeader=httpConnection.getHeaderFieldKey(i); )/B' ODa
if(sHeader!=null) 9rd7l6$R"
{ {I]X-+D|_
if(sHeader.equals("Content-Length")) 7GyJmzEE
{ L,KK{o|Eq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qjtrU#n
break; Z>O2
} fw[Z7`\Q5
} 88]UA
else 0-N"_1k|?
break; "b#L8kN
} nc0!ag
} !_ng_,J
catch(IOException e){e.printStackTrace ();} @$e!|.{1q
catch(Exception e){e.printStackTrace ();} 2a\?Q|1C
Cq<a|t
$_u9Y!
Utility.log(nFileLength); App9um3:
figCeJ!W4
K<_bG<tm_
return nFileLength; ]P5|V4FXo
} T&/ ]|4
LH"CIL2
*[QFIDn:
//保存下载信息（文件指针位置） h VQj$TA
private void write_nPos() !:N&tuJEv
{ 7FTf8
try{ #cZ<[K q6
output = new DataOutputStream(new FileOutputStream(tmpFile)); `L. kyL
output.writeInt(nStartPos.length); [q%Rx!L
for(int i=0;i<nStartPos.length;i++) >@mvb@4*
{ 7a<-}>sU
// output.writeLong(nPos); k4AF .U`I
output.writeLong(fileSplitterFetch.nStartPos); gXQ s)Eyv
output.writeLong(fileSplitterFetch.nEndPos); w<0F-0:8
} 9(CY"Tc3
output.close(); BbV@ziL
} o~(/Twxam
catch(IOException e){e.printStackTrace ();} y9#r SA*
catch(Exception e){e.printStackTrace ();} nKO4o8js{{
} S 6|#9C&
[s"e?Qee
Jw b'5[R
//读取保存的下载信息（文件指针位置） 3T|xUY)G4
private void read_nPos() ?KKu1~a_
{ v{T%`WuPRf
try{ !qQB}sAf
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?|`Ba-
int nCount = input.readInt(); a9"1a'
nStartPos = new long[nCount]; 3 cb$g
nEndPos = new long[nCount]; ?q%&"
for(int i=0;i<nStartPos.length;i++) 3Aqw)B'"_
{ X>$s>})Y
nStartPos = input.readLong(); ^_Ap?zn
nEndPos = input.readLong(); -fA1_ ?7S
} ^tFbg+.
input.close(); *MG*]\D
} )qL UHE=
catch(IOException e){e.printStackTrace ();} s[}4Q|s%
catch(Exception e){e.printStackTrace ();} TGxmc37?
} t 5{Y'
NQdz]o
B}&9+2M
private void processErrorCode(int nErrorCode) *wd@YMOP
{ W|yFjE&dr
System.err.println("Error Code : " + nErrorCode); xeGl}q|
} "~|;XoMU
Pcs62aE
'WC> _L
//停止文件下载 WCpCWtmy
public void siteStop() !gKz=-C
{ !SxZN dv
bStop = true; '20SoVp
for(int i=0;i<nStartPos.length;i++) N"M?kk,
fileSplitterFetch.splitterStop(); !VXs yH3r5
xyvG+K&
H({Y
} )}[:.Zg,3/
} 2`ED?F68gH
//负责部分文件的抓取 p# 4@
**FileSplitterFetch.java n-5@<y^
*/ n_qDg
package NetFox; V|njgcn d
}iZ>Gm'5
KBO{g:"
import java.io.*; c@ea ;Cv
import java.net.*; 4P(ysTuM
[Dv6z t>
D|lm,
public class FileSplitterFetch extends Thread { Onqd2'%<
&AS<2hB
]\8{z"
String sURL; //File URL KkF3E*q\H
long nStartPos; //File Snippet Start Position `Qrrnq
long nEndPos; //File Snippet End Position 2!y%nkO*
int nThreadID; //Thread's ID -y+u0,=p.
boolean bDownOver = false; //Downing is over UyWKE<
boolean bStop = false; //Stop identical ENEnHu^
FileAccessI fileAccessI = null; //File Access interface |9D;2N(&!
"\:ZH[j
F:P&hK
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException qOi3`6LCV
{ '~Z#h P
this.sURL = sURL; FV1!IE-}-
this.nStartPos = nStart; 51Nh"JTy
this.nEndPos = nEnd; Kr*s]O
nThreadID = id; EA/+~ux
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2S{IZ]
} ;44?`[oP
qUMM}ls
2Y+8!4^L a
public void run() &7gE=E(M
{ %L^S;v3
while(nStartPos < nEndPos && !bStop) @rh1W$
{ YnCWmlC
X`QfOs#\
ic+tn9f\
try{ IIW6;jS
URL url = new URL(sURL); S(5aJ[7Zm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x!<?/I)X
httpConnection.setRequestProperty("User-Agent","NetFox"); `T;M=S^y*E
String sProperty = "bytes="+nStartPos+"-"; Hsoe?kUHF
httpConnection.setRequestProperty("RANGE",sProperty); A^a9,T
Utility.log(sProperty); @+S5"W
<^Hh5kfS'
gXR1nnK
InputStream input = httpConnection.getInputStream(); <AzM~]"3
//logResponseHead(httpConnection); r}gp{Pf7e
8")1,
Xu1tN9:oE
byte[] b = new byte[1024]; $g|/.XH%
int nRead; S"Q$ Ol"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T]5JsrT
{ a*8^M\>m4
nStartPos += fileAccessI.write(b,0,nRead); D\:~G}M
//if(nThreadID == 1) Cu%|}xq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N o}Ly{
} d45JT?qg&
=;1MpD
8: KlU(J
Utility.log("Thread " + nThreadID + " is over!"); 27;t,Oq}
bDownOver = true; |<@X* #X5
//nPos = fileAccessI.write (b,0,nRead); NA,)FmQjk
} >Fzu]G4]
catch(Exception e){e.printStackTrace ();} >Ic)RPO9
} (wNL,<%~
} /lQGFLZL
/&>6#3df-
ZQHANr= 6
//打印回应的头信息 ~CQYF,[Th
public void logResponseHead(HttpURLConnection con) ?PIOuN=
{ N'fE^jqU
for(int i=1;;i++) %2<G3]6^U
{ [Ng#/QXk{
String header=con.getHeaderFieldKey(i); #^- U|~,
if(header!=null) N1RZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r@3VN~
Utility.log(header+" : "+con.getHeaderField(header)); -*sDa6L
else uvK1gJrA)
break; "8Ud&o
} p;dH[NW
} \e5bxc
?~e 8:/@
1/Pou)D
public void splitterStop() @)>9l&
{ /q4<ZS#
bStop = true; Y~T;{&wi
} ZJ9J*5!C
[s-Km/
CT@JNG$<"
} [YY[E 7
!3{> F"
3_W1)vd{
/* T`f6`1x
**FileAccess.java ( w(GJ/g
*//文件访问(定位，写) DFKU?#R
package NetFox; {I|iUfy
import java.io.*; >A#wvQl7
`}ak;^Me
+A 6xY
public class FileAccessI implements Serializable{ `1F[.DdF
=dD<[Iz6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g&y'#,'Q~,
RandomAccessFile oSavedFile; dUOvv/,FZT
long nPos; lBS!=/7
G\S\Qe{P~
Yxye?R-:
public FileAccessI() throws IOException utxT$1iJn~
{ 6D,xs}j1
this("",0); Ep/4o<N(
} f}g)3+i
a;J{'PHu
!8^:19+
public FileAccessI(String sName,long nPos) throws IOException ^GG6%=g'
{ $Scb8<
oSavedFile = new RandomAccessFile(sName,"rw"); 4]jN@@
this.nPos = nPos; 3!M;Z7qF]
oSavedFile.seek(nPos); 0S <;T+WA
} [Q&{#%M
@O#4duM4Qz
&K5wCNX1
public synchronized int write(byte[] b,int nStart,int nLen) bE _=L=NG
{ |?6r&bT
int n = -1; vh3Xd\N
try{ d?(#NP#;
oSavedFile.write(b,nStart,nLen); pIdJ+gu(s
n = nLen; (.a:jL$
} 'NF_!D
catch(IOException e) EotZ$O=
{ :nYl]Rm
e.printStackTrace (); `T2RaWR4=
} i,NU%be
} 5i0R
L6yRN>5aE
return n; |LA./%U
} hM^#X,7
!0:uM)_k
Uj&2'>MJ$
} !_rAAY
U^SJWYi<Y
vt}+d StUm
/* bFk >IifN
**SiteInfoBean.java So?SBh1C
*/ yS0YWqv]6@
package NetFox; Ub=g<MYHV
;rWgt!l
)O~LXK=b
public class SiteInfoBean { F2!C^r,~L
DK 4 8
& .VciSq6
private String sSiteURL; //Site's URL =!m5'$Uz>
private String sFilePath; //Saved File's Path YG ,
private String sFileName; //Saved File's Name :5hKE(3Q
private int nSplitter; //Count of Splited Downloading File S05+G}[$
`oP :F[B
2='gC|&s6
public SiteInfoBean() :4s{?IY)l
{//nSplitter的缺省值为5 U<J4\|1?7'
//default value of nSplitter is 5 y?j#;n0
this("","","",5); ~*RG|4#
} B}_*0D
s^+h>
I\E`xkbBu
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x!GHUz*:uz
{ p\OUxAm
sSiteURL= sURL; oLK-~[p
sFilePath = sPath; $Kgw6
sFileName = sName; PjZsMHW%
this.nSplitter = nSpiltter; =TKu2
Qa@b-v'by
:U_k*9z}=
} 8&?Kg>M
*YmR7g|k
Rd~-.&
public String getSSiteURL() -N;$L~`iAt
{ S]&f+g}&w
return sSiteURL; P34UD:
} 3D L7
[4L[.N@
i]&C=X
public void setSSiteURL(String value) uFQ;}k;}
{ .CGPG,\2
sSiteURL = value; dbM~41C6
} =K'X:UM
jp=z ^l
+(n&>75
public String getSFilePath() n{sF'n</
{ )D'SfNx#{
return sFilePath; -7E)u
} l~P%mVC3m
GaV6h|6_
o2M+=O@
public void setSFilePath(String value) Xc"l')1H
{ "B`k
sFilePath = value; |a9d]^
} {*utke]}*
3 RB+
to9~l"n.s
public String getSFileName() 'fpm] *ig
{ ~[n]la
return sFileName; [7x,&
} C\"nlNKw
2ZTz{|y
7#/->Y
public void setSFileName(String value) e4:,W+g,9
{ s Dq{h
sFileName = value; dy/\>hu
} Zo$,{rl
\dvzL(,
pJ8;7u
public int getNSplitter() yM* CA,(c
{ WcRTv"4&
return nSplitter; QuFzj`(
} d^uE4F}
_0HCtx ;
z!`aJE/
public void setNSplitter(int nCount) X}jWNN
{ >O0z+tj
nSplitter = nCount; 5e)2Jt:
} 4pU|BL\j
} !97U2L4
VtM:~|v
j&6O1
/* Mw{0A\6
**Utility.java vP k\b 3E
*/ tjONN(K`
package NetFox; j%w}hGW%,
=yT3#A~<G
C1V:_-
public class Utility { /NE<?t N
}G{'Rb
TNi4H:\
public Utility() SynL%Y9)|,
{ w_gFN%8
@^q|C&j
;i;2cq
} ucP"<,a
<H; z4
//线程睡眠 `5SLo=~
public static void sleep(int nSecond) i sK_t*
{ fRcs@yZnS
try{ f&=WgITa
Thread.sleep(nSecond); -_%8Q#"
} R=7,F6.
catch(Exception e) v8{ jEAK
{ eT!*_.' e
e.printStackTrace (); v d{`*|x
} &XvSAw+D@
} to2#PXf]y
'R-Ly^:Qd
//日志 0\B31=N(
public static void log(String sMsg) /JcfAY
{ ,0pCc<
System.err.println(sMsg); _ ^2\/@
} HpXQD;
`/e EdqT
pqT+lai)#
public static void log(int sMsg) fen~k#|l
{ DqH?:`G
System.err.println(sMsg); `] fud{
} $.5f-vQp
} q HU}EEv
Y^Y1re+}
NMy+=GZu^
/* `SfBT1#5G
**TestMethod.java nt:d,H<p
*/ ^ UDNp.6k
package NetFox; t@#l0lu$
Yk^clCB{A(
&i5MRw_]]
public class TestMethod { id?B<OM
G~+BO'U9'G
v'e5j``=
public TestMethod() 63NhD
{ ///xx/weblogic60b2_win.exe nOQvBc
try{ m>:zwz< ;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $sxm MP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,_iR
SiteFileFetch fileFetch = new SiteFileFetch(bean); T?4I\SG
fileFetch.start(); LkwjEJQf
} sX c|++
catch(Exception e){e.printStackTrace ();} |19zjhl
r7zS4;b
=>mx>R`S
} vU9j|z
q(XO_1W0V
%>z)Q
public static void main(String[] args) 05ZF>`g*
{ Vb++K0CK
new TestMethod(); +FBUB
} 5*hA6Ex7
} (/[wM>q:r
点击下载更多相关资料