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)); '+X9MzU*\
} 3A} ntA!
for(int i=0;i<nEndPos.length-1;i++) J 6S
{ I#Tl
nEndPos = nStartPos[i+1]; Hf %;FaJ=
} ^aZ Wu|p
nEndPos[nEndPos.length-1] = nFileLength; +>OEp* j
} DZXv3gnX
} Z<r&- !z
|"P5%k#6^>
P N_QK Z
//启动子线程 Y#6@0Nn[G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^D B0C
for(int i=0;i<nStartPos.length;i++) ;<q@>p[
{ /:e|B;P`k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .#h]_%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3MjMN%{P
nStartPos,nEndPos,i); ;:9 x.IkxC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); va;d[D,
fileSplitterFetch.start(); `>8|
} &/\0_CoTR\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (U`7[F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X5U!25d]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M14_w,
nEndPos = " + nFileLength); &nn.h@zje
// fileSplitterFetch[nPos.length-1].start(); %4L|#^7:
^B& Z
U)p2PTfB
//等待子线程结束 B>Nxc@=D
//int count = 0; oT|E\wj
//是否结束while循环 z<<` 1wqg
boolean breakWhile = false; 3Uag[ms
6XQ)Q)
66'TdF]"
while(!bStop) h)wR[N]n
{ 6w}:w?=6
write_nPos(); MO#%w
Utility.sleep(500); o-O/MS
breakWhile = true; XtfL{Fy|T
u'K<-U8H
>/bl r}5 H
for(int i=0;i<nStartPos.length;i++) lGLZIp
{ RFK N,oB
if(!fileSplitterFetch.bDownOver) \\)-[4uC
{ /2HwK/RZ
breakWhile = false; %k$C
break; Gs?W7}<$
} }UGPEf\
} Zc9 n0t[
if(breakWhile) "-xC59,
break; :{66WSa@Dd
o3WkbMJWM
?>o39|M_w
//count++; LOida#R
//if(count>4) ^m1Rw|
// siteStop(); .X2mEnh
} c>UITM=!I
2CxdNj
?|hzAF"U
System.err.println("文件下载结束！"); e#'`I^8l
} KFV]2mFN
catch(Exception e){e.printStackTrace ();} wqGZkFg1
} 2tr2:PB`
pb{P[-f
iqoPD4A
//获得文件长度 Nl@Hx
public long getFileSize() t'Q48QAb?
{ _ _)Z Q
int nFileLength = -1; IeU.T@ $
try{ x9_ Lt4
URL url = new URL(siteInfoBean.getSSiteURL()); H7SqM D*y9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +Zr03B
httpConnection.setRequestProperty("User-Agent","NetFox"); zIo))L
mtOrb9`m
nlY ^
int responseCode=httpConnection.getResponseCode(); W;-Qze\D
if(responseCode>=400) u%h<5WNh<
{ _+;x4K;
processErrorCode(responseCode); z{n=G
return -2; //-2 represent access is error r\NnWS J
} J5o"JRJ"
So8P8TCK
UJm`GO
String sHeader; sJ?kp^!g
W"Rii]GK"
O.$<Bf9
for(int i=1;;i++) nu3 A'E`'k
{ Z?x]HB`r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {[9^@k
//Utility.log(in.readLine()); WWO jyj
sHeader=httpConnection.getHeaderFieldKey(i); WWe.1A,
if(sHeader!=null) LTY.i3
{ FCe503qND$
if(sHeader.equals("Content-Length")) x9ws@=[:
{ 0?:ZERv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]t=>#
break; u3ZG;ykM
} xxiLi46/
} 'RA[_Z
else e!-'O0-Kw
break; HIU@m<
} |-|BM'Y
} A|&EI-In
catch(IOException e){e.printStackTrace ();} VC+\RB#:-
catch(Exception e){e.printStackTrace ();} ;|^fAc~9{r
*@ o3{0[Z
@1+/r?b
Utility.log(nFileLength); WIGb7}egR
t!=S[
<7&b|f$CL
return nFileLength; k@Tt,.];
} cnc$^[c
0PfFli`2;
@<PL
//保存下载信息（文件指针位置） 4Oy c D
private void write_nPos() _YJwF1e+M
{ NWpRzh8$u
try{ j>T''Tf
output = new DataOutputStream(new FileOutputStream(tmpFile)); !^7:Rr_
output.writeInt(nStartPos.length); [Vf|4xcD
for(int i=0;i<nStartPos.length;i++) m88~+o<G%
{ 1)R)+`y
// output.writeLong(nPos); z%KChU
output.writeLong(fileSplitterFetch.nStartPos); qb<gh D=j
output.writeLong(fileSplitterFetch.nEndPos); s_[?(Ip{
} S3<v?tqLr
output.close(); b#m47yTW9<
} Gs6#aL}]R
catch(IOException e){e.printStackTrace ();} r%#qbsN
catch(Exception e){e.printStackTrace ();} ~4^e a
} g3Q #B7A
yS43>UK_W+
b?$09,{0
//读取保存的下载信息（文件指针位置） 4TKi)0 #7
private void read_nPos() }cT}G;L'-
{ 3pp w_?k
try{ R3PhKdQ"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +{I\r|
int nCount = input.readInt(); 'KL(A-}!
nStartPos = new long[nCount]; \\qg2yI
nEndPos = new long[nCount]; ?*@h]4+k'
for(int i=0;i<nStartPos.length;i++) dF,FH-
{ 5^dw!^d
nStartPos = input.readLong(); `R> O5Rv
nEndPos = input.readLong(); t5k&xV=~ #
} )yP>}ME
input.close(); o7+/v70D
} > 95Cs`>d
catch(IOException e){e.printStackTrace ();} [jw o D
catch(Exception e){e.printStackTrace ();} _#O?g=1
} T42g4j/l~
$VA4% 9
zT% kx:Fk
private void processErrorCode(int nErrorCode) h[]N=X
{ 6!nb)auVi
System.err.println("Error Code : " + nErrorCode); MUrY>FYgx
} 2z\F m/Z.
b{rmxtx
RtL<hD
//停止文件下载 ^ztf:'l@C
public void siteStop() CA4-&O"
{ o^?{j*)g
bStop = true; WI6E3,ejB1
for(int i=0;i<nStartPos.length;i++) K*9b `%
fileSplitterFetch.splitterStop(); =;H'~
%\cC]<>
@nP}q!y
} {Y[D!W2y
} DVJc-.x8
//负责部分文件的抓取 VO Qt{v{1|
**FileSplitterFetch.java A 5 X+Z
*/ Ic K=E]p
package NetFox; mz*z1`\7v\
:RsPGj6
2M?lgh4"
import java.io.*; pL@zZK0
import java.net.*; m_2P{
!r*;R\!n2
x]oQl^F
public class FileSplitterFetch extends Thread { Q*.FUV&;
/aG>we
`5Btg. &
String sURL; //File URL hD1AK+y
long nStartPos; //File Snippet Start Position Wts{tb
long nEndPos; //File Snippet End Position `4bd,
int nThreadID; //Thread's ID shT[|@"C
boolean bDownOver = false; //Downing is over >@U<?wP
boolean bStop = false; //Stop identical <o+ 7U
FileAccessI fileAccessI = null; //File Access interface 0JNOFX
)VMBo6:+
lM,zTNu-z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #sU~fq
{ _oTT3[7P
this.sURL = sURL; *BsDHq-F~
this.nStartPos = nStart; xbC8Amo;8"
this.nEndPos = nEnd; UD2<!a'T
nThreadID = id; +^?-}v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2g6_qsqi
} //lZmyP?
Iv72;ZCh?6
]7kGHIJ|
public void run() s;s-6%p
{ |WU`p
while(nStartPos < nEndPos && !bStop) nnL$m_K~
{ oks=|'&
_]UDmn[C
9*;isMkq<
try{ ;jU-<
URL url = new URL(sURL); -]\E}Ti
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); df6Ν4L
httpConnection.setRequestProperty("User-Agent","NetFox"); xzl4v=7
String sProperty = "bytes="+nStartPos+"-"; I~LQ1_
httpConnection.setRequestProperty("RANGE",sProperty); F/*fQAa"
Utility.log(sProperty); }Tr83B|
x7Rq|NQ
t;dQ~e20
InputStream input = httpConnection.getInputStream(); s}#[*WOc
//logResponseHead(httpConnection); IS2Ij
s~Wu0%])Q
; axaZV
byte[] b = new byte[1024]; K#UA M.
int nRead; -`dxx)x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) urXb!e{l
{ fslk7RlSKg
nStartPos += fileAccessI.write(b,0,nRead); NzAtdcwR
//if(nThreadID == 1) mK40 f
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^lai!uZVa
} LnTe_Q7_
90iW-"l+[
l~4e2xoT
Utility.log("Thread " + nThreadID + " is over!"); /;nO<X:XV
bDownOver = true; N~}v:rK>g
//nPos = fileAccessI.write (b,0,nRead); V\K m% vP
} ;D"P9b]9$
catch(Exception e){e.printStackTrace ();} s$>m0^
} :+ 9Ft>
} 8U2wH
,eeL5V
Ot$cmBhw!
//打印回应的头信息 r(1pvcWY-
public void logResponseHead(HttpURLConnection con) df4^C->:
{ ;}eEG{`Y
for(int i=1;;i++) A,lw-(.z4Z
{ ss`q{ARb
String header=con.getHeaderFieldKey(i); k;fnC+Y$s
if(header!=null) YY:iPaGO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wAYzR$i
Utility.log(header+" : "+con.getHeaderField(header)); ]u4>;sa
else udEb/7ZL
break; Fm$n@RbX
} DAMpR3
} hw ;dm
y>7VxX0xi
<Xs@ \
public void splitterStop() ?%dCU~ z
{ bpF@}#fT
bStop = true; |T$a+lHMD
} eW"x%|/Q7
<S8I"8{Mb
*M5$ h*;v
} 2>MP:yY;K
Eo {1y
Sa[EnC
/* c(Uj'uLc
**FileAccess.java +A'q#~yILa
*//文件访问(定位，写) K*Nb_|~
package NetFox; >|_gT%]5
import java.io.*; 1RI#kti-"
1FD7~S|
1(:b{Bl
public class FileAccessI implements Serializable{ (Y'UvZlM%P
c;b[u:>~-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xyS2_Q
RandomAccessFile oSavedFile; kKxL04
long nPos; []=FZ`4
~b>nCP8q
<nOuyGIZ
public FileAccessI() throws IOException ^B<PD]
{ OUlxeo/
this("",0); GG@I!2,_
} q(ZB.
]|C_`,ux
45r]wT(C
public FileAccessI(String sName,long nPos) throws IOException B c,"12
{ fR]p+\#8u*
oSavedFile = new RandomAccessFile(sName,"rw"); `eMrP`
this.nPos = nPos; F1?CqN M
oSavedFile.seek(nPos); (opROsFh
} .KiPNTh'
B%%.@[o,
-(/2_&"
public synchronized int write(byte[] b,int nStart,int nLen) 3D?IG\3
{ :Bx+WW&P.i
int n = -1; dDv{9D,
try{ B&%L`v2[
oSavedFile.write(b,nStart,nLen); f"ZqA'KB#
n = nLen; zx\.2<K
} ;uM34^
catch(IOException e) ,-cpsN
{ J+/}K>2#
e.printStackTrace (); 2p$n*|T&c
} %Lh-aP{[e
wE,=%?"
I<D&,LFH*w
return n; vpeq:h
} vKU]80T
S 0R8'Y
[Vrc:%Jk
} S F&M (=w<
G?Qe"4 .
L?3VyBE
/* [ -9)T
**SiteInfoBean.java V9+xL 1U#
*/ =Q/w%8G
package NetFox; W;3 R;
1?D8|<
"jl1.Ah
public class SiteInfoBean { {&\J)oZ
X;s3y{ku
t/v@vJ`vSH
private String sSiteURL; //Site's URL nu4Pc
private String sFilePath; //Saved File's Path otWo^CE$
private String sFileName; //Saved File's Name jGk7=}nw
private int nSplitter; //Count of Splited Downloading File VRtbHam
i;[h 9=\/
R7E]*:0}
public SiteInfoBean() XsAY4WTS
{//nSplitter的缺省值为5 L"""\5Bn(
//default value of nSplitter is 5 $Qn&jI38
this("","","",5); 9O),/SH;:
} g>6:CG"
HO266M
89*S?C1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bh=\
{ J>f /u:.
sSiteURL= sURL; 3q'K5} _
sFilePath = sPath; v;)BVv
sFileName = sName; <ldid]o #
this.nSplitter = nSpiltter; c+szU}(f6(
.Lr`j8
:@:g*w2K
} r:fwrC
P\D[n-&
68vxI|EZ
public String getSSiteURL() Q9`s_4
{ 06PhrPVa!\
return sSiteURL; ?,WUJH?^
} )v${&H
iP~sft6
fswZM\@
public void setSSiteURL(String value) M.o?CX'
{ GYFgEg}
sSiteURL = value; k TFz_*6.
} B"~U<6s0
PLO\L W
"F&Tnhh4
public String getSFilePath() b cC\
{ l9]o\JFXk
return sFilePath; *Zc9yZl2
} Rb{+Ki
5/Ydv RB67
aF D="Zh
public void setSFilePath(String value) 48lzOG
{ s ;48v
sFilePath = value; eA`]KalH
} u=(H#o<#
t@X M /=d
3wV86tH%
public String getSFileName() TAXd,z N
{ F?!FD>L{`
return sFileName; BfX%|CWh
} 0Wa#lkn$I
g;$E1U=R-E
].LJt['%8
public void setSFileName(String value) f&K}IM8& #
{ Q]!6uA$A
sFileName = value; cL6 6gOEL
} wG_4$kyj
(:ZPt(1
EJO.'vQ
public int getNSplitter() 4;?1Kb#
{ ?A|zRj{
return nSplitter; <MRC%!.
} G?>qd}]y0L
K3Huu!Tr
#]"/{Z
public void setNSplitter(int nCount) 1Pu ,:Jt
{ Q?Wr7
nSplitter = nCount; ,Yo: &>As
} x<8\-
} t9ER;.e
>Ja0hS{*
fv:L\N1u
/* 3)dP7rmZ
**Utility.java sc<kiL
*/ A8J?A#R*{q
package NetFox; ',DeP>'%>
o\d |CE;>
TV? ^c?{5
public class Utility { g .3f2w
$,!hD\a
p#)e:/Qy
public Utility() ,Ak ^nX
{ Nc,*hsx'
fQxSMPWB
tAaYL \~
} *8/VSs
e "_&z# 2_
//线程睡眠 D4d]3|/T
public static void sleep(int nSecond) o.v2z~V
{ /({P1ti:C
try{ dZF8R
Thread.sleep(nSecond); ohtT O]\
} D^$]>-^
catch(Exception e) S=4R5igrC
{ V_jiOT!
e.printStackTrace (); +5#x6[
} !TGr.R
} P?xA$_+
6F,/w:
//日志 %z=`JhE"Q
public static void log(String sMsg) jn~!V!++
{ %t q&
System.err.println(sMsg); Kf|0*c
} (s&ORoVGn
g083J}08
^mAJ[^%
public static void log(int sMsg) Q Qi@>v|d
{ cFw3Iw"JJ
System.err.println(sMsg); B+|IZoR
} 2f `&WUe
} -W9gH
9g96 d-
ci;&CHa
/* -7&?@M,u
**TestMethod.java j+nv=p
*/ (p^S~Ax
package NetFox; FbmsN)mv!%
u9BjgK(M
f0OgK<.>T
public class TestMethod { s~=g*99H
KLW&bJ$|j
S3QaYq"v
public TestMethod() 1}`2\3,
{ ///xx/weblogic60b2_win.exe rJX\6{V!_
try{ !F-sA: xq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); TKd6MZhT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gj)uyjct
SiteFileFetch fileFetch = new SiteFileFetch(bean); *]>])ms)
fileFetch.start(); XYMxG:
} FQ1arUOFW,
catch(Exception e){e.printStackTrace ();} ghX:"vV{n
$:(z}sYQ7
0Lx3]"v
} ?H<~ac2e
\d:h$
PFm\[2
public static void main(String[] args) )}quw"H
{ g(nK$,c
new TestMethod(); ERp{gB2U?
} w?*jdwh,'
} ^zHRSO
点击下载更多相关资料