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)); FOa2VP%
} \a:-xwUu<
for(int i=0;i<nEndPos.length-1;i++) u_=>r_J[b
{ t-FrF</0
nEndPos = nStartPos[i+1]; $a')i<m^g
} yX\~{%
nEndPos[nEndPos.length-1] = nFileLength; N8wA">u
} CfLPs)\ACm
} q_6<}2m,U
3k+46Wp
Mc|UD*Z
//启动子线程 %yy|B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pr"q-S>E
for(int i=0;i<nStartPos.length;i++) g*U[?I"sC
{ (Sj?BZjC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6K.0dhl>`B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -A8CW9|mk
nStartPos,nEndPos,i); ~:A=o?V2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~RM_c
fileSplitterFetch.start(); jW|M)[KJN
} 9&4z4@on
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %tz foiJ%P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); orF8%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |>p?Cm
nEndPos = " + nFileLength); 62OZj%CXN
// fileSplitterFetch[nPos.length-1].start(); &ZPyZj
u_)'}
k8sjW!2
//等待子线程结束 $T'lWD*
//int count = 0; [{-;cpM\
//是否结束while循环 ue6&)7:~
boolean breakWhile = false; C'z}jM`g
gDsb~>rb|
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while(!bStop) pu+jw<7
{ ]+78 "(
write_nPos(); >x1?t
Utility.sleep(500); i\P)P!
breakWhile = true; rcMSso2
SnW>`
_$qH\>se
for(int i=0;i<nStartPos.length;i++) LT '2446
{ &FzZpH
if(!fileSplitterFetch.bDownOver) #.W<[KZf
{ ytGcigw(P
breakWhile = false; ,dk!hm u
break; tsTCZ);(
} [lAZ)6E~=
} 4}HY= 0Um
if(breakWhile) v+`gQXJ"G
break; .37Jrh0Iv
7pz #%Hf
sZPA(N?
//count++; FAd4p9[Y
//if(count>4) }7|UA%xz
// siteStop(); $>PV6
} ||kUi=5
|Xk>a7X
39,7N2uY
System.err.println("文件下载结束！"); |`6*~ciUV
} xrl!$xE GX
catch(Exception e){e.printStackTrace ();} b\Gw|?Rv
} ],ISWb
KdtQJ:_`k
+(| ,Ke
//获得文件长度 lK3Z}e*eXQ
public long getFileSize() (E?X@d iu
{ m&8'O\$
int nFileLength = -1; ^NiS7)FX
try{ %FO#j6
URL url = new URL(siteInfoBean.getSSiteURL()); Tf?|*P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .~dNzonq
httpConnection.setRequestProperty("User-Agent","NetFox"); -|A`+1-R+
1$ C\`
\B~}s}
int responseCode=httpConnection.getResponseCode(); Qc]Ki3ls
if(responseCode>=400) u IGeSd5B
{ dBMr%6tz
processErrorCode(responseCode); =6:>C9
return -2; //-2 represent access is error J PK(S~
} <C,lHt
-}9a%
&C=[D_h
String sHeader; ^8eu+E.{
[kyIF\0
RwptFO
for(int i=1;;i++) f& >[$zh
{ 8!(09gW'>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E;AOCbV*$
//Utility.log(in.readLine()); JQ)w/@Vu=
sHeader=httpConnection.getHeaderFieldKey(i); xF8^#J6>
if(sHeader!=null) 0'0GAh2
{ jou741
if(sHeader.equals("Content-Length")) f/NfvLi(AU
{ m3E`kW|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Wc qUF"A
break; 7[?{wbq
} "nEfk{g
} qt!0#z8
else Ryrvu1 k
break; P4S]bPIp
} YZ0Jei8+-
} @is!VzE
catch(IOException e){e.printStackTrace ();} TO~Z6NA0
catch(Exception e){e.printStackTrace ();} ^J-\s_)"
NhYce>
B78e*nNS#2
Utility.log(nFileLength); _)?59
B6#^a
J}'a|a@bk
return nFileLength; X1PXX!]lo[
} 8\/$cP"<^
%DR8M\d1~H
I=G-(L/&
//保存下载信息（文件指针位置） . +
private void write_nPos() <@z!kl
{ HXp$\%A)
try{ E\Et,l#|LY
output = new DataOutputStream(new FileOutputStream(tmpFile)); (6#, $Ze
output.writeInt(nStartPos.length); YZyV
for(int i=0;i<nStartPos.length;i++) )eaEc9o>
{ :sL?jGk\
// output.writeLong(nPos); `}Z`aK
output.writeLong(fileSplitterFetch.nStartPos); [Y_CRxa\u
output.writeLong(fileSplitterFetch.nEndPos); hiQ#<
} mxfmK +'_
output.close(); FLzC kzJ:6
} wYAi-gdOi
catch(IOException e){e.printStackTrace ();} \x9.[?;=e
catch(Exception e){e.printStackTrace ();} BL^\"Xh$|
} |qFCzK9tD/
LW '3m5
>`(]&o6<$
//读取保存的下载信息（文件指针位置） VW/ICX~"d
private void read_nPos() &K.js
{ yrVk$k#6}
try{ %!r@l7<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); U8gf_R'
int nCount = input.readInt(); A5[iFT>
nStartPos = new long[nCount]; :[C"}mR1
nEndPos = new long[nCount]; o!-kwtw`l
for(int i=0;i<nStartPos.length;i++) cA8A^Iv:0
{ f5ttQ&@FF
nStartPos = input.readLong(); C_ 4(-OWq
nEndPos = input.readLong(); JULns#tx}
} {\62c;.
input.close(); y1c2(K>tu
} +l)[A{
catch(IOException e){e.printStackTrace ();} #M~6A^)
catch(Exception e){e.printStackTrace ();} a*(,ydF|L
} l}MVk%[
yJn<S@)VT:
Qf#=Y j
private void processErrorCode(int nErrorCode) '`nf7b(
{ VY|'7in"M
System.err.println("Error Code : " + nErrorCode); ,\Uc/wR
} ziTE*rNJ
sRkPXzK
x=%wPVJ
//停止文件下载 e=u?-8
public void siteStop() > t~2
{ |Jpi|'
bStop = true; sf5F$
for(int i=0;i<nStartPos.length;i++) ~,O&A B
fileSplitterFetch.splitterStop(); 0wnC"2GUX
,?/AIL]_
6[~_;0
} fIwG9cR
} *mtS\J
//负责部分文件的抓取 3 =-XA2zJ
**FileSplitterFetch.java ]r.95|V*
*/ wMvAm%}+
package NetFox; fuao*L]
~lH_d[
G'IRqO*]
import java.io.*; wx[Y2lUh6
import java.net.*; uP NZ^lM
6s(.ul
%&}gt+L(M
public class FileSplitterFetch extends Thread { tx_h1[qi
h= Mmd
C=,O'U(ep
String sURL; //File URL m[8?d~
long nStartPos; //File Snippet Start Position $;VY`n
long nEndPos; //File Snippet End Position (F=q/lK$
int nThreadID; //Thread's ID *pj^d><
boolean bDownOver = false; //Downing is over :xy4JRcF
boolean bStop = false; //Stop identical i!u:]14>
FileAccessI fileAccessI = null; //File Access interface XkRPD
>\4"k4d}
R8N*. [
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException X-k$6}D
{ Mp,aQ0bNS
this.sURL = sURL; ag{cm'.
this.nStartPos = nStart; caD)'FSES
this.nEndPos = nEnd; +Jw+rjnP
nThreadID = id; $*q^7ME
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )y"8Bx=x4
} UR<a7j"@2
AXT(D@sI=
2C[xrZa^
public void run() o_R_
{ .{,fb
while(nStartPos < nEndPos && !bStop) ,0\Pr
{ 4D=^24f`0
Aw"Y_S8.
v4Mn@e_#c
try{ aaRc?b'/
URL url = new URL(sURL); C7Ny-rj}IA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gph:'3 *X
httpConnection.setRequestProperty("User-Agent","NetFox"); ?M9?GodbP.
String sProperty = "bytes="+nStartPos+"-"; zTS P8Q7
httpConnection.setRequestProperty("RANGE",sProperty); hmp!|Q[)
Utility.log(sProperty); CX3yIe~u
:J;&Z{
kG>m(n
InputStream input = httpConnection.getInputStream(); wrm ReT?
//logResponseHead(httpConnection); /ei(Q'pc[
B0$ge"FK9
0'zX6%
byte[] b = new byte[1024]; 7 V3r!y
int nRead; KvY1bMU!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *|Bt!
{ n7VQi+i'
nStartPos += fileAccessI.write(b,0,nRead); Z# o;H$
//if(nThreadID == 1) 8Os: SC@Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wn/Y5
} gn)>(MG
jeWI<ms
5fY7[{2
Utility.log("Thread " + nThreadID + " is over!"); SL5QhP
bDownOver = true; fjh,e
//nPos = fileAccessI.write (b,0,nRead); we&D"V
} cH6<'W{*
catch(Exception e){e.printStackTrace ();} +<rWYF(ii/
} Gc,6;!+(
} Ex-?[Hq
1+v!)Y>Z&
H$rNT/C
//打印回应的头信息 rcUJOI
public void logResponseHead(HttpURLConnection con) \'.|7{Xu
{ k7)<3f3&S.
for(int i=1;;i++) 'mYUAVmSC#
{ F2!]T=
String header=con.getHeaderFieldKey(i); ;!pSYcT,
if(header!=null) 4_W*LG~2s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )MeeF-Ad6
Utility.log(header+" : "+con.getHeaderField(header)); O#n=mJ
else Dks"(0g
break; _fjHa6S
} ^8V8,C)
} /Y0oA3am
WwF2Ry^a
cI (}
public void splitterStop() a_(T9pr
{ iyTKy+3A
bStop = true; 'cPE7uNT
} !EOYqD
o]TKL'gW
0S#T}ITm4Z
} PrvV]#O*
X?++I4\
f,'^"Me$c
/* 6Sz|3ms
**FileAccess.java 1~y\MD*-j
*//文件访问(定位，写) ")i_{C,b^
package NetFox; khVfc
import java.io.*; ]PQ6 em
o}e]W,
#b>D^=NV>)
public class FileAccessI implements Serializable{ cCv@fks
"R^0eNv$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @cB6,iUr
RandomAccessFile oSavedFile; )-^[;:B\k"
long nPos; >)bn #5
Xq%ijo
"@UyUL
public FileAccessI() throws IOException Dd'J"|jF38
{ ^\g?uH6k U
this("",0); >l^[73,]L
} &0RKNpwg
.f9&.H#
j5!pS xOC
public FileAccessI(String sName,long nPos) throws IOException `%_(_%K
{ M.``o1b
oSavedFile = new RandomAccessFile(sName,"rw"); r1[#_A`Yn
this.nPos = nPos; PYyT#AcW2
oSavedFile.seek(nPos); AHet,N
} -=GmI1:=$4
u9j1>QU
h3j`X'
public synchronized int write(byte[] b,int nStart,int nLen) GP0}I@>?
{ r<!/!}fE,
int n = -1; zxC~a97`
try{ C&f{LpB`
oSavedFile.write(b,nStart,nLen); OZ4%6/
n = nLen; `>u^Pm
} oT i$@q
catch(IOException e) ?0?+~0sI
{ thSXri?kl
e.printStackTrace (); 4^7*R
} #B5-3CwB
ONMR2J(
"10.,QK
return n; 'o|=_0-7W
} qPn!.m$/
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WO=P~F<
} C ett*jm_
og`g]Z<I
T/P
/* KJW^pAj$B
**SiteInfoBean.java jdd3[
*/ A'suZpL
package NetFox; /X;! F>
eA-$TSWh
o,!W,sx_
public class SiteInfoBean { En ]"^*
j`QXl
Sr+ &
private String sSiteURL; //Site's URL \RmU6(;IQ
private String sFilePath; //Saved File's Path &W%fsy<
private String sFileName; //Saved File's Name y$+_9VzYB
private int nSplitter; //Count of Splited Downloading File q3ebps9^
wDKA1i%G
h3V; J
public SiteInfoBean() >S@><[C
{//nSplitter的缺省值为5 Q&vU|y
//default value of nSplitter is 5 emG1Wyl
this("","","",5); o$Z]qhq
} O +Xu?W]
|`O210B@
EO\- J-nM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6 -IThC
{ H={5>;8G
sSiteURL= sURL; 0}-MWbG
sFilePath = sPath; LRPdA "Z
sFileName = sName; v,c;dlg_
this.nSplitter = nSpiltter; J:l%
NW~`oc)NS
.e|\Bf0P
} 6t'vzcQs
$u, ~183
mV|Z5=f
public String getSSiteURL() QURpg/<U
{ */j[n$K>~`
return sSiteURL; +K48c,gt?
} BP=<TRp.
.2SD)<}(9
aPHNX)
public void setSSiteURL(String value) sM@1Qyv&0
{ te+r.(p
sSiteURL = value; gP?.io9Oi
} "(yw(/
p5#UH
E2Ec`o
public String getSFilePath() jBJ|%KM
{ MZ_dI"J,
return sFilePath; d[sY]_ dj
} rGQY
nxs'qX(D
CPJ%<+4%b
public void setSFilePath(String value) jR"ACup(
{ <1E5[9 q
sFilePath = value; _@O.EksY3r
} 8i^d*:R
.s>.O6(^%
uM2 .?>`X
public String getSFileName() Q$x 3uH\@
{ !DXK\,;>
return sFileName; -~]]%VJP|
} ):nC&M\W~
k.wm{d]J
{=,+;/0
public void setSFileName(String value) ^@;P-0Sy
{ R?8/qGSVqJ
sFileName = value; nQd~i0`vB
} gqDSHFm:
ZQ[s/
S{UEV7d:n0
public int getNSplitter() M+WN\.2pX
{ R RnT.MU
return nSplitter; yAu.=Eo7
} ?, cI!c`
p;)@R$*
VTn6@z_ x
public void setNSplitter(int nCount) vO8CT-)
{ Oox,4&
nSplitter = nCount; EB8<!c ?
} ~Z5Wwp]a
} *P+8^t#Vp
te&p1F
3H`ES_JL
/* .|GnTC q
**Utility.java uk)D2.eS,
*/ a t%qowt
package NetFox; }kMKA.O"
9Qn*frdY,
>(a[b@[K
public class Utility { qwYq9A$+
=6[R,{|C
]GXE2A_i;
public Utility() PGA `R
{ }PzHtA,V
'Xg9MS&
,<fs+oi
} -{Fy@$!
#z9@x}p5g
//线程睡眠 1V;,ZGI*
public static void sleep(int nSecond) ]9~6lx3/
{ fi'\{!!3m^
try{ VX e7b
Thread.sleep(nSecond); %R?#Y1Tq;
} [W=6NAd
catch(Exception e) B2,JfKk/
{ /086qB|
e.printStackTrace (); / a$B8,
} jWh}cM=
} =p&uQ6.i+
sF1j4 NC
//日志 >{=~''d,w
public static void log(String sMsg) )0{ZZ-beG
{ y-o54e$4Cq
System.err.println(sMsg); o*xft6U
} n4 J*04K
n hGh5,
?$%2\"wX~7
public static void log(int sMsg) z=Khbh
{ J;Veza
System.err.println(sMsg); F"t.ND
} )OV2CP
} {Zf 9} !qF
nH|7XY9"
K7]QgfpSZ
/* AI2@VvB
**TestMethod.java myDcr|j-a
*/ -h{|u{t
package NetFox; 1IWP~G
1D)=q^\I
$mF9os-
public class TestMethod { wQN/MYF[
.a `ojT
a fUOIM
public TestMethod() Mtq^6`JJ'
{ ///xx/weblogic60b2_win.exe tQcn%CK
try{ d8M8O3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EGK7)O'W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !Q5NV4gd+
SiteFileFetch fileFetch = new SiteFileFetch(bean); \mDBOC0eK
fileFetch.start(); =\i{dj
} 2q%vd=T
catch(Exception e){e.printStackTrace ();} gtRs||
?=%#lZ&?
$;B0x
} S/xCX!
vABUUAo!Jr
nx@h
public static void main(String[] args) tz/NR/[
{ &HJ'//bv
new TestMethod(); O@sJ#i>
} poVtg}n
} K1m'20U
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