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)); fVdu9 l
} eo.B0NZsF
for(int i=0;i<nEndPos.length-1;i++) ,zxv>8Nt
{ \Pe+]4R-Xo
nEndPos = nStartPos[i+1]; P4+PY 8
} b/ h#{'
nEndPos[nEndPos.length-1] = nFileLength; rj4R/{h
} {kr14l*2
} M5L/3qLh1
~qK/w0=j
\)ZCB7|
//启动子线程 }<*KM)%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tf[)| /M
for(int i=0;i<nStartPos.length;i++) 3Vak C
{ i4XiwjCHN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {faIyKtW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M+:9U&>
nStartPos,nEndPos,i); )ybF@emc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~R50-O
fileSplitterFetch.start(); z\woTL6D]
} {Byh:-e<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6RDy2JAOP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yT~x7,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BfD&e`KI
nEndPos = " + nFileLength); \NKQ:F1
// fileSplitterFetch[nPos.length-1].start(); dcyHp>\)|
%.onO0})
7+qKA1t^
//等待子线程结束 ''3I0X*!
//int count = 0; q%dbx:y#
//是否结束while循环 ?-)v{4{s
boolean breakWhile = false; P%N)]b<c*
qB&Je$_uh
dP`B9>r
while(!bStop) B&6lG!K'?
{ |68k9rq
write_nPos(); i4nFjz
Utility.sleep(500); tBX71d T
breakWhile = true; VKf&}u/
/'b7q y
d[XMQX
for(int i=0;i<nStartPos.length;i++) "\=Phqw
{ Lj3Pp$h
if(!fileSplitterFetch.bDownOver) U]@?[+I0]
{ ,]]*}4[r
breakWhile = false; 8_"NF%%(n
break; Y*S:/b~y
} U3Z-1G~*r
} kg\8 (@h]
if(breakWhile) <Y2$'ETD
break; 4u"Bll
D2=zrU3Y64
b};o:
//count++; Rd|8=`)
//if(count>4) OHrzN']
// siteStop(); z,4 D'F&
} oR/_{#Mz"
\ Ce*5h
)ax>*
System.err.println("文件下载结束！"); /?($W|9+l
} [m%]C
catch(Exception e){e.printStackTrace ();} y*6/VSRkt4
} "?<h,Hvi
c*(^:#"9
't5`Ni
//获得文件长度 m^=El7+
public long getFileSize() N/--6)5~0
{ 3!vzkBr
int nFileLength = -1; ?~!9\dek,
try{ n?;rWq"
URL url = new URL(siteInfoBean.getSSiteURL()); xu%eg]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1<5Ug8q
httpConnection.setRequestProperty("User-Agent","NetFox"); HIx%c5^
~_c1h@
VxuV`Plf
int responseCode=httpConnection.getResponseCode(); $mh\`
if(responseCode>=400) D9?.Ru0.
{ R=F_U
processErrorCode(responseCode); 0U H]
return -2; //-2 represent access is error \4^rb?B
} Z#bO}!
D W^Zuu/)
,wXmJ)/WZ
String sHeader; )*S:C
Kf*Dy:e
^$sqU
for(int i=1;;i++) !?/:p.
{ P^48]Kj7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S#$Kmm |
//Utility.log(in.readLine()); 0bT[05.
sHeader=httpConnection.getHeaderFieldKey(i); KIag(!&
if(sHeader!=null) Wpi35JrC
{ [uLsM<C
if(sHeader.equals("Content-Length")) 4+s6cQ]S`
{ !8|}-eFY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7(N+'8
break; <aDZ{T%
} [~2imS
} I[d<SHo
else (xRcG+3];
break; : -d_
} @NqwJ.%g
} BP0:<vK{
catch(IOException e){e.printStackTrace ();} ;R[3nb9%
catch(Exception e){e.printStackTrace ();} 2\QsF,@`YU
Dfa3&##{
?%}!_F`h%
Utility.log(nFileLength); 0GXY2+p}S
CgrQ"N5
J}:.I>
return nFileLength; XNv2xuOcJ
} ~~ rR< re
!hhL",
j)6p>6
//保存下载信息（文件指针位置） zdd-n[%@V
private void write_nPos() \r[u>7I
{ IT&,?u%
try{ Y`Io}h G$
output = new DataOutputStream(new FileOutputStream(tmpFile)); W ';X4e
output.writeInt(nStartPos.length); i>s
for(int i=0;i<nStartPos.length;i++) -p.\fvip
{ 7-!n-
// output.writeLong(nPos); DQm%=ON7
output.writeLong(fileSplitterFetch.nStartPos); Zo yO[#
output.writeLong(fileSplitterFetch.nEndPos); VL$ T
} NX.xEW@
output.close(); %&| uT
} %kjG[C
catch(IOException e){e.printStackTrace ();} !W9:)5^X
catch(Exception e){e.printStackTrace ();} ]p3f54!
} ow.!4kx{d
wz*iwd-
RbXR/Rd
//读取保存的下载信息（文件指针位置） 5$D"uAp<V
private void read_nPos() d#H9jg15e
{ o1x1SH
try{ ,7]hjf_h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A>1$?A8Q
int nCount = input.readInt(); JHt U"
nStartPos = new long[nCount]; EZ]4cd/i
nEndPos = new long[nCount]; )J}v.8
for(int i=0;i<nStartPos.length;i++) U5OX.0
{ 9ziFjP+1
nStartPos = input.readLong(); <78|~SKAV
nEndPos = input.readLong(); bYnq,JRA
} $2?AJ/2r$b
input.close(); E)gD"^rex
} Mzp<s<BX
catch(IOException e){e.printStackTrace ();} 7MLLx#U
catch(Exception e){e.printStackTrace ();} YAOfuas]j
} jk03 Hd
DfD >hf/
2!Dz9m3
private void processErrorCode(int nErrorCode) !S#3mT-
{ R[a-"
System.err.println("Error Code : " + nErrorCode); .qO4ceW2-~
} 1x:W 3.
9Yv:6@.F
VP~2F E
//停止文件下载 O {1" I
public void siteStop() iM)K:L7d
{ =GPXuo
bStop = true; Nc7"`!;-
for(int i=0;i<nStartPos.length;i++) |Ev|A9J!
fileSplitterFetch.splitterStop(); bOFzq>k_
f\]?,
<gkE,e9
} <46&R[17M
} A iM ukd,
//负责部分文件的抓取 i}sAF/
**FileSplitterFetch.java fY[Fwjj3
*/ (?7=,A7^
package NetFox; d+D~NA[M
oLT#'42+H
t]$n~!
import java.io.*; [-])$~WfW
import java.net.*; U]=yCEb8p
z'EQdQ)
hul,Yd) Z
public class FileSplitterFetch extends Thread { /\w4k
AafS6]y
$^ee~v;m4
String sURL; //File URL N3n]
long nStartPos; //File Snippet Start Position &Q883A J
long nEndPos; //File Snippet End Position w\bwa!3Y
int nThreadID; //Thread's ID .B:ZyTI
boolean bDownOver = false; //Downing is over K381B5_h
boolean bStop = false; //Stop identical J:yv82
FileAccessI fileAccessI = null; //File Access interface wUv?;Y$C
b>;?{
Rql/@j`JX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ga5Q
{ yYA*5 7^A
this.sURL = sURL; V`^*Z}d9
this.nStartPos = nStart; ,t9EL 21
this.nEndPos = nEnd; yV(#z2|
nThreadID = id; 79v+ze
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,|:.0g[n
} gwoe1:F:J
*#T: _
k83K2>]
public void run() 'Qy6m'esW
{ j=l2\W#}
while(nStartPos < nEndPos && !bStop) J\L'HIs
{ %Jt35j@Ee
nqj(V
yE8D^M|g
try{ u}@N Qeg
URL url = new URL(sURL); ba|xf@=&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,8@<sFB'
httpConnection.setRequestProperty("User-Agent","NetFox"); D&%8JL
String sProperty = "bytes="+nStartPos+"-"; J=` 8
httpConnection.setRequestProperty("RANGE",sProperty); NN*L3yx
Utility.log(sProperty); jIubJQR~
<fvu) f
3 7BSJ
InputStream input = httpConnection.getInputStream(); P0l fK}
//logResponseHead(httpConnection); 4&mY-N7A
JbPkC*.
LZV-E=`
byte[] b = new byte[1024]; pU7;!u:c4%
int nRead; {r_HcI(h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qUJ"* )S
{ 5Z>a}s_i
nStartPos += fileAccessI.write(b,0,nRead); $6rm;UH
//if(nThreadID == 1) a{kJ`fK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )p\`H;7*V4
} lVvcrU
^4n#''wJ
zZCl]cql
Utility.log("Thread " + nThreadID + " is over!"); =XR~I
bDownOver = true; {-4+=7Sg1
//nPos = fileAccessI.write (b,0,nRead); 9O;Sn+
} 6$urrSQ`N0
catch(Exception e){e.printStackTrace ();} &=[!L0{
} @z1QoZ^w
} \zBi-GI7
<P h50s4
jIs>>
//打印回应的头信息 Cqr{Nssu
public void logResponseHead(HttpURLConnection con) cq I $9
{ z!g$#hmL>
for(int i=1;;i++) mw"FQ?bJ
{ iB)\*)
String header=con.getHeaderFieldKey(i); ]?y~;-^
if(header!=null) #[prG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qO>UN[Y
Utility.log(header+" : "+con.getHeaderField(header)); ?X|)0o
else [MIgQ.n
break; cY5&1Shb~
} 05wkUo:9
} X:W\EeH
;J W]b]
Hu|Tj<S
public void splitterStop() vb>F)X?b_
{ AU9C#;JD
bStop = true; JvAXLT
} oMbd1uus
:s *
|5~Oh`w
} kLgkUck8]
T?1BcY
c(Dp`f,
/* =Y2 Rht
**FileAccess.java 4/(#masIL
*//文件访问(定位，写) ZXnacc~s
package NetFox; u"0{) ,
import java.io.*; al[^pPKZ
i@rtt M
,WyEwc]
public class FileAccessI implements Serializable{ p/Ul[7A4e
KU8,8:yY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @aS)=|Ls\
RandomAccessFile oSavedFile; 0F)v9EK(W4
long nPos; sC3Vj(d!i
fu!T4{2
$ar^U
public FileAccessI() throws IOException m,HE4`g
{ ai<qK3!O
this("",0); HYdM1s6vo
} sQgz}0_=)
zH1;h
X_78;T)uA
public FileAccessI(String sName,long nPos) throws IOException J1w[gf]J
{ g *,O
oSavedFile = new RandomAccessFile(sName,"rw"); #L.,aTA<
this.nPos = nPos; sa.H,<;
oSavedFile.seek(nPos); VP1hocW
} F6U#EvL
y.Z_\@
l= {Y[T&
public synchronized int write(byte[] b,int nStart,int nLen) (2b${Q@V
{ cW*v))@2
int n = -1; 5UQ{qm*Q
try{ fqI67E$59
oSavedFile.write(b,nStart,nLen); )c11_1;
n = nLen; daSe0:daJ
} %Y~"Stmx
catch(IOException e) 7T/BzXr,B
{ \c\~k0u
e.printStackTrace (); iy~h|YK;
} 'w,gYW
KS*,'hvY
Z#.d7B"
return n; *EuX7LEu_
} l,o'J%<%
1m5l((d
Ey7zb#/<!
} O>DS%6/G
%_|KiW
Hhtl~2t!0
/* D&FDPaJM
**SiteInfoBean.java Q"I(3 tp9[
*/ bUcp8
package NetFox; `}ak]Z_
h\!8*e;RAW
G' U_I
public class SiteInfoBean { ]$2 yV&V&
e 6mZ;y5_
f&CQn.K"
private String sSiteURL; //Site's URL O[d#-0s
private String sFilePath; //Saved File's Path 1%_RXQVG
private String sFileName; //Saved File's Name i bzY&f
private int nSplitter; //Count of Splited Downloading File Phi5;U!
QD7KE6KP'
=DdPwr 0Op
public SiteInfoBean() M0$MK>
{//nSplitter的缺省值为5 %np(z&@wi
//default value of nSplitter is 5 "s|P,*Xf
this("","","",5); K+)3 LR^
} 6,5h4[eF*
NFTv4$5d
rXW.F'=K6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4w+AOWjd
{ S TWH2_`
sSiteURL= sURL; tMw65Xei6b
sFilePath = sPath; U5C]zswL
sFileName = sName; ,\i*vJ#f
this.nSplitter = nSpiltter; X$UK;O
?3~t%Q`
vb[0H{TT2
} '9!_:3[d\]
0J+WCm`
S${%T$>
public String getSSiteURL() :fj>JF\[
{ vD8pVR+
return sSiteURL; %%K3J<5
} }Nr6oUn
XncX2E4E
Z}t;:yhR
public void setSSiteURL(String value) MiZ<v/L2
{ ow'G&<0b
sSiteURL = value; HrE,K\^
} AZ(zM.y!#_
g)6>=Qo`8E
\0~?i6o
public String getSFilePath() rf=l1GW
{ <P#BQt f
return sFilePath; [y8(v ~H
} \lG)J0
C<=rnIf'
%.d.h;^T
public void setSFilePath(String value) $9?:P}$v
{ CF>&mXg\
sFilePath = value; WOn<JCh]
} curYD~7
oaQW~R`_
f+9WGNpw
public String getSFileName() E"'u2jEG^
{ 'ge$}L}4
return sFileName; s=:)!M.i
} ng/h6 S
Ub\^3f
w<H2#d>5!@
public void setSFileName(String value) w=]A;GgA
{ [z"E"_r~%Y
sFileName = value; ?;o0~][!
} [;{xiW4V]
I=dn]}b#P
{d<XDx4`
public int getNSplitter() qRaPh:Q'
{ kxKb}>=
return nSplitter; f?:=@35
} /ckkqk"
rGQD+ d
3Iqvc v
public void setNSplitter(int nCount) ?5CE<[
{ hqln6m
nSplitter = nCount; Qw5-/p=t
} &OJ?Za@p@)
} hY!ek;/Gc
6~sU[thGW
"Bwz Fh
/* 4!Radl3`
**Utility.java c3GBY@m
*/ `Njvk
package NetFox; <pV8 +V)
zgz!"knVx
j_d}?jh
public class Utility { p>eYi \'
9{4oz<U
8x-19#
public Utility() /fUdb=!Z
{ cWo>DuW&
Rd HCbk
IuP~Vt{m
} ?{aC-3VAT
z2{y<a9;?
//线程睡眠 mKu,7nMvF
public static void sleep(int nSecond) >yKz8SV#
{ $1B?@~&
try{ 0R? @JC
Thread.sleep(nSecond); U]}FA2
} eH7x>[lH.
catch(Exception e) /ojx$Um
{ qCI7)L`
e.printStackTrace (); \]4EAKJE
} qpFxl
} =8#.=J[/
,mx\ -lWFy
//日志 ;Q,t65+Am
public static void log(String sMsg) 0?oL zw&
{ p*5_+u
System.err.println(sMsg); m8PS84."]M
} lTu& 9)
?\8
I5E=Ujc_
public static void log(int sMsg) 4Cu\|"5)
{ $b2~Wj*-nJ
System.err.println(sMsg); ]e),#_M
} "p3<-06
} %y9sC1T
L7{}`O/g7
5qH*"i+|s
/* V*PL_|Q5
**TestMethod.java OU.}H $x"
*/ Q*I8RAfd
package NetFox; CR23$<FC
@Ol(:{<
!AJkd.
public class TestMethod { f6K.F
vGlVr.)
0ZwXuq
public TestMethod() k L6s49
{ ///xx/weblogic60b2_win.exe I;"pPJ3G
try{ Q<u?BA/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pl3ap(/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >i*,6Psl[Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); XQn1B3k+
fileFetch.start(); xE;O =mI
} G3:!]}
catch(Exception e){e.printStackTrace ();} w>9d^kU'
dq.U#Rhrx
<-?C\c~G@
} iii|;v]+
Z5(9=8hB/
X-nC2[tu'W
public static void main(String[] args) ws9IO ?|&G
{ X uE: dL?
new TestMethod(); 1|4,jm$
} 3%5YUG@
} (eU4{X7
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