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)); G5~ Jp#uA
} nY7 ZK
for(int i=0;i<nEndPos.length-1;i++) 7I>@PVN
{ C^vB&3ghi
nEndPos = nStartPos[i+1]; fbaQXM
} v{7Jzjd
nEndPos[nEndPos.length-1] = nFileLength; 6BT o%
} ;Js-27_0
} fg1_D
-ZXC^zt
x O`#a=
//启动子线程 UR;FW`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'Q\I@s }
for(int i=0;i<nStartPos.length;i++) mouLjT&p
{ Q)}_S@v|%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _G]f v'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), VFLxxFJ
nStartPos,nEndPos,i); \OMWE/qMy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +c@s
fileSplitterFetch.start(); cTW3\S=
} NEInro<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ra%" +=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l*;Isz:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", V@6,\1#`|
nEndPos = " + nFileLength); P9j[ NEV
// fileSplitterFetch[nPos.length-1].start(); 8.9TWsZ
A1`y_ Aj
=<nx[J
//等待子线程结束 7VWq8FH`
//int count = 0; 5c*kgj:x
//是否结束while循环 |> mx*G
boolean breakWhile = false; WVPnyVDc
XI+m
WJ)( *1
while(!bStop) cfn\De%.
{ >U/m/H'
write_nPos(); #sLyU4QV
Utility.sleep(500); /(#;(]
breakWhile = true; gWcl@|I;\
$ekJs/I&
qi!Nv$e
for(int i=0;i<nStartPos.length;i++) $f`\TKlN
{ mx`C6G5
if(!fileSplitterFetch.bDownOver) ]F:5-[V#
{ +r0ItqkM
breakWhile = false; IBYRuaEB
break; (7 i@@
} vb 2mY
} }%z {tn
if(breakWhile) e.X*x4*>~
break; 9|19ia@[\
i}C9
hq}kAv4B=
//count++; D,FX&{TYU
//if(count>4) p-d2HXo
// siteStop(); S%ULGX:@ga
} ESdjDg$[u
:{za[,
N5$IVz}
System.err.println("文件下载结束！"); 1k&**!S]%
} qcYF&
catch(Exception e){e.printStackTrace ();} y%* hHnGd
} ~y@,d
yQ5F'.m9e
R0>GM`{
//获得文件长度 1\GS"4~P
public long getFileSize() &_mOw.
{ j*uc$hC"
int nFileLength = -1; !)1r{u
try{ 7g'jg7
URL url = new URL(siteInfoBean.getSSiteURL()); 3f;W+^NY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jb. V4
httpConnection.setRequestProperty("User-Agent","NetFox"); w9QY2v,U
nW1Obu8x|
Gn}G$uk61
int responseCode=httpConnection.getResponseCode(); <pAN{:
if(responseCode>=400) KW^#DI6tr
{ qY^OO~[
processErrorCode(responseCode); pwq a/Yi
return -2; //-2 represent access is error &PJ&XTR
} j6zZ! k
1:2t4}
!L..I2'
String sHeader; )2 E7>SQc~
{.vU;
~j}7Fre
for(int i=1;;i++) M'Ec:p=X"
{ d@o1<Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `~${fs{-`/
//Utility.log(in.readLine()); /yRP>CX~
sHeader=httpConnection.getHeaderFieldKey(i); s d-5AE
if(sHeader!=null) ["N{6d&Q
{ qo2/?]
if(sHeader.equals("Content-Length")) /%W&zd=%#
{ mJjd2a"vi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !U}dYB:O
break; =uM2l
} lFHj]%Y
} {rp5qgVE<
else :el]IH
break; xiv1y4(%
} g\%vkK&I
} D]NfA2B7
catch(IOException e){e.printStackTrace ();} ,MH9e!
catch(Exception e){e.printStackTrace ();} 9 U6cM-p?
]xO`c
+Usy
Utility.log(nFileLength); |7 .WP;1
JA .J~3
H}TzNs
return nFileLength; u 3&9R)J1
} 0FL PZaRP
zq(R!a6
Q&p'\6~
//保存下载信息（文件指针位置） 9NX/OctFa'
private void write_nPos() Dwvd
{ nYfZ[Q>v
try{ LP_w6fjT
output = new DataOutputStream(new FileOutputStream(tmpFile)); Knd2s~S
output.writeInt(nStartPos.length); G5JZpB#o
for(int i=0;i<nStartPos.length;i++) {yPJYF_l
{ 8KQD w:
// output.writeLong(nPos); &<Gs@UX~w
output.writeLong(fileSplitterFetch.nStartPos); Qw&It
output.writeLong(fileSplitterFetch.nEndPos); ?Q`u\G3.m
} _*(n2'2B
output.close(); 0~.OMG:=
} n2<#]2h
catch(IOException e){e.printStackTrace ();} +YS0yTWeX
catch(Exception e){e.printStackTrace ();} Gag=GHG
} (QARle(i
$j ZU(<4,
XMt5o&U1
//读取保存的下载信息（文件指针位置） 3+[R !
private void read_nPos() EfTuHg$pe
{ [N$#&4{Je
try{ =!@5!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gO{XD.s
int nCount = input.readInt(); KJ/ *BBf
nStartPos = new long[nCount]; ^o`;C\
nEndPos = new long[nCount]; *b< a@
for(int i=0;i<nStartPos.length;i++) .?C-J
{ cjTV~(i'4A
nStartPos = input.readLong(); .fZ*N/
nEndPos = input.readLong(); ;cye 'E
} v61'fQ1Qg!
input.close(); pA ,xDs@37
} VR/*h%
catch(IOException e){e.printStackTrace ();} 4tv}5llSG
catch(Exception e){e.printStackTrace ();} &W'X3!Te
} ?8{x/y:
:E$<!q
%TOYU(k
private void processErrorCode(int nErrorCode) $-tgd<2h
{ F_Pv\?35z
System.err.println("Error Code : " + nErrorCode); g;|3n&
} /hNZ7\|P
@zz4,,]
TB!z:n
//停止文件下载 _[eAA4h
public void siteStop() rKK{*%n
{ UK{6Rh ;
bStop = true; GS!7HphR
for(int i=0;i<nStartPos.length;i++) ;rD M%S@
fileSplitterFetch.splitterStop(); Rds_Cd C
=TTk5(m
7RH1,k
} )Ha`>
} "4 Lt:o4x
//负责部分文件的抓取 dI[hQxU
**FileSplitterFetch.java , [V#o-Z
*/ L?WF[nFR
package NetFox; G;^},%<
b.Yl0Y
1WArgR
import java.io.*; %fv;C
import java.net.*; ]\fXy?2
A7|CG[wZ
BCrX>Pp}r
public class FileSplitterFetch extends Thread { @raw8w\Zj+
@W{VT7w
J.R|Xd
String sURL; //File URL "s:eH"_s
long nStartPos; //File Snippet Start Position -AJ$-y
long nEndPos; //File Snippet End Position 0`{3|g
int nThreadID; //Thread's ID dKKh^D`~
boolean bDownOver = false; //Downing is over Z9TUaMhF
boolean bStop = false; //Stop identical .Mn+Bd4f
FileAccessI fileAccessI = null; //File Access interface eM3-S=R?<g
I04GQql
1c$<z~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UJ}Xa&*H\
{ ZQ&A'(tt4
this.sURL = sURL; @xO?SjH
this.nStartPos = nStart; G`a,(<kT;
this.nEndPos = nEnd; 9;fyC=
nThreadID = id; 7W{xK'|]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 3 &aBU[
} Aqc Cb[1r
fmDn1N-bG
2l7Sbs7
public void run() /b44;U`v5-
{ hI&ugdf
while(nStartPos < nEndPos && !bStop) Z~JX@s0v
{ 3)?v
*{ =5AW}o
2jMV6S9
try{ 72YL
URL url = new URL(sURL); FuA8vTV{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y([""z3<w
httpConnection.setRequestProperty("User-Agent","NetFox"); %Ydzzr3
String sProperty = "bytes="+nStartPos+"-"; M[;N6EJH
httpConnection.setRequestProperty("RANGE",sProperty); Qh3V[br
Utility.log(sProperty); QG|KZ8uO
c@+;4Iz
-{ae
InputStream input = httpConnection.getInputStream(); 8 |@WuD
//logResponseHead(httpConnection); %lr<;
i?*_-NAm
I6k S1
byte[] b = new byte[1024]; [f_4%Now
int nRead; rh8.kW-K_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :9_N Y"P
{ sSh=Idrx
nStartPos += fileAccessI.write(b,0,nRead); e)(m0m\
//if(nThreadID == 1) B/iRR2h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j-?zB.jAh
} %XpYiW#AK
?gq',FFDq
qWQ7:*DL
Utility.log("Thread " + nThreadID + " is over!"); BIFuQ?j3
bDownOver = true; -w0U}Te^
//nPos = fileAccessI.write (b,0,nRead); Up(Jw-.
} Rk1B \L|M
catch(Exception e){e.printStackTrace ();} ^m3[mY [a
} QGWfF,q
} oAMB}a;
\Mujx3Fmvx
<@Lw '
//打印回应的头信息 (>E}{{>2r
public void logResponseHead(HttpURLConnection con) L>,j*a_[
{ @YH<Hc
for(int i=1;;i++) CL~21aslI
{ MzF9 &{N
String header=con.getHeaderFieldKey(i); 'CrBxaA]s
if(header!=null) &$'=SL(Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LC!ZeW35
Utility.log(header+" : "+con.getHeaderField(header)); bIX'|=
else d1MVhE
break; ]<V,5'xh
} _li\b-
} 1j_x51p
NXwlRMbo
Gk.;<d
public void splitterStop() Esc*+}ck
{ !'-|]xx(
bStop = true; !k=>Wb8n2
} Ik92='Z
dIOj]5H3F
<2\4eusk
} LPg1G+e
@Ju!|G9z/p
NwK(<dzG
/* )$# Ku2X
**FileAccess.java QQd%V#M?
*//文件访问(定位，写) *@M7J
package NetFox; SqiLp!Y`
import java.io.*; /1Xji0LK
v{R:F
jh3LD6|s}
public class FileAccessI implements Serializable{ `7;I*|
D]I]I!2c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IX|2yu4
RandomAccessFile oSavedFile; ?\HXYCi0r
long nPos; :&]THUw
. PzlhTL7
2Z ? N
public FileAccessI() throws IOException dMA"% R
{ ~}SOd<n)|
this("",0); UUxDW3K
} $ }u,uI
/r4QDwu
aZe[Nos
public FileAccessI(String sName,long nPos) throws IOException yM3]<~m
{ Qi_De '@
oSavedFile = new RandomAccessFile(sName,"rw"); G1Qc\mp
this.nPos = nPos; (HHVup1f
oSavedFile.seek(nPos); -?8;-h, h
} (IbT5
)8H5ovj.
zUw9
public synchronized int write(byte[] b,int nStart,int nLen) Z/z(P8#U\
{ u>G#{$)
int n = -1; FyXz(l:
try{ _&/FO{F@m
oSavedFile.write(b,nStart,nLen); -L9I;]:KY
n = nLen; cVzOW|NVx
} &ZjQa.-U>
catch(IOException e) pg}9baW?
{ H8>u:
e.printStackTrace (); EDm,Y
} =h~\nTN
MDfE(cn2q
/Z:\=0`
return n; D4:c)}
} w$JG:y#
BF*]l8p
{r9fKA
} yDt3)fP#
FW)G5^Tf
49o5"M(
/* Kn]c4h}@b5
**SiteInfoBean.java -U6" Ce
*/ DA[s k7
package NetFox; RH,1U3?
p,y(Fc~]g'
R<}Yf[TQ
public class SiteInfoBean { |%F[.9Dp
$K)9(DD
0|0<[:(hc
private String sSiteURL; //Site's URL uvo2W!
private String sFilePath; //Saved File's Path C|kZT<,]
private String sFileName; //Saved File's Name MIcF"fB![
private int nSplitter; //Count of Splited Downloading File e1e2Wk
*mQOW]x%
3>[_2}l
public SiteInfoBean() Z4\$h1tl
{//nSplitter的缺省值为5 *$ZLu jy7
//default value of nSplitter is 5 *"N756Cj
this("","","",5); )V!dmVQq{g
} +LwE=unS
:y)'_p *l/
<y+8\m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S[o_$@|
{ Qrt[MJ+#
sSiteURL= sURL; +L4_]
sFilePath = sPath; i,=CnZCh
sFileName = sName; b|i94y(
this.nSplitter = nSpiltter; mQQ5>0^m
QdM&M^
pN+lC[C
} ^-3R+U- S
90%alG1>y
)v!>U<eprD
public String getSSiteURL() D`=hP(y^
{ QI@!QU$K&
return sSiteURL; 9JHu{r"M
} 6?U2Et
.P[ %t=W
*KP 60T
public void setSSiteURL(String value) 9aw- n*<
{ ~]71(u2
sSiteURL = value; o=`FGowF
} W s!N%%g
X<4h"W6
gi;#?gps
public String getSFilePath() ~eH+*U|\|M
{ \lVX~r4
return sFilePath; $I%75IZ
} *$nz<?
4_3 DQx9s
?XVJ$nzW
public void setSFilePath(String value) gB!K{ Io'
{ m:77pE&o
sFilePath = value; UE4zmIq
} h' OLj#H
X0X!:gX
F=C8U$'S
public String getSFileName() X!0s__IOc
{ V~y4mpfX
return sFileName; !=(~e':Gv
} N@UO8'"9K&
EM+_c)d}
]k[y#oB
public void setSFileName(String value) pU`4bT(w%
{ fDmGgD?
sFileName = value; %(`4wo},
} pb~&gliW
c43"o
N 3)OH6w"
public int getNSplitter() pA9:1*+;;
{ |q?I(b4Q@
return nSplitter; i)V-q9\
} PgZ~of&
U!sv6=(y@
:U`8s#
public void setNSplitter(int nCount) UOrfwK
{ 36D-J)-Z
nSplitter = nCount; ;|v6^2H"
} ]*+ozAG4
} dB7E&"f
^'DrU<o
24 S,w>j
/* t@-:e^ v
**Utility.java v~:$]a8
*/ 3\6UH
package NetFox; T!o 4k
#2c-@),
5-|fp(Ww_W
public class Utility { Qci<cVgP
FJ3Xeos4|
h3.wR]ut
public Utility() pmAir:
{ 5fS89?/?
xUE9%qO
Ue|]M36
} ]@bo;.
Au'[|Prr
//线程睡眠 Sk@~}
public static void sleep(int nSecond) Fl GKy9k
{ vkan+~H
try{ ='=\!md
Thread.sleep(nSecond); 2~+Iu+
} ?6@Y"5 z3g
catch(Exception e) e[}R1/!L
{ w/s{{X<bF
e.printStackTrace (); Qz;2RELz
} >lqWni
} 'sI=*c
1cS{3
//日志 z#b31;A@$
public static void log(String sMsg) _Tyj4t0ElV
{ 6C>x,kU
System.err.println(sMsg); 6o&{~SV3
} FA\gz?h
}2M2R}D
krm&.J
public static void log(int sMsg) Y;>0)eP
{ 93:s[bmx
System.err.println(sMsg); H@er"boi
} +O:Qw[BL/Z
} ['m@RJm+
W&y%fd\&3
VA_\Z
/* w5|az6wZB!
**TestMethod.java ( B$;'U<
*/ XiI@Px?FL
package NetFox; pLL ^R
Dq+rEt
]J)WcM:
public class TestMethod { L's_lC
C^RO@kM
$(_Xt-6
public TestMethod() uD_|/(
{ ///xx/weblogic60b2_win.exe <1]#E@
try{ RLr;]j8cm
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *""'v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uY5&93R
SiteFileFetch fileFetch = new SiteFileFetch(bean); FLY#
fileFetch.start(); [Fe`}F}Co8
} *iS<]y
catch(Exception e){e.printStackTrace ();} G}mJtXT#=
+r9:n(VP
p_=^E*J]
} YD$fN"}-
;7&RmIXKh'
~^=QBwDW8N
public static void main(String[] args) lKEdpF<
{ 98bmia&H
new TestMethod(); v#:#w.]-Y
} YSk,kU
} 0*W=u-|s6
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