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)); u:"mq.Q
} 8 =J6{{E
for(int i=0;i<nEndPos.length-1;i++) |W{z,e01x
{ $t[`}I }
nEndPos = nStartPos[i+1]; z\Qg 3BS
} He&dVP
nEndPos[nEndPos.length-1] = nFileLength; ]<TgBo|
} epz2d~;
} mltN$b%G=d
=yvyd0|35
2hu;N
//启动子线程 6g( 2O[n.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WG(tt.
for(int i=0;i<nStartPos.length;i++) U%j=)VD])
{ O"_FfwO a
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *H:;pIWP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4l>/6LNMF
nStartPos,nEndPos,i); PNc^)|4^Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IjJ3./L!5
fileSplitterFetch.start(); QT^W00h
} xZbm,.v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \q%li)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H@5:x8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -F@Rpfrj_#
nEndPos = " + nFileLength); /]iv9e{uh(
// fileSplitterFetch[nPos.length-1].start(); Rq9v+Xq2
UiF?Nx~
1JJQ(b
//等待子线程结束 RLecKw&1{3
//int count = 0; LlX 7g_!
//是否结束while循环 vM|?;QM
boolean breakWhile = false; n%W~+
EKq9m=Ua@o
VO[s:e9L
while(!bStop) 3*XX@>|o
{ @dD70T
write_nPos(); (fb&5=Wzw
Utility.sleep(500); o#H"tYP
breakWhile = true; )O2giVq7[0
CzST~*lH
~vBmW_j
for(int i=0;i<nStartPos.length;i++) 3[aCy4O
{ fg+Q7'*Vq
if(!fileSplitterFetch.bDownOver) gx@b|rj;
{ jA<v<oV
breakWhile = false; ZrXvR`bsw
break; .6f %"E,
} [6)`wi
} 4LJUO5(y@
if(breakWhile) r9z/hm}E
break; jZ7#xRt5w
@kRe0:t
jQC6N#L
//count++; FC/m,D50oI
//if(count>4) rh?!f(_@
// siteStop(); w\8grEj
} Cf J@|Rh
kbBX\*{yh
7bCTR2e\@w
System.err.println("文件下载结束！"); $kvF]|<bu
} Vb|DNl@
catch(Exception e){e.printStackTrace ();} q2Ax-#
} a~DR$^m
j+w*Absh
uXNJ{]o
//获得文件长度 lrU}_`
public long getFileSize() tWdj"n%
{ UYD(++
int nFileLength = -1; Z?O aY4
try{ h 5t,5e}
URL url = new URL(siteInfoBean.getSSiteURL()); `lqMifD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )pW(Cp
httpConnection.setRequestProperty("User-Agent","NetFox"); 03iO4yOu
8'@pX<
W2qW`Ujo{
int responseCode=httpConnection.getResponseCode(); =>n:\_*M
if(responseCode>=400) xaAJ>0IM
{ ?)'j;1_=E3
processErrorCode(responseCode); #ZeZs31
return -2; //-2 represent access is error Uw)?u$+ P
} o5@ l!NQ
#4Xe zj,g*
"Z#97Jc+J
String sHeader; w}K<,5I>
0^?(;AK
z2A7:[
for(int i=1;;i++) `.>2h}op
{ n,bZj<3t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (Lo<3a-]
//Utility.log(in.readLine()); Jou~>0,/j
sHeader=httpConnection.getHeaderFieldKey(i); =YE"6iU
if(sHeader!=null) 1 nIb/nY
{ :L&-
if(sHeader.equals("Content-Length")) LoPWho[8
{ S%R:GZEf_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :S{[^-"
break; %j^[%&pT
} =Bu d!
} .3Jggp
else #x"4tI
break; r>eOq[z
} 0jro0f'
} {ckA
catch(IOException e){e.printStackTrace ();} mrS:||,_
catch(Exception e){e.printStackTrace ();} gmJiKuAL5
Xv|~1v%s7
k?o(j/
Utility.log(nFileLength); I)U|~N
^ RU"v>
C(Yk-7
return nFileLength; APsd^J
} A=Q"IdK
/9/=]
h?p&9[e`
//保存下载信息（文件指针位置） @D[jUC$E
private void write_nPos() X25cU{
{ Q Bc\=}
try{ lGwX.cA!'
output = new DataOutputStream(new FileOutputStream(tmpFile)); LBk1Qw}-
output.writeInt(nStartPos.length); hvnZ 2x.?d
for(int i=0;i<nStartPos.length;i++) RM|<(kq
{ .\7R/cP}{A
// output.writeLong(nPos); ~raRIh=
output.writeLong(fileSplitterFetch.nStartPos); lCr
output.writeLong(fileSplitterFetch.nEndPos); ;HlVU
} =q.2S;?
output.close(); B- N
} AA:Ch?
catch(IOException e){e.printStackTrace ();} 6! \a8q'z
catch(Exception e){e.printStackTrace ();} _S7GkpoK
} <*<7p{x
ff**)Xdh
l}&egq DC
//读取保存的下载信息（文件指针位置） n9B1NM5 \
private void read_nPos() jFZJ #'CNS
{ 3l0x~
try{ 3+;]dqZ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v<,?%(g)7
int nCount = input.readInt(); qY]IX9'kV
nStartPos = new long[nCount]; cxFfAk\,en
nEndPos = new long[nCount]; {a-p/\U
for(int i=0;i<nStartPos.length;i++) S^HuQe!#
{ I $!Y
nStartPos = input.readLong(); 4E}]>
nEndPos = input.readLong(); w^sM,c5d
} r]iec{ ^
input.close(); _'JKPD[
} Xhe25
catch(IOException e){e.printStackTrace ();} MR=>DcR
catch(Exception e){e.printStackTrace ();} zHw[`"[
} 0.4c|-n
2~AGOx
6Daz1Pxd+
private void processErrorCode(int nErrorCode) ^n"ve2
{ ~T7\lJ{%G
System.err.println("Error Code : " + nErrorCode); &EYO[~D06
} ?*zRM?*
J 6U3}SO=y
rLGh>bw#`3
//停止文件下载 ev7Y^
public void siteStop() |_{-hNiz0
{ y,v*jE
bStop = true; Lj6$?(x}
for(int i=0;i<nStartPos.length;i++) <?5 ,3`V
fileSplitterFetch.splitterStop(); bm*Ell\a.
sNZ{OD+
JeU|e$I4>
} WUkx v*
} 5K|1Y#X
//负责部分文件的抓取 V)V\M6
**FileSplitterFetch.java c~[L;_
*/ ZP61T*n
package NetFox; w&:"x@ -|
Gt{~u^<
8q{ %n
import java.io.*; tbrjTeC
import java.net.*; Fr?o 4E6h
N>giFj[dD
^P >; %
public class FileSplitterFetch extends Thread { fn>MOD!l
Z.Z+cFi
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String sURL; //File URL n,SDJsS^
long nStartPos; //File Snippet Start Position JL45!+
long nEndPos; //File Snippet End Position (dvCejc^p
int nThreadID; //Thread's ID vG`R.
boolean bDownOver = false; //Downing is over _ #288`bU
boolean bStop = false; //Stop identical h lD0^8S
FileAccessI fileAccessI = null; //File Access interface 7Rqjf6kX`O
v@TP_Ka
y[BUWas(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jk,:IG
{ ZgVYC4=Q-\
this.sURL = sURL; p@!{Sh
this.nStartPos = nStart; z)I.^
this.nEndPos = nEnd; T|`nw_0
nThreadID = id; AI}29L3C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !%>p;H%0
} PB*mD7"
3Z;`n,g
9ar+Ph@*
public void run() TC;2K,.#k
{ 4Z5ZV!
while(nStartPos < nEndPos && !bStop) DS0c0lsx
{ JJ[.K*dO
Z;`ts/?SY]
oY{L0B[
try{ 42kr&UY&
URL url = new URL(sURL); |{udd~oE&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Elw fqfO
httpConnection.setRequestProperty("User-Agent","NetFox"); fw Ooi'jb
String sProperty = "bytes="+nStartPos+"-"; p3>p1tC
httpConnection.setRequestProperty("RANGE",sProperty); *J,VvO9
Utility.log(sProperty); T+7-6y+ d
6Ty;m>j
?G%C}8a
InputStream input = httpConnection.getInputStream(); MlVN'w
//logResponseHead(httpConnection); bII pJQ1.[
-}Vnr\f
i_8v >F
byte[] b = new byte[1024]; Q{1Q w'+@
int nRead; ?_*X\En*3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \7o&'zEw
{ 9}LcJ
nStartPos += fileAccessI.write(b,0,nRead); P0,@#M&
//if(nThreadID == 1) Lq<#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |tF:]jnIt
} BU],,t\
?o307r
y5gTd_-
Utility.log("Thread " + nThreadID + " is over!"); Dz4e.tvN
bDownOver = true; tGv5pe*r
//nPos = fileAccessI.write (b,0,nRead); .BP@1K
} t[/WGF&(R
catch(Exception e){e.printStackTrace ();} =?hGa;/rb
} },<(VhP
} %X)w$}WH
MHNuA,cz
91'i7&~xdG
//打印回应的头信息 KG7~)g
public void logResponseHead(HttpURLConnection con) +ve S~
{ oZm)@Vv;
for(int i=1;;i++) ~.\CG'g
{ &p|+K XIf
String header=con.getHeaderFieldKey(i); tP/0_^m
if(header!=null) b?S,%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x UM,"+h
Utility.log(header+" : "+con.getHeaderField(header)); OI:G~Wg
else ?Vg251-H
break; jNRR=0
} &5k$v^W5
} HoE@t-S
5eS0 B{,c
U4`6S43ki
public void splitterStop() ;nS.t_UW.
{ gp@X(d
bStop = true; tgk] sQY
} YQ/
R.nAD{>h*
!V/Vy/'`*
} C]/]ot0%t
vl1`s ^}R
$=&a0O#
/* v0psth?qV
**FileAccess.java $aIq>vJO9
*//文件访问(定位，写) c:? tn
package NetFox; 02+ k,xFb
import java.io.*; [{R^!Az&b<
*nZe|)m
?w/i;pp<,
public class FileAccessI implements Serializable{ 3(?V!y{@
S)`%clN}J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B8J_^kd
RandomAccessFile oSavedFile; 7T7 A[A\
long nPos; l=+hs
,v<GSiO
7nsn8WN[
public FileAccessI() throws IOException 8rZJvE#c
{ y^OT0mZkg
this("",0); QlxzWd3=q
} | R\PQ/)
P_7QZ0k/
OO$YwOKS
public FileAccessI(String sName,long nPos) throws IOException 8s+9PE
{ lk/T|0])
oSavedFile = new RandomAccessFile(sName,"rw"); 'c]Fhe fb
this.nPos = nPos; Ddu1>"p-x
oSavedFile.seek(nPos); F"|OcKAA}h
} 0[\sz>@
>]/RlW[
0Wd2Z-I
public synchronized int write(byte[] b,int nStart,int nLen) C_5o&O8Bc
{ Ufw_GYxan
int n = -1; Z|t`}lK
try{ ([g[\c,H
oSavedFile.write(b,nStart,nLen); Sm7O%V8{p
n = nLen; Dt#( fuk#
} *P:!lO\|
catch(IOException e) /w|!SZB
{ V= wWY*C
e.printStackTrace (); HGiO}|q:
} #3~#`&
:r+BL@9
o54/r#~fi
return n; Yee% <<S
} )c6t`SBwi
@XJzM]*w&
0pfgE=9
} Qq7%{`<}
fpPB_P{Ua
tZL|;K
/* s@$SM,tnn
**SiteInfoBean.java s!g06F
*/ 59R%g .2Y
package NetFox; ;:WM^S
uge~*S
r*F^8_YMK
public class SiteInfoBean { +sY8<y@%
6d;_}
4{v?<x8
private String sSiteURL; //Site's URL 6?`3zdOeO
private String sFilePath; //Saved File's Path c*!xdK
private String sFileName; //Saved File's Name )i^+=TZq
private int nSplitter; //Count of Splited Downloading File Jc=~BT_G
eV5 e:9
>LAhc7I
public SiteInfoBean() f,(@K%
{//nSplitter的缺省值为5 6,raRg6
//default value of nSplitter is 5 <(E9U.
this("","","",5); 6Cpn::WW}
} QJH((
xo GX&^=
7*MjQzg-P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NScUlR"nE
{ A[hvT\X
sSiteURL= sURL; eWk W,a
sFilePath = sPath; 6Zx'$F.iqK
sFileName = sName; :OKU@l|
this.nSplitter = nSpiltter; 'Szk!,_
@{ CP18~:
UCBx?9O/0
} $/)0iL{0
KvvG H-]
(?vKe5
public String getSSiteURL() Z~{0x#?4%
{ 4#Rq}/h
return sSiteURL; RD_l
} 8mnzxtk
m=#<
JY0}#FtgV
public void setSSiteURL(String value) dfR?O#JPU
{ ?y|8bw<
sSiteURL = value; ba"_!D1
} EmYu]"${1
+ab#2~,)
4|INy=<"t
public String getSFilePath() gk^`-`P
{ b8O }XB
return sFilePath; 1,Uf-i
} C'&t@@:
w:|YOeP
b/g~;| <
public void setSFilePath(String value) XTKAy;'5
{ k%K\~U8"
sFilePath = value; O|e/(s?$
} W*Gp0pX
N 6t`45
m^%Xl@V:c-
public String getSFileName() z#Cgd-^7.#
{ OlcWptM$
return sFileName; (U_dPf
} F!MxC
"tUc
"o>` Y
public void setSFileName(String value) y"nL9r.,:
{ ,0^9VWZV
sFileName = value; 5cZKk/"Ad}
} KKGwMJku}
|n~Vpy
K-6+fgeB
public int getNSplitter() rrc>O*>{i
{ *<l9d
return nSplitter; #(dERET*
} F m$;p6&j
tKLAA+Z
be(p13&od
public void setNSplitter(int nCount) |>Wi5h{6X
{ x-Fl|kwX.5
nSplitter = nCount; QV*W#K\7q
} qy,X#y'FuE
} e=4k|8G
MtXd}/
V?C_PMa
/* W}.p,d
**Utility.java F94Qb}
*/ :qxd s>Xm
package NetFox; 3=Va0}#&
7p+uHm
JNSH'9!n6
public class Utility { hZDv5]V:0
O/{W:hJjd
.ta*M{t
public Utility() G{{Or
{ pNzpT!}H>
m9li%p
HHaerc
} O\[Td
MnT+p[.
//线程睡眠 jY8u1z
public static void sleep(int nSecond) QAK.Qk?Qu
{ RWK##VHK
try{ SPY4l*kX
Thread.sleep(nSecond); f')3~)"
} '$5o5\
catch(Exception e) GcA!I!j/
{ a&~]77)
e.printStackTrace (); )`gE-udR
} #^;^_
} 8- ]7>2?_
WA79(B
//日志 G)wIxm$?0
public static void log(String sMsg) "K$ y(}C
{ gKay3}w
System.err.println(sMsg); `@r#o&
} y1zep\-D
h| +(
K#],4OG
public static void log(int sMsg) *3We5
{ wfc[B;K\
System.err.println(sMsg); n\D3EP<s
} D:Y`{{
} l5d> YTK+5
OJ\rT.{
TAn.5 wH9t
/* w=H4#a?fc
**TestMethod.java SsF 5+=A
*/ M[ZuXH}
package NetFox; mca9 +v
jw!QjVuRN%
BA+:}81&<q
public class TestMethod { /,Sd
!saKAb}d7H
k&>l#oH
public TestMethod() JI}p{yI
{ ///xx/weblogic60b2_win.exe S.Fip_
try{ ]0wmvTR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3tTz$$-#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |uE_aFQs
SiteFileFetch fileFetch = new SiteFileFetch(bean); X@7K#@5
fileFetch.start(); 07dUBoq
} ,.+"10=N.
catch(Exception e){e.printStackTrace ();} D3emO'`gQ
vDAv/l9
pY9>z;qD
} tFd^5A*
_\Cd.
y|+ltAK
public static void main(String[] args) T\h_8
{ v1j]&3O
new TestMethod(); xR,;^R|C
} R.)U<`||
} !jDqRXi(
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