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)); ,wy;7T>ODd
} Y@qugQM>
for(int i=0;i<nEndPos.length-1;i++) ^N`KT
{ yN06` =
nEndPos = nStartPos[i+1]; w7\vrS>&
} e)3Mg^
nEndPos[nEndPos.length-1] = nFileLength; GoPMWbI7
} @gQ?cU7
} l>J%Q^
NGZtlNvh
Bx.hFEL
//启动子线程 dKL9}:oUa
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z80*Ylx
for(int i=0;i<nStartPos.length;i++) eKU4"XTk
{ Oi{J}2U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K7/&~;ZwT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), P2U4,?_e
nStartPos,nEndPos,i); ?}EWfsA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S&;)F|-q
fileSplitterFetch.start(); aJc>"#+ o
} X7gB.=\X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >y!O_@>z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m |.0$+=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ISTAJ8" D
nEndPos = " + nFileLength); u;b6uE
// fileSplitterFetch[nPos.length-1].start(); $}EARW9
n"Jj'8k
hqwsgJ
//等待子线程结束 wzZ]| C(vp
//int count = 0; A>(EM}\,
//是否结束while循环 T~4HeEG>uH
boolean breakWhile = false; :R3&R CTZ
IWwOP{ <ZQ
/gn\7&=P
while(!bStop) >,rzPc)
{ zB\ 8<97C
write_nPos(); W>'gG}.
Utility.sleep(500); }"q#"s
breakWhile = true; QX_![|=
A.YK=_J
W&m3"~BJ
for(int i=0;i<nStartPos.length;i++) kHQn'r6
{ WMFn#.aY5
if(!fileSplitterFetch.bDownOver) &?']EcU5h9
{ w[G-=>;
breakWhile = false; CI+liH
break; d[E= HN
} }R:oWR
} `[ZA#8Ma
if(breakWhile) 5cl^:Ua
break; V=+p8nE0
TaKCN
"`'+@KlE
//count++; ur]WNk8bN
//if(count>4) UY:Be8C A
// siteStop(); DYew6B-
} dLf ;g}W
TBHd)BhI.
0 eOdE+
System.err.println("文件下载结束！"); H/*i-%]v+(
} ")fgQ3XZ
catch(Exception e){e.printStackTrace ();} K5(T7S
} x26 sH5
HhzPKd
m 7+=w>o
//获得文件长度 <&4~Z! O
public long getFileSize() 3[~LmA
{ _sHeB7K
int nFileLength = -1; dp3TJZ+U
try{ n9 Jev_!A
URL url = new URL(siteInfoBean.getSSiteURL()); G)""^YB-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~\%H0.P6
httpConnection.setRequestProperty("User-Agent","NetFox"); IY?o \vC
bf\ Uq<&IJ
q"-Vh,8h
int responseCode=httpConnection.getResponseCode(); ~fO#En
if(responseCode>=400) d 5hx%M
{ wOH 3[SKo
processErrorCode(responseCode); /&!o]fU1C
return -2; //-2 represent access is error TNcMrbWA
} A\ tBmL_s
ZV07;`I
za8+=?
String sHeader; u#->?
qz!^< M
lDs C>L-F
for(int i=1;;i++) qtP*O#1q
{ uYd_5 nw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g~OG~g@
//Utility.log(in.readLine()); uLN.b339
sHeader=httpConnection.getHeaderFieldKey(i); yT(86#st
if(sHeader!=null) Mv7tK l
{ BJsN~`=r
if(sHeader.equals("Content-Length")) .;D'
{ fY|vq amA;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); oK&G
break; a$LoQ<f_
} TQ5kT?/{
} 5%DHF-W)
else Q%t _Epe
break; wJ7Fnj>u%
} ASNo6dP7
} >DW%i\k1V~
catch(IOException e){e.printStackTrace ();} li~=85 J
catch(Exception e){e.printStackTrace ();} H#bu3*'
F+V[`w*k
"2I{T
Utility.log(nFileLength); #Vm)wH3
R7x*/?
_cbXzSYq&
return nFileLength; b+71`aD0
} W#9LK Jj
/NVyzM51V
zG&yu0;D6
//保存下载信息（文件指针位置） u 0 K1n_
private void write_nPos() QW%xwV?8
{ QX9['B<
try{ 6%T_;"hb
output = new DataOutputStream(new FileOutputStream(tmpFile)); -"xC\R
output.writeInt(nStartPos.length); I>>X-}
for(int i=0;i<nStartPos.length;i++) qPCI@5n3T?
{ az Oib=3fz
// output.writeLong(nPos); 'EkjySZ]F{
output.writeLong(fileSplitterFetch.nStartPos); X|60W
output.writeLong(fileSplitterFetch.nEndPos); <|:$_&(
} `iwGPG!
output.close(); 3d_g@x#9
} )KYU[
catch(IOException e){e.printStackTrace ();} 6x8lnXtA
catch(Exception e){e.printStackTrace ();} qp]sVY
} 4WQ 96|F
YMn=9EUp
#YLI"/Kn
//读取保存的下载信息（文件指针位置） x}N1Wl=8g
private void read_nPos() &)EL%o5
{ a+n?y)u
try{ [g:KFbEY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PMiG:bM
int nCount = input.readInt(); xllmF)]*Y
nStartPos = new long[nCount]; 7L!q{%}
nEndPos = new long[nCount]; )/t=g
for(int i=0;i<nStartPos.length;i++) Uql7s:!,U
{ 'ExQG$t
nStartPos = input.readLong(); "ScY'<
nEndPos = input.readLong(); vn96o]n
} E~,Wpl}
input.close(); <*$IZl6I
} &>hln<a>
catch(IOException e){e.printStackTrace ();} 1.j;Xo/+:V
catch(Exception e){e.printStackTrace ();} 8#a2 kR<b
} $yMNdBI[
?w@KF%D
jiLt *>I
private void processErrorCode(int nErrorCode) Oxh.&
{ 97VS xhr
System.err.println("Error Code : " + nErrorCode); [JVUa2Sm
} T-lHlm
>zv}59M
UC"_#!3
//停止文件下载 [b@9V_
public void siteStop() F#7A6|
{ IQ9Rvnna
bStop = true; ==~ lc;
for(int i=0;i<nStartPos.length;i++) K_BF=C.k
fileSplitterFetch.splitterStop(); {`[u XH?3d
z)pp{
>2< Jb!f&
} 0bR})}a+Yg
} :FI4GR*?
//负责部分文件的抓取 XFvPc
**FileSplitterFetch.java eX{Tyd{
*/ ixo?o]Xb`
package NetFox; Qx[ nR/
C.{z+
n0=[N'Tw3
import java.io.*; >)iCKx
import java.net.*; v iM6q<Ht
Z_?r5M;
LgoUD*MbQ
public class FileSplitterFetch extends Thread { 1V2"sE
OW8"7*irT
?rv5Z^D'
String sURL; //File URL e/V8lo
long nStartPos; //File Snippet Start Position GAcU8MD
long nEndPos; //File Snippet End Position 8@4)p.{5I
int nThreadID; //Thread's ID *'ex>4^
boolean bDownOver = false; //Downing is over 5TcirVO82
boolean bStop = false; //Stop identical ik|iAWy
FileAccessI fileAccessI = null; //File Access interface 'B$qq[l]S
E.OL_\
q|wwfPez7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R9V v*F]m@
{ v8o{3wJ
this.sURL = sURL; (]p,Z<f
this.nStartPos = nStart; ,;-55|o\V
this.nEndPos = nEnd; 1\BQq
nThreadID = id; 9WsGoZPn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i.*Utm`1"e
} qUF}rlS=r
iKuSk~
NhA_dskvo
public void run() 3_+$x4%
{ Fm{`?!
while(nStartPos < nEndPos && !bStop) `SO"F,
{ E;^~}
<eG8xC
*%xmCPJ
try{ X3;|h93.a
URL url = new URL(sURL); or1D 6*'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &B5@\Hd;
httpConnection.setRequestProperty("User-Agent","NetFox"); )6:nJ"j#
String sProperty = "bytes="+nStartPos+"-"; g{?]a'?
httpConnection.setRequestProperty("RANGE",sProperty); ] 6rr;S
Utility.log(sProperty); y9L:2f\
Wo+'j $k
5//.q;z
InputStream input = httpConnection.getInputStream(); SB'$?Kh
//logResponseHead(httpConnection); X"qC&oZmf
:TzHI
d*xKq"+ &E
byte[] b = new byte[1024]; 6P KH%
int nRead; 4RV5:&ALLS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o Z#4<7K
{ tMWsgK.B
nStartPos += fileAccessI.write(b,0,nRead); 8P'zQ:#RV
//if(nThreadID == 1) -hIDL'5u-I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ou<Vg\Mu
} 2qD80W<1
a,sU-w!X'
h&}XG\ioNA
Utility.log("Thread " + nThreadID + " is over!"); F7zBm53
bDownOver = true; 4^mpQ.]lO
//nPos = fileAccessI.write (b,0,nRead); Cp2$I<T
} @< @\CiM
catch(Exception e){e.printStackTrace ();} ^q0Ox&X
} $pm5G} .
} Z@I.socA
k6vY/)-S
sA u ;i
//打印回应的头信息 Vg)]F+E
public void logResponseHead(HttpURLConnection con) J`8bh~7
{ ,U#$Qb 12
for(int i=1;;i++) w1+xlM,,9
{ r-$SF5uv
String header=con.getHeaderFieldKey(i); |?Z;tAF!
if(header!=null) `|i[*+WC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GX+oA]
Utility.log(header+" : "+con.getHeaderField(header)); D|[~Py
else sinnHQ
break; 76rNs|z~
} i|5K4Puu
} ^Fr82rJs
W=$d|*$
=gb.%a{R
public void splitterStop() Ol9'ZB|R
{ (&U8NeWZ
bStop = true; k]=Yi;
} $6a55~h|(
=sk]/64h``
}.x&}FqXE
} hi I`ot
jc|"wN]
5!T\L~tyt
/* m%-
**FileAccess.java 6+9inWTT(
*//文件访问(定位，写) 4Y[uqn[
package NetFox; SoY=
import java.io.*; _T 5ZL
bt/u^E
j`Xe0U<
public class FileAccessI implements Serializable{ R&BbXSIDX
vt" 7[!O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h9,ui^#d$
RandomAccessFile oSavedFile; {%K(O$H#
long nPos; {[ j+y
]R8}cbtU
ROr..-[u
public FileAccessI() throws IOException Pd@y+|
{ *t'qn
this("",0); TM8WaH
} t7#C&B
8lo /BGxS>
{]aB3
public FileAccessI(String sName,long nPos) throws IOException &n.7~C]R
{ [WDtr8L
oSavedFile = new RandomAccessFile(sName,"rw"); AKVll
this.nPos = nPos; gu[3L
oSavedFile.seek(nPos); h^h!OQKQ
} DbdxHuKa>
!YlyUHD
jj,Y:
public synchronized int write(byte[] b,int nStart,int nLen) FfnW
{ LY%`O#i.
int n = -1; Br2ZloJ@+
try{ G!J{$0.
oSavedFile.write(b,nStart,nLen); x;,H>!r"i
n = nLen; ]urrAIK
} ^d!(8vh
catch(IOException e) *7'}"@@
{ `k}
e.printStackTrace (); ewYZ} "o
} T/#$44ub
&y?L^Aq
FTx&] QN?
return n; }5Yd:%u5
} jFBLElE
_e<3 g9bj
p.9VyM
} beyC't
S.bB.<
8S_i;
/* n%lY7.z8d
**SiteInfoBean.java _u$X.5Q;
*/ b$kCyOg
package NetFox; ?d)I!x,;;
d>z?JDt
=6Dz<Lq
public class SiteInfoBean { Re3vW re
1/>#L6VAZ
'"{ IV
private String sSiteURL; //Site's URL _C3l2v'I$
private String sFilePath; //Saved File's Path __\Tv>Y
private String sFileName; //Saved File's Name V45\.V
private int nSplitter; //Count of Splited Downloading File Aen)r@Y:
u:r'&#jb~@
)x1LOMe
public SiteInfoBean() ln#Jb&u
{//nSplitter的缺省值为5 DGMvYNKTj
//default value of nSplitter is 5 ~U+SK4SK:o
this("","","",5); rmj?jBKQU
} (^-i[aJY
lPL>8.j
FWNO/)~t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KS($S(Fi
{ c0v;r4Jo#j
sSiteURL= sURL; )K2,h5zU
sFilePath = sPath; F0O"rN{
sFileName = sName; <S'5`-&
this.nSplitter = nSpiltter; L0?-W%$>
LOf0_g/
B[:-SWd
} 9ZjSM,+
d(RSn|[0
u|l]8T9L
public String getSSiteURL() xy>~15
{ )v&r^DR_
return sSiteURL; b&BSigrvou
} e;:~@cB,c
", b}-B
,/n<Qg"`
public void setSSiteURL(String value) DN)Ehd.
{ SV;S`\i
sSiteURL = value; LJK<Xen
} ngM>Tzirt
@[M5$,"
&]gw[ `
public String getSFilePath() v=15pW
{ (;2J}XQvO~
return sFilePath; ]K'iCYY
} "f|\":\
*i#m5f}
1<RB}M
public void setSFilePath(String value) n5i#GvO^
{ V3O<l}ak
sFilePath = value; D&q-L[tA@
} PDaD:}9
eIjn~2^
G"3)\FEM
public String getSFileName() o*7`r~
{ Z)cGe1?q
return sFileName; gR)T(%W
} _idTsd:\
O-r,&W
FBpf_=(_1
public void setSFileName(String value) Nq|b$S[4
{ 6T>e~<^
sFileName = value; f8um.Xnp6
} .b*%c?e
a=*&OW
s u]x
public int getNSplitter() 5\Sm^t|Tx
{ yrO\\No#H
return nSplitter; %k(V 2]WF
} |T:'G
6XPf0Gl
{f;]
public void setNSplitter(int nCount) 9mW95YI S
{ I%]L
nSplitter = nCount; $Il?[4FF
} 2Uf]qQ1
} a>jiq8d]4
B.nq3;Y
[UN`~
/* )N!-g47o%#
**Utility.java Jwzkd"D
*/ z>$AZ>t%J$
package NetFox; ]F[ V6`H
;E0Xn-o_
\Ub=Wm\
public class Utility { >D'Kt?L<]m
o.-rdP0P>
GmoY~}cg~
public Utility() "|&xUWJ!)
{ >(Mu9ie*`
bgs2~50
,zmGKn#n2
} z7X[$T$V
dZ'hTzw~
//线程睡眠 _&s37A&\
public static void sleep(int nSecond) ni$7)YcF
{ `4E6&&E+S
try{ ^s<p5V
Thread.sleep(nSecond); ,gHgb
} 7XLz Ewa
catch(Exception e) 6@_Vg~=S
{ ?0HPd5=<v
e.printStackTrace (); 0KknsP7
} sr(f9Vl
} 0^htwec!
wmu#@Hf/[h
//日志 o'S&YD
public static void log(String sMsg) 03aa>IO
{ 9 z_9yT
System.err.println(sMsg); Dg](?^
} %j9'HtjEa
rdd%"u+
SenDJv00
public static void log(int sMsg) 8':^tMd
{ M5DW!^
System.err.println(sMsg); I6}ineps
} 5N=QS1<$5
} J6}J/
'Dl31w%:
bbevy!m
/* T@c{5a
**TestMethod.java `8$gaA*
*/ Z~O1$,Z
package NetFox; Aa^%_5
i^LLKx7M&
9L+dN%C
public class TestMethod { &_cMbFLBP
\ UCOe
(dl7+
public TestMethod() Y>}[c
{ ///xx/weblogic60b2_win.exe *,Bo $:(n
try{ /$v0Rq9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ik_u34U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8RC7Ei
SiteFileFetch fileFetch = new SiteFileFetch(bean); rOC2 S(m
fileFetch.start(); OmO/x
} 9Yg=4>#$
catch(Exception e){e.printStackTrace ();} I8=p_Ie
Si[:l
E;7vGGf]
} ]mEY/)~7
t)Q6A@$:
Ra%" +=
public static void main(String[] args) XI#1)
{ =m{]Xep
new TestMethod(); NijvFT$V1
} .32]$vx
} Nrp0z:
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