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)); \(fq8AL?
} Xu#:Fe}:
for(int i=0;i<nEndPos.length-1;i++) Xpl?g=B&u
{ Xm|ib%no
nEndPos = nStartPos[i+1]; nP1GW6Pu
} 76bc]o#
nEndPos[nEndPos.length-1] = nFileLength; Y@%`ZPJ
} n=o_1M|
} Za%LAyT_s
qjAh6Q/E`
*ik/p
//启动子线程 #tDW!Xv?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Y)Tl<
for(int i=0;i<nStartPos.length;i++) 5g>wV
{ CTp!di|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7$7n71o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H\#:,s{1
nStartPos,nEndPos,i); ")%r}:0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [!~}S
fileSplitterFetch.start(); ){ gAj
} .6m_>Y6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [zh"x#AyI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;LQ9#M?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CGZ^hoh/
nEndPos = " + nFileLength); "!KpXBc,>
// fileSplitterFetch[nPos.length-1].start(); 56{I`QjX
3m=2x5{L
~O03Sit-
//等待子线程结束 v{y{sA
//int count = 0; 3sbK7,4
//是否结束while循环 {G*OR,HN
boolean breakWhile = false; 3?`"
?WHy0x20
#epy%>
while(!bStop) p`P~i&_
{ mCdgKr|n
write_nPos(); d~Mg vh'
Utility.sleep(500); i_ QcC
breakWhile = true; J@]k%h
w4%AJmt
{Uq:Xw
for(int i=0;i<nStartPos.length;i++) H;S%Y`V
{ |=5/Rax^
if(!fileSplitterFetch.bDownOver) 0+`Pg
{ hO( RZ'{
breakWhile = false; *||d\peQ
break; g_z/{1$
} t&}6;z 3
} A,#2^dR
if(breakWhile) SaO3zz@L
break; {rXs:N@
61@EDIYPc
o8ppMM8_R[
//count++; XUSvhr$|
//if(count>4) !#}7{
// siteStop(); FS@A8Bb
} H l<$a"K7\
X3B{8qx_>
:2y"3azxk
System.err.println("文件下载结束！"); "HlgRp]u
} Ns=AjhLc z
catch(Exception e){e.printStackTrace ();} ZnfNQl[
} +iA=y=;blH
NXU`wnVJ
aE/D*.0NI
//获得文件长度 lddp^ #f
public long getFileSize() T3pdx~66
{ |B^G:7c
int nFileLength = -1; Vmi{X b]<
try{ ~uj;qq
URL url = new URL(siteInfoBean.getSSiteURL()); YRcps0Dx9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L*]0"E
httpConnection.setRequestProperty("User-Agent","NetFox"); Xy7Z38G
jd:B \%#![
1RqgMMJL
int responseCode=httpConnection.getResponseCode(); ,t,wy37*D
if(responseCode>=400) k;Fh4Hv
{ \40YGFO
processErrorCode(responseCode); &.N$
return -2; //-2 represent access is error r;m`9,RW
} |vILp/"9=W
%*W<vu>H
<Kt3PyF
String sHeader; >M;u*Go`QO
g^~Kze
gEJi[E@
for(int i=1;;i++) _[K#O,D,
{ aGoE,5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7r 0,> 3"
//Utility.log(in.readLine()); ;3m!:l
sHeader=httpConnection.getHeaderFieldKey(i); i8PuC^]
if(sHeader!=null) N1x@-/xa|
{ ^b-18 ~s
if(sHeader.equals("Content-Length")) m,_d^
{ %XTA;lrz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <@uOCRbV
break; la^ DjHA$
} vkcRm`.
} #A<P6zJXR
else 0q6I;$H
break; Ee2c5C!|C
} RBGX_v?
} v:|(8Y
catch(IOException e){e.printStackTrace ();} tE"Si<[]H$
catch(Exception e){e.printStackTrace ();} .$rC0<G[K
ra6o>lI(,
Vpp&|n9^
Utility.log(nFileLength); Y+-xvx :
6Bt=^~d
<4`eQ
return nFileLength; ;4#D,zlO^
} LE=k
[QczlwmO
e@]Wh)
//保存下载信息（文件指针位置） pa<qZZ
private void write_nPos() #kmh:P
{ _GoVx=t
try{ KL?)akk
output = new DataOutputStream(new FileOutputStream(tmpFile)); H+C6[W=
output.writeInt(nStartPos.length); L;6.r3bL
for(int i=0;i<nStartPos.length;i++) #AViM_u
{ olYsT**'
// output.writeLong(nPos); d"Q |I
output.writeLong(fileSplitterFetch.nStartPos); , c;eN
output.writeLong(fileSplitterFetch.nEndPos); \nvAa_,
} {]}s#vvy
output.close(); b1`r!B,
} Rf"Mr:^
catch(IOException e){e.printStackTrace ();} e}{U7xQm1
catch(Exception e){e.printStackTrace ();} $t=O:
} 3f76kl(&
KeBQH8A1N
*nTU#U
//读取保存的下载信息（文件指针位置） -9Ws=r0R
private void read_nPos() &h~aChJ
{ MXvXVhCU
try{ ;%!m<S|%k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [rYT
int nCount = input.readInt(); YJF#)TkF
nStartPos = new long[nCount]; !?FK We
nEndPos = new long[nCount]; 1s7^uA$}6
for(int i=0;i<nStartPos.length;i++) 2k -+^}r
{ C!x/ ^gw
nStartPos = input.readLong(); E^Gg '1
nEndPos = input.readLong(); ?.bnIwQe
} <,1fkq>,
input.close(); C;rG]t^%
} KFWJ}pNq
catch(IOException e){e.printStackTrace ();} _^t-9
catch(Exception e){e.printStackTrace ();} {Gi h&N
} GA3sRFZdQ
=U-r*sGLN
)Hw:E71h2
private void processErrorCode(int nErrorCode) UWXm?v2j
{ 7"v$- Wy
System.err.println("Error Code : " + nErrorCode); -w6 "?
} mDMt5(.
4&X*pL2;
g /+oZU
//停止文件下载 WE!vSZ3R
public void siteStop() 'c`jyn
{ (?&=T.*^
bStop = true; LXfCmc9|Z
for(int i=0;i<nStartPos.length;i++) 0tz:Wd*<
fileSplitterFetch.splitterStop(); K%g;NW
nKh&-E
}At{'8*n
} fnu"*5bE
} DPDe>3Mi[
//负责部分文件的抓取 lPP,`
**FileSplitterFetch.java .0y%5wz8j
*/ !]?$f=
package NetFox; P\R27Jd
g@v s*xE
+C{p%`<
import java.io.*; A}VYb:u/
import java.net.*; 8HErE<_(
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r0dDHj~F
public class FileSplitterFetch extends Thread { 6L4$vJ
6j9)/HP
c+' =hR[
String sURL; //File URL &*,:1=p
long nStartPos; //File Snippet Start Position c|~6Ie
long nEndPos; //File Snippet End Position e 9$C#D>D
int nThreadID; //Thread's ID }xb=<
boolean bDownOver = false; //Downing is over OEgI_=B
boolean bStop = false; //Stop identical le>Wm&E
FileAccessI fileAccessI = null; //File Access interface m~l F`?
qoU3"8
$&P?l=UG
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rP=sG;d
{ f"5g>[1
this.sURL = sURL; +Ezgn/bS&
this.nStartPos = nStart; JWO=!^
this.nEndPos = nEnd; $.mQ7XDA9
nThreadID = id; ]o/|na*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 fZWGn6$
} rXi uwz\
TCVl8)j
E@)\Lc~
public void run() j -O2aL
{ KpiF0K
while(nStartPos < nEndPos && !bStop) 9h,u6e
{ 5_o$<\I\
./-JbW
h1"zV6U
try{ J{"kw1Lu
URL url = new URL(sURL); b!>\2DlyJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vd9@Dy
httpConnection.setRequestProperty("User-Agent","NetFox"); <eN R8(P
String sProperty = "bytes="+nStartPos+"-"; Uu p(6`7
httpConnection.setRequestProperty("RANGE",sProperty); ~|+zJ5
Utility.log(sProperty); Y}R}-+bD/
S[:xqzyDg
irBDGT~
InputStream input = httpConnection.getInputStream(); Ze^jG-SL$9
//logResponseHead(httpConnection); q }C+tn"\
GR4?BuY,
H^%.=kf
byte[] b = new byte[1024]; -`c:}m
int nRead; Ju` [m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kAzd8nJ'
{ T)CzK<LbR
nStartPos += fileAccessI.write(b,0,nRead); ^(x^6d
//if(nThreadID == 1) <I*x0BM=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q}AE.Ef@<
} x2VBm$>
/'DwfX
V~{ _3YY
Utility.log("Thread " + nThreadID + " is over!"); ,K9f_bv
bDownOver = true; t` ^Vb-
//nPos = fileAccessI.write (b,0,nRead); rJfqA@
} *gsAn<
catch(Exception e){e.printStackTrace ();} {y^3> 7
} =d;Vk
} *e"a0
cd@.zg'sYn
8%{q%+
//打印回应的头信息 !UBO_X%dz
public void logResponseHead(HttpURLConnection con) V1=*z
{ =H]F`[B=
for(int i=1;;i++) "kW!{n
{ TJ@Cjy%
String header=con.getHeaderFieldKey(i); -C7FuD[Xw
if(header!=null) 0(>rG{u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ph:3|d
Utility.log(header+" : "+con.getHeaderField(header)); Mio>{%/
else g9h(sLSF
break; 25{ uz
} **_&i!dtL
} ")#<y@Rv
ak:v3cQR
qztV,R T
public void splitterStop() > 6CV4 L
{ !3&kQpF
bStop = true; 8|1^|B(l
} Eh8Pwt7C@
2h~-
f?fKhu2
} >%b\yl%0
SqPtWEq@P
Sq]pQ8
/* jB$SUO`*
**FileAccess.java g;p)n
*//文件访问(定位，写) H3/caN:
package NetFox; 1cN')"
import java.io.*; VAQ)Hc]
&&8'0.M{
M7}Q=q\9
public class FileAccessI implements Serializable{ |!z2oO
cL7g}$W$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C"<s/h
RandomAccessFile oSavedFile; TvhJVVQ+?
long nPos; %FkLQ+v/<
Xh3;
.#6MQJ]OH
public FileAccessI() throws IOException RNJFSD.
{ Va<HU:<
this("",0); jRZ%}KX
} 0NE{8O0;Fr
5a`%)K
|WQ9a' '
public FileAccessI(String sName,long nPos) throws IOException O_,O,1
{ &]p}+{ (>
oSavedFile = new RandomAccessFile(sName,"rw"); ".2K9j7$
this.nPos = nPos; f_mhD dq
oSavedFile.seek(nPos); .QWhK|(.!
} =jAFgwP\
lP<I|O=z
Se^^E.Z,W
public synchronized int write(byte[] b,int nStart,int nLen) Rs;15@t@
{ -e-e9uP
int n = -1; E0f{iO;}
try{ xN->cA$A
oSavedFile.write(b,nStart,nLen); y2Bh?>pg
n = nLen; :J_oj:0r"f
} Pi6C/$ K
catch(IOException e) 5>0.NiXGf'
{ _kraMQ>
e.printStackTrace (); nS.G~c|
} 2!&pEqs
kEN#u
%CH6lY=lI
return n; ]?l{j
} O12Q8Oj!0
@"87F{!
H'g?llh1J
} 4cgIEw[6
S>:,z}i
=]>%t]
/* 4*H"Z(HP
**SiteInfoBean.java >%%=0!,yX
*/ -$k>F#
package NetFox; xF8S*,#,*
I}0_nge
_9If/RD
public class SiteInfoBean { j'rS&BIG
m2bDHQ+
ur%$aX)
private String sSiteURL; //Site's URL y;`eDS'0.N
private String sFilePath; //Saved File's Path wz(K*FP
private String sFileName; //Saved File's Name 440FhDMj
private int nSplitter; //Count of Splited Downloading File pWaPC/,g
*o?i:LE]
Fz"ff4Bx [
public SiteInfoBean() f05d ;
{//nSplitter的缺省值为5 #gZ|T M/h
//default value of nSplitter is 5 ~9M!)\~
this("","","",5); ;IP~Tb]&
} D!3{gV#
&w\I<J`T
yXfMzG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P'[<AZ
{ KX+ey8@[
sSiteURL= sURL; H#(<-)j0_
sFilePath = sPath; "ED8z|]j
sFileName = sName; DguB
this.nSplitter = nSpiltter; !q/5yEJ>h
M[P^]J@
T 1Cs>#)
} M}FWBs'*|
05e>\}{0
1"E\C/c
public String getSSiteURL() F+aQ $pQ
{ :F(9"L
return sSiteURL; LJuW${Y
} I0w%8bs
Gp2!xKgm
lgD]{\O$ip
public void setSSiteURL(String value) &d^=siL
{ %$X\"
sSiteURL = value; Xa,&ef&q
} ^X?D#\
i57( $1.
3:`XG2'
public String getSFilePath() *8A6Q9YT
{ X>,A
return sFilePath; #BJ\{"b_}z
} ,)#.a%EKA
;;#nV$
y:so L:(F
public void setSFilePath(String value) EZj1jpL
{ @EZ>f5IO+
sFilePath = value; C3"&sdLb$
} oXal
rxE&fjW
0D3OE.$0
public String getSFileName() JZx%J)
{ [X"k> Sq
return sFileName; VTw/_Hf2p
} W<'<'z5
$$gtZ{ukQ
0s%6n5>
public void setSFileName(String value) hPO>,j^
{ P;U@y"s
sFileName = value; >4)g4~'n!
} Rt4di^v
KTmaglgp
Bymny>.M
public int getNSplitter() WYO\'W
{ OgMI
return nSplitter; +VOb
} *\q8BZ
rg)h5G
#+G`!<7/@f
public void setNSplitter(int nCount) }~zO+Wf2
{ [m#NfA:h,
nSplitter = nCount; xs1bxJ_R
} kK?zVH-!
} j#igu#MB*
P$30
I'A:J
/* yYX :huw
**Utility.java SaNN;X0
*/ FAtWsk*pgY
package NetFox; %$9:e J?
#"r kuDO
EAyukM2
public class Utility { G8P+A1 f/>
n~%}Z[5D
7^wE$7hS
public Utility() !R{em48D
{ AU`OESSI
iS05YW
p#<nK+6.8
} U.Hdbmix
)E~mJln
//线程睡眠 @_O3&ZK
public static void sleep(int nSecond) ?`i|"y#
{ ?*o;o?5s^
try{ *`.LA@bHU
Thread.sleep(nSecond); +$~8)95<B
} Iaa|qJ4
catch(Exception e) n)CH^WHL&
{ RAOKZ~`
e.printStackTrace (); BvJ\x)
} 8bGD
} $Sw,hb
T#N80BH[
//日志 UzJ!Y/5
public static void log(String sMsg) ASq`)Rz
{ /&6Q)
System.err.println(sMsg); !PI0oh
} !qS05
+{^'i P
~Jxlj(" 0(
public static void log(int sMsg) B3.X}ys#
{ `&,_xUA
System.err.println(sMsg); /J.0s0@
} H<z30r/-w
} Di])<V
pLo;#e8'f
m9I(TOw
/* tnJ`D4
**TestMethod.java 1O4D+0@
*/ Vy r] x
package NetFox; w'XSb.$_m
x{j+}'9
T7s+9CE
public class TestMethod { 2_I+mQ
-G!6U2*#
`|JI\&z
public TestMethod() 4V>vg2 d
{ ///xx/weblogic60b2_win.exe K"I{\/x@
try{ D/*vj|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (I!1sE!?1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2X^iV09
SiteFileFetch fileFetch = new SiteFileFetch(bean); fGo_NB
fileFetch.start(); kp.|gzA6
} Ltl]j*yei
catch(Exception e){e.printStackTrace ();} W n6,U=$3
IY~ {)X
$Uy#/MX
} H!#5!m&
sB8p( L
%'kX"}N/
public static void main(String[] args) epYj+T
{ > `0| X
new TestMethod(); yq!CWXZ2
} ~6MMErSj
} (w}r7`n
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