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)); -DO*,Eecv
} w"CcWng1
for(int i=0;i<nEndPos.length-1;i++) ~3{C&c
{ \ B~9Ue!
nEndPos = nStartPos[i+1]; zS Yh ?NB5
} LhZWK^!{S
nEndPos[nEndPos.length-1] = nFileLength; /H)K_H#|;
} o W)M&$oS
} n'/w(o$&
:!a9|Fh~
:<%q9)aPf`
//启动子线程 n2bL-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mm3goIi;Y
for(int i=0;i<nStartPos.length;i++) n6gYZd
{ S7Xr~5>X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J&{qe@^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WgdL^PN(h
nStartPos,nEndPos,i); 9Z0(e!b4S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WUid5e2
fileSplitterFetch.start(); /j]r?KAzw
} @!\g+z_"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p{j }%)6n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @:@0}]%z9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,L+tm>I
nEndPos = " + nFileLength); n:?fv=9n
// fileSplitterFetch[nPos.length-1].start(); ^4LkKYMS
F|*{Ma
d{.cIv
//等待子线程结束 a;Ic!:L
//int count = 0; {~yj]+Im
//是否结束while循环 PUB|XgQDY:
boolean breakWhile = false; =*.Nt*;;
4z-sR/d
3G9YpA_}X
while(!bStop) b#-5b%ON
{ pti`q)
write_nPos(); 9i)E<.6
Utility.sleep(500); LxkToO{
breakWhile = true; XD`QU m
4BG6C'`%
L<>;E
for(int i=0;i<nStartPos.length;i++) tb7Wr1$<
{ #Zpp*S55
if(!fileSplitterFetch.bDownOver) 8<$6ufvOv
{ j380=?7
breakWhile = false; Qp7|p
break; cL&V2I5O
} bz_Zk
} lgZ3=h
if(breakWhile) 4Vj|k\vE4
break; Lj"~6l`)
xm>RLx}9
DCb\=E
//count++; ze Qgg|;
//if(count>4) c,KT1me
// siteStop(); YzU(U_g$
} ;YxQo o>
v*5n$UFV
W|@EKE.k
System.err.println("文件下载结束！"); (US]e un
} OpY2Z7_
catch(Exception e){e.printStackTrace ();} %R5APMg1
} n.C.th >Y1
=+q9R`!L]
BVxg=7%St
//获得文件长度 }cyHR1K
public long getFileSize() #Nxk3He]8
{ 2O {@W +Mt
int nFileLength = -1; @FL?,_,Y{
try{ XOO!jnQu
URL url = new URL(siteInfoBean.getSSiteURL()); St&xe_:^<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~.M{n&NM
httpConnection.setRequestProperty("User-Agent","NetFox"); bD<[OerG
9|T%q2O
nMD^x
int responseCode=httpConnection.getResponseCode(); ahkSEE{
if(responseCode>=400) |")}p=
{ [JFmhLP9
processErrorCode(responseCode); `pF|bZ?v
return -2; //-2 represent access is error \pZ,gF;y
} 4EzmH)4G
#M6@{R2_
o)'T#uK
String sHeader; %y33evX/B
s bd;Kn
*52*IRH
for(int i=1;;i++) go/]+vD
{ 5n1;@Vr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xL4qt=
//Utility.log(in.readLine()); $ud5bT{n
sHeader=httpConnection.getHeaderFieldKey(i); DW@PPvfs
if(sHeader!=null) y]9 3z!#Z
{ m/n_e g
if(sHeader.equals("Content-Length")) ys:1%D,,_
{ `pzp(\lc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e0"R7a
break; tfj6#{M5
} i$)bZr\
} =,KRZqz
else &TE=$a:d&
break; 9 )u*IGj
} 6 k+FTDL
} CJk$o K{Q
catch(IOException e){e.printStackTrace ();} H r?G_L
catch(Exception e){e.printStackTrace ();} .&.j?kb
O^hWG ~o
4H8vB^
Utility.log(nFileLength); AD=@
Ae:(_UJz
npg.*I/>
return nFileLength; 0 V*Di2
} ~WU _u,:
U?JZ23>bbw
>- ]tOH,0
//保存下载信息（文件指针位置） kVw5z3]Xg
private void write_nPos() KgX~PP>
{ *}Zd QJL
try{ cBM A.'uIL
output = new DataOutputStream(new FileOutputStream(tmpFile)); ),0_ C\
output.writeInt(nStartPos.length); 8I04Nx
for(int i=0;i<nStartPos.length;i++) oAe]/j$
{ ]K0<DO9
// output.writeLong(nPos); UA/Q3)
output.writeLong(fileSplitterFetch.nStartPos); mv%fX2.
output.writeLong(fileSplitterFetch.nEndPos); lz@fXaZM
} szMh}q"u
output.close(); LYNd^}
} :U)q(.53
catch(IOException e){e.printStackTrace ();} \%=\_"^?
catch(Exception e){e.printStackTrace ();} ln)_Jf1r
} 8s pGDg\g
CL|t!+wU/
_KC)f'Cx
//读取保存的下载信息（文件指针位置） ej>8$^y
private void read_nPos() ]p:x,%nm
{ <i"U%Ds(
try{ {NXc<0a(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v'Gqdd-#)
int nCount = input.readInt(); 9kL'"0c
nStartPos = new long[nCount]; Ra<mdteZT
nEndPos = new long[nCount]; 9r@r\-
for(int i=0;i<nStartPos.length;i++) :pcKww|V
{ }UZ$<81=
nStartPos = input.readLong(); 6Lz{/l8
nEndPos = input.readLong(); -X5rGp++
} dG}fpQ3&
input.close(); X{\>TOk
} +[8s9{1{C
catch(IOException e){e.printStackTrace ();} mb~w .~%
catch(Exception e){e.printStackTrace ();} 048BQ
} v5i[jM8
!OekN,6
:.f =>s]
private void processErrorCode(int nErrorCode) pa Uh+"y>
{ F.ryeOJ
System.err.println("Error Code : " + nErrorCode); PcC9)x
} p>h B&h
2<)63[YO
Fh9`8
//停止文件下载 ~Y@(
public void siteStop() e4u$+
{ qCOv4b`
bStop = true; >/nS<y>
for(int i=0;i<nStartPos.length;i++) VS@o_fUx)
fileSplitterFetch.splitterStop(); kX."|]
E8J`7sa
%h 6?/
} )Xg,;^
} zI8Q "b
//负责部分文件的抓取 A>(m}P
**FileSplitterFetch.java *,{. oO9#
*/ ;H/*%2
package NetFox; 2+ F34
&^FCp'J-
iq-n(Rfw~
import java.io.*; 2-j+-B|i
import java.net.*; ,.uu/qV}w
RzQ1Wq
55MsF}p
public class FileSplitterFetch extends Thread { 8:0QIkqk
/ *xP`'T
JVf8KHDj
String sURL; //File URL `DIIJ<;g
long nStartPos; //File Snippet Start Position ^-cj=on=Q
long nEndPos; //File Snippet End Position hNmC(saMGm
int nThreadID; //Thread's ID A U9Y0<
boolean bDownOver = false; //Downing is over GLQ1rT
boolean bStop = false; //Stop identical R<{bb'
FileAccessI fileAccessI = null; //File Access interface G$XvxJ
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%sP C3L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zg+78
{ N[d*_KN.!
this.sURL = sURL; [ \ LA
this.nStartPos = nStart; f;`pj`-k%
this.nEndPos = nEnd; dX{|-;6vm
nThreadID = id; N~_GJw@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zvYkWaa_Qz
} xu(5U`K
L0ig%
E ;65kZ
public void run() y[Zl,v7
{ S-WD?BFC
while(nStartPos < nEndPos && !bStop) 7SLJLn3d
{ Ac'[(
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I]bqle0M
try{ PN[ `p1F
URL url = new URL(sURL); 1%Xwk2l,8b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uFOxb}a9v
httpConnection.setRequestProperty("User-Agent","NetFox"); m5Q,RwJ!xK
String sProperty = "bytes="+nStartPos+"-"; &$tBD@7
httpConnection.setRequestProperty("RANGE",sProperty); `}#(Ze*V:
Utility.log(sProperty); =Ig'Aw$x
v Ic0V
3P~I'FQ
InputStream input = httpConnection.getInputStream(); u@5vK2
//logResponseHead(httpConnection); /:d03N\9k
_}R?&yO
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byte[] b = new byte[1024]; ewg&DBbN"
int nRead; Gf\Dc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LvgNdVJDP|
{ [>QV^2'Z
nStartPos += fileAccessI.write(b,0,nRead); W&ya_iP~C
//if(nThreadID == 1) !c[(#g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \c3zK|^
} ^ }Rqe
A|1 TE$
/uS(Z-@
Utility.log("Thread " + nThreadID + " is over!"); e}yoy+9
bDownOver = true; r,X5@/
//nPos = fileAccessI.write (b,0,nRead); z=:<]j#=
} -jnx0{/
catch(Exception e){e.printStackTrace ();} |ybW
} n#t{3qzpD
} .ii9-+_
l_GvdD
dOh'9kk3
//打印回应的头信息 ]C_g:|q
public void logResponseHead(HttpURLConnection con) =G3O7\KmH
{ S453oG"
for(int i=1;;i++) l?v`kAMR
{ &cztUM(
String header=con.getHeaderFieldKey(i); ,}2yxo;i
if(header!=null) H$TYp
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0KO_bF#EB=
Utility.log(header+" : "+con.getHeaderField(header)); {I+
else 6I GUp
break; /1 lIV_Z
} s `fIeP
} u,e'5,`N
{$z)7s
H((! BRl
public void splitterStop() L&M6s f$N
{ :W(3<D7\
bStop = true; LWE[]1=
} nlJ~Q_E(
o:B?gDM
. [DCL
} /3->TS
qawb9Iud0
^_ <jg0V
/* c=]qUhnH
**FileAccess.java w6DK&@w`'/
*//文件访问(定位，写) y%)5r}S^
package NetFox; rOQhS]TP*
import java.io.*; Bf!i(gM
s$`g%H>
Ci6yH( RE
public class FileAccessI implements Serializable{ hV|pH)Nu{
Bv_C *vW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q<W9<&VZe
RandomAccessFile oSavedFile; Jv1igA21_h
long nPos; 3"=%[
0jCYOl
^{&Vv(~!Q
public FileAccessI() throws IOException H?98^y7
{ Xr\|U89P
this("",0); 1;cV [&3
} le*mr0a
uU(G&:@
6OR5zXpk
public FileAccessI(String sName,long nPos) throws IOException %}jwuNGA
{ 9k8ftxB^
oSavedFile = new RandomAccessFile(sName,"rw"); -BUxQ8/,
this.nPos = nPos; x)0g31 49
oSavedFile.seek(nPos); 9t@^P^}=\m
} ?hUC#{
4GWt.+{J$
YVt#( jl
public synchronized int write(byte[] b,int nStart,int nLen) nM:e<`r
{ p'UYHt
int n = -1; ]:`q/iS&
try{ :q=u+h_
oSavedFile.write(b,nStart,nLen); 02E-|p;
n = nLen; "&?F6Pi
} 3Tze`Q 9
catch(IOException e) y~'F9E!i
{ ppr95Y]^
e.printStackTrace (); d%_v eVIe
} ].53t"*
(pM5B8U
S|!)_RL
return n; a@`15O:
} f`'?2
K=Z~$)Og)
ULc oti=,
} ^$qr6+
z-fP#.
[uK*=K/v
/* ]-"~?
**SiteInfoBean.java s\ft:a@
*/ IJHNb_Cku
package NetFox; 0,+RF"R
%T@3-V_
gTWl];xja
public class SiteInfoBean { MMg"G6?
[of{~
\Z9+U:n
private String sSiteURL; //Site's URL hZNS$
private String sFilePath; //Saved File's Path 7=C$*)x
private String sFileName; //Saved File's Name 1gk{|keh
private int nSplitter; //Count of Splited Downloading File K6<@DP+/
y1R53u`;L
K{)N:|y%!$
public SiteInfoBean() 1}+lL)-!
{//nSplitter的缺省值为5 1A\Jh3;Q
//default value of nSplitter is 5 i zJa`K
this("","","",5); mh`~1aEr
} Eukj2a
)RA$E`!b
QX}O{LQR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0'y9HE'e
{ ,E,oz{,i(
sSiteURL= sURL; *,qW9z
sFilePath = sPath; S <~"\<ED
sFileName = sName; X,VOKj.%
this.nSplitter = nSpiltter; '>dsROB->
3vRRL
|9>?{ B\a
} _kUf[&
@IL_
}T=0]u4,
public String getSSiteURL() S9kagiFX\
{ 8a{S*
return sSiteURL; BeP]M1\?>
} q#9JJWSs
>7%Gd-;l
CVfQ
public void setSSiteURL(String value) $1<V'b[E
{ +Hx$ABH
sSiteURL = value; [1{#a {4
} MX!t/&X(n
p6~\U5rXm
mFCDwh]
public String getSFilePath() db$wKvO1
{ 0<f\bY02
return sFilePath; v+XB$j^H
} H]e%8w))0
sevaNs
p)l>bC?3
public void setSFilePath(String value) 4+&4
{ 3S4'x4*
sFilePath = value; 5J!ncLNm{
} 3[8F:I0UL
|"V]$s$ c
s5{N+O)~S
public String getSFileName() Fw,'a
{ >C,=elM
return sFileName; QC@nRy8%
} S[p.`<{J
3^p<Wx
/C)mx#h]
public void setSFileName(String value) bvdAOvxChW
{ pqmb&"l
sFileName = value; .b'o}DLa
} ygt7;};!
cQkH4>C~
9WN4eC$
public int getNSplitter() p.{9OrH(4
{ r&F(VF0 6
return nSplitter; W 2/`O?
} ybWb'+x
Vgy}0pCl
E-Z6qZ^
public void setNSplitter(int nCount) D)C^'/8q
{ &8VB{S>r
nSplitter = nCount; b[+G+V
} ^7Sk`V
} [k~V77w 14
R5O{;/w
MExP'9
/* +E.}k!y
**Utility.java i4 BCm/h
*/ 8r"$o1!
package NetFox; 6J/"1_
jP*5(*[&y
DRS68^
public class Utility { {&tbp Bl#
+ 3+^J?N
fq*.4s #
public Utility() ?-"xP'#
{ RU} M&&
6=ukR=]v
y$6m|5
} -]8cw#y 0A
3;fuz Kk@b
//线程睡眠 _-^bAr`z
public static void sleep(int nSecond) S3cjw9V
{ *}BaO*A
try{ MUo}Qi0K
Thread.sleep(nSecond); Z";~]]$!Y
} K9JW&5Q
catch(Exception e) x!6&)T?!n
{ U@#YKv
e.printStackTrace (); =4RXNWkud
} x13t@b
} y+3< ] N
B8Ob~?
//日志 }e}J6[wP
public static void log(String sMsg) H(qDQqJHYy
{ W<Ms0
System.err.println(sMsg); &,?bX])
} f{ZOH<"Lo
4;G:.k!K
:?1r.n
public static void log(int sMsg) J*)Vpk
{ CiE
System.err.println(sMsg); h-0sDt pR
} 'FB?#C%U
} 6=V&3|"
T /iKz
Yh`P+L
/* p-]vf$u
**TestMethod.java &\(p<TF
*/ W/*2I3a
package NetFox; ,TrrqCw>
dP8b\H
$umh&z/
public class TestMethod { WfbG }%&J
Y02 cX@K6
SKTf=rY
public TestMethod() 5<o8prtB
{ ///xx/weblogic60b2_win.exe j$l[OZ:#
try{ /S29\^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lR5< G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Wn*>h'R
SiteFileFetch fileFetch = new SiteFileFetch(bean); #:rywz+
fileFetch.start(); IooAXwOF
} 3*@ sp
catch(Exception e){e.printStackTrace ();} r^3QDoy
%'2DEt??
j{)_&|^{
} #X&`gDW
y,$kU1yH7
fmH"&>Loc
public static void main(String[] args) CXqU<a&
{ )6?(K"T
new TestMethod(); a]NQlsE}l
} an+`>}]F
} lq2P10j@
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