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)); _){|/Zd
} g/GI'8EMj
for(int i=0;i<nEndPos.length-1;i++) [&TF]az
{ |$WHw*F^
nEndPos = nStartPos[i+1]; *i"9D:
} xm m,-u
nEndPos[nEndPos.length-1] = nFileLength; o/AG9|()4
} ~j!n`#.\
} i"Jy>'
(4H\ho8+mp
SioeIXU
//启动子线程 h.<f%&)F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d`sZ"8}j
for(int i=0;i<nStartPos.length;i++) vC]X>P5Px
{ *byUqY3(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i?T-6{3I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q 3WD!Z8y
nStartPos,nEndPos,i); cU;Bm}U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w2B)$u
fileSplitterFetch.start(); wNa5qp 0
} =!TUf/O-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L>Y+}]~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C[FHqo9M?H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PT>b%7Of
nEndPos = " + nFileLength); @A[)\E1
// fileSplitterFetch[nPos.length-1].start(); %. 1/#{
1]xmOx[mb
n_kwtWX(
//等待子线程结束 \8CCa(H
//int count = 0; >}SEU-7&\
//是否结束while循环 GcO2oq
boolean breakWhile = false; `KQx#c>'
jg$qp%7i%
80nEQT y
while(!bStop) 6,t6~Uo/
{ & SXw=;B
write_nPos(); yP58H{hQM8
Utility.sleep(500); 7?dWAUF
breakWhile = true; O-, "/Z
* + T(i
! ._q8q\
for(int i=0;i<nStartPos.length;i++) &}DfIP<
{ y##h(y
if(!fileSplitterFetch.bDownOver) .}__XWK5
{ CW1l;uwtU
breakWhile = false; 9p_?t'&>q
break; @a8lF$<
} Tm"H9
} oidZWy
if(breakWhile) Jm_)}dj3o
break; '_v~+
V%-hP~nyBx
qda 2
//count++; ebA:Sq:w
//if(count>4) dIC\U
// siteStop(); 0)&!$@HW
} x%dny]O1;
VMah3T!
%lCZ7z2o
System.err.println("文件下载结束！"); H-_gd.VD
} !Fl'?Kz
catch(Exception e){e.printStackTrace ();} g*$2qKm
} 12`u[O}\}-
>axeUd+@i
w$ 8r<?^3
//获得文件长度 cSt)Na~C
public long getFileSize() e!VtDJDS
{ <+QdBp'd;
int nFileLength = -1; GDLw_usV
try{ xvl$,\iqE
URL url = new URL(siteInfoBean.getSSiteURL()); v,")XPY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8maWF.xq
httpConnection.setRequestProperty("User-Agent","NetFox"); x/,;:S
12 p`ZD=
9E7G%-
int responseCode=httpConnection.getResponseCode(); t}+/GSwT
if(responseCode>=400) TpU\IQ
{ tF;0P\i
processErrorCode(responseCode); =Jm[1Mgt
return -2; //-2 represent access is error ^s)`UZ<C=
} W9SU1{*9
0? {ADQz
4*EMd!E=<
String sHeader; ,YD7p= PY
kjYM&q
Dg&6@c|
for(int i=1;;i++) x^1udK^re
{ v3r3$(Hr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?V6,>e_+
//Utility.log(in.readLine()); #E]K*mE'
sHeader=httpConnection.getHeaderFieldKey(i); #/>TuJc
if(sHeader!=null) um,f!ho-U
{ FGDVBUY@
if(sHeader.equals("Content-Length")) 0pE>O7
{ =:rg1wo"c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $tZ {>!N
break; 5`^@k<
} SAP/jD$5]>
} N{%7OG
else Vk{;g
break; zYzV!s2^
} P j
} C|ZPnm>f30
catch(IOException e){e.printStackTrace ();} RU)(|;
catch(Exception e){e.printStackTrace ();} wn"}<ka
"BQnP9
Z- feMM
Utility.log(nFileLength); C8m9H8Qm
W3le)&
I}PI
return nFileLength; C]!2
} 9q'&tU'a=c
kY)Vr3uGA
i$NlS}W
//保存下载信息（文件指针位置） (d_z\U7l
private void write_nPos() ](Fey0@
{ /DAR'9@h
try{ J?o
output = new DataOutputStream(new FileOutputStream(tmpFile)); qb? <u
output.writeInt(nStartPos.length); ! I:N<
for(int i=0;i<nStartPos.length;i++) kX8C'D4 gX
{ Yw|v5/>
// output.writeLong(nPos); hl1IG !
output.writeLong(fileSplitterFetch.nStartPos); 8^>qor.]M
output.writeLong(fileSplitterFetch.nEndPos); /2p*uv}IP
} &N^j }^ Z
output.close(); = wz}yfdrC
} }zGx0Q
catch(IOException e){e.printStackTrace ();} |.k'?!
catch(Exception e){e.printStackTrace ();} g*YDgY
} J5{;+ysUMl
?c#s}IH
-Q20af-
//读取保存的下载信息（文件指针位置） c5ij2X|I
private void read_nPos() Y5aG^wE[:
{ E0ED[d,
try{ ^8 VW$}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KW:N 6w
int nCount = input.readInt(); I[?\Or
nStartPos = new long[nCount]; nXT`7
nEndPos = new long[nCount]; =v:?rY}
for(int i=0;i<nStartPos.length;i++) gkr9+
{ 81Z;hO"~
nStartPos = input.readLong(); f"s_dR
nEndPos = input.readLong(); \]>YLyG
} L$5,RUy
input.close(); 6q^$}eOt
} FJ3S
catch(IOException e){e.printStackTrace ();} @1*^ttC
catch(Exception e){e.printStackTrace ();} phy}Hk/
} O=jLZ2os
zM0}(5$m
sT?{
private void processErrorCode(int nErrorCode) e"hfeNphz
{ Uj5-x%~
System.err.println("Error Code : " + nErrorCode); h4]^~stI
} iwF_'I$#N
'WW:'[Syn'
@} Ig*@
//停止文件下载 cQEUHhRg!
public void siteStop() FI^Wh7J
{ FOF@@C~aH
bStop = true; }y6|H,t9
for(int i=0;i<nStartPos.length;i++) %Y&48''"
fileSplitterFetch.splitterStop(); M/ 64`lcb
j!4{+&Laq
X /c8XLe"
} JVoC2Z<
} ^5X?WA,Z99
//负责部分文件的抓取 X$!fR >Zc
**FileSplitterFetch.java x17:~[c']
*/ HTL6;87w+]
package NetFox; ':n`0+Eh
e0(/(E:
\HO)ss)"
import java.io.*; GxhE5f;
import java.net.*; |u>V> PN
v.]{b8RR
$5XAS
public class FileSplitterFetch extends Thread { Cfi4~&
BdD]HXB|_
%r|sb=(yT
String sURL; //File URL t=Oq<r
long nStartPos; //File Snippet Start Position Tf3CyH!k
long nEndPos; //File Snippet End Position S/E&&{`ls
int nThreadID; //Thread's ID "WKOlfPa
boolean bDownOver = false; //Downing is over QATRrIj{e
boolean bStop = false; //Stop identical Bc8&-eZ,
FileAccessI fileAccessI = null; //File Access interface DXf
"1,*6(;:
9:2Bt <q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m.+h@
{ jG1(Oe;#
this.sURL = sURL; hNXZL>6
this.nStartPos = nStart; *J4!+GD
this.nEndPos = nEnd; ^os_j39N9
nThreadID = id; {dF@Vg_n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L-Q8iFW'
} #zP-,2!r
@V 'HX
$+80V{J#
public void run() DzR,ou
{ ! yJ0Am>
while(nStartPos < nEndPos && !bStop) 0BXr[%{`
{ eay|>xa2
atZe`0
2.Z#\6Vj
try{ ^;F/^_
URL url = new URL(sURL); fizW\f8ai
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); & R_?6*n
httpConnection.setRequestProperty("User-Agent","NetFox"); ovp/DM
String sProperty = "bytes="+nStartPos+"-"; Qhj']>#g
httpConnection.setRequestProperty("RANGE",sProperty); 1i#y>fUj
Utility.log(sProperty); !SK`!/7c?
X2V+cre
;y(;7n_ a
InputStream input = httpConnection.getInputStream(); IT NFmD
//logResponseHead(httpConnection); OP\jO DX
\lg ^rfj
7I ~O|Mw
byte[] b = new byte[1024]; 1KUjb@"
int nRead; |pHlBzHj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P7w RX F{
{ ku,{NY f^Y
nStartPos += fileAccessI.write(b,0,nRead); O[ z0+Q?6Z
//if(nThreadID == 1) &KMI C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lyc6nP;F
} +[ ?!@)
` +YtTK
#H7 SLQr\
Utility.log("Thread " + nThreadID + " is over!"); JLm3qIC
bDownOver = true; Dspvc
//nPos = fileAccessI.write (b,0,nRead); |-ZML~2S=h
} vP,pK=5
catch(Exception e){e.printStackTrace ();} Zd-qBOB2L
} 6 5zx<
} hr]+4!/
Vja 4WK*
Un8' P8C
//打印回应的头信息 (EcP'F*;;y
public void logResponseHead(HttpURLConnection con) pT=^o
{ [.>=>KJ_
for(int i=1;;i++) 79 4UY
{ K1X-<5]{
String header=con.getHeaderFieldKey(i); M.Q HE2
if(header!=null) 4AL,=C3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PV\J] |d,%
Utility.log(header+" : "+con.getHeaderField(header)); {-I+
else c!HGiqp
break; oOprzxf"+Z
} *m]Y6
} {*;8`+R&
K\ Wzh;
g#i~^4-1
public void splitterStop() x"Ll/E)\v]
{ Pt85q?->
bStop = true; _xAru9=n^
} vk|f"I
B{\Y~>]Pj
KGDN)@D
} (LsVd2AbR
d_(>:|oh
z$1|D{
/* Vl+UC1M}B>
**FileAccess.java EPW4 h/I
*//文件访问(定位，写) hRXnig{;3
package NetFox; @N '_qu
import java.io.*; Z4G%Ve[
1^^{;R7N
&PXT$x[i
public class FileAccessI implements Serializable{ oC" [rn
a)W|gx6Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y 22Ai
RandomAccessFile oSavedFile; pF6u3]
long nPos; o;wSG81
o.r D
l'm|**
public FileAccessI() throws IOException ~H#c-B
{ |};d:LwX
this("",0); #qVvh3#g
} w&YUb,{Y
?J6Ek*E#
#NyO'
public FileAccessI(String sName,long nPos) throws IOException )7Hx<?P
{ RNB-W%
oSavedFile = new RandomAccessFile(sName,"rw"); bCP2_h3*
this.nPos = nPos; "{@[06|1
oSavedFile.seek(nPos); ps:"0^7
} `\:Ede
&(<>} r
<`-sS]=d}
public synchronized int write(byte[] b,int nStart,int nLen) o.Ww.F
{ QN;5+p[N
int n = -1; Mm,\e6#*
try{ M5RN Z%
oSavedFile.write(b,nStart,nLen); M p<r`PM2
n = nLen; #<Y3*^~5d
} CSjd&G*ZB
catch(IOException e) 3_G0eIE"u
{ i<m) s$u
e.printStackTrace (); dSjO12b
} 7_36xpw
gHh(QRA
"E7<S5cr
return n; >lmqPuf
} aVHID{Gf Z
+uF}mZS^
\a0{9Xx F
} ir}*E=*
u0)O Fz
Vxrj(knck,
/* M&=SvM.f
**SiteInfoBean.java fiC0'4.,
*/ ?v,c)
package NetFox; tMdSdJ8
V1P]pP
?$)a[UnqX
public class SiteInfoBean { <9H3d7%
Q7pCF,;
F+VNrt-
private String sSiteURL; //Site's URL Lm!]m\LRZD
private String sFilePath; //Saved File's Path ox<6qW
private String sFileName; //Saved File's Name &!;o[joG
private int nSplitter; //Count of Splited Downloading File >~7XBb08
3;b)pQ~6CJ
mGg/F&G9
public SiteInfoBean() {88|J'*L
{//nSplitter的缺省值为5 D',7T=C
//default value of nSplitter is 5 yS K81`
this("","","",5); `tO t+>YWn
} @lM-+q(tl
B]hRYU
r]}6iF.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <%^WZ:c
{ <% mD#S
sSiteURL= sURL; 6;~V@t
sFilePath = sPath; o S{hv:)>
sFileName = sName; b!MN QGs
this.nSplitter = nSpiltter; <Ed;tq
9pi{)PDJ
Q7`)&^ Hx
} @)MG&X
jB9~'>JY
S_*Gv O
public String getSSiteURL() rpEIDhHv
{ 2T%sHp~qt
return sSiteURL; e6J>qwD?
} kDJqT
|61ns6i!
4TQmEM,
public void setSSiteURL(String value) Dg~m}La
{ eo;MFd%;
sSiteURL = value; AD!w:jT9
} f"\klfrRI_
#v$wjqK5
-1$z=,q'
public String getSFilePath() (!m6>m2
{ IrRe6nf@K
return sFilePath; :Eh}]_
} GXLh(d!C
d/+s-g p
g>7i2
public void setSFilePath(String value) "tOm
{ %Y/;jCY
sFilePath = value; bFG?mG:
} {[bpvK
pi70^`@'B
[Djx@x
public String getSFileName() | Wj=%Ol%o
{ '8R5Tl
return sFileName; $AZ=;iP-
} g;q.vHvsc"
@b2?BSdUp
1Xh@x
public void setSFileName(String value) T.QJ#vKO0
{ "Ar|i8^G3
sFileName = value; [#X}(
} x~m$(LT
~Sf'bj;(
-d2)
public int getNSplitter() 7Kj7or|
{ 4!3<[J;N;
return nSplitter; ~kpa J'm
} :|&6x!
v9TIEmZ
W4#DeT
public void setNSplitter(int nCount) ^K8XY@{&
{ AfZGI'%4[a
nSplitter = nCount; \Lbwfd=
} grI#'x
} ;K4=fHl
k^KpQ&n
j)nE!GKD(
/* Mj2Dat`p9
**Utility.java EKw)\T1
*/ aWvC-vZk
package NetFox; zLxuxf~4@
[P6A$HC<
BTOl`U
public class Utility { lR F5/
TR `C|TV>
Zu~t )W
public Utility() 2h}FotlO
{ "-5FUKI-
qauvwAMuX
lA6{TH.x
} pp#!sRUKPV
%k"hzjXAw
//线程睡眠 -IDhK}C&T
public static void sleep(int nSecond) =_6 Q26
{ yk^2<?z>2
try{ A;^{%S
Thread.sleep(nSecond); x a\~(B.
} 23+JuXC6>
catch(Exception e) ': Ek3'L
{ VY|UB7,C
e.printStackTrace (); n~jW
} D4@(_6^
} Du-Q~I6
]|IeE!6
//日志 WhFE{-!gX
public static void log(String sMsg) vZ6R>f
{ P $r!u%W
System.err.println(sMsg); J!Rqm!)q
} VVuNU"-
f*m^x7
I;<__
public static void log(int sMsg) l4I',79l
{ Y_XRf8Sw
System.err.println(sMsg); jrm^n_6};
} R(}!gv}s
} ;d}n89DXj
%X\Rfn0J"
A-^B?E
/* ;?-{Uk
**TestMethod.java E1A5<^t
*/ O|9Nl*rXz
package NetFox; q}E'x/s2m
h9nh9a(2
hA`9[58/
public class TestMethod { 0N6 X;M{zh
,oEAWNbgQ
K)\D,5X^
public TestMethod() d(5j#?
{ ///xx/weblogic60b2_win.exe p-z!i+
try{ .Rb4zLYL*w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Vrp]YRL`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D [v225
SiteFileFetch fileFetch = new SiteFileFetch(bean); mndEB!b
fileFetch.start(); ,yfJjV*I
} JmBMc}54
catch(Exception e){e.printStackTrace ();} c[C(3c|n
ILHn~d IC
g,RhUt9
} ;>]dwsA*P
Z]OX6G
0h('@Hb.K#
public static void main(String[] args) 4i29nq^n
{ ,M\/[_:
new TestMethod(); LG?b]'#
} bvJ*REPL?
} +xr;X 9
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