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)); "-0pz\a
} vR6^n~
for(int i=0;i<nEndPos.length-1;i++) pl jV|.?
{ ]ro1{wm!WU
nEndPos = nStartPos[i+1]; x?k
} A^T~@AO
nEndPos[nEndPos.length-1] = nFileLength; #U",,*2
} "sX[p
} DuTlYXM2^
2.HZ+1
*@-q@5r}!
//启动子线程 4=?Ok":8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8>%jZ%`a
for(int i=0;i<nStartPos.length;i++) /{eih]`x(
{ ,wry u|7"$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;[WSf{k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O4b-A3:
nStartPos,nEndPos,i); 9E->;0-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H3p4,Y}'#
fileSplitterFetch.start(); g(@$uJ
} ^Ff~j&L@{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y]z)jqX<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?1-n\ka
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", aIzp\$NWVK
nEndPos = " + nFileLength); [#STR=_f
// fileSplitterFetch[nPos.length-1].start(); )+jK0E1
g9FVb7In_
eI/\I:G{f
//等待子线程结束 Rk437vQD,
//int count = 0; \dp9@y[^
//是否结束while循环 'gk81@|
boolean breakWhile = false; zJy 89ib'
h+zkVRyA
v$.JmL0^J
while(!bStop) "lv:hz
{ 94qHY1rp
write_nPos(); brYYuN|Vc
Utility.sleep(500); Ru vG1"
breakWhile = true; j(@g
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}C`}wS3i
for(int i=0;i<nStartPos.length;i++) RAD4q"}k
{ X-G~/n-x
if(!fileSplitterFetch.bDownOver) ])$."g
{ s0`|G|.}
breakWhile = false; ={mPg+Ei'
break; j &0fC!k
} =E"kv!e
} m>Z\ rqOK
if(breakWhile) Ul$X%
break; ig.6[5a\
.^)C:XiW
LAK-!!0X
//count++; !Z+*",]_
//if(count>4) 5ykk11!p$
// siteStop(); U'h[{ek
} )L(d$N=Bd
'n>3`1E,
J1c&"Oh
System.err.println("文件下载结束！"); lkSz7dr@
} (8@hF#N1
catch(Exception e){e.printStackTrace ();} [FAOp@7W
} lE2wkY9^/
[)J49
Vlp*'2VO
//获得文件长度 L?D~~Jb
public long getFileSize() iZkW+5(
{ ~-`BSR
int nFileLength = -1; `%mBu`A
try{ p~d)2TC4#
URL url = new URL(siteInfoBean.getSSiteURL()); }VGI Y>v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u':0"5}
httpConnection.setRequestProperty("User-Agent","NetFox"); :m)Rmwn_
E-tNB{r@
+Qi52OG
int responseCode=httpConnection.getResponseCode(); }TX'Z?Lq
if(responseCode>=400) D|Ihe%w-
{ +SuUI-.
processErrorCode(responseCode); ku[=QsMv
return -2; //-2 represent access is error x3I%)@-Z
} c~pUhx1(
,Zcx3C:#
tXG4A$(2&
String sHeader; Hs4zJk
P^_d$
r"u(!~R
for(int i=1;;i++) 'Qs3
{ !s[j1=y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6(<~1{ X%
//Utility.log(in.readLine()); iM\ZJ6
sHeader=httpConnection.getHeaderFieldKey(i); Y9H *S*n
if(sHeader!=null) ev;5?9\E
{ tN'- qdm
if(sHeader.equals("Content-Length")) O%++0k;
{ Pdo5sve
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {HRxyAI!
break; A^r [_dyZ
} *F8uu.
} C!/8e (!N
else ".Deu|>
break; ^?^|Y?f2P?
} dn)tP6qc/
} J\dhi{0
catch(IOException e){e.printStackTrace ();} k+Ma_H`
catch(Exception e){e.printStackTrace ();} G$x["
QhE("}1
rD(ep~^M
Utility.log(nFileLength); Dpp52UnTE
Ng;b!S
d$?n6|4
return nFileLength; ,f/IG.
} _"w!KNX>(~
++{+ #s6
T\e)Czz2-
//保存下载信息（文件指针位置） WfjUJw5x"s
private void write_nPos() _KkVI7a
{ x4m_(CtK
try{ :J4C'N
output = new DataOutputStream(new FileOutputStream(tmpFile)); "w|k\1D
output.writeInt(nStartPos.length); Ppb2"Ik
for(int i=0;i<nStartPos.length;i++) seD+~Y\z
{ xX4^nem\G
// output.writeLong(nPos); z`r4edk3
output.writeLong(fileSplitterFetch.nStartPos); *}iT6OJ
output.writeLong(fileSplitterFetch.nEndPos); Wn,g!rB^@
} o2e h)rtB
output.close(); Ko]h r
} EPd.atA
catch(IOException e){e.printStackTrace ();} U5ud?z()OA
catch(Exception e){e.printStackTrace ();} {}_Oo%IVGK
} n,Mw# r?y
Y)j,(9
5$"[gdt)T
//读取保存的下载信息（文件指针位置） ={i&F
private void read_nPos() +$mskj0s
{ ]MA)='~
try{ bQN4ozSi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f+*2K^B
int nCount = input.readInt(); O"-PNF,J
nStartPos = new long[nCount]; _467~5JkU
nEndPos = new long[nCount]; &\]f!'jV
for(int i=0;i<nStartPos.length;i++) \=G Xe.}4d
{ zQ|x>3
nStartPos = input.readLong(); U/&qV"Ih
nEndPos = input.readLong(); VQNH@g^gqr
} owY_cDzrH
input.close(); \7tvNa,C
} 0!'M#'m
catch(IOException e){e.printStackTrace ();} 7/OOq=z
catch(Exception e){e.printStackTrace ();} o(SJuZC/U
} Z-p^3t'{
&lfF!
Pymh^i
private void processErrorCode(int nErrorCode) l'{goyf
{ Y)5uK:)^
System.err.println("Error Code : " + nErrorCode); nPIR1Z
} 4!s k3Cw{
e"H+sM26-
i K[8At"Xo
//停止文件下载 Di1G
public void siteStop() B l/e>@M
{ z` ?xS
bStop = true; Rw=E_q{
for(int i=0;i<nStartPos.length;i++) ,G/X"t ~
fileSplitterFetch.splitterStop(); jeBj
I/-w65J]
CY).I`aJ
} z`:^e1vG
} gGdYh.K&e5
//负责部分文件的抓取 awW\$Q
**FileSplitterFetch.java `M<G8ob
*/ S"A_TH
package NetFox; C`_D{r
:@8.t,|
! tPK"k
import java.io.*; 1:s~ ]F@
import java.net.*; :8L61d2(
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9*Twx&
public class FileSplitterFetch extends Thread { m1; <T@
k 5r*?Os
v;qL?_:=c
String sURL; //File URL vHe.+XY
long nStartPos; //File Snippet Start Position F"#*8P
long nEndPos; //File Snippet End Position WIlS^?5I<
int nThreadID; //Thread's ID J& SuUh<
boolean bDownOver = false; //Downing is over z}N^`_ *
boolean bStop = false; //Stop identical ~4` ec
FileAccessI fileAccessI = null; //File Access interface yWk:u 5
C)^\?DH
vCo}-b-j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^g){)rz|
{ p;Ok.cXVp
this.sURL = sURL; 0 S8{VZpy
this.nStartPos = nStart; ;RZa<2
this.nEndPos = nEnd; ^a5~FI:
nThreadID = id; jtpNo~O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &'2l_b
} kV%y%l(6
,^66`C[G
P3FpU<OBwp
public void run() 2m}]z.w#
{ 2xBGs9_Y
while(nStartPos < nEndPos && !bStop) JJOs L!@
{ |Qq'_4:
^n5QKHD
[c%}L 3B
try{ g8@HAV^H
URL url = new URL(sURL); \/%Q PE8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .%h_W\M<l
httpConnection.setRequestProperty("User-Agent","NetFox"); U]&%EqLS
String sProperty = "bytes="+nStartPos+"-"; mYRR==iDL
httpConnection.setRequestProperty("RANGE",sProperty); r~a}B.pj
Utility.log(sProperty); [/^g) ^s:
m,_oX1h
o|.me G
InputStream input = httpConnection.getInputStream(); b|'LtL$Y
//logResponseHead(httpConnection); jXva?_
gz:c_HJ
S%|' /cFo
byte[] b = new byte[1024]; sW`iXsbWM>
int nRead; OVK(:{PwS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y mSaIf
{ 2uB26SEIl
nStartPos += fileAccessI.write(b,0,nRead); udr'~,R
//if(nThreadID == 1) U.)eJ1a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "d*
} dQo$^?
ht!:e>z&4
goWt!,&f
Utility.log("Thread " + nThreadID + " is over!"); }E_zW.{!
bDownOver = true; j+v)I=
//nPos = fileAccessI.write (b,0,nRead); 7cSvAX0Z.
} 0drc^rj !
catch(Exception e){e.printStackTrace ();} >CA1Ub&ls
} M/ \~
} BNLall
SK2pOZN
v3]M;Y\
//打印回应的头信息 N#qoKY(#
public void logResponseHead(HttpURLConnection con) wOSNlbQ5jl
{ #jR?C9&!(
for(int i=1;;i++) nI` 1@vB&
{ ,peFNpi
String header=con.getHeaderFieldKey(i); 0(.C f.B~
if(header!=null) of<OOh%3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DvKMb-*S
Utility.log(header+" : "+con.getHeaderField(header)); Cu5 - w
else \Bf{/r5x
break; [#V!XdQ,
} 3 g!h4?^
} {<Zqw]
)v.FAV:
+<#-52br\
public void splitterStop() #7)6X:/O
{ 7wiu%zfa:=
bStop = true; riQ?'!a7
} HxAa,+k
z(` kWF1<
OTm"Iwzu@
} Ds$;{wl#x
F U%b"gP^
6 >2! kM7
/* D=+sD"<|
**FileAccess.java 7X"cu6%\
*//文件访问(定位，写) JD.z}2+
package NetFox; kSrzIq<xre
import java.io.*; 7hQl,v< 5
awtzt?VtLh
'McVaPav
public class FileAccessI implements Serializable{ [ ff.R
A#{*A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o!N@W
RandomAccessFile oSavedFile; *0tNun 5=3
long nPos; r>OE[C69
CK%W+";
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public FileAccessI() throws IOException UJ+JVj
{ _7VU ,
this("",0); 2I5@zm ea
} MDZb|1.AT
MiI7s;
UHwrssX&3
public FileAccessI(String sName,long nPos) throws IOException $$w 1%#F=
{ NjLd-v"2
oSavedFile = new RandomAccessFile(sName,"rw"); ^YV[1~O
this.nPos = nPos; <XU]%}o
oSavedFile.seek(nPos); "O{sdVS
} G"(!5+DLy
4H)a7<,
W\.(~-(So
public synchronized int write(byte[] b,int nStart,int nLen) .FyC4"b=c
{ U/;Vge8{
int n = -1; 1>LquZ+Kj
try{ scmbDaOn
oSavedFile.write(b,nStart,nLen); %\u>%s<9
n = nLen; "@_f>3z
} ?uLqB@!2
catch(IOException e) v,! u{QP
{ iW)Ou?aS
e.printStackTrace (); .T2I]d
} {WChD&v
~V5jjx*
;F-kE4w
return n; s5 BV8 M
} ~PHG5?X
c'C2V9t
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} lH8?IkK,g
CS
F~6[DqF\|
/* W0Vjs|/
**SiteInfoBean.java 78kk"9h'
*/ X|:O`b$G
package NetFox; $0 )K [K
@,hvXl-G*
`O F\f
public class SiteInfoBean { 43YusUv
+|N"i~f>j
rx<fjA%
private String sSiteURL; //Site's URL ftbu:RtK^^
private String sFilePath; //Saved File's Path @r<w|x}
private String sFileName; //Saved File's Name !|]%^G
private int nSplitter; //Count of Splited Downloading File bZ=d!)%P-{
}j QwP3eY
QHeUpJ/^
public SiteInfoBean() u<[Y6m
{//nSplitter的缺省值为5 l%fl=i~oN
//default value of nSplitter is 5 >8c9-dTmf
this("","","",5); 4f+Ke*^[RA
} xE:p)B-]
:v+39
zB4gnVhus|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) juM?y'A
{ &j$k58mX
sSiteURL= sURL; o{/D:B
sFilePath = sPath; %%#zO Z
sFileName = sName; 5E]I
this.nSplitter = nSpiltter; %NuS!v>
Sn0 Gw
y~w$>7U.
} %~@}wHMB
S&yCclM
Xv6s,<#\
public String getSSiteURL() 5_PD?lg
{ KpWQ;3D2
return sSiteURL; g]S.u8K8m
} DY%E&Vd:h
'<O& :
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public void setSSiteURL(String value) K=;p^dE
{ KQh'5o&
sSiteURL = value; D`+'#%%x
} JA&w"2X*E
%*,'&S
0I,-1o|s
public String getSFilePath() %NKf@If)
{ d)LifsD)
return sFilePath; ~FJd{$2x`
} u(P D+Gz
,JR7N_"I
B<W{kEY
public void setSFilePath(String value) 2`x[y?Tn
{ 3a =KgOvp
sFilePath = value; NVQIRQ.
} r__uPyIMG/
?>e-6*.
lUDzfJ}3
public String getSFileName() h_J'dJS
{ ,oR}0(^"\<
return sFileName; ,>)/y
} EBJaFz'
r>5,U:6Q/
*@dqAr%
public void setSFileName(String value) SJL?(S*
{ C{4[7
sFileName = value; RszqDm
} Pr" 2d\
B?k75G
\ ^_3Yw
public int getNSplitter() YS&3+Tp
{ v~j21`
return nSplitter; |]V0sgpoZ
} \S _ycn
(@]{=q<
"gYn$4|R7*
public void setNSplitter(int nCount) zXB.)4T
{ 3(X"IoNQ
nSplitter = nCount; lbMb
} ">|fB&~A
} iCx}v[;Ol
AFyf7^^k
VCtj8hKDr
/* kd2+k4@#
**Utility.java ZPHB$]ri
*/ ><%z~s
package NetFox; )jvYJ9s
*?cE]U6;
.:E%cL +h
public class Utility { A^xDAxk
+n7bbuxj(X
X180_Kt2
public Utility() ^2=11
{ TX$j-TM'
#Fq6-]y1")
{eL XVNR7R
} ;V@o 2a
G7b>r
//线程睡眠 &G:#7HX@-
public static void sleep(int nSecond) ;>bcI).
{ EHmw(%a|+
try{ ]FP(,:Yw
Thread.sleep(nSecond); Enyx+]9
} )V7bi^r
catch(Exception e) SRyAW\*LWU
{ Zgd| J T7
e.printStackTrace (); It&$R`k
} mGb,oj7l
} (V5_q,2
D}OvD |<-
//日志 <7-3j{065
public static void log(String sMsg) 4vC { G.
{ gy0l@ 5 N
System.err.println(sMsg); /3{jeU.k
} .*+%-%CbP
{94qsVxQZ
O8qA2@,
public static void log(int sMsg) eh`n?C
{ /SO 4O|b
System.err.println(sMsg); )ERmSWq/u
} _NA[g:DZ&O
} ye4 T2=
%v5IR
HJ~0_n&
/* rE)lt0mkv
**TestMethod.java K?`Fpg(
*/ Em?bV(
package NetFox; `saDeur#X
0ZcvpR?G
.'aW~WR
public class TestMethod { XnR9/t
/x\{cHAt8J
UDl[
public TestMethod() ,ELbm
{ ///xx/weblogic60b2_win.exe \iVb;7r)9:
try{ vr/*z euA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A0JlQE&U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UaG })
SiteFileFetch fileFetch = new SiteFileFetch(bean); d.>Zn?u4L
fileFetch.start(); :%!`R72
} 6ZKSet8
catch(Exception e){e.printStackTrace ();} kbu.KU+
@M=xdZNyJ
B*B}eXUph
} R<]f[
!X5n'1&
|}$ZOwc
public static void main(String[] args) $IUe](a{d
{ Qx<86aKkF
new TestMethod(); w`ebZa/j
} NFsj ~6F#
} !Z(3dtUy
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