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)); d}?KPJ{
} PbxQ \.
for(int i=0;i<nEndPos.length-1;i++) X g7xy>{]
{ <?;KF2A({
nEndPos = nStartPos[i+1]; PRyzvc~
} 6"[,
nEndPos[nEndPos.length-1] = nFileLength; m^RO*n.
} hSps9*y
} 0;w 4WJJ
u,=?|M\
hDoFF8)c
//启动子线程 . Wd0}?}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?c_:S]^
for(int i=0;i<nStartPos.length;i++) &(o&Y
{ #'i,'h+F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |hDN$By
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0x&L'&SpN
nStartPos,nEndPos,i); x>4p6H{]0'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3RlNEc%)
fileSplitterFetch.start(); lF7".
} ]haQ#e}WH
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '['x'G50
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g>b{hkIXg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 931GJA~g
nEndPos = " + nFileLength); o~xGE6A*"
// fileSplitterFetch[nPos.length-1].start(); d?/g5[
J-klpr#
x],XiSyp
//等待子线程结束 7coVl$_Zl
//int count = 0; zqXDD; w3
//是否结束while循环 ]-+l.gVFW
boolean breakWhile = false; HYJEz2RF
/;y`6WG%2
NOAz"m+o
while(!bStop) ( YZ2&
{ S,Qa\\~z
write_nPos(); -" r4
Utility.sleep(500); fCO<-L9k$
breakWhile = true; 5@W63!N
@6;ZP1
0uGTc[^^M
for(int i=0;i<nStartPos.length;i++) cp`ZeLz2^
{ BuitM|k'
if(!fileSplitterFetch.bDownOver) y<BG-
{ Xoq -
breakWhile = false; ;<F^&/a|yQ
break; $p}q,f.
} E;k$ICOXA
} }1a(*s,s-^
if(breakWhile) XZTH[#MqeI
break; KfC{/J\
m.5@qmQ
eG dFupfz
//count++; G]Im.x3O-
//if(count>4) vZqW,GDfXo
// siteStop(); hfvC-f97L
} au+:-Khm
]%G#x
[KW)z#`*
System.err.println("文件下载结束！"); e?GzvM'2
} ^>fr+3a"P
catch(Exception e){e.printStackTrace ();} 3@0!]z^W
} *^Z -4
GJF ,w{J
y"_rDj`
//获得文件长度 O^3XhTW^\~
public long getFileSize() aOUTKyR ~
{ *iSE)[W
int nFileLength = -1; $>wN:uN(
try{ .F\[AD 5
URL url = new URL(siteInfoBean.getSSiteURL()); Iq{/-,v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nk$|nn9#'
httpConnection.setRequestProperty("User-Agent","NetFox"); W=n Hi\jLV
@cG+D
0yb9R/3.
int responseCode=httpConnection.getResponseCode(); YEB7X>p#
if(responseCode>=400) --vJR/-
{ +5:9?&lH
processErrorCode(responseCode); }JUc!cH8z
return -2; //-2 represent access is error ,OkI0[
} GN+,9
iqWkhJphv
_Qb].~
String sHeader; J!QIMA4{
-(#`JT8
0OtUb:8LX
for(int i=1;;i++) qzu(4*Gk6
{ |k: FNu]C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Jg.^h1>x
//Utility.log(in.readLine()); 1 a%1C`d
sHeader=httpConnection.getHeaderFieldKey(i); #A< |qd
if(sHeader!=null) !H9zd\wc
{ R0q|{5S
if(sHeader.equals("Content-Length")) DKNcp8<J
{ C5X!H_p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Kj-zEl
break; &mba{O
} |Fx~M,Pzg
} 1b2xWzpG
else Xw162/:h
break; N=@8~{V.
} 3Z}KRsp3
} PoRP]Q*n
catch(IOException e){e.printStackTrace ();} 4`?WdCW8
catch(Exception e){e.printStackTrace ();} @~i :8
+a+DiD>./
v#5hK<9
Utility.log(nFileLength); LS<*5HWX
,jy9\n*<t9
Q_k'7Z\g$
return nFileLength; iW[%|ddk
} _6aI>b#yL
z;&J9r$`
b>& 3XDz
//保存下载信息（文件指针位置） Q6r
private void write_nPos() WvcPOt8Bp>
{ :;&3"-
try{ TO/SiOd
output = new DataOutputStream(new FileOutputStream(tmpFile)); @Fb 2c0?Y
output.writeInt(nStartPos.length); ]C-a[
for(int i=0;i<nStartPos.length;i++) -_>E8PhM
{ tYhNr
// output.writeLong(nPos); fDChq[LAn
output.writeLong(fileSplitterFetch.nStartPos); T>5N$i
output.writeLong(fileSplitterFetch.nEndPos); Et&PzDvU
} <4"Bb_U
output.close(); LiEDTXRz
} W;F=7[h
catch(IOException e){e.printStackTrace ();} CI|#,^
catch(Exception e){e.printStackTrace ();} @3?dI@i(
} XU`vs`/
"OrF81
,,h>_IA
//读取保存的下载信息（文件指针位置） h0-CTPQ7A
private void read_nPos() u)Vn7zh
{ ?+byRoY>&g
try{ NLev(B:OQH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t2FA|UF
int nCount = input.readInt(); 07vzVsQ}p
nStartPos = new long[nCount]; ?|GwuG8g
nEndPos = new long[nCount]; 0)9n${P7d
for(int i=0;i<nStartPos.length;i++) $$T a
{ tG0 &0`
nStartPos = input.readLong(); S6{y%K2y&
nEndPos = input.readLong(); 8y]{I^z}
} Lv-M.
input.close(); Tqx
} +"VXw2R_e
catch(IOException e){e.printStackTrace ();} rpL]5e!
catch(Exception e){e.printStackTrace ();} [4mIww%
} Ro#O{
&M#}?@!C
oLt%i:,A
private void processErrorCode(int nErrorCode) p7,dl*'
{ +GNXV-S
System.err.println("Error Code : " + nErrorCode); [XD3}'Aa
} fLuOxYQbf
%eJE@$
vZ|Wj] ;o
//停止文件下载 0w6"p>s>c
public void siteStop() 2-rfFqpe
{ |1m2h]];Q
bStop = true; \*30E<;C_
for(int i=0;i<nStartPos.length;i++) N{K[sXCW
fileSplitterFetch.splitterStop(); :MF+`RpL
o^x,JT
^:ehG9
} 2nI^fVR%\
} uh3<%9#\k
//负责部分文件的抓取 S|_"~Nd=
**FileSplitterFetch.java c,5yH
*/ L ?S#3@Pa
package NetFox; Ots]y
S\6.vw!'
\WM"VT
import java.io.*; +VO(6Jn
import java.net.*; dMa6hI{k
3/CKy##r%]
]fU0;jzX
public class FileSplitterFetch extends Thread { Bv^5L>JZ/
F>aaUj
P5Pb2|\*
String sURL; //File URL piAFxS<6
long nStartPos; //File Snippet Start Position v.>95|8
long nEndPos; //File Snippet End Position X>Y>1fI.
int nThreadID; //Thread's ID ov|pXi<e
boolean bDownOver = false; //Downing is over WCg&*
boolean bStop = false; //Stop identical knRs{1}Pw{
FileAccessI fileAccessI = null; //File Access interface ^x}k1F3
B?;P:!/1
W9jxw4)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rf =Wq_
{ !4T7@V`G
this.sURL = sURL; |GP1[Q{
this.nStartPos = nStart; #M[%JTTn
this.nEndPos = nEnd; 'H'R6<z5
nThreadID = id; 32K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f+4j ^y}
} )/BbASO$)Z
6f;20dn6
m@g9+7
public void run() EskD)Sl
{ +{s -Fg
while(nStartPos < nEndPos && !bStop) a7TvX{<d
{ XK/bE35%^!
d08:lYQ
Url8&.pw
try{ *^p^tK
URL url = new URL(sURL); )Vpt.4IBd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A_I\6&b4
httpConnection.setRequestProperty("User-Agent","NetFox"); q'`LwAU}
String sProperty = "bytes="+nStartPos+"-"; XM:\N$tg
httpConnection.setRequestProperty("RANGE",sProperty); _i2k$Nr
Utility.log(sProperty); "IRF^1 p
N$P\$
otdm rw|
InputStream input = httpConnection.getInputStream(); />V& OX`
//logResponseHead(httpConnection); :+meaxbu
cA B<'44R
QJU\YH%}
byte[] b = new byte[1024]; A%.ZesjAx
int nRead; o|y1m7X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jL:GP}I=
{ ZO]P9b
nStartPos += fileAccessI.write(b,0,nRead); a}'dIDj
//if(nThreadID == 1) S.*LsrSV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _''9-t;n,
} k6(0:/C
8l >Xbz
0uJ??4N9
Utility.log("Thread " + nThreadID + " is over!"); e}TDo`q
bDownOver = true; T}Ve:S
//nPos = fileAccessI.write (b,0,nRead); Up\ k67
} ria.MCe\!
catch(Exception e){e.printStackTrace ();} X>U _v
} 0G(|`xG1q
} RdLk85<n
`':G92}#
OF O,5
//打印回应的头信息 mD;ioaE
public void logResponseHead(HttpURLConnection con) g\G}b
{ xi15B5_Ps
for(int i=1;;i++) !Mj28
{ 3% O[W
String header=con.getHeaderFieldKey(i); Lm'+z97
if(header!=null) oh,29Gg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FA}y"I'W
Utility.log(header+" : "+con.getHeaderField(header)); ;.3 {}.Y
else 3shd0q<
break; P}"uC`036
} kp^q}iS
} 7 /XfPF
&M6Zsmo
!>EK %OO
public void splitterStop() m`Pk)c0
{ Sn[/'V^$a
bStop = true; )&93YrHgC
} W'R^GIHs
T (? CDc+
(9v%66y
} a( SJ5t?-2
oH(=T/{
P 4+}<5
/* }gKJ~9Jg
**FileAccess.java O[F
*//文件访问(定位，写) /&zlC{:G92
package NetFox; 1Hs'YzvY
import java.io.*; 5.QY{+k
I8{ mkh
M[ ON2P;
public class FileAccessI implements Serializable{ ^SW0+O
B{>x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4++pK;I
RandomAccessFile oSavedFile; =-/sB>-C
long nPos; eZ{Ce.lNR
bmO(tQS$5
r\FduyOXv
public FileAccessI() throws IOException DSK?7F$_oE
{ 3(_:"?xA
this("",0); ,6SzW+L7
} Ht|"91ZC5
x@tI
kzC4V
public FileAccessI(String sName,long nPos) throws IOException ogJ *
{ $>rKm
oSavedFile = new RandomAccessFile(sName,"rw"); +HlZ?1g
this.nPos = nPos; \Yh*ywwP#
oSavedFile.seek(nPos); |g1Pr9{wy
} I/go$@E"
p;~oIy\,
.pIO<ZAFT
public synchronized int write(byte[] b,int nStart,int nLen) %$67*pY'JH
{ -@.FnFa
int n = -1; `bF4/iBW
try{ 0U?(EJ
oSavedFile.write(b,nStart,nLen); 5RyxVC0<
n = nLen; /ACau<U]t
} XHh*6Yt_ (
catch(IOException e) I!T=$Um
{ b"w@am>&
e.printStackTrace (); YmLpGqNv
} .z^O y_S{
ubMN
f( <O~D
return n; NKl`IiGv
} pRA%07?W
s01=C3
Cng_*\=O
} FSYs1Li_C
|\W~+}'g~
b(t8TR#-
/* H\$uRA oo*
**SiteInfoBean.java -FW^fGS+
*/ u-*z#e_L0
package NetFox; `x;m@\R
c[Z#q*Q
G|TnvZ KX
public class SiteInfoBean { /z:1nq
o $'K}U
0S$TLbx
private String sSiteURL; //Site's URL ?RS4oJz,5g
private String sFilePath; //Saved File's Path _}.WRFIJ@L
private String sFileName; //Saved File's Name p5l|qs
private int nSplitter; //Count of Splited Downloading File Gh352
tTT :r),}$
e@iz`~[
public SiteInfoBean() V>c !V9w
{//nSplitter的缺省值为5 `> +:38
//default value of nSplitter is 5 Q=Liy@/+!
this("","","",5); o>|DT(Ib
} FsS.9 `B
1C0' Gf)3
XW~a4If
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LMuDda
{ ]~!CJ8d
sSiteURL= sURL; 5F#FC89Kk
sFilePath = sPath; T[MDjhv'
sFileName = sName; tToP7q^
this.nSplitter = nSpiltter; \UZ7_\
@76I8r5l
zx@L sp
} c/V0AKkS 8
Rln\
syCT)}T6z
public String getSSiteURL() }$LnjwM;,
{ 1fC)&4W
return sSiteURL; IkO[R1K
} <k{_YRB
HVK0NI
n%Oq"`w4
public void setSSiteURL(String value) Q{CRy-ha
{ $F NH:r<
sSiteURL = value; N%%trlDXD
} Lcf?VV}
>=;hnLu
`U&'71B^
public String getSFilePath() 1L?d/j
{ 3#y`6e=5
return sFilePath; [z!pm-Ir
} u=Xpu,q
P"o|kRO
*$Zy|&[Z
public void setSFilePath(String value) +O^} t
{ u?F.%j-
sFilePath = value; AnK X4Q
} 3*\hGt,ZP
aU_l"+5>vq
CeM%?fr5
public String getSFileName() 2/\I/QkTs
{ Mi\- 9-
return sFileName; YFW/ Fa\7
} j8aH*K-l{
h6n!"z8H
,<Wt8'e
public void setSFileName(String value) F{c8{?:
{ M^Tm{`O!
sFileName = value; ;aD?BD__Z
} .{|SKhXk
*\cU}qjk
1 1(GCu
public int getNSplitter() r$Ni>[as
{ C|[x],JCS
return nSplitter; ddd2w
} 1(RRjT9
I:6XM?
eu":\ks
public void setNSplitter(int nCount) Z?V vFEt%
{ <PM.4B@
nSplitter = nCount; z, FPhbFn
} 1/&^~'
} C](djkA$
pG'?>]Rt4
2EYWX!Bx
/* Y*{5'q+2
**Utility.java c *<m.
*/ btC6R>0
package NetFox; pF9WKpzE
u:tcL-;U
ei"c|/pO
public class Utility { [j0jAl
J8ScKMUN2
@(+\*]?^&
public Utility() \DWKG~r-%
{ )>"pm{g2
_~*j=XRs
'St?nW3
} /Ak\Q5O'3
<0? r# }
//线程睡眠 rY8(`a
public static void sleep(int nSecond) S9ic4rcd
{ ?M6)O?[
try{ f(5;Rf(
Thread.sleep(nSecond); esq~Ehr=
} R&g&BF
catch(Exception e) f6nuh&!-
{ UZmo?&y
e.printStackTrace (); d|)ARRW
} #p]V?
} Z9q4W:jyS
.mcohfR
//日志 S%B56|'
public static void log(String sMsg) Ye$; d ~
{ 7G*rxn"d
System.err.println(sMsg); Gm\)1b
} Z'l!/l!
U<>@)0~7g!
ZS=;)
public static void log(int sMsg) q&_\A0
{ @&%/<|4P5
System.err.println(sMsg); BUV4L5(
} %4t?X
} NU+PG`Vb
y>#kT
\I^"^'CP
/* y7+n*|H
**TestMethod.java [2>zaag
*/ 9I$}=&"
package NetFox; :eT\XtxM~{
fY?:SPR+
EyA(W;r.
public class TestMethod { qR_Np5nHF
}Kp$/CYd
bg_io*K
public TestMethod() 3gD <!WI
{ ///xx/weblogic60b2_win.exe 2X*n93AQi
try{ b?VByJl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7/_|/4&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5e1oxSU
SiteFileFetch fileFetch = new SiteFileFetch(bean); Gpcordt/
fileFetch.start(); PRx-0S
} &;p}HL,
catch(Exception e){e.printStackTrace ();} A f!`7l-
E:+r.r"Y
6@3v+Vf'
} !!8;ZcL}Z
ZX.,<vumSy
fe"w--v
public static void main(String[] args) >Z<ZT
{ 7GG`9!l]D
new TestMethod(); mwN"Cu4t
} m7RyFnR2
} .j"heYF)
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