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)); #z*,CU#S9d
} H_DCdUgC'
for(int i=0;i<nEndPos.length-1;i++) 1 em,/>"
{ za>UE,?h
nEndPos = nStartPos[i+1]; t]yxLl\
} tE7jTe
nEndPos[nEndPos.length-1] = nFileLength; m&UP@hUV-
} 'cW^S7
} H U|.5tP
v= 55{
,fkvvM{mq
//启动子线程 Td=4V,BN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -8TJ:#|N
for(int i=0;i<nStartPos.length;i++) #~*v##^vFH
{ )h{&O ,s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z'z)Oo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rbw$=bX}
nStartPos,nEndPos,i); "yn~axk7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;H_/o+
fileSplitterFetch.start(); Dyov}y
} rf.pT+g.P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \Pg~j\;F]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3nq?Y8yac
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +)Z]<O
nEndPos = " + nFileLength); fE#(M+(<
// fileSplitterFetch[nPos.length-1].start(); M tN>5k c
CVj^{||eF
oaY_6
//等待子线程结束 ;O"?6d0
//int count = 0; TR"C<&y$j
//是否结束while循环 *c0H_8e
boolean breakWhile = false; @T'^V0!-q:
t un}rdb
\iuR+I
while(!bStop) lSj gN~:z
{ p8rh`7
write_nPos(); l& :EKh
Utility.sleep(500); ]K=#>rZrB
breakWhile = true; ( ;FxKm<P@
DJP6Z
B VBn.ut
for(int i=0;i<nStartPos.length;i++) ]P4WfV d
{ R=D]:u<P
if(!fileSplitterFetch.bDownOver) Njq}M/{U
{ o-,."|6
breakWhile = false; vwCQvt
break; rPV Q#iB
} (I[_}l
} 615Ya<3f8
if(breakWhile) ,6)N.
break; H?$dnwR
xEb>6+-F@
#8$?# dT
//count++; Y"Cf84E
//if(count>4) @=-(H<0
// siteStop(); P"YdB|I
} eV;r /4
i_Kwxn$
E C?}iP
System.err.println("文件下载结束！"); 0YH5B5b
} =7Ln&tZ
catch(Exception e){e.printStackTrace ();} }0'=}BE
} xQoZ[
u?osX;'w
L\:|95Yq
//获得文件长度 H4$qM_N
public long getFileSize() 'o AmA=
{ !8{VLg
int nFileLength = -1; ?Oyo /?/
try{ 5cSiV7#Y:
URL url = new URL(siteInfoBean.getSSiteURL()); @Jt$92i5PS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -JW~_Q[
httpConnection.setRequestProperty("User-Agent","NetFox"); S}6Ld(_
5NU{y+
Ln"wjO,
int responseCode=httpConnection.getResponseCode(); @HT\Y%E
if(responseCode>=400) =|3BkmO
{ "J VIkC
processErrorCode(responseCode); m%'nk"p9
return -2; //-2 represent access is error L9GLjRp-
} q+g,?;Yx
b--=GY))F
~Y 6'sM|
String sHeader; O<u=Vz3c~0
S{c/3k~
_~kw^!p>Kr
for(int i=1;;i++) 'Wlbh:=$
{ bJd|mm/v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =i/Df?
//Utility.log(in.readLine()); {)YbksrJ{
sHeader=httpConnection.getHeaderFieldKey(i); @rl5k(
if(sHeader!=null) r- 8Awa
{ ^y+k6bE
if(sHeader.equals("Content-Length")) Z,&O8Jelf
{ |OeyPD#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _v!7 |&\
break; GQ2GcX(E(
} aZ#FKp^8H
} rRTKF0+
else |IgR1kp+.
break; >m%_`68
} "1O_h6C
} n,N->t$i
catch(IOException e){e.printStackTrace ();} i3-5~@M
catch(Exception e){e.printStackTrace ();} 2)}n"ibbT
Q*DT" W/0
m\:^9A4HCg
Utility.log(nFileLength); V!}I$JiJ
]RVu[k8
>xWS>
return nFileLength; -@v^. @[Z&
} iZGbNN
Lg:1zC
Wu>]R'C
//保存下载信息（文件指针位置） @0+\:F
private void write_nPos() P1#g{f
{ 5Xq+lLW>
try{ G%F#I
output = new DataOutputStream(new FileOutputStream(tmpFile)); B=SA +{o
output.writeInt(nStartPos.length); SN6 QX!3
for(int i=0;i<nStartPos.length;i++) Ly=.
{ pPReo)
// output.writeLong(nPos); ~q>jXi
output.writeLong(fileSplitterFetch.nStartPos); :;$MUOps
output.writeLong(fileSplitterFetch.nEndPos); /[R=-s ;
} inu.U[.
output.close(); RdCGK?s
} aDS:82GMQ
catch(IOException e){e.printStackTrace ();} V@'Xj .ze
catch(Exception e){e.printStackTrace ();} l@`k:?
} p=+Y7NE)
[(X~C*VdxM
0h-NT\m
//读取保存的下载信息（文件指针位置） &;Ncc,jb
private void read_nPos() O,$*`RZpx
{ fB2ILRc
try{ FZ*"^=)`G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); " ityx?
int nCount = input.readInt(); CD1Ma8I8
nStartPos = new long[nCount]; R|?n
nEndPos = new long[nCount]; Np\NStx2
for(int i=0;i<nStartPos.length;i++) snbXAx1L
{ SSe;&Jk2d
nStartPos = input.readLong(); ={g"cx
nEndPos = input.readLong(); Et6j6gmif
} ko%mZ0Y
input.close(); Z$z-Hx@%
} uQ=u@qtp
catch(IOException e){e.printStackTrace ();} FSuC)Xg
catch(Exception e){e.printStackTrace ();} Fe8X@63
} 3M#x)cW
"&_+!TBg,
M$x,B#b
private void processErrorCode(int nErrorCode) xQR/Xp!h
{ ; _%zf5;'
System.err.println("Error Code : " + nErrorCode); #JUh"8N'
} aB%.]bi
T{prCM
| BaEv\$K
//停止文件下载 yY]x''K
public void siteStop() &dB@n15'A
{ xM())Z|2
bStop = true; "rdpA[>L
for(int i=0;i<nStartPos.length;i++) FM]clC;X?
fileSplitterFetch.splitterStop(); +|C@B`h
ch#)XomN
3MQHoxX
} WUS%4LL(
} _'p/8K5)=
//负责部分文件的抓取 =CzGI|pb
**FileSplitterFetch.java T m"B
*/ |AvPg
package NetFox; .7.G}z1
k$=L&id
le:}MM
import java.io.*; R3g)LnN
import java.net.*; gmp@ TY=:L
@tT`s^e
O%%Q./oh
public class FileSplitterFetch extends Thread { $uLTYu
@5d^ C
6{I7=.V
String sURL; //File URL &D<6Go/)_*
long nStartPos; //File Snippet Start Position >p&"X 2 @
long nEndPos; //File Snippet End Position &5}YTKe}|
int nThreadID; //Thread's ID JCH9~n.
boolean bDownOver = false; //Downing is over UV(`.
boolean bStop = false; //Stop identical x@X2r
FileAccessI fileAccessI = null; //File Access interface h<L_ =)lH
a>C;HO
:@(1~Hm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6TRLHL~B
{ 2UQF:R?LQ
this.sURL = sURL; Zx8$M5
this.nStartPos = nStart; iKq_s5|sW
this.nEndPos = nEnd; (ot,CpI(I
nThreadID = id; "%K'~"S#Q,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H~*N:$C
} F=5+JjrX
)]n>.ZmLCB
g Cp`J(2v:
public void run() kNP-+o
{ KXZG42w
while(nStartPos < nEndPos && !bStop) LYAGpcG
{ <hzHrx'o{
Cuylozj$&
Dx\~#$S!=
try{ f0eQq;D$K
URL url = new URL(sURL); PE.UNo>o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S))B^).0-
httpConnection.setRequestProperty("User-Agent","NetFox"); *vQ 6LF;y
String sProperty = "bytes="+nStartPos+"-"; =pzTB-G
httpConnection.setRequestProperty("RANGE",sProperty); 42e[OG-
Utility.log(sProperty); lP=,|xFra
J"#6m&R_q
)P?0YC
InputStream input = httpConnection.getInputStream(); xM{[~Kh_x
//logResponseHead(httpConnection); ,7$&gx>2&
}S"gZ6
w#2apaz
byte[] b = new byte[1024]; >'n[B
int nRead; AK lra$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z/Wf
{ Wrbv<8}%c
nStartPos += fileAccessI.write(b,0,nRead); ke@OG! M/
//if(nThreadID == 1) _9-;35D_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _W@sFv%sj
} */~|IbZ`o
DK2Wjr;
.|"E:qTD
Utility.log("Thread " + nThreadID + " is over!"); ,&Zp^
bDownOver = true; =ZSYg K
//nPos = fileAccessI.write (b,0,nRead); .NWsr*Tel
} A46dtFD{
catch(Exception e){e.printStackTrace ();} CUB;0J(
} ?i_2ueVR
} Vuy%7H
TlO=dLR7d
LQqba4$
//打印回应的头信息 irh Z
public void logResponseHead(HttpURLConnection con) 2K3j3|T
{ l_2Xao$
for(int i=1;;i++) &n]v
{ BZOl&G(
String header=con.getHeaderFieldKey(i); Z9H2! Cp
if(header!=null) ^0"fPG`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GRpwEfG
Utility.log(header+" : "+con.getHeaderField(header)); t<+>E_Xw
else Z$i?p;HnW
break; "cS7E5-|
} 0^L:`[W+
} |0^IX
;"f9"
&'neOf/~
public void splitterStop() R,7.o4Wt
{ p%Q{Rqc)
bStop = true; e`B!)Sr
} x`2dN/wDhf
;B<rw^h5
+ S5uxO
} Tq^B>{S"
(^T}6t3+4
ZCK#=:ln
/* /:-ig .YY
**FileAccess.java ; p+C0!B2
*//文件访问(定位，写) \k$cg~
package NetFox; )4ok@^.
import java.io.*; { zL4dJw
F:Vl\YZ
Hl}m*9<9us
public class FileAccessI implements Serializable{ >y}> 5kv
7u1o>a%9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hQ)?LPUB
RandomAccessFile oSavedFile; Yjy%MR
long nPos; 8eCh5*_$
amQiH!}8R
'mv|6Y
public FileAccessI() throws IOException _x-2tnIxXv
{ D41.$t[
this("",0); }WR@%)7ay
} #cikpHLXG
"<L9-vb
gjJ:s,Fg
public FileAccessI(String sName,long nPos) throws IOException W;X:U.
{ i'ZnU55=
oSavedFile = new RandomAccessFile(sName,"rw"); u9 *ic~Nh
this.nPos = nPos; G=Xas"|
oSavedFile.seek(nPos); 5a5JOl$8
} 4X:mb}(
<e|B7<.
Sw{rNzh%$
public synchronized int write(byte[] b,int nStart,int nLen) C:!&g~{cKi
{ fX LsLh+~D
int n = -1; B|>eKI
try{ }PMlG
oSavedFile.write(b,nStart,nLen); IQ JFL +f
n = nLen; GB*^?Ii
} !bW^G} <t
catch(IOException e) W9GjUswv!
{ 3;//o<
e.printStackTrace (); P=ubCS'
} j;_E0j#
1"l48NLL|
3!KyO)8
return n; *TL3-S?
} So NgDFD
wG 5H^>6u>
[MAvU?;
} E0A[{UA
-t*P=V|@
O/l/$pe
/* h?QGJ^#8
**SiteInfoBean.java gE23C*!'&:
*/ H'@@%nO(
package NetFox; =4/K#cQ
%u?A>$Jn
P?=}}DI
public class SiteInfoBean { |l~#qeZ%
=EHKu|rX~
P!R`b9_U
private String sSiteURL; //Site's URL H/0b3I^
private String sFilePath; //Saved File's Path |i(@1 l
private String sFileName; //Saved File's Name Z%{`j!!p
private int nSplitter; //Count of Splited Downloading File ) Cm95,Y
{ZUgyGE{
TaG(sRI
public SiteInfoBean() $3Sm?
{//nSplitter的缺省值为5 @ +>>TGC
//default value of nSplitter is 5 nI`9|W
this("","","",5); 5N#Sic M
} (]"`>,ray
>)F)@KAuN4
[WR*u\FF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V4<f4|IL
{ *Fd(
sSiteURL= sURL; ZjgfkZAS
sFilePath = sPath; dsZ-|C
sFileName = sName; KctbNMU]k
this.nSplitter = nSpiltter; 2 o5u02x
`$] ZT>&
\uOR1z
} _BND{MsX
_y9NDLRs8
.|LY /q\A
public String getSSiteURL() 9'O@8KB_
{ \k%j
return sSiteURL; RPTIDA))
} u0Opn=(_
?2S<D5MSb
Cyp%E5b7
public void setSSiteURL(String value) 'Y5l3xQk
{ %PM8;]
sSiteURL = value; WQNFHRfO*n
} {%v{iE>
%bB:I1V\
~T\:".C
public String getSFilePath() :w9s bW
{ 9d+z?J:
return sFilePath; E>1%7" i<
} hhJ>>G4R2
(7|!%IO.
-aM7>YR
public void setSFilePath(String value) \~:_h#bW
{ X> V`)
sFilePath = value; -pN'r/$3V
} K^[Dz\ov5
j'LO'&sQ(
@=6$ImU
public String getSFileName() _^NL{R/
{ oazy%n(KZ
return sFileName; q[~+Zm
} 8sU}[HH*1
IoxdWQ4]A
iRI7x)^0"z
public void setSFileName(String value) 0PJ7o#}_{@
{ SuJ4)f;'0
sFileName = value; "tU,.U
} *qw//W
bP1]:^ x@W
3Ebkq[/*%
public int getNSplitter() 4nD U-P#f
{ CQET
return nSplitter; 82w=t
} cG4$)q;q
wGx*Xy1n<
q4KYC!b
public void setNSplitter(int nCount) Z:<6Ck
{ NfXEW-
nSplitter = nCount; oedLe9!
} Si=u=FI1e
} [_3L
f5vsxP)Y[
X/<Q3AK
/* }&/_ S
**Utility.java +#7)'c
*/ T']G:jkb
package NetFox; \']_y\
>?^_JEC6
Qr]`flQ8
public class Utility { =.6JvX<d1*
, n47.S
cy( WD#^
public Utility() Y~-P9
{ ck#MpQ!An
),4cb
%gV~e@|
} Kd').w
oz/Nx{bg
//线程睡眠 q,2 +\i
public static void sleep(int nSecond) eGlPi|
{ ,&rHBNS
try{ rL<a^/b/=
Thread.sleep(nSecond); E9v_6d[
} = GZ,P (
catch(Exception e) >jg"y
{ OVU+V 0w1a
e.printStackTrace (); rI;tMNs
} 9\a;75a
} "tg?V
pcO0xrI
//日志 oC1Nfc+
public static void log(String sMsg) ^#&:-4/
{ ffoLCx4o0E
System.err.println(sMsg); vjO@"2YEw
} 5YnTGf&
:B5M#D!dO
^U]B&+m
public static void log(int sMsg) ;wj8:9 ;
{ QX|y};7\e
System.err.println(sMsg); :6y;U
} Gq9pJ
} v0'`K 5M
"/qm,$
I2<5#|CXpZ
/* >sm<$'vZ/
**TestMethod.java -)$5[jM]
*/ )~H&YINhn
package NetFox; #Bi8>S
B0"55g*c
nypG
public class TestMethod { 0XUWK@)P
y6N }R
hSF4-Vvb
public TestMethod() _!Ir|j.A
{ ///xx/weblogic60b2_win.exe h!q_''*;
try{ $ {5|{`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hYEUiQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .GOF0puiM
SiteFileFetch fileFetch = new SiteFileFetch(bean); &ub0t9R
fileFetch.start(); {~+o+LV
} VJ()sbl{k
catch(Exception e){e.printStackTrace ();} &BS*C} },
rM{V>s:N
*_CzCl^
} xJ|_R,>.H
0`%Ask
We?cRb
public static void main(String[] args) g]E>e v{`
{ CH+mzy
new TestMethod(); u#~q86k
} ;{f4E)t 7
} qttJ*zu
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