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)); h;Hg/jv
} ($nQmr;t
for(int i=0;i<nEndPos.length-1;i++) !;3hN$5
{ Mz7qC3Z
nEndPos = nStartPos[i+1]; o5B]?ekpq
} >:Y"DX-
nEndPos[nEndPos.length-1] = nFileLength; !zVjbYWY
} vh"wXu
} HPMj+xH
uG7?:) pxv
d\ I6Wn
//启动子线程 _u3%16,o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &w!(.uDO
for(int i=0;i<nStartPos.length;i++) r2%Qk
{ Tw,|ZA4XH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bMq)[8,N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /IQ$[WR cx
nStartPos,nEndPos,i); K 0e*K=UM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L35]'Jua
fileSplitterFetch.start(); s6F0&L;N&
} w=_q<1a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H Y~[/H+:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1B#iJZ}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gy1R.SN
nEndPos = " + nFileLength); (gRTSd T?
// fileSplitterFetch[nPos.length-1].start(); }<qZXb1
*ESi~7;#
<a&w$Zc/
//等待子线程结束 tmd{Gx}c
//int count = 0; "!Qi$ ]
//是否结束while循环 `>4"i+NFF8
boolean breakWhile = false; W|Cs{rBc?
pocXQEg$]
:HM~!7e
while(!bStop) Q#F9&{'l
{ d]USk&8
write_nPos(); /PVx
Utility.sleep(500); bE,#,
breakWhile = true; P~#LbUP(
ZkWMo=vL
#_Zkke~{
for(int i=0;i<nStartPos.length;i++) JXV#V7
{ 4p7j"d5
if(!fileSplitterFetch.bDownOver) )(OGo`4Qz
{ O1@3V/.Wu
breakWhile = false; O=eU38n:5u
break; j u&v4]
} d}aMdIF!e
} {Hie%2V
if(breakWhile) /2''EF';
break; !UR3`Xk
nq,:UYNJ
w`EC6ZN
//count++; <isU D6TC
//if(count>4) 0nvT}[\H*
// siteStop(); .+mP#<mAg
} \T[OF8yhW
ex#-,;T
)gz]F_
System.err.println("文件下载结束！"); 7xM4=\~OG
} ]*U+nG
catch(Exception e){e.printStackTrace ();} uGn BlR$}
} nXk9 IG(
~$ Po3]{s
q6hH]Q>w*
//获得文件长度 tSY4'
public long getFileSize() 2s=zT5
{ uP$i2Cy
int nFileLength = -1; #S]O|$&*
try{ zJh!Q**
URL url = new URL(siteInfoBean.getSSiteURL()); m^zD']
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -]-0]*oAp
httpConnection.setRequestProperty("User-Agent","NetFox"); @=}NMoNH
=jA.INin4
W4qnXD1n
int responseCode=httpConnection.getResponseCode(); <pXOE-G5
if(responseCode>=400) _+)n}Se
{ -7XaS&.4
processErrorCode(responseCode); z8r?C
return -2; //-2 represent access is error i!fk'Yt%
} <(~Wg{
>l=jJTJ;q
S|;}]6p
String sHeader; GY5JPl
\II^&xSF
+3M1^:
for(int i=1;;i++) Y] UoV_
{ $C,`^n'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /cVZ/"
//Utility.log(in.readLine()); ?=1i:h
sHeader=httpConnection.getHeaderFieldKey(i); zo8&(XS
if(sHeader!=null) ~]Av$S
{ fGW~xul_
if(sHeader.equals("Content-Length")) 3g56[;Up?
{ ,&s"f4Mft
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D(&Zq7]n
break; C!nbl+75
} Z#l6BXK
} >)Bv>HM
else 4N1)+W8k*
break; $VP\Ac,!
} l)~$/#k
} >]A#_p
catch(IOException e){e.printStackTrace ();} 3[?;s}61
catch(Exception e){e.printStackTrace ();} EY.m,@{
,1.Td=lY$
~ 588md :
Utility.log(nFileLength); sHV?njZd
K@oyvJ$
!aJ6Uf%R
return nFileLength; biForT_no
} t0?tXe.B
meXwmO
kY9$ M8b
//保存下载信息（文件指针位置） '#oH1$W]
private void write_nPos() KdzV^6K<c
{ ?5^DQ|Hg ^
try{ 9l|*E
output = new DataOutputStream(new FileOutputStream(tmpFile)); U'~]^F%eyu
output.writeInt(nStartPos.length); 16nU`TN
for(int i=0;i<nStartPos.length;i++) J/,m'wH
{ E8t{[N6d
// output.writeLong(nPos); tO D}&
output.writeLong(fileSplitterFetch.nStartPos); @Jb-[W$*
output.writeLong(fileSplitterFetch.nEndPos); AM#s2.@
} M"msLz
output.close(); OB^j b8
} MX+gc$Y O
catch(IOException e){e.printStackTrace ();} [M:<!QXw
catch(Exception e){e.printStackTrace ();} $:UD #eh0?
} Y:Jgr&*,z
+1\t0P24
QF22_D<.}J
//读取保存的下载信息（文件指针位置） 2^Z"4t4
private void read_nPos() t1$pl6&,
{ zyt >(A1
try{ tWQ$`<h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 92N`Q}
int nCount = input.readInt(); LY#V)f
nStartPos = new long[nCount]; v0bP|h[t
nEndPos = new long[nCount]; M6V^ur 1
for(int i=0;i<nStartPos.length;i++) 64<*\z_
{ znIS2{p/`
nStartPos = input.readLong(); [o7Qr?RN
nEndPos = input.readLong(); g@>93j=cZU
} T&:~=
input.close(); ZXIz.GFy+
} THgEHR0,}[
catch(IOException e){e.printStackTrace ();} ~~m(CJ4S
catch(Exception e){e.printStackTrace ();} I SdB5Va
} 0< }BSv
Q~rE+?n9F
]mC5Z6,1s
private void processErrorCode(int nErrorCode) k\g:uIsv$
{ >LPIvmT4D?
System.err.println("Error Code : " + nErrorCode); 9ESV[
} 4AF.KX7
OsRizcgdA
b dC
//停止文件下载 F%O+w;J4
public void siteStop() Q|U [|U
{ .*J /F$
bStop = true; 9g.5:
for(int i=0;i<nStartPos.length;i++) _?eT[!oO8
fileSplitterFetch.splitterStop(); r8[)Ccv
NfmHa
[h8macx
} mMO]l(a&
} H6/gRv@
//负责部分文件的抓取 \Xr*1DI<
**FileSplitterFetch.java WSGho(\
*/ .Sv/0&O
package NetFox; 7")~JBH
+wI<w|!
8PWEQ<ev7>
import java.io.*; bU/YU0ZIT
import java.net.*; b"B:DDw00
I<+:Ho=6
BKgCuz:y
public class FileSplitterFetch extends Thread { vTIRydg2b
x+DecO2
cIP%t pTW.
String sURL; //File URL H?V b
long nStartPos; //File Snippet Start Position ;<nJBZB9u
long nEndPos; //File Snippet End Position tZu1jBO_Q4
int nThreadID; //Thread's ID GR_caP
boolean bDownOver = false; //Downing is over %joU}G;"
boolean bStop = false; //Stop identical 8xkLfN|N=
FileAccessI fileAccessI = null; //File Access interface JY~CMR5#.O
)CgH|z:=b
D'BGoVP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Iv*u#]{t
{ yM,Y8^
this.sURL = sURL; 8# x7q>?
this.nStartPos = nStart; b/ h#{'
this.nEndPos = nEnd; !/=.~B
nThreadID = id; r\)bN4-g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l kyK
} Z#YNL-x
tg\o"QKW9
0Q)YZ2
public void run() b`F]oQ_*
{ DKkilqVM
while(nStartPos < nEndPos && !bStop) z\woTL6D]
{ \1QY=}
yT~x7,
?nq%'<^^
try{ c5:X$k\
URL url = new URL(sURL); (L(n%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |"+Ufw^
httpConnection.setRequestProperty("User-Agent","NetFox"); NFR>[L V
String sProperty = "bytes="+nStartPos+"-"; h[Uo6`
httpConnection.setRequestProperty("RANGE",sProperty); gYe6(l7m
Utility.log(sProperty); yrd1J$
i4nFjz
"M3;>"`G
InputStream input = httpConnection.getInputStream(); IDL0!cF
//logResponseHead(httpConnection); \f)GW$`
h_SkX@"/-
),|z4~
byte[] b = new byte[1024]; K9y~ e
int nRead; U3Z-1G~*r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0%4OmLBT
{ 0m"Ni:KEf
nStartPos += fileAccessI.write(b,0,nRead); QHc([%oV
//if(nThreadID == 1) *ZxurbX#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oR/_{#Mz"
} _uXb>V*8
c*\;!dbP
1:>F{g
Utility.log("Thread " + nThreadID + " is over!"); $L?KNXHAF!
bDownOver = true; 0/9]TIc
//nPos = fileAccessI.write (b,0,nRead); S>S7\b'
} 3!vzkBr
catch(Exception e){e.printStackTrace ();} ]vP}K
} xu%eg]
} N_Kdi%q
z^z`{B
8ZLHN',
//打印回应的头信息 c&FOt
public void logResponseHead(HttpURLConnection con) 0U H]
{ j<k6z
for(int i=1;;i++) #V%98|"
{ x~wS/y
String header=con.getHeaderFieldKey(i); / *PHX@
if(header!=null) 6bLn8UT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %OHZOs
Utility.log(header+" : "+con.getHeaderField(header)); _53~D=
else qb/}&J7+
break; ,&qC R sw
} 4+s6cQ]S`
} [.1MElM
[/%N2mj
x5mg<y2`Ng
public void splitterStop() )>S,#_e*b
{ ]bY]YNt{7]
bStop = true; @NqwJ.%g
} GNe^~
2vX $:4
d]"4aS
} I "~.p='
VqpC@C$
~~ rR< re
/* y& 1@d+Lf
**FileAccess.java {svo!pN:
*//文件访问(定位，写) =R|XFZ,
package NetFox; s&(;
import java.io.*; ,3y9yJQa*#
7-!n-
mpMAhm:
public class FileAccessI implements Serializable{ Zrr)<'!i
z+yIP ?s}(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wz*iwd-
RandomAccessFile oSavedFile; d6YXITL)\>
long nPos; 4]ni-u0*
,7]hjf_h
qul#)HI
public FileAccessI() throws IOException x9 %=d
{ UI+6\ 3
this("",0); /uj^w&l#
} (^m] 7l
c{BAQZVc
f7lj,GAZ
public FileAccessI(String sName,long nPos) throws IOException AcPLJ!y
{ MQ-u9=ys
oSavedFile = new RandomAccessFile(sName,"rw"); :~vodh
this.nPos = nPos; :Kwu{<rJ!(
oSavedFile.seek(nPos); ehr-o7](
} +*]$PVAFA
|'nQvn:{
Og/aTR<;=
public synchronized int write(byte[] b,int nStart,int nLen) bOFzq>k_
{ ` 3qf}=Z`
int n = -1; ^{4BcM7eH
try{ &>,;ye>A
oSavedFile.write(b,nStart,nLen); Q'/sP 5Pj
n = nLen; X8$Mzeq
} *9^8NY]
catch(IOException e) h*k V@Dc
{ %8FfP5#
e.printStackTrace (); wtY)(ka
} 4]h/t&ppq
Z8#nu
?e$&=FC0;
return n; c>_ti+
} GfE>?mG
-e/}DGL
rexv)!J
} FvpU]
9\_AB.Z:
.N X9Ab
/* h;gc5"mG
**SiteInfoBean.java ,|:.0g[n
*/ WigtTAh4
package NetFox; dLiiJ6pl*
j=l2\W#}
djdTh +>28
public class SiteInfoBean { Qr$'Q7
u}@N Qeg
&B{zS K$N
private String sSiteURL; //Site's URL 1=R$ RI
private String sFilePath; //Saved File's Path NN*L3yx
private String sFileName; //Saved File's Name nR{<xD^
private int nSplitter; //Count of Splited Downloading File 8;@y\0
4&mY-N7A
z9aR/:W}
public SiteInfoBean() XV]N}~h o`
{//nSplitter的缺省值为5 |OH*c3~r
//default value of nSplitter is 5 Nk7y2[
this("","","",5); $6rm;UH
} |?T=4~b
Ei!Z]jeK
^4n#''wJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0/R;g~q@
{ N%dY.Fk
sSiteURL= sURL; FRQ.ix2
sFilePath = sPath; yB UQ!4e
sFileName = sName; TKB8%/_p
this.nSplitter = nSpiltter; 1Wpu
IuXgxR%
d$$5&a
} jIs>>
2;v:Z^&
32ki ?\P
public String getSSiteURL() \s)MNs
{ eFiG:LS7
return sSiteURL; 6>]_H(z7
} cGlN*GJ*H
;M~,S^U
w%])
public void setSSiteURL(String value) $s7U |F,I
{ syX?O'xJ
sSiteURL = value; 8_%GH}{
} o/{`\4
q;eb
ED` 1)1<
public String getSFilePath() T?1BcY
{ r&LZH.$oh
return sFilePath; :!aLa}`@
} v`|]57?A
+xYu@r%R
?}?"m:=
public void setSFilePath(String value) 5;)^o3X>
{ '4'Z
sFilePath = value; ]+I9{%zB%8
} 1V2]@VQF
};'@'
ai<qK3!O
public String getSFileName() 9Q9{>d#"
{ X_78;T)uA
return sFileName; yY#h1
} #L.,aTA<
:?xH)J,imk
_mm(W=KiL
public void setSFileName(String value) y(|#!m?@
{ KYiJXE[Q-
sFileName = value; yr%[IX]R
} ZxtO.U2
fqI67E$59
Z1fY' f
public int getNSplitter() ]wid;<
{ O:0{vu9AQ
return nSplitter; ZUS-4'"$
} sK#)k\w>
Z )c\B
l,o'J%<%
public void setNSplitter(int nCount) }#s{."
{ Mxl;Im]!`.
nSplitter = nCount; /l<(i+0
} 6xDk3
} +2iD9X{$MX
^iONC&r
LzL)qdL
/* u[**,.Ecg
**Utility.java 5Y+YN1
*/ /phMrL=
package NetFox; :E-$:\V0}k
"mQp#d/'
"s|P,*Xf
public class Utility { O7 ;=g!j
azZtuDfv
L(|K{vHh]
public Utility() ''auu4vF
{ VzXVy)d
iZG-ca
!L.R"8!
} +q pW"0[
q0}u%Yz
//线程睡眠 _&]7
public static void sleep(int nSecond) n#6{K6}k~
{ ;+DEU0|pe
try{ zg ,=A?
Thread.sleep(nSecond); ))AxU!*.
} +.~K=.O)
catch(Exception e) x\'3UKQP+^
{ AZ(zM.y!#_
e.printStackTrace (); S*<Jy(:n
} e.vt"eRB
} LF7 }gQs ^
[y8(v ~H
//日志 m}z6Bbis0
public static void log(String sMsg) "_&ZRcd*
{ $9?:P}$v
System.err.println(sMsg); "m{i`<,
} /wEl\Kx
(eF[nfM
}Hb0@ b_
public static void log(int sMsg) 9C)VW
{ <n,QSy#
System.err.println(sMsg); ng/h6 S
} 5Xr})%L
} __eB 7]#E
|yz[mP*;o
@&G}'6vF!
/* w)|9iL8
**TestMethod.java <cOjtq,0
*/ 8Ygf@*9L4
package NetFox; ^1~lnD~0
K&&T:'=/
%~:\f#6
public class TestMethod { R +@|#!
\ n2MP
M@KQOAzt
public TestMethod() ~D@YLW1z(
{ ///xx/weblogic60b2_win.exe ,y'6vW`%g9
try{ wlP3 XF?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L~f~XgQ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C$0u-Nx8
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,vLQx\m{
fileFetch.start(); ujnT B*Cqc
} A{4,ih"5
catch(Exception e){e.printStackTrace ();} 4 .c1
5eL b/,R
$1B?@~&
} UF^[?M =
q)9n%- YgP
V|@bITJ?7
public static void main(String[] args) *lA+-gkK*
{ \]4EAKJE
new TestMethod(); Csy$1;"A
} ,mx\ -lWFy
} q6rkp f,Tl
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