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)); m$hkmD|
} '~7zeZ'
for(int i=0;i<nEndPos.length-1;i++) ?I+$KjE+
{ 6Hy_7\$(-
nEndPos = nStartPos[i+1]; 0"GLgj:9
} $Fi1Bv)
nEndPos[nEndPos.length-1] = nFileLength; b?!S$Sxz
} S{)K_x
} ^xScVOdP
L&=r-\.ev
u(hJyo}
//启动子线程 0N]\f.=`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; GjN6Af~}
for(int i=0;i<nStartPos.length;i++) 92C; a5s
{ 7hLh}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >o3R~ [
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4MzPm~Ct
nStartPos,nEndPos,i); }}rp/16
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j0Cj&x%qF}
fileSplitterFetch.start(); zN)).a
} Ek_<2!%X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '-XO;{,-R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C CLc,r>)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", UUvCi+W
nEndPos = " + nFileLength); bVa?yWb.
// fileSplitterFetch[nPos.length-1].start(); .kkhW8:
6]?W&r|0I
KW ZEi?
//等待子线程结束 jS8B:>
//int count = 0; [#G*GAa6*
//是否结束while循环 ^wwS`vPb
boolean breakWhile = false; @Jqo'\~&
M0?%r`
ly_8p63-
while(!bStop) A>mk0P)~Q
{ LylCr{s7
write_nPos(); 8\C][ y
Utility.sleep(500); _ShWCU-~Z
breakWhile = true; <c<!|<x
fz8 41 <Y
B~@Gfb>`'
for(int i=0;i<nStartPos.length;i++) .A_R6~::
{ @SaxM4
if(!fileSplitterFetch.bDownOver) ;n|%W,b-
{ &m\Uc
breakWhile = false; oSjYp(h:
break; 0ZLLbEfnPB
} 4pelIoj
} u]`0QxvZ
if(breakWhile) yh|+Usa
break; 9:=:P>
3^$=XrD
Bc-/s(/Eq
//count++; kkMChe};5
//if(count>4) m6}_kzFz
// siteStop(); {.;qz4d`
} 3` D['
N_Zd.VnY
%~>-nqS
System.err.println("文件下载结束！"); E`C!q X>
} Oz&*A/si+3
catch(Exception e){e.printStackTrace ();} 5DkEJk7a
} "3a}~J<g
V,8Z!.MG
:>_oOn[_
//获得文件长度 *DZ7,$LQ~D
public long getFileSize() [7LdTY"Tl
{ D,lY_6=
int nFileLength = -1; &h!O<'*2
try{ 4}UJBb?
URL url = new URL(siteInfoBean.getSSiteURL()); F0r2=f(?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zw'050~-
httpConnection.setRequestProperty("User-Agent","NetFox"); agkKm?xIL
7|_2@4-W6
Z#^|h0
int responseCode=httpConnection.getResponseCode(); !;d>}iE
if(responseCode>=400) &#gh :5
{ JR&yaOws
processErrorCode(responseCode); 5v`lCu]
return -2; //-2 represent access is error :)T*:51{#
} D:z_FNN
R?tjobk!
+ 660/ e8N
String sHeader; UlNV%34"
mI:^lp
R7!v=X]i
for(int i=1;;i++) M`@ASL:u
{ Xh3b=i|K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @0C[o9
//Utility.log(in.readLine()); CPeu="[
sHeader=httpConnection.getHeaderFieldKey(i); NpKyrXDJv
if(sHeader!=null) dD~H ft
{ WU@_aw[
if(sHeader.equals("Content-Length")) c5 AaUza
{ Q"c/]Sk)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z5*(xony0
break; N[fwd=$\#
} xirq$sEl
} M&gi$Qs[E
else T/ eX7p1
break; WSv%Rxr8L
} $;~YgOVZ5
} P|p X F~
catch(IOException e){e.printStackTrace ();} )`ixT)
catch(Exception e){e.printStackTrace ();} C@zG(?X
rl$"~/ oz
:O,r3O6
Utility.log(nFileLength); CF\wR;6k
ue@W@pj
jt9- v-
return nFileLength; >ke.ZZV?
} oR,zr
_iEnS4$A8
;volBfv
//保存下载信息（文件指针位置） }; M@JMu,
private void write_nPos() rwio>4=
{ $/@ L
try{ ZJF+./vN
output = new DataOutputStream(new FileOutputStream(tmpFile)); `g)
output.writeInt(nStartPos.length); B*Om\I
for(int i=0;i<nStartPos.length;i++) HVhd#Q;
{ UugR
// output.writeLong(nPos); BSB&zp
output.writeLong(fileSplitterFetch.nStartPos); qbCU&G|)
output.writeLong(fileSplitterFetch.nEndPos); f1elzANy
} PlK3;
output.close(); 7zA+UWr
} =PNkzFUo
catch(IOException e){e.printStackTrace ();} l?V#;
catch(Exception e){e.printStackTrace ();} A"s?;hv\fS
} gu~R4@3
B.;@i;7L
3^-R_
//读取保存的下载信息（文件指针位置） @uN+]e+3
private void read_nPos() >H5t,FfQL
{ ocMTTVo
try{ kzNRRs\e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KK4e'[Wf
int nCount = input.readInt(); (!J;g|58
nStartPos = new long[nCount]; 7 b(
nEndPos = new long[nCount]; YjJ^SU`*
for(int i=0;i<nStartPos.length;i++) Q-#<{' (
{ H+]h+K9\7
nStartPos = input.readLong(); 3/uvw>$
nEndPos = input.readLong(); LHu
} 5JK'2J&
input.close(); %g89eaEZ
} B!8X?8D
catch(IOException e){e.printStackTrace ();} eH!V%dX
catch(Exception e){e.printStackTrace ();} {D :WXvI
} !<VP[%2L~
|%fNLUJ)
*A8Et5HAv
private void processErrorCode(int nErrorCode) l{ql'm
{ :RJo#ape
System.err.println("Error Code : " + nErrorCode); j6$@vA)
} _3wK: T{:
*:"60fkoU
e8oAGh"
//停止文件下载 $>uUn3hSx\
public void siteStop() 4K dYiuz0`
{ !$ii*}
bStop = true; =h +SZXe<r
for(int i=0;i<nStartPos.length;i++) }Qe(6'l_
fileSplitterFetch.splitterStop(); K ;]dZ8
+ @|u8+
W/WP }QM
} N;BuBm5K
} 1>Vq<z
//负责部分文件的抓取 ?m7i7Dz
**FileSplitterFetch.java T /IX(b'<
*/ H"k\(SPVS
package NetFox; 4g}r+!T
92.Rjz;=9?
eT5IL(mH
import java.io.*; H\E%.QIx
import java.net.*; ?"<m{,yQI
*zDDi(@vtK
M5dEZ
public class FileSplitterFetch extends Thread { -MsL>F.]
FwHqID_!:l
"lC>_A
String sURL; //File URL "Ms{c=XPK
long nStartPos; //File Snippet Start Position ?u".*!%
long nEndPos; //File Snippet End Position ;;XY&J
int nThreadID; //Thread's ID bwP@}(K
boolean bDownOver = false; //Downing is over [cZ/)tm
boolean bStop = false; //Stop identical ) R5j?6}xF
FileAccessI fileAccessI = null; //File Access interface .0gfP4{1{
*=v%($~PK6
w^ofH-R/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aaN/HE_
{ .3n\~Sn
this.sURL = sURL; i O?f&u
this.nStartPos = nStart; `,/5skeJ
this.nEndPos = nEnd; f\q5{#"z
nThreadID = id; L]"$dF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b\o>4T
} < .e4
3fXrwmBT8
1q5S"=+W[
public void run() Q8QB{*4
{ vdB2T2F
while(nStartPos < nEndPos && !bStop) i^Jw`eAmT
{ F^%\AA]8
PO0Od z
m$(OQ,E
try{ Mw-L?j0o[k
URL url = new URL(sURL); W?P4oKsql*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4${3e Sg_
httpConnection.setRequestProperty("User-Agent","NetFox"); _5(p=Zc
String sProperty = "bytes="+nStartPos+"-"; "$K]+0ryG<
httpConnection.setRequestProperty("RANGE",sProperty); Z1+Ewq3m
Utility.log(sProperty); O{7#Xj :_
3vAP&i'I
*b0z/6
InputStream input = httpConnection.getInputStream(); z j#<X
//logResponseHead(httpConnection); @|">j#0
V lO^0r^z
be]/ROP>H
byte[] b = new byte[1024]; sKR%YK "A
int nRead; KHC Fz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AW|SD
{ "iX\U'`
nStartPos += fileAccessI.write(b,0,nRead); 0:4>rYBC
//if(nThreadID == 1) _K'Y`w']
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \+Y=}P>
} 0c!^=(
KD+&5=Y
`_ M+=*}
Utility.log("Thread " + nThreadID + " is over!"); 4oryTckS
bDownOver = true; Iw( wT_
//nPos = fileAccessI.write (b,0,nRead); Knb(MI6
} b2[U3)|oO
catch(Exception e){e.printStackTrace ();} OkISRj'!U
} IuAu_`,Ndi
} Fn4yx~0
O:T 49:R}r
|*h{GX.(
//打印回应的头信息 |]?W`KN0
public void logResponseHead(HttpURLConnection con) 8f)pf$v`
{ -wl&~}%M
for(int i=1;;i++) dV'^K%#
{ eX}aa0
String header=con.getHeaderFieldKey(i); /?XI,#j3kM
if(header!=null) \Zx&J.D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EL z5P}L6
Utility.log(header+" : "+con.getHeaderField(header)); Ars*H,9>e
else f2SJ4"X
break; s?->2gxhx
} Y+vIU*O
} +\&6Zbn
i`];xNR'
O<,\tZ'N
public void splitterStop() @]2aPs} }6
{ 'o0o.&/=
bStop = true; yIngenr$
} xSlgq|8
2|B@s3a
8<C@I/
} $9X?LGUz
vJVh%l+
}''0N1,/
/* NYG!\u\Rm
**FileAccess.java :5T=y @
*//文件访问(定位，写) ~EXCYUp4v
package NetFox; X !0 7QKs
import java.io.*; F Qk
S'ms>ZENC
S0:Oep
public class FileAccessI implements Serializable{ k&f/f
]F>#0Rdc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CAom4Sp'
RandomAccessFile oSavedFile; {TJBB/B1
long nPos; `D=`xSEYl
UhkL=+PD
O#O"]A
public FileAccessI() throws IOException `T7TWv"M
{ `l.bU3C
this("",0); /0fsn_
} ;E.f%
n$7*L9)(C
NW3qs`$-(
public FileAccessI(String sName,long nPos) throws IOException 8+".r2*_iO
{ fB,eeT1v?h
oSavedFile = new RandomAccessFile(sName,"rw"); $ywROa]
this.nPos = nPos; 0a<h,s0"2
oSavedFile.seek(nPos); 8tna<Hx
} /7p(%vr
41+WIa L
l`:u5\ rM
public synchronized int write(byte[] b,int nStart,int nLen) 1ZYo-a;)
{ Ej6ho0_
int n = -1; @)[8m8paV
try{ R)*l)bpZ#
oSavedFile.write(b,nStart,nLen); p$jAq~C
n = nLen; >b5 ;I1o=y
} g"Ueo'd*
catch(IOException e) c$BH`" <*
{ HJym|G>%?
e.printStackTrace (); BtKor6ba
} XD0a :T)
6Uq;]@k%
4(oU88z
return n; ;~d$OM
} 9^?muP<A
^q&|7Ou-
PE/uB,Wl
} P?n4B \!
^EkxZ4*g
5jwv!L<n
/* bqA`oRb\
**SiteInfoBean.java H<<t^,E^.t
*/ mTUoFXX[
package NetFox; &=n/h5e0t&
%xQ'i4`
2e-bt@0t
public class SiteInfoBean { <%m1+%mA.
!7)#aXt&
ANM=:EtP
private String sSiteURL; //Site's URL /QVwZrch
private String sFilePath; //Saved File's Path K\8zhY
private String sFileName; //Saved File's Name Qo^(r$BD
private int nSplitter; //Count of Splited Downloading File I_Gz~qk6
mD&I6F[s
%eIaH!x:
public SiteInfoBean() 74:~F)BP
{//nSplitter的缺省值为5 rKFnivGT
//default value of nSplitter is 5 $M!iQ"bb
this("","","",5); w4}Q6_0v
} K{`R`SXD
q+*\'H>
P6La)U`VA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xfI0P0+
{ yE,qLiH
sSiteURL= sURL; ,c?( |tF
sFilePath = sPath; $ xHtI]T
sFileName = sName; ^E8qI8s
this.nSplitter = nSpiltter; q165S
OgC,oj,!/
(EosLn h0
} 8-k`"QI=
^ +@OiL>&i
kN{$-v=K
public String getSSiteURL() ISK 8t
{ h!|Uj
return sSiteURL; P:vp/x!
} @H4]Gp ]
fsw[R0B
\f(zMP
public void setSSiteURL(String value) E"S#d&9
{ |o9`h9i
sSiteURL = value; u7RlxA:
} w%iwxo
`sso Wn4
W}3%BWn
public String getSFilePath() } eHxw+.
{ S$$SLy:P
return sFilePath; #Ktk["6
} L97 ~ma
:3 Hz!iZM
2PRiiL@
public void setSFilePath(String value) >JsVIfAF
{ Z}\,rex
sFilePath = value; _&9P&Zf4
} [TUs^%2@
<;?1#ok
~xsJML
public String getSFileName() ISFNP&&K
{ esBv,b?*
return sFileName; !u8IZpf
} S5ai@Ksf
{,h_T0D^j
bfZt<-
public void setSFileName(String value) ~]d9 J
{ JA9NTu(
sFileName = value; jXALL8[c
} D&uaA-;s
&S66M2
aQ\SV0PI
public int getNSplitter() h%W,O,K/
{ ji\LC%U-
return nSplitter; rXMc0SPk
} z\ONwMl
|nnFjGC`~
VV}"zc^
public void setNSplitter(int nCount) f+s)A(?3
{ #V]8FW
nSplitter = nCount; |gu@b~8
} _b-g^#L%
} Qb>("j~Z
r2'K'?T3
w@Q~ax/
/* x4wTQ$*1
**Utility.java u pUJF`3
*/ O#18a,o@
package NetFox; }s@IQay+
*C+[I
?Sa,n^b*H
public class Utility { J(/J;PW
y }R2ZO
wXqwb|2
public Utility() iV?8'^
{ YzM/?enK}T
:{Z%dD
"j?xgV
} !> +Lre@
%5KK#w "
//线程睡眠 lt:&lIW,3
public static void sleep(int nSecond) N}7b^0k
{ 0n`Temb/
try{ sH2xkUp
Thread.sleep(nSecond); XP%_|Q2X
} 7_qsVhh]$E
catch(Exception e) |ZifrkD=
{ =1R 2`H\
e.printStackTrace (); =LK`mNA
} .B2e$`s$
} M!!vr8}
^q/^.Gf
//日志 ,P`GIGvkA
public static void log(String sMsg) ^b|? ?9&
{ SIR2 Kc0
System.err.println(sMsg); ~p n$'1Q
} MoEh25U.
M.MQ?`_"b
"a'I^B/
public static void log(int sMsg) N: 38N
{ o~9*J)X5i
System.err.println(sMsg); i>CR{q
} Ti0kfjhX7
} !.O[@A\.-
K,|3?CjS
GIpYx`mHi
/* y&8`NS#_p?
**TestMethod.java -@#],s7
*/ xy!E_CuC$
package NetFox; 1(# H%
,Fkq/h
#`%S[)RT
public class TestMethod { A=|a!N/
P(8 uL|^
|P|2E~[r
public TestMethod() &Fuk+Cu{
{ ///xx/weblogic60b2_win.exe Zj ` ;IYFG
try{ fB]2"(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xele;)Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); aCQ[Uc<B:
SiteFileFetch fileFetch = new SiteFileFetch(bean); /`aPV"$M
fileFetch.start(); t4:/qy
} 7zE1>.
catch(Exception e){e.printStackTrace ();} m zoH$@
=X[?d/[
!XI9evJw
} s!D2s2b9e
fQ!W)>mi
u0oTqD?
public static void main(String[] args) T>#~.4A0
{ BOM0QskLf
new TestMethod(); ,d_rK\J
} N!dBF t"
} $qZ6i
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