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)); *#n?6KqZ
} 4gRt^T-?
for(int i=0;i<nEndPos.length-1;i++) RO10$1IW.2
{ sVjM^y24
nEndPos = nStartPos[i+1]; (" ,(@nS
} Oi~]~+2
nEndPos[nEndPos.length-1] = nFileLength; z%cpV{Nu
} RV2s@<0p
} [EX@I =?
/v^1/i
Aa#WhF
//启动子线程 9Nkr=/I"P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^Cm9[1p
for(int i=0;i<nStartPos.length;i++) Vs0T*4C=n
{ 5u=(zg
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?%Pd:~4D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lNw8eT~2
nStartPos,nEndPos,i); D:yj#&I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (E.,kcAJ
fileSplitterFetch.start(); OE4hGxG
} SK@%r
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cb5Rr+K=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C~&~Ano,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )`sEdVxbr
nEndPos = " + nFileLength); L9Gxqw
// fileSplitterFetch[nPos.length-1].start(); i{9_C/
snW=9b)m
,%zU5hh
//等待子线程结束 nn0`A3
//int count = 0; :"pA0oB
//是否结束while循环 ,iQRf@#W_b
boolean breakWhile = false; p[zKc2TPk
?k*%r;e>
=d{B.BP(
while(!bStop) 9 Z5!3
{ $%3"@$
write_nPos(); ? !dy
Utility.sleep(500); DnZkZ;E/
breakWhile = true; [1\k'5rp
!M&Qca2
PDEeb.(.
for(int i=0;i<nStartPos.length;i++) !&n'1gJ)kd
{ oJLpFL
if(!fileSplitterFetch.bDownOver) wM"PJG
{ /4}B}"`Sl=
breakWhile = false; R2 I 7d'|v
break; <Xsy{7
} 1JFCYJy
} U^n71m>]%T
if(breakWhile) XIAHUT5~J
break; _8f? H#&
VT;Vm3\
d*e0/#s
//count++; +@ FM~q
//if(count>4) ]hPu
// siteStop(); IgsK7wn
} ^bZ'z
%)|pUa&
ey~5DY7
System.err.println("文件下载结束！"); Lcx)wof
} j<HBzqP%6
catch(Exception e){e.printStackTrace ();} oVK3=m@{
} S{qc1qj
1j9R^
tLz,t&h
//获得文件长度 i Sm .E
public long getFileSize() ID#p5`3n
{ m!qbQMXn
int nFileLength = -1; yFYFFv\?
try{ z;dFS
URL url = new URL(siteInfoBean.getSSiteURL()); 3Dd"qON!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZJ$nHS?ra
httpConnection.setRequestProperty("User-Agent","NetFox"); R8*z}xy{
" aEk#W
G=.vo3
int responseCode=httpConnection.getResponseCode(); ^{IF2_h"
if(responseCode>=400) 3($cBC
{ $E j;CN59
processErrorCode(responseCode); $mV1K)ege
return -2; //-2 represent access is error 907N;r
} q$|Wxnz
vSOO[.=
NM`5hd{
String sHeader; :oYz=c
h2b,(
zXop@"(e
for(int i=1;;i++) 8R) 0|v&;
{ j>{Dbl:#2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cILI%W1
//Utility.log(in.readLine()); A*$JF>`7
sHeader=httpConnection.getHeaderFieldKey(i); j;GH|22
if(sHeader!=null) JBYmy_Su
{ %z0;77[1I
if(sHeader.equals("Content-Length")) )\qA[rTG
{ C V{kP8#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); . paA0j
break; -&Cb^$.-x
} ","O8'$OC
} Hd/|f;
else YT*_ vmJV
break; bc?\lD$$
} {Tps3{|wt
} >o]!-46
catch(IOException e){e.printStackTrace ();} R 2{kS
catch(Exception e){e.printStackTrace ();} al<;*n{/
>{seaihK
OzVCqq"]
Utility.log(nFileLength); O3YD jas
VP7g::Ab
}f~:>N#
return nFileLength; + Z7 L&BI
} MsaD@JY.y
R;G"LT
%M=Ob k
//保存下载信息（文件指针位置） P?#I9y7iP
private void write_nPos() /#lqv)s'
{ StuQ}
try{ r@O5{V
output = new DataOutputStream(new FileOutputStream(tmpFile)); m#i5}uHHg
output.writeInt(nStartPos.length); DFk0"+Ky
for(int i=0;i<nStartPos.length;i++) m=qEQy6#2u
{ B$Z%_j&
// output.writeLong(nPos); z154lY}K
output.writeLong(fileSplitterFetch.nStartPos); u{6b>c|,X
output.writeLong(fileSplitterFetch.nEndPos); .+@;gVZx1
} XtJIaD|:3
output.close(); ^5MPK@)c,/
} !a.|URa7
catch(IOException e){e.printStackTrace ();} yGxAur=dE
catch(Exception e){e.printStackTrace ();} (R9{wGV [
} kK,Ne%}a2K
V!{}%;f
+2KYtyI
//读取保存的下载信息（文件指针位置） Ao0p=@Y
private void read_nPos() ~$WBcqo
{ cbton<r~
try{ Z8Jrt3l{2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )wt mc4'
int nCount = input.readInt(); R7nT,7k.
nStartPos = new long[nCount]; '4"9f]:
nEndPos = new long[nCount]; `X:o]t@
for(int i=0;i<nStartPos.length;i++) DL t"cAW
{ FQ3{~05T
nStartPos = input.readLong(); RZ6[+Ygn
nEndPos = input.readLong(); b-`=^ny)K
} /O^aFIxk
input.close(); '[Ue0r<jn
} [f1'Qb
catch(IOException e){e.printStackTrace ();} Fv<^\q
catch(Exception e){e.printStackTrace ();} Fx3CY W
} F3%8E<QZd;
-lb,0
5}+&Em":
private void processErrorCode(int nErrorCode) YLx4qE
{ lWR".
System.err.println("Error Code : " + nErrorCode); d :a*;F
} RCL}bE
-](NMRqfN
C'wRF90
//停止文件下载 0E<xzYo
public void siteStop() MzRliH8e
{ `hVi!Q]*P
bStop = true; w|k?2 ?&
for(int i=0;i<nStartPos.length;i++) ~fht [S?@M
fileSplitterFetch.splitterStop(); x}tg/`.=z
v>[U*E
w YEkWB^
} t)i{=8rq
} 2m*g,J?ql
//负责部分文件的抓取 (\I9eBm
**FileSplitterFetch.java &tJ!cTA.-
*/ ;!C~_{/t
package NetFox; VqIzDs
}x9D;%)/
UqA<rW
import java.io.*; }MiEbLduN
import java.net.*; R/O>^s!Co
TdCC,/c3
B1U<m=Y
public class FileSplitterFetch extends Thread { sU=7)*$
g0Ff$-#7
:kU-ol$
String sURL; //File URL *6`};ASK
long nStartPos; //File Snippet Start Position BKV,V/*p
long nEndPos; //File Snippet End Position *B3 4
int nThreadID; //Thread's ID ,u<oAI`
boolean bDownOver = false; //Downing is over gB)Cmw*
boolean bStop = false; //Stop identical k vQ] }`a
FileAccessI fileAccessI = null; //File Access interface PsMp&~^
0DsW1
'Zket=Sm;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r3BQo[ 't
{ y"L7.B
this.sURL = sURL; og~Uv"&?T
this.nStartPos = nStart; Po1/_#mu
this.nEndPos = nEnd; 0XWhSrHM
nThreadID = id; h3`\L4b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =>LQW;Sjz
} E5+-N
j(>~:9I`
|b+ZKRW
public void run() !!\x]$v
{ }|j\QjH
while(nStartPos < nEndPos && !bStop) _-R&A@
{ y[64O x
KB$SB25m
6]^~yby P
try{ Pe,:FIp,
URL url = new URL(sURL); 0|=,!sY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `:Bm@eN
httpConnection.setRequestProperty("User-Agent","NetFox"); 7/969h^s
String sProperty = "bytes="+nStartPos+"-"; SmUj8?6"
httpConnection.setRequestProperty("RANGE",sProperty); !LX)
Utility.log(sProperty); $[xS>iuD
r1A<XP|1?I
49Q tfk
InputStream input = httpConnection.getInputStream(); QUO'{;,
//logResponseHead(httpConnection); Yf?hl
csd~)a nb
GD-cP5$
byte[] b = new byte[1024]; v[+ ]
int nRead; {S$61ut
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) np6R\Q!&
{ Q{:=z6&
nStartPos += fileAccessI.write(b,0,nRead); #WlTE&
//if(nThreadID == 1) nSr_sD6"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gtwUY$
} >At* jg48
@d1YN]ede
qGXY
Utility.log("Thread " + nThreadID + " is over!"); >|1$Pv?
bDownOver = true; -FGM>~x
//nPos = fileAccessI.write (b,0,nRead); /7fD;H^*
} C)?tf[!_6
catch(Exception e){e.printStackTrace ();} g@2f&m
} 'o]kOp@q
} @9e}kiW
ak"W/"2:
_C54l
//打印回应的头信息 !Pc&Sg
public void logResponseHead(HttpURLConnection con) Wi+}qO
{ F^Y%Q(Dd7w
for(int i=1;;i++) i1 >oRT{Z
{ m|]:oT`M
String header=con.getHeaderFieldKey(i); Ju@8_ ?8=
if(header!=null) A:4?Jd>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xS+!/pBf"Y
Utility.log(header+" : "+con.getHeaderField(header)); 9q]n&5
else k4-S:kVo
break; ;W?mQUo:P8
} (&!RX.i
} Ial"nV0>0
Kn*LwWne
5kik+
public void splitterStop() &Sdf0"
{ 3]li3B'
bStop = true; )qua0'y]@
} X#<+D1P
!!+LFe4su
;wa#m1
} VD~ %6AjyN
"8iIOeY-\
P}=U #AV4
/* '>k1h.i
**FileAccess.java yXT.]%)
*//文件访问(定位，写) 0t(2^*I?>
package NetFox; d<cqY<y VA
import java.io.*; _A~>?gJ;,
Y&j'2!g
TZ#^AV=ae
public class FileAccessI implements Serializable{ @+7CfvM
q|sT4} =
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 T"/dn%21
RandomAccessFile oSavedFile; ] B?NDxU
long nPos; v|R#[vtFd
8bdx$,$k
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public FileAccessI() throws IOException V<ii
{ ^6QzaC3
this("",0); `b KJ
} KU^|T2s%
:{s0tw>Z
[4r<WvUaM
public FileAccessI(String sName,long nPos) throws IOException )4R[C={
{ *M-'R*Np
oSavedFile = new RandomAccessFile(sName,"rw"); &fW'_,-
this.nPos = nPos; 3vHkhhYQ
oSavedFile.seek(nPos); u&Yd+');
} "$.B@[iY@
[0!*<%BgK'
meYGIP:n
public synchronized int write(byte[] b,int nStart,int nLen) v,!`A!{D
{ *G8Z[ht%r
int n = -1; R0urt
try{ Py\/p Fvg
oSavedFile.write(b,nStart,nLen); 5fy{!
n = nLen; a$3]`
} iXLH[uhO;
catch(IOException e) y9U~4
{ `LNKbTc[m
e.printStackTrace (); b$sT`+4q
} 30YH}b#B
>avkiT2
X]_9g[V
return n; u{cb[M
} xYY^tZIV
Y,?kS dS
d~q7!
} (6i4N2
?u5jXJ0L
u%5 ,U-
/* hh[x(O)TC~
**SiteInfoBean.java `{NbMc\ ]
*/ ]:}7-;$V
package NetFox; iD<}r?Z
%@8#+#@J0
C@g/{?\
public class SiteInfoBean { 1'H!S%fS
QT=i>X
G!Yt.M0
private String sSiteURL; //Site's URL .O SQ8W}
private String sFilePath; //Saved File's Path o$#q/L
private String sFileName; //Saved File's Name t$b5,"G1
private int nSplitter; //Count of Splited Downloading File <Y"HCa{
U,8mYv2|
BKV:U\QZ
public SiteInfoBean() 6]mAtA`Y
{//nSplitter的缺省值为5 d4)0G-|
//default value of nSplitter is 5 MkWbPm)
this("","","",5); p*l=rni4
} H`,t"I
b#*"eZj
t]T't='
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K1w:JA6(
{ L) UCVm
sSiteURL= sURL; 2t?Vl%<
sFilePath = sPath; =7EkN% V:{
sFileName = sName; )6%a9&~H
this.nSplitter = nSpiltter; `Ue5;<K-/
j Y(|z*|
]MC5 uKn
} [#fz[U
zYM0?O8pJ~
-XnOj2
public String getSSiteURL() 4?]s%2U6
{ -wVuM.n(Z
return sSiteURL; FH{p1_kZ=
} {{AZW
sq@c?!'
(wvU;u
public void setSSiteURL(String value) q.j$]?PQ
{ 4>/i,_&K K
sSiteURL = value; 2cwJ);Eg2
} iba8G]2
z/nW;ow
gGx<k3W^
public String getSFilePath() ND/oKM+?
{ h gu\~}kD
return sFilePath; 6!8uZ>u%Vg
} )@<HG$#
|{RCvm
!}sF#
public void setSFilePath(String value) R+2~%|{d
{ ],{M``]q
sFilePath = value; 24sQon
} w_DaldK*
s<oT,SPt
PS0/Ok
public String getSFileName() cH5RpeP
{ 221}xhn5
return sFileName; Htfq?\ FD
} "1`w>(=
<sX_hIA^Fx
yZ]?-7
public void setSFileName(String value) [[xnp;-;
{ g?K? Fn.}
sFileName = value; a-AA$U9hj
} *$3p3-
$M~`)UeV_
c7R&/JV
public int getNSplitter() c=^69>w
{ BU7QK_zT:
return nSplitter; B1]FB|0's
} =1xVw5^F
Cq3Au%7
cQsSJBZ[v5
public void setNSplitter(int nCount) ]:m4~0^#-(
{ MP.ye|i4Q
nSplitter = nCount; Kjpsz];
} ,XI=e=
} g4{0
F~~9/#
T!Lv%i*|Y
/* %Aa_Bumf*:
**Utility.java @Y<fj^]k
*/ }:[MSUm5
package NetFox; O&}R
rDu?XJA
KuEM~Q=
public class Utility { R]RLy#j
SR`A]EC(V
6q7jI )l
public Utility() s@Loax6@B
{ /iJsa&W}
2sVDv@2
?}S!8;d
} 6WoFf
h 0)oQrY
//线程睡眠 NRk^Z)
public static void sleep(int nSecond) O;T)u4Q&3
{ %eGD1.R
try{ M'oQ<,yW-
Thread.sleep(nSecond); i8DYC=r
} uaxkGEXr
catch(Exception e) j 20mZ
{ ,dFY]
e.printStackTrace (); 2vddx<&
} dj}P|v/;z
} )Y"t$Iw"
#-{ljjMQI
//日志 G^SDB!/@J
public static void log(String sMsg) NE3/>5
{ )bpdj,
System.err.println(sMsg); AgB$ w4
} <y"lL>JR
- s2Yhf
Q5IN1 ^=HF
public static void log(int sMsg) 6Q&i=!fQ
{ &4)PW\ioY
System.err.println(sMsg); 0UGAc]!/RZ
} 238z'I+$G/
} zm4e+v-
m`b:#z
ie7TO{W
/* /b6j<]H
**TestMethod.java PWfd<Yf!
*/ 1{ ehnH
package NetFox; q!q=axfMD
w(ic$
8^R~qpg%
public class TestMethod { u/wWD@,
z^y -A?
GkKoc v
public TestMethod() FY]Et=p
{ ///xx/weblogic60b2_win.exe ~dLe9-_9
try{ ?3i<^@?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5"+;}E|q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dbF9%I@
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5j _[z|W2
fileFetch.start(); J`wx72/-ZW
} U;gy4rj
catch(Exception e){e.printStackTrace ();} k_Lv\'Ok
HDz"i
'[bw7T
} rKl
:z$+leNH\
8P&z@E{y
public static void main(String[] args) Qr?(2t#
{ 0.1?hb|p5T
new TestMethod(); 9Dyy&$s
} q@Zeu\T,*#
} nzU0=w}V
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