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)); (NBq!;_2,x
} ?yq1\G)]
for(int i=0;i<nEndPos.length-1;i++) "2'pS<|
{ +/E yX=
nEndPos = nStartPos[i+1]; F};G&
} =,-&h V
nEndPos[nEndPos.length-1] = nFileLength; ]wQ#8}zO
} BL^8gtdn
} Z`)}1|~B
M[@=m[#a
AGdFJ>/
//启动子线程 ,y57tY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jw"]U jub
for(int i=0;i<nStartPos.length;i++) 3 O)^Hq+9
{ nBA0LIb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?{ 0MF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {yPiBu
nStartPos,nEndPos,i); /=bg(?nX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CI )89`
fileSplitterFetch.start(); k7gm)}RKcu
} DJmT]Q]o)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0cwb^ffN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e5 ?;{H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", TEK]$%2
nEndPos = " + nFileLength); eaxp(VX?oy
// fileSplitterFetch[nPos.length-1].start(); [*k25N
Iw<: k
dk^Uf84.Gr
//等待子线程结束 kCu"G
//int count = 0; ~X`_g/5X
//是否结束while循环 };:+0k/
boolean breakWhile = false; MZ{gU>K+
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u,R;=DNl
while(!bStop) z[I3k
{ `;9Z?]}`
write_nPos(); 1%nE
Utility.sleep(500); FesXY856E
breakWhile = true; [Ie;Jd>gG
}op0`-Xb
K; +w'/{
for(int i=0;i<nStartPos.length;i++) Ae0jfTv
{ fgW>U*.ar
if(!fileSplitterFetch.bDownOver) n!r<\4I
{ (0=e ,1 n
breakWhile = false; H7xyK
break; "0(H! }D
} [a<ucJ
} &C.{7ZNt
if(breakWhile) )r)3.|wJm
break; H40~i=.
7( &\)qf=n
!`rR;5&sT
//count++; ^rmcyy8;g
//if(count>4) 'V=i;2mB*
// siteStop(); :q.g#:1s
} tR,&|?0
i7D)'4gkW
NT^m.o~4
System.err.println("文件下载结束！"); LB1AjNJ
} YQ&Ww|xe
catch(Exception e){e.printStackTrace ();} 5p.vo"7
} KZ"&c~[
<QUjhWxDb
+ti_?gfx
//获得文件长度 }W:Rg}v
public long getFileSize() H+oQ L(i|_
{ t4RI%m\
int nFileLength = -1; &.zG?e.
try{ KkIxtFM
URL url = new URL(siteInfoBean.getSSiteURL()); g/o@,_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `FjU2 O
httpConnection.setRequestProperty("User-Agent","NetFox"); J 8z|ua
"h-G=vo,kl
[f^:V:){
int responseCode=httpConnection.getResponseCode(); g9A8b(>F&@
if(responseCode>=400) 6`tc]a"#Zb
{ @2LpI*]C
processErrorCode(responseCode); s\)0f_I
return -2; //-2 represent access is error zPonG d1
} LRJY63A
Md4hd#z
HinPO
String sHeader; mzh8<w?ns
{<~oa+"
$S_xrrE#
for(int i=1;;i++) M x/G^yO9
{ ,eI2#6w|C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3y[6n$U&
//Utility.log(in.readLine()); ^dR="N
sHeader=httpConnection.getHeaderFieldKey(i); ;.O#|Z[
if(sHeader!=null) MY8[)<q"
{ )Vn(J#s
if(sHeader.equals("Content-Length")) }de{-
{ Yq6e=?-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <sALA~p|0
break; 7Rba@ cs9
} Xjy5Yj
} |6cz r
else PQu_]cXI
break; Ix-bJE6+I,
} >FVBn;1
} {Dc{e5K
catch(IOException e){e.printStackTrace ();} N(6Q`zs
catch(Exception e){e.printStackTrace ();} >1}RiOd3
4"om;+\
I%^Bl:M
Utility.log(nFileLength); K1th>!JW'
6n|R<DO%\
p;y\%i_
return nFileLength; Y#VtZTcT
} eWN[EJI<
GOKca%DT=
,2|(UTv
//保存下载信息（文件指针位置） Oc Gg'R7
private void write_nPos() mMNT.a
{ XF6ed
try{ 'n>v}__&|
output = new DataOutputStream(new FileOutputStream(tmpFile)); sjZ@}Vk3b
output.writeInt(nStartPos.length); gB3Tz(!
for(int i=0;i<nStartPos.length;i++) 4Y2!q$}I+
{ 8|z@"b l)
// output.writeLong(nPos); lU`}
output.writeLong(fileSplitterFetch.nStartPos); H%peE9>$
output.writeLong(fileSplitterFetch.nEndPos); !Ojf9 6is
} ^&!SnM
output.close(); Smt&/~7D%
} 6m~N2^z
catch(IOException e){e.printStackTrace ();} 4N!Eqw
catch(Exception e){e.printStackTrace ();} e5}KzFZmZ
} LLMom.
!kTI@103Wd
)K.'sX{B
//读取保存的下载信息（文件指针位置） 8]`LRzM
private void read_nPos() wNfWHaH" m
{ + a,x
try{ }akF=/M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); aqw;T\GI+~
int nCount = input.readInt(); )S8fFV
nStartPos = new long[nCount]; l_ES$%d
nEndPos = new long[nCount]; &OMe'P
for(int i=0;i<nStartPos.length;i++) e5GJ:2sH
{ <o aVI?
nStartPos = input.readLong(); Vx~N`|yY
nEndPos = input.readLong(); #:)yh]MP
} V-7A80!5
input.close(); RBA{!
} apkmb<
catch(IOException e){e.printStackTrace ();} mj7Em&
catch(Exception e){e.printStackTrace ();} Xi:y35q
} ,rU>)X
;X zfd
U2DE zr
private void processErrorCode(int nErrorCode) ,S%DHT
{ vNA~EV02
System.err.println("Error Code : " + nErrorCode); EOn[!
} Pf,lZU?f
]\.3<^
3G.-JLhs
//停止文件下载 s|O4>LsG
public void siteStop() <5xlP:Cx
{ O-N@HZC
bStop = true; PCcI(b>?l
for(int i=0;i<nStartPos.length;i++) Lj,!025
fileSplitterFetch.splitterStop(); |4_[wX r
h{Zd, 9H
gK6_vS4K)
} m%p;>:"R
} pR,eus;8
//负责部分文件的抓取 D-S"?aO-
**FileSplitterFetch.java j,J/iJs
*/ {SOy-
package NetFox; ~stG2^"[
?O|CY
UWPzRk#s"
import java.io.*; l2S1?*
import java.net.*; 3c|u2Pl
m35$4
~\QN.a
public class FileSplitterFetch extends Thread { :W6R]y
*;0Ods+IcY
,QZNH?Cp/
String sURL; //File URL xV+cX*4h
long nStartPos; //File Snippet Start Position qQ/<\6Sl
long nEndPos; //File Snippet End Position *@-a{T}
int nThreadID; //Thread's ID AnD#k]
boolean bDownOver = false; //Downing is over # VAL\Z
boolean bStop = false; //Stop identical iuGly~
FileAccessI fileAccessI = null; //File Access interface 8ED}!;ZU
Es^=&2''
Q\qI+F2?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {*NM~yQ
{ upc-Qvk
this.sURL = sURL; #FwTV@
this.nStartPos = nStart; dSkx*#FEE
this.nEndPos = nEnd; 9N*!C{VW
nThreadID = id; -h`[w:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 iYR`|PJi
} 6z3`*B
}[O/u <Z
c)q'" r
public void run() -NL=^O$G
{ y/\0qQ/
while(nStartPos < nEndPos && !bStop) P6~&,a
{ 5W4Tp% Lda
}n;.E&<[
Pg%k>~i
try{ G{!adBna
URL url = new URL(sURL); %'3Y?d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rWS],q=c
httpConnection.setRequestProperty("User-Agent","NetFox"); 11Y4oS
String sProperty = "bytes="+nStartPos+"-"; s<b(@L 1
httpConnection.setRequestProperty("RANGE",sProperty); 9_&N0>OF
Utility.log(sProperty); 0\tdxi
TMAart;<
3zsjL=ta
InputStream input = httpConnection.getInputStream(); 032PR;]
//logResponseHead(httpConnection); A` )A=L
eZ`x[g%1
$:!L38[7$
byte[] b = new byte[1024]; 0WO-+eRB/
int nRead; )>+J`NFa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _Y8RP%
{ {u@w^ hZ$
nStartPos += fileAccessI.write(b,0,nRead); O[|prk,
//if(nThreadID == 1) /~6)Vt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d:GAa
} f`Wces=5
wVac6q
QKt+Orz
Utility.log("Thread " + nThreadID + " is over!"); =Dc9|WuHN
bDownOver = true; C[2LP$6*/
//nPos = fileAccessI.write (b,0,nRead); 1yT\|2ARZ%
} 34s>hm=0.
catch(Exception e){e.printStackTrace ();} d.:.f_|
} a$2WL g,
} VcpN PU6
LP:U6 Z
US2Tdmy@05
//打印回应的头信息 &?(472<f**
public void logResponseHead(HttpURLConnection con) daN#6e4Z+;
{ .~Y% AI
for(int i=1;;i++) GGF;4
{ ("T8mt[w>
String header=con.getHeaderFieldKey(i); /}&@1
if(header!=null) r]yI5 ;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :j[a X7Sq2
Utility.log(header+" : "+con.getHeaderField(header)); c,FhI~>R
else D4;6}gRC
break; ;UoXj+Z
} F?.J1]
} g6l&;S40
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eW.[M?,
public void splitterStop() {q^?Rw
{ \rPT7\ZA
bStop = true; _^Yav.A=
} n.tJ-l5[
DfX}^'#m+
d_w^u|(K
} `@#,5S$ E
q+)csgN
~RIn7/A
/* d`ESe'j:
**FileAccess.java 6j5?&)xJ
*//文件访问(定位，写) QCVwslj,K
package NetFox; F]k$O$)0
import java.io.*; BzyzOtBp3L
," ~4l&
x39n7+j4
public class FileAccessI implements Serializable{ XJ9l,:c,
WlfS|/\%V^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &Dw8GU}1
RandomAccessFile oSavedFile; #M5[TN!
long nPos; .pd_SQ~
qwmZOR#
o])2_e5
public FileAccessI() throws IOException F2k)hG*|{
{ jm$v0=W9#
this("",0); 5p5S_%R$e
} ?Rg8u
B}A7Usm
G>H',iOI
public FileAccessI(String sName,long nPos) throws IOException ({l!'>?
{ ?iQA>P9B
oSavedFile = new RandomAccessFile(sName,"rw"); wU=@,K
this.nPos = nPos; 2O~I.(9(
oSavedFile.seek(nPos); ~IP3~m D
} 1XvB,DhJ
2gC.Z:}
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public synchronized int write(byte[] b,int nStart,int nLen) h=Xr J
{ SpG^kI #
int n = -1; ?]bZ6|;2
try{ SOPQg?'n=V
oSavedFile.write(b,nStart,nLen); rBUdHd9
n = nLen; eE'2B."F
} 4lqowg0
catch(IOException e) QA3q9,C"
{ )^o7%KX
e.printStackTrace (); {}TR'Y4
} SKf[&eP,G
TXlxnB
ua-cX3E
return n; !SFF 79$c
} Y=#g_(4*
2Hp#~cE+.
ZxRD+`
} tE: m& ;I
qq+fUfB2:
!a[1rQH
/* `Al5(0Q
**SiteInfoBean.java >|[74#}7
*/ u}7#3JfLn
package NetFox; yn[^!GuJ_
mt+IB4`
coxMsDs
public class SiteInfoBean { wM;9plYlw0
,ij"&XA
45hjN6
private String sSiteURL; //Site's URL :(|;J<R%_
private String sFilePath; //Saved File's Path Ba\l`$%X
private String sFileName; //Saved File's Name JWa9[Dj
private int nSplitter; //Count of Splited Downloading File )bqfj>%#c
'j)xryw
,4-) e
public SiteInfoBean() I]]3=?Y
{//nSplitter的缺省值为5 rmW,#
//default value of nSplitter is 5 }wh)I]]U
this("","","",5); lglC1W-q
} _d'x6$Jg
8gv\`
TvE M{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A3p@hQl
{ 3+<}Hm+
sSiteURL= sURL; LsnM5GU7
sFilePath = sPath; Bf;dp`(/
sFileName = sName; !79^M
this.nSplitter = nSpiltter; u6AReL'f
;~$_A4;
?*~W
} BpL,<r,
4+od N.
jmbwV,@Q2
public String getSSiteURL() +-=w`
{ ysV0Ed
return sSiteURL; G}d-L!YbE'
} M1^?_;B
y]B?{m``6
ca@0?q#
public void setSSiteURL(String value) ,BCtNt(
{ {H+~4XG
sSiteURL = value; m]8rljo
} wuCiO;w
XYtDovbv&
Kv'2^B
public String getSFilePath() 05mjV6j7m
{ G[1:<Vg8
return sFilePath; t<M^/xe2
} Y]aVa2!Wb
cF9bSY_Eh
5w)tsGX\
public void setSFilePath(String value) 4k5X'&Q
{ =EI>@Y"
sFilePath = value; -y70-K3
} )-q#hY
FUic7>
")MjR1p
public String getSFileName() eAh~`
{ }{Ab:+aNd
return sFileName; 7U>Xi'?
} f]MKNX
`iYiAc
MaDdiyeC
public void setSFileName(String value) <rZ(B>$
{ jj2 [Zh/h
sFileName = value; E|OB9BOS
} @sUYjB
W($}G_j[B1
^'j? {@
public int getNSplitter() h/E+r:2]
{ We&~]-b AW
return nSplitter; ME"B1Se\
} 22aS <@}
Y;$wD9W
{"T$jV:GB
public void setNSplitter(int nCount) tHAr9
{ P;_}nbB
nSplitter = nCount; t*Hr(|.
} FCL7Tn
} !n9H[QP^9
f]Jn\7j4
UnSi=uj
/* )Il) H
**Utility.java GCaiogiBg
*/ G?`{OW3:_
package NetFox; KE>|,Ur
|>_e&}Y%L
nn[OC=cDN
public class Utility { P2la/jN
^3re*u4b=
L'(ei7Z
public Utility() je_:hDr
{ !1G6ZC:z
}7?n\I+n"
S7i,oP7
} F|mppY'<J
ca )n*SD
//线程睡眠 -rg >y!L
public static void sleep(int nSecond) 2F5*C
{ "[A]tklP
try{ ^j~CYzmt
Thread.sleep(nSecond); =CBY_
} MZJ@qIg[Y
catch(Exception e) v_U+wga
{ i2bkgyzB.
e.printStackTrace (); Xy(8}
} `Hlv*" w$
} ZC7ZlL_
0iS"V^aH
//日志 PB[Y^q
public static void log(String sMsg) a-[:RJW
{ !*I0}I ~
System.err.println(sMsg); )gNS%tc*K
} h"#[{$(
LDX>S*cL
1u`{yl*+?
public static void log(int sMsg) LVHIQ9
{ <!qN<#$y
System.err.println(sMsg); PMOyZ3
} YCBp]xuE
} {3)^$F=T
!H)Cua)
+K2p2Dw(k
/* }N^3P0XjYq
**TestMethod.java 76IjM4&a
*/ C!,|Wi2&
package NetFox; )By#({O
M\m6|P
,a6Oi=+>/U
public class TestMethod { b=87k
9nGS"E l{
PiL[&_8g
public TestMethod() `8x.Mv
{ ///xx/weblogic60b2_win.exe D MzDV_
try{ 2)-V\:;js
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); s?j||
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N6R0$Br
SiteFileFetch fileFetch = new SiteFileFetch(bean); +cXdF
fileFetch.start(); 1uwzo9Yg
} QV%,s!_b
catch(Exception e){e.printStackTrace ();} 1r:i'cWh
P<E!ix
w^EUBRI-
} b^s>yN
;o#wK>pk%M
.&Ik(792Z&
public static void main(String[] args) .\rJ|HpZ1J
{ 1yK=Yf%B
new TestMethod(); =w,cdU*
} KtMD?
} V#Pz`D
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