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)); \(PohwWWo
} /c$\X<b);
for(int i=0;i<nEndPos.length-1;i++) dDD<E?TjD
{ 'Vr$MaO
nEndPos = nStartPos[i+1]; LFZiPu
} _6k*'aT~FK
nEndPos[nEndPos.length-1] = nFileLength; Maqf[ Vky
} e|rg;`AW
} 4:sjH.u<
$XU5??8
.p ls!
//启动子线程 NB7Y{) w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6MG9a>=
for(int i=0;i<nStartPos.length;i++) +@Ad1fJi
{ z*a8sr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WA$>pG5s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `T2$4>!
nStartPos,nEndPos,i); e2+BWKaU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e*
fileSplitterFetch.start(); lg}HGG
} ;@nFVy>U
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9ktEm|F3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v6GsoQmA
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", '&FjW-`" G
nEndPos = " + nFileLength); BYM3jXWi0v
// fileSplitterFetch[nPos.length-1].start(); u0RS)&
`Ci4YDaz;k
(5<^p&
//等待子线程结束 phYDs9-K
//int count = 0; &W6^6=E{g
//是否结束while循环 8CC/BOe
boolean breakWhile = false; 3p*-tBOO
B(DrY1ztj
8seBT;S
while(!bStop) #g5^SR|qE
{ UkfB^hA
write_nPos(); 70B)|<$
Utility.sleep(500); {C^@Q"I
breakWhile = true; e#/kNHl
l+wc'=]
6e25V4e?I
for(int i=0;i<nStartPos.length;i++) j}+5vB|0
{ -Z^4L
if(!fileSplitterFetch.bDownOver) 7@PIM5h
{ Sg] J7;]
breakWhile = false; Dz_eB"}
break; eX2<}'W<
} q6wr=OWD
} (D{Ys'{q
if(breakWhile) @("}]/O V:
break; \m@Y WO?L
q9dLHi<1
hxC!+ArVe
//count++; \h3e-)
//if(count>4) ACV ek
// siteStop(); mEQ!-p
} mYNEz @
d `j?7Z
., :uZyG
System.err.println("文件下载结束！"); @ERu>nSP
} 3D)b*fPc
catch(Exception e){e.printStackTrace ();} `ycU-m==
} 1.R kIB
mjEs5XCC"
bj"z8kP
//获得文件长度 G5{Ot>;*%
public long getFileSize() PaVO"y]C
{ 4VIg>EL*
int nFileLength = -1; B50 [O!
try{ Yb=6C3l@
URL url = new URL(siteInfoBean.getSSiteURL()); %{STz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,w&:_n
httpConnection.setRequestProperty("User-Agent","NetFox"); z};ZxN
?En7_X{C?
>IR$e=5$
int responseCode=httpConnection.getResponseCode(); .^XHuN&
if(responseCode>=400) $o^e:Y, a
{ 0RyFv+
processErrorCode(responseCode); M^ 5e~y
return -2; //-2 represent access is error r]t )x*
} M}!A]@
5 R*lVUix
<*YO~S(R
String sHeader; {Bvm'lq`
e d;"bb
:l~EE!
for(int i=1;;i++) y`b\;kd
{ ] C,1%(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a9[<^
//Utility.log(in.readLine()); 6+8mV8{-8
sHeader=httpConnection.getHeaderFieldKey(i); y[:q"BB3
if(sHeader!=null) hNO)~rt
{ Qcgu`]7}
if(sHeader.equals("Content-Length")) aFG3tuaKrQ
{ Q>IH``1*e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G{A)H_o*
break; B+Q+0tw*i
} PEy/k.
} ja75c~RUw
else kZK//YN#
break; m %Y(O
} a)S(p1BGg
} Vr\Q`H.
catch(IOException e){e.printStackTrace ();} .M+v?Ad
catch(Exception e){e.printStackTrace ();} `r]TA]DR
fqX~xp
&gWiu9WbS
Utility.log(nFileLength); fkBLrw
,|iy1yg(
7(@(Hm
return nFileLength; hpjUkGm5
} `x4E;Wjv
;ct)H* y
#Jv43L H
//保存下载信息（文件指针位置） 4 iKR{P6
private void write_nPos() (h|ch#
{ wlL8X7+:
try{ bHJoEYY^
output = new DataOutputStream(new FileOutputStream(tmpFile)); vQy$[D*
output.writeInt(nStartPos.length); \KNdZC?V2
for(int i=0;i<nStartPos.length;i++) 9H[/Tj-;
{ ~BtKd*~*
// output.writeLong(nPos); & L3UlL
output.writeLong(fileSplitterFetch.nStartPos); :Dt\:`(r'
output.writeLong(fileSplitterFetch.nEndPos); &8waih(|
} [='p!7z
output.close(); 33,;iE
} /4^G34
catch(IOException e){e.printStackTrace ();} ) (+)Q'*
catch(Exception e){e.printStackTrace ();} joY1(Y
} +!Q!m 3/I
:;q>31:h
s><IykIi
//读取保存的下载信息（文件指针位置） PK_Fx';ke^
private void read_nPos() ^J0zXe -d
{ 90?,-6
try{ m,=)qex
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9ptZVv=O
int nCount = input.readInt(); ~~U<
nStartPos = new long[nCount]; C(xqvK~p
nEndPos = new long[nCount]; 1Jl{1;c
for(int i=0;i<nStartPos.length;i++) g%X&f_@
{ yB=C5-\F
nStartPos = input.readLong(); !8we8)7
nEndPos = input.readLong(); 32s5-.{c/f
} IvFR <n
input.close(); c%jsu"
} W0C{~|e
catch(IOException e){e.printStackTrace ();} ]c5DOv&
catch(Exception e){e.printStackTrace ();} V;H d)v(j
} W^003*m~~K
p "/(>8
wH+FFXGJs
private void processErrorCode(int nErrorCode) 7[4_+Q:}
{ /tG5!l
System.err.println("Error Code : " + nErrorCode); j p!
} 4[2=L9MIo~
7U&5^s )J
u82h6s<'W
//停止文件下载 txj wZ_p
public void siteStop() Po'-z<}wS
{ oSN8Xn*qr
bStop = true; Q^*G`&w,
for(int i=0;i<nStartPos.length;i++) TNyK@~#m
fileSplitterFetch.splitterStop(); D8)O4bh
UCe,2v%
K5 5} Wi
} r hiS
} Y0@'za^y
//负责部分文件的抓取 m5X3{[a:
**FileSplitterFetch.java `l+ >iM
*/ \d `dV0X
package NetFox; JX2mTQ
AF6d#Klog
$?[1#%
import java.io.*; BO?mQu~
import java.net.*; N|UBaPS|o
nw~/~eM5=
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public class FileSplitterFetch extends Thread { CWE Ejl
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LN@lrC7X
String sURL; //File URL di8W2cwz
long nStartPos; //File Snippet Start Position -@YVe:$%b
long nEndPos; //File Snippet End Position ^^n+
int nThreadID; //Thread's ID Zx}NFcn
boolean bDownOver = false; //Downing is over M,.b`1-w
boolean bStop = false; //Stop identical rFKo E%
FileAccessI fileAccessI = null; //File Access interface ?l6>6a7
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@/CRIei
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g2+l@$W
{ 2>!_B\%)H
this.sURL = sURL; e*Uz#w:
this.nStartPos = nStart; ~bQFk?ZN+
this.nEndPos = nEnd; y3&Tv
nThreadID = id; :'5G_4y)h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &/B2)l6a
} hg[l{)Q
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public void run() LL|_c4$Ky
{ AzHIp^
while(nStartPos < nEndPos && !bStop) %00k1*$
{ >$7wA9YhL
844tXMtPB\
iYO wB'z
try{ }4bB7,j
URL url = new URL(sURL); ^4u3Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .jU|gf:x
httpConnection.setRequestProperty("User-Agent","NetFox"); '+o:,6
String sProperty = "bytes="+nStartPos+"-"; , aRJ!AZ
httpConnection.setRequestProperty("RANGE",sProperty); AIvL#12
Utility.log(sProperty); GNhtnB
JLy)}8I
w\"n!^ms
InputStream input = httpConnection.getInputStream(); TEaD-mY3
//logResponseHead(httpConnection); GibggOj2Q,
`-72>F;T
&rl]$Mtt
byte[] b = new byte[1024]; $I}Hk^X
int nRead; )8 "EI-/.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W2r6jm!
{ :$SRG^7md
nStartPos += fileAccessI.write(b,0,nRead); ch5`fm
//if(nThreadID == 1) ?)Czl4J
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %=NM_5a}]
} egxJ3.
}5o~R~H
%!ER@&1f&
Utility.log("Thread " + nThreadID + " is over!"); Q.pEUDq/
bDownOver = true; wzHjEW
//nPos = fileAccessI.write (b,0,nRead); zCBtD_@
} 5`{|[J_[
catch(Exception e){e.printStackTrace ();} 1K? & J2
} 5CY@R
} }%o+1 <=
j,|1y5f
1^x2WlUm4
//打印回应的头信息 4i[v ew
public void logResponseHead(HttpURLConnection con) NgE&KPj\
{ !OuTXa,IH
for(int i=1;;i++) \pewbu5^
{ u/!mN2{Rd
String header=con.getHeaderFieldKey(i); ;G%wc!
if(header!=null) .UT,lqEkv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); we:5gK&
Utility.log(header+" : "+con.getHeaderField(header)); u'$yYzBE
else \4\\575zp'
break; K+h9bI/Sf
} ~q8V<@?
} r3c\;Ra7
"x:)$@
|L.~Amd
public void splitterStop() !ulLGmUn
{ 0'V-
bStop = true; SQ^^1.V&/Y
} G>q{~HE1
^O$[Y9~*
S0Bl?XsD_
} d5sGkR`(
4ye`;hXy
CQ8o9A/
/* (1elF)
**FileAccess.java @KW+?maW
*//文件访问(定位，写) Ghq'k:K,
package NetFox; S\v&{
import java.io.*; :d% -,v
y1\^v_.^
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public class FileAccessI implements Serializable{ ]:E! i^C`Z
UwL"%0u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @8<uAu%
RandomAccessFile oSavedFile; y`B!6p 5j
long nPos; YAC zznN
Z;~E+dXC
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public FileAccessI() throws IOException L$TKO,T
{ 0ZID @^
this("",0); C(t6;&H
} R 6yvpH
$NGtxZp
*Xtc`XH
public FileAccessI(String sName,long nPos) throws IOException S~a:1 _Wl
{ _[OEE<(
oSavedFile = new RandomAccessFile(sName,"rw"); B> "r-O
this.nPos = nPos; #`#aSqGmc
oSavedFile.seek(nPos); $L#Z?76v
} 9CU6o:'fW
ETWmeMN
,?~UpsUx
public synchronized int write(byte[] b,int nStart,int nLen) }b]y 0"
{ sO4}kxZ
int n = -1; jVFRqT%
try{ Hj4w i|
oSavedFile.write(b,nStart,nLen); 1-]x
n = nLen; Q0"F>%Cn
} 8.Own=G?
catch(IOException e) I`$I0
{ *~<]|H5~
e.printStackTrace (); |3T|F3uEX
} K9N0kBJ0<
4FHX#`
*sIG&
return n; cA*X$j6
} ,Qi|g'a
qT>& v_<
.'2gJ"?,
} dt0E0i
/2\=sTd
QGz3id6
/* -^xKG'uth
**SiteInfoBean.java NF)\">Ye
*/ 19-yM`O
package NetFox; Ty4%du6?d
;7`um
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public class SiteInfoBean { f}ij=Y9
[#rdfN'?U
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private String sSiteURL; //Site's URL "`gZy)E
private String sFilePath; //Saved File's Path "JLhOTPaHf
private String sFileName; //Saved File's Name |e;z"-3
private int nSplitter; //Count of Splited Downloading File M^Ay,jK!
jc~*#\N
2c`=S5
public SiteInfoBean() VJtTbt;>
{//nSplitter的缺省值为5 )I-?zyL
//default value of nSplitter is 5 I;.E}k
this("","","",5); I4X+'fW,
} rbZ6V :
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.,K?\WZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `k%#0E*H
{ s!fY^3
sSiteURL= sURL; l=?y=2+
sFilePath = sPath; o^"3C1j
sFileName = sName; ggsi`Z{j?
this.nSplitter = nSpiltter; QT l._j@
(?3\.tQ}}
D!$ =oK
} `ur9KP4Dq
[qMO7enu#
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public String getSSiteURL() :ItW|
{ D!T4k]^
return sSiteURL; Qbpl$L
} x[~OVG0M*
y-q?pqt
Qr-J-2s?B
public void setSSiteURL(String value) *vE C,)
{ K2K6
sSiteURL = value; A.x}%v,E
} [ .uaO
,fJ(.KI0
yB{o_1tc
public String getSFilePath() 'wnY>hN
{ @,`=~_J
return sFilePath; Z?aR9OTP
} LA%al @
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ZboJszNb;
public void setSFilePath(String value) u0hbM9U>
{ GZVl384@
sFilePath = value; Xq!tXJ)
} Wc>)/y5$
"UnSZ[;t
}V,M0b>
public String getSFileName() na:^7:I
{ wSF#;lqd
return sFileName; CyDf[C)=
} #R4KBXN
m1i$>9,
ZM, ^R?e
public void setSFileName(String value) )K3 vzX
{ TN aff
sFileName = value; |L{dQ)-'l
} k0Yixa
6YGr"Kj &
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public int getNSplitter() %GiO1:t
{ K -1~K
return nSplitter; :.df(1(RL
} +%9Y7qol
t3JPxg]0k'
^V]DY!@k3_
public void setNSplitter(int nCount) *sVxjZvV
{ M=_CqK*
nSplitter = nCount; j&GKpt
} rqJj!{<B
} wGX"R5
c&(,
Utp\}0GZY
/* *3Z#r
**Utility.java y36aoKH
*/ J"|$V#
package NetFox; @sO.g_yM
lf#six
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public class Utility { kcUt!PL
zZiVBUmE<
^ ?9 ~R"
public Utility() sH: &OaA
{ `"Pd$jW
SX;IUvVE5
KrH;o)|
} 3$;v# P$%N
vdzC2T
//线程睡眠 QNEaj\
public static void sleep(int nSecond) O v6=|]cW
{ 3i~{x[Jc
try{ q[K)bg{HB
Thread.sleep(nSecond); Fj4:_(%nG
} J1t?Qj;f3
catch(Exception e) i+3b)xtW7
{ }clNXtN
e.printStackTrace (); WLH2B1_):
} Ta$<#wb
} 6}2Lt[>O
i%w'Cs0y
//日志 9x< 8(]\
public static void log(String sMsg) tWIhbt
{ 5GP'cE
System.err.println(sMsg); ccAEN
} k2;yl_7
J(60eTwQ
*L_wRhhk
public static void log(int sMsg) u5[Wr:
{ F!8425oAw
System.err.println(sMsg); (aLnbJeJ
} _qfdk@@g
} ~8K~@e$./
j!pxG5%
1'U-n{fD
/* SZEr
**TestMethod.java r@aFB@
*/ e2v,#3Q\
package NetFox; .H"gH-I
Lm/^ 8V+
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public class TestMethod { :tMWy m
~mU#u\r(*
e^fjla5
public TestMethod() m6}"g[nN
{ ///xx/weblogic60b2_win.exe E#OKeMK
try{ %* 8QLI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ):\L#>:w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $: -Ptm@
SiteFileFetch fileFetch = new SiteFileFetch(bean); fO+;%B
fileFetch.start(); &q+ %OPV
} l6RJour
catch(Exception e){e.printStackTrace ();} v,s]:9f`\>
4YJs4CB
;a|A1DmZ
} #~Q0s)Ze
Ty5\zxC|
w t}a`hxu
public static void main(String[] args) %u#pl=k}
{ } ?
new TestMethod(); !&X}?NK
} /3fo=7G6
} $W)FpN;CW/
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