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)); c# WIB 4
} )hK1W\5
for(int i=0;i<nEndPos.length-1;i++) s B!2't
{ `jCq`-.
nEndPos = nStartPos[i+1]; SlUt&+)
} 2N_9S?a3sK
nEndPos[nEndPos.length-1] = nFileLength; ^ px)W,O
} n0ls a@l
} IN94[yW{1
r#K"d
58_aI?~>>
//启动子线程 ki|w?0s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j_~lc,+m
for(int i=0;i<nStartPos.length;i++) '#x<Fo~hT
{ Q$DF3[NC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k3t2{=&'&x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [0hZg
nStartPos,nEndPos,i); 7$I *ju_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .AZ+|?d
fileSplitterFetch.start(); cOEzS
} FI(M 1iJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U>_#,j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9:6d,^X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *gXm&/2*
nEndPos = " + nFileLength); 5V/CYcO
// fileSplitterFetch[nPos.length-1].start(); bLyG3~P;0
-<B{?D
NbW5a3=
//等待子线程结束 <(-4?"1
//int count = 0; 9 !qVYU42(
//是否结束while循环 ^o*$+DbC
boolean breakWhile = false; zs@[!?A,
d@t3C8
$~*d.
while(!bStop) 98eS f
{ MHKB:t]hA
write_nPos(); Gu9x4p
Utility.sleep(500); )d-{#
breakWhile = true; EM.rO/qcW
uDi#a~m@
%uLyL4*L(p
for(int i=0;i<nStartPos.length;i++) 9CTvG zkw
{ $U/_8^6B0
if(!fileSplitterFetch.bDownOver) Q CB~x2C
{ >zAI#N4
breakWhile = false; k|T0Bly3P
break; kXbdR
} 7%4@*
} 1 +'HKT}
if(breakWhile) bwAL:
break; & A<Pf.Us
;F<)BEXC<
h8_~ OX
//count++; ' ! ls"qo
//if(count>4) rfNt
// siteStop(); gJ>HFid_C
} Af"vSL
"A?_)=zZ
'%"#]
System.err.println("文件下载结束！"); p,w6D,h
} Ey"<hAF
catch(Exception e){e.printStackTrace ();} 1"CbuV 6
} %U)M?UNjw
i@ avm7
L~FE;*>7
//获得文件长度 g#ONtY@*U
public long getFileSize() F-n1J?4b
{ AFSFXPl "
int nFileLength = -1; H;n(qBSB
try{ S[ ,r.+
URL url = new URL(siteInfoBean.getSSiteURL()); C&'Y@GE5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {XNu4d9w(
httpConnection.setRequestProperty("User-Agent","NetFox"); 8Cr?0Z
q}["Nww-
jTx,5s-
int responseCode=httpConnection.getResponseCode(); [Pt5c6L:
if(responseCode>=400) V-w[\u
{ ynN[N(m#
processErrorCode(responseCode); G{ $Zg
return -2; //-2 represent access is error %R{clbbbn
} -h8!O+7 .
}?Y+GT"E
BE}qwP^
String sHeader; lA<IcW
k|7XC@i]%
P( W8XC
for(int i=1;;i++) o;JBe"1
{ I -obfyije
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jjm-%W@
//Utility.log(in.readLine()); u[oYVpe)IG
sHeader=httpConnection.getHeaderFieldKey(i); &7X0 ;<
if(sHeader!=null) >:`Y]6z
{ Q=9S?p M
if(sHeader.equals("Content-Length")) .0q %A1H
{ [J+K4o8L<A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "t"=9:_t
break; |C S[>0mV!
} <u"#Jw/VP
} yREO;m|o
else n6nwda
break; c"J(? 1O
} %;PPu$8K9
} W3K"5E0ck
catch(IOException e){e.printStackTrace ();} ^dP@QMly6
catch(Exception e){e.printStackTrace ();} R#bg{|
o=_4v^
<..%@]+
Utility.log(nFileLength); f|FQd3o)
_wf"E(c3D
9bXU!l[
return nFileLength; }~-)31e'`
} ^ :Q |,oy
' n~N*DH
h3xX26l
//保存下载信息（文件指针位置） 4#=!VK8ZH
private void write_nPos() Xb3vvHdI
{ eeb8v:4
try{ # dxlU/*
output = new DataOutputStream(new FileOutputStream(tmpFile)); g m],
output.writeInt(nStartPos.length); s:cS 9A8
for(int i=0;i<nStartPos.length;i++) .?S#DS )
{ sa+:c{
// output.writeLong(nPos); rsP-?oD8)
output.writeLong(fileSplitterFetch.nStartPos); 2#1FI0,Pa*
output.writeLong(fileSplitterFetch.nEndPos); $X~=M_W
} =W !m`
output.close(); lLtC9:
} ^O\tN\g;c
catch(IOException e){e.printStackTrace ();} aM.l+DP
catch(Exception e){e.printStackTrace ();} foE2rV/Y
} O,JthlAV4
=OO_TPEZ
kZGhE2np
//读取保存的下载信息（文件指针位置） /IV:JVT
private void read_nPos() `U`Z9q5-
{ nhXa&Nro
try{ n3b@6V1_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7X}_yMxc
int nCount = input.readInt(); iJrscy-
nStartPos = new long[nCount]; B{1+0k
nEndPos = new long[nCount]; a9jY^E'|n
for(int i=0;i<nStartPos.length;i++) ,%nmCetD@
{ l/rhA6kEU
nStartPos = input.readLong(); s[s6E`Q
nEndPos = input.readLong(); 3+ i(fg_
} ]P<&CEk
input.close(); }>frK#S
} vW)GUAF[
catch(IOException e){e.printStackTrace ();} 'T|.<u@~
catch(Exception e){e.printStackTrace ();} 'OX6eY5
} ;-]f4O8
RXx +rdF0
:f/ p5c
private void processErrorCode(int nErrorCode) Va*Uwy?x/)
{ m_Fw;s/9
System.err.println("Error Code : " + nErrorCode); [[s k
} \v-> '
(J^ Tss
Ugdm"
//停止文件下载 ]&G5/]f
public void siteStop() 9I.v?Tap
{ Bxa],inuZ
bStop = true; 8v]{ 5
for(int i=0;i<nStartPos.length;i++) [Z5x_.k"I
fileSplitterFetch.splitterStop(); hCxL4LrF
Bgs~1E@8V
v\MH;DW^Z
} Rthu8NKn
} ,<vrDHR
//负责部分文件的抓取 -I_lCZ{Nbi
**FileSplitterFetch.java /d{L]*v)]
*/ QOF;j#H^
package NetFox; q90S>c,
ToMX7xz6
q/B+F%QiMQ
import java.io.*; pKH4?F
import java.net.*; Txfb-f!mv\
hr{%'DAS
I Mv^ 9T:
public class FileSplitterFetch extends Thread { _N-7H\hF
VmUM_Q~
q!H3JL
String sURL; //File URL -y\N9
long nStartPos; //File Snippet Start Position ./fEx 'E
long nEndPos; //File Snippet End Position i Lm1l
int nThreadID; //Thread's ID / P:Hfq
boolean bDownOver = false; //Downing is over 5PPy+36<~
boolean bStop = false; //Stop identical 7GIv3Dc
FileAccessI fileAccessI = null; //File Access interface ,X$Avdc2
*g,?13Q_
Hwc{%.%ae
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7O9s5
{ SQ Fey~
this.sURL = sURL; v|/3Mi9mz
this.nStartPos = nStart; u:S@'z>
this.nEndPos = nEnd; dH/t|.%
nThreadID = id; NSgHO`gU8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w7Pe<vT
} =Hx~]1
n% `r
5"gRz9Ta`
public void run() 6_y|4!,:W
{ #PrV)en
while(nStartPos < nEndPos && !bStop) z8j(SI;3
{ 4y1>!~f
.#:,j1L"53
9V],X=y~
try{ 9kF#*
URL url = new URL(sURL); BH-[q9pf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0`P]fL+&
httpConnection.setRequestProperty("User-Agent","NetFox"); rq1kj 8%2
String sProperty = "bytes="+nStartPos+"-"; osd^SnL1/5
httpConnection.setRequestProperty("RANGE",sProperty); jccW8g~ ~
Utility.log(sProperty); uTU4Fn\$L
X]yERaJ,i
FR}H$R7#
InputStream input = httpConnection.getInputStream(); |g7h#F~
//logResponseHead(httpConnection); R2$U K
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Lmwh`oOl
byte[] b = new byte[1024]; 7idi&h"
int nRead; )KqR8UO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _onp%*
{ q`aY.dD=O
nStartPos += fileAccessI.write(b,0,nRead); ys/mv'#>
//if(nThreadID == 1) hf<$vRti>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Idlu1g
} W"kw>JEt
{}pqxouE
q~J oGTv
Utility.log("Thread " + nThreadID + " is over!"); ,z1!~gIal
bDownOver = true; m IzBK]@^
//nPos = fileAccessI.write (b,0,nRead); aE BP9RX}z
} =4e=wAO(i
catch(Exception e){e.printStackTrace ();} 'Y[A'.*}4
} , Ln
} C|f7L>qe
,GX~s5S8
F36ViN\b
//打印回应的头信息 e(#IewKp
public void logResponseHead(HttpURLConnection con) .gN$N=7<
{ >J}n@MZ
for(int i=1;;i++) v{2DBr
{ +V9B
String header=con.getHeaderFieldKey(i); DAnb.0
if(header!=null) s$Zq/l$1x
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v'Vt .m&9&
Utility.log(header+" : "+con.getHeaderField(header)); y5/6nvH_6
else <{/;1Dru
break; g6g$nY@Jm
} kV ,G,wo
} M{xVkXc>
Q)S>VDLA
,<3uc
public void splitterStop() 8rwYNb.P
{ CofH}-
bStop = true; g(<T u^F
} &G/|lv>j
3eTrtCe$
d;~ 3P
} OB6J.dF[%
jJVT_8J
]G0dS Fh{j
/* h}|6VJ@.
**FileAccess.java P>Q{He:
*//文件访问(定位，写) !&`}]qQZ
package NetFox; qWO]s=V!
import java.io.*; e3eVvl5]
\2Og>{"U
Y}LLOj@L
public class FileAccessI implements Serializable{ .Z=Ce!
$_C+4[R?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 st?gA"5w
RandomAccessFile oSavedFile; &$qF4B*
long nPos; W|dpFh`
b]*X<,p
CV&zi6
public FileAccessI() throws IOException gg-};0P-
{ H&X:!xa5
this("",0); \+k, :8s/
} [$l"-*s4
\sK:W|yy
3ai (x1%
public FileAccessI(String sName,long nPos) throws IOException $n= O
{ LJGJ|P
oSavedFile = new RandomAccessFile(sName,"rw"); QjA&IZEC
this.nPos = nPos; G#H9g PY
oSavedFile.seek(nPos); u#`+[AC`
} 47IY|Jdz
*hVb5CS
[pii
public synchronized int write(byte[] b,int nStart,int nLen) XOrcygb2
{ XGfzEld2"
int n = -1; -bypuMQ-p
try{ ll^DY hx}
oSavedFile.write(b,nStart,nLen); }^"0T-ua
n = nLen; P##Z[$IJ3
} &=6%>
catch(IOException e) a3q\<"|
{ ->\N_|_
e.printStackTrace (); nv"G;W
} =3*Jj`AV
9x=3W?K:,
4O!E|/`wO
return n; 2FGx _Y
} $uCiXDKCq
XaW4C-D&
sAi&A9"*
} `(!NYx
j 1(T )T
_gKu8$o=-
/* Z,WubX<
**SiteInfoBean.java 7JI:=yY!>:
*/ !z MDP/V
package NetFox; b^ sb]bZW
I"1CgKYK^+
e*:}$u8a
public class SiteInfoBean { {"m0)G,G
p1D()-
9? 2
private String sSiteURL; //Site's URL lUv=7" [
private String sFilePath; //Saved File's Path y"vX~LR
private String sFileName; //Saved File's Name ,/&Z3e
private int nSplitter; //Count of Splited Downloading File @`wn<%o$
|5,<jyp
tMFsA`ng
public SiteInfoBean() h4(JUio
{//nSplitter的缺省值为5 *69c-`o
//default value of nSplitter is 5 j0FW8!!-g
this("","","",5); 3B{[%#vO
} ?,07;>&
]#zZWg zv
e.l!3xY2'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /s|{by`we4
{ :y#T9R9
sSiteURL= sURL; R"+wih
sFilePath = sPath; +K^h!d]
sFileName = sName; ,r=re!QI7
this.nSplitter = nSpiltter; =Vb~s+YW
q[ULGv
.:y5U}vR
} ^s{hs(8%R
:p>hW!~
Ma6W@S
public String getSSiteURL() l~J*' m2
{ IU#x[P!
return sSiteURL; 5ZK&fKeCF
} d~@q%-`lA
/r^[a,Q#x
b9Y_!Qe
public void setSSiteURL(String value) -$JO8'TP
{ q8xd*--#
sSiteURL = value; hj!+HHYSk
} b5pMq$UVL
~Ky4+\6o>
!][F
public String getSFilePath() )(m0cP{7
{ 5mgHlsDzu
return sFilePath; y-B=W]E
} *C6D3y
:#u}.G
r_U>VT^E:
public void setSFilePath(String value) uS<_4A;sD,
{ $^_|j1z#i
sFilePath = value; y=aV=qD
} K2rzhHfb
T8XY fcc*h
$`ztiVu3
public String getSFileName() ? \m3~6y
{ S1bAu <
return sFileName; *Zbuq8>
} G[Tl%w
cozXb$bBY
gU1#`r>[)
public void setSFileName(String value) CO^Jz
{ cCiI{
sFileName = value; >w|*ei:@S
} P)6lu8zQ
t6lE#<xZV;
n~gLPHY
public int getNSplitter() idc4Cf+4
{ A\QJLWBv^$
return nSplitter; 7:Ztuc]
} ?=Db@97
1;lmu]I>)
>#(n"RCHf
public void setNSplitter(int nCount) !HK^AwNY
{ u[oUCTY
nSplitter = nCount; S%mfs!E>
} Ug%_@t/?
} jQh^WmN
{Wv%zA*8
>v+jh(^
/* Y`GOER
**Utility.java d=3'?l`
*/ _yH`t[
package NetFox; }-DE`c
OCV+h'
l7}g^\I
public class Utility { K@u&(}
m:+8J,jW
gfa[4 z
public Utility() Q2|p\rO
{ _\8qwDg"#e
aP-<4uGx
Ykqyk')wm
} bzZ>lyH
b-^p1{A0zW
//线程睡眠 kkCZNQ~I
public static void sleep(int nSecond) 3Q By\1h.
{ HU;#XU1
try{ {~Tg7<\L
Thread.sleep(nSecond); LnsD
} Ao9R:|9
catch(Exception e) DcD{*t?x
{ 1Sz A3c
e.printStackTrace (); :t("L-GPW
} c64v,Hj9
} ,'fxIO
)_7>nuQ6
//日志 u1^wDc*xg
public static void log(String sMsg) PWr(*ZP>hI
{ =8{WZCW5
System.err.println(sMsg); +A8j@d#:
} MGpt}|t-
;#/@+4@a&
MCTsi:V>+
public static void log(int sMsg) \nqkA{;B{
{ p0:kz l4$
System.err.println(sMsg); OO) ~HV4\
} p#P~Q/;
} |N/G'>TS
BUZ _)
H^%lDz
/* L1{GL #qV
**TestMethod.java 5z}w}zdg
*/ dl-l"9~;
package NetFox; b7`D|7D
u{<"NR h
|*5 =_vF
public class TestMethod { #-VMg+14
hfWFD,
`>C<}xO
public TestMethod() 2x]>l? 5b
{ ///xx/weblogic60b2_win.exe `fNpY#QsN
try{ xw5d|20b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [Nm4sI11
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Sjj>#}U
SiteFileFetch fileFetch = new SiteFileFetch(bean); friWW^
fileFetch.start(); 1c4/}3*
} DOS0;^f
catch(Exception e){e.printStackTrace ();} 0|4%4Mt
[lzN !!B!
op2Of<{h
} F9"w6;hh
Ex amD">T
Uu s.
public static void main(String[] args) /^SAC%PD
{ /6uT6G+(z}
new TestMethod(); "I6P=]|b
} /*FH:T<V
} uA tV".
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