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)); ,LSF@1|Fx
} (i.MxGDd
for(int i=0;i<nEndPos.length-1;i++) ]N*q3y|)
{ ]\v'1m"
nEndPos = nStartPos[i+1]; drBWo|/
} `a["`N^
nEndPos[nEndPos.length-1] = nFileLength; lV?rC z
} !?DPI)
} 4+:Q"
2_x}wB0P
_;O$ot\5
//启动子线程 )r~$N0\D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %DqF_4U9
for(int i=0;i<nStartPos.length;i++) A@Z&ZBDg
{ ?#-"YO7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3=o3VGZP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U)=StpTT
nStartPos,nEndPos,i); B0?E$8a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |+~CdA
fileSplitterFetch.start(); Pg{Dy>&2`I
} pZ/x,b#.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7 }4T)k(a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C;0H _
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YjdCCju
nEndPos = " + nFileLength); b*',(J94
// fileSplitterFetch[nPos.length-1].start(); RgHPYf{
L}h?nWm8
~%qHJ4C
//等待子线程结束 izebQVQO*
//int count = 0; azr|Fz/
//是否结束while循环 -N<s =
boolean breakWhile = false; ax[-907
D?44:'x+-
RI!!?hYm
while(!bStop) g;i>nzf
{ B# |w}hj
write_nPos(); $ii/Q:w T"
Utility.sleep(500); Om0Z\GP=
breakWhile = true; @.yp IE\
?SK1*; i
!>TVDN>
for(int i=0;i<nStartPos.length;i++) b2aPo M=
{ "o*(i7T=n
if(!fileSplitterFetch.bDownOver) *NS:X7p!V
{ q{ItTvL
breakWhile = false; {VE\}zKF
break; fJBp,{0
} g>12!2}
} BD&JbH!(
if(breakWhile) 3V?JX5X\
break; ]{jdar^
iOkRB[hi
e%uPZ >'q
//count++; oTS*k: C'
//if(count>4) luACdC
// siteStop(); -|\V'
} ;+'x_'a
c~3OK_k
V2Q2(yvdJ
System.err.println("文件下载结束！"); |Gx-c ,{{
} OCnQSkj
catch(Exception e){e.printStackTrace ();} QFY1@2EC
} F"FGPk
OBqaf )W
wb~#=6Y
//获得文件长度 l ~CYxO
public long getFileSize() yw `w6Z3K
{ X`/8fag
int nFileLength = -1; w6zB uW
try{ wwE`YY
URL url = new URL(siteInfoBean.getSSiteURL()); |k1(|)%G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V|e9G,z~A
httpConnection.setRequestProperty("User-Agent","NetFox"); VI: !#
}enm#0Ha
PN:/lIO
int responseCode=httpConnection.getResponseCode(); hm*1w6 =
if(responseCode>=400) )D\!#<#h
{ (S$ziV
processErrorCode(responseCode); rV*9=
return -2; //-2 represent access is error 8fRk8
} Au<NUc 2
u&z5)iU
2kzm(K
String sHeader; s_S[iW`l=
XZde}zUWn
piIj t
for(int i=1;;i++) pKJ0+mN#"
{ :c[iS~ ~Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w/BaaF.0
//Utility.log(in.readLine()); _^]2??V
sHeader=httpConnection.getHeaderFieldKey(i); -7,xjn
if(sHeader!=null) c}v>Mx
{ ZFpi'u.&
if(sHeader.equals("Content-Length")) )65 o
{ <Dojl #
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5V5Nx(31i
break; .`*h2
} Y` t-Bg!~
} Teh _
else -XBD WV
break; i,|2F9YH
} `d]D=DtH
} BQ!v\1'C
catch(IOException e){e.printStackTrace ();} P7np -I*
catch(Exception e){e.printStackTrace ();} CzDJbvv]
8-]\C
zV {_dO
Utility.log(nFileLength); 'qel3Fs"
)RV.N}NU
<*k]Aa3y
return nFileLength; MG6taOO!
} UP]X,H~stU
EAafi<n
Zpc R
//保存下载信息（文件指针位置） n1n->l*HGP
private void write_nPos() R@zl?>+
{ xNDX(_U>\
try{ <4UF/G)
output = new DataOutputStream(new FileOutputStream(tmpFile)); H{qQ8j)
output.writeInt(nStartPos.length); W Cz+
for(int i=0;i<nStartPos.length;i++) ip.aM#
{ ${fJ]
// output.writeLong(nPos); o&WKk5$
output.writeLong(fileSplitterFetch.nStartPos); s.ywp{EF
output.writeLong(fileSplitterFetch.nEndPos); =, kH(rp2
} >wx1M1
output.close(); f4{O~?=
} <E/"v
catch(IOException e){e.printStackTrace ();} wP:ab
catch(Exception e){e.printStackTrace ();} yvN;|R
} gLp7<gx6
vu7F>{D
.$&_fUY
//读取保存的下载信息（文件指针位置） )/uu~9SFd
private void read_nPos() o}QtKf)W
{ U4PnQ K,
try{ `wrN$&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =?9z6=
int nCount = input.readInt(); fu 0]BdM
nStartPos = new long[nCount]; !.\-l2f
nEndPos = new long[nCount]; 4l)Q
for(int i=0;i<nStartPos.length;i++) |a!y%R=
{ \ct7~!qM
nStartPos = input.readLong(); FQ6jM~
nEndPos = input.readLong(); XQW9/AzNf
} 2g'o5B\*
input.close(); /D@(o`a
} )Pj8{.t4
catch(IOException e){e.printStackTrace ();} x,LQA0
catch(Exception e){e.printStackTrace ();} zNg8Oq&
} 67,@*cK3?J
[&_c.ti
#ArMX3^+w7
private void processErrorCode(int nErrorCode) d4(!9O.\
{ >U4hsr05
System.err.println("Error Code : " + nErrorCode); w&U>w@H^
} q2>dPI;3T
( q8uB
RxUABF8b
//停止文件下载 s}m.r5
public void siteStop() 1UyQ``v/
{ 0J \hku\
bStop = true; svT1b'=\$I
for(int i=0;i<nStartPos.length;i++) H<YhO&D*u
fileSplitterFetch.splitterStop(); Y#[Wv1hi
A08b=S
:Ca]/]]
} ;_]Z3
} >o45vB4o
//负责部分文件的抓取 2p6`@8*34
**FileSplitterFetch.java 4|yZA*Q^
*/ @20~R/vh
package NetFox; &uX|Ksq
cwK+{*ZH/
;`p!/9il
import java.io.*; dF (m!P/R
import java.net.*; Lc0yLm
<Oyxzs
a d,0*(</
public class FileSplitterFetch extends Thread { iD/r8_}
wfE%` 1
Z{#;my*X|
String sURL; //File URL B%~D`[~?
long nStartPos; //File Snippet Start Position 3jaY\(`%h
long nEndPos; //File Snippet End Position WZ#|?pJ
int nThreadID; //Thread's ID 6X1_NbC
boolean bDownOver = false; //Downing is over d|~A>YZ
boolean bStop = false; //Stop identical k~P{Rm;F
FileAccessI fileAccessI = null; //File Access interface rEWPVT
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W5#5RK"uX
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "@h 5 SF
{ |N^z=g P[
this.sURL = sURL; kVG]zt2
this.nStartPos = nStart; NEY b-#v
this.nEndPos = nEnd; [p 6#fG *
nThreadID = id; zSU06Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }zK/43Vx
} ohy?l
jT6zpi~]E
9S_N*wC.
public void run() T@. $Zpz
{ q1d'L*
while(nStartPos < nEndPos && !bStop) x?|C-v
{ c[a1 Md&
*,Mg
Xy;!Q`h(
try{ .JJ^w!|>#
URL url = new URL(sURL); NbDfD3 1GK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G0u3*.
httpConnection.setRequestProperty("User-Agent","NetFox"); a%h'utF{[
String sProperty = "bytes="+nStartPos+"-"; #_zd`s3k
httpConnection.setRequestProperty("RANGE",sProperty); Qey6E9eCA
Utility.log(sProperty); C6"bGA
4Pm+0=E
p| #gn<z}
InputStream input = httpConnection.getInputStream(); O8J:Tw}M*
//logResponseHead(httpConnection); @|2}*_3\
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guD?~-Q
byte[] b = new byte[1024]; lQ}e"#<
int nRead; &dC #nw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @3UVl^T
{ =XT'D@q~W
nStartPos += fileAccessI.write(b,0,nRead); wu2AhMGmw
//if(nThreadID == 1) JW5SBt>
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w|1Gb[
} <_|H]^o
bnWKfz5
/@*J\0h(-
Utility.log("Thread " + nThreadID + " is over!"); O>![IH(L
bDownOver = true; 0M?nXHA[
//nPos = fileAccessI.write (b,0,nRead); 8J-;/
} !Qg%d&q.Sx
catch(Exception e){e.printStackTrace ();} ;[_w&"[6a
} JqDj)}fzX
} K7x,>
,yC-QFQE
p2=Sbb
//打印回应的头信息 x%;Q /7&$
public void logResponseHead(HttpURLConnection con) UJ0Dy` f
{ Qbc62qFu!
for(int i=1;;i++) L-ZJ[#D
{ o6} +5
String header=con.getHeaderFieldKey(i); 0shNwV1zF
if(header!=null) wFW2m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Efb S*f5
Utility.log(header+" : "+con.getHeaderField(header)); P7Th94
else WAj26";M(
break; {,5=U@J
} '(/ZJ88JP
} ,H3C\.%w\
.2xp.i{
!n`ogzOh
public void splitterStop() =f)S=0UF
{ VesO/xG<
bStop = true; o3;u*f0rWn
} X-Sso9/q.
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zN\~v
} NRS!Ox
{C%/>e2-%
N_vVEIO9
/* 7eh|5e$@
**FileAccess.java mf26AIlkQ
*//文件访问(定位，写) 5k`[a93T
package NetFox; F_SkS?dB
import java.io.*; tVhY=X{N?
OpwZTy}1}
YkcX#>,
public class FileAccessI implements Serializable{ ;3n0 bKDY
}*n(RnCn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lQ%]](a6
RandomAccessFile oSavedFile; 's{-1aW
long nPos; h(;qnV'c
}P$48o VY
uP/WRQ{rW>
public FileAccessI() throws IOException jl<rxO?-F
{ Rk PY@>
this("",0); s0Ii;7fA{
} &)vX7*j
xDBEs*
F<?e79},`
public FileAccessI(String sName,long nPos) throws IOException I`44}oJ
{ XM/P2=;
oSavedFile = new RandomAccessFile(sName,"rw"); +a&-'`7g
this.nPos = nPos; h^P>pI~
oSavedFile.seek(nPos); %PG::b
} *@Z/L26s;=
`4cs.ab
r'hr'wZ
public synchronized int write(byte[] b,int nStart,int nLen) #R|M(Z">q
{ laM0W5
int n = -1; g1\4Jb
try{ RB_7S!qC5
oSavedFile.write(b,nStart,nLen); gKg2Ntxj
n = nLen; 8w|j Z@
} yI9l*'
catch(IOException e) >taS<.G
{ pBt/vSad
e.printStackTrace (); \n850PS
} @A6\v+ih
(Jfi 3 m
+1p>:cih
return n; 0D>~uNcT}
} }H{{@RU
1vu4}%nD
8\8uXOS
} gQ h0-Dnw
]Bs ?
L6j 5pI
/* $*%Ml+H-
**SiteInfoBean.java uLb- NxQ-
*/ dUn8Xqj1
package NetFox; d@"eWvnlZ
-!MDYj+U
ja~b5Tf9
public class SiteInfoBean { @( 9#\%=
#hd<5+$U}l
JBE'B Q@
private String sSiteURL; //Site's URL /,5`#Gte_
private String sFilePath; //Saved File's Path >w9)c|
private String sFileName; //Saved File's Name q4 'x'8
private int nSplitter; //Count of Splited Downloading File |Xd[%W)
5v~Y>
$'X*L e@k
public SiteInfoBean() tZa)sbz
{//nSplitter的缺省值为5 B>o\;)l3O
//default value of nSplitter is 5 xn@?CP`-y
this("","","",5); scqG$~O)
} 1q~U3'l:$
!j4C:L3F
"JVzv U]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5%?La`C9[
{ P,iLqat
sSiteURL= sURL; )X\.Xr-6q
sFilePath = sPath; 5DyN=[b
sFileName = sName; c ~YD|l
this.nSplitter = nSpiltter; *^c4q|G.-
v!@/
ItKwB+my
} 1elcP`N1
2O9dU 5b
R^](X*
public String getSSiteURL() )gR14a
{ Lj(hk@
return sSiteURL; )dF(5,y)
} A>>@&c:(
P>pkLP} Vo
R_vZh|
public void setSSiteURL(String value) )0AE*S
{ 'QT(TF>
sSiteURL = value; =JO|m5z8>
} =oT@h 9VI
U]hQ#a+
Ffj:xZ9rk
public String getSFilePath() kc8GnKM&mc
{ Q(k$HP
return sFilePath; wc bs-arH
} Cqg}dXn'
2y_rsu\
J~gfMp.
public void setSFilePath(String value) f`A
{ r-N2*uYtu
sFilePath = value; lu(G3T8
} (P`{0^O"}
8ZG'?A+{
#4na>G|
public String getSFileName() TWx<)
{ |,sUD/rt
return sFileName; J@Zm8r<
} ).oqlA!
XN=<s;U
5\=9&{WjND
public void setSFileName(String value) ts?b[v
{ ,C&h~uRi#f
sFileName = value; 6^{ hY^Z
} lBG*P>;
82J0t}:U
'12|:t&7
public int getNSplitter() #Z$6> Xt
{ & p_;&P_
return nSplitter; ` V^#Sb
} i $I|JJJ
:-"J)^V
{]D!@87
public void setNSplitter(int nCount) x;Gyo
{ j~Gu;%tq
nSplitter = nCount; bq(*r:`"
} [PX'Jer
} X'?v8\mPK
&2xYG{Z
Jh466; E
/* [0&Lvx
**Utility.java lh#GD"^(w&
*/ wkJB5i^<w
package NetFox; GV[%P
_L$)~},cT
=r-Wy.a@
public class Utility { Cg{$$&_(Hj
qsk71L
er#we=h
public Utility() lZ)u4_
{ Z,4=<;PF
t91CxZQ^s
f2yv7t T
} #[KwR\b{:+
:X4\4B*~
//线程睡眠 M9&tys[KX
public static void sleep(int nSecond) $s]@%6f
{ 8V|-BP5^
try{ zfo.S[R@
Thread.sleep(nSecond); _-!6@^+
} CIaabn
catch(Exception e) 6wu/6DO
{ GzB%vsv95
e.printStackTrace (); "V^jAPDXb
} %[Ds-my2
} I^ >zr.zA
&9ZIf#R
//日志 H~G=0_S
public static void log(String sMsg) CqX%V":2
{ aZ0H)
System.err.println(sMsg); d.}rn"(z
} 8U(a&G6gn
F Qk;
AQV3ZVP
public static void log(int sMsg) ncA2en?
{ hT]p8m aRZ
System.err.println(sMsg); M^[jA](a
} qt:->yiq+
} Wey\GQ`"8
'PYl%2
HkV/+ {;S~
/* ~%}g"|o
**TestMethod.java d:wAI|
*/ 2 sOc]L:9
package NetFox; 4dok/ +Ec
4[-9$ r
)Z_i[1V
public class TestMethod { uB^]5sqfk
nx+& {hn(
*7vPU:Q[
public TestMethod() 6,h<0j{
{ ///xx/weblogic60b2_win.exe jF5JpyOc
try{ &%bX&;ECzf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LPNv4lT[u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |kd^]!_
SiteFileFetch fileFetch = new SiteFileFetch(bean); <qy+@t
fileFetch.start(); .iS]aJJ
} xD#/@E1'Y
catch(Exception e){e.printStackTrace ();} .iYgRW=T
MmK\|CtV
$-0u`=!
} %51pfuL
>I!(CM":s$
zc{C+:3$^
public static void main(String[] args) 2~4C5@SxL
{ P>kx{^
new TestMethod(); 4HHf3j!5
} k^]~NP
} ;i:7E#@
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